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

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

BACKGROUND/AIMS: Saccharomyces boulardii (S. boulardii) has been reported to be beneficial in the treatment of inflammatory bowel disease, however, little is known about its mechanism of action. Peroxisome proliferator- activated receptor-gamma (PPAR-gamma) is recently found to regulate inflammation in intestinal epithelial cells. We hypothesized that the anti-inflammatory effects of S. boulardii are mediated, in part, through PPAR-gamma. To test this hypothesis, we examined the ability of S. boulardii to modulate the expression of PPAR-gamma in human colon cells. METHODS: Effects of S. boulardii on survival and proliferation of HT-29 human colon cells were assessed by MTT and [3H]thymidine incorporation assays. PPAR-gamma expression was assessed by Western blot and RT-PCR. Induction of interleukin-8 (IL-8) expression by tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), or lipopolysaccharide (LPS) was assessed by RT-PCR. RESULTS: S. boulardii did not affect viability and proliferation of HT-29 cells. S. boulardii up-regulated PPAR-gamma expression at both mRNA and protein levels. Pretreatment of HT-29 cells with S. boulardii blocked PPAR-gamma down-regulation by TNF-alpha, IL-1beta, or LPS, whereas it ameliorated IL-8 response to these proinflammatory factors. CONCLUSIONS: S. boulardii stimulates PPAR-gamma expression and reduces response of human colon cells to proinflammatory cytokines.
Cell Proliferation ; Colon/*metabolism ; *Gene Expression ; HT29 Cells ; Humans ; Interleukin-1/metabolism ; Interleukin-8/metabolism ; Lipopolysaccharides/pharmacology ; PPAR gamma/genetics/*metabolism ; Saccharomyces/*physiology

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

Recent evidences suggest that the activation of peroxisome proliferator-activated receptor (PPAR)-gamma, which is an important transcriptional factor in adipocyte differentiation, also plays an important role in the bone microenvironment. The objective of the study was to clarify whether Pro12Ala polymorphism was related to the serum OPG levels and bone mineral metabolism in healthy Korean women. In 239 Korean women (mean age 51 years), who participated in medical check-up program in a health promotion center, anthropometric measurements, lumbar spine and femoral neck bone mineral density (BMD), bone turnover markers, such as serum total alkaline phosphatase (ALP) levels, urine deoxypyridinoline levels, and 24-h urine calcium excretion were measured. Serum levels of OPG were measured with ELISA method. DNAs were extracted from the samples and the genotyping of the Pro12Ala polymorphism (rs1801282) in the PPAR-gamma gene was performed via an allelic discrimination assay using a TaqMan probe. In addition, we examined the haplotype analysis between two polymorphisms of PPAR-gamma gene, Pro12Ala in exon B and C161T in exon 6 (rs3856806). Allelic frequencies were 0.950 for Pro allele and 0.050 for Ala allele, which was in compliance with Hardy- Weinberg equilibrium, and there was no Ala12Ala genotype among the genotyped subjects. Mean serum OPG level was significantly lower (P=0.035), and serum total ALP was significantly higher (P=0.014) in the Pro12Ala genotype group compared with the Pro12Pro genotype group, which were consistently significant even after adjustment for weight, height, and serum follicle stimulating hormone (FSH). In multiple regression analysis with serum OPG as the dependent variable and age, weight, ALP, femoral neck BMD and Pro12Ala genotype included in the model, only Pro12Ala genotype was significant determinant of serum OPG level (beta=-0.136, P=0.035). The haplotype analysis with C161T polymorphism revealed that subjects with Ala and T alleles showed significantly lower serum OPG levels compared with those with Pro12Pro/CC genotype, which were consistently significant even after adjustment for age, weight, height and FSH (P=0.010). This result suggests statistically significant association of Pro12Ala polymorphisms with serum OPG levels in Korean females.
Alanine/genetics ; *Amino Acid Substitution ; Asian Continental Ancestry Group ; Bone Density/physiology ; Bone and Bones/*metabolism ; Enzyme-Linked Immunosorbent Assay ; Female ; Gene Frequency ; Humans ; Korea ; Middle Aged ; *Mutation ; Osteoprotegerin/*blood/metabolism ; PPAR gamma/*genetics/metabolism ; Polymorphism, Genetic ; Proline/genetics

OBJECTIVETo study the effect of conjugated linoleic acid (CLA) on expression of adiponectin in white adipose tissue of obese rats.

