Peroxisome proliferator-activated receptor gamma inhibits hepatic fibrosis in rats

BACKGROUND:Hepatic fibrosis is a necessary step in the development of hepatic cirrhosis.In this study we used lentiviral vector-mediated transfection technology to evaluate the effect of peroxisome proliferator-activated receptor gamma(PPAR-γ) on rat hepatic fibrosis. METHODS:Hepatic fibrosis in rats was induced by CCl4 for 2 weeks(early fibrosis)and 8 weeks(sustained fibrosis).The rats were randomly divided into four groups:normal control, fibrosis,blank vector,and PPAR-γ.They were infected with the recombinant lentiviral expression vector carrying the rat PPAR-γgene by portal vein injection.The liver of the rats was examined histologically and hydroxyproline was assessed.In vitro primary hepatic stellate cells(HSCs)were infected with the recombinant lentiviral expression vector carrying the rat PPAR-γgene.The status of HSC proliferation was measured by the MTT assay.The protein levels of PPAR-γ,α-smooth muscle actin(α-SMA)and type I collagen expression were evaluated by the Western blotting method. RESULTS:In vitro studies revealed that expression of PPAR-γ inhibited expression ofα-SMA and type I collagen in activated HSCs(P<0.01)as well as HSC proliferation(P<0.01).In vivo experiments indicated that in the early hepatic fibrosis group,the hydroxyproline content and the level of collagen I protein in the liver in the PPAR-γtransfected group were not significantly different compared to the hepatic fibrosis group and the blank vector group;whereas the expressions of PPAR-γ andα-SMA were different compared to the hepatic fibrosis group(P<0.01).In the sustained hepatic fibrosis group,there were significant differences in the hydroxyproline content and the expression of PPAR-γ,α-SMA,and type I collagen between each group.CONCLUSION:PPAR-γcan inhibit HSC proliferation and hepatic fibrosis,and suppressα-SMA and type I collagen expression.

Effect of ligand of peroxisome proliferator-activated receptor γ on the biological characters of hepatic stellate cells

AIM： To study the effect of rosiglitazone, which is a ligand of peroxisome proliferator-activated receptor gamma （PPARy）, on the expression of PPARy in hepatic stellate cells （HSCs） and on the biological characteristics of HSCs. METHODS： The activated HSCs were divided into three groups： control group, 3 μmol/L rosiglitazone group, and 10 μmol/L rosiglitazone group. The expression of PPARγ, α-smooth muscle actin （α-SMA）, and type Ⅰ and Ⅲ collagen was detected by RT-PCR, Western blot and immunocytochemical staining, respectively. Cell proliferation was determined with methylthiazolyltetrazolium （MTT） colodmetric assay. Cell apoptosis was demonstrated with flow cytometry. RESULTS： The expression of PPARγ at mRNA and protein level markedly increased in HSCs of 10 μmol/L rosiglitazone group （tvalue was 10.870 and 4.627 respectively, P〈0.01 in both）. The proliferation of HSCs in 10 μmol/L rosiglitazone group decreased significantly （t = 5.542, P〈0.01）, α-SMA expression level and type Ⅰ collagen synthesis ability were also reduced VS controls （tvalue = 10.256 and 14.627 respectively, P〈0.01 in both）. The apoptotic rate of HSCs significantly increased in 10 μmol/L rosiglitazone group vs control （X^2= 16.682, P〈0.01）. CONCLUSION： By increasing expression of PPARγ in activated HSCs, rosiglitazone, an agonist of PPARγ, decreases α-SNA expression and type Ⅰ collagen synthesis, inhibits cell proliferation, and induces cell apoptosis.

Protective effect of ghrelin on left ventricular remodeling in spontaneously hypertensive rats is associated with the peroxisome proliferator-activated receptor gamma-dependent pathway

