海蓬子皂苷甲调控SHP/STAT信号通路抗肝癌的研究

目的研究海蓬子皂苷甲(bigelovii A,BA)诱导细胞凋亡的作用及其机制。方法使用MTT实验检测BA对肿瘤细胞增殖的抑制作用;流式细胞仪分析BA对细胞凋亡的影响;Western blot分析p-STAT3、STAT3、p-STAT5、STAT5、SHP-1、SHP-2的表达。结果20和40μmol·L^-1 BA可诱导HepG2细胞发生凋亡,具有剂量依赖性。10、20和40μmol·L^-1 BA可抑制IL6诱导的STAT3和STAT5磷酸化,但酪氨酸磷酸酶抑制剂过钒酸钠可逆转该抑制作用,且20μmol·L^-1 BA能激活蛋白酪氨酸磷酸酶SHP-1和SHP-2。结论BA可能通过SHP-1/SHP-2和STAT3/STAT5通路诱导HepG2细胞凋亡。     

阿托伐他汀抑制肝癌细胞增殖作用的研究

摘要　目的：体外观察阿托伐他汀对人肝癌HepG2细胞增殖、细胞周期及COX-2蛋白表达的影响。方法：取对数期人肝癌HepG2细胞,加入阿托伐他汀使其终浓度为0μM、0.1μM、1μM、10μM、100μM,采用细胞计数法及噻唑蓝(MTT)法观察阿托伐他汀对HepG2细胞增殖的影响,流式细胞仪(FCM)研究阿托伐他汀对细胞周期的作用,免疫细胞化学观察阿托伐他汀对COX-2蛋白表达的影响。结果：1.体外阿托伐他汀呈浓度和时间依赖性地抑制HepG2细胞的增殖,但0.1μM组与0μM组差异无统计学意义。2. 细胞周期分析显示,阿托伐他汀作用24h后,呈浓度依赖性改变细胞周期分布,一方面增高G0/G1期细胞的比例,一方面降低S期及G2/M期的细胞比例,但细胞凋亡不明显。3.体外阿托伐他汀呈浓度依赖性地抑制HepG2细胞COX-2蛋白的表达。结论：体外阿托伐他汀对HepG2细胞增殖有抑制作用,该作用可能与使细胞生长阻滞于G0/G1期及抑制COX-2蛋白表达有关。     

厄洛替尼通过下调CD44表达抑制非小细胞肺癌转移的机制研究

目的 探讨表皮生长因子受体酪氨酸激酶抑制剂(EGFR-TKI)下调黏附分子CD44表达抑制非小细胞肺癌转移的机制.方法 采用MTT法检测厄洛替尼对HCC827细胞株的增殖抑制效应及计算药物作用48 h的IC50;采用Transwell和划痕实验检测3组[control、EGF(50 ng/ml)刺激组、厄洛替尼(0.323 μmol/L)处理组]细胞侵袭迁移能力的变化;采用流式细胞术及Western blot方法分别从细胞及蛋白水平检测3组[control、EGF(50 ng/ml)刺激组、厄洛替尼(0.323 μmol/L)处理组]细胞CD44表达水平变化.结果 MTT结果显示,随着药物浓度升高,厄洛替尼对细胞的增殖抑制率也逐渐增大,差异有统计学意义(P＜ 0.05);IC50为0.323 μmol/L.Transwell及划痕实验结果显示,厄洛替尼阻断EGFR信号通路后可降低细胞的侵袭迁移能力(P＜0.05).流式细胞术及Western blot检测三组细胞CD44表达水平变化结果显示:当使用EGF刺激细胞后,CD44表达明显上调,而使用厄洛替尼阻断EGFR信号通路后CD44表达则被明显下调(P＜0.05).结果提示,厄洛替尼抑制肿瘤转移可能与改变CD44表达有关.结论 使用厄洛替尼阻断EGFR信号通路后,可间接下调与肿瘤转移密切相关的黏附分子CD44的表达,进而发挥抑制肿瘤转移的作用.     

