泡沫细胞ABCA1和microRNA-33基因表达机制的探讨

目的通过利用人急性单核细胞白血病细胞系-1(THP-1)源性泡沫细胞为研究对象,观察细胞内三磷酸腺苷结合盒转运蛋白1(ABCA1)和microRNA-33的基因表达情况。方法建立泡沫细胞模型,采用半定量RT-PCR和荧光定量PCR检测THP-1细胞、巨噬细胞与泡沫细胞ABCA1和microRNA-33基因表达水平变化。结果与对照组的THP-1细胞比较,巨噬细胞组ABCA1和microRNA-33基因表达水平无明显变化(P>0.05),泡沫细胞组ABCA1基因表达水平明显提高,而microRNA-33基因表达水平明显下降,差异有统计学意义(P<0.05)。结论胆固醇逆向转运需ABCA1基因参与,ABCA1介导泡沫细胞胆固醇流出,而microRNA-33基因与ABCA1基因表达呈负相关。     

心肌细胞缺氧中番茄红素对自噬的作用

目的探讨在心肌缺氧损伤中,番茄红素的作用及对自噬的影响。方法原代培养乳鼠心肌细胞予以无血清、无糖培养及缺氧干预,模拟心肌缺血,用番茄红素干预。在光学显微镜下观察缺氧后心肌细胞的形态;利用CCK-8法测量心肌细胞的存活率;及免疫印迹方法检测自噬相关基因LC3蛋白表达。结果 1番茄红素提高了心肌缺氧时细胞的存活率。2番茄红素增加了LC3蛋白的表达。3自噬的阻断剂3-甲基腺嘌呤(3-MA)削弱了番茄红素保护心肌细胞的作用。结论番茄红素可能通过激活自噬来提高心肌细胞抗缺血缺氧的能力。     

整合素β3在异丙肾上腺素诱导的心肌细胞损伤与凋亡中的作用

目的:探讨整合素β3(integrin β3,ITGB3)在β-肾上腺素受体(β-adrenergic receptor,β-AR)激动剂异丙肾上腺素(isoprenaline,ISO)诱导的心肌细胞损伤与凋亡中的作用及其机制。方法:心肌细胞随机分为对照组(Con组)、siRNA-ITGB3处理组(Con+si-ITGB3组)、ISO组、ISO+siRNA-ITGB3处理组(ISO+si-ITGB3组)。采用CCK-8检测细胞活性,TUNEL染色检测细胞凋亡,GFP-LC3腺病毒检测细胞自噬流强度,RT-PCR检测ITGB3 mRNA的表达;蛋白质印迹法检测细胞蛋白质水平。结果:在10μmol/L的ISO刺激后,心肌细胞活力下降、且随刺激时间的延长,细胞活力下降程度增加。siRNA-ITGB3干扰能够下调ISO诱导的ITGB3表达,抑制ISO所致的细胞活力下降。siRNAITGB3干扰能够抑制ISO诱导细胞凋亡,抑制促凋亡蛋白cleaved-caspase-3和Bax蛋白表达,上调抗凋亡蛋白Bcl-2表达;siRNA-ITGB3干扰能够增强GFP-LC3表达、促进自噬蛋白Beclin1,LC3-I/LC3-II积累,降低p62水平,抑制ISO所致的细胞自噬水平的下降。结论:ITGB3表达下调能激活细胞自噬,抑制ISO诱导的心肌细胞损伤与凋亡。     

