HIF-1α Protects Granulosa Cells From Hypoxia-Induced Apoptosis During Follicular Development by Inducing Autophagy

Hypoxia, NSAIDs, and autism: A biocultural analysis of stressors in gametogenesis

Cultural and generational trends have increasingly favored "anti-inflammatory" action, innovating a new class of analgesic, non-steroidal anti-inflammatory drugs (NSAIDs) in the 20th century. The modern human body has been molded over evolutionary time and while acknowledging inflammation can be pathologically entwined, it also serves an important role in healthy folliculogenesis and ovulation, shaping cues that drive needed vascular change. This review argues that because of anti-inflammatory action, the cultural invention of NSAIDs represents a particular stressor on female reproductive-age bodies, interacting with natural, underlying variation and placing limits on healthy growth and development in the follicles, creating potential autism risk through hypoxia and mutagenic or epigenetic effects. Since testes are analogs to ovaries, the biological grounding extends naturally to spermatogenesis. This review suggests the introduction of over-the-counter NSAIDs in the 1980s failed to recognize the unique functioning of reproductive-age bodies, challenging the cyclical inflammation needed for healthy gamete development. NSAIDs are framed as one (notable) stressor in an anti-inflammatory era focused on taming the risks of inflammation in modern human life.

Liraglutide Improves PCOS Symptoms in Rats by Targeting FDX1

BACKGROUND

Polycystic ovary syndrome (PCOS) is a gynecological endocrine disorder characterized by ovulatory disorders, hyperandrogenemia, and polycystic changes in the ovaries. FDX1 is a ferredoxin-reducing protein on human mitochondria that plays an important role in steroid anabolism. Liraglutide, a glucagon-like peptide-1 receptor agonist (GLP-1RA), has recently emerged as a potential therapeutic agent for PCOS. Recent studies have suggested that FDX1 may be associated with the development of PCOS. This study aims to explore the pivotal role of FDX1 in the amelioration of PCOS through liraglutide intervention.

MATERIALS AND METHODS

A PCOS rat model was induced via subcutaneous DHEA injections. Following successful model establishment, the rats were treated with liraglutide combined with metformin, or with each drug individually, over a six-week period. After 6 weeks of treatment, we assessed changes in body weight, fasting blood glucose, sex hormone levels, estrous cycle regularity, ovarian morphology, FDX1 expression in ovarian tissue, and ovarian ROS levels.

RESULTS

PCOS rats exhibited significant increases in body weight and fasting blood glucose levels, disrupted estrous cycles, and polycystic ovarian morphology. FDX1 expression was notably reduced in the ovarian tissues of PCOS rats. Treatment with liraglutide, both alone and in combination with metformin, led to improvements in body weight, fasting blood glucose, sex hormone balance, estrous cycle regularity, ovarian morphology, and ovarian ROS levels. Notably, FDX1 expression was significantly restored in all treatment groups, with the most substantial increase observed in the liraglutide-treated group.

CONCLUSION

This study suggests that FDX1 could serve as a potential biomarker for elucidating the underlying mechanisms of liraglutide's therapeutic effects in PCOS management.

High coverage of targeted lipidomics revealed lipid changes in the follicular fluid of patients with insulin-resistant polycystic ovary syndrome and a positive correlation between plasmalogens and oocyte quality

Background

Polycystic ovary syndrome with insulin resistance (PCOS-IR) is the most common endocrine and metabolic disease in women of reproductive age, and low fertility in PCOS patients may be associated with oocyte quality; however, the molecular mechanism through which PCOS-IR affects oocyte quality remains unknown.

Methods

A total of 22 women with PCOS-IR and 23 women without polycystic ovary syndrome (control) who underwent in vitro fertilization and embryo transfer were recruited, and clinical information pertaining to oocyte quality was analyzed. Lipid components of follicular fluid (FF) were detected using high-coverage targeted lipidomics, which identified 344 lipid species belonging to 19 lipid classes. The exact lipid species associated with oocyte quality were identified.