蛋白酶体抑制剂MG132诱导HepG2细胞凋亡及其机制研究

目的观察蛋白酶体抑制剂MG132对人肝癌细胞HepG2的致凋亡作用,并从泛素蛋白酶体途径(UPP)相关基因E1、E2和E3及天冬氨酸特异的半胱氨酸蛋白酶3(Caspase3)表达初步探讨MG132的致细胞凋亡机制。方法采用多个浓度(2、5、10μmol·L-1)的蛋白酶体抑制剂MG132处理HepG2细胞;流式细胞术检测细胞周期和细胞凋亡率,DNA琼脂糖凝胶电泳检测细胞凋亡;逆转录聚合酶链反应(RTPCR)检测UPP相关基因E1、E2、E3和凋亡相关基因Caspase3的转录水平;免疫细胞化学检测Caspase3蛋白表达。结果对照组HepG2细胞凋亡率低于5%,在2、5和10μmol·L-1MG132作用下,细胞凋亡率分别为42.9%、66.1%、72.8%,MG132诱导HepG2细胞凋亡具有量效关系;RTPCR检测发现细胞内UPP相关基因E1、E2、E3mRNA表达下降,而凋亡相关基因Caspase3mRNA表达上调;免疫组化检测Caspase3蛋白表达水平升高。结论蛋白酶体抑制剂MG132能够诱导HepG2细胞凋亡,其机制可能与MG132抑制UPP活性,使细胞内Caspase3蛋白降解减少,同时上调Caspase3基因转录,促进细胞凋亡。     

RhoC/ROCK2 promotes vasculogenic mimicry formation primarily through ERK/MMPs in hepatocellular carcinoma

OBJECTIVE Our previous study reported that rho-associated coiled-coil containing kinases(ROCKs)were involved in vasculogenic mimicry(VM) formation in hepatocellular carcinoma(HCC). This study focused on clarifying potential mechanisms of Rho C/ROCK on VM formation in hepatocellular carcinoma(HCC). METHODS In total, 80 cases of HCC tissues and adjacent nontumorous liver tissues were used to identify VM in HCC tissues by PAS/CD34 double staining. Kaplan-Meier analysis was conducted to test the predictive relationship between Rho C/ROCK expression and patient prognosis.Furthermore, we stably overexpressed Rho C and inhibited Rho C, ROCK1 or ROCK2 expression to clarify the effect of Rho C/ROCK on VM formation in vitro and in vivo.RESULTS Rho C expression was up regulated in HCC tissues, especial y the VM-positive(VM+) group, compared to non-cancerous tissues(P<0.01), and patients with high expression of Rho C had shorter survival times(P<0.01). Cel motility and VM formation significantly decreased after knockdown of Rho C, while overexpressing Rho C led to the opposite result. Compared to ROCK1 sh RNA,ROCK2 sh RNA could largely affects VM formation, cell motility and the key VM factors and the epithelial-mesenchymal transition(EMT) markers in vitro and in vivo. Moreover, p-ERK, p-MEK, p-FAK and p-paxillin levels clearly altered following the change of Rho C, but ROCK2 little affected expression of p-FAK. CONCLUSION Rho C/ROCK2 may have a major effect on VM in HCC via ERK/MMPs signaling and might be a potential therapeutic target for the treatment of HCC.     

Effects of squalene on expression of LDLR in HepG2 cells and its mechanism北大核心CSCD

