gw9662 and Disease-Models--Animal

Colitis-associated colorectal cancer (CAC) is a severe complication of inflammatory bowel disease (IBD), resulting from long-term inflammation in the intestines. The primary cause of CAC is the imbalance of oxidative metabolism in intestinal cells, triggered by excessive reactive oxygen (ROS) and nitrogen (NO) species production due to prolonged intestinal inflammation. This imbalance leads to genomic instability caused by DNA damage, eventually resulting in the development of intestinal cancer. Previous studies have demonstrated that astragaloside IV is effective in treating dextran sulfate sodium salt (DSS)-induced colitis, but there is currently no relevant research on its efficacy in treating CAC.. To investigate the effect of astragaloside IV against CAC and the underlying mechanism, C57 mice were treated with (20, 40, 80 mg/kg) astragaloside IV while CAC was induced by intraperitoneal injection of 10 mg/kg azoxymethane (AOM) and ad libitum consumption of 2% dextran sulfate sodium salt (DSS). We re-verified the activating effects of astragaloside IV on PPARγ signaling in IEC-6 cells, which were reversed by GW9662 (the PPARγ inhibitor).. Our results showed that astragaloside IV significantly improved AOM/DSS-induced CAC mice by inhibiting colonic shortening, preventing intestinal mucosal damage, reducing the number of tumors and, the expression of Ki67 protein. In addition, astragaloside IV could activate PPARγ signaling, which not only promoted the expression of Nrf2 and HO-1, restored the level of SOD, CAT and GSH, but also inhibited the expression of iNOS and reduced the production of NO in the intestine and IEC-6 cells. And this effect could be reversed by GW9662 in vitro. Astragaloside IV thus decreased the level of ROS and NO in the intestinal tract of mice, as well as reduced the damage of DNA, and therefore inhibited the occurrence of CAC.. Astragaloside IV can activate PPARγ signaling in intestinal epithelial cells and reduces DNA damage caused by intestinal inflammation, thereby inhibiting colon tumourigenesis. The novelty of this study is to use PPARγ as the target to inhibit DNA damage to prevent the occurrence of CAC.

Topics: Animals; Azoxymethane; Carcinogenesis; Cell Transformation, Neoplastic; Colitis; Dextran Sulfate; Disease Models, Animal; Inflammation; Mice; Mice, Inbred C57BL; PPAR gamma; Reactive Oxygen Species

Peroxisome proliferator-activated receptor-gamma (PPARγ) is critical in protecting against inflammatory and oxidative stresses post brain injury. We have previously reported that rosiglitazone, an agonist of PPARγ, was effective to prevent microglia from apoptosis and ameliorate neuronal injuries post intracerebral hemorrhage (ICH) with suppression of matrix metalloproteinase-9 (MMP9) expression. However, molecular mechanisms linking how PPARγ decreases MMP9 remain unknown. Here, we hypothesize that PPARγ downregulates MMP9 expression post hemorrhage by inhibiting nuclear factor kappa B (NF-κB), an upstream regulator of MMPs gene and also key transcription factor involved in the control of immune and neuroinflammatory responses. We found both in vivo and in vitro that PPARγ was significantly downregulated post ICH with prominent increases of NF-κB and MMP9. Activation of PPARγ using rosiglitazone decreased the expression of both NF-κB and MMP9, while reversed effects were observed when administrating the PPARγ antagonist GW9662. Besides, inhibiting NF-κB by JSH-23 also suppressed the expression of MMP9, with only limited effect on PPARγ. Further studies revealed prominent colocalizations of NF-κB with PPARγ and MMP9, respectively. Finally, direct interactions of NF-κB with PPARγ and MMP9 gene were also confirmed, respectively, by protein and chromatin immunoprecipitations. These results suggested a role of NF-κB in mediating the reduction of MMP9 by PPARγ, potentially providing a new therapeutic target for brain hemorrhage.

Topics: Anilides; Animals; Cell Line; Cerebral Hemorrhage; Disease Models, Animal; Down-Regulation; Humans; Male; Matrix Metalloproteinase 9; Mice; NF-kappa B; Phenylenediamines; PPAR gamma; Rats; Rosiglitazone

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

The present study aims to reveal the molecular mechanism of peroxisome proliferator-activated receptor γ (PPARγ) on sepsis-induced acute lung injury (ALI). To do that, the rat injury model was established using cecal ligation and perforation (CLP) method, followed by different treatments, and the rats were divided into Sham group, CLP group, CLP + rosiglitazone (PPARγ agonist) group, CLP + GW9662 (PPARγ inhibitor) group, CLP + bpV (phosphatase and tensin homolog (PTEN) inhibitor) group, CLP + GW9662 + bpV group. Compared with Sham group, the mRNA and protein expression levels of PPARγ were down-regulated, the inflammation levels were elevated, and the apoptosis was increased in CLP group. After treatment with rosiglitazone, the protein expression level of PPARγ was significantly up-regulated, the phosphorylation level of PTEN/β-catenin pathway was decreased, the PTEN/β-catenin pathway was inhibited, the lung injury, inflammation and apoptosis were reduced. The opposite effect was observed after treatment with GW9662. Besides, bpV inhibited PTEN/β-catenin pathway, and relieved the lung tissue injury. The overexpression of PPARγ reduced inflammatory response and inhibited apoptosis in sepsis-induced ALI. Furthermore, PPARγ relieved the sepsis-induced ALI by inhibiting the PTEN/β-catenin pathway.

Topics: Acute Lung Injury; Anilides; Animals; Apoptosis; beta Catenin; Disease Models, Animal; Lung; Male; Phosphorylation; Pneumonia; PPAR gamma; PTEN Phosphohydrolase; Pulmonary Edema; Rats, Sprague-Dawley; Rosiglitazone; Sepsis; Signal Transduction

Acute lung injury (ALI), manifested by progressive hypoxemia and respiratory distress, is associated with high morbidity and mortality, which lacks the effective therapies in clinics. Our previous studies demonstrated that maresin1 (MaR1), a specialized proresolving mediator, could effectively mitigate the inflammation of lipopolysaccharide (LPS)-induced ALI. However, whether MaR1 impacts the macrophage polarization to alleviate ALI remains unclear. Our study explored the effects and underlying mechanisms of MaR1 on the macrophage phenotypes in ALI.. Male BALB/c mice were subjected to endotracheal instillation of LPS to induce ALI and then intravenously injected with MaR1 or normal saline. Intraperitoneal administration of peroxisome proliferator-activated receptor-γ (PPAR-γ) inhibitor GW9662 was given 30 mins before MaR1. We measured the pathohistologic changes, pulmonary edema, inflammatory cytokines, and the flow cytometry of macrophage phenotypes.. Our results illustrated that MaR1 ameliorated lung injury and increased monocyte or macrophage recruitment and the release of anti-inflammatory cytokines. The flow cytometry showed that MaR1 promoted polarization of CD11c. MaR1 was able to promote M2 macrophage polarization by reversing LPS-mediated PPAR-γ inhibition, thereby expediting the recovery of LPS-stimulated ALI.

Topics: Acute Lung Injury; Anilides; Animals; Disease Models, Animal; Docosahexaenoic Acids; Humans; Lipopolysaccharides; Macrophages; Male; Mice; PPAR gamma; Signal Transduction

Previous reports have demonstrated that the newly identified lipid mediator protectin DX (PDX) could effectively attenuate multiple organ injuries in sepsis. The aim of our study was to clarify whether PDX could improve acute lung injury (ALI) induced by sepsis and elucidate the relevant potential mechanism. After inducing sepsis by the cecal ligation and puncture approach, mice were treated with a high or low dose of PDX. Pathological changes in the pulmonary tissue were analyzed by hematoxylin-eosin staining, and lung injury score was evaluated. Lung permeability and edema were assessed by lung wet/dry ratio, and protein and cellular load of the bronchoalveolar lavage fluid (BALF). Inflammatory cytokine levels in BALF were measured by ELISA and the expression of PPARγ in the lung tissue was analyzed by immunoblotting. The results suggested that PDX could diminish the inflammatory response in lung tissue after sepsis by upregulating PPARγ and inhibiting the phosphorylation and activation of NF-κB p65. PDX treatment lowered the levels of pro-inflammation cytokines IL-1β, IL-6, TNF-α, and MCP-1, and the levels of anti-inflammatory cytokine IL-10 was increased in the BALF. It also improved lung permeability and reduced lung injury. Furthermore, the protective effect of PDX on lung tissue could be reversed by GW9662, a specific PPAR-γ antagonist. Taken together, our study indicated that PDX could ameliorate the inflammatory response in ALI by activating the PPARγ/NF-κB pathway in a mouse model of sepsis.

Topics: Acute Lung Injury; Anilides; Animals; Anti-Inflammatory Agents; Bronchoalveolar Lavage Fluid; Cytokines; Disease Models, Animal; Docosahexaenoic Acids; Humans; Inflammation; Inflammation Mediators; Lung; Male; Mice; PPAR gamma; Sepsis; Signal Transduction; Transcription Factor RelA

There is a major clinical need for new therapies for the treatment of chronic itch. Many of the molecular components involved in itch neurotransmission are known, including the neuropeptide NPPB, a transmitter required for normal itch responses to multiple pruritogens in mice. Here, we investigated the potential for a novel strategy for the treatment of itch that involves the inhibition of the NPPB receptor NPR1 (natriuretic peptide receptor 1). Because there are no available effective human NPR1 (hNPR1) antagonists, we performed a high-throughput cell-based screen and identified 15 small-molecule hNPR1 inhibitors. Using in vitro assays, we demonstrated that these compounds specifically inhibit hNPR1 and murine NPR1 (mNPR1). In vivo, NPR1 antagonism attenuated behavioral responses to both acute itch- and chronic itch-challenged mice. Together, our results suggest that inhibiting NPR1 might be an effective strategy for treating acute and chronic itch.

Topics: Animals; Behavior, Animal; Cell-Free System; Dermatitis, Contact; Disease Models, Animal; Ganglia, Spinal; Humans; Mice, Inbred C57BL; Mice, Knockout; Neurons; Pruritus; Receptors, Atrial Natriuretic Factor; Reproducibility of Results; Signal Transduction; Small Molecule Libraries

Topics: Anilides; Animals; Diet, High-Fat; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation; Hep G2 Cells; Hepatocytes; Humans; Lipid Metabolism; Lipogenesis; Liver; Mice; MicroRNAs; Non-alcoholic Fatty Liver Disease; PPAR gamma; RNA, Long Noncoding; Triglycerides

To date, the neuroprotective effects of statins on intracerebral hemorrhage (ICH) are not well established. This study explored the effect and potential mechanism of simvastatin treatment on ICH. In the present study, the effects of simvastatin on hematoma absorption, neurological outcome, CD36 expression and microglia polarization were examined in rat model of ICH model. In the meantime, inhibitory effect of PPARγ inhibitor GW9662 was investigated following ICH. Additionally, the effect of simvastatin on PPARγ activation was also investigated in rat ICH model and primary microglia culture. Much more, the role of PPARγ and CD36 in simvastatin-mediated erythrocyte phagocytosis was also detected by using in vivo or in vitro phagocytosis models, respectively. After ICH, simvastatin promoted hematoma absorption and improved neurological outcome after ICH while upregulating CD36 expression and facilitating M2 phenotype polarization in perihematomal microglia. In addition, simvastatin increased PPARγ activation and reinforced microglia-induced erythrocyte phagocytosis in vivo and in vitro. All above effects of simvastatin were abolished by PPARγ inhibitor GW9662. In conclusion, our data suggested that simvastatin could enhance hematoma clearance and attenuate neurological deficits possibly by activating PPARγ.

Topics: Anilides; Animals; Anticholesteremic Agents; Antigens, CD; Cell Count; Cerebral Hemorrhage; Disease Models, Animal; Electrophoretic Mobility Shift Assay; Enzyme Inhibitors; Hematoma; Male; Microglia; Neurologic Examination; Phagocytosis; PPAR gamma; Protein Transport; Rats; Rats, Sprague-Dawley; Simvastatin; Time Factors

PPAR-gamma (γ) is highly expressed in macrophages and its activation affects their polarization. The effect of PPAR-γ activation on Kupffer cells (KCs) and liver ischemia-reperfusion injury (IRI) has not yet been evaluated. We investigated the effect of PPAR-γ activation on KC-polarization and IRI.. Seventy percent (70%) liver ischemia was induced for 60mins. PPAR-γ-agonist or vehicle was administrated before reperfusion. PPAR-γ-antagonist was used to block PPAR-γ activation. Liver injury, necrosis, and apoptosis were assessed post-reperfusion. Flow-cytometry determined KC-phenotypes (pro-inflammatory Nitric Oxide +, anti-inflammatory CD206+ and anti-inflammatory IL-10+).. Liver injury assessed by serum AST was significantly decreased in PPAR-γ-agonist versus control group at all time points post reperfusion (1hr: 3092±105 vs 4469±551; p = 0.042; 6hr: 7041±1160 vs 12193±1143; p = 0.015; 12hr: 5746±328 vs 8608±1259; p = 0.049). Furthermore, liver apoptosis measured by TUNEL-staining was significantly reduced in PPAR-γ-agonist versus control group post reperfusion (1hr:2.46±0.49 vs 6.90±0.85%;p = 0.001; 6hr:26.40±2.93 vs 50.13±8.29%; p = 0.048). H&E staining demonstrated less necrosis in PPAR-γ-agonist versus control group (24hr:26.66±4.78 vs 45.62±4.57%; p = 0.032). The percentage of pro-inflammatory NO+ KCs was significantly lower at all post reperfusion time points in the PPAR-γ-agonist versus control group (1hr:28.49±4.99 vs 53.54±9.15%; p = 0.040; 6hr:5.51±0.54 vs 31.12±9.58%; p = 0.009; 24hr:4.15±1.50 vs 17.10±4.77%; p = 0.043). In contrast, percentage of anti-inflammatory CD206+ KCs was significantly higher in PPAR-γ-agonist versus control group prior to IRI (8.62±0.96 vs 4.88 ±0.50%; p = 0.04). Administration of PPAR-γ-antagonist reversed the beneficial effects on AST, apoptosis, and pro-inflammatory NO+ KCs.. PPAR-γ activation reduces IRI and decreases the pro-inflammatory NO+ Kupffer cells. PPAR-γ activation can become an important tool to improve outcomes in liver surgery through decreasing the pro-inflammatory phenotype of KCs and IRI.

Topics: Alanine Transaminase; Anilides; Animals; Apoptosis; Aspartate Aminotransferases; Cell Polarity; Cytokines; Disease Models, Animal; Kupffer Cells; Lectins, C-Type; Liver; Male; Mannose Receptor; Mannose-Binding Lectins; Mice; Mice, Inbred C57BL; Necrosis; Nitric Oxide; PPAR gamma; Receptors, Cell Surface; Reperfusion Injury; Rosiglitazone; Thiazolidinediones

The aim of this study is to investigate the role of peroxisome proliferator-activated receptor-gamma isoform (PPARγ), in trigeminal neuropathic pain utilizing a novel mouse trigeminal inflammatory compression (TIC) injury model.. The study determined that the PPARγ nuclear receptor plays a significant role in trigeminal nociception transmission, evidenced by: 1) Intense PPARγ immunoreactivity is expressed 3 weeks after TIC nerve injury in the spinal trigeminal caudalis, the termination site of trigeminal nociceptive nerve fibers. 2) Systemic administration of a PPARγ agonist, pioglitazone (PIO), attenuates whisker pad mechanical allodynia at doses of 300 mg/kg i.p. and 600 mg/kg p.o. 3) Administration of a PPARγ antagonist, GW9662 (30 mg/kg i.p.), prior to providing the optimal dose of PIO (300 mg/kg i.p.) blocked the analgesic effect of PIO.. This is the first study localizing PPARγ immunoreactivity throughout the brainstem trigeminal sensory spinal nucleus (spV) and its increase three weeks after TIC nerve injury. This is also the first study to demonstrate that activation of PPARγ attenuates trigeminal hypersensitivity in the mouse TIC nerve injury model. The findings presented here suggest the possibility of utilizing the FDA approved diabetic treatment drug, PIO, as a new therapeutic that targets PPARγ for treatment of patients suffering from orofacial neuropathic pain.

