肾炎大鼠肾小球α-SMA表达与基质增生的关系

The Relationship of Glomerular α SMA Expression to Mesangial Matrix Proliferation in Rat with Nephrotoxic Nephritis

为了进一步了解肾小球α平滑肌肌动蛋白（αｓｍｏｔｈｍｕｓｃｌｅａｃｔｉｎ，αＳＭＡ）的表达与肾炎发病时肾小球基质增生的关系，我们观察了大鼠肾毒血清肾炎（ｎｅｐｈｒｏｔｏｘｉｃｎｅｐｈｒｉｔｉｓ，ＮＴＮ）发病１～１４ｄ肾脏组织形态、肾功能、肾小球αＳＭＡ和血小板衍生的生长因子（ｐｌａｔｅｌｅｔｄｅｒｉｖｅｄｇｒｏｗｔｈｆａｃｔｏｒ，ＰＤＧＦ）以及基质成分纤维连接蛋白（Ｆｉｂｒｏｎｅｃｔｉｎ，ＦＮ）、胶原Ⅲ和Ⅳ型的表达，并对αＳＭＡ、ＰＤＧＦ及基质成分间进行相关性分析。研究显示，ＮＴＮ第３天大鼠肾小球表达αＳＭＡ和ＰＤＧＦ，先于ＦＮ的表达和胶原Ⅳ型的增多。在ＮＴＮ第７和１４天，αＳＭＡ和ＰＤＧＦ表达增加，并且两者间及与ＦＮ和胶原Ⅳ型之间呈显著正相关。在ＮＴＮ各时间点均未能在肾小球中检测出胶原Ⅲ型的存在。研究表明，注射抗血清引起的肾小球免疫损伤刺激肾小球系膜细胞表达αＳＭＡ是系膜细胞被激活后大量分泌基质的标志。系膜区ＰＤＧＦ的分泌进一步加强了系膜细胞αＳＭＡ的表达及基质增生。

Kidney histology, renal function, glomerular α smooth muscle actin (α SMA),Platelet derired growth factor(PDGF), fibronectin(FN),collagen Ⅲ and Ⅳ were detected in rat with nephrotoxic nephritis (NTN) form day 1 to day 14. The correlations between glomerular α SMA expression and mesangial matrix components as well as PDGF were analysed in order to understand further the relationship of glomerular α SMA expression to mesangial matrix proliferation. The results showed that α SMA and PDGF appeared in glomerulus of NTN on day 3 and preceded the appearance of glomerular FN and increase in glomerular collagen Ⅳ. More increaes in glomerular α SMA and PDGF which paralleled with FN and collagen Ⅳ was observed on day 7 and day 14 of NTN. No glomerular expression of collagen Ⅲ was noted in control or NTN rats at any points of time course. Our studies suggested that α SMA was a marker of matrix secretion form mesangial cell after its immuneinsult by nephrotoxic serum. The increase in PDGF in glomerulus enhanced glomerular α SMA expression and mesangial matrix proliferation.