Aim To investigate the effect of squalene on LDLR expression in HepG2 cells and its mechanism of down-regulated cholesterol. Methods The proliferation of HepG2 cells exposed to squalene at different concentrations was measured by MTT assay. The effect of squalene on the expression of LDLR in HepG2 cells was measured by flow cytometry and fluorescence mi-croscopy. The effect of different concentrations of squalene on the interaction between SCAP and Insig2, two key protein molecules of SREBP pathway, was assayed by FRET technology. Results MTT results showed that squalene had inhibitory effect on the proliferation of HepG2 cells in a dose-dependent manner. Flow cytometry and fluorescence microscopy results showed that squalene enhanced LDLR expression in HepG2 cells compared with the control group. The results of FRET technology revealed that compared with model control group, the YFP fluorescence value in Squalene group dramatically declined, and the YFP fluorescence value of each drug group decreased with the range of 5-25 |xmol L1 squalene concentration. Conclusions Squalene may promote the expression of LDLR in HepG2 cells through inhibiting the interaction between SCAP and Insig2 proteins in SREBP pathway, which may confirm that squalene is a potential novel drug for the down-regulation of cholesterol level. © 2018 Publication Centre of Anhui Medical University. All rights reserved.     

2-脱氧葡萄糖联合二甲双胍抗人肝癌HepG2细胞作用及与AMPK、mTOR相关性研究

目的 考察2-脱氧葡萄糖（2-DG）联合二甲双胍（Met）协同抗人肝癌HepG2细胞作用并探索其机制。方法 刃天青法测定2-DG及Met单独及联合应用对HepG2细胞的生长抑制作用,利用金氏公式计算联合用药Q值;利用高内涵细胞成像系统考察单独及联合用药对细胞线粒体膜电位及活性氧产生的影响;Western blotting检测Cleave-Caspase 3、p-AMPK及p-mTOR的蛋白变化;考察AMPK及mTOR抑制剂对联合用药后细胞生长抑制作用的影响。结果 2-DG、Met单独应用的IC₅₀值分别为2.45及16.35 mmol/L,联合用药对细胞生长抑制具有协同作用,Q值均大于1.15;联合用药能显著降低细胞内线粒体膜电位及p-mTOR蛋白表达,显著增加细胞内活性氧产生及Cleave-Caspase3、p-AMPK蛋白表达;抑制AMPK或mTOR能显著增加联合用药对细胞的生长抑制作用（P<0.05、0.01）。结论 2-DG联合Met具有协同抑制HepG2细胞增殖作用,其机制与降低细胞线粒体膜电位,促进活性氧产生、细胞凋亡,以及非AMPK依赖性的抑制mTOR活化有关。     

长链非编码RNA转化生长因子-β诱导HOXA转录物调控KHDRBS3介导的肿瘤干细胞机制研究

目的研究长链非编码RNA(LncRNA)转化生长因子(TGF)-β诱导HOXA转录物(HIT)在胰腺癌组织中的表达及其与细胞转移间的关系及机制。方法培养人肾上皮细胞系293T并进行HIT干扰载体的慢病毒细胞包装,构建Capan-1干扰HIT细胞模型,分为对照组、干扰1#组及干扰2#组,以Transwell侵袭及迁移实验检测各组细胞侵袭及迁移数量的变化,以蛋白质印迹(Western Blot)法检测各组细胞KHDRBS3及CD44的蛋白表达变化。结果对照组、干扰#1组及干扰#2组中HIT mRNA表达水平分别为1.00±0.07,0.36±0.02及0.30±0.03,KHDRBS3 mRNA表达水平分别为1.00±0.11,1.22±0.13及0.93±0.09,CD44 mRNA表达水平分别为1.00±0.09,0.61±0.06及0.46±0.04,KHDRBS3蛋白相对表达水平分别为0.81±0.06,0.12±0.01及0.18±0.02,CD44蛋白相对表达水平分别为0.57±0.06,0.19±0.02及0.23±0.03,每视野侵袭细胞数分别为(66.0±7.4),(32.5±5.1)和(26.1±5.8)个,每视野迁移细胞数分别为(71.6±8.0),(21.5±3.7)及(24.9±4.2)个,干扰#1组及干扰#2组侵袭及迁移细胞数显著低于对照组(P<0.01);干扰1#组及干扰2#组KHDRBS3蛋白及CD44 mRNA和蛋白表达明显低于对照组(P<0.01)。结论LncRNA HIT在胰腺癌组织中高表达,且可通过激活KHDRBS3/CD44通路,促进胰腺癌细胞的侵袭转移能力。     