Results

The number (rate) of two pronuclear (2PN) zygotes, the number (rate) of 2PN cleaved embryos, and the number of high-quality embryos were significantly lower in the PCOS-IR group. A total of 19 individual lipid classes and 344 lipid species were identified and quantified. The concentrations of the 19 lipid species in the normal follicular fluid (control) ranged between 10-3 mol/L and 10-9 mol/L. In addition, 39 lipid species were significantly reduced in the PCOS-IR group, among which plasmalogens were positively correlated with oocyte quality.

Conclusions

This study measured the levels of various lipids in follicular fluid, identified a significantly altered lipid profile in the FF of PCOS-IR patients, and established a correlation between poor oocyte quality and plasmalogens in PCOS-IR patients. These findings have contributed to the development of plasmalogen replacement therapy to enhance oocyte quality and have improved culture medium formulations for oocyte in vitro maturation (IVM).

A matter of new life and cell death: programmed cell death in the mammalian ovary

BACKGROUND

The mammalian ovary is a unique organ that displays a distinctive feature of cyclic changes throughout the entire reproductive period. The estrous/menstrual cycles are associated with drastic functional and morphological rearrangements of ovarian tissue, including follicular development and degeneration, and the formation and subsequent atrophy of the corpus luteum. The flawless execution of these reiterative processes is impossible without the involvement of programmed cell death (PCD).

MAIN TEXT

PCD is crucial for efficient and careful clearance of excessive, depleted, or obsolete ovarian structures for ovarian cycling. Moreover, PCD facilitates selection of high-quality oocytes and formation of the ovarian reserve during embryonic and juvenile development. Disruption of PCD regulation can heavily impact the ovarian functions and is associated with various pathologies, from a moderate decrease in fertility to severe hormonal disturbance, complete loss of reproductive function, and tumorigenesis. This comprehensive review aims to provide updated information on the role of PCD in various processes occurring in normal and pathologic ovaries. Three major events of PCD in the ovary-progenitor germ cell depletion, follicular atresia, and corpus luteum degradation-are described, alongside the detailed information on molecular regulation of these processes, highlighting the contribution of apoptosis, autophagy, necroptosis, and ferroptosis. Ultimately, the current knowledge of PCD aberrations associated with pathologies, such as polycystic ovarian syndrome, premature ovarian insufficiency, and tumors of ovarian origin, is outlined.

CONCLUSION

PCD is an essential element in ovarian development, functions and pathologies. A thorough understanding of molecular mechanisms regulating PCD events is required for future advances in the diagnosis and management of various disorders of the ovary and the female reproductive system in general.

Melatonin regulates autophagy in granulosa cells from patients with premature ovarian insufficiency via activating Foxo3a

Premature ovarian insufficiency (POI) is a diverse form of female infertility characterized by a decline in ovarian function before the age of 40. Melatonin (MT) is a potential clinical treatment for restoring or safeguarding ovarian function in POI. However, the specific therapeutic mechanism underlying this effect remains unclear. To address this, we conducted experiments using human granulosa cells (GCs) from both POI and normal patients. We examined the expression levels of autophagy-related genes and proteins in GCs through qRT-PCR and western blot analysis. Autophagy flux was monitored in GCs infected with GFP-LC3-adenovirus, and the regulatory function of MT in autophagy was investigated. Additionally, we employed pharmacological intervention of autophagy using 3-Methyladenine (3-MA) and RNA interference of Forkhead box O-3A (FOXO3A) to elucidate the mechanism of MT in the autophagy process. Compared to GCs from normal patients, GCs from POI patients exhibited irregular morphology, decreased proliferation, increased apoptosis, and elevated ROS levels. The expression of autophagy-related genes was downregulated in POI GCs, resulting in reduced autophagic activity. Furthermore, MT levels were decreased in POI GCs, but exogenous MT effectively activated autophagy. Mechanistically, melatonin treatment downregulated FOXO3A expression and induced phosphorylation in POI GCs. Importantly, silencing FOXO3A abolished the protective effect of melatonin on GCs. These findings indicate that autophagy is downregulated in POI GCs, accompanied by a deficiency in MT. Moreover, we demonstrated that supplementing MT can rescue autophagy levels and enhance GC viability through the activation of FOXO3A signaling. Thus, MT-FOXO3A may serve as a potential therapeutic target for POI treatment.

