高糖对系膜细胞胞外调节蛋白激酶表达及细胞外基质合成的影响

目的：探讨高糖环境下系膜细胞中胞外调节蛋白激酶（ERK）转导途径活性和转化生长因子-β1（TGF-β1）mRNA表达的变化。方法：分离培养大鼠肾脏系膜细胞,调整培养液浓度为以下3组,即正常糖组、高糖组、甘露醇组。分别予干预12h、24h、48h后用免疫细胞化学法和Western-blot法对系膜细胞中磷酸化ERK1/2（pERK1/2）的表达进行定位、定性及半定量分析,用RT-PCR法检测细胞中TGF-β1 mRNA的表达,放免法测定各组细胞上清中Ⅳ型胶原的含量。结果：高糖组系膜细胞中pERK1/2蛋白的表达较正常糖组明显增高并由胞浆向胞核内转移,随培养时间延长其表达呈上升趋势（P〈0.01）,高糖组TGF-β1 mRNA的表达及细胞上清液Ⅳ型胶原的含量均高于正常糖组（P〈0.01）,甘露醇组上述指标较正常糖组略有升高,但两组间无统计学意义（P〉0.05）。结论：高糖环境下系膜细胞中ERK信号转导通路被激活,TGF-β1 mRNA表达上调,可能是糖尿病肾病系膜细胞受损,肾小球硬化的机制之一。     

转染Megsin基因对体外系膜细胞增殖和Ⅳ型胶原分泌的影响及机制

目的 了解Megsin基因高表达对体外系膜细胞增殖和Ⅳ型胶原分泌的影响，并探讨其机制。 方法 构建大鼠Megsin基因真核表达载体，体外转染系膜细胞。3H-胸腺嘧啶(3H-TdR)掺入法检测系膜细胞增殖情况。RT-PCR方法检测系膜细胞血小板源生长因子(PDGF)-BB、IL-1β、IL-6、IL-10、TGF-β1和TNF-α mRNA表达变化。ELISA法检测细胞培养上清PDGF-BB、TGF-β1和Ⅳ型胶原浓度。观察PDGF-BB中和抗体对大鼠系膜细胞转染Megsin基因后细胞增殖和TGF-β1 mRNA表达的影响。 结果 大鼠系膜细胞转染Megsin基因后，细胞内3H-TdR掺入量显著增加，PDGF-BB和TGF-β1 mRNA表达显著上调，细胞培养上清PDGF-BB、TGF-β1和Ⅳ型胶原的浓度显著升高，3者与转染Megsin基因呈明显时间依赖性关系。PDGF-BB中和抗体显著抑制系膜细胞转染Megsin基因后细胞内3H-TdR的掺入，并下调稳定表达Megsin基因的大鼠系膜细胞TGF-β1 mRNA表达。结论 Megsin基因高表达在体外可促进系膜细胞PDGF-BB和TGF-β1的表达和分泌，进而促进系膜细胞增生和Ⅳ型胶原分泌。     

megsin基因转染对高糖环境中肾小球系膜细胞增殖和基质金属蛋白酶2及其抑制因子表达的影响

目的 观察megsin基因转染对高糖环境中肾小球系膜细胞基质金属蛋白酶2（MMP-2）和组织金属蛋白酶抑制因子2（TIMP-2）的表达及Ⅳ型胶原水平的影响,探讨megsin与系膜细胞增殖和细胞外基质代谢的关系。 方法 高糖环境中培养小鼠肾小球系膜细胞,分别于培养12、24、48 h末,应用MTT法检测细胞增殖程度;Western印迹法检测系膜细胞megsin、MMP-2、TIMP-2蛋白表达水平;放免法检测细胞培养上清Ⅳ型胶原浓度。 结果 高糖环境中肾小球系膜细胞megsin、TIMP-2表达上调,MMP-2表达下调,细胞增殖明显,细胞上清液中Ⅳ型胶原浓度升高。megsin基因转染后上述变化趋势更加显著。 结论 megsin可诱导系膜细胞增殖,并通过上调TIMP-2、下调MMP-2抑制细胞外基质降解,是加速肾小球硬化的可能机制之一。     

