Skip to main content
Chinese Journal of Hepatology logoLink to Chinese Journal of Hepatology
. 2019 Dec 20;27(12):989–993. [Article in Chinese] doi: 10.3760/cma.j.issn.1007-3418.2019.12.011

磷酸酶张力蛋白同源物基因表达下调对体外活化肝星状细胞p130Crk相关底物蛋白及桩蛋白信号转导的影响

Effect of downregulation of phosphatase and tensin homolog gene expression on p130crk- related substrate protein and paxillin signaltransduction in activated hepatic stellate cells in vitro

Hao Lisen 1,通信作者:, Zhang Penglei 1, Liu Bo 1, Zhang Guangling 2, Chen Jing 3, Song Jie 1, Zhang Mingting 1, Jin Limin 1
Editor: 孙 宇航
PMCID: PMC12814639  PMID: 31941261

Abstract

Objective

To investigate the role of adenovirus-mediated short hairpin RNA (sh RNA) in down-regulating the expression of phosphatase and tensin homologue deleted on chromosome ten (PTEN) on p130Crk-related substrates(p130 Cas) and paxillin signal transduction to activate hepatic stellate cell (HSC) in vitro.

Methods

The rat hepatic stellate cellline, HSC-T6 was cultured and activated in vitro. The adenovirus was used as a vector to transiently transfect sh RNA targeting PTEN to activate HSC in vitro, and then PTEN low expression model of activated HSC in vitro was established. Western blot and real-time fluorescence quantitative PCR were used to detect the protein and mRNA expression of PTEN, p130cas and paxillin in activated HSC. The experiment was divided into control group (HSC were transfected with DMEM medium instead of adenovirus),Ad-GFP group (HSC were infected with empty the adenovirus expressing green fluorescent protein (GFP) alone),and Ad-sh RNA/PTEN group (HSC were infected with the recombinant adenovirus containing both sh RNA targeting PTEN and GFP gene). One-way analysis of variance was used for comparison of multiple groups, and LSD test was used for inter-group comparison.

Results

sh RNA targeting PTEN was successfully transfected and significantly down-regulated the PTEN protein and mRNA expression of HSC in vitro (P<0.05), and the PTEN low expression model of HSC in vitro was successfully constructed. Compared with the expression of p130cas mRNA in the three groups of HSC, the expression fold of p130cas mRNA in the Ad-GFP group and the Ad-sh RNA /PTEN group was 1.01 times and 1.52 times, respectively. The expression of p130cas mRNA in HSC of the Ad-sh RNA/PTEN group was significantly higher than control group and Ad-GFP group (P<0.05), but there was no statistically significant difference between the control group and the Ad-GFP group (P>0.05). The expression of p130cas protein in the three groups was higher than that in the control group (0.74±0.07) and the Ad-GFP group (0.72±0.02); P<0.05, but there was no statistically significant difference between the Ad-GFP group and the control group (P>0.05). The expression of paxillin mRNA in the three groups of HSCs was compared with the expression of paxillin mRNA in the control group of HSC being 1, the expression folds of paxillin mRNA in the Ad-GFP group and Ad-sh RNA/ PTEN group were 0.97 times and 1.58 times, respectively. The expression of paxillin mRNA in the Ad-sh RNA/ PTEN group was higher than that in the control group and the Ad-GFP group (P<0.05), and there was no statistically significant difference between the control group and the Ad-GFP group (P>0.05). The expression of paxillin protein in the three groups of HSCs was higher in the Ad-sh RNA / PTEN group (0.91±0.05) than control group (0.46±0.03) and Ad-GFP group (0.50±0.04),P<0.05, and there was no statistically significant difference between the Ad-GFP group and the control group (P>0.05).

Conclusion

Down-regulation of PTEN expression can significantly boost p130cas and signaltransduction activity of paxillin protein in activated HSC in vitro.

