15-deoxyprostaglandin-j2 and Disease-Models--Animal

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily. PPARgamma regulates several metabolic pathways by binding to sequence-specific PPAR response elements in the promoter region of target genes, including lipid biosynthesis and glucose metabolism. Synthetic PPARgamma agonists have been developed, such as the thiazolidinediones rosiglitazone and pioglitazone. These act as insulin sensitizers and are used in the treatment of type 2 diabetes. Recently however, PPARgamma ligands have been implicated as regulators of cellular inflammatory and immune responses. They are thought to exert anti-inflammatory effects by negatively regulating the expression of pro-inflammatory genes. Several studies have demonstrated that PPARgamma ligands possess anti-inflammatory properties and that these properties may prove helpful in the treatment of inflammatory diseases of the airways. This review will outline the anti-inflammatory effects of synthetic and endogenous PPARgamma ligands and discuss their potential therapeutic effects in animal models of inflammatory airway disease.

Topics: Animals; Anti-Inflammatory Agents; Asthma; Benzimidazoles; Clinical Trials as Topic; Disease Models, Animal; Fatty Acids; Humans; Ligands; PPAR gamma; Prostaglandin D2; Pulmonary Disease, Chronic Obstructive; Pulmonary Fibrosis; Thiazolidinediones

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors that are related to retinoid, steroid and thyroid hormone receptors. The PPAR subfamily comprises three members: PPAR-alpha, PPAR-beta and PPAR-gamma. PPARs have recently been implicated as regulators of cellular proliferation and inflammatory responses. Furthermore, it has been demonstrated that PPAR-gamma and PPAR-alpha reduce lung injury associated with inflammation and shock.

Topics: Animals; Anti-Inflammatory Agents; Disease Models, Animal; Humans; Ligands; PPAR alpha; PPAR gamma; Prostaglandin D2; Respiratory Distress Syndrome; Rosiglitazone; Thiazolidinediones

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of proteins. The role of PPARs in regulating the transcription of genes involved in glucose and lipid metabolism has been extensively characterized. Interestingly, PPARs have also been demonstrated to mediate inflammatory responses. Microglia participate in pathology associated with multiple sclerosis (MS). Upon activation, microglia produce molecules including NO and TNF-alpha that can be toxic to CNS cells including myelin-producing oligodendrocytes and neurons, which are compromised in the course of MS. Previously, we and others demonstrated that PPAR-gamma agonists including 15d-PGJ(2) are effective in the treatment of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. PPAR-gamma modulation of EAE may occur, at least in part, by inhibition of microglial cell activation. Here, we indicate that 15d-PGJ(2) is a more potent inhibitor of microglial activation than thiazolidinediones, which are currently used to treat diabetes. Furthermore, 15d-PGJ(2) acts cooperatively with 9-cis retinoic acid, the ligand for the retinoid X receptor (RXR), in inhibiting microglial cell activation. This suggests that 15d-PGJ(2) and 9-cis RA inhibit cell activation through the formation of PPAR-gamma/RXR heterodimers. Interestingly, PGA(2), which like 15d-PGJ(2) is a cyclopentenone prostaglandin, but which unlike 15d-PGJ(2) does not bind PPAR-gamma, is a potent inhibitor of microglial cell activation. Collectively, these studies suggest that 15d-PGJ(2) inhibits microglial cell activation by PPAR-gamma-dependent as well as PPAR-gamma-independent mechanisms. The studies further suggest that the PPAR-gamma agonist 15d-PGJ(2) in combination with retinoids may be effective in the treatment of MS.

Topics: Animals; Disease Models, Animal; Humans; Microglia; Models, Biological; Multiple Sclerosis; Neurons; PPAR gamma; Prostaglandin D2; Tretinoin

