The SET protein promotes androgen production in testicular Leydig cells

Structural analysis of polysaccharide from Inonotus obliquus and investigate combined impact on the sex hormones, intestinal microbiota and metabolism in SPF male mice

The dysregulation of sex hormone levels is associated with metabolic disorders such as obesity. Inonotus obliquus polysaccharide (IOP) exhibits a promising therapeutic effect on conditions like obesity and diabetes, potentially linked to its influence on intestinal microbiota and metabolism. The exact cause and mechanisms that link sex hormones, gut microbiota and metabolism are still unknown. In this research, we examined the molecular weight, monosaccharide composition, and glycosidic bond type of IOP. We found that IOP mostly consists of alpha-structured 6‑carbon glucopyranose, with a predominant (1 → 4) linkage to monosaccharides and a uniform distribution. Following this, we administered two different concentrations of IOP to mice through gavage. The results of the enzyme-linked immunosorbent assay (ELISA) demonstrated a significant increase in testosterone (T) levels in the IOP group as compared to the control group. Additionally, the results of tissue immunofluorescence indicated that increased IOP led to a decrease in adiponectin content and an increase in SET protein expression. The study also revealed changes in the intestinal microbiota and metabolic changes in mice through 16S rRNA data and non-targeted LC-MS data, respectively. The study also found that IOP mainly affects pathways linked to glycerophospholipid metabolism. In addition, it has been observed that there is an increase in the number of beneficial bacteria, such as the Eubacterium coprostanoligenes group and g.Lachnospiraceae NK4A136 group, while the levels of metabolites that are linked to obesity or diabetes, such as 1,5-anhydrosorbitol, are reduced. Furthermore, biomarker screening has revealed that the main microorganism responsible for the differences between the three groups is g.Erysipelatoclostridiaceae. In summary, these findings suggest that IOP exerts its therapeutic effects through a synergistic interplay between sex hormones, gut microbiome composition, and metabolic processes.

Immunolocalization and expression of Siglec5 protein in the male reproductive tract of dromedary camel during rutting season

Lectins are carbohydrate-binding proteins that are highly selective for sugar groups on other molecules. Siglec5 is a cell-surface lectin that belongs to the sialic acid-binding Ig-like lectins (Siglecs) and acts as a suppressor of immune responses. In this study, immunohistochemistry, western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detect the expression of Siglec5 in the male reproductive tract of dromedary camels during the rutting season. Siglec5 displayed strong immunostaining in the cranial and caudal testicular regions and moderate immunostaining in the rete testis. Different parts of the epididymis showed varying immunoreactions to Siglec5. The spermatozoa in the testes and epididymis also showed positive immunostaining for Siglec5, whereas, the vas deferens showed negative immunostaining for the protein. The results obtained by western blotting confirmed the immunohistochemical detection of the protein in the testicular and epididymal tissues. The results of qRT-PCR showed that Siglec mRNA was expressed differently in each part of the testis and epididymis; the highest levels of expression were observed in the caudal part of the testis and in the head of the epididymis. In conclusion, the present study revealed that Siglec5 is mainly located in the testis and epididymis, where sperm production and maturation occur. Therefore, this protein may play an essential role in the development, maturation and protection of camel sperm.

BMI1 promotes steroidogenesis through maintaining redox homeostasis in mouse MLTC-1 and primary Leydig cells

In males, aging is accompanied by decline in serum testosterone levels due to impairment of testicular Leydig cells. The polycomb protein BMI1 has recently been identified as an anti-aging factor. In our previous study, BMI1 null mice showed decreased serum testosterone and Leydig cell population, excessive oxidative stress and p16/p19 signaling activation. However, a cause-and-effect relationship between phenotypes and pathways was not investigated. Here, we used the rescue approach to study the role of oxidative stress or p16/p19 in BMI1-mediated steroidogenesis. Our results revealed that treatment with antioxidant NAC, but not down-regulation of p16/p19, largely rescued cell senescence, DNA damage and steroidogenesis in BMI1-deficient mouse MLTC-1 and primary Leydig cells. Collectively, our study demonstrates that BMI1 orchestrates steroidogenesis mainly through maintaining redox homeostasis, and thus, BMI1 may be a novel and potential therapeutic target for treatment of hypogonadism.

Age-related changes in serum reproductive hormone levels and prevalence of androgen deficiency in Chinese community-dwelling middle-aged and aging men: Two cross-sectional studies in the same population

To investigate the age-related nomograms and change trends of reproductive hormones, and prevalence of androgen deficiency (AD) in middle-aged and aging men from 2 studies.Two cross-sectional studies were conducted at 5-year intervals in Chinese community-dwelling men living in the same area. A total of 434 (Study 1, S1) and 944 (Study 2, S2) men aged 40 to 69 years were recruited as subjects and 59 (S1) and 98 (S2) men aged 20 to 39 years as controls to measure serum reproductive hormone levels.Serum total testosterone (TT) levels did not change significantly in S1, whereas TT levels increased in S2 with aging. Serum calculated free testosterone (cFT) levels gradually decreased with aging; however, only men aged 40 to 69 years showed this trend in S2. Serum luteinizing hormone (LH) and sex hormone binding globulin (SHBG) levels gradually increased, and serum testosterone secretion index (TSI) and free testosterone index (FTI) levels gradually decreased with male aging. The mean annual decrease values of serum cFT were 2.705 pmol/l in S1 and 1.060 pmol/l in S2. The cut-off values for AD in S1 and S2 were 9.13 nmol/l and 9.35 nmol/l for TT, and 169.00 pmol/l and 213.90 pmol/l for cFT. Using TT or cFT cut-off values, mean AD prevalence was 14.52% or 44.70% in S1, and 6.36% or 16.53% in S2. Based on cFT cut-off values, prevalence of AD increased gradually with male aging in a range of 25.30% to 61.63% in S1 and 1.20% to 23.03% in S2.The change patterns of serum LH, SHBG, TSI and FTI levels in middle-aged and aging males were consistent; however, there were differences in serum TT and cFT change patterns in S1 and S2 with male aging. cFT cut-off values were the optimal metric to evaluate AD, which can be present a ladder-like change in prevalence of different age groups.