EVIDENCE FOR INVOLVEMENT OF PROTEASOME COMPLEX

蛋白酶体复合物参与的证据

• 批准号: 6665848
• 负责人: G KWON
• 金额: $ 15.75万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6665848
• 关键词: biological products; biomedical resource; carbohydrates; cardiovascular system; clinical research; female; gas; human subject; musculoskeletal system; nutrition; nutrition related tag; physical fitness; respiratory system; spectrometry; women's health

Interleukin-1( (IL-1) has been implicated as an effector molecule of (-cell destruction in autoimmune diabetes. IL-1 inhibits insulin secretion from pancreatic (-cells by stimulating the expression of inducible nitic oxice synthase (iNOS) that generates nitric oxide. IL-1 also induces co-expression of the inducible isoform of cyclooxygenase (COX-2) and overproduction of proinflammatory prostaglandins and their precursor arachidonic acid, as demonstrated by isotope dilution mass spectrometry. The current studies characterize the involvement of protease(s) in the signaling pathway of IL-1-induced iNOS and COX-2 expression. Biochemical and molecular studies were performed using the rat insulinoma (-cell line, RINm5F. A serine protease inhibitor, N(-p-tosyl-L-lysine chloromethyl ketone (TLCK) and a proteasome complex (26S) inhibitor, MG 132, inhibited Il-1-induced nitrite formation, an oxidation product of nitric oxide produced by iNOS, in a concentration-dependen t manner. Both TLCK and MG 132 also inhibited iNOS gene expression at the level of mRNA and protein. TLCK and MG 132 also inhibited IL-1 induced COX-2 enzyme activity (PGE2 formation) and COX-2 gene expression at the level of mRNA and protein. In human islets, the proteasome inhibitor, MG 132, also inhibited the formation of the products of iNOS and COX-2 enzyme activity, nitrite and PGE2 respectively. These findings suggested that the inhibitory action of TLCK and MG 132 on iNOS and COX-2 expression precedes transcription. The transcription factor, NF(B, is essential for activation of a number of cytokine-inducible enzymes and was evaluated as a possible site of protease action necessary for IL-1 induced co-expression of iNOS and COX-2. TLCK and MG 132 inhibited both IL-1 induced activation of NF(B and degradatin of 1(B( by islets and RINm5F cells. These results implicate protease activation as an early signaling event in IL-1-induced inhibition of (-cell function.

白介素-1（（IL-1）已被视为效应分子 （ - 自身免疫性糖尿病的细胞破坏。IL-1抑制胰岛素 胰腺的分泌（ - 通过刺激表达 产生一氧化氮的诱导氮氧氧化酶合酶（iNOS）。 IL-1还诱导了诱导同工型的共表达 环氧合酶（COX-2）和促炎性过量 前列腺素及其前体的花生四烯酸，如证明 通过同位素稀释质谱法。 当前的研究 表征蛋白酶在信号通路中的参与 IL-1诱导的iNOS和COX-2表达。 生化和分子 使用大鼠胰岛素瘤（-CELL系，RINM5F）进行研究。 丝氨酸蛋白酶抑制剂N（-p-甲基-l-赖氨酸氯甲基酮 （TLCK）和蛋白酶体复合物（26S）抑制剂Mg 132，抑制 IL-1诱导的亚硝酸盐形成，一氧化氮的氧化产物 由iNOS以浓度依赖性t的方式产生。 TLCK和MG 132也抑制了iNOS基因表达 mRNA和蛋白质水平。 TLCK和MG 132也抑制了IL-1 诱导的COX-2酶活性（PGE2形成）和COX-2基因 mRNA和蛋白质水平的表达。 在人类胰岛中， 蛋白酶体抑制剂Mg 132也抑制了形成 iNOS和COX-2酶活性，亚硝酸盐和PGE2的产品 分别。 这些发现表明 iNOS和COX-2表达上的TLCK和Mg 132先于转录。 转录因子NF（B，对于激活A是必不可少的 细胞因子诱导酶的数量，并被评估为 IL-1诱导的共表达所必需的蛋白酶动作部位 iNOS和COX-2。 TLCK和Mg 132抑制了这两种IL-1诱导 NF的激活（B和1的脱脂蛋白1（B（由胰岛和RINM5F细胞）。 这些结果暗示蛋白酶激活作为早期信号传导 IL-1诱导的抑制（ - 细胞函数）中的事件。