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

15-Deoxy-delta (12,14)-prostaglandin J2 (15d-PgJ2) is a potent bioactive lipid mediator, known to possess several roles in cell regulation and differentiation along with antimicrobial efficacy against different bacterial and viral infections. In the present study, we investigated the therapeutic efficacy and mechanism of action of 15d-PgJ2 in vitro in Leishmania donovani promastigotes and infected J774 macrophages, and in vivo in Balb/c mice/golden hamster model of experimental visceral leishmaniasis. 15d-PgJ2 effectively killed L. donovani promastigotes and amastigotes in vitro with IC50 of 104.6 and 80.09 nM, respectively. At 2 mg/kg (mice) and 4 mg/kg (hamster) doses, 15d-PgJ2 decreased >90 % spleen and liver parasite burden. It significantly reduced interleukin (IL)-10 and transforming growth factor (TGF)-β synthesis in infected macrophages and splenocytes. 15d-PgJ2 induced reactive oxygen species (ROS)-dependent apoptosis of promastigotes by triggering phosphatidyl serine externalization, mitochondrial membrane damage and inducing caspase-like activity. In vitro drug interaction studies revealed an indifference to the synergistic association of 15d-PgJ2 with Miltefosine and Amphotericin-B (Amp-B). Moreover, when combined with sub-curative doses of Miltefosine and Amphotericin-B, 15d-PgJ2 resulted in >95 % parasite removal. Our results suggested that 15d-PgJ2 induces mitochondria-dependent apoptosis of L. donovani and is a good therapeutic candidate for adjunct therapy against experimental visceral leishmaniasis.. 15d-PgJ2 effectively eliminated both promastigotes and amastigotes form of L. donovani. 15d-PgJ2 decreased parasite burden from infected mice and hamsters with reduced Th2 cytokines. 15d-PgJ2 induced ROS-mediated mitochondrial apoptosis of L. donovani promastigotes. 15d-PgJ2 is a good therapeutic candidate for adjunct therapy with Miltefosine and Amp-B.

Topics: Amphotericin B; Animals; Antiprotozoal Agents; Apoptosis; Cell Line; Cricetulus; Disease Models, Animal; Drug Administration Schedule; Female; Interleukin-10; Leishmania donovani; Leishmaniasis, Visceral; Life Cycle Stages; Liver; Macrophages; Male; Mice; Mice, Inbred BALB C; Mitochondria; Phosphorylcholine; Prostaglandin D2; Reactive Oxygen Species; Spleen; Transforming Growth Factor beta; Treatment Outcome

In this study, we confirmed a protective effect of 15d-PGJ2 in concanavalin A (ConA)-induced fulminant hepatitis in mice and investigated the potential mechanism.. Balb/C mice were injected with ConA (25mg/kg) to induce acute fulminant hepatitis, and 15d-PGJ2 (2.5-10μg) was administered 30min after the ConA injection. The histological grade, pro-inflammatory cytokine and ROS levels, apoptosis and autophagy activity, the expression of HO-1, Nrf2, JNK and Bcl-2 activity were determined 2, 4, and 8h after the ConA injection.. Following ConA challenge, the expression of cytokines tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) was up-regulated. Treatment with 15d-PGJ2 reduced the pathological effects of ConA-induced fulminant hepatitis and significantly reduced the levels of TNF-α, IL-1β and ROS after injection. 15d-PGJ2 inhibited apoptosis and autophagic cell death, facilitated Nrf2 nuclear translocation, increased HO-1 expression and suppressed the JNK activation.. 15d-PGJ2 alleviates ConA-induced acute liver injury in mice by up-regulating the anti-oxidative stress factor HO-1 and reducing the production of cytokines and ROS, thereby inhibiting hepatic cell autophagy probably induced by ROS.

Topics: Acute Disease; Animals; Autophagy; Cell Nucleus; Concanavalin A; Disease Models, Animal; Enzyme Activation; Heme Oxygenase-1; Hepatitis; Hepatocytes; Interleukin-1beta; JNK Mitogen-Activated Protein Kinases; Liver; Male; Mice, Inbred BALB C; NF-E2-Related Factor 2; Phagosomes; Prostaglandin D2; Reactive Oxygen Species; Tumor Necrosis Factor-alpha; 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

Macrophages undergo a transition from pro-inflammatory to healing-associated phenotypes that is critical for efficient wound healing. However, the regulation of this transition during normal and impaired healing remains to be elucidated. In our studies, the switch in macrophage phenotypes during skin wound healing was associated with up-regulation of the peroxisome proliferator-activated receptor (PPAR)γ and its downstream targets, along with increased mitochondrial content. In the setting of diabetes, up-regulation of PPARγ activity was impaired by sustained expression of IL-1β in both mouse and human wounds. In addition, experiments with myeloid-specific PPARγ knockout mice indicated that loss of PPARγ in macrophages is sufficient to prolong wound inflammation and delay healing. Furthermore, PPARγ agonists promoted a healing-associated macrophage phenotype both in vitro and in vivo, even in the diabetic wound environment. Importantly, topical administration of PPARγ agonists improved healing in diabetic mice, suggesting an appealing strategy for down-regulating inflammation and improving the healing of chronic wounds.

