Administration of visfatin during superovulation improves developmental competency of oocytes and fertility potential in aged female mice

Exogenous visfatin suppresses pituitary gonadotrophins and stimulates testosterone secretion in a male mouse

Visfatin expression has been shown in the testis and pituitary. However, the role of visfatin in the pituitary and testis axis is fragmentary. Furthermore, no study has shown the effects of visfatin on the pituitary gonadotrophins and testicular steroid hormonal secretions in a male mouse. The present study has investigated the effects of exogenous visfatin (most likely a state of hypervisfatinemia) on the gonadotrophins, testosterone, estradiol, androstenedione, and progesterone in a male mouse. The exogenous visfatin was given for 35 days, which covers one spermatogenic cycle. The circulating testosterone was elevated after visfatin treatment, along with down-regulation of AR and steroidogenic markers in the testis. However, the expression of CYP17 was up-regulated in visfatin-treated testis. Visfatin treatment also elevated apoptosis in the different germ cells of the testis. The levels of circulating LH and FSH were also suppressed after visfatin treatment. The immunolocalization of AR exhibited decreased abundance in the pituitary of visfatin-treated mice; thus, it can be suggested that pituitary gonadotrophins secretion might be suppressed by direct action of visfatin rather than via elevated testosterone. In conclusion, our results showed that exogenous visfatin suppresses gonadotrophins and stimulates testicular testosterone secretions in a differential manner. Visfatin has inhibitory effects on pituitary gonadotrophins secretion and stimulatory effects on testosterone secretion from the testis. Thus, conditions similar to hypervisfatinemia likely impair the release of hormones from the pituitary and testis.

Nicotinamide dual treatment enhances morula-to-blastocyst transition through binding to Zonula Occludens-1 protein

Nicotinamide (NAM) is a widely utilized compound in cell culture systems, yet its role during the morula-to-blastocyst transition remains underexplored. This study investigates the effects of NAM supplementation during both in vitro maturation (IVM) of oocytes and late-stage embryo culture (IVC3; the morula stage) on blastocyst development, metabolic flux, mitochondrial bioenergetics, and pluripotency of cells. Bovine oocytes were subjected to dual NAM treatment during IVM and IVC3 and its impact was assessed through cleavage and blastocyst development rates, mitochondrial membrane potential (ΔΨm), and the expression of key metabolic and pluripotency markers using RT-qPCR and immunofluorescence. Additionally, molecular docking was performed to evaluate NAM's interaction with Zonula Occludens-1 (ZO-1) protein. Dual NAM administration significantly increased both blastocyst formation and hatching rates. Computational modeling revealed a strong binding affinity (-6.44 kcal/mol) between NAM and the ZO-1 protein, associated with the morula-to-blastocyst transition. Quantitative RT-PCR analysis showed upregulation of genes related to NAD + biosynthesis (NAMPT, MDH1), glycolysis (PFK1), glycogenesis (GSK-3A), and mitochondrial bioenergetics (SDHA, ND2, ATPase8, TFAM) in NAM-treated group. Additionally, mitochondrial profiling demonstrated enhanced polarization, and OCT4 expression was elevated in NAM-treated embryos. These findings underscore NAM's potential role in enhancing morula-to-blastocyst transition, improving embryonic development through metabolic and mitochondrial regulation, as well as pluripotency factor enhancement.

Evaluation of Serum Adipokine Levels in Girls With Central Precocious Puberty

PURPOSE

Adipose tissue has an important endocrine function by secreting a variety of hormones known as adipokines, such as Visfatin, Omentin-1 and Chemerin. On the other hand, these hormones are also secreted from places other than fatty tissues in the girl's genital system. The goal of this study was to demonstrate the secretory status of adipokines in patients with central precocious puberty (CPP) and their utility in the diagnosis of precocious puberty.

METHOD

A total of 105 patients were included in the study (53 in the CPP group and 52 in the control group). The following were used as the CPP diagnostic criteria; breast development, basal LH measurement higher than 0.3 IU/L, peak LH level ≥ 5 IU/L, peak LH/FSH ratio ≥ 0.66 (after 0.1 mg GnRH stimulation test) and a difference of at least 1 year between bone and chronological age.

RESULTS

A statistically significant difference was detected between the groups in serum Omentin-1 and Chemerin levels, and no significant differences were detected between the groups in Visfatin values. The cut-off values for the diagnosis of CPP were calculated as ≤ 48.9 with 81% sensitivity and 54% specificity for Omentin-1, and as ≥ 417 with 85% sensitivity and 60% specificity for Chemerin.

CONCLUSION

In our study, we found that Omentin-1 level decreased and Chemerin level increased in lean girls with CPP. More studies are needed to elucidate how adipokines play roles in explaining the onset of CPP, and whether they may be used as a reliable marker for the diagnosis of CPP.

New aspect on the regulation of in vitro oocyte maturation: role of the obesity, neuropeptides and adipokines

Oocyte quality determinants and nuclear and cytoplasmic maturation establish essential processes for fertilization and further development of the conceptus. Moreover, female fertility is strongly dependent on the metabolic status of the organism. Numerous sources indicate that obesity impairs ovarian function including oocyte physiology by inhibiting nuclear maturation, stimulating lipotoxicity and inflammation, enabling cumulus cells apoptosis, promoting reactive oxygen species formation and ultimately imposing pathogenic effects on mitochondria leading to infertility. Whereas, the number of overweight and obese individuals has reached alarming levels over the past decades, what is more, by 2030, the prevalence of overweight and obesity might reach 65.3% in adults in China and 78% in the USA. Thus, relationships between reproduction and metabolism are being intensively studied to prevent obesity-induced infertility. The metabolic markers of oocyte condition and function are adipokines and neuropeptides, which regulate food intake, lipid and glucose metabolism, insulin resistance and impart significant influences on reproduction. Thus, in this review, we focus on interrelationships between obesity, oocyte maturation and the role of selected neuropeptides and adipokines including leptin, adiponectin, kisspeptin, nesfatin-1, phoenixin, visfatin, chemerin and vaspin.

Visfatin exerts an anti-proliferative and pro-apoptotic effect in the human placenta cells†

Visfatin regulates energy homeostasis, metabolism, inflammation, and reproduction via the hypothalamus-pituitary-ovary axis. Our previous study showed the visfatin gene and protein expression in the human placenta. This study aimed to investigate the in vitro effect of visfatin on the proliferation and apoptosis of placental JEG-3 and BeWo cells but also in villous explants collected from normal pregnancies and complicated by intrauterine growth restriction (IUGR), preeclampsia (PE), and gestational diabetes mellitus (GDM). We studied placenta cells viability, proliferation, cell cycle, proliferation/apoptotic factors and insulin receptor (INSR) expression, DNA fragmentation, CASP3/7 activity, and phosphorylation of ERK1/2, AKT, AMPKα, STAT3 with their involvement after pharmacological inhibition in visfatin action on proliferation and apoptosis. Visfatin (1, 10, 100 ng/mL) decreased the viability and proliferation of JEG-3 after 48 h, and a similar effect was observed via co-administration of visfatin (10 ng/mL) and insulin (10 ng/mL) in JEG-3 and BeWo after 48 h and 72 h, respectively. Visfatin reduced the transition from the G2/M phase, and expression of PCNA or cyclins D, E, A, and B in JEG-3 and PCNA in normal, IUGR, PE, and GDM placentas. It increased DNA fragmentation, CASP3/7 activity, P53, BAX/BCL2, CASP9, CASP 8, CASP3 levels in BeWo, and CASP3 expression in tested placentas. Furthermore, visfatin modulated INSR, ERK1/2, AKT, AMPKα, and STAT3 expression in JEG-3 and BeWo, and its anti-proliferative and pro-apoptotic effects occurred via mentioned factors. In conclusion, visfatin, by affecting the proliferation and apoptosis of human placenta cells, may be an important factor in the development and function of the organ.

