Association of β3 Adrenergic Receptor and Peroxisome Proliferator-activated Receptor Gamma 2 Polymorphisms With Insulin Sensitivity:A Twin Study

Objective To study the effect of β3 adrenergic receptor （β3AR） Trp64Arg and peroxisome proliferator activated receptor gamma 2 （PPAR72） Prol2Ala polymorphisms on insulin resistance. Methods One hundred and eight dizygotic twin pairs were enrolled in this study. Microsatellite polymorphism was used to diagnose zygosity of twins. Insulin sensitivity was estimated with logarithm transformed homeostasis model assessment （HOMA）. PCR-RFLP analysis was performed to detect the variants. As a supplement to the sib-pair method, identity by state （IBS） was used to analyze the association of polymorphisms with insulin sensitivity. Results The genotype frequencies of Trp64Trg, Trp64Arg, and Arg64Arg were 72.3%, 23.8%, and 3.9%, respectively, while the genotype frequencies of Pro12Pro, Pro12Ala, and Ala12Ala were 89.9%, 9.6%, and 0.5%, respectively. For β3AR Trp64Arg the interclass co-twin correlations of Waist-to-hip ratio （WHR）, blood glucose （GLU）, and insulin （INS）, homeostasis model assessment insulin resistance index （HOMA-IR） of the twin pairs sharing 2 alleles of IBS were greater than those sharing 0-1 allele of IBS, and HOMA4R had statistic significance. For PPAR3t2 Prol2Ala most traits of twin pairs sharing 2 alleles of IBS had greater correlations and statistic significance in body mass index （BMI）, WHR, percent of body fat （PBF） and GLU, but there were low correlations of either insulin or HOMA-IR of twin pairs sharing 1 or 2 alleles of IBS. The combined effects of the two variations showed less squared significant twin-pair differences of INS and HOMA-IR among twins sharing 4 alleles of IBS. Condusions β3AR Trp64Arg and PPAR）,2 Pro 12Ala polymorphisms might be associated with insulin resistance and obesity, and there might be slight synergistic effects between this two gene loci, and further studies are necessary to confirm this finding.

Effects of peroxisome proliferator-activated receptor-β/δ on sepsis induced acute lung injury

Background Acute lung injury （ALI） and acute respiratory distress syndrome （ARDS） are the first steps in the development of multiple organ failure induced by sepsis.A systemic excessive inflammatory reaction is currently the accepted mechanism of the pathogenesis of sepsis.Several studies have suggested a protective role of the peroxisome proliferator activated receptor-β/δ （PPAR-β/δ） in related inflammatory diseases.But the role of PPARβ/δ in ALI remains uncertain.The aim of this study was to investigate the role and possible mechanism of PPARβ/δ in ALI induced by sepsis.Methods Cecal ligation and puncture （CLP） was used as a sepsis model.Rats were randomly divided into four groups,the control group （CON,n=6）,sham-operation group （SHAM,n=12）,cecal ligation and puncture group （CLP,n=30）,GW501516 group （CLP＋GW,n=25）,which underwent CLP and were subcutaneously injected with the PPAR-β/δ agonist GW501516 （0.05 mg/100 g body weight）.Survival was monitored to 24 hours after operation.Blood pressure,serum creatinine,blood urea nitrogen,aspartate aminotrasferase and alanine aminotrasferase were measured after CLP.Concentrations of tumor necrosis factor α （TNF-α） and interleukin （IL）-1β in serum were detected by enzyme linked immunosorbent assay （ELISA） kits.Lung tissue samples were stained with H＆E and scored according to the degree of inflammation.Bacterial colonies were counted in the peritoneal fluid.Alveolar macrophages were cultured and incubated with GW501516 （0.15 μmol/L） and PPARβ/δ adenovirus and then treated with Lipopolysaccharide （2 μg/ml） for 2 hours.The TNF-α,IL-1β and IL-6 RNA in lung and alveolar macrophages were determined by real-time PCR.Phosphorylation of signal transducer and activator of transcription 3 （STAT3） in lung and alveolar macrophages was detected by Western blotting.Results GW501516 significantly increased the survival of septic rats,decreased histological damage of the lungs,reduced inflammatory cytokines in serum and lung tissues of septic rats and did not increase counts of peritoneal bacteria.In vitro,GW501516 and over-expression of PPARβ/δ attenuated gene expression of TNF-α,IL-1β and IL-6 in alveolar macrophages.Both in vivo and in vitro,PPARβ/δ inhibited the phosphorylation of STAT3.Conclusion PPARβ/δ plays a protective role in sepsis induced ALI via suppressing excessive inflammation.