Topics: Administration, Cutaneous; Animals; Cells, Cultured; Diabetes Mellitus, Type 1; Disease Models, Animal; Female; Humans; Interleukin-1beta; Leg Ulcer; Macrophages; Male; Mice, Inbred C57BL; Mice, Knockout; Phenotype; PPAR gamma; Prostaglandin D2; Receptors, Interleukin-1 Type I; Rosiglitazone; Skin; Thiazolidinediones; Time Factors; Wound Healing

Peroxisome proliferator-activated receptor-γ (PPAR-γ) has recently emerged as potential therapeutic agents for cerebral ischemia-reperfusion (I/R) injury because of anti-neuronal apoptotic actions. However, whether PPAR-γ activation mediates neuronal autophagy in such conditions remains unclear. Therefore, in this study, we investigated the role of PPAR-γ agonist 15-PGJ(2) on neuronal autophagy induced by I/R. The expression of autophagic-related protein in ischemic cortex such as LC3-II, Beclin 1, cathepsin-B and LAMP1 increased significantly after cerebral I/R injury. Furthermore, increased punctate LC3 labeling and cathepsin-B staining occurred in neurons. Treatment with PPAR-γ agonist 15d-PGJ(2) decreased not only autophagic-related protein expression in ischemic cortex, but also immunoreactivity of LC3 and cathepsin-B in neurons. Autophagic inhibitor 3-methyladenine (3-MA) decreased LC3-II levels, reduced the infarct volume, and mimicked some protective effect of 15d-PGJ(2) against cerebral I/R injury. These results indicate that PPAR-γ agonist 15d-PGJ(2) exerts neuroprotection by inhibiting neuronal autophagy after cerebral I/R injury. Although the molecular mechanisms underlying PPAR-γ agonist in mediating neuronal autophagy remain to be determined, neuronal autophagy may be a new target for PPAR-γ agonist treatment in cerebral I/R injury.

Topics: Animals; Autophagy; Brain Ischemia; Cathepsin B; Disease Models, Animal; Humans; Male; Mice; Microtubule-Associated Proteins; Neurons; Neuroprotective Agents; PPAR gamma; Prostaglandin D2; Reperfusion Injury

We evaluate the immunomodulation of Peroxisome proliferator-activated receptor-γ (PPAR-γ) agonists 15d-PGJ(2) and rosiglitazone (RGZ) in a model of chronic eosinophilia. 15d-PGJ(2) and RGZ significantly reduce eosinophil migration into the peritoneal cavity and down-regulate the eosinopoiesis. The synthesis of IL-5 was decreased after the treatment with 15d-PGJ(2) and RGZ corroborating with the eosinophil migration inhibition. However, IgE was decreased only after the administration of 15d-PGJ(2) in part due to B-cell inhibition. We also observed a decrease in the synthesis of IL-33, IL-17 and IL-23, suggesting that besides the modulation of Th2 pattern, there is a modulation via IL-23 and IL-17 suggesting a role of these cytokines in the eosinophil recruitment. In fact IL-17(-/-) mice failed to develop an eosinophilic response. Altogether, the results showed that PPAR-γ agonists mainly 15d-PGJ(2), have therapeutic efficacy in eosinophil-induced diseases with an alternative mechanism of control, via IL-23/IL-17 and IL-33.

