Ovarian Corpora Lutea Research Articles

Obesity induced by a high-fat diet changes p62 protein levels in mouse reproductive organs.

Obesity is one of the major risk factor for infertility since it causes decreased quality and quantity of gametes and a disrupted uterine environment which might result in miscarriage, stillbirth, and fetal abnormal growth. Obesity induces oxidative stress which is strongly associated with infertility. The clearing of oxidative stress by autophagy is maintained through the p62/ Keap1/Nrf2 pathway. In this pathway, oxidative stress induces p62 for binding to Keap1, thereby Keap1 cannot bind to the Nrf2 transcription factor. Then, Nrf2 translocates into the nucleus and initiates antioxidant-related gene expression. While p62, bound to Keap1, acts as an adaptor protein between autophagosome and damaged substrates which needs to be degraded for homeostasis. Up to date, obesity is strongly linked to abnormal autophagy activity. However, p62 protein expression has not been investigated in the obese ovary, testis, and uterus in detail. Thus, in the present study, we aimed to evaluate the effects of a high-fat diet (HFD)-induced obesity on p62 protein levels of the ovary, testis, and uterus in mice. Our results demonstrated that the p62 expression level was significantly altered by HFD in uterine glands, epithelium, myometrium, and stroma, and in the ovarian corpus luteum, testicular spermatogonium and spermatocytes.

The potential role of Ral-interacting protein 76 and vascular endothelial growth factor on angiogenesis in the tumor and ovarian corpus luteum microenvironment.

Tumors and the ovarian corpus luteum have complex mechanisms in the growth microenvironment. Angiogenesis is especially important for demonstrating the molecular mechanism of dynamic cellular function in tumors and corpus luteum. Angiogenesis in tumors and corpus luteum seems to have a similar function, and Ral-interacting protein 76 (RLIP76) and vascular endothelial growth factor (VEGF) are expressed in the tissues of tumors and ovarian corpus luteum. RLIP76 is a potential factor with VEGF in the tumor and corpus luteum angiogenesis. RLIP76 regulates a small GTPase (R-Ras) in cell survival, spreading, and migration. VEGF activates angiogenic functions in tumor and endothelial cells. Hypoxia-inducible factor-1 (HIF-1) is important in tumor growth, tumor angiogenesis, and corpus luteum. VEGF and HIF-1 regulate the angiogenic function of RLIP76, and RLIP76 controls vascular growth in endothelial and tumor cells. RLIP76, R-Ras, VEGF, and HIF-1 may be useful in the research of corpus luteum and cancer therapy and the study of mechanisms of tumor and corpus luteum angiogenesis. This review will help to elucidate the roles of RLIP76 and VEGF in tumor and corpus luteum angiogenesis, tumorigenesis, and the specific regulation of RLIP76 and VEGF. Thus, we reviewed the potential role of RLIP76 and VEGF in the angiogenesis of the tumor and corpus luteum in the tumor and ovarian microenvironment.

The effect of melatonin on the Bcl-2 and Bad proteins expression in ovarian corpus luteum cells after exposure to experimental hyperthermia

Background. There is growing interest in determining the role of melatonin in the regulation of proliferation and apoptosis of ovarian cells at various diseases and destabilizing influences. It is believed that the choice between the implementation of a cell death or survival program determines the ratio of anti-apoptotic and pro-apoptotic proteins.The aim. To identify the effect ofmelatonin onthe expression ofanti-apoptotic Bcl-2 and pro-apoptotic Bad and the Bcl-2/Bad ratio in the ovarian luteocytes of Wistar rats in the acute (day 3) and recovery (days 7 and 14) periods after a single exposure to experimental hyperthermia.Methods. Warming up took no more than 17 minutes. Melatonin was injected subcutaneously (0.1 mg in 0.2 ml of physiological solution) for 3 days after experimental hyperthermia. Comparison groups included rats with physiological solution injection (control) and animals after experimental hyperthermia + physiological solution injection. The Bad and Bcl-2 expression was determined immunohistochemically on days 3, 7 and 14 after experimental hyperthermia + physiological solution or melatonin injection.Results. On the day 3 after experimental hyperthermia, the effect of the hormone was not detected. A week after experimental hyperthermia + melatonin injection, the Bad expression area decreased more significantly than in rats after experimental hyperthermia + physiological solution injection, which led to an increase in Bcl-2/ Bad ratio. This indicated an increase in anti-apoptotic protection, blocking the development of the internal apoptosis pathway at this time. 2 weeks after experimental hyperthermia + physiological solution injection, the Bcl-2 area decreased more significantly than the Bad area. As a result, the Bcl-2/Bad ratio decreased almost 2-fold compared to the control group. This indicated the activation of the “mitochondrial branch” of luteocyte apoptosis. 2 weeks after experimental hyperthermia + melatonin injection, the Bad and Bcl-2 areas decreased synchronously, which restored Bcl-2/ Bad to control values.Conclusion. The melatonin injection after experimental hyperthermia shifts the ratio of Bcl-2/Bad expression areas towards an increase in anti-apoptotic Bcl2 already a week after the recovery period and promotes earlier normalization of Bcl-2/Bad to physiological levels (as early as 2 weeks after experimental hyperthermia + melatonin injection).