Background Studies suggested that exogenous ghrelin administration could prevent early left ventricular remodeling in rats with myocardial infarction. We investigated herein whether ghrelin attenuated left ventricular remodeling induced by hypertension and whether ghrelin＇s effect was mediated through the peroxisome proliferator-activated receptor gamma （PPAR-y）-dependent pathway. Methods Spontaneously hypertensive rats （8-week-old males） were randomly divided into three groups with 12 rats in each： ghrelin group （received ghrelin 100 IJg/kg subcutaneously （sc） twice daily）; ghrelin＋GW9662 group （received the PPAR-y antagonist GW9662 at 2 mg/kg sc, and then ghrelin as above）; saline controls. Normal male Wistar Kyoto rats （n=-12） served as normal controls. Four weeks later, the effects of ghrelin on cardiac remodeling were evaluated by echocardiographic, hemodynamic, and histopathological examination, and gene expression analysis （PPAR-y protein and mRNA expression）. The serum levels of C-reactive protein （CRP） and tumor necrosis factor （TNF）-a were detected by enzyme linked immunosorbent assay. Results Ghrelin prevented ventricular remodeling, increased PPAR-y expression in the myocardium, suppressed collagen I and collagen Ill mRNA expression, and also decreased the serum levels of TNF-a, but not CRP. All abovementioned effects of ghrelin were inhibited by GW9662. Conclusion Ghrelin inhibited ventricular remodeling induced by hypertension, and the preventive effects of ghrelin may be mediated by the anti-inflammatory actions of the PPAR-y-dependent pathway.

Peroxisome proliferator-activated receptor gamma signaling in human sperm physiology

Peroxisome proliferator-activated receptor gamma （PPARy） is a member of the PPARs, which are transcription factors of the steroid receptor superfamily. PPARy acts as an important molecule for regulating energy homeostasis, modulates the hypothalamic-pituitary-gonadal （HPG） axis, and is reciprocally regulated by HPG. In the human, PPARγprotein is highly expressed in ejaculated spermatozoa, implying a possible role of PPARγ signaling in regulating sperm energy dissipation. PPARγ protein is also expressed in Sertoli cells and germ cells （spermatocytes）. Its activation can be induced during capacitation and the acrosome reaction. This mini-review will focus on how PPARy signaling may affect fertility and sperm quality and the potential reversibility of these adverse effects.

Hepatic lipid homeostasis by peroxisome proliferator-activated receptor gamma 2

Peroxisome proliferator-activated receptor gamma(PPARγor PPARG)is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily.It plays a master role in the differentiation and proliferation of adipose tissues.It has two major isoforms,PPARγ1 and PPARγ2,encoded from a single gene using two separate promoters and alternative splicing.Among them,PPARγ2 is most abundantly expressed in adipocytes and plays major adipogenic and lipogenic roles in the tissue.Furthermore,it has been shown that PPARγ2 is also expressed in the liver,specifically in hepatocytes,and its expression level positively correlates with fat accumulation induced by pathological conditions such as obesity and diabetes.Knockout of the hepatic Pparg gene ameliorates hepatic steatosis induced by diet or genetic manipulations.Transcriptional activation of Pparg in the liver induces the adipogenic program to store fatty acids in lipid droplets as observed in adipocytes.Understanding how the hepatic Pparg gene expression is regulated will help develop preventative and therapeutic treatments for non-alcoholic fatty liver disease(NAFLD).Due to the potential adverse effect of hepatic Pparg gene deletion on peripheral tissue functions,therapeutic interventions that target PPAR g for fatty liver diseases require fine-tuning of this gene's expression and transcriptional activity。

Association between peroxisome proliferator-activated receptor-γ coactivator-1α gene polymorphisms and type 2 diabetes in southern Chinese population:role of altered interaction with myocyte enhancer factor 2C

Background Some single nucleotide polymorphisms （SNPs） in the peroxisome proliferator-activated receptor-y coactivator （PGC）-1α gene have been reported to be associated with type 2 diabetes in different populations, and studies on Chinese patients yielded controversial results. The objective of this case-control study was to explore the relationship between SNPs of PGC-1α and type 2 diabetes in the southern Chinese population and to determine whether the common variants： Gly482Ser and Thr394Thr, in the PGC-1α gene have any impacts on interaction with myocyte enhancer factor （MEF） 2C. Methods The SNPs in all exons of the PGC-1α gene was investigated in 50 type 2 diabetic patients using polymerase chain reaction-single strand conformational polymorphism （PCR-SSCP） and direct sequencing. Thereafter, 263 type 2 diabetic patients and 282 healthy controls were genotyped by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP）. A bacterial two-hybrid system and site-directed mutagenesis were used to investigate whether Gly482Ser and Thr394Thr variants in the PGC-1α gene alter the interaction with MEF2C. Results Three frequent SNPs （Thr394Thr, Gly482Ser and Thr528Thr） were found in exons of the PGC-1α gene. Only the Gly482Ser variant had a different distribution between diabetic patients and healthy subjects, with the 482Ser allele more frequent in patients than in controls （40.1% vs 29.3%, P〈0.01）. Even in controls, the 482Ser（A） carriers were more likely to have higher levels of total cholesterol and low-density lipoprotein cholesterol than the 482Gly（G） carriers. The 394A-482G-528A haplotype was associated with protection from diabetes, while the 394A-482A-528A was associated with the susceptibility to diabetes. The bacterial two-hybrid system and site-directed mutagenesis revealed that the 482Ser variant was less efficient than the 482Gly variant to interact with MEF2C, whereas the 394Thr （A） had a synergic effect on the interaction between 482Ser variant and MEF2C. Conclusions The results suggested that the 482Ser variant of PGC-1α conferred the susceptibility to type 2 diabetes in the southern Chinese population. The underlying mechanism may be attributable, at least in part, to the altered interaction between the different variants （Gly482Ser, Thr394Thr） in the PGC-1α gene and MEF2C.

