p38MAPK介导的血管紧张素Ⅱ的促肝星状细胞增殖作用

p38 MAPK-mediated proliferation-promoting effect of angiotensin Ⅱ on hepatic stellate cells

目的:探讨血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)促进肝星状细胞(hepatic stellate cell,HSC)增殖的相关信号机制.方法:原代培养HSC,应用Western blot检测血管紧张素Ⅱ对HSC p38丝裂原活化蛋白激酶(p38 mitogen-activated protein kinases,p38 MAPK)表达的影响.并应用p38 MAPK抑制剂SB203580与HSC共培养,观察p38 MAPK抑制剂对血管紧张素Ⅱ促进HSC分泌转化生长因子-β1(transforming growth factor-β1,TGF-β1)以及增加β1(Ⅰ)、β1(Ⅳ)型胶原(Col)表达的影响.结果:Western blot结果显示不同浓度的AngⅡ(10-8、10-7、10-6moL/L)作用24h后,HSC p38MAPK的相对含量明显增高(0.45±0.052,0.61±0.026,0.87±0.032),与正常对照组(0.27±0.020)相比具有统计学差异(P<0.0005).与正常对照组相比,10-6moL/L AngⅡ作用24h后能够明显促进HSC增殖(0.1073±0.0093vs0.5233±0.0240,P<0.0005);促进TGF-β1分泌(10.6ng/mL±0.98ng/mL vs100.8ng/mL±3.67ng/mL,P<0.0005);促进α1(Ⅰ)、α1(Ⅳ)Col mRNA表达(1.13±0.053vs3.74±0.047;1.35±0.035vs4.07±0.072,P<0.0005).但当加入SB203580预先阻断p38MAPK活性后,AngⅡ引起的上述作用明显减弱(0.2033±0.0176vs0.5233±0.0240;21.07ng/mL±2.08ng/mL vs100.8ng/mL±3.67ng/mL;1.16±0.024vs3.74±0.047;1.56±0.075vs4.07±0.072,P<0.0005).结论:AngⅡ通过p38MAPK通路促进HSC增殖和TGF-β1分泌.

AIM： To elucidate the signal transduction mech- anism by which angiotensin Ⅱ promotes the proliferation of hepatic stellate cells （HSCs）. METHODS： The influence of angiotensin Ⅱ on p38 MAPK expression in primarily cultured HSCs was detected by Western blot. The p38 MAPK inhibitor SB203580 was incubated with HSCs to observe its effect on angiotensin Ⅱ -induced transforming growth factor-β （TGF-β） secretion and collagen I and IV expression. RESULTS： Western blot analysis showed that, compared to the normal saline group, treatment with angiotensin Ⅱ （10-8, 10-7, 10-6 rnoL/L） for24 h significantly induced p38 MAPK expression （0.45 ± 0.052, 0.61 ± 0.026, 0.87 ± 0.032 vs 0.27 ± 0.020, all P 〈 0.0005）. Compared to the normal saline group, treatment with angiotensin Ⅱ （10-6 moL/L） for 24 h significantly induced HSC proliferation （0.1073 ± 0.0093 vs 0.5233 ± 0.0240, P 〈 0.0005）, promoted incretion of TGF-βI （10.6 ng/mL ± 0.98 ng/mL vs 100.8 ng/mL ± 3.67 ng/ mL, P 〈 0.0005）, and increased the expression of collagen β1（ I ） and β1（1X7） （1.13 ± 0.053 vs 3.74 ± 0.047; 1.35 ± 0.035 vs 4.07 ± 0.072; both P 〈 0.0005）. Pre-treatment with SB203580 significantly atten- uated the effect of angiotensin Ⅱ on the above parameters in HSCs （0.2033 ± 0.0176 vs 0.5233 ± 0.0240; 21.07 ng/mL ± 2.08 ng/mL vs 100.8 ng/ mL ± 3.67 ng/mL; 1.16 ± 0.024 vs 3.74 ± 0.047; 1.56 ± 0.075 vs 4.07 ± 0.072, all P 〈 0.0005）.CONCLUSION： Angiotensin Ⅱ induces HSC proliferation and increases expression of TGFq31 via the p38 MAPK pathway.