缬沙坦对高糖上调系膜细胞细胞外调节蛋白激酶表达的影响

目的观察在高糖刺激下，系膜细胞细胞外调节蛋白激酶（ERKI／2）的活性变化以及缬沙坦对其影响，探讨缬沙坦保护肾脏作用的可能机制。方法原代培养大鼠肾脏系膜细胞，随机分为4组：低糖组（NG，d-葡萄糖5．5mmol／L）、高糖组（HG，d-葡萄糖30mmol／L）、甘露醇组（MG，d-葡萄糖5．5mmol／L＋甘露醇24．5mmol／L）和缬沙坦组（HG＋Val，d-葡萄糖30mmol／L＋缬沙坦10μmol／L）。用免疫细胞化学法及Western印迹法对系膜细胞中磷酸化ERK1／2（p-ERK1／2）的表达进行定位及半定量分析；RT—PCR法检测细胞中TGF-β1 mRNA的表达；放射免疫法测定各组细胞上清中Ⅳ型胶原的含量。结果高糖组系膜细胞中P-ERK1／2蛋白的表达较低糖组明显增高，并由胞质向胞核内转移，呈时间依赖方式（P〈0．01）；TGF-β1 mRNA及细胞上清液中Ⅳ型胶原水平均高于低糖组（P〈0．01）。而缬沙坦组上述指标均较同时相点高糖组显著降低，差异有统计学意义（P〈0．01）。甘露醇组与低糖组各指标间差异均无统计学意义。结论高糖可显著激活系膜细胞ERK信号通路，缬沙坦可抑制高糖的激活作用。     

缬沙坦对高糖环境下系膜细胞GLUT1表达的影响

目的：探讨葡萄糖转运蛋白1（GLUT1）在糖尿病肾病发生、发展中的作用以及缬沙坦的肾脏保护机制。方法：体外培养大鼠肾小球系膜细胞,设正常对照组、甘露醇组、高糖非处理组及高糖＋缬沙坦组,Westernblot法检测GLUT1蛋白水平,RT-PCR法检测转化生长因子-β1（TGF-β1）mRNA水平,放免法测定细胞上清中Ⅳ型胶原含量。结果：高糖非处理组GLUT1蛋白、TGF-β1mRNA及细胞上清液Ⅳ型胶原含量均高于正常对照组（P〈0.01,P〈0.05）,缬沙坦干预后上述各指标明显降低（P〈0.01）。结论：高糖刺激使肾小球系膜细胞GLUT1蛋白表达增高;高糖状态下,缬沙坦具有不依赖于其调节肾脏血流动力学改变的肾脏保护作用,该作用可能与其抑制系膜细胞GLUT1过表达,减少TGF-β1与Ⅳ型胶原合成有关。     

百令胶囊对大鼠肾小球系膜细胞增殖、Ⅳ型胶原及TGF-β1 mRNA表达的影响

目的：观察百令胶囊对高糖刺激后系膜细胞增殖、Ⅳ型胶原（typeⅣCollagen,ⅣC）、转化生长因子-β1（TGF-β1）mRNA表达的影响。方法：培养正常SD大鼠系膜细胞,高浓度葡萄糖刺激系膜细胞,加入百令胶囊、苯那普利含药血清后,用四甲基偶氮唑盐（MTT）光吸收法观察肾小球系膜细胞增殖;酶联免疫吸附法（ELISA）测量培养细胞上清液中ⅣC的含量;实时荧光逆转录聚合酶链反应（real-time RT-PCR）测定TGF-β1mRNA的表达。结果：百令胶囊、苯那普利含药血清在24 h可抑制高糖对大鼠肾小球系膜细胞的促增殖作用,72 h最为明显（P〈0.01）;高糖刺激后ⅣC、TGF-β1mRNA在肾小球系膜细胞内表达增多（P〈0.01）,百令胶囊、苯那普利含药血清能明显抑制肾小球系膜细胞增殖（P〈0.01）、ⅣC分泌及TGF-β1mRNA的高表达（P〈0.05）。百令胶囊与苯那普利组之间差异无统计学意义（P〉0.05）。结论：百令胶囊可降低高糖致系膜细胞增殖,抑制高糖所致ⅣC分泌,抑制高糖引起的TGF-β1mRNA过度表达,这可能是其防治糖尿病肾病的作用机制。     