Effect of Peroxisome Proliferator-Activated Receptor-γ Coactivator-1 Alpha Variants on Spontaneous Clearance and Fibrosis Progression during Hepatitis C Virus Infection in Moroccan Patients

Hepatitis C virus(HCV)is still one of the main causes of liver disease worldwide.Metabolic disorders,including nonalcoholic fatty liver disease(NAFLD),induced by HCV have been shown to accelerate the progression of fibrosis to cirrhosis and to increase the risk of hepatocellular carcinoma.An optimal peroxisome proliferator-activated receptor gamma coactivator 1-alpha(PPARGC1A)activity is crucial to prevent NAFLD installation.The present study aims to investigate the associations between two common PPARGC1A polymorphisms(rs8192678 and rs12640088)and the outcomes of HCV infection in a North African context.A series of 592 consecutive Moroccan subjects,including 292 patients with chronic hepatitis C(CHC),100 resolvers and 200 healthy controls were genotyped using a TaqMan allelic discrimination assay.PPARGC1A variations at rs8192678 and rs12640088 were not associated with spontaneous clearance of HCV infection(adjusted ORs=0.76 and 0.79 respectively,P[0.05,for both).Furthermore,multivariable logistic regression analysis showed that both SNPs were not associated with fibrosis progression(OR=0.71;95%CI 0.20–2.49;P=0.739;OR=1.28;95%CI 0.25–6.54;P=0.512,respectively).We conclude that,in the genetic context of South Mediterranean patients,rs8192678 and rs12640088 polymorphisms of PPARGC1 A are neither associated with spontaneous clearance nor with disease progression in individuals infected with HCV.

Analysis of an adult diabetes mellitus caused by a rare mutation of the gene:A case report

BACKGROUND This study presents the clinical and genetic mutation characteristics of an unusual case of adult-onset diabetes mellitus occurring in adolescence,featuring a unique mutation in the peroxisome proliferator-activated receptor gamma(PPARG)gene.Data Access Statement:Research data supporting this publication are available from the NN repository at www.NNN.org/download/.CASE SUMMARY The methodology employed entailed meticulous collection of comprehensive clinical data from the probands and their respective family members.Additionally,high-throughput sequencing was conducted to analyze the PPARG genes of the patient,her siblings,and their offspring.The results of this investigation revealed that the patient initially exhibited elevated blood glucose levels during pregnancy,accompanied by insulin resistance and hypertriglyceridemia.Furthermore,these strains displayed increased susceptibility to diabetic kidney disease without any discernible aggregation patterns.The results from the gene detection process demonstrated a heterozygous mutation of guanine(G)at position 284 in the coding region of exon 2 of PPARG,which replaced the base adenine(A)(exon2c.284A>Gp.Tyr95Cys).This missense mutation resulted in the substitution of tyrosine with cysteine at the 95th position of the translated protein.Notably,both of her siblings harbored a nucleotide heterozygous variation at the same site,and both were diagnosed with diabetes.CONCLUSION The PPARG gene mutation,particularly the p.Tyr95Cys mutation,may represent a newly identified subtype of maturity-onset diabetes of the young.This subtype is characterized by insulin resistance and lipid metabolism disorders.

