补肾降脂方通过PPARγ-LXRα-ABCA1通路干预ApoE-/-小鼠动脉粥样硬化的效应机制

目的探讨补肾降脂方通过PPARγ-LXRα-ABCA1通路干预ApoE-/-小鼠动脉粥样硬化(AS)的效应机制。方法采用高脂饮食喂饲ApoE-/-小鼠复制AS模型,随机分为ApoE-/-小鼠+高脂饮食喂饲组(模型组)、ApoE-/-小鼠+高脂饮食喂饲+补肾降脂方组(补肾组)、ApoE-/-小鼠+高脂饮食喂饲+阿托伐他汀组(他汀组),同品系、同周龄雄性C57BL/6小鼠为正常对照组(正常组),每组25只。各组给予相应干预12周。HE、油红O染色法分别检测小鼠主动脉窦、肝脏组织病理形态及脂质蓄积,Filipin染色法检测小鼠主动脉窦游离胆固醇;ELISA法检测小鼠外周血血清脂质(TC、TG、LDL-C、HDL-C)含量;Western blot法检测小鼠主动脉、肝脏组织PPARγ、LXRα及ABCA1蛋白表达。结果高脂饮食喂饲的ApoE-/-小鼠呈典型的AS病变,主动脉窦可见大面积AS斑块及红染脂质,游离胆固醇增多;肝脏组织可见肝细胞结构紊乱,红染脂质蓄积;血清TC、LDL-C含量升高,HDL-C含量降低;主动脉及肝脏组织PPARγ、LXRα、ABCA1蛋白表达降低。与模型组比较,补肾组小鼠主动脉窦AS斑块面积、红染脂质、游离胆固醇均减少;肝脏组织肝细胞结构大部分清晰可见,红染脂质减少;血清TC、LDL-C含量降低;主动脉及肝脏组织PPARγ、LXRα、ABCA1蛋白表达上调。结论补肾降脂方可能通过调控PPARγ-LXRα-ABCA1通路进而有效干预治疗动脉粥样硬化。

Effect of astragaloside Ⅳ on lipid and glucose metabolism in acute myocardial infarction through PPARγ pathway

OBJECTIVE To investigate the effects of astragaloside IV(which can be extracted from the traditional Chinese medicine Astragalus membranaceus)on lipid and glucose metabolism in acute myocardial infarction(AMI).METHODS Model of heart failure(HF)after AMI was established with ligation of left anterior descending artery on Sprague-Dawley(SD)rats.The rats were divided into three groups:sham,model and astragaloside IV treatment group.Twenty-eight days after treatment(astragaloside IV,20 mg·kg-1 daily),hematoxylin-eosin(HE)staining was applied to visualize cardiomyocyte morphological changes.High performance liquid chromatography(HPLC)was performed to assess the contents of adenosine phosphates in heart.Positron emission tomography and computed tomography(PET-CT)was conducted to evaluate the cardiac glucose metabolism.Expressions of key molecules such as peroxisome proliferatoractivated receptor γ(PPARγ),sterol carrier protein 2(SCP2)and long chain acyl CoA dehydrogenase(ACADL)were measured by Western blotting and immunohistochemistry.Oxygen-glucose deprivation-reperfusion(OGD/R)-induced H9C2 injury cardiomyocyte model was adopted for potential mechanism research in vitro.RESULTS Treatment with astragaloside Ⅳ rescued hearts from structural and functional damages as well as inflammatory infiltration.Levels of adenosine triphosphate(ATP)and energy charge(EC)in astragaloside IV group were also up-regulated compared to model group.Further results demonstrated that critical enzymes both in lipid metabolism and glucose metabolism compro mised in model group compared to sham group.Intriguingly,astragalosideⅣcould up-regulate critical enzymes including ACADL and SCP2 in lipid metabolism accompanying with promoting effect on molecules in glycolysis simultaneously.Results on upstreaming signaling pathway demonstrated that astragaloside Ⅳ could dramatically increase the expres sions of PPARγ.In vitro study suggested the efficacy of astragalosideⅣcould be blocked by T0070907,a selective PPARγ inhibitor.CONCLUSION Astragaloside IV has cardioprotective effect in improving cardiac function and energy metabolism through regulating lipid and glucose metabolism.The effects may be mediated by PPARγ pathway.

