Angiotensin Ⅱ induces the release of inflammation factors via TLR4-MyD88 pathway in rat tubular epithelial cells
10.3760/cma.j.issn.1001-7097.2010.10.012
- VernacularTitle:血管紧张素Ⅱ通过TLR4-MyD88途径诱导大鼠肾小管上皮细胞炎性因子释放
- Author:
Jinlei LV
;
Ruhan JIA
;
Guohua DING
;
Qinkai CHEN
- Publication Type:Journal Article
- Keywords:
Angiotensin Ⅱ;
Tubular epithelial cells;
Toll like receptor 4;
Inflammation factor;
Heat shock protein 47
- From:
Chinese Journal of Nephrology
2010;26(10):780-784
- CountryChina
- Language:Chinese
-
Abstract:
Objective To observe the release of inflammation-related factors after angiotensin Ⅱ (Ang Ⅱ ) stimulation in rat tubular epithelial cells (NRK-52E), to analyze whether these effects were mediated by TLR4-MyD88 pathway, and to reveal the novel mechanism of injury by Ang Ⅱ on NRK-52E cells. Methods After synchronization, cells incubated with AngⅡ (10-7 mmol/L) were used as the stimulation group, cells without stimulation were as normal control. To determine the role of TLR4 and the adaptor MyD88, equal number of NRK-52E cells was added with 10-5 mmol/L candesartan or 20 mg/L TLR4 blocking peptide for 1 h and then incubated with Ang Ⅱ (10-7 mmol/L) respectively. RT-PCR was used to analyze TLR4 mRNA and MyD88 mRNA expression. Immunofluorescence and confocal microscopy were used to observe TLR4 protein expression. ELISA was used to detect the concentration of tumor necrosis factor-alpha (TNF-α) and heat shock protein 47(HSP47) in cell supernatant respectively. Results TLR4 and MyD88 were highly expressed in Ang Ⅱ-induced NRK-52E cells (P＜0.01), and the TNF-α and HSP47 levels were also increased markedly compared with control group (P＜0.01). In NRK-52E cells that were pre-incubated with candesartan, TLR4 and MyD88 expression were obviously inhibited,subsequently, HSP47 and TNF-α production decreased remarkably compared with Ang Ⅱ group (P＜0.01). TLR4 blocking peptide had the similar effect in a dose-dependent manner, in which its effect was dependent on inhibiting TLR4-MyD88 expression. Conclusion The mechanism of Ang Ⅱ -induced injury effect on NRK-52E cells is related to the increase of TLR4-MyD88 activity,which is followed by the enhance of TNF-α and HSP47 expression. This process is inhibited by candesartan via modulation of innate immune pathway.