细胞外信号调节激酶信号通路与醛糖还原酶对转化生长因子β1诱导人系膜细胞纤连蛋白表达的影响

目的　探讨细胞外信号调节激酶（ERK）信号通路与醛糖还原酶（AR）在非高糖条件下对转化生长因子（TGF）β1诱导人系膜细胞（HMC）细胞外基质成分纤连蛋白（FN）表达的影响。 方法　应用醛糖还原酶抑制剂（ARI）、ERK信号通路抑制剂U0126、转染pCDNA3-AR及AR-siRNA分别作用于HMC后,再用TGF-β1刺激,观察刺激前后HMC表达FN的情况。Western印迹检测HMC内FN和AR的变化,实时定量PCR鉴定转染和干扰效果。 结果 HMC在TGF-β1作用后,AR、FN 和磷酸化ERK（p-ERK）蛋白表达升高,与对照组比较,分别升高了1.8、1.9倍（均P < 0.05）和5.1倍（P < 0.01）。使用ARI孵育后,再用TGF-β1刺激,与单独使用TGF-β1刺激组比较,FN蛋白表达量约为对照组的30%（P < 0.01）;用ERK信号通路抑制剂后,再用TGF-β1刺激,FN蛋白表达量约为对照组的10%（P < 0.01）;转染pCDNA3-AR后,HMC中AR mRNA表达增多,为对照组10倍以上（P < 0.01）,FN蛋白表达增加到对照组的2.5倍（P < 0.05）,再用TGF-β1刺激,FN蛋白表达增加到对照组的3.6倍（P < 0.05）;转染AR-siRNA后,HMC中AR mRNA表达减少,干扰效率大于80%（P < 0.01）,AR、FN及p-ERK蛋白表达减少,分别约为对照组的20%、24%、7%（均P < 0.01）,再用TGF-β1刺激,FN蛋白表达仍然减少,为对照组的25%（P < 0.01）。 结论　AR基因参与TGF-β1诱导的HMC细胞外基质表达过程的调控,在肾小球硬化过程中起一定作用,且这一过程与ERK信号通路的活化有关。     

megsin基因对高糖环境中肾小球系膜细胞炎性介质的影响

megsin表达增多可能与以系膜细胞增生和细胞外基质沉积为主的肾小球疾病关系密切[1].炎性反应在糖尿病肾病(DN)的发生发展中起关键作用已被广泛接受.单核细胞趋化蛋白1( MCP-1)过度表达介导大量巨噬细胞趋化和激活,加重糖尿病肾损伤.经检索,尚未见关于megsin与MCP-1的关系,及其在DN发病机制中的作用的报道.本实验通过体外转染megsin基因,观察高糖环境下megsin基因对系膜细胞MCP-1表达及Ⅳ型胶原分泌的影响,探讨megsin在DN发生、发展中的作用机制.     

霉酚酸对高糖环境下肾小球系膜细胞外基质的影响

目的：通过检测霉酚酸酯（MMF）的代谢产物霉酚酸（mycophenolic acid,MPA）对高糖环境下大鼠肾小球系膜细胞（mesangial cells,MCs）增殖、转化生长因子-β1（transformation growth factor-β1,TGF-β1）和细胞外基质的主要成分：纤维连接蛋白（fibrin,FN）、层黏连蛋白（laminin,LN）和胶原Ⅳ（typeⅣ collagen,ColⅣ）分泌的影响,探讨MPA对糖尿病肾病（diabetic nephropathy,DN）的保护机制。方法：四甲基偶氮唑盐微量酶反应比色法测定高糖及高糖加入不同浓度MPA（1～10μmol/L）后对大鼠MCs增殖的影响,ELASE的方法测定各组24h、48h、72hFN、LN、ColⅣ的表达,荧光定量多聚酶链反应的方法检测各组标本中TGF-β1 mRNA的表达,并进行统计学分析。结果：高糖可以诱导MCs增殖及TGF-β1、FN、LN、ColⅣ的表达,MPA抑制高糖环境下MCs增殖和FN、LN和ColⅣ分泌并呈剂量时间依赖性,MPA可以呈剂量依赖性抑制高糖环境下MCs分泌TGF-β1,各组之间有统计学差异（P〈0.05）。结论：MPA可以通过抑制高糖环境下MCs的增殖和TGF-β1的分泌,从而抑制系膜外基质增多、系膜区扩张,有效阻止细胞外基质积聚,从而防止肾小球硬化,延缓DN的发展。     