Topics: Analgesics, Non-Narcotic; Anilides; Animals; Disease Models, Animal; Facial Pain; Hyperalgesia; Male; Mice, Inbred C57BL; Neuralgia; Pioglitazone; PPAR alpha; PPAR delta; PPAR gamma; Random Allocation; Thiazolidinediones; Trigeminal Nerve Injuries; Trigeminal Nuclei; Vibrissae

TRPML1 is reported to be involved in the pathogenesis of Alzheimer's disease (AD) by regulating autophagy; however, the underlying mechanism is not completely clear.. We developed an APP/PS1 transgenic animal model that presents with AD. TRPML1 was also overexpressed in these mice. Protein expression levels were determined by Western blot. Morris water maze (MWM) and recognition tasks were performed to characterize cognitive ability. TUNEL assays were analysed for the detection of neuronal apoptosis. Primary neurons were isolated and treated with the vehicle, Aβ1-42 or Aβ1-42 + mTOR activator, as well as infected with the recombinant adenovirus TRPML1 overexpression vector in vitro. Cell viability was measured by the MTS assay, and lysosomal Ca2+ was also measured.. In the APP/PS1 transgenic mice, TRPML1 was downregulated, the PPARγ/AMPK signalling pathway was activated, the mTOR/S6K signalling pathway was suppressed, and autophagic lysosome reformation (ALR)-related proteins were upregulated. TRPML1 overexpression or treatment with PPARγ and AMPK inhibitors or an mTOR activator reduced the expression levels of ALR-related proteins, rescued the memory and recognition impairments and attenuated neuronal apoptosis in mice with the APP/PS1 transgenes. In vitro experiments showed that TRPML1 overexpression or treatment with the mTOR activator propranolol attenuated the Aβ1-42-suppressed cell viability and the Aβ1-42-decreased lysosomal [Ca2+] ion concentration in primary neurons. TRPML1 overexpression or treatment with the mTOR activator propranolol also attenuated the Aβ1-42-inhibited mTOR/S6K signalling pathway and the Aβ1-42-induced ALR-related protein expression levels.. TRPML1 is involved in the pathogenesis of AD by regulating autophagy at least in part through the PPARγ/AMPK/mTOR signallingpathway.

Topics: Alzheimer Disease; AMP-Activated Protein Kinases; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Anilides; Animals; Autophagy; Calcium; Cell Survival; Disease Models, Animal; Disease Progression; Humans; Lysosomes; Maze Learning; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neurons; Peptide Fragments; PPAR gamma; Propranolol; Signal Transduction; TOR Serine-Threonine Kinases; Transient Receptor Potential Channels

The ketogenic diet (KD) is an effective therapy primarily used in pediatric patients whom are refractory to current anti-seizure medications. The mechanism of the KD is not completely understood, but is thought to involve anti-inflammatory and anti-oxidant processes. The nutritionally-regulated transcription factor peroxisome proliferator activated receptor gamma, PPARγ, regulates genes involved in anti-inflammatory and anti-oxidant pathways. Moreover, endogenous ligands of PPARγ include fatty acids suggesting a potential role in the effects of the KD. Here, we tested the hypothesis that PPARγ contributes to the anti-seizure efficacy of the KD. We found that the KD increased nuclear protein content of the PPARγ2 splice variant by 2-4 fold (P<0.05) in brain homogenates from wild-type (WT) and epileptic Kv1.1 knockout (KO) mice, while not affecting PPARγ1. The KD reduced the frequency of seizures in Kv1.1KO mice by ~70% (P<0.01). GW9662, a PPARγ antagonist, prevented KD-mediated changes in PPARγ2 expression and prevented the anti-seizure efficacy of the KD in Kv1.1KO mice. Further supporting the association of PPARγ2 in mediating KD actions, the KD significantly prolonged the latency to flurothyl-induced seizure in WT mice by ~20-35% (P<0.01), but was ineffective in PPARγ2KO mice and neuron-specific PPARγKO mice. Finally, administering the PPARγ agonist pioglitazone increased PPARγ2 expression by 2-fold (P<0.01) and reduced seizures in Kv1.1KO mice by ~80% (P<0.01). Our findings implicate brain PPARγ2 among the mechanisms by which the KD reduces seizures and strongly support the development of PPARγ2 as a therapeutic target for severe, refractory epilepsy.

Topics: 3-Hydroxybutyric Acid; Age Factors; Anilides; Animals; Animals, Newborn; Anticonvulsants; Blood Glucose; Brain; Convulsants; Diet, Ketogenic; Disease Models, Animal; Drinking; Epilepsy; Flurothyl; Gene Expression Regulation, Developmental; Hypoglycemic Agents; Kv1.1 Potassium Channel; Mice; Mice, Inbred C57BL; Mice, Knockout; Pioglitazone; PPAR gamma; Thiazolidinediones

Neuroinflammation plays a key role in many neurodegenerative disorders, including postoperative cognitive decline (POCD). Growing evidence has demonstrated that activation of the peroxisome proliferator-activated receptor-γ (PPARγ) attenuates the inflammatory response and improves cognitive dysfunction associated with many neuropsychiatric disorders. We hypothesize that down-regulation of PPARγ is linked to neuroinflammation and the subsequent cognitive deficits observed in an animal model of POCD. In the present study, the POCD animal model was established by performing an exploratory laparotomy under isoflurane anesthesia in 20-month-old male C57BL/6 mice. Behavioral tests, inflammatory biomarkers, including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β, ionized calcium-binding adaptor molecule-1 (IBA1)-positive cells, as well as glial fibrillary acidic protein (GFAP)-positive cells and brain-derived neurotrophic factor (BDNF), were measured. Herein, we showed that surgery induced profound impairment in cognition that was associated with significant decreases in PPARγ and BDNF expression, and significant increases in IL-1β, IBA1-positive cells, and GFAP-positive cells in the hippocampus. As expected, the PPARγ agonist pioglitazone attenuated the surgery-induced inflammatory changes and rescued the associated cognitive impairment. However, these beneficial effects were abolished by the PPARγ specific antagonist GW9662, suggesting a pivotal role of the PPARγ pathway in the pathogenesis of POCD. Taken together, our results provide evidence that down-regulation of PPARγ may be involved in neuroinflammation and subsequent POCD, and suggest that activation of PPARγ by pioglitazone may represent a new way to prevent or treat POCD.

Topics: Aging; Anilides; Animals; Brain-Derived Neurotrophic Factor; Cells, Cultured; Cognitive Dysfunction; Cytokines; Disease Models, Animal; Hippocampus; Humans; Inflammation Mediators; Laparotomy; Male; Mice; Mice, Inbred C57BL; Microglia; Neurogenic Inflammation; Pioglitazone; Postoperative Complications; PPAR gamma; Thiazolidinediones

Increasing evidence suggests that inflammation and oxidative stress may contribute to the development of major depressive disorder (MDD). Apigenin, a type of bioflavonoid widely found in citrus fruits, has a number of biological actions including anti-inflammatory and antioxidant effects. Although apigenin has potential antidepressant activity, the mechanisms of this effect remain unclear. The present study aims to investigate the effects of apigenin on behavioral changes and inflammatory responses induced by chronic unpredictable mild stress (CUMS) in rats. GW9662, a selective peroxisome proliferator-activated receptor gamma (PPARγ) inhibitor, was administered 30 min before apigenin. We found that treatment with apigenin (20mg/kg, intragastrically) for three weeks remarkably ameliorated CUMS-induced behavioral abnormalities, such as decreased locomotor activity and reduced sucrose consumption. In response to oxidative stress, the NLRP3 inflammasome was activated and IL-1β secretion increased in the prefrontal cortex (PFC) of CUMS rats. However, apigenin treatment upregulated PPARγ expression and downregulated the expression of NLRP3, which subsequently downregulated the production of IL-1β. In addition, GW9662 diminished the inhibitory effects of apigenin on the NLRP3 inflammasome. In conclusion, our results demonstrate that apigenin exhibits antidepressant-like effects in CUMS rats, possibly by inhibiting IL-1β production and NLRP3 inflammasome expression via the up-regulation of PPARγ expression.

Topics: Anilides; Animals; Apigenin; Behavior, Animal; Carrier Proteins; Depression; Disease Models, Animal; Inflammasomes; Interleukin-1beta; Male; NLR Family, Pyrin Domain-Containing 3 Protein; PPAR gamma; Prefrontal Cortex; Rats; Rats, Sprague-Dawley; Stress, Psychological

Dysregulation of the inflammatory response against infection contributes to mortality in sepsis. Inflammation provides critical host defense, but it can cause tissue damage, multiple organ failure, and death. Because the nuclear transcription factor peroxisome proliferator-activated receptor γ (PPARγ) exhibits therapeutic potential, we characterized the role of PPARγ in sepsis. We analyzed severity of clinical signs, survival rates, cytokine production, leukocyte influx, and bacterial clearance in a cecal ligation and puncture (CLP) model of sepsis in Swiss mice. The PPARγ agonist rosiglitazone treatment improved clinical status and mortality, while increasing IL-10 production and decreasing TNF-α and IL-6 levels, and peritoneal neutrophil accumulation 24 h after CLP. We noted increased bacterial killing in rosiglitazone treated mice, correlated with increased generation of reactive oxygen species. Polymorphonuclear leukocytes (PMN) incubated with LPS or Escherichia coli and rosiglitazone increased peritoneal neutrophil extracellular trap (NET)-mediated bacterial killing, an effect reversed by the PPARγ antagonist (GW 9662) treatment. Rosiglitazone also enhanced the release of histones by PMN, a surrogate marker of NET formation, effect abolished by GW 9662. Rosiglitazone modulated the inflammatory response and increased bacterial clearance through PPARγ activation and NET formation, combining immunomodulatory and host-dependent anti-bacterial effects and, therefore, warrants further study as a potential therapeutic agent in sepsis.

Topics: Anilides; Animals; Disease Models, Animal; Escherichia coli; Extracellular Traps; Male; Mice; Neutrophils; PPAR gamma; Rosiglitazone; Sepsis; Signal Transduction; Thiazolidinediones

Germinal matrix hemorrhage remains the leading cause of morbidity and mortality in preterm infants in the United States with little progress made in its clinical management. Survivors are often afflicted with long-term neurological sequelae, including cerebral palsy, mental retardation, hydrocephalus, and psychiatric disorders. Blood clots disrupting normal cerebrospinal fluid circulation and absorption after germinal matrix hemorrhage are thought to be important contributors towards post-hemorrhagic hydrocephalus development. We evaluated if upregulating CD36 scavenger receptor expression in microglia and macrophages through PPARγ stimulation, which was effective in experimental adult cerebral hemorrhage models and is being evaluated clinically, will enhance hematoma resolution and ameliorate long-term brain sequelae using a neonatal rat germinal matrix hemorrhage model. PPARγ stimulation (15d-PGJ2) increased short-term PPARγ and CD36 expression levels as well as enhanced hematoma resolution, which was reversed by a PPARγ antagonist (GW9662) and CD36 siRNA. PPARγ stimulation (15d-PGJ2) also reduced long-term white matter loss and post-hemorrhagic ventricular dilation as well as improved neurofunctional outcomes, which were reversed by a PPARγ antagonist (GW9662). PPARγ-induced upregulation of CD36 in macrophages and microglia is, therefore, critical for enhancing hematoma resolution and ameliorating long-term brain sequelae.

Topics: Anilides; Animals; Animals, Newborn; Brain; CD36 Antigens; Central Nervous System Agents; Disease Models, Animal; Gene Knockdown Techniques; Hematoma; Intracranial Hemorrhages; Macrophage Activation; Microglia; Neuroprotective Agents; PPAR gamma; Prostaglandin D2; Random Allocation; Rats, Sprague-Dawley; RNA, Small Interfering; Up-Regulation

Oroxyloside, as a metabolite of oroxylin A, may harbor various beneficial bioactivities which have rarely been reported in the previous studies. Here we established the dextran sulfate sodium (DSS)-induced experimental colitis and evaluated the anti-inflammatory effect of oroxyloside in vivo. As a result, oroxyloside attenuated DSS-induced body weight loss, colon length shortening and colonic pathological damage. Furthermore, oroxyloside inhibited inflammatory cell infiltration and decreased myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) activities as well. The production of pro-inflammatory cytokines in serum and colon was also significantly reduced by oroxyloside. We unraveled the underlying mechanisms that oroxyloside inhibited NF-κB pathway by activating Peroxisome Proliferator-Activated Receptor γ (PPARγ) to attenuate DSS-induced colitis. Moreover, we investigated the anti-inflammatory effect and mechanisms of oroxyloside in the mouse macrophage cell line RAW264.7 and bone marrow derived macrophages (BMDM). Oroxyloside decreased several LPS-induced inflammatory cytokines, including IL-1β, IL-6 and TNF-α in RAW264.7 and BMDM. We also found that oroxyloside inhibited LPS-induced activation of NF-κB signaling pathway via activating PPARγ in RAW 264.7 and BMDM. Docking study showed that oroxyloside could bind with PPARγ. GW9662, the inhibitor of PPARγ, and PPARγ siRNA transfection blocked the effect of oroxyloside on PPARγ activation. Our study suggested that oroxyloside prevented DSS-induced colitis by inhibiting NF-κB pathway through PPARγ activation. Therefore, oroxyloside may be a promising and effective agent for inflammatory bowel disease (IBD).

Topics: Anilides; Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Line; Colitis; Dextran Sulfate; Disease Models, Animal; Female; Flavones; Gene Expression Regulation; Glucuronides; Interleukin-1beta; Interleukin-6; Macrophages; Mice; Mice, Inbred C57BL; Molecular Docking Simulation; NF-kappa B; Nitric Oxide Synthase Type II; Peroxidase; PPAR gamma; RNA, Small Interfering; Signal Transduction; Tumor Necrosis Factor-alpha

Treatment of painful neuromas remains a challenge and the mechanism of neuroma-associated pain is not yet fully understood. In this study, we aimed to observe the expression of alpha smooth muscle actin (α-SMA) in traumatic neuromas and to investigate its possible roles in the cause of neuropathic pain in a rat model. The rat sciatic nerve was used and the experiment was divided into two parts. In part I, our results showed significantly higher levels of α-SMA and the pain marker c-fos in the autotomy group than in the no-autotomy group. In part II, the expression of α-SMA in neuromas was down- and up-regulated using SB-431542 and GW9662, respectively. A significant correlation between autotomy scores and the expression level of α-SMA was found (R = 0.957; p < 0.001) and the expression level of α-SMA was positively related to the autotomy scores (R(2) = 0.915, p < 0.001). We concluded that the expression of α-SMA plays certain roles in the neuroma-associated pain, either as a direct cause of pain or as an indirect marker of existence of local mechanical stimuli. Our findings may provide new insights into the development of new treatment modalities for the management of intractable painful neuromas.

Topics: Actins; Anilides; Animals; Benzamides; Blotting, Western; Dioxoles; Disease Models, Animal; Humans; Immunohistochemistry; Neuralgia; Neuroma; Pilot Projects; Proto-Oncogene Proteins c-fos; Rats; Sciatic Nerve; Sciatic Neuropathy; Spinal Cord; Spinal Cord Dorsal Horn; Wounds and Injuries

Cannabinoid and PPAR receptors show well established interactions in a set of physiological effects. Regarding the seizure-modulating properties of both classes of receptors, the present study aimed to evaluate the roles of the PPAR-gamma, PPAR-alpha and CB1 receptors on the anticonvulsant effects of WIN 55,212-2 (WIN, a non selective cannabinoid agonist). The clonic seizure thresholds after intravenous administration of pentylenetetrazole (PTZ) were assessed in mice weighing 23-30 g. WIN increased the seizure threshold dose dependently. Pretreatment with pioglitazone, as a PPARγ agonist, potentiated the anticonvulsant effects of WIN, while PPARγ antagonist inhibited these anticonvulsant effects partially. On the other hand PPARα antagonist reduced the anticonvulsant effects of WIN significantly. Finally the combination of CB1 antagonist and PPARα antagonist could completely block the anticonvulsant properties of WIN. Taken together, these results show for the first time that a functional interaction exists between cannabinoid and PPAR receptors in the modulation of seizure susceptibility.

