粉防己碱对转化生长因子-β1诱导的人近端小管上皮细胞转分化的干预作用及机制

目的探讨粉防己碱(tetrandrine,Tet)对转化生长因子-β1(TGF-β1)诱导的人近端肾小管上皮细胞(HK-2)转分化的拮抗效应及其机制。方法体外培养的HK-2随机分为正常对照组、Tet组(100ng/ml)、TGF-β1(5ng/ml)组和TGF-β1(5ng/ml)+Tet(100ng/ml)组。Westernblot法检测细胞中TβRI蛋白、SnoN蛋白水平、Smad7蛋白水平和Smad2/3磷酸化水平的改变;半定量反转录-聚合酶链式反应(RT-PCR)方法观察细胞中TβRI mRNA、Smad7 mRNA、SnoN mRNA表达的改变。免疫荧光检测间充质细胞标记物α-平滑肌肌动蛋白(α-SMA)的表达。结果 Tet能抑制TGF-β1诱导α-SMA的表达,显著上调SnoN mRNA和蛋白的表达(P<0.01);Tet对TβRI表达、Smad2/3的磷酸化及Smad7的表达没有影响。结论 Tet能抑制人近端小管上皮细胞转分化,其机制与Tet上调SnoN表达有关。     

TGF-β1/Smad信号通路在大黄素干预人肾小管上皮细胞转分化中的作用

目的:探讨大黄素干预白蛋白诱导人肾小管上皮细胞(HK-2)发生转分化过程中是否涉及对TGF-β1/Smad信号通路的调控.方法:用5 mg/mL人白蛋白刺激体外培养的HK-2细胞,观察细胞形态变化,RT-PCR法检测α-SMA、E-cadherin、TGF-β1、Smad2 mRNA的表达水平.结果:白蛋白呈时间依赖性诱导α-SMA、TGF-β1、Smad2 mRNA的表达上调,E-cadherin mRNA的表达下调.使用一定浓度的大黄素干预后,明显抑制了白蛋白诱导的上述效应.相关性分析显示:TGF-β1、Smad2 mRNA的表达与α-SMA mRNA的表达呈正相关,与E-cadherin mRNA的表达呈负相关.结论:大黄素抑制人白蛋白诱导的HK-2细胞转分化过程中,TGF-β1/Smad信号通路发挥了重要作用.     

Gli1对TGF-β1诱导的肾小管上皮细胞间质转分化和胶原合成的影响

目的探讨锌指转录因子1(Gli1)对转化生长因子-β1(TGF-β1)诱导的肾小管上皮细胞间质转分化和胶原合成的影响。方法培养肾小管上皮细胞NRK-52E,分为Control、TGF-β1(TGF-β1诱导)、sh-NC+TGF-β1(转染阴性对照shRNA,TGF-β1处理)和sh-Gli1+TGF-β1(转染Gli1 shRNA,TGF-β1处理)组共4组,应用qRT-PCR和Western blot分别检测细胞中Gli1表达水平,ELISA检测细胞培养液上清中纤维连接蛋白(FN)和Ⅰ型胶原酶(ColⅠ)水平,Western blot检测细胞中α-平滑肌肌动蛋白(α-SMA)和Ras相关C3肉毒素底物1(Rac1)蛋白表达水平。结果 TGF-β1组肾小管上皮细胞中Gli1 mRNA和蛋白表达量均高于Control组;肾小管上皮细胞中Gli1 mRNA和蛋白表达量,TGF-β1和sh-NC+TGF-β1组均高于sh-Gli1+TGF-β1组;FN和ColⅠ水平,Control组均低于TGF-β1、sh-NC+TGF-β1和sh-Gli1+TGF-β1组,TGF-β1和sh-NC+TGF-β1组均高于sh-Gli1+TGF-β1组;α-SMA和Rac1蛋白表达,Control组均低于TGF-β1、sh-NC+TGF-β1和sh-Gli1+TGF-β1组,TGF-β1和sh-NC+TGF-β1组均高于sh-Gli1+TGF-β1组,差异有统计学意义(P0.05或P0.01)。结论下调Gli1减弱TGF-β1条件下肾小管上皮细胞间质转分化和胶原合成水平。     

