Department of Pediatrics, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA.
Biomolecules. 2024 Sep 18;14(9):1171. doi: 10.3390/biom14091171.
Leydig cells are the primary source of testosterone or androgen production in male mammals. The blood-testis barrier (BTB) maintains structural integrity and safeguards germ cells from harmful substances by blocking their entry into the seminiferous tubules. L-cysteine is essential to the production of glutathione, a powerful antioxidant crucial to protecting against oxidative stress-induced damage. Animal studies have demonstrated the protective effect of L-cysteine in preventing testicular damage caused by chemicals or radiation. This study examines whether L-cysteine enhances the expression of testosterone biosynthesis and the BTB genes in human Leydig cells and THP-1 monocytes. The Leydig cells and THP-1 monocytes were treated with L-cysteine for 24 h. RNA was extracted following treatment, and the gene expression was analyzed using quantitative RT-PCR. Testosterone levels in the cell supernatant were measured using an ELISA kit. L-cysteine treatment in Leydig cells significantly upregulated the expression of ( = 0.03) and the BTB genes ( = 0.03), ( = 0.02), and ( = 0.02). Similarly, L-cysteine significantly upregulated the expression of ( = 0.03) and ( < 0.01), and the BTB genes ( = 0.04), ( < 0.01), ( < 0.01), ( < 0.01), and ( = 0.03) in THP-1 monocytes. Further, L-cysteine supplementation increased the testosterone secretion levels in human Leydig cells. The findings suggest that L-cysteine supplementation could be used as an adjuvant therapy to promote the integrity of the BTB genes, testosterone biosynthesis and secretion, and the maintenance of testicular functions, which in turn mitigates the risk of male infertility.
间质细胞是雄性哺乳动物睾酮或雄激素产生的主要来源。血睾屏障 (BTB) 通过阻止有害物质进入生精小管来维持结构完整性并保护生殖细胞免受有害物质的侵害。L-半胱氨酸是谷胱甘肽产生所必需的，谷胱甘肽是一种强大的抗氧化剂，对于防止氧化应激引起的损伤至关重要。动物研究已经证明了 L-半胱氨酸在预防化学物质或辐射引起的睾丸损伤方面的保护作用。本研究探讨了 L-半胱氨酸是否增强人间质细胞和 THP-1 单核细胞中睾酮生物合成和 BTB 基因的表达。用 L-半胱氨酸处理间质细胞和 THP-1 单核细胞 24 小时。处理后提取 RNA，并用定量 RT-PCR 分析基因表达。使用 ELISA 试剂盒测量细胞上清液中的睾酮水平。L-半胱氨酸处理显著上调了间质细胞中 （ = 0.03）和 BTB 基因 （ = 0.03）、 （ = 0.02）和 （ = 0.02）的表达。同样，L-半胱氨酸显著上调了 THP-1 单核细胞中 （ = 0.03）和 （ < 0.01）以及 BTB 基因 （ = 0.04）、 （ < 0.01）、 （ < 0.01）、 （ < 0.01）和 （ = 0.03）的表达。此外，L-半胱氨酸补充增加了人间质细胞中睾酮的分泌水平。这些发现表明，L-半胱氨酸补充剂可用作辅助治疗方法，以促进 BTB 基因、睾酮生物合成和分泌以及睾丸功能的完整性，从而降低男性不育的风险。
