The Role of Peroxisome Proliferator Activated Receptor γ (PPARγ) Ligands on Foam Cells Formation Derived From Murine Norovirus-1 (MNV-1) Infected Macrophage

Abstract@#Introduction: Atherosclerosis is a chronic inflammatory disease initiated by the accumulation of macrophage derived foam cells in the intima layer of artery. In mice model of atherosclerosis, murine norovirus-4 has been shown to accelerate atherogenesis. In cells, lipid biometabolism is regulated by peroxisome proliferator activated receptor γ (PPARγ). Since PPARγ is predominantly expressed in macrophages and mice macrophages are MNV-1 proliferation-permissive host, we hypothesised that PPARγ ligands may regulate atherogenesis. Methods: MNV-1 was generated via RNA-based recovery system and used to infect the RAW 264.7 cells, then subjected to oxidized low-density lipoprotein (oxLDL)-loaded and treated with ciglitazone or 15-deoxy-Delta(12,14)-PGJ(2)(15d-PGJ2). Foam cell formation was evaluated and the MNV-1 infection in all treatments was confirmed using virus titration (50% tissue culture infective dose; TCID50) and polymerase chain reaction (PCR). Results: Increment of lipid droplets was observed in all oxLDL treatment involving MNV-1 infection, ciglitazone or 15d-PGJ2 in the cytosol of RAW 264.7 cells over time compared to non-oxLDL treated cells. From the cholesterol ester (CE) content analysis amongst the oxLDL-loaded cells however, we found MNV-1 did not elicit increment of CE content. Treatment with 15d-PGJ2 resulted in increase of the CE content in oxLDL-treated cells. Interestingly, MNV-1 and ciglitazone had synergistic effect in reducing the CE content in oxLDL-treated cells. Conclusion: oxLDL stimulates foam cells formation in RAW 264.7 cells. However, MNV-1 infection did not contribute to RAW 264.7 cells derived-foam cells formation. On the other hand, 15d-PGJ2 promotes foam cells formation whilst ciglitazone inhibits the formation of foam cells derived from MNV-1-infected macrophages.

HIV-1 Tat Protein-dependent Cytotoxicity is Attenated by 15-deoxy-Delta12,14-Prostaglandin J2 in Rat Hippocampal Slices: Involvement of the ERK1/2 Signaling Pathway

15-deoxy-delta12,14 prostaglandin J2 (15d-PGJ2) may hold promise in treatment of the pathologies associated with human immunodeficiency virus (HIV) infection of the central nervous system. However, its precise role and neuroprotective mechanism in the hippocampus remain poorly understood. In the present study, rat hippocampal slices were stimulated with HIV-1 Tat protein to investigate the protective role of 15d-PGJ2 on the hippocampal cytotoxicity. Full-length HIV-1 Tat protein (Tat1-86), but neither its Tat32-62 nor Tat30-86 fragment, significantly induced cytotoxicity in the hippocampus, the brain region most commonly damaged in HIV-associated dementia. This Tat-induced cytotoxicity was associated with inactivation of MEK/extracellular signal-regulated kinase (ERK) signaling pathway. In contrast, Tat1-86 did not alter Wnt signaling pathway necessary for cell survival. Pretreatment of slices with 15d-PGJ2 markedly reduced Tat-driven cytotxicity. Interestingly, this reduction was accompanied by suppression of ERK inactivation in response to Tat. Moreover, the inhibition of the MEK/ERK pathway with SL327 enhanced the Tat-induced cytotoxicity, confirming the ERK-dependent mechanism of Tat-driven cytotoxicity. Collectively, these data demonstrate that the protective action of 15d-PGJ2 against the hippocampal cytotoxicity upon Tat stimulation is exerted through suppression of Tat-mediated ERK1/2 inactivation.

15d-PGJ2 modulates acute immune responses to Trypanosoma cruzi infection

The acute phase of Trypanosoma cruzi infection is associated with a strong inflammatory reaction in the heart characterised by a massive infiltration of immune cells that is dependent on the T. cruzi strain and the host response. 15d-PGJ2 belongs to a new class of anti-inflammatory compounds with possible clinical applications. We evaluated the effects of 15d-PGJ2 administered during the acute phase of T. cruzi infection in mice. Mice were infected with the Colombian strain of T. cruzi and subsequently treated with 15d-PGJ2 repeatedly for seven days. The inflammatory infiltrate was examined by histologic analysis. Slides were immunohistochemically stained to count the number and the relative size of parasite nests. Infection-induced changes in serum cytokine levels were measured by ELISA. The results demonstrated that treatment with 15d-PGJ2 reduced the inflammatory infiltrate in the skeletal muscle at the site of infection and decreased the number of lymphocytes and neutrophils in the blood. In addition, we found that 15d-PGJ2 led to a decrease in the relative volume density of amastigote nests in cardiac muscle. T. cruzi-infected animals treated with 15d-PGJ2 displayed a statistically significant increase in IL-10 levels with no change in IFN-ã levels. Taken together, we demonstrate that treatment with 15d-PGJ2 in the acute phase of Chagas disease led to a controlled immune response with decreased numbers of amastigote nests, as measured by the volume density.