Topics: Allergens; Animals; Cell Movement; Cell Proliferation; Disease Models, Animal; Eosinophilia; Eosinophils; Flow Cytometry; Immunoglobulin E; Inflammation; Interleukins; Leukocyte Count; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; PPAR gamma; Prostaglandin D2; Rosiglitazone; Thiazolidinediones

The 15-deoxy-(Δ12,14)-PG J(2) (15d-PGJ(2)) has demonstrated excellent anti-inflammatory results in different experimental models. It can be used with a polymeric nanostructure system for modified drug release, which can change the therapeutic properties of the active principle, leading to increased stability and slower/prolonged release. The aim of the current study was to test a nanotechnological formulation as a carrier for 15d-PGJ(2), and to investigate the immunomodulatory effects of this formulation in a mouse periodontitis model. Poly (D,L-lactide-coglycolide) nanocapsules (NC) were used to encapsulate 15d-PGJ(2). BALB/c mice were infected on days 0, 2, and 4 with Aggregatibacter actinomycetemcomitans and divided into groups (n = 5) that were treated daily during 15 d with 1, 3, or 10 μg/kg 15d-PGJ(2)-NC. The animals were sacrificed, the submandibular lymph nodes were removed for FACS analysis, and the jaws were analyzed for bone resorption by morphometry. Immunoinflammatory markers in the gingival tissue were analyzed by reverse transcriptase-quantitative PCR, Western blotting, or ELISA. Infected animals treated with the 15d-PGJ(2)-NC presented lower bone resorption than infected animals without treatment (p < 0.05). Furthermore, infected animals treated with 10 μg/kg 15d-PGJ(2)-NC had a reduction of CD4(+)CD25(+)FOXP3(+) cells and CD4/CD8 ratio in the submandibular lymph node (p < 0.05). Moreover, CD55 was upregulated, whereas RANKL was downregulated in the gingival tissue of the 10 μg/kg treated group (p < 0.05). Several proinflammatory cytokines were decreased in the group treated with 10 μg/kg 15d-PGJ(2)-NC, and high amounts of 15d-PGJ(2) were observed in the gingiva. In conclusion, the 15d-PGJ(2)-NC formulation presented immunomodulatory effects, decreasing bone resorption and inflammatory responses in a periodontitis mouse model.

Topics: Actinobacillus Infections; Aggregatibacter actinomycetemcomitans; Animals; Anti-Inflammatory Agents, Non-Steroidal; Bone Resorption; Disease Models, Animal; Gingiva; Mice; Mice, Inbred BALB C; Mice, Inbred DBA; Nanocapsules; Periodontitis; Prostaglandin D2

Cyclopentenone prostaglandins (CyPGs), such as 15-deoxy-Δ(12,14) -prostaglandin J(2) (15d-PGJ(2)), are active prostaglandin metabolites exerting a variety of biological effects that may be important in the pathogenesis of neurological diseases. Ubiquitin-C-terminal hydrolase L1 (UCH-L1) is a brain specific deubiquitinating enzyme whose aberrant function has been linked to neurodegenerative disorders. We report that [15d-PGJ(2)] detected by quadrapole mass spectrometry (MS) increases in rat brain after temporary focal ischemia, and that treatment with 15d-PGJ(2) induces accumulation of ubiquitinated proteins and exacerbates cell death in normoxic and hypoxic primary neurons. 15d-PGJ(2) covalently modifies UCH-L1 and inhibits its hydrolase activity. Pharmacologic inhibition of UCH-L1 exacerbates hypoxic neuronal death while transduction with a TAT-UCH-L1 fusion protein protects neurons from hypoxia. These studies indicate that UCH-L1 function is important in hypoxic neuronal death and that excessive production of CyPGs after stroke may exacerbate ischemic injury by modification and inhibition of UCH-L1.

Topics: Animals; Cell Hypoxia; Cells, Cultured; Disease Models, Animal; Hypoxia-Ischemia, Brain; Nerve Degeneration; Prostaglandin D2; Rats; Rats, Sprague-Dawley; Transduction, Genetic; Ubiquitin Thiolesterase

