scholarly journals Local Cortisol Elevation Contributes to Endometrial Insulin Resistance in Polycystic Ovary Syndrome

2018 ◽  
Vol 103 (7) ◽  
pp. 2457-2467 ◽  
Author(s):  
Jia Qi ◽  
Wangsheng Wang ◽  
Qinling Zhu ◽  
Yaqiong He ◽  
Yao Lu ◽  
...  

Abstract Context Endometrial insulin resistance (IR) may account for the endometrial dysfunction in polycystic ovary syndrome (PCOS). The underlying mechanism remains to be elucidated. Objective To investigate whether the abundance of 11β-hydroxysteroid dehydrogenases (11β-HSDs) 1 and 2 and cortisol as well as the insulin signaling pathway are altered in PCOS endometrium and to clarify the relationship between endometrial IR and local cortisol. Design We measured cortisol and cortisone concentrations, 11β-HSD1 and 11β-HSD2, and core insulin signaling molecules in endometrial biopsies collected from non-PCOS and PCOS with or without IR patients on the seventh day after human chorionic gonadotropin injection. We also studied the effects of cortisol on glucose uptake and the insulin signaling pathway in primary cultured endometrial epithelial cells (EECs). Results The cortisol concentration was elevated, whereas 11β-HSD2 expression was diminished in endometrial biopsies obtained from PCOS with IR patients compared with those from non-PCOS and PCOS without IR patients. The implantation rate was relatively impaired and the endometrial insulin signaling pathway was defective in PCOS with IR patients. In addition, cortisol attenuated insulin-stimulated glucose uptake in EECs, which was mediated by inhibition of Akt phosphorylation and glucose transporter type 4 translocation via induction of phosphatase and tensin homolog deleted on chromosome ten (PTEN). Conclusions Decreased oxidation of cortisol and defects of insulin signaling in endometrium were observed in PCOS with IR patients. The excessive cortisol level, derived from the reduction of 11β-HSD2, might contribute to the development of endometrial IR by inhibiting the insulin signaling pathway via induction of PTEN expression in EECs.

2009 ◽  
Vol 16 (3-4) ◽  
pp. 129-136 ◽  
Author(s):  
Romina Fornes ◽  
Paulina Ormazabal ◽  
Carlos Rosas ◽  
Fernando Gabler ◽  
David Vantman ◽  
...  

PLoS ONE ◽  
2020 ◽  
Vol 15 (8) ◽  
pp. e0235404 ◽  
Author(s):  
Hongying Kuang ◽  
Yuwei Duan ◽  
Dan Li ◽  
Yanwen Xu ◽  
Wenxia Ai ◽  
...  

1998 ◽  
Vol 274 (5) ◽  
pp. R1446-R1453 ◽  
Author(s):  
T. S. David ◽  
P. A. Ortiz ◽  
T. R. Smith ◽  
J. Turinsky

Rat epididymal adipocytes were incubated with 0, 0.1, and 1 mU sphingomyelinase/ml for 30 or 60 min, and glucose uptake and GLUT-1 and GLUT-4 translocation were assessed. Adipocytes exposed to 1 mU sphingomyelinase/ml exhibited a 173% increase in glucose uptake. Sphingomyelinase had no effect on the abundance of GLUT-1 in the plasma membrane of adipocytes. In contrast, 1 mU sphingomyelinase/ml increased plasma membrane content of GLUT-4 by 120% and produced a simultaneous decrease in GLUT-4 abundance in the low-density microsomal fraction. Sphingomyelinase had no effect on tyrosine phosphorylation of either the insulin receptor β-subunit or the insulin receptor substrate-1, a signaling molecule in the insulin signaling pathway. It is concluded that the incubation of adipocytes with sphingomyelinase results in insulin-like translocation of GLUT-4 to the plasma membrane and that this translocation does not occur via the activation of the initial components of the insulin signaling pathway.


2010 ◽  
Vol 206 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Eliana H Akamine ◽  
Anderson C Marçal ◽  
João Paulo Camporez ◽  
Mara S Hoshida ◽  
Luciana C Caperuto ◽  
...  

Besides the effects on peripheral energy homeostasis, insulin also has an important role in ovarian function. Obesity has a negative effect on fertility, and may play a role in the development of the polycystic ovary syndrome in susceptible women. Since insulin resistance in the ovary could contribute to the impairment of reproductive function in obese women, we evaluated insulin signaling in the ovary of high-fat diet-induced obese rats. Female Wistar rats were submitted to a high-fat diet for 120 or 180 days, and the insulin signaling pathway in the ovary was evaluated by immunoprecipitation and immunoblotting. At the end of the diet period, we observed insulin resistance, hyperinsulinemia, an increase in progesterone serum levels, an extended estrus cycle, and altered ovarian morphology in obese female rats. Moreover, in female obese rats treated for 120 days with the high-fat diet, the increase in progesterone levels occurred together with enhancement of LH levels. The ovary from high-fat-fed female rats showed a reduction in the insulin receptor substrate/phosphatidylinositol 3-kinase/AKT intracellular pathway, associated with an increase in FOXO3a, IL1B, and TNFα protein expression. These changes in the insulin signaling pathway may have a role in the infertile state associated with obesity.