Evaluation of the effectiveness of treatment of cows with persistent ovarian corpus luteum

The article presents the results of studies on the use of the drug regostenol in persistent ovarian corpus luteum. The studies were carried out in JSC "PZ" Meliorator "of the Saratov region, where they noted the widespread obstetric and gynecological pathology in cows. Among these diseases, 43.91% are functional disorders of the ovaries. Persistent corpus luteum was recorded in 12.69% of animals. After the use of regostenol, 91.67% of cows showed the stage of excitation of the sexual cycle, and the time for the onset of the first sexual cycle came in 5.2 ± 0.03 days. In the control group of cows, no manifestations of sexual cyclicity occurred. Experimental studies have shown that after the use of regostenol in cows with a persistent corpus luteum, 75.0% of animals became pregnant with an insemination index of 1.8. Whereas in the control group, all animals remained infertile. The data obtained indicate the expediency of using the drug, since it allows achieving the manifestation of sexual cyclicity after prolonged anaphradesia and fertilization of most of the cows after insemination.

Basic fibroblast growth factor induces proliferation and collagen production by fibroblasts derived from the bovine corpus luteum†.

Cyclic regression of the ovarian corpus luteum, the endocrine gland responsible for progesterone production, involves rapid matrix remodeling. Despite fibroblasts in other systems being known for producing and maintaining extracellular matrix, little is known about fibroblasts in the functional or regressing corpus luteum. Vast transcriptomic changes occur in the regressing corpus luteum, among which are reduced levels of vascular endothelial growth factor A (VEGFA) and increased expression of fibroblast growth factor 2 (FGF2) after 4 and 12h of induced regression, when progesterone is declining and the microvasculature is destabilizing. We hypothesized that FGF2 activates luteal fibroblasts. Analysis of transcriptomic changes during induced luteal regression revealed elevations in markers of fibroblast activation and fibrosis, including fibroblast activation protein (FAP), serpin family E member 1 (SERPINE1), and secreted phosphoprotein 1 (SPP1). To test our hypothesis, we treated bovine luteal fibroblasts with FGF2 to measure downstream signaling, type 1 collagen production, and proliferation. We observed rapid and robust phosphorylation of various signaling pathways involved in proliferation, such as ERK, AKT, and STAT1. From our longer-term treatments, we determined that FGF2 has a concentration-dependent collagen-inducing effect, and that FGF2 acts as a mitogen for luteal fibroblasts. FGF2-induced proliferation was greatly blunted by inhibition of AKT or STAT1 signaling. Our results suggest that luteal fibroblasts are responsive to factors that are released by the regressing bovine corpus luteum, an insight into the contribution of fibroblasts to the microenvironment in the regressing corpus luteum.

MiR-665 overexpression inhibits the apoptosis of luteal cells in small ruminants suppressing HPGDS

