gw9662 and Inflammation

Efferocytosis can resolve airway inflammation and enhance airway tolerance in allergic asthma. While previous work has reported that progranulin (PGRN) regulated macrophage efferocytosis, but it is unclear whether PGRN-mediated efferocytosis is associated with asthma. Here, we found that in an ovalbumin (OVA)-induced allergic asthma model, the airway inflammation was suppressed and the apoptosis in lung tissues was ameliorated in PGRN-deficient mice. In contrast, PGRN knockdown in human bronchial epithelial cells increased apoptosis in vitro. Furthermore, PGRN-deficient macrophages had significantly stronger efferocytosis ability than wild type (WT) macrophages both in vitro and in vivo. PGRN-deficient peritoneal macrophages (PMs) exhibited increased expression of genes associated with efferocytosis including milk fat globule-epidermal growth factor 8 (MFG-E8), peroxisome proliferator-activated receptor gamma (PPAR-γ) and sirtuin1 (SIRT1) and increased capacity to produce the anti-inflammatory mediator interleukin (IL)-10 during efferocytosis. GW9662, the inhibitor of PPAR-γ, abolished increased efferocytosis and MFG-E8 expression in PGRN-deficient PMs suggesting that PGRN deficiency enhanced MFG-E8-mediated efferocytosis through PPAR-γ. Correspondingly, efferocytosis genes were increased in the lungs of OVA-induced PGRN-deficient mice. GW9662 treatment reduced MFG-E8 expression but did not significantly affect airway inflammation. Our results demonstrated that PGRN deficiency enhanced efferocytosis via the PPAR-γ/MFG-E8 pathway and this may be one of the reasons PGRN deficiency results in inhibition of airway inflammation in allergic asthma.

Topics: Animals; Asthma; Factor VIII; Humans; Inflammation; Macrophages; Mice; PPAR gamma; Progranulins

Proline-serine-threonine phosphatase-interacting protein 2 (PSTPIP2) plays a role in inflammatory disease. In diabetes, very little is known about PSTPIP2 until now. Hence, this study aimed to determine PSTPIP2 functional role in diabetes.. Diabetes mouse model was constructed by feeding high fat diet (HFD). Intraperitoneal glucose tolerance test and intraperitoneal insulin tolerance test were examined the glucose and insulin tolerance. The expression of genes and proteins was detected by quantitative real time PCR, immunohistochemistry and western blotting. The pathological changes of epididymal adipose tissues were examined by hematoxylin-eosin staining. RAW264.7 macrophages were treated with GW9662 (PPARγ antagonist). Flow cytometry examined the proportion of M1/M2 macrophages.. HFD enhanced the body weight, glucose and insulin tolerance, and inhibited PSTPIP2 expression in mice. PSTPIP2 overexpression alleviated glucose and insulin tolerance, reduced inflammation and macrophage accumulation in the epididymal adipose tissues of diabetic mice. The expression of iNOS and TNF-α was increased, the expression of IL-10 and Arg-1 was decreased in diabetic mice, which was abrogated by PSTPIP2 overexpression. In vitro, PSTPIP2 overexpression reduced the proportions of iNOS-positive cells and enhanced the proportions of CD206-positive cells in RAW264.7 cells. PPARγ and p-STAT6 were up-regulated, STAT6 was down-regulated in RAW264.7 cells. GW9662 impaired PSTPIP2 overexpression-mediated up-regulation of Arg-1, YM-1 and FIZZ1 in RAW264.7 cells.. PSTPIP2 alleviates obesity associated adipose tissue inflammation and insulin resistance in diabetic mice through promoting M2 macrophage polarization via activation of PPARγ, suggesting that PSTPIP2 is a prospective target for diabetes treatment.

Topics: Adipose Tissue; Animals; Diabetes Mellitus, Experimental; Diet, High-Fat; Glucose; Inflammation; Insulin Resistance; Insulins; Macrophage Activation; Macrophages; Mice; Mice, Inbred C57BL; Obesity; PPAR gamma

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

PPAR-γ anti-inflammatory functions have received significant attention since its agonists have been shown to exert a wide range of protective effects in many experimental models of neurologic diseases. Rice bran is very rich in polyunsaturated fatty acids, which are reported to act as PPAR-γ partial agonists. Herein, the anti-inflammatory effect of rice bran extract (RBE) through PPAR-γ activation was evaluated in LPS-induced neuroinflammatory mouse model in comparison to pioglitazone (PG) using 80 Swiss albino mice. RBE (100 mg/kg) and PG (30 mg/kg) were given orally for 21 days and LPS (0.25 mg/kg) was injected intraperitoneally for the last 7 days. TNF-α and COX-2 brain contents were evaluated by real-time PCR and immunohistochemical analysis. In addition, NFκB binding to its response element was evaluated alongside with the effect of treatments on IκB gene expression. Furthermore, PPAR-γ sumoylation was also studied. Finally, histopathological examination was performed for different brain areas. RBE administration was found to protect against the LPS-induced inflammatory effects by decreasing the inflammatory mediator expression in mice brains. It also decreased PPAR-γ sumoylation without significant effect on IκB expression or NFκB binding to its response element. The majority of the effects were attenuated in presence of PPAR-γ antagonist (GW9662). Level of significance was set to P < 0.05. Such findings highlight the agonistic effect of RBE component(s) on PPAR-γ and support the hypothesis of involvement of PPAR-γ activation in its neuroprotective effect.

Topics: Anilides; Animals; Brain; Cyclooxygenase 2; Esters; Fatty Acids; Gene Expression Regulation; Inflammation; Lipopolysaccharides; Male; Mice; Neuroprotective Agents; NF-kappa B; NF-KappaB Inhibitor alpha; Oryza; Pioglitazone; Plant Extracts; PPAR gamma; Protein Binding; Response Elements; Sumoylation; Tumor Necrosis Factor-alpha; Up-Regulation

Telmisartan ameliorates inflammation in various brain disorders through angiotensin II type 1 receptor (AT1) blockade and peroxisome proliferator-activated receptor gamma (PPARγ) activation. Soluble β-amyloid oligomers (AβOs) play a causative role in neuronal dysfunction and memory loss in Alzheimer's disease. In addition to directly targeting neurons, AβOs may also activate microglia to trigger toxic proinflammatory responses. Here, we investigated whether and how telmisartan ameliorates inflammatory responses in AβO-stimulated microglia. A mouse-derived BV2 microglial cell line lacking AT1 expression was selected as an in vitro model. Telmisartan not only inhibited AβO-induced proinflammatory interleukin (IL)-1β and tumor necrosis factor-α (TNF-α) expression, but also increased anti-inflammatory IL-10 expression, which was not affected by AβO stimulation. Telmisartan also inhibited AβO-induced nuclear factor (NF)-κB activity and phosphorylation of Akt and ERK, two upstream regulators of NF-κB activation. These anti-inflammatory effects were antagonized by PPARγ inhibitor GW9662. In addition, telmisartan increased the expression of PTEN (phosphate and tensin homolog deleted on chromosome 10), a lipid and protein phosphatase; PPARγ inhibitor GW9662 reversed this effect, indicating that telmisartan-induced PTEN expression is PPARγ dependent. The PTEN inhibitor blocked the effects of telmisartan on Akt and ERK phosphorylation, NF-κB transcriptional activity, and IL-1β and TNF-α production, but failed to reverse IL-10 expression. This data indicates that telmisartan-induced IL-10 expression is PPARγ-dependent but PTEN-independent. Altogether, telmisartan ameliorated AβO-induced microglial inflammation by inhibiting NF-κB-mediated proinflammatory cytokine expression via the PPARγ/PTEN pathways and by increasing PPARγ-mediated anti-inflammatory IL-10 expression. Telmisartan may present a promising therapy for the treatment of AβO pathology.

