15-deoxy-Δ12,14-prostaglandin J2 relieved acute liver injury by inhibiting macrophage migration inhibitory factor expression via PPARγ in hepatocyte

15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) exhibited potential to alleviate liver inflammation in chronic injury but was less studied in acute injury. Acute liver injury was associated with elevated macrophage migration inhibitory factor (MIF) levels in damaged hepatocytes. This study aimed to investigate the regulatory mechanism of hepatocyte-derived MIF by 15d-PGJ2 and its subsequent impact on acute liver injury. In vivo, mouse models were established by carbon tetrachloride (CCl4) intraperitoneal injection, with or without 15d-PGJ2 administration. 15d-PGJ2 treatment reduced the necrotic areas induced by CCl4. In the same mouse model constructed using enhanced green fluorescent protein (EGFP)-labeled bone marrow (BM) chimeric mice, 15d-PGJ2 reduced CCl4 induced BM-derived macrophage (BMM, EGFP+F4/80+) infiltration and inflammatory cytokine expression. Additionally, 15d-PGJ2 down-regulated liver and serum MIF levels; liver MIF expression was positively correlated with BMM percentage and inflammatory cytokine expression. In vitro, 15d-PGJ2 inhibited Mif expression in hepatocytes. In primary hepatocytes, reactive oxygen species inhibitor (NAC) showed no effect on MIF inhibition by 15d-PGJ2; PPARγ inhibitor (GW9662) abolished 15d-PGJ2 suppressed MIF expression and antagonists (troglitazone, ciglitazone) mimicked its function. In Pparg silenced AML12 cells, the suppression of MIF by 15d-PGJ2 was weakened; 15d-PGJ2 promoted PPARγ activation in AML 12 cells and primary hepatocytes. Furthermore, the conditioned medium of recombinant MIF- and lipopolysaccharide-treated AML12 respectively promoted BMM migration and inflammatory cytokine expression. Conditioned medium of 15d-PGJ2- or siMif-treated injured AML12 suppressed these effects. Collectively, 15d-PGJ2 activated PPARγ to suppress MIF expression in injured hepatocytes, reducing BMM infiltration and pro-inflammatory activation, ultimately alleviating acute liver injury.

The role of peroxisome-proliferator-activating receptor gamma agonists: rosiglitazone and 15-deoxy-delta12,14-prostaglandin J2 in chronic experimental cyclosporine A-induced nephrotoxicity

Cyclosporine A(CsA) is an immunosuppressor frequently used in the transplant surgery and in the treatment of autoimmune diseases. The therapeutic benefits of CsA are often limited by it's main side effect-nephrotoxicity. Mechanisms of chronic CsA- induced renal damage include: activation of renin-angiotensin-aldosterone system, upregulation of transforming growth factor beta (TGF-β), oxidative stress. This study was undertaken to investigate the protective effect of the peroxisome-proliferator-activated receptors gamma (PPARs-γ) agonists: rosiglitazone and 15-deoxy-Δ12,14-prostaglandin J2 (PGDJ2), against CsA-induced kidney injury in male Wistar rats. CsA was administered subcutaneously at a dose of 15 mg/kg/day for 28 days. Both PPAR-γ agonists were given for 28 days 0.5 hour before the administration of CsA. Rosiglitazone was administered orally at a dose of 8 mg/kg/day and PGDJ2 was given intraperitoneally at a dose of 30 μg/kg/day. CsA induced renal failure was evidenced by increased serum levels of urea, uric acid and creatinine. Serum concentrations of GSH and GSSG, lipid peroxidation products as well as NAD+/NADH, NADP+/NADPH and ADP/ATP ratios showed, that CsA induced oxidative stress and evoked an imbalanced red-ox state in the kidney. Light and electron microscope studies showed degenerative changes within renal tubules with damage to their mitochondria, interstitial fibrosis and arteriolopathy. Immunohistochemical expression of profibrotic TGF-β was assessed. The biochemical and morphological changes induced by CsA were limited by administration of both rosiglitazone and PGDJ2. Ultrastructural examination of renal tubular epithelial cells showed marked improvement within mitochondria. Our results indicate that both PPAR-γ agonists used in the experiment may play an important role in protecting against CsA-induced damage in the kidney.

15-deoxy-Δ¹²,¹⁴-prostaglandin J₂ ameliorates endotoxin-induced acute lung injury in rats

BACKGROUND

A proinflammatory milieu emerging in the lung due to neutrophil accumulation and activation is a key in the pathogenesis of acute lung injury (ALI). 15-deoxy-Δ(12, 14)-prostaglandin J2 (15d-PGJ2), one of the terminal products of the cyclooxygenase-2 pathway, is known to be the endogenous ligand of peroxisome proliferator-activated receptor γ (PPAR-γ) with multiple physiological properties. Growing evidence indicates that 15d-PGJ2 has anti-inflammatory, antiproliferative, cytoprotective and pro-resolving effects. We investigated whether 15d-PGJ2 has a protective effect against endotoxin-induced acute lung injury in rats.

METHODS

Twenty-four male Wistar rats were randomly assigned into four groups (n = 6 per group): sham+vehicle group, sham+15d-PGJ2 group, LPS+vehicle group, and LPS+15d-PGJ2 group. The rats were given either lipopolysaccharide (LPS, 6 mg/kg intravenously) or saline, and pretreated with 15d-PGJ2 (0.3 mg/kg intravenously) or its vehicle (dimethyl sulphoxide) 30 minutes before LPS. Histological alterations, wet/dry weight (W/D) ratio and myeloperoxidase (MPO) activity as well as tumor necrosis factor (TNF)-α and cytokine-induced neutrophil chemoattractant-1 (CINC-1) levels were determined in lung tissues four hours after LPS injection. Immunohistochemical analysis for intercellular adhesion molecule-1 (ICAM-1) expression and Western blotting analysis for nuclear factor (NF)-κB p65 translocation and IκBα protein levels were also studied.

RESULTS

15d-PGJ2 pretreatment significantly attenuated LPS-induced lung injury, and reduced the increased W/D ratio, MPO activity, TNF-α, CINC-1 levels, and ICAM-1 expression in the lung. 15d-PGJ2 also suppressed the nuclear NF-κB p65 translocation and increased cytosolic IκBα levels.

CONCLUSIONS

15d-PGJ2 protects against endotoxin-induced acute lung injury, most likely through the reduction of proinflammatory protein levels during endotoxemia subsequent to the inhibition of NF-κB activation.

PGJ(2) provides prolonged CNS stroke protection by reducing white matter edema

Few clinically effective approaches reduce CNS-white matter injury. After early in-vivo white matter infarct, NFκB-driven pro-inflammatory signals can amplify a relatively small amount of vascular damage, resulting in progressive endothelial dysfunction to create a severe ischemic lesion. This process can be minimized by 15-deoxy-Δ(12,14)-prostaglandin J2 (PGJ(2)), an analog of the metabolically active PGD(2) metabolite. We evaluated PGJ(2)'s effects and mechanisms using rodent anterior ischemic optic neuropathy (rAION); an in vivo white matter ischemia model. PGJ(2) administration systemically administered either acutely or 5 hours post-insult results in significant neuroprotection, with stereologic evaluation showing improved neuronal survival 30 days post-infarct. Quantitative capillary vascular analysis reveals that PGJ(2) improves perfusion at 1 day post-infarct by reducing tissue edema. Our results suggest that PGJ(2) acts by reducing NFκB signaling through preventing p65 nuclear localization and inhibiting inflammatory gene expression. Importantly, PGJ(2) showed no in vivo toxicity structurally as measured by optic nerve (ON) myelin thickness, functionally by ON-compound action potentials, on a cellular basis by oligodendrocyte precursor survival or changes in ON-myelin gene expression. PGJ(2) may be a clinically useful neuroprotective agent for ON and other CNS infarcts involving white matter, with mechanisms of action enabling effective treatment beyond the currently considered maximal time for intervention.

15-Deoxy-Δ¹²,¹⁴ prostaglandin J₂ reduces the formation of atherosclerotic lesions in apolipoprotein E knockout mice

Aim

15-Deoxy-Δ^12,14 Prostaglandin J₂ (15d-PGJ₂) is a ligand of peroxisome proliferator-activated receptor γ (PPARγ) having diverse effects such as the differentiation of adipocytes and atherosclerotic lesion formation. 15d-PGJ₂ can also regulate the expression of inflammatory mediators on immune cells independent of PPARγ. We investigated the antiatherogenic effect of 15d-PGJ₂.

Methods

We fed apolipoprotein (apo) E-deficient female mice a Western-type diet from 8 to 16 wk of age and administered 1 mg/kg/day 15d-PGJ₂ intraperitoneally. We measured atherosclerotic lesions at the aortic root, and examined the expression of macrophage and inflammatory atherosclerotic molecules by immunohistochemical and real-time PCR in the lesion.

Results

Atherosclerotic lesion formation was reduced in apo E-null mice treated with 15d-PGJ₂, as compared to in the controls. Immunohistochemical and real-time PCR analyses showed that the expression of MCP-1, TNF-α, and MMP-9 in atherosclerotic lesions was significantly decreased in 15d-PGJ₂ treated mice. The 15d-PGJ₂ also reduced the expression of macrophages and RelA mRNA in atherosclerotic lesions.