【Key words】: Hepatic fibrosis, Hepatic stellate cells, Paxillin, Signal transduction


肝纤维化是肝脏对各种损伤产生的修复反应,逐渐进展可演变为肝硬化,肝星状细胞(hepatic stellate cells, HSC)是参与肝纤维化病理过程的最重要细胞[1]。当肝脏受到损伤后,活化HSC在肝损伤部位黏附迁移导致损伤区域活化HSC的数量增多,进而促进肝纤维化的形成及发展[1,2]。在多种恶性肿瘤中表达缺失或下调的第10号染色体缺失的磷酸酶张力蛋白同源物基因(phosphatase and tensin homology deleted on chromosome ten,PTEN),可通过负性调控肿瘤细胞的黏着斑激酶(focal adhesion kinase, FAK),进而下调其下游信号p130 Crk相关底物蛋白(p130 Crk-associated substrate, p130Cas)及桩蛋白(paxillin)抑制肿瘤细胞的黏附及迁移[3,4,5]。而本课题组前期研究结果显示,PTEN表达下调可通过增强FAK信号转导活性促进体外活化大鼠HSC的黏附及迁移[6,7]。但PTEN表达下调对活化HSC p130cas及桩蛋白的影响仍不清楚。为此,本研究以腺病毒为载体,将靶向PTEN的RNA干扰序列——短发夹RNA(short hairpin RNA, sh RNA)转染体外培养的活化大鼠HSC,构建体外活化HSC的PTEN低表达模型,观察PTEN表达下调对体外活化HSC p130cas及桩蛋白信号转导的影响,以期为深化肝纤维化的病理生理机制研究提供实验依据。

材料与方法

1.试剂:携带靶向PTEN的sh RNA及表达绿色荧光蛋白(green fluorescent protein, GFP)的重组腺病毒(Ad-sh RNA/PTEN)由武汉浙玛生物技术公司协助构建;仅表达GFP的空病毒(Ad-GFP)由第三军医大学祝善俊教授惠赠,通过反复感染293T细胞获得所需腺病毒;表型活化的大鼠肝星状细胞系HSC-T6购自中国医学科学院北京肿瘤研究所;DMEM培养液购自美国Gibco公司;小鼠抗PTEN单克隆抗体、兔抗桩蛋白单克隆抗体均购自英国Abcam公司;兔抗P130Cas单克隆抗体、兔抗3-磷酸甘油醛脱氢酶(glyseraldehyde-3-phosphate dehydrogenase, GAPDH)单克隆抗体购自美国Affinity公司;辣根过氧化物酶标记的山羊抗兔及山羊抗小鼠免疫球蛋白G购自美国KRL公司;RIPA裂解液购自上海贝博生物科技有限公司;逆转录反应体系、Platinum SYBR Green qPCR Super Mix-UDG购自上海英俊生物技术有限公司。

2.腺病毒转染体外活化HSC:在细胞培养瓶中接种HSC-T6,以含10%胎牛血清的DMEM培养活化肝星状细胞,按感染倍数100确定所需病毒量(细胞数×感染倍数);在细胞培养瓶中加入用DMEM培养液稀释的病毒液;病毒液与细胞充分接触后,放入5%CO2、37℃孵箱中培养,并每隔15 min摇晃培养瓶1次以促进感染,2h后补充完全培养基,24h后更换培养基继续培养。分别于腺病毒感染HSC12、24、48、72h在倒置荧光显微镜下观察细胞的荧光表达并计算转染效率。腺病毒感染HSC 48h转染效率>80%,48h与72h GFP阳性表达的HSC数量无明显差别,但感染72h细胞脱落更广泛,表明腺病毒感染HSC 48h转染效率已达到最高,后续试验将采用腺病毒感染48h的HSC进行。实验分组:(1)对照组:以DMEM代替腺病毒液转染HSC;(2)Ad-GFP组:转染仅表达GFP的空病毒Ad-GFP;(3)Ad-sh RNA/PTEN组:转染携带靶向PTEN的sh RNA并表达GFP的重组腺病毒Ad-sh RNA/PTEN。