Danggui Shaoyao powder improves hepatic lipid metabolism in atherosclerosis mice via PPARγ-LXRα-ABCA1 pathway regulation

Objective To observe the effects of Danggui Shaoyao powder(DSP)on hepatic lipid metabolism and further explore its mechanism of action by peroxisome proliferator-activated receptor(PPARγ)-liver X receptor(LXRα)-adenosine triphosphate(ATP)-binding cassette transporter A1(ABCA1)pathway regulation.Methods Eight C57BL/6J male mice were selected as the control group,and 24 ApoE^(−/−)male mice were randomly divided into the atherosclerosis model(AS)group,atorvastatin calcium(AC)group,and DSP group(n=8 each group).To establish an AS model,ApoE^(−/−)mice were fed a high-fat diet for 16 weeks.Pathologic changes in the aortic vasculature and liver were identified using Oil Red O staining.Triglyceride(TG),cholesterol(TC),and low-density lipoprotein cholesterol(LDL-C)levels were determined in the livers using a single-reagent GPO-PAP method.Fluorescence quantitative polymerase chain reaction and western blot were used to observe and evaluate the mRNA and protein expression of the PPARγ-LXRα-ABCA1 intermediates in the liver.Results After 16 weeks of a high-fat diet,ApoE−/−mice showed more Oil Red O staining in the aorta and liver compared to the CONT group.Compared to the AS group,the DSP and AC treatment reduced aortic plaque and hepatic lipid deposition to varying degrees.Furthermore,DSP significantly reduced the hepatic lipid area in ApoE^(−/−)mice(P<.001)and decreased the levels of TG,TC,and LDL-C in liver(P<.001,P=.027,P<.001,respectively).DSP also significantly increased the levels of PPARγ,LXRα,ABCA1,and ABCG1 mRNA expression,as well as the PPARγ,LXRα,ABCA1,and ABCG1 protein expression in liver.Conclusion DSP improved hepatic lipid metabolism via PPARγ-LXRα-ABCA1 pathway modulation for AS treatment.

Parboiled rice supplementation alleviates high-fat diet-induced hyperlipidemia by regulating genes and gut microbiota in mice

Dietary parboiled rice(PR)has a low risk of disease,but little is known about the contribution of PR to the prevention of hyperlipidemia.The potential role and underlying mechanisms of PR in hyperlipidemia were evaluated in this study.Male C57BL/6J mice were fed with a normal diet,high-fat diet(HFD)containing refined rice(HFDRR)or PR(HFDPR).It was found that PR intervention improved lipid accumulation in mice.Transcriptomic data analysis revealed that 27 genes were up-regulated(mostly involved in lipid breakdown)and 86 genes were down-regulated(mostly involved in inflammatory responses)in the HFDPR group compared to the HFDRR group.And 15 differentially expressed genes(DEGs)were validated by quantitative real-time PCR(RT-qPCR),while protein interaction network showed that protein tyrosine phosphatase receptor type C(PTPRC)has a central role.The gut microbiota of mice was also altered after different dietary treatments,with higher ratio of Firmicutes and Bacteroidetes,increased abundances of Ruminococcaceae,Lachnospiraceae,Christensenellaceae,Porphyromonadaceae,Rikenellaceae and Prevotellaceae,and decreased abundances of Lactobacillaceae,Peptostreptococcaceae,Erysipelotrichaceae and Actinobacteria in the HFDRR group.In addition,it was observed that PPAR signaling pathway may act as a bridge between DEGs and differential gut microbiota.These results suggested that PR can prevent hyperlipidemia by modulating liver genes and gut microbiota.

