Rougier J P, Moullier P, Piedagnel R, Ronco P M
Institut National de la Santé et de la Recherche Médicale, Unit 64, Hôpital Tenon, Paris, France.
Kidney Int. 1997 Jan;51(1):337-47. doi: 10.1038/ki.1997.42.
Peritoneal mesothelial cells are directly exposed to hyperosmolar dialysates which may enhance extracellular matrix accumulation and hence compromise ultrafiltration. Because these cells are laid on a type IV collagen containing basement membrane, we examined the pattern of type IV collagenases produced by cultured human mesothelial cells and their regulation by hyperosmolality and TGF beta 1. A cell line (HMrSV5) exhibiting major features of normal peritoneal mesothelial cells was derived from a primary culture retrovirally transduced with SV40 large-T antigen. Zymography and Western blot analysis showed that: (i) human peritoneal mesothelial cells produced and excreted MMP2 and MMP9 and their inhibitors TIMP1 and TIMP2; (ii) hyperosmolality drastically reduced the expression of MMP9 irrespective of the osmolyte used in a time- and concentration-dependent manner; (iii) TGF beta 1 unexpectedly increased MMP9 activity and protein in exponentially growing cells and could restore MMP9 activity suppressed by hyperosmolality in confluent cultures. To exclude a specific effect of SV40 large-T antigen on matrix metalloproteinases production and regulation, these results were confirmed in primary cultures derived from visceral peritoneal samples from different donors. Therefore, the hyperosmolality of dialysates may favor an accumulation of type IV collagen and thickening of peritoneal basement membrane, while TGF beta 1 released during infections may induce the degradation of type IV collagen and its replacement by interstitial collagens.
腹膜间皮细胞直接暴露于高渗透析液中，这可能会增强细胞外基质的积累，从而损害超滤功能。由于这些细胞位于含有IV型胶原的基底膜上，我们研究了培养的人腹膜间皮细胞产生的IV型胶原酶模式及其受高渗和转化生长因子β1（TGFβ1）的调节情况。一种表现出正常腹膜间皮细胞主要特征的细胞系（HMrSV5）源自用SV40大T抗原进行逆转录病毒转导的原代培养物。酶谱分析和蛋白质印迹分析表明：（i）人腹膜间皮细胞产生并分泌基质金属蛋白酶2（MMP2）和基质金属蛋白酶9（MMP9）及其抑制剂金属蛋白酶组织抑制因子1（TIMP1）和金属蛋白酶组织抑制因子2（TIMP2）；（ii）高渗以时间和浓度依赖性方式显著降低MMP9的表达，而与所用的渗透剂无关；（iii）TGFβ1意外地增加了指数生长细胞中MMP9的活性和蛋白含量，并能恢复汇合培养物中被高渗抑制的MMP9活性。为了排除SV40大T抗原对基质金属蛋白酶产生和调节的特异性影响，在来自不同供体的脏腹膜样本的原代培养物中证实了这些结果。因此，透析液的高渗可能有利于IV型胶原的积累和腹膜基底膜的增厚，而感染期间释放的TGFβ1可能诱导IV型胶原的降解并被间质胶原所取代。