吡格列酮对大鼠缺血/再灌注心肌过氧化物酶体增殖物受体γ辅激活因子lα表达的影响

目的观察吡格列酮对大鼠缺血/再灌注损伤心肌过氧化物酶体增殖物受体γ辅激活因子lα(PGC-lα)表达的影响。方法 24只SD大鼠随机分为4组(n=6):缺血/再灌注组、吡格列酮5 mg/(kg·d)组、吡格列酮10 mg/(kg·d)组、吡格列酮10 mg/(kg·d)+过氧化物酶体增殖物激活受体γ(PPARγ)特异性阻断剂GW9662组,利用在体结扎左前降支的方法建立缺血/再灌注损伤模型,脱氧核糖核苷酸末端转移酶介导的缺口末端标记法(TUNEL法)检测心肌细胞凋亡,RT-PCR方法检测心肌组织PGC-lαmRNA的变化,Western blot检测心肌组织PGC-lα蛋白的变化。结果 TUNEL法显示吡格列酮抑制缺血/再灌注心肌细胞凋亡[(21.4±8.8)%、(17.3±8.7)%、(40.1±12.3)%,P<0.05)],吡格列酮上调PGC-lα表达(P<0.05),GW9662逆转吡格列酮对凋亡细胞的抑制作用(P<0.05),抑制吡格列酮促进PGC-lα表达上调的作用(P<0.05)。结论吡格列酮抑制缺血/再灌注损伤诱导的心肌细胞凋亡,吡格列酮促进PGC-lα上调,这两种作用是由PPARγ介导的。

Heme oxygenase-1 prevents liver fibrosis in rats by regulating the expression of PPAR_γ and NF-_κB

AIM:To investigate the effects of heme oxygenase(HO)-1 on liver fibrosis and the expression of peroxisome proliferator-activated receptor gamma(PPARγ) and nuclear factor-kappa B(NF-κB) in rats.METHODS:Sixty Wistar rats were used to construct liver fibrosis models and were randomly divided into 5 groups:group A(normal,untreated),group B(model for 4 wk,untreated),group C(model for 6 wk,untreated),group D [model for 6 wk,treated with zinc protoporphyrin Ⅸ(ZnPP-Ⅸ) from week 4 to week 6],group E(model for 6 wk,treated with hemin from week 4 to week 6).Next,liver injury was assessed by measuring serum alanine aminotransferase(ALT),aspartate aminotransferase(AST) and albumin levels.The degree of hepatic fibrosis was evaluated by measuring serum hyaluronate acid(HA),type Ⅳ collagen(Ⅳ-C) and by histological examination.Hydroxyproline(Hyp) content in the liver homogenate was determined.The expres-sion levels of alpha-smooth muscle actin(α-SMA) in liver tissue were measured by real-time quantitative polymerase chain reaction(RT-PCR).The expression levels of PPARγ and NF-κB were determined by RT-PCR and Western blotting.RESULTS:The expression of HO-1 increased with the development of fibrosis.Induction of HO-1 by hemin significantly attenuated the severity of liver injury and the levels of liver fibrosis as compared with inhibition of HO-1 by ZnPP-Ⅸ.The concentrations of serum ALT,AST,HA and Ⅳ-C in group E decreased compared with group C and group D(P < 0.01).Amount of Hyp and α-SMA in the liver tissues in group E decreased compared with group C(0.62 ± 0.14 vs 0.84 ± 0.07,1.42 ± 0.17 vs 1.84 ± 0.17,respectively,P < 0.01) and group D(0.62 ± 0.14 vs 1.11 ± 0.16,1.42 ± 0.17 vs 2.56 ± 0.37,respectively,P < 0.01).The expression of PPARγ at levels of transcription and translation decreased with the development of fibrosis especially in group D;and it increased in group E compared with groups C and D(0.88 ± 0.15 vs 0.56 ± 0.19,0.88 ± 0.15 vs 0.41 ± 0.11,respectively,P < 0.01).The expression of NF-κB increased with the development of fibrosis especially in group D;and it decreased in group E compared with groups C and D(1.43 ± 0.31 vs 1.89 ± 0.29,1.43 ± 0.31 vs 2.53 ± 0.54,respectively,P < 0.01).CONCLUSION:Our data demonstrate a potential mechanism that HO-1 can prevent liver fibrosis by enhancing the expression of PPARγ and decreasing the expression of NF-κB in liver tissues.

Mitofusin2 Decreases Intracellular Cholesterol of Oxidized LDL-Induced Foam Cells from Rat Vascular Smooth Muscle Cells

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 traffick- ing of intracellular cholesterol in the foam ceils 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 （PPARy）. The rVSMCs were co-cultured with oxi- dized low density lipoprotein （LDL, 80 ~tg/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 ex- pression levels significantly increased when the titer of Adv-Mfn2 increased （P〈0.05）. At 24 or 48 h af- ter 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 sig- nificantly 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 pro- tein 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 PPARy was not significantly increased （P〉0.05）, the phosporylation levels of PPARy were signifi- cantly 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＇/phosporylation and then increasing pro- tein expression levels of ABCAI and ABCG1, which may be helpful to suppress the formation of foam cells.

