TYROSINE KINASE INVOLVEMENT IN IL-1-BETA-INDUCED EXPRESSION OF INOS BY BETA-CELLS PURIFIED FROM ISLETS OF LANGERHANS
TYROSINE KINASE INVOLVEMENT IN IL-1-BETA-INDUCED EXPRESSION OF INOS BY BETA-CELLS PURIFIED FROM ISLETS OF LANGERHANS
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DOI：
10.1152/ajpcell.1994.267.1.c48
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发表时间：
1994-07-01
影响因子：
--
通讯作者：
MCDANIEL, ML
中科院分区：
文献类型：
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作者：
CORBETT, JA;KWON, G;MCDANIEL, ML
一氧化氮被认为介导细胞因子对大鼠和人胰岛葡萄糖刺激的胰岛素分泌的抑制作用。本研究的目的是：1）确定细胞因子刺激后胰岛中表达的细胞因子诱导型一氧化氮合酶（iNOS）亚型的细胞来源; 2）确定酪氨酸激酶活性是否参与细胞因子诱导的iNOS表达。在这份报告中，我们证明了细胞因子白细胞介素-1 β（IL-1 β）刺激iNOS的表达和一氧化氮的形成（确定由亚硝酸盐形成，一氧化氮的稳定氧化产物）由分离的完整大鼠胰岛和原代β细胞纯化的荧光激活细胞分选（FACS）。mRNA转录抑制剂放线菌素D可抑制IL-1 β诱导的iNOS表达和亚硝酸盐形成。IL-1 β不诱导诱导表达iNOS的FACS纯化的α-细胞的其他主要的内分泌细胞类型的胰岛。酪氨酸激酶抑制剂染料木黄酮和除莠霉素A阻止IL-1 β诱导的免疫可沉淀iNOS的表达和胰岛、胰岛素瘤RINm 5 F细胞和FACS纯化的β细胞的亚硝酸盐释放。通过对从RINm 5 F细胞中分离的总RNA进行北方印迹分析，证实了除草霉素A和染料木黄酮也可阻止IL-1 β诱导的iNOS mRNA积累。这些发现表明酪氨酸激酶活化参与了IL-1 β诱导的胰岛素分泌β细胞表达iNOS。胰岛素分泌β细胞特异性表达iNOS引起了人们对一氧化氮可能参与自身免疫性糖尿病病因学过程中发生的β细胞选择性破坏的可能性的兴趣。
Nitric oxide is believed to mediate the inhibitory effects of cytokines on glucose-stimulated insulin secretion by both rat and human islets. The aims of this study were 1) to determine the cellular source of the cytokine-inducible isoform of nitric oxide synthase (iNOS) expressed in islets following cytokine stimulation and 2) to determine whether tyrosine kinase activity participates in cytokine-induced iNOS expression. In this report we demonstrate that the cytokine interleukin-1 beta (IL-1 beta) stimulates the expression of iNOS and the formation of nitric oxide (as determined by nitrite formation, a stable oxidative product of nitric oxide) by isolated intact rat islets and by primary beta-cells purified by fluorescence-activated cell sorting (FACS). Both the expression of iNOS and nitrite formation induced by IL-1 beta were prevented by the mRNA transcriptional inhibitor actinomycin D. IL-1 beta did not induce the expression of iNOS by FACS-purified alpha-cells the other major endocrine cell type of the islet. The tyrosine kinase inhibitors genistein and herbimycin A prevented IL-1 beta-induced expression of immunoprecipitable iNOS and nitrite release by islets, by insulinoma RINm5F cells, and by FACS-purified beta-cells. Herbimycin A and genistein also prevented IL-1 beta-induced iNOS mRNA accumulation as determined by Northern blot analysis of total RNA isolated from RINm5F cells. These findings indicate tyrosine kinase activation participates in IL-1 beta-induced expression of iNOS by the insulin-secreting beta-cell. Specific expression of iNOS by the insulin-secreting beta-cell raises interest in the possibility that nitric oxide may participate in selective destruction of beta-cells that occurs during the etiology of autoimmune diabetes.