Chicken chemerin alone or in mixture with adiponectin-visfatin impairs progesterone secretion by primary hen granulosa cells

Adipokines including adiponectin (ADIPO), chemerin (CHEM) and visfatin (VISF) are involved in metabolism and reproductive functions. These 3 adipokines are present in ovarian cells in different preovulatory follicles in hens. We have previously shown that VISF and ADIPO are able to modulate in vitro steroid production by hen granulosa cells (GCs). It is, however, unclear whether CHEM acts on hen ovarian cells. In addition, no study has yet investigated the effect of a mixture of several adipokines such ADIPO, VISF, and CHEM on GCs from different preovulatory follicles. In this study, we investigated the effect of CHEM alone and in combination with ADIPO and VISF on cell viability, proliferation and progesterone secretion in cultured granulosa cells (GCs) from the largest follicles F1 and smaller ones (F3/F4) in the presence of gonadotropins (oLH and oFSH) or hIGF-1. First, various concentrations of chemerin were examined (0, 12, 25, 50, and 100 ng/mL) and then we determined the response to CHEM (at 25 ng/mL) in combination with ADIPO (10 µg/mL) and VISF (100 ng/mL). Chemerin exposure did not affect F1 and F3/F4 granulosa cell viability and proliferation whatever the concentation and in the presence of the mixture. However, it reduced progesterone secretion in dose dependent manner in both F1 and F3/F4 follicles. Furthermore, this CHEM inhibitory effect was significantly higher when CHEM was combined with ADIPO and VISF. Furthermore, CHEM reduced significantly oLH and oFSH- induced progesterone secretion in F1 GCs and oFSH and hIGF-1-induced progesterone secretion in F3/F4 GCs. Interestingly, this inhibitory effect of CHEM was similar in F1 GCs when CHEM was in mixture with ADIPO and VISF whereas it was significantly higher in F3/F4 GCs. Taken together, CHEM impairs progesterone secretion in cultured hen GCs and this inhibitory effect can be potentiated when it is in combination with other adipokines.

Intra-testicular visfatin inhibition disrupts androgen and estrogen signalling in the mouse testis

Visfatin is expressed in the testis of chicken, humans and rodents; however, direct role of visfatin in the adult testis has not been studied. We investigated testicular responses after intra-testicular injection of FK866. The effects of visfatin inhibition were accessed at 24 hrs and 1 week post FK866 treatment. The testicular histoarchitecture were degenerated after 24 hrs of FK866 treatment along with supressed testosterone and proliferating markers and resumption in these parameters showed after 1 week. The expression of AR and ERα were down-regulated after 1 week of FK866 treatment. The expression of BCl2 was down-regulated along with a slight elevation of caspase3 after 24 hrs; however, both proteins still showed suppressed expression after 1 week. Furthermore, ERβ expression, 3βHSD, and 17βHSD were down-regulated in both groups compared to the control. Despite the down-regulation of some factors, the testicular proliferation and histoarchitecture showed resumption in the testis after 1 week of FK866 treatment. This could be due to increased testosterone secretion by suppressing aromatase expression. In conclusion, our result is the first report on the direct role of visfatin in the adult testis. Visfatin has a stimulatory role in testosterone synthesis and proliferation in the testis. Moreover, some deregulated factors in the testis after 1 week of FK866 treatment, despite normal histoarchitecture treatment, could be a compensatory mechanism after visfatin inhibitions.

In vitro effect of visfatin on endocrine functions of the porcine corpus luteum

Previously, we demonstrated the expression of visfatin in porcine reproductive tissues and its effect on pituitary endocrinology. The objective of this study was to examine the visfatin effect on the secretion of steroid (P4, E2) and prostaglandin (PGE2, PGF2α), the mRNA and protein abundance of steroidogenic markers (STAR, CYP11A1, HSD3B, CYP19A1), prostaglandin receptors (PTGER2, PTGFR), insulin receptor (INSR), and activity of kinases (MAPK/ERK1/2, AKT, AMPK) in the porcine corpus luteum. We noted that the visfatin effect strongly depends on the phase of the estrous cycle: on days 2-3 and 14-16 it reduced P4, while on days 10-12 it stimulated P4. Visfatin increased secretion of E2 on days 2-3, PGE2 on days 2-3 and 10-12, reduced PGF2α release on days 14-16, as well as stimulated the expression of steroidogenic markers on days 10-12 of the estrous cycle. Moreover, visfatin elevated PTGER mRNA expression and decreased its protein level, while we noted the opposite changes for PTGFR. Additionally, visfatin activated ERK1/2, AKT, and AMPK, while reduced INSR phosphorylation. Interestingly, after inhibition of INSR and signalling pathways visfatin action was abolished. These findings suggest a regulatory role of visfatin in the porcine corpus luteum.

Visfatin impact on the proteome of porcine luteal cells during implantation

Visfatin (VIS) is a hormone belonging to the adipokines' group secreted mainly by the adipose tissue. VIS plays a crucial role in the control of energy homeostasis, inflammation, cell differentiation, and angiogenesis. VIS expression was confirmed in the hypothalamic-pituitary-gonadal (HPG) axis structures, as well as in the uterus, placenta, and conceptuses. We hypothesised that VIS may affect the abundance of proteins involved in the regulation of key processes occurring in the corpus luteum (CL) during the implantation process in pigs. In the present study, we performed the high-throughput proteomic analysis (liquid chromatography with tandem mass spectrometry, LC-MS/MS) to examine the in vitro influence of VIS (100 ng/mL) on differentially regulated proteins (DRPs) in the porcine luteal cells (LCs) on days 15-16 of pregnancy (implantation period). We have identified 511 DRPs, 276 of them were up-regulated, and 235 down-regulated in the presence of VIS. Revealed DRPs were assigned to 162 gene ontology terms. Western blot analysis of five chosen DRPs, ADAM metallopeptidase with thrombospondin type 1 motif 1 (ADAMTS1), lanosterol 14-α demethylase (CYP51A1), inhibin subunit beta A (INHBA), notch receptor 3 (NOTCH3), and prostaglandin E synthase 2 (mPGES2) confirmed the veracity and accuracy of LC-MS/MS method. We indicated that VIS modulates the expression of proteins connected with the regulation of lipogenesis and cholesterologenesis, and, in consequence, may be involved in the synthesis of steroid hormones, as well as prostaglandins' metabolism. Moreover, we revealed that VIS affects the abundance of protein associated with ovarian cell proliferation, differentiation, and apoptosis, as well as CL new vessel formation and tissue remodelling. Our results suggest important roles for VIS in the regulation of ovarian functions during the peri-implantation period.

Status of visfatin in female reproductive function under normal and pathological conditions: a mini review

Adipokines are now well-known to regulate reproduction. Visfatin is an adipokine expressed in the hypothalamus, pituitary, ovary, uterus, and placenta of different species, and since it has been found to modulate the endocrine secretion of the hypothalamus, pituitary gland and ovary, it may be considered a novel regulator of female reproduction. Although the majority of the literature explored its role in ovarian regulation, visfatin has also been shown to regulate uterine remodeling, endometrial receptivity and embryo development, and its expression in the uterus is steroid dependent. Like other adipokines, visfatin expression and levels are deregulated in pathological conditions including polycystic ovary syndrome. Thus, the present mini-review focuses on the role of visfatin in female reproduction under both physiological and pathological conditions.

Adiponectin and visfatin expression profile in extra-embryonic annexes and role during embryo development in layer and broiler chickens

Some evidence showed differences between layer and broiler embryo development. We recently showed that two adipokines, adiponectin and visfatin are expressed in the extra embryonic membranes and fluids. However, their role in the embryo development is unknown. Thus, our objectives were 1. to compare the expression of AdipoQ and its receptors AdipoR1 and AdipoR2 and visfatin in extra-embryonic annexes in broiler and layer breeders during the embryo development and 2. to investigate the role of two adipokines in embryo development in both broiler and layer breed after in ovo injection of blocking antibodies against chicken adiponectin or visfatin. We found that adiponectin, AdipoR1, AdipoR2 and visfatin were mainly more expressed in the allantoic that in amniotic membranes. In addition, these expressions increased according the stage of embryo development. We observed a higher expression in layer than in broiler of AdipoQ in allantoic membranes at ED14 and ED18, of AdipoR1 and AdipoR2 in both allantoic and amniotic membranes at ED7 and ED14 and of visfatin only in allantoic membrane from ED7 to ED18. AdipoQ and visfatin were absent in amniotic fluid at ED7 but present at ED14 or ED18 where higher concentrations were detected in layer than in broiler. Interestingly, we showed a strong positive correlation between Adipo and visfatin concentration in amniotic fluid and the body weight of embryo in both breeds. However, after in ovo injection of Adipo antibodies we did not observe any effect on the embryo mortality whereas injection of visfatin antibodies increased in a dose dependent manner the embryo mortality in both breeds. Taken together, Adipo and visfatin are higher expressed in layer than broiler in extra-embryonic membranes and amniotic fluid. Our data suggest also that visfatin could be a main regulator of embryo development.

