Signaling Proteins That Regulate Spermatogenesis Are the Emerging Target of Toxicant-Induced Male Reproductive Dysfunction

There is emerging evidence that environmental toxicants, in particular endocrine disrupting chemicals (EDCs) such as cadmium and perfluorooctanesulfonate (PFOS), induce Sertoli cell and testis injury, thereby perturbing spermatogenesis in humans, rodents and also widelife. Recent studies have shown that cadmium (e.g., cadmium chloride, CdCl2) and PFOS exert their disruptive effects through putative signaling proteins and signaling cascade similar to other pharmaceuticals, such as the non-hormonal male contraceptive drug adjudin. More important, these signaling proteins were also shown to be involved in modulating testis function based on studies in rodents. Collectively, these findings suggest that toxicants are using similar mechanisms that used to support spermatogenesis under physiological conditions to perturb Sertoli and testis function. These observations are physiologically significant, since a manipulation on the expression of these signaling proteins can possibly be used to manage the toxicant-induced male reproductive dysfunction. In this review, we highlight some of these findings and critically evaluate the possibility of using this approach to manage toxicant-induced defects in spermatrogenesis based on recent studies in animal models.

Icariin improves testicular dysfunction via enhancing proliferation and inhibiting mitochondria-dependent apoptosis pathway in high-fat diet and streptozotocin-induced diabetic rats

Background Diabetes mellitus (DM), a chronic metabolic disease, severely impairs male reproductive function. However, the underpinning mechanisms are still incompletely defined, and there are no effective strategies or medicines for these reproductive lesions. Icariin (ICA), the main active component extracted from Herba epimedii, is a flavonoid traditionally used to treat testicular dysfunction. Whether ICA can improve male reproductive dysfunction caused by DM and its underlying mechanisms are still unclear. In this study, by employing metformin as a comparative group, we evaluated the protective effects of ICA on male reproductive damages caused by DM and explored the possible mechanisms. Methods Rats were fed with a high fat diet (HFD) and then intraperitoneally injected with streptozotocin (STZ) to induce diabetes. Diabetic rats were randomly divided into T2DM + saline group, T2DM + metformin group and T2DM + ICA group. Rats without the treatment of HFD and STZ were used as control group. The morphology of testicular tissues was examined by histological staining. The mRNA expression levels were determined by quantitative real-time PCR. Immunostaining detected the protein levels of proliferating cell nuclear antigen (PCNA), hypoxia-inducible factor 1-alpha (HIF-1α) and sirtuin 1 (SIRT1) in testicular tissues. TUNEL assay was performed to determine cell apoptosis in the testicular tissues. The protein expression levels of HIF-1α and SIRT1 in the testicular tissues were determined by western blot assay. Results ICA effectively improved male reproductive dysfunction of diabetic rats. ICA administration significantly decreased fasting blood glucose (FBG) and insulin resistance index (IRI). In addition, ICA increased testis weight, epididymis weight, sperm number, sperm motility and the cross-sectional area of seminiferous tubule. ICA recovered the number of spermatogonia, primary spermatocytes and Sertoli cells. Furthermore, ICA upregulated the expression of PCNA, activated SRIT1-HIF-1α signaling pathway, and inhibited intrinsic mitochondria dependent apoptosis pathway by upregulating the expression of Bcl-2 and downregulating the expression of Bax and caspase 3. Conclusion These results suggest that ICA could attenuate male reproductive dysfunction of diabetic rats possibly via increasing cell proliferation and decreasing cell apoptosis of testis. ICA potentially represents a novel therapeutic strategy against DM-induced testicular damages.

