Triptolide inhibits the tubulointerstitial fibrosis in rats of unilateral ureteral obstruction by up-regulating Ski expression

Objective To investigate the effects of triptolide on tubulointerstitial fibrosis in rats kidneys with the unilateral ureteral obstruction (UUO) by examining the expression of collagen type Ι (Col-Ι), Ski, Smad3, TGF-β1. Methods Sixty male SD rats were divided into three groups: Sham operation group (Sham group), UUO group and triptolide (0.2 mg•kg-1•d-1) treatment group. The levels of blood urea nitrogen (BUN), serum creatinine (Scr), pathological changes were measured. Col-Ι, Ski and Smad3 expressions were assessed by immunohistochemistry. Protein and mRNA expressions of Ski, Smad3, TGF-β1 were assessed by Western blotting and real-time PCR. Results Compared with Sham group, Scr and BUN increased significantly in UUO group (P＜0.05). Interstitial fibrosis was prominent and renal interstitial injury score increased significantly in UUO group (P＜0.05). The expressions of Col-Ι and Smad3 were increased in UUO group (P＜0.05). Compared with Sham group, the protein expressions of TGF-β1 and Smad3 were increased, the Ski protein was decreased in UUO group (P＜0.05). In triptolide group, the morphological changes were notably reduced (P＜0.05). Comparison with UUO group, triptolide could increase the protein and mRNA expressions of Ski significantly, and decreased the protein and mRNA expressions of Smad3 and TGF-β1 (P＜0.05). Conclusion Triptolide can reduce the tubulointerstitial fibrosis by up-regulating Ski, and down-regulating TGF-β1 and Smad3.     

核心岩藻糖基转移酶siRNA抑制肾小管上皮细胞转化生长因子β-Smad2/3通路活化

目的 探讨α-1,6核心岩藻糖基转移酶（FUT8）小分子干扰RNA（siRNA）对肾小管上皮细胞转化生长因子（TGF）β-Smad2/3信号通路的影响。 方法 HK-2细胞共分为6组：正常组、阴性对照组、TGF-β1组、TGF-β1加FUT8干扰组、TGF-β1加阴性对照组、FUT8干扰组。利用外源性TGF-β1激活HK-2细胞TGF-β-Smad2/3信号通路。应用siRNA技术沉默FUT8。用免疫荧光方法测定细胞表面核心岩藻糖链表达;用免疫沉淀、凝集素免疫印迹以及免疫双染的方法测定FUT8基因沉默后TGF-βⅡ型受体（TGF-βRⅡ）、TGF-βⅠ型受体（ALK-5）的核心岩藻糖基化变化,并检测Smad2/3蛋白表达和磷酸化（p）-Smad2/3蛋白表达及其核转位的变化。 结果 与正常组及阴性对照组相比,加入5 μg/L的TGF-β1孵育HK-2细胞48 h,能显著上调 TGF-βRⅡ和ALK-5蛋白表达水平（P < 0.05）,导致p-Smad2/3表达水平明显升高（P < 0.05）,并促使其发生核转位。HK-2细胞表面存在核心岩藻糖链表达。与正常组及阴性对照组相比,TGF-β1孵育后,TGF-βRⅡ与ALK-5两种受体的核心岩藻糖链均显著升高（P < 0.05）,FUT8 siRNA能显著抑制TGF-βRⅡ与ALK-5核心岩藻糖链表达（P < 0.05）,从而抑制p-Smad2/3表达升高（P < 0.05）及其核转位,但不影响TGF-βRⅡ和 ALK-5的蛋白表达（P > 0.05）。 结论 在肾小管上皮细胞中,TGF-βRⅡ和ALK-5蛋白翻译后的核心岩藻糖基化修饰是它们发挥生物学功能所需要的,阻止TGF-βRⅡ和ALK-5的核心岩藻糖基化,能抑制TGF-β-Smad2/3信号转导通路的活化。     

