Department of Preventive Medicine, School of Health Sciences, Wuhan University, Donghu Road 115, Wuhan 430071, China.
Department of Preventive Medicine, School of Health Sciences, Wuhan University, Donghu Road 115, Wuhan 430071, China.
Toxicol In Vitro. 2019 Apr;56:30-40. doi: 10.1016/j.tiv.2019.01.001. Epub 2019 Jan 4.
Sertoli cells (SCs) provide lactate as an energy substrate to develop germ cells during spermatogenesis. Lead (Pb) and cadmium (Cd) can induce SC toxicity. However, the mechanisms remain unclear. This study aimed to investigate the molecular mechanisms by which Pb and Cd alter lactate transport and production by SCs. Mouse SC line (15P-1 cells) were cultured in the absence and presence of lead acetate (PbAc, 1, 10, 20 and 30 μM) or cadmium chloride (CdCl, 0.5, 5, 10 and 15 μM) for 24 h. The results showed that PbAc exposure significantly decreased lactate dehydrogenase (LDH) activity and mRNA level, intracellular and extracellular lactate, and MCT4 and CD147 protein levels but increased MCT4 and CD147 mRNA levels. However, PbAc did not alter the glucose uptake, glucose transporters 1 (GLUT1) and 3 (GLUT3) mRNA expression of SCs. Thus, PbAc mainly decreased lactate production by inhibiting LDH activity. In CdCl-treated SCs, intracellular lactate content increased but extracellular lactate content decreased significantly, P < .05. The glucose uptake, LDH activity, and mRNA expression of GLUT1, GLUT3 and LDH, all significantly increased. But the mRNA and protein levels of MCT4 and CD147 significantly decreased. Moreover, the fluorescence intensity of co-localizations of the MCT4-CD147 complex dose-dependently decreased in the cell membrane. Thus, CdCl may reduce lactate export by suppressing MCT4 and CD147 expression. These results suggest that PbAc and CdCl disrupt lactate production and transport in mouse SCs by disturbing glycolysis or inhibiting MCT4-CD147 transporter expression and co-localizations.
支持细胞(SCs)为精母细胞的发育提供了乳酸作为能量底物。铅(Pb)和镉(Cd)会导致 SC 毒性。然而,其机制尚不清楚。本研究旨在探讨 Pb 和 Cd 改变 SC 乳酸转运和产生的分子机制。将小鼠 SC 系(15P-1 细胞)在无铅醋酸盐(PbAc,1、10、20 和 30μM)或氯化镉(CdCl,0.5、5、10 和 15μM)存在或不存在的情况下培养 24h。结果表明,PbAc 暴露显著降低乳酸脱氢酶(LDH)活性和 mRNA 水平、细胞内和细胞外乳酸以及 MCT4 和 CD147 蛋白水平,但增加了 MCT4 和 CD147 mRNA 水平。然而,PbAc 并未改变 SC 的葡萄糖摄取、葡萄糖转运蛋白 1(GLUT1)和 3(GLUT3)mRNA 表达。因此,PbAc 主要通过抑制 LDH 活性降低乳酸产生。在 CdCl 处理的 SC 中,细胞内乳酸含量增加,但细胞外乳酸含量显著减少,P<0.05。葡萄糖摄取、LDH 活性以及 GLUT1、GLUT3 和 LDH 的 mRNA 表达均显著增加。但 MCT4 和 CD147 的 mRNA 和蛋白水平显著降低。此外,MCT4-CD147 复合物的荧光强度在细胞膜中呈剂量依赖性降低。因此,CdCl 可能通过抑制 MCT4 和 CD147 表达来减少乳酸外排。这些结果表明,PbAc 和 CdCl 通过干扰糖酵解或抑制 MCT4-CD147 转运体表达和共定位来破坏小鼠 SC 中乳酸的产生和转运。