细胞因子信号传导抑制蛋白1抑制高糖诱导的肾小球系膜细胞单核细胞趋化蛋白1的表达

目的 探讨细胞因子信号传导抑制蛋白1(SOCS-1)对高糖状态下肾小球系膜细胞单核细胞趋化蛋白1（MCP-1）表达的影响。 方法 体外培养人肾小球系膜细胞,应用脂质体2000分别转染pCR3.1-SOCS-1表达质粒和pCR3.1 空质粒载体,G418筛选阳性克隆。分别采用低糖（5.5 mmol/L）、高糖（30 mmol/L）、低糖+甘露醇（24.5 mmol/L甘露醇）和JAK-STAT信号通路抑制剂AG490 （10 μmol/L）进行刺激。Western印迹检测系膜细胞SOCS-1、信号转导和转录活化因子1、3（STAT1、STAT3）及其磷酸化蛋白（p-STAT1、p-STAT3）的表达。ELISA法和放免法测定细胞上清液中MCP-1、FN和Ⅳ型胶原的含量。RT-PCR法检测SOCS-1和MCP-1 mRNA的表达。 结果 高糖刺激系膜细胞SOCS-1蛋白和mRNA表达呈时间依赖性变化, 4 h表达达到峰值,然后逐渐减低,24 h达基线水平。与低糖组相比,高糖组系膜细胞STAT1和STAT3磷酸化水平显著上调（P < 0.01）; MCP-1 mRNA水平表达显著上调[（0.39±0.05）比（0.16±0.02）,P < 0.01];上清液中MCP-1[（459±67）比（241±19） ng/L]、FN[（5.84±0.61）比（3.41±0.31） mg/L]和Ⅳ型胶原[（16.45±2.30）比（9.56±1.52） μg/L] 含量均显著增加（均P < 0.01）。与空载体对照组相比,SOCS-1过表达组系膜细胞STAT1和STAT3的磷酸化水平显著下降（P < 0.05）;MCP-1 mRNA表达下调[（0.34±0.04）比（0.42±0.05）,P < 0.05]; 上清液中MCP-1[(387±47）比（463±56） ng/L]、 FN[（4.61±0.57）比（5.76±0.74） mg/L]和Ⅳ型胶原[(13.4±2.32)比（17.1±2.57） μg/L] 含量显著减少（均P < 0.05）。与高糖组相比,AG490组系膜细胞MCP-1 mRNA（0.31±0.04）表达显著下调;上清液中MCP-1[（361±53） ng/L]、FN[（5.46±0.71）mg/L]和Ⅳ型胶原[（15.2±1.97） μg/L]含量均减少。 结论 SOCS-1过表达抑制高糖状态下肾小球系膜细胞MCP-1及细胞外基质的分泌可能部分是通过影响STAT1和STAT3的激活而实现。     