冬虫夏草菌粉对5/6肾大部切除大鼠肾脏纤维化的抑制作用及机制

目的 探讨冬虫夏草菌粉对5/6肾大部切除术大鼠肾脏纤维化的抑制作用及其可能机制.方法 30只雄性SD大鼠随机分为3组:假手术组(Sham组,n=10)、5/6肾大部切除模型组(SNx组,n=10)以及5/6肾大部切除+冬虫夏草菌粉干预组(CS组,n=10).术前及术后4、8、12周分别检测大鼠体质量、尿蛋白量变化,并于术后第12周末处死大鼠,检测血尿素氮、肌酐变化,取肾组织切片行HE、Masson染色观察肾脏病理变化,免疫组化观察转化生长因子β1(TGF-β1)及其Ⅰ型受体(TβR Ⅰ)、Ⅱ型受体(TβR Ⅱ)的表达,免疫荧光观察E-c adherin、α-SMA的表达,Western印迹法检测肾脏组织TGF-β1、TβR Ⅰ、TβR Ⅱ、磷酸化(p)Smad2/3、Smad7、E钙黏蛋白(E-cadherin)、α平滑肌肌动蛋白(α-SMA)的表达.结果 术后CS组大鼠的体质量高于SNx组,尿蛋白量及血尿素氮、血肌酐低于SNx组.肾脏组织病理分析显示,CS组肾小球硬化、肾小管间质损伤程度均显著低于SNx组(均P＜0.01).CS组TGF-β1、TβR Ⅰ、TβR Ⅱ、p-Smad2/3蛋白表达量均显著低于SNx组(均P＜0.05),E-cadherin蛋白表达量显著高于SNx组(P＜0.05),α-SMA蛋白表达量显著低于SNx组(P＜0.05),Smad7蛋白表达量显著高于SNx组(P＜0.05).结论 冬虫夏草菌粉对5/6肾大部切除大鼠肾脏纤维化具有明显的抑制作用,其机制可能是与其抑制TGF-β1及其下游信号通路以及抑制EMT的发生有关.     

Effects and the possible mechanism of histone deacetylase inhibitor SAHA on the interstitial fibrosis induced by diabetes

Objective To explore the effects and possible mechanism of histone deacetylase inhibitor SAHA on the interstitial fibrosis induced by diabetes. Methods The SD rats were divided into three groups: control group (Con, n=9), diabetes mellitus (DM) group (n=9) and SAHA treatment group (n=9). The diabetic rat model was established by injecting streptozotocin (STZ) through tail vein. After 8 weeks, the SAHA treatment group rats were fed with a SAHA solution (25 mg?kg-1?d-1) by gastric gavage. After 16 weeks, all rats were sacrificed to detect relevant biochemical parameters, and observe the changes of pathomorphology in kidney. In addition, immunohistochemistry staining and Western blotting were employed to detect the protein expressions of transforming growth factor-β1 (TGF-β1), Smad2, Smad3, p-Smad2, p-Smad3, Smad7, collagen-Ⅰ and collagen-Ⅲ, respectively. Results Compared with Con group, the levels of blood glucose (BG), urinary trace albumin/urinary creatinine (ACR), triglyceride (TG) and total cholesterol (TC) in the diabetic group were all increased significantly (all P＜0.05), the protein expressions of TGF-β1, p-Smad2, p-Smad3, collagen-Ⅰ and collagen-Ⅲ in kidney were all increased in diabetic group (all P＜0.05), and the expression of Smad7 was significantly reduced (P＜0.05). Compared with DM group, the levels of ACR was reduced, the renal fibrosis was alleviated, the protein expressions of TGF-β1, p-Smad2, p-Smad3, collagen-Ⅰ and collagen-Ⅲ in SAHA group were all decreased (all P＜0.05), and the expression of Smad7 was increased significantly (P＜0.05). Conclusion SAHA may restore the protein level of Smad7 by enhancing protein stability, then promote the moderate transduction of TGF-β1/Smads signaling pathway, which reduce the fibrosis of renal tubules in diabetic rats.     

CIP4对转化生长因子β1诱导的人肾小管上皮细胞-间充质转分化的影响

目的 观察骨架调节蛋白CIP4（Cdc42 interacting protein 4）对转化生长因子β1（TGF-β1）诱导的人肾小管上皮细胞-间充质转分化（EMT）的影响,并探讨其产生的机制。 方法 10 ?滋g/L TGF-β1刺激72 h诱导人近端肾小管上皮细胞（HK-2细胞）向间充质转分化。Western印迹法检测各组细胞内E-cadherin和α-SMA蛋白的表达。倒置显微镜观察细胞形态的变化。根据GenBank人CIP4的完全cDNA序列,设计1条特异性干扰CIP4表达的RNA片段（CIP4-siRNA）和含野生型CIP4的重组真核表达质粒（pcDNA3.1-hCIP4）,利用lipofactamine 2000将其转染HK-2细胞。Western 印迹法检测对照组、TGF-β1刺激组、CIP4-siRNA转染组、pcDNA3.1-CIP4转染组细胞内CIP4、E-cadherin和α-SMA蛋白的表达,共聚焦显微镜观察 E-cadherin和α-SMA蛋白的分布改变;用PI3K-Akt特异性抑制剂渥曼青霉素（wortmannin） 1 μmol/L干预TGF-β1刺激的HK-2细胞48 h,Western 印迹法检测对照组和干预组CIP4表达的变化。 结果 TGF-β1干预后HK-2细胞E-cadherin蛋白表达显著减少（P ＜ 0.05）,α-SMA蛋白表达显著增多（P ＜ 0.05）,细胞形态由典型的上皮细胞向肌成纤维细胞转变,表明TGF-β1诱导肾小管上皮细胞EMT模型成功。CIP4-siRNA抑制TGF-β1诱导的HK-2细胞表达CIP4后,E-cadherin蛋白表达显著增多（P ＜ 0.05）,α-SMA蛋白表达显著减少（P ＜ 0.05）,部分逆转了上述TGF-β1诱导的肾小管上皮细胞EMT。pcDNA3.1-hCIP4转染使CIP4高表达后,HK-2细胞E-cadherin蛋白表达显著减少（P ＜ 0.05）,α-SMA蛋白表达显著增多（P ＜ 0.05）,诱导了肾小管上皮细胞EMT。用渥曼青霉素干预TGF-β1刺激的HK-2细胞48 h,CIP4可能蛋白表达显著减少（P ＜ 0.05）。 结论 TGF-β1通过PI3K-Akt途径上调CIP4表达,CIP4可能进一步参与TGF-β1诱导的肾小管上皮细胞EMT过程。     