Conclusion

This is the first report 15d-PGJ₂, a natural PPARγ agonist, can improve atherosclerotic lesions in vivo. 15d-PGJ₂ may be a beneficial therapeutic agent for atherosclerosis.

Dual functions of prostaglandin D2 in murine contact hypersensitivity via DP and CRTH2

Prostaglandin D2 (PGD2) exerts its effects through two distinct receptors: the chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) and the D prostanoid (DP) receptor. Our previous study demonstrated that CRTH2 mediates contact hypersensitivity (CHS) in mice. However, the function of DP receptor remains to be fully established. In this study, we examine the pathophysiological roles of PGD2 using DP-deficient (DP(-/-)) and CRTH2/DP-deficient (CRTH2(-/-)/DP(-/-)) mice to elucidate receptor-mediated PGD2 action in CHS. We observed profound exacerbation of CHS in DP(-/-) mice. CRTH2(-/-)/DP(-/-) mice showed similar exacerbation, but to a lesser extent. These symptoms were accompanied by increased production of interferon-γ and IL-17. The increase in IL-17 producing γδ T cells was marked and presumably contributed to the enhanced CHS. DP deficiency promoted the in vivo migration of dendritic cells to regional lymph nodes. A DP agonist added to DCs in vitro was able to inhibit production of IL-12 and IL-1β. Interestingly, production of IL-10 in dendritic cells was elevated via the DP pathway, but it was lowered by the CRTH2 pathway. Collectively, PGD2 signals through CRTH2 to mediate CHS inflammation, and conversely, DP signals to exert inhibitory effects on CHS. Thus, we report opposing functions for PGD2 that depend on receptor usage in allergic reactions.

15-deoxy-D12,14-prostaglandin J2 suppresses RANTES expression by inhibiting NADPH oxidase activation in Helicobacter pylori-infected gastric epithelial cells

Peroxisome proliferators-activated receptor-γ (PPAR-γ) is a ligand-activated transcription factor. 15 deoxy-(12,14) prostaglandin J(2) (15d-PGJ(2)) is a potent PPAR-γ ligand and acts as an anti-inflammatory agent via PPAR-γ-dependent and independent mechanisms. Helicobacter pylori (H. pylori) induces gastric inflammation by inducing the activation of oxidant-sensitive transcription factor NF-κB and cytokine expression in gastric epithelial cells. Since 15d-PGJ(2) inhibits NF-κB activation in various cells, it may suppress H. pylori-induced inflammatory signaling and cytokine expression in gastric epithelial cells. The present study aims to determined the effect of 15d-PGJ(2) on the activation of inflammatory mediators Jak/Stat (Janus kinase/signal transducers and activators of transcription) and induction of cytokine RANTES in H. pylori-infected gastric epithelial AGS cells. Since NADPH oxidase is a candidate for the production of reactive oxygen species in H. pylori-infected gastric epithelial cells, we determined the effect of 15d-PGJ(2) on the activation of NADPH oxdase. AGS cells were cultured in the presence of H. pylori treated with or without 15d-PGJ(2). The activations of NADPH oxidase and Jak1/Stat3, the levels of H(2)O(2) and RANTES in the medium, and DNA binding activity of Stat3 were assessed. A Jak/Stat3 specific inhibitor AG490 and an inhibitor of NADPH oxidase diphenyleneiodonium (DPI) were treated to determine the direct involvement of Jak/Stat and NADPH oxidase on the production of H(2)O(2) and RANTES in H. pylori-infected cells. H. pylori induced the production of H(2)O(2) and RANTES as well as the activations of NADPH oxidase and Jak1/Stat3, which were inhibited by the treatment of 15d-PGJ(2). DPI suppressed H. pylori-induced alterations similar to 15d-PGJ(2). However, AG490 had no effect on NADPH oxidase activation, but reduced the level of RANTES in the medium released from H. pylori-infected cells.

CONCLUSION

NADPH oxidase activation is an upstream signaling of Jak1/Stat3 activation and induction of RANTES in H. pylori-infected AGS cells. 15d-PGJ(2), inhibits the activations of NADPH oxidase and Jak1/Stat3 and RANTES expression, suggesting that 15d-PGJ(2) may be beneficial for the treatment of H. pylori-induced gastric inflammation.

Select cyclopentenone prostaglandins trigger glutathione efflux and the role of ABCG2 transport

Electrophilic cyclopentenone prostaglandins (cyPGs), such as 15-deoxy-Delta(12,14)-prostaglandin J(2) (15dPGJ(2)), initiate redox-based cell signaling responses including increased intracellular glutathione (GSH) synthesis. We investigated whether cyPGs facilitated GSH efflux and if members of the ATP-binding cassette (ABC) protein family mediated the efflux. Four human cell lines were treated with 1-6 microM cyPGs for 48 h. Media and cells were harvested for GSH measurements using HPLC-EC. CyPG treatment increased extracellular GSH levels two- to threefold over controls in HN4 and C38 cells and five- to sixfold in SAEC and MDA 1586 cells and was dependent on increased GSH synthesis. Our studies show that prostaglandin D(2) and its metabolites, prostaglandin J(2) and 15dPGJ(2), specifically induce GSH efflux compared to other eicosanoids. These higher extracellular GSH levels were associated with protection from tert-butylhydroperoxide. Superarray analysis of ABC transporters suggested only ABCG2 expression had a positive relationship in the four cell types compared with extracellular GSH increases after cyPG treatment. The ABCG2 substrate Hoechst 33342 inhibited extracellular GSH increase after 15dPGJ(2) treatment. We report for the first time that ABCG2 may play a role in GSH efflux in response to cyPG treatment and may link inflammatory signaling with antioxidant adaptive responses.

The cyclopentenone 15-deoxy-delta 12,14-prostaglandin J(2) delays lipopolysaccharide-induced preterm delivery and reduces mortality in the newborn mouse

Intrauterine infection is a common trigger for preterm birth and is also a risk factor for the subsequent development of neurodevelopmental abnormalities in the neonate. Bacterial lipopolysaccharide (LPS) binds to toll-like receptor-4 (TLR-4) to activate proinflammatory signaling pathways, which are implicated in both preterm delivery and antenatal brain injury. The transcription factor nuclear factor-kappaB (NF-kappaB) is a key player in the orchestration of the inflammatory response and has a central role in parturition. Here we show that intrauterine administration of TLR-4-specific LPS to pregnant mice results in the activation of NF-kappaB in the maternal uterus and the fetal brain, up-regulation of proinflammatory proteins cyclooxygenase-2, chemokine ligand 1, ChemoKine (C-C motif) ligand 2, and cytosolic phospholipase A(2) in myometrium, and induction of preterm delivery. 15-Deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) is an antiinflammatory prostaglandin that plays a role in promoting the resolution of inflammation. We report that coadministration of 15d-PGJ(2) and LPS to pregnant mice delays LPS-induced preterm delivery and confers protection from LPS-induced fetal mortality. This is associated with inhibition of myometrial NF-kappaB, cytosolic phospholipase A(2), and c-Jun N-terminal kinase activation, and of inflammatory protein synthesis. Therefore 15d-PGJ(2) has anti-inflammatory effects via inhibition of multiple aspects of inflammation-driven TRL-4 signaling pathway. Thus, 15d-PGJ(2) or compounds with similar antiinflammatory functions may have potential as therapeutic agents in the management of preterm labor with the added advantage of preventing detrimental effects to the fetus that may result from infection/inflammation.

15-Deoxy-delta 12,14-prostaglandin J2 (15d-PGJ 2) sensitizes human leukemic HL-60 cells to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis through Akt downregulation

While tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a promising new agent for the treatment of cancer, resistance to TRAIL remains a therapeutic challenge. Identifying agents to use in combination with TRAIL to enhance apoptosis in leukemia cells would increase the potential utility of this agent as a therapy for leukemia. Here, we show that 15-deoxy-Delta(12,14)-prostaglandin J2 (15d-PGJ2), a natural ligand for peroxisome proliferator-activated receptor gamma (PPARgamma), can sensitize TRAIL-resistant leukemic HL-60 cells to TRAIL-induced apoptosis. The sensitization to TRAIL-induced apoptosis by 15d-PGJ2 was not blocked by a PPARgamma inhibitor (GW9662), suggesting a PPARgamma-independent mechanism. This process was accompanied by activation of caspase-8, caspase-9, and caspase-3 and was concomitant with Bid and PARP cleavage. We observed significant decreases in XIAP, Bcl-2, and c-FLIP after cotreatment with 15d-PGJ2 and TRAIL. We also observed the inhibition of Akt expression and phosphorylation by cotreatment with 15d-PGJ2 and TRAIL. Furthermore, inactivation of Akt by Akt inhibitor IV sensitized human leukemic HL-60 cells to TRAIL, indicating a key role for Akt inhibition in these events. Taken together, these findings indicate that 15d-PGJ2 may augment TRAIL-induced apoptosis in human leukemia cells by down-regulating the expression and phosphorylation of Akt.

