Assessment of progesterone synthesis and its regulation role on dihydrotestosterone secretion in sheep epididymis

Integrated cell metabolomics and network pharmacology approach deciphers the anti-testosterone deficiency mechanisms of Bushen Zhuanggu Tang

Testicular dysfunction is distinguished by a deficiency in testosterone levels, which can be attributed to the occurrence of oxidative stress injury in Leydig cells. The empirical prescription known as Bushen Zhuanggu Tang, developed by a highly experienced traditional Chinese medicine practitioner with six decades of clinical expertize, aligns with the traditional Chinese medicine principle of "kidney governing bone". Researchers have demonstrated that the administration of BSZGT can effectively enhance testosterone production. The objective of this study is to investigate the potential anti-testicular dysfunction effects of BSZGT and elucidate its underlying mechanism in an in vitro setting. Specifically, the impact of oxidative stress induced by H2O2 on the activity and testosterone levels of Leydig cells (TM3) was examined. Furthermore, the utilization of UPLC-QE-Qrbitrap-MS enabled the identification of the involvement of BSZGT in various metabolic pathways, including arginine biosynthesis, amino acyl-tRNA biosynthesis, Alanine, aspartate and glutamine metabolism, and Citrate Cycle, through the modulation of 25 distinct metabolites. Additionally, a network pharmacological analysis was conducted to investigate the pivotal protein targets associated with the therapeutic effects of BSZGT. The findings demonstrate the identification of six key proteins (CYP19A1, CYP1B1, ALOX5, ARG1, XDH, and MPO) that play a significant role in augmenting testicular function through their involvement in the ovarian steroid production pathway. In summary, our study presents a comprehensive research methodology that combines cell metabonomics and network pharmacology to enhance the discovery of new therapeutic agents for TD.

The role of GnRH in Tibetan male sheep and goat reproduction

The hypothalamic-pituitary-gonadal (HPG) axis connects the hypothalamus, pituitary gland, and gonads. The regulation of reproductive processes includes integrating various factors from structural functions and environmental conditions in the HPG axis, with the outcome indication of these processes being the pulsatile secretion of gonadotropin-releasing hormone (GnRH) from the hypothalamus. These factors include feed consumption and nutritional condition, sex steroids, season/photoperiod, pheromones, age, and stress. GnRH pulsatile secretion affects the pattern of gonadotropin secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which then regulates both endocrine function and gamete maturation in the gonads. This regulates gonadotropins and testosterone (T) production. There is evidence that in males, GnRH participates in a variety of host behavioural and physiological processes such as the release of reproductive hormones, progression of spermatogenesis and sperm function, aggressive behaviour, and physiological metabolism. GnRH activates receptors expressed on Leydig cells and Sertoli cells, respectively to stimulate T secretion and spermatogenesis in the testis. Photoperiod affects the reproductive system of the hypothalamic-pituitary axis via rhythmic diurnal melatonin secretion. Increased release of melatonin promotes sexual activity, GnRH production, LH stimulation, and T production. This induces testicular functions, spermatogenesis, and puberty. GnRH reduces the release of LH by the pituitary through the cascade effect and decreases plasma concentration of T. Gut microbiota maintain sex steroid homeostasis and may induce reduction in reproduction productivity. Recently, findings of kisspeptin-neurokinin-dynorphin neuronal network in the brain have resulted in fast advances in how GnRH secretion is controlled. Emerging studies have also indicated that other neuropeptide analogues could be used in control reproduction procedures in various goat and sheep breeds. The Tibetan male sheep and goats reproduce on a seasonal basis and have high reproductive performance. This is a review for the role of GnRH in Tibetan male sheep and goats reproduction. This is intended to enhance reproductive knowledge for understanding the key roles of GnRH relating to male reproductive efficiency of Tibetan sheep or goats.

Effect of dihydrotestosterone on melatonin secretion and the expression of melatonin receptors and apoptosis-related factors in sheep epididymides

Melatonin (MEL) is involved in homeostasis of the epididymis lumen environment. Dihydrotestosterone (DHT) partakes in the development of gonads and organs in male animals. However, whether MEL secretion, the expression of its receptors, MT1 and MT2, and sheep epididymal epithelial cell apoptosis is regulated by DHT remains unclear. In this study, we used immunohistochemical staining to detect the distribution patterns of DHT synthetases [5α-reductase (5α-red)] and its androgen receptor (AR) in sheep epididymides. 5α-red1, 5α-red2, and AR were positively expressed in sperm, epididymal epithelial cells, and the smooth muscle cells of the caput, corpus, and cauda regions of the epididymis. DHT concentration and the expression levels of 5α-red and AR in the caput, corpus, and cauda regions were measured by enzyme-linked immunosorbent assay, liquid chromatography-mass spectrometry, real-time quantitative polymerase chain reaction, and western blot analysis. DHT concentration in the caput was significantly higher than those in corpus and cauda, probably because of the high expression of 5α-red2 in the caput and secretion and transport of DHT by the testicles. DHT inhibited MEL secretion, the expression of its membrane receptors, and MEL synthetases in cultured sheep epididymal epithelial cells in vitro. In addition, the Bax/Bcl-2 ratio, ACT CASP3, and caspase-3 mRNA expression were also decreased. The decreasing effect was partially reversed after flutamide treatment. Therefore, DHT regulates sheep epididymal function by influencing MEL expression and apoptosis-related factors. This study provides basic data for further research on the reproductive physiology of male animals.