CIP4在肾间质纤维化中的表达及作用

目的 观察骨架调节蛋白CIP4（Cdc42 interacting protein-4）在肾纤维化过程中表达水平、细胞内定位及高表达的CIP4基因对人肾小管上皮细胞E钙黏蛋白（E-cadherin）、波形蛋白（vimentin）的表达和β连环素（β-catenin）酪氨酸磷酸化水平的影响。 方法 体外实验以人近端肾小管上皮细胞（HK-2细胞）为研究对象,10 μg/L TGF-β1刺激72 h诱导HK-2细胞转分化; Western 印迹法检测各组细胞内CIP4、E-cadherin、vimentin蛋白的表达;RT-PCR法检测细胞内CIP4 mRNA表达水平;激光共聚焦显微镜观察CIP4在细胞内定位。体内实验以SD大鼠为研究对象,5/6肾切除法制作慢性肾纤维化模型;常规检测BUN和Scr水平;Masson染色检测肾组织纤维化水平;免疫组化法检测肾组织内CIP4蛋白的表达和分布。脂质体法介导含野生型CIP4的重组真核表达质粒pcDNA3.1-CIP4或pcDNA3.1-Zeo（空载体）转染HK-2细胞,Wetern 印迹法检查转染的效率。稳定转染成功后,Wetern 印迹法检测正常组、pcDNA-CIP4转染组和空载体转染组细胞内E-cadherin、vimentin蛋白的表达和β-catenin酪氨酸磷酸化水平。 结果 正常HK-2细胞表达E-cadherin和少量的CIP4,几乎不表达vimentin。TGF-β1干预组细胞vimentin蛋白表达增加（P ＜ 0.05）,E-cadherin蛋白表达减少（P ＜ 0.05）,CIP4 mRNA和蛋白表达均显著增多（P ＜ 0.05）。CIP4在正常细胞内大部分在细胞膜,少量在细胞质,在转分化的HK-2细胞表达显著增多,并向细胞质和细胞核聚集。假手术组大鼠肾功能正常,肾组织内未见明显纤维化组织,CIP4在肾小管表达较少,肾小球内几乎不表达;模型组大鼠BUN和Scr增高,肾组织内可见明显纤维化组织,CIP4在肾小管表达明显增加。pcDNA3.1-CIP4转染组较正常组和空载体转染组细胞内CIP4表达增多（P ＜ 0.05）,β-catenin酪氨酸磷酸化水平和vimentin蛋白表达增加（P ＜ 0.05）,而E-cadherin蛋白表达减少（P ＜ 0.05）。 结论 CIP4高表达可能参与肾小管上皮细胞-间充质细胞转分化,促进肾间质纤维化。     

Effects of 1,25-dihydroxyvitamin D3 on the expression of connective tissue growth factor and heat shock protein 47 in peritoneum fibrosis rats