microRNA-206对低氧诱导心肌细胞凋亡的作用及其可能机制

目的探讨microRNA-206(miR-206)在低氧诱导的原代心肌细胞凋亡中的作用及可能的作用机制。方法将心肌细胞分成六组,正常组、低氧组、miR-206模拟物组、miR-206模拟物-NC组、miR-206抑制剂组和miR-206抑制剂-NC组,其中正常组心肌细胞未转染,正常培养,低氧组心肌细胞未转染,经过低氧处理,miR-206模拟物组、miR-206模拟物-NC组心肌细胞经低氧处理后分别转染miR-206模拟物及其阴性对照序列,miR-206抑制剂组和miR-206抑制剂-NC组心肌细胞在低氧处理后分别转染miR-206抑制剂及其阴性对照序列。设置不同低氧处理时间(0 h、12 h、24 h和48 h)处理心肌细胞,同时正常组细胞正常培养,四甲基偶氮唑盐微量酶反应比色法(MTT)检测细胞增殖情况,qRT-PCR检测miR-206表达情况,采用流式细胞术、免疫组化检测和Western blot法检测细胞凋亡情况。MTT检测六组心肌细胞增殖变化情况,流式细胞术检测细胞凋亡改变情况,qRT-PCR检测表皮生长因子受体(EGFR)-低氧诱导因子1α(HIF-1α)信号通路mRNA表达情况,Western Blot检测EGFR-HIF-1α信号通路蛋白表达情况。结果 MTT结果显示心肌细胞随低氧处理时间增加增殖呈下降趋势,低氧处理24 h和48 h细胞增殖显著低于正常组(P 0. 05);免疫组化检测结果可知,低氧诱导48 h后,心肌细胞内凋亡蛋白cleaved-caspas3显著增加;流式细胞仪检测结果可知低氧诱导24 h、48 h后细胞凋亡呈时间依赖性增加; Western blot鉴定并证实细胞凋亡相关蛋白表达增加及抗凋亡蛋白表达的下降;心肌细胞随低氧处理时间增加miR-206表达呈上升趋势,处理24 h和48 h的miR-206表达量显著高于正常组(P 0. 05)。miR-206模拟物转染组细胞增殖显著增加,凋亡明显下降,miR-206抑制剂组增殖显著下降,凋亡显著增加(P 0. 05)。qRT-PCR法检测发现干扰后各组EGFR、HIF-1α和胰岛素样生长因子1(IGF-1)的mRNA水平无变化,但Western blot结果显示miR-206模拟物组较其阴性对照组EGFR和HIF-1α蛋白表达水平降低,而miR-206抑制剂组较其阴性对照组EGFR和HIF-1α蛋白表达水平升高。结论 MiR-206在缺氧的心肌细胞中会异常增高,高表达的miR-206可通过负调控EGFR-IGF-1-HIF-1α信号通路影响心肌细胞的增殖和凋亡。     

鸡内金提取物通过调节肺泡巨噬细胞自噬水平减轻尘肺大鼠肺间质纤维化的机制

目的探究鸡内金提取物通过调节肺泡巨噬细胞自噬水平减轻尘肺大鼠肺间质纤维化的机制。方法选择30只雄性SD大鼠根据随机数字表法分为3组,每组10只。对照组为没有粉尘接触的健康SD大鼠;模型组采用一次性除尘方法建立大鼠矽肺模型;治疗组采用一次性除尘方法建立大鼠矽肺模型,每天灌服鸡内金提取物0.2 g。定量逆转录PCR(RT-qPCR)分析自噬相关基因(Beclin、LC3-Ⅱ和LC3-Ⅰ)和凋亡相关基因(Bcl-2)的mRNA表达。培养后6、12、24 h,MTT检测巨噬细胞的活力。培养后12、24 h,通过划痕实验测定细胞的划痕间隙距离。酶联免疫吸附试验法检测促炎因子白细胞介素-1β(IL-1β)和肿瘤坏死因子-α(TNF-α)的水平。蛋白质印迹检测大鼠肺部纤连蛋白、Ⅰ型胶原蛋白、基质金属蛋白酶-9(MMP-9)、基质金属蛋白酶-12(MMP-12)、诱导型一氧化氮合酶(iNOS)和重组人精氨酸酶1(Arg1)的蛋白表达。结果模型组大鼠Beclin、LC3-Ⅱ/LC3-ⅠmRNA表达、IL-1β和TNF-α水平以及纤连蛋白、Ⅰ型胶原蛋白、MMP-9、MMP-12蛋白和iNOS蛋白表达水平均较对照组显著升高,Bcl-2 mRNA和Arg1蛋白表达水平均较对照组显著降低(P<0.05),治疗组大鼠Beclin、LC3-Ⅱ/LC3-ⅠmRNA表达、IL-1β和TNF-α水平以及纤连蛋白、Ⅰ型胶原蛋白、MMP-9、MMP-12蛋白和iNOS蛋白表达水平均较模型组显著降低,Bcl-2 mRNA和Arg1蛋白表达水平均较模型组显著升高(P<0.05)。培养后6、12、24 h,模型组较对照组细胞活力降低(P<0.05),治疗组大鼠较模型组细胞活力升高(P<0.05)。培养后12、24 h,模型组大鼠细胞划痕间隙距离较对照组降低(P<0.05),治疗组大鼠细胞划痕间隙距离较模型组升高(P<0.05)。结论鸡内金提取物通过诱导肺泡巨噬细胞自噬而发挥抗炎和抗纤维化作用。自噬通过抑制纤连蛋白、Ⅰ型胶原蛋白、MMP-9和MMP-12的表达,来保护肺泡巨噬细胞免受二氧化硅诱导的细胞凋亡,从而进一步减少由二氧化硅颗粒引起的炎症因子的分泌和最终的纤维化。     