Endocrinology ◽  
2016 ◽  
Vol 157 (10) ◽  
pp. 3709-3718 ◽  
Author(s):  
Meihua Hao ◽  
Feng Yuan ◽  
Chenchen Jin ◽  
Zehong Zhou ◽  
Qi Cao ◽  
...  

Polycystic ovary syndrome (PCOS) progression involves abnormal insulin signaling. SH2 domain-containing adaptor protein (Lnk) may be an important regulator of the insulin signaling pathway. We investigated whether Lnk was involved in insulin resistance (IR). Thirty-seven women due to receive laparoscopic surgery from June 2011 to February 2012 were included from the gynecologic department of the Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University. Samples of polycystic and normal ovary tissues were examined by immunohistochemistry. Ovarian cell lines underwent insulin stimulation and Lnk overexpression. Expressed Lnk underwent coimmunoprecipitation tests with green fluorescent protein-labeled insulin receptor and His-tagged insulin receptor substrate 1 (IRS1), and their colocalization in HEK293T cells was examined. Ovarian tissues from PCOS patients with IR exhibited higher expression of Lnk than ovaries from normal control subjects and PCOS patients without IR; mainly in follicular granulosa cells, the follicular fluid and plasma of oocytes in secondary follicles, and atretic follicles. Lnk was coimmunoprecipitated with insulin receptor and IRS1. Lnk and insulin receptor/IRS1 locations overlapped around the nucleus. IR, protein kinase B (Akt), and ERK1/2 activities were inhibited by Lnk overexpression and inhibited further after insulin stimulation, whereas IRS1 serine activity was increased. Insulin receptor (Tyr1150/1151), Akt (Thr308), and ERK1/2 (Thr202/Tyr204) phosphorylation was decreased, whereas IRS1 (Ser307) phosphorylation was increased with Lnk overexpression. In conclusion, Lnk inhibits the phosphatidylinositol 3 kinase-AKT and MAPK-ERK signaling response to insulin. Higher expression of Lnk in PCOS suggests that Lnk probably plays a role in the development of IR.


Author(s):  
Feng-Yu Zhong ◽  
Jing Li ◽  
Yu-Mei Wang ◽  
Yao Chen ◽  
Jia Song ◽  
...  

AbstractThe incidence of obesity has increased rapidly, becoming a worldwide public health issue that involves insulin resistance. A growing number of recent studies have demonstrated that microRNAs play a significant role in controlling the insulin signaling network. For example, miR-506-3p expression has been demonstrated to correlate with insulin sensitivity; however, the underlying mechanism remains unknown. In this study, we found that miR-506-3p enhanced glucose uptake by 2-deoxy-D-glucose uptake assays and regulated the protein expression of key genes involved in the PI3K/AKT insulin signaling pathway including IRS1, PI3K, AKT, and GlUT4. We next predicted ribosomal protein S6 kinase B1 (S6K1) to be a candidate target of miR-506-3p by bioinformatics analysis and confirmed using dual-luciferase assays that miR-506-3p regulated S6K1 expression by binding to its 3′-UTR. Moreover, modulating S6K1 expression counteracted the effects of miR-506-3p on glucose uptake and PI3K/AKT pathway activation. In conclusion, miR-506-3p altered IR in adipocytes by regulating S6K1-mediated PI3K/AKT pathway activation. Taken together, these findings provide novel insights and potential targets for IR therapy.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Nuzhat Shaikh ◽  
Roshan Dadachanji ◽  
Srabani Mukherjee

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy affecting women of childbearing age causing not only reproductive but also metabolic anomalies. PCOS women present with ovulatory dysfunction, abnormal hormones, hyperandrogenemia, obesity, and hyperinsulinemia. It is a heterogeneous disorder which results from interaction of multiple genes along with environmental factors. Insulin resistance is a central key element contributing to PCOS pathogenesis and is further aggravated by obesity. Insulin regulates metabolic homeostasis and contributes to ovarian steroidogenesis. Candidate gene analyses have dissected genes related to insulin secretion and action for their association with PCOS susceptibility. Although a large number of genomic variants have been shown to be associated with PCOS, no single candidate gene has emerged as a convincing biomarker thus far. This may be attributed to large amount of heterogeneity observed in this disorder. This review presents an overview of the polymorphisms in genes related to insulin signaling and their association with PCOS and its related traits.


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