Induction and function of lipocalin prostaglandin D synthase in host immunity

Although mainly expressed in neuronal cells, lipocalin-type PGD synthase (L-PGDS) is detected in the macrophages infiltrated to atherosclerotic plaques. However, the regulation and significance of L-PGDS expression in macrophages are unknown. Here, we found that treatment of macrophages with bacterial endotoxin (LPS) or Pseudomonas induced L-PGDS expression. Epigenetic suppression of L-PGDS expression in macrophages blunted a majority of PGD(2) produced after LPS treatment. Chromatin immunoprecipitation assays show that L-PGDS induction was regulated positively by AP-1, but negatively by p53. L-PGDS expression was detected in whole lung and alveolar macrophages treated with LPS or Pseudomonas. L-PGDS overexpressing transgenic mice improved clearance of Pseudomonas from the lung compared with nontransgenic mice. Similarly, intratracheal instillation of PGD(2) enhanced removal of Pseudomonas from the lung in mice. In contrast, L-PGDS knockout mice were impaired in their ability to remove Pseudomonas from the lung. Together, our results identify induction of L-PGDS expression by inflammatory stimuli or bacterial infection, the regulatory mechanism of L-PGDS induction, and the protective role of L-PGDS expression in host immune response. Our study suggests a potential therapeutic usage of L-PGDS or PGD(2) against Pseudomonas pneumonia.

THE PPARγ LIGAND 15d-PGJ2 MODULATES MACROPHAGE ACTIVATION AFTER INJURY IN A MURINE TRAUMA MODEL

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.

Anti-inflammatory effects of PPAR-gamma agonists directly correlate with PPAR-gamma expression during acute pancreatitis

Peroxisome proliferator-activated receptors (PPARs) are ligand-inducible transcription factors that regulate cellular energy and lipid metabolism. PPAR-gamma agonists also have potent anti-inflammatory properties through down-regulation of early inflammatory response genes. The role of PPAR-gamma in acute pancreatitis has not been adequately examined. In this study, we determined the effect of PPAR-gamma agonists on the severity of pancreatitis and sought to correlate PPAR-gamma expression in pancreatic acinar cells and the severity of acute pancreatitis in vivo. Acute pancreatitis was induced in mice by hyperstimulation with the cholecystokinin analog, cerulein. PPAR-gamma agonists were administered by intraperitoneal injection 15-30 minutes before induction of pancreatitis (pretreatment) or at various times after induction of pancreatitis (treatment). Pancreata and serum were harvested over the course of 24 hours. Serum amylase activity and glucose levels were measured. Pancreata were used for histological evaluation as well as protein and mRNA analysis. Pretreatment of mice with the PPAR-gamma agonists 15-deoxy-Delta12, 14-prostaglandin J(2), or troglitazone significantly reduced the severity of pancreatitis in a dose-dependent manner. This reduction was indicated by reduced serum amylase activity and histological damage (leukocyte infiltration, vacuolization, and necrosis). Although cerulein decreased PPAR-gamma expression in the pancreas, pretreatment with agonists maintained PPAR-gamma expression early in acute pancreatitis. The expression of PPAR-gamma inversely correlated with pancreatitis severity and expression of the proinflammatory cytokines, interleukin-6, and tumor necrosis factor-alpha. Treatment with troglitazone after the induction of pancreatitis reduced serum amylase activity. The results suggest that PPAR-gamma plays a direct role in the inflammatory cascade during the early events of acute pancreatitis. Our data are the first to demonstrate that PPAR-gamma agonists represent a promising therapeutic strategy for acute pancreatitis.

15-Deoxy-Δ12,14-prostaglandin J2 induces death receptor 5 expression through mRNA stabilization independently of PPARγ and potentiates TRAIL-induced apoptosis

15-Deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)), the terminal derivative of the PGJ series, is emerging as a potent antineoplastic agent among cyclopentenone prostaglandins derivatives and also known as the endogenous ligand of peroxisome proliferator-activated receptor gamma (PPARgamma). On the other hand, death receptor 5 (DR5) is a specific receptor for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which is one of the most promising candidates for new cancer therapeutics. Here, we report that 15d-PGJ(2) induces DR5 expression at both mRNA and protein levels, resulting in the synergistic sensitization of TRAIL-induced apoptosis in human neoplastic cells, such as Jurkat human leukemia cells or PC3 human prostate cancer cells. 15d-PGJ(2) significantly increased DR5 mRNA stability, whereas it did not activate DR5 promoter activity. Synthetic PPARgamma agonists, such as pioglitazone or rosiglitazone, did not mimic the DR5-inducing effects of 15d-PGJ(2), and a potent PPARgamma inhibitor GW9662 failed to block DR5 induction by 15d-PGJ(2), suggesting PPARgamma-independent mechanisms. Cotreatment with 15d-PGJ(2) and TRAIL enhanced the sequential activation of caspase-8, caspase-10, caspase-9, caspase-3, and Bid. DR5/Fc chimera protein, zVAD-fmk pancaspase inhibitor, and caspase-8 inhibitor efficiently blocked the activation of these apoptotic signal mediators and the induction of apoptotic cell death enhanced by cotreatment with 15d-PGJ(2) and TRAIL. Moreover, a double-stranded small interfering RNA targeting DR5 gene, which suppressed DR5 up-regulation by 15d-PGJ(2), significantly attenuated apoptosis induced by cotreatment with 15d-PGJ(2) and TRAIL. These results suggest that 15d-PGJ(2) is a potent sensitizer of TRAIL-mediated cancer therapeutics through DR5 up-regulation.

Peroxisome proliferator-activated receptors and acute lung injury

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.

PPARgamma-independent induction of growth arrest and apoptosis in prostate and bladder carcinoma

Background

Although PPARγ antagonists have shown considerable pre-clinical efficacy, recent studies suggest PPARγ ligands induce PPARγ-independent effects. There is a need to better define such effects to permit rational utilization of these agents.

Methods

We have studied the effects of a range of endogenous and synthetic PPARγ ligands on proliferation, growth arrest (FACS analysis) and apoptosis (caspase-3/7 activation and DNA fragmentation) in multiple prostate carcinoma cell lines (DU145, PC-3 and LNCaP) and in a series of cell lines modelling metastatic transitional cell carcinoma of the bladder (TSU-Pr1, TSU-Pr1-B1 and TSU-Pr1-B2).

Results

15-deoxy-prostaglandin J₂ (15dPGJ2), troglitazone (TGZ) and to a lesser extent ciglitazone exhibited inhibitory effects on cell number; the selective PPARγ antagonist GW9662 did not reverse these effects. Rosiglitazone and pioglitazone had no effect on proliferation. In addition, TGZ induced G0/G1 growth arrest whilst 15dPGJ2 induced apoptosis.

Conclusion

Troglitazone and 15dPGJ2 inhibit growth of prostate and bladder carcinoma cell lines through different mechanisms and the effects of both agents are PPARγ-independent.

15-Deoxy-Δ12,14-prostaglandin J2 attenuates development of cyclophosphamide-induced cystitis in rats

OBJECTIVES

To investigate whether an endogenous prostaglandin (PG) D2 metabolite, 15-deoxy-Delta12,14-PGJ2 (15d-PGJ2), can attenuate cyclophosphamide (CYP)-induced cystitis in the rat.

METHODS

Male Sprague-Dawley rats received a single intraperitoneal injection of CYP (200 mg/kg). In a separate group of animals, 15d-PGJ2 (10 and 100 microg/kg intraperitoneal bolus 10 minutes before and 24 hours after CYP injection) or a selective inducible nitric oxide synthase (iNOS) inhibitor, N-(3-(aminomethyl)benzyl)acetamidine ([1400W] 10 mg/kg intraperitoneal bolus 10 minutes before and 12 and 24 hours after CYP injection), was administered. At 48 hours after CYP injection, the rats were killed, and tissues were removed for evaluation of cystitis.

RESULTS

CYP injection resulted in severe cystitis. 15d-PGJ2, as well as 1400W, significantly reduced the increase in plasma protein extravasation (Evans blue dye method), iNOS enzymatic activity, urinary excretion of nitric oxide metabolites, and myeloperoxidase activity in the bladder caused by CYP. Moreover, 15d-PGJ2 significantly decreased the cytokine interleukin-1beta in the bladder. In addition, 15d-PGJ2 significantly reduced the degree of CYP-induced bladder tissue damage and increase in immunohistochemical staining for iNOS in the bladder.

CONCLUSIONS

These results indicate that 15d-PGJ2 can attenuate the development of CYP-induced cystitis by suppression of cytokine production and iNOS induction. Thus, treatment with cyclopentenone prostaglandins such as 15d-PGJ2 may be effective against CYP-induced cystitis.

[Stress and inflammatory bowell disease (I.B.D). Therapeutic strategies]

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.

A PPAR-gamma ligand, 15-deoxy-Delta12,14-prostaglandin J(2), inhibited gastric mucosal injury induced by ischemia-reperfusion in rats

INTRODUCTION

Recent studies have demonstrated the anti-inflammatory action of 15-deoxy-Delta12,14-prostaglandin J(2) (15d-PGJ(2)), a derivative of the PGD(2) metabolic pathway. Acute inflammation, including neutrophil activation, plays a critical role in the pathogenesis of ischemia-reperfusion (I/R). The aim of the present study was to determine the effect of 15d-PGJ(2) on I/R-induced gastric mucosal injury in rats.