白藜芦醇通过激活mTOR/自噬抑制缺氧缺糖/复氧复糖诱导的PC12细胞损伤及凋亡

目的:白藜芦醇对缺氧缺糖/复氧复糖(OGD/R)诱导的PC12细胞损伤及凋亡的影响及作用机制。方法:以PC12细胞建立OGD/R自噬性损伤模型,设置空白对照组、模型组、不同浓度(5、10μmol/L)白藜芦醇组,自噬抑制剂(3-MA)组。使用CCK-8试剂盒检测PC12的增殖能力;流式细胞术检测各组细胞凋亡率;ELISA检测各组细胞培养液中TNF-α和IL-6的浓度变化;DHE荧光探针检测ROS的变化;特定试剂盒检测乳酸脱氢酶(LDH)、丙二醛(MDA)、超氧化物歧化酶(SOD)、还原型谷胱甘肽(GSH-PX)含量;Westernblot法检测各组mTOR的磷酸化情况及LC3-Ⅱ、Beclin-1蛋白表达。结果:与空白对照组相比模型组能够显著降低PC12的增殖能力,增加细胞中ROS的含量和凋亡率,诱导TNF-α和IL-6分泌,LDH、MDA含量显著增加,SOD、GSH-PX活性显著下降,而P-mTOR/mTOR、LC3-Ⅱ、Beclin-1表达增加(P<0.01)。与模型组比较,不同浓度白藜芦醇作用PC12时,细胞存活率逐渐上升,ROS含量及凋亡率逐渐下降,LDH、MDA含量减少,SOD、GSH-PX活性随之上升,TNF-α和IL-6分泌显著下降,P-mTOR/mTOR、LC3-Ⅱ、Beclin-1表达进一步增加(P<0.01)。自噬抑制剂(3-MA)组上述指标的检测结果与白藜芦醇组相反。结论:白藜芦醇可能部分通过激活mTOR/自噬通路对神经细胞发挥保护作用。     

1,25-二羟维生素D_3对人结肠癌细胞凋亡和自噬的影响及机制研究

目的观察1, 25-二羟维生素D_3[1, 25-(OH)_2D_3]对人结肠癌HCT-116细胞凋亡和自噬的影响并初步探讨其机制。方法体外培养人结肠癌细胞HCT-116,分成对照组、低剂量组、中剂量组、高剂量组和联合组[1, 25-(OH)_2D_3高剂量联合腺苷单磷酸活化蛋白激酶(AMPK)抑制剂]共5组,观察并比较各组细胞凋亡和自噬情况。结果低剂量组、中剂量组、高剂量组的HCT-116细胞凋亡程度、自噬程度及cleaved Caspase3、cleaved Caspase8、LC3Ⅱ/LC3Ⅰ、Beclin-1、p-AMPK蛋白表达水平高于对照组, p-mTOR蛋白表达水平低于对照组,差异有统计学意义(P0.05)。联合组的HCT-116细胞凋亡程度、自噬程度及cleaved Caspase3、cleaved Caspase8、LC3Ⅱ/LC3Ⅰ、Beclin-1、p-AMPK蛋白表达水平低于高剂量组, p-mTOR蛋白表达水平高于高剂量组,差异有统计学意义(P0.05)。结论 1, 25-(OH)_2D_3可通过调控AMPK/mTOR信号通路增强结肠癌细胞凋亡和自噬,发挥抗肿瘤作用。     

姜黄素诱导K562细胞自噬的抗瘤作用研究

目的研究姜黄素诱导自噬对K562细胞增殖的作用。方法采用MTT法检测不同浓度的姜黄素及自噬特异性抑制剂3-MA对K562细胞存活率的影响;通过Western blot法检测自噬标志蛋白Beclin1及LC3-Ⅱ/LC3-Ⅰ的水平评价自噬;应用实时定量PCR法检测BCR-ABL融合基因的表达。结果姜黄素以剂量、时间依赖方式抑制K562细胞增殖;与加入3-MA的对照组相比,Beclin1的水平及LC3-Ⅱ/LC3-Ⅰ的比值明显升高;姜黄素可导致BCRABL融合基因的水平降低。结论姜黄素诱导自噬可抑制K562细胞增殖并下调BCR-ABL融合基因的表达水平。     

