OBJECTIVE: To study the protective effect of enhanced peroxisome proliferator activated receptor γ (PPARγ) pathway against apoptosis of long-term cultured primary nerve cells. METHODS: A natural aging model was established in primary rat nerve cells by long-term culture for 22 days. The cells were divided into control group, 0.1, 1.0, 5.0, and 10 μmol/L GW9662 intervention groups, and 0.1, 1.0, 5.0, and 10 μmol/L pioglitazone intervention groups. The cell viability was assessed using MTT assay and the cell morphological changes were observed after the treatments to determine the optimal concentrations of GW9662 and pioglitazone. Double immunofluorescence labeling and flow cytometry were used to observe the changes in the number of viable cells and cell apoptosis following the treatments; immunocytochemical staining was used to assess the changes in the anti-oxidation ability of the treated cells. RESULTS: The optimal concentrations of GW9662 and pioglitazone determined based on the cell viability and morphological changes were both 1 μmol/L. Compared with the control group, GW9662 treatment significantly lowered while pioglitazone significantly increased the total cell number and nerve cell counts ( < 0.05), and nerve cells in the cell cultures maintained a constant ratio at about 80% in all the groups ( > 0.05). GW9662 significantly enhanced while pioglitazone significantly lowered the cell apoptosis rates compared with the control group ( < 0.05). GW9662 obviously lowered SOD activity and GSH content in G group ( < 0.05) and increased MDA content in the cells ( < 0.05), and pioglitazone resulted in reverse changes in SOD, GSH and MDA contents in the cells ( < 0.05). CONCLUSIONS Activation of PPARγ pathway protects long-term cultured primary nerve cells by enhancing cellular anti-oxidant capacity and reducing cell apoptosis, suggesting a potential strategy for anti-aging treatment of the nervous system through intervention of the PPARγ pathway.
Anilides ; administration & dosage ; pharmacology ; Animals ; Apoptosis ; Cell Proliferation ; Cell Survival ; Cells, Cultured ; Cellular Senescence ; physiology ; Neurons ; cytology ; PPAR gamma ; metabolism ; Pioglitazone ; administration & dosage ; pharmacology ; 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

In gliomas, the canonical Wingless/Int (WNT)/β-catenin pathway is increased while peroxisome proliferator-activated receptor gamma (PPAR-γ) is downregulated. The two systems act in an opposite manner. This review focuses on the interplay between WNT/β-catenin signaling and PPAR-γ and their metabolic implications as potential therapeutic target in gliomas. Activation of the WNT/β-catenin pathway stimulates the transcription of genes involved in proliferation, invasion, nucleotide synthesis, tumor growth, and angiogenesis. Activation of PPAR-γ agonists inhibits various signaling pathways such as the JAK/STAT, WNT/β-catenin, and PI3K/Akt pathways, which reduces tumor growth, cell proliferation, cell invasiveness, and angiogenesis. Nonsteroidal anti-inflammatory drugs, curcumin, antipsychotic drugs, adiponectin, and sulforaphane downregulate the WNT/β-catenin pathway through the upregulation of PPAR-γ and thus appear to provide an interesting therapeutic approach for gliomas. Temozolomide (TMZ) is an antiangiogenic agent. The downstream action of this opposite interplay may explain the TMZ-resistance often reported in gliomas.
Animals ; Brain Neoplasms ; metabolism ; therapy ; Dacarbazine ; analogs & derivatives ; pharmacology ; Down-Regulation ; drug effects ; Glioma ; metabolism ; therapy ; Humans ; PPAR gamma ; metabolism ; Temozolomide ; Wnt Signaling Pathway ; drug effects ; physiology

OBJECTIVE: To investigate the effect of limb remote ischemic preconditioning (RIPC) on hepatic ischemia/reperfusion (IR) injury and the underlying mechanisms.
 METHODS: Rats were subjected to partial hepatic IR (60 min ischemia followed by 24 hours reperfusion) with or without RIPC, which was achieved by 3 cycles of 10 min-occlusion and 10 min-
reperfusion at the bilateral femoral arteries interval 30 min before ischemia. Some rats were treated with a new PPAR-γ inhibitor, T0070907, before RIPC.
 RESULTS: At the end of reperfusion, liver injury was significantly increased (increases in Suzike's injury score, AST and ALT release), concomitant with elevated oxidative stress (increases in MDA formation, MPO activity, as well as the decrease in SOD activity) and inflammation (increases in TNF-α and IL-6 levels, decrease in IL-10 content). RIPC improved liver function and reduced histologic damage, accompanied by the increased PPAR-γ activation and autophagosome formation as well as the reduced autophagosome clearance. The beneficial effects of RIPC were markedly attenuated by T0070907, an inhibitor of PPAR-γ.
 CONCLUSION RIPC exerts the protective effects on liver by activation of autophagy via PPAR-γ.
Animals ; Autophagy ; drug effects ; genetics ; physiology ; Extremities ; Interleukin-10 ; metabolism ; Interleukin-6 ; metabolism ; Ischemia ; Ischemic Preconditioning ; methods ; Liver ; injuries ; Liver Diseases ; prevention & control ; Oxidative Stress ; drug effects ; PPAR gamma ; antagonists & inhibitors ; Rats ; Reperfusion Injury ; prevention & control ; Tumor Necrosis Factor-alpha ; metabolism

