Genetic Prediction of Osteoporosis by Anti-Müllerian Hormone Levels and Reproductive Factors in Women: A Mendelian Randomization Study.

Previous observational studies have suggested that anti-Müllerian hormone (AMH) and reproductive factors are linked to reduced bone mineral density (BMD) and an increased risk of osteoporosis (OP) in women. However, related studies are limited, and these traditional observational studies may be subject to residual confounders and reverse causation, while also lacking a more comprehensive observation of various reproductive factors. Univariate and multivariate two-sample Mendelian randomization analyses were conducted to determine the causal associations of AMH levels and six reproductive factors with BMD and OP, using the random-effects inverse-variance weighted method. Heterogeneity was assessed using Cochran's Q-statistic, and sensitivity analyses were performed to identify causal correlations. Age at menarche (AAM) was negatively associated with total body BMD (TB-BMD) in females aged 45-60 and over 60 years, as well as with heel bone mineral density (eBMD). Conversely, age at natural menopause (ANM) was positively associated with TB-BMD in the same age ranges and with eBMD. ANM was only causally associated with self-reported OP and showed no significant correlation with definitively diagnosed OP. Neither AMH level nor other reproductive factors were significantly associated with a genetic predisposition to BMD at any age and OP. Later AAM and earlier ANM are significantly genetically causally associated with decreased BMD but not with OP. AMH levels, length of menstrual cycle, age at first birth, age at last birth, and number of live births, in terms of genetic backgrounds, are not causally related to BMD or OP.

Epidemiologic and genetic associations of female reproductive disorders with depression or dysthymia: a Mendelian randomization study.

Observational studies have previously reported an association between depression and certain female reproductive disorders. However, the causal relationships between depression and different types of female reproductive disorders remain unclear in terms of direction and magnitude. We conducted a comprehensive investigation using a two-sample bi-directional Mendelian randomization analysis, incorporating publicly available GWAS summary statistics. Our aim was to establish a causal relationship between genetically predicted depression and the risk of various female reproductive pathological conditions, such as ovarian dysfunction, polycystic ovary syndrome(PCOS), ovarian cysts, abnormal uterine and vaginal bleeding(AUB), endometriosis, leiomyoma of the uterus, female infertility, spontaneous abortion, eclampsia, pregnancy hypertension, gestational diabetes, excessive vomiting in pregnancy, cervical cancer, and uterine/endometrial cancer. We analyzed a substantial sample size, ranging from 111,831 to 210,870 individuals, and employed robust statistical methods, including inverse variance weighted, MR-Egger, weighted median, and MR-PRESSO, to estimate causal effects. Sensitivity analyses, such as Cochran's Q test, MR-Egger intercept test, MR-PRESSO, leave-one-out analysis, and funnel plots, were also conducted to ensure the validity of our results. Furthermore, risk factor analyses were performed to investigate potential mediators associated with these observed relationships. Our results demonstrated that genetic predisposition to depression or dysthymia was associated with an increased risk of developing PCOS (OR = 1.43, 95% CI 1.28-1.59; P = 6.66 × 10-11), ovarian cysts (OR = 1.36, 95% CI 1.20-1.55; P = 1.57 × 10-6), AUB (OR = 1.41, 95% CI 1.20-1.66; P = 3.01 × 10-5), and endometriosis (OR = 1.43, 95% CI 1.27-1.70; P = 2.21 × 10-7) after Bonferroni correction, but no evidence for reverse causality. Our study did not find any evidence supporting a causal or reverse causal relationship between depression/dysthymia and other types of female reproductive disorders. In summary, our study provides evidence for a causal relationship between genetically predicted depression and specific types of female reproductive disorders. Our findings emphasize the importance of depression management in the prevention and treatment of female reproductive disorders, notably including PCOS, ovarian cysts, AUB, and endometriosis.

Catalpol alleviates hypoxia ischemia-induced brain damage by inhibiting ferroptosis through the PI3K/NRF2/system Xc-/GPX4 axis in neonatal rats.

