Uterine receptivity is critical for establishing and maintaining pregnancy. For the endometrium to become receptive, stromal cells must differentiate into decidual cells capable of secreting factors necessary for embryo survival and placental development. Although there are multiple reports of autophagy induction correlated with endometrial stromal cell (ESC) decidualization, the role of autophagy in decidualization has remained elusive. To determine the role of autophagy in decidualization, we utilized 2 genetic models carrying mutations to the autophagy gene Atg16L1. Although the hypomorphic Atg16L1 mouse was fertile and displayed proper decidualization, conditional knockout in the reproductive tract of female mice reduced fertility by decreasing the implantation rate. In the absence of Atg16L1, ESCs failed to properly decidualize and fewer blastocysts were able to implant. Additionally, small interfering RNA knock down of Atg16L1 was detrimental to the decidualization response of human ESCs. We conclude that Atg16L1 is necessary for decidualization, implantation, and overall fertility in mice. Furthermore, considering its requirement for human endometrial decidualization, these data suggest Atg16L1 may be a potential mediator of implantation success in women.

Background Sexual transmission and persistence of Zika virus (ZIKV) in the male reproductive tract has raised concerned for potential damaging effects on function. Animal studies have demonstrated that ZIKV virus can infect and damage the testis and epididymis, and these results has been correlated to lower sperm counts in ZIKV-infected humans. The prostate plays a vital role in the male reproductive tract, with acute and chronic prostatitis linked to male infertility. Methods In this study, we evaluated the effects of ZIKV virus on the prostate in mice and nonhuman primates. Results In mice, ZIKV infected the prostate and triggered inflammation that persisted even after virus clearance. Evidence of chronic prostatitis associated with ZIKV infection remained for several months. Similar histological findings were observed in the prostate of ZIKV-infected rhesus macaques. Conclusions These studies establish that ZIKV replicates in the prostate and can cause acute and chronic inflammatory and proliferative changes in mouse and nonhuman primate models.

An adapted strain of Zika virus (ZIKV) has been shown to negatively impact male reproductive tissues in a mouse model, specifically the epididymis and testes.1 Studies in our laboratory have confirmed that ZIKV also exhibits tropism to the female reproductive tract and causes acute inflammation and follicular apoptosis. However, the immune response in the ovary has not been fully characterized. The objective of this study was to characterize the immune response in the ovary following ZIKV infection in a murine model. Female mice (C57BL/6, 7 weeks) were inoculated via a subcutaneous route with 106 focus forming units (FFU) of a mouse-adapted ZIKV strain (Dakar 41519). Ovaries from infected and control mice were collected at 7, 14, or 21 days post-infection. Viral titers were determined with quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Cell apoptosis in the ovary was detected by immunofluorescence TUNEL staining. Immunohistochemistry (IHC) was performed on ovarian tissue sections for inflammatory cell markers including CD45, CD4, and CD8α. Inflammatory cells counts were compared between infected and control mice, controlling for ovarian volume. The experiments above were also performed on mice with a knockout for recombination activating gene 1 (RAG-1), which lack mature functional B and T lymphocytes. ZIKV RNA was detected in the ovarian tissue of infected mice (N=26) at all time points (4-5 Log10 FFU equivalents/gram of tissue). Ovarian viral titers were higher than corresponding values in the serum. Cellular apoptosis was present in degenerating follicles in both infected (N=5) and uninfected (N=5) ovaries, but was significantly increased in the ZIKV exposed animals at the day 7 time point (p=0.04). IHC demonstrated increased CD45+ cells, a pan-lymphocyte marker, in infected ovaries at day 7 (N=5, p=0.02). IHC also demonstrated an increase in T cell infiltration (by both markers CD4 and CD8α) in infected ovaries at all time points (N=4, p<0.05). When these experiments were performed on RAG-1 knockout mice, IHC did not demonstrate any T-cell infiltration in infected or control ovaries, consistent with the expected phenotype. Viral titers in RAG-1 knockout mice were comparable to the mice with intact RAG-1, but ZIKV infected ovaries did not show a similar increase in follicular apoptosis. ZIKV exhibits tropism to the ovary and causes an acute oophoritis dominated by a T lymphocyte infiltrate. This immune response mediates follicular apoptosis in the acute stage of infection. Tissue destruction is not seen in a T cell deficient mouse model, highlighting the importance of cell-mediated immunity in the response to ZIKV.

Recent human and animal studies investigating the roles of the genome, epigenome, and environmental cues have identified associations between offspring predisposition to life-long obesity/metabolic disease and epigenetic modifications such as DNA methylation. This review explores the mechanisms by which maternal exposures impair the health of not only the next generation but also potentially future generations of offspring.