Dual therapy of rosiglitazone/pioglitazone with glimepiride on diabetic nephropathy in experimentally induced type 2 diabetes rats

Diabetic nephropathy is a major cause of end-stage renal disease （ESRD） in the general population. It is estimated that diabetic nephropathy will eventually develop in about 40% of all patients with diabetes; therefore, prevention is critical for delaying the development and progression of diabetic kidney disease. Despite extensive efforts, medical advances are still not successful enough to prevent the progression of the disease. In the present study, we focused on the comparison of combination therapies and whether they offered additional renoprotection. Type 2 diabetes mellitus was induced by intraperitoneally administering streptozotocin （90 mg/kg） in neonatal rats and then these rats were treated with rosiglitazone （1.0 mg/kg） in combination with glimepiride （0.5 mg/kg） or with pioglitazone （2.5 mg/kg） in combination with glimepiride （0.5 mg/kg）. Diabetic nephropathy markers were evaluated by biochemical and ELISA kits and renal structural changes were examined by light microscopy and transmission electron microscopy. Results show that the combination of pioglitazone with glimepiride is more effective in amelioration of diabetic nephropathy than rosiglitazone with glimepiride drug therapy due to glycemic control, suppressing albumin excretion rate, total protein excretion rate and augmented TNF-α signaling during the development of streptozotocin induced type 2 diabetic nephropathy.

Influence of Ciglitazone on A549 Cells Growth in vitro and in vivo and Mechanism

The effect and mechanism of the ciglitazone on lung cancer cells A549 growth in vitro and in vivo were studied. Various concentrations of ciglitazone were added to the cultured A549 line, and the proliferation and differentiation of A549 cells were examined by MTT and cytometry analysis. A549 cells （1 × 10^6/mouse） were inoculated subcutaneously into 20 nude mice, which were randomly divided into two groups., the control group, the ciglitazone treated group. The weights of subcutaneous tumors were measured, The expression of cyclin D1 and P21 in the lung was detected by immohistochemistry and Western blot respectively. The results showed that the proliferation of A549 was inhibited significantly by ciglitazone in a dose- and time-dependent manner. There were more ceils arrested in G1/G0 phase and the expression of PPARγ was markedly upregulated in ciglitazone-treated group. Direct injection of ciglitazone into A549-induced tumors could suppress tumor growth in nude mice and the growth inhibitory rate was 36 %. The expression of cyclin D1 was decreased and P21 increased significantly in ciglitazone-treated group as compared with control group. It was concluded that ciglitazone could inhibit A549 proliferation dose-dependently and time-dependently and induce differentiation, ,which might be related to the modulation of cell cycle interfered by PPARγ.

Curcumin inhibits beta-amyloid protein 40/42 expression in the brain in a concentration-and time-dependent manner

Several studies have demonstrated that the amount of beta-amyloid （Aβ） protein in the brain can be lowered by down-regulating Aβ production, promoting Aβ degradation, reducing Aβ oligomerization or deposition, thereby alleviating symptoms of Alzheimer＇s disease. Curcumin has been known to be a peroxisome proliferator activated receptor gamma （PPARy） agonist and can obviously inhibit Aβ production and oligomerization. This study investigated the effects of curcumin on the G-site APP cleaving enzyme 1 （BACE1） activity and PPARy expression in human neuroblastoma SH-SY5Y cells, and validated the inhibitory effects of curcumin on Aβ40/42 expression in the brain. Results revealed that PPARy mRNA and protein expression in the human neuroblastoma SH-SY5Y cells significantly increased with increasing curcumin concentration and time course （P 〈 0.05）; BACE1 mRNA and protein expression and Aβ40/42 production significantly decreased with increasing curcumin concentration and time course （P 〈 0.05）. The changes in PPARy and BACE1 expression during Aβ production could be reversed by the PPARy antagonist GW9662. These findings indicate that curcumin reduced Aβ production by activating PPARy expression and inhibiting BACE1 expression in a concentration- and time-dependent manner.

