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。