3.蛋白质印迹法(Western blot)法检测体外活化肝星状细胞的PTEN、p130Cas及桩蛋白的蛋白表达:腺病毒感染HSC48h,收集各组HSC并提取细胞蛋白,应用BCA蛋白定量法测定蛋白水平,十二烷基硫酸钠-聚丙烯酰胺凝胶电泳,于冰上湿转,用含5%牛血清清蛋白的TBST封闭2h,加入小鼠抗PTEN单克隆抗体(1∶100稀释)、兔抗p130Cas单克隆抗体(1∶1 000稀释)、兔抗桩蛋白单克隆抗体(1∶5 000稀释)、兔抗GAPDH单克隆抗体(1 ∶3 000稀释),4℃过夜,TBST振摇洗膜4次,10min/次,以封闭液稀释的辣根过氧化物酶标记的山羊抗小鼠及山羊抗兔免疫球蛋白G(1∶5 000稀释)室温孵育2h,TBST洗膜4次,10min/次。加入ECL显色液(1∶1)避光1min,随即放入生物分子成像仪进行免疫显色,所得图像用Image图像处理软件定量分析,结果以目的蛋白与GAPDH的积分吸光度值的比值表示。

4.实时荧光定量PCR检测体外活化HSC的PTEN、P130Cas及桩蛋白mRNA表达:收集各组HSC,按Trizol试剂盒说明提取各组HSC的总RNA,逆转录合成cDNA;目的基因PTEN、p130Cas、桩蛋白及内参照GAPDH引物由上海生工生物工程有限公司合成。引物序列:PTEN上游引物为5′-TCCTGCAGAAAGACTTGAAGGT-3′,下游引物为5′-GCTGTGGTGGGTTATGGTCT-3′,扩增产物大小为182bp;P130Cas上游引物为5′-TCTCCGGATGGCCAGTATGA-3′,下游引物为5′-TCCAGTTGGCCTTTTCCCTG-3′,扩增产物大小为149bp;桩蛋白上游引物为5′-GTCCAGA AGGGTTCCACGAG-3′,下游引物为5′-GCAGGA ATGGGCCTAACAGA-3′,扩增产物大小437bp;GAPDH上游引物为5′-GGCTCATGACCACAGTC CAT-3′,下游引物为5′-ACATTGGGGGTAGGAA CACG-3′,扩增产物大小为202bp。在Mastercycler ep Real Plex4实时荧光定量PCR仪上进行扩增。采用相对定量2-ΔΔCt法比较各组HSC的PTEN、p130Cas及桩蛋白mRNA表达差异[8]。

5.统计学方法:计量资料以均数±标准差(Inline graphic±s)表示,采用SPSS19.0统计软件进行分析,多组间均数比较采用单因素方差分析,组间比较采用LSD检验。P<0.05为差异有统计学意义。

结果

1.成功构建体外活化HSC的PTEN低表达模型:腺病毒感染HSC 48h,实时荧光定量PCR检测3组HSC的PTENmRNA表达,以对照组HSC的PTENmRNA表达量为1,则Ad-GFP组及Ad-sh RNA/PTEN组HSC的PTENmRNA相对对照组的表达倍数分别为1.01倍、0.54倍,Ad-sh RNA/PTEN组HSC的PTEN mRNA表达量显著低于对照组及Ad-GFP组(P<0.05),对照组与Ad-GFP组之间HSC的PTEN mRNA表达量差异无统计学意义(P>0.05)。Western blot检测3组HSC的PTEN蛋白表达,Ad-sh RNA/PTEN组(0.19±0.04)显著低于对照组(0.44±0.02)及Ad-GFP组(0.36±0.05),P<0.05,而对照组与Ad-GFP组之间差异无统计学意义,P>0.05。上述结果显示靶向PTEN的sh RNA成功转染体外活化HSC,并显著下调HSC的PTEN表达,体外活化HSC的PTEN低表达模型成功构建(表1、图1)。

表1. 3组肝星状细胞的PTEN mRNA相对表达水平比较(n=6,x¯±s).