METHODSMale Wistar rats were randomly divided into control group, high-fat group and high fat + CLA group (0.75 g, 1.50 g, 3.00 g per hundred gram diet weight), we observed the effect of CLA on serum insulin and glucose levels of obese rats, and the reverse transcription polymerase chain reaction (RT-PCR) technique was used to measure the expression level of adiponectin and peroxisome proliferator-activated receptor-gamma (PPARgamma) mRNA.

RESULTSThe serum insulin and glucose levels of obese rats were (11.11 +/- 2.73) microIU/ml, (5.09 +/- 0.66) mmol/L. The supplement of CLA decreased the hyperinsulinemia and hyperglycemia, the serum insulin in CLA group (0.75 g, 1.50 g, 3.00 g per hundred gram diet weight) were (6.99 +/- 1.77) microIU/ml, (7.36 +/- 1.48) microIU/ml, (7.85 +/- 1.60) microIU/ml (P < 0.05), and glucose were (4.28 +/- 0.72) mmol/L, (4.18 +/- 0.55) mmol/L (P < 0.05), (4.06 +/- 0.63) mmol/L (P < 0.05), CLA can increase the expression of adiponectin and PPARgamma in adipose tissue of obese rat.

CONCLUSIONThe CLA might improve the insulin resistance of the obese rat and increase the expression of adiponectin mRNA, which might possibly act through activating PPARgamma.

Adiponectin ; biosynthesis ; genetics ; Adipose Tissue ; metabolism ; Animals ; Insulin Resistance ; physiology ; Linoleic Acids, Conjugated ; pharmacology ; Male ; Obesity ; metabolism ; PPAR gamma ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction

This paper was aimed to investigate the effects of ATP-sensitive potassium channels on the proliferation and differentiation of rat preadipocytes. We examined the expression of sulphonylurea receptor 2 (SUR2) mRNA in preadipocytes and adipocytes obtained by inducing for 5 d and the effects of the inhibitor (glibenclamide) and opener (diazoxide) of ATP-sensitive potassium channels on the expression of SUR2 mRNA in preadipocytes by real-time PCR. Preadipocyte proliferation and cell cycle were measured by MTT spectrophotometry and flow cytometer. The content of intracellular lipid was measured by oil red O staining, cell diameter was determined by Image-Pro Plus 5.0 software and the expression of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) mRNA was estimated by RT-PCR. SUR2 mRNA was expressed in both preadipocytes and adipocytes obtained by inducing for 5 d, and the expression in adipocytes was obviously higher than that in preadipocytes. Glibenclamide inhibited the expression of SUR2 mRNA in preadipocyte, promoted preadipocyte proliferation in a dose-dependent manner, increased the cell percentages in G(2)/M + S phase, increased lipid content, augmented adipocyte diameter, and promoted the expression of PPAR-gamma mRNA. But the actions of diazoxide were contrary to those of glibenclamide. These results suggest that ATP-sensitive potassium channels regulate the proliferation and differentiation of preadipocytes, and PPAR-gamma is probably involved in the effect of ATP-sensitive potassium channels.
ATP-Binding Cassette Transporters ; genetics ; metabolism ; Adipocytes ; cytology ; Animals ; Cell Differentiation ; physiology ; Cell Proliferation ; Cells, Cultured ; KATP Channels ; physiology ; Male ; Obesity ; pathology ; PPAR gamma ; metabolism ; Potassium Channels, Inwardly Rectifying ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Drug ; genetics ; metabolism ; Sulfonylurea Receptors

