OBJECTIVETo investigate the effects of pioglitazone on transforming growth factor beta1 (TGFbeta1) expression in ischemia/reperfusion injury myocardium of rats.

METHODSThirty SD rats were randomly divided into five groups (n = 6): ischemia/reperfusion group, pioglitazone 5 mg/(kg x d) group, pioglitazone 10 mg/(kg x d) group, pioglitazone 20 mg/(kg x d) group and pioglitazone 20 mg/(kg x d) + peroxisome proliferator-activated receptor gamma (PPARgamma) specific antagonist GW9662 group. Left anterior descending coronary artery of rats were ligated for 30 min and reperfused for 120 min to establish the model of ischemia/reperfusion in vivo. RT-PCR was performed to detect the expression of TGFbeta1 mRNA. Western blot was performed to detect the expression of TGFbeta1 protein.

RESULTSMyocardial apoptosis was significantly suppressed by pioglitazone. Pioglitazone upregulated TGFPbeta1 expression both in mRNA and protein level. GW9662 reversed the inhibition of myocardial apoptosis and the upregulation of TGFbeta1 expression by pioglitazone.

CONCLUSIONPioglitazone can inhibit the myocardial apoptosis induced by ischemia/reperfusion. Pioglitazone may protect the myocardium from ischemia/reperfusion via upregulation of TGFbeta1. This protection may be mediated by PPARgamma.

Anilides ; pharmacology ; Animals ; Apoptosis ; Male ; Myocardial Reperfusion Injury ; metabolism ; Myocardium ; metabolism ; PPAR gamma ; antagonists & inhibitors ; Rats ; Rats, Sprague-Dawley ; Thiazolidinediones ; pharmacology ; Transforming Growth Factor beta1 ; metabolism

Objective To investigate the effect of 15-Deoxy-△(12,14)-prostaglandin J2 (15 d-PGJ2) on the expression of macrophage migration inhibitory factor (MIF) and its underlying mechanism in J774A.1. Methods The murine monocyte/macrophage cell line J774A.1 were divided into six groups:lipopolysaccharide (LPS) group,incubated with 1 μg/ml LPS for 1 h;normal control group,incubated with PBS for 1 h;negative control group,incubated with 5 μmol/L 15 d-PGJ2 for 1 h;15 d-PGJ2 group,incubated with 5 μmol/L 15 d-PGJ2 for 1 h followed by 1 μg/ml LPS for 1 h;GW9662 group,incubated with 5 μmol/L 15 d-PGJ2 for 1 h following GW9662 10 μmol/L for 1 h,and then incubated with 1 μg/ml LPS for 1 h;and Vehicle group,control of GW9662,GW9662 was replaced by its solvent DMSO. The expression of MIF was detected via immunofluorescence and agarose gel electrophoresis. RT-qPCR and Western blotting were used to test whether 15 d-PGJ2 could regulate mRNA and protein expression of MIF in J774A.1 upon LPS challenge. The effect of peroxisome proliferator-activated receptor-γ (PPAR-γ) antagonist GW9662 on the regulation of MIF by 15 d-PGJ2 was observed. The effects of 15 d-PGJ2 on the nuclear translocation of PPAR-γ upon LPS challenge were detected via high content screening analysis. Results MIF DNA and protein expressions were detected in J774A.1. MIF mRNA expression was up-regulated (1.75±0.09,P=0.037) when challenged with LPS and 15 d-PGJ2 inhibited its upregulation (0.84±0.08,P=0.026) in J774A.1. The protein level was consistent with the mRNA level. PPAR-γ antagonist GW9662 reversed the effect of 15 d-PGJ2 (mRNA,1.48±0.06,P=0.016;protein,1.28). Furthermore,nuclear translocation of PPAR-γ was regulated by 15 d-PGJ2 in J774A.1 upon LPS challenge(1.39±0.02 vs. 1.01±0.03,P=0.003). Conclusion 15 d-PGJ2 may down-regulate the MIF expression in J774A.1 in a PPAR-γ-dependent manner.
Anilides ; pharmacology ; Animals ; Cell Line ; Intramolecular Oxidoreductases ; metabolism ; Lipopolysaccharides ; Macrophage Migration-Inhibitory Factors ; metabolism ; Mice ; Monocytes ; drug effects ; PPAR gamma ; antagonists & inhibitors ; Prostaglandin D2 ; analogs & derivatives ; pharmacology