组别 ΔCt ΔΔCt PTEN mRNA相对表达水平(2-ΔΔCt)
对照组 9.09±0.01 0 1
Ad-GFP组 9.08±0.01 -0.01 1.01
Ad-shRNA/PTEN组 9.18±0.01 0.09 0.54a

注:PTEN:第10号染色体缺失的磷酸酶张力蛋白同源物基因;Ad-GFP:仅表达绿色荧光蛋白的空病毒;Ad-shRNA/PTEN:携带靶向PTEN的短发夹RNA及表达绿色荧光蛋白的重组腺病毒;a:与对照组及Ad-GFP组比较,P<0.05

图1. 3组肝星状细胞的PTEN、p130Cas及桩蛋白的蛋白表达.

图1

注:Ad-GFP:仅表达绿色荧光蛋白的空病毒;Ad-sh RNA/PTEN:携带靶向PTEN的短发夹RNA及表达绿色荧光蛋白的重组腺病毒;PTEN:第10号染色体缺失的磷酸酶张力蛋白同源物基因;p130Cas:p130 Crk相关底物蛋白;paxillin:桩蛋白;GAPDH:3-磷酸甘油醛脱氢酶

2.PTEN表达下调对体外活化HSC的p130Cas表达影响:腺病毒感染HSC48h,实时荧光定量PCR检测3组HSC的p130Cas mRNA表达,以对照组HSC的p130Cas m RAN表达量为1,则Ad-GFP组和Ad-sh RNA/PTEN组HSC的p130Cas mRNA相对对照组的表达倍数分别为1.01倍、1.52倍,Ad-sh RNA/PTEN组HSC的p130Cas mRNA表达量明显高于对照组及Ad-GFP组(P<0.05),而对照组与Ad-GFP组之间差异无统计学意义,P>0.05(表2)。进一步应用Western blot技术检测各组HSC的p130Cas蛋白表达,Ad-sh RNA/PTEN组(0.93±0.08)显著高于对照组(0.74±0.07)及Ad-GFP组(0.72±0.02), P<0.05,而对照组与Ad-GFP组之间差异无统计学意义,P>0.05(图1)。

表2. 3组肝星状细胞的p130Cas mRNA相对表达水平比较(n=6,x¯±s).

组别 ΔCt ΔΔCt p130Cas mRNA相对表达水平(2-ΔΔCt)
对照组 16.72±0.03 0 1
Ad-GFP组 16.70±0.03 -0.02 1.01
Ad-shRNA/PTEN组 16.12±0.04 -0.60 1.52a

注:Ad-GFP:仅表达绿色荧光蛋白的空病毒;Ad-shRNA/PTEN:携带靶向PTEN的短发夹RNA及表达绿色荧光蛋白的重组腺病毒;p130Cas:p130 Crk相关底物蛋白;a:与对照组及Ad-GFP组比较,P<0.05

3.PTEN表达下调对体外活化HSC的桩蛋白表达影响:腺病毒感染HSC48h,应用实时荧光定量PCR检测3组HSC的桩蛋白mRNA表达,以对照组HSC的桩蛋白mRNA表达量为1,则Ad-GFP组和Ad-sh RNA/PTEN组HSC的桩蛋白mRNA相对对照组的表达倍数分别为0.97倍、1.58倍,Ad-sh RNA/PTEN组HSC的桩蛋白mRNA表达明显高于对照组及Ad-GFP组(P<0.05),而对照组与Ad-GFP组之间差异无统计学意义,P>0.05(表3)。进一步应用Western blot技术检测各组HSC的桩蛋白蛋白表达,Ad-sh RNA/PTEN组(0.91±0.05)显著高于对照组(0.46±0.03)及Ad-GFP组(0.50±0.04),P<0.05;而对照组与Ad-GFP组之间差异无统计学意义,P>0.05(图1)。

表3. 3组肝星状细胞的桩蛋白mRNA相对表达水平比较(n=6,x¯±s).