Topics: Amyloid beta-Protein Precursor; Angiotensin II Type 1 Receptor Blockers; Anilides; Animals; Cell Line; Cytokines; Humans; Inflammation; Inflammation Mediators; Mice; Microglia; PPAR gamma; PTEN Phosphohydrolase; Signal Transduction; Telmisartan

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

It is known that cerebral ischemia can cause brain inflammation and adiposome can serve as a depot of inflammatory mediators. In the study, the pro-inflammatory and pro-death role of adiposome in ischemic microglia and ischemic brain was newly investigated. The contribution of PPARγ to adiposome formation was also evaluated for the first time in ischemic microglia. Focal cerebral ischemia/reperfusion (I/R) animal model and the in vitro glucose-oxygen-serum deprivation (GOSD) cell model were both applied in the study. GOSD- or I/R-induced adiposome formation, inflammatory activity, cell death of microglia, and brain infarction were, respectively, determined, in the absence or presence of NS-398 (adiposome inhibitor) or GW9662 (PPARγ antagonist). GOSD-increased adiposome formation played a critical role in stimulating the inflammatory activity (production of TNF-α and IL-1β) and cell death of microglia. Similar results were also found in ischemic brain tissues. GOSD-induced PPARγ partially contributed to the increase of adiposomes and adiposome-mediated inflammatory responses of microglia. Blockade of adiposome formation with NS-398 or GW9662 significantly reduced not only the inflammatory activity and death rate of GOSD-treated microglia but also the brain infarct volume and motor function deficit of ischemic rats. The pathological role of microglia-derived adiposome in cerebral ischemia has been confirmed and attributed to its pro-inflammatory and/or pro-death effect upon ischemic brain cells and tissues. Adiposome and its upstream regulator PPARγ were therefore as potential targets for the treatment of ischemic stroke. Therapeutic values of NS-398 and GW9662 have been suggested.

Topics: Anilides; Animals; Animals, Newborn; Brain Ischemia; Cell Death; Culture Media, Serum-Free; Cyclooxygenase 2; Down-Regulation; Glucose; Inflammation; Interleukin-1beta; Lipid Droplets; Male; Microglia; Motor Activity; Neurons; Nitrobenzenes; Oxygen; PPAR gamma; Rats, Sprague-Dawley; Reperfusion Injury; Stroke; Sulfonamides; Tumor Necrosis Factor-alpha

Our previous studies have indicated that osthole may ameliorate the hepatic lipid metabolism and inflammatory response in nonalcoholic steatohepatitic rats, but the underlying mechanisms remain unclear. This study aimed to determine whether the effects of osthole were mediated by the activation of hepatic peroxisome proliferator-activated receptor α/γ (PPARα/γ). A rat model with steatohepatitis was induced by orally feeding high-fat and high-sucrose emulsion for 6 weeks. These experimental rats were then treated with osthole (20 mg/kg), PPARα antagonist MK886 (1 mg/kg) plus osthole (20 mg/kg), PPARγ antagonist GW9662 (1 mg/kg) plus osthole (20 mg/kg) and MK886 (1 mg/kg) plus GW9662 (1 mg/kg) plus osthole (20 mg/kg) for 4 weeks. The results showed that after osthole treatment, the hepatic triglycerides, free fatty acids, tumor necrosis factor-α, monocyte chemotactic protein-1, interleukin-6 (IL-6), IL-8 and liver index decreased by 52.3, 31.0, 32.4, 28.9, 36.3, 29.3 and 29.9%, respectively, and the score of steatohepatitis also decreased by 70.0%, indicating that osthole improved the hepatic steatosis and inflammation. However, these effects of osthole were reduced or abrogated after simultaneous addition of the specific PPARα antagonist MK886 or/and the PPARγ antagonist GW9662, especially in the co-PPARα/γ antagonists-treated group. Importantly, the osthole-induced hepatic expressions of PPARα/γ proteins were decreased, and the osthole-regulated hepatic expressions of lipogenic and inflammatory gene proteins were also reversed by PPARα/γ antagonist treatment. These findings demonstrated that the ameliorative effect of osthole on nonalcoholic steatohepatitis was mediated by PPARα/γ activation, and osthole might be a natural dual PPARα/γ activator.

Topics: Anilides; Animals; Coumarins; Fatty Acids, Nonesterified; Fatty Liver; Indoles; Inflammation; Lipid Metabolism; Liver; Male; PPAR alpha; PPAR gamma; Rats; Rats, Sprague-Dawley; Triglycerides

6-Shogaol, a pungent agent isolated from Zingiber officinale Roscoe, has been known to have anti-tumor and anti-inflammatory effects. However, the anti-inflammatory effects and biological mechanism of 6-Shogaol in LPS-activated BV2 microglia remains largely unknown. In this study, we evaluated the anti-inflammatory effects of 6-Shogaol in LPS-activated BV2 microglia. 6-Shogaol was administrated 1 h before LPS treatment. The production of inflammatory mediators were detected by ELISA. The expression of NF-κB and PPAR-γ were detected by western blot analysis. Our results revealed that 6-Shogaol inhibited LPS-induced TNF-α, IL-1β, IL-6, and PGE2 production in a concentration dependent manner. Furthermore, 6-Shogaol inhibited LPS-induced NF-κB activation by inhibiting phosphorylation and nuclear translocation of NF-κB p65. In addition, 6-Shogaol could increase the expression of PPAR-γ. Moreover, inhibition of PPAR-γ by GW9662 could prevent the inhibition of 6-Shogaol on LPS-induced inflammatory mediator production. In conclusion, 6-Shogaol inhibits LPS-induced inflammation by activating PPAR-γ.

Topics: Anilides; Animals; Catechols; Cell Line; Cell Survival; Cytokines; Inflammation; Inflammation Mediators; Lipopolysaccharides; Mice; Microglia; NF-kappa B; PPAR gamma

Atherosclerosis is a vascular disease with plaque formation and growth. Instable plaque with chronic inflammation is closely related to adverse cardiac outcomes. Pigment epithelium-derived factor (PEDF) is an endogenous multifunctional cytokine that possesses the ability of anti-inflammation. The aim of this study is to detect whether PEDF has protective effect on the stability of atherosclerotic plaque and to explore whether the effect of anti-inflammation involved.. ApoE. PEDF has protective effect on increasing AS plaque stability through ameliorating macrophage inflammation. PPAR-γ and downstream MAPKs were involved in the mechanism.

