Zaher Merhi

Role of vitamin D in ovarian physiology and its implication in reproduction: a systematic review.

OBJECTIVE To report an update on the role of vitamin D (VD) in ovarian physiology with a focus on genes involved in steroidogenesis, follicular development, and ovarian reserve, as well as ovulatory dysfunction associated with polycystic ovary syndrome (PCOS), and ovarian response to assisted reproductive technology (ART). DESIGN Systematic review. SETTING Not applicable. PATIENT(S) Human, animal, and cell culture models. INTERVENTION(S) Pubmed literature search. MAIN OUTCOME MEASURE(S) Granulosa cell function, serum antimüllerian hormone (AMH), AMH and its receptor gene expression, soluble receptor for advanced glycation end-products (sRAGE), PCOS parameters, and ART outcome. RESULT(S) In human granulosa cells, VD alters AMH signaling, FSH sensitivity, and progesterone production and release, indicating a possible physiologic role for VD in ovarian follicular development and luteinization. In the serum, 25-hydroxyvitamin D (25OH-D) is positively correlated with AMH, and appropriate VD supplementation in VD-depleted women can suppress the seasonal changes that occur in serum AMH. In VD-deficient women with PCOS, VD supplementation lowers the abnormally elevated serum AMH levels, possibly indicating a mechanism by which VD improves folliculogenesis. The antiinflammatory sRAGE serum levels significantly increase in women with PCOS after VD replacement. Although follicular fluid 25OH-D correlates with IVF outcomes, there is a lack of data pertaining to the impact of VD supplementation on pregnancy rates following IVF. CONCLUSION(S) This review underscores the need for understanding the mechanistic actions of VD in ovarian physiology and the critical need for randomized trials to elucidate the impact of VD supplementation on controlled ovarian hyperstimulation/IVF outcome and ovulatory dysfunction associated with PCOS.

Impact of bariatric surgery on female reproduction

OBJECTIVE To evaluate the current literature on the impact and potential mechanisms of surgical weight loss on female reproduction, with a focus on changes in reproductive hormone profile, fertility status, measures of ovarian reserve, efficacy of oral contraception, sexuality, and pregnancy. DESIGN Appraisal of articles relevant to surgical weight loss and female reproduction. RESULT(S) The altered reproductive hormone profile associated with morbid obesity seems to reverse, either partially or totally, after surgical weight loss. Although bariatric surgery seems to improve fertility status and many of the complications associated with obesity in pregnancy, it may be linked to oral contraceptive failure. Although müllerian-inhibiting substance is a direct measure of ovarian reserve, its level changes with obesity and after surgical weight loss. There is a decrease or no change in the risk of miscarriage after bariatric surgery. An improvement in sexual function may follow dramatic surgical weight reduction; however, the possibility of a detrimental influence afterward can occur. CONCLUSION(S) The increasing popularity of bariatric surgery in reproductive-age women calls for greater clinician awareness of its impact on female reproduction.

Advanced glycation end products and their relevance in female reproduction

STUDY QUESTION Do advanced glycation end products (AGEs) and their receptors play a role in female reproduction? SUMMARY ANSWER AGEs might contribute to the etiology of polycystic ovary syndrome (PCOS) and infertility. WHAT IS KNOWN ALREADY The endogenous AGEs are produced in the body by chemical reactions. Exogenous sources of AGEs are diet and smoking. AGEs have been proposed to be among the main intermediaries involved in several diseases, such as metabolic syndrome, type 2 diabetes mellitus, cardiovascular disease, ovarian aging, inflammation, neurodegenerative disorders and PCOS. STUDY DESIGN, SIZE, DURATION A systematic review was performed for all available basic science and clinical peer-reviewed articles published in PubMed from 1987 to date. Abstracts of annual meetings of the Endocrine Society and American Society for Reproductive Medicine were also reviewed. PARTICIPANTS/MATERIALS, SETTING, METHODS A total of 275 publications and scientific abstracts were identified from the initial search. Sixty-two papers and four published scientific abstracts were selected for full review. The main outcomes were the regulatory effects of AGEs on: (i) granulosa cells, adipocyte physiology, obesity and insulin resistance in women with PCOS and in polycystic ovary animal models and (ii) infertility and measures of ovarian reserve. MAIN RESULTS AND THE ROLE OF CHANCE There is an intricate relationship between the AGE-RAGE (receptor for AGEs) system and some aspects of PCOS, such as granulosa cell dysfunction, adipocyte pathophysiology, obesity and insulin resistance. Additionally, irregular ovarian AGE signaling might in part explain the abnormal ovarian histology observed in women with PCOS. The ovarian dysfunction due to AGEs in women without PCOS suggests a role for the AGE-RAGE system in the ovarian follicular environment, and might relate to assisted reproduction technology outcome and measures of ovarian reserve. LIMITATIONS, REASONS FOR CAUTION The body of literature currently available limits these findings. The results obtained from granulosa cell lines and animal models may not fully extrapolate to humans. WIDER IMPLICATIONS OF THE FINDINGS This review underscores a critical need to unveil the exact mechanistic actions of AGEs in reproductive physiology and more specifically the hypothalamic-pituitary-ovarian axis. AGE inhibitors might present an emerging therapeutic approach with significant applications in the context of PCOS and infertility. STUDY FUNDING/COMPETING INTEREST(S) American Society for Reproductive Medicine New Investigator Award and University of Vermont College of Medicine Internal Funds. No competing interests.