Hypoxic-ischemic encephalopathy (HIE) is a brain damage caused by perinatal hypoxia and blood flow reduction. Severe HIE leads to death. Available treatments remain limited. Oxidative stress and nerve damage are major factors in brain injury caused by HIE. Catalpol, an iridoid glucoside found in the root of Rehmannia glutinosa, has antioxidant and neuroprotective effects. This study examined the neuroprotective effects of catalpol using a neonatal rat HIE model and found that catalpol might protect the brain through inhibiting neuronal ferroptosis and ameliorating oxidative stress. Behavior tests suggested that catalpol treatment improved functions of motor, learning, and memory abilities after hypoxic-ischemic injury. Catalpol treatment inhibited changes to several ferroptosis-related proteins, including p-PI3K, p-AKT, NRF2, GPX4, SLC7A11, SLC3A2, GCLC, and GSS in HIE neonatal rats. Catalpol also prevented changes to several ferroptosis-related proteins in PC12 cells after oxygen-glucose deprivation. The ferroptosis inducer erastin reversed the protective effects of catalpol both in vitro and in vivo. We concluded that catalpol protects against hypoxic-ischemic brain damage (HIBD) by inhibiting ferroptosis through the PI3K/NRF2/system Xc-/GPX4 axis.

Immunity and reproduction protective effects of Chitosan Oligosaccharides in Cyclophosphamide/Busulfan-induced premature ovarian failure model mice.

Introduction: Premature ovarian failure (POF) is a major cause of infertility among women of reproductive age. Unfortunately, there is no effective treatment available currently. Researchers have shown that immune disorders play a significant role in the development of POF. Moreover, growing evidence suggest that Chitosan Oligosaccharides (COS), which act as critical immunomodulators, may have a key role in preventing and treating a range of immune related reproductive diseases. Methods: KM mice (6-8 weeks) received a single intraperitoneal injection of cyclophosphamide (CY, 120mg/kg) and busulfan (BUS, 30mg/kg) to establish POF model. After completing the COS pre-treatment or post-treatment procedures, peritoneal resident macrophages (PRMs) were collected for neutral erythrophagocytosis assay to detect phagocytic activity. The thymus, spleen and ovary tissues were collected and weighed to calculate the organ indexes. Hematoxylin-eosin (HE) staining was performed to observe the histopathologic structure of those organs. The serum levels of estrogen (E2) and progesterone (P) were measured via the enzyme-linked immunosorbent assay (ELISA). The expression levels of immune factors including interleukin 2 (IL-2), interleukin 4 (IL-4), and tumor necrosis factor α (TNF-α), as well as germ cell markers Mouse Vasa Homologue (MVH) and Fragilis in ovarian tissue, were analyzed by Western blotting and qRT-PCR. In addition, ovarian cell senescence via p53/p21/p16 signaling was also detected. Results: The phagocytic function of PRMs and the structural integrity of thymus and spleen were preserved by COS treatment. The levels of certain immune factors in the ovaries of CY/BUS- induced POF mice were found to be altered, manifested as IL-2 and TNF-α experiencing a significant decline, and IL-4 presenting a notable increase. Both pre-treatment and post-treatment with COS were shown to be protective effects against the damage to ovarian structure caused by CY/BUS. Senescence-associated ß-galactosidase (SA-ß-Gal) staining results showed that COS prevents CY/BUS-induced ovarian cell senescence. Additionally, COS regulated estrogen and progesterone levels, enhanced follicular development, and blocked ovarian cellular p53/p21/p16 signaling which participating in cell senescence. Conclusion: COS is a potent preventative and therapeutic medicine for premature ovarian failure by enhancing both the ovarian local and systemic immune response as well as inhibiting germ cell senescence.

Chito-oligosaccharides and macrophages have synergistic effects on improving ovarian stem cells function by regulating inflammatory factors.