Topics: Anilides; Animals; Anticonvulsants; Benzoxazines; Cannabinoid Receptor Antagonists; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Male; Mice; Morpholines; Naphthalenes; Oxazoles; Pentylenetetrazole; Peroxisome Proliferator-Activated Receptors; Pioglitazone; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Seizures; Thiazolidinediones; Tyrosine

Epidemiological evidence indicates that thyrotropin (TSH) is positively correlated with the severity of obesity. However, the mechanism remains unclear. Here, we show that TSH promoted triglyceride (TG) synthesis in differentiated adipocytes in a thyroid hormone-independent manner. Mice with subclinical hypothyroidism, which is characterized by elevated serum TSH but not thyroid hormone levels, demonstrated a 35% increase in the total white adipose mass compared with their wild-type littermates. Interestingly, Tshr KO mice, which had normal thyroid hormone levels after thyroid hormone supplementation, resisted high-fat diet-induced obesity. TSH could directly induce the activity of glycerol-3-phosphate-acyltransferase 3 (GPAT3), the rate-limiting enzyme in TG synthesis, in differentiated 3T3-L1 adipocytes. However, following either the knockdown of Tshr and PPARγ or the constitutive activation of AMPK, the changes to TSH-triggered GPAT3 activity and adipogenesis disappeared. The over-expression of PPARγ or the expression of an AMPK dominant negative mutant reversed the TSH-induced changes. Thus, TSH acted as a previously unrecognized master regulator of adipogenesis, indicating that modification of the AMPK/PPARγ/GPAT3 axis via the TSH receptor might serve as a potential therapeutic target for obesity.

Topics: 3T3-L1 Cells; Adipocytes; Adipogenesis; Adipose Tissue, White; AMP-Activated Protein Kinases; Anilides; Animals; Body Weight; Cells, Cultured; Diet, High-Fat; Disease Models, Animal; Glycerol-3-Phosphate O-Acyltransferase; Hypothyroidism; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; Phosphorylation; PPAR gamma; Receptors, Thyrotropin; RNA Interference; RNA, Messenger; RNA, Small Interfering; Thyrotropin; Triglycerides

Notoginsenoside R1 (NTR1) is the main active ingredient of the well-known traditional Chinese herbal medicine Panax notoginseng, the root of Panax notoginseng (Burk.) F. H. Chen. Studies demonstrated that NTR1 may have some neuronal protective effects. Alzheimer's disease (AD) is a neurodegenerative disease characterized by β -amyloid protein (Aβ) deposition, neurofibrillary tangle formation and neuronal loss. This study was designed to explore the protective effect of NTR1 on an APP/PS1 double-transgenic mouse model of AD and investigate the possible mechanism. The 3-month-old mice were fed with 5 mg/(kg•d), 25 mg/(kg•d) NTR1 or vehicle via oral gavage for 3 months and changes in behavior, neuropathology, and amyloid pathology were investigated. The mice with NTR1 treatment showed significant amelioration in the cognitive function and increased choline acetyl transferase expression, as compared to the vehicle treated mice. NTR1 treatment inhibited Aβ accumulation and increased insulin degrading enzyme expression in both APP/PS1 mice and N2a-APP695sw cells, suggesting that of NTR1 may exert its protective effects through the enhancement of the Aβ degradation. Furthermore, our data showed that the increased level of peroxisome proliferator-activated receptor γ (PPARγ) and the up-regulation of insulin degrading enzyme induced by NTR1 were inhibited by administration of GW9662 (a PPARγ antagonist), indicating that the effect of NTR1 was mediated, at least in part, by PPARγ. Thus, our findings provide the evidences that NTR1 has protective effect on AD mouse model and NTR1 may be a potential candidate for AD treatment.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Anilides; Animals; Cell Line, Tumor; Central Nervous System Agents; Choline O-Acetyltransferase; Cognition; Disease Models, Animal; Ginsenosides; Humans; Insulysin; Male; Mice, Inbred C57BL; Mice, Transgenic; Neuroprotective Agents; PPAR gamma; Presenilin-1; Random Allocation; Up-Regulation

Breast cancer is the major cause of cancer death in women worldwide. The most common site of metastasis is bone. Bone metastases obstruct the normal bone remodeling process and aberrantly enhance osteoclast-mediated bone resorption, which results in osteolytic lesions. 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) is an endogenous ligand of peroxisome proliferator-activated receptor gamma (PPARγ) that has anti-inflammatory and antitumor activity at micromolar concentrations through PPARγ-dependent and/or PPARγ-independent pathways. We investigated the inhibitory activity of 15d-PGJ2 on the bone loss that is associated with breast cancer bone metastasis and estrogen deficiency caused by cancer treatment. 15d-PGJ2 dose-dependently inhibited viability, migration, invasion, and parathyroid hormone-related protein (PTHrP) production in MDA-MB-231 breast cancer cells. 15d-PGJ2 suppressed receptor activator of nuclear factor kappa-B ligand (RANKL) mRNA levels and normalized osteoprotegerin (OPG) mRNA levels in hFOB1.19 osteoblastic cells treated with culture medium from MDA-MB-231 cells or PTHrP, which decreased the RANKL/OPG ratio. 15d-PGJ2 blocked RANKL-induced osteoclastogenesis and inhibited the formation of resorption pits by decreasing the activities of cathepsin K and matrix metalloproteinases, which are secreted by mature osteoclasts. 15d-PGJ2 exerted its effects on breast cancer and bone cells via PPARγ-independent pathways. In Balb/c nu/nu mice that received an intracardiac injection of MDA-MB-231 cells, subcutaneously injected 15d-PGJ2 substantially decreased metastatic progression, cancer cell-mediated bone destruction in femora, tibiae, and mandibles, and serum PTHrP levels. 15d-PGJ2 prevented the destruction of femoral trabecular structures in estrogen-deprived ICR mice as measured by bone morphometric parameters and serum biochemical data. Therefore, 15d-PGJ2 may be beneficial for the prevention and treatment of breast cancer-associated bone diseases.

Topics: Anilides; Animals; Bone Neoplasms; Bone Resorption; Breast Neoplasms; Cell Line, Tumor; Cell Movement; Cell Survival; Disease Models, Animal; Estrogens; Female; Humans; Male; Mice; Mice, Nude; Osteoclasts; Osteolysis; Osteoprotegerin; Ovariectomy; Parathyroid Hormone-Related Protein; PPAR gamma; Prostaglandin D2; RANK Ligand

Inflammation and renin-angiotensin system activity in the brain contribute to hypertension through effects on fluid intake, vasopressin release, and sympathetic nerve activity. We recently reported that activation of brain peroxisome proliferator-activated receptor (PPAR)-γ in heart failure rats reduced inflammation and renin-angiotensin system activity in the hypothalamic paraventricular nucleus and ameliorated the peripheral manifestations of heart failure. We hypothesized that the activation of brain PPAR-γ might have beneficial effects in angiotensin II-induced hypertension. Sprague-Dawley rats received a 2-week subcutaneous infusion of angiotensin II (120 ng/kg per minute) combined with a continuous intracerebroventricular infusion of vehicle, the PPAR-γ agonist pioglitazone (3 nmol/h) or the PPAR-γ antagonist GW9662 (7 nmol/h). Angiotensin II+vehicle rats had increased mean blood pressure, increased sympathetic drive as indicated by the mean blood pressure response to ganglionic blockade, and increased water consumption. PPAR-γ mRNA in subfornical organ and hypothalamic paraventricular nucleus was unchanged, but PPAR-γ DNA-binding activity was reduced. mRNA for interleukin-1β, tumor necrosis factor-α, cyclooxygenase-2, and angiotensin II type 1 receptor was augmented in both nuclei, and hypothalamic paraventricular nucleus neuronal activity was increased. The plasma vasopressin response to a 6-hour water restriction also increased. These responses to angiotensin II were exacerbated by GW9662 and ameliorated by pioglitazone, which increased PPAR-γ mRNA and PPAR-γ DNA-binding activity in subfornical organ and hypothalamic paraventricular nucleus. Pioglitazone and GW9662 had no effects on control rats. The results suggest that activating brain PPAR-γ to reduce central inflammation and brain renin-angiotensin system activity may be a useful adjunct in the treatment of angiotensin II-dependent hypertension.

Topics: Angiotensin II; Anilides; Animals; Blood Pressure; Brain; Disease Models, Animal; Hypertension; Infusions, Intraventricular; Infusions, Subcutaneous; Male; Pioglitazone; PPAR gamma; Rats; Rats, Sprague-Dawley; Renin-Angiotensin System; Sympathetic Nervous System; Thiazolidinediones; Ventricular Remodeling

Peroxisome proliferator-activated receptor (PPAR) α/γ may control lipid metabolism and inflammatory response by regulating the downstream target genes, and play a crucial role in the process of non-alcoholic steatohepatitis (NASH) formation, but the difference and interaction between PPARα and PPARγ are poorly understood. The rat model with NASH was established by orally feeding high-fat and high-sucrose emulsion for 6weeks. The results shown that after the model rats were simultaneously treated with PPARα/γ agonists, the total cholesterol (TC), triglyceride (TG) and inflammatory cytokine levels in serum and hepatic tissue, the hepatic steatosis and inflammatory cellular infiltration were decreased, and were consistent with the results of hepatic lipogenic gene and nuclear factor (NF)-κB protein expressions. Conversely, these indexes were increased by PPARα/γ antagonist treatment. Compared with the model group, the serum free fatty acid (FFA) level was increased in the PPARα agonist-treated group, decreased in the PPARγ agonist-treated group, and unchanged in the PPARα/γ agonists-treated group. The hepatic FFA level was low in the PPARα/γ agonists-treated groups, but no significant variation in the PPARα/γ antagonists-treated groups. The increments of hepatic reduced glutathione (GSH) and superoxide dismutase (SOD) contents in the PPARα/γ agonists-treated groups were accompanied by decreased hepatic malondialdehyde (MDA) content. These findings demonstrated that PPARα/γ activation might decrease the hepatic lipid accumulation, oxidative stress and inflammatory cytokine production, and PPARγ could counterbalance the adverse effect of PPARα on circulating FFA. It was concluded that the integrative application of PPARα and PPARγ agonists might exert a synergic inhibitory effect on NASH formation through the modulation of PPARα/γ-mediated lipogenic and inflammatory gene expressions.

Topics: Anilides; Animals; Chemokine CCL2; Cytokines; Disease Models, Animal; Fatty Acids, Nonesterified; Fenofibrate; Gene Expression Regulation; Glutathione; Indoles; Inflammation; Interleukin-6; Interleukin-8; Lipid Metabolism; Liver; Male; Malondialdehyde; NF-kappa B; Non-alcoholic Fatty Liver Disease; Oxidative Stress; PPAR alpha; PPAR gamma; Rats; Rats, Sprague-Dawley; Rosiglitazone; Superoxide Dismutase; Thiazolidinediones; Tumor Necrosis Factor-alpha

In our previous studies, we found that a single ultralow dose of tetrahydrocannabinol (THC; 0.002 mg/kg, three to four orders of magnitude lower than the conventional doses) protects the brain from different insults that cause cognitive deficits. Because various insults may trigger a neuroinflammatory response that leads to secondary damage to the brain, the current study tested whether this extremely low dose of THC could protect the brain from inflammation-induced cognitive deficits. Mice received a single injection of THC (0.002 mg/kg) 48 hr before or 1-7 days after treatment with lipopolysccharide (LPS; 10 mg/kg) and were examined with the object recognition test 3 weeks later. LPS caused long-lasting cognitive deficits, whereas the application of THC before or after LPS protected the mice from this LPS-induced damage. The protective effect of THC was blocked by the cannabinoid (CB) 1 receptor antagonist SR14176A but not by the CB2 receptor antagonist SR141528 and was mimicked by the CB1 agonist ACEA but not by the CB2 agonist HU308. The protective effect of THC was also blocked by pretreatment with GW9662, indicating the involvement of peroxisome proliferator-activated receptor-γ. Biochemical examination of the brain revealed a long-term (at least 7 weeks) elevation of the prostaglandin-producing enzyme cyclooxygenase-2 in the hippocampus and in the frontal cortex following the injection of LPS. Pretreatment with the extremely low dose of THC tended to attenuate this elevation. Our results suggest that an ultralow dose of THC that lacks any psychotrophic activity protects the brain from neuroinflammation-induced cognitive damage and might be used as an effective drug for the treatment of neuroinflammatory conditions, including neurodegenerative diseases.

Topics: Anilides; Animals; Arachidonic Acids; Brain; Camphanes; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Cognition Disorders; Cyclooxygenase 2; Disease Models, Animal; Dose-Response Relationship, Drug; Dronabinol; Encephalitis; Lipopolysaccharides; Male; Mice; Mice, Inbred ICR; PPAR gamma; Pyrazoles; Recognition, Psychology

The present study investigated the effect of hesperidin, a natural flavonoid, in cardiac ischemia and reperfusion (I/R) injury in diabetic rats. Male Wistar rats with diabetes were divided into five groups and were orally administered saline once daily (IR-sham and IR-control), Hesperidin (100 mg/kg/day; IR-Hesperidin), GW9962 (PPAR-γ receptor antagonist), or combination of both for 14 days. On the 15th day, in the IR-control and IR-treatment groups, rats were subjected to left anterior descending (LAD) coronary artery occlusion for 45 minutes followed by a one-hour reperfusion. Haemodynamic parameters were recorded and rats were sacrificed; hearts were isolated for biochemical, histopathological, ultrastructural and immunohistochemistry. In the IR-control group, significant ventricular dysfunctions were observed along with enhanced expression of pro-apoptotic protein Bax. A decline in cardiac injury markers lactate dehydrogenase activity, CK-MB and increased content of thiobarbituric acid reactive substances, a marker of lipid peroxidation, and TNF-α were observed. Hesperidin pretreatment significantly improved mean arterial pressure, reduced left ventricular end-diastolic pressure, and improved both inotropic and lusitropic function of the heart (+LVdP/dt and -LVdP/dt) as compared to IR-control. Furthermore, hesperidin treatment significantly decreased the level of thiobarbituric acid reactive substances and reversed the activity of lactate dehydrogenase towards normal value. Hesperidin showed anti-apoptotic effects by upregulating Bcl-2 protein and decreasing Bax protein expression. Additionally, histopathological and ultrastructural studies reconfirmed the protective action of hesperidin. On the other hand, GW9662, selective PPAR-γ receptor antagonist, produced opposite effects and attenuated the hesperidin induced improvements. The study for the first time evidence the involvement of PPAR-γ pathway in the cardioprotective activity of hesperidin in I/R model in rats.

Topics: Anilides; Animals; bcl-2-Associated X Protein; Cardiotonic Agents; Creatine Kinase, MB Form; Diabetes Mellitus, Experimental; Disease Models, Animal; Hemodynamics; Hesperidin; Lipid Peroxidation; Male; Microscopy, Electron, Transmission; Myocardial Ischemia; Myocardium; PPAR gamma; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Wistar; Tumor Necrosis Factor-alpha

Behavioral sensitization (B.S.) is a pathophysiological animal model for stimulant-induced psychosis and addiction. Accumulated evidence indicates that inflammatory processes are involved in psychostimulants effects in the CNS. Cannabinoids like WIN55,212-2 act as potential activators of PPAR-γ and affects the inflammatory status of the CNS. The purpose of this study is to determine PPAR-γ role in induction and expression of B.S. and the coincident inflammatory responses developed by WIN55,212-2 (WIN). Using open-field test, locomotor activity was monitored in animals treated with intraperitoneal low-dose WIN single or repeated injections. Concurrent striatal COX-2 and TNF-α levels and PPAR-γ activity were determined by immunoblotting assay. Effects of concomitant chronic or acute PPAR-γ pharmacological inhibition (with GW9662) were then investigated on behavioral and biochemical variables. WIN enhanced locomotor activity and while administered chronically augmented cytosolic COX-2 and TNF-α and also PPAR-γ nuclear levels. GW9662 co-administration completely prevented the induction of sensitizing effects of chronic WIN and altered the inflammatory responses. However, the expression of B.S. was intensified with GW9662 as assessed by increased locomotion after WIN challenge following 48 h withdrawal. Neuroinflammation and locomotor excitability in animals received just a single-dose WIN were also escalated with GW9662. Our findings conclude that PPAR-γ could play different key roles during B.S. development by WIN. Although PPAR-γ is mostly known for neuroprotective and anti-inflammatory effects, our data indicate that it mediates the B.S. induction by chronic WIN. However, while the B.S. was induced, PPAR-γ could play a homeostatic role opposing the expressed B.S. escalation.