Evidence has shown that microRNA-665 (miR-665) is highly expressed in the mid-luteal phase compared with the early and end-luteal phase of the corpus luteum (CL) life cycle. However, whether miR-665 is a positive regulator of the life span of the CL is still unknown. The objective of this study is to explore the effect of miR-665 on the structural luteolysis in the ovarian CL. In this study, the targeting relationship between miR-665 and hematopoietic prostaglandin synthase (HPGDS) was firstly verified by dual luciferase reporter assay. Then, quantitative real-time PCR (qRT-PCR) was used to detect the expression of miR-665 and HPGDS in luteal cells. Following miR-665 overexpression, the apoptosis rate of the luteal cells was determined using flow cytometry; B-cell lymphoma-2 (BCL-2) and caspase-3 mRNA and protein were measured using qRT-PCR and Western blot (WB) analysis. Finally, the DP1 and CRTH2 receptors of PGD2, a synthetic product of HPGDS, were localized using immunofluorescence. Results confirmed that HPGDS was a direct target gene of miR-665, and miR-665 expression was negatively correlated with HPGDS mRNA expression in luteal cells. Meanwhile, after miR-665 was overexpressed, the apoptotic rate of the luteal cells showed a significant decrease (P < 0.05) and this was accompanied by elevated expression levels of anti-apoptotic factor BCL-2 mRNA and protein and decreased expression levels of apoptotic factor caspase-3 mRNA and protein (P < 0.01). Moreover, the immune fluorescence staining results showed that the DP1 receptor was also significantly decreased (P < 0.05), but the CRTH2 receptor was significantly increased (P < 0.05) in luteal cells. Overall, these results indicate that miR-665 reduces the apoptosis of luteal cells via inhibiting caspase-3 expression and promoting BCL-2 expression, and the biological function of miR-665 may be attributed to its target gene HPGDS which regulates the balance of DP1 and CRTH2 receptors expression in luteal cells. As a consequence, this study suggests that miR-665 might be a positive regulator of the life span of the CL rather than destroy the integrity of CL in small ruminants.

Reproductive and endocrine effects of artemisinin, piperaquine, and artemisinin-piperaquine combination in rats

Background:The WHO recommends artemisinin-based combination regimens for uncomplicated Plasmodium falciparum malaria. One such combination is artemisinin-piperaquine tablets (ATQ). ATQ has outstanding advantages in anti-malarial, such as good efficacy, fewer side effects, easy promotion and application in deprived regions. However, the data about the reproductive and endocrine toxicity of ATQ remains insufficient. Thus, we assessed the potential effects of ATQ and its individual components artemisinin (ART) and piperaquine (PQ) on the reproductive and endocrine systems in Wistar rats.Methods:The unfertilized female rats were intragastric administrated with ATQ (20, 40, and 80 mg/kg), PQ (15, 30, and 60 mg/kg), ART (2.5, 5, and 10 mg/kg), or water (control) for 14 days, respectively. The estrous cycle and serum levels of estradiol (E2), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), prostaglandin (PG), and adrenocorticotropic hormone (ACTH) were determined. The weights of the kidney, adrenal gland, uterus, and ovaries were measured. The histopathological examinations of the adrenal gland, ovary, uterus, and mammary gland were performed.Results:Compared with the control group, there were no significant differences in the examined items of female rats in the ART groups, including general observation, estrous cycle, hormonal level, organ weight, and histopathological examination. The estrous cycle of female rats was disrupted within 4–7 days after ATQ or PQ administration, and then in a persistent dioestrus phase. At the end of administration, ATQ and PQ at three doses induced decreased PG, increased ACTH, increased adrenal weight and size, and pathological lesions in the adrenal gland and ovary, including vasodilation and hyperemia in the adrenal cortex and medulla as well as hyperplasia and vacuolar degeneration, ovarian corpus luteum surface hyperemia, numerous but small corpus luteum, and disordered follicle development. But the serum levels of E2, FSH, LH, and PRL did not change obviously. These adverse effects in ATQ or PQ treated rats could not completely disappear after 21 days of recovery.Conclusion:Based on the results of this study, ART had no obvious reproductive and endocrine effects on female rats, while ATQ and PQ caused adrenal hyperplasia, increased ACTH, decreased PG, blocked estrus, corpus luteum surface hyperemia, and disrupted follicle development in female rats. These events suggest that ATQ and PQ may interfere with the female reproductive and endocrine systems, potentially reducing fertility.

Giant Ovarian Corpus Luteum Cysts Associated with Natural Pregnancy in Woman with Polycystic Ovary Syndrome