Topics: Anilides; Animals; Anti-Inflammatory Agents; Apolipoproteins E; Diet, High-Fat; Eye Proteins; Inflammation; Macrophages; Mice; Mitogen-Activated Protein Kinases; Nerve Growth Factors; Plaque, Atherosclerotic; PPAR gamma; Protective Factors; Serpins; Signal Transduction

Uncontrolled hyperglycemia accelerates endothelial damage and vascular inflammation caused by proinflammatory cytokines including tumor necrosis factor α (TNFα), which leads to arteriosclerotic cardiovascular diseases such as myocardial infarction. Telmisartan, an angiotensin II type 1 receptor blocker (ARB), is prescribed for treatment of hypertensive patients with concurrent diabetes mellitus (DM). Although a few clinical trials have suggested that telmisartan decreases cardiovascular complications in diabetic patients, the molecular mechanism for the beneficial effects remains elusive. Here, we investigated a molecular mechanism and effects of telmisartan on the expression of vascular cell adhesion molecule-1 (VCAM-1) and attachment of monocytes onto endothelial cells induced by TNFα in hyperglycemia-treated bovine aortic endothelial cells (BAEC). Telmisartan dose-dependently decreased hyperglycemia-aggravated IκB kinase β (IKKβ) expression and nuclear factor-κB (NF-κB) p65-Ser(536) phosphorylation, which accompanied a decrease in VCAM-1 expression and THP-1 monocytes adhesion. Among ARBs, including losartan and fimasartan, only telmisartan showed the inhibitory effects on expression of VCAM-1 and IKKβ, and phosphorylation of NF-κB p65-Ser(536). The telmisartan's beneficial effects were not changed by pretreatment with GW9662, a specific and irreversible peroxisome proliferator-activated receptor γ (PPARγ) antagonist, although GW9662 clearly inhibited rosiglitazone-induced CD36 expression. Finally, ectopic expression of wild type (WT)-IKKβ significantly restored telmisartan-attenuated VCAM-1 expression, NF-κB p65-Ser(536) phosphorylation, and THP-1 monocytes adhesion. Taken together, our findings demonstrate that telmisartan ameliorates hyperglycemia-exacerbated vascular inflammation, at least in part, by decreasing expression of IKKβ and VCAM-1 independently of PPARγ. Telmisartan may be useful for the treatment of DM-associated vascular inflammation and cardiovascular diseases.

Topics: Angiotensin II Type 1 Receptor Blockers; Anilides; Animals; Benzimidazoles; Benzoates; Cattle; Cell Adhesion; Diabetes Mellitus; Endothelial Cells; Humans; Hyperglycemia; I-kappa B Kinase; Inflammation; Monocytes; PPAR gamma; Rosiglitazone; Telmisartan; Thiazolidinediones; Transcription Factor RelA; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1

Citral is an active compound of lemongrass oil which has been reported to have anti-inflammatory effects. In this study, we investigated the effects of citral on lipopolysaccharide (LPS)-induced inflammatory response in a rat model of peritonitis and human umbilical vein endothelial cells (HUVECs). LPS was intraperitoneally injected into rats to establish a peritonitis model. The HUVECs were treated with citral for 12 h before exposure to LPS. The levels of TNF-α and IL-8 were measured using ELISA. Western blotting was used to detect the expression of VCAM-1, ICAM-1, NF-κB, and PPAR-γ. The results showed that citral had a protective effect against LPS-induced peritonitis. Citral decreased the levels of WBCs and inflammatory cytokines TNF-α and IL-6. Citral also inhibited LPS-induced myeloperoxidase (MPO) activity in the peritoneal tissue. Treatment of HUVECs with citral significantly inhibited TNF-α and IL-8 expression induced by LPS. LPS-induced VCAM-1 and ICAM-1 expression were also suppressed by citral. Meanwhile, we found that citral inhibited LPS-induced NF-κB activation in HUVECs. Furthermore, we found that citral activated PPAR-γ and the anti-inflammatory effects of citral can be reversed by PPAR-γ antagonist GW9662. In conclusion, citral inhibits LPS-induced inflammatory response via activating PPAR-γ which attenuates NF-κB activation and inflammatory mediator production.

Topics: Acyclic Monoterpenes; Anilides; Animals; Anti-Inflammatory Agents; Cell Adhesion; Enzyme Activation; Human Umbilical Vein Endothelial Cells; Humans; Inflammation; Intercellular Adhesion Molecule-1; Interleukin-6; Interleukin-8; Leukocyte Count; Lipopolysaccharides; Monoterpenes; Neutrophils; NF-kappa B; Peritonitis; Peroxidase; Plant Oils; PPAR gamma; Rats; Terpenes; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1

Peroxisome proliferator-activated receptor-gamma (PPARγ) is considered to be an important transcriptional factor in regulation of macrophages differentiation and activation. We have synthesized a series of novel structural molecules based on GW9662's structure (named BZ-24, BZ-25 and BZ-26), and interaction activity was calculated by computational docking. BZ-26 had shown stronger interaction with PPARγ and had higher transcriptional inhibitory activity of PPARγ with lower dosage compared with GW9662. BZ-26 was proved to inhibit inflammatory macrophage differentiation. LPS-induced acute inflammation mouse model was applied to demonstrate its anti-inflammatory activity. And the results showed that BZ-26 administration attenuated plasma tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) secretion, which are vital cytokines in acute inflammation. The anti-inflammatory activity was examined in THP-1 cell line, and TNF-α, IL-6 and MCP-1, were significantly inhibited. The results of Western blot and luciferase reporter assay indicated that BZ-26 not only inhibited NF-κB transcriptional activity, but also abolished LPS-induce nuclear translocation of P65. We also test BZ-26 action in tumor-bearing chronic inflammation mouse model, and BZ-26 was able to alter macrophages phenotype, resulting in antitumor effect. All our data revealed that BZ-26 modulated LPS-induced acute inflammation via inhibiting inflammatory macrophages differentiation and activation, potentially via inhibition of NF-κB signal pathway.

Topics: Anilides; Animals; Cell Differentiation; Female; HEK293 Cells; Humans; Inflammation; Inflammation Mediators; Macrophages; Male; Mice; Mice, Inbred BALB C

The primary physiological function of Krüppel-like zinc-finger transcription factor (KLF5) is the regulation of cardiovascular remodeling. Vascular remodeling is closely related to the amelioration of various ischemic diseases. However, the underlying correlation of KLF5 and ischemia is not clear. In this study, we aim to investigate the role of KLF5 in myocardial ischemia reperfusion (IR) injury and the potential mechanisms involved. Cultured H9C2 cells were subjected to oxygen-glucose deprivation/reperfusion (OGD/Rep) to mimic myocardial IR injury in vivo. Expressions of KLF5 and PPARγ were distinctly inhibited, and PGC-1α expression was activated at 24h after myocardial OGD/Rep injury. After myocardial OGD/Rep injury, we found that KLF5 overexpression down-regulated levels of TNF-α, IL-1β, IL-6 and IL-8. Through the analysis of lactate dehydrogenase (LDH) release, we demonstrate that KLF5 overexpression reduced the release of OGD/Rep-induced LDH. KLF5 overexpression significantly enhanced cell activity and decreased cell apoptosis during OGD/Rep injury. Compared with the OGD/Rep group, cells overexpressing KLF5 showed anti-apoptotic effects, such as decreased expression of Bax and cleaved caspase-3 as well as increased Bcl-2 expression. KLF5 overexpression activated PPARγ, a protein involved in OGD/Rep injury, and increased levels of PGC-1α, while TNF-α expression was remarkably inhibited. In addition, GW9662, a PPARγ receptor antagonist, reversed the expression of PPARγ/PGC-1α/TNF-α and cell activity induced by KLF5 overexpression. The effects of KLF5 overexpression on PPARγ/PGC-1α/TNF-α and cell activity were abolished by co-treatment with GW9662. Taken together, these results suggest that KLF5 can efficiently alleviate OGD/Rep-induced myocardial injury, perhaps through regulation of the PPARγ/PGC-1α/TNF-α pathway.