丹酚酸A诱导HepG2细胞凋亡及抑制c-Met表达

目的通过研究丹酚酸A（salvianol acid A,SalA）对肝癌HepG2细胞株c-Met蛋白表达的影响,探讨SalA抑制肝癌细胞增殖,诱导细胞凋亡的可能作用机制。方法以肝癌HepG2细胞株为研究对象,采用MTT法及流式细胞术检测SalA作用后细胞存活、增殖及凋亡情况;同时运用Westernblot法及PCR法检测HepG2细胞c-Met及其下游信号通路中关键蛋白和基因表达的改变。结果肝癌HepG2细胞经SalA处理后,其细胞增殖显著抑制,细胞凋亡比例亦升高,且呈浓度依赖性;同时HepG2细胞中c-Met及其下游信号分子AKT的磷酸化水平显著下调,凋亡相关蛋白Bax、caspase-3和caspase-9的表达亦明显上调。结论SalA能有效抑制肝癌HepG2细胞的增殖并诱导细胞凋亡,其作用机制可能与其抑制HepG2细胞中c-Met蛋白及其下游信号通路中AKT蛋白的磷酸化水平有关。     

Saikosaponin-b regulates the proliferation and apoptosis of HepG2 cells by targeting the MACC1/c-Met/Akt signaling pathway

OBJECTIVE Metastasis-associated in colon cancer-1(MACC1)is an oncogene that has been newly identified.It promotes tumor proliferation and invasion via the MET pathway.Our study investigated the effects of Saikosaponin-b(SS-b)on the proliferation and apoptosis of HepG2 cells and its regulation on MACC1/c-Met/Akt signaling pathway.METHODS HepG2 cells were treated with SS-b(10-800 g·L~(-1))for 48 h in vitro.The CCK-8 assay was used to assess cell proliferation,and cell apoptosis was determined by Hoechst33258 staining,AnnexinⅤ/PI staining and caspase 3 assay.RT-PCR was used to examine the expression of MACC1,c-MET and hepatocyte growth factor(HGF)mR NA.MACC1 protein was detected by Western blot and immunohistochemistry.The protein expressions of p-cMET,c-MET,p-AKT,AKT,p-BAD,BAD were measured by Western blot.RESULTS SS-b inhibited the growth of HepG2 cells in dose-dependent way and induced cell apoptosis significantly.HepG2 cells showed karyopyknosis,fragmentation and fluorescence highlight in SS-b treatment group.FCM results showed that apoptosis rate of HepG2 cells increased with SS-b concentration.The immunofluorescence results showed that the MACC1 expression decreased significantly in HepG2 cells treated with SS-b.The expression levels of MACC1,c-MET and HGF mR NA in HepG2 cells were significantly inhibited by SS-b.SS-b also significantly decreased the protein expressions of MACC1,p-c-MET and p-AKT while increased the expression of p-BAD and caspase 3 in HepG2 cells(P<0.05).CONCLUSION SS-b inhibited the proliferation and induced the apoptosis of HepG2 cells by targeting the MACC1/c-Met/Akt signaling pathway.     