Topics: Anilides; Animals; Benzoxazines; Biomarkers; Cannabinoids; Corpus Striatum; Cyclooxygenase 2; Disease Models, Animal; Exploratory Behavior; Gene Expression Regulation; Inflammation; Injections, Intraperitoneal; Injections, Intraventricular; Locomotion; Male; Morpholines; Naphthalenes; PPAR gamma; Psychomotor Agitation; Rats; Rats, Wistar; Receptors, Cannabinoid; Tumor Necrosis Factor-alpha

Telmisartan and losartan, angiotensin II type 1 (AT1) receptor antagonists, are used to manage hypertension. We previously reported that telmisartan, a partial agonist of peroxisome proliferator-activated receptor-γ (PPAR-γ), exhibited stronger vasoprotection than the same dose of losartan in normotensive chronic kidney disease (CKD) rats. We investigated whether telmisartan could inhibit vascular dysfunction in hypertensive CKD rats, via both AT1 receptor blockade and PPAR-γ activation, more effectively than losartan, which decreased blood pressure to a similar extent as telmisartan.. Two or three branches of the left renal artery were ligated and the right kidney was removed to make hypertensive CKD rats. Telmisartan (5 mg/kg), losartan (10 mg/kg) or telmisartan plus the PPAR-γ antagonist GW9662 was administered.. Blood pressure was increased in CKD rats. Telmisartan and losartan decreased blood pressure to the same levels. Impaired endothelium-dependent vasodilation, hyperplasia and decreased phospho-eNOS (Ser(1177)) expression in CKD rat aortas were improved by telmisartan. The aortic infiltration by macrophages and expression of osteopontin were enhanced in CKD rats and suppressed by telmisartan. GW9662 partly canceled the normalization of vascular dysfunction. While losartan attenuated vascular changes, the extent of this attenuation was greater in the telmisartan-treated group.. Telmisartan exhibited vasoprotection via PPAR-γ agonistic properties in hypertensive CKD rats.

Topics: Angiotensin II Type 1 Receptor Blockers; Anilides; Animals; Aorta; Benzimidazoles; Benzoates; Blood Pressure; Disease Models, Animal; Drug Partial Agonism; Endothelium, Vascular; Hypertension; Losartan; Male; Nitric Oxide Synthase Type III; PPAR gamma; Rats; Rats, Wistar; Telmisartan; Vasodilation

Huntington's disease (HD) is a devastating genetic neurodegenerative disease caused by CAG trinucleotide expansion in the exon-1 region of the huntingtin gene. Currently, no cure is available. It is becoming increasingly apparent that mutant Huntingtin (HTT) impairs metabolic homeostasis and causes transcriptional dysregulation. The peroxisome proliferator-activated receptor gamma (PPAR-γ) is a transcriptional factor that plays a key role in regulating genes involved in energy metabolism; recent studies demonstrated that PPAR-γ activation prevented mitochondrial depolarization in cells expressing mutant HTT and attenuated neurodegeneration in various models of neurodegenerative diseases. PPAR-γ-coactivator 1α (PGC-1 α) transcription activity is also impaired by mutant HTT. We now report that the PPAR-γ agonist, rosiglitazone (RSG), significantly attenuated mutant HTT-induced toxicity in striatal cells and that the protective effect of RSG is mediated by activation of PPAR-γ. Moreover, chronic administration of RSG (10 mg/kg/day, i.p) significantly improved motor function and attenuated hyperglycemia in N171-82Q HD mice. RSG administration rescued brain derived neurotrophic factor(BDNF) deficiency in the cerebral cortex, and prevented loss of orexin-A-immunopositive neurons in the hypothalamus of N171-82Q HD mice. RSG also prevented PGC-1α reduction and increased Sirt6 protein levels in HD mouse brain. Our results suggest that modifying the PPAR-γ pathway plays a beneficial role in rescuing motor function as well as glucose metabolic abnormalities in HD.

Topics: Adenosine Triphosphate; Anilides; Animals; Brain; Brain-Derived Neurotrophic Factor; Cell Line; Disease Models, Animal; Gene Expression Regulation; Glutamates; Humans; Huntingtin Protein; Huntington Disease; Hyperglycemia; Intracellular Signaling Peptides and Proteins; L-Lactate Dehydrogenase; Male; Mice; Mice, Transgenic; Movement Disorders; Nerve Tissue Proteins; Neurons; Neuropeptides; Neuroprotective Agents; Orexins; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; PPAR gamma; RNA, Messenger; Rosiglitazone; Sirtuins; Thiazolidinediones; Trans-Activators; Transcription Factors; Transfection; Trinucleotide Repeat Expansion

Peroxisome proliferator-activated receptor gamma (PPARγ) transcriptionally modulates fat metabolism and also plays a role in pathological conditions such as cancer, neurodegenerative disease and inflammation. PPARγ imaging agents are potential tools for investigating these diseases.. Four analogs of GW9662, a PPARγ antagonist, with different fluorine-containing substituents at the para-position of the aniline ring were synthesized and evaluated using two different receptor binding assays for measuring PPARγ affinity. Micro-positron emission tomography (PET) imaging studies were performed in a transgenic mouse model having a heart-specific overexpression of PPARγ.. All four analogs were found to have binding affinities that were comparable to or better than the reference antagonist, GW9662, using a scintillation proximity assay (SPA). However, only the chloro-based analogs (compounds 3 and 4) had activity in a whole-cell assay measuring activation of the PPARγ/retinoid X receptor complex. The microPET imaging studies in an MHC-PPARγ transgenic mouse model showed high uptake and PPARγ-specific binding for the irreversible antagonist [(18)F]3, whereas the corresponding reversible methoxy analog ([(18)F]5) displayed only nonspecific uptake in heart.. The results of this preliminary study show that the irreversible antagonist [(18)F]3 may represent a novel strategy for imaging PPARγ in vivo with PET.

Topics: Anilides; Animals; Biological Assay; Disease Models, Animal; Female; Fluorine Radioisotopes; Heart; Heart Diseases; Ligands; Male; Mice; Mice, Transgenic; Positron-Emission Tomography; PPAR gamma; Rats; Rats, Zucker; Retinoid X Receptors; Tissue Distribution

Baicalin, a herb-derived flavonoid compound, has beneficial activities, including the modulation of oxidative stress and inflammation. Nuclear receptor peroxisome proliferator-activated receptor-γ (PPARγ) is a ligand-activated transcription factor that plays an important role in regulating nuclear factor-κB (NF-κB)-induced age-related inflammation. We investigated the anti-inflammatory action of baicalin, which depends on its ability to activate PPARγ, and subsequently to suppress NF-κB. We examined baicalin-treated kidney tissue from 24-month-old Fischer 344 aged rats (10 or 20 mg/kg/day for 10 days) and baicalin-fed mice (10 mg/kg/day for 3 days) for in vivo investigations, and used endothelial YPEN-1 cells for in vitro studies. In the baicalin-fed aged rats, there was a marked enhancement of both nuclear protein levels and DNA binding activity of PPARγ, and a decreased expression of NF-κB target genes (VCAM-1, IL-1β, and IL-6) compared with non-baicalin-fed aged rats. Furthermore, to confirm the anti-inflammatory action of PPARγ activated by baicalin, we used lipopolysaccharide (LPS)-treated cells and mice. The results showed that baicalin induced PPARγ-selective activation in YPEN-1 cells, and that the effects of baicalin were blocked by the PPARγ receptor antagonist, GW9662. In addition, baicalin treatment prevented RS generation, NF-κB activation and the expression of pro-inflammatory genes, whereas it increased PPARγ expression in LPS-treated cells and mouse kidney. Our data suggest that baicalin-induced PPARγ expression reduced age-related inflammation through blocking pro-inflammatory NF-κB activation. These results indicate that baicalin is a novel PPARγ activator and that this agent may have the potential to minimize inflammation.

Topics: Age Factors; Aging; Anilides; Animals; Anti-Inflammatory Agents; Antioxidants; Cell Line; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelial Cells; Flavonoids; Inflammation Mediators; Kidney; Lipopolysaccharides; Male; Mice; Mice, Inbred ICR; Nephritis; NF-kappa B; PPAR gamma; Rats; Rats, Inbred F344; Transfection; Up-Regulation

Berberine hydrochloride (BBR), a plant alkaloid, has been used to treat intestinal inflammation or infection for years. Cyclooxygenase-2 (COX-2) is pro-inflammatory mediator and involved in the induction of gut inflammation. The expression of COX-2 in small bowel mucosa was determined and the mechanism by which BBR modulated COX-2 expression was explored in a rat model of endotoxemia induced by lipopolysaccharide (LPS). The results showed that without LPS stimulation COX-2 was constitutively expressed at low levels in control rats. LPS challenge rapidly induced COX-2 gene transcription resulting in high levels of inducible COX-2 expression in endotoxemic rats. BBR pre- and post-treatment had no marked effect on constitutive COX-2 expression but inhibited inducible COX-2 overexpression. LPS challenge increased the expression and phosphorylation of peroxisome proliferator-activated receptor gamma (PPARγ), p38 and activating transcription factor 2 and 3 (ATF2, ATF3), but the effects of LPS were inhibited by BBR treatment. GW9662 did not influence constitutive COX-2 expression but enhanced inducible COX-2 overproduction. Besides, GW9662 abolished the inhibitory effect of BBR on inducible COX-2, p38, ATF2, 3 expression and phosphorylation. Collectively, these results indicated that BBR gavage could attenuate the overexpression of inducible COX-2, not constitutive COX-2, in ileal mucosa during acute endotoxemia in part via activation of PPARγ pathway, which negatively interfered with p38/ATFs cascade.

Topics: Anilides; Animals; Berberine; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Disease Models, Animal; Endotoxemia; Escherichia coli; Ileum; Intestinal Mucosa; Lipopolysaccharides; Male; PPAR gamma; Rats; Rats, Sprague-Dawley; RNA, Messenger

Angiotensin (Ang) II type 1 receptor blockers have demonstrated beneficial effects beyond blood pressure control in the treatment of chronic kidney disease. There is clinical evidence that telmisartan is more effective than losartan in reducing proteinuria in hypertensive patients with diabetic nephropathy, because it is a partial agonist of peroxisome-proliferator activated receptor-γ (PPARγ), as well as an Ang II type 1 receptor blocker (AMADEO Study [A comparison of telMisartan versus losArtan in hypertensive type 2 DiabEtic patients with Overt nephropathy]). In this study, we examined the role of PPARγ activation in the renal protective actions of telmisartan using Ang II type 1 receptor-deficient mice. Renal injury was induced in Ang II type 1 receptor-deficient mice by producing unilateral ureteral obstruction, which exhibited severe renal interstitial fibrosis and inflammation. In these mice, telmisartan prevented hydronephrosis induced by unilateral ureteral obstruction more strongly than did losartan. Importantly, the prevention of renal atrophy and fibrosis by telmisartan was significantly attenuated by GW9662, a PPARγ antagonist. Interestingly, the downstream effector of PPARγ activation by telmisartan is hepatocyte growth factor (HGF), a well-known antifibrotic factor, because renal HGF expression was significantly increased by telmisartan, and a neutralizing antibody against HGF diminished the renal protective action of telmisartan. These beneficial changes by telmisartan were associated with a decrease in the expression of transforming growth factor-β1 and other proinflammatory and profibrotic cytokine genes through PPARγ/HGF activation. Our findings provide evidence of organ protective actions of telmisartan through the PPARγ/HGF pathway, independent of Ang II type 1 receptor blockade. Further development of the next generation of Ang II type 1 receptor blockers with added organ protective actions, such as PPARγ activation, might provide new beneficial drugs to treat renal and cardiovascular diseases.

Topics: Angiotensin II Type 1 Receptor Blockers; Anilides; Animals; Antibodies; Benzimidazoles; Benzoates; Cells, Cultured; Disease Models, Animal; Fibroblasts; Hepatocyte Growth Factor; Hydronephrosis; Kidney; Losartan; Male; Mice; Mice, Knockout; PPAR gamma; Receptor, Angiotensin, Type 1; Signal Transduction; Telmisartan; Transforming Growth Factor beta; Ureteral Obstruction

Telmisartan, an angiotensin II type 1 receptor blocker, reportedly exhibits a partial peroxisome proliferator-activated receptor (PPAR)-γ agonistic action. To test whether telmisartan ameliorates vascular injury in the chronic kidney disease model rat through the PPAR-γ pathway, telmisartan (5 mg/kg per day, orally), losartan (5 mg/kg per day, orally) or telmisartan plus PPAR-γ antagonist, GW9662 (1 mg/kg/day, i.p.), was administered for 14 days to subtotal nephrectomized rats (Nx). There was no significant difference in systolic blood pressure or fasting blood glucose values among all groups. Subtotal nephrectomy significantly aggravated the levels of urinary protein excretion, blood urea nitrogen and plasma malondialdehyde concentration, which were attenuated by telmisartan or losartan treatment. Vasodilation in response to acetylcholine in the aortic ring was impaired in the Nx, and improved by treatment with telmisartan. Immunohistochemical analysis revealed that the infiltration of adventitial areas by macrophages and expression of osteopontin and vascular cell adhesion molecule-1 were enhanced in the Nx aorta and the overexpression was suppressed by telmisartan. The increased NADPH oxidase-derived superoxide production in the aorta from the Nx rat was suppressed by telmisartan. Cotreatment with GW9662 partly blunted the normalization of vascular dysfunction and inflammation. While losartan also attenuated these vascular changes in the Nx rats, the extent of the attenuation was significantly greater in the telmisartan-treated group than in the losartan-treated group. These results suggest that, in addition to a class effect of angiotensin II type 1 receptor blockers, telmisartan exerted vasoprotective effects through its PPAR-γ agonistic property in rats with renal failure.

Topics: Acetylcholine; Angiotensin II Type 1 Receptor Blockers; Anilides; Animals; Aorta; Benzimidazoles; Benzoates; Blood Urea Nitrogen; Disease Models, Animal; Inflammation; Kidney Failure, Chronic; Losartan; Male; Malondialdehyde; Nephrectomy; PPAR gamma; Rats; Rats, Wistar; Telmisartan; Vasodilation

Several recent studies have shown that angiotensin type 1 receptor (AT1) antagonists such as candesartan inhibit the microglial inflammatory response and dopaminergic cell loss in animal models of Parkinson's disease. However, the mechanisms involved in the neuroprotective and anti-inflammatory effects of AT1 blockers in the brain have not been clarified. A number of studies have reported that AT1 blockers activate peroxisome proliferator-activated receptor gamma (PPAR γ). PPAR-γ activation inhibits inflammation, and may be responsible for neuroprotective effects, independently of AT1 blocking actions.. We have investigated whether oral treatment with telmisartan (the most potent PPAR-γ activator among AT1 blockers) provides neuroprotection against dopaminergic cell death and neuroinflammation, and the possible role of PPAR-γ activation in any such neuroprotection. We used a mouse model of parkinsonism induced by the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and co-administration of the PPAR-γ antagonist GW9662 to study the role of PPAR-γ activation. In addition, we used AT1a-null mice lesioned with MPTP to study whether deletion of AT1 in the absence of any pharmacological effect of AT1 blockers provides neuroprotection, and investigated whether PPAR-γ activation may also be involved in any such effect of AT1 deletion by co-administration of the PPAR-γ antagonist GW9662.. We observed that telmisartan protects mouse dopaminergic neurons and inhibits the microglial response induced by administration of MPTP. The protective effects of telmisartan on dopaminergic cell death and microglial activation were inhibited by co-administration of GW9662. Dopaminergic cell death and microglial activation were significantly lower in AT1a-null mice treated with MPTP than in mice not subjected to AT1a deletion. Interestingly, the protective effects of AT1 deletion were also inhibited by co-administration of GW9662.. The results suggest that telmisartan provides effective neuroprotection against dopaminergic cell death and that the neuroprotective effect is mediated by PPAR-γ activation. However, the results in AT1-deficient mice show that blockage of AT1, unrelated to the pharmacological properties of AT1 blockers, also protects against dopaminergic cell death and neuroinflammation. Furthermore, the results show that PPAR-γ activation is involved in the anti-inflammatory and neuroprotective effects of AT1 deletion.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Analysis of Variance; Angiotensin II Type 1 Receptor Blockers; Anilides; Animals; Benzimidazoles; Benzoates; Brain; Cell Death; Disease Models, Animal; Dopaminergic Neurons; Encephalitis; Gene Expression Regulation; Lectins; Leukocyte Common Antigens; Male; Mass Spectrometry; Mice; Mice, Inbred C57BL; Mice, Knockout; Microglia; MPTP Poisoning; PPAR gamma; Receptor, Angiotensin, Type 1; Telmisartan; Tyrosine 3-Monooxygenase

Peroxisome proliferator-activated receptor γ (PPARγ) agonists have been shown to provide neuroprotection in a number of neurodegenerative diseases including Parkinson's disease and Alzheimer's disease. These protective effects are primarily considered to result from the anti-inflammatory actions of PPARγ, however, there is increasing evidence that anti-oxidant mechanisms may also contribute. This study explored the impact of the PPARγ agonist rosiglitazone and the PPARγ antagonist GW9662 in the MPP(+)/MPTP (1-methyl-4-phenylpyridinium/1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) model of Parkinson's disease, focussing on oxidative stress mechanisms. Rosiglitazone attenuated reactive oxygen species formation induced by MPP(+) in SH-SY5Y cells concurrent with an upregulation of glutathione-S-transferase activity, but not superoxide dismutase activity. These responses were not attenuated by cotreatment with GW9662 suggesting that PPARγ activation is not required. The localisation of PPARγ in vivo to dopaminergic neurons of the substantia nigra pars compacta (SNpc) was established by immunohistochemistry and PPARγ levels were found to be upregulated 7 days after MPTP treatment. The importance of PPARγ in protecting against MPTP toxicity was confirmed by treating C57BL6 mice with GW9662. Treatment with GW9662 increased MPTP-induced neuronal loss in the SNpc whilst not affecting MPTP-induced reductions in striatal dopamine and 3,4-dihdroxyphenylacetic acid. GW9662 also caused neuronal loss in the SNpc of saline-treated mice. The evidence presented here supports the role of anti-oxidant mechanisms in the protective effects of PPARγ agonists in neurodegenerative diseases, but indicates that these effects may be independent of PPARγ activation. It also demonstrates the importance of PPARγ activity for neuronal survival within the SNpc.

