Bouwens L, Lu W G, De Krijger R
Laboratory of Experimental Pathology, Free University Brussels (V.U.B), Belgium.
Diabetologia. 1997 Apr;40(4):398-404. doi: 10.1007/s001250050693.
The morphogenesis and growth of the endocrine pancreas has not been well investigated in man although it represents an important issue in diabetology. We examined human fetal pancreas from 12 to 41 weeks of gestation immunocytochemically to evaluate proliferative activity with the Ki-67 marker, and cytodifferentiation with cytokeratin 19 (ductal cells), synaptophysin (all endocrine cells), and insulin, glucagon, somatostatin and pancreatic polypeptide (islet cell types). Ki-67 labelling was found in all these cell types but was much higher in ductal cells than in islet cells. An intermediate population expressed synaptophysin but lacked islet hormones. With increasing gestational age the Ki-67 labelling index decreased from 17 to 4% in ductal cells, from 9 to 1% in synaptophysin-positive cells, and from 3 to 0.1% in insulin- or glucagon-positive cells. From 12 to 16 weeks, all epithelial cells including the endocrine islet cells expressed cytokeratin 19. Thereafter cytokeratin 19 expression decreased and eventually disappeared from most islet cells, whereas strong expression remained in the ductal cells. We show that differentiated human islet cells have only very limited proliferative capacity, and we demonstrate the existence of transitional differentiation stages between ductal and islet cells.
尽管内分泌胰腺的形态发生和生长在糖尿病学中是一个重要问题，但在人类中尚未得到充分研究。我们对妊娠12至41周的人胎儿胰腺进行了免疫细胞化学检查，以评估用Ki-67标记物的增殖活性，以及用细胞角蛋白19（导管细胞）、突触素（所有内分泌细胞）、胰岛素、胰高血糖素、生长抑素和胰多肽（胰岛细胞类型）的细胞分化。在所有这些细胞类型中都发现了Ki-67标记，但导管细胞中的标记比胰岛细胞中的标记高得多。一个中间群体表达突触素，但缺乏胰岛激素。随着胎龄增加，导管细胞中Ki-67标记指数从17%降至4%，突触素阳性细胞中从9%降至1%，胰岛素或胰高血糖素阳性细胞中从3%降至0.1%。从12至16周，包括内分泌胰岛细胞在内的所有上皮细胞都表达细胞角蛋白19。此后，细胞角蛋白19表达下降，最终在大多数胰岛细胞中消失，而在导管细胞中仍保持强表达。我们表明，分化的人胰岛细胞增殖能力非常有限，并且我们证明了导管细胞和胰岛细胞之间存在过渡分化阶段。