Challenging cell phone impact on reproduction: A Review

PurposeThe radiofrequency electromagnetic radiation (RF-EMR) produced by cell phones can enhance the excitability of the brain and has recently been classified as carcinogenic. The suggested use of hands-free kits lowers the exposure to the brain, but it might theoretically increase exposure to the reproductive organs. This report summarizes the potential effects of RF-EMR on reproductive potentials in both males and females.MethodsA critical review of the literature pertaining to the impact of cell phone RF-EMR on reproduction in male and female animals and humans was performed, with a focus on gonad metabolism, apoptosis of reproductive cells, fertility status, and serum reproductive hormones.ResultsWhile some animal and human studies revealed alterations in reproductive physiology in both males and females, others did not report any association. The in vitro and in vivo studies to date are highly diverse, very inconsistent in conduct and, in many cases, report different primary outcomes.ConclusionThe increasing use of cell phone warrants well-designed studies to ascertain the effect of their RF-EMR on reproduction.

Circulating vitamin D correlates with serum antimüllerian hormone levels in late-reproductive-aged women: Women's Interagency HIV Study

OBJECTIVE To study the correlation between circulating 25-hydroxyvitamin D (25OH-D) levels and serum antimüllerian hormone (AMH) in women enrolled in the Womens Interagency HIV Study. DESIGN Cross-sectional study. SETTING None. PATIENT(S) All premenopausal women (n = 388) with regular menstrual cycles were included and subdivided into three groups: group 1 with age <35 years (n = 128), group 2 with age 35-39 years (n = 119), and group 3 with age ≥40 years (n = 141). INTERVENTION(S) Serum for 25OH-D, AMH, fasting glucose and insulin, and creatinine levels. MAIN OUTCOME MEASURE(S) Correlation between 25OH-D and AMH before and after adjusting for HIV status, body mass index, race, smoking, illicit drug use, glucose and insulin levels, estimated glomerular filtration rate, and geographic site of participation. RESULT(S) After adjusting for all covariates, the regression slope in all participants for total 25OH-D predicting log(10)AMH for 25-year-olds (youngest participant) was -0.001 (SE = 0.008); and for 45-year-olds (oldest participant) the corresponding slope was +0.011 (SE = 0.005). Fasting insulin level was negatively correlated with serum AMH. The regression slope for the correlation between 25OH-D and AMH in group 1 was +0.002 (SE = 0.006); in group 2 was +0.006 (SE = 0.005); and in group 3 was +0.011 (SE = 0.005). There was no association between HIV and AMH. CONCLUSION(S) A novel relationship is reported between circulating 25OH-D and AMH in women aged ≥40 years, suggesting that 25OH-D deficiency might be associated with lower ovarian reserve in late-reproductive-aged women.

Age-related LH surge dysfunction correlates with reduced responsiveness of hypothalamic anteroventral periventricular nucleus kisspeptin neurons to estradiol positive feedback in middle-aged rats.

Female reproductive aging in rats is characterized by reduced gonadotropin releasing hormone (GnRH) neuronal activation under estradiol positive feedback conditions and a delayed and attenuated luteinizing hormone (LH) surge. The newly identified excitatory neuropeptide kisspeptin is proposed to be a critical mediator of the pubertal transition and the ovarian steroid-induced LH surge. We previously showed that estradiol induces less kisspeptin mRNA expression in the anterior hypothalamus [anatomical location of anteroventral periventricular nucleus (AVPV)] in middle-aged than in young rats and intrahypothalamic infusion of kisspeptin restores LH surge amplitude in middle-aged females. Thus, reduced kisspeptin neurotransmission may contribute to age-related LH surge abnormalities. This study tested the hypothesis that middle-aged females will also exhibit reduced numbers of kisspeptin immunopositive neurons in the AVPV under estradiol positive feedback conditions. Using immunohistochemistry, we demonstrate that middle-aged females primed with ovarian steroids have fewer AVPV kisspeptin immunopositive neurons than young females. Age did not affect kisspeptin mRNA expression in the pituitary, numbers of kisspeptin immunopositive neurons in the arcuate nucleus, or estradiol-dependent reductions in kisspeptin mRNA expression in the posterior hypothalamus (containing the arcuate nucleus). These data strongly suggest that age-related LH surge dysfunction results, in part, from a reduced sensitivity of AVPV kisspeptin neurons to estradiol and hence decreased availability of AVPV kisspeptin neurons to activate GnRH neurons under positive feedback conditions.