Objective To investigate the expression of connective tissue growth factor (CTGF) and heat shock protein 47 (HSP47) in peritoneum fibrosis rats, and the mechanism of 1,25-dihydroxyvitamin D3 [1,25-(OH)2-VitD3] in inhibiting the peritoneum fibrosis. Methods Adult male Sprague-Dawley rats were randomly divided into 3 groups: control group (n=8), model group (n=8) and 1,25-dihydroxyvitamin D3 group (VitD3, n=8). The model of peritoneum fibrosis rats were induced by daily intraperitoneally injection of 15% chlorhexidine gluconate (CHX) 0.2 ml/d with 0.1% glucose for 4 weeks. Rats in VitD3 group were also treated with 1,25-(OH)2-VitD3 [i.p. 6 ng?(100 g)-1?d-1]. Peritoneal transport function, renal function, peritoneum thickness and serum level of 25 hydroxyvitamin D3 were detected. In vitro, primary cultured peritoneal mesothelial cells were divided into control group, high glucose group (HG, 2.5%), CTGF siRNA intervention group (CTGF siRNA+HG), VitD3 intervention group (VitD3+HG) and combined intervention group (CTGF siRNA+VitD3+HG). Real-time PCR, Western blotting and immunofluorescence were applied to measure the expression of CTGF and HSP47, also ELISA was used to detect the protein level of FN in peritoneum and peritoneal mesothelial cells. Results Compared with control group, the peritoneal ultrafiltration in peritoneum fibrosis rats were significantly decreased (P＜0.05), the absorbance level of peritoneal fibrosis, peritoneum thickness, the rate of dialysate urea nitrogen and blood urea nitrogen (DUN/BUN) and the expressions of CTGF and HSP47 were increased (all P＜0.05). After application of 1,25-dihydroxyvitamin D3, peritoneal fibrosis lesion was significantly improved, the peritoneum thickness, the expressions of CTGF and HSP47 were decreased (all P＜0.05). In vitro, 2.5% high glucose induced-peritoneal mesothelial cells were respectively treated by CTGF siRNA, 1,25-(OH)2-VitD3 and combined interventions, the expression of FN, CTGF and HSP47 was significantly lower than that in high glucose group (all P＜ 0.05). Conclusions The expression of CTGF and HSP47 is significantly increased in peritoneal fibrosis rats. 1,25-(OH)2-VitD3 may ameliorate the progression of peritoneal fibrosis via reducing the expression of CTGF, decreasing the expression of HSP47 and FN.     

热休克蛋白47在转化生长因子β1诱导肾小管间质纤维化中的作用

目的 探讨热休克蛋白47（HSP47）在肾小管间质纤维化中的作用及其可能机制。 方法 常规培养人肾小管上皮细胞（HK-2）,分为对照组、转化生长因子β1（TGF-β1）组、HSP47-siRNA组。RT-PCR检测HSP47、胶原Ⅳ、纤连蛋白（FN）、组织型纤溶酶原激活物抑制剂1（PAI-1）的mRNA表达。Western印迹检测HSP47、胶原Ⅳ、FN蛋白表达。ELISA检测PAI-1的蛋白量。 结果 HK-2细胞有HSP47表达。不同浓度TGF-β1（0、2.5、5、10 μg/L）干预不同时间（12、24、48 h）时,HSP47基因和蛋白表达呈浓度和时间依赖性增高,10 μg/L TGF-β1干预HK-2细胞48 h时,HSP47 mRNA和蛋白表达最强。不同浓度 TGF-β1（0、5、10 μg/L）干预HK-2不同时间（12、24、48 h）时,胶原Ⅳ、FN 、PAI-1 mRNA和蛋白表达亦呈浓度和时间依赖性增高,10 μg/L TGF-β1作用48 h时,3者mRNA和蛋白表达最强。与TGF-β1组比较,HSP47-siRNA组的HSP47、胶原Ⅳ、FN、PAI-1 mRNA和蛋白表达都明显下调。 结论 HSP47可促进肾小管间质纤维化,其机制可能与上调胶原Ⅳ、FN、PAI-1表达有关。     

Expression of tumor necrosis factor-α induced protein 8 like-1 in cisplatin-induced acute kidney injury models