Reversal of P-glycoprotein-mediated Multidrug Resistance in SGC7901/VCR Cells by PPARγ Activation by Troglitazone

Over-expression of P-glycoprotein(P-gp),an ATP-dependent drug efflux pump,represents one of the major mechanisms that contribute to multidrug resistance(MDR) in cancer cells.This study examined the effects of troglitazone,a ligand of peroxisome proliferator-activated receptor gamma(PPARγ),on P-gp-mediated MDR in SGC7901/VCR cells(a vincristine-resistant human gastric cancer cell line).The expression of P-gp was detected by RT-PCR and Western blotting,respectively.The SGC7901/VCR cells were treated with 0.1 mg/L vincristine(VCR) alone or in combination with 1,5,10 μmol/L troglitazone for 24 h.PPARγ was measured by electrophoretic mobility shift assay(EMSA).The intracellular concentration of Rhodamine123(Rh123,a fluorescent P-gp substrate) was assayed to evaluate the activity of P-gp.The cell cycle and apoptosis were measured by flow cytometry.The results showed that the P-gp was increasingly expressed in SGC7901,BGC823 and SGC7901/VCR cells in turn,suggesting that MDR in the SGC7901/VCR cells was mediated by the increased expression of P-gp.In the SGC7901/VCR cells,the expression level of total PPARγ was increased,however,the protein level and activity of PPARγ in the nuclei of cells decreased significantly.Troglitazone elevated the PPARγ activity in SGC7901/VCR cells in a dose-dependent manner.Troglitazone decreased the P-gp expression and markedly enhanced the accumulation of Rh123 in SGC7901/VCR cells in a dose-dependent manner.We also found that troglitazone significantly increased the percentage of SGC7901/VCR cells in the G2/M phase and decreased the cell percentage in G1 and S phase in a dose-dependent manner.Troglitazone significantly increased the apoptotic rate of SGC7901/VCR cells treated by VCR or ADR in a dose-dependent manner.It was concluded that P-gp-overexpressed SGC7901/VCR cells have minor endogenous PPARγ activity.Elevation of the PPARγ activity by troglitazone can reverse P-gp-mediated MDR via down-regulating the expression and activity of P-gp in SGC7901/VCR cells.It was suggested that troglitazone can dramatically enhance the sensitivity of P-gp-mediated MDR cancer cells to chemotherapeutic agents.

微小RNA-130b在嘌呤霉素氨基核苷诱导的足细胞损伤中的作用及机制

目的探讨微小RNA-130b(miR-130b)在嘌呤霉素氨基核苷(puromycin aminonucleoside,PAN)诱导的足细胞损伤中的作用及机制。方法小鼠肾脏足细胞系MPC5予以PAN 25、50、100μg/mL干预,实时定量PCR检测MPC5细胞系内miR-130b及其宿主基因2610318N02Rik(RIK)表达;转染miR-130b抑制剂(miR-130b inhibitor)或对照(NC inhibitor)后予以PAN 100μg/mL刺激,24 h后采用Western blot检测足细胞裂孔膜蛋白Synaptopodin和Nephrin蛋白表达变化;采用鬼笔环肽染色检测足细胞骨架改变;采用流式细胞技术检测细胞凋亡变化;采用Targetscan 7.2预测miR-130b潜在靶基因,Western blot检测miR-130b模拟物(mimic)对于潜在靶基因PGC1α蛋白表达的影响;采用双荧光素酶报告基因系统检测miR-130b mimic对于荧光活性的影响。结果PAN可以抑制足细胞内的miR-130b及宿主基因RIK表达;与转染NC inhibitor组比较,miR-130b inhibitor提高足细胞裂孔膜蛋白synaptopodin和nephrin表达;鬼笔环肽染色显示抑制miR-130b可以部分缓解PAN诱导的足细胞骨架紊乱及重组;流式细胞技术检测结果示干扰足细胞miR-130b表达可以减少PAN诱导的细胞凋亡;Targetcan 7.2分析显示PGC1α是miR-130b的潜在靶基因,Western blot结果显示,转染miR-130b mimic可以降低足细胞内PGC1α表达;双荧光素酶报告基因系统结果示,与NC mimic及突变的PGC1α3’-UTR共转染组比较,miR-130b mimic与野生型PGC1α3’-UTR共转染组荧光素酶活性降低。结论miR-130b通过靶向抑制PGC1α表达参与PAN诱导的足细胞损伤。

Mitochondrial dysfunction in a rat model and the related risk of metabolic disorders