过表达SOCS3对西格列汀改善胰岛素抵抗作用的影响

目的:探究过表达SOCS3对西格列汀(sitagliptin,SITA)在改善脂质代谢和氧化应激,以减轻棕榈酸(palrnitic acid,PA)介导的HepG2细胞胰岛素抵抗(insulin resistance,IR)中的作用。方法:MTT法检测PA与SITA对肝癌细胞HepG2增殖活性的影响;将HepG2分为4组:Control组,PA组,PA+SITA+pEX-RB-NC组和PA+SITA+pEX-RB-SOCS3组;油红O染色检测细胞中脂质的积聚水平,RT-PCR检测细胞中SREBP1c和PPARα的mRNA表达,DCFH-DA法检测细胞中ROS的水平,RT-PCR与试剂盒检测细胞中CAT与GPx的mRNA表达与酶活性;Western blot试验检测细胞IR通路中p-IRS-1^Ser307/IRS-1、p-AKT^Ser473/AKT、p-GSK3β^Ser9/GSK3β的比值。结果:与Control组相比,SITA能削弱PA诱导的HepG2细胞活力损伤(P＜0.05),且PA组、PA+SITA+pEX-RB-NC组和PA+SITA+pEX-RB-SOCS3组中富含大量红色脂滴,SREBP1c与PPARα的mRNA水平、ROS、CAT与GPx表达及p-IRS-1^Ser307/IRS-1、p-AKT^Ser473/AKT、p-GSK3β^Ser9/GSK3β比值均明显升高(P＜0.05);但与PA组相比,PA+SITA+pEX-RB-NC组除CAT、GPx及p-IRS-1^Ser307/IRS-1、p-AKT^Ser473/AKT、p-GSK3β^Ser9/GSK3β比值升高外(P＜0.05),其他检测指标均显著降低(P＜0.05),PA+SITA+pEX-RB-SOCS3组中上述指标均无明显改变(P＞0.05)。结论:SITA可抑制脂质代谢和氧化应激,从而以减轻PA介导的肝细胞IR,而该作用能够被过表达SOCS3所抵消。     

纳米雄黄对MCF-7乳腺癌干细胞的体外抑制作用

目的 研究纳米雄黄对乳腺癌干细胞的体外抑制作用.方法 以人乳腺癌MCF-7亲本细胞为对象,采用无血清培养法培养获得乳腺癌干细胞.以阿霉素(1 mg/L)为阳性对照,以相同质量浓度的水飞雄黄为参照,采用CCK-8法检测纳米雄黄对MCF-7亲本细胞及干细胞增殖的影响;借助悬浮球形成及分化实验、划痕实验、Transwell侵...     

Involvement of asymmetric dimethylarginine and Rho kinase in the vascular remodeling in monocrotaline-induced pulmonary hypertension

Recent studies have shown that the plasma level of asymmetric dimethylarginine (ADMA) was increased accompanied by the decreased dimethylarginine dimethylaminohydrolase (DDAH) activity in pulmonary hypertension (PH) and ADMA was able to regulate pulmonary endothelial cells mobility through increasing the activity of Rho kinase (ROCK). This work was conducted to explore the role of ADMA/DDAH pathway in vascular remodeling in PH and the underlying mechanisms. The rat model of PH was established by a single injection of monocrotaline (60 mg/kg, s.c.). The pulmonary arterial pressure, the remodeling of pulmonary artery, the hypertrophy of right ventricle, the plasma levels of ADMA and NO, the expression of DDAH2, ROCK1 or ROCK2 and the ROCK activity were determined. In vitro studies, the pulmonary artery smooth muscle cells (PASMCs) were isolated and cultured. The effect of ADMA on PASMCs proliferation and ROCK activation was investigated. The results showed that the injection of monocrotaline successfully induced PH characterized by the increased pulmonary arterial pressure, vascular remodeling and right ventricle hypertrophy. The plasma level of ADMA was elevated concomitantly with the increased ROCK activity and ROCK1 expression as well as the decreased DDAH2 expression in pulmonary arteries. In the cultured PASMCs, ADMA promoted cellular proliferation accompanied by the increased ROCK1 expression and ROCK activity, which was attenuated by the ROCK inhibitor or by the intracellular antioxidant. These results suggest that ADMA could promote the proliferation of PASMCs through activating ROCK pathway, which may account for, at least partially, the vascular remodeling in monocrotaline-induced PH.     