犀角地黄汤对缺血性脑卒中再灌注大鼠模型自噬水平的调节机制分析

目的探讨犀角地黄汤对缺血性脑卒中(AIS)再灌注大鼠模型自噬水平的调节机制。方法无特定病原级雄性大鼠60只,随机分为假手术组(A组,只分离颈总动脉不插入线栓)、AIS再灌注组(B组,构建AIS再灌注模型)、AIS再灌注+犀角地黄汤组(C组,于构建AIS再灌注模型前30 min经腹腔注射10 mg/kg犀角地黄汤)、AIS再灌注+犀角地黄汤+JNK抑制剂组(D组,于构建AIS再灌注模型前30 min经腹腔注射10 mg/kg犀角地黄汤和JNK抑制剂),每组各15只。于建模后24 h麻醉大鼠取脑组织做切片,分别进行神经功能评分、自噬超微结构观察、Western Blot检测自噬蛋白Beclin 1和微管相关蛋白轻链3(LC3)表达、TTC测定大鼠脑梗死体积、TUNEL染色法检测细胞凋亡率。结果构建AIS再灌注模型后,与A组大鼠比较,其余组大鼠神经功能均出现异常,自噬泡增加,Beclin 1、LC3蛋白表达增加。与B组比较,C组大鼠神经功能评分、自噬水平、脑梗死体积、Beclin 1、LC3蛋白表达、神经细胞凋亡率降低(P <0. 05);与C组比较,D组大鼠自噬水平显著降低,神经功能进一步改善(P <0. 05)。结论 AIS再灌注后神经细胞损伤严重、自噬水平升高,犀角地黄汤可通过激活JNK通路显著降低自噬水平而降低神经功能损伤,这可能为AIS再灌注后神经损伤提供新的治疗靶点。     

白藜芦醇通过促进自噬减轻糖尿病大鼠心肌缺血再灌注损伤的实验研究

目的:探讨白藜芦醇减轻糖尿病大鼠心肌缺血再灌注损伤的保护机制及其对心肌细胞自噬的影响。方法:用链脲佐菌素(Streptozotocin,STZ)诱导建立糖尿病大鼠模型,选取35只糖尿病造模成功大鼠,随机分为假手术组、白藜芦醇未手术组、缺血再灌注损伤模型组、白藜芦醇治疗组、白藜芦醇+胰岛素联合治疗组,每组各7只。通过结扎-放松左冠状动脉制备缺血再灌注损伤模型。通过亚甲蓝染色观察心肌梗死面积变化;在透射电镜下观察自噬泡;采用蛋白质印迹(Western blotting)法检测微管相关蛋白1轻链3(microtubule-associated protein 1 light chain 3,LC3)Ⅰ和Ⅱ、自噬相关基因5(autophagy related gene 5,Atg5)、Beclin-1的表达水平及腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)和雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)的表达及磷酸化水平。结果:白藜芦醇治疗组与白藜芦醇+胰岛素联合治疗组心肌梗死面积显著小于缺血再灌注损伤模型组(P0.05)。电镜结果显示,白藜芦醇治疗与白藜芦醇+胰岛素联合治疗可促进糖尿病大鼠缺血再灌注损伤心肌细胞的自噬,改善心肌细胞结构。缺血再灌注损伤模型组大鼠心肌细胞中LC3-Ⅱ、Atg5、Beclin-1表达水平较假手术组显著降低(P0.05),而LC3-Ⅰ表达水平差异无统计学意义(P0.05);白藜芦醇治疗组及白藜芦醇+胰岛素联合治疗组Atg5、Beclin-1表达水平均显著高于缺血再灌注损伤模型组,且白藜芦醇+胰岛素联合治疗组Beclin-1表达水平高于白藜芦醇治疗组(P0.05);各组之间mTOR、AMPK表达水平差异无统计学意义(P0.05),但白藜芦醇治疗组及白藜芦醇+胰岛素联合治疗组AMPK磷酸化水平显著高于缺血再灌注损伤模型组,而mTOR磷酸化水平则显著低于缺血再灌注损伤模型组(P0.05)。结论:白藜芦醇可能通过激活AMPK、抑制mTOR通路,上调LC3-Ⅱ、Atg5、Beclin-1的表达,促进自噬,抑制缺血再灌注损伤,减少心肌梗死面积,从而保护糖尿病大鼠心肌细胞。     