OBJECTIVE:To explore whether kidney Yang deficiency(KYD)is prone to metabolic disorders may be linked to impaired mitochondrial function in thermogenesis and metabolic tissues.METHODS:A rat model of KYD was used,which was established using Sprague Dawley rat dams with warm preference subjected to herbal treatment that can improve kidney Yang.The human relevance was confirmed by reduced serum corticosterone levels,and increased preference for warm location.RESULTS:KYD Rats were underdeveloped.Adenosinetriphosphate(ATP)production was reduced in the brown fat,but increased in the muscle.However,oxidative phosphorylated complexes to generate ATP and mitochondrial biogenesis marker were reduced in both tissues.When the second insult of high-fat diet(HFD)was introduced,KYD rats gained less weight yet developed more severe lipid and glucose metabolic disorders.This may be driven by disregulated liver gluconeogenesis marker forkhead box protein O1 and lipid metabolic regulator cholesterol 7 alpha-hydroxylase.CONCLUSION:KYD rats exhibited reduced mitochondrial function in the brown fat,but were partially compensated by skeletal muscle,associated with the phenotype of warm preference and metabolic disorder,which was further exacerbated by additional HFD consumption.Future studies can focus on treatment targetting mitochondria function to reverse this phenotype.

Rumen microbiota-host transcriptome interaction mediates the protective effects of trans-10,cis-12 CLA on facilitating weaning transition of lambs

Developing alternatives to antibiotics for prevention of gastrointestinal dysbiosis in early-weaning farmed animals is urgently needed.This study was to explore the potential effects of trans-10,cis-12 conjugated linoleic acid(CLA)on maintaining ruminal homeostasis of young ruminants during the weaning transition period.Thirty neonatal lambs were selected(6 lambs per group)and euthanized for rumen microbial and epithelial analysis.The lambs were weaned at 28 d and experienced the following 5 treatments:euthanized on d 28 as the pre-weaning control(CON0),fed starter feed for 5(CON5)or 21(CON21)d,fed starter feed with 1%of CLA supplemented for 5(CLA5)or 21(CLA21)d.Results showed that the average daily weight gain and dry matter intake were significantly higher in CLA5 than CON5 group.As compared with the CON5 and CON21 group,the relative abundances of volatile fatty acid(VFA)producing bacteria including Bacteroides,Treponema,Parabacteroides and Anaerovibrio,as well as the concentrations of acetate,butyrate and total VFA were significantly increased in CLA5 and CLA21 group,respectively.Integrating microbial profiling and epithelial transcriptome results showed that 7 downregulated inflammatory signaling-related host genes IL2RA,CXCL9,CD4,CCR4,LTB,SPP1,and BCL2A1 with CLA supplementation were significantly negatively correlated with both VFA concentration and VFA producing bacteria,while 3(GPX2,SLC27A2 and ALDH3A1)and 2(GSTM3 and GSTA1)upregulated metabolism-related genes,significantly positively correlated with either VFA concentration or VFA producing bacteria,respectively.To confirm the effects of CLA on epithelial signal transduction,in vitro experiment was further conducted by treating rumen epithelial cells without or with IL-17A+TNF-αfor 12 h after pretreatment of 100μM CLA or not(6 replicates per treatment).The results demonstrated the anti-inflammatory effect of CLA via suppressing the protein expression of NF-кB p-p65/p65 with the activation of peroxisome proliferator-activated receptor gamma(PPARγ).In conclusion,CLA supplementation enhanced the ruminal microbiota-driven transcriptional regulation in healthy rumen epithelial development via rumen VFA production,and CLA may therefore serve as an alternative way to alleviate early-weaning stress and improve physiological and metabolic conditions of young ruminants.

Pioglitazone ameliorates nonalcoholic steatohepatitis by down-regulating hepatic nuclear factor-kappa B and cyclooxygenases-2 expression in rats

