Peroxisome proliferator activated receptor gamma interacts with bone morphogenetic protein, Wnt, TAZ, and insulin-like growth factor-I, which are required for the process of osteoblast differentiation, regulating the mesenchymal stem cells (MSCs) into adipocytes and osteoblasts differentiation, thus impact on the osteoblast-mediated bone formation in bone remodeling, and, through RANKL and other factors directly or indirectly, regulate osteoclast-mediated bone resorption. This article reviews new researches for the influence of peroxisome proliferator activated receptor gamma on osteoblast and osteoclast function in bone remodeling.
Bone Remodeling ; physiology ; Humans ; Osteoblasts ; physiology ; Osteoclasts ; physiology ; PPAR gamma ; physiology

Airway Remodeling ; physiology ; Animals ; Asthma ; metabolism ; Disease Models, Animal ; PPAR gamma ; biosynthesis ; Rats

OBJECTIVE: To investigate the inhibitory effect of genistein on activation of hepatic stellate cells (HSCs) and the role of the autophagy pathway regulated by PPAR-γ in mediating this effect. METHODS: Cultured HSC-T6 cells were exposed to different concentrations of genistein for 48 h, and HSC activation was verified by detecting the expressions of -SMA and 1(I) collagen; autophagy activation in the cells was determined by detecting the expressions of LC3-II and p62 using Western blotting. The autophagy inhibitor 3-MA was used to confirm the role of autophagy in genistein-induced inhibition of HSC activation. A PPAR-γ inhibitor was used to explore the role of PPAR-γ in activating autophagy in the HSCs. RESULTS: Genistein at concentrations of 5 and 50 μmol/L significantly inhibited the expressions of -SMA and 1(I) collagen ( < 0.05), markedly upregulated the expressions of PPAR-γ and the autophagy-related protein LC3-II ( < 0.05) and significantly down-regulated the expression of the ubiqutin-binding protein p62 ( < 0.05) in HSC-T6 cells. The cells pretreated with 3-MA prior to genistein treatment showed significantly increased protein expressions of -SMA and 1(I) collagen compared with the cells treated with genistein only ( < 0.05). Treatment with the PPAR-γ inhibitor obviously lowered the expression of LC3-II and enhanced the expression p62 in genistein-treated HSC-T6 cells, suggesting the activation of the autophagy pathway. CONCLUSIONS PPAR-γ- regulated autophagy plays an important role in mediating genistein-induced inhibition of HSC activation .
Anticarcinogenic Agents ; pharmacology ; Autophagy ; Collagen Type I ; Genistein ; pharmacology ; Hepatic Stellate Cells ; Humans ; PPAR gamma ; physiology

Obesity is a leading risk factor for insulin resistance, hypertension, hyperlipidemia, and cardiovascular complications, collectively referred to as metabolic diseases. Given the prevalence of obesity and its associated medical problems, new strategies are required to prevent or treat obesity and obesity-related metabolic effects. Here we summarize contributors of obesity, and molecular mechanisms controlling adipogenesis from studies in mammalian systems. We also discuss the possibilities of using Drosophila as a genetic model system to advance our understanding of players in fat biology.
Animals ; Drosophila/*physiology ; Humans ; Metabolic Syndrome X/*etiology/metabolism/prevention & control ; Obesity/*complications/metabolism/prevention & control ; PPAR gamma/metabolism/physiology

Animals ; Brain Ischemia ; drug therapy ; Cyclooxygenase Inhibitors ; pharmacology ; Flurbiprofen ; analogs & derivatives ; Male ; Neuroprotective Agents ; pharmacology ; PPAR gamma ; physiology