Visfatin Affects the Transcriptome of Porcine Luteal Cells during Early Pregnancy

Visfatin/NAMPT (VIS), the hormone exerting a pleiotropic effect, is also perceived as an important factor in the regulation of reproductive processes and pregnancy maintenance. Previous studies confirmed its involvement in the control of porcine pituitary and ovary function. In this study, we hypothesized that VIS may affect the global transcriptome of luteal cells and thus regulate the functioning of the ovaries. Illumina's NovaSeq 6000 RNA sequencing was performed to investigate the differentially expressed genes (DEGs) and long non-coding RNAs (DELs) as well as the occurrence of differential alternative splicing events (DASs) in the porcine luteal cells exposed to VIS (100 ng/mL) during the implantation period. The obtained results revealed 170 DEGs (99 up- and 71 downregulated) assigned to 45 functional annotations. Moreover, we revealed 40 DELs, of which 3 were known and 37 were described for the first time. We identified 169 DASs events. The obtained results confirmed a significant effect of VIS on the transcriptome and spliceosome of luteal cells, including the genes involved in the processes crucial for successful implantation and pregnancy maintenance as angiogenesis, steroidogenesis, inflammation, cell development, migration, and proliferation.

Pathophysiology of obesity-related infertility and its prevention and treatment by potential phytotherapeutics

BACKGROUND

Obesity is a complex multifactorial disease in which the accumulation of excess body fat has adverse health effects, as it can increase the risk of several problems, including infertility, in both men and women. Obesity and infertility have risen together in recent years. Against this background, the present review aims to highlight the impact of obesity on infertility and the underlying pathophysiology of obesity-related infertility (ORI) in men and women, and to provide readers with knowledge of current trends in the effective development of phytotherapeutics for its treatment.

METHODS

We thoroughly searched in PubMed, MEDLINE, Scopus, EMBASE, and Google Scholar to find all relevant papers on ORI and the therapeutic effects of phytotherapeutics on ORI in men and women.

RESULTS

The extensive search of the available literature revealed that obesity affects reproductive function through several complex mechanisms such as hyperlipidaemia, hyperinsulinaemia, hyperandrogenism, increased body mass index, disruption of the hormonal milieu, systemic inflammation, oxidative stress, alterations in epigenetics and dysbiosis. On the other hand, several studies reported that phytotherapeutics has a broad therapeutic spectrum of action by improving sex hormone homeostasis, ovarian dysfunction, menstrual cycle and inhibiting ovarian hyperplasia, as well as down-regulating ovarian apoptosis, inflammation and oxidative stress, and controlling metabolic dysfunction in obese women. Male infertility is also addressed by phytotherapeutics by suppressing lipogenesis, increasing testosterone, 3β-HSD and 17β-HSD levels, improving sperm parameters and attenuating testicular dyslipidaemia, oxidative stress, inflammation and germ cell apoptosis.

CONCLUSIONS

In the present review, we discussed the effects of obesity on reproductive dysfunction in men and women and the underlying pathophysiology of ORI. In addition, the therapeutic effect of phytotherapeutics against ORI was highlighted.

Expression of visfatin in the ovarian follicles of prepubertal and mature gilts and in vitro effect of gonadotropins, insulin, steroids, and prostaglandins on visfatin levels

Recent studies have demonstrated that visfatin participates in the regulation of female reproduction. Due to the lack of data concerning the level of visfatin in the ovarian follicles of pigs, one of the most economically important livestock species, the aim of this study was to investigate the expression and localisation of visfatin and the follicular fluid concentration in the ovarian follicles of prepubertal and mature gilts. We also aimed to examine the in vitro effects of gonadotropins (LH, FSH), insulin, progesterone (P4), oestradiol (E2), prostaglandin E2 (PGE2) and F2α (PGF2α) on visfatin levels. In the present study, we have demonstrated that visfatin expression is dependent on the maturity of the animals and the stage of ovarian follicle development. Visfatin signal was detected in individual follicular compartments from primordial to antral follicles and even in atretic follicles. We have shown that the expression of visfatin in granulosa cells was higher than in theca cells. The level of visfatin is upregulated by LH, FSH, E2, and P4 and downregulated by insulin, while prostaglandins have modulatory effects, dependent on the dose and type of ovarian follicular cells. To summarise, our research has shown that visfatin is widely expressed in the ovarian follicles of prepubertal and mature pigs, and its expression is regulated by gonadotropins, insulin, steroids, and prostaglandins, suggesting that visfatin appears to be an important intra-ovarian factor that could regulate porcine ovarian follicular function.

Visfatin in the porcine pituitary gland: expression and regulation of secretion during the oestrous cycle and early pregnancy

Visfatin is a multifunctional protein which, besides the control of energy homeostasis, seems to be also involved in the regulation of female fertility through the influence on the endocrine hypothalamus-pituitary-gonadal axis, including the pituitary. The aim of this study was to investigate the expression of visfatin mRNA and protein in the anterior (AP) and posterior pituitary lobes of the pig during the oestrous cycle and early pregnancy. In AP, we also examined colocalisation of visfatin with pituitary tropic hormones. Moreover, we aimed to evaluate the in vitro effects of GnRH, FSH, LH, and insulin on visfatin protein concentration and secretion in AP cells during the cycle. The study showed that visfatin is present in all types of porcine pituitary endocrine cells and its expression is reliant on stage of the cycle or pregnancy. GnRH, FSH, LH and insulin stimulated visfatin secretion by AP cells on days 17 to 19 of the cycle, while on days 2 to 3 visfatin release was enhanced only by LH. Summarising, visfatin is locally produced in the pituitary in a way dependent on hormonal milieu typical for reproductive status of pigs. Further research is required to clarify the role of visfatin in the pituitary gland.

Effects of resveratrol on HIF-1α/VEGF pathway and apoptosis in vitrified duck ovary transplantation

Preservation of ovarian tissues is an effective way to ensure genetic diversity of susceptible natural bird populations that are in danger of extinction. We examined whether the addition of the plant phenol resveratrol to vitrification solutions ameliorates the damaging effects of tissue hypoxia and reperfusion injury when the tissues are transplanted. Duck ovary tissues were frozen in the presence of varying concentrations of resveratrol in cryopreservation solutions and then transplanted under the renal capsules of 2-day-old Shelducks. Samples of the transplanted tissues were examined on days 3- and 9- post transplantation for activation of hypoxia-, antioxidant- and apoptosis-related gene expression and apoptosis. Resveratrol significantly increased expression of VEGF, HIF-1α, Nrf2, CAT and Bcl-2 mRNA and decreased BAX and Caspase-3 mRNA and reduced numbers of TUNEL-positive cells after vitrification and heterotopic ovarian transplantation. Resveratrol improved the antioxidant capacity, reduced apoptosis and activated the HIF-1α/VEGF pathway to promote angiogenesis 3- and 9-days following transplantation. These results indicated that the addition of resveratrol to vitrification solutions intended for long-term cryopreservation of ovary tissues improves survival in storage and the grafts following transplantation. This study provides a theoretical basis for the successful transplantation of avian ovarian tissue after vitrification.

Comparative proteomics of ovaries elucidated the potential targets related to ovine prolificacy

Small Tail Han (STH) sheep, a unique Chinese breed, is recognized for its early maturity, year-round estrus, and prolificacy. However, the molecular mechanism of its high prolificacy has not been fully elucidated. The Proteomics approach is feasible and effective to reveal the proteins involved in the complex physiological processes of any organism. Given this, we performed the protein expression profiling of ovarian tissues during the luteal phase using polytocous STH sheep (litter size ≥2, three consecutive lambings) and monotocous STH sheep (litter size =1, three consecutive lambings) (PL vs. ML), and the follicular phase using polytocous STH sheep (litter size ≥2, three consecutive lambings) and monotocous STH sheep (litter size =1, three consecutive lambings) (PF vs. MF), respectively. Parallel Reaction Monitoring (PRM) was conducted to validate the differentially abundant proteins (DAPs). The tandem mass tag (TMT) quantitative proteomic results showed that a total of 5,237 proteins were identified, of which 49 and 44 showed differential abundance in the PL vs. ML and PF vs. MF groups, respectively. Enrichments analyses indicated that the DAPs including TIA1 cytotoxic granule-associated RNA-binding protein-like 1 (TIAL1), nicotinamide phosphoribosyltransferase (NAMPT), and cellular retinoic acid-binding protein 1 (CRABP1) were enriched at the luteal phase, while TIAL1, inhibin beta-a-subunit (A2ICA4), and W5PG55 were enriched at the follicular phase, potentially mediating reproductive processes in polytocous ewes. Furthermore, six DAPs were verified using PRM, confirming the accuracy of the TMT data acquired in this study. Together, our work expanded the database of indigenous sheep breeds and provided new ovarian candidate molecular targets, which will help in the study of the genetic mechanisms of ovine prolificacy.

