Expression of adenosine 5'-monophosphate-Activated protein kinase (AMPK) in ovine testis (Ovis aries): In vivo regulation by nutritional state

Presence, Tissue Localization, and Gene Expression of the Adiponectin Receptor 1 in Testis and Accessory Glands of Male Rams during the Non-Breeding Season

Adiponectin (ADIPOQ) is a member adipocytokines, and its actions are supported by two receptors, ADIPOQ receptor 1 and -2, respectively (ADIPOR1 and -R2). Our study was performed to evaluate the ADIPOR1 presence and location and its gene expression in reproductive tissues of the male ram, during its non-breading season. The different portions of the male ram reproductive system (testis, epididymis, seminal vesicle, ampoule vas deferens, bulb-urethral gland) were collected in a slaughterhouse. Immunohistochemistry showed ADIPOR1 positive signals in the cytoplasm of all the glandular epithelial cells, with a location near the nucleus; in the testes, the positive reaction was evidenced in the cytoplasm in the basal portion of the germinal epithelial cells. The immune reaction intensity was highest (p < 0.001) in the prostate and seminal vesicles glands than that of other parts of the ram reproductive tract. RT-qPCR detected the ADIPOR1 transcript in the testes, epididymis, vas deferens, bulbourethral glands, seminal vesicles, and prostate; the expression levels were high (p < 0.01) in the prostate and low (p < 0.01) in the testis, epididymis, and bulbourethral glands. The present results evidenced the possible ADIPOQ/ADIPOR1 system's role in regulating the testicular activity of male rams during the non-breading season.

Oral Exposure to Genistein during Conception and Lactation Period Affects the Testicular Development of Male Offspring Mice

Simple Summary

Spermatogenesis and hormones secretions are important life-threating and complicated process, which can be affected by environmental estrogens. Genistein, a type of isoflavones, widely exists in the soybean products diet, which exerts a controversial role in reproductive regulation for its special structures or functions. The results of the study revealed that low-dose genistein treatment increased the level of testosterone in the mice serum, and positively regulated expression of spermatogenesis-related genes, which enhanced spermatogenesis and testicular development. However, High-dose genistein treatment induced apoptosis of germ cells and inhibited proliferation of germ cells during spermatogenesis. Reproductive alterations in the structures and functions of testis were dose-dependent in different genistein treatments.

Abstract

Sexual hormones are essential for the process of spermatogenesis in the testis. However, the effect of maternal genistein (GEN) on the pups’ testicular development remain-unclear. Our present study evaluated the effects of supplementing GEN for parental and offspring mice on the reproductive function and growth performance of the male pups. Mothers during gestation and lactation period were assigned to a control diet (CON group), low dose GEN (LGE group) diet (control diet +40 mg/kg GEN), and high dose of GEN (HGE group) diet (control diet +800 mg/kg GEN). Their male offspring underwent the same treatment of GEN after weaning. LGE treatment (40 mg/kg GEN) significantly increased body weights (p < 0.001), testes weights (p < 0.05), diameters of seminiferous tubule (p < 0.001) and heights of seminiferous epithelium (p < 0.05) of offspring mice. LGE treatment also increased serum testosterone (T) levels and spermatogenesis scoring (p < 0.05). However, HGE treatment (800mg/kg GEN) significantly decreased body weights (p < 0.001), testes weights (p < 0.05) and testis sizes (p < 0.001). Furthermore, mRNA expressions of ESR2 (p < 0.05), CYP19A1 (p < 0.001), SOX9 (p < 0.001) and BRD7 (p < 0.001) in testis of mice were increased in the LGE group. Similarly, HGE treatment increased mRNA expressions of ESR2 (p < 0.05) and CYP19A1 (p < 0.001). However, mRNA expressions of SOX9 and BRD7 were decreased significantly in the HGE group (p < 0.001). Meanwhile, higher ratio apoptotic germ cells and abnormal sperms were detected in the HGE group (p < 0.001). In conclusion, exposure to a low dose of GEN during fetal and neonatal life could improve testicular development of offspring mice, whereas, unfavorable adverse effects were induced by a high dose of GEN.