Background Pioglitazone is effective in nonalcoholic steatohepatitis （NASH）, but the mechanisms of action are not completely understood. This study was designed to investigate the effects of pioglitazone on hepatic nuclear factor-kappa B （NF-KB） and cyclooxygenases-2 （COX-2） expression in NASH rats. Methods Thirty Sprague-Dawley male rats were randomly assigned to a control group （n=10）, NASH group （n=10）, and pioglitazone treatment group （n=10）. Liver tissues were processed for histology by hematoxylin ＆ eosin and Masson stained. Serum alanine aminotransferase （ALT）, cholesterol, triglyceride, fasting blood glucose （FBG）, fasting insulin （FINS） levels and biochemical parameters of antioxidant enzyme activities, tumor necrosis factor alpha （TNF-a）, prostaglandin E2 （PGE2） levels in serum and liver were measured. The mRNA and protein expression of peroxisome proliferator-activated receptor gamma （PPARy）, NF-KB and COX-2 were determined by real-time polymerase chain reaction, Western blotting and immunohistochemistry. One-way analysis of variance （ANOVA） and Wilcoxon＇s signed-rank test was used for the statistical analysis. Results There were severe steatosis, moderate inflammatory cellular infiltration and fibrosis in NASH rats. After pioglitazone treatment, steatosis, inflammation and fibrosis were significantly improved compared with the NASH group （X2=20.40, P 〈0.001; X2=20.17, P 〈0.001; X2=13.98, P=0.002）. Serum ALT, cholesterol, triglyceride, FBG, FINS levels were significantly elevated in the NASH group （P 〈0.05）. In the NASH group, total anti-oxidation competence （T-AOC）, superoxide dismutase （SOD）, catalase （CAT）, glutathione peroxidase （GSH-PX） and malondialdehyde （MDA） levels in serum and liver were conspicuous disordered than those parameters in the control group. Meanwhile, TNF-a and PGE2 levels in serum and liver were significantly increased compared with the control group. Immunohistochemistry showed NF-KB and COX-2 expression in liver was significantly elevated. However, PPARy level was decreased in the NASH group. Real-time PCR and Western blotting revealed mRNA and protein expression of COX-2 were increased in the NASH group compared with the control group （0.57±0.08 vs. 2.83±0.24; 0.38±0.03 vs. 1.00±0.03, P 〈0.001 and P=-0.004, respectively）. After pioglitazone intervention, all of those parameters markedly improved （P 〈0.05 or P 〈0.01）. Conclusion Down-regulating hepatic NF-KB and COX-2 expression, at least in part, is one of the possible therapeutic mechanisms of pioglitazone in NASH rats.

Efficacy of Dangua Fang(丹瓜方) on endothelial cells damaged by oxidative stress

OBJECTIVE: To evaluate the protective effects of serum containing Dangua Fang( 丹 瓜 方) on vascular endothelium damaged by oxidative stress. METHODS: Five experiments were completed in this paper. In the first experiment, we found the most suitable serum containing Dangua Fang by comparing groups with different serum containing Dangua Fang. In the second experiments we analyzed Dangua Fang influencing endothelial cell viability and apoptosis and cell cycle. The third experiment on Dangua Fang intervention of mitochondrial respiratory chain. The fourth experiment on Dangua Fang intervention of mitochondrial membrane potential. And finally, on the fifth experiment we researched the mechanism of Dangua Fang improving mitochondrial function by comparing the Na~+-k~+-ATPase and peroxisome proliferator-activated receptor-gamma coactivator-1alpha(PGC-1α) in the Dangua group with the diazoxide group and Co Q+Vit C group. RESULTS: We compared the control group in the first experiments and the OD values in DZ1 group was the most significant in all intervening groups. The recipe of DZ1(5% serum containing Dangua Fang) was used in the following experiments. Compared with the control group, cell viability, cell cycle(G2 + S), cytochrome c oxidase(COX), R3 red/green, R2 red/green, R1 red/green decreased and apoptosis, succinate dehydrogenase(SDH), green(R2 + R3), Na+-k+-ATPase, PGC-1α increased in the model group. Compared with the model group, cell viability, G2+S, COX, R3 red/green, R2 red/green, R1 red/green raised and apoptosis, green(R2 + R3), Na-K-ATPase decreased in the Dangua group;G2 + S, R3 red/green, R2 red/green, R1 red/green raised and green(R2 + R3) decreased in the Co Q + Vit C group. Na-K-ATPase increased in the combined group(P < 0.05 or < 0.01). CONCLUSIONS: Dangua Fang protects oxidative stressinduced endothelial cells damaged by promotion of mitochondrial biogenesis, reduction of Na~+-K~+-ATPase activity and regulation of mitochondrial respiratory chain function restoring mitochondrial membrane potential.