Objective To investigate the expression and role of the tumor necrosis factor-α (TNF-α) induced protein 8 like-1 (TIPE1) in acute kidney injury (AKI) induced by cisplatin in animal model and cells. Methods Twelve male C57BL/6 mice aged 6-8 weeks were randomly divided into the control group and the model group. Mice in the model group received a single intraperitoneal injection of 20 mg/kg of cisplatin (20 mg/kg saline in the control group). All mice were euthanized after 5 days. Meanwhile, serum and kidney samples were collected. The levels of serum creatinine (Scr) and blood urea nitrogen (BUN) were detected by biochemical kits. Renal histopathological changes in mice were observed by HE staining. The expression of TIPE1 in kidney was examined using immunohistochemistry. qRT-PCR was used for testing the relative expression of TIPE1 mRNA in mice kidney. Western blotting was used for testing TIPE1 and NGAL protein relative expression in mice kidney. Human kidney proximal tubular cells (HK-2) were stimulated with 20 μmol/L cisplatin for 0, 6, 12 and 24 h to establish cisplatin-induced AKI cell model. The expressions of TIPE1 mRNA and protein were detected by qRT-PCR and Western blotting in HK-2 cells. The expression of TIPE1 gene in HK-2 cells was silenced by lentivirus containing TIPE1 siRNA sequence. Then, TIPE1 stable knockout HK-2 cell strains were treated with 20 μmol/L of cisplatin for 24 hours. The protein expression of tubular damage marker neutrophil gelatinase-associated lipocalin (NGAL), microtubule-associated protein 1 light chain 3 (LC3) and Beclin1 in HK-2 cells were detected by Western blotting. Results Compared with the control group, the expressions of TIPE1 mRNA and protein were up-regulated and NGAL protein expression was increased significantly in renal tissue of the model group (all P＜0.05). The expressions of TIPE1 mRNA and protein were remarkably increased with the prolongation of cisplatin treatment in HK-2 cells (both P＜0.05). Compared with the scramble siRNA group, the protein expressions of NGAL, LC3-Ⅱ and Beclin1 were increased significantly in the TIPE1 siRNA group after lentivirus interfered with the expression of TIPE1 gene in HK-2 cells (all P＜0.05). Conclusions The mRNA and protein expressions of TIPE1 are increased in acute kidney injury models. Gene silencing of TIPE1 can promote the expressions of early renal tubular damage marker and autophagy-related proteins, which indicates the excessive autophagy aggravates renal tubular injury. It is suggested that TIPE1 may be involved in the pathogenesis of acute kidney injury.     

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.     

NPHP1 knockdown induces epithelial-mesenchymal transition in Madin-Darby canine kidney cells

Objective To explore the impacts of NPHP1 knockdown on the phenotype of Madin-Darby canine kidney (MDCK) cells. Methods The expression of NPHP1 in MDCK cells was knockdown by siRNA interference. Cells were divided into normal control group, negative control group and siRNA group. The cellular morphology and migration were observed by light microscope. The mRNA expressions and activities of matrix metalloproteinases 2 and 9 (MMP2 and MMP9) were detected by real time PCR and gelatin zymography. The mRNA and protein expressions of E-cadherin, β-catenin, zonula occluden-1 (ZO-1), ZO-1-associated nucleic acid binding protein (ZONAB) and α-smooth muscle actin (α-SMA) were analyzed by real time PCR, Western blotting and immunocytochemistry. Results Compared with those in normal control group, in siRNA group the mRNA expressions of E-cadherin, β-catenin and ZO-1 decreased, and MMP9, MMP2, α-SMA and ZONAB increased after interfering NPHP1 24 h (all P＜0.05); the protein expressions of E-cadherin, β-catenin and ZO-1 decreased and ZONAB and α-SMA increased after 48 h (all P＜0.05), and MDCK cells became elongated with enhanced migration capacity; siRNA cells had decreased expressions of E-cadherin and β-catenin on the membrane, but increased expression of ZONAB in cytoplasm and nucleoplasm after 72 h, and α-SMA was also observed in some interfered cells. Conclusions NPHP1 knockdown induces epithelial-mesenchymal transition in MDCK cells, and ZO-1/ZONAB signaling pathway was activated. These changes may associate with renal interstitial fibrosis of Nephronophthisis type I.     

Smad锚着蛋白在糖尿病肾病肾小管上皮细胞转分化中的作用及机制研究

目的 研究Smad锚着蛋白(SARA)在高葡萄糖诱导的HK-2细胞转分化中的作用及相关机制.方法 用高浓度葡萄糖(30 mmol/L D-葡萄糖)刺激HK-2细胞,分别采用细胞免疫荧光、Western印迹及实时定量PCR等方法检测HK-2细胞波形蛋白(vimentin)、紧密连接蛋白(ZO-1)、SARA、转化生长因子β1(TGF-β1)、Smad2及Smad3的表达.分别转染全长SARA质粒[SARA (WT)]及敲除SBD结构域的SARA质粒[SARA(dSBD)],检测转染后高糖诱导的HK-2细胞Vimentin、ZO-1、Smad2、Smad3、p-Smad2、p-Smad3表达的变化.结果 高糖刺激时,HK-2细胞出现转分化 ;ZO-1蛋白和mRNA表达呈时间依赖性下调 ;vimentin蛋白和mRNA表达呈时间依赖性上调,而SARA蛋白和mRNA表达呈时间依赖性下调 ;TGF-β1、Smad3蛋白和mRNA表达呈时间依赖性上调 ;Smad2 mRNA表达呈时间依赖性上调,而其蛋白表达呈时间依赖性下调 ;Smad2和Smad3磷酸化,Smad3活化时间更长.与高糖刺激组相比,转染全长SARA质粒[SARA (WT)]过表达SARA使HK-2细胞ZO-1表达上调(P＜0.05) ;vimentin表达下调(P＜0.05) ;Smad2蛋白表达上调,但mRNA表达无明显变化 ;Smad2活化时间延长.转染SARA(dSBD)质粒对高糖诱导的HK-2细胞ZO-1、vimentin、Smad2的表达无影响,对Smad2和Smad3的磷酸化亦无明显影响.结论 高糖诱导的HK-2细胞转分化过程中,TGF-β1信号通路活化,SARA的表达下调.过表达SARA可能通过上调Smad2的蛋白表达,延长Smad2活化时间,从而抑制TGF-β1信号传导,进而抑制高糖诱导的HK-2细胞转分化进程.     