A 29-year-old nulliparous woman with polycystic ovary syndrome and no history of ovarian cyst was admitted to obstetric clinic for prenatal screening at 20-week spontaneous gestation of twins. An ultrasound examination showed multicompartmental cysts whose diameters were 20 cm and 15 cm on the left and right ovaries, respectively. A cancer antigen 125 (CA-125) test showed an elevated level of 209.0 U/mL, and the level of alpha fetoprotein (AFP) was 170.0 ng/mL. A diagnosis of physiological cysts was considered. Then, the woman was conservatively managed, and cesarean delivery was scheduled. The size of the cysts increased gradually with the week of gestation, and the diameters got their maximum at 30 cm and 20 cm for each side until 30 weeks (Fig. 1). Unfortunately, she presented spontaneous premature labor then. No adverse maternal or neonatal outcomes were reported. At her 2-month check after delivery, the CA-125 and alpha fetoprotein decreased to normal range. Nevertheless, 6 months after delivery, the sizes of the ovaries were still 20 cm and 10 cm in diameter at the left and right sides, respectively, accompanied by intermittent abdominal pain. Subsequently, she underwent single-port laparoscopic oophorocystectomy (Fig. 2). Pathological analysis revealed bilateral corpus albicans (Fig. 3). The patient recovered smoothly. We present a case of physiological ovarian cysts of unusual size during pregnancy with elevated CA-125, resulting in premature delivery. Expectant management may be considered for giant lutein cyst in pregnancy. However, if there is any suspicion of a malignancy or complications caused by cysts, ovarian cystectomy during pregnancy should be performed.Fig. 2Laparoscopy revealed the huge polycystic ovaries. (A) The pelvis was filled with giant cysts. (B) The left ovary (yellow arrow) was squeezed by the cysts.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig. 3The pathologic photomicrograph revealed corpus albicans.View Large Image Figure ViewerDownload Hi-res image Download (PPT) The authors thank Lei Pan and Kui Li, who aided in data collection and image production.

Ex Vivo Study of Macroscopic Feature and Sonogram Imaging of Bovine Ovarian Corpus Luteum

In the clinical procedure, corpus luteum identification in the ovary is important to determine the reproductive status of cows. There are two methods to determine corpus luteum in live cows, rectal palpation and ultrasound examination. However, real imaging cannot be obtained by these methods. Thus, the current study aimed to describe the macroscopic feature and sonogram imaging of the corpus luteum in the bovine ovary as an ex vivo study. Twenty-eight pairs of bovine ovaries from a slaughterhouse were used in this study. Ovaries were classified based on the diameter of the corpus luteum crown into five categories (≤0.5, 0.5-1, 1-1.5, &gt;1.5cm, and none). We observed and measured the corpus luteum crown and corpus luteum tissue using a vernier calliper and ultrasound. Descriptive and statistical analyses were carried out using the SAS program. The corpus luteum crown was identified as a circular folding tissue on the ovary surface, during corpus luteum tissue as a yellowish lobed structure by macroscopic observation and hypoechoic structure by ultrasonography. Ovaries with corpus luteum crown diameter 0.5-1.0cm were dominant (41%). However, we found no correlation between the area of the corpus luteum crown with the area of corpus luteum tissue by macroscopic (P=0.121) and ultrasound observation (P=0.151). The Corpus luteum crown and corpus luteum tissue described in this study can be used as a reference by practitioners. Further correlation analysis is needed between corpus luteum crown and corpus luteum tissue in live cows.

Exposure to Benzo(a)pyrene damages mitochondrial function via suppressing mitochondrial melatonin receptors in ovarian corpus luteum during early pregnancy

Benzo(a)pyrene (BaP) is a well-known environmental endocrine pollutant, which has ovarian toxicity in mammals. Ovarian corpus luteum (CL), as the main source of progesterone synthesis in early pregnant female, requires a large number of mitochondria for energy supply. We previously demonstrated that BaP and its metabolite benzo(a)pyren-7, 8-dihydrodiol-9, 10-epoxide (BPDE) inhibited the ovarian melatonin receptors (MTRs) expression and decreased the levels of estrogen and progesterone during early pregnancy in mice. Emerging researches show that MTRs also exist on mitochondrial membrane and participate in the regulation of mitochondrial function. However, the relationship between BaP, MTRs on mitochondrial membrane and mitochondrial function remains unknown. Consequently, this study focuses on the effect and potential mechanism of BaP on ovarian luteal mitochondrial function during early pregnancy. We found that BaP and its metabolite BPDE decreased MTRs in early pregnant CL and luteinized KGN cells, especially in mitochondria. Furthermore, BaP or BPDE up-regulated the expression of SIRT3, Mfn2 and Drp-1, damaged mitochondrial morphology and decreased the MMP and the ATP levels, thereby causing mitochondrial dysfunction. Notably, activation of the MTRs on mitochondrial membrane by MTRs agonist ramelteon partially alleviated BPDE-induced up-regulation of SIRT3, Mfn2 and Drp-1, reduced mitochondrial fragmentation and enhanced the MMP and the ATP levels, thus restoring the expression of steroid rate-limiting enzymes. Together, these findings firstly proved that BaP and BPDE down-regulate MTRs on mitochondrial membrane, and further injure mitochondrial function in early pregnant rats’ CL, which provides a new insight for understanding the exact mechanism of the BaP-induced ovarian toxicity.