Neuronal PPARαdeficiency-induced axonal mitochondrial transport defects underly isch⁃emic stroke pathology

OBJECTIVE Peroxisome proliferator activated receptor alpha(PPARα)is an important protective factor in neurovascular diseases such as ischemic stroke.Although PPARαexpression is higher in neurons than astrocytes and microglia,the pathophysiological functions of neuronal specific-PPARαin isch⁃emic stroke remains unknown.Here,we report that neuronal PPARαdeficiency is a key factor of neuronal injury.PPARαexpression markedly decreased in neurons after ischemic stroke.METHODS AND RESULTS Neuronal-specific PPARαknockout(NCKO)exacerbates neuronal damage and brain ischemic injury.PPARαdefi⁃ciency disrupts axonal microtubule organization and mitochondrial transport by decreasing the expression of dynein light chain Tctex-type 1(Dynlt1),which is implicated in cytoprotective role with damaged neurons.Furthermore,resto⁃ration of Dynlt1 expression in neurons of NCKO mice rescue mitochondrial transport disorder,cognitive deficits and brain ischemic injury asso⁃ciated with PPARαdeletion.CONCLUSION These results reveal a critical role for neuronal PPARαin ischemic brain injury by modulating axonal mitochondrial transportation.

Identification and Expression of PPAR in Sinonovacula constricta and Their Potential Regulatory Effects on Δ6 Fad Transcription

Peroxisome proliferator activated receptors(PPAR)are kinds of key transcriptional factors in regulating LC-PUFA biosynthesis.Until now,little is known about PPAR in marine molluscs as well as in other invertebrates.Sinonovacula constricta is the first marine mollusc that is proved to possess the complete LC-PUFA biosynthetic pathway,and it can be a perfect representative to clarify this situation.In this study,the molecular properties of S.constricta PPAR were characterized,and corresponding potential regulatory roles in S.constrictaΔ6 fatty acyl desaturase(Fad)transcription were estimated by dual luciferase assay.Results showed that two PPAR homologs(PPAR_a and_b)were identified in S.constricta.They both contain typical features of vertebrate PPAR,suggesting highly conserved functional regions in PPAR.By phylogenetic comparison,they are clearly different with vertebrate PPAR and can be divided into two distinctive sub-groups.Moreover,they show a high expression level in gill,labial palps,mantle and intestine.Their down-regulated expressions in trochophore larva and veliger larva might be attributed to food-deprivation.Additionally,the transcriptional activity of S.constrictaΔ6 Fad promoter was significantly activated by both PPAR_a and_b,indicating that S.constricta PPAR might play a role in the regulation of LC-PUFA biosynthesis.To our knowledge,this is the first systematic analysis of PPAR in a marine mollusc.The results will provide a valuable reference for further researches on the function of marine molluscan PPAR and their underlying mechanisms in regulating LC-PUFA biosynthesis.