BACKGROUND: Chronic low-grade inflammation and ovarian germline stem cells (OGSCs) aging are important reasons for the decline of ovarian reserve function, resulting in ovarian aging and infertility. Regulation of chronic inflammation is expected to promote the proliferation and differentiation of OGSCs, which will become a key means for maintaining and remodeling ovarian function. Our previous study demonstrated that Chitosan Oligosaccharides (Cos) promoted the OGSCs proliferation and remodelled the ovarian function through improving the secretion of immune related factors,but the mechanism remains unclear, and the role of macrophages, the important source of various inflammatory mediators in the ovary needs to be further studied. In this study, we used the method of macrophages and OGSCs co-culture to observe the effect and mechanism of Cos on OGSCs, and explore what contribution macrophages give during this process. Our finding provides new drug treatment options and methods for the prevention and treatment of premature ovarian failure and infertility. METHODS: We used the method of macrophages and OGSCs co-culture to observe the effect and mechanism of Cos on OGSCs, and explore the important contribution of macrophages in it. The immunohistochemical staining was used to locate the OGSCs in the mouse ovary. Immunofluorescent staining, RT-qPCR and ALP staining were used to identify the OGSCs. CCK-8 and western blot were used to evaluate the OGSCs proliferation. ß-galactosidase(SA-ß-Gal) staining and western blot were used to detect the changing of cyclin-dependent kinase inhibitor 1A(P21), P53, Recombinant Sirtuin 1(SIRT1) and Recombinant Sirtuin 3(SIRT3). The levels of immune factors IL-2, IL-10, TNF-α and TGF-ß were explored by using Western blot and ELISA. RESULTS: We found that Cos promoted OGSCs proliferation in a dose-and time-dependent manner, accompanied by IL-2, TNF-α increase and IL-10, TGF-ß decrease. Mouse monocyte-macrophages Leukemia cells(RAW) can also produce the same effect as Cos. When combined with Cos, it can enhance the proliferative effect of Cos in OGSCs, and further increase IL-2, TNF-α and further decrease IL-10, TGF-ß. The macrophages can enhance the proliferative effect of Cos in OGSCs is also associated with the further increase in IL-2, TNF-α and the further decrease in IL-10, TGF-ß. In this study, we determined that the anti-aging genes SIRT-1 and SIRT-3 protein levels were increased by Cos and RAW respectively, whereas the senescence-associated SA-ß-Gal and aging genes P21 and P53 were decreased. Cos and RAW had a protective effect on OGSCs delaying aging. Furthermore, RAW can further decrease the SA-ß-Gal and aging genes P21 and P53 by Cos, and further increase SIRT1 and SIRT3 protein levels in OGSCs by Cos. CONCLUSION: In conclusion, Cos and macrophages have synergistic effects on improving OGSCs function and delaying ovarian aging by regulating inflammatory factors.

Chitosan oligosaccharide improves ovarian granulosa cells inflammation and oxidative stress in patients with polycystic ovary syndrome.

Introduction: Polycystic Ovary Syndrome (PCOS) is the most common reproductive endocrine disorder among women of reproductive age, which is one of the main causes of anovulatory infertility. Even though the rapidly developed assisted reproductive technology (ART) could effectively solve fertility problems, some PCOS patients still have not obtained satisfactory clinical outcomes. The poor quality of oocytes caused by the abnormal follicular development of PCOS may directly contribute to the failure of ART treatment. Ovarian granulosa cells (GCs) are the most closely related cells to oocytes, and changes in their functional status have a direct impact on oocyte formation. Previous studies have shown that changes in the ovarian microenvironment, like oxidative stress and inflammation, may cause PCOS-related aberrant follicular development by impairing the physiological state of the GCs. Therefore, optimizing the ovarian microenvironment is a feasible method for enhancing the development potential of PCOS oocytes. Methods: In this study, we first detected the expression of inflammatory-related factors (TGF-ß1, IL-10, TNFα, IL-6) and oxidative stress-related factors (HIF-1α and VEGFA), as well as the proliferation ability and apoptosis level of GCs, which were collected from control patients (non-PCOS) and PCOS patients, respectively. Subsequently, human ovarian granulosa cell line (KGN) cells were used to verify the anti-inflammatory and anti-oxidative stress effects of chitosan oligosaccharide (COS) on GCs, as well as to investigate the optimal culture time and concentration of COS. The optimal culture conditions were then used to culture GCs from PCOS patients and control patients. Results: The results showed that GCs from PCOS patients exhibited obvious inflammation and oxidative stress and significantly reduced proliferation and increased apoptosis. Furthermore, COS can increase the expression of anti-inflammatory factors (TGF-ß1 and IL-10) and decrease the expression of pro-inflammatory factors (TNFα and IL-6), as well as promote the proliferation of GCs. Moreover, we found that COS can reduce the level of reactive oxygen species in GCs under oxidative stress by inhibiting the expression of HIF-1α and VEGFA and by suppressing the apoptosis of GCs induced by oxidative stress. Conclusion: We find that inflammation and oxidative stress exist in the GCs of PCOS patients, and COS can reduce these factors, thereby improving the function of GCs.

