Effect of Vitamin D3 on Mitochondrial Biogenesis in Granulosa Cells Derived from Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is an endocrine disorder diagnosed by anovulation hyperandrogenism. Hyperandrogenism increases apoptosis, which will eventually disturb follicular growth in PCOS patients. Since mitochondria regulate apoptosis, they might be affected by high incidence of follicular atresia. This may cause infertility. Since vitamin D3 has been shown to improve the PCOS symptoms, the aim of study was to investigate the effects vitamin D3 on mtDNA copy number, mitochondrial biogenesis, and membrane integrity of granulosa cells in a PCOS-induced mouse model. In this experimental study, the PCOS mouse model was induced by dehydroepiandrosterone (DHEA). Granulosa cells after identification by follicle-stimulating hormone receptor (FSHR) were cultured in three groups: 1. granulosa cells treated with vitamin D3 (100 nM for 24 hours), 2. granulosa cells without any treatments, 3. Non-PCOS granulosa cells (control group). Mitochondrial biogenesis gene (TFAM) expression was compared between different groups using real-time PCR. mtDNA copy number was also investigated by qPCR. The mitochondrial structure was evaluated by transmission electron microscopy (TEM). Hormonal levels were measured by an enzymelinked immunosorbent assay (ELISA) kit. The numbers of pre-antral and antral follicles increased in PCOS group in comparison with the non-PCOS group. Mitochondrial biogenesis genes were downregulated in granulosa cells of PCOS mice when compared to the non-PCOS granulosa cells. However, treatment with vitamin D3 increased mtDNA expression levels of these genes compared to PCOS granulosa cells with no treatments. Most of the mitochondria in the PCOS group were spherical with almost no cristae. Our results showed that in the PCOS group treated with vitamin D3, the mtDNA copy number increased significantly in comparison to PCOS granulosa cells with no treatments. According to this study, we can conclude, vitamin D3 improves mitochondrial biogenesis and membrane integrity, mtDNA copy number in granulosa cells of PCOS mice which might improve follicular development and subsequently oocyte quality.

Safaei Z ，Bakhshalizadeh SH ，Nasr Esfahani MH ，Akbari Sene A ，Najafzadeh V ，Soleimani M ，Shirazi R ... -  《-》

Vitamin D3 affects mitochondrial biogenesis through mitogen-activated protein kinase in polycystic ovary syndrome mouse model.

Polycystic ovarian syndrome (PCOS) is a disorder characterized by oligomenorrhea, anovulation, and hyperandrogenism. Altered mitochondrial biogenesis can result in hyperandrogenism. The goal of this study was to examine the effect of vitamin D3 on mitochondrial biogenesis of the granulosa cells in the PCOS-induced mouse model. Vitamin D3 applies its effect via the mitogen-activated pathway kinase-extracellular signal-regulated kinases (MAPK-ERK1/2) pathway. The PCOS mouse model was induced by the injection of dehydroepiandrosterone (DHEA). Isolated granulosa cells were subsequently treated with vitamin D3, MAPK activator, and MAPK inhibitor. Gene expression levels were measured using real-time polymerase chain reaction. MAPK proteins were investigated by western blot analysis. We also determined reactive oxygen species (ROS) levels with 2', 7'-dichlorofluorescein diacetate. Mitochondrial membrane potential (mtMP) was also measured by TMJC1. Mitochondrial biogenesis (peroxisome proliferator-activated receptor gamma coactivator 1-α and nuclear respiratory factor), antioxidant (superoxide dismutase, glutathione peroxidase, and catalase), and antiapoptotic (B-cell lymphoma-2) genes were upregulated in the PCOS mice that treated with vitamin D3 compared with the PCOS mice without any treatment. Vitamin D3 and MAPK activator-treated groups also reduced ROS levels compared with the nontreated PCOS group. In summary, vitamin D3 and MAPK activator increased the levels of mitochondrial biogenesis, MAPK pathway, and mtMP markers, while concomitantly decreased ROS levels in granulosa cells of the PCOS-induced mice. This study suggests that vitamin D3 may improve mitochondrial biogenesis through stimulation of the MAPK pathway in cultured granulosa cells of DHEA-induced PCOS mice which yet to be investigated.

Safaei Z ，Bakhshalizadeh S ，Nasr-Esfahani MH ，Akbari Sene A ，Najafzadeh V ，Soleimani M ，Shirazi R ... -  《-》

Modulation of steroidogenesis by vitamin D3 in granulosa cells of the mouse model of polycystic ovarian syndrome.

Bakhshalizadeh S ，Amidi F ，Alleyassin A ，Soleimani M ，Shirazi R ，Shabani Nashtaei M ... -  《-》

Vitamin D3 regulates steroidogenesis in granulosa cells through AMP-activated protein kinase (AMPK) activation in a mouse model of polycystic ovary syndrome.

Bakhshalizadeh S ，Amidi F ，Shirazi R ，Shabani Nashtaei M ... -  《-》

Activation of TGF-β1/Smad3 signaling pathway inhibits the development of ovarian follicle in polycystic ovary syndrome by promoting apoptosis of granulosa cells.

To investigate the role of the transforming growth factor-β1 (TGF-β1)/Smad3 signaling pathway in development of ovarian follicle by promoting apoptosis of granulosa cells in polycystic ovary syndrome (PCOS). A total of 54 female rats were obtained and randomly assigned into the PCOS (n = 27) and control groups ( n = 27). PCOS rat models were constructed using the dehydroepi-androsterone method to observe ovarian morphology and ultrastructure. Chemiluminescence immunoassay was performed to detect the levels of luteinizing hormone, follicle stimulating hormone, estradiol, progesterone, and testosterone. The release of TGF-β1 in follicular fluid and serum was tested by the enzyme-linked immunosorbent assay. Expression of p-Smad3 significantly increased in granulosa cells of PCOS group. In terms of the Smad2 protein, there was no significant difference between the PCOS and control group. In comparison to the control group, the number of normal secondary follicles and normal antral follicles were significantly decreased, whereas the number of hypogenetic secondary follicles undergoing atresia and antral follicles were significantly elevated in the PCOS group. Furthermore, the thickness of granulosa cells decreased and the apoptosis of granulosa cells increased in the PCOS group compared with the control one. These results indicate that p-Smad3 may have a close relationship with apoptosis of granulosa cells, the mechanism is that the TGF-β1/Smad3 signaling pathway may inhibit development of ovarian follicle of PCOS by regulating the apoptosis of granulosa cells.

Shen H ，Wang Y 《-》