胰岛素受体底物2(IRS2)是一种在胰岛素信号传导中发挥关键作用的蛋白质,是胰岛素受体底物家族的一员。IRS2在多种细胞类型中表达,包括胰腺β细胞、大脑神经元、脂肪细胞等。它通过与胰岛素受体结合,激活下游的磷脂酰肌醇3激酶(PI3K)/Akt信号通路,从而调节细胞生长、代谢和生存。IRS2的异常表达或功能改变与多种疾病的发生发展相关,包括2型糖尿病、阿尔茨海默病、肥胖症等。
IRS2在胰腺β细胞中表达,参与β细胞的生长、分化和功能维持。研究表明,激活转录因子3(ATF3)是一种应激诱导的促凋亡基因,可以下调IRS2基因的表达,导致β细胞凋亡,从而在糖尿病的发生发展中发挥作用[1]。此外,IRS2还参与神经系统的发育和功能。研究表明,在记忆形成过程中,IRS2基因的表达水平会发生变化,提示胰岛素/IGF系统在神经激活的早期阶段发挥作用[2]。
IRS2基因多态性也与多种疾病相关。研究发现,IRS2基因变异与胰岛素抵抗和心外膜脂肪(EF)厚度相关,而EF厚度与内脏脂肪、认知能力和代谢心血管疾病风险相关[3]。此外,IRS2基因多态性还与多囊卵巢综合征(PCOS)的临床特征相关,如高雄激素血症、胰岛素抵抗、多囊卵巢形态和肥胖[4]。IRS2还参与调节牛奶脂肪的合成。研究表明,miR-200a可以通过靶向IRS2抑制PI3K/Akt信号通路,从而调节牛奶脂肪的合成[5]。
IRS2的缺失会导致年轻成年雄性小鼠在C57BL/6J遗传背景下出现海马相关行为改变,包括能量和营养传感器(如AMPK和GLUT3)的异常改变、核心体温降低以及脑内温度传感器异常改变[6]。此外,IRS2缺失还会导致胰岛素受体、胰岛素受体底物1和2、胰岛素诱导基因1和2、Ras相关蛋白和脑特异性血管生成抑制剂1相关蛋白2基因表达的改变,以及缺氧和葡萄糖或谷氨酰胺剥夺对基因表达的影响[7]。
miR-181b也可以通过靶向IRS2抑制TAG合成,并通过调节Hippo通路中的多个基因,如LATS1和YAP1,来调节脂肪代谢[8]。IRS2在雌性生殖系统中也发挥着重要作用。研究表明,IRS2在雌性小鼠的卵巢、输卵管和子宫中均有表达,并且其表达水平随着发情周期的变化而变化[9]。
综上所述,IRS2是一种在多种生物学过程中发挥重要作用的蛋白质。IRS2的异常表达或功能改变与多种疾病的发生发展相关,包括2型糖尿病、阿尔茨海默病、肥胖症等。IRS2的研究有助于深入理解胰岛素信号传导的生物学功能和疾病发生机制,为疾病的治疗和预防提供新的思路和策略[1-9]。
参考文献:
1. Li, Dan, Yin, Xin, Zmuda, Erik J, White, Morris F, Hai, Tsonwin. 2007. The repression of IRS2 gene by ATF3, a stress-inducible gene, contributes to pancreatic beta-cell apoptosis. In Diabetes, 57, 635-44. doi:. https://pubmed.ncbi.nlm.nih.gov/18057093/
2. Shvadchenko, Anastasia M, Volobueva, Maria N, Ivanova, Violetta O, Bal, Natalia V, Balaban, Pavel M. . New Context Significantly Changes Expression of Irs2 Gene in Hippocampal Areas. In Biochemistry. Biokhimiia, 87, 1243-1251. doi:10.1134/S0006297922110037. https://pubmed.ncbi.nlm.nih.gov/36509718/
3. Mazzoccoli, Gianluigi, Dagostino, Mariangela Pia, Paroni, Giulia, Greco, Antonio, De Cosmo, Salvatore. 2017. Analysis of MTNR1B gene polymorphisms in relationship with IRS2 gene variants, epicardial fat thickness, glucose homeostasis and cognitive performance in the elderly. In Chronobiology international, 34, 1083-1093. doi:10.1080/07420528.2017.1340894. https://pubmed.ncbi.nlm.nih.gov/28708046/
4. Gu, Heng, Li, Longyu, Zhou, Bingyi, Wei, Xiangcai, Zhong, Xingmin. . Single nucleotide polymorphisms in binding site of miRNA-135a and targeted gene IRS2 are correlated with multiple clinical features of PCOS: A study in Chinese women. In Technology and health care : official journal of the European Society for Engineering and Medicine, 30, 71-80. doi:10.3233/THC-228007. https://pubmed.ncbi.nlm.nih.gov/35124585/
5. Tan, Jianbing, Yang, Benshun, Qiu, Liang, Zan, Linsen, Yang, Wucai. 2024. Bta-miR-200a Regulates Milk Fat Biosynthesis by Targeting IRS2 to Inhibit the PI3K/Akt Signal Pathway in Bovine Mammary Epithelial Cells. In Journal of agricultural and food chemistry, 72, 16449-16460. doi:10.1021/acs.jafc.4c02508. https://pubmed.ncbi.nlm.nih.gov/38996051/
6. Tanokashira, Daisuke, Wang, Wei, Maruyama, Megumi, White, Morris F, Taguchi, Akiko. 2021. Irs2 deficiency alters hippocampus-associated behaviors during young adulthood. In Biochemical and biophysical research communications, 559, 148-154. doi:10.1016/j.bbrc.2021.04.101. https://pubmed.ncbi.nlm.nih.gov/33940386/
7. O'Brien, R M, Streeper, R S, Ayala, J E, Stadelmaier, B T, Hornbuckle, L A. . Insulin-regulated gene expression. In Biochemical Society transactions, 29, 552-8. doi:. https://pubmed.ncbi.nlm.nih.gov/11498027/
8. Minchenko, D O, Kharkova, A P, Hubenia, O V, Minchenko, O H. . Insulin receptor, IRS1, IRS2, INSIG1, INSIG2, RRAD, and BAIAP2 gene expressions in glioma U87 cells with ERN1 loss of function: effect of hypoxia and glutamine or glucose deprivation. In Endocrine regulations, 47, 15-26. doi:. https://pubmed.ncbi.nlm.nih.gov/23363253/
9. Chen, Zhi, Shi, HuaiPing, Sun, Shuang, Cao, DuoYao, Luo, Jun. 2016. MicroRNA-181b suppresses TAG via target IRS2 and regulating multiple genes in the Hippo pathway. In Experimental cell research, 348, 66-74. doi:10.1016/j.yexcr.2016.09.004. https://pubmed.ncbi.nlm.nih.gov/27616141/