Female germline stem cells: aging and anti-aging.

The delay of ovarian aging and the fertility preservation of cancer patients are the eternal themes in the field of reproductive medicine. Acting as the pacemaker of female physiological aging, ovary is also considered as the principle player of cancer, cardiovascular diseases, cerebrovascular diseases, neurodegenerative diseases and etc. However, its aging mechanism and preventive measures are still unclear. Some researchers attempt to activate endogenous ovarian female germline stem cells (FGSCs) to restore ovarian function, as the most promising approach. FGSCs are stem cells in the adult ovaries that can be infinitely self-renewing and have the potential of committed differention. This review aims to elucidate FGSCs aging mechanism from multiple perspectives such as niches, immune disorder, chronic inflammation and oxidative stress. Therefore, the rebuilding nichs of FGSCs, regulation of immune dysfunction, anti-inflammation and oxidative stress remission are expected to restore or replenish FGSCs, ultimately to delay ovarian aging.

Chitosan Oligosaccharides Alleviate H2O2-stimulated Granulosa Cell Damage via HIF-1α Signaling Pathway.

Oocyte maturation disorder and decreased quality are the main causes of infertility in women, and granulosa cells (GCs) provide the only microenvironment for oocyte maturation through autocrine and paracrine signaling by steroid hormones and growth factors. However, chronic inflammation and oxidative stress caused by ovarian hypoxia are the largest contributors to ovarian aging and GC dysfunction. Therefore, the amelioration of chronic inflammation and oxidative stress is expected to be a pivotal method to improve GC function and oocyte quality. In this study, we detected the protective effect of chitosan oligosaccharides (COS), on hydrogen peroxide- (H2O2-) stimulated oxidative damage in a human ovarian granulosa cell line (KGN). COS significantly increased cell viability, mitochondrial function, and the cellular glutathione (GSH) content and reduced apoptosis, reactive oxygen species (ROS) content, and the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), 4-hydroxynonenal (4-HNE), hypoxia-inducible factor-1α (HIF-1α), and vascular endothelial-derived growth factor (VEGF) in H2O2-stimulated KGN cells. COS treatment significantly increased levels of the TGF-ß1 and IL-10 proteins and decreased levels of the IL-6 protein. Compared with H2O2-stimulated KGN cells, COS significantly increased the levels of E2 and P4 and decreased SA-ß-gal protein expression. Furthermore, COS caused significant inactivation of the HIF-1α-VEGF pathway in H2O2-stimulated KGN cells. Moreover, inhibition of this pathway enhanced the inhibitory effects of COS on H2O2-stimulated oxidative injury and apoptosis in GCs. Thus, COS protected GCs from H2O2-stimulated oxidative damage and apoptosis by inactivating the HIF-1α-VEGF signaling pathway. In the future, COS might represent a therapeutic approach for ameliorating disrupted follicle development.

Effects of chitooligosaccharide-zinc on the ovarian function of mice with premature ovarian failure via the SESN2/NRF2 signaling pathway.

