酸性成纤维细胞生长因子对庆大霉素诱导的肾小管上皮细胞损伤的保护作用

目的研究酸性成纤维细胞生长因子(aFGF)对庆大霉素引起的体外培养的大鼠肾小管上皮细胞损害的保护作用。方法大鼠肾皮质经研磨、过网、胰蛋白酶消化,进行肾小管上皮细胞的体外培养。用庆大霉素建立损伤模型,观察aFGF对损伤的肾小管上皮细胞的保护作用。结果①经形态学观察、GM组与对照组比较,CAT、SOD、Na^+,K^+-ATP酶活性下降,而NAG活性和MDA升高(P<0.01),提示肾小管上皮细胞的培养和庆大霉素损伤的建模成功。②aFGF+GM组与GM组比较,各生化和酶学指标差异均有显著性(P<0.01);而aFGF+GM组与对照组比较,CAT、NAG、Na^+,K^+-ATP酶活性差异无显著性,但SOD活性下降、MDA升高差异仍有显著性(P<0.05)。结论aFGF对庆大霉素诱导的肾小管上皮细胞损伤有明显的保护作用。

复方积雪草有效组分干预肾小管上皮细胞Toll样受体4表达的实验研究

目的:探讨复方积雪草有效组分-积雪草苷/大黄素干预肿瘤坏死因子α(TNF-α)诱导的小鼠肾小管上皮细胞(mTEC)Toll样受体4(TLR4)mRNA及蛋白的表达水平。方法:采用mTEC,模型组用TNF-α5ng/mL诱导,治疗组在TNF-α诱导的同时,以不同浓度的积雪草苷合大黄素进行干预,于24h后分别提取细胞RNA及上清,应用逆转录-聚合酶链反应(RT-PCR)和流式细胞术(FCM)分别检测mTECTLR4 mRNA和膜蛋白的表达。结果:正常mTEC具有TLR4 mRNA和蛋白表达,经TNF-α诱导后TLR4表达明显上调,当积雪草苷合大黄素干预浓度达4μg/mL+0.4μg/mL时,能够抑制TLR4 mRNA及蛋白的表达水平。结论:复方积雪草有效组分能够抑制TNF-α上调所致的肾小管上皮细胞TLR4过度表达,从而缓解肾脏局部失控性炎症反应。

缺血再灌注损伤对新生鼠肾小管上皮细胞细丝蛋白的影响

目的 通过研究缺血再灌注不同时段细丝蛋白在肾小管上皮细胞中的分布变化 ,探讨细丝蛋白在肾脏缺血再灌注损伤中所起的作用。方法 建立新生大鼠不同时段的肾脏缺血再灌注模型 ,通过免疫荧光法检测细丝蛋白在肾小管上皮细胞上的分布及其表达量。结果 细丝蛋白在正常时主要分布在肾小管上皮细胞基底部附近 ,缺血 0 .5 h时其分布变化不明显 ,再灌注 0 .5 h后 ,细丝蛋白开始向胞浆转移 ,并出现在细胞顶部和肾小管腔内 ,再灌注 2 h这种改变最明显并伴肾小管结构的破坏 ;从再灌注 2 4h起开始进入恢复阶段 ,细丝蛋白逐渐重新回到基底部 ,再灌注 12 0 h后恢复阶段基本结束 ,肾小管结构正常。结论 细丝蛋白在缺血再灌注时分布发生改变 。

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）48h，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（10μg／L）刺激NRK-52E细胞48h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。

Effects of saponin from the seed of Litchi chinensis Sonn on TGF-β1, FN and SOCS-1 in renal tubular epithelial cells under high glucose

Objective:To investigate the effect of saponin from the seed of Litchi chinensis Sonn(SLS)on the growth and apoptosis of human kidney epithelial cells(HKC)cultured in high glucose.Methods:HKC were cultured in DMEM/F12 medium supplemented with 30 mmol/L glucose and treated with or without SLS.In the normal group,isometric DMEM/F12 medium with 5.5mmol/L glucose was added.The secretion of TGF-β1 and fibronectin(FN)were detected by ELISA.Cell apoptosis was detected by the method of Annexin V-FITC/PI double staining.Western blot was used to detect the level of suppressor of cytokine signaling-1(SOCS-1).Results:The result of ELISA showed that the secretion of TGF-β1 and FN was decreased in SLS groups compared with those in 30 mmol/L glucose treated group(P<0.05).There were more cells apoptosis in 30 mmol/L glucose treated group than that in the normal group(P<0.01).Compared with the 30 mmol/L glucose treated group,the apoptosis of HKC were significantly decreased in SLS groups(P<0.01).Western blot showed that the level of SOCS-1 in high glucose+SLS group was decreased(P<0.01),compared with the high glucose group.Conclusion:SLS can reduce the secretion of TGF-β1 and FN in HKC by reducing the deposition of extracellular matrix.SLS also significantly reduced the apoptosis of HKC by inhibiting the level of SOCS-1.These results suggest the roles of SLS in preventing the progress of glomerular sclerosis.

