A FISCHER RAT SUBSTRAIN DEFICIENT IN DIPEPTIDYL PEPTIDASE-IV ACTIVITY MAKES NORMAL STEADY-STATE RNA LEVELS AND AN ALTERED PROTEIN - USE AS A LIVER-CELL TRANSPLANTATION MODEL
A FISCHER RAT SUBSTRAIN DEFICIENT IN DIPEPTIDYL PEPTIDASE-IV ACTIVITY MAKES NORMAL STEADY-STATE RNA LEVELS AND AN ALTERED PROTEIN - USE AS A LIVER-CELL TRANSPLANTATION MODEL
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DOI：
10.1042/bj2730497
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发表时间：
1991-02-01
影响因子：
4.1
通讯作者：
DOYLE, D
中科院分区：
文献类型：
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作者：
THOMPSON, NL;HIXSON, DC;DOYLE, D
二肽基肽酶 IV (DPPIV) 是一种丝氨酸外切蛋白酶，在肾、肝和小肠上皮细胞中高水平表达。 最近 Watanabe、Kohima 和 Fujimoto [(1987) Experientia 43, 400-401] 和 Gossrau 等人。 [（1990）组织化学。 J. 22, 172-173]报道Fischer 344大鼠缺乏这种酶。 我们检查了美国和德国供应商提供的 Fischer 344 大鼠中的 DPPIV 表达，发现美国 Fischer 大鼠的肝脏与其德国对应大鼠相比，表达活性 DPPIV (D+)。 Northern 肝脏 RNA 分析显示，美国 D+ 大鼠和德国 (D-) 大鼠的 3.4 kb 和 5.6 kb DPPIV 转录物水平相当。 DPPIV 的单克隆抗体 (MAb) 236.3 免疫沉淀来自表面标记的 D+ 肝细胞的 150 kDa 酶活性（105 kDa，变性）蛋白质，并与小管和窦膜发生反应（如免疫荧光显微镜所示）。 MAb 236.3 无法免疫沉淀 D- 细胞提取物中的标记肽，也无法对 D- 肝切片进行染色。 DPPIV 特异性多克隆抗体 (PAb) 免疫沉淀 D+ 肝细胞提取物中的酶活性肽和 D- 肝细胞提取物中较小的无活性肽。 用 MAb 236.3 和 PAb 从 D+ 提取物中免疫沉淀的 DPPIV 肽图是相同的，但与 PAb 识别的 D- 肝细胞成分的肽图不同。 因此，D-大鼠中DPPIV缺陷的分子基础似乎是缺少由MAb 236.3识别的表位的无酶活性蛋白质的翻译。 我们利用这些 D- 大鼠作为宿主，对 D+ Fischer 大鼠的肝细胞进行同基因移植。 DPPIV 表达在移植细胞中稳定，使它们能够轻松与周围的 D 组织区分开来。
Dipeptidyl peptidase IV (DPPIV) is a serine exoproteinase expressed at high levels in epithelial cells of kidney, liver and small intestine. Recently Watanabe, Kohima & Fujimoto [(1987) Experientia 43, 400-401] and Gossrau et al. [(1990) Histochem. J. 22, 172-173] reported that Fischer 344 rats are deficient in this enzyme. We have examined DPPIV expression in Fischer 344 rats available from U.S. and German suppliers and find that livers of the U.S. Fischer rats, in contrast with their German counterparts, express active DPPIV (D+). Northern analysis of liver RNA showed comparable levels of 3.4 kb and 5.6 kb DPPIV transcripts in both D+ rats from the U.S. and German (D-) rats. Monoclonal antibody (MAb) 236.3 to DPPIV immunoprecipitated a 150 kDa enzymically active (105 kDa, denatured) protein from surface-labelled D+ hepatocytes and reacted with canalicular and sinusoidal membranes (as shown by immunofluorescence microscopy). MAb 236.3 failed to immunoprecipitate a labelled peptide from D- cell extract or to stain D- liver sections. Polyclonal antibody (PAb) specific for DPPIV immunoprecipitated an enzymically active peptide from D+ hepatocyte extracts and a smaller, inactive peptide from D- hepatocyte extracts. Peptide maps of DPPIV immunoprecipitated from D+ extracts with MAb 236.3 and PAb were identical, but differed from that of the D- hepatocyte component recognized by PAb. The molecular basis of the DPPIV deficiency in the D- rats thus appears to be the translation of an enzymically inactive protein missing the epitope recognized by MAb 236.3. We have exploited these D- rats as hosts for syngeneic transplantation of liver cells from D+ Fischer rats. DPPIV expression is stable in the transplanted cells and allows them to be readily distinguished from the surrounding D- tissue.