SIRT1 and antioxidants in infertile females: Exploration of the role of vitamin D

BACKGROUND

Deficiency of silent information regulator 1 (SIRT1) can trigger inflammation, mitochondrial malfunctioning, and apoptosis through the hypothalamic-pituitary-ovarian axis, producing poor quality oocytes, leading to infertility. Normal vitamin D (VD) levels promote SIRT1 activity required for optimal fertility, and low levels of either may result in fertility problems owing to cell-membrane de-stabilization, increased autophagy, DNA damage leading to increased reactive oxygen species and mitochondrial dysfunction. Therefore, in this study, we want to estimate the levels of VD, SIRT1 and antioxidants (MnSOD; manganese superoxide dismutase, GR; glutathione reductase, visfatin) and oxidants (adrenaline & cortisol) in individuals living with infertility and explore the association of VD with SIRT1 expression (levels), antioxidants, and oxidants contributing to infertility in women. The significance of this study is that it highlights the importance of maintaining optimal levels of VD for reproductive health in females.

METHODS

This cross-sectional study included 342 (135 infertile and 207 fertile) female subjects. Serum levels of MnSOD, SIRT1, visfatin, GR, VD, adrenaline, and cortisol were analyzed by ELISA and were compared in fertile and infertile samples using the Mann Whitney U test.

RESULTS

There were significantly high levels of VD, SIRT1, GR, MnSOD and visfatin in fertile female participants. However, mean adrenaline and cortisol levels were higher in infertile samples with a significant negative correlation with VD. A significant negative correlation of VD with MnSOD, SIRT1, visfatin and GR was observed (p <0.01). In VD subset groups, MnSOD levels were significantly high in VD sufficient groups however, adrenaline and cortisol levels were significantly high in groups suffering from VD deficiency.

CONCLUSIONS

Deficiency of VD is associated with a decrease in SIRT1 and other antioxidants, which may deter natural reproductive functions leading to infertility. Further studies are required to determine the cause-effect relationship of VD deficiency on conception and interpretation of the involved mechanism.

Computer simulation approach to the identification of visfatin-derived angiogenic peptides

Angiogenesis plays an essential role in various normal physiological processes, such as embryogenesis, tissue repair, and skin regeneration. Visfatin is a 52 kDa adipokine secreted by various tissues including adipocytes. It stimulates the expression of vascular endothelial growth factor (VEGF) and promotes angiogenesis. However, there are several issues in developing full-length visfatin as a therapeutic drug due to its high molecular weight. Therefore, the purpose of this study was to develop peptides, based on the active site of visfatin, with similar or superior angiogenic activity using computer simulation techniques.Initially, the active site domain (residues 181∼390) of visfatin was first truncated into small peptides using the overlapping technique. Subsequently, the 114 truncated small peptides were then subjected to molecular docking analysis using two docking programs (HADDOCK and GalaxyPepDock) to generate small peptides with the highest affinity for visfatin. Furthermore, molecular dynamics simulations (MD) were conducted to investigate the stability of the protein-ligand complexes by computing root mean square deviation (RSMD) and root mean square fluctuation(RMSF) plots for the visfatin-peptide complexes. Finally, peptides with the highest affinity were examined for angiogenic activities, such as cell migration, invasion, and tubule formation in human umbilical vein endothelial cells (HUVECs). Through the docking analysis of the 114 truncated peptides, we screened nine peptides with a high affinity for visfatin. Of these, we discovered two peptides (peptide-1: LEYKLHDFGY and peptide-2: EYKLHDFGYRGV) with the highest affinity for visfatin. In an in vitrostudy, these two peptides showed superior angiogenic activity compared to visfatin itself and stimulated mRNA expressions of visfatin and VEGF-A. These results show that the peptides generated by the protein-peptide docking simulation have a more efficient angiogenic activity than the original visfatin.

Evidence of the inhibitory role of visfatin in the testicular activity of mice during the infantile stage

Adipokines have emerged as regulators of gonadal function in many mammalian and non-mammalian species. In the present study, we have investigated the developmental expression of testicular and ovarian visfatin along with its possible role in the testicular activity infantile stages. Previously, our group has the extensive role of ovarian visfatin in relation to steroidogenesis, proliferation, and apoptosis in female mice. To the best of our knowledge, no study has shown the role of visfatin in mice testis. Our results from the previous study and present study showed that visfatin in the testis and ovaries are developmentally regulated. To unravel the role of visfatin, we have used FK866, as visfatin inhibitor. FK866 was used as a visfatin inhibitor, to decipher the role of visfatin in the testis of mice. Our results showed that visfatin expression in the testis was developmentally regulated in the testis. Leydig cells as well as germ have shown the presence of visfatin in mice testis, which suggest its role in testicular steroidogenesis and spermatogenesis. Furthermore, visfatin inhibition by FK866 significantly increased the testosterone secretion, and expression of AR, Bcl2, and ERα. The expression of GCNA was upregulated by FK866 treatment. These results suggest that visfatin has an inhibitory role in testicular steroidogenesis and germ cell proliferation in the infantile stage. Further research is required to define the precise role of visfatin in infantile mice testis.

Expression and regulation of visfatin/NAMPT in the porcine corpus luteum during the estrous cycle and early pregnancy

Visfatin/NAMPT creates a hormonal link between energy metabolism and female reproduction. A recent study documented visfatin expression in the ovary and its action on follicular cells; however, the expression of visfatin in luteal cells is still unknown. The aim of this study, therefore, was to investigate the transcript and protein expression of visfatin as well as its immunolocalization in the corpus luteum (CL) and to examine the involvement of extracellular signal-regulated kinases (ERK1/2) in the regulation of visfatin level in response to LH, insulin, progesterone (P₄), prostaglandin E₂ (PGE₂) and F_2α (PGF_2α). Corpora lutea were harvested from gilts on days 2-3, 10-12 and 14-16 of the estrous cycle and on days 10-11, 12-13, 15-16 and 27-28 of pregnancy. The current study demonstrated that visfatin expression depends on hormonal status related to the phase of the estrous cycle or early pregnancy. Visfatin was immunolocalized to the cytoplasm of small and large luteal cells. Moreover, visfatin protein abundance was increased by P₄, and decreased by both prostaglandins, while LH and insulin have modulatory effects, depending on the phase of the cycle. Interestingly, LH, P₄ and PGE₂ effects were abolished in response to the inhibition of ERK1/2 kinase. Thus, this study demonstrated that expression of visfatin in the porcine CL is determined by the endocrine status related to the estrous cycle and early pregnancy and by the action of LH, insulin, P₄ and prostaglandins via activation of the ERK1/2 pathway.

New Aspects of Corpus Luteum Regulation in Physiological and Pathological Conditions: Involvement of Adipokines and Neuropeptides

The corpus luteum is a small gland of great importance because its proper functioning determines not only the appropriate course of the estrous/menstrual cycle and embryo implantation, but also the subsequent maintenance of pregnancy. Among the well-known regulators of luteal tissue functions, increasing attention is focused on the role of neuropeptides and adipose tissue hormones-adipokines. Growing evidence points to the expression of these factors in the corpus luteum of women and different animal species, and their involvement in corpus luteum formation, endocrine function, angiogenesis, cells proliferation, apoptosis, and finally, regression. In the present review, we summarize the current knowledge about the expression and role of adipokines, such as adiponectin, leptin, apelin, vaspin, visfatin, chemerin, and neuropeptides like ghrelin, orexins, kisspeptin, and phoenixin in the physiological regulation of the corpus luteum function, as well as their potential involvement in pathologies affecting the luteal cells that disrupt the estrous cycle.

Adipokines in metabolic and reproductive functions in birds: An overview of current knowns and unknowns

Adipose tissue is now recognized as an active endocrine organ, which synthesizes and secretes numerous peptides factors called adipokines. In mammals, they exert pleiotropic effects affecting energy metabolism but also fertility. In mammals, secretion of adipokines is altered in adipose tissue dysfunctions and may participate to obesity-associated disorders. Thus, adipokines are promising candidates both for novel pharmacological treatment strategies and as diagnostic tools. As compared to mammals, birds exhibit several unique physiological features, which make them an interesting model for comparative studies on endocrine control of metabolism and adiposity and reproductive functions. Some adipokines such as leptin and visfatin may have different roles in avian species as compared to mammals. In addition, some of them found in mammals such as CCL2 (chemokine ligand 2), resistin, omentin and FGF21 (Fibroblast Growth factor 21) have not yet been mapped to the chicken genome model and among its annotated gene models. This brief review aims to summarize data (structure, metabolic and reproductive roles and molecular mechanisms involved) related to main avian adipokines (leptin, adiponectin, visfatin, and chemerin) and we will briefly discuss the adipokines that are still lacking in avian species.