Investigating mechanism of Jiang-zhi-dai-pao-cha for treatment of hyperlipidemia by network pharmacology

Objective:To collect the main components and targets of Jiang-zhi-dai-pao-cha(JZDPC)and investigate the mechanism of JZDPC for the treatment of hyperlipidemia by network pharmacology.Methods:The components and targets of JZDPC were searched from ETCM databases,the targets related to hyperlipidemia were searched from DisGeNET and GeneCards databases,and then the intersection targets and corresponding key components were obtained.Cytoscape 3.8.2 software was used to construct and analyze networks,and then Metascape online database was applied for gene ontology(GO)enrichment analysis and Kyoto Encyclopedia of genes and genomes(KEGG)pathway enrichment analysis of core putative targets.Results:There were 99 overlapping targets between JZDPC and hyperlipidemia,among which NR3C1,ESR1,NR1I2,NFKB1,ESR2,ALOX5,PTGS1,PPARA,RXRA,LPL,PLA2G1B,PYGM,CYP2C9 were the core putative targets,and many members of nuclear receptor 1(NR1)subfamily were included.The core components of JZDPC,such as Ursolic Acid,β-Sitosterol,Resveratrol,Arirubic Acid,Alisol A,Oleanolic Acid,Rhein,Chrysophanol and Emodin,can regulate blood lipid by regulating a series of signaling pathways including the above core potential targets,such as non-alcoholic fatty liver disease(NAFLD)signaling pathway,pathways in cancer,arachidonic acid(AA)metabolism signaling pathway and peroxisome proliferator activated receptor(PPAR)signaling pathway,Starch and sucrose metabolism signaling pathway,etc.They play many roles in the treatment of hyperlipidemia by participating in lipid synthesis and metabolism,anti inflammation,anti oxidative stress,regulating hormone levels and carbohydrate metabolism.Conclusion:Network pharmacology provides a theoretical basis for investigating the mechanism of action of JZDPC,and the NAFLD signaling pathway is one of the most valuable pathways.

Effects of elafibranor on liver fibrosis and gut barrier function in a mouse model of alcohol-associated liver disease

BACKGROUND Alcohol-associated liver disease(ALD)is a leading cause of liver-related morbidity and mortality,but there are no therapeutic targets and modalities to prevent ALD-related liver fibrosis.Peroxisome proliferator activated receptor(PPAR)α and δ play a key role in lipid metabolism and intestinal barrier homeostasis,which are major contributors to the pathological progression of ALD.Meanwhile,elafibranor(EFN),which is a dual PPARαand PPARδagonist,has reached a phase III clinical trial for the treatment of metabolic dysfunctionassociated steatotic liver disease and primary biliary cholangitis.However,the benefits of EFN for ALD treatment is unknown.AIM To evaluate the inhibitory effects of EFN on liver fibrosis and gut-intestinal barrier dysfunction in an ALD mouse model.METHODS ALD-related liver fibrosis was induced in female C57BL/6J mice by feeding a 2.5% ethanol(EtOH)-containing Lieber-DeCarli liquid diet and intraperitoneally injecting carbon tetrachloride thrice weekly(1 mL/kg)for 8 weeks.EFN(3 and 10 mg/kg/day)was orally administered during the experimental period.Histological and molecular analyses were performed to assess the effect of EFN on steatohepatitis,fibrosis,and intestinal barrier integrity.The EFN effects on HepG2 lipotoxicity and Caco-2 barrier function were evaluated by cell-based assays.RESULTS The hepatic steatosis,apoptosis,and fibrosis in the ALD mice model were significantly attenuated by EFN treatment.EFN promoted lipolysis and β-oxidation and enhanced autophagic and antioxidant capacities in EtOH-stimulated HepG2 cells,primarily through PPARαactivation.Moreover,EFN inhibited the Kupffer cell-mediated inflammatory response,with blunted hepatic exposure to lipopolysaccharide(LPS)and toll like receptor 4(TLR4)/nuclear factor kappa B(NF-κB)signaling.EFN improved intestinal hyperpermeability by restoring tight junction proteins and autophagy and by inhibiting apoptosis and proinflammatory responses.The protective effect on intestinal barrier function in the EtOH-stimulated Caco-2 cells was predominantly mediated by PPARδ activation.CONCLUSION EFN reduced ALD-related fibrosis by inhibiting lipid accumulation and apoptosis,enhancing hepatocyte autophagic and antioxidant capacities,and suppressing LPS/TLR4/NF-κB-mediated inflammatory responses by restoring intestinal barrier function.

