低密度脂蛋白对大鼠肾小球系膜细胞分泌系膜基质的影响

The effect of low density lipoproteins on the production of extracellular matrix by cultured rat mesangial cells in vitro

目的应用培养的大鼠肾小球系膜细胞（ＭＳＣ），在体外研究低密度脂蛋白（ＬＤＬ）对ＭＳＣ分泌Ⅳ型胶原以及层粘连蛋白（ＬＮ）ｍＲＮＡ表达的影响。方法用不同浓度人血提纯的ＬＤＬ（０，２５，５０，１００，１５０，２００μｇ／ｍｌ）与第３～１０代转种的大鼠ＭＳＣ共同孵育４８小时后，ＥＬＩＳＡ法测定培养上清液中Ⅳ型胶原的含量，并提取细胞总ＲＮＡ经Ｎｏｒｔｈｅｒｎ杂交检测ＬＮｍＲＮＡ的表达。结果ＬＤＬ在５０μｇ／ｍｌ浓度时即可刺激ＭＳＣ分泌Ⅳ型胶原蛋白，并增加ＬＮｍＲＮＡ的表达，且随ＬＤＬ浓度的增加Ⅳ型胶原的分泌及ＬＮｍＲＮＡ的表达也增加。结论ＬＤＬ可能通过刺激ＭＳＣ产生过多的细胞外基质而在肾小球硬化的过程中起重要作用。

Objective Hyperlipidemia and abnormalities in lipid metabolism may contribute to the progression of renal injury, in which increased LDL was proven to be an important factor. The aim of this study was to determine the effect of LDL on the production of type Ⅳ collagen and mRNA expression of laminin (LN) by cultured rat mesangial cells in vitro. Methods LDL was prepared from normal human plasma. Subconfluent mesangial cells monolayers grown in serum free culture medium for 24 hr were challenged with LDL (0, 25, 50, 100, 150, 200 μg/ml) for 48 hr. Production of type Ⅳ collagen in the culture medium was evaluated with an ELISA kit; total RNA was extracted from mesangial cells treated with all concentrations of LDL, and Northern blotting was performed with cDNA for LN. Results LDL stimulated type Ⅳ collagen production and LN mRNA expression in the concentrtion of 50 μg/ml. Secretion of type Ⅳ collagen and expression of LN mRNA increased as LDL concentration increased. Conclusion LDL may play an important role in the pathogenesis of glomerulosclerosis by stimulating the accumulation of extracellular matrix.