SELF-ACTUALIZATION AND LIFE-MEANING ORIENTATIONS OF WOMEN WITH REPRODUCTIVE DYSFUNCTION OF VARIOUS ETIOLOGIES

Представлен сравнительный анализ особенностей самоактуализации и смысложизненных ориентаций женщин с нарушеннной репродуктивной функцией и женщин с сохранной репродуктивной сферой. Всего в исследовании приняло участие 200. В ходе исследования обнаружены статистически достоверные различия в показателях самоактуализации и смысложизненных ориентациях у двух групп женщин. Представлены процентные соотношения различий в уровнях выраженности данных показателей. A comparative analysis of the features of self-actualization and life-meaning orientations of women with impaired reproductive function and women with preserved reproductive sphere is presented. A total of 200 women participated in the study. The study revealed statistically significant differences in the indicators of self-actualization and life-meaning orientations in the two groups of women. The percentages of differences in the levels of severity of these indicators are presented.

A Review on the Reproductive Dysfunction in Farmed Finfish

Globally, fish production in the wild is decreasing, and different aquaculture systems are presently being used for broodstock development in the captivity. Seasonally, broodstock raised in captivity exhibit different form of reproductive dysfunction at the level of the brain-pituitary-gonad (BPG) axis. Primarily, vitellogenic completion and final oocyte maturation are inhibited in females, and males fail to spermiate spontaneously in the captivity. Reproductive dysfunctions are also observed during sexual differentiation, pubertal onset and sex conversion periods in teleosts. To overcome these problems, different hormonal preparations, primarily gonadotropin-releasing hormones (GnRH) are used. In recent years, kisspeptins have been shown to be potent in inducing gonadal growth and maturation in teleost fish. Understanding the form of reproductive dysfunction is important in formulating suitable hormonal preparations for inducing gametogenesis. The paper reviews the problem of reproductive dysfunction and their possible reason for formulating different hormonal preparations.

Changes in Expressions of Spermatogenic Marker Genes and Spermatogenic Cell Population Caused by Stress

Many young adults are in a state of stress due to social and psychological pressures, which may result in male reproductive dysfunction. To provide new insight into this phenomenon, we investigated the effect of stress on the regulation of key genes and biological events in specific stages of spermatogenesis. After establishing rat stress models of different time durations, we observed pathological changes in testis through haematoxylin and eosin staining, and analysed gene expression in testis by RNA-seq, bioinformatic analysis, and reverse transcription qPCR (RT-qPCR). Immunohistochemistry (IHC) with the TissueFAXS quantitative imaging system was used to verify changes of different population of spermatogenic cells marked by differentially expressed marker genes. Our results showed that prolonged stress can lead to pathological changes in the testes, such as thinning of the spermatogenic epithelium, a decreased number of spermatogenic epithelial cells, the disordered arrangement of spermatogenic cells, and a decreased number of mature sperms. RNA-seq revealed that key marker spermatogenesis-related genes such as Stra8, Sycp3, Piwil1, and Tnp1 had significantly decreased expression levels in chronic stress groups, and this was confirmed by RT-qPCR and IHC. Collectively, these findings suggest that chronic stress causes damaging pathological changes in testis and dysregulates the marker genes of specific stages of spermatogenesis and change the population of spermatogenic cells, which may be a critical responsible for male reproductive dysfunction.

Abstract 16: Altered Testicular Macrophage Polarization Is Associated With Reproductive Dysfunction In Hypertensive Mice

