Melatonin alleviates insulin resistance through the PI3K/AKT signaling pathway in ovary granulosa cells of polycystic ovary syndrome.
Polycystic ovary syndrome (PCOS) is a common endocrine gynecological disorder. Insulin resistance (IR) is a major cause of PCOS. Melatonin, a critical endogenous hormone, has beneficial effects on the female reproductive system. This study aims to investigate the molecular effect of melatonin on IR in human ovarian granulosa cells (GCs). Hormone levels of the subjects were determined through clinical examination. The expression levels of insulin receptor substrate (IRS)-1 and glucose transporter (GLUT4) in GCs from PCOS patients and a human granulosa cell line (SVOG) were examined using qRT-PCR and western blot. The IR cell model was established by inducing SVOG cells with palmitic acid (PA). IR was detected in GCs of PCOS patients and SVOG by measuring glucose content and glucose uptake. Cell viability and apoptosis levels were detected by CCK-8 assay and flow cytometry. PI3K/Akt pathway expression in SVOG was assessed by western blot. PCOS patients had higher levels of luteinizing hormone (LH), testosterone, and LH/follicle-stimulating hormone. PA decreased cell viability, promoted apoptosis, and reduced glucose uptake in SVOG cells. IRS-1 and GLUT4 mRNA and protein expression was downregulated, and glucose uptake capacity was reduced in PCOS GCs and SVOG cells. Melatonin significantly upregulated IRS-1 and GLUT4 expression, downregulated p-IRS-1 (Ser307), and improved glucose uptake in PCOS patients' GCs and SVOG cells. PA decreased PI3K and Akt phosphorylation, whereas melatonin increased p-PI3K and p-Akt levels. Melatonin can reduce IR in GCs and PA-induced SVOG cells via the PI3K/Akt signaling pathway, providing more evidence for treating polycystic ovary syndrome.
Guo R
，Zheng H
，Li Q
，Qiu X
，Zhang J
，Cheng Z
... -
《-》
Guizhi Fuling Wan reduces autophagy of granulosa cell in rats with polycystic ovary syndrome via restoring the PI3K/AKT/mTOR signaling pathway.
Guizhi Fuling Wan (GFW) is a traditional Chinese medicine used to remove blood stasis and dissipate phlegm for treating gynecological diseases that was invented by Zhang Zhongjing in the Eastern Han dynasty. In recent years, GFW has been widely used to treat patients with polycystic ovary syndrome (PCOS). Clinical and animal studies have shown that it is effective in the treatment of PCOS, but its mechanism is unknown. Generally, it works by regulating autophagy via the PI3K/AKT/mTOR signaling pathway.
This study investigated the effects and mechanism of GFW in PCOS rats with insulin resistance (IR) in order to provide better understanding of its observed clinical effects and a theoretical basis for the study of traditional Chinese medicine.
Eighty-four female Sprague-Dawley rats were randomly divided into seven groups (n = 12 per group): 1) control, 2) PCOS model, 3) low-dose GFW, 4) medium-dose GFW, 5) high-dose GFW, 6) metformin, and 7) medium-dose GFW plus LY294002. In all non-control groups, we induced PCOS through daily letrozole combined with intragastric high-fat emulsion for 21 days. After treatment, rats were sacrificed and serum follicle-stimulating hormone (FSH), testosterone (T), progesterone, luteinizing hormone (LH), 17β-estradiol, fasting insulin (FINS), and fasting plasma glucose levels were measured by enzyme-linked immunosorbent assay (ELISA). The LH/FSH ratios and HOMA-IR values were calculated. Ovarian morphology was observed by hematoxylin and eosin staining, and all follicles were counted under a microscope. MDC-positive vesicles were used as markers to detect autophagy, and the expression levels of p62, Beclin1, and LC3-II were examined by immunostaining. Western blotting was used to measure PI3K/AKT/mTOR pathway activation, granulosa cell apoptosis, and autophagy.
Compared with the PCOS model group, GFW-treated rats had less atretic and cystic follicles, and more mature follicles and corpus lutea. The GFW-treated rats had lower serum T, LH, and FINS levels than the PCOS model group, as well as lower LH/FSH ratios and HOMA-IR values. GFW treatment resulted in significantly reduced levels of cleaved-Caspase-3, cleaved-Caspase-9, BAX, Beclin1, Atg5, and LC3-II. Phosphorylation of PI3K, AKT, and mTOR was significantly higher in GFW-treated rats compared with the PCOS model group. The phosphorylation of PI3K, AKT, and mTOR was decreased with the use of a PI3K antagonist.
Our results indicate that GFW inhibited granulosa cell autophagy and promoted follicular development to attenuate ovulation disorder in PCOS-IR rats. This was associated with activation of the PI3K/AKT/mTOR signaling pathway.