ABCA1 overexpression leads to hyperalphalipoproteinemia and increased biliary cholesterol excretion in transgenic mice

The discovery of the ABCA1 lipid transporter has generated interest in modulating human plasma HDL levels and atherogenic risk by enhancing ABCA1 gene expression. To determine if increased ABCA1 expression modulates HDL metabolism in vivo, we generated transgenic mice that overexpress human ABCA1 (hABCA1-Tg). Hepatic and macrophage expression of hABCA1 enhanced macrophage cholesterol efflux to apoA-I; increased plasma cholesterol, cholesteryl esters (CEs), free cholesterol, phospholipids, HDL cholesterol, and apoA-I and apoB levels; and led to the accumulation of apoE-rich HDL1. ABCA1 transgene expression delayed 125I-apoA-I catabolism in both liver and kidney, leading to increased plasma apoA-I levels, but had no effect on apoB secretion after infusion of Triton WR1339. Although the plasma clearance of HDL-CE was not significantly altered in hABCA1-Tg mice, the net hepatic delivery of exogenous 3H-CEt-HDL, which is dependent on the HDL pool size, was increased 1.5-fold. In addition, the cholesterol and phospholipid concentrations in hABCA1-Tg bile were increased 1.8-fold. These studies show that steady-state overexpression of ABCA1 in vivo (a) raises plasma apoB levels without altering apoB secretion and (b) raises plasma HDL-C and apoA-I levels, facilitating hepatic reverse cholesterol transport and biliary cholesterol excretion. Similar metabolic changes may modify atherogenic risk in humans.     

Monocyte/macrophage expression of ABCA1 has minimal contribution to plasma HDL levels

Excess accumulation of cholesterol in macrophages results in foam cell production and lesion development. Recent studies have demonstrated that ATP-binding cassette protein A1 (ABCA1) is highly regulated in macrophages and mediates the efflux of cholesterol and phospholipids to apolipoproteins, a process necessary for HDL formation. The goal of this study was to determine the contribution of monocyte/macrophage ABCA1 to HDL formation in vivo. We generated mice expressing ABCA1 in macrophages and mice with selected inactivation of ABCA1 in macrophages by bone marrow transplantation in ABCA1-deficient (ABC1(-/-)) and wild-type (WT) mice. At all times, the level of HDL in ABC1(-/-) recipient mice remained low relative to WT recipient mice irrespective of the genotype of the donor macrophage ABCA1 or high-fat feeding. Expression of WT macrophage ABCA1 in ABC1(-/-) mice resulted in a small but significant increase in apoA-I levels starting 2 weeks after transplantation. No further increase in apoAI was observed up to 14 weeks after transplantation. The increase in apoAI was accompanied by a small but significant increase in HDL cholesterol 6 weeks after transplantation. The HDL formed as a consequence of the expression of WT macrophage ABCA1 migrated to the alpha position in a two-dimensional gel electrophoresis. These results demonstrate that monocyte/macrophage ABCA1 contributes to HDL formation; however, the contribution to the overall plasma HDL levels is minimal.     

Apoptotic cells trigger a membrane-initiated pathway to increase ABCA1

Macrophages clear millions of apoptotic cells daily and, during this process, take up large quantities of cholesterol. The membrane transporter ABCA1 is a key player in cholesterol efflux from macrophages and has been shown via human genetic studies to provide protection against cardiovascular disease. How the apoptotic cell clearance process is linked to macrophage ABCA1 expression is not known. Here, we identified a plasma membrane–initiated signaling pathway that drives a rapid upregulation of ABCA1 mRNA and protein. This pathway involves the phagocytic receptor brain-specific angiogenesis inhibitor 1 (BAI1), which recognizes phosphatidylserine on apoptotic cells, and the intracellular signaling intermediates engulfment cell motility 1 (ELMO1) and Rac1, as ABCA1 induction was attenuated in primary macrophages from mice lacking these molecules. Moreover, this apoptotic cell–initiated pathway functioned independently of the liver X receptor (LXR) sterol–sensing machinery that is known to regulate ABCA1 expression and cholesterol efflux. When placed on a high-fat diet, mice lacking BAI1 had increased numbers of apoptotic cells in their aortic roots, which correlated with altered lipid profiles. In contrast, macrophages from engineered mice with transgenic BAI1 overexpression showed greater ABCA1 induction in response to apoptotic cells compared with those from control animals. Collectively, these data identify a membrane-initiated pathway that is triggered by apoptotic cells to enhance ABCA1 within engulfing phagocytes and with functional consequences in vivo.     