Chitooligosaccharide-zinc (COS·Zn) is a powerful anti-oxidant and anti-aging scavenger, whose anti-oxidative ability immensely exceeds vitamin C. Therefore, this study was aimed to investigate the protective effects of COS·Zn against premature ovarian failure (POF) and potential mechanisms. Female KM adult mice were divided into the following groups: a treatment group (150 mg·kg-1·d-1 COS·Zn), a treatment group (300 mg·kg-1·d-1 COS·Zn), a prevention group, two control groups and two CY/BUS groups. COS·Zn (150, 300 mg·kg-1·d-1) and COS·Zn (300 mg·kg-1·d-1) were therapeutically and preventatively administered to POF mice in the treatment and prevention studies, respectively. All the groups were administered for 21 days. Fewer primary and secondary follicles were observed in the COS·Zn-treated groups (including the treatment and prevention groups) than those of the control groups. Meanwhile, the ovarian index and the levels of FSH and LH notably increased in the treatment and prevention groups compared with those in the CY/BUS group. The levels of MVH, OCT4 and PCNA in the treatment group (300·kg-1·d-1 COS·Zn) and MVH in the prevention group remarkably increased compared with those in the CY/BUS groups. Meanwhile, the levels of P53 and P16 protein were down-regulated in the treatment and prevention groups compared with those in the CY/BUS groups. Additionally, the amounts of Sestrin2 (SESN2) and SOD2 protein were obviously higher in the treatment group (150 mg·kg-1·d-1 COS·Zn) than those in the CY/BUS groups. Similarly, the amounts of NRF2 and SESN2 protein were up-regulated in the prevention group. Besides, an increased GSH level was observed in the two treatment groups, compared with that in the CY/BUS groups, and the same trend was also present in the prevention group. Taken together, COS·Zn improves the ovarian and follicular development through regulating the SESN2/NRF2 signaling pathway. These results suggest the role of COS·Zn as a novel agent for the treatment and prevention of POF.

PAQR7: An intermediary mediating nongenomic progesterone action in female reproductive tissue.

Progestin and adipoQ receptor 7 (PAQR7) as an indispensable member of membrane progestin receptors in the Progestin and adipoQ receptor (PAQR) family that mediates nongenomic progesterone actions, initiated rapidly at the cell surface. Previous research demonstrated the distribution of PAQR7, which was mainly expressed in reproductive tissues, including ovary and testis. In the male reproductive system, PAQR7 is involved in progestin-induced sperm hypermotility. However, reports studying PAQR7 in female reproductive tissue mainly concentrate on oocyte maturation in fish, its expression in the ovary and gestational tissue, and regulation of uterine functions in mammals. Despite recent advances, many aspects of progestin signaling through PAQR7 are still unclear, especially in female reproductive tissue. Therefore, we reveal the structure and characteristics of PAQR7 and conclude the putative progestin-induced action mediated by PAQR7 in female reproductive tissue, such as the development of ovarian follicles, apoptosis of granulosa cells, oocyte maturation, and development of certain diseases, among others, to review the function of PAQR7 in the female reproductive system in detail.

Effects of shikonin on the development of ovarian follicles and female germline stem cells.

OBJECTIVE: To investigate the effects and potential mechanism of action of shikonin (SHK) on the development of ovarian follicles and female germline stem cells (FGSCs). METHODS: Female Kunming adult mice were administered SHK (0, 20 and 50 mg/kg) by oral gavage. Cultures of FGSCs were treated with SHK 32 µmol/l for 24 h. The ovarian index in mouse ovaries was calculated. Numbers of primordial, primary and atretic follicles were counted. Germline stem cell markers and apoptosis were examined. Levels of glutathione (GSH), superoxide dismutase (SOD) and reactive oxygen species (ROS) were measured. RESULTS: Both doses of SHK significantly decreased the ovarian index, the numbers of primordial follicles, primary follicles and antral follicles in mice. SHK significantly increased the numbers of atretic follicles and atretic corpora lutea. SHK promoted apoptosis in vivo and in vitro. SHK significantly decreased the levels of the germline stem cell markers. SHK significantly lowered GSH levels and the activity of SOD in the peripheral blood from mice, whereas SHK significantly elevated cellular ROS content in FGSCs. CONCLUSIONS: These current results suggested that follicular development and FGSCs were suppressed by SHK through the induction of apoptosis and oxidative stress might be involved in this pathological process.

The role of Chito-oligosaccharide in regulating ovarian germ stem cells function and restoring ovarian function in chemotherapy mice.

