1. LNK promotes granulosa cell apoptosis in PCOS via negatively regulating insulin-stimulated AKT-FOXO3 pathway
- Author
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Min Tan, Dongzi Yang, Dongyong Yang, Yang Ye, Xiaozhu Zhong, Miao Ding, Xiaomiao Zhao, Yanxiang Cheng, Sushi Jiang, and Guijun Guan
- Subjects
Adult ,Aging ,medicine.medical_specialty ,endocrine system ,LNK ,medicine.medical_treatment ,In Vitro Techniques ,Mice ,Young Adult ,Insulin resistance ,Internal medicine ,insulin resistance ,medicine ,Animals ,Humans ,Insulin ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Adaptor Proteins, Signal Transducing ,Mice, Knockout ,Granulosa Cells ,Chemistry ,Forkhead Box Protein O3 ,FOXO3 ,apoptosis ,Cell Biology ,medicine.disease ,Polycystic ovary ,Endocrinology ,Apoptosis ,polycystic ovary syndrome ,Female ,Signal transduction ,Proto-Oncogene Proteins c-akt ,Research Paper ,Signal Transduction - Abstract
Background Polycystic ovary syndrome (PCOS), which is often accompanied by insulin resistance, is closely related to increased apoptosis of ovarian granulosa cells. LNK is an important regulator of the insulin signaling pathway. When insulin binds to the receptor, the PI3K/AKT/FOXO signaling pathway is activated, and FOXO translocates from the nucleus to the cytoplasm, thereby inhibiting the expression of pro-apoptotic genes. Methods Granulosa cells were collected from PCOS patients to investigate the relationship between LNK, cell apoptosis and insulin resistance. KGN cells underwent LNK overexpression/silence and insulin stimulation. The AKT/FOXO3 pathway was studied by western blot and immunofluorescence. LNK knockout mice were used to investigate the effect of LNK on the pathogenesis of PCOS. Results The level of LNK was higher in PCOS group than control group. LNK was positively correlated with granulosa cell apoptosis and insulin resistance, and negatively correlated with oocyte maturation rate. LNK overexpression in KGN cells inhibited insulin-induced AKT/FOXO3 signaling pathway, causing nucleus translocation of FOXO3 and promoting granulosa cell apoptosis. LNK knockout partially restored estrous cycle and improved glucose metabolism in PCOS mice. Conclusions LNK was closely related to insulin resistance and apoptosis of granulosa cells via the AKT/FOXO3 pathway. LNK knockout partially restored estrous cycle and improved glucose metabolism in PCOS mice, suggesting LNK might become a potential biological target for the clinical treatment of PCOS.
- Published
- 2021