Nuclear receptors and non-alcoholic fatty liver disease:An update

Non-alcoholic fatty liver disease(NAFLD)has become the leading cause of chronic liver disease in adults and children worldwide.The symptoms of NAFLD range from simple steatosis and non-alcoholic stea-tohepatitis(NASH)to hepatic fibrosis or cirrhosis,even ultimately develops to hepatocellular carcinoma.Nuclear receptors(NRs)are a superfamily of ligand-activated transcription factors,most of which are ligand-activated that control cellular homeostasis in the liver and other tissues.A growing number of studies demonstrated the important role of NRs in NAFLD.In this review,the current findings on the role of NRs in NAFLD are summarized and future perspectives to target NRs for NAFLD are discussed.

A novel vanadium complex VO(p-dmada)inhibits neuroinflammation induced by lipopolysaccharide

Uncontrolled microglial activation is decisively involved in the neuroinflammatory pathogenesis of brain diseases. Consequently, suppression of microglial overactivation appears to be a strategy for the prevention of nerve injury. In this paper, a novel vanadium complex, vanadyl N-(p-N,Ndimethylaminophenylcarbamoylmethyl)iminodiacetate(VO(p-dmada)), was synthesized from vanadyl sulfate and N,N-dimethyl-p-phenylenediamine, which was structurally characterized by Fourier transform infrared spectrum and ESI-MS analysis. The effect of VO(p-dmada) on neuroinflammation was investigated by using the models of lipopolysaccharide(LPS)-induced BV2 microglial cells and BALB/c mice.Our data demonstrated that VO(p-dmada) significantly suppressed microglial activation by downregulating inflammatory mediators and associated proteins, and inactivating nuclear factor-κ B(NF-κ B) signaling pathway. VO(p-dmada) also upregulated peroxisome proliferator activated receptor gamma(PPARγ) by reducing transglutaminase 2 and heat shock protein 60 expression. Co-treatment with PPARγ antagonist GW9662 significantly impeded the inhibitory effect of VO(p-dmada) on LPS-induced neuroinflammation.These cumulative findings demonstrated that VO(p-dmada) is a potential new drug for the treatment of neuroinflammation-related neurodegenerative diseases.

Design,synthesis and evaluation of PPAR gamma binding activity of 2-thioxo-4-thiazolidinone derivatives

We designed and synthesized a series of 2-thioxo-4-thiazolidinone derivatives and evaluated them on peroxisome proliferator activated receptor γ（PPARγ） binding activities.Through the biological assays,compounds 18 and 38 were highlighted with K_i values of 12.15 nmol/Land 14.46 nmol/L,respectively.Then structure-activity relationship（SAR） was analyzed to screen privileged structural modifications.Moreover,molecular fitting of these compounds onto the approved drug Rosightazone in the PPARγligand binding domain was performed to elucidate the SAR and explore potential receptor-ligand interactions.These results demonstrate that the 2-thioxo-4-thiazolidinones can be considered as new promising molecular probes with excellent binding activities to PPARγ.

Protective Effect of Telmisartan on Endothelial Cells Exposed to High Glucose Levels in vitro

Objectives To investigate the effect of telmisartan on human umbilical vein endothelial cells （HUVEC） exposed to high glucose in vitro and the related mechanism. Methods HUVECs were incubated with telmisartan and glucose （5 mmol/L, 30 mmot/L） at 0 h, 12 h, 24 h, 36 h, 48 h, respectively. The level of malondialdehyde （MDA） and superoxide dismutase （SOD） in the supernatant of cultured endothelial cells was measured by thiobarbituric acid test and xanthine oxidase test. The expression of PPAR-γ was determined at 24 hour with Western blot technique. Results When the endothelial cells were cultured in high glucose environment, the MDA level was significantly increased, but the SOD activity and the protein expression of PPAR-γ were markedly decreased. However, the high glucose-induced effects were inhibited by telmisartan intervention. Conclusion Telmisartan can decrease oxidative stress and increase PPAR-γ expression of endothelial cells in high glucose environment. （S Chin J Cardio12009 ; 10 （4） ： 222 -226）