In recent years, the discovery of ovarian germ stem cells (OGSCs) has provided a new research direction for the treatment of female infertility. The ovarian microenvironment affects the proliferation and differentiation of OGSCs, and immune cells and related cytokines are important components of the microenvironment. However, whether improving the ovarian microenvironment can regulate the proliferation of OGSCs and remodel ovarian function has not been reported. In this study, we chelated chito-oligosaccharide (COS) with fluorescein isothiocyanate (FITC) to track the distribution of COS in the body. COS was given to mice through the best route of administration, and the changes in ovarian and immune function were detected using assays of organ index, follicle counting, serum estrogen (E2) and anti-Mullerian hormone (AMH) levels, and the expression of IL-2 and TNF-α in the ovaries. We found that COS significantly increased the organ index of the ovary and immune organs, reduced the rate of follicular atresia, increased the levels of E2 and AMH hormones, and increased the protein expression of IL-2 and TNF-α in the ovary. Then, COS and OGSCs were co-cultured to observe the combination of COS and OGSCs, and measure the survival rate of OGSCs. With increasing time, the fluorescence intensity of cells gradually increased, and the cytokines IL-2 and TNF-α significantly promoted the proliferation of OGSCs. In conclusion, COS could significantly improve the ovarian and immune function of chemotherapy model mice, and improve the survival rate of OGSCs, which provided a preliminary blueprint for further exploring the mechanism of COS in protecting ovarian function.

Controlling chronic low-grade inflammation to improve follicle development and survival.

Chronic low-grade inflammation is one cause of follicle development disturbance. Chronic inflammation exists in pathological conditions such as premature ovarian failure, physiological aging of the ovaries, and polycystic ovary syndrome. Inflammation of the whole body can affect oocytes via the follicle microenvironment, oxidative stress, and GM-CSF. Many substances without toxic side-effects extracted from natural organisms have gradually gained researchers' attention. Recently, chitosan oligosaccharide, resveratrol, anthocyanin, and melatonin have been found to contribute to an improvement in inflammation. This review discusses the interrelationships between chronic low-grade inflammation and follicle development, the underlying mechanisms, and methods that may improve follicle development by controlling the level of chronic low-grade inflammation.

[Expression relationship of Hippo signaling molecules and ovarian germline stem cell markers in the ovarian aging process of women and mice].

The present study was aimed to investigate the expression relationship of Hippo signaling molecules and ovarian germline stem cell (OGSC) markers in the development schedule of OGSCs during ovarian aging in women and mice. The ovaries of 2-month-old mature (normal control) and 12-month-old (physiological ovarian aging) KM mice were sampled, and the ovarian cortex samples of young (postpuberty to 35 years old), middle age (36-50 years old) and menopausal period (51-60 years old) women were obtained with consent. The mice model of pathological ovarian aging was established by intraperitoneal injection of cyclophosphamide/busulfan (CY/BUS). HE staining was used to detect the changes of follicles at different stages, and the localization and expression changes of Hippo signaling molecules and OGSCs related factors (MVH/OCT4) were detected by immunohistochemistry and immunofluorescence staining. Western blot was used to detect the protein expression levels of the major molecules in the Hippo signaling pathway and OGSCs related factors. The results showed that there were not any normal follicles, but a few atresia follicles in the ovaries from physiological and pathological ovarian aging mice. Compared with the normal control mice, both the physiological and pathological ovarian aging mice showed decreased protein expression levels of the main Hippo signaling molecules (pYAP1) and MVH/OCT4; Whereas only the pathological ovarian aging mice showed increased ratio of pYAP1/YAP1. In comparison with the young women, the middle age and menopausal women showed looser structure of ovarian surface epithelium (OSE) and less ovarian cortical cells. The protein expression level of LATS2 in the OSE was the highest in young women, MST1 expression was the lowest in the menopausal period women, and the expression levels of YAP1 and pYAP1 were the highest in middle age women. Compared with the young women, the middle age and menopausal period women exhibited significantly decreased ratio of OSE pYAP1/YAP1, whereas there was no significant difference between them. The expression level of MVH protein in OSE from the young women was significantly higher than those of the middle age and menopausal period women. These results indicate that there is an expression relationship between the main molecules of Hippo signaling pathway and OGSCs related factors, which suggests that Hippo signaling pathway may regulate the expression levels of OGSCs related factors, thus participating in the process of physiological and pathological degeneration of ovarian.