Elevated circulating proinflammatory (M1) and decreased anti-inflammatory (M2) macrophages contribute to hypertension (HTN) and end-organ damage. HTN is associated with reproductive dysfunction in men. However, the impact of HTN on testicular macrophages and inflammation is unknown. We hypothesized that HTN increases M1 and decreases M2 testicular macrophages, which is associated with inflammation and reproductive dysfunction. Male mice were made hypertensive by either providing L-arginine methyl ester hydrochloride (L-NAME) (0.5 mg/mL) in the drinking water for 3 weeks [L-NAME-induced HTN (LHTN)] or L-NAME water for 2 weeks, followed by a 2-week washout period and a subsequent 3-week 4% high salt diet [salt-sensitive hypertension (SSHTN)]. Control (C) mice received tap water and normal diet. Flow cytometry analysis revealed a significant increase in both M1 (C: 15%±1, LHTN: 22%±2; p<0.05) and M2 (C: 10%±1, LHTN: 21%±2; p<0.05) macrophages in testes from LHTN mice. Similarly, testes from SSHTN mice had a significant increase in M1 (C: 17%±1, SSHTN: 28%±2; p<0.05) but had a significant decrease in M2 (C: 14%±1, SSHTN: 7%±1; p<0.05) macrophages. Testes from both hypertension models had a significant increase in gene expression of the proinflammatory cytokines TNFa, IFNg, IL-1b, IL-6, and IL-17. Sperm concentration (C: 8.5±0.7, LHTN: 6.5±0.2, SSHTN: 4.7±0.5; both p<0.05) and the percentage of sperm mitochondrial activity (C: 88%±3, LHTN: 71±5, SSHTN: 64%±3; both p<0.05) were decreased significantly in both hypertension groups. Hypertensive mice presented a significantly increased percentage of sperm with abnormal morphology (C: 5%±1, LHTN: 8%±1, SSHTN: 13%±2; both p<0.05) and damaged acrosome (C: 1.4%±0.2, LHTN: 2.8%±0.2, SSHTN: 4%±0.5; both p<0.05). There was a significant decrease in gene expression of the hormone receptors AR, ERa, and LHR, and the steroidogenic enzymes StAR, 3bHSD, 17bHSD, and CYP17a1 in the testes of LHTN and SSHTN mice. These data demonstrate that HTN alters testicular macrophage polarization which is associated with inflammation and impaired reproductive health. Therapeutic strategies may be developed to improve reproductive health in male hypertensive patients by targeting testicular macrophage imbalance.

Abstract P217: Imbalance Of M1/M2 Macrophages In Ovaries Of Hypertensive Mice Is Associated With Reproductive Dysfunction And Lymphangiogenesis

Macrophages are the principal immune cells in ovaries. Besides protecting against invading pathogens and antigens, macrophages also play an essential role in folliculogenesis, ovulation, luteinization, lymphangiogenesis, and other functions. An imbalance in M1/M2 macrophages is observed in systemic circulation in patients and animals with hypertension (HTN). Although studies have demonstrated an association between HTN and reproductive dysfunction in females, the effect of HTN on ovarian M1/M2 ratio and lymphatics is largely unknown. We hypothesized that L-NAME-induced HTN (LHTN) and salt-sensitive hypertension (SSHTN) may increase the M1/M2 balance in ovaries which is associated with lymphangiogenesis and reproductive dysfunction in mice. Female mice were either provided L-NAME (0.5 mg/mL) in their drinking water for 3 weeks or L-NAME for 2 weeks, followed by a 2-week washout period and subsequent 3-week 4% high salt diet (SSHTN). Control mice (C) received tap water and normal diet. Flow cytometry analysis revealed a significant decrease in M1 (C: 46%±1, LHTN: 33%±2; p<0.05) and an increase in M2 (C: 7%±1, LHTN: 12%±1; p<0.05) macrophages in ovaries from LHTN mice. In SSHTN mice, ovaries had significantly increased M1 (C: 24%±1, SSHTN: 44%±2; p<0.05) and decreased M2 (C: 12%±1, SSHTN: 4%±1; p<0.05) macrophages. There was a significant increase in gene expression of the hormone receptors AR, FSHR, ERa, ERb, and LHR, and the steroidogenic enzymes StAR, 3bHSD, CYP11a1, and CYP17a1. Ovaries of hypertensive mice had a significant increase in gene expression of the lymphatic vessel markers Lyve-1, Podoplanin, and Prox-1, the lymphangiogenic growth factor VEGF-C and receptors VEGFR-2 and VEGFR-3. Taken together these data demonstrate that HTN disturbs M1/M2 macrophages in ovaries and is associated with reproductive dysfunction and lymphangiogenesis. Manipulation of M1/M2 ratio may be a therapeutic opportunity to improve reproductive health in hypertensive women.