Urolithin a alleviates oxidative stress-induced senescence in nucleus pulposus-derived mesenchymal stem cells through SIRT1/PGC-1α pathway

BACKGROUND In degenerative intervertebral disc(IVD),an unfavorable IVD environment leads to increased senescence of nucleus pulposus(NP)-derived mesenchymal stem cells(NPMSCs)and the inability to complete the differentiation from NPMSCs to NP cells,leading to further aggravation of IVD degeneration(IDD).Urolithin A(UA)has been proven to have obvious effects in delaying cell senescence and resisting oxidative stress.AIM To explore whether UA can alleviate NPMSCs senescence and to elucidate the underlying mechanism.METHODS In vitro,we harvested NPMSCs from rat tails,and divided NPMSCs into four groups:the control group,H2O2 group,H2O2+UA group,and H2O2+UA+SR-18292 group.Senescence-associatedβ-Galactosidase(SA-β-Gal)activity,cell cycle,cell proliferation ability,and the expression of senescence-related and silent information regulator of transcription 1/PPAR gamma coactivator-1α(SIRT1/PGC-1α)pathway-related proteins and mRNA were used to evaluate the protective effects of UA.In vivo,an animal model of IDD was constructed,and Xrays,magnetic resonance imaging,and histological analysis were used to assess whether UA could alleviate IDD in vivo.RESULTS We found that H2O2 can cause NPMSCs senescence changes,such as cell cycle arrest,reduced cell proliferation ability,increased SA-β-Gal activity,and increased expression of senescence-related proteins and mRNA.After UA pretreatment,the abovementioned senescence indicators were significantly alleviated.To further demonstrate the mechanism of UA,we evaluated the mitochondrial membrane potential and the SIRT1/PGC-1αpathway that regulates mitochondrial function.UA protected mitochondrial function and delayed NPMSCs senescence by activating the SIRT1/PGC-1αpathway.In vivo,we found that UA treatment alleviated an animal model of IDD by assessing the disc height index,Pfirrmann grade and the histological score.CONCLUSION In summary,UA could activate the SIRT1/PGC-1αsignaling pathway to protect mitochondrial function and alleviate cell senescence and IDD in vivo and vitro.

Pomegranate peel polyphenols alleviate insulin resistance through the promotion of insulin signaling pathway in skeletal muscle of metabolic syndrome rats

Insulin resistance(IR) has been considered to be an important causative factor of metabolic syndrome(Met S). The present study investigated whether pomegranate peel polyphenols(PPPs) could prevent the development of Met S by improving IR in rats. Male Sprague-Dawley(SD) rats were fed high fat diet(HFD) to induce Met S and supplemented with different dosages of PPPs for 12 weeks. The results showed that HFD-induced insulin resistant rats had disordered metabolism of blood glucose, blood lipid, and terrible muscle fiber morphology when compared with normal diet-fed rats, but PPPs treatment at a dosage of 300 mg/kg·day significantly reversed these negative effects. Moreover, in skeletal muscle tissue of insulin resistant rats, PPPs treatments significantly increased the protein expressions of insulin receptor(Ins R) and phosphorylated insulin receptor substrate 1(IRS-1), stimulated peroxisome proliferator activated receptor gamma(PPARγ) and phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT/PKB) signaling pathway, and aggrandized the protein levels of phosphorylated glycogen synthase kinase-3β(GSK-3β) and glucose transporter 4(GLUT4). Our results suggest that PPPs possess of the beneficial effects on alleviating IR by enhancing insulin sensitivity and regulating glucose metabolism.