Fluorofenidone reduces renal fibrosis in diabetic kidney disease mice

Objective To investigate the effects of fluorofenidone (AKF-PD) on diabetic kidney disease in db/db mice and its possible mechanisms. Methods (1) Fifty-six mice aged 8 weeks (half male and half female), including 42 db/db mice and 14 wild-type mice were studied. Forty-two db/db mice randomly were divided into model group (mock-treated diabetic db/db mice), AKF-PD (250 mg?kg-1?d-1) treatment group and losartan (20 mg?kg-1?d-1) treatment group. Wild-type mice and model mice were treated with vehicle (0.5% sodium carboxymethylcellulose), while the treatment groups received either AKF-PD or losartan. After 18 weeks, the blood glucose and urinary albumin were measured, the pathological changes of kidney were observed by PAS staining. The protein expressions of type Ⅳ collagen and fibronectin (FN) in kidney tissue were detected by immunohistochemistry. (2) Mouse glomerular mesangial cells (MES-13 cells) were divided into six groups: normal glucose group (5.5 mmol/L glucose), hypertonic group (5.5 mmol/L glucose+19.5 mmol/L mannitol), high glucose group (25.0 mmol/L glucose), AKF-PD group (25.0 mmol/L glucose+400 mg/L AKF-PD) and losartan group (25.0 mmol/L glucose+2 μmol/L losartan). After 72 h treatment, the expressions of type Ⅰ collagen, type Ⅳ collagen and transforming growth factor-β1 (TGF-β1) mRNA were detected by real-time PCR, and the content of TGF-β1 protein in the culture supernatant was detected by ELISA. Results (1) Compared with the wild type mice, model mice had increased weight, blood glucose and glomerulosclerosis index (all P＜0.01), accompanied with heavy albuminuria, glomerular hypertrophy, mesangial area expansion and deposition of collagen type Ⅳ and FN (all P＜0.01). Compared with model mice, in AKF-PD and losartan groups 24 h urinary albumin and glomerulosclerosis index decreased (all P＜0.01), glomerular hypertrophy and mesangial area expansion alleviated, and the protein expressions of collagen type Ⅳ and FN were inhibited (all P＜0.01). (2) Compared with the normal glucose group, the mRNA expressions of type Ⅰ collagen and type Ⅳ collagen increased in high glucose group, meanwhile the mRNA and protein expressions of TGF-β1 increased (all P＜0.01). In AKF-PD and losartan groups the expressions of type Ⅰ collagen, type Ⅳ collagen and TGF-β1 were inhibited as compared with high glucose group (all P＜0.05). Conclusion Fluorofenidone may play an anti-fibrotic effect in db/db mice by reducing the expression of TGF-β1 and inhibiting collagen synthesis in glomerular mesangial cells.     

Effects of pirfenidone on renal fibrosis in mice with diabetic nephropathy and its mechanisms

Objective To investigate effects of pirfenidone (PFD) on diabetic nephropathy model in db/db mice and to explore its possible mechanisms. Methods (1) Wild-type mice were as the normal control group, and db/db mice were divided into model group and PFD group, with 6 mice in each group. In the PFD group mice were administered continuously by 250 mg?kg-1?d-1 PFD for 18 weeks, and mice in the other two groups were administered by 0.5% sodium carboxymethyl cellulose. Blood glucose and 24 h urinary albumin were measured. The pathological changes of renal tissue were evaluated by PAS staining, PASM staining, Masson staining and Sirius red staining. The expression of collagen type Ⅳ in kidney tissues was detected by immunohistochemistry. (2) Mouse mesangial cells (SV40 MES-13 cells) were cultured as research objects. They were divided into control group, hyperosmolar group, high glucose (HG) group, and 50, 100, 200, 400, 800, 1600 mg/L PFD+HG group. BrdU cell proliferation test was used to evaluate cell proliferation rate. Cells were divided into control group, hyperosmolar group, HG group and PFD+HG group. The mRNA expressions of α-smooth muscle actin (α-SMA), collagen type Ⅰ, collagen type Ⅳ, transforming growth factor-β1 (TGF-β1), interleukin (IL)-1β, IL-6 and monocyte chemotactic protein-1 (MCP-1) were detected by real-time PCR. Results (1) Compared with normal control group, the model mice had higher weight, blood glucose and 24 h urinary albumin, accompanied with glomerular hypertrophy, mesangial area expansion, tubulointerstitial fibrosis and deposition of collagen type Ⅳ (all P＜0.05). Compared with those in model group, in PFD group 24 h urinary albumin decreased, glomerular hypertrophy, mesangial area expansion and tubulointerstitial fibrosis alleviated, and the protein expression of collagen type Ⅳ inhibited (all P＜0.05). (2) Compared with those in HG group, MES-13 cell proliferation rates of 100, 200, 400, 800, 1600 mg/L PFD+HG groups decreased (all P＜0.05), and the mRNA expressions of α-SMA, collagen type Ⅰ, collagen type Ⅳ, TGF-β1, IL-1β, IL-6 and MCP-1 reduced in 400 mg/L PFD+HG group (all P＜0.05). Conclusions PFD can inhibit high glucose-induced proliferation and activation of glomerular mesangial cells, decrease the expression of TGF-β1 and proinflammatory factors, as well as reduce the synthesis of collagen, which improve renal fibrosis of db/db mice.     