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

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

OBJECTIVETo study the expression of Galectin-9 and Tim-3 in lungs of mice with asthma and the effect of rosiglitazone (PPAR-&gamma; agonist) on their expression.

METHODSFortyfive BALB/c SPF female mice were randomized into control group and asthma groups with and without rosiglitazone intervention. After ovalbumin stimulation and rosiglitazone intervention the pathological changes of the lung tissues were observed. Galectin-9 and Tim-3 mRNA levels in lung tissues were determined using RT-PCR. The levels of IL-4 and IFN-&gamma; in peripheral blood were measured using ELISA.

RESULTSThe expression of Galectin-9 and Tim-3 mRNA of lung tissues in the untreated asthma group increased significantly compared with the control and the rosiglitazone treated groups (P<0.05). A significantly increased blood expression of IL-4 and a significantly decreased blood expression of IFN-&gamma; were found in the untreated asthma group compared with the control and the rosiglitazone-treated groups (P<0.05). The expression of Galectin-9 and Tim-3 mRNA was positively correlated with blood IL-4 level (r=0.792, r=0.794 respectively; P<0.05), but negatively correlated with blood IFN-&gamma; level (r=-0.692, r=-0.757 respectively; P<0.05).

CONCLUSIONSGalectin-9 and Tim-3 mRNA levels in lungs increase in mice with asthma and significantly correlate with the levels of blood Th1/Th2 cytokines. This suggests that Galectin-9 and Tim-3 are closely related to inflammatory process in asthma. Rosiglitazone treatment may decrease the expression of Galectin-9 and Tim-3.

Animals ; Asthma ; drug therapy ; immunology ; pathology ; Female ; Galectins ; genetics ; Hepatitis A Virus Cellular Receptor 2 ; Interferon-gamma ; blood ; Interleukin-4 ; blood ; Lung ; metabolism ; pathology ; Mice ; Mice, Inbred BALB C ; PPAR gamma ; physiology ; RNA, Messenger ; analysis ; Receptors, Virus ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Th1 Cells ; immunology ; Th2 Cells ; immunology ; Thiazolidinediones ; therapeutic use

OBJECTIVETo observe the effect of pioglitazone on hypoxia/reoxygenation injury and the expression of protein kinase C (PKC) in neonatal rat cardiomyocytes.

METHODSNeonatal Sprague-Dawley rat cardiomyocytes in primary culture were treated with pioglitazone or GW9662 for 24 h prior to hypoxia/reoxygenation injury. Cardiomyocyte apoptosis was evaluated with Hoechst33258 staining and the expression of PKC was detected using Western blotting.

RESULTSIn the early stage of hypoxia/reoxygenation injury, the apoptosis rates of the cardiomyocytes increased significantly from (0.20∓0.03)% of the control level to (12.22∓1.45)% (P<0.05). Pretreatment with pioglitazone significantly lowered the apoptosis rate of the cardiomyocytes with hypoxia/reoxygenation injury to (8.32∓0.89)%, and this effect was antagonized by GW9662, a specific blocker of peroxisome proliferators activated receptors &gamma; (PPAR&gamma;). Pioglitazone did not cause increased expression of PKC in the cardiomyocytes.

CONCLUSIONPioglitazone can ameliorate neonatal rat cardiomyocyte injury induced by hypoxia/reoxygenation partially by activating PPAR&gamma; and does not increase the expression of PKC in the cells.

Animals ; Animals, Newborn ; Apoptosis ; drug effects ; Cell Hypoxia ; physiology ; Female ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Myocardial Reperfusion Injury ; physiopathology ; prevention & control ; Myocytes, Cardiac ; enzymology ; pathology ; PPAR gamma ; metabolism ; Potassium Channels ; metabolism ; Primary Cell Culture ; Protein Kinase C ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Thiazolidinediones ; pharmacology

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