BACKGROUND/AIMS: Ligands for peroxisome proliferator-activated receptor gamma (PPAR gamma), a member of the ligand-activated nuclear receptor superfamily, exhibit anti-tumoral effects and are associated with de novo synthesis of proteins involved in regulating the cell cycle and cell survival/death. Helicobacter pylori (H. pylori) is an etiologic agent for gastric adenocarcinoma, and raises the cell turnover of gastric epithelium. The aim of this study was to investigate the effect of PPAR gamma ligand rosiglitazone on the cell proliferation and the expressions of p27 and Skp2 protein in H. pylori infected gastric epithelial cells. METHODS: We examined the expression of PPAR gamma by Western blot in H. pylori infected AGS human gastric epithelial cells. The effect of rosiglitazone on the survival of H. pylori infected AGS cells was assessed by cell viability assay. After the treatment of rosiglitazone in H. pylori infected AGS cells, the expressions of p27 and Skp2 were assessed by Western blot. RESULTS: The expression of PPAR gamma protein was increased in H. pylori infected AGS cells. Cell growth was inhibited and decreased in dose- and time- dependent manner in H. pylori infected AGS cells treated with rosiglitazone. A decrease in Skp2 expression and a reciprocal increase in p27 expression were found in dose- and time-dependent manner in H. pylori infected AGS cells treated with rosiglitazone. CONCLUSIONS: Rosiglitazone inhibited the growth of H. pylori infected AGS cells. Rosiglitazone attenuated Skp2 expression, thereby promoting p27 accumulation in H. pylori infected human gastric epithelial cells. Further studies will be needed to find the effects of accumulation on cell turnover in H. pylori infection and the role in the H. pylori-associated gastric carcinogenesis.
Anti-Bacterial Agents/*pharmacology ; Cell Line ; Cell Proliferation ; Cyclin-Dependent Kinase Inhibitor p27/*metabolism ; Epithelial Cells/metabolism/*microbiology ; Gastric Mucosa/cytology/metabolism/*microbiology ; *Helicobacter pylori ; Humans ; PPAR gamma/antagonists &inhibitors/metabolism ; S-Phase Kinase-Associated Proteins/*metabolism ; Thiazolidinediones/*pharmacology

Oxidized LDL (OxLDL), a causal factor in atherosclerosis, induces the expression of heat shock proteins (Hsp) in a variety of cells. In this study, we investigated the role of CD36, an OxLDL receptor, and peroxisome proliferator-activated receptor gamma (PPAR gamma) in OxLDL-induced Hsp70 expression. Overexpression of dominant-negative forms of CD36 or knockdown of CD36 by siRNA transfection increased OxLDL-induced Hsp70 protein expression in human monocytic U937 cells, suggesting that CD36 signaling inhibits Hsp70 expression. Similar results were obtained by the inhibition of PPAR gamma activity or knockdown of PPAR gamma expression. In contrast, overexpression of CD36, which is induced by treatment of MCF-7 cells with troglitazone, decreased Hsp70 protein expression induced by OxLDL. Interestingly, activation of PPAR gamma through a synthetic ligand, ciglitazone or troglitazone, decreased the expression levels of Hsp70 protein in OxLDL-treated U937 cells. However, major changes in Hsp70 mRNA levels were not observed. Cycloheximide studies demonstrate that troglitazone attenuates Hsp70 translation but not Hsp70 protein stability. PPAR gamma siRNA transfection reversed the inhibitory effects of troglitazone on Hsp70 translation. These results suggest that CD36 signaling may inhibit stress- induced gene expression by suppressing translation via activation of PPAR gamma in monocytes. These findings reveal a new molecular basis for the anti-inflammatory effects of PPAR gamma.
Antigens, CD36/*physiology ; Cell Line, Tumor ; Chromans/pharmacology ; Cycloheximide/pharmacology ; HSP70 Heat-Shock Proteins/*biosynthesis ; Humans ; Lipoproteins, LDL/pharmacology/*physiology ; Monocytes/drug effects/metabolism ; PPAR gamma/agonists/antagonists & inhibitors/*physiology ; Protein Synthesis Inhibitors/pharmacology ; Signal Transduction ; Thiazolidinediones/pharmacology

