Zenilman M E, Chen J, Magnuson T H
Department of Surgery, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York 10461, USA.
Pancreas. 1998 Oct;17(3):256-61. doi: 10.1097/00006676-199810000-00005.
The pancreatic regenerating gene (reg I) is expressed in the exocrine pancreas and is involved in islet regeneration. Reg I protein has been shown to be mitogenic to beta- and ductal cell lines, but not mature islets. In this study, we tested the effect of two isolates of reg I on primary cultures of ductal cells. Rat pancreatic ductal cells were isolated by collagenase digestion and isolated colonies were maintained in culture. The cells were proven to be ductal in origin by their morphology and by immunofluorescent staining with epithelial markers. Reg I was isolated from human pancreatic extracts or from the rat acinar cell line AR42J by sequential ammonium sulfate precipitation and acid precipitation. Cells were cultured with doses of reg I for 72 h, pulsed with 10 microM bromodeoxyuridine (BrdU) for 2 h. After fixation, nuclei were double-stained with propidium iodide and BrdU monoclonal antibody. The percentages of nuclei positive for BrdU were calculated from at least five colonies per group. A 10-nM concentration of human reg I increased BrdU incorporation by 2.3-fold over controls, rat reg I increased it by 1.4-fold (p < 0.05). When compared to their effects on the ductal cell line ARIP, both human and rat reg I were 100 times more potent on the primary cultures of ductal cells. We conclude that human and rat reg I proteins are mitogenic to primary cultures of ductal cells. Although principally a product of the acinar cell, reg I appears to be a stimulus of ductal cell growth and, in this fashion, may modulate the expansion of the pancreatic ductal population during islet regeneration.
胰腺再生基因（reg I）在外分泌胰腺中表达，并参与胰岛再生。Reg I蛋白已被证明对β细胞系和导管细胞系有促有丝分裂作用，但对成熟胰岛无此作用。在本研究中，我们测试了两种reg I分离物对导管细胞原代培养物的影响。通过胶原酶消化分离大鼠胰腺导管细胞，并将分离的集落维持在培养中。通过细胞形态学以及用上皮标志物进行免疫荧光染色，证明这些细胞起源于导管。通过连续硫酸铵沉淀和酸沉淀从人胰腺提取物或大鼠腺泡细胞系AR42J中分离出Reg I。细胞用不同剂量的reg I培养72小时，用10微摩尔溴脱氧尿苷（BrdU）脉冲处理2小时。固定后，细胞核用碘化丙啶和BrdU单克隆抗体进行双重染色。从每组至少五个集落中计算BrdU阳性细胞核的百分比。10纳摩尔浓度的人reg I使BrdU掺入量比对照增加2.3倍，大鼠reg I使其增加1.4倍（p<0.05）。与它们对导管细胞系ARIP的作用相比，人和大鼠reg I对导管细胞原代培养物的作用效力均高100倍。我们得出结论，人和大鼠reg I蛋白对导管细胞原代培养物有促有丝分裂作用。尽管reg I主要是腺泡细胞的产物，但它似乎是导管细胞生长的刺激物，并且以这种方式可能在胰岛再生过程中调节胰腺导管群体的扩增。
