Patel Shishir K, Singh Shio K
Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, India.
Andrology. 2020 Nov;8(6):1815-1823. doi: 10.1111/andr.12864. Epub 2020 Jul 27.
We have recently shown that QRFP and its receptor are predominantly expressed in germ cells, Sertoli cells and Leydig cells in mice testes.
The present study investigated the role of QRFP in testicular steroidogenesis in mice.
Both ex vivo and in vivo experiments were performed. For ex vivo, testicular tissues were cultured with 0, 10, 100 and 1000 nM QRFP, with or without hCG, for 6, 12 and 24 h, and media were used for testosterone assay. The hCG-stimulated testicular tissues were used for immunoblot of SF1, StAR, CYP11A1, 3β- and 17β-HSD. For in vivo, mice received bilateral intratesticular injection of saline or 0.3, 1 and 3nmol QRFP and were killed at 6, 12 and 24 h post-injection. Testosterone in serum was measured at above durations, while qRT-PCR of HMG-CoA synthase 1 and SR-B1 and immunoblot of steroidogenesis-related markers were performed at 24 h post-injection.
Testosterone production under basal and hCG-stimulated conditions increased in a time-dependent manner, and QRFP supplementation to testicular culture caused an increase and a decrease in hormone production. The effect of QRFP on testosterone production under hCG-stimulated culture or in vivo conditions at 6 and 24h was similar. At 6h, testosterone production increased at 10 and 100 nM and also at 0.3 and 1nmol QRFP, while it decreased at 1000 nM and 3 nmol doses. At 24 h, testosterone level decreased at lower concentrations (10 nM and 0.3 nmol) and thereafter increased at middle (100nM and 1nmol) and higher (1000 nM and 3 nmol) concentrations under both hCG-stimulated culture and in vivo.
QRFP induced production of testosterone by modulating steroidogenic machinery at optimal doses and durations. Further, findings of in vivo study indicate that QRFP besides directly regulating testicular steroidogenesis may also have modulated other factors which act together in a holistic manner to control steroidogenesis.
我们最近发现，促性腺激素释放激素相关肽（QRFP）及其受体主要在小鼠睾丸的生殖细胞、支持细胞和间质细胞中表达。
本研究探讨QRFP在小鼠睾丸类固醇生成中的作用。
进行了体外和体内实验。体外实验中，将睾丸组织分别与0、10、100和1000 nM的QRFP一起培养，添加或不添加人绒毛膜促性腺激素（hCG），培养6、12和24小时，然后用培养基进行睾酮测定。用hCG刺激的睾丸组织进行类固醇生成因子1（SF1）、类固醇生成急性调节蛋白（StAR）、细胞色素P450侧链裂解酶（CYP11A1）、3β-羟基类固醇脱氢酶（3β-HSD）和17β-羟基类固醇脱氢酶（17β-HSD）的免疫印迹分析。体内实验中，小鼠双侧睾丸内注射生理盐水或0.3、1和3 nmol的QRFP，并在注射后6、12和24小时处死。在上述时间段测量血清中的睾酮水平，在注射后24小时进行羟甲基戊二酸单酰辅酶A合酶1（HMG-CoA synthase 1）和清道夫受体B1（SR-B1）的定量逆转录聚合酶链反应（qRT-PCR）以及类固醇生成相关标志物的免疫印迹分析。
在基础和hCG刺激条件下，睾酮的产生呈时间依赖性增加，向睾丸培养物中添加QRFP导致激素产生增加和减少。QRFP在hCG刺激培养或体内条件下对6小时和24小时睾酮产生的影响相似。在6小时时，10和100 nM以及0.3和1 nmol QRFP剂量下睾酮产生增加，而在1000 nM和3 nmol剂量下减少。在24小时时，在hCG刺激培养和体内条件下，较低浓度（10 nM和0.3 nmol）下睾酮水平降低，此后在中等浓度（100 nM和1 nmol）和较高浓度（1000 nM和3 nmol）下升高。
QRFP在最佳剂量和持续时间下通过调节类固醇生成机制诱导睾酮的产生。此外，体内研究结果表明，QRFP除了直接调节睾丸类固醇生成外，还可能调节了其他一些因素，这些因素共同以整体方式控制类固醇生成。
