Marti H P, McNeil L, Thomas G, Davies M, Lovett D H
Department of Medicine, San Francisco VAMC-University of California, San Francisco 94121.
Biochem J. 1992 Aug 1;285 ( Pt 3)(Pt 3):899-905. doi: 10.1042/bj2850899.
A polymerase chain reaction (PCR)-based homology cloning strategy was used to define the spectrum of stromelysin-like matrix metalloproteinases (MMPs) synthesized by cultured glomerular mesangial cells (MC). Using this technique, cDNAs encoding an unusual, truncated member of the MMP family, punctuated (putative) metalloproteinase (PUMP-1), were exclusively isolated. Incubation with the cytokines interleukin 1 and tumour necrosis factor increased the abundance of PUMP-1 mRNA in mesangial cells. The mesangial PUMP-1 mRNA is processed in a tissue-specific manner, yielding a transcript containing repeated 3'-untranslated region ATTTA motifs commonly found in cytokines with limited mRNA stability. Polyclonal antibodies prepared against the C-terminal region of the PUMP-1 protein documented release of this enzyme by cultures of cytokine-stimulated MC and permitted identification of PUMP-1-expressing mesangial cells within clinical biopsy specimens of acute glomerulonephritis. These findings represent new molecular and clinical evidence that non-malignant cells process and secrete this unusual member of the MMP family in a cytokine-mediated, tissue-specific manner. Mesangial synthesis of PUMP-1 may contribute to the progression of injury during glomerular inflammatory states.
采用基于聚合酶链反应（PCR）的同源克隆策略来确定培养的肾小球系膜细胞（MC）合成的基质溶解素样基质金属蛋白酶（MMPs）谱。利用该技术，专门分离出了编码MMP家族一个不寻常的截短成员——点状（假定）金属蛋白酶（PUMP-1）的cDNA。用细胞因子白细胞介素1和肿瘤坏死因子孵育可增加系膜细胞中PUMP-1 mRNA的丰度。系膜PUMP-1 mRNA以组织特异性方式进行加工，产生一种转录本，其包含在mRNA稳定性有限的细胞因子中常见的重复3'-非翻译区ATTTA基序。针对PUMP-1蛋白C末端区域制备的多克隆抗体证明了细胞因子刺激的MC培养物释放这种酶，并允许在急性肾小球肾炎的临床活检标本中鉴定表达PUMP-1的系膜细胞。这些发现代表了新的分子和临床证据，即非恶性细胞以细胞因子介导的组织特异性方式加工和分泌MMP家族的这个不寻常成员。PUMP-1的系膜合成可能有助于肾小球炎症状态下损伤的进展。