Testosterone in Males as Enhanced by Onion (Allium Cepa L.)

Testosterone (17β-Hydroxyandrost-4-en-3-one) is the main sex hormone in males. Maintaining and enhancing testosterone level in men is an incessant target for many researchers. Examples of such research approaches is to utilize specific types of food or dietary supplements as a safe and easily reached means. Here, specifically, since 1967 until now, many research studies have revealed the effect of onion on testosterone; however, this link has yet to be collectively reviewed or summarized. To accomplish this contribution, we searched the Scopus, Web of Science, and PubMed databases for full articles or abstracts (published in English language) from April 1967 through December 2018 using the keywords “onion” versus “testosterone”. In addition, a number of related published articles from the same databases were included to improve the integrity of the discussion, and hence the edge of the future directions. In summary, there is an evidence that onions enhance testosterone level in males. The mechanisms by which this occurs is mainly by increasing the production of luteinizing hormone, enhancing the antioxidant defense mechanism in the tests, neutralizing the damaging effects of the generated free radicals, ameliorating insulin resistance, promoting nitric oxide production, and altering the activity of adenosine 5′-monophosphate -activated protein kinase. However, this effect requires further approval in humans, mainly by conducting clinical trials.

4-Bromodiphenyl ether delays pubertal Leydig cell development in rats

Polybrominated diphenyl ethers are a class of brominated flame retardants that are potential endocrine disruptors. 4-Bromodiphenyl ether (BDE-3) is the most abundant photodegradation product of higher polybrominated diphenyl ethers. However, whether BDE-3 affects Leydig cell development during puberty is still unknown. The objective of this study was to explore effects of BDE-3 on the pubertal development of rat Leydig cells. Male Sprague Dawley rats (35 days of age) were gavaged daily with BDE-3 (0, 50, 100, and 200 mg/kg body weight/day) for 21 days. BDE-3 decreased serum testosterone levels (1.099 ± 0.412 ng/ml at a dose of 200 mg/kg BDE-3 when compared to the control level (2.402 ± 0.184 ng/ml, mean ± S.E.). BDE-3 decreased Leydig cell size and cytoplasmic size at a dose of 200 mg/kg, decreased Lhcgr, Star, Dhh, and Sox9 mRNA levels at ≥ 100 mg/kg and Scarb1, Cyp11a1, Hsd17b3, and Fshr at 200 mg/kg. BED-3 also decreased the phosphorylation of AKT1, AKT2, ERK1/2, and AMPK at 100 or 200 mg/kg. BDE-3 in vitro induced ROS generation, inhibited androgen production, down-regulated Lhcgr, Scarb1, Star, Cyp11a1, Hsd3b1, Srd5a1, and Akr1c14 expression in immature Leydig cells after 24-h treatment. In conclusion, the current study indicates that BDE-3 disrupts Leydig cell development via suppressing AKT, ERK1/2, and AMPK phosphorylation and inducing ROS generation.

AMPK Function in Mammalian Spermatozoa

AMP-activated protein kinase AMPK regulates cellular energy by controlling metabolism through the inhibition of anabolic pathways and the simultaneous stimulation of catabolic pathways. Given its central regulator role in cell metabolism, AMPK activity and its regulation have been the focus of relevant investigations, although only a few studies have focused on the AMPK function in the control of spermatozoa's ability to fertilize. This review summarizes the known cellular roles of AMPK that have been identified in mammalian spermatozoa. The involvement of AMPK activity is described in terms of the main physiological functions of mature spermatozoa, particularly in the regulation of suitable sperm motility adapted to the fluctuating extracellular medium, maintenance of the integrity of sperm membranes, and the mitochondrial membrane potential. In addition, the intracellular signaling pathways leading to AMPK activation in mammalian spermatozoa are reviewed. We also discuss the role of AMPK in assisted reproduction techniques, particularly during semen cryopreservation and preservation (at 17 °C). Finally, we reinforce the idea of AMPK as a key signaling kinase in spermatozoa that acts as an essential linker/bridge between metabolism energy and sperm's ability to fertilize.