Retinopathy of prematurity (ROP) is a major cause of visual handicap in the pediatric population. To date, this disorder is thought to stem from deficient retinal vascularization. Intriguingly, functional electrophysiological studies in patients with mild or moderate ROP and in the oxygen-induced retinopathy (OIR) model in rats reveal central photoreceptor disruption that overlies modest retinal vessel loss; a paucity of retinal vasculature occurs predominantly at the periphery. Given that choroidal circulation is the major source of oxygen and nutrients to the photoreceptors, the authors set out to investigate whether the choroidal vasculature system may be affected in OIR.. Rat models of OIR treating newborn animals with 80% or 50/10% alternated oxygen level for the first two postnatal weeks were used to mimic ROP in humans. Immunohistology staining and vascular corrosion casts were used to investigate the vessel layout of the eye. To investigate the effect of 15-deoxy-Δ12,14-PGJ(2) (15d-PGJ(2); a nonenzymatic product of prostaglandin D(2)) on endothelial cells, in vitro cell culture and ex vivo choroid explants were employed and intravitreal injections were performed in animals.. The authors herein demonstrate that deficient vascularity occurs not only in the retinal plexus but also in the choroid. This sustained, marked choroidal degeneration is specifically confined to central regions of the retina that present persistent photoreceptor loss and corresponding functional deficits. Moreover, the authors show that 15d-PGJ(2) is a prominent contributor to this choroidal decay.. The authors demonstrate for the first time pronounced, sustained choroidal vascular involution during the development of ROP. Findings also suggest that effective therapeutic strategies to counter ROP should consider choroidal preservation.

Topics: Animals; Animals, Newborn; Blotting, Western; Choroid; Choroid Diseases; Corrosion Casting; Disease Models, Animal; Electroretinography; Endothelium, Vascular; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Humans; Infant, Newborn; Microscopy, Electron, Scanning; Microscopy, Fluorescence; Night Vision; Oxygen; Photoreceptor Cells, Vertebrate; Prostaglandin D2; Rats; Rats, Sprague-Dawley; Retinopathy of Prematurity

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

Growth hormone-releasing peptides (GHRPs) as CD36 selective ligands feature potent anti-atherosclerotic activity that is associated with an upregulation of the peroxisome proliferator-activated receptor gamma (PPARgamma)-liver X receptor alpha (LXRalpha)-ATP-binding cassette (ABC) transporter pathway. However, the mechanism involved in PPARgamma activation in response to CD36 signalling has yet to be determined. Therefore, the present study aims to elucidate the upstream molecular mechanisms through which EP 80317, a selective CD36 ligand, promotes lipid efflux from macrophages through PPARgamma activation.. [3H]-Cholesterol- and [3H]-methylcholine chloride-labelled murine macrophages treated with EP 80317 showed a significant increase in cholesterol and phospholipid efflux to both apolipoprotein A-I and high-density lipoprotein in a CD36-dependent manner. Lipid efflux was associated with enhanced activation of PPARgamma. The signalling pathway by which this CD36 ligand promoted lipid efflux involved an increase in intracellular 15-deoxy-Delta(12,14)-prostaglandin J2 (15d-PGJ2) levels induced by extracellular signal-regulated kinase 1/2 (ERK1/2)-dependent cyclooxygenase-2 (COX-2) expression, leading to PPARgamma activation. In agreement, EP 80317-mediated cholesterol efflux was abrogated by inhibitors of PPARgamma, ERK1/2, and COX-2 as well as ABC transporter inhibitors, whereas a p38 mitogen-activated protein kinase inhibitor had no effect.. These findings suggest a central role for the prostanoid 15d-PGJ2 in PPARgamma activation and the upregulation of the ABC transporter pathway in response to CD36 activation by synthetic GHRPs analogues. The resulting enhanced cholesterol efflux might explain, at least in part, the atheroprotective effect of selective CD36 ligands.

Topics: Animals; Apolipoprotein A-I; Apolipoproteins E; Atherosclerosis; ATP Binding Cassette Transporter 1; ATP Binding Cassette Transporter, Subfamily G, Member 1; ATP-Binding Cassette Transporters; Biological Transport; Cardiovascular Agents; CD36 Antigens; Cell Line; Cholesterol; Cyclooxygenase 2; Disease Models, Animal; Lipoproteins; Lipoproteins, HDL; Macrophages, Peritoneal; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinase Kinases; Oligopeptides; Phospholipids; PPAR gamma; Prostaglandin D2; Signal Transduction; Time Factors