15-Deoxy-Delta(12,14)-Prostaglandin J2 Upregulates the Expression of LPS-Induced IL-8/CXCL8 mRNA in Vascular Smooth Muscle Cells from Spontaneously Hypertensive Rats

BACKGROUND: 15d-PGJ2 has been known to act as an anti-inflammatory agent and has anti-hypertensive effects. As a result of these properties, we examined the effect of 15d-PGJ2 on the LPS-induced IL-8/CXCL8 mRNA expression in VSMCs from SHR. METHODS: Effect and action mechanism of 15d-PGJ2 on the expression of LPS-induced IL-8/CXCL8 mRNA in VSMCs from SHR and WKY were examined by using real-time polymerase chain reaction, electrophoretic mobility shift assay for NF-kappaB avtivity, Western blotting analysis for ERK and p38 phosphorylation and flow cytometry for NAD(P)H oxidase activity. RESULTS: 15d-PGJ2 decreased the expression of LPS-induced IL-8/CXCL8 mRNA in WKY VSMCs, but increased the expression of LPS-induced IL-8/CXCL8 mRNA in SHR VSMCs. The upregulatory effect of 15d-PGJ2 in SHR VSMCs was mediated through PPAR gamma, and dependent on NF-kappaB activation and ERK phosphorylation. However, inhibition of the p38 signaling pathway augmented the upregulatory effect of 15d-PGJ2 on LPS-induced IL-8/CXCL8 mRNA. A NAD(P)H oxidase inhibitor inhibited the upregulatory effect of 15d-PGJ2 on LPS-induced IL-8/CXCL8 mRNA expression in SHR VSMCs, and an increase in NAD(P)H oxidase activity was detected in SHR VSMCs treated with 15d-PGJ2/LPS. CONCLUSION: Our results indicate that the upregulatory effect of 15d-PGJ2 on LPS-induced IL-8/CXCL8 expression in SHR VSMCs is mediated through the PPAR gamma and ERK pathway, and may be related to NAD(P)H oxidase activity. However, p38 inactivation may also play an important role in 15d-PGJ2/LPS-induced IL-8/CXCL8 expression in SHR VSMCs.

Inhibitory Effect of 15-Deoxy-Delta(12,14)-Prostaglandin J(2) on the MUC8 Expression in the Human Airway Epithelial Cells / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Among the numerous mucin genes, MUC8 is regarded as one of the most important mucin genes which are related with upper airway disease such as a nasal polyp. 15-Deoxy-delta(12,14)-prostaglandin J(2)(15d-PGJ(2)), the most recently discovered prostaglandin, has been known to have multiple cellular functions, including anti-inflammatory and cytoprotective effects. However, the effect of 15d-PGJ(2) on mucin gene expression or mucin production has not yet been investigated. The purpose of this study was to determine the effect of 15d-PGJ(2) on interleukin-1beta (IL-1beta)-induced MUC8 gene expression and mucin secretion in the cultured NCI-H292 cells and human nasal polyp epithelial cells. SUBJECTS AND METHOD: The MUC8 mRNA levels were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and MUC8 mucin levels were measured using an enzyme-linked immunosorbent assay (ELISA) in the cultured epithelial cells stimulated by IL-1beta. 15d-PGJ(2) was added 1 hour before stimulation. RESULTS: 15d-PGJ(2) attenuated the IL-1beta-induced MUC8 mRNA expression and mucin secretion with a dose-dependent pattern in both cultured NCI-H292 cells and human nasal polyp epithelial cells. CONCLUSION: These results suggest that 15d-PGJ(2) may be considered as an effective agent for the control of airway mucus hypersecretion through the down-regulation of MUC8 gene.

Expression of PPAR? in gastric carcinma tissue and effect of its ligand on human gastric carcinoma cell growth / 基础医学与临床

Objective To investigate the expression of peroxisome proliferator-activated receptor?(PPAR?) in human gastric carcinoma and the effect of its ligand 15-deoxy-△~(12,14)-Prostagliandxin J_(2)(15d-PGJ_(2)) on the growth of human gastric carcinoma MGC803 cells.Methods PPAR? and survivin mRNA were examined by RT-PCR;PPAR?,survivin,Skp2 and p27 protein were examined in cells by Western blot;proliferation was examined by MTT assay,apoptosis and cell cycle distribution were examined by flow cytometry;PPAR? protein in tissue was examined by immunohistochemistry;morphological change of apoptosis was examined by Hoechst33342 staining.Results The positive rate of PPAR? protein was significantly higher in gastric carcinomas 75.0%(40 cases) than in their paired adjacent mucosa(25.0%)((40 cases))(and)(normal)(mucosa)(20.0%(40cases)),(and)(there)(was)(no) difference between the latterones. The positive rate of PPAR?mRNA and protein were significantly higher in intestinal gastric carcinoma 95.0%(20 cases)than that in diffuse gastric carcinoma 55.0%(20 cases).Proliferation inhibition rate and apoptosis rate of MGC803 cells after_()24h were all significantly higher following 5,10,20,30 and (40 mol/L) 15d-PGJ_(2)treatment than(0 mol/L)(P