糖肾方对糖尿病肾病大鼠肾组织TGF-β1及MMP-9表达的影响

目的：研究糖肾方对糖尿病肾病大鼠肾组织TGF-β1、MMP-2、MMP-9及Ⅳ型胶原表达的影响,探讨糖肾方对糖尿病肾病大鼠肾脏的保护机制。方法：50只Wistar大鼠随机分为空白组、模型组、蒙诺组（0．833mg／kg）、糖肾方大剂量组（2．67g／kg）、糖肾方小剂量组（1．33g／kg）,每组10只,利用单侧肾切除加腹腔注射链脲佐菌素造成糖尿病肾病大鼠模型,连续给药20周。动态检测血糖和尿蛋白／肌酐水平;取肾组织进行病理组织学观察并对肾小球硬化和肾小管间质纤维化程度进行评分;RT-PCR方法检测TGF-β1、MMP-2及MMP-9 mRNA表达,免疫组化方法检测肾组织TGF-β1及Ⅳ型胶原表达。结果：大剂量糖肾方能显著降低糖尿病肾病大鼠尿蛋白／肌酐（P〈0．05）,降低肾小球硬化指数（P〈0．01）和肾小管间质纤维化指数（P〈0．01）,减少TGF-β1mRNA与蛋白表达（P〈0．05）,增加MMP-9mRNA表达（P〈0．05）,减少Ⅳ型胶原蛋白表达（P〈0．05）。结论：糖肾方可减轻实验大鼠肾小球硬化和肾小管间质纤维化,其作用机制可能与抑制TGF-β1表达和提高MMP-9mRNA水平有关。     

塞来昔布对Han：SPRD大鼠肾细胞外基质重塑的影响

目的 研究塞来昔布（CXB）对Han：SPRD大鼠肾细胞外基质（ECM）重塑的影响,探讨其抑制多囊肾肾间质纤维化的作用机制。 方法 选取杂合（cy/+）交配后第4代雄性、3周龄、体质量（68.5±16.6） g的Han：SPRD大鼠共57只,随机分成对照组（CXB：0 mg&#8226;kg-1&#8226;d-1）、CXB小剂量组（CBX：3 mg&#8226;kg-1&#8226;d-1）、CXB大剂量组（CBX：10 mg&#8226;kg-1&#8226;d-1）,每组19只。另选19只SD大鼠作为正常对照。饲料中加入CXB喂食13周后,处死动物。倒置显微镜下分析肾组织纤维化指数;实时荧光定量PCR检测肾组织胶原Ⅳ（COLⅣ）、基质金属蛋白酶（MMP）2、金属蛋白酶2组织抑制剂（TIMP）和转化生长因子（TGF）β1 mRNA的表达;免疫荧光共聚焦扫描法检测COLⅣ、MMP-2、TIMP-2、TGF-β1与PCNA共染的蛋白丰度;蛋白免疫印迹法检测TGF-β1的表达。 结果 与对照组相比,小剂量组和大剂量组均能显著减少肾囊肿指数（42.90±6.56和47.10±7.28比64.80±62.71,均P < 0.05）、纤维化指数（11.20±2.63和10.10±3.30比16.30±4.16,均P < 0.05）和间质炎性细胞的浸润（2.60±0.26和2.80±0.31比3.70±0.33,均P < 0.05）。小剂量组和大剂量组COLⅣ、TIMP-2和TGF-β1 mRNA的表达量显著低于对照组（均P < 0.05 ）,而MMP-2 mRNA的表达量显著高于对照组（均P < 0.05）。小剂量组和大剂量组COLⅣ荧光强度较对照组显著减弱,差异有统计学意义（20.30±5.11比61.40±4.51,P < 0.01;27.50±6.73比61.40±4.51,P < 0.05）。小剂量组和大剂量组MMP-2/TIMP-2比值较对照组增高,差异有统计学意义（4.88±1.52 和3.63±1.67比0.35±0.13,均P < 0.05）。小剂量组和大剂量组TGF-β1蛋白表达比对照组均显著减少。 结论 塞来昔布可能通过下调TGF-β1、增加MMP-2/TIMP-2比值、促进胶原Ⅳ的降解来抑制肾小管间质的纤维化。     

