School of Public Health, Nantong University, 9 Sheyuan Rd., Nantong, 226019, PR China.
School of Public Health, Nantong University, 9 Sheyuan Rd., Nantong, 226019, PR China.
Toxicology. 2021 Feb 15;449:152663. doi: 10.1016/j.tox.2020.152663. Epub 2020 Dec 24.
Perfluorooctane sulfonate (PFOS), a stable end-product of perfluorinated compounds (PFCs), is associated with male reproductive disorders, but its underlying mechanisms are still unclear. We used in vivo and in vitro models to investigate the effects of PFOS on testosterone biosynthesis and related mechanisms. First, male ICR mice were orally administered PFOS (0-10 mg/kg/bw) for 4 weeks. Bodyweight, sperm count, reproductive hormones, mRNA expression of the genes related to testosterone biosynthesis, and the protein expression of protein kinase A (PKA), p38 mitogen-activated protein kinase (MAPK), cAMP-response element binding protein (CREB), CREB regulated transcription coactivator 2 (CRTC2) and steroidogenic acute regulatory protein (StAR) were evaluated. Furthermore, mouse primary Leydig cells were used to delineate the molecular mechanisms that mediate the effects of PFOS on testosterone biosynthesis. Our results demonstrated that PFOS dose-dependently decreased sperm count, testosterone level, CRTC2/StAR expression, and damaged testicular interstitium morphology, paralleled by increase in phosphorylated PKA, CREB and p38 in testes. Additionally, similar to the in vivo results, PFOS significantly decreased testosterone secretion, CRTC2/StAR expression, interaction between CREB and CRTC2 and binding of CREB/CRTC2 to StAR promoter region, paralleled by increase in phosphorylated-p38, PKA, and CREB expression. Meanwhile, inhibition of p38 by SB203580, or inhibition of PKA by H89 can significantly alleviate the above PFOS-induced effects. As such, the present study highlights a role of the CREB/CRTC2/StAR signaling pathway in PFOS-induced suppression of testosterone biosynthesis, advancing our understanding of molecular mechanisms for PFOS-induced male reproductive disorders.
全氟辛烷磺酸（PFOS）是全氟化合物（PFCs）的稳定终产物，与男性生殖障碍有关，但其潜在机制尚不清楚。我们使用体内和体外模型来研究 PFOS 对睾丸酮生物合成的影响及其相关机制。首先，雄性 ICR 小鼠经口给予 PFOS（0-10mg/kg/bw）4 周。评估体重、精子计数、生殖激素、与睾丸酮生物合成相关基因的 mRNA 表达、蛋白激酶 A（PKA）、p38 丝裂原活化蛋白激酶（p38MAPK）、cAMP 反应元件结合蛋白（CREB）、CREB 调节转录共激活因子 2（CRTC2）和类固醇急性调节蛋白（StAR）的蛋白表达。此外，使用小鼠原代 Leydig 细胞阐明介导 PFOS 对睾丸酮生物合成影响的分子机制。结果表明，PFOS 呈剂量依赖性地降低精子计数、睾丸酮水平、CRTC2/StAR 表达和睾丸间质损伤，同时睾丸中磷酸化 PKA、CREB 和 p38 增加。此外，与体内结果相似，PFOS 显著降低睾丸酮分泌、CRTC2/StAR 表达、CREB 和 CRTC2 之间的相互作用以及 CREB/CRTC2 与 StAR 启动子区域的结合，同时磷酸化-p38、PKA 和 CREB 表达增加。同时，p38 的抑制（SB203580）或 PKA 的抑制（H89）可显著缓解上述 PFOS 诱导的作用。因此，本研究强调了 CREB/CRTC2/StAR 信号通路在 PFOS 诱导的睾丸酮生物合成抑制中的作用，加深了我们对 PFOS 诱导的男性生殖障碍的分子机制的理解。