Betulinic acid enhances 1alpha,25-dihydroxyvitamin D3-induced differentiation in human HL-60 promyelocytic leukemia cells

Betulinic acid (BA) is a pentacyclic triterpene found in a number of medicinal plants and has been shown to cause apoptosis in a number of cell lines. We report here that BA may also have an effect on HL-60 cell differentiation. BA was cytotoxic to HL-60 cells with an IC50 of 5.7 microM after a 72-h treatment. Flow cytometry analysis showed that after exposure to 1-12 microM of BA for 72 h, approximately 10% of viable cells were in the sub-G1, presumably apoptotic, phase. At the same time differentiation was induced in approximately 10% (at 1 microM BA) to a maximum of 20% (at 6 microM BA) of cells as judged by the NBT-reduction test, and the expression of membrane markers CD11b and CD14. On the other hand, at 1 and 5 nM, 1alpha,25-dihydroxyvitamin D3 (DHD3) induced differentiation in approximately 10 and 70% of cells, respectively. At 1 nM DHD3, the addition of 1 microM BA increased differentiated cells from 10 to 43% and with 3 microM BA the increase was to 80%. BA also enhanced the effects of DHD3 in the expansion of the G1 cell population with a concomitant decrease of S phase cells. The effects of DHD3 and BA on CD11b and CD14 expression were inhibited by PD98059, a MEK inhibitor. Our results suggest that BA may enhance the effect of DHD3 in inducing mitogen-activated protein kinase kinase/extracellular signal-regulated protein kinase-mediated HL-60 cell differentiation.     

Oestrogen improves glucose metabolism and insulin signal transduction in HepG2 cells

1. Many clinical studies have suggested a relationship between oestrogen and insulin sensitivity. In the present study, HepG2 cells were divided into four groups: (i) control, incubated with 1 nmol/L insulin; (ii) the HI group, which was incubated with 100 nmol/L insulin to induce insulin resistance; (iii) the E2 group, in which control cells were incubated with 1 nmol/L insulin plus 1 nmol/L oestradiol; and (iv) the HI + E2 group, in which insulin-resistant cells were incubated with 100 nmol/L insulin + 1 nmol/L oestradiol. 2. A high concentration of insulin decreased the activity of phosphofructo-1-kinase (PFK), pyruvate dehydrogenase (PDH) and glycogen synthase (GS), as well as decreasing the expression of insulin receptor (IR) and insulin receptor substrate-2 (IRS-2). High insulin had no effect on glucose transport or the expression of insulin receptor-1 (IRS-1). 3. The addition of oestradiol to control cells increased glucose transport, the activity of PFK, PDH and GS and the expression of IRS-1 and IRS-2, but had no effect on the expression of IR. 4. Treatment of insulin-resistant HepG2 cells with oestradiol attenuated HI-induced decreases, except for IR, and the expression of IRS-1 was significantly higher than control, attaining levels seen in group 3. The expression of IRS-2 was significant higher than in insulin-resistant cells, but did not reach control levels. Changes in the activity of PFK, PDH and GS were the same as the changes seen in the expression of IRS-2. 5. These results suggest that high concentrations of insulin induce insulin resistance in HepG2 cells, whereas oestradiol improves glucose metabolism and insulin signal transduction of cells by enhancing the activity of key enzymes involved in glucose metabolism and the expression of IRS-1 and IRS-2.     