Ovarian luteal category at the time of exogenous progesterone treatment alters pre-ovulatory follicle size and pregnancy outcome but not initial GnRH treatment in repeat-breeder crossbred dairy heifers submitted to the 7-day fixed-time AI protocol

Repeat breeding is a substantial problem in heifer and cow breeding leading to greater infertility for female dairy herds. The aim of present study was to investigate the impact of corpus luteum (CL) presence and category and the first gonadotropin-releasing hormone (GnRH) administration concurrent with exogenous progesterone (P4) treatment on the largest follicle (LF) size and pregnancy rate (PR) in repeat-breeder crossbred dairy heifers submitted to the fixed-time artificial insemination (AI) protocol. Heifers (n= 243) were synchronised with (+GnRH) or without (–GnRH) first GnRH in the 7-day P4-GnRH-prostaglandin F2α-based programme. Each GnRH group was divided on presence of CL into two groups (+CL and –CL) in a 2 × 2 factorial arrangement. The PR was similar among –GnRH–CL (20.7%), –GnRH+CL (68.8%), +GnRH–CL (30.4%), and +GnRH+CL (68.3%) groups. However, presence of CL in heifers produced a 43.6% increase in PR compared to PR of heifers without CL (odds ratio = 6.550). Heifers bearing large-sized CL had greater large-sized LF on the day of fixed-time AI and PR. Plasma P4 concentration was positively related with CL diameter (r= 0.845; p < 0.001). The diameter of ovarian LF on the day of fixed-time AI was positively associated with P4 concentrations (r= 0.512; p < 0.001). We highlight that ovarian CL presence and category at the time of exogenous P4 treatment alters pre-ovulatory follicle size and PR but not initial GnRH treatment in repeat-breeder crossbred dairy heifers submitted to service with the 7-day fixed-time AI programme.

Experimental hyperthermia: expression of proteins involved in the regulation of ovarian corpus luteum apoptosis in the acute and recovery periods

Background.Heat shock effects can initiate apoptosis of oocytes and corpus luteum cells in mammalian ovaries. During folliculogenesis, follicular apoptosis is regulated by Bcl-2 and BAX proteins which are key effectors of granular cell death. Mechanisms of disruption of the ovarian corpus luteum development under heat stress remain largely unclear.Aim of the research: to identify the expression features of anti-apoptotic Bad and proapoptotic Bcl-2 proteins in the rat ovarian luteocytes in the acute (by day 3) and recovery (by days 7 and 14) periods after a single exposure of experimental hyperthermia (EH) (rectal temperature 43.5 °C).Materials and methods. The expression of Bad and Bcl-2 was determined immunohistochemically using an indirect two-stage streptavidin-biotin method.Results. On day 3 after EH, the expression areas of both Bad and Bcl-2 increased 2-fold, but the ratio of Bcl-2/Bad areas did not change, indicating that the intensity of apoptosis along the mitochondrial pathway in luteocytes in the acute period was maintained within physiological values. On day 7, the Bad and Bcl-2 expression areas remained at the level of day 3, but the Bcl-2/Bad index decreased, indicating the activation of the apoptosis internal pathway in the ovarian corpus luteum cells. By day 14, the protein expression areas decreased (Bad – by 1.7 times, Bcl-2 – by 3.2 times) compared to the acute period, and the Bcl-2/Bad index decreased by 2 times compared to the control and the acute period group.Conclusion. The observed predominance of proapoptotic Bad protein over antiapoptotic Bcl-2 in luteocytes on day 14 after EH indicates the anti-apoptotic protection violation, which leads to the apoptosis mitochondrial pathway activation of the latter. A decrease in Bcl-2 expression can be regarded as a manifestation of the defective luteocytes removal mechanism and the body’s desire to normalize the ovarian-uterine cycle disrupted by high temperature exposure.