Topics: Anilides; Animals; Antioxidants; Cell Line, Tumor; Disease Models, Animal; Humans; Male; Mice; Mice, Inbred C57BL; Neuroprotective Agents; Oxidative Stress; Parkinson Disease; PPAR gamma; Rosiglitazone; Thiazolidinediones

We reported previously that an angiotensin II type 1 receptor blocker, telmisartan, improved cognitive decline with peroxisome proliferator-activated receptor-γ activation; however, the detailed mechanisms are unclear. Enhanced blood-brain barrier (BBB) permeability with alteration of tight junctions is suggested to be related to diabetes mellitus. Therefore, we examined the possibility that telmisartan could attenuate BBB impairment with peroxisome proliferator-activated receptor-γ activation to improve diabetes mellitus-induced cognitive decline. Type 2 diabetic mice KKA(y) exhibited impairment of cognitive function, and telmisartan treatment attenuated this. Cotreatment with GW9662, a peroxisome proliferator-activated receptor-γ antagonist, interfered with these protective effects of telmisartan against cognitive function. BBB permeability was increased in both the cortex and hippocampus in KKA(y) mice. Administration of telmisartan attenuated this increased BBB permeability. Coadministration of GW9662 reduced this effect of telmisartan. Significant decreases in expression of tight junction proteins and increases in matrix metalloproteinase expression, oxidative stress, and proinflammatory cytokine production were observed in the brain, and treatment with telmisartan restored these changes. Swollen astroglial end-feet in BBB were observed in KKA(y) mice, and this change in BBB ultrastructure was decreased in telmisartan. These effects of telmisartan were weakened by cotreatment with GW9662. In contrast, administration of another angiotensin II type 1 receptor blocker, losartan, was less effective compared with telmisartan in terms of preventing BBB permeability and astroglial end-foot swelling, and coadministration of GW9662 did not affect the effects of losartan. These findings are consistent with the possibility that, in type 2 diabetic mice, angiotensin II type 1 receptor blockade with peroxisome proliferator-activated receptor-γ activation by telmisartan may help with protection against cognitive decline by preserving the integrity of the BBB.

Topics: Analysis of Variance; Angiotensin II Type 1 Receptor Blockers; Anilides; Animals; Benzimidazoles; Benzoates; Blood Glucose; Blood-Brain Barrier; Blotting, Western; Cognition Disorders; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Losartan; Male; Maze Learning; Mice; Mice, Inbred C57BL; PPAR gamma; Random Allocation; Sensitivity and Specificity; Telmisartan

Telmisartan is an angiotensin II receptor blocker, which acts as a partial agonist of peroxisome proliferator activator receptor-γ (PPAR-γ). Because PPAR-γ initiates a variety of antiinflammatory responses, the effect on myocardial ischemia is to be elucidated.. The left anterior descending arteries were ligated to induce myocardial infarction in rats. The animals were assigned to 4 groups: (1) control (saline, n = 6), (2) telmisartan (10 mg·kg·d, n = 6), (3) telmisartan + GW9662 (PPAR-γ-antagonist) (10 mg·kg·d of telmisartan and 1 mg·kg·d of GW9662, n = 6), and (4) amlodipine (10 mg·kg·d, n = 8) groups. Telmisartan reduced mean blood pressure compared with that in the control group. There was no statistical difference among the telmisartan, telmisartan + GW9662 and amlodipine groups. The end-diastolic left ventricular diameter was smaller in telmisartan group compared with that in the control group; GW9662 negated the effect of telmisartan. The thickness of the ventricular septum was kept in the telmisartan group compared with that in the control group; GW9662 negated the effect. Histopathologic analyses showed that telmisartan suppressed myocardial fibrosis compared with that of the control, whereas GW9662 negated the telmisartan effect.. Telmisartan suppresses pathological remodeling by PPAR-γ agonistic activities independent of its antihypertensive effects.

Topics: Amlodipine; Angiotensin II Type 1 Receptor Blockers; Anilides; Animals; Antihypertensive Agents; Benzimidazoles; Benzoates; Blood Pressure; Calcium Channel Blockers; Cells, Cultured; Disease Models, Animal; Drug Partial Agonism; Fibrosis; Hypertrophy, Left Ventricular; Male; Matrix Metalloproteinase 2; Myocardial Infarction; Myocardium; Pioglitazone; PPAR gamma; Rats; Rats, Sprague-Dawley; Stroke Volume; Telmisartan; Thiazolidinediones; Time Factors; Ventricular Function, Left; Ventricular Remodeling

The purpose of this study was to test the hypothesis that activation of endogenous peroxisome proliferator-activated receptor (PPARγ) inhibits induction of early growth response factor-1 (Egr-1), which is rapidly induced in the pancreas following cerulein intraperitoneal injection. Acute pancreatitis was induced in mice by hourly intraperitoneal injection of cerulein. Pioglitazone was administered prophylactically and pancreatic inflammation was assessed. AR42J cells were stimulated with caerulein 10⁻⁸ M co-incubated in presence of different concentration of pioglitazone. The expression of PPARγ, Egr-1, and the target genes of Egr-1 were studied by real-time reverse transcriptase polymerase chain reaction (PCR), Western blot, and immunohistochemistry. In vitro, a PPAR-γ activator (pioglitazone) strikingly diminished Egr-1 mRNA and protein expression corresponding to Egr-1. In vivo, treatment with pioglitazone prior to the intraperitoneal injection of cerulein induction of Egr-1 and its target genes such as, monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-1 (MIP-1). The inhibitory effect of pioglitazone on Egr-1 expression induced by cerulein was almost fully restored by GW9662. Activation of PPAR-γ suppressed the activation of Egr-1 and its inflammatory gene targets and provided potent protection against pancreas injury. These data suggest a new mechanism in which PPAR-γ activation may decrease tissue inflammation in response to a cerulein insult.

Topics: Acinar Cells; Acute Disease; Anilides; Animals; Cell Line, Tumor; Ceruletide; Chemokine CCL2; Chemokines; Disease Models, Animal; Early Growth Response Protein 1; Hypoglycemic Agents; Male; Pancreatitis; Pioglitazone; PPAR gamma; Rats; Rats, Sprague-Dawley; RNA, Messenger; Severity of Illness Index; Thiazolidinediones; Translational Research, Biomedical

Telmisartan is a well-established angiotensin II type 1 receptor blocker that improves insulin sensitivity in animal models of obesity and insulin resistance, as well as in humans. Telmisartan has been reported to function as a partial agonist of the peroxisome proliferator-activated receptor (PPAR) γ, which is also targeted by the nicotinamide adenine dinucleotide (NAD)-dependent deacetylase (SIRT1). Here, we investigated the pathways through which telmisartan acts on skeletal muscle, in vitro as well as in vivo.. Nine-week-old male db/db mice were fed a 60% high-fat diet, with orally administrated either vehicle (carboxymethyl-cellulose, CMC), 5 mg/kg telmisartan, or 5 mg/kg telmisartan and 1 mg/kg GW9662, a selective irreversible antagonist of PPARγ, for 5 weeks. Effects of telmisartan on Sirt1 mRNA, AMPK phosphorylation, and NAD+/NADH ratio were determined in C2C12 cultured myocytes.. Telmisartan treatment improved insulin sensitivity in obese db/db mice fed a high-fat diet and led to reduction in the size of hypertrophic pancreatic islets in these mice. Moreover, in vitro treatment with telmisartan led to increased expression of Sirt1 mRNA in C2C12 skeletal muscle cells; the increase in Sirt1 mRNA in telmisartan-treated C2C12 myoblasts occurred concomitantly with an increase in AMPK phosphorylation, an increase in NAD+/NADH ratio, and increases in the mRNA levels of PGC1α, FATP1, ACO, and GLUT4.. Our results indicate that telmisartan acts through a PPARγ-independent pathway, but at least partially exerts its effects by acting directly on skeletal muscle AMPK/SIRT1 pathways.

Topics: Adipocytes; Administration, Oral; AMP-Activated Protein Kinases; Angiotensin II Type 1 Receptor Blockers; Anilides; Animals; Benzimidazoles; Benzoates; Cell Line; Diabetes Mellitus; Diet, High-Fat; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme Activation; Fatty Acid Transport Proteins; Glucose Transporter Type 4; Hypertrophy; Insulin; Islets of Langerhans; Male; Mice; Muscle Fibers, Skeletal; Muscle, Skeletal; NAD; Obesity; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Phosphorylation; PPAR gamma; RNA, Messenger; Signal Transduction; Sirtuin 1; Telmisartan; Time Factors; Trans-Activators; Transcription Factors

Telmisartan, an angiotensin type 1 receptor blocker, is used in the management of hypertension to control blood pressure. In addition, telmisartan has a partial agonistic effect on peroxisome proliferator activated receptor γ (PPARγ). Recently, the effects of telmisartan on spatial memory or the inflammatory response were monitored in a mouse model of Alzheimer's disease (AD). However, to date, no studies have investigated the ameliorative effects of telmisartan on impaired spatial memory and the inflammatory response in an AD animal model incorporating additional cerebrovascular disease factors. In this study, we examined the effect of telmisartan on spatial memory impairment and the inflammatory response in a rat model of AD incorporating additional cerebrovascular disease factors. Rats were subjected to cerebral ischemia and an intracerebroventricular injection of oligomeric or aggregated amyloid-β (Aβ). Oral administration of telmisartan (0.3, 1, 3 mg/kg/d) seven days after ischemia and Aβ treatment resulted in better performance in the eight arm radial maze task in a dose-dependent manner. Telmisartan also reduced tumor necrosis factor α mRNA expression in the hippocampal region of rats with impaired spatial memory. These effects of telmisartan were antagonized by GW9662, an antagonist of PPARγ. These results suggest that telmisartan has ameliorative effects on the impairment of spatial memory in a rat model of AD incorporating additional cerebrovascular disease factors via its anti-inflammatory effect.

Topics: Alzheimer Disease; Amyloid; Angiotensin II Type 1 Receptor Blockers; Anilides; Animals; Anti-Inflammatory Agents; Benzimidazoles; Benzoates; Brain Ischemia; Cerebrovascular Disorders; Cerebrum; Disease Models, Animal; Dose-Response Relationship, Drug; Hippocampus; Inflammation; Male; Maze Learning; Memory; Memory Disorders; PPAR gamma; Rats; Rats, Wistar; Telmisartan; Tumor Necrosis Factor-alpha

In the present study we investigated the role of potassium (K(+)) channels and peroxisome proliferator-activated receptor gamma (PPARγ) in the antidepressant-like effect of bis selenide in the mouse tail suspension test (TST). Intracerebroventricular (i.c.v.) pretreatment with tetraethyl ammonium (TEA, a non-specific inhibitor of K(+) channels, 25 pg/site), glibenclamide (an ATP-sensitive K(+) channel inhibitor, 0.5 pg/site), charybdotoxin (a large and intermediate conductance calcium-activated K(+) channel inhibitor, 25 pg/site) or apamin (a small-conductance calcium-activated K(+) channel inhibitor, 10 pg/site) produced a synergistic action with a sub effective dose of bis selenide (0.1 mg/kg, per oral--p.o.). Picrotoxin (1 mg/kg, intraperitoneally--i.p.) pretreatment did not prevent the reduction in immobility time elicited by bis selenide (1 mg/kg, p.o.) in the TST. The reduction in the immobility time elicited by an effective dose of bis selenide (1 mg/kg, p.o.) was prevented by the pretreatment of mice with cromakalim, minoxidil (K(+) channel openers, 10 μg/site, i.c.v.) and GW 9662 (a PPARγ antagonist, 10 μg/site, i.c.v.). The findings clearly suggest that an acute oral dose of bis selenide produced an antidepressant-like effect in the mouse TST by a mechanism that involves the K(+) channels and PPARγ receptors.

Topics: Analysis of Variance; Anilides; Animals; Antidepressive Agents; Behavior, Animal; Cromakalim; Disease Models, Animal; Exploratory Behavior; Freezing Reaction, Cataleptic; Hindlimb Suspension; Male; Mice; Organoselenium Compounds; Potassium Channel Blockers; Potassium Channels; PPAR gamma

Pioglitazone and rosiglitazone belong to the class of thiazolidinediones (TZDs). They were first developed as antioxidants and then approved for the clinical treatment of insulin resistance and Type 2 diabetes. TZDs bind with high affinity and activate peroxisome proliferator-activated receptor-gamma (PPARγ) receptors, which in the brain are expressed both in neurons and in glia.. We evaluated the effect of PPARγ activation by TZDs on alcohol drinking, relapse-like behavior, and withdrawal in the rat. We also tested the effect of TZDs on alcohol and saccharin self-administration.. We showed that activation of PPARγ receptors by pioglitazone (0, 10, and 30 mg/kg) and rosiglitazone (0, 10 and 30 mg/kg) given orally selectively reduced alcohol drinking. The effect was blocked by pretreatment with the selective PPARγ antagonist GW9662 (5 μg/rat) given into the lateral cerebroventricle, suggesting that this TZD's effect is mediated by PPARγ receptors in the central nervous system. Pioglitazone abolished reinstatement of alcohol seeking, a relapse-like behavior, induced by yohimbine, a pharmacologic stressor, but did not affect cue-induced relapse. In the self-administration experiments, pioglitazone reduced lever pressing for alcohol but not for saccharin. Finally, pioglitazone prevented the expression of somatic signs of alcohol withdrawal.. These findings provide new information about the role of brain PPARγ receptors and identify pioglitazone as candidate treatments for alcoholism and possibly other addictions.

Topics: Adrenergic alpha-2 Receptor Antagonists; Alcohol Drinking; Alcohols; Analysis of Variance; Anilides; Animals; Behavior, Animal; Blood Glucose; Conditioning, Operant; Cues; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Food Preferences; Gene Expression Regulation; Hypoglycemic Agents; Male; Pioglitazone; PPAR gamma; Rats; Rats, Sprague-Dawley; Rosiglitazone; Self Administration; Substance Withdrawal Syndrome; Thiazolidinediones; Yohimbine

Non-alcoholic fatty liver disease is associated with multiple comorbid conditions, including diabetes, obesity, infection, and malnutrition. Mice with hepatocyte-specific disruption of growth hormone (GH) signaling develop fatty liver (FL), although the precise mechanism underlying this finding remains unknown. Because GH signals through JAK2, we developed mice bearing hepatocyte-specific deletion of JAK2 (referred to herein as JAK2L mice). These mice were lean, but displayed markedly elevated levels of GH, liver triglycerides (TGs), and plasma FFAs. Because GH is known to promote lipolysis, we crossed GH-deficient little mice to JAK2L mice, and this rescued the FL phenotype. Expression of the fatty acid transporter CD36 was dramatically increased in livers of JAK2L mice, as was expression of Pparg. Since GH signaling represses PPARγ expression and Cd36 is a known transcriptional target of PPARγ, we treated JAK2L mice with the PPARγ-specific antagonist GW9662. This resulted in reduced expression of liver Cd36 and decreased liver TG content. These results provide a mechanism for the FL observed in mice with liver-specific disruption in GH signaling and suggest that the development of FL depends on both GH-dependent increases in plasma FFA and increased hepatic uptake of FFA, likely mediated by increased expression of CD36.