Smad4 siRNA对乳腺癌细胞侵袭力和MMP-9表达的影响

目的:探讨Smad4特异性小分子干扰RNA(siRNA)对乳腺癌MDA-MB-231细胞侵袭力及MMP-9表达的影响。方法:构建Smad4 siRNA,将细胞分为空白对照组,Smad4 siRNA转染组,TGF-β处理组,Smad4 siRNA转染+TGF-β处理组。首先用Western blot法检测转染Smad4 siRNA后细胞中Smad4蛋白的表达,以及用荧光素酶报告基因法检测TGF-β处理后细胞Smad结合元件(4xSBE)的活性;然后用Transwell小室模型和Western blot法检测各组细胞的黏附侵袭能力以及基质金属蛋白酶9(MMP-9)蛋白的表达水平。结果:转染Smad4 siRNA后,乳腺癌细胞的Smad4蛋白表达及其TGF-β诱导的4xSBE活性增强均被明显抑制(均P<0.05);与对照组细胞比较,细胞经TGF-β刺激后的侵袭能力及MMP-9的表达量均明显增加(均P<0.05),但预先转染Smad4 siRNA的细胞的上述TGF-β刺激作用被明显抑制(均P<0.05),单纯Smad4 siRNA转染对细胞的侵袭能力及MMP-9的表达量无明显影响。结论:Smad4 siRNA能减弱TGF-β诱导的MDA-MB-231细胞的侵袭能力,该作用可能与其抑制MMP-9的表达有关。     

Effect of tet methylcytosine dioxygenase 2 on the regulation of transforming growth factor-β1 expression in mesangial cells induced by high glucose

Objective To investigate the role of tet methylcytosine dioxygenase 2 (TET2) in the regulation of transforming growth factor-β1 (TGF-β1) expression in human glomerular mesangial cells induced by high glucose. Methods Cultured human glomerular mesangial cells were divided into normal control group (5.5 mmol/L glucose) and high glucose group (30.0 mmol/L glucose) which was cultured for 12 h to 72 h. The gene expression of TET2 in mesangial cells were inhibited by small molecule chemical called SC1, and which were divided into high glucose group (30.0 mmol/L glucose+DMEM), DMSO group (30.0 mmol/L glucose+0.1%DMSO) and SC1 group (30.0 mmol/L glucose+3 μmol/L SC1). The mRNA and protein expression of TGF-β1, TET1 to 3 and α-smooth muscle actin (α-SMA) was detected by quantitative real-time PCR and Western blotting. Methylation of CpG islands in the regulation region of TGF-β1 was detected by bisulfite sequencing PCR (BSP). The activity of mesangial cell proliferation was assessed by colorimetry of thiazolyl blue (MTT). Results Compared with normal control group, the mRNA and protein expression of TET2 in mesangial cells induced by high glucose was increased significantly in a time-dependent manner (all P＜0.05), but the expression of TET1 and TET3 was not affected. Meanwhile methylation rate of 4 CG sites from 24 h to 72 h were decreased in the first exon of TGF-β1 (P＜0.01), but not in the promoter. Compared with high glucose group, when the expression of TET2 was inhibited by SC1, the methylation rate of TGF-β1 was recovered evidently (P＜0.05), the mRNA and protein expression of TGF-β1 and α-SMA was suppressed, and the proliferation of mesangial cells was decreased (all P＜0.05). Conclusions Demethylation of the CpG island mediated by TET2 may play an important role in the expression of TGF-β1 and mesangial cell phenotype transformation induced by high glucose.     