Nampt affects mitochondrial function in aged oocytes by mediating the downstream effector FoxO3a

Maternal aging can impair the quality and decrease the developmental competence of ovulated oocytes. In this study, compromised germinal vesicle breakdown (GVBD) was found in aged mice oocytes. Furthermore, we observed increased reactive oxygen species (ROS) and mitochondrial Ca²⁺ levels, along with reduced mitochondrial temperature in aged oocytes. Maternal aging also changed the crotonylation level in oocytes. Forkhead box O3 (FoxO3a), a member of the forkhead protein family involved in the regulation of cell survival and life span reached a peak level in the metaphase II stage. Compared with a younger group, FoxO3a expression increased in aged oocytes. Intracellular localization of FoxO3a changed from the cytoplasm to chromatin in response to aging. The expression of the upstream regulator nicotinamide-phosphoribosyltransferase (Nampt) peaked in the GVBD stage. Moreover, Nampt expression was increased in aged oocytes, and more intense staining of Nampt was found in aged mice ovary. To further study the role of Nampt in mitochondrial function, specific agonist P7C3 and inhibitor FK866 were applied to aged oocytes, and FK866 significantly decreased adenosine triphosphate and mitochondrial membrane potential. In conclusion, mitochondrial dysfunction in aged oocytes was associated with elevated FoxO3a, and suppression of Nampt could further impair mitochondrial function.

Reproductive roles of novel adipokines apelin, visfatin, and irisin in farm animals

The adipose tissue has a substantial impact on reproduction in mammals, specifically in females. As an energy depository organ, it is precisely associated with the reproductive success of mammals. Adipose tissue secretes many single molecules that are called 'adipokines' which mainly act as endocrine hormones. Adipokines homeostasis is fundamental to energy regulation, metabolic and cardiovascular diseases. The endocrine function of adipokines is influential for the long-term control of energy metabolism and performs an important function in metabolic state and fertility modulation. During the last years, new roles for adipokines have been appearing in the field of fertility. The adipokines have functions in reproduction at levels of the hypothalamus, the pituitary, and the gonads in humans, rodents, and other animals. Normal levels of adipokines are indispensable to protect the integrity of the hypothalamus-hypophysis-gonadal axis, regular ovulatory processes, and successful embryo implantation. Leptin and adiponectin are the most studied adipokines, but also the novel adipokines; apelin, visfatin, and irisin are important adipokines having several functions within the reproductive tract. Due to the known and unknown effects of these novel adipokines in the reproduction of farm animals, in this review, we will highlight the reproductive functions of apelin, visfatin, and irisin and summarize the known reproductive effects in farm animals to introduce the gaps for future studies in farm animals.

Role of adipokines in the ovarian function: Oogenesis and steroidogenesis

Adipokines are mainly produced by adipose tissue; however, their expression has been reported in other organs including female reproductive tissues. Therefore, adipokines have opened new avenues of research in female fertility. In this regard, studies reported different roles for certain adipokines in ovarian function, although the role of other recently identified adipokines is still controversial. It seems that adipokines are essential for normal ovarian function and their abnormal levels could be associated with ovarian-related disorders. The objective of this study is to review the available information regarding the role of adipokines in ovarian functions including follicular development, oogenesis and steroidogenesis and also their involvement in ovary-related disorders.

Plasma level and expression of visfatin in the porcine hypothalamus during the estrous cycle and early pregnancy

Visfatin appears to be an energy sensor involved in the regulation of female fertility, which creates a hormonal link integrating the control of energy homeostasis and reproduction. This study evaluates the expression levels of visfatin gene and protein in selected areas of the porcine hypothalamus responsible for gonadotropin-releasing hormone synthesis: the mediobasal hypothalamus (MBH) and preoptic area (POA), and visfatin concentrations in the blood plasma. The tissue samples were harvested from gilts on days 2-3, 10-12, 14-16, and 17-19 of the estrous cycle, and on days 10-11, 12-13, 15-16, 27-28 of pregnancy. Visfatin was localized in the cytoplasm and nucleus of cells creating both studied hypothalamic structures. The study demonstrated that visfatin gene and protein expression in MBH and POA depends on hormonal status related to the phase of the estrous cycle or early pregnancy. Blood plasma concentrations of visfatin during the estrous cycle were higher on days 2-3 in relation to other studied phases of the cycle, while during early pregnancy, the highest visfatin contents were observed on days 12-13. This study demonstrated visfatin expression in the porcine hypothalamus and its dependence on the hormonal milieu related to the estrous cycle and early pregnancy.

Visfatin protein may be responsible for suppression of proliferation and apoptosis in the infantile mice ovary

Visfatin is an important adipokines, which are expressed in different tissues including ovary of mammals. The postnatal ovary in rodents undergoes dramatic changes of intra-ovarian factors in relation to proliferation and apoptosis. There are studies which showed that gonadal visfatin changes in postnatal life. However, role of visfatin in the early postnatal period i.e. infantile period has not been studied. Therefore, the present study was aimed to explore the role of visfatin in the early postnatal ovarian functions. Furthermore, to explore the role of visfatin, the endogenous visfatin was inhibited from PND14-PND21 by FK866 with dose of 1.5 mg/kg. Our results showed gain in body weight and ovarian weight after visfatin inhibition. The inhibition of visfatin increased the ovarian proliferation (increase in PCNA, GCNA expression and BrdU incorporation) and apoptosis (increase in BAX and active caspase3 expression). Moreover, visfatin inhibition decreased the expression of antiapoptotic/survival protein, BCL2 in the ovary. These findings suggest that visfatin in the infantile ovary may suppress the proliferation and apoptosis by up-regulating BCL2 expression. An interesting finding has been observed that circulating estrogen and progesterone remain unaffected, although visfatin inhibition up-regulated ER-β and down-regulated ER-α. It may also be suggested that visfatin could regulates proliferation and apoptosis via modulating estrogen signaling. In conclusion, visfatin inhibits the proliferation and apoptosis without modulating the ovarian steroid biosynthesis and visfatin mediated BCL2 expression could also be mechanism to preserve the good quality follicle in early postnatal period.

Inhibition of visfatin/NAMPT affects ovarian proliferation, apoptosis, and steroidogenesis in pre-pubertal mice ovary

Pubertal ovarian function might be dependent on the factors present in the pre-pubertal stages. Visfatin regulates ovarian steroidogenesis in adult. To date, no study has investigated the role of visfatin either in pre-pubertal or pubertal mice ovary. Thus, we investigated the role of visfatin in pre-pubertal mice ovary in relation to steroidogenesis and proliferation and apoptosis in vitro by inhibiting the endogenous visfatin by a specific inhibitor, FK866. Inhibition of visfatin increased the estrogen secretion and also up-regulated the expression of CYP11A1, 17βHSD and CYP19A1 in mice ovary. Furthermore, active caspase3 was up-regulated along with the down-regulation of BAX and BCL2 in the pre-pubertal ovary after visfatin inhibition. The expression of GCNA, PCNA, and BrdU labeling was also decreased by FK866 treatment. These results suggest that visfatin inhibits steroidogenesis, increases proliferation, and suppresses apoptosis in the pre-pubertal mice ovary. So, visfatin is a new regulator of ovary function in pre-pubertal mice.

Nampt-mediated spindle sizing secures a post-anaphase increase in spindle speed required for extreme asymmetry

Meiotic divisions in oocytes are extremely asymmetric and require pre- and post-anaphase-onset phases of spindle migration. The latter induces membrane protrusion that is moulded around the spindle thereby reducing cytoplasmic loss. Here, we find that depleting the NAD biosynthetic enzyme, nicotinamide phosphoribosyl-transferase (Nampt), in mouse oocytes results in markedly longer spindles and compromises asymmetry. By analysing spindle speed in live oocytes, we identify a striking and transient acceleration after anaphase-onset that is severely blunted following Nampt-depletion. Slow-moving midzones of elongated spindles induce cortical furrowing deep within the oocyte before protrusions can form, altogether resulting in larger oocyte fragments being cleaved off. Additionally, we find that Nampt-depletion lowers NAD and ATP levels and that reducing NAD using small molecule Nampt inhibitors also compromises asymmetry. These data show that rapid midzone displacement is critical for extreme asymmetry by delaying furrowing to enable protrusions to form and link metabolic status to asymmetric division.

Meiotic cell division in oocytes is asymmetric and requires microtubule spindle migration after anaphase-onset. Here, the authors show that Nampt, an enzyme of the Nicotinamide adenine dinucleotide (NAD) biosynthetic pathway, contributes to post-anaphase spindle migration and oocyte division asymmetry by controlling spindle length.