Paxillin knockout in mouse granulosa cells increases fecundity†

Paxillin is an intracellular adaptor protein involved in focal adhesions, cell response to stress, steroid signaling, and apoptosis in reproductive tissues. To investigate the role of paxillin in granulosa cells, we created a granulosa-specific paxillin knockout mouse model using Cre recombinase driven by the Anti-Müllerian hormone receptor 2 gene promoter. Female granulosa-specific paxillin knockout mice demonstrated increased fertility in later reproductive age, resulting in higher number of offspring when bred continuously up to 26 weeks of age. This was not due to increased numbers of estrous cycles, ovulated oocytes per cycle, or pups per litter, but this was due to shorter time to pregnancy and increased number of litters in the granulosa-specific paxillin knockout mice. The number of ovarian follicles was not significantly affected by the knockout at 30 weeks of age. Granulosa-specific paxillin knockout mice had slightly altered estrous cycles but no difference in circulating reproductive hormone levels. Knockout of paxillin using clustered regularly interspaced short palindromic repeat-associated protein 9 (CRISPR-Cas9) in human granulosa-derived immortalized KGN cells did not affect cell proliferation or migration. However, in cultured primary mouse granulosa cells, paxillin knockout reduced cell death under basal culture conditions. We conclude that paxillin knockout in granulosa cells increases female fecundity in older reproductive age mice, possibly by reducing granulosa cell death. This study implicates paxillin and its signaling network as potential granulosa cell targets in the management of age-related subfertility.

The physiological functions and therapeutic potential of exosomes during the development and treatment of polycystic ovary syndrome

Polycystic ovary syndrome is a very common disease of gynecological endocrine, accompanied by irregular menstruation, hyperandrogenism, metabolic abnormalities, reproductive disorders and other clinical symptoms, which seriously endangers women's physical and mental health, but its etiology and pathogenesis are not completely clear. Recently, the contribution of exosomes to the diagnosis and treatment of various diseases in the biomedical field has attracted much attention, including PCOS. Exosomes are extracellular vesicles secreted by cells, containing various biologically active molecules such as cell-specific proteins, lipids, and nucleic acids. They are important signaling regulators in vivo and widely participate in various physiopathological processes. They are new targets for disease diagnosis and treatment. Considering the important role of non-coding RNAs during the development and treatment of PCOS, this article takes exosomal miRNAs as the breakthrough point for elucidating the physiological functions and therapeutic potential of exosomes during the development and treatment of PCOS through analyzing the effects of exosomal miRNAs on ovarian follicle development, hormone secretion, oxidative stress, inflammatory response and insulin resistance, thus providing new research directions and theoretical basis for PCOS pathogenesis, clinical diagnosis and prognosis improvement.

The role of HIF-1α-mediated autophagy in ionizing radiation-induced testicular injury