Adipose Rheb deficiency promotes miR-182-5p expression via the cAMP/PPARγsignaling pathway

Dysregulation of microRNAs(miRNAs)in adipocytes plays a critical role in the pathogenesis of obesity.However,the signaling mechanisms regulating miRNAs production in adipose tissue remain largely unclear.Here,we show that adipose tissue-specific knockout of Ras homolog enriched in brain(Rheb),a direct upstream activator of mTOR,increases miR-182-5p level in mouse subcutaneous white adipose tissues.Interestingly,the inhibition of mTOR signaling by rapamycin has no effect on miR-182-5p level in primary subcutaneous white adipocytes,suggesting the presence of a mTOR-independent mechanism regulating Rheb-mediated miR-182-5p expression.Consistent with this view,Rheb-ablation activates the cAMP/PPARγsignaling pathway.In addition,treatment of white adipocytes with pioglitazone,a PPARγagonist,dramatically upregulates miR-182-5p levels.Our study reveals a unique mechanism by which Rheb regulates miR-182-5p in adipocytes.Given that increasing miR-182-5p in adipose tissue promotes beige fat development,our study also suggests a unique mechanism by which Rheb promotes thermogenesis and energy expenditure.

Blockade of Arf1-mediated lipid metabolism in cancers promotes tumor infiltration of cytotoxic T cells via the LPE-PPARγ-NF-κB-CCL5 pathway

Tumor immunotherapy has achieved breakthroughs in a variety of tumors. However, the systemic absence of T cells in tumors and immunosuppressive tumor microenvironment so far limits the efficacy of immunotherapy to a small population of patients. Therefore, novel agents to increase T-cell tumor infiltration are urgently needed in the clinic. We recently found that inhibition of the ADP-ribosylation factor 1 (Arf1)-mediated lipid metabolism not only kills cancer stem cells (CSCs) but also elicits an anti-tumor immune response. In this study, we revealed a mechanism that targeting Arf1 promotes the infiltration of cytotoxic T lymphocytes (CTLs) into tumors through the C-C chemokine ligand 5 (CCL5)- C-C chemokine receptor type 5 (CCR5) pathway. We found that blockage of Arf1 induces the production of the unsaturated fatty acid (PE 18:1) that binds and sequestrates peroxisome proliferator- activated receptor-γ (PPARγ) from the PPARγ-nuclear factor-κB (NF-κB) cytoplasmic complex. The released NF-κB was then phospho-rylated and translocated into the nucleus to regulate the transcription of chemokine CCL5. CCL5 promoted infiltration of CTLs for tumor regression. Furthermore, the combination of the Arf1 inhibitor and programmed cell death protein 1 (PD-1) blockade induced an even stronger anti-tumor immunity. Therefore, targeting Arf1 represents a novel anti-tumor immune approach by provoking T-cell tumor infiltration and may provide a new strategy for tumor immunotherapy.

基于PPARγ-LXRα-ABCA1通路的中药降脂成分研究

目的利用药效团和分子对接等模拟方法,基于过氧化物酶体增殖物激活型受体γ(PPARγ)-肝X受体α(LXRα)-三磷酸腺苷结合盒转运体Al(ABCA1)通路发现中药中具有降脂作用的潜在活性化合物。方法首先,选择PPARγ和LXRα作为研究载体,分别构建其激动剂的药效辨识模型。通过对药效团模型的验证与评价,获得PPARγ和LXRα的最优药效团模型。随后,利用最优药效团模型筛选中药化学成分数据库(TCMD),结合Lipinski五规则及化合物与药效团模型的匹配度,得到初筛化合物。最后,利用分子对接方法进一步精简筛选结果,保留对接打分值较高的化合物,并分析其关键氨基酸,分别得到PPARγ和LXRα的潜在激动剂。结果本研究构建了PPARγ激动剂的最优药效团模型,包括1个氢键受体、1个疏水基团和2个芳香基团;LXRα的最优药效团模型,包括2个氢键受体、1个疏水基团和2个芳香基团。同时利用分子对接方法构建PPARγ和LXRα的蛋白三维模型,并将其用于分子对接研究。结合药效团及Lipinski五规则的筛选结果,分别获得20个和180个初筛化合物。依据筛选标准(打分值和关键氨基酸),最终确定鹰爪木脂醇和桧双黄酮为PPARγ的潜在激动剂,栝楼酯碱和刘寄奴酰胺为LXRα的潜在激动剂。筛选得到的PPARγ和LXRα潜在激动剂可以通过分别作用于PPARγ-LXRα-ABCA1通路上的对应靶标协同发挥降脂作用。结论本研究高效、快速的筛选了TCMD中具有潜在活性的PPARγ和LXRα激动剂,用于协同上调ABCA1的表达,为高脂血症的药物研发提供先导化合物。