Inhibitory effects of ligand of PPAR-? combined with DDP activation on proliferation of cells and induction of apoptosis of human pulmonary carcinoma PLA-801D cells in vitro / 吉林大学学报(医学版)

Objective To investigate the effects of 15-deoxy-?12,14-prostaglandin J2(15d-PGJ2) and DDP on the growth of human pulmonary carcinoma PLA-801D cells and the mechanisms of apoptosis.Methods The human pulmonary carcinoma PLA-801D cells were selected and added to each well of 96-well place and cultivated for 24 h.Then the cells were treated with different concentrations of 15d-PGJ2(0,5,10,20,40 and 80 ?g?L-1) or 15d-PGJ2 combined with DDP(3 mg?L) for 24 h.0 ?g?L-1 15d-PGJ2 group was control group.The morphological changes of cells were observed under inverted microscope.Microculture tetrazolium(MTT)dye was applied to detect the proliferation of the human pulmonary carcinoma PLA-801D cells treated with 15d-PGJ2 and DDP.Diphenylamine assay(DPA) was used to evaluate the activation.Flow cytometry assay(FCM) was used to detect the apoptosis proportion and the changes of cell cycle.Results When the human pulmonary carcinoma PLA-801D cells were treated with low-concentration 15d-PGJ2 alone(5,10 and 20 ?g?L-1),no significant difference was observed in the inhibitory rate of cell growth and the apoptotic indexes such as the apoptosis proportion,the percent of DNA fragmentation and the activity of caspase-3 compared with control group(P

Role of Cyclooxygenase-2 (COX-2) and Peroxisome Proliferator-Activated Receptor (PPAR) in Gastric Cancer / 대한소화기학회지

BACKGROUND/AIMS: Gastric cancer is still the most frequently diagnosed malignancy in Korea. It has been reported that COX-2 and PPAR are involved in multi-step gastric carcinogenesis. The aim of the present study was to examine the expression of COX-2 and PPAR in gastric cancer. METHODS: A total of 75 subjects including 45 patients with gastric cancer and 30 controls were enrolled. All subjects underwent upper gastrointestinal endoscopic examination with tissue collection. mRNA extraction from the tissues and real-time PCR for COX-2, PPAR-delta, and PPAR-gamma were performed. Gastric mucosal concentration of PGE2, which is a final product of COX-2, and 15d-PGJ2, which is a ligand of PPAR-gamma, were measured by the enzyme immunoassay method. RESULTS: COX-2 mRNA expression was significantly higher in both early gastric cancer tissues (EGC, 8.32 +/- 4.84 micro gram/micro L, p<0.005) and advanced gastric cancer tissues (AGC, 8.16 +/- 2.67 micro gram/micro L, p<0.001) than in non-cancerous tissues of controls (3.46 +/- 1.72 micro gram/micro L). There was no significant difference of PPAR-delta and PPAR-gamma mRNA expression between gastric cancer tissues and controls. Mucosal PGE2 concentration was significantly higher in both EGC tissues (5.31 +/- 0.49 micro gram/mg protein, p<0.001) and AGC tissues (5.46 +/- 0.54 micro gram/mg protein, p<0.001) than in non-cancerous tissues of controls (4.22 +/- 0.8 micro gram/mg protein). There was no significant difference of 15d-PGJ2 concentration between gastric cancer tissues and controls. CONCLUSIONS: COX-2 overexpression and increased PGE2 concentration in gastric tissues may play an important role in gastric carcinogenesis. However, the role of PPAR (delta and gamma) and 15d-PGJ2 in gastric carcinogenesis is uncertain. Further studies are needed.

Effect of 15d-PGJ_2 on proliferation and apoptosis of HSC-T6 / 中国药理学通报

Aim To evaluate the effect of 15d-PGJ2 on up-regulated expression of PPAR? and inducing HSC apoptosis and inhibiting HSC proliferation. Methods The rat liver stellate cell line (HSC-T6) was cultured in DMEM, and treated with PPAR? agonist 15d-PGJ2 of different concentrations. The expression of PPAR? mRNA was detected by RT-PCR. The protein expression of NF-?B was examined by Western blot. The cell proliferation rate of HSC-T6 was determined by MTT colorimetric assay. The cell cycle and apoptosis ratio were measured using flow cyto -metry analysis. Results The proliferation rate of the rat liver stellate cell line (HSC-T6) was significantly inhibited by 15d-PGJ2 (vs controls, P