Circulating miRNA-130b-3p promotes epithelial-to-mesenchymal transition in renal tubular epithelial cells by inhibiting expression of ERBB2IP and PPARγ

Objective To investigate a possible molecular mechanism of MiRNA-130b-3p involved in renal damage. Methods Human renal tubular epithelial cells (HK-2) were transfected with MiR-130b-3p mimics or normal control mimics. Then HK-2 cells were stimulated with 10 μg/L recombinant TGF-β1 for 72 h. After 72 h, the mRNA and protein expression of Collegen Ⅳ, α-smooth muscle actin (α-SMA), Collegen Ⅰand E-cadherin were quantified by real-time PCR and Western blotting. The mRNA and protein expression of ERBB2IP and PPARγ were also detected. The reporter plasmids containing ERBB2IP 3'-UTR and PPARγ 3'-UTR were constructed. The activity of ERBB2IP and PPARγ were detected by dual luciferase report system. Results Compared to NC mimic group,transfection of HK-2 cells with MiR-130b-3p mimics resulted in significantly increased expression of mRNA and protein of Collegen Ⅳ, α-SMA, Collegen Ⅰ, and decreased expression of E-cadherin after stimulating by TGF-β1 (all P＜0.05). And MiR-130b-3p mimic could significantly down-regulate the mRNA and protein expression of ERBB2IP and PPARγ in HK-2 cells (all P＜0.05) whether in the presence of TGF-β1 or not. The dual luciferase reporter assay showed that MiR-130b-3p induced decreased ERBB2IP 3'-UTR luciferase activity compared to NC mimic group, but there was no significant difference between NC mimic group and mut-MiR-130b-3p mimic group. MiR-130b-3p mimic+mut-PPARγ-3'UTR cotransfection group had lower PPARγ luciferase activity than NC mimic + mut-PPARγ-3'UTR group , and MiR-130b-3p+PPARγ-3'UTR group got lower further (all P＜0.01). Conclusions MiR-130b-3p promotes epithelial-to-mesenchymal transition (EMT) in renal tubular epithelial cells by directly targeting at the 3'-UTR of ERBB2IP and PPARγ, which may play an important role in renal damage of early stage lupus nephritis.     

单侧输尿管梗阻大鼠肾脏转化生长因子β受体亚型表达的变化

目的 探讨转化生长因子β（TGF-β）Ⅰ型受体（RⅠ）、Ⅱ型（RⅡ）受体以及下游Smad蛋白在单侧输尿管梗阻（UUO）大鼠模型肾脏中表达及意义。 方法 90只雌性Wistar大鼠随机分为正常对照组（CON组）、假手术组（SOR组）和单侧输尿管梗阻组（UUO组）,分别于术后1、3、7、14、21 d处死,检测各组大鼠肾功能;PAS与Masson染色观察大鼠肾间质病理形态改变;实时定量PCR基因芯片分析正常大鼠和肾间质纤维化大鼠肾组织TGF-βⅠ、Ⅱ、Ⅲ型受体及Smad蛋白家族表达。筛选出差异表达的受体亚型,进一步应用实时荧光定量PCR、蛋白免疫印迹法、免疫荧光法检测和验证筛选出的差异受体亚型在不同分期肾间质纤维化大鼠肾组织的分布和表达。 结果 与CON组相比,UUO组大鼠的Scr及BUN于术后3 d开始升高（P < 0.05）,第21天达峰值（P < 0.01）;UUO组术后3 d肾间质可见明显炎性细胞浸润;14 d后出现明显肾小管萎缩;21 d可见明显肾间质纤维化。UUO组肾组织TGF-βⅠ型受体ALK-5、ALK-7和TGF-βRⅡ的mRNA表达于术后3 d上升并随梗阻时间延长逐渐增加（P < 0.05）,于14 d达到峰值（均P < 0.01）;ALK-6的mRNA表达于术后3 d下降（P < 0.05）并随梗阻时间延长逐渐减少,于14 d达谷值（P < 0.01）。ALK-5、ALK-6、ALK-7和TGF-βRⅡ蛋白表达与基因表达一致。Smad2/3及磷酸化（p）-Smad2/3的蛋白表达于术后3 d上升（均P < 0.05）并随梗阻时间延长逐渐增加,于14 d达到峰值（均P < 0.01）。 结论 在肾间质纤维化进展中不同TGF-β受体亚型存在不同的变化规律并与肾间质纤维化进展密切关联。     