Testis, as a key organ for maintaining male fertility, are extremely sensitive to ionizing radiation (IR). IR-induced testicular dysfunction and infertility are common adverse effects of radiation therapy in patients with pelvic cancer. To study the phenotype and mechanism of IR-induced testicular injury, the mice were irradiated with different radiation doses (0, 2 and 5 Gy) below the semi-lethal dose for one month. Our present results showed that testicular weight and the serum testosterone levels significantly decreased with the structural injury of the testis in an IR dose-dependent manner, indicating that IR caused not only the structural damage of the testis, but also the functional damage. Further analysis by TUNEL staining and Western blotting found that IR induced the apoptosis in a dose-dependent manner as indicated by increased expressions of cleaved caspase3, p53 and Bax on Day 15 after IR treatment. Combined with significantly increased oxidative stress, these results indicated that IR-induced testicular damage may be a long-term, progressively aggravated process, accompanied by apoptosis. Given the role of autophagy in apoptosis, the present study also detected and analyzed the localization and expressions of autophagy-related proteins LC-3I/II, beclin1, p62 and Atg12 in testicular cells, and found that LC-3II, beclin1 and Atg12 expressions significantly increased in the testicular cells of mice irradiated with 2 Gy and 5 Gy, while p62 expression significantly decreased with 5 Gy, implying autophagy was involved in the apoptosis of testicular cells induced by IR. Furthermore, the expressions of HIF-1α and BNIP3 were significantly enhanced in the testis cells of mice irradiated with 2 Gy and 5 Gy, suggesting the potential role of HIF-1α/BNIP3-mediated autophagy in the apoptosis of testicular cells induced by IR. Taken together, our findings demonstrated that HIF-1α/BNIP3-mediated autophagy not only plays a protective effect on the testicular cells of mice irradiated with 2 Gy, but also induces the apoptosis of the testicular cells of mice irradiated with 5 Gy, indicating the double effects on apoptosis, which will help us further understanding the molecular mechanisms of IR-induced testicular injury, and will facilitate us further studies on testicular radioprotection.

Therapeutic Effects and Molecular Mechanism of Chlorogenic Acid on Polycystic Ovarian Syndrome: Role of HIF-1alpha

Chlorogenic acid (CGA) is a powerful antioxidant polyphenol molecule found in many diets and liquid beverages, playing a preventive and therapeutic role in various diseases caused by oxidative stress and inflammation. Recent research has found that CGA can not only improve clinical symptoms in PCOS patients but also improve follicular development, hormone status, and oxidative stress in PCOS rats, indicating the therapeutic effect of CGA on PCOS. Notably, our previous series of studies has demonstrated the expression changes and regulatory mechanisms of HIF-1alpha signaling in PCOS ovaries. Considering the regulatory effect of CGA on the HIF-1alpha pathway, the present article systematically elucidates the therapeutic role and molecular mechanisms of HIF-1alpha signaling during the treatment of PCOS by CGA, including follicular development, steroid synthesis, inflammatory response, oxidative stress, and insulin resistance, in order to further understand the mechanisms of CGA effects in different types of diseases and to provide a theoretical basis for further promoting CGA-rich diets and beverages simultaneously.

BNIP3-mediated autophagy via the mTOR/ULK1 pathway induces primordial follicle loss after ovarian tissue transplantation

PURPOSE

To explore the underlying mechanism of primordial follicle loss in the early period following ovarian tissue transplantation (OTT).

METHODS

BNIP3 was selected through bioinformatic protocols, as the hub gene related to autophagy during OTT. BNIP3 and autophagy in mice ovarian grafts and in hypoxia-mimicking KGN cells were detected using immunohistochemistry, transmission electron microscopy (TEM), western blotting, qPCR, and fluorescence staining. The regulatory role played by BNIP3 overexpression and the silencing of KGN cells in autophagy via the mTOR/ULK1 pathway was investigated.

RESULTS

Ultrastructure examination showed that autophagic vacuoles increased after mice ovarian auto-transplantation. The BNIP3 and autophagy-related proteins (Beclin-1, LC3B, and SQSTM1/p62) in mice ovarian granulosa cells of primordial follicle from ovarian grafts were altered compared with the control. Administration of an autophagy inhibitor in mice decreased the depletion of primordial follicles. In vitro experiments indicated that BNIP3 and autophagy activity were upregulated in KGN cells treated with cobalt chloride (CoCl2). The overexpression of BNIP3 activated autophagy, whereas the silencing of BNIP3 suppressed it and reversed the autophagy induced by CoCl2 in KGN cells. Western blotting analysis showed the inhibition of mTOR and activation of ULK1 in KGN cells treated with CoCl2 and in the overexpression of BNIP3, and the opposite results following BNIP3 silencing. The activation of mTOR reversed the autophagy induced by BNIP3 overexpression.

