PAF通过PKCβ途径对系膜细胞分泌细胞外基质的影响

Effects of PAF on extracellular matrix secreted by mesangial cells by PKCβⅠ pathway

目的探讨血小板活化因子(PAF)是否通过高糖可激活蛋白激酶C-β(PKCβ)途径调节高糖高脂环境下细胞外基质(ECM)的分泌。方法将人肾小球系膜细胞分成6组:正常对照组、PAF组、PAF+LY333531组、高糖高脂组、高糖高脂+PAF组、高糖高脂+PAF+LY333531组;ELISA法测定各组中纤维联接蛋白(Fn)及Ⅳ型胶原(ColⅣ)含量,实时定量PCR测定PKCβⅠmRNA表达水平。结果与正常对照组比较,其他5组Fn、ColⅣ、PKCβⅠmRNA表达增加(P<0.05);与PAF组比较,PAF+LY333531组Fn、ColⅣ、PKCβⅠmRNA表达减少(P<0.05);与高糖高脂+PAF+LY333531组比较,高糖高脂组、高糖高脂+PAF组Fn、ColⅣ、PKCβⅠmRNA表达显著增加(P<0.05)。结论高糖高脂环境下PAF通过促进PKCβⅠ表达刺激Fn、ColⅣ分泌;当加入LY333531时,ECM分泌减少,PKCβⅠ抑制剂对肾脏可能具有一定的保护作用。

Objective To investigate whether platelet activating factor（PAF） regulates extracellular matrix（ECM） secretion in high glucose（HG） and lysophosphatidylcholine （LPC） environment by PKC[5 I pathway. Methods Human glomerular mesangial cells were divided into six groups： normal control group, PAF group, PAF ＋ LY333531 group,HG ＋ LPC group, HG ＋ LPC ＋ PAF group, HG ＋ LPC ＋ PAF ＋ LY333531 group. ELISA assay was used to detect Fn, Col IV content in supernatant of each group. Real-time quantitative PCR was used to deter- mine the expression level of PKCβ I mRNA. Results Compared with normal control group, the expressions of Fn and Col IV and PKCI5 I RNA in other five groups were significantly increased（ P 〈 O. 05 ）. Compared with PAF group, the expressions of Fn and Col IV and PKC~ I RNA in group PAF ＋ LY333531 were decreased（P 〈 O. 05） , and the expressions of Fn and Col IV and PKCD I RNA in groups HG ＋ LPC and HG ＋ LPC ＋ PAF were significantly higher than those in group HG ＋ LPC ＋ PAF ＋ LY333531 （P 〈 O. 05 ）. Conclusion PAF can stimulate the secretion of Fn and Col IV by promoting the expression of PKCβI in the high glucose and high fat environ- ment. When the LY333531 is added, the secretion of ECM is reduced and the PKCβ I inhibitor may have protec- tive effect on the kidney.