Macrophage ABCA1 and ABCG1, but not SR-BI, promote macrophage reverse cholesterol transport in vivo

Macrophage ATP-binding cassette transporter A1 (ABCA1), scavenger receptor class B type I (SR-BI), and ABCG1 have been shown to promote cholesterol efflux to extracellular acceptors in vitro and influence atherosclerosis in mice, but their roles in mediating reverse cholesterol transport (RCT) from macrophages in vivo are unknown. Using an assay of macrophage RCT in mice, we found that primary macrophages lacking ABCA1 had a significant reduction in macrophage RCT in vivo, demonstrating the importance of ABCA1 in promoting macrophage RCT, however substantial residual RCT exists in the absence of macrophage ABCA1. Using primary macrophages deficient in SR-BI expression, we found that macrophage SR-BI, which was shown to promote cholesterol efflux in vitro, does not contribute to macrophage RCT in vivo. To investigate whether macrophage ABCG1 is involved in macrophage RCT in vivo, we used ABCG1-overexpressing, -knockdown, and -knockout macrophages. We show that increased macrophage ABCG1 expression significantly promoted while knockdown or knockout of macrophage ABCG1 expression significantly reduced macrophage RCT in vivo. Finally, we show that there was a greater decrease in macrophage RCT from cells where both ABCA1 and ABCG1 expression were knocked down than from ABCG1-knockdown cells. These results demonstrate that ABCA1 and ABCG1, but not SR-BI, promote macrophage RCT in vivo and are additive in their effects.     

Antagonism of miR-33 in mice promotes reverse cholesterol transport and regression of atherosclerosis

Plasma HDL levels have a protective role in atherosclerosis, yet clinical therapies to raise HDL levels have remained elusive. Recent advances in the understanding of lipid metabolism have revealed that miR-33, an intronic microRNA located within the SREBF2 gene, suppresses expression of the cholesterol transporter ABC transporter A1 (ABCA1) and lowers HDL levels. Conversely, mechanisms that inhibit miR-33 increase ABCA1 and circulating HDL levels, suggesting that antagonism of miR-33 may be atheroprotective. As the regression of atherosclerosis is clinically desirable, we assessed the impact of miR-33 inhibition in mice deficient for the LDL receptor (Ldlr-/- mice), with established atherosclerotic plaques. Mice treated with anti-miR33 for 4 weeks showed an increase in circulating HDL levels and enhanced reverse cholesterol transport to the plasma, liver, and feces. Consistent with this, anti-miR33-treated mice showed reductions in plaque size and lipid content, increased markers of plaque stability, and decreased inflammatory gene expression. Notably, in addition to raising ABCA1 levels in the liver, anti-miR33 oligonucleotides directly targeted the plaque macrophages, in which they enhanced ABCA1 expression and cholesterol removal. These studies establish that raising HDL levels by anti-miR33 oligonucleotide treatment promotes reverse cholesterol transport and atherosclerosis regression and suggest that it may be a promising strategy to treat atherosclerotic vascular disease.     