CONCLUSIONS

BNIP3-induced autophagy is crucial in primordial follicle loss during OTT procedure, and BNIP3 is a potential therapeutic target for primordial follicle loss after OTT.

Diabetes-Induced Autophagy Dysregulation Engenders Testicular Impairment via Oxidative Stress

Testes produce sperms, and gamete generation relies on a proper niche environment. The disruption of hierarchical regulatory homeostasis in Leydig or Sertoli cells may evoke a sterile phenotype in humans. In this study, we recapitulated type 2 diabetes mellitus by using a high-fat diet- (HFD-) fed mouse model to identify the phenotype and potential mechanism of diabetes-induced testicular impairment. At the end of the study, blood glucose levels, testosterone structure, testicular antioxidant capacity, and testosterone level and the expression of hypoxia-inducible factor- (HIF-) 1α, apoptosis-related protein cleaved-caspase3, and autophagy-related proteins such as LC3I/II, p62, and Beclin1 were evaluated. We found that long-term HFD treatment causes the development of diabetes mellitus, implicating increased serum glucose level, cell apoptosis, and testicular atrophy (P < 0.05 vs. Ctrl). Mechanistically, the results showed enhanced expression of HIF-1α in both Sertoli and Leydig cells (P < 0.05 vs. Ctrl). Advanced glycation end products (AGEs) were demonstrated to be a potential factor leading to HIF-1α upregulation in both cell types. In Sertoli cells, high glucose treatment had minor effects on Sertoli cell autophagy. However, AGE treatment stagnated the autophagy flux and escalated cell apoptosis (P < 0.05 vs. Ctrl+Ctrl). In Leydig cells, high glucose treatment was adequate to encumber autophagy induction and enhance oxidative stress. Similarly, AGE treatment facilitated HIF-1α expression and hampered testosterone production (P < 0.05 vs. Ctrl+Ctrl). Overall, these findings highlight the dual effects of diabetes on autophagy regulation in Sertoli and Leydig cells while imposing oxidative stress in both cell types. Furthermore, the upregulation of HIF-1α, which could be triggered by AGE treatment, may negatively affect both cell types. Together, these findings will help us further understand the molecular mechanism of diabetes-induced autophagy dysregulation and testicular impairment, enriching the content of male reproductive biology in diabetic patients.

Effects of exogenous spermidine on autophagy and antioxidant capacity in ovaries and granulosa cells of Sichuan white geese

Autophagy can inhibit ovarian senescence induced by oxidative stress and regulate follicle development and atresia, but its mechanism is still unclear. Exogenous spermidine can induce autophagy and scavenge reactive oxygen species (ROS). In this experiment, oxidative stress in Sichuan white geese ovaries and follicular granulosa cells (GCs) was caused by 3-nitropropionic acid (3-NPA) and spermidine was added to explore the effect of exogenous spermidine inducing autophagy and inhibiting oxidative stress in vivo and in vitro. Research results showed that putrescine, spermidine and spermine contents in goose ovaries in the group treated with spermidine combined with 3-NPA were 2.70, 1.94, and 1.70 times higher than those in the group treated with 3-NPA, respectively (P < 0.05). The contents of spermidine and spermine in GCs were 1.37 and 0.89 times higher in the spermidine in combination with the 3-NPA group than in the 3-NPA group, respectively (P < 0.05). LC3 and p62 were mainly expressed in the follicular granulosa layer. The LC3-II/I ratio and p62 level in GCs in the spermidine combined with 3-NPA treatment group were 1.37 and 0.77 times higher than that of the 3-NPA treatment group, respectively (P < 0.05). 3-NPA treatment significantly increased ROS level and the apoptosis rate in GCs, while the combined treatment of spermidine and 3-NPA reversed this change (P < 0.05). In conclusion, spermidine alleviated the oxidative damage induced by 3-NPA by improving the antioxidant capacity of ovaries and follicular GCs of Sichuan white geese and may be alleviated by inducing autophagy in GCs.