凝血酶敏感蛋白-1在慢性移植肾病大鼠肾组织中的表达及意义

目的:探讨大鼠肾组织凝血酶敏感蛋白-1的表达与慢性移植肾病的关系。方法:依照国际标准CAN实验大鼠模型,以F344大鼠作供者,Lewis大鼠作受者,行原位异体肾移植,建立大鼠CAN模型,作为CAN组。以Lewis大鼠做供、受体,行原位异体肾移植,作为对照组。16周后,观察两组大鼠肾功能、肾组织学改变;免疫组织化学法检测肾组织TSP-1及TGF-β1的表达。结果:与对照组比较,CAN组大鼠24h尿蛋白定量、血肌酐明显升高(P<0.01);根据Banff 97评分标准,对照组未见明显病理改变,而CAN组肾小球硬化率达24%以上,可见明显的肾小管萎缩、间质纤维化及严重的血管内膜纤维化,两组移植肾Banff评分结果差异显著(P<0.01);TSP-1在对照组弱表达,TGF-β1仅有少量表达,而CAN组TSP-1、TGF-β1阳性表达面积显著增强,可见于肾小球系膜细胞、肾小管上皮细胞、肾间质细胞。结论:TSP-1在CAN大鼠移植肾组织中高表达,可能作为TGF-β1的上游分子参与TGF-β1介导的慢性移植肾病变的发生发展。     

糖尿病大鼠肾小管上皮细胞-肌成纤维细胞转分化及氯沙坦对其的影响

【目的】观察糖尿病大鼠肾小管上皮细胞-肌成纤维细胞转分化(TEMT)及氯沙坦干预对其的影响。【方法】雄性Wistar大鼠随机分为正常对照组和糖尿病模型组;后者经STZ诱导糖尿病模型成功后再随机分为糖尿病组和氯沙坦干预组[氯沙坦20mg/(kg·d)]。分别于第8周和第16周时每组各处死5只大鼠。测定24h尿蛋白排泄量、血肌酐;留取肾组织作HE和Masson染色,观察肾小管间质损伤指数、肾间质胶原面积;免疫组织化学法检测肾小管上皮细胞α-平滑肌肌动蛋白(α-SMA)、波形蛋白(Vimentin)和转化生长因子-β1(TGF-β1)表达,并作半定量分析。【结果】①与对照组相比,糖尿病模型组大鼠肾小管间质损伤指数和肾间质胶原面积明显增加(P<0.01);②糖尿病组大鼠肾小管上皮细胞α-SMA、Vimentin和TGF-β1阳性表达均显著高于对照组,α-SMA表达和TGF-β1表达呈正相关(rs=0.810,P<0.01)。③氯沙坦组尿蛋白排泄量、肾小管间质损伤和间质纤维化程度较糖尿病组减轻,肾小管上皮细胞α-SMA、Vimentin与TGF-β1表达强度较糖尿病组显著下调(P<0.01)。【结论】①糖尿病大鼠肾脏病理进程中存在TEMT;②氯沙坦可下调糖尿病大鼠肾小管上皮细胞TGF-β1、Vimentin、α-SMA表达,阻抑糖尿病肾小管上皮细胞发生TEMT而发挥肾脏保护作用。     

肾衰3号颗粒剂对阿霉素肾病大鼠转化生长因子-β1表达的影响

目的:观察慢性肾功能衰竭(CRF)转化生长因子-β1(TGF-β1)的表达,探讨中药肾衰3号颗粒剂缓解CRF恶化的作用机制.方法:60只Wistar大7.5 mg/kg造成阿霉素肾病模型；观察24 h尿蛋白量、血肌酐(SCr)、尿素氮(BUN)、肌酐清除率(CCr)及肾小管间质病理变化;免疫组化法观察TGF-β1、血小板源性生长因子-β(PDGF-β)在肾脏的表达及药物影响.结果:中药高剂量组尿蛋白含量、SCr、BUN改善程度均较其他治疗组明显,与模型组相比差异显著(P均<0.01);肾小管间质病变减轻最为明显;TGF-β1主要表达于肾小球内皮细胞和肾小管上皮细胞,PDGF-β主要表达于肾小球系膜区及肾小管近曲和远曲上皮细胞,且阳性表达率均为各组最低(TGF-β1为25.0%,PDGF-β为33.3%).结论:肾衰3号颗粒剂对CRF的保护作用机制可能是通过下调TGF-β1表达而减少肾小球细胞外基质沉积,下调PDGF-β表达而减少肾小球系膜细胞过度增殖.     