BACKGROUND AND OBJECTIVES: Several studies have shown that angiotensin II receptor blockers (ARBs) improve endothelial function and arterial stiffness. Telmisartan is a highly selective ARB that activates peroxisome proliferator-activated receptor gamma (PPARgamma). The purpose of this study was to evaluate the effects of telmisartan, such as endothelial function, arterial stiffness, and insulin sensitivity, in patients with essential hypertension. SUBJECTS AND METHODS: Thirty-nine patients with essential hypertension were administered telmisartan (80 mg once daily) using an open-labeled and prospective protocol. The patients were examined before and 8 weeks after treatment to assess changes in flow mediated-vasodilation (FMD), pulse wave velocity (PWV), quantitative insulin-sensitivity check index (QUICKI), homeostasis model assessment (HOMA), and adiponection. RESULTS: The systolic and diastolic blood pressure (BP) decreased from 153+/-15 mmHg and 90+/-13 mmHg to 137+/-16 mmHg and 84+/-10 mmHg after telmisartan treatment, respectively (p<0.01). Telmisartan therapy increased the FMD from 7.6+/-3.5 to 9.0+/-2.8% (p<0.01). The following parameters of arterial stiffness were significantly improved after telmisartan therapy: brachial-ankle pulse wave velocity (baPWV), from 17.2+/-3.1 to 15.9+/-2.6 m/sec; heart-carotid PWV (hcPWV), from 9.7+/-1.8 to 9.0+/-1.9 m/sec; and heart-femoral PWV (hfPWV), from 11.3+/-1.9 to 10.7+/-1.9 m/sec (p<0.01). There were no changes in QUICKI, the HOMA level, and plasma adiponectin (p=NS). CONCLUSION:These results suggest that telmisartan is effective in improving endothelial function and arterial stiffness in patients with essential hypertension.
Adiponectin ; Angiotensin II Type 1 Receptor Blockers ; Angiotensin Receptor Antagonists ; Arteriosclerosis ; Benzimidazoles ; Benzoates ; Blood Pressure ; Endothelium, Vascular ; Homeostasis ; Humans ; Hypertension ; Insulin Resistance ; Plasma ; PPAR gamma ; Prospective Studies ; Pulse Wave Analysis ; Vascular Stiffness

Animals ; Cells, Cultured ; Cyclosporine ; antagonists & inhibitors ; Fibronectins ; biosynthesis ; genetics ; Hepatocytes ; cytology ; drug effects ; PPAR gamma ; biosynthesis ; genetics ; Protective Agents ; pharmacology ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Thiazolidinediones ; pharmacology ; Transforming Growth Factor beta1 ; biosynthesis ; genetics