Roles of HIF-1α/BNIP3 mediated mitophagy in mitochondrial dysfunction of letrozole-induced PCOS rats

Mitochondrial dysfunction plays a crucial role in the pathological physiology of polycystic ovary syndrome (PCOS). Mitochondrial quality control system is vital to maintaining mitochondrial function, includes mitochondrial biosynthesis, dynamics and mitophagy. While mitophagy as a specific autophagy, plays an important role in the mitochondrial quality control system and is mediated by some signaling pathways to eliminate the excessive production of reactive oxygen species (ROS), such as hypoxia-inducible factor (HIF)-1α/B-cell lymphoma-2 adenovirus E1B 19 kDa interacting protein 3 (BNIP3). Our previous studies have found that excessive production of ROS and the decreased expression of HIF-1α in the ovaries of PCOS rats. Thus, we hypothesized that excessive ROS leads to mitochondrial dysfunction, attenuates HIF-1α/BNIP3-mediated mitophagy in the ovaries of PCOS rats, and further reduces the mitophagic defense. Firstly, the oxidative stress status was detected and found excessive ROS damages ovarian tissue in PCOS rats. Secondly, the marker proteins of mitochondrial biosynthesis/dynamics and amount were examined and found that their expression levels were abnormal, which showed that the abnormal mitochondrial quality control system leads to accumulate the excess or damaged mitochondria in PCOS ovaries. Finally, we detected the HIF-1α/BNIP3 pathway and found HIF-1α-mediated mitophagy is impaired in the ovaries of PCOS rats. Together, these results clearly demonstrated excessive ROS causes mitochondrial dysfunction via the abnormal mitochondrial quality control system, and attenuates HIF-1α/BNIP3-mediated mitophagic defense in the granulosa cells of PCOS rats, which will provide a new direction for further understanding the role of HIF-1α in the molecular mechanism of mitochondrial dysfunction in PCOS ovaries.

Expression profile of the Kisspeptin/Kiss1r system and angiogenic and immunological mediators in the ovary of cyclic and pregnant cats

The Kisspeptin/Kiss1r system has been studied in mammalian ovaries. However, there are still no studies on the modulation of this system and its relationship with angiogenic and immunological mediators in the ovary of domestic cats, especially during pregnancy. We evaluated the expression of Kisspeptin/Kiss1r and angiogenic and immunological mediators during folliculogenesis, luteogenesis and luteal regression of cyclic and pregnant cats. The ovary exhibited moderate to intense expression for Kiss1, VEGF, Flk-1, INFγ and MIF in oocytes and the follicular wall, while Kiss1r expression was low in granulosa cells. In these cells, there was also a greater expression of Kiss1, INFγ and MIF, mainly in secondary follicles, while tertiary and preovulatory follicles exhibited greater expression of VEGF and Flk-1 in this layer. In luteogenesis, Kiss1 immunostaining was higher in mature corpora lutea (MCL) of pregnant cats compared to vacuolated CL (VCL) and corpus albicans (CA). Pregnancy also increased the luteal gene expression of Kiss1 as well as Kiss1, Kiss1r, Flk-1, and MIF immunostaining in MCL, while reduced the area of VEGF expression in VCL and luteal mRNA expression of Mif when compared to non-pregnant animals. In addition, positive gene correlation between Kiss1r and Mif was observed in the CL. Kiss1, Kiss1r, Vegf and Mif expression were lower in the CA of cats in anestrus. These findings reveal that the expression of Kisspeptin/Kiss1r and angiogenic and immunological mediators, in the ovary of domestic cats, depend on the follicular and luteal stage, and the luteal expression of these mediators is influenced by pregnancy.