Topics: Anilides; Animals; Apoptosis; Cytokines; Cytoprotection; Down-Regulation; Gene Expression Regulation; Glucose; Inflammation; Inflammation Mediators; Kruppel-Like Transcription Factors; Myocardium; Myocytes, Cardiac; Oxygen; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; PPAR gamma; Rats; Reperfusion; Signal Transduction; Tumor Necrosis Factor-alpha; Up-Regulation

Protocatechuic acid (PCA), a major metabolite of anthocyanins, has been shown to have antioxidant, antitumoral, and anti-inflammatory activities. In this study, we investigated the anti-inflammatory effects of PCA on lipopolysaccharide (LPS)-induced inflammatory response in human gingival fibroblasts (HGFs). The effects of PCA on LPS-induced inflammatory cytokines IL-6 and chemokines IL-8 in HGFs were detected by ELISA. The expression of NF-κB and PPAR-γ was detected by Western blot analysis. Our results demonstrated that PCA suppressed IL-6 and IL-8 production in LPS-stimulated HGFs. We also found that PCA inhibited LPS-induced NF-κB activation. Furthermore, the inhibition of PCA on LPS-induced IL-6 and IL-8 production can be reversed by PPAR-γ antagonist GW9662. In conclusion, the anti-inflammatory mechanism of PCA is associated with activating PPAR-γ, thereby inhibiting LPS-induced inflammatory response.

Topics: Anilides; Anti-Inflammatory Agents; Antioxidants; Cell Survival; Enzyme Activation; Gingiva; Humans; Hydroxybenzoates; Inflammation; Interleukin-6; Interleukin-8; Lipopolysaccharides; NF-kappa B; Periodontal Diseases; PPAR gamma

(18)F-2-deoxy-2-fluoro-d-glucose ((18)F-FDG) positron emission tomography (PET) has been used for imaging human cancers for several decades. Despite its extensive use, (18)F-FDG PET imaging has limitations in the tumor findings. The goal of this study was to investigate the potential of a PPAR-γ agonist pioglitazone (PIO) to distinguish tumors and inflammatory lesions in (18)F-FDG PET imaging.. Studies of cellular uptake of (18)F-FDG and Western blot were performed in macrophage (RAW264.7) and three tumor cell lines (A549, KB, and MDA-MB-231) after treatment with PIO. In vivo microPET/CT imaging and biodistribution were performed in animal models.. The uptake of (18)F-FDG in the macrophages was decreased and uptake of (18)F-FDG in the tumor cells was increased when these cells were treated with PIO. Western blot showed that the expression of Glut1 was reduced by treatment of PIO in the macrophage cells, whereas the expression of Glut1 in the tumor cells was increased. In vivo PET/CT imaging revealed that (18)F-FDG uptake (%ID/g) in the tumors was enhanced from 4.05±1.46 to 5.28±1.92 for A549, from 3.9±0.5 to 4.9±0.2 for KB, and from 9.14±0.86 to 13.48±2.07 for MDA-MB-231 tumors after treatment with PIO. Unlike tumors, the RAW264.7 xenograft model showed the reduced (18)F-FDG uptake in the inflammatory lesion from 11.74±1.19 to 6.50±1.47. The results of biodistribution also showed that (18)F-FDG uptake in the tumors were increased after treatment of PIO. However, the uptake of inflammation lesions was reduced.. In this study, we demonstrated the effect of a PPAR-γ agonist PIO on (18)F-FDG uptake in tumors and inflammation in vitro and in vivo. PIO has potential to differentiate tumors and inflammatory lesions on (18)F-FDG PET imaging.

Topics: Anilides; Animals; Biological Transport; Cell Line, Tumor; Diagnosis, Differential; Female; Fluorodeoxyglucose F18; Gene Expression Regulation, Neoplastic; Glucose; Glucose Transporter Type 1; Glucose Transporter Type 3; Humans; Inflammation; Macrophages; Mice; Neoplasms; Pioglitazone; Positron-Emission Tomography; PPAR gamma; Thiazolidinediones; Tissue Distribution

The aim of this study was to find the protective role of Telmisartan (TS) in LPS intoxicated neuronal cells and elucidate the possible neuroprotective mechanism of action.. TLR4 and AT1R specific primers were designed and used in rtPCR to confirm the receptor expression in IMR-32 and Neuro2A cell lines. The protective effect of TS was assayed by MTT assay. The mechanism of action of TS was elucidated by assessing the expression and activation of TLR4 specific adaptor proteins SARM and MyD88, phosphorylated NFκB, PPARγ, MAPK p38, c-JNK, ERK by Western blotting. Selective PPARγ antagonist GW9662 was used to confirm the link between PPARγ activation and TLR4 mediated NFκB inflammatory mechanisms. The pro-inflammatory cytokines TNFα, IL1β, and IL-6 and anti-inflammatory cytokine IL10 release were measured by ELISA.. IMR-32 cells expressed TLR4 receptor and Neuro2A cells expressed both AT1R and TLR4 receptors. TS significantly protected both the cell lines from LPS intoxication. TS significantly suppressed the TLR4 mediated inflammatory response by PPARγ and SARM protein activation and the effect was reversed significantly by selective PPARγ antagonist GW9662, confirming the existence of link between PPARγ activation and TLR4 mediated inflammation via SARM.. LPS intoxicated human neuronal IMR-32 cells can be a good in vitro model to study inflammatory mediated neurodegeneration due to TLR4 receptor expression. Our study strongly recommends that the PPARγ activating pleiotropic effect of TS is responsible for the protective effect in LPS induced TLR4 mediated inflammation via SARM adaptor protein in the IMR-32 cell line.