OBJECTIVE: To investigate the effect of mevastatin (Mev) on the expression of peroxisome-proliferator-activated receptor-gamma (PPAR-gamma) mRNA and differentiation of Thyroid-associated ophthalmopathy (TAO) derived orbital preadipocytes in vitro. METHODS: Orbital adipose tissues were obtained from TAO patients undergoing orbital decompression surgery. The orbital preadipocytes cultured from the orbital adipose tissues were divided into Group A (a control group) and Group B (an intervention group). Group B was subdivided into Group B1-B5, all groups were stimulated to differentiate into mature adipocytes with cocktail differentiation medium.The entire course of differentiation was 10 d. The differentiation of orbital preadipocytes in Group A was induced with routine inducer,while at in Group B1,B2, and B3 was interfered with 5 micromol/L (B1), 10 micromol/L(B2),20 micromol/L (B3) mevastatin respectively during the whole process of differentiation. The differentiation of orbital preadipocytes in Group B4 and B5 was interfered with 10 micromol/L mevastatin day 4 (B4) or day 8 (B5) of the differentiation process until the entire course was over. Intracellular fat accumulation in differentiated adipocytes was determined by oil red O staining. The value of optical absorption was measured at 492 nm with enzyme-linked immunosorbent assay. The expression of PPAR-gamma mRNA was detected by reverse transcription polymerase chain reaction. RESULTS: The light absorption value (A) and PPAR-gamma mRNA expression of differentiated cells in Group A,B1,B2,and B3 decreased successively,and there was significant difference in any of the 2 groups among Group A, B1 and B2, and B3 (P<0.05). The value A and PPAR-gamma mRNA expression of differentiated cells in Group A, B4, and B2 decreased successively, and the difference in any of the 2 groups among these 3 groups was significant. However, there were no significant difference between Group A and B5. CONCLUSION Mevastatin inhibits the differentiation of TAO derived orbital preadipocytes by blocking PPAR-gamma mRNA expression. The degree of inhibition is not only concentration-dependent but also associated with the stage of differentiation. The earlier the differentiation, the stronger the inhibition.
Adipocytes ; pathology ; Adipose Tissue ; pathology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Depression, Chemical ; Graves Ophthalmopathy ; pathology ; Humans ; Lovastatin ; analogs & derivatives ; pharmacology ; Orbit ; PPAR gamma ; antagonists & inhibitors ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism

During chronic inflammatory response, mono- cytes/macrophages produce 92-kDa matrix metalloproteinase-9 (MMP-9), which may contribute to their extravasation, migration and tissue remodeling. Activation of peroxisome proliferator- activated factor receptor-gamma (PPAR-gamma) has been shown to inhibit MMP-9 activity. To evaluate whether ox-LDL, a PPAR-gamma activator, inhibits PMA-induced MMP-9 expression and activity, and if so, whether CD36 and PPAR-gamma are involved in this process, we investigated the effect of ox-LDL on MMP-9 expression and activity in PMA-activated human monocytic cell line U937. PMA-induced MMP-9 expression and activity were suppressed by the treatment with ox-LDL (50 micrigram/ml) or PPAR-gamma activators such as troglitazone (5 micrometer), ciglitazone (5 micrometer), and 15d- PGJ2 (1 micrometer) for 24 h. This ox-LDL or PPAR-gamma activator-mediated inhibition of micrometer P-9 activity was diminished by the pre-treatment of cells with a blocking antibody to CD36, or PGF2a (0.3 micrometer), which is a PPAR-gamma inhibitor, as well as overexpression of a dominant-negative form of CD36. Taken together, these results suggest that ox-LDL suppresses PMA-induced MMP-9 expression and activity through CD36-mediated activation of PPAR-gamma.
Antibodies, Blocking/pharmacology ; Antigens, CD36/immunology/*physiology ; Cells, Cultured ; Chromans/pharmacology ; Gelatinase B/antagonists & inhibitors/genetics/*metabolism ; Humans ; Lipoproteins, LDL/pharmacology/*physiology ; Monocytes/drug effects/*enzymology/metabolism ; NF-kappa B/antagonists & inhibitors ; PPAR gamma/*metabolism ; Prostaglandin D2/*analogs & derivatives/pharmacology ; RNA, Messenger/analysis/metabolism ; Research Support, Non-U.S. Gov't ; Tetradecanoylphorbol Acetate/antagonists & inhibitors/pharmacology ; Thiazolidinediones/pharmacology ; Transcription, Genetic/drug effects

