Tang Tian-feng, Zhou Qiao-ling, Zhu Li-li, Tang Rong, Ao Xiang
Department of Nephrology, Xiangya Hospital, Central South University, Changsha 410008, China.
Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2008 Oct;33(10):958-65.
To determine the mechanism of Toll-like receptor 4(TLR4) in hypertensive renal injury and the protective effect of fosinopril(Fos) and losartan(Los).
NRK-52E was incubated into 5 groups: NRK-52E (normal control), NRK-52E+AngII, NRK-52E+AngII+Fos(10(-5) mmol/L),and NRK-52E+AngII+Los(10(-5) mmol/L), NRK-52E +AngII+Fos(10(-5) mmol/L)+Los(10(-5) mmol/L). TLR4-specific RNAi plasmids were stably transfected into NRK-52E. After 24 h, TLR4, IL-6, and TNF-alpha mRNAs were examined by reverse transcription-polymerase chain reaction(RT-PCR). TLR4 proteins were detected by Western blot, NF-kappaB nuclear translocations were tested by immunocytochemistry,and IL-6 and TNF-alpha supernatant levels were tested by enzyme linked immuno-sorbent assay(ELISA).
TLR4, NF-kappaB, IL-6,and TNF-alpha were highly expressed in AngII induced NRK-52E(P<0.01). In NRK-52E that was stably transfected TLR4-special RNAi plamids, TLR4 protein and mRNA expression were obviously inhibited(P<0.05). After stimulation by AngII, the TLR4, IL-6, TNF-alpha levels in the stabe transfection group were increased compared with the normal group(P<0.05). Fos or/and Los down-regulated TLR4, IL-6, and TNF-alpha expressions(P<0.05), but no cooperation was observed.
TLR4 may lead to inflammatory reaction in hypertensive renal injury. Fos or/and Los can decrease the expressions of TLR4 and correlate inflammatory factors, which may be part of the renal protective mechanism.
探讨Toll样受体4(TLR4)在高血压肾损伤中的作用机制以及福辛普利(Fos)和氯沙坦(Los)的保护作用。
将NRK-52E细胞分为5组:NRK-52E(正常对照组)、NRK-52E+AngII、NRK-52E+AngII+Fos(10⁻⁵ mmol/L)、NRK-52E+AngII+Los(10⁻⁵ mmol/L)、NRK-52E+AngII+Fos(10⁻⁵ mmol/L)+Los(10⁻⁵ mmol/L)。将TLR4特异性RNA干扰质粒稳定转染至NRK-52E细胞。24小时后,采用逆转录-聚合酶链反应(RT-PCR)检测TLR4、IL-6和TNF-α mRNA;采用蛋白质印迹法检测TLR4蛋白;采用免疫细胞化学法检测NF-κB核转位;采用酶联免疫吸附测定(ELISA)检测IL-6和TNF-α上清液水平。
TLR4、NF-κB、IL-6和TNF-α在AngII诱导的NRK-52E细胞中高表达(P<0.01)。在稳定转染TLR4特异性RNA干扰质粒的NRK-52E细胞中,TLR4蛋白和mRNA表达明显受到抑制(P<0.05)。AngII刺激后,稳定转染组的TLR4、IL-6、TNF-α水平较正常组升高(P<0.05)。Fos或/和Los下调TLR4、IL-6和TNF-α的表达(P<0.05),但未观察到协同作用。
TLR4可能导致高血压肾损伤中的炎症反应。Fos或/和Los可降低TLR4及相关炎症因子的表达,这可能是其肾脏保护机制的一部分。