Topics: Angiotensin II Type 1 Receptor Blockers; Anilides; Armadillo Domain Proteins; Benzimidazoles; Benzoates; Cell Line; Cytokines; Cytoskeletal Proteins; Enzyme-Linked Immunosorbent Assay; Humans; Inflammation; Inflammation Mediators; Lipopolysaccharides; Neurons; Neuroprotective Agents; Receptor, Angiotensin, Type 1; Reverse Transcriptase Polymerase Chain Reaction; Telmisartan; Toll-Like Receptor 4

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

Improper macrophage activation is pathogenically linked to various metabolic, inflammatory, and immune disorders. Therefore, regulatory proteins controlling macrophage activation have emerged as important new therapeutic targets. We recently demonstrated that netrin-1 regulates inflammation and infiltration of monocytes and ameliorates ischemia-reperfusion-induced kidney injury. However, it was not known whether netrin-1 regulates the phenotype of macrophages and the signaling mechanism through which it might do this. In this study, we report novel mechanisms underlying netrin-1's effects on macrophages using in vivo and in vitro studies. Overexpression of netrin-1 in spleen and kidney of transgenic mice increased expression of arginase-1, IL-4, and IL-13 and decreased expression of COX-2, indicating a phenotypic switch in macrophage polarization toward an M2-like phenotype. Moreover, flow cytometry analysis showed a significant increase in mannose receptor-positive macrophages in spleen compared with wild type. In vitro, netrin-1 induced the expression of M2 marker expression in bone marrow-derived macrophages, peritoneal macrophages, and RAW264.7 cells, and suppressed IFNγ-induced M1 polarization and production of inflammatory mediators. Adoptive transfer of netrin-1-treated macrophages suppressed inflammation and kidney injury against ischemia-reperfusion. Netrin-1 activated PPAR pathways and inhibition of PPAR activation abolished netrin-1-induced M2 polarization and suppression of cytokine production. Consistent with in vitro studies, administration of PPAR antagonist to mice abolished the netrin-1 protective effects against ischemia-reperfusion injury of the kidney. These findings illustrate that netrin-1 regulates macrophage polarization through PPAR pathways and confers anti-inflammatory actions in inflammed kidney tissue.

Topics: Anilides; Aniline Compounds; Animals; Inflammation; Interferon-gamma; Kidney; Kidney Diseases; Macrophage Activation; Macrophages, Peritoneal; Male; Maleimides; Mice; Mice, Transgenic; Nerve Growth Factors; Netrin-1; PPAR gamma; PPAR-beta; Reperfusion Injury; Spleen; Tumor Suppressor Proteins

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

TNFα plays an important role in the adipocyte dysfunction, including lipolysis acceleration, insulin resistance and changes of adipokines. Recently, we showed that paeoniflorin attenuates adipocyte lipolysis and inhibits the phosphorylation of ERK, JNK, IKK stimulated by TNFα. However, the effects of paeoniflorin on adipocytes insulin resistance and changes of adipokines remain unknown. The aim of the current study was to investigate the role of paeoniflorin in preventing insulin resistance or inflammation in 3T3-L1 adipocytes treated with TNFα. Our results showed that paeoniflorin restored insulin-stimulated [(3)H]2-DOG uptake, which was reduced by TNFα, with concomitant restoration in serine phosphorylation of IRS-1 and insulin-stimulated phosphorylation of AKT in adipocytes. Paeoniflorin attenuated TNFα-mediated suppression of the expressions of PPARγ and PPARγ target genes, and the improvement of paeoniflorin on TNFα-induced insulin resistance was attenuated by GW9662, an antagonist of PPARγ activity. Moreover, paeoniflorin could inhibit the expressions and secretions of IL-6 and MCP-1 from adipocytes induced by TNFα. These results, together with our previous data, indicate that paeoniflorin exerts a beneficial effect on adipocytes to prevent TNFα-induced insulin resistance and inflammatory adipokine release. Our studies provide important evidence for an ability of paeoniflorin in amelioration of TNFα-induced adipocyte dysfunction, which would be helpful to clarify its potential role in the treatment of obesity.

Topics: 3T3-L1 Cells; Adipocytes; Adipokines; Anilides; Animals; Benzoates; Bridged-Ring Compounds; Chemokine CCL2; Drugs, Chinese Herbal; Gene Expression; Glucose; Glucosides; Inflammation; Insulin; Insulin Receptor Substrate Proteins; Insulin Resistance; Interleukin-6; Mice; Monoterpenes; Obesity; Paeonia; Phosphorylation; PPAR gamma; Proto-Oncogene Proteins c-akt; Tumor Necrosis Factor-alpha

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

The role of angiotensin II type 2 (AT(2)) receptor stimulation in the pathogenesis of insulin resistance is still unclear. Therefore we examined the possibility that direct AT(2) receptor stimulation by compound 21 (C21) might contribute to possible insulin-sensitizing/anti-diabetic effects in type 2 diabetes (T2DM) with PPARγ activation, mainly focusing on adipose tissue.. T2DM mice, KK-Ay, were subjected to intraperitoneal injection of C21 and/or a PPARγ antagonist, GW9662 in drinking water for 2 weeks. Insulin resistance was evaluated by oral glucose tolerance test, insulin tolerance test, and uptake of 2-[(3)H] deoxy-D-glucose in white adipose tissue. Morphological changes of adipose tissues as well as adipocyte differentiation and inflammatory response were examined.. Treatment with C21 ameliorated insulin resistance in KK-Ay mice without influencing blood pressure, at least partially through effects on the PPARγ pathway. C21 treatment increased serum adiponectin concentration and decreased TNF-α concentration; however, these effects were attenuated by PPARγ blockade by co-treatment with GW9662. Moreover, we observed that administration of C21 enhanced adipocyte differentiation and PPARγ DNA-binding activity, with a decrease in inflammation in white adipose tissue, whereas these effects of C21 were attenuated by co-treatment with GW9662. We also observed that administration of C21 restored β cell damage in diabetic pancreatic tissue.. The present study demonstrated that direct AT(2) receptor stimulation by C21 accompanied with PPARγ activation ameliorated insulin resistance in T2DM mice, at least partially due to improvement of adipocyte dysfunction and protection of pancreatic β cells.

Topics: Adiponectin; Adipose Tissue; Anilides; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Inflammation; Insulin; Insulin Resistance; Male; Mice; Pancreas; PPAR gamma; Receptor, Angiotensin, Type 2; Sulfonamides; Thiophenes; Tumor Necrosis Factor-alpha

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

The pathogenesis of non-alcoholic steatohepatitis is still unclear. We have demonstrated previously that peroxisome proliferator activated receptor gamma (PPARγ) ligand protects against inflammation and fibrogenesis in experimental non-alcoholic steatohepatitis. We aim to elucidate the effect and the mechanism of PPARγ itself on nutritional fibrotic steatohepatitis in mice.. C57BL/6J mice were fed with methionine-choline deficient (MCD) diet for 8 weeks to induce fibrotic steatohepatitis. Mice fed the MCD diet were treated with adenovirus carrying PPARγ (Ad-PPARγ), Ad-PPARγ plus PPARγ agonist rosiglitazone, or PPARγ antagonist 2-chloro-5-nitrobenzaniliden (GW9662), respectively. The effects of up-regulation of PPARγ in the presence or absence of its agonist/or antagonist were assessed by comparing the severity of hepatic injury, activation of hepatic stellate cells and the expression of adiponectin, heme oxygenase-1, and fibrogenic related genes.. Mice fed with MCD diet for 8 weeks showed severe hepatic injury including hepatic steatosis, inflammatory infiltration, and fibrosis. Administration of Ad-PPARγ significantly lowered serum alanine aminotransferase level and ameliorated hepatic steatosis, necroinflammation, and fibrosis. These effects were associated with enhanced expression of PPARγ, up-regulated expression of adiponectin and heme oxygenase-1, and down-regulated expression of tumor necrosis factor alpha, interleukin-6, α-smooth muscle actin, transforming growth factor beta 1, matrix metallopeptidase-2, and -9. Administration of GW9662 promoted the severity of liver histology.. The present study provided evidences for the protective role of overexpressing PPARγ in ameliorating hepatic fibrosing steatohepatitis in mice. Modulation of PPARγ expression might serve as a therapeutic approach for fibrotic steatohepatitis.

