Bao Zi-Qiang, Liao Ting-Ting, Yang Wei-Rong, Wang Yi, Luo Hong-Yan, Wang Xian-Zhong
Chongqing Key Laboratory of Forage and Herbivore, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China.
Chongqing Key Laboratory of Forage and Herbivore, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China; Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Acton, ACT, Australia.
Theriogenology. 2017 Jan 1;87:339-348. doi: 10.1016/j.theriogenology.2016.09.016. Epub 2016 Sep 15.
This study aimed to determine whether heat stress (HS) could induce autophagy in immature boar Sertoli cells (SCs) and test whether HS-induced autophagy could regulate lactate secretion by SCs. Cultured immature boar SCs were incubated at 43 °C for 30 minutes. The ratio of LC3B-II to LC3B-I and the mRNA transcript levels of LC3B showed time-dependent changes 0 to 48 hours after HS treatment, which peaked at 24 hours and increased by 30.25% or 260%, respectively, compared with control SCs. The density of autolysosomes, which were labeled with a red dye, was higher at 24 hours than at any other time point. However, the apoptosis rate, cleavage of caspase-3, and mRNA transcript levels of CASP3 (caspase-3) at 24 hours after HS were lower than at 12 hours. Furthermore, lactate secretion, and mRNA transcript levels of SLC2A3 (GLUT3), LDHA (LDHA), and SLC16A1 (MCT1) also showed time-dependent changes with a peak at 24 hours. In addition, LY294002 (20 μM) significantly inhibited changes in ratio of LC3B-II to LC3B-I, LC3B mRNA transcript levels, and autolysosome formation. It also resulted in significantly less lactate secretion and increased apoptosis but showed no effect on B-cell lymphoma-2 expression in heat-treated immature SCs. These findings indicated that HS-induced autophagy regulates lactate secretion by inhibiting apoptosis and increasing mRNA transcript and protein levels of SLC2A3, LDHA, and SLC16A1, which suggests that HS-induced autophagy may enhance lactate secretion by SCs.
本研究旨在确定热应激（HS）是否能诱导未成熟公猪支持细胞（SCs）发生自噬，并检测HS诱导的自噬是否能调节SCs的乳酸分泌。将培养的未成熟公猪SCs在43℃孵育30分钟。HS处理后0至48小时，LC3B-II与LC3B-I的比值以及LC3B的mRNA转录水平呈现时间依赖性变化，在24小时达到峰值，与对照SCs相比分别增加了30.25%或260%。用红色染料标记的自溶酶体密度在24小时时高于其他任何时间点。然而，HS处理后24小时的凋亡率、半胱天冬酶-3的裂解以及CASP3（半胱天冬酶-3）的mRNA转录水平低于12小时。此外，乳酸分泌以及SLC2A3（葡萄糖转运蛋白3，GLUT3）、LDHA（乳酸脱氢酶A，LDHA）和SLC16A1（单羧酸转运蛋白1，MCT1）的mRNA转录水平也呈现时间依赖性变化，在24小时达到峰值。此外，LY294002（20μM）显著抑制了LC3B-II与LC3B-I的比值变化、LC3B mRNA转录水平以及自溶酶体形成。它还导致乳酸分泌显著减少且凋亡增加，但对热处理的未成熟SCs中的B细胞淋巴瘤-2表达没有影响。这些发现表明，HS诱导的自噬通过抑制凋亡并增加SLC2A3、LDHA和SLC16A1的mRNA转录和蛋白水平来调节乳酸分泌，这表明HS诱导的自噬可能增强SCs的乳酸分泌。
