Shen Haoran, Xu Xiao, Fu Zhongpeng, Xu Chengjie, Wang Yao
Department of Gynecology, Obstetrics & Gynecology Hospital of Fudan University, Shanghai 200011, PR China.
Department of Obstetrics and Gynecology, Zhongshan Hospital, Fudan University, Shanghai 200032, PR China.
Metabolism. 2022 Jun;131:155164. doi: 10.1016/j.metabol.2022.155164. Epub 2022 Feb 23.
Polycystic ovary syndrome (PCOS) is a hormonal disorder characterized by hyperandrogenism, ovulatory dysfunction, and insulin resistance. Evidence suggests that aberrations in insulin signaling-associated pathways may underlie PCOS pathogenesis. Our aim was to investigate the molecular mechanisms underlying PCOS and associated insulin resistance using in silico analyses, in vitro cell models, and in vivo murine models.
R-based bioinformatics analysis was performed on granulosa cell microarray data from three human cohorts: healthy control, PCOS patients without insulin resistance, and PCOS patients with insulin resistance. Transgenic human granulosa cell models were utilized for in vitro studies. Transgenic murine models of dehydroepiandrosterone (DHEA)-induced PCOS were utilized for in vivo studies.
Sorbin and SH3 Domain Containing 1 (SORBS1), the parent gene of the insulin receptor-associated Casitas B-lineage lymphoma protein (CBL)-associated protein (CAP), is a key downregulated gene in PCOS patients with insulin resistance. CAP binding to CBL reduced CBL phosphorylation, CBL-phosphoinositide 3-kinase (PI3K) p85α interactivity, protein kinase B (Akt) phosphorylation, and NFκB-induced inflammatory marker expression but enhanced CRKII-mediated membrane GLUT4 translocation in granulosa cells. In contrast, the tyrosine kinase Lck/Yes-Related Novel Protein (LYN) is upregulated in PCOS patients with insulin resistance. LYN binding to CBL enhanced CBL phosphorylation, CBL-PI3K p85α interactivity, Akt phosphorylation, and NFκB-induced inflammatory marker expression but did not impact membrane GLUT4 translocation. In PCOS mice, Cap overexpression, Cap transactivation by metformin, or enhancing Cbl-CrkII binding improved insulin sensitivity and ovarian dysfunction (i.e., estrous cycle disruption, cyst-like follicle formation, and sex hormone dysregulation). In contrast, Lyn knockdown, Lyn inhibition by PP2, or CBL-PI3K p85α blockade improved only ovarian dysfunction. Cbl phosphomutant overexpression (which enhances Cbl-CrkII binding but blocks Cbl-PI3K p85α binding) ameliorated both ovarian dysfunction and insulin resistance.
The interactions of CAP and LYN with CBL, and the resulting effects on CBL phosphorylation and activity, may play an important role in PCOS pathogenesis. Targeting these players may be a viable therapeutic strategy for PCOS.
多囊卵巢综合征（PCOS）是一种激素紊乱疾病，其特征为高雄激素血症、排卵功能障碍和胰岛素抵抗。有证据表明，胰岛素信号相关通路的异常可能是PCOS发病机制的基础。我们的目的是使用计算机分析、体外细胞模型和体内小鼠模型来研究PCOS及相关胰岛素抵抗的分子机制。
对来自三个人类队列（健康对照、无胰岛素抵抗的PCOS患者和有胰岛素抵抗的PCOS患者）的颗粒细胞微阵列数据进行基于R的生物信息学分析。利用转基因人类颗粒细胞模型进行体外研究。利用脱氢表雄酮（DHEA）诱导的PCOS转基因小鼠模型进行体内研究。
含Sorbin和SH3结构域蛋白1（SORBS1）是胰岛素受体相关的Casitas B系淋巴瘤蛋白（CBL）相关蛋白（CAP）的母基因，是有胰岛素抵抗的PCOS患者中一个关键的下调基因。CAP与CBL结合可降低CBL磷酸化、CBL-磷脂酰肌醇3激酶（PI3K）p85α相互作用、蛋白激酶B（Akt）磷酸化以及NFκB诱导的炎症标志物表达，但可增强颗粒细胞中CRKII介导的膜葡萄糖转运蛋白4（GLUT4）转位。相反，酪氨酸激酶Lck/Yes相关新蛋白（LYN）在有胰岛素抵抗的PCOS患者中上调。LYN与CBL结合可增强CBL磷酸化、CBL-PI3K p85α相互作用、Akt磷酸化以及NFκB诱导的炎症标志物表达，但不影响膜GLUT4转位。在PCOS小鼠中，Cap过表达、二甲双胍激活Cap或增强Cbl-CrkII结合可改善胰岛素敏感性和卵巢功能障碍（即发情周期紊乱、囊状卵泡形成和性激素失调）。相反，Lyn基因敲低、PP2抑制Lyn或阻断CBL-PI3K p85α仅可改善卵巢功能障碍。Cbl磷酸化突变体过表达（可增强Cbl-CrkII结合但阻断Cbl-PI3K p85α结合）可改善卵巢功能障碍和胰岛素抵抗。
CAP和LYN与CBL的相互作用以及由此对CBL磷酸化和活性产生的影响可能在PCOS发病机制中起重要作用。针对这些因素可能是PCOS一种可行的治疗策略。