Paeonia lactiflora improves ovarian function and oocyte quality in aged female mice

Although ovarian aging is a key cause of decreased ovarian function and oocyte quality, it remains a problem in infertility treatment. Therefore, this study is aimed to investigate whether Paeonia lactiflora (PL), a herb improves ovarian function and oocyte quality using aged female mice. C57BL/6 female mice aged 8 months were treated orally every day with PL of 26.5 mg/kg (n=7) and 53 mg/kg (n=7) of body weight for 4 weeks using an oral zoned needle. The control group (n=7) was treated with normal saline. Ovaries and serum were collected for the H&E stain and the evaluation of reactive oxygen species (ROS) levels, respectively. In the second experiment, female mice were orally administered with PL (26.5 mg/kg: n=12, 53 mg/kg: n=12, control: n=12) and then superovulated with PMSG and hCG, and mated with male mice. Zygotes were retrieved and cultured for 4 days. Ovaries were provided for examination of expressions of genes associated with angiogenesis (VEGF and visfatin), anti-aging (Sirt1 and Sirt2), and follicular development (c-Kit, BMP-15, and GDF-9). PL significantly increased numbers of surviving follicles (primordial, primary, secondary, and antral), numbers of zygotes retrieved, embryo development rate, and ovarian expression of VEGF, visfatin, c-Kit, BMP-15, and GDF-9 at both doses. However, ovarian expression of Sirt1 and Sirt2 was increased at 53.0 mg/kg of PL. ROS levels were not affected by PL. These results suggest that PL may possess beneficial effects regarding ovarian function and oocyte quality, possibly by activation of ovarian angiogenesis and follicular development.

Adipokines Expression and Effects in Oocyte Maturation, Fertilization and Early Embryo Development: Lessons from Mammals and Birds

Some evidence shows that body mass index in humans and extreme weights in animal models, including avian species, are associated with low in vitro fertilization, bad oocyte quality, and embryo development failures. Adipokines are hormones mainly produced and released by white adipose tissue. They play a key role in the regulation of energy metabolism. However, they are also involved in many other physiological processes including reproductive functions. Indeed, leptin and adiponectin, the most studied adipokines, but also novel adipokines including visfatin and chemerin, are expressed within the reproductive tract and modulate female fertility. Much of the literature has focused on the physiological and pathological roles of these adipokines in ovary, placenta, and uterine functions. The purpose of this review is to summarize the current knowledge regarding the involvement of leptin, adiponectin, visfatin, and chemerin in the oocyte maturation, fertilization, and embryo development in both mammals and birds.

Uterine Cells Improved Ovarian Function in a Murine Model of Ovarian Insufficiency

Primary ovarian insufficiency (POI) is defined as ovarian dysfunction in women younger than 40 years. It affects 1% of the women in this age-group and can occur iatrogenically after chemotherapy. Stem cells have been used in attempt to restore ovarian function in POI. In particular, endometrial mesenchymal stem cells (eMSCs) are easily obtainable in humans and have shown great potential for regenerative medicine. Here, we studied the potential for uterine cell (UC) suspensions containing eMSCs to improve ovarian function in a murine model of chemotherapy-induced POI. Green fluorescent protein (GFP)-labeled UC or phosphate-buffered solution (PBS) was delivered intravenously after chemotherapy. There was a significant increase in oocytes production and serum anti-Müllerian hormone concentrations after 6 weeks, as well as a 19% higher body mass in UC-treated mice. Similarly, we observed an increased number of pups in mice treated with UC than in mice treated with PBS. None of the oocytes or pups incorporated GFP, suggesting that there was no contribution of these stem cells to the oocyte pool. We conclude that treatment with UC indirectly improved ovarian function in mice with chemotherapy-induced POI. Furthermore, our study suggests that endometrial stem cell therapy may be beneficial to young women who undergo ovotoxic chemotherapy.

Involvement of Novel Adipokines, Chemerin, Visfatin, Resistin and Apelin in Reproductive Functions in Normal and Pathological Conditions in Humans and Animal Models

It is well known that adipokines are endocrine factors that are mainly secreted by white adipose tissue. Their central role in energy metabolism is currently accepted. More recently, their involvement in fertility regulation and the development of some reproductive disorders has been suggested. Data concerning the role of leptin and adiponectin, the two most studied adipokines, in the control of the reproductive axis are consistent. In recent years, interest has grown about some novel adipokines, chemerin, visfatin, resistin and apelin, which have been found to be strongly associated with obesity and insulin-resistance. Here, we will review their expression and role in male and female reproduction in humans and animal models. According to accumulating evidence, they could regulate the secretion of GnRH (Gonadotropin-Releasing Hormone), gonadotropins and steroids. Furthermore, their expression and that of their receptors (if known), has been demonstrated in the human and animal hypothalamo-pituitary-gonadal axis. Like leptin and adiponectin, these novel adipokines could thus represent metabolic sensors that are able to regulate reproductive functions according to energy balance changes. Therefore, after investigating their role in normal fertility, we will also discuss their possible involvement in some reproductive troubles known to be associated with features of metabolic syndrome, such as polycystic ovary syndrome, gestational diabetes mellitus, preeclampsia and intra-uterine growth retardation in women, and sperm abnormalities and testicular pathologies in men.

Ovarian Expression of Adipokines in Polycystic Ovary Syndrome: A Role for Chemerin, Omentin, and Apelin in Follicular Growth Arrest and Ovulatory Dysfunction?

Adipokines are a potential link between reproduction and energy metabolism and could partly explain some infertilities related to some pathophysiology, such as polycystic ovary syndrome (PCOS). However, adipokines were predominantly assessed in blood samples, while very little is known concerning their variations in follicular fluid (FF) and ovarian granulosa cells (GCs) of PCOS women. Thus, the objectives of our study were to investigate adiponectin, chemerin, resistin, visfatin, omentin, and apelin ovarian expression in PCOS women in comparison with controls and women with only a polycystic ovary morphology. In total, 78 women undergoing an in vitro fertilization procedure were divided into three groups: 23 PCOS women, 28 women presenting only ≥12 follicles per ovary (ECHO group), and 27 control women. Each group almost equally included normal weight and obese women. Follicular fluid (FF) concentration and granulosa cells (GCs) mRNA expression of adipokines and their receptors were assessed by ELISA and RT-qPCR, respectively. Omentin levels in FF and GC were higher in PCOS than in ECHO and control women, while apelin expression was increased in both PCOS and ECHO groups. FF chemerin concentration was predominant in normal-weight PCOS women compared to BMI (Body Mass Index)-matched ECHO and control women, while GC mRNA levels were higher in the obese PCOS group than in the ECHO one. Compared to PCOS, ECHO women had increased FF adiponectin concentrations and lower plasma AMH levels. The FF concentration of all adipokines was higher in obese subjects except for adiponectin, predominant in normal-weight women. In conclusion, women with PCOS expressed higher GC chemerin and omentin, whereas the ECHO group presented higher levels of FF adiponectin and apelin and lower plasma AMH and LH concentrations. Chemerin, omentin, and apelin expression was differently regulated in women with PCOS, suggesting their possible role in follicular growth arrest and ovulatory dysfunction characterizing PCOS pathogenesis.

Lineage tracing suggests that ovarian endosalpingiosis does not result from escape of oviductal epithelium

Most high-grade serous carcinomas are thought to arise from Fallopian tube epithelium (FTE), but some likely arise outside of the tube, perhaps from ectopic tubal-type epithelium known as endosalpingiosis. Importantly, the origin of endosalpingiosis is poorly understood. The proximity of the tubal fimbriae to the ovaries has led to the proposal that disruptions in the ovarian surface that occur during ovulation may allow detached FTE to implant in the ovary and form tubal-type glands and cysts. An alternative model suggests that cells present in ectopic locations outside the Müllerian tract retain the capacity for multi-lineage differentiation and can form glands with tubal-type epithelium. We used double transgenic Ovgp1-iCreER^T2 ;R26R^LSL-eYFP mice, which express an eYFP reporter protein in OVGP1-positive tissues following transient tamoxifen (TAM) treatment, to track the fate of oviductal epithelial cells. Cohorts of adult mice were given TAM to activate eYFP expression in oviductal epithelium, and ovaries were examined at time points ranging from 2 days to 12 months post-TAM. To test whether superovulation might increase acquisition of endosalpingiosis, additional cohorts of TAM-treated mice underwent up to five cycles of superovulation and ovaries were examined at 1, 6, and 12 months post-TAM. Ovaries were sectioned in their entirety to identify endosalpingiosis. Immunohistochemical staining for PAX8, tubulin, OVGP1, and eYFP was employed to study endosalpingiosis lesions. Ovarian endosalpingiosis was identified in 14.2% of TAM-treated adult mice. The endosalpingiotic inclusion glands and cysts were lined by secretory and ciliated cells and expressed PAX8, tubulin, OVGP1, and eYFP. Neither age nor superovulation was associated with a significant increase in endosalpingiosis. Endosalpingiosis was also occasionally present in the ovaries of pre-pubertal mice. The findings imply that ovarian endosalpingiosis in the mouse does not likely arise as a consequence of detachment and implantation of tubal epithelium and other mechanisms may be relevant. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Visfatin and resistin in gonadotroph cells: expression, regulation of LH secretion and signalling pathways