Prostaglandin E2 receptor subtype 3-siRNA reduces the mesangial cell damage induced by TGF-β1through inhibiting MAPK pathway in mice

Objective To investigate the effects and mechanisms of prostaglandin E2 receptor subtype 3 (EP3) on transforming growth factor β1 (TGF-β1)-induced mouse mesangial cells damage. Methods Primary mouse mesangial cells were separated and cultured. Three siRNAs were synthesized and transfected into mesangial cells for silencing EP3 by LipofectamineTM 2000 and the best one was chosen. MCs were grouped into: (1)control group; (2)TGF-β1 (10 μg/L) group; (3)NC-siRNA plus TGF-β1 (10 μg/L) group; (4) EP3-siRNA group; (5)EP3-siRNA plus TGF-β1 (10 μg/L). Then the proliferation of MCs was evaluated by CCK-8 assay. The expression of PGE2 and cAMP in cell supernatant were detected by ELISA. The mRNA and protein expression of fibronectin (FN), connective tissue growth factor (CTGF), cyclooxygenase-2 (COX2), membrane-bound prostaglandin E2 synthase 1 (mPGES1) were detected by real-time quantitative PCR and Western blotting. The phosphorylation of p38 MAPK and ERK1/2 was decected by Western blotting. Results Compared with control group, the cell proliferation induced by TGF-β1 was increased (P＜0.05), the expression of PGE2 and cAMP were improved, mRNA and protein expression of FN, CTGF, COX2 and mPGES1 were up-regulated (all P＜0.05). Compared with TGF-β1 group, the cell proliferation in EP3-siRNA plus TGF-β1 group was reduced, the expression of FN, CTGF, COX2 and mPGES1 mRNA and protein were downregulated (all P＜0.05), the phosphorylation of ERK1/2, p38 MAPK were also declined (P＜0.05). Conclusion EP3-siRNA may reduce TGF-β1-induced cell damage through upregulating the expression of cAMP, repressing the activity of ERK1/2 and p38 MAPK, inhibiting the expression of COX2 mPGES1 and PGE2 by feedback, then decreased the expression of FN and CTGF.     

Smad3沉默对IGFBPrP1诱导肝星状细胞分泌细胞外基质作用的影响

目的 明确胰岛素样生长因子结合蛋白相关蛋白1(insulin-like growth factor binding protein related protein1,IGFBPrP1)是否通过Smad3信号通路影响肝星状细胞分泌细胞外基质.方法 (1)化学合成2对针对Smad3基因的siRNAs(siRNA1,siRNA2),转染肝星状细胞株(HSC-T6).采用实时定量PCR和Western blot法筛选抑制效率较高的siRNA用于干扰实验;(2)将肝星状细胞株(HSC-T6)分为4组:阴性对照组、siRNA-Smad3转染组、siRNA-Smad3+IGFBPrP1组和IGFBPrP1组.将筛选的抑制效率较高的siRNA转染HSC-T6细胞株,田Western b1ot检测各组Smad3、纤维连接蛋白及Ⅰ型胶原的表达.结果 (1)siRNA2-Smad3对Smad3的抑制效率较高;(2)与阴性对照组相比,siRNA-Smad3转染组Smad3蛋白的表达显著下降(P＜0.01).与IGFBPrP1组相比,siRNA-Smad3+IGFBPrP1组纤维连接蛋白和Ⅰ型胶原蛋白的表达均显著降低(P＜0.01).结论 IGFBPrP1影响肝星状细胞分泌细胞外基质的机制之一是通过Smad3信号通路来实现的.

Abstract：

Objective To identify the effect of IGFBPrP1 on the secretion of extracellular matrix in hepatic stellate cells through the Smad3 signaling pathway. Methods (1)Two pairs of chemically synthesized siRNAs (siRNA1, siRNA2) targeting Smad3 were transfected into HSC-T6 cells,real-time PCR and Western blot were used to evaluate the silence efficiency, and the better siRNA was used. (2)HSC-T6 cells were divided into four groups: Negative control group, siRNA-Smad3 transfection group, siRNA-Smad3+IGFBPrP1 group and IGFBPrP1 group. The better siRNA was chosen to transfect into HSC-T6 cells. The protein expressions of Smad3, fibronectin and Collagen Ⅰ were evaluated by Western blot. Results (1)siRNA2-Smad3 inhibited Smad3 gene expression stronger than another siRNA. (2)After transfection of siRNA2-Smad3, the protein expression of Smad3 was significantly decreased compared to the negative control group(P＜0.01). The protein expression of fibronectin and Collagen Ⅰ in IGFBPrP1 stimulating HSCs treated with siRNA2-Smad3 were significantly decreased compared to that in IGFBPrP1 stimulating HSC without siRNA2-Smad3 (P ＜0. 01 ).Conclusion IGFBPrP1 induces the secretion of extracellular matrix in hepatic stellate cells through the Smad3 signaling pathway.     