Vitamin D alters genes involved in follicular development and steroidogenesis in human cumulus granulosa cells.

CONTEXT Vitamin D deficiency is common among reproductive-aged women and has a role in female reproduction. OBJECTIVE This study evaluated the role of 1,25-dihydroxyvitamin D3 (vit D3) in ovarian follicular development and steroidogenesis by using a human granulosa cell (GC) model. DESIGN, SETTING, AND PARTICIPANTS Fifty-four women who underwent in vitro fertilization were enrolled. INTERVENTION Follicular fluid (FF) and mural and cumulus GCs were collected from small and large follicles. In separate experiments, primary cumulus GCs were cultured with or without vit D3 followed by RT-PCR for mRNA expression levels. The effect of recombinant anti-Mullerian hormone (AMH) on nuclear localization of phospho-Smad 1/5/8 was evaluated in the presence or absence of vit D3 by using immunofluorescence. 25-Hydroxyvitamin D levels in FF as well as cell culture media AMH, progesterone, and estradiol (E2) concentrations were determined by ELISA and RIA. MAIN OUTCOME MEASURES The following were measured: 1) mRNA expression levels; 2) 3β-hydroxysteroid dehydrogenase (3β-HSD) enzyme activity; 3) FSH-induced aromatase mRNA and E2 production; and 4) nuclear localization of phospho-Smad 1/5/8. RESULTS In a multivariate analysis, 25 OH-D levels in FF negatively correlated with AMH and AMH receptor (AMHR)-II mRNA levels in cumulus GCs of small follicles. Compared with women with replete 25-hydroxyvitamin D levels in FF, those with insufficient/deficient levels had a 2-fold increase in AMHR-II mRNA levels in cumulus GCs of small follicles (P = .02). Treatment with vit D3 caused a decrease in AMHR-II and FSH receptor mRNA but an increase in 3-βHSD mRNA levels compared with control (P < .05). Vit D3 enhanced 3-βHSD enzyme activity as assessed by increasing progesterone release; however, vit D3 did not affect FSH-induced aromatase mRNA and E2 production, but it decreased the phosphorylation of Smad 1/5/8 and its nuclear localization. CONCLUSION These data suggest that vit D3 alters AMH signaling and steroidogenesis in human cumulus GCs, possibly reflecting a state of GC luteinization potentiation.

Live birth derived from oocyte spindle transfer to prevent mitochondrial disease

Mutations in mitochondrial DNA (mtDNA) are maternally inherited and can cause fatal or debilitating mitochondrial disorders. The severity of clinical symptoms is often associated with the level of mtDNA mutation load or degree of heteroplasmy. Current clinical options to prevent transmission of mtDNA mutations to offspring are limited. Experimental spindle transfer in metaphase II oocytes, also called mitochondrial replacement therapy, is a novel technology for preventing mtDNA transmission from oocytes to pre-implantation embryos. Here, we report a female carrier of Leigh syndrome (mtDNA mutation 8993T > G), with a long history of multiple undiagnosed pregnancy losses and deaths of offspring as a result of this disease, who underwent IVF after reconstitution of her oocytes by spindle transfer into the cytoplasm of enucleated donor oocytes. A male euploid blastocyst wasobtained from the reconstituted oocytes, which had only a 5.7% mtDNA mutation load. Transfer of the embryo resulted in a pregnancy with delivery of a boy with neonatal mtDNA mutation load of 2.36-9.23% in his tested tissues. The boy is currently healthy at 7 months of age, although long-term follow-up of the childs longitudinal development remains crucial.

Vitamin D increases serum levels of the soluble receptor for advanced glycation end products in women with PCOS.