Upregulation of the PPAR signaling pathway and accumulation of lipids are related to the morphological and structural transformation of the dragon-eye goldfish eye

Goldfish comprise around 300 different strains with drastically altered and aesthetical morphologies making them suitable models for evolutionary developmental biology.The dragon-eye strain is characterized by protruding eyes(analogous to those of Chinese dragons).Although the strain has been selected for about 400 years,the mechanism of its eye development remains unclear.In this study,a stable dragon-eye goldfish strain with a clear genetic background was rapidly established and studied.We found that upregulation of the PPAR signaling pathway accompanied by an increase in lipid accumulation might trigger the morphological and structural transformation of the eye in dragon-eye goldfish.At the developmental stage of proptosis(eye protrusion),downregulation of the phototransduction pathway was consistent with the structural defects and myopia of the dragon-eye strain.With the impairment of retinal development,cytokine-induced inflammation was activated,especially after proptosis,similar to the pathologic symptoms of many human ocular diseases.In addition,differentially expressed transcription factors were significantly enriched in the PAX and homeobox families,two well-known transcription factor families involved in eye development.Therefore,our findings reveal the dynamic changes in key pathways during eye development in dragon-eye goldfish,and provide insights into the molecular mechanisms underlying drastically altered eyes in goldfish and human ocular disease.

Opposite Interplay Between the Canonical WNT/β-Catenin Pathway and PPAR Gamma： A Potential Therapeutic Target in Gliomas

In gliomas, the canonical Wingless/Int（WNT）/b-catenin pathway is increased while peroxisome proliferator-activated receptor gamma（PPAR-c） is downregulated.The two systems act in an opposite manner. This review focuses on the interplay between WNT/b-catenin signaling and PPAR-c and their metabolic implications as potential therapeutic target in gliomas. Activation of the WNT/bcatenin pathway stimulates the transcription of genes involved in proliferation, invasion, nucleotide synthesis,tumor growth, and angiogenesis. Activation of PPAR-c agonists inhibits various signaling pathways such as the JAK/STAT, WNT/b-catenin, and PI3 K/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/b-catenin pathway through the upregulation of PPAR-c 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.

蛹虫草多糖促进CETP-tg小鼠胆固醇逆转运

目的:本研究验证蛹虫草多糖(CMPS)在体内外促进胆固醇逆向转运(RCT)的效应,并探讨相关机制。方法:采用CETP-tg小鼠作为动物模型,通过同位素示踪技术检测体内的RCT效率;酶法测定血浆脂质水平。采用RAW264.7巨噬细胞源性泡沫细胞作为细胞模型,油红O染色和总胆固醇试剂盒检测泡沫细胞胆固醇外排后剩余脂质含量。Western blot分析泡沫细胞及小鼠肝脏内涉及胆固醇转运、摄取、转化的相关蛋白水平。结果:CMPS灌胃4周后,高脂饮食CETP-tg小鼠血浆总胆固醇(TC)、低密度脂蛋白胆固醇及高密度脂蛋白胆固醇浓度分别降低24%、23%和22%,体内RCT过程加速,血浆、胆汁、肠道及粪便外排通路中3H-胆固醇放射活性明显升高,同时,肝脏中胆固醇受体SR-B1和LDLR及转化酶CYP7A1蛋白表达上调,分别增加了105%、71%和58%。体外实验显示:CMPS促进了巨噬细胞源性泡沫细胞胆固醇外排,细胞内脂质和TC水平明显降低,同时,上调了巨噬细胞PPARγ-LXRα-ABCA1/ABCG1信号通路相关蛋白的表达。结论:CMPS促进了外周巨噬细胞中多余胆固醇的流出和体内胆固醇经肝脏途径外排,其机制可能与PPARγ-LXRα-ABCA1/ABCG1通路激活有关。