Impact of STAT1-siRNA transfection on the expressions of STAT3 and transforming growth factor β1 in human glomerulur mesangial cells induced by high glucose

Objective To observe the cell proliferation and the protein expression of STAT1,phosphorylation of STAT1 (p-STAT1), STAT3, p-STAT3 and transforming growth factor β1 (TGF-β1) in human glomerulur mesangial cells (HMCs) induced by high glucose after STAT1-siRNA transfection. Methods Three STAT1-siRNA sequences were designed and synthetized. HMCs in 6-well plate were transiently transfected with STAT1-siRNA using Lipofectamine 2000. After transfection for 48 h or 72 h, STAT1 mRNA and protein expression were detected by real-time PCR and Western blotting, respectively, to choose the effective sequence in later experiments. After transfection for 24 h and stimulated with 25 mmol/L glucose for 24 h, 48 h, 72 h, cell proliferation was measured by MTT assays, the protein expressions of STAT1, p-STAT1, STAT3 and p-STAT3 were detected by Western blotting, the expression of TGF-β1 was detected by ELISA in each group. Results High glucose could stimulate HMCs proliferation. The protein expressions of p-STAT1, p-STAT3 and TGF-β1 were increased in the group stimulated by high glucose (P＜0.05). The protein expressions of p-STAT3 and TGF-β1 were further increased in HMCs induced by high glucose after STAT1-siRNA transfection (P＜0.05). Conclusions Under high glucose conditions, JAK-STAT signal transduction pathway of HMCs can be activated, then it is far greater when HMCs are induced by high glucose after STAT1-siRNA transfection. The secretion of TGF-β1 is increased in HMCs under the state of high glucose, and it is further increased after STAT1-siRNA transfection, which is related to the kidney fibrosis.     

Role of β-catenin signaling pathway in the epithelial to mesenchymal transition induced by parathyroid hormone in renal tubular epithelial cells

Objective To investigate the effect of parathyroid hormone (PTH) on the epithelial to mesenchymal transition (EMT) in human renal proximal tubular epithelial cells (HK-2 cells), and determine the role of β-catenin signaling pathway. Method The expression of α-smooth muscle actin (α-SMA), E-cadherin and β-catenin in HK-2 cells was measured by real-time PCR, Western blotting and immunofluorescence technique. The signaling pathway by which PTH activated EMT in HK-2 cells was identified by using synthetic β-catenin siRNA. Results Parathyroid hormone (10-10 mol/L) increased α-SMA expression and decreased E-cadherin expression in HK-2 cells (P＜0.01, respectively). Untreated cells showed the expression of E-cadherin, whereas α-SMA staining was noticeably increased in cells treated with PTH. β-catenin activity was significantly increased after exposed to PTH. Theα-SMA expression was decreased strongly and E-cadherin expression was increased after β-catenin siRNA transfection (all P＜0.05). Conclusion PTH significantly induces epithelial to mesenchymal transition in HK-2 cells throughβ-catenin signaling pathway.     

热休克蛋白72肽结合区对肾小管上皮间质转分化的影响

目的 探讨热休克蛋白72肽结合区在肾小管上皮间质转分化(EMT)过程中的作用和可能机制.方法 应用质粒转染方法分别诱导热休克蛋白72(HSP72)野生型、肽结合区缺失型(HSP72-△PBD)和肽结合区(PBD)的表达.用转化生长因子β1(TGF-β1)刺激大鼠肾小管上皮细胞(NRK-52E)48 h,Western印迹和免疫荧光染色检测细胞E-钙黏蛋白(cadherin),α-平滑肌肌动蛋白(SMA),HSP72和Smad3/磷酸化(p)-Smad3蛋白表达.结果 TGF-β1(10 μg/L)刺激NRK-52E细胞48 h后上调α-SMA和下调E-cadherin蛋白表达水平.Western印迹及细胞免疫荧光显示,过表达HSP72和PBD能明显减轻TGF-β1诱导的NRK-52E细胞E-cadherin蛋白表达下调和α-SMA蛋白表达上调,而过表达HSP72-△PBD不能改变上述蛋白的表达.此外,过表达HSP72和PBD显著抑制Smad3的磷酸化.结论 HSP72抑制Smad3活化和EMT的发生可能与PBD的功能有关.