Topics: Anilides; Animals; CD36 Antigens; Disease Models, Animal; Fatty Acids, Nonesterified; Fatty Liver; Female; Gene Deletion; Growth Hormone; Hepatocytes; Janus Kinase 2; Liver; Male; Mice; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Knockout; Mice, Mutant Strains; Organ Specificity; PPAR gamma; Signal Transduction; Triglycerides

The effect of berberine hydrochloride (BBR) on inducible cyclooxygenase-2 (COX-2) in small intestinal mucosa and related mechanisms was investigated in a rat model of acute endotoxemia. The results showed that lipopolysaccharide (LPS) increased COX-2 expression, whereas SB202190 and BBR curtailed it. LPS increased phosphorylation of mucosal p38 MAPK and ATF2 as well as production of ATF2, whereas BBR attenuated these effects. LPS upregulated mucosal peroxisome proliferator-activated receptor gamma (PPARγ), but BBR reduced this receptor. GW9662 aggravated LPS-induced and reversed BBR-attenuated COX-2 expression. The findings showed that BBR ameliorated COX-2 overexpression partially via modulation of p38 and PPARγ pathways during acute endotoxemia.

Topics: Acute Disease; Anilides; Animals; Anti-Inflammatory Agents; Berberine; Coptis; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Disease Models, Animal; Endotoxemia; Enzyme Inhibitors; Imidazoles; Intestinal Mucosa; Intestine, Small; Lipopolysaccharides; Male; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Phytotherapy; Plant Extracts; PPAR gamma; Pyridines; Rats; Rats, Sprague-Dawley; Rhizome; Up-Regulation

Rosiglitazone (RGZ), a peroxisome proliferator-activated receptor (PPAR)-γ agonist, has been demonstrated to possess cardioprotective properties during ischemia-reperfusion. However, this notion remains controversial as recent evidence has suggested an increased risk in cardiac events associated with long-term use of RGZ in patients with type 2 diabetes. In this study, we tested the hypothesis that acute RGZ treatment is beneficial during I/R by modulating cardioprotective signaling pathways in a nondiabetic mouse model. RGZ (1 μg/g) was injected intravenously via the tail vein 5 min before reperfusion. Myocardial infarction was significantly reduced in mice treated with RGZ compared with vehicle controls (8.7% ± 1.1% vs. 20.2% ± 2.5%, P < 0.05). Moreover, isolated hearts were subjected to 20 min of global, no-flow ischemia in an ex vivo heart perfusion system. Postischemic recovery was significantly improved with RGZ treatment administered at the onset of reperfusion compared with vehicle (P < 0.001). Immunoblot analysis data revealed that the levels of both phospho-AMP-activated protein kinase (Thr(172)) and phospho-Akt (Ser(473)) were significantly upregulated when RGZ was administered 5 min before reperfusion compared with vehicle. On the other hand, inflammatory signaling [phospho-JNK (Thr(183)/Tyr(185))] was significantly downregulated as a result of RGZ treatment compared with vehicle (P < 0.05). Intriguingly, pretreatment with the selective PPAR-γ inhibitor GW-9662 (1 μg/g iv) 10 min before reperfusion significantly attenuated these beneficial effects of RGZ on the ischemic heart. Taken together, acute treatment with RGZ can reduce ischemic injury in a nondiabetic mouse heart via modulation of AMP-activated protein kinase, Akt, and JNK signaling pathways, which is dependent on PPAR-γ activation.

Topics: AMP-Activated Protein Kinases; Anilides; Animals; Cardiotonic Agents; Disease Models, Animal; Drug Administration Schedule; Enzyme Activation; Injections, Intravenous; JNK Mitogen-Activated Protein Kinases; Male; Mice; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; Phosphorylation; PPAR gamma; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Pyrazoles; Pyrimidines; Rosiglitazone; Signal Transduction; Thiazolidinediones; Time Factors; Ventricular Function, Left; Ventricular Pressure

Experimental and clinical data support the notion that peroxisome proliferator-activated receptor γ (PPARγ) activation is associated with anti-atherosclerosis as well as anti-diabetic effect. Telmisartan, an angiotensin receptor blocker (ARB), acts as a partial PPARγ agonist. We hypothesized that telmisartan protects against diabetic vascular complications, through PPARγ activation. We compared the effects of telmisartan, telmisartan combined with GW9662 (a PPARγ antagonist), and losartan with no PPARγ activity on vascular injury in obese type 2 diabetic db/db mice. Compared to losartan, telmisartan significantly ameliorated vascular endothelial dysfunction, downregulation of phospho-eNOS, and coronary arterial remodeling in db/db mice. More vascular protective effects of telmisartan than losartan were associated with greater anti-inflammatory effects of telmisartan, as shown by attenuation of vascular nuclear factor kappa B (NFκB) activation and tumor necrosis factor α. Coadministration of GW9662 with telmisartan abolished the above mentioned greater protective effects of telmisartan against vascular injury than losartan in db/db mice. Thus, PPARγ activity appears to be involved in the vascular protective effects of telmisartan in db/db mice. Moreover, telmisartan, but not losartan, prevented the downregulation of vascular PPARγ in db/db mice and this effect of telmisartan was cancelled by the coadministration of GW9662. Our data provided the first evidence indicating that PPARγ activity of telmisartan contributed to the protective effects of telmisartan against diabetic vascular complication. PPARγ activity of telmisartan was involved in the normalization of vascular PPARγ downregulation in diabetic mice. Thus, telmisartan seems to exert vascular protective effects in hypertensive patients with diabetes.

Topics: Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Anilides; Animals; Benzimidazoles; Benzoates; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Disease Models, Animal; Male; Mice; Mice, Inbred C57BL; Obesity; PPAR gamma; Telmisartan

Peroxisome proliferator-activated receptor α (PPAR-α) is a ligand-activated transcription factor that exerts strong effects on metabolic pathways. Our aim was to elucidate the effect of clofibrate, a PPAR-α agonist, on the longitudinal muscle of the mouse distal colon. We initially found that clofibrate induced a relaxation response in this muscle. Notably, the PPAR-α antagonists GW9662 and T0070907 did not attenuate this clofibrate-induced relaxation. The structurally related PPAR-α agonists fenofibrate and bezafibrate induced relaxation in the distal colon as effectively as clofibrate. In contrast, wy-14643, which activates PPAR-α more selectively than clofibrate, had no effect. Furthermore, clofibrate-induced relaxation was not affected by N-nitro-L-arginine, an NO synthase inhibitor, 1H-[1,2,4]-oxadiazolo-[4,3- a]quinoxaline-1-one, a soluble guanylate cyclase inhibitor, or H89, a protein kinase A inhibitor. Tetrodotoxin, an Na⁺ channel blocker, and glibenclamide, apamin, charybdotoxin and XE991, various K⁺ channel blockers, had no effect on clofibrate-induced relaxation. Importantly, clofibrate induced a relaxation response that was not accompanied by any alteration in the cytoplasmic Ca²⁺ concentration in the longitudinal muscle of the mouse distal colon. Moreover, calyculin A, a myosin light-chain phosphatase (MLCP) inhibitor, attenuated clofibrate-induced relaxation. Our findings indicate that clofibrate relaxes the longitudinal smooth muscle of the mouse distal colon by regulating MLCP activity.

Topics: Anilides; Animals; Anticholesteremic Agents; Benzamides; Calcium; Clofibrate; Colon; Cyclic AMP-Dependent Protein Kinases; Disease Models, Animal; Drug Evaluation, Preclinical; Guanylate Cyclase; Male; Marine Toxins; Mice; Mice, Inbred C57BL; Muscle Contraction; Muscle Relaxation; Muscle, Smooth; Myosin-Light-Chain Phosphatase; Nitric Oxide Synthase; Oxazoles; Potassium Channel Blockers; PPAR alpha; Pyridines; Pyrimidines; Receptors, Cytoplasmic and Nuclear; Sodium Channel Blockers; Soluble Guanylyl Cyclase

Curcuma longa (turmeric) has a long history of use in Ayurvedic medicine as a treatment for inflammatory conditions. The purpose of the present study was to investigate the preventive effects of curcumin against acute pancreatitis (AP) induced by caerulein in mouse and to elucidate possible mechanism of curcumin action.. Curcumin (50 mg/kg/day) was intraperitoneally injected to Kun Ming male mice for 6 days, followed by injection of caerulein to induce AP. GW9662 (0.3 mg/kg), a specific peroxisome proliferator-activated receptor gamma (PPARγ) antagonist, was intravenously injected along with curcumin. Murine macrophage RAW264.7 cells were treated with 100 μmol/l curcumin for 2 h, and then stimulated with 0.1 μ g/ml lipopolysaccharide (LPS). Serum amylase and transaminase levels were measured at 10 h after AP. TNF-α level in mouse serum and cell culture medium were detected by ELISA. Expression of PPARγ and NF-κB were analyzed by RT-PCR and Western blot.. Curcumin significantly decreased the pancreas injury and reversed the elevation of serum amylase, ALT and AST activities and TNF-α level in mice with AP. Curcumin treatment inhibited the elevation of NF-κB-p65 in the nucleus of mouse pancreas AP group and RAW264.7 cells, but significantly increased the expression of PPARγ. GW9662 could abolish the effects of curcumin on serum levels of amylase, ALT, AST, TNF-α, and NF-κB level.. Our results suggest that curcumin could attenuate pancreas tissue and other organ injury by inhibiting the release of inflammatory cytokine TNF-α. These effects may involve upregulation of PPARγ and subsequent downregulation of NF-κB.

Topics: Alanine Transaminase; Amylases; Anilides; Animals; Cell Nucleus; Ceruletide; Curcuma; Curcumin; Disease Models, Animal; Gene Expression Regulation; Inflammation; Lipopolysaccharides; Macrophages; Male; Mice; NF-kappa B; Pancreatitis; Plant Extracts; PPAR gamma; Transaminases; Tumor Necrosis Factor-alpha

Accumulating evidences have demonstrated the beneficial actions of peroxisome proliferator-activated receptor gamma (PPAR gamma) in a variety of animal stroke models. Following middle cerebral artery occlusion (60 min) and 2-24 hr reperfusion in rats, we observed cerebral ischemia/reperfusion (I/R) induced up-regulation of PPAR gamma protein expression and translocation from the cytoplasm into the nucleus in a time-dependent manner. We also found that PPAR gamma agonist rosiglitazone enhanced whereas PPAR gamma antagonist GW9662 inhibited the alteration of PPAR gamma stimulated by I/R, suggesting that the changes of PPAR gamma may result from the activation by endogenous ligands. Moreover, the link between the 12/15-lipoxygenase and the production of activating ligands for PPAR gamma has been proved in various tissues. However, the relation of them in brain tissue has not been identified. We demonstrated that the I/R-induced PPAR gamma alteration was reversed by baicalein, the specific inhibitor of 12/15-lipoxygenase. Baicalein treatment significantly inhibited the up-regulation of PPAR gamma expression and, furthermore, suppressed PPAR gamma nuclear accumulation as well as maintained PPAR gamma cytoplasmic retention. Together, these results suggest that I/R induces both PPAR gamma expression and translocation, probably through the activation by endogenous ligands in a 12/15-lipoxygenase inhibitor-sensitive way.

Topics: Anilides; Animals; Antioxidants; Cell Nucleus; Cerebral Cortex; Cytosol; Disease Models, Animal; Flavanones; Hypoglycemic Agents; Infarction, Middle Cerebral Artery; Male; PPAR gamma; Protein Transport; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Rosiglitazone; Thiazolidinediones; Time Factors; Up-Regulation

Systemic administration of thiazolidinediones reduces peripheral inflammation in vivo, presumably by acting at peroxisome proliferator-activated receptor gamma (PPARgamma) in peripheral tissues. Based on a rapidly growing body of literature indicating the CNS as a functional target of PPARgamma actions, we postulated that brain PPARgamma modulates peripheral edema and the processing of inflammatory pain signals in the dorsal horn of the spinal cord. To test this in the plantar carrageenan model of inflammatory pain, we measured paw edema, heat hyperalgesia, and dorsal horn expression of the immediate-early gene c-fos after intracerebroventricular (ICV) administration of PPARgamma ligands or vehicle. We found that ICV rosiglitazone (0.5-50 microg) or 15d-PGJ(2) (50-200 microg), but not vehicle, dose-dependently reduced paw thickness, paw volume and behavioral withdrawal responses to noxious heat. These anti-inflammatory and anti-hyperalgesia effects result from direct actions in the brain and not diffusion to other sites, because intraperitoneal and intrathecal administration of rosiglitazone (50 microg) and 15d-PGJ(2) (200 microg) had no effect. PPARgamma agonists changed neither overt behavior nor motor coordination, indicating that non-specific behavioral effects do not contribute to PPAR ligand-induced anti-hyperalgesia. ICV administration of structurally dissimilar PPARgamma antagonists (either GW9662 or BADGE) reversed the anti-inflammatory and anti-hyperalgesic actions of both rosiglitazone and 15d-PGJ(2). To evaluate the effects of PPARgamma agonists on a classic marker of noxious stimulus-evoked gene expression, we quantified Fos protein expression in the dorsal horn. The number of carrageenan-induced Fos-like immunoreactive profiles was less in rosiglitazone-treated rats as compared to vehicle controls. We conclude that pharmacological activation of PPARgamma in the brain rapidly inhibits local edema and the spinal transmission of noxious inflammatory signals.

Topics: Anilides; Animals; Benzhydryl Compounds; Brain; Central Nervous System Agents; Disease Models, Animal; Edema; Epoxy Compounds; Gene Expression; Inflammation; Male; Pain; PPAR gamma; Prostaglandin D2; Proto-Oncogene Proteins c-fos; Rats; Rats, Sprague-Dawley; Rosiglitazone; Spinal Cord; Thiazolidinediones

MicroRNAs (miRNAs) regulate various cardiac processes including cell proliferation and apoptosis. Pioglitazone (PIO), a peroxisome proliferator-activated receptor (PPAR)-gamma agonist, protects against myocardial ischaemia-reperfusion (IR) injury. We assessed the effects of PPAR-gamma activation on myocardial miRNA levels and the role of miRNAs in IR injury.. We evaluated the expression changes of miRNAs in the rat heart after PIO administration using miRNA arrays and then confirmed the result by northern blot. miR-29a and c levels decreased remarkably after 7-day treatment with PIO. In H9c2 cells, the effects of PIO and rosiglitazone on miR-29 expression levels were blocked by a selective PPAR-gamma inhibitor GW9662. Downregulation of miR-29 by antisense inhibitor or by PIO protected H9c2 cells from simulated IR injury, indicated as increased cell survival and decreased caspase-3 activity. In contrast, overexpressing miR-29 promoted apoptosis and completely blocked the protective effect of PIO. Antagomirs against miR-29a or -29c significantly reduced myocardial infarct size and apoptosis in hearts subjected to IR injury. Western blot analyses demonstrated that Mcl-2, an anti-apoptotic Bcl-2 family member, was increased by miR-29 inhibition.. Downregulation of miR-29 protected hearts against IR injury. The modulation of miRNAs can be achieved by pharmacological intervention. These findings provide a rationale for the development of miRNA-based strategies for the attenuation of IR injury.