The worldwide upward trend in obesity has been dramatic, now affecting more than 20% of American women of reproductive age. Obesity is associated with many adverse maternal and fetal effects prenatally, but it also exerts a negative influence on female fertility. Obese women are more likely to have ovulatory dysfunction due to dysregulation of the hypothalamic-pituitary-ovarian axis. Women with polycystic ovarian syndrome who are also obese demonstrate a more severe metabolic and reproductive phenotype. Obese women have reduced fecundity even when eumenorrheic and demonstrate poorer outcomes with the use of in vitro fertilization. Obesity appears to affect the oocyte and the preimplantation embryo, with disrupted meiotic spindle formation and mitochondrial dynamics. Excess free fatty acids may have a toxic effect in reproductive tissues, leading to cellular damage and a chronic low-grade inflammatory state. Altered levels of adipokines, such as leptin, in the obese state can affect steroidogenesis and directly affect the developing embryo. The endometrium is also susceptible, with evidence of impaired stromal decidualization in obese women. This may explain subfecundity due to impaired receptivity, and may lead to placental abnormalities as manifested by higher rates of miscarriage, stillbirth, and preeclampsia in the obese population. Many interventions have been explored to mitigate the effect of obesity on infertility, including weight loss, physical activity, dietary factors, and bariatric surgery. These data are largely mixed, with few high quality studies to guide us. As we improve our understanding of the pathophysiology of obesity in human reproduction we hope to identify novel treatment strategies.

The current global obesity pandemic is clearly linked to both the increasing prevalence of, and preference for, foods high in calories, specifically fat and sucrose, and declining levels of daily physical activity. A less commonly discussed possible explanation is that risk of obesity begins in utero as a result of developmental plasticity during early life. This idea fits into the broader Developmental Origins of Health and Diseases (DOHAD) hypothesis, which holds that stressful in utero exposure manifests as disease in adulthood. In this review, we highlight several studies that have revealed the role of epigenetics in multigenerational transmission of developmentally programmed obesity and associated cardiometabolic disease.

An adapted strain of Zika virus (ZIKV) has been shown to negatively impact male reproductive tissues in a mouse model, specifically the epididymis and testes.1 We were interested in potential effects of ZIKV in the murine female reproductive tract, specifically the ovary, which is resistant to damage by most viral pathogens. Laboratory research in a murine model. Female mice (C57BL/6, 7 weeks) were inoculated via a subcutaneous route with 106 focus forming units (FFU) of a mouse-adapted ZIKV strain (Dakar 41519). Ovaries from infected and control mice were collected at 7, 14, or 21 days post-infection. Viral titers were determined with quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Viral RNA in situ hybridization was performed on ovarian tissue using a probe targeting ZIKV RNA. Cellular apoptosis in the ovary was detected by immunofluorescence TUNEL staining. The effect of ZIKV on ovarian reserve was investigated by superovulating infected and control mice with pregnant mare’s serum gonadotropin (PMSG) at 90 days post-infection. Oocytes were collected and quantified, and meiotic spindle architecture compared with immunofluorescence. These ovaries were then serially sectioned, stained with hematoxylin and eosin (H&E), and follicular counts performed. ZIKV RNA was detected in the ovarian tissue of infected mice (N=26) at all time points (4-5 Log10 FFU equivalents/gram of tissue). Ovarian viral titers were higher than corresponding values in the serum. In situ hybridization for ZIKV RNA on day 7 post-infection showed positive staining in both follicular and stromal compartments (N=3). Cellular apoptosis was present in degenerating follicles in both infected (N=15) and uninfected (N=9) ovaries, but was significantly increased in the ZIKV exposed animals (p=0.03). In the superovulated day 90 mice, there was no difference in the number of oocytes collected between previously infected (N=4) and uninfected (N=4) females (mean 20 v 15 oocytes, respectively). There was also no difference in spindle architecture observed. Follicular counts demonstrated a trend toward less antral follicles in the infected mice (p=0.055), but numbers of primordial, primary, and secondary follicles did not differ. Our data indicates that ZIKV demonstrates tissue tropism to the ovary as evidenced by high viral titers and the presence of hybridized viral RNA in ovarian tissue. During the acute phase of infection, ZIKV may increase follicular atresia and turnover. ZIKV may negatively impact the response to gonadotropin stimulation as evidenced by fewer antral follicles after superovulation, but depletion of the resting follicular pool has not been demonstrated in our murine model.