Topics: Adenoviridae; Anilides; Animals; beta-Galactosidase; Choline; Diet; Fatty Liver; Genetic Vectors; Inflammation; Liver Cirrhosis; Liver Cirrhosis, Experimental; Male; Methionine; Mice; Mice, Inbred C57BL; PPAR gamma; Random Allocation; Rosiglitazone; Thiazolidinediones; Transfection

Endocannabinoids have both anti-inflammatory and neuroprotective properties against harmful stimuli. We previously demonstrated that the endocannabinoid 2-arachidonoylglycerol (2-AG) protects hippocampal neurons by limiting the inflammatory response via a CB(1) receptor-dependent MAPK/NF-κB signalling pathway. The purpose of the present study was to determine whether PPARγ, an important nuclear receptor, mediates 2-AG-induced inhibition of NF-κB phosphorylation and COX-2 expression, and COX-2-enhanced miniature spontaneous excitatory postsynaptic currents (mEPSCs).. By using a whole-cell patch clamp electrophysiological recording technique and immunoblot analysis, we determined mEPSCs, expression of COX-2 and PPARγ, and phosphorylation of NF-kB in mouse hippocampal neurons in culture.. Exogenous and endogenous 2-AG-produced suppressions of NF-κB-p65 phosphorylation, COX-2 expression and excitatory synaptic transmission in response to pro-inflammatory interleukin-1β (IL-1β) and LPS were inhibited by GW9662, a selective PPARγ antagonist, in hippocampal neurons in culture. PPARγ agonists 15-deoxy-Δ(12,14) -prostaglandin J(2) (15d-PGJ(2)) and rosiglitazone mimicked the effects of 2-AG on NF-κB-p65 phosphorylation, COX-2 expression and mEPSCs, and these effects were eliminated by antagonism of PPARγ. Moreover, exogenous application of 2-AG or elevation of endogenous 2-AG by inhibiting its hydrolysis with URB602 or JZL184, selective inhibitors of monoacylglycerol lipase (MAGL), prevented the IL-1β- and LPS-induced reduction of PPARγ expression. The 2-AG restoration of the reduced PPARγ expression was blocked or attenuated by pharmacological or genetic inhibition of the CB(1) receptor.. Our results suggest that CB(1) receptor-dependent PPARγ expression is an important and novel signalling pathway in endocannabinoid 2-AG-produced resolution of neuroinflammation in response to pro-inflammatory insults.

Topics: Anilides; Animals; Arachidonic Acids; Benzodioxoles; Biphenyl Compounds; Cannabinoid Receptor Modulators; Cells, Cultured; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Endocannabinoids; Excitatory Postsynaptic Potentials; Glycerides; Hippocampus; Inflammation; Interleukin-1beta; Lipopolysaccharides; Mice; Monoacylglycerol Lipases; Neurons; NF-kappa B; Phosphorylation; Piperidines; PPAR gamma; Prostaglandin D2; Receptor, Cannabinoid, CB1; Rosiglitazone; Signal Transduction; Synaptic Transmission; Thiazolidinediones

Inflammation may play an important role in the pathogenesis of kidney disease. Agonists of the peroxisome proliferator-activated receptor-γ (PPAR-γ), such as rosiglitazone, have been recently demonstrated to regulate inflammation by modulating the production of inflammatory mediators. The purpose of this study was to examine the effects of rosiglitazone on lipopolysaccharide (LPS)-induced kidney inflammation and to explore the mechanism of its renoprotection.. Mice were treated with LPS with or without pretreatment with rosiglitazone. Blood urea nitrogen (BUN), creatinine levels, the urinary albumin-to-creatinine ratio, macrophage infiltration, monocyte chemoattractant protein-1 (MCP-1) expression, PPAR-γ expression, and NF-κB and PPAR-γ activity were investigated. HK-2 cells were maintained under defined in vitro conditions, treated with either rosiglitazone and/or the PPAR-γ antagonist GW9662, and then stimulated with LPS. MCP-1, IL-8, IL-6, NF-κB activity and PPAR-γ expression were investigated.. Compared to the LPS only group, pretreatment with rosiglitazone in vivo significantly attenuated the BUN levels macrophage infiltration, MCP-1 overexpression and NF-κB activity (p < 0.05). Rosiglitazone also restored PPAR-γ expression and protein activity, which were reduced significantly in the LPS only group (p < 0.05). Furthermore, in the LPS-stimulated HK-2 cells, rosiglitazone downregulated MCP-1, IL-8 and IL-6 expression as well as NF-κB activation and increased PPAR-γ expression (p < 0.05). These effects were diminished by GW9662.. These results showed that pretreatment with rosiglitazone could attenuate kidney inflammation through the activation of PPAR-γ, suppression of MCP-1 overproduction and NF-κB activation. Rosiglitazone had a protective effect via a PPAR-γ-dependent pathway in LPS-treated HK-2 cells.

Topics: Anilides; Animals; Blood Urea Nitrogen; Chemokine CCL2; Creatinine; Humans; Hypoglycemic Agents; Inflammation; Interleukin-6; Interleukin-8; Lipopolysaccharides; Male; Mice; NF-kappa B; PPAR gamma; Reactive Oxygen Species; Rosiglitazone; Thiazolidinediones; Time Factors

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

This protocol describes microsphere-based protease assays for use in flow cytometry and high-throughput screening. This platform measures a loss of fluorescence from the surface of a microsphere due to the cleavage of an attached fluorescent protease substrate by a suitable protease enzyme. The assay format can be adapted to any site or protein-specific protease of interest and results can be measured in both real time and as endpoint fluorescence assays on a flow cytometer. Endpoint assays are easily adapted to microplate format for flow cytometry high-throughput analysis and inhibitor screening.

Topics: Animals; Biotinylation; Flow Cytometry; Fluorescence Resonance Energy Transfer; Green Fluorescent Proteins; High-Throughput Screening Assays; Humans; Inflammation; Kinetics; Microspheres; Peptide Hydrolases; Peptides; Reproducibility of Results; Temperature

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

Inflammation and immune response have been implicated in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH). Recently, increased TLR4 expression has been associated with the development of cerebral vasospasm in a rabbit model of SAH. Peroxisome proliferator-activated receptor gamma (PPARgamma) agonists, effective inhibitors of TLR4 activation, may modulate the vasospasm progression via their anti-inflammation effects. We investigate whether the blood component oxyhemoglobin (OxyHb) can induce the expression of Toll-like receptor (TLR) 4 in vascular smooth muscle cells (VSMCs), and evaluate the modulatory effects of PPARgamma agonist rosiglitazone on OxyHb-induced inflammation in VSMCs. Cultured VSMCs incubated with or without rosiglitazone were exposed to OxyHb at 10muM for up to 48h. Expression of TLR4 was assessed by immunocytochemistry and Western blot analysis. Production of tumor necrosis factor alpha (TNF-alpha) in conditioned medium were quantified by ELISA. A marked increase of TLR4 production and TNF-alpha release was observed at 48h after cells were treated with OxyHb. Rosiglitazone reduced TLR4 immunocytochemistry staining and protein production significantly in VSMCs. A specific antagonist for PPARgamma, GW9662, could reverse the anti-inflammatory effects of rosiglitazone. The results demonstrated that OxyHb exposure could induce TLR4 activation in cultured VSMCs. Rosiglitazone suppressed TLR4 expression and cytokine release via the activation of PPARgamma and may have a therapeutic potential for the treatment of vasospasm following SAH.