METHODS

Gastric mucosal damage was induced in male Wistar rats by clamping the celiac artery for 30 min followed by reperfusion. 15d-PGJ(2) (0.01-1.0 mg/kg) was given to the rats intraperitoneally 1 h before the vascular clamping. The area of gastric mucosal erosions (erosion index) was measured. Thiobarbituric acid reactive substances (TBARS) and tissue-associated myeloperoxidase (MPO) activity were measured in the gastric mucosa as indices of lipid peroxidation and neutrophil infiltration. The expression of tumor necrosis factor-alpha (TNF-alpha) in gastric mucosa was measured by ELISA. In addition, to elucidate whether the protective effects of 15d-PGJ(2) are related to the activation of the PPAR-gamma receptor, we also investigated the effects of a PPAR-gamma antagonist, GW9662.

RESULTS

After 60 min of reperfusion, the area of gastric erosion index had significantly increased from the mean basal levels. The increase in the erosion index was significantly inhibited by pretreatment with 15d-PGJ(2) in a dose-dependent manner. On the other hand, GW9662 reversed the protective effect of 15d-PGJ(2). The concentration of TBARS and MPO activity in the gastric mucosa were both significantly increased after I/R, and pretreatment with 15d-PGJ(2) significantly reduced these increases. The TNF-alpha content was significantly higher in the I/R group than in the sham-operated group. However, the increase in TNF-alpha was significantly inhibited by pretreatment with 15d-PGJ(2).

CONCLUSIONS

15d-PGJ(2) significantly inhibited the severity of acute gastric mucosal injury induced by I/R in rats through PPAR-gamma-dependent mechanisms. This effect may be due, in part, to a reduction in the infiltration of neutrophils into the gastric mucosa, possibly via the inhibition of inflammatory cytokine.

15-DEOXY-??12,14-PROSTAGLANDIN J2 (15D-PGJ2), A PEROXISOME PROLIFERATOR ACTIVATED RECEPTOR ?? LIGAND, REDUCES TISSUE LEUKOSEQUESTRATION AND MORTALITY IN ENDOTOXIC SHOCK

Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a nuclear receptor that requires ligand activation for transcription. Experimental studies have shown that 15-deoxy-Delta-PGJ2 (15d-PGJ2) is a natural PPARgamma ligand which has potent anti-inflammatory properties. This study was designed to examine the effect and the molecular mechanisms of 15d-PGJ2 on tissue neutrophil infiltration and survival in endotoxic shock. Male Swiss albino mice were subjected to intraperitoneal injection of Escherichia coli lipopolysaccharide (LPS, 25 mg/kg). Three hours after LPS mice received vehicle or 15d-PGJ2 (1 mg/kg) and continued treatment every 12 hours. Survival was monitored for 72 hours. In a separate experiment, mice were sacrificed 6 hours after LPS and tissue examined. In vehicle-treated mice, LPS injection resulted in a survival rate of 9%. Marked lung injury was characterized by hemorrhage, infiltration of inflammatory cells and reduction of alveolar space. Elevated levels of myeloperoxidase activity in lung and small intestine were indicative of infiltration of neutrophils. Increased expression of intercellular adhesion molecule-1, vascular cellular adhesion molecule-1 and E-selectin were observed in the lung and small intestine. These inflammatory events were associated with reduced expression of PPARgamma and with activation of nuclear factor-kappaB (NF-kappaB) in the lung. Treatment with 15d-PGJ2 improved survival rate to 55%, downregulated expression of adhesion molecules and reduced neutrophil infiltration in tissues. These beneficial effects were associated with reduced activation of NF-kappaB DNA binding, whereas expression and DNA binding of PPARgamma and expression of the cytoprotective heat shock protein (HSP) 70 were increased in the lung. Our data demonstrate that 15d-PGJ2 ameliorates endotoxic shock most likely through repressing the proinflammatory pathway of NF-kappaB and enhancement of the cytoprotective heat shock response.

Peroxisome proliferator activated receptor-γ ligands induced cell growth inhibition and its influence on matrix metalloproteinase activity in human myeloid leukemia cells

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is one of the best characterized nuclear hormone receptors (NHRs) in the superfamily of ligand-activated transcriptional factors. PPAR-gamma ligands have recently been demonstrated to affect proliferation, differentiation and apoptosis of different cell types. The present study was undertaken to investigate PPAR-gamma ligands induced cell growth inhibition and its influence on matrix metalloproteinase MMP-9 and MMP-2 activities on leukemia K562 and HL-60 cells in vitro. The results revealed that PPAR-gamma expression was detectable in the two kinds of leukemia cells; Both 15-deoxy-delta(12,14)-prostaglandin J2(15d-PGJ2) and troglitazone (TGZ) have significant growth inhibition effects on these two kinds of leukemia cells. These two PPAR-gamma ligands could inhibit the leukemic cell adhesion to the extracellular matrix (ECM) proteins and the invasion through matrigel matrix. The expressions of MMP-9 and MMP-2 as well as their gelatinolytic activities in both HL-60 and K562 cells were inhibited by 15d-PGJ2 and TGZ significantly. We therefore conclude that PPAR-gamma ligands 15d-PGJ2 and TGZ have significant growth inhibition effects on myeloid leukemia cells in vitro, and that PPAR-gamma ligands can inhibit K562 and HL-60 cell adhesion to and invasion through ECM as well as downregulate MMP-9 and MMP-2 expressions. The data suggest that PPAR-gamma ligands may serve as potential anti-leukemia reagents.

Cardioprotective effects of peroxisome proliferator activated receptor gamma activators on acute myocarditis: anti-inflammatory actions associated with nuclear factor kappaB blockade

OBJECTIVE

To test the hypothesis that activation of peroxisome proliferator activated receptor gamma (PPAR-gamma) reduces experimental autoimmune myocarditis (EAM) associated with inhibitor kappaB (IkappaB) alpha induction, blockade of nuclear factor kappaB (NF-kappaB), and inhibition of inflammatory cytokine expression.

METHODS

EAM was induced in Lewis rats by immunisation with porcine cardiac myosin. PPAR-gamma activators 15-deoxy-Delta(12,14)-prostaglandin J2 (15d-PGJ2) and pioglitazone (PIO) were administered to rats with EAM.

RESULTS

Enhanced PPAR-gamma expression was prominently stained in the nuclear and perinuclear regions of infiltrating inflammatory cells. Administration of 15d-PGJ2 and PIO greatly reduced the severity of myocarditis and suppressed myocardial mRNA and protein expression of inflammatory cytokines in rats with EAM. In addition, treatment with PPAR-gamma activators enhanced IkappaB concentrations in the cytoplasmic fractions and nuclear fractions from inflammatory myocardium. Concurrently, NF-kappaB was greatly activated in myocarditis; this activation was blocked in the 15d-PGJ2 treated and PIO treated groups.

CONCLUSIONS

PPAR-gamma may have a role in the pathophysiology of EAM. Because an increase in IkappaB expression and inhibition of translocation of the NF-kappaB subunit p65 to the nucleus in inflammatory cells correlated with the protective effects of PPAR-gamma activators, these results suggest that PPAR-gamma activators act sequentially through PPAR-gamma activation, IkappaB induction, blockade of NF-kappaB activation, and inhibition of inflammatory cytokine expression. These results suggest that PPAR-gamma activators such as 15d-PGJ2 and PIO may have the potential to modulate human inflammatory heart diseases such as myocarditis.

Ligands for peroxisome proliferator-activated receptor gamma have potent antitumor effect against human renal cell carcinoma

OBJECTIVES

To examine whether peroxisome proliferator-activated receptor gamma (PPARgamma) is expressed in human renal cell carcinoma (RCC) cells, and whether activation of PPARgamma by its ligands can have multiple antitumor effects on human RCC cells in vitro.

METHODS

We examined the expression of PPARgamma in four human RCC cell lines by reverse transcriptase-polymerase chain reaction and immunocytochemical staining. The effects of two PPARgamma ligands, pioglitazone and 15-deoxy-Delta12,14-prostaglandin J2, on cell proliferation were investigated by 3-[4,5-dimethylthiazol-2-thiazoly]-2,5-diphenyltetrazolium bromide assay. The induction of apoptosis by the ligands was examined using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling method and Annexin V assay. Furthermore, we investigated whether these ligands suppressed the production of angiogenic factors, vascular endothelial growth factor and basic fibroblast growth factor, by enzyme-linked immunosorbent assay.

RESULTS

PPARgamma and retinoid X receptor, which forms a heterodimer with PPARgamma, were expressed in all RCC cell lines. In addition, immunocytochemical studies showed expression of PPARgamma protein in the RCC cells. PPARgamma ligands inhibited the cell growth in all cells in a dose-dependent manner. These ligands also induced apoptosis. Furthermore, secretion of both vascular endothelial growth factor and basic fibroblast growth factor was inhibited by these ligands in a dose-dependent and time-dependent manner.

CONCLUSIONS

Ligands for PPARgamma have multiple antitumor effects in human RCC cells in vitro. Activation of the PPARgamma pathway may be a new strategy for treatment of patients with RCC.