Intrinsic innervation of the ovary and its variations in the rat senescence process

Ovarian functions decrease with perimenopause. The ovary has extrinsic innervation, but the neural influence on ovarian functions and dysfunction is not well-studied. The present study aimed to biochemically and morphometrically characterize the intrinsic neurons in ovaries from young adult, middle-aged, and senescent Long Evans CII-ZV rats (3, 12, and 15 months old, respectively). Ovaries were extracted from four rats of each age group (n = 12 total), cryopreserved, and processed for immunofluorescence studies with the primary NeuN/β-tubulin and NeuN/tyrosine hydroxylase (TH) antibodies. The soma area and number of intrinsic neurons in the ovarian stroma, surrounding follicles, corpus luteum, or cyst were evaluated. The intrinsic neurons were grouped in cluster-like shapes in ovarian structures. In senescent rats, the intrinsic neurons were mainly localized in the ovarian stroma and around the cysts. The number of neurons was lower in senescent rats than in young adult rats (p < 0.05), but the soma size was larger than in young adult rats. Immunoreactivity to TH indicated the presence of noradrenergic neurons in the ovary with the same characteristics as NeuN/β-tubulin, which indicates that they are part of the same neuronal group. Taken together, the findings indicate that the intrinsic neurons may be related to the loss of ovarian functions associated with aging.

Expression pattern of ZNF33B in bovine ovaries and the effect of its polymorphism on superovulation traits

ZNF33B belongs to recently duplicated Krüppel-associated box domain zinc finger proteins (KRAB-ZFPs), which is widely present in various organs, and some evidence showed that its expression is altered in the ovary undergoing superovulation. In this study, the expression of ZNF33B in ovary and early embryo was determined by immunohistochemistry and immunofluorescence techniques. Results showed that the expression of ZNF33B in the ovary was mainly in the cytoplasm of oocytes and granulosa luteal cells of ovarian corpus luteum and significantly reduced during follicular ovulation to luteal degeneration. The expression of ZNF33B in the early embryo transferred from the nucleus to the whole cell, suggesting that the expression of ZNF33B is spatiotemporally specific. Then, in combination with the single nucleotide polymorphism (SNP) database, the g.-61GT mutant of the 5-untranslated region (5 UTR) of the ZNF33B gene was screened out from 556 Changbaishan black cattle, and the frequency of the mutant gene was counted. The statistics of superovulation and superovulation traits confirmed significant differences between the two genotypes in the quantity and quality of oocytes obtained after superovulation. This study confirmed, for the first time, the effect of ZNF33B gene polymorphism on superovulation traits and suggested that the mutation could provide a basis for cattle breeding and improving animal fertility.

Exposure to benzo(a)pyrene suppresses mitophagy via ANT1-PINK1-Parkin pathway in ovarian corpus luteum during early pregnancy

Exposure to benzo (a)pyrene (BaP) has been confirmed to interfere with embryo implantation. As the primary organ of progesterone synthesis during early pregnancy, the ovarian corpus luteum (CL) is essential for embryo implantation and pregnancy maintenance. We previously demonstrated that BaP impaired luteal function, but the molecular mechanism remains unclear. In CL cells, mitochondria are the main sites of progesterone synthesis. Mitophagy, a particular type of autophagy, regulates mitochondrial quality by degrading damaged mitochondria and ensuring the homeostasis of cell physiology. Therefore, the present study investigated the effects and the potential molecular mechanisms of BaP on ovarian mitophagy during early pregnancy. We found that BaP and its metabolite, BPDE, inhibited autophagy and PINK1/Parkin-mediated mitophagy in the pregnant ovaries and luteinized granulosa cell, KGN. Notably, adenine nucleotide translocator 1 (ANT1), a crucial mediator of PINK1-dependent mitophagy, was suppressed by BaP and BPDE both in vivo and in vitro. The inhibition of ANT1 leads to the decrease in the PINK1 bound to the outer membrane of mitochondria and consequently reduces recruitment of Parkin to the mitochondria, which is required for the subsequent clearance of mitochondria. Meanwhile, exposure to BPDE also damaged mitochondrial function, causing the reduction in mitochondrial potential and ATP production. Overexpression of ANT1 in KGN cells partially relieved the inhibition of mitophagy caused by BPDE, restored mitochondrial function and expression of hormone synthesis-associated genes. Collectively, our study firstly clarified that BaP and BPDE suppress mitophagy of CL cells via the ANT1-PINK1-Parkin pathway, which provides a new insight to explore the detailed mechanism of the BaP-induced ovarian toxicity.

Protein Kinase A and 5' AMP-Activated Protein Kinase Signaling Pathways Exert Opposite Effects on Induction of Autophagy in Luteal Cells.