CONTEXT Elevation of serum proinflammatory advanced glycation end products (AGEs) is involved in the pathogenesis of polycystic ovary syndrome (PCOS). The soluble receptor for AGEs (sRAGE) acts as a decoy by binding circulating AGEs. Vitamin D supplementation attenuates the deposition of AGEs in the vascular system of diabetic animals and improves some metabolic aspects of vitamin D-deficient women with PCOS. Additionally, serum anti-Mullerian hormone (AMH) is elevated in women with PCOS, reflecting abnormal ovarian folliculogenesis. OBJECTIVE The objective of the study was to evaluate the effect of 1,25 dihydroxyvitamin D3 (vit D3) supplementation on serum sRAGE and AMH in vitamin D-deficient women with PCOS. DESIGN, SETTINGS, PARTICIPANTS, AND INTERVENTION: Sixty-seven women with (n = 22) or without (control; n = 45) PCOS who were diagnosed with vitamin D deficiency were enrolled. Fifty-one women were replaced with oral vit D3 for 8 weeks (16 with PCOS and 35 controls) and 16 women were not treated (six with PCOS and 10 controls). Serum 25-hydroxyvitamin D (25 OH-D), sRAGE, and AMH concentrations were measured at baseline and after vit D3 supplementation in the treated group and 8 weeks apart in the nontreated group. MAIN OUTCOME MEASURE(S) Changes in serum sRAGE and AMH concentrations after vit D3 replacement were measured. RESULTS In all participants, there was a negative correlation between body mass index and serum sRAGE levels (r = -0.3, P = .01). In women with PCOS, but not in controls, vit D3 increased serum sRAGE (P = .03) and decreased serum AMH levels (P < .001). The increase in serum sRAGE positively correlated with the increase in serum 25 OH-D after supplementation in women with PCOS (r = 0.6, P = .01). CONCLUSION In women with PCOS, vit D3 might exert a protective effect against the inflammatory action of AGEs by increasing circulating sRAGE. The normalization in serum AMH induced by vit D3 replacement suggests an improvement in folliculogenesis.

Leptin suppresses anti-Mullerian hormone gene expression through the JAK2/STAT3 pathway in luteinized granulosa cells of women undergoing IVF

STUDY QUESTION Do the adipocytokines, leptin and adiponectin affect the granulosa cell expression of anti-Mullerian hormone (AMH) and its receptor (AMHR-II)? SUMMARY ANSWER Leptin suppresses AMH mRNA levels in human luteinized granulosa cells through the JAK2/STAT3 pathway, while adiponectin has no such effect. WHAT IS KNOWN ALREADY AMH is one of the most reliable markers of ovarian reserve. Serum AMH levels decline with obesity. Obesity is associated with elevated leptin and reduced adiponectin levels. STUDY DESIGN, SIZE AND DURATION This prospective study included 60 infertile women undergoing fresh IVF and ICSI cycles utilizing autologous oocytes at Montefiores Institute for Reproductive Medicine and Health between July 2010 and April 2012. PARTICIPANTS/MATERIALS, SETTING, METHODS Follicular fluid was collected from small (SFs; <14 mm) and large follicles (LFs; ≥14 mm) from 38 participants. Total RNA was extracted separately from mural and cumulus granulosa cells and mRNA levels were measured by RT-PCR. In an additional group of participants (N = 22), primary cumulus and mural granulosa cells (pooled SFs and LFs) were cultured in media alone or with addition of either leptin (N = 7), adiponectin (N = 8) or JAK2/STAT3 inhibitor + leptin (N = 7), and AMH and AMHR-II mRNA levels measured. Levels of AMH, leptin and adiponectin protein were measured in follicular fluid. MAIN RESULTS AND THE ROLE OF CHANCE AMH and AMHR-II mRNA and follicular fluid AMH protein levels were inversely correlated with age. AMH mRNA expression was six times higher in cumulus compared with mural granulosa cells in SFs (P< 0.05) and eight times higher in cumulus compared with mural granulosa cells in LFs (P < 0.001). In follicular fluid, leptin protein level positively correlated (r = 0.7, P = 0.03), while adiponectin protein level inversely correlated (r = -0.46, P = 0.02) with BMI. Leptin treatment suppressed AMH and AMHR-II mRNA in both cumulus and mural granulosa cells (all P < 0.05). In the presence of JAK2/STAT3 inhibitor, leptin treatment did not alter AMH but continued to suppress AMHR-II mRNA in cumulus cells (P = 0.02). Adiponectin treatment did not alter AMH or AMHR-II mRNA levels. LIMITATIONS, REASONS FOR CAUTION This study included a luteinized granulosa cell model as these cells were collected from women who were hyperstimulated with gonadotrophins. The results obtained may not fully extrapolate to non-luteinized granulosa cells. WIDER IMPLICATIONS OF THE FINDINGS Leptin may program abnormal AMH signaling, thereby resulting in ovarian dysfunction. This study opens a new perspective for understanding the low ovarian reserve seen in obese women and provides new insights into potential mechanisms that explain the lower AMH seen in obese women. Whether our findings explain the worse response to ovulation induction observed in obese women needs to be further elucidated.