阿利吉仑对2型糖尿病db/db小鼠肾脏损伤的保护作用

目的 观察肾素抑制剂阿利吉仑对2型糖尿病db/db小鼠肾脏损伤的保护作用。 方法 8周龄db/db和db/m小鼠行单侧肾切除,16周进入实验,分为4组：db/m小鼠对照组（db/m组）、db/db糖尿病小鼠对照组（db/db组）、db/db糖尿病小鼠阿利吉仑3 mg&#8226;kg-1&#8226;d-1治疗组（db/db+A3组）和db/db糖尿病小鼠阿利吉仑25 mg&#8226;kg-1&#8226;d-1治疗组(db/db+A25组)。阿利吉仑溶于磷酸盐缓冲液（PBS,350 mg/L）皮下泵入（0.25 μl/h）给药,疗程４周。治疗前后检测体质量、血糖、糖化血红蛋白、尿蛋白量、血压水平;PAS染色观察肾脏组织学变化;ELISA法检测肾皮质转化生长因子β1（TGF-β1）和纤溶酶原激活抑制因子1（PAI-1）含量;间接免疫荧光检测肾小球Ⅳ型胶原（ColⅣ）和纤连蛋白（FN）表达;实时定量PCR检测TGF-β1、PAI-1、ColⅣ、FN和肾素mRNA表达;放射免疫法检测肾皮质肾素活性和血管紧张素Ⅱ（AngⅡ）水平。 结果 与db/m组小鼠比较,db/db组小鼠有大量蛋白尿,肾小球细胞外基质沉积增加,TGF-β1、PAI-1、ColⅣ和FN蛋白及mRNA表达增加,同时肾皮质肾素mRNA、肾素活性和AngⅡ水平增高（均P < 0.05）。阿利吉仑25 mg&#8226;kg-1&#8226;d-1治疗在没有影响血压情况下,显著减少db/db小鼠24 h尿蛋白量,减少肾小球细胞外基质沉积,减少TGF-β1、PAI-1、ColⅣ、FN蛋白和mRNA表达,同时降低肾皮质肾素活性和AngⅡ水平（均P < 0.05）。 结论 阿利吉仑对2型糖尿病db/db小鼠肾脏损伤有保护作用。     

高糖和血管紧张素Ⅱ对人肾小管上皮细胞Toll样受体4信号表达及炎性和纤维化因子的影响

Objective To investigate the effects of angiotensinⅡ(AngⅡ) or high glucose on the toll-like receptor 4 (TLR4) expression, inflammatory cytokines and fibrotic factors in human tubular epithelial cells (HK-2), revealing the innate immune-related pathogenesis of diabetic nephropathy (DN) which may have clinical implications. Methods Three TLR4 siRNA sequences were designed and synthetized. After transfection, the most effective siRNA was selected to use for further expriments. The experiment consisted of 2 parts. Part 1: Cells were divided into three groups: normal-glucose group (NG, 5.5mmol/L glucose), mannose group (M, 5.5 mmol/L glucose+19.5 mmol/L mannose), High-glucose group (HG, 25 mmol/L glucose), preliminary validated the effects of high glucose and high osmotic pressure. Part 2: Cells were divided into seven groups: NG group, HG group, AngⅡgroup, AngⅡ+ negative group, HG+ negative group, AngⅡ+ siRNA group and HG+ siRNA group. Real time PCR was used to analyze the mRNA expression of TLR4, myeloid differentiation factor 88 (MyD88), heat shock protein 47 (HSP47). Western blotting was used to observe the protein expression of TLR4, MyD88, HSP47, NF-κB, type Ⅳ collagen (ColIV). ELISA was used to detect the expression of monocyte chemotactic protein-1 (MCP-1) and interleukin-6 (IL-6). Results Compared with NG group, TLR4, MyD88, HSP47 mRNA and TLR4, MyD88, NF-κB, ColⅣ, HSP47 protein were highly expressed under high glucose or AngⅡconditions (P＜0.01), and the expression levels of MCP-1 and IL-6 also increased significantly (P＜0.01). Compared with HG or AngⅡ group, the above indicators were obviously inhibited in the TLR4 siRNA groups (P＜0.01). Comparison between blank vector transfected groups and HG group as well as AngⅡ group indicated no statistic significance (P＞0.05). Conclusions Both AngⅡ and high glucose stimulate TLR4 expression, which result in the up-regulation of inflammatory and fibrotic factors in HK-2. Specific target of TLR4 gene silencing can block the TLR4 pathway that is activated by high glucose and AngⅡ, and thus reduce the inflammatory and fibtogenic factors' release. TLR4 signal is the common innate immune response pathway which induces the release of inflammatory and fibrotic factors in HK-2 under high glucose or high angiotension conditions.