Black phosphorus quantum dots induce myocardial inflammatory responses and metabolic disorders in mice

As an ultrasmall derivative of black phosphorus(BP)sheets,BP quantum dots(BP-QDs)have been effectively used in many fields.Currently,information on the cardiotoxicity induced by BP-QDs remains limited.We aimed to evaluate BP-QD-induced cardiac toxicity in mice.Histopathological examination of heart tissue sections was performed.Transcriptome sequencing,real-time quantitative PCR(RT–qPCR),western blotting,and enzyme-linked immunosorbent assay(ELISA)assays were used to detect the m RNA and/or protein expression of proinfammatory cytokines,nuclear factor kappa B(NF-κB),phosphatidylinositol3 kinase-protein kinase B(PI3K-AKT),peroxisome proliferator-activated receptor gamma(PPARγ),and glucose/lipid metabolism pathway-related genes.We found that heart weight and heart/body weight index(HBI)were significantly reduced in mice after intragastric administration of 0.1 or 1 mg/kg BP-QDs for 28 days.In addition,obvious infammatory cell infiltration and increased cardiomyocyte diameter were observed in the BP-QD-treated groups.Altered expression of proinfammatory cytokines and genes related to the NF-κB signaling pathway further confirmed that BP-QD exposure induced infammatory responses.In addition,BP-QD treatment also affected the PI3K-AKT,PPARγ,thermogenesis,oxidative phosphorylation,and cardiac muscle contraction signaling pathways.The expression of genes related to glucose/lipid metabolism signaling pathways was dramatically affected by BP-QD exposure,and the effect was primarily mediated by the PPAR signaling pathway.Our study provides new insights into the toxicity of BP-QDs to human health.

卵巢局部糖原合成酶激酶3β过表达对大鼠卵巢功能的影响及补肾化痰方干预机制

目的:探讨大鼠卵巢局部糖原合成酶激酶3β(GSK3β)基因过表达对卵巢功能的影响及补肾化痰方的干预作用。方法:将SD大鼠随机分为对照组,模型组,补肾化痰方低、中、高剂量组。对照组大鼠给予卵巢包膜内10μL 0.9%氯化钠溶液注射,其余4组动物均卵巢包膜内注射10μL Lenti-GSK3β病毒溶液。各组分别给予0.9%氯化钠溶液及相应剂量的补肾化痰方药物灌胃,治疗15d后,检测卵巢组织中细胞凋亡水平,凋亡相关因子、胰岛素信号通路因子、甾体激素合成关键酶及PPARγ-LXRα信号通路关键因子的表达水平以及血清睾酮(T)、孕酮(Prog)、雌二醇(E_2)、卵泡刺激素(FSH)及促黄体生成素(LH)水平。结果:与对照组比较,模型组大鼠卵巢组织TUNEL染色阳性细胞核密度增加,卵巢组织甾体激素合成酶HSD3β、CYP17a1 mRNA表达水平上升及血清T水平显著上升(P<0.05,P<0.01);与模型组比较,各给药组对卵巢组织TUNEL染色后阳性细胞核密度及胰岛素信号通路关键因子的表达水平差异无统计学意义,但能以剂量依赖的方式激活PPARγ-LXRα信号通路,降低CYP17a1、HSD3βmRNA的表达水平(除补肾化痰方低剂量组CYP17a1)及血清T水平(除补肾化痰方低剂量组外)(P<0.05,P<0.01)。结论:卵巢GSK3β基因表达水平的上升可能是卵巢胰岛素信号通路异常所体现出的结果,而非造成PCOS患者卵巢病理变化的直接原因;补肾化痰方可能激活PPARγ-LXRα信号通路调节PCOS患者异常的生殖内分泌临床表型。