Mitofusin2 (Mfn2) plays a pivotal role in the proliferation and apoptosis of vascular smooth muscle cells (VSMCs). The purpose of this study was to investigate the effects of Mfn2 on the trafficking of intracellular cholesterol in the foam cells derived from rat VSMCs (rVSMCs) and also to investigate the effects of Mfn2 on the expression of adenosine triphosphate-binding cassette subfamily A member 1 (ABCA1), adenosine triphosphate-binding cassette subfamily G member 1 (ABCG1) and peroxisome proliferator-activated receptor gamma (PPAR&gamma;). The rVSMCs were co-cultured with oxidized low density lipoprotein (LDL, 80 μg/mL) to produce foam cells and cholesterol accumulation in cells. Before oxidized LDL treatment, different titers (20, 40 and 60 pfu/cell) of recombinant adenovirus containing Mfn2 gene (Adv-Mfn2) were added into the culture medium for 24 h to transfect the Mfn2 gene into the rVSMCs. Then the cells were harvested for analyses. The protein expression of Mfn2 was significantly higher in Adv-Mfn2-transfected group than in untransfected group (P<0.05), and the expression levels significantly increased when the titer of Adv-Mfn2 increased (P<0.05). At 24 or 48 h after oxidized LDL treatment, rVSMCs became irregular and their nuclei became larger, and their plasma abounded with red lipid droplets. However, the number of red lipid droplets was significantly decreased in Adv-Mfn2-transfected group as compared with untransfected group. At 48 h after oxidized LDL treatment, the intracellular cholesterol in rVSMCs was significantly increased (P<0.05), but it was significantly decreased in Adv-Mfn2-transfected group as compared with untransfected group (P<0.05), and it also significantly decreased when the titer of Adv-Mfn2 increased (P<0.05). The mRNA and protein expression levels of ABCA1 and ABCG1 were significantly increased in Adv-Mfn2-transfected group as compared with untransfected group (P<0.05). Though the mRNA and protein expression levels of PPAR&gamma; was not significantly increased (P>0.05), the phosporylation levels of PPAR&gamma; were significantly decreased in Adv-Mfn2-transfected group as compared with untransfected group (P<0.05). These results suggest that the transfection of Adv-Mfn2 can significantly reduce intracellular cholesterol in oxidized LDL-induced rVSMCs possibly by decreasing PPAR&gamma; phosporylation and then increasing protein expression levels of ABCA1 and ABCG1, which may be helpful to suppress the formation of foam cells.
ATP Binding Cassette Transporter 1 ; metabolism ; ATP Binding Cassette Transporter, Sub-Family G, Member 1 ; ATP-Binding Cassette Transporters ; metabolism ; Animals ; Cell Differentiation ; physiology ; Cells, Cultured ; Cholesterol ; metabolism ; Foam Cells ; cytology ; metabolism ; Intracellular Fluid ; metabolism ; Lipoproteins, LDL ; metabolism ; Membrane Proteins ; genetics ; metabolism ; Mitochondrial Proteins ; genetics ; metabolism ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Oxidation-Reduction ; PPAR gamma ; metabolism ; Rats

BACKGROUND: Visual-spatial neglect (VSN) is a neuropsychological syndrome, and right-hemisphere stroke is the most common cause. The pathogenetic mechanism of VSN remains unclear. This study aimed to investigate the behavioral and event-related potential (ERP) changes in patients with or without VSN after right-hemisphere stroke. METHODS: Eleven patients with VSN with right-hemisphere stroke (VSN group) and 11 patients with non-VSN with right-hemisphere stroke (non-VSN group) were recruited along with one control group of 11 age- and gender-matched healthy participants. The visual-spatial function was evaluated using behavioral tests, and ERP examinations were performed. RESULTS: The response times in the VSN and non-VSN groups were both prolonged compared with those of normal controls (P < 0.001). In response to either valid or invalid cues in the left side, the accuracy in the VSN group was lower than that in the non-VSN group (P < 0.001), and the accuracy in the non-VSN group was lower than that in controls (P < 0.05). The P1 latency in the VSN group was significantly longer than that in the control group (F[2, 30] = 5.494, P = 0.009), and the N1 amplitude in the VSN group was significantly lower than that in the control group (F[2, 30] = 4.343, P = 0.022). When responding to right targets, the left-hemisphere P300 amplitude in the VSN group was significantly lower than that in the control group (F[2, 30] = 4.255, P = 0.025). With either left or right stimuli, the bilateral-hemisphere P300 latencies in the VSN and non-VSN groups were both significantly prolonged (all P < 0.05), while the P300 latency did not differ significantly between the VSN and non-VSN groups (all P > 0.05). CONCLUSIONS Visual-spatial attention function is impaired after right-hemisphere stroke, and clinicians should be aware of the subclinical VSN. Our findings provide neuroelectrophysiological evidence for the lateralization of VSN.
Adult ; Aged ; Cerebral Infarction ; physiopathology ; Electrophysiology ; Female ; Humans ; Male ; Middle Aged ; Neuropsychological Tests ; Nitric Oxide Synthase Type III ; genetics ; PPAR gamma ; genetics ; Perceptual Disorders ; genetics ; metabolism ; physiopathology ; Polymorphism, Genetic ; genetics ; Reaction Time ; genetics ; physiology ; Reactive Oxygen Species ; metabolism ; Stroke ; genetics ; metabolism ; physiopathology ; Superoxide Dismutase ; genetics

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