麝香通心滴丸对心肌细胞缺氧/复氧损伤的保护作用

目的探讨麝香通心滴丸（STDP）对心肌细胞缺氧/复氧的保护作用。 方法建立心肌缺氧/复氧模型。将H9c2细胞分为5组：对照组（细胞正常培养,不做任何处理）、模型组、STDP组（在复氧前40 min给予STDP 50 mg / L）、3-甲基腺嘌呤（3-MA）组（在复氧前40 min给予3-MA 5 mmol / L）及STDP + 3-MA组（在复氧前40 min分别给予STDP 50 mg / L及3-MA 5 mmol / L）。采用细胞计数试剂盒8（CCK-8）法检测各组细胞存活率,并测定各组细胞乳酸脱氢酶（LDH）、丙二醛及肌酸激酶水平。采用流式细胞仪检测各组细胞的细胞凋亡率,实时荧光定量PCR检测信使RNA（mRNA）自噬相关基因Beclin-1、Atg5的表达水平,并通过Western-blotting检测各组细胞自噬相关蛋白LC3Ⅱ / LC3Ⅰ、低氧诱导因子1α（HIF-1α）、Bcl-2 /腺病毒E1B 19 kDa相互作用蛋白3（BNIP3）、Beclin-1、Atg5的表达水平。 结果各组细胞存活率比较,差异有统计学意义（F = 85.893,P = 0.028）,且STDP组细胞存活率较模型组、3-MA组及STDP + 3-MA组细胞存活率均显著升高[（90 ± 7）%、（63 ± 5）%、（80 ± 5）%、（81 ± 6）%,P均< 0.05]。各组细胞LDH、丙二醛、肌酸激酶水平,细胞凋亡率,Beclin-1 mRNA、Atg5 mRNA以及LC3Ⅱ / LC3Ⅰ、HIF-1α、BNIP3、Beclin-1、Atg5蛋白表达水平的比较,差异均有统计学意义（F = 78.381、23.519、48.376、22.726、6.315、5.294、75.219、116.546、21.125、39.724、65.247,P均< 0.05）。进一步两两比较发现,在STDP组细胞中,LDH[（92 ± 6）、（194 ± 13）、（195 ± 11）、（192 ± 10）μmol / L,P均< 0.05]、丙二醛[（12.5 ± 0.7）、（17.2 ± 1.2）、（18.5 ± 1.6）、（17.9 ± 1.0）μmol / L,P均< 0.05]、肌酸激酶[（19.9 ± 1.0）、（34.3 ± 2.2）、（35.3 ± 2.2）、（34.8 ± 2.5）μmol / L,P均< 0.05]水平,细胞凋亡率[（5.8 ± 0.8）%、（8.8 ± 0.9）%、（7.6 ± 0.7）%、（7.3 ± 0.5）%,P均< 0.05]较模型组、3-MA组及STDP + 3-MA组均明显降低;Beclin-1 mRNA、Atg5 mRNA、LC3Ⅱ / LC3Ⅰ、BNIP3、Beclin-1、Atg5蛋白表达水平较模型组均明显降低,而较3-MA组及STDP + 3-MA组均显著升高（P均< 0.05）;HIF-1α蛋白表达水平较模型组、3-MA组及STDP + 3-MA组均明显升高（P均< 0.05）。 结论STDP可通过调控HIF-1α / BNIP3信号通路发挥对心肌细胞缺氧/复氧损伤的保护作用。     

大黄通过改善线粒体自噬缓解急性胰腺炎大鼠内质网应激和脂质代谢障碍的机制

目的探讨大黄通过改善线粒体自噬缓解急性胰腺炎大鼠内质网应激和脂质代谢障碍的机制。方法选取100只SD大鼠,按随机数字表法分为空白对照组、模型组、大黄低(0.5 mL/kg)、中(1.0 mL/kg)、高(2.0 mL/kg)剂量组,每组20只,除空白对照组其余各组均构建急性胰腺炎模型。蛋白质印迹法检测线粒体自噬相关蛋白[微管相关蛋白1轻链3-Ⅰ(LC3-Ⅰ)、微管相关蛋白1轻链3-Ⅱ(LC3-Ⅱ)和自噬相关蛋白5(ATG5)]、内质网应激相关蛋白[磷酸化α亚基的真核起始因子2(p-eIF2α)、葡萄糖调节蛋白78(GRP78)以及转录因子C/EBP同源蛋白(CHOP)]的表达。全自动生化分析仪测定各组大鼠总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)水平;酶联免疫吸附试验(ELISA)法检测超氧化物歧化酶(SOD)、丙二醛(MDA)和谷胱甘肽(GSH)水平以及炎性因子白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)和肿瘤坏死因子-α(TNF-α)水平。结果与空白对照组比较,模型组大鼠线粒体自噬相关蛋白(LC3-Ⅰ、LC3-Ⅱ和ATG5)和内质网应激相关蛋白(p-eIF2α、GRP78、CHOP)相对表达量显著升高,差异均有统计学意义(P<0.05);与模型组比较,大黄低、中、高剂量组大鼠线粒体自噬相关蛋白和内质网应激相关蛋白相对表达量均显著降低,差异均有统计学意义(P<0.05)。与空白对照组比较,模型组大鼠TC、TG、LDL-C、MDA、IL-6、IL-1β、TNF-α水平均显著升高,HDL-C、SOD和GSH水平显著降低,差异均有统计学意义(P<0.05);与模型组比较,大黄低、中、高剂量组大鼠TC、TG、LDL-C、MDA、IL-6、IL-1β、TNF-α水平显著降低,HDL-C、SOD和GSH水平显著增加,差异均有统计学意义(P<0.05),且大黄的作用呈剂量依赖性。结论大黄能够通过改善线粒体自噬来缓解急性胰腺炎大鼠内质网应激和脂质代谢障碍水平,且2.0 mL/kg的大黄效果最佳。     