Topics: Anilides; Animals; Apoptosis; bcl-2-Associated X Protein; Blotting, Northern; Blotting, Western; Caspase 3; Cell Line; Cell Survival; Disease Models, Animal; Down-Regulation; Gene Expression Profiling; Mice; MicroRNAs; Myeloid Cell Leukemia Sequence 1 Protein; Myocardial Reperfusion Injury; Myocardium; Oligonucleotide Array Sequence Analysis; Oligonucleotides, Antisense; Phosphorylation; Pioglitazone; PPAR gamma; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Rats; Rosiglitazone; Thiazolidinediones; Time Factors; Transfection

The insulin-sensitizing drug pioglitazone has been reported to be protective against myocardial infarction. However, its precise mechanism is unclear. Rabbits underwent 30 min of coronary occlusion followed by 48 h of reperfusion. Rabbits were assigned randomly to nine groups (n = 10 in each): the control group (fed a normal diet), pioglitazone group (fed diets containing 1 mg.kg(-1).day(-1) pioglitazone), pioglitazone + 5-hydroxydecanoic acid (HD) group [fed the pioglitazone diet + 5 mg/kg iv 5-HD, a mitochondrial ATP-sensitive K(+) (K(ATP)) channel blocker], pioglitazone + GW9662 group [fed the pioglitazone diet + 2 mg/kg iv GW9662, a peroxisome proliferator activated receptor (PPAR)-gamma antagonist], GW9662 group (fed a normal diet + iv GW9662), pioglitazone + wortmannin group [fed the pioglitazone diet + 0.6 mg/kg iv wortmannin, a phosphatidylinositol (PI)3-kinase inhibitor], wortmannin group (fed a normal diet + iv wortmannin), pioglitazone + nitro-l-arginine methyl ester (l-NAME) group [fed the pioglitazone diet + 10 mg/kg iv l-NAME, a nitric oxide synthase (NOS) inhibitor], and l-NAME group (fed a normal diet + iv l-NAME). All groups were fed the diets for 7 days. The risk area and nonrisk area of the left ventricle (LV) were separated by Evans blue dye, and the infarct area was determined by triphenyltetrazolium chloride staining. The infarct size was calculated as a percentage of the LV risk area. Western blotting was performed to assess levels of Akt and phospho-Akt and phospho-endothelial NOS (eNOS) in the myocardium following reperfusion. The infarct size was significantly smaller in the pioglitazone group (21 +/- 2%) than in the control group (43 +/- 3%). This effect was abolished by GW9662 (42 +/- 3%), wortmannin (40 +/- 3%), or l-NAME (42 +/- 7%) but not by 5-HD (24 +/- 5%). Western blotting showed higher levels of phospho-Akt and phospho-eNOS in the pioglitazone group. Pioglitazone reduces the myocardial infarct size via activation of PPAR-gamma, PI3-kinase, Akt, and eNOS pathways, but not via opening the mitochondrial K(ATP) channel. Pioglitazone may be a novel strategy for the treatment of diabetes mellitus with coronary artery disease.

Topics: Androstadienes; Anilides; Animals; Blood Glucose; Blotting, Western; Decanoic Acids; Disease Models, Animal; Enzyme Activation; Hemodynamics; Hydroxy Acids; Hypoglycemic Agents; Male; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase Type III; Phosphatidylinositol 3-Kinases; Phosphorylation; Pioglitazone; Potassium Channel Blockers; Potassium Channels; PPAR gamma; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Rabbits; Thiazolidinediones; Time Factors; Ventricular Function, Left; Wortmannin

Recent evidences show that peroxisome proliferator-activated receptor gamma (PPARgamma) is involved in the modulation of the amyloid-beta (Abeta) cascade causing Alzheimer's disease (AD) and treatment with PPARgamma agonists protects against AD pathology. However, the function of PPARgamma steady-state activity in Abeta cascade and AD pathology remains unclear. In this study, an antagonist of PPARgamma, GW9662, was injected into the fourth ventricle of APP/PS1 transgenic mice to inhibit PPARgamma activity in cerebellum. The results show that inhibition of PPARgamma significantly induced Abeta levels in cerebellum and caused cerebellar motor dysfunction in APP/PS1 transgenic mice. Moreover, GW9662 treatment markedly decreased the cerebellar levels of insulin-degrading enzyme (IDE), which is responsible for the cellular degradation of Abeta. Since cerebellum is spared from significant Abeta accumulation and neurotoxicity in AD patients and animal models, these findings suggest a crucial role of PPARgamma steady-state activity in protection of cerebellum against AD pathology.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Anilides; Animals; Cerebellum; Disease Models, Animal; Hippocampus; Mice; Mice, Transgenic; Motor Activity; Movement Disorders; PPAR gamma

The pathological hallmark of Alzheimer disease is deposition of amyloid-beta protein (Abeta) in the brain. Telmisartan is a unique angiotensin II receptor blocker with peroxisome proliferator-activated receptor-gamma (PPAR-gamma)-stimulating activity. Activation of PPAR-gamma is expected to prevent inflammation and Abeta accumulation in the brain. We investigated the possible preventive effect of telmisartan on cognitive decline in an Alzheimer disease mouse model via PPAR-gamma activation. Here, male ddY mice underwent ICV injection of Abeta 1-40. Cognitive function was evaluated by the Morris water maze test. A low dose of telmisartan (0.35 mg/kg per day) was administered in drinking water with or without GW9662, a PPAR-gamma antagonist. Cerebral blood flow was evaluated by laser speckle flowmetry. Inflammatory cytokine levels were measured by quantitative RT-PCR. Abeta 1-40 ICV injection significantly impaired cognitive function. Pretreatment with telmisartan improved this cognitive decline to a similar level to that in control mice. Cotreatment with GW9662, a PPAR-gamma antagonist, attenuated this telmisartan-mediated improvement of cognition. Treatment with telmisartan enhanced cerebral blood flow and attenuated the Abeta-induced increase in expression of cytokines, such as tumor necrosis factor-alpha and inducible NO synthase in the brain. Interestingly, coadministration of GW9662 cancelled these beneficial effects of telmisartan. Abeta 1-40 concentration in the brain was significantly decreased by treatment with telmisartan, whereas administration of GW9662 attenuated the decrease in telmisartan-mediated Abeta 1-40 concentration. Taken together, our findings suggest that even a low dose of telmisartan had a preventive effect on cognitive decline in an Alzheimer disease mouse model, partly because of PPAR-gamma activation.

Topics: Administration, Oral; Alzheimer Disease; Amyloid beta-Peptides; Angiotensin II Type 1 Receptor Blockers; Anilides; Animals; Benzimidazoles; Benzoates; Cerebellum; Cognition Disorders; Disease Models, Animal; Dose-Response Relationship, Drug; Injections, Intraventricular; Male; Maze Learning; Mice; Mice, Inbred Strains; Nitric Oxide Synthase Type II; PPAR gamma; Regional Blood Flow; Telmisartan; Tumor Necrosis Factor-alpha

Several studies have evaluated thiazolidinedione therapy as medical treatments for some central nervous system disorders, such as cognitive deficits associated with neurodegenerative disorders. However, there is limited data to support a direct role for peroxisome proliferator-activated receptor-γ agonists in depression. Therefore, the aim of this study was to investigate antidepressant-like activity of rosiglitazone using the mouse tail suspension test and the rat forced swimming test, two models sensitive to the effects of antidepressants. In the tail suspension test, 5 days of treatment with rosiglitazone (8.5 or 17 mg/kg, orally) reduced immobility time. In the forced swimming test, rosiglitazone (6 or 12 mg/kg, orally) treatment decreased immobility time and increased climbing. These effects were not accompanied by any alteration in locomotor activity in the open field test. Rosiglitazone treatment (6 or 12 mg/kg, orally) significantly reduced plasma corticosterone levels in rats. GW9662 significantly inhibited the rosiglitazone-induced reduction in the duration of immobility. In summary, this study suggests that rosiglitazone possesses a specific antidepressant-like activity in behavioral models and that this effect may be mediated by reduction of plasma corticosterone level.

Topics: Anilides; Animals; Antidepressive Agents; Corticosterone; Depressive Disorder; Disease Models, Animal; Drug Evaluation, Preclinical; Immobility Response, Tonic; Male; Mice; Motor Activity; PPAR gamma; Rats; Rats, Wistar; Rosiglitazone; Swimming; Thiazolidinediones

Peroxisome proliferator-activated receptor type gamma (PPARgamma) is a subgroup of the PPAR transcription factor family. Recent studies indicate that loss of PPARgamma is associated with the development of pulmonary hypertension (PH). We hypothesized that the endothelial dysfunction associated with PPARgamma inhibition may play an important role in the disease process by altering cellular gene expression and signaling cascades. We utilized microarray analysis to determine if PPARgamma inhibition induced changes in gene expression in pulmonary arterial endothelial cells (PAEC). We identified 100 genes and expressed sequence tags (ESTs) that were upregulated by >1.5-fold and 21 genes and ESTs that were downregulated by >1.3-fold (P < 0.05) by PPARgamma inhibition. The upregulated genes can be broadly classified into four functional groups: cell cycle, angiogenesis, ubiquitin system, and zinc finger proteins. The genes with the highest fold change in expression: hyaluronan-mediated motility receptor (HMMR), VEGF receptor 2 (Flk-1), endothelial PAS domain protein 1 (EPAS1), basic fibroblast growth factor (FGF-2), and caveolin-1 in PAEC were validated by real time RT-PCR. We further validated the upregulation of HMMR, Flk-1, FGF2, and caveolin-1 by Western blot analysis. In keeping with the microarray results, PPARgamma inhibition led to re-entry of cell cycle at G(1)/S phase and cyclin C upregulation. PPARgamma inhibition also exacerbated VEGF-induced endothelial barrier disruption. Finally we confirmed the downregulation of PPARgamma and the upregulation of HMMR, Flk-1, FGF2, and Cav-1 proteins in the peripheral lung tissues of an ovine model of PH. In conclusion, we have identified an array of endothelial genes modulated by attenuated PPARgamma signaling that may play important roles in the development of PH.

Topics: Anilides; Animals; Arteries; Blood-Air Barrier; Cattle; Cell Adhesion; Cell Cycle; Cell Proliferation; Disease Models, Animal; Endothelial Cells; Gene Expression Profiling; Gene Expression Regulation; Humans; Hypertension, Pulmonary; Lung; Neovascularization, Physiologic; PPAR gamma; Reproducibility of Results; Reverse Transcriptase Polymerase Chain Reaction; Sheep; Ubiquitin; Vascular Endothelial Growth Factor A; Zinc Fingers

Neutrophils (polymorphonuclear leukocytes [PMNs]) are critical to the immune response, including clearance of infectious pathogens. Sepsis is associated with impaired PMN function, including chemotaxis. PMNs express peroxisome proliferator-activated receptor-gamma (PPAR-gamma), a ligand-activated nuclear transcription factor involved in immune and inflammatory regulation. The role of PPAR-gamma in PMN responses, however, is not well characterized. We report that freshly isolated human PMNs constitutively express PPAR-gamma, which is up-regulated by the sepsis-induced cytokines TNF-alpha and IL-4. PMN chemotactic responses to formylmethionyl-leucyl-phenylalanine (fMLP) and IL-8 were dose-dependently inhibited by treatment with the PPAR-gamma ligands troglitazone and 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) and by transfection of PMN-like HL-60 cells with a constitutively active PPAR-gamma construct. Inhibition of chemotaxis by PPAR-gamma ligands correlated with decreases in extracellular signal-regulated kinase-1 and -2 activation, actin polymerization, and adherence to a fibrinogen substrate. Furthermore, PMN expression of PPAR-gamma was increased in sepsis patients and mice with either of 2 models of sepsis. Finally, treatment with the PPAR-gamma antagonist GW9662 significantly reversed the inhibition of PMN chemotaxis and increased peritoneal PMN recruitment in murine sepsis. This study indicates that PPAR-gamma activation is involved in PMN chemotactic responses in vitro and may play a role in the migration of these cells in vivo.

Topics: Actins; Anilides; Animals; Antineoplastic Agents; Cell Adhesion; Chemotaxis; Chromans; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Fibrinogen; HL-60 Cells; Humans; Inflammation; Interleukin-4; Interleukin-8; Male; Mice; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; N-Formylmethionine Leucyl-Phenylalanine; PPAR gamma; Prostaglandin D2; Sepsis; Thiazolidinediones; Troglitazone; Tumor Necrosis Factor-alpha; Up-Regulation

To clarify the role of peroxisome proliferator activated receptor gamma (PPARgamma) in neuropathic pain, we examined the effect of pioglitazone, a PPARgamma agonist, on tactile allodynia and thermal hyperalgesia in a neuropathic pain model. Mice were subjected to partial sciatic nerve ligation (PSL) and given pioglitazone (1 - 25 mg/kg, p.o.) once daily. PPARgamma was distributed in the neurons of the dorsal root ganglion and the dorsal horn of the spinal cord and in the adipocytes at the epineurium of the sciatic nerve in naive mice. PSL elicited tactile allodynia and thermal hyperalgesia for two weeks. Administration of pioglitazone for the first week after PSL attenuated thermal hyperalgesia and tactile allodynia, which was dose-dependent and blocked by GW9662 (2 mg/kg, i.p.), a PPARgamma antagonist. Administration of pioglitazone for the second week also relieved tactile allodynia, but administration one week before PSL had no effect. A single administration of pioglitazone to mice on day 7 of PSL did not alter tactile allodynia and thermal hyperalgesia. PSL-induced upregulation of tumor necrosis factor-alpha and interleukin-6, which are essential for neuropathic pain, was suppressed by pioglitazone for the first week. This suggests that pioglitazone alleviates neuropathic pain through attenuation of proinflammatory cytokine upregulation by PPARgamma stimulation.

Topics: Adipocytes; Analgesics; Anilides; Animals; Disease Models, Animal; Dose-Response Relationship, Drug; Ganglia, Spinal; Hot Temperature; Hyperalgesia; Inflammation Mediators; Interleukin-6; Ligation; Male; Mice; Mice, Inbred ICR; Pain Measurement; Pioglitazone; Posterior Horn Cells; PPAR gamma; Sciatic Nerve; Sciatic Neuropathy; Thiazolidinediones; Time Factors; Touch; Tumor Necrosis Factor-alpha

We have previously reported that prostaglandin A(1) (PGA(1)) reduces infarct size in rodent models of focal ischemia. This study seeks to elucidate the possible molecular mechanisms underlying PGA(1)'s neuroprotective effects against ischemic injury. Rats were subjected to permanent middle cerebral artery occlusion (pMCAO) by intraluminal suture blockade. PGA(1) was injected intracerebroventricularly (icv) immediately after ischemic onset. Western blot analysis was employed to determine alterations in IkappaBalpha, pIKKalpha, and peroxisome proliferator-activated receptor-gamma (PPAR-gamma). Immunohistochemistry was used to confirm the nuclear translocation of nuclear factor-kappaB (NF-kappaB) p65 and the expression of PPAR-gamma. RT-PCR was used to detect levels of c-Myc mRNA. The contribution of PPAR-gamma to PGA(1)'s neuroprotection was evaluated by pretreatment with the PPAR-gamma irreversible antagonist GW9662. A brief increase in pIKKalpha levels and rapid reduction in IkappaBalpha were observed after ischemia. PGA(1) blocked ischemia-induced increases in pIKKalpha levels and reversed the decline in IkappaBalpha levels. Ischemia-induced nuclear translocation of NF-kappaB p65 was attenuated by PGA(1). PGA(1) also repressed the ischemia-induced increase in expression of NF-kappaB target gene c-Myc mRNA. Immunohistochemistry demonstrated an increase in PPAR-gamma immunoreactivity in the nucleus of striatal cells at 3 hr after pMCAO. Western blot analysis revealed that the expression of PPAR-gamma protein significantly increased at 12 hr and peaked at 24 hr. PGA(1) enhanced the ischemia-triggered induction of PPAR-gamma protein. Pretreatment with the irreversible PPAR-gamma antagonist GW9662 attenuated PGA(1)'s neuroprotection against ischemia. These findings suggest that PGA(1)-mediated neuroprotective effect against ischemia appears to be associated with blocking NF-kappaB activation and likely with up-regulating PPAR-gamma expression.