Inflamm-Aging: A New Mechanism Affecting Premature Ovarian Insufficiency.

The normal function of ovaries, along with the secretion of sex hormones, is among the most important endocrine factors that maintain the female sexual characteristics and promote follicular development and ovulation. Premature ovarian insufficiency (POI) is a common cause in the etiology of female infertility. It is defined as the loss of ovarian function before the age of 40. The characteristics of POI are menstrual disorders, including amenorrhea and delayed menstruation, accompanied by a raised gonadotrophin level and decreased estradiol level. Inflammatory aging is a new concept in the research field of aging. It refers to a chronic and low-degree proinflammatory state which occurs with increasing age. Inflammatory aging is closely associated with multiple diseases, as excessive inflammation can induce the inflammatory lesions in certain organs of the body. In recent years, studies have shown that inflammatory aging plays a significant role in the pathogenesis of POI. This paper begins with the pathogenesis of inflammatory aging and summarizes the relationship between inflammatory aging and premature ovarian insufficiency in a comprehensive way, as well as discussing the new diagnostic and therapeutic methods of POI.

Hippo pathway functions as a downstream effector of AKT signaling to regulate the activation of primordial follicles in mice.

Clarifying the molecular mechanisms by which primordial follicles are initiated is crucial for the prevention and treatment of female infertility and ovarian dysfunction. The Hippo pathway has been proven to have a spatiotemporal correlation with the size of the primordial follicle pool in mice in our previous work. But the role and underlying mechanisms of the Hippo pathway in primordial follicle activation remain unclear. Here, the localization and expression of the core components were examined in primordial follicles before and after activation. And the effects of the Hippo pathway on primordial follicle activation were determined by genetically manipulating yes-associated protein 1 (Yap1), the key transcriptional effector. Furthermore, an AKT specific inhibitor (MK2206) was added to determine the interaction between the Hippo pathway and AKT, an important signaling regulator of ovarian function. Results showed that the core components of the Hippo pathway were localized in both primordial and primary follicles and the expression levels of them changed significantly during the initiation of primordial follicles. Yap1 knockdown suppressed primordial follicle activation, while its overexpression led to the opposite trend. MK2206 downregulated the ratio of P-MST/MST1 and upregulated the ratio of P-YAP1/YAP1 significantly, whereas Yap1-treatment had no influence on AKT. In addition, YAP1 upregulation partially rescued the suppression of the primordial follicle activation induced by MK2206. Our findings revealed that the Hippo-YAP1 regulates primordial follicular activation, which is mediated by AKT signaling in mice, thus providing direct and new evidence to highlight the role of Hippo signaling in regulating ovarian follicles development.

Research advances in the regulation of the putative ovarian germline stem cell niche on female germline stem cells.

Stem cells are ideal seeding cells, which have the potential for self-renewal and multiple differentiation, and they play a fundamental role in maintaining homeostasis and regenerating and repairing tissue. The discovery of female germline stem cells (FGSCs) brings much hope for the postnatal renewal of oocytes and solving some female infertility problems. Ovarian function declines with increasing female age. Moreover, ovarian germline stem cell niche-aging could be the main cause of ovarian senescence, which ultimately leads to decreased follicle generation, declining female fertility, and age-related diseases, such as osteoporosis and ovarian cancer. The ovarian germline stem cell niche is the surrounding microenvironment in which FGSCs live, and it helps control the biological characteristics of FGSCs in many ways, such as nutritional supply and immunological cytokine secretion. This paper reviews the knowledge about the ovarian germline stem cell niche and its probable regulatory mechanisms on FGSCs, which provides valuable scientific information and scope for the prevention and treatment of ovarian senescence. Abbreviations: BMP: bone morphogenetic protein; Dpp: decapentaplegic; FGSC: female germline stem cell; IL, interleukin; OGSC: ovarian germline stem cells; ROS: reactive oxygen species; TGF, transforming growth factor; TNF, tumor necrosis factor.

Tri-ortho-cresyl phosphate (TOCP) induced ovarian failure in mice is related to the Hippo signaling pathway disruption.