Topics: Anilides; Animals; Cells, Cultured; Culture Media, Conditioned; Down-Regulation; Inflammation; Male; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Oxyhemoglobins; PPAR gamma; Rats; Rats, Sprague-Dawley; Rosiglitazone; Subarachnoid Hemorrhage; Thiazolidinediones; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha; Vasodilator Agents; Vasospasm, Intracranial

Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder. Accumulating data indicate that astrocytes play an important role in the neuroinflammation related to the pathogenesis of AD. It has been shown that microglia and astrocytes are activated in AD brain and amyloid-beta (Abeta) can increase the expression of cyclooxygenase 2 (COX-2), interleukin-1, and interleukin-6. Suppressing the inflammatory response caused by activated astrocytes may help to inhibit the development of AD. Curcumin is a major constituent of the yellow curry spice turmeric and proved to be a potential anti-inflammatory drug in arthritis and colitis. There is a low age-adjusted prevalence of AD in India, a country where turmeric powder is commonly used as a culinary compound. Curcumin has been shown to suppress activated astroglia in amyloid-beta protein precursor transgenic mice. The real mechanism by which curcumin inhibits activated astroglia is poorly understood. Here we report that the expression of COX-2 and glial fibrillary acidic protein were enhanced and that of peroxisome proliferator-activated receptor gamma (PPARgamma) was decreased in Abeta(25-35)-treated astrocytes. In line with these results, nuclear factor-kappaB translocation was increased in the presence of Abeta. All these can be reversed by the pretreatment of curcumin. Furthermore, GW9662, a PPARgamma antagonist, can abolish the anti-inflammatory effect of curcumin. These results show that curcumin might act as a PPARgamma agonist to inhibit the inflammation in Abeta-treated astrocytes.

Topics: Amyloid beta-Peptides; Anilides; Animals; Animals, Newborn; Astrocytes; Cells, Cultured; Curcumin; Cyclooxygenase 2; Glial Fibrillary Acidic Protein; Inflammation; Nerve Tissue Proteins; Nuclear Proteins; PPAR gamma; Rats; Rats, Sprague-Dawley

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

Milk consumption from early childhood on has been found to be inversely correlated with allergic sensitization and the onset of bronchial asthma. We tested whether cis-9,trans-11-conjugated linoleic acid (c9,t11-CLA), naturally occurring in milk fat, may prevent allergic sensitization and inhibit airway inflammation in a murine asthma model. BALB/c mice were fed a diet enriched in 1 wt% of c9,t11-CLA or a control diet 7 d prior to and for 32 d during sensitization [d 1 and 14, 100 mg/L ovalbumin (OVA) in adjuvant vs. PBS] and airway challenges (d 28-30, 1% OVA in PBS vs. PBS). Subgroups of mice were coadministered 20 micromol/L of the selective PPARgamma antagonist GW9662 during each OVA challenge. C9,t11-CLA feeding resulted in significantly reduced IgE production and allergen-induced in vivo airway hyperresponsiveness. Further, less mucous plugging of segmental bronchi and significantly reduced interleukin-5 and eosinophils were determined in bronchoalveolar lavage fluids of c9,t11-CLA-fed mice. C9,t11-CLA feeding prevented the downregulation of PPARgamma mRNA in the lung tissues observed after allergen sensitization and airway challenges in control mice. The inhibitory effects of c9,t11-CLA on airway inflammation were partially prevented by coadministration of GW9962. Further, c9,t11-CLA feeding resulted in a significantly lower concentration of the eicosanoid precursor, arachidonic acid, in tissue lipids. These findings demonstrate that dietary c9,t11-CLA can reduce allergic airway inflammation, most likely via a PPARgamma-related mechanism and by reducing eicosanoid precursors. They give new insights into the fatty acid-mediated mechanism of immunomodulation and may represent a step toward an attractive novel strategy in the dietary prevention and treatment of allergic asthma.

Topics: Airway Resistance; Anilides; Animals; Base Sequence; Bronchoalveolar Lavage Fluid; Dietary Fats, Unsaturated; DNA Primers; Female; Hypersensitivity; Inflammation; Linoleic Acids, Conjugated; Mice; Mice, Inbred BALB C; Ovalbumin; PPAR gamma; Respiratory System; RNA, Messenger

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a nuclear receptor that regulates diverse biological functions including inflammation. The PPARgamma ligands have been reported to exert cardioprotective effects and attenuate myocardial reperfusion injury. Here, we examined the molecular mechanisms of their anti-inflammatory effects. Male Wistar rats were subjected to myocardial ischemia and reperfusion and were treated with the PPAR-gamma ligands, 15-deoxy-Delta-prostaglandin J2 (15d-PGJ2) or ciglitazone, or with vehicle only, in the absence or presence of the selective PPAR-gamma antagonist GW-9662. In vehicle-treated rats, myocardial injury was associated with elevated tissue activity of myeloperoxidase, indicating infiltration of neutrophils, and elevated plasma levels of creatine kinase and tumor necrosis factor-alpha. These events were preceded by activation of the nuclear factor-kappaB pathway. The PPAR-gamma DNA binding was also increased in the heart after reperfusion. Treatment with ciglitazone or 15d-PGJ2 reduced myocardial damage and neutrophil infiltration and blunted creatine kinase levels and cytokine production. The beneficial effects of both ligands were associated with enhancement of PPAR-gamma DNA binding and reduction of nuclear factor-kappaB activation. Treatment with 15d-PGJ2, but not ciglitazone, enhanced DNA binding of heat shock factor 1 and upregulated the expression of the cardioprotective heat shock protein 70. Treatment with 15d-PGJ2, but not ciglitazone, also induced a significant increase in nuclear phosphorylation of the prosurvival kinase Akt. The cardioprotection afforded by ciglitazone was attenuated by the PPAR-gamma antagonist GW-9662. In contrast, GW-9662 did not affect the beneficial effects afforded by 15d-PGJ2. Thus, our data suggest that treatment with these chemically unrelated PPAR-gamma ligands results in diverse anti-inflammatory mechanisms.