辛伐他汀对高糖培养肾小管上皮细胞RANTES和TGF-β1表达的影响

目的:探讨高糖环境中人近端肾小管上皮细胞(HK-2)RANTES(regulated upon activation normal T cell expressed and secreted)和转化生长因子β1(TGF-β1)表达变化及辛伐他汀(Sim)的干预作用.方法:原代培养HK-2分为正常糖对照组(NG)、甘露醇组(MG)、高糖组(HG)、HG+ Sim 2 μmol/L干预组(HG+Sim2)、HG+Sim 4μmol/L干预组(HG+Sim4),RT-PCR法测定细胞RANTES和TGF-β1 mRNA表达,ELISA法检测细胞上清液中RANTES、TGF-β1蛋白含量.结果:RANTES、TGF-β1的mRNA和蛋白在NG及MG仅有少量表达,而在HG则明显升高(P＜0.05);加入Sim后,上述表达均较前下降(P＜0.05),具有浓度依赖性.各组HK-2表达的RANTES和TGF-β1无论是mRNA还是蛋白之间均存在显著正相关(P＜0.01).结论:高糖促进HK-2 RANTES、TGF-β1的表达,而Sim明显抑制高糖环境中上述因子的过度表达,发挥肾脏保护作用.     

TGF-β1诱导体外培养人肾小管上皮细胞的表型转化

目的观察TGF-β1诱导体外培养人肾小管上皮细胞系HK-2细胞的表型转化。方法免疫细胞化学染色和RT-PCR方法检测TGF-β1诱导培养HK-2细胞,其上皮细胞标记物和间充质细胞标记物表达的改变。结果在TGF-β1浓度分别为1μg/L、5μg/L和10μg/L条件下,诱导培养HK-2细胞48h,免疫细胞化学染色显示各诱导组细胞均出现了间充质细胞标记物α-平滑肌动蛋白(α-SMA)的可疑阳性表达;继续诱导72h,细胞α-SMA阳性表达明确;同时上皮细胞标记物E-钙粘连蛋白表达明显降低甚至消失,广谱角蛋白阳性表达未见明显改变。在TGF-β1浓度为5μg/L诱导组,α-SMA阳性表达为最强。RT-PCR结果也显示TGF-β1诱导42h,HK-2细胞出现了间质细胞标记物α-SMA和波形蛋白mRNA表达的增高,间充质细胞标记物mRNA表达的增高也是以5μg/L TGF-β1组为最明显,上皮细胞标记物细胞角蛋白-19mRNA的阳性表达未见明显改变。结论 TGF-β1可诱导体外培养HK-2细胞出现上皮向间充质细胞的表型转化,表型转化能力与TGF-β1剂量相关。     

白细胞介素-1β在人肾小管上皮细胞转分化中的作用及Janus激酶2抑制剂AG490的影响

目的 探讨Janus激酶2抑制剂AG490对白细胞介素-1β(IL-1β)诱导人肾小管上皮细胞转分化的影响. 方法 将体外培养人肾近曲小管上皮细胞株(HKCs)分为空白对照组、IL-1β(5 ng/ml)刺激组及AG490干预组(IL-1β 5 ng/ml+AG490 10 μmol/L).分别于处理后24、48、72 h收集细胞,采用免疫细胞化学染色和蛋白质免疫印迹法(Western blotting)检测细胞角蛋白-18(CK-18)、α-平滑肌肌动蛋白(α-SMA)蛋白表达. 结果 正常肾小管上皮细胞内其自身标志物CK-18高表达(1.25±0.08),而α-SMA表达很少(0.17±0.01).IL-1β刺激组随刺激时间延长CK-18表达逐渐减少(24 h:0.69±0.04,48 h:0.52±0.03,72 h:0.30±0.01),而α-SMA蛋白合成逐渐增加(24 h:0.56±0.04,48 h:1.05±0.07,72 h:1.43±0.07),与空白对照组比较差异均有统计学意义(均P＜0.05).AG490干预能使CK-18的表达逐渐恢复(24 h:1.07±0.07,48 h:0.93±0.06,72 h:0.83±0.06),并减弱IL-1β对肾小管上皮细胞α-SMA蛋白的诱导作用(24 h:0.33±0.01,48 h:0.52±0.01,72 h:0.61±0.04),且作用显著(均P＜0.05).免疫细胞化学染色观察结果与其一致. 结论 炎症因子IL-1β通过降低肾小管上皮细胞CK-18表达,上调α-SMA表达,促使肾小管上皮细胞转分化为肌成纤维细胞;Janus激酶2抑制剂AG490能部分阻断IL-1β对肾小管上皮细胞的促转分化作用.     