As a plasticizer widely used in society, tri-ortho-cresyl phosphate (TOCP) is reported to inhibit spermatogenesis and growth of spermatogonial stem cells. However, its effects on female reproductive system are virtually unknown. The present study investigated the effects of TOCP on ovarian follicle development by using mouse model of chronic TOCP exposure, and examined the expression of the core components of the Hippo pathway, which had been proven to be crucial for ovarian follicle development. Furthermore, through up-regulation of Hippo-yes-associated protein 1 (Yap1) in ovaries, the potential protective effects of Yap1 over-expression on TOCP-induced ovarian dysfunction were observed. The results showed that TOCP impaired ovarian function in a dose-dependent manner, and the expression of the Hippo pathway changed significantly in TOCP-exposed ovaries. Further, YAP1 over-expression partially reversed the TOCP-induced ovarian impairment. Collectively, these data indicate that the Hippo pathway is involved in the mechanism by which TOCP elicits ovarian function impairment.

Mechanism for the Decision of Ovarian Surface Epithelial Stem Cells to Undergo Neo-Oogenesis or Ovarian Tumorigenesis.

The ovary is surrounded by a whitish layer of mesodermally derived ovarian surface epithelium (OSE) that lines the intraembryonic celom and comprises simple squamous to cuboidal to low pseudostratified columnar epithelial cells. Its integrity is maintained by simple desmosomes, incomplete tight junctions, several integrins and cadherins. Recent research has found that ovarian stem cells (OSCs) exist within the OSE and may be responsible for both neo-oogenesis and ovarian cancer during adult life. The factors determining whether OSCs undergo neo-oogenesis or ovarian cancer are of great interest to researchers and clinicians. Accumulating evidence suggests the mechanism for the decision of ovarian surface epithelial stem cells to undergo either neo-oogenesis or ovarian cancer transformation may comprise both internal and external factors. Here, we review recent progress on how the internal factors, including genes, signaling pathways and lncRNA: OSE stem cells mediate the development and progression of ovarian cancer through various genes such as p53, KRAS, BRAF, and PTEN, and mutations in PIK3CA, and through various signaling pathways, including TGF-B pathway, Wnt signaling pathway, Notch signaling pathway, NF-kB signal transducer and transcriptional activator 3 (STAT3) pathway and Hedghog (HH) pathway. A series of expressions of IncRNA have changed in epithelial ovarian cancer tissues and cell lines compared to normal ovarian tissues and cell lines. As well as external factors, including incessant ovulation, gonadotropin and chronicinflammation: Frequent ovulation, without long-term dormancy, increases the risk of illness, because repeated rupture and repair at the ovulation site provides an opportunity for the accumulation of genetic aberrations; FSH affects all aspects of ovarian cancer metastasis, such as inhibition of apoptosis, through Induction of increased expression of VEGFA (VEGF) to support tumor growth, promote vascular growth, and possibly alter certain oncogenic pathways, thereby promoting proliferation and invasive phenotypic inflammation contributes to tumorigenesis, which help determine whether OSCs undergo neo-oogenesis or ovarian tumorigenesis. Understanding this issue is critical for developing novel strategies for premature ovarian failure and ovarian cancer prevention and therapy.

Ovarian Stem Cell Nests in Reproduction and Ovarian Aging.

The fixed primordial follicles pool theory, which monopolized reproductive medicine for more than one hundred years, has been broken by the discovery, successful isolation and establishment of ovarian stem cells. It has brought more hope than ever of increasing the size of primordial follicle pool, improving ovarian function and delaying ovarian consenescence. Traditional view holds that stem cell aging contributes to the senility of body and organs. However, in the process of ovarian aging, the main factor leading to the decline of the reproductive function is the aging and degradation of ovarian stem cell nests, rather than the senescence of ovarian germ cells themselves. Recent studies have found that the immune system and circulatory system are involved in the formation of ovarian germline stem cell niches, as well as regulating the proliferation and differentiation of ovarian germline stem cells through cellular and hormonal signals. Therefore, we can improve ovarian function and delay ovarian aging by improving the immune system and circulatory system, which will provide an updated program for the treatment of premature ovarian failure (POF) and infertility.