Obesity negatively affects many aspects of the human body including reproductive function. In females, the root of the decline in fertility is linked to problems in the oocyte. Problems seen in oocytes that positively correlate with increasing BMI include changes to the metabolism, lipid accumulation, meiosis, and metaphase II (MII) spindle structure. Studies in mice indicate that dietary interventions fail to reverse these problems. How exercise affects the oocytes has not been addressed. Therefore, we hypothesized an exercise intervention would improve oocyte quality. Here we show that in a mouse model of an exercise, intervention can improve lipid metabolism in germinal vesicle (GV) stage oocytes. Oocytes significantly increased activity and transcription of the β-oxidation enzyme hydroxyacyl-coenzyme A dehydrogenase in response to exercise training only if the mice had been fed a high-fat diet (HFD). An exercise intervention also reversed the lipid accumulation seen in GV stage oocytes of HFD females. However, delays in meiosis and disorganized MII spindles remained present. Therefore, exercise is able to improve, but not reverse, damage imparted on oocytes as a result of an HFD and obesity. By utilizing an exercise intervention on an HFD, we determined only lipid content, and lipid metabolism is changed in GV oocytes. Moving forward, interventions to improve oocyte quality may need to be more targeted to the oocyte specifically. Because of the HFD-induced deficiency in β-oxidation, dietary supplementation with substrates to improve lipid utilization may be more beneficial.

The most significant increase in metabolic syndrome over the previous decade occurred in women of reproductive age, which is alarming given that metabolic syndrome is associated with reproductive problems including subfertility and early pregnancy loss. Individuals with metabolic syndrome often consume excess fructose, and several studies have concluded that excess fructose intake contributes to metabolic syndrome development. Here, we examined the effects of increased fructose consumption on pregnancy outcomes in mice. Female mice fed a high-fructose diet (HFrD) for 6 weeks developed glucose intolerance and mild fatty liver but did not develop other prominent features of metabolic syndrome such as weight gain, hyperglycemia, and hyperinsulinemia. Upon mating, HFrD-exposed mice had lower pregnancy rates and smaller litters at midgestation than chow-fed controls. To explain this phenomenon, we performed artificial decidualization experiments and found that HFrD consumption impaired decidualization. This appeared to be due to decreased circulating progesterone as exogenous progesterone administration rescued decidualization. Furthermore, HFrD intake was associated with decreased bone morphogenetic protein 2 expression and signaling, both of which were restored by exogenous progesterone. Finally, expression of forkhead box O1 and superoxide dismutase 2 [Mn] proteins were decreased in the uteri of HFrD-fed mice, suggesting that HFrD consumption promotes a prooxidative environment in the endometrium. In summary, these data suggest that excess fructose consumption impairs murine fertility by decreasing steroid hormone synthesis and promoting an adverse uterine environment.

CONTEXT:Polyunsaturated fatty acids (PUFAs) and their metabolism may be important in normal reproductive function and fertility. Associations between physiologic PUFAs and pregnancy have not been established in women.OBJECTIVE:The purpose of this study was to investigate associations between serum levels of PUFAs and embryo implantation in women undergoing in vitro fertilization (IVF).DESIGN:This was a prospective cohort study conducted between 2010 and 2012.SETTING:The study was conducted at the Washington University Reproductive Medicine Center.PATIENTS:Participants were 200 women undergoing IVF and participating in an ongoing specimen tissue bank.INTERVENTION:Fasting serum PUFAs were measured with liquid chromatography-mass spectroscopy. PUFAs measured included linoleic acid (LA), α-linolenic acid (ALA), eicosapentaenoic acid, arachidonic acid, and docosahexaenoic acid.MAIN OUTCOME MEASURES:Relationships between serum levels of measured PUFAs and embryo implantation in women undergoing IVF were analyzed.RESULTS:In unadjusted analyses, none of the PUFAs alone were associated with a chance of pregnancy; however, women with increased LA:ALA ratios had a higher chance of pregnancy compared with women with lower LA:ALA ratios (relative risk, 1.52; 95% confidence interval, 1.09-2.13). This relationship held after multivariable logistic regression adjusting for age, antral follicle count, body mass index, history of previous pregnancy, and history of endometriosis (odds ratio, 2.7; 95% confidence interval, 1.3-5.7). Embryo implantation rates were also weakly associated with LA:ALA ratios (r = 0.21, P = .003).CONCLUSIONS:Our work shows that increased ω-6 to ω-3 PUFA ratios in women undergoing IVF are associated with increased implantation and pregnancy rates. Prospective trials are needed to determine whether manipulation of PUFA ratios through diet or pharmacologic intervention may benefit women planning to conceive.