15d-prostaglandin J2 reduces multiple organ failure caused by wall-fragment of Gram-positive and Gram-negative bacteria

Septic shock is still the major cause of death in surgical intensive care units. Both gram-positive (G+) and gram-negative (G-) bacteria have been isolated in the blood of a large portion of septic patients, and these polymicrobial infections often have a higher mortality than infections due to a single organism. Cell wall fragments from G+ and G- bacteria synergise to cause shock and multiple organ dysfunction in vivo (G+/G- shock). Male Wistar rats were anaesthetised and received a coadministration of wall fragments from G+ and G- bacteria, Staphilococcus aureus (S. aureus) peptidoglycan [0.3 mg/kg, intravenously (i.v.)] and Escherichia coli (E. coli) lipopolysaccharide (1 mg/kg, i.v.) or vehicle (saline, 1 ml/kg, i.v.). G+/G- shock for 6 h resulted in an increase in serum levels of creatinine (indicator of renal dysfunction), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (gamma-GT), bilirubin (markers for hepatic injury and dysfunction) and creatine kinase (CK, an indicator of neuromuscular, skeletal muscle or cardiac injury). Pretreatment of rats with the peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonist 15d-prostaglandin J2 (0.3 mg/kg, i.v., 30 min prior to G+/G-) reduced the multiple organ injury/dysfunction caused by coadministration of peptidoglycan+lipopolysaccharide. The selective PPAR-gamma antagonist GW9662 (2-Chloro-5-nitrobenzanilide) (1 mg/kg, i.v., given 45 min prior to G+/G-) abolished the protective effects of 15d-prostaglandin J2. 15d- prostaglandin J2 did not affect the biphasic fall in blood pressure or the increase in heart rate caused by administration of peptidoglycan+lipopolysaccharide. The mechanism(s) of the protective effect of this cyclopentenone prostaglandin are-at least in part-PPAR-gamma dependent, as the protection afforded by 15d-prostaglandin J2 was reduced by the PPAR-gamma antagonist GW9662. We propose that 15d-prostaglandin J2 or other ligands for PPAR-gamma may be useful in the therapy of the organ injury associated with septic shock.

Prostaglandin D2 Inhibits IgE-Mediated Scratching by Suppressing Histamine Release From Mast Cells

Effects of prostaglandin (PG) D(2), PGE(2), and PGI(2) on itch-associated scratching responses of mice and histamine release from the rat basophilic leukemia cell line RBL-2H3 were examined. PGD(2) and ketotifen but not PGE(2) and PGI(2) suppressed the scratching caused by ovalbumin injected into ovalbumin-sensitized mice. Ketotifen also suppressed compound 48/80-induced scratching but not PGD(2), PGE(2), and PGI(2). In vitro, PGD(2) suppressed the antigen-induced histamine release from RBL-2H3 cells, but PGE(2) and PGI(2) did not. These findings suggest that PGD(2) specifically suppressed IgE-mediated scratching by inhibiting IgE-mediated histamine release from mast cells.

Differential peroxisome proliferator-activated receptor-gamma isoform expression and agonist effects in normal and malignant prostate cells

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is being studied intensively for its role in carcinogenesis and in mediating the effects of prostate cancer treatment and prevention drugs. Prostate cancers express abundant and higher constitutive levels of PPAR-gamma than do normal prostate cells and are growth inhibited by ligand activation of PPAR-gamma. However, little is known about the role of PPARs in tumorigenesis or in normal prostate epithelial cells (EC). We examined the expression, phosphorylation patterns, and functions of the human PPAR (hPPAR)-gamma1 and hPPAR-gamma2 isoforms in normal prostate ECs to determine if activation of the receptor is sufficient for PPAR-gamma ligand activity in prostate cells. We found that ECs did not express either PPAR-gamma1 or PPAR-gamma2 protein and were not sensitive to growth inhibition by the PPAR-gamma ligand 15-deoxy-Delta12,14-prostaglandin J(2) (15d-PGJ(2)). In contrast, prostate cancer cells (PC-3), which express PPAR-gamma1 receptor isoform, are growth inhibited by PPAR-gamma ligand. Forced expression of hPPAR-gamma1 or hPPAR-gamma2 made ECs sensitive to 15d-PGJ(2) and led to reduced cellular viability. The direct repeat-1 promoter containing PPAR response elements was transactivated in ECs expressing exogenous PPAR-gamma1 or PPAR-gamma2, indicating that either isoform can be active in these cells. 15-Lipoxygenase-2, expressed at high levels in ECs, was down-regulated by transfecting PPAR-gamma expression construct (either gamma1 or gamma2 isoform) into ECs. Addition of PPAR-gamma ligand 15-hydroxyeicosatetraenoic acid in the presence of PPAR-gamma expression caused further down-regulation of 15-lipoxygenase-2. Our data illustrate that a PPAR-gamma ligand (15d-PGJ(2)) activates PPAR-gamma1 and selectively induces cell death in human prostate cancer cells but not in normal prostate ECs. These findings have important implications for the development of PPAR-gamma-targeting agents that prevent or treat prostate cancer and spare normal prostate cells.

Effect of 15-deoxy-delta 12,14-prostaglandin J2 on acute lung injury induced by lipopolysaccharide in mice

15-Deoxy-delta(12,14)-prostaglandin J(2) (15d-prostaglandin J(2)) has received attention for its anti-inflammatory properties. The present study investigated the efficacy of 15d-prostaglandin J(2) on acute lung injury induced by lipopolysaccharide in mice. ICR mice were administered with 15d-prostaglandin J(2) (10 microg/kg, 100 microg/kg, or 1 mg/kg) before intratracheal challenge with lipopolysaccharide (125 microg/kg). Treatment with 15d-prostaglandin J(2) did not ameliorate rather enhanced at a dose of 1 mg/kg the neutrophilic lung inflammation and pulmonary edema by lipopolysaccharide. The enhancement was concomitant with the increased lung expression of interleukin-1 beta, macrophage inflammatory protein-1 alpha, and macrophage chemoattractant protein-1. 15d-prostaglandin J(2) increased the nuclear protein expression of peroxisome proliferator-activated receptor (PPAR)-gamma and inhibited the nuclear localization of nuclear factor-kappa B related to lipopolysaccharide. 15d-prostaglandin J(2) increased the phosphorylation of c-Jun in the presence or absence of lipopolysaccharide. Our data suggest that 15d-prostaglandin J(2) may not be useful but potentially harmful for the therapeutic option of acute lung injury.

The cyclopentenone prostaglandin 15-deoxy-Delta(12,14)-prostaglandin J2 ameliorates ischemic acute renal failure

OBJECTIVE

Here we investigate the effects of the endogenous prostaglandin D2 metabolite 15-deoxy-Delta(12,14)-prostaglandin J2, on the renal dysfunction and injury caused by ischemia/reperfusion of the kidney.

METHODS

Male Wistar rats, subjected to bilateral renal ischemia for 45 min followed by reperfusion for up to 48 h, were administered 15-deoxy-Delta(12,14)-prostaglandin J2 (1 mg/kg, intravenously) 5 min prior to and again after 3 or 12 h reperfusion.

RESULTS

15-deoxy-Delta(12,14)-prostaglandin J2 significantly reduced (i) renal and tubular dysfunction (serum urea and creatinine levels, creatinine clearance, fractional excretion of Na+ (FENA)), (ii) tubular and reperfusion-injury (urinary N-acetyl-beta-D-glucosaminidase, aspartate aminotransferase (ASP) and gamma-glutamyltransferase (gamma-GT)) and (iii) histological evidence of renal injury. 15-deoxy-Delta(12,14)-prostaglandin J2 also improved renal function (plasma creatinine levels) and reduced the histological signs of renal injury (after 48 h reperfusion). Administration of 15-deoxy-Delta(12,14)-prostaglandin J2 markedly reduced the expression of inducible nitric oxide synthase (iNOS) and intercellular adhesion molecule-1 during reperfusion (determined using immunohistochemistry). Immunohistochemical analysis of p65 translocation and Western blot analysis of IkappaB-alpha degradation revealed that 15-deoxy-Delta(12,14)-prostaglandin J2 inhibited the activation of nuclear factor (NF)-kappaB in renal cells. Subsequently, 15d-PGJ2 was able to significantly reduce nitric oxide production during renal ischemia/reperfusion and by primary cultures of rat proximal tubular (PT) cells incubated with interferon-gamma and bacterial lipopolysaccharide (LPS) in combination.

CONCLUSIONS

We demonstrate here, for the first time, that 15-deoxy-Delta(12,14)-prostaglandin J2 significantly reduces renal ischemia/reperfusion-injury via reduction of pro-inflammatory gene expression during reperfusion subsequent to the inhibition of the activation of NF-kappaB.

Role of peroxisome proliferator-activated receptor-gamma in the protection afforded by 15-deoxydelta12,14 prostaglandin J2 against the multiple organ failure caused by endotoxin

OBJECTIVE

The cyclopentenone prostaglandin 15-deoxydelta-prostaglandin J2 (15 d-PGJ2) exerts potent anti-inflammatory effects in vivo, which are in part due to the activation of peroxisome proliferator-activated receptor (PPAR)-gamma. Here we investigate the effects of 15 d-PGJ2 on the multiple organ injury/dysfunction associated with severe endotoxemia.

DESIGN

Prospective, randomized study.

SETTING

University-based research laboratory.

SUBJECTS

Seventy anesthetized male Wistar rats.