TGF-β1和(或)三氧化二砷作用于HL-60细胞后P27~(Kip1)表达及凋亡情况的研究

本研究观察三氧化二砷(As2O3)和/或TGF-β1对HL-60细胞凋亡及细胞周期的影响,以及作用前后P27Kip1、内源性TGF-β1、cyclinE和BCL-2的变化情况。As2O3和/或TGF-β1作用于HL-60细胞,用细胞形态学观察及流式细胞术检测细胞凋亡和细胞周期改变情况,应用免疫组织化学检测药物处理前后P27Kip1、内源性TGF-β1、cyclinE以及BCL-2表达的变化情况。结果表明:As2O3和TGF-β1单用均可以诱导HL-60细胞发生凋亡,联合处理对HL-60细胞生长抑制作用强于单药处理,其中5μmol/LAs2O3作用最强,5ng/mlTGF-β1处理可引起HL-60细胞的细胞周期阻滞于G1期(p0.05)。5ng/mlTGF-β1和联合处理组P27Kip1的表达较对照组增强(p0.05);5μmol/LAs2O3处理组P27Kip1的表达与对照组比较无明显差异(p0.05)。5ng/mlTGF-β1和联合处理组均可见cyclinE蛋白表达下调(p0.05)。5μmol/LAs2O3和联合处理组可见内源性TGF-β1表达上调(p0.05)。结论:As2O3、外源性TGF-β1均可诱导HL-60细胞凋亡,联合处理组诱导凋亡作用强于对照组和单药处理组,TGF-β1处理可引起HL-60细胞周期阻滞于G1期。TGF-β1诱导HL-60细胞凋亡过程中P27Kip1表达增强,拮抗cyclinE和BCL-2的作用,细胞周期阻滞,诱导细胞发生凋亡,这表明P27Kip1是TGF-β引起细胞周期阻滞的关键效应物,外源性TGF-β1又通过上调内源性TGF-β1的表达增强As2O3诱导原代APL细胞凋亡的作用。     

Genetic polymorphism of cytochrome P450 1A1 (Cyp1A1) and glutathione transferases (M1, T1 and P1) among Africans.

The co-ordinate expression and regulation of the drug metabolising enzymes, cytochrome P4501A1 (CYPlAl) and glutathione transferases (GSTM1, GSTT1 and GSTP1), and their metabolic balance in the cells of target organs may determine whether exposure to carcinogens results in cancer. Besides showing variability in activity due to induction and inhibition, these enzymes also exhibit genetic polymorphism that alter enzyme levels and activity. We determined frequencies of common allelic variants of CYP1A1 and glutathione (M1, T1 and P1) among Tanzanians, South African Venda and Zimbabweans using PCR/restriction fragment length polymorphism techniques. The CYP1A1 Val462 mutant variant was found at a frequency of 1.3% among 114 subjects. The GSTM1*0 genotype was found at a frequency of 29% and 33% among Tanzanian psychiatric patients and healthy volunteers, respectively. Similarly, the GSTT1*0 polymorphism was present with a frequency of 25% in both the psychiatric patients and healthy controls. The frequency of GSTP1 Val105 variant was 16%, 12% and 21% among Tanzanians, South African Venda and Zimbabweans, respectively. We conclude here that CYP1A1 Val462 polymorphism is very rare among Africans. This is the first report of the GSTP1 Val105 variant frequency in African populations. We show here that there are no differences in frequencies of the variant alleles for CYP1A1, GSTM1, GSTT1 and GSTP1 in the three African populations.     

Influenza A (H1N1) vs non-H1N1 ARDS: Analysis of clinical course

Purpose

The purpose of the study is to compare H1N1-induced acute respiratory distress syndrome (ARDS) with ARDS due to other causes of severe community-acquired pneumonia focusing on pulmonary function.

Materials and methods

This is a retrospective data analysis of adult ARDS patients between January 2009 and December 2010 in an ARDS referral center. Patient characteristics, severity of illness scores, modalities, and duration of extracorporeal lung support were evaluated as well as intensive care unit stay and survival. Parameters of mechanical ventilation and pulmonary function were analyzed on day of admission and over the consecutive 10 days using a nonparametric analysis of longitudinal data in a 2-factorial design. In a logistic regression analysis, risk factors for extracorporeal lung support were investigated.

Results

Twenty-one patients with H1N1-ARDS and 41 with non-H1N1-ARDS were identified. Gas exchange was more severely impaired in patients with H1N1-ARDS over course of time. Extracorporeal membrane oxygenation was more frequently needed in H1N1-ARDS. Despite significantly prolonged weaning off extracorporeal lung support and intensive care unit stay in H1N1 patients, the proportion of survivors did not differ significantly. Only Sepsis-Related Organ Failure Assessment score could be identified as an independent predictor of extracorporeal lung support.

Conclusions

Clinical course of H1N1-ARDS is substantially different from non-H1N1-ARDS. Affected patients may require extensive therapy including extracorporeal lung support in ARDS referral centers.