Visfatin and resistin appear to interfere with reproduction in the gonads, but their potential action at the hypothalamic-pituitary level is not yet known. The aim of the present study was to investigate the mRNA and protein expression of these adipokines in murine gonadotroph cells and to analyse the effects of different concentrations of recombinant mouse visfatin and resistin (0.01, 0.1, 1 and 10ngmL^-1) on LH secretion and signalling pathways in LβT2 cells and/or in primary female mouse pituitary cells. Both visfatin and resistin mRNA and protein were found in vivo in gonadotroph cells. In contrast with resistin, the primary tissue source of visfatin in the mouse was the skeletal muscle, and not adipose tissue. Visfatin and resistin both decreased LH secretion from LβT2 cells after 24h exposure of cells (P<0.03). These results were confirmed for resistin in primary cell culture (P<0.05). Both visfatin (1ngmL^-1) and resistin (1ngmL^-1) increased AMP-activated protein kinase α phosphorylation in LβT2 cells after 5 or 10min treatment, up to 60min (P<0.04). Extracellular signal-regulated kinase 1/2 phosphorylation was transiently increased only after 5min resistin (1ngmL^-1) treatment (P<0.01). In conclusion, visfatin and resistin are expressed in gonadotroph cells and they may affect mouse female fertility by regulating LH secretion at the level of the pituitary.

Chicken Is a Useful Model to Investigate the Role of Adipokines in Metabolic and Reproductive Diseases

Reproduction is a complex and essential physiological process required by all species to produce a new generation. This process involves strict hormonal regulation, depending on a connection between the hypothalamus-pituitary-gonadal axis and peripheral organs. Metabolic homeostasis influences the reproductive functions, and its alteration leads to disturbances in the reproductive functions of humans as well as animals. For a long time, adipose tissue has been recognised as an endocrine organ but its ability to secrete and release hormones called adipokines is now emerging. Adipokines have been found to play a major role in the regulation of metabolic and reproductive processes at both central and peripheral levels. Leptin was initially the first adipokine that has been described to be the most involved in the metabolism/reproduction interrelation in mammals. In avian species, the role of leptin is still under debate. Recently, three novel adipokines have been discovered: adiponectin (ADIPOQ, ACRP30), visfatin (NAMPT, PBEF), and chemerin (RARRES2, TIG2). However, their mode of action between mammalian and nonmammalian species is different due to the different reproductive and metabolic systems. Herein, we will provide an overview of the structure and function related to metabolic and reproductive mechanisms of the latter three adipokines with emphasis on avian species.

Stimulation of ovarian follicle growth after AMPK inhibition

Previous studies showed that the protein kinase B (Akt)–mammalian target of rapamycin (mTOR) and Hippo signaling Yes-associated protein (YAP) pathways play important roles in promoting follicle growth. Additionally, other studies demonstrated that 5′ adenosine monophosphate-activated protein kinase (AMPK) is an upstream regulatory element of mTOR and YAP. Here, we used AMPK inhibitor (Compound C) toin vitrocultured ovaries from 10-day-old mice followed byin vivografting into adult hosts or toin situtreated ovaries of 3-week-old mice by intrabursal injection followed by gonadotropin stimulation. We found that the phosphorylation of ovarian mTOR and downstream proteins (ribosomal protein S6 (S6) and eukaryotic translation initiation factor 4B (eIF4B)) was upregulated following Compound C administration, whereas tuberous sclerosis complex 2 (TSC2) phosphorylation was downregulated. Additionally, treatment with Compound C increased hypoxia-inducible factor 1-alpha (Hif1a), vascular endothelial growth factor A (Vegfa), VEGF receptor 2 (Vegfr2) and connective tissue growth factor (Ctgf) mRNA levels. Furthermore, treatment of 10-day-old mice with Compound C promoted the growth of preantral and antral follicles accompanied by enhanced angiogenesis.In situintrabursal injection with Compound C, followed by controlled ovarian hyperstimulation, increased the number of ovulated oocytes in 3-week-old mice, and these oocytes could be successfully fertilized, leading to the delivery of healthy pups. Our results demonstrated that treatment with AMPK inhibitor resulted in the activation of the mTOR signaling pathway, increases inCtgfexpression in mouse ovaries, stimulation of follicle development and promotion of ovarian angiogenesis for ovary growth.

Oocyte activation and latent HIV-1 reactivation: AMPK as a common mechanism of action linking the beginnings of life and the potential eradication of HIV-1

In all mammalian species studied to date, the initiation of oocyte activation is orchestrated through alterations in intracellular calcium (Ca(2+)) signaling. Upon sperm binding to the oocyte plasma membrane, a sperm-associated phospholipase C (PLC) isoform, PLC zeta (PLCζ), is released into the oocyte cytoplasm. PLCζ hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP2) to produce diacylglycerol (DAG), which activates protein kinase C (PKC), and inositol 1,4,5-trisphosphate (IP3), which induces the release of Ca(2+) from endoplasmic reticulum (ER) Ca(2+) stores. Subsequent Ca(2+) oscillations are generated that drive oocyte activation to completion. Ca(2+) ionophores such as ionomycin have been successfully used to induce artificial human oocyte activation, facilitating fertilization during intra-cytoplasmic sperm injection (ICSI) procedures. Early studies have also demonstrated that the PKC activator phorbol 12-myristate 13-acetate (PMA) acts synergistically with Ca(2+) ionophores to induce parthenogenetic activation of mouse oocytes. Interestingly, the Ca(2+)-induced signaling cascade characterizing sperm or chemically-induced oocyte activation, i.e. the "shock and live" approach, bears a striking resemblance to the reactivation of latently infected HIV-1 viral reservoirs via the so called "shock and kill" approach, a method currently being pursued to eradicate HIV-1 from infected individuals. PMA and ionomycin combined, used as positive controls in HIV-1 latency reversal studies, have been shown to be extremely efficient in reactivating latent HIV-1 in CD4(+) memory T cells by inducing T cell activation. Similar to oocyte activation, T cell activation by PMA and ionomycin induces an increase in intracellular Ca(2+) concentrations and activation of DAG, PKC, and downstream Ca(2+)-dependent signaling pathways necessary for proviral transcription. Interestingly, AMPK, a master regulator of cell metabolism that is activated thorough the induction of cellular stress (e.g. increase in Ca(2+) concentration, reactive oxygen species generation, increase in AMP/ATP ratio) is essential for oocyte maturation, T cell activation, and mitochondrial function. In addition to the AMPK kinase LKB1, CaMKK2, a Ca(2+)/calmodulin-dependent kinase that also activates AMPK, is present in and activated on T cell activation and is also present in mouse oocytes and persists until the zygote and two-cell stages. It is our hypothesis that AMPK activation represents a central node linking T cell activation-induced latent HIV-1 reactivation and both physiological and artificial oocyte activation. We further propose the novel observation that various compounds that have been shown to reactivate latent HIV-1 (e.g. PMA, ionomycin, metformin, bryostatin, resveratrol, etc.) or activate oocytes (PMA, ionomycin, ethanol, puromycin, etc.) either alone or in combination likely do so via stress-induced activation of AMPK.

VISFATIN (NAMPT) Improves In Vitro IGF1-Induced Steroidogenesis and IGF1 Receptor Signaling Through SIRT1 in Bovine Granulosa Cells

VISFATIN is a novel adipokine, also known as a nicotinamide phosphorybosyltransferase (NAMPT), that is able to modulate different processes, including lipid and glucose metabolism, oxidative stress, inflammation, and insulin resistance. Recent data suggest that it also plays a role in reproductive function in rats, humans, and chickens. Here we identified VISFATIN in the bovine ovary and investigated the in vitro effects of this hormone on granulosa cell steroidogenesis and proliferation and oocyte maturation. By RT-PCR, immunoblotting, and immunohistochemistry, we found VISFATIN in various ovarian cells, including granulosa and theca cells, corpus luteum, and oocytes. In cultured bovine granulosa cells, we showed that IGF1 (10(-8) M) and VISFATIN (10 and 100 ng/ml) but not FSH (10(-8) M) increased mRNA expression levels of NAMPT after 48 h of stimulation. Moreover, we observed that human recombinant VISFATIN (hVisf, 10 ng/ml, 48 h) increased the release of progesterone and estradiol secretion, and this was associated with an increase in the protein level of STAR, the HSD3B activity, and the phosphorylation levels of IGF1R and MAPK ERK1/2 in the presence or absence of IGF1 (10(-8) M). All these effects were abolished when NAMPT was knocked down and when the sirtuin pharmacological inhibitors CHIC-35 (60 nM) and EX-527 (0.5 μM) were preincubated in bovine granulosa cells. Thus, in cultured bovine granulosa cells, VISFATIN improves basal and IGF1-induced steroidogenesis and IGF1 receptor signaling through SIRT1.