TGFβ/smad pathway is recognized as an important signal pathway to promote the pathogenesis of atherosclerosis (AS). Peroxisome proliferator-activated receptor &gamma; (PPAR&gamma;) activation is considered to be important in modulating AS. Herein, we investigated the regulation of PPAR&gamma; on c-Ski, the repressor of TGFβ/smad pathway, in rat AS model and cultured vascular smooth muscle cells (VSMCs). c-Ski mRNA and protein expression were detected by real-time PCR and Western blot, respectively, in vivo and in vitro with treatment of PPAR&gamma; agonist rosiglitazone and antagonist GW9662. The proliferation and collagen secretion of VSMCs after c-Ski transfection were investigated. The underlying mechanism was further investigated by online program NUBIScan and luciferase reporter gene analysis. Results showed that both mRNA and protein expressions of c-Ski in the AS lesions was down-regulated in vivo, while in cultured VSMCs, c-Ski transfection significantly suppressed the proliferation and collagen secretion of rat VSMCs. Rosiglitazone significantly up-regulated mRNA and protein levels of c-Ski in VSMCs, which could be blocked by GW9662. Online NUBIScan analysis suggested possible PPAR&gamma; binding sites in the promoter region of c-Ski. In addition, luciferase activity of c-Ski reporter gene was also increased obviously in the presence of rosiglitazone. These results indicate that c-Ski is one of the newly found target genes of PPAR&gamma; and thus involved in the anti-AS effect of PPAR&gamma;.
Anilides ; pharmacology ; Animals ; Atherosclerosis ; physiopathology ; Cells, Cultured ; Male ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; metabolism ; PPAR gamma ; agonists ; antagonists & inhibitors ; physiology ; Proto-Oncogene Proteins ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar ; Repressor Proteins ; genetics ; metabolism ; Signal Transduction ; Smad Proteins ; metabolism ; Thiazolidinediones ; pharmacology ; Transforming Growth Factor beta ; metabolism ; Up-Regulation

PURPOSE: Imbalances between osteogenic and adipogenic differentiation leads to diseases such as osteoporosis. The aim of our study was to demonstrate the differences in extracellular signal-regulated kinase (ERK) phosphorylation during both adipogenesis and osteogenesis of human bone marrow-derived stem cells (BMSCs). MATERIALS AND METHODS: Using troglitazone, GW9662 and U0126, we investigated their role in hBMSC differentiation to adipogenic and osteogenic fates. RESULTS: ERK1/2 inhibition by U0126 suppressed proliferator-activated receptor (PPAR)gamma expression and lipid accumulation, while it decreased the mRNA expression of adipogenic genes (lipoprotein lipase, PPARgamma, and adipocyte protein) and osteogenic genes (type I collagen and osteopontin). ERK phosphorylation was transient and decreased during adipogenesis, whereas it occurred steadily during osteogenesis. Troglitazone, a PPARgamma agonist, induced adipogenesis by inhibiting ERK phosphorylation even in an osteogenic medium, suggesting that ERK signaling needs to be shut off in order to proceed with adipose cell commitment. Cell proliferation was greatly increased in osteogenesis but was not changed during adipogenesis, indicating that ERK might play different roles in cellular proliferation and differentiation between the two committed cell types. CONCLUSION: The duration and magnitude of ERK activation might be a crucial factor for the balance between adipogenesis and osteogenesis in human bone marrow-derived stem cells.
Adipogenesis/*drug effects/genetics ; Adult ; Anilides/pharmacology ; Bone Marrow Cells/*cytology/drug effects/metabolism ; Butadienes/pharmacology ; Cell Differentiation/drug effects ; Cells, Cultured ; Chromans/pharmacology ; Extracellular Signal-Regulated MAP Kinases/*metabolism ; Female ; Humans ; Male ; Middle Aged ; Nitriles/pharmacology ; Osteogenesis/*drug effects/genetics ; PPAR gamma/agonists/antagonists & inhibitors ; Phosphorylation/drug effects ; Reverse Transcriptase Polymerase Chain Reaction ; Stem Cells/*cytology/drug effects/*metabolism ; Thiazolidinediones/pharmacology