Protective efficacy of Shenge San(参蛤散) on mitochondria in H9c2 cardiomyocytes

OBJECTIVE: To investigate whether peroxisome proliferator-activated receptor γ-coactivator-1α/nuclear respiratory factor 1(PGC-1α/NRF1) activity can protect mitochondrial function in the setting of cardiac hypertrophy and improve cardiomyocyte energy metabolism. METHODS: Cardiac hypertrophy was modeled in H9c2 cells treated with isoproterenol(ISO) to assess the effects of Shenge San( 参 蛤 散, SGS) on cell viability and mitochondrial membrane potential. We assessed mitochondrial complex m RNA levels and mitochondrial oxidative phosphorylation factor m RNA and protein levels. RESULTS: Compared with the 100 μM ISO group, cell size was significantly decreased in the 0.3 mg/m L SGS and 20 μM ZLN005(PGC-1α activator) groups(P < 0.01). Compared with the SGS(0.3) +ISO group, we observed lower phosphorylated adenosine monophosphateactivated kinase(AMPK) protein levels in the ISO and ZLN005+SGS+ISO groups(P < 0.01). Compared with the compound C group, SGS significantly increased PGC-1α expression in ISO-induced cardiac hypertrophy cells(P < 0.01), and this was inhibited by compound C pretreatment(P < 0.05). Compared with the ISO group, the mitochondrial red-green fluorescence ratio increased in the 0.3 mg/m L SGS group(P < 0.05). m RNA levels of cytochrome c oxidase subunit 1(CO1) in the ISO and compound C groups were lower than those in control group(P < 0.01), and the m RNA levels of CO1 and ATP8 were significantly lower in the ISO and compound C groups versus control(P < 0.01). Compared with the SGS(0.3) +ISO group, ATP synthetase subunit 8(ATP8) m RNA was significantly decreased in the ISO group(P < 0.01) and compound C+SGS+ISO group(P < 0.05). Compared with the SGS(0.3) +ISO group, NRF1 m RNA levels were significantly decreased(P < 0.05) in the ISO and compound C+SGS+ISO groups. CONCLUSIONS: SGS can attenuate ISO-induced cardiomyocyte hypertrophy, restore the decrease in mitochondrial membrane potential, and upregulate PGC-1α/NRF1 levels. Notably, these effects can be blocked by AMPK inhibitor-compound C.

Study on the relationship between relieving energy crisis in myofascial trigger points with An-Pressing manipulation and AMPK/PGC-1α pathway activation

Objective To explore the mechanism of An-Pressing manipulation in relieving energy crisis in chronic myofascial trigger points(MTrPs)by observing the effects of An-Pressing manipulation on adenosine triphosphate(ATP),adenosine 5′-monophosphate(AMP)-activated protein kinase(AMPK)/peroxisome proliferator-activated receptorγcoactivator 1α(PGC-1α)pathway and mitochondrial ultrastructure of skeletal muscle cells in MTrPs rats.Methods Forty-eight male Sprague-Dawley rats were randomly divided into a blank group,a model group,a lidocaine group,and an An-Pressing manipulation group,with 12 rats in each group.The model group,lidocaine group and An-Pressing manipulation group were used to replicate the MTrPs rat model by blunt shock and centrifugal motion method.After modeling,the An-Pressing manipulation group was subjected to 7 times An-Pressing manipulation,once every other day;the lidocaine group was treated with 3 times of injection of lidocaine at the MTrPs,once every 6 d.The blank group and the model group were fed normally without intervention.After the intervention,local muscle tissue was taken to detect the content of ATP and the expression of AMPK,phosphorylated AMPK(phospho-AMPK),PGC-1α,and glucose transporter 4(GluT4),and the ultrastructure of mitochondria was observed under an electron microscope.Results Compared with the blank group,the ATP content in the model group was decreased(P<0.05),the protein expression levels of phospho-AMPK,PGC-1α,and GluT4 and the ratio of phospho-AMPK to AMPK were decreased(P<0.05);under the electron microscope,the number of mitochondria decreased,and they were deformed,small in volume,and had deformed cristae.Compared with the model group,the ATP contents in the An-Pressing manipulation group and the lidocaine group were increased(P<0.05),and the protein expression levels of phospho-AMPK,PGC-1α,and GluT4 and the ratio of phospho-AMPK to AMPK were increased(P<0.05);under the electron microscope,the number of mitochondria increased,the shape and size of the mitochondria were basically normal,and the cristae could be seen.Compared with the lidocaine group,phospho-AMPK and the ratio of phospho-AMPK to AMPK in the An-Pressing manipulation group were increased(P<0.05);under the electron microscope,the numbers of mitochondria were similar,and the shape and size of the mitochondria were basically normal without swelling,and the cristae could be observed.Conclusion An-Pressing manipulation can increase the ATP content in MTrPs tissue,improve the expression levels of PGC-1α and GluT4 proteins and the ratio of phospho-AMPK to AMPK;its mechanism may relate to the activation of AMPK/PGC-1α signaling pathway to promote the repair of mitochondrial damages.