Sonic hedgehog signaling in kidney fibrosis: a master communicator

The hedgehog signaling cascade is an evolutionarily conserved pathway that regulates multiple aspects of embryonic development and plays a decisive role in tissue homeostasis. As the best studied member of three hedgehog ligands, sonic hedgehog(Shh) is known to be associated with kidney development and tissue repair after various insults. Recent studies uncover an intrinsic link between dysregulated Shh signaling and renal fibrogenesis. In various types of chronic kidney disease(CKD), Shh is upregulated specifically in renal tubular epithelium but targets interstitial fibroblasts, thereby mediating a dynamic epithelialmesenchymal communication(EMC). Tubule-derived Shh acts as a growth factor for interstitial fibroblasts and controls a hierarchy of fibrosis-related genes, which lead to the excessive deposition of extracellular matrix in renal interstitium. In this review, we recapitulate the principle of Shh signaling, its activation and regulation in a variety of kidney diseases. We also discuss the potential mechanisms by which Shh promotes renal fibrosis and assess the efficacy of blocking this signaling in preclinical settings. Continuing these lines of investigations will provide novel opportunities for designing effective therapies to improve CKD prognosis in patients.

Effect of Tangnaikang on TGF-β_1-induced transdifferentiation of human renal tubular epithelial HK-2 cells

OBJECTIVE： To explore the function of Tangnai- kang （TNK） in the prevention and treatment of re- nal interstitial fibrosis through transdifferentiation of the human renal tubular epithelial cell line HK-2 induced bytransforming growth factor-β1 （TGF-β1）. METHODS： HK-2 cells cultured in dulbecco＇s modi- fied eagle medium/F12 （1：1） with 10% fetal calf se- rum were divided into six groups： blank control group, TGF-β1 group （TGF-β1 10 ng/mL）, serum con- trol group （TGF-β1 10 ng/mL ＋ 10% serum）, treat- ment group 1 （TGF-β1 10 ng/mL ＋ 5% TNK serum）, treatment group 2 （TGF-β1 10 ng/mL＋10% TNK se-rum）, and treatment group 3 （TGF-β1 10 ng/mL＋ 20% TNK serum）. Cell proliferation was detected by 4,5-Dimethylthiazol-2-yl）-2,5-diphenyltetrazoliu m bromide assay. Expression of a-smooth muscle ac- tin （a-SMA） and E-cadherin were observed by im- munohistochemical assay. The contents of collagen Ⅰ （Col Ⅰ）, collagen Ⅲ（ColⅢ）, and fibronectin （FN） in the culture medium supernatant were detected by ELISA. RESULTS： E-cadherin was expressed and α-SMA was not expressed in normal HK-2 cells. In HK-2 cells cultured with TGF-β1, α-SMA expression signifi- cantly increased, HK-2 cells significantly proliferat- ed, and secretion of Col Ⅰ, Col Ⅲ, and FN significantly increased compared with the blank control group （all P〈0.05）. In the HK-2 cells cultured with TGF-β1 and TNK serum, the expression of α-SMA signifi- cantly decreased, the expression of E-cadherin sig- nificantly increased, and the cell proliferation and the secretion of Col Ⅰ, Col Ⅲ and FN were significant- ly inhibited compared with the TGF-β1 group （all P〈 0.05. CONCLUSION： TNK can inhibit cell proliferation and reduce secretion of Col Ⅰ, Col Ⅲ, and FN.This in- dicates that TNK can inhibit transdifferentiation of human renal tubular epithelial cells induced by TGF-β1, with the effect of preventing and treating renal interstitial fibrosis.

Theoretical energy consumption analytical method for metal separation process

The theoretical energy consumption(TEC)analytical methods and the calculated models for the electrolytic and thermal reduction metal separation processes have been put forward based on thermodynamics and physical chemistry principles,providing theoretical foundation for choosing the optimum metal separation methods.Based on the models,the TECs of the Mg separation processes are taken as an example,and have been calculated and analyzed contrastively,including the MgCl_2 electrolytic method,the MgO electrolytic method with inert electrode and with carbon anode,and the silicothermic method.It is shown that the thermal method is more reasonable than the electrolytic methods to separate Mg under low efficiency of coal power generation.

Hydraulic pressure inducing renal tubular epithelial-myofibroblast transdifferentiation in vitro

Objective： The effects of hydraulic pressure on renal tubular epithelial-myofibroblast transdifferentiation （TEMT） were investigated. Methods： We applied hydraulic pressure （50 cmH2O） to normal rat kidney tubular epithelial cells （NRK52E） for different durations. Furthermore, different pressure magnitudes were applied to cells. The morphology, cytoskeleton, and expression ofmyofibroblastic marker protein and transforming growth factor-β1 （TGF-β1） of NRK52E cells were examined. Results Disorganized actin filaments and formation of curling clusters in actin were seen in the cytoplasm of pressurized cells. We verified that de novo expression α-smooth muscle actin induced by pressure, which indicated TEMT, was dependent on both the magnitude and duration of pressure. TGF-β1 expression was significantly upregulated under certain conditions, which implies that the induction of TEMT by hydraulic pressure is related with TGF-β1. Conclusion： We illustrate for the first time that hydraulic pressure can induce TEMT in a pressure magnitude- and duration-dependent manner, and that this TEMT is accompanied by TGF-β1 secretion.