EXPRESSION OF PROTEIN-TYROSINE KINASES IN ISLET CELLS - POSSIBLE ROLE OF THE FLK-1 RECEPTOR FOR BETA-CELL MATURATION FROM DUCT CELLS
EXPRESSION OF PROTEIN-TYROSINE KINASES IN ISLET CELLS - POSSIBLE ROLE OF THE FLK-1 RECEPTOR FOR BETA-CELL MATURATION FROM DUCT CELLS
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DOI：
10.3109/08977199409010985
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发表时间：
1994-01-01
期刊：
影响因子：
1.8
通讯作者：
WELSH, M
中科院分区：
文献类型：
--
作者：
OBERG, C;WALTENBERGER, J;WELSH, M
为了阐明β细胞复制和胰岛素产生的重要基因的表达，以来自不同胰岛素产生细胞的单链cDNA为模板，使用蛋白酪氨酸激酶(PTKs)的特异性引物进行聚合酶链式反应(PCR)。在RINm5F细胞和胎鼠胰岛中，PTK胎肝激酶-1(Flk-1)受体在其他受体和胞浆酪氨酸激酶中均有表达。为了阐明刺激Flk-1受体的可能作用，在该受体的配体血管内皮生长因子(VEGF)存在的情况下，培养胎鼠胰岛样结构。研究发现，血管内皮细胞生长因子可刺激胰岛素含量/胰岛DNA比率和胰岛素在培养液中的积聚，但不影响β细胞的复制速度。为了探讨Flk-1受体在胰腺中的表达定位，对胎儿胰腺连续切片进行了Flk-1和胰岛素的免疫组织化学染色。Flk-1在内皮样细胞和胰管衬里细胞中有表达。后者被认为含有内分泌胰腺的前体细胞。总之，特定的蛋白酪氨酸激酶在胰岛细胞中表达，并可能参与胰岛功能的调节。具体地说，受体PTK Flk-1可能在胰管细胞的β细胞成熟过程中发挥作用。
To elucidate the expression of genes of importance for beta-cell replication and the production of insulin, single-stranded cDNAs from different preparations of insulin producing cells were used as template for the polymerase chain reaction (PCR) using primers specific for protein tyrosine kinases (PTKs). In RINm5F cells, as well as in fetal rat islets, the receptor PTK fetal liver kinase-1 (Flk-1) was expressed among other receptor and cytoplasmic tyrosine kinases. To elucidate the putative effects of stimulation of the Flk-1 receptor, fetal rat islet-like structures were cultured in the presence of the ligand for this receptor, vascular endothelial growth factor (VEGF). VEGF was found to stimulate both the insulin content/ islet DNA ratio and the accumulation of insulin in the culture medium without affecting the rates of beta-cell replication. To investigate the localization of expression of the Flk-1 receptor in the pancreas, serial sections of fetal pancreata were immunostained for Flk-1 and insulin. Expression of Flk-1 was detected in endothelial-like cells and cells lining pancreatic ducts. The latter are considered to contain precursor cells for the endocrine pancreas. In conclusion, specific protein tyrosine kinases are expressed in islet cells, and are presumably participating in the regulation of islet function. Specifically, the receptor PTK Flk-1 may play a role of beta-cell maturation from pancreatic duct cells.