烟酸和普罗布考联合应用对巨噬细胞胆固醇流出的影响

【目的】探讨烟酸、普罗布考单独及联合作用对巨噬细胞胆固醇流出的影响及其机制。【方法】巨噬细胞264．7分别给予烟酸（1．0mM）、普罗布考（50μM）、烟酸加普罗布考（1．0mM＋50μM）干预24h后,收集细胞,反转录聚合酶链反应测定巨噬细胞B族清道夫受体I（SR-BI）、三磷酸腺苷结合盒转运A1（ABCAl）和三磷酸腺苷结合盒转运体G1（ABCGl）mRNA表达,采用液体闪烁计数器检测细胞内胆固醇流出情况。【结果】与对照组比较,烟酸和普罗布考单独作用及联合应用均促进巨噬细胞胆固醇流出,但联合作用组与单独作用组之间效果差异无显著性（P〉0．05）。烟酸及普罗布考对巨噬细胞SR-BI mRNA的表达无影响;对ABCA1 mRNA的表达有相反作用;二者均增加巨噬细胞ABCG1 mRNA的表达,并促进其介导的胆固醇流出。【结论】烟酸和普罗布考联合应用可促进巨噬细胞胆固醇流出;ABCG1-HDL途径在胆固醇流出中占有更重要的地位,这可能为解释烟酸和普罗布考抗动脉粥样硬化的机制提供有用的线索。     

同型半胱氨酸对THP-1单核细胞源性泡沫细胞形成中ABCA1、ACAT1表达的影响

目的探讨同型半胱氨酸(Hcy)对THP-1单核细胞源性泡沫细胞形成中三磷酸腺苷-结合转运子A1(ABCA1)和酰基辅酶A:胆固醇酰基转移酶(ACAT1)表达的影响。方法将THP-1单核细胞与佛波酯(PMA)、氧化低密度脂蛋白(ox-LDL)共同培养,复制泡沫细胞模型,并分别用50、100、200、500μmol/L Hcy和100μmol/L Hcy+叶酸+维生素B12(Vit B12)干预72 h,并设对照组(不加入Hcy)。采用油红O染色检测泡沫细胞的形成。采用酶终点法测定细胞内总胆固醇(TC)、游离胆固醇(FC)和胆固醇酯(CE)含量的变化,观察Hcy对泡沫细胞CE流出的影响。采用荧光定量逆转录-聚合酶链反应(RT-PCR)测定ABCA1、ACAT1 mRNA表达;免疫印迹法检测ABCA1、ACAT1蛋白表达。结果油红O染色显示Hcy加剧了泡沫细胞的形成,但不呈量效关系。实验组(加入50、100、200、500μmol/L Hcy和100μmol/L Hcy+叶酸+Vit B12)泡沫细胞阳性百分率均高于对照组(P<0.05、P<0.01),以100μmol/L Hcy组效应最为明显(P<0.01)。在Hcy的干预下,泡沫细胞胞内TC、FC、CE流出减少,与对照组比较差异有统计学意义(P<0.05),以100μmol/L Hcy组效应最为明显(P<0.01)。100μmol/L Hcy+叶酸+VitB12组与100μmol/L Hcy组比较,前者泡沫细胞形成减少,胆固醇流出增多。RT-PCR结果显示ABCA1 mRNA表达下调,ACAT1 mRNA表达上调,均以100μmol/L Hcy组效应最为明显(P<0.01);免疫印迹法检测ABCA1、ACAT1蛋白的表达与其mRNA表达一致。结论 Hcy下调了ABCA1的表达,上调了ACAT1的表达,促使了泡沫细胞形成。