INTERVENTIONS

Rats received either Escherichia coli lipopolysaccharide (endotoxin, 6 mg/kg intravenously) or vehicle (saline, 1 mL/kg intravenously). 15 d-PGJ2 (0.3 mg/kg intravenously) or vehicle (10% dimethyl sulfoxide) was administered 30 mins before endotoxin. The selective PPAR-gamma antagonist GW9662 (0.3 mg/kg intravenously) or its vehicle (10% dimethyl sulfoxide) was given 45 mins before endotoxin.

MEASUREMENTS AND MAIN RESULTS

Endotoxemia for 6 hrs increased serum concentrations of creatinine (indicator of renal dysfunction), aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, bilirubin (markers for hepatic injury and dysfunction), lipase (indicator of pancreatic injury), and creatine kinase (an indicator of neuromuscular skeletal muscle or cardiac injury). The potent PPAR-gamma agonist 15 d-PGJ2 attenuated the increases in the serum concentrations of these variables, indicating a protective effect of 15 d-PGJ2 against the multiple organ injury/dysfunction caused by endotoxin. The specific PPAR-gamma antagonist GW9662 reduced the protective effects afforded by 15 d-PGJ2. 15 d-PGJ2 did not affect the biphasic decrease in blood pressure or the increase in heart rate caused by endotoxemia.

CONCLUSIONS

The potent PPAR-gamma agonist 15 d-PGJ2 reduces the multiple organ injury and dysfunction, but not the hypotension, caused by endotoxin in the rat. The mechanisms of the protective effect of this cyclopentenone prostaglandin are--at least in part--PPAR-gamma dependent, as the protection afforded by 15 d-PGJ2 was reduced by the PPAR-gamma antagonist GW9662. We propose that 15 d-PGJ2 or other ligands for PPAR-gamma may be useful in treating organ injury associated with endotoxic shock.

Ligands for the peroxisome proliferator-activated receptor-gamma and the retinoid X receptor exert additive anti-inflammatory effects on experimental autoimmune encephalomyelitis

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a member of the nuclear-receptor superfamily that binds to DNA with retinoid X receptors (RXRs) as PPAR-RXR heterodimers. In experimental autoimmune encephalomyelitis (EAE), the gene expression of PPAR-gamma was demonstrated in spinal cord during the course of EAE. Administration of 15-deoxy-(12,14)-prostaglandin J2 (15d-PGJ2) or 9-cis-retinoic acid (RA) alone at the onset of clinical signs of EAE reduced the severity of disease, however, their combination resulted in enhanced amelioration of disease. These results suggest that use of RXR specific ligands may be highly effective when combined with PPAR-gamma agonists in the treatment of autoimmune demyelinating diseases such as multiple sclerosis (MS).

[Peroxisome proliferation-activated receptor-gamma ligands ameliorate autoimmune myocarditis associated with inhibition of T cell immunity]

OBJECTIVE

To investigate the role of peroxisome proliferator-activated receptor-gamma (PPAR gamma) on autoimmune myocarditis, and to test the hypothesis that PPAR-gamma ligands reduce experimental autoimmune myocarditis (EAM) associated with inhibition of the expansion and activation of self-sensitive T cells.

METHODS

EAM was induced in Lewis rats by immunization with porcine cardiac myosin. Then the rats were divided into 3 groups of 9 rats: PPAR-gamma ligand 15-deoxy-(12,14)-PGJ(2) (15d-PGJ(2)) group (15d-PGJ(2) was injected intraperitoneally at the dosage of 200 microg.kg(-1).d(-1)), pioglitazone (PIO) group (PIO was mixed with the food and than fed at the dosage of 10 mg.kg(-1).d(-1)), and positive control group (phosphate-buffered saline was injected intraperitoneally). Nine normal rats were used as normal controls. Three weeks later, the rats underwent thoracotomy to undergo pathologic examination. The numbers of CD4(+) cells, CD8(+) cells, and macrophages were calculated by microscopy. Immunohistochemistry was used to examine the location and expression of PPAR gamma. Western blotting was used to examine the relative amount of PPAR gamma protein. The proliferative response and the cytotoxicity of T cell-enriched splenocytes and lymph node cells were determined. Another rats were killed 12 days after immunization. Their spleens and lymph nodes were taken out. T-cell rich splenocytes and cells from the lymph nodes were cultured. Cardiac myosin and 15d-PGJ(2) were added. [(3)H] thymine was added 72 hours after. ELISA was used to examine the interferon-gamma (IFN-gamma) in the supernatant. 15d-PGJ(2), PIO, or PBS were given to immunize the rats. The rats were killed 12 days after. The lymph nodes were taken out to make single cell suspension. (51)Cr was used to label the cells so as to calculate the %cytotoxicity.

RESULTS

All immunized rats showed myocarditis. The numbers of CD4(+) cells, CD8(+) T cells, and macrophages, were 18 +/- 5, 7 +/- 2, and 45 +/- 8/six 0.25 mm x 0.25 mm squares. PPAR gamma was mainly located in the nuclear and perinuclear regions of infiltrating inflammatory cells, such as mononuclear cells and macrophage-like cells. The expression of PPAR gamma in the myocardium of EAM rats was 3.7 times higher than of the normal rats. The heart weight/body weight ratio, pericardial effusion scores, macroscopic scores and microscopic scores of the 15d-PGJ group were significantly lower than those of the positive control group. The numbers of CD4(+) cells of the 15d-PGJ and PIO groups were 8 +/- 2 and 10 +/- 3, both significantly lower than that of the positive control group (both P < 0.01), the numbers of CD8(+) cells of the 15d-PGJ and PIO groups were 3 +/- 1 and 4 +/- 2 respectively, both significantly lower than that of the positive control group (P < 0.01 and P < 0.05), and the numbers of macrophages of the 15d-PGJ and PIO groups were 22 +/- 4 and 26 +/- 6 respectively, both significantly lower than that of the positive control group (both P < 0.01). The myocardiogenicity and the severity of myocarditis of the 15d-PGJ(2)- and PIO-groups were at lower degrees compared with those of the positive control group. The % cytotoxic activity was 10.2% +/- 2.6% in the 15d-PGJ(2) group and was 11.6% +/- 3.7% in the PIO group, both significantly lower than that of the positive control group (37.7% +/- 8.4%, both P < 0.01) Stimulated by cardiac myosin, the T-cell rich splenocytes and cells from lymph nodes showed obvious proliferation and production of IFN-gamma. The cardiac myosin-stimulated cell proliferation and production of IFN-gamma in the 15d-PGJ(2) and PIO groups were significantly reduced in comparison with those in the positive control group.

CONCLUSION

PPAR-gamma ligands ameliorate EAM associated with inhibition of expansion and activation of the self-sensitive T cells.

Peroxisome Proliferator Activator Receptor-γ Ligands, 15-Deoxy-Δ12,14-Prostaglandin J2 and Ciglitazone, Reduce Systemic Inflammation in Polymicrobial Sepsis by Modulation of Signal Transduction Pathways

Peroxisome proliferator activator receptor-gamma (PPARgamma) is a nuclear receptor that controls the expression of several genes involved in metabolic homeostasis. We investigated the role of PPARgamma during the inflammatory response in sepsis by the use of the PPARgamma ligands, 15-deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)) and ciglitazone. Polymicrobial sepsis was induced by cecal ligation and puncture in rats and was associated with hypotension, multiple organ failure, and 50% mortality. PPARgamma expression was markedly reduced in lung and thoracic aorta after sepsis. Immunohistochemistry showed positive staining for nitrotyrosine and poly(ADP-ribose) synthetase in thoracic aortas. Plasma levels of TNF-alpha, IL-6, and IL-10 were increased. Elevated activity of myeloperoxidase was found in lung, colon, and liver, indicating a massive infiltration of neutrophils. These events were preceded by degradation of inhibitor kappaBalpha (IkappaBalpha), activation of IkappaB kinase complex, and c-Jun NH(2)-terminal kinase and, subsequently, activation of NF-kappaB and AP-1 in the lung. In vivo treatment with ciglitazone or 15d-PGJ(2) ameliorated hypotension and survival, blunted cytokine production, and reduced neutrophil infiltration in lung, colon, and liver. These beneficial effects of the PPARgamma ligands were associated with the reduction of IkappaB kinase complex and c-Jun NH(2)-terminal kinase activation and the reduction of NF-kappaB and AP-1 DNA binding in the lung. Furthermore, treatment with ciglitazone or 15d-PGJ(2) up-regulated the expression of PPARgamma in lung and thoracic aorta and abolished nitrotyrosine formation and poly(ADP-ribose) expression in aorta. Our data suggest that PPARgamma ligands attenuate the inflammatory response in sepsis through regulation of the NF-kappaB and AP-1 pathways.

2-Cyclopenten-1-one and prostaglandin J2reduce restenosis after balloon angioplasty in rats: role of NF-κB

The aim of this study was to evaluate, using a rat model of balloon angioplasty, whether prostaglandin (PG) J(2) and 2-cyclopenten-1-one are able to reduce restenosis. We found that both PGJ(2) and 2-cyclopenten-1-one, administered by local application on carotid arteries, caused a dose-dependent inhibition of neointimal formation. Furthermore, both agents prevented vascular negative remodeling. The effect of these compounds on restenosis was correlated with an inhibition of nuclear factor-kappaB (NF-kappaB) activation as well as of intercellular adhesion molecule-1 (ICAM-1) protein expression in injured carotid arteries of control animals. Our results show that cyclopentenone PGs and their derivatives reduce restenosis and may have therapeutic relevance for the prevention of human restenosis.