Maternal diabetes is associated with morphological placental abnormalities and foeto-placental impairments. These alterations are linked with a dysregulation of the activity of matrix metalloproteinases (MMPs). We investigated the action of 15deoxyDelta(12,14) prostaglandin J(2) (15dPGJ(2)), a natural ligand of the peroxisome proliferator activated receptor (PPAR) gamma, on MMP-2 and MMP-9 activities and tissue inhibitors of matrix metalloproteinases (TIMP) levels in foetuses and placentas from diabetic rats.. Diabetes was induced in rat neonates by a single streptozotocin administration (90 mg kg(-1) s.c.). At 13.5 days of gestation, foetal and placental homogenates were prepared for the determination of PPARgamma levels (western blot) and 15dPGJ(2) concentration (enzyme-immunoassay), whereas the in vitro effect of 15dPGJ(2) (2 microM) was evaluated on placental and foetal MMPs and TIMP activities (zymography and reverse zymography), nitrate/nitrite concentrations (Griess method) and thiobarbituric acid reactive substances (TBARS).. PPARgamma was increased while 15dPGJ(2) was decreased in placentas and foetuses from diabetic rats. 15dPGJ(2) additions were able to reduce the high activities of MMP-2 and MMP-9 present in diabetic placental tissues. 15dPGJ(2) additions reduced MMP-2 activity in control and diabetic foetuses. TIMP-3 levels were decreased in diabetic placentas and 15dPGJ(2) was able to enhance them to control values. Nitrates/nitrites and TBARS, metabolites of MMPs activators, were increased in the diabetic placenta and reduced by 15dPGJ(2).. This study demonstrates that 15dPGJ(2) is a potent modulator of the balance between MMP activities and TIMP levels, which is needed in the correct formation and function of the placenta and foetal organs.

Topics: Animals; Diabetes Mellitus; Disease Models, Animal; Female; Fetus; Gelatinases; Matrix Metalloproteinases; Nitric Oxide; Placenta; PPAR gamma; Pregnancy; Prostaglandin D2; Rats; Rats, Wistar; Tissue Inhibitor of Metalloproteinases

Phagocytosis is necessary to eliminate the hematoma after intracerebral hemorrhage (ICH); however, release of proinflammatory mediators and free radicals during phagocyte activation is toxic to neighboring cells, leading to secondary brain injury. Promotion of phagocytosis in a timely and efficient manner may limit the toxic effects of persistent blood products on surrounding tissue and may be important for recovery after ICH.. Intrastriatal blood injection in rodents and primary microglia in culture exposed to red blood cells were used to model ICH and to study mechanisms of hematoma resolution and phagocytosis regulation by peroxisome proliferator-activated receptor gamma (PPARgamma) in microglia/macrophages.. Our study demonstrated that the PPARgamma agonist, rosiglitazone, promoted hematoma resolution, decreased neuronal damage, and improved functional recovery in a mouse ICH model. Microglia isolated from murine brains showed more efficient phagocytosis in response to PPARgamma activators. PPARgamma activators significantly increased PPARgamma-regulated gene (catalase and CD36) expression, whereas reducing proinflammatory gene (tumor necrosis factor-alpha, interleukin-1beta, matrix metalloproteinase-9, and inducible nitric oxide synthase) expression, extracellular H(2)O(2) level, and neuronal damage. Phagocytosis by microglia was significantly inhibited by PPARgamma gene knockdown or neutralizing anti-CD36 antibody, whereas it was enhanced by exogenous catalase.. PPARgamma in macrophages acts as an important factor in promoting hematoma absorption and protecting other brain cells from ICH-induced damage.

Topics: Animals; Animals, Newborn; CD36 Antigens; Cells, Cultured; Cerebral Hemorrhage; Cytokines; Disease Models, Animal; Enzyme Activators; Erythrocytes; Hematoma; Hydrogen Peroxide; Male; Mice; Mice, Inbred C57BL; Microglia; Neurons; Nitric Oxide Synthase Type II; Phagocytosis; PPAR gamma; Prostaglandin D2; Severity of Illness Index; Time Factors

