低密度脂蛋白活化人肾小管上皮细胞促进肾间质成纤维细胞生物学表型的改变  

Human proximal tubular epithelial cells activated by low density lipoprotein promote phenotypic changes in renal interstitial fibroblasts

作　　者：李健[1] 李晓玫[1] 王海燕[1] 

机构地区：[1]北京大学肾脏病研究所北京大学第一医院肾内科,100034

出　　处：《中华医学杂志》2000年第10期787-791,共5页National Medical Journal of China

基　　金：教育部博士点基金!资助项目 (982 0 ) ;跨世纪优秀人才基金!资助项目 (39910 2 10 474 2 31 C0 4)

摘　　要：目的　观察低密度脂蛋白 (LDL)对近曲肾小管上皮细胞 (HK 2 )的作用 ;探讨经LDL活化的HK 2对肾间质成纤维细胞 (RIFB)生物学表型的影响。方法　用3H TdR掺入和细胞计数法评价细胞增殖 ;Northern和Western杂交方法检测α 平滑肌肌动蛋白 (α SM actin) ;间接竞争抑制酶联免疫吸附法测定纤粘连蛋白和层粘连蛋白含量 ;3H 脯氨酸掺入法测定细胞总胶原成分的合成 ;逆转录聚合酶链反应法观察Ⅲ型胶原mRNA表达。结果　LDL(10 0～ 5 0 0 μg/ml)能够促进HK 2细胞增殖 2 2～3 8倍 ,并上调α SM actinmRNA表达 ,使其蛋白质合成增加 1 2～ 2 4倍 ,并促进纤粘连蛋白分泌。LDL刺激的HK 2条件培养液对RIFB的DNA合成无影响 ,但可显著上调细胞内α SM actin的蛋白合成 ;LDL(2 5 0 μg/ml或 5 0 0 μg/ml)刺激的HK 2条件培养液能够促进RIFB总胶原成分的合成、使细胞分泌纤粘连蛋白和层粘连蛋白增加、并能够显著上调Ⅲ型胶原mRNA表达。结论　LDL具有促进HK 2增殖、表型转化和纤粘连蛋白分泌的作用。LDL活化的HK 2能够调节RIFB生物学表型、促进细胞外基质产生。Objective To study the effects of low density lipoprotein (LDL) on human proximal tubular epithelial cells (HK 2), and further examine the effects of HK 2 activated by LDL on phenotypic changes in human renal interstitial fibroblasts (RIFB). Methods 3H thymidine incorporation and direct cell counting were performed to detect cell proliferation. Message RNA and protein of α smooth muscle actin (α SM actin) were analyzed by Northern and Western blot. Fibronectin or laminin levels were determined using an inhibition enzyme linked immunosorbant assay. After exposed to LDL activated HK 2 conditioned media (CM), total collagen synthesis or collagen Ⅲ mRNA expression was measured by proline incorporation or RT PCR in primary cultures of RIFB. Results Incubation of HK 2 with LDL (100～500 μg/ml) for 72 hours stimulated HK 2 proliferation. mRNA expression, protein synthesis of α SM actin and secretory fibronectin level were up regulated by LDL at a concentration of 250 μg/ml. When exposed to CM from LDL treated HK 2, thymidine incorporation rate was not changed in RIFB, but α SM actin production was significantly enhanced. CM from LDL treated HK 2 also showed the stimulated proline incorporation and secretion of fibronectin or laminin. Expression collegen Ⅲ mRNA was up regulated by CM from LDL treated HK 2 cells. Conclusion The results indicate that LDL stimulates HK 2 cells proliferation, phenotypic changes and fibronectin synthesis. Human proximal tubular epithelial cells activated by LDL modulate the phenotype and matrix production in RIFB.

关 键 词：肾疾病 低密度脂蛋白 肾小管上皮细胞 RIFB 

分 类 号：R692[医药卫生—泌尿科学]