This study was aimed to investigate the effect of stress induced by high-intensity exercises on the cardiovascular system. In the epidemiological investigation, 200 subjects (test group) engaged in special high-intensity exercises, and 97 who lived and worked in the same environment and conditions as those in the test group, but did not participate in the exercises served as controls. In the second part of the study, 50 mice were randomly divided into control group, exhaustive swimming group, white noise group, exhaustive swimming plus white noise group, and pioglitazone intervention group. The results showed that the plasma concentrations of the myocardial injury markers heart fatty acid-binding protein (H-FABP), C-reactive protein (CRP), β-endorphin (β-EP) and levels of psychological stress were significantly increased in test group as compared with control group; special high-intensity exercises resulted in a significant elevation of the incidence of cardiac arrhythmias. Animal experiments showed that the plasma levels of corticosterone (CORT) and troponin I (TnI) were raised while the level of SOD was reduced in exhaustive swimming group, white noise group, and exhaustive swimming plus white noise group. The expression levels of PPAR&gamma; mRNA and protein were decreased in myocardial tissues in these groups as well. HE staining showed no remarkable change in myocardial tissues in all the groups. Treatment with pioglitazone significantly decreased the plasma levels of TnI and CORT, while increased the level of SOD and the expression levels of PPAR&gamma; mRNA and protein. It was concluded that the high-intensity exercises may induce a heavy physical and psychological stress and predispose the subjects to accumulated fatigue and sleep deprivation; high-intensity exercises also increases the incidence of arrhythmias and myocardial injury. PPAR&gamma; may be involved in the physical and psychological changes induced by high-intensity exercises.
Animals ; Heart Injuries ; physiopathology ; Male ; Mice ; PPAR gamma ; genetics ; physiology ; RNA, Messenger ; genetics ; Real-Time Polymerase Chain Reaction ; Stress, Physiological

Peroxisome proliferator-activated receptor gamma (PPARgamma) belongs to a nuclear receptor superfamily; members of which play key roles in the control of body metabolism principally by acting on adipose tissue. Ligands of PPARgamma, such as thiazolidinediones, are widely used in the treatment of metabolic syndromes and type 2 diabetes mellitus (T2DM). Although these drugs have potential benefits in the treatment of T2DM, they also cause unwanted side effects. Thus, understanding the molecular mechanisms governing the transcriptional activity of PPARgamma is of prime importance in the development of new selective drugs or drugs with fewer side effects. Recent advancements in molecular biology have made it possible to obtain a deeper understanding of the role of PPARgamma in body homeostasis. The transcriptional activity of PPARgamma is subject to regulation either by interacting proteins or by modification of the protein itself. New interacting partners of PPARgamma with new functions are being unveiled. In addition, post-translational modification by various cellular signals contributes to fine-tuning of the transcriptional activities of PPARgamma. In this review, we will summarize recent advancements in our understanding of the post-translational modifications of, and proteins interacting with, PPARgamma, both of which affect its transcriptional activities in relation to adipogenesis.
Gene Expression Regulation ; Homeostasis ; *Models, Genetic ; PPAR gamma/genetics/metabolism/*physiology ; *Protein Processing, Post-Translational ; Sumoylation ; Transcription Factors/metabolism/physiology ; Ubiquitination

OBJECTIVEPPAR-gamma is associated with the differentiation, apoptosis, proliferation and cytokine secretion of immunologic cells. This study investigated peripheral blood lymphoblastic PPAR-gamma mRNA expression and its correlation with plasma IL-13 contents in children with acute idiopathic thrombocytopenic purpura (ITP).

METHODSFifty-three children with acute ITP who were in line with the standard test between September 2007 and July 2008 were enrolled. Fifty healthy children during the same period were used as the control group. PPAR-gamma mRNA expression in peripheral blood lymphocytes were detected by RT-PCR. Plasma IL-13 contents were detected using ELISA.

RESULTSPPAR-gamma mRNA expression in peripheral blood lymphocytes from acute ITP children were significantly higher than that in the control group (0.78 +/- 0.03 vs 0.52 +/- 0.05; P< 0.05). Plasma IL-13 contents in children with acute ITP were also significantly higher than those in the control group (160.21 +/- 34.26 pg/mL vs 121.42 +/- 12.69 pg/mL; P< 0.05). There was a positive correlation between plasma IL-13 level and lymphoblastic PPAR-gamma mRNA expression in children with ITP (r=0.89, P< 0.05).

CONCLUSIONSPPAR-gamma mRNA expression in peripheral blood lymphocytes increased and were positively correlated with plasma IL-13 contents in children with acute ITP, suggesting that PPAR-gamma and IL-13 might participate in the pathogenesis of acute ITP.

Acute Disease ; Child ; Child, Preschool ; Female ; Humans ; Interleukin-13 ; blood ; physiology ; Lymphocytes ; metabolism ; Male ; PPAR gamma ; genetics ; physiology ; Purpura, Thrombocytopenic, Idiopathic ; etiology ; immunology ; RNA, Messenger ; analysis

BACKGROUNDMicroRNAs (miRNAs) function as essential posttranscriptional modulators of gene expression, and are involved in a wide range of physiologic and pathologic states, including cancer. Numerous miRNAs are deregulated in hepatocellular carcinoma (HCC). This study aimed to investigate the role of miR-27a in the development of HCC.