Topics: Active Transport, Cell Nucleus; Anilides; Animals; Brain Infarction; Brain Ischemia; Corpus Striatum; Cytoprotection; Disease Models, Animal; I-kappa B Proteins; Infarction, Middle Cerebral Artery; Male; Nerve Degeneration; Neuroprotective Agents; NF-kappa B; PPAR gamma; Prostaglandins A; Proto-Oncogene Proteins c-myc; Rats; Rats, Sprague-Dawley; RNA, Messenger; Transcription Factor RelA; Up-Regulation

Telmisartan is a unique angiotensin II (Ang II) receptor blocker (ARB) with selective peroxisome proliferator-activated receptor-gamma (PPAR gamma). We therefore investigated the effects of telmisartan on endothelial function and atherosclerotic change in genetically hyperlipidemic rabbits, compared with candesartan, an ARB without PPAR gamma activity.. A total of 30 Watanabe heritable hyperlipidemic (WHHL) rabbits equally derived (n = 6 each) were treated with (1) vehicle (control), (2) GW9662, a PPAR gamma antagonist (0.5 mg/kg per day), (3) telmisartan (5 mg/kg per day), (4) telmisartan + GW9662, (5) candesartan (5 mg/kg per day) for 8 weeks. After treatment, acetylcholine (ACh)-induced nitric oxide production was measured as a surrogate for endothelium protective function, and vascular nitrotyrosine (a product of superoxide and nitric oxide) was measured for assessing dysfunctional endothelial nitric oxide synthase activity. Plaque area was quantified by histology.. Telmisartan increased ACh-induced nitric oxide by 5.5 nmol/l, significantly more than control. Interestingly, cotreatment with GW9662 significantly attenuated telmisartan-induced ACh-induced nitric oxide almost to the levels observed with candesartan. Vascular nitrotyrosine concentration was 1.4 pmol/mg protein in the control group and significantly higher than that in the telmisartan or candesartan group. The lowest nitrotyrosine concentration was observed in the telmisartan group, which was significantly lower than that in the candesartan or telmisartan + GW9662 group. Histology of the thoracic aorta revealed that the plaque area was more significantly decreased in the telmisartan group than in the candesartan or telmisartan + GW9662 group.. In addition to a class effect of ARBs, telmisartan may have additional effects on nitric oxide bioavailability and atherosclerotic change through its PPAR gamma-mediated effects in genetically hyperlipidemic rabbits.

Topics: Angiotensin II Type 1 Receptor Blockers; Anilides; Animals; Aorta, Abdominal; Aorta, Thoracic; Atherosclerosis; Benzimidazoles; Benzoates; Biphenyl Compounds; Disease Models, Animal; Hyperlipidemias; Male; Nitric Oxide; PPAR gamma; Rabbits; Telmisartan; Tetrazoles; Up-Regulation

Peroxisome proliferator-activated receptor (PPAR) is a ligand-activated transcriptional factor that regulates lipid metabolism and inflammation. Behavioral sensitization is an experimental model of psychostimulant psychosis; it is elicited by repeated administration of psychostimulants and has recently been implicated in brain inflammation. We examined the involvement of PPARgamma, one of the isotypes of PPAR, in development of behavioral sensitization to the stimulant effect of methamphetamine (METH) (1 mg/kg, subcutaneously) in mice. Repeated administration of METH (once daily for 5 days) enhanced the locomotor-activating effect of METH, which was reproduced by METH challenge on withdrawal day 7 (test day 12). The protein level and the activity of PPARgamma were significantly increased in the nuclear fraction of whole brain after 5 days of METH administration (test day 5) and on withdrawal day 7 (test day 12). Both pioglitazone and ciglitazone (PPARgamma agonists; 0.5-5.0 microg, intracerebroventricularly (i.c.v.), once daily) prevented the expression of behavioral sensitization to METH challenge on withdrawal day 7, but not the sensitization that occurred during repeated administration of METH. In addition, the magnitude of expression of behavioral sensitization was augmented by treatments with GW9662 (a PPARgamma antagonist; 0.5-5.0 microg i.c.v., once daily) during the withdrawal period. The pioglitazone-induced alleviation of behavioral sensitization was synergistically facilitated by simultaneous i.c.v. injection of 9-cis-retinoic acid (1.0 microg), an agonist for the retinoid X receptor which is a ligand-activated nuclear receptor that forms heterodimers with PPAR. These results suggest that PPARgamma has a significant role in the expression of behavioral sensitization to METH in mice.

Topics: Amphetamine-Related Disorders; Anilides; Animals; Behavior, Animal; Brain; Brain Chemistry; Cell Nucleus; Disease Models, Animal; Dopamine Uptake Inhibitors; Electrophoretic Mobility Shift Assay; Encephalitis; Hypoglycemic Agents; Male; Methamphetamine; Mice; Mice, Inbred ICR; Motor Activity; Nucleus Accumbens; Pioglitazone; PPAR gamma; Psychoses, Substance-Induced; Retinoid X Receptors; Reward; Thiazolidinediones

Thiazolidinediones (TZDs) are synthetic agonists of the ligand-activated transcription factor peroxisome proliferator-activated receptor-gamma (PPARgamma). TZDs are known to curtail inflammation associated with peripheral organ ischemia. As inflammation precipitates the neuronal death after stroke, we tested the efficacy of TZDs in preventing brain damage following transient middle cerebral artery occlusion (MCAO) in adult rodents. As hypertension and diabetes complicate the stroke outcome, we also evaluated the efficacy of TZDs in hypertensive rats and type-2 diabetic mice subjected to transient MCAO. Pre-treatment as well as post-treatment with TZDs rosiglitazone and pioglitazone significantly decreased the infarct volume and neurological deficits in normotensive, normoglycemic, hypertensive and hyperglycemic rodents. Rosiglitazone neuroprotection was not enhanced by retinoic acid x receptor agonist 9-cis-retinoic acid, but was prevented by PPARgamma antagonist GW9662. Rosiglitazone significantly decreased the post-ischemic intercellular adhesion molecule-1 expression and extravasation of macrophages and neutrophils into brain. Rosiglitazone treatment curtailed the post-ischemic expression of the pro-inflammatory genes interleukin-1beta, interleukin-6, macrophage inflammatory protein-1alpha, monocyte chemoattractant protein-1, cyclooxygenase-2, inducible nitric oxide synthase, early growth response-1, CCAAT/enhancer binding protein-beta and nuclear factor-kappa B, and increased the expression of the anti-oxidant enzymes catalase and copper/zinc-superoxide dismutase. Rosiglitazone also increased the expression of the anti-inflammatory gene suppressor of cytokine signaling-3 and prevented the phosphorylation of the transcription factor signal transducer and activator of transcription-3 after focal ischemia. Thus, PPARgamma activation with TZDs might be a potent therapeutic option for preventing inflammation and neuronal damage after stroke with promise in diabetic and hypertensive subjects.

Topics: Anilides; Animals; Cerebral Infarction; Chemotaxis, Leukocyte; Cytokines; Diabetes Mellitus, Type 2; Disease Models, Animal; Encephalitis; Hypertension; Intercellular Adhesion Molecule-1; Ischemic Attack, Transient; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Neuroprotective Agents; Pioglitazone; PPAR gamma; Rats; Rats, Inbred SHR; Rats, Sprague-Dawley; Rosiglitazone; Superoxide Dismutase; Superoxide Dismutase-1; Suppressor of Cytokine Signaling 3 Protein; Suppressor of Cytokine Signaling Proteins; Thiazolidinediones

Peroxisome proliferator-activated receptor gamma (PPAR-gamma) is a nuclear membrane-associated transcription factor that governs the expression of various inflammatory genes. PPAR-gamma agonists protect peripheral organs from ischemic injury. In the present study, we investigated whether the PPAR-gamma agonist rosiglitazone is neuroprotective against focal ischemic brain injury. C57/B6 mice underwent 1.5-h middle cerebral artery occlusion, and received either vehicle or rosiglitazone treatment of 0.75, 1.5, 3, 6 or 12 mg/kg (n = 9 per group). Cerebral infarct volume, neurological function, expression of pro-inflammatory proteins and neutrophil accumulation were assessed after ischemia and reperfusion. At 48 h after ischemia, infarct volume was significantly decreased with 3-12 mg/kg of rosiglitazone, with a time window of efficacy of 2 h after ischemia at the optimal dose (6 mg/kg). Neutrophil accumulation was significantly decreased in the brain parenchyma of rosiglitazone-treated mice. Ischemia-induced expression of several inflammatory cytokines and chemokines was markedly reduced in rosiglitazone-treated brains, as determined using proteomic-array analysis. Rosiglitazone treatment improved neurological function at 7 days after ischemia. Moreover, in cultured cortical primary microglia, rosiglitazone attenuated inflammatory responses by decreasing lipopolysaccharide-induced release of tumor necrosis factor-alpha, interleukin (IL)-1beta and IL-6. These results suggest that the PPAR-gamma agonist rosiglitazone has neuroprotective properties that are at least partially mediated via anti-inflammatory actions, and is thus a potential novel therapeutic agent for stroke.

Topics: Anilides; Animals; Animals, Newborn; Behavior, Animal; Blood Pressure; Body Temperature; Brain Ischemia; Cells, Cultured; Cerebral Infarction; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Gene Expression; Gene Expression Regulation; Granulocyte Colony-Stimulating Factor; Immunohistochemistry; Infarction, Middle Cerebral Artery; Intercellular Adhesion Molecule-1; Interleukin-3; Lectins; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Microglia; Neuroprotective Agents; Peroxidase; PPAR gamma; Psychomotor Performance; Recombinant Fusion Proteins; Recombinant Proteins; Reperfusion; Rosiglitazone; Thiazolidinediones

Peroxisome proliferator-activated receptor gamma (PPARgamma) has been reported to play an important role to regulate adiposity and insulin sensitivity. It is not clear whether antagonism of PPARgamma using a synthetic ligand has significant effects on adipose tissue weight and glucose metabolism in vivo. The aim of this study is to examine the effects of a synthetic PPARgamma antagonist (GW9662) on adiposity and glycemic control in high-fat (HF) diet-fed mice. First the properties of GW9662 as a PPARgamma antagonist were estimated in vitro. GW9662 displaced [(3)H]rosiglitazone from PPARgamma with K(i) values of 13nM, indicating that the affinity of GW9662 for PPARgamma was higher than that of rosiglitazone (110nM). GW9662 had no effect on PPARgamma transactivation in cells expressing human PPARgamma. Treatment of 3T3-L1 preadipocytes with GW9662 did not increase aP2 expression or [(14)C]acetic acid uptake. GW9662 did not recruit transcriptional cofactors to PPARgamma. Limited trypsin digestion of the human PPARgamma/GW9662 complex showed patterns of digestion distinct from those of rosiglitazone. This suggests that the binding characteristics between GW9662 and PPARgamma are different from those of rosiglitazone. Treatment of HF diet-fed mice with GW9662 revealed that this compound prevented HF diet-induced obesity without affecting food intake. GW9662 suppressed any increase in the amount of visceral adipose tissue, but it did not change HF diet-induced glucose intolerance. These data indicate that antagonism of PPARgamma using a synthetic ligand suppresses the increased adiposity observed in HF diet-induced obesity, and that a PPARgamma antagonist could possibly be developed as an anti-obesity drug.

Topics: 3T3-L1 Cells; Adipocytes; Anilides; Animals; Binding, Competitive; Body Weight; Dietary Carbohydrates; Dietary Fats; Disease Models, Animal; Glucose Tolerance Test; Hepatocytes; Male; Mice; Mice, Inbred C57BL; Obesity; PPAR gamma; Rosiglitazone; Thiazolidinediones

Peroxisome proliferator-activated receptors (PPARs) are activated by an array of polyunsaturated fatty acid derivatives, oxidized fatty acids, and phospholipids and are proposed to be important modulators of immune and inflammatory responses. Recently, we showed that activation of PPAR-gamma alters the maturation process of dendritic cells (DCs), the most potent antigen-presenting cells. In the present report, we investigated the possibility that, by targeting DCs, PPAR-gamma activation may be involved in the regulation of the pulmonary immune response to allergens. Using a model of sensitization, based on the intratracheal transfer of ovalbumin (OVA)-pulsed DCs, we show that rosiglitazone, a selective PPAR-gamma agonist, reduces the proliferation of Ag-specific T cells in the draining mediastinal lymph nodes but, surprisingly enough, dramatically increases the production of the immunoregulatory cytokine interleukin (IL)-10 by T cells, as compared to control mice sensitized with OVA-pulsed DCs. After aerosol challenge, the recruitment of eosinophils in the bronchoalveolar lavage fluids was strongly reduced compared to control mice. Finally, T cells from the mediastinal lymph nodes produced higher amounts of IL-10 and interferon-gamma. Inhibition of IL-10 activity with anti-IL-10R antibodies partly restored the inflammation. The specificity of the phenomenon was confirmed by treating OVA-pulsed DCs with ciglitazone, another PPAR-gamma agonist, and by using GW9662, a PPAR-gamma antagonist. Our data suggest that PPAR-gamma activation prevents induction of Th2-dependent eosinophilic airway inflammation and might contribute to immune homeostasis in the lung.

Topics: Anilides; Animals; Asthma; Cell Movement; Cytokines; Dendritic Cells; Disease Models, Animal; Eosinophils; Inflammation; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Receptors, Cytoplasmic and Nuclear; Rosiglitazone; T-Lymphocytes; Thiazolidinediones; Transcription Factors; Vasodilator Agents

Neointimal lesions are characterized by accumulation of cells within the arterial wall and are a prelude to atherosclerotic disease. Here we report that a brief exposure to either alkyl ether analogs of the growth factor-like phospholipid lysophosphatidic acid (LPA), products generated during the oxidative modification of low density lipoprotein, or to unsaturated acyl forms of LPA induce progressive formation of neointima in vivo in a rat carotid artery model. This effect is completely inhibited by the peroxisome proliferator-activated receptor (PPAR)gamma antagonist GW9662 and mimicked by PPARgamma agonists Rosiglitazone and 1-O-hexadecyl-2-azeleoyl-phosphatidylcholine. In contrast, stearoyl-oxovaleryl phosphatidylcholine, a PPARalpha agonist and polypeptide epidermal growth factor, platelet-derived growth factor, and vascular endothelial growth factor failed to elicit neointima. The structure-activity relationship for neointima induction by LPA analogs in vivo is identical to that of PPARgamma activation in vitro and disparate from that of LPA G protein-coupled receptor activation. Neointima-inducing LPA analogs up-regulated the CD36 scavenger receptor in vitro and in vivo and elicited dedifferentiation of cultured vascular smooth muscle cells that was prevented by GW9662. These results suggest that selected LPA analogs are important novel endogenous PPARgamma ligands capable of mediating vascular remodeling and that activation of the nuclear transcription factor PPARgamma is both necessary and sufficient for neointima formation by components of oxidized low density lipoprotein.

Topics: Analysis of Variance; Anilides; Animals; Arteriosclerosis; Calmodulin-Binding Proteins; Carotid Artery Diseases; CD36 Antigens; Cells, Cultured; Disease Models, Animal; DNA Primers; Growth Substances; Ligands; Lipoproteins, LDL; Lysophospholipids; Male; Muscle, Smooth; Rats; Rats, Sprague-Dawley; Receptors, Cytoplasmic and Nuclear; Receptors, G-Protein-Coupled; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Rosiglitazone; Structure-Activity Relationship; Thiazolidinediones; Time Factors; Transcription Factors

Allergic asthma is characterized by airway hyperresponsiveness, eosinophilia, and mucus accumulation and is associated with increased IgE concentrations. We demonstrate here that peroxisome proliferator-activated receptors (PPARs), PPAR-alpha and PPAR-gamma, which have been shown recently to be involved in the regulation of various cell types within the immune system, decrease antigen-induced airway hyperresponsiveness, lung inflammation, eosinophilia, cytokine production, and GATA-3 expression as well as serum levels of antigen-specific IgE in a murine model of human asthma. In addition, we demonstrate that PPAR-alpha and -gamma are expressed in eosinophils and their activation inhibits in vitro chemotaxis and antibody-dependent cellular cytotoxicity. Thus, PPAR-alpha and -gamma (co)agonists might be of therapeutic interest for the regulation of allergic or inflammatory reactions by targeting both regulatory and effector cells involved in the immune response.

Topics: Anilides; Animals; Asthma; Chemotaxis; Disease Models, Animal; DNA-Binding Proteins; Down-Regulation; Eosinophils; GATA3 Transcription Factor; Humans; Inflammation; Lung; Mice; Mice, Inbred BALB C; Mice, Knockout; Rats; Receptors, Cytoplasmic and Nuclear; Respiratory Hypersensitivity; Rosiglitazone; Thiazoles; Thiazolidinediones; Trans-Activators; Transcription Factors