芦丁对慢性脑低灌注大鼠海马组织神经元损伤及RhoA/ROCK信号通路的影响

目的 探讨芦丁对慢性脑低灌注大鼠海马组织神经元损伤及Ras同源基因家族成员A（RhoA）/Rho相关卷曲螺旋蛋白激酶（ROCK）信号通路的影响。方法 将SD大鼠随机分为假手术组、模型组、芦丁低剂量组（20 mg/kg）、芦丁中剂量组（40 mg/kg）、芦丁高剂量组（80 mg/kg）、RhoA抑制剂组（Rhosin hydrochloride,40 mg/kg）,每组9只。除假手术组外,其余各组大鼠均通过结扎颈动脉构建慢性脑低灌注大鼠模型,按照各组给药剂量进行干预处理,每天给药1次,持续4周。采用Morris水迷宫实验测定大鼠的认知功能和记忆能力,苏木素-伊红染色观察大鼠海马组织神经元状态,TUNEL染色检测大鼠海马组织神经元凋亡情况,透射电镜观察大鼠海马组织神经元超微结构,蛋白免疫印迹法检测大鼠海马组织凋亡相关蛋白[胱天蛋白酶-3（Caspase-3）、B淋巴细胞瘤-2相关X蛋白（Bax）]及RhoA/ROCK通路相关蛋白表达情况。结果 与假手术组相比,模型组大鼠海马组织神经元数量减少,神经元超微结构、细胞器结构严重受损,逃避潜伏期、海马组织神经元凋亡率、凋亡相关蛋白（Caspase-3、Bax）、RhoA、ROCK1、ROCK2蛋白表达显著升高（P<0.05）,穿越平台次数显著减少（P<0.05）;与模型组相比,芦丁各剂量组及RhoA抑制剂组大鼠神经元数量显著增多,神经元超微结构、细胞器受损等均得到一定的恢复,逃避潜伏期、海马组织神经元凋亡率、凋亡相关蛋白（Caspase-3、Bax）、RhoA、ROCK1、ROCK2蛋白表达显著降低（P<0.05）,穿越平台次数显著增多（P<0.05）,且芦丁各剂量组呈剂量依赖效应;芦丁高剂量组与RhoA抑制剂组上述指标比较差异均无统计学意义。结论 芦丁可能通过抑制RhoA/ROCK信号通路缓解慢性脑低灌注引起的大鼠神经元损伤。     

晚期糖基化终产物对人肝癌细胞HepG2增殖的影响

目的探讨糖尿病晚期糖基化终产物(AGEs)对肝癌细胞HepG2增殖的影响及其机制。方法体外培养人肝癌细胞HepG2,以终浓度分别为100、200和400μg/ml的AGEs处理细胞24h,并设正常对照组进行比较。运用细胞计数试剂盒8研究AGEs对HepG2增殖的影响,流式细胞术检测细胞周期的改变,Western blot检测肝癌细胞抗凋亡基因表达。结果 AGEs呈浓度依赖性显著促进HepG2细胞增殖(P<0.05)。与对照组比较,200μg/ml AGEs干预24h后可以减少HepG2细胞G1期百分率,同时增加S期百分率(P<0.05)。AGEs可致细胞抗凋亡基因B细胞淋巴瘤-白血病2(Bcl-2)相关蛋白表达增加。结论 AGEs能促进HepG2细胞的增殖,其机制可能与上调Bcl-2相关蛋白表达,加速细胞G1期向S期转换相关。     

Protective role of metabolism by intestinal microflora in butyl paraben-induced toxicity in HepG2 cell cultures

Parabens are alkyl esters of p-hydroxybenzoic acid (BA), including methyl paraben (MP), ethyl paraben, propyl paraben (PP), and butyl paraben (BP). In the present study, possible role of metabolism by fecalase in BP-induced cytotoxicity was investigated in HepG2 cell cultures. As an intestinal bacterial metabolic system, a human fecalase prepared from human fecal specimen was employed. Among the parabens tested, cytotoxicity of BP was most severe. BA, the de-esterified metabolite, did not induce cytotoxicity when compared to other parabens. When BP was incubated with fecalase, it rapidly disappeared, in association with reduced cytotoxicity in HepG2 cells. In addition, BP incubated with fecalase significantly caused an increase in Bcl-2 expression together with a decrease in Bax expression and cleaved caspase-3. Moreover, anti-apoptotic effect by the incubation of BP with fecalase was also confirmed by the TUNEL assay. Furthermore, BP induced a sustained activation of the phosphorylation of JNK only when it was treated alone. Meanwhile, BP-induced cell death was reversed by the pre-incubation of BP with either fecalase or SP600125. Taken together, the findings suggested that metabolism of BP by human fecalase might have protective effects against BP-induced toxicity in HepG2 cells.