Topics: Anilides; Animals; Creatine Kinase; DNA-Binding Proteins; Heat Shock Transcription Factors; HSP70 Heat-Shock Proteins; Hypoglycemic Agents; Immunologic Factors; Inflammation; Ligands; Male; Myocardial Reperfusion Injury; Neutrophil Infiltration; NF-kappa B; Peroxidase; PPAR gamma; Prostaglandin D2; Proto-Oncogene Proteins c-akt; Rats; Rats, Wistar; Signal Transduction; Thiazolidinediones; Transcription Factors; Tumor Necrosis Factor-alpha; Up-Regulation

Inflammatory mechanisms may play an important role in the pathogenesis of cisplatin nephrotoxicity. Agonists of the peroxisome proliferator-activated receptor-gamma (PPARgamma), such as rosiglitazone, have been recently demonstrated to regulate inflammation by modulating the production of inflammatory mediators and adhesion molecules. The purpose of this study was to examine the protective effects of rosiglitazone on cisplatin nephrotoxicity and to explore the mechanism of its renoprotection.. Mice were treated with cisplatin with or without pre-treatment with rosiglitazone. Renal functions, histological findings, aquaporin 2 (AQP2) and adhesion molecule expression, macrophage infiltration and tumour necrosis factor-alpha (TNF-alpha) levels were investigated. The effect of rosiglitazone on nuclear factor (NF)-kappaB activity and on viability was examined using cultured human kidney (HK-2) cells.. Rosiglitazone significantly decreased both the damage to renal function and histological pathology after cisplatin injection. Pre-treatment with rosiglitazone reduced the systemic levels of TNF-alpha and down-regulated adhesion molecule expression in addition to the infiltration of inflammatory cells after cisplatin administration. Rosiglitazone restored the decreased AQP2 expression after cisplatin treatment. Pre-treatment with rosiglitazone blocked the phosphorylation of the p65 subunit of NF-kappaB in cultured HK-2 cells. Rosiglitazone had a protective effect via a PPARgamma-dependent pathway in cisplatin-treated HK-2 cells.. These results showed that pre-treatment with rosiglitazone attenuates cisplatin-induced renal damage through the suppression of TNF-alpha overproduction and NF-kappaB activation.

Topics: Anilides; Animals; Apoptosis; C-Peptide; Cell Line; Chromans; Cisplatin; Drug Evaluation, Preclinical; Glioma; Humans; Hypoglycemic Agents; Inflammation; Insulin; Intercellular Adhesion Molecule-1; Kidney; Kidney Diseases; Kidney Function Tests; Kidney Tubules, Proximal; Macrophages; Male; Mice; Mice, Inbred C57BL; Monocytes; PPAR gamma; Prostaglandin D2; Protein Transport; Rosiglitazone; Thiazolidinediones; Transcription Factor RelA; Troglitazone; Tumor Necrosis Factor-alpha

In most neurodegenerative disorders, including multiple sclerosis, Parkinson disease, and Alzheimer disease, a massive neuronal cell death occurs as a consequence of an uncontrolled inflammatory response, where activated astrocytes and microglia and their cytotoxic agents play a crucial pathological role. Current treatments for these diseases are not effective. In the present study we investigate the effect of thiadiazolidinone derivatives, which have been recently suggested to play a role in neurodegenerative disorders. We have found that thiadiazolidinones are potent neuroprotector compounds. Thiadiazolidinones inhibited inflammatory activation of cultured brain astrocytes and microglia by diminishing lipopolysaccharide-induced interleukin 6, tumor necrosis factor alpha, inducible nitric-oxide synthase, and inducible cyclooxygenase type 2 expression. In addition, thiadiazolidinones inhibited tumor necrosis factor-alpha and nitric oxide production and, concomitantly, protected cortical neurons from cell death induced by the cell-free supernatant from activated microglia. The neuroprotective effects of thiadiazolidinones are completely inhibited by the peroxisome proliferator-activated receptor gamma antagonist GW9662. In contrast the glycogen synthase kinase 3beta inhibitor LiCl did not show any effect. These findings suggest that thiadiazolidinones potently attenuate lipopolysaccharide-induced neuroinflammation and reduces neuronal death by a mechanism dependent of peroxisome proliferator-activated receptor gamma activation.

Topics: Alitretinoin; Anilides; Animals; Anti-Inflammatory Agents; Apoptosis; Astrocytes; Brain; Cell Death; Cell Line; Cell-Free System; Cells, Cultured; Cyclooxygenase 2; Dose-Response Relationship, Drug; Enzyme Inhibitors; Glutamic Acid; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hippocampus; Immunohistochemistry; In Vitro Techniques; Inflammation; Interleukin-6; Lipopolysaccharides; Lithium Chloride; Mice; Microscopy, Confocal; Microscopy, Fluorescence; Models, Chemical; Neurodegenerative Diseases; Neuroglia; Neurons; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Nitrites; PPAR gamma; Prostaglandin-Endoperoxide Synthases; Rats; Staurosporine; Thiazolidinediones; Time Factors; Transfection; Tretinoin; Tumor Necrosis Factor-alpha

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

Membrane-associated prostaglandin (PG) E(2) synthase-1 (mPGES-1) catalyzes the conversion of PGH(2) to PGE(2), which contributes to many biological processes. Peroxisome proliferator-activated receptor gamma (PPARgamma) is a ligand-activated transcription factor and plays an important role in growth, differentiation, and inflammation in different tissues. Here, we examined the effect of PPARgamma ligands on interleukin-1beta (IL-1beta)-induced mPGES-1 expression in human synovial fibroblasts. PPARgamma ligands 15-deoxy-Delta(12,14) prostaglandin J(2) (15d-PGJ(2)) and the thiazolidinedione troglitazone (TRO), but not PPARalpha ligand Wy14643, dose-dependently suppressed IL-1beta-induced PGE(2) production, as well as mPGES-1 protein and mRNA expression. 15d-PGJ(2) and TRO suppressed IL-1beta-induced activation of the mPGES-1 promoter. Overexpression of wild-type PPARgamma further enhanced, whereas overexpression of a dominant negative PPARgamma alleviated, the suppressive effect of both PPARgamma ligands. Furthermore, pretreatment with an antagonist of PPARgamma, GW9662, relieves the suppressive effect of PPARgamma ligands on mPGES-1 protein expression, suggesting that the inhibition of mPGES-1 expression is mediated by PPARgamma. We demonstrated that PPARgamma ligands suppressed Egr-1-mediated induction of the activities of the mPGES-1 promoter and of a synthetic reporter construct containing three tandem repeats of an Egr-1 binding site. The suppressive effect of PPARgamma ligands was enhanced in the presence of a PPARgamma expression plasmid. Electrophoretic mobility shift and supershift assays for Egr-1 binding sites in the mPGES-1 promoter showed that both 15d-PGJ(2) and TRO suppressed IL-1beta-induced DNA-binding activity of Egr-1. These data define mPGES-1 and Egr-1 as novel targets of PPARgamma and suggest that inhibition of mPGES-1 gene transcription may be one of the mechanisms by which PPARgamma regulates inflammatory responses.

Topics: Amino Acid Motifs; Anilides; Binding Sites; Blotting, Western; Cell Division; Cell Nucleus; Chromans; DNA-Binding Proteins; DNA, Complementary; Dose-Response Relationship, Drug; Early Growth Response Protein 1; Fibroblasts; Genes, Dominant; Genes, Reporter; Humans; Immediate-Early Proteins; Immunologic Factors; Inflammation; Interleukin-1; Intramolecular Oxidoreductases; Ligands; Peroxisome Proliferators; Plasmids; Promoter Regions, Genetic; Prostaglandin D2; Prostaglandin-E Synthases; Protein Binding; Pyrimidines; Receptors, Cytoplasmic and Nuclear; Reverse Transcriptase Polymerase Chain Reaction; RNA; Synovial Membrane; Thiazolidinediones; Time Factors; Transcription Factors; Transcription, Genetic; Transfection; Troglitazone

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