The effects of vitamin C and vitamin B12 on improving spermatogenesis in mice subjected to long-term scrotal heat stress.

Objective: Scrotal hyperthermia poses a significant threat to spermatogenesis and fertility in mammalian species. This study investigated the effects of vitamin B12 and vitamin C on spermatogenesis in adult male mice subjected to long-term scrotal hyperthermia. The rationale is based on the sensitivity of germ cells and epididymal sperm to increased scrotal temperatures. While various factors, both internal and external, can raise the testicular temperature, this study focused on the potential therapeutic roles of vitamins B12 and C. Methods: After inducing scrotal hyperthermia in mice, vitamin B12 and vitamin C were administered for 35 days. We assessed sperm parameters, serum testosterone levels, stereological parameters, the percentage of apoptotic cells, reactive oxygen species (ROS) levels, and glutathione (GSH) levels. Additionally, real-time polymerase chain reaction was used to analyze the expression of the c-kit, stimulated by retinoic acid gene 8 (Stra8), and proliferating cell nuclear antigen (Pcna) genes. Results: Vitamin C was more effective than vitamin B12 in improving sperm parameters and enhancing stereological parameters. The study showed a significant decrease in apoptotic cells and a beneficial modulation of ROS and GSH levels following vitamin administration. Moreover, both vitamins positively affected the expression levels of the c-kit, Stra8, and Pcna genes. Conclusion: This research deepens our understanding of the combined impact of vitamins B12 and C in mitigating the effects of scrotal hyperthermia, providing insights into potential therapeutic strategies for heat stress-related infertility. The findings highlight the importance of considering vitamin supplementation as a practical approach to counter the detrimental effects of elevated scrotal temperatures on male reproductive health.

Sertoli cell-conditioned medium can improve blood-testis-barrier function and spermatogenesis in azoospermia mice induced by scrotal hyperthermia: An experimental study.

Background: An increase in the temperature of the testis is associated with damage to the epithelium of seminiferous tubules and disruption of sperm production. Objective: The current study aimed to investigate the effect of the Sertoli cell-conditioned medium (SCCM) on the blood-testis-barrier associated genes and spermatogenesis process following scrotal hyperthermia. Materials and Methods: In this experimental study, 40 adult NMRI mice (8 wk, 25-30 gr) were allocated into 4 groups: I) control, II) DMEM (10 µl Dulbecco's Modified Eagle Medium), III) scrotal hyperthermia, and IV) scrotal hyperthermia+SCCM (10 µl SCCM). Hyperthermia was induced by placing the mice scrotum in water at 43 C for 20 min every other day for 10 days. Mice were treated every other day for 5 wk. Then the animals were euthanized, and the tails of epididymis were removed to analyze sperm parameters, testis were taken for stereological assessment, reactive oxygen spices and glutathione levels, and the expression of Ocln, Gja1, Cdh2, and Itgb1. Results: The results of sperm analysis indicated that SCCM-treated mice significantly increased sperm count and motility and reduced DNA fragmentation. In addition, histological and molecular findings showed that the volume of testicular tissue, the number of germ cells, the glutathione level, and the expression of Ocln, Gja1, Cdh2, and Itgb1 genes were significantly increased in the SCCM-treated mice. Conclusion: Findings suggest that growth factors of SCCM stimulate the proliferation and differentiation of germ cells through paracrine effects and upregulate the blood-testis-barrier-associated genes in mice subjected to scrotal hyperthermia.

Targeted Deletion of Los1 Homologue Affects the Production of a Recombinant Model Protein in Pichia pastoris.

Background: The methylotrophic yeast Pichia pastoris is an appealing production host for a variety of recombinant proteins, including biologics. In this sense, various genetic- and non-genetic-based techniques have been implemented to improve the production efficiency of this expression platform. Loss of supression (Los1) encodes a non-essential nuclear tRNA exporter in Saccharomyces cerevisiae, which its deletion extends replicative lifespan. Herein, a los1-deficient strain of P. pastoris was generated and characterized. Methods: A gene disruption cassette was prepared and transformed into an anti-CD22-expressing strain of P. pastoris. A δ los1 mutant was isolated and confirmed. The drug sensitivity of the mutant was also assessed. The growth pattern and the level of anti-CD22 single-chain variable fragment (scFv) expression were compared between the parent and mutant strains. Resuults: The los1 homologue was found to be a non-essential gene in P. pastoris. Furthermore, the susceptibility of los1 deletion strain to protein synthesis inhibitors was altered. This strain showed an approximately 1.85-fold increase in the extracellular level of anti-CD22 scFv (p < 0.05). The maximum concentrations of total proteins secreted by δ los1 and parent strains were 125 mg/L and 68 mg/L, respectively. Conclusion: The presented data suggest that the targeted disruption of los1 homologue in P. pastoris can result in a higher expression level of our target protein. Findings of this study may improve the current strategies used in optimizing the productivity of recombinant P. pastoris strains.