组别 ΔCt ΔΔCt p130Cas mRNA相对表达水平(2-ΔΔCt)
对照组 8.96±0.04 0 1
Ad-GFP组 9.00±0.16 0.04 0.97
Ad-shRNA/PTEN组 8.30±0.23 -0.66 1.58a

注:Ad-GFP:仅表达绿色荧光蛋白的空病毒;Ad-shRNA/PTEN:携带靶向PTEN的短发夹RNA及表达绿色荧光蛋白的重组腺病毒;a:与对照组及Ad-GFP组比较,P<0.05

讨论

p130Cas是一种黏着斑相关蛋白,不仅参与细胞黏着斑的组成及其相关信号转导,并可作为接头蛋白与Crk和Src结合,在细胞与细胞外基质的黏附及细胞迁移中发挥重要作用[9]。而桩蛋白则是另一种与细胞黏附及迁移有关的黏着斑相关蛋白,主要定位于黏着斑,不仅参与黏着斑的组装,还可与踝蛋白、丝氨酸/苏氨酸磷酸酶激酶及酪氨酸蛋白激酶等许多分子结合,参与细胞黏附及迁移的调控[10,11]。p130Cas、桩蛋白及FAK均是参与黏着斑组成的黏着斑相关蛋白,但从信号转导角度看,p130Cas和桩蛋白是位于整合素/FAK信号转导下游的信号分子,当整合素被激活后,其β亚基与FAK结合形成复合物使FAK活化,进而激活细胞内p130Cas及桩蛋白信号通路[10,12]。

本研究以HSC-T6为研究对象,以腺病毒为载体将靶向PTEN的sh RNA转染体外活化HSC,在证实sh RNA下调HSC的PTEN表达后,采用Western blot及实时荧光定量PCR技术检测了活化HSC的p130Cas及桩蛋白表达变化。结果显示,PTEN表达下调使体外活化HSC的p130Cas及桩蛋白的蛋白及mRNA表达明显上调。这与PTEN表达下调对肿瘤细胞p130Cas及桩蛋白信号转导的影响相一致。结合本课题组的前期研究结果[6,7],提示PTEN低表达可能通过增强活化HSC的FAK/p130Cas及桩蛋白信号转导,进而促进活化HSC的黏附及迁移参与了肝纤维化的病理过程。如果使活化HSC的PTEN过表达,进而抑制活化HSC的FAK/p130Cas及桩蛋白信号转导,将可能阻止肝纤维化的进展。

利益冲突

所有作者均声明不存在利益冲突

作者贡献声明

郝礼森:进行课题设计与实施、撰写论文、并对文章负责;张朋垒、刘博:进行课题实施、资料收集整理、撰写论文;章广玲、陈静:进行质量控制及审校;宋洁、张明婷、靳丽敏:进行资料收集、统计学分析

Funding Statement

基金项目:河北省自然科学基金(H2013209327);中国肝炎防治基金会天晴肝病研究基金(CFHPC20132078)

Fund programs: Hebei Province Natural Science Foundation (H2013209327);Tianqing Liver Disease Research Fund of China Foundation for Hepatitis Prevention and Treatment (CFHPC20132078)