Peroxisome proliferation-activated receptor-γ ligands ameliorate experimental autoimmune myocarditis

BACKGROUND

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) ligands have been shown to ameliorate a variety of inflammatory conditions. The present study tested the hypothesis that PPAR-gamma ligands reduce experimental autoimmune myocarditis (EAM) associated with inhibition of the expansion and activation of T cells, as well as suppression of the expression of proinflammatory cytokines.

METHODS AND RESULTS

EAM was induced in Lewis rats by immunization with porcine cardiac myosin. PPAR-gamma ligands, 15-deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)) 200 microg/kg/day i.p. and pioglitazone (PIO) 10 mg/kg/day orally, were administered for 3 weeks to rats with EAM. The results showed that enhanced PPAR-gamma expression was prominently stained in the nuclear and perinuclear regions of infiltrating inflammatory cells. Administration of PPAR-gamma ligands markedly reduced the severity of myocarditis, as shown by comparing the heart weight/body weight ratio, pericardial effusion scores, macroscopic scores and microscopic scores. PPAR-gamma ligands suppressed myocardial mRNA expression of inflammatory cytokines and the expression of interleukin (IL)-1beta protein in rats with EAM. In addition, 15d-PGJ(2) and PIO treatment suppressed the proliferative response and interferon-gamma production of T cell-enriched splenocytes from rats with EAM. Furthermore, the cytotoxic activity and myocardiogenic potential of these T cells were inhibited by 15d-PGJ(2) treatment.

CONCLUSIONS

PPAR-gamma may play a role in the pathophysiology of EAM. PPAR-gamma ligands ameliorate the EAM associated with suppression of the expansion and activation of myocardiogenic T cells, as well as inhibition of the expression of proinflammatory cytokines. These results suggest that PPAR-gamma ligands such as 15d-PGJ(2) and PIO may have the potential to modulate human inflammatory heart diseases such as myocarditis.

Anti-inflammatory activity of 15-deoxy-delta12,14-PGJ2 and 2-cyclopenten-1-one: role of the heat shock response

The transcription factor heat shock factor 1 (HSF1) plays a key role in the expression of several genes, such as heat shock protein (hsp) genes, which are cytoprotective against several pathological conditions, including inflammation. Cyclopentenone prostaglandins (cyPG) are able to activate HSF1 and induce the synthesis of the 70-kDa hsp (hsp70) in mammalian cells. These molecules are characterized by the presence of a reactive alpha,beta-unsatured carbonyl group in the cyclopentane ring (cyclopentenone) which is the key structure for triggering HSF1 activation. In the present study, we investigated, in carrageenin hind-paw edema, an acute model of inflammation, the effect of double-stranded oligodeoxynucleotides with consensus HSF1 sequence as transcription factor decoys to inhibit HSF1 binding to native DNA sites. We show that HSF1 activation and hsp72 expression occurs in inflamed tissue and that this effect is associated with the remission of the inflammatory reaction. Moreover, we studied the effect of prostaglandin 15-deoxy-delta12,14-prostaglandin (PG) J2, of its precursor, PGD2 and, for the first time in vivo, the effect of the cyclopentenone ring structure itself, 2-cyclopenten-1-one. Our results demonstrated that all agents used had anti-inflammatory properties and that this effect was associated with HSF1-induced hsp72 expression in vivo, suggesting that the use of cyclopentenone derivatives may represent a novel therapeutic approach to the treatment of inflammatory diseases.

The cyclopentenone prostaglandin 15-deoxy-delta(12,14)- PGJ2 attenuates the development of colon injury caused by dinitrobenzene sulphonic acid in the rat

1. Inflammatory bowel disease (IBD) is characterized by oxidative and nitrosative stress, leukocyte infiltration, and increased expression of the adhesion molecules intercellular adhesion molecule 1 (ICAM-1) in the colon. Recent evidence also suggests that the cyclopentenone prostaglandin (PG) 15-deoxy-delta(12,14)-PGJ(2) (15d- PGJ(2)) functions as an early anti-inflammatory signal. 2. The aim of the present paper is to investigate the effects of 15d-PGJ(2) in rats subjected to experimental colitis. 3. Colitis was induced in rats by intra-colonic instillation of dinitrobenzene sulphonic acid (DNBS). 15d-PGJ(2) was administered daily as intraperitoneal injection (20 or 40 microg kg(-1)). On day 4, animals were sacrificed and tissues were taken for histological and biochemical analysis. 4. 15d-PGJ(2) significantly reduced the degree of haemorrhagic diarrhoea and weight loss caused by administration of DNBS. 15d-PGJ(2) also caused a substantial reduction of (i) the degree of colonic injury, (ii) the rise in myeloperoxidase (MPO) activity (mucosa), (iii) the increase in the tissue levels of malondialdehyde (MDA) and (iv) of the pro-inflammatory cytokines tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta). 5. Furthermore, 15d-PGJ(2) reduced the increase in immunohistochemical staining for (i) inducible nitric oxide synthase (iNOS), (ii) nitrotyrosine and (iii) poly (ADP-ribose) polymerase (PARP), as well as (iv) the increased expression of ICAM-1 caused by DNBS in the colon. 6. Electrophoresis mobility shift assay (EMSA) of inflamed colon revealed that 15d- PGJ(2) also caused a substantial reduction of the activation of nuclear factor-kappaB (NF-kappaB). Furthermore, 15d-PGJ(2) stimulates the activation of heat shock protein 72 (hsp72) in the inflamed colon, as assessed by Western blot analysis. 7. In conclusion, 15d-PGJ(2) reduces the development of experimental colitis.

Ligands of the peroxisome proliferator-activated receptors (PPAR-gamma and PPAR-alpha) reduce myocardial infarct size

This study was designed to investigate the effects of various chemically distinct activators of PPAR-gamma and PPAR-alpha in a rat model of acute myocardial infarction. Using Northern blot analysis and RT-PCR in samples of rat heart, we document the expression of the mRNA for PPAR-gamma (isoform 1 but not isoform 2) as well as PPAR-beta and PPAR-alpha in freshly isolated cardiac myocytes and cardiac fibroblasts and in the left and right ventricles of the heart. Using a rat model of regional myocardial ischemia and reperfusion (in vivo), we have discovered that various chemically distinct ligands of PPAR-gamma (including the TZDs rosiglitazone, ciglitazone, and pioglitazone, as well as the cyclopentanone prostaglandins 15D-PGJ2 and PGA1) cause a substantial reduction of myocardial infarct size in the rat. We demonstrate that two distinct ligands of PPAR-alpha (including clofibrate and WY 14643) also cause a substantial reduction of myocardial infarct size in the rat. The most pronounced reduction in infarct size was observed with the endogenous PPAR-gamma ligand, 15-deoxyDelta12,14-prostagalndin J2 (15D-PGJ2). The mechanisms of the cardioprotective effects of 15D-PGJ2 may include 1) activation of PPAR-alpha, 2) activation of PPAR-gamma, 3) expression of HO-1, and 4) inhibition of the activation of NF-kappaB in the ischemic-reperfused heart. Inhibition by 15D-PGJ2 of the activation of NF-kappaB in turn results in a reduction of the 1) expression of inducible nitric oxide synthase and the nitration of proteins by peroxynitrite, 2) formation of the chemokine MCP-1, and 3) expression of the adhesion molecule ICAM-1. We speculate that ligands of PPAR-gamma and PPAR-alpha may be useful in the therapy of conditions associated with ischemia-reperfusion of the heart and other organs. Our findings also imply that TZDs and fibrates may help protect the heart against ischemia-reperfusion injury. This beneficial effect of 15D-PGJ2 was associated with a reduction in the expression of the 1) adhesion molecules ICAM-1 and P-selectin, 2) chemokine macrophage chemotactic protein 1, and 3) inducible isoform of nitric oxide synthase. 15D-PGJ2 reduced the nitration of proteins (immunohistological analysis of nitrotyrosine formation) caused by ischemia-reperfusion, likely due to the generation of peroxynitrite. Not all of the effects of 15D-PGJ2, however, are due to the activation of PPAR-gamma. For instance, exposure of rat cardiac myocytes to 15D-PGJ2, but not to rosiglitazone, results in an up-regulation of the expression of the mRNA for heme-oxygenase-1 (HO-1). Taken together, these results provide convincing evidence that several, chemically distinct ligands of PPAR-gamma reduce the tissue necrosis associated with acute myocardial infarction.