In the absence of pregnancy the ovarian corpus luteum undergoes regression, a process characterized by decreased production of progesterone and structural luteolysis involving apoptosis. Autophagy has been observed in the corpus luteum during luteal regression. Autophagy is a self-degradative process important for balancing sources of cellular energy at critical times in development and in response to nutrient stress, but it can also lead to apoptosis. Mechanistic target of rapamycin (MTOR) and 5′ AMP-activated protein kinase (AMPK), key players in autophagy, are known to inhibit or activate autophagy, respectively. Here, we analyzed the signaling pathways regulating the initiation of autophagy in bovine luteal cells. In vivo studies showed increased activating phosphorylation of AMPKα (Thr172) and elevated content of LC3B, a known marker of autophagy, in luteal tissue during PGF2α-induced luteolysis. In vitro, AMPK activators 1) stimulated phosphorylation of regulatory associated protein of MTOR (RPTOR) leading to decreased activity of MTOR, 2) increased phosphorylation of Unc-51-Like Kinase 1 (ULK1) and Beclin 1 (BECN1), at sites specific for AMPK and required for autophagy initiation, 3) increased levels of LC3B, and 4) enhanced colocalization of autophagosomes with lysosomes indicating elevated autophagy. In contrast, LH/PKA signaling in luteal cells 1) reduced activation of AMPKα and phosphorylation of RPTOR, 2) elevated MTOR activity, 3) stimulated phosphorylation of ULK1 at site required for ULK1 inactivation, and 4) inhibited autophagosome formation as reflected by reduced content of LC3B-II. Pretreatment with AICAR, a pharmacological activator of AMPK, inhibited LH-mediated effects on RPTOR, ULK1 and BECN1. Our results indicate that luteotrophic signaling via LH/PKA/MTOR inhibits, while luteolytic signaling via PGF2α/Ca2+/AMPK activates key signaling pathways involved in luteal cell autophagy.

Influence of Age and Breed on Bovine Ovarian Capillary Blood Supply, Ovarian Mitochondria and Telomere Length

Worldwide, dairy cows of the type of high-producing cattle (HPC) suffer from health and fertility problems at a young age and therefore lose productivity after an average of only three lactations. It is still contentious whether these problems are primarily due to genetics, management, feeding or other factors. Vascularization plays a fundamental role in the cyclic processes of reproductive organs, as well as in the regeneration of tissues. In a previous study, HPC were shown to have a greater ovarian corpus luteum vascularization compared to dual-purpose breeds. We hypothesize that this activated angiogenesis could likely lead to an early exhaustion of HPC′s regenerative capacity and thus to premature reproductive senescence. The objective of this study was to investigate if a HPC breed (Holstein-Friesian, HF) exhibits higher ovarian angiogenesis than a dual-purpose breed (Polish Red cow, PR) and if this is related to early ovarian aging and finally reproductive failure. For this purpose, we assessed the degree of vascularization by means of ovarian blood vessel characterization using light microscopy. As indicators for aging, we measured ovarian mitochondrial size and telomere length in peripheral leukocytes. We report in this study that in both breeds the distance between capillaries became smaller with increasing age and that the mean telomere length decreased with increasing age. The only difference between the two breeds was that PR developed larger capillaries than HF. Neither a relationship between telomere length, nor the morphology of the mitochondrial apparatus and nor angiogenesis in HF was proven. Although the data trends indicated that the proportion of shortened telomeres in HF was higher than in the PR, no significant difference between the two breeds was detected.

Anti-Mullerian Hormone and Macrophage Migration Inhibitory Factor Determine the Reproductive Health of Ladakhi Women Residing at 3,500 m.

Shaw, Snigdha, Himashree Gidugu, Gopinath Bhaumik, Maramreddy Prasanna Kumar Reddy, Usha Panjwani, and Dishari Ghosh. Anti-Mullerian hormone and macrophage migration inhibitory factor determine the reproductive health of Ladakhi women residing at 3,500 m. High Alt Med Biol. 22:317-326, 2021. Background: Reproductive health of Ladakhi high-altitude (HA) native females was investigated for the first time in this study. Available literature suggest that, female reproductive cycle and hormonal profile varies in different HA populations due to heterogeneity. Although these studies illustrate some progress on the role of HA hypoxia, it still leaves scope for evaluation of the remaining mechanisms involved in the maintenance of reproductive health in this contemporary population. Materials and Methods: Menstrual details, phasic variations in circulatory steroid hormones, and gonadotropins along with oxytocin in sea level (SL) and HA (∼3,500 m) native females of India were assessed. Moreover, ovarian reserve marker anti-Mullerian hormone (AMH) and proinflammatory cytokine macrophage migration inhibitory factor (MIF) were measured. Results: A difference in Ladakhi women was registered compared to SL, regarding luteinizing hormone (LH) (2.6 mIU/ml vs. 4.4 mIU/ml, p < 0.05) and progesterone (P) (4.1 ng/ml vs. 9.4 ng/ml, p < 0.05) levels in their luteal phase. Reduced LH might contribute to poor development of the ovarian corpus luteum, subsequently diminish P level. Decreased AMH level in three age groups: 21-30 years (1.4 ng/ml vs. 3.2 ng/ml, p < 0.01), 31-40 years (0.6 ng/ml vs. 2.1 ng/ml, p < 0.01), and >40 years (0.4 ng/ml vs. 1.7 ng/ml, p < 0.01) of Ladakhi women were recorded than their SL counterpart. Elevated oxytocin (83.5 ng/ml vs. 76.3 ng/ml, p < 0.05) and MIF levels (70.2 ng/ml vs. 49.7 ng/ml, p < 0.01) along with low P and AMH levels delineated the reason for recorded early menopause (43.9 years), shorter reproductive span (∼29 years), and history of miscarriage in HA dwellers compared to SL. Conclusion: Therefore, the findings insinuated that the response of the reproductive system to hypoxia in Ladakhi women differs from SL women, and the adaptive response in these women might be in favor of their reproductive health.