In macrophages, peroxisome proliferator-activated receptor gamma (PPARgamma) has been shown to be important for differentiation, and it serves as a negative regulator of activation. Major trauma/injury causes a dramatic host response that disrupts cellular immune homeostasis and initiates an inflammatory cascade that predisposes the injured host to subsequent infections. In prior studies using a murine trauma model consisting of femur fracture and hemorrhage, splenic macrophages from traumatized mice had significantly enhanced LPS-induced cyclooxygenase enzyme (subtype 2) and iNOS production as well as elevated levels of inflammatory cytokines at 1 week after injury compared with uninjured controls. These up-regulated cellular responses corresponded to increased mortality when animals were challenged with LPS or Candida. In the current study, we used the injury model to determine the effect of treatment of injured mice with the endogenous PPARgamma ligand 15-deoxy-Delta(12-, 14)-PGJ2 (15d-PGJ2). It was found that in vivo 15d-PGJ2 treatment significantly reduced the levels of inflammatory mediators produced by splenic macrophages 7 days after injury. The mechanism of inhibition is dependent on PPARgamma because concomitant treatment of animals with the PPARgamma antagonist GW9662 reversed the inhibitory effect of 15d-PGJ2. Endogenous PPARgamma modulated activation of LPS-induced p38 mitogen-activated protein kinase. Furthermore, treatment of injured mice with 15d-PGJ2 conferred a significant survival advantage after infectious challenge induced by cecal ligation and puncture. Thus, this PPARgamma ligands significantly attenuate the postinjury inflammatory response and improve survival after infectious challenge.

Topics: Animals; Disease Models, Animal; Female; Macrophage Activation; Macrophages; Mice; Mice, Inbred BALB C; PPAR gamma; Prostaglandin D2; Wounds and Injuries

Topics: Acute Disease; Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Proliferation; Chronic Disease; Disease Models, Animal; Gene Expression Regulation; Humans; Inflammation; Lipid Metabolism; Lipids; Lymphocytes; Mice; Models, Biological; Peritonitis; Prostaglandin D2; Time Factors

Clinical and animal studies indicate that stress can contribute to the onset and/or the worsening of the course of inflammatory bowel diseases (IBD). In a model (inmobilisation stress for 6 h.) in rats it has been demonstrated that stress increases colonic inflammatory damage, as well as antiinflammatory prostaglandins and of the nuclear receptor PPARgamma. This inflammation is followed by an increase in the permeability of the colonic mucosa barrier and a decrease in IgA levels. All these parameters contribute to the bacterial traslocation to other organs. PPARgamma agonists drugs prevent these inflammatory changes as well as the disfunction of the mucosal colonic barrier, which suggests its use in the worsening episodes of IBD produced by stress.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Bacterial Translocation; Colitis, Ulcerative; Disease Models, Animal; Humans; Immobilization; Immunoglobulin A; Inflammatory Bowel Diseases; PPAR gamma; Prostaglandin D2; Prostaglandins; Rats; Rosiglitazone; Stress, Psychological; Thiazolidinediones; Time Factors

In both type 2 diabetes and insulin-resistance syndromes, hyperglycemia and advanced glycation end products (AGEs) activate the transcription factor nuclear factor-kappaB (NF-kappaB) through a mechanism that partly involves the generation of reactive oxygen species (ROS). The contribution of hyperinsulinemia in this sequence has not been completely elucidated. In this work we investigated the actions of insulin and PPAR-gamma on the stimulation by AGEs of NF-kappaB protein expression in cultured aortic vascular smooth-muscle cells (VSMCs) from non-insulin-dependent diabetic rats and nondiabetic rats. The expression of proteins was evaluated with the use of Western immunoblotting. Incubations (24 hours) of VSMCs with 10 to 100 microg/mL glycated bovine serum albumin (AGE- BSA) increased NF-kappaB protein expression in both models. PPAR-gamma protein expression was only enhanced at concentrations of 500 to 1000 microg/mL (AGE-BSA). In the presence of insulin (10-100 nmol/L), the stimulation of NF-kappaB protein expression by AGE-BSA (100 microg/mL) was decreased, whereas the expression of PPAR-gamma, protein was enhanced. 15-Deoxyprostaglandin J2, a direct activator of PPAR-gamma, decreased AGE-BSA-stimulated NF-kappaB expression. These findings suggest that insulin decreases the incidence of alterations in VSMCs induced by AGEs through the reduction of NF-kappaB and an increase in PPAR-gamma protein expression (as far as the model could be extrapolated to in vivo situations). These data may help justify current therapeutic approaches involving the use of insulin and PPAR-gamma agonists.

Topics: Animals; Cattle; Diabetes Mellitus, Type 2; Disease Models, Animal; Dose-Response Relationship, Drug; Glycated Serum Albumin; Glycation End Products, Advanced; Glycosylation; Insulin; Male; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; NF-kappa B; PPAR gamma; Prostaglandin D2; Rats; Rats, Wistar; Serum Albumin; Serum Albumin, Bovine