METHODSThe expression of MiR-27a was measured by quantitative real-time polymerase chain reaction (qRT-PCR). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was used to examine changes in the viability of HepG2, Bel-7402, Bel-7404 hepatoma cell lines associated with up-regulation or down-regulation of miR-27a. A dual-luciferase activity assay was used to verify a target gene of miR-27a. Immunohistochemistry, qRT-PCR, Western blotting analysis, and cell cycle and apoptosis flow cytometric assays were used to elucidate the mechanism by which miR-27a modulates liver cancer cell proliferation.

RESULTSThe expression of miR-27a was significantly increased in HCC tissues and HepG2, Bel-7402, Bel-7404 hepatoma cell lines (P < 0.05). We also found that the down-regulation of miR-27a in HepG2 cells dramatically inhibited proliferation, blocked the G1 to S cell cycle transition and induced apoptosis (P < 0.05). In addition, miR-27a directly targeted the 3'- untranslated region of peroxisome proliferator-activated receptor &gamma; (PPAR-&gamma;), and ectopic miR-27a expression suppressed PPAR-&gamma; expression on the mRNA and protein levels. The rosiglitazone-induced overexpression of PPAR-&gamma; attenuated the effect of miR-27a in HCC cells.

CONCLUSIONSOur findings suggested that miRNA-27a promoted HCC cell proliferation by regulating PPAR-&gamma; expression. MiR-27a may provide a potential therapeutic strategy for HCC treatment.

Carcinoma, Hepatocellular ; genetics ; metabolism ; Cell Proliferation ; genetics ; physiology ; Gene Expression Regulation, Neoplastic ; Hep G2 Cells ; Humans ; Liver Neoplasms ; genetics ; metabolism ; MicroRNAs ; genetics ; physiology ; PPAR gamma ; metabolism

BACKGROUNDPeroxisome proliferator-activated receptor-gamma (PPARgamma) is a kind of ligand-activated transcription factors binding to peroxisome proliferator response element (PPRE), a specific recognition site. It is thought to play a critical role in glucose and lipid metabolism and in inflammation control. The aim of this study was to establish a new cellular model for the quick screening of lipid-lowering drugs, which may be effective as PPAR-gamma ligands on the PPRE-mediated pathway regulatory system.

METHODSTwo plasmids were constructed: pXOE-PPARgamma, in which the human PPARgamma gene was in the downstream of TFIIIA gene promoter, and pLXRN-PPRE-d2EGFP, in which the enhanced green fluorescent protein (EGFP) gene was subcloned into PPRE. The xenopus oocytes were injected with these two plasmids, and consequently treated with prostaglandin E1, pioglitazone, and different kinds of lipid-lowering drugs. After 3 days, the oocytes were observed under a fluorescence microscope. To confirm the drug action,we injected pXOE-PPARgamma plasmid into the oocytes, which then treated with prostaglandin E1 and Hawthorn flavonoids. The mass of expressed lipoprotein lipase (LPL) in the cells was determined by enzyme labeling linked immunosorbent assay (ELISA).

RESULTSThe expression of EGFP was only induced by prostagalandin E1, pioglitazone, Hawthorn flavonoids. A concentration-response relationship was seen between expressed EGFP and Hawthorn flavonoids. The levels of LPL in both Hawthorn flavonoids groups and PPARgamma ligand prostagalandin E1 group injected with pXOE-PPARgamma plasmid increased significantly (< 0.001) compared with controls, and a concentration-response relationship was observed between LPL mass and Hawthorn flavonoids.

CONCLUSIONSIt is possible to establish a PPRE regulatory EGFP reporter system in xenopus oocytes to monitor the activity of PPARgamma ligand. Hawthorn flavonoids can increase the expression of gene downsteam of PPRE by effect on the PPRE pathway regulatory system.

Alprostadil ; pharmacology ; Animals ; Crataegus ; Female ; Hypolipidemic Agents ; pharmacology ; Lipoprotein Lipase ; biosynthesis ; Medicine, Chinese Traditional ; Oocytes ; metabolism ; PPAR gamma ; physiology ; Peroxisome Proliferators ; pharmacology ; Plasmids ; Response Elements ; physiology ; Xenopus