Contraceptive Activity of Vitex doniana Stem Bark Methanol Extract in Female Albino Rats

Aims: The acceptability and accessibility of modern contraceptive drugs are limited especially in northern Nigeria. These contraceptives also have numerous side effects hence there is need to search for safe natural alternatives from medicinal plants. This research was aimed at evaluating the contraceptive effect of stem bark methanol extract of Vitex doniana in female albino rats.&#x0D; Place and Duration of Study: Department of Biochemistry, Faculty of Life Science, Kebbi State University of Science and Technology Aliero, Kebbi State, Nigeria. Between August 2019 to July 2020.&#x0D; Methodology: Vitex doniana stem bark was extracted with methanol and the extract was subjected to qualitative phytochemical screening. Acute toxicity (LD50) of V. doniana stem bark extract was determined using up and down method and anti-fertility effect was evaluated via (anti-ovulation, anti-implantation and serum hormonal assay).&#x0D; Results: The results for phytochemical screening showed the presence of alkaloids, flavonoids, tannins, steroids, glycoside, balsam and volatile oil. The LD50 of the extract was estimated to be greater than 5000 mg/kg as no mortality or any sign of toxicity are recorded within 14 days. The anti-fertility studies, methanol stem bark extract of Vitex doniana showed anti-ovulation activity through alteration of estrous cycle, changes in the histology of ovarian corpus luteum and decreasing number of follicles of extract treatment groups compared to control. Serum hormonal assay showed significant decrease (P&lt;0.05) in oestrogen and progesterone level respectively in the extract treated groups compared to control group. Also, anti-implantation effect was observed in drug treated group (levenogesterel) and group treated with 400 mg/kg of V. doniana stem bark as there was no evidence of conception.&#x0D; Conclusion: The present study revealed that methanol stem bark extract of Vitex doniana is relatively nontoxic at acute dose and possess a moderate amount of antifertility agent.

The Role of the Guanosine Nucleotide-Binding Protein in the Corpus Luteum.

Simple SummaryThis review aims to discuss the role of the guanosine nucleotide-binding protein (RAS) family in the biological events that occur during the formation and regression of the corpus luteum in the ovary. RAS proteins mediate extracellular signals, transduce through their receptors via multiple signaling pathways, and regulate a wide array of cellular processes. RAS exhibits a notable function in the regulation of vascular endothelial growth factor, fibroblast growth factor, insulin-like growth factor, angiopoietins (ANPT), and hypoxia-inducible factor (HIF). RAS proteins appear to be involved in several factors that are notably associated with the regulation of the corpus luteum. Further research is necessary to enhance our understanding of the role of the RAS family in the ovarian corpus luteum.The corpus luteum is a temporary endocrine gland in the ovary. In the ovarian cycle, repeated patterns of specific cellular proliferation, differentiation, and transformation occur that accompany the formation and regression of the corpus luteum. Molecular mechanism events in the ovarian microenvironment, such as angiogenesis and apoptosis, are complex. Recently, we focused on the role of RAS protein in the ovarian corpus luteum. RAS protein plays a vital role in the modulation of cell survival, proliferation, and differentiation by molecular pathway signaling. Additionally, reproductive hormones regulate RAS activity in the cellular physiological function of ovarian follicles during pre-ovulatory maturation and ovulation. Thus, we have reviewed the role of RAS protein related to the biological events of the corpus luteum in the ovary.