Liu M
，Zhu H
，Zhu Y
，Hu X
... -
《-》
Up-regulation of miR-133a-3p promotes ovary insulin resistance on granulosa cells of obese PCOS patients via inhibiting PI3K/AKT signaling.
MicroRNAs are a type of non-coding single-stranded RNA, which is involved in the regulation of ovary insulin resistance (IR). This study aims to explore the underlying mechanisms of miR-133a-3p regulating ovary IR in obese polycystic ovary syndrome (PCOS).
Granulosa cells (GCs) were extracted from follicular fluids of PCOS patients (obese PCOS group and non-obese PCOS group) and healthy women (control group). The expression of miR-133a-3p in GCs was detected by qRT-PCR. The targets and pathways of miR-133a-3p were predicted by bioinformatics analyses. The protein levels of PI3K, p-AKT, GLUT4, p-GSK-3β, and p-FOXO1 were measured by Western blotting.
MiR-133a-3p was highly expressed in GCs from PCOS patients, especially in obese PCOS patients. The protein levels of PI3K and p-AKT was downregulated in GCs from PCOS patients. There were 11 target genes of miR-133a-3p enriching in PI3K/AKT signaling pathway. miR-133a-3p mimic downregulated the expression of PI3K, p-AKT, and GLUT4, and upregulated the protein levels of p-GSK-3β and p-FOXO1. miR-133a-3p inhibitor presented the opposite effect of miR-133a-3p mimic.
MiR-133a-3p promotes ovary IR on GCs of obese PCOS patients via inhibiting PI3K/AKT signaling pathway. This study lays a foundation for further research on the mechanism of ovary IR in obese PCOS patients.
Yang X
，Wang K
，Lang J
，Guo D
，Gao H
，Qiu Y
，Jin X
，Zhang M
，Shi J
，Ma Q
，Ma Q
，Wen Z
... -
《BMC Womens Health》
Liuwei Dihuang Pills alleviate the polycystic ovary syndrome with improved insulin sensitivity through PI3K/Akt signaling pathway.
Polycystic ovary syndrome (PCOS) is a complex gynecological endocrine disease commonly occurred in women of childbearing age. The main hallmark of PCOS includes elevated androgen production and insulin resistance (IR). Liuwei Dihuang Pills (LWDH Pills), a commonly prescribed traditional Chinese medicine (TCM) is widely used as a tonic prescription to treat diabetes, female menopause syndrome and other symptoms with'Kidney-Yin' deficiency. It has been reported the effects LWDH pills on PI3K/Akt signaling pathway in T2DM treatment. Recent studies have also indicated that the treatment of menopausal syndrome may be associated with the ovarian sexual hormone levels regulated by LWDH pills to alleviate female infertility. However, its potential benefits on PCOS have not been fully elucidated.
The primary aim of this study was to investigate the alterations of PI3K/Akt pathway in polycystic ovary syndrome-insulin resistance (PCOS-IR) progression induced by letrozole combined with high fat diet (HFD) and then to explore the detailed mechanism of LWDH Pills to alleviate PCOS.
The female Sprague-Dawley rats were continuously treated with letrozole (p.o administration at 1 mg kg-1·day-1) and HFD for 21 days to establish the PCOS-IR model. Concurrently, metformin (200 mg kg-1·day-1) or LWDH Pills was orally administrated (1.2 or 3.6 g kg-1·day-1) to intervene disease progression. The ovarian pathology was evaluated by HE (hematoxylin-eosin) staining. The serum sexual hormones, follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, testosterone, progesterone and fasting insulin (FINS) were determined by radioimmunoassay. The protein expressions of IRS-1, PI3Kp85α, Akt and FoxO1a were analyzed by western blotting, while the mRNA levels of follicle-stimulating hormone receptor (FSHR) and Cyp19a1 in ovarian tissue were measured by qPCR.
The upregulated phosphorylation of IRS-1 (S307), down-regulated phosphorylation of PI3Kp85α, Akt, and FoxO1a were significantly reversed by LWDH Pills (3.6 g kg-1·day-1) in PCOS-IR rats with up-regulated mRNA levels of FSHR and Cyp19a1 in ovary. Also, the index of insulin resistance was gradually adjusted to normal by LWDH Pills. The serum levels of FSH, estradiol, progesterone levels were significantly raised while LH, testosterone were reduced. The ovarian polycystic changes were alleviated while the atresia follicles were reduced.
LWDH Pills therapy obviously improved the ovarian polycystic pathogenesis and regained the development of follicles via upregulating Cyp19a1, alleviated insulin resistance through acting on PI3K/Akt signaling pathway. These findings have provided scientific evidence for LWDH Pills to treat PCOS.
Qiu Z
，Dong J
，Xue C
，Li X
，Liu K
，Liu B
，Cheng J
，Huang F
... -
《-》
ResearchGate
(全网免费下载)
钛学术
(全网免费下载)
