Sterol regulatory element-binding protein-1c knockdown protected INS-1E cells from lipotoxicity
Sterol regulatory element-binding protein-1c knockdown protected INS-1E cells from lipotoxicity
复制标题
甾醇调节元件结合蛋白-1c 敲低可保护 INS-1E 细胞免受脂毒性
DOI：
10.1111/j.1463-1326.2009.01093.x
复制
发表时间：
2010-01-01
影响因子：
5.8
通讯作者：
Tian, H.
中科院分区：
文献类型：
--
作者：
Li, J.;Liu, X.;Tian, H.
研究设计和方法：我们将INS-1 E胰腺β细胞系暴露于棕榈酸或油酸，并测量葡萄糖刺激的胰岛素分泌（GSIS）。FFA对固醇调节元件结合蛋白（SREBP）-1c脂肪生成途径以及参与β细胞功能的基因（包括AMPK）表达的影响（AMP活化蛋白激酶），UCP-2（解偶联蛋白-2），IRS-2（胰岛素受体底物-2），PDX-1检测胰腺十二指肠同源框蛋白1（pancreatic duodenal homeobox-1）、葡萄糖转运蛋白2（glucose transporter-2）和B细胞淋巴瘤/白血病2（Bcl-2）的表达。通过MitoCapture、Annexin V-Cy 3或末端脱氧核苷酸转移酶介导的dUTP缺口末端标记测定来确定这些暴露的细胞的凋亡。通过油红O染色或TG提取来测量细胞脂质积累。结果：FFA处理后INS-1 E细胞SREBP-1c过表达，GSIS受损，脂质积聚，细胞凋亡。另外，在暴露的细胞中，成脂基因和UCP-2的表达上调，而AMPK、IRS-2、PDX-1、GLUT-2和Bcl-2的表达下调。然而，这些脂肪酸的脂毒性作用在很大程度上防止诱导的SREBP-1C小干扰RNA.Conclusions：这些数据表明FFA治疗和SREBP-1C在INS-1 E细胞激活之间的强相关性。SREBP-1c可能是导致β细胞脂毒性的主要因素，并且SREBP-1c敲低可以保护INS-1 E细胞免受脂毒性，这暗示了治疗与脂毒性相关的糖尿病的治疗潜力。
Research design and methods: We exposed INS-1E pancreatic beta-cell line to palmitate or oleate, and measured the glucose stimulated insulin secretion (GSIS). The effect of FFA on sterol regulatory element-binding protein (SREBP)-1c lipogenic pathway, and expression of genes involved in beta-cell functions, including AMPK (AMP-activated protein kinase), UCP-2 (uncoupling protein-2), IRS-2 (insulin receptor substrate-2), PDX-1 (pancreatic duodenal homeobox-1), GLUT-2 (glucose transporter-2) and B cell lymphoma/leukaemia-2 (Bcl-2) were investigated. Apoptosis of these exposed cells was determined by MitoCapture, Annexin V-Cy3 or terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. Cell lipid accumulation was measured by oil red O staining or TG extraction. Also SREBP-1c expression knockdown were used.Results: FFA treatment resulted in SREBP-1c overexpression, impaired GSIS, lipid accumulation, apoptosis of INS-1E cells. In addition, the expression of lipogenic genes and UCP-2 were upregulated, but AMPK, IRS-2, PDX-1, GLUT-2 and Bcl-2 were downregulated in the exposed cells. However, these lipotoxic effects of FFA were largely prevented by induction of a SREBP-1c small interfering RNA.Conclusions: These data suggest a strong correlation between FFA treatment and SREBP-1c activation in INS-1E cells. SREBP-1c might be a major factor responsible for beta-cell lipotoxicity, and SREBP-1c knockdown could protect INS-1E cells from lipotoxicity, which is implicating a therapeutic potential for treating diabetes related to lipotoxicity.