The cyclopentenone prostaglandin 15-deoxy-Delta(12,14)-prostaglandin J(2) attenuates the development of acute and chronic inflammation

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-gamma receptor subtype seems to play a pivotal role in the regulation of cellular proliferation and inflammation. Recent evidence also suggests that the cyclopentenone prostaglandin (PG) 15-deoxyDelta(12,14)-PGJ(2) (15d-PGJ(2)), which is a metabolite of prostaglandin D(2), functions as an endogenous ligand for PPAR-gamma. We postulated that 15d-PGJ(2) would attenuate inflammation. In the present study, we have investigated the effects of 15d-PGJ(2) of acute and chronic inflammation (carrageenan-induced pleurisy and collagen-induced arthritis, respectively) in animal models. We report for the first time, to our knowledge, that 15d-PGJ(2) (given at 10, 30, or 100 microg/kg i.p. in the pleurisy model or at 30 microg/kg i.p every 48 h in the arthritis model) exerts potent anti-inflammatory effects (e.g., inhibition of pleural exudate formation, mononuclear cell infiltration, delayed development of clinical indicators, and histological injury) in vivo. Furthermore, 15d-PGJ(2) reduced the increase in the staining (immunohistochemistry) for nitrotyrosine and poly (ADP-ribose) polymerase and the expression of inducible nitric-oxide synthase and cyclooxygenase-2 in the lungs of carrageenan-treated mice and in the joints from collagen-treated mice. Thus, 15d-PGJ(2) reduces the development of acute and chronic inflammation. Therefore, the cyclopentenone prostaglandin 15d-PGJ(2) may be useful in the therapy of acute and chronic inflammation.

Peroxisome proliferator-activated receptor-gamma agonists inhibit experimental allergic encephalomyelitis by blocking IL-12 production, IL-12 signaling and Th1 differentiation

Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a nuclear receptor transcription factor that regulates adipocyte differentiation and glucose homeostasis. PPARgamma agonists are potent therapeutic agents for the treatment of type 2 diabetes and obesity. PPARgamma agonists also prevent inflammation in animal models, suggesting their use for the treatment of human inflammatory diseases. Experimental allergic encephalomyelitis (EAE) is a Th1 cell-mediated inflammatory demyelinating disease model of multiple sclerosis (MS) and IL-12 plays a crucial role in the pathogenesis of EAE and MS. In this study we have examined the effect of PPARgamma agonists on the pathogenesis of EAE. In vivo treatment of SJL/J mice with PPARgamma agonists, 15-deoxydelta(12,14) prostaglandin J2 or Ciglitazone, decreased the duration and clinical severity of active immunization and adoptive transfer models of EAE. PPARgamma agonists inhibited EAE in association with a decrease in IL-12 production and differentiation of neural antigen-specific Th1 cells. In vitro treatment of activated T cells with PPARgamma agonists inhibited IL-12-induced activation of JAK-STAT signaling pathway and Th1 differentiation. These findings highlight the fact that PPARgamma agonists regulate central nervous system inflammation and demyelination by inhibiting IL-12 production, IL-12 signaling and Th1 differentiation in EAE.

Peroxisome proliferator-activated receptor-gamma agonist 15-deoxy-Delta(12,14)-prostaglandin J(2) ameliorates experimental autoimmune encephalomyelitis

Peroxisome proliferator-activated receptors (PPAR) are members of a nuclear hormone receptor superfamily that includes receptors for steroids, retinoids, and thyroid hormone, all of which are known to affect the immune response. Previous studies dealing with PPAR-gamma expression in the immune system have been limited. Recently, PPAR-gamma was identified in monocyte/macrophage cells. In this study we examined the role of PPAR-gamma in experimental autoimmune encephalomyelitis (EAE), an animal model for the human disease multiple sclerosis. The hypothesis we are testing is whether PPAR-gamma plays an important role in EAE pathogenesis and whether PPAR-gamma ligands can inhibit the clinical expression of EAE. Initial studies have shown that the presence of the PPAR-gamma ligand 15-deoxy-Delta(12,14)-PGJ(2) (15d-PGJ2) inhibits the proliferation of Ag-specific T cells from the spleen of myelin basic protein Ac(1-11) TCR-transgenic mice. 15d-PGJ2 suppressed IFN-gamma, IL-10, and IL-4 production by both Con A- and myelin basic protein Ac(1-11) peptide-stimulated lymphocytes as determined by ELISA and ELISPOT assay. Culture of encephalitogenic T cells with 15d-PGJ2 in the presence of Ag reduced the ability of these cells to adoptively transfer EAE. Examination of the target organ, the CNS, during the course of EAE revealed expression of PPAR-gamma in the spinal cord inflammatory infiltrate. Administration of 15d-PGJ2 before and at the onset of clinical signs of EAE significantly reduced the severity of disease. These results suggest that PPAR-gamma ligands may be a novel therapeutic agent for diseases such as multiple sclerosis.

15-deoxy-delta(12,14)-PGJ(2) induces synoviocyte apoptosis and suppresses adjuvant-induced arthritis in rats

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily and have a dominant regulatory role in adipocyte and monocyte differentiation. PPAR-gamma agonists are also negative regulators of macrophage activation and have modulatory effects on tumorigenesis. In this study we demonstrate that synovial tissue localized expression of PPAR-gamma in patients with rheumatoid arthritis (RA). We detected markedly enhanced expression of PPAR-gamma in macrophages, as well as modestly enhanced expression in the synovial lining layer, fibroblasts, and endothelial cells. Activation of the PPAR-gamma by 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) and the synthetic PPAR-gamma ligand (troglitazone) induced RA synoviocyte apoptosis in vitro. Moreover, intraperitoneal administration of these PPAR-gamma ligands ameliorated adjuvant-induced arthritis with suppression of pannus formation and mononuclear cell infiltration in female Lewis rats. Anti-inflammatory effects of 15d-PGJ(2) were more potent than troglitazone. These findings suggest that PPAR-gamma may be an important immunoinflammatory mediator and its ligands, especially 15d-PGJ(2), may be useful in the treatment of RA.

Synergistic antiproliferative effect of delta 12-prostaglandin J2 (delta 12-PGJ2) and hyperthermia on human esophageal cancer cell lines

delta 12-PGJ2, one of the cyclopentenone prostaglandins and the ultimate metabolite of prostaglandin D2, has been reported to have potent antiproliferative activity on various tumor cells in vitro and in vivo. In this study, the combined effect of delta 12-PGJ2 and hyperthermia on six established cell lines of human esophageal carcinoma (SGF series) was analyzed by an in vitro assay, and the degree of apoptosis induced by this combination was examined to clarify the mechanism of supra-additive effects. In five SGF cell lines, except SGF-7 cells, combination therapy with delta 12-PGJ2 and hyperthermia showed synergistic antiproliferative effects. The supra-additive combined effect of delta 12-PGJ2 and hyperthermia on esophageal cancer cells is attributed to the synergistic induction of apoptosis. delta 12-PGJ2 induced G1 accumulation and apoptosis was induced by delta 12-PGJ2 from G1 phase. Hyperthermia induced G1 accumulation and apoptosis was induced by hyperthermia during all cell phases. Both augmented G1 arrest followed by G1 phase-selective induction of apoptosis and increased apoptotic induction without cell-cycle specificity are responsible for the synergism of combined treatment with delta 12-PGJ2 and hyperthermia.

Pulmonary hypertension in lambs with congenital diaphragmatic hernia: vasodilator prostaglandins, isoprenaline, and tolazoline

After antenatal induction of diaphragmatic hernias in fetal lambs, prostaglandins D2, E1, and I2 were compared to tolazoline, or isoprenaline, for the treatment of pulmonary hypertension. When rendered hypoxic, these, and normal lambs, showed an increase in pulmonary artery pressure, a decrease in systemic pressure, and a decrease in pulmonary blood flow. All of the drugs altered that response, but to different degrees. None of the drugs tested was consistently successful in reversing the adverse affects of hypoxia, but prostaglandin D2 came closest to the ideal vasodilator, decreasing the pulmonary artery pressure in all seven hypoxic lambs having a diaphragmatic hernia. There was a concomitant increase in pulmonary blood flow in six; in the remaining lamb the decrease in blood flow induced by the hypoxia was arrested. At the same time, there was an increase in systemic artery pressure in three, the decrease was arrested in two, but the decrease continued in the other two. Isoprenaline was a more effective drug than tolazoline, producing an increase in pulmonary blood flow in five of the seven lambs, with minor decreases in systemic pressure in five. Tolazoline improved blood flow in three of six lambs (not all lambs survived the full study), with a marked decrease in systemic pressure in four of them. Prostaglandin D2 seems to be a useful drug for the treatment of patients having diaphragmatic hernias and pulmonary hypertension, and warrants further study. Isoprenaline was the most effective of the readily available drugs tested in this animal model.

Augmentation of antiproliferative activity of recombinant human tumor necrosis factor by delta 12-prostaglandin J2

The effects of tumor necrosis factor (TNF) and cyclopentenone prostaglandins (PGA2 and delta 12-PGJ2), singly and in combination, against proliferation in three human gynecologic tumor cell lines (HeLa S3, HHUA, and CAOV-3) were examined in vitro. The HeLa S3 and CAOV-3 cells were unresponsive to TNF, and the HHUA cells exhibited a minimal degree of responsiveness to TNF. The HeLa S3 and HHUA cells were responsive dose-dependently to PGA2, and the CAOV-3 cells were slightly responsive to PGA2. All three cell lines were highly responsive to delta 12-PGJ2. The synergistic antiproliferative effect of TNF and delta 12-PGJ2 appeared in all three cell lines. Pretreatment with delta 12-PGJ2 enhanced the effectiveness of TNF in these cell lines, but not vice versa. A synergistic interaction between TNF and PGA2 was absent in these three cell lines. These results suggest that a combined treatment with TNF and delta 12-PGJ2 could provide a new approach to obtaining increased responses in clinical trials.