Effects of anti-Müllerian hormone and follicle stimulating hormone levels on in vitro fertilization pregnancy rate

OBJECTIVES

To analyze the relationship between in vitro fertilization (IVF) pregnancy rate and basal serum hormone levels before patients begin an IVF course.

MATERIALS AND METHODS

In this retrospective study, we analyzed patients with anti-Müllerian hormone (AMH) data and IVF data from January 2009 to October 2012. Pregnancy rates were calculated by AMH and follicle stimulating hormone quartiles and analyzed using the independent samples t test. Furthermore, patients were divided into three groups by age. The Chi-square test was used to assess the association between the parameters and IVF pregnancy rates.

RESULTS

From the 910 IVF treatment courses, 377 (41.4%) clinical pregnancies resulted. The pregnant and nonpregnant groups differed significantly in age and FSH and AMH levels. The pregnancy rate was 53.3% for patients aged <32 years and 22.1% for patients aged >38 years. The pregnancy rate was 53.4% for patients with FSH levels <5.6 mIU/mL and 25.8% for patients with FSH levels >8.9 mIU/mL. The pregnancy rate was 56.8% for patients with AMH levels >4.0 ng/mL and 20.0% for patients with AMH levels <1.1 ng/mL. Furthermore, among patients aged <40 years, AMH and FSH were significantly associated with pregnancy rate. Higher pregnancy rates were found among the groups with higher AMH levels than in groups with lower AMH levels.

CONCLUSION

For patients aged <40 years, basal serum AMH level and FSH level affected the IVF pregnancy rate, and patients with higher AMH levels had better pregnancy rates.

Expression and effect of NAMPT (visfatin) on progesterone secretion in hen granulosa cells

In mammals, nicotinamide phosphoribosyltransferase (NAMPT) is an adipokine produced by adipose tissue that is found in intracellular and extracellular compartments. The intracellular form of NAMPT is a nicotinamide phosphoribosyltransferase, whereas the extracellular form is considered an adipokine. In humans, NAMPT regulates energy metabolism and reproductive functions, such as ovarian steroidogenesis. To date, no study has investigated the role of NAMPT in hen ovaries. We investigated whether NAMPT is present in hen ovarian follicles and its role in granulosa cells. Using RT-PCR, western blotting and immunocytochemistry, we detected mRNA transcripts and proteins related to NAMPT in theca and granulosa cells from pre-ovulatory follicles. Using RT-PCR, we demonstrated that mRNA NAMPT levels were higher in granulosa cells than they were in theca cells and that during follicle development, theca cell levels decreased, whereas levels remained unchanged in granulosa cells. NAMPT protein quantities were significantly higher in theca cells than they were in granulosa cells, but they were unchanged during follicular development. Plasma NAMPT levels, as determined by ELISA and immunoblotting, were significantly lower in adult hens than they were in juveniles. In vitro, treatment with human recombinant NAMPT (100 ng/ml, 48 h) halved basal and IGF1-induced progesterone secretion, and this was associated with a reduction in STAR and HSD3B protein levels and MAPK3/1 phosphorylation levels in granulosa cells. These effects were abolished by the addition of FK866, a specific inhibitor of NAMPT enzymatic activity. Moreover, NAMPT had no effect on granulosa cell proliferation. In conclusion, NAMPT is present in hen ovarian cells and inhibits progesterone production in granulosa cells.

Differential expression of pluripotent and germ cell markers in ovarian surface epithelium according to age in female mice

BACKGROUND

Many studies have proposed that putative ovarian stem cells (OSCs) derived from the ovarian surface epithelium (OSE) layer of adult mammalian ovaries can produce oocytes. Few studies have reported that ovaries of aged mammalian females including mice and women possess rare premeiotic germ cells that can generate oocytes. However, no studies have reported the changes of OSCs according to the age of the female. Therefore, this study evaluated pluripotent and germ cell marker expression in the intact ovary, scraped OSE, and postcultured OSE according to age in female mice.

METHODS

C57BL/6 female mice of 2 age groups (6-8 and 28-31 weeks) were superovulated by injection with 5 IU equine chorionic gonadotropin (eCG). Both ovaries were removed after 48 hours and scrapped to obtain OSE. Gene expressions of pluripotent (Oct-4, Sox-2, Nanog) and germ cell markers (c-Kit, GDF-9, and VASA) were evaluated by RT-PCR. VASA and GDF-9 were immune-localized in oocyte-like structures.

RESULTS

Expressions of germ cell markers in the intact ovary were significantly decreased in aged females, whereas expressions of pluripotent markers were not detected, regardless of age. Scraped OSE expression of all pluripotent and germ cell markers, except for c-Kit, was similar between both age groups. Three weeks postcultured OSE had significantly decreased expression of GDF-9 and VASA , but not c-Kit, in old mice, as compared to young mice; however there was no difference in the expression of other genes. The number of positively stained Oct-4 by immunohistochemistry in postcultured OSE was 2.5 times higher in young mice than aged mice. Oocyte-like structure was spontaneously produced in postcultured OSE. However, while that of young mice revealed a prominent nucleus, zona pellucida-like structure and cytoplasmic organelles, these features were not observed in old mice.

CONCLUSIONS

These results show that aged female mice have putative OSCs in OSE, but their differentiation potential, as well as the number of OSCs differs from those of young mice.

Association between follicular fluid leptin and serum insulin levels in nonoverweight women with polycystic ovary syndrome

Aims. We evaluated the links between leptin and visfatin levels and fertilization rates in nonoverweight (NOW) women with PCOS (NOW-PCOS) from Apulia undergoing in vitro fertilization/embryo transfer (IVF). Materials and Methodology. We recruited 16 NOW women with PCOS (NOW-PCOS) and 10 normally ovulating NOW women (control-NOW). All women underwent IVF. Androgens, 17-β-estradiol (17β-E₂), and insulin levels were measured in plasma and/or serum and leptin and visfatin levels were assayed in both serum and follicular fluid (FF-leptin, FF-visfatin). Results. In NOW-PCOS, both serum and FF-leptin were significantly lower than in control-NOW. In NOW-PCOS, significant correlations were found between BMI and serum leptin and insulinemia and FF-leptin. By contrast, in control-NOW, FF-leptin levels were not correlated with insulinemia. Serum visfatin levels were not significantly different in NOW-PCOS and control-NOW, but FF-visfatin levels were 1.6-fold higher, although not significantly, in NOW-PCOS than in control-NOW. Conclusions. Both serum leptin levels and FF-leptin are BMI- and insulin-related in Southern Italian NOW-PCOS from Apulia. In line with other reports showing that FF-leptin levels are predictive of fertilization rates, lower than normal FF-leptin levels in NOW-PCOS may explain their lower fertilization rate and this may be related to the level of insulin and/or insulin resistance.

Adipokines and the female reproductive tract

It is well known that adipose tissue can influence puberty, sexual maturation, and fertility in different species. Adipose tissue secretes molecules called adipokines which most likely have an endocrine effect on reproductive function. It has been revealed over the last few years that adipokines are functionally implicated at all levels of the reproductive axis including the gonad and hypothalamic-pituitary axis. Many studies have shown the presence and the role of the adipokines and their receptors in the female reproductive tract of different species. These adipokines regulate ovarian steroidogenesis, oocyte maturation, and embryo development. They are also present in the uterus and placenta where they could create a favorable environment for embryonic implantation and play a key role in maternal-fetal metabolism communication and gestation. Reproductive functions are strongly dependent on energy balance, and thereby metabolic abnormalities can lead to the development of some pathophysiologies such as polycystic ovary syndrome (PCOS). Adipokines could be a link between reproduction and energy metabolism and could partly explain some infertility related to obesity or PCOS.

Management of reproduction and pregnancy complications in maternal obesity: which role for dietary polyphenols?

Obesity is a global and dramatic public health problem; maternal obesity represents one of the main risk factors of infertility and pregnancy complications as it is associated with adverse maternal and offspring outcomes. In the last few years, adipose tissue dysfunction associated with altered adipocytokine secretion has been suggested to play a critical role in all the phases of reproductive process. Obesity is a nutrition-related disorder. In this regard, dietary intervention strategies, such as high intake of fruit and vegetables, have shown significant effects in both preserving health and counteracting obesity-associated diseases. Evidence has been provided that polyphenols, important constituents of plant-derived food, can influence developmental program of oocyte and embryo, as well as pregnancy progression by modulating several cellular pathways. This review will examine the controversial results so far obtained on adipocytokine involvement in fertility impairment and pregnancy complications. Furthermore, the different effects exerted by polyphenols on oocyte, embryo, and pregnancy development will be also taken in account.