Department of Zoology, Maitreyi College, University of Delhi, Delhi, India.
Department of Zoology, Miranda House, University of Delhi, Delhi, India.
J Endocrinol. 2024 Oct 29;263(3). doi: 10.1530/JOE-24-0146. Print 2024 Dec 1.
The novel adipokine asprosin, produced by the furin enzymatic cleavage of profibrillin 1 protein (encoded by the Fbn1 gene), is implicated in regulating many physiological functions, including reproduction in mammals. In males, asprosin is reported to increase sperm density, sperm motility, and steroid production by interacting with Olfr734, which belongs to the G-protein-coupled receptor family (GPCR). In 2023, our group predicted and characterized asprosin in silico for the first time and demonstrated the robust expression of fbn1, and furin in the gonads of teleost spotted snakehead (ss) Channa punctata. Taking it forward, in the current study, we have investigated the effect of asprosin on the testicular functions of the spotted snakehead. As C. punctata is a seasonal breeder, the reproductive-phase-dependent expression of fbn1 in the testis was analyzed, showing significant upregulation during the preparatory and post-spawning phases. Additionally, bacterially overexpressed recombinant asprosin of C. punctata was purified to study the effect of ss asprosin on gametogenesis and steroidogenesis. Ex vivo treatment with recombinant asprosin resulted in significant upregulation of spermatogenic marker genes pcna, aldh1a2, cyp26a1, and sycp3. Asprosin also enhanced the gene expression of gonadotropin receptors, as well as sex steroid receptors, in addition to steroidogenic genes star and cyp17a1. Further exploring the downstream signaling cascade, the second messenger of GPCRs, cAMP levels following asprosin treatment were analyzed. Asprosin treatment prominently enhanced cAMP levels, thereby indicating the involvement of GPCR in the transduction of asprosin action. Hence, the study elucidates the regulation of male reproductive function by asprosin in spotted snakeheads.
新发现的脂肪因子阿普索林由原纤维蛋白 1 蛋白（Fbn1 基因编码）经弗林蛋白酶酶切产生，参与调节许多生理功能，包括哺乳动物的生殖功能。有报道称，在雄性动物中，阿普索林通过与属于 G 蛋白偶联受体家族（GPCR）的 Olfr734 相互作用，增加精子密度、精子活力和类固醇生成。2023 年，我们小组首次对鱼类（点带石斑鱼）的阿普索林进行了计算机预测和鉴定，并证明了 fbn1 和弗林在性腺中的表达丰度较高。在此基础上，本研究进一步探讨了阿普索林对点带石斑鱼睾丸功能的影响。由于点带石斑鱼是季节性繁殖者，因此分析了 fbn1 在睾丸中的生殖期依赖性表达，结果表明在预备期和产卵后期显著上调。此外，我们还通过细菌过表达重组阿普索林来研究 ss 阿普索林对配子发生和类固醇生成的影响。重组阿普索林的离体处理导致精子发生标记基因 pcna、aldh1a2、cyp26a1 和 sycp3 的显著上调。阿普索林还增强了促性腺激素受体、性类固醇受体以及类固醇生成基因 star 和 cyp17a1 的基因表达。进一步探索 GPCR 下游信号级联，分析了阿普索林处理后第二信使 cAMP 的水平。阿普索林处理显著增强了 cAMP 水平，表明 GPCR 参与了阿普索林作用的转导。因此，本研究阐明了阿普索林在点带石斑鱼雄性生殖功能中的调节作用。