参考文献

  • [1].Puche JE, Saiman Y, Friedman SL. Hepatic stellate cells and liver fibrosis[J]. Compr Physiol, 2013,3(4):1473-1492. DOI: 10.1002/cphy.c120035. [DOI] [PubMed] [Google Scholar]
  • [2].Lee UE, Friedman SL. Mechanisms of hepatic fibrogenesis[J]. Best Pract Res Clin Gastroenterol, 2011,25(2):195-206. DOI: 10.1016/j.bpg.2011.02.005. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [3].Zhang LL, Liu J, Lei S, et al. PTEN inhibits the invasion and metastasis of gastric cancer via downregulation of FAK expression[J]. Cell Signal, 2014,26(5):1011-1020. DOI: 10.1016/j.cellsig.2014.01.025. [DOI] [PubMed] [Google Scholar]
  • [4].Tamura M, Gu J, Takino T, et al. Tumor suppressor PTEN inhibition of cell invasion, migration, and growth: differential involvement of focal adhesion kinase and p130Cas[J]. Cancer Res, 1999,59(2):442-449. [PubMed] [Google Scholar]
  • [5].Haier J, Nicolson GL. PTEN regulates tumor cell adhesion of colon carcinoma cells under dynamic conditions of fluid flow[J]. Oncogene, 2002,21(9):1450-1460. DOI: 10.1038/sj.onc.1205213. [DOI] [PubMed] [Google Scholar]
  • [6].郝 礼森,张 家琪,刘 博,et al.PTEN表达下调促进体外活化大鼠肝星状细胞黏附[J].基础医学与临床,2017,37(3):364-368. DOI: 10.3969/j.issn.1001-6325.2017.03.021.28350573 [DOI] [Google Scholar]; Hao LS, Zhang JQ, Liu B, et al. Down-regulation of PTEN expression promotes the adhesion in activated rat hepatic stellate cells in vitro[J]. Basic Clinical Medicine, 2017,37(3):364-368. DOI: 10.3969/j.issn.1001-6325.2017.03.021. [DOI] [Google Scholar]
  • [7].郝 礼森,张 家琪,刘 博,et al.体外RNA干扰下调PTEN表达对肝星状细胞系HSC-T6迁移的影响[J].中华肝脏病杂志,2017,25(3):223-225. DOI: 10.3760/cma.j.issn.1007-3418.2017.03.012. [DOI] [PMC free article] [PubMed] [Google Scholar]; Hao LS, Zhang JQ, Liu B, et al. The influence of down-regulation of PTEN by RNA interference on the migration in activated hepatic stellate cells (HSC-T6) in vitro[J]. Chin J Hepatol, 2017,25(3):223-225. DOI: 10.3760/cma.j.issn.1007-3418.2017.03.012. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • [8].Arocho A, Chen B, Ladanyi M, et al. Validation of,the 2-DeltaDelta Ct calculation as an alternate method of data analysis for quantitative PCR of BCR-ABL P210 transcripts[J]. Diagn Mol Pathol, 2006,15(1):56-61. DOI: 10.1097/00019606-200603000-00009. [DOI] [PubMed] [Google Scholar]
  • [9].Tazaki T, Miyazaki K, Hiyama E, et al. Functional analysis of Src homology 3- encoding exon (exon 2) of p130Cas in primar y fibroblasts derived from exon 2- specific knockout mice[J]. Genes Cells, 2008,13(2):145-157. DOI: 10.1111/j.1365-2443.2007.01156.x. [DOI] [PubMed] [Google Scholar]
  • [10].Panetti TS. Tyrosine phosphorylation of paxillin, FAK, and p130CAS: effects on cell spreading and migration[J]. Front Biosci, 2002,7:d143-d150. [DOI] [PubMed] [Google Scholar]
  • [11].Zaidel-Bar R, Milo R, Kam Z, et al. A paxillin tyrosine phosphorylation switch regulates the assembly and form of cell-matrix adhesions[J]. J Cell Sci, 2007,120(Pt 1):137-148. DOI: 10.1242/jcs.03314. [DOI] [PubMed] [Google Scholar]
  • [12].Zhang C, Miller DJ, Guibao CD, et al. Structural and functional insights into the interaction between the Cas family scaffolding protein p130Cas and the focal adhesion-associated protein paxillin[J]. J Biol Chem, 2017,292(44):18281-18289. DOI: 10.1074/jbc.M117.807271. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Chinese Journal of Hepatology are provided here courtesy of Second Affiliated Hospital of Chongqing Medical University

RESOURCES