Laboratory of Metabolic Manipulation of Herbivorous Animal Nutrition, College of Animal Science and Technology, Yangzhou University, Yangzhou, China.
Joint International Research Laboratory of Agriculture and Agri-Product Safety, Ministry of Education of China, Yangzhou University, Yangzhou, China.
J Nutr. 2021 Apr 8;151(4):1038-1046. doi: 10.1093/jn/nxaa428.
Previous studies demonstrated that dietary l-arginine (Arg) alters the equilibrium between reactive oxygen species (ROS) generation and biological defenses to resist oxidant-induced toxicity. Whether supplying Arg can protect ovine intestinal epithelial cells (OIECs) from hydrogen peroxide (H2O2)-induced oxidative damage is unclear.
The current study aimed to examine the effect of Arg on mitophagy, mitochondrial dysfunction, and apoptosis induced by H2O2 in OIECs.
The OIECs were incubated in Arg-free DMEM supplemented with 100 μM Arg (CON) or 350 μM Arg (ARG) alone or with 150 μM H2O2 (CON + H2O2, ARG + H2O2) for 24 h. Cellular apoptosis, mitochondrial function, autophagy, and the related categories of genes and proteins were determined. All data were analyzed by ANOVA using the general linear model procedures of SAS (SAS Institute) for a 2 × 2 factorial design.
Relative to the CON and ARG groups, H2O2 administration resulted in 44.9% and 26.5% lower (P < 0.05) cell viability but 34.7% and 61.8% greater (P < 0.05) ROS concentration in OIECs, respectively. Compared with the CON and CON + H2O2 groups, Arg supplementation led to 40.7% and 28.8% lower (P < 0.05) ROS concentration but 14.9%-49.0% and 29.3%-64.1% greater (P < 0.05) mitochondrial membrane potential, relative mitochondrial DNA content, and complex (I-IV) activity in OIECs, respectively. Compared with the CON and CON + H2O2 groups, Arg supplementation led to 33.9%-53.1% and 22.4%-49.1% lower (P < 0.05) mRNA abundance of proapoptotic genes, respectively. Relative to the CON and CON + H2O2 groups, Arg supplementation resulted in 33.0%-59.2% and 14.6%-37.7% lower (P < 0.05) abundance of proapoptotic, mitophagy, and cytoplasmic cytochrome c protein, respectively.
Supply of Arg protects OIECs against H2O2-induced damage partly by improving mitochondrial function and alleviating cellular apoptosis and autophagy.
先前的研究表明，膳食左旋精氨酸（Arg）可改变活性氧（ROS）生成与生物防御之间的平衡，从而抵抗氧化剂诱导的毒性。目前尚不清楚补充 Arg 是否可以保护绵羊肠道上皮细胞（OIECs）免受过氧化氢（H2O2）诱导的氧化损伤。
本研究旨在研究 Arg 对 H2O2 诱导的 OIECs 细胞发生的线粒体自噬、线粒体功能障碍和细胞凋亡的影响。
将 OIECs 在不含 Arg 的 DMEM 中孵育，补充 100 μM Arg（CON）或 350 μM Arg（ARG），或同时补充 150 μM H2O2（CON+H2O2，ARG+H2O2）24 小时。测定细胞凋亡、线粒体功能、自噬以及相关基因和蛋白的分类。所有数据均采用 SAS（SAS Institute）通用线性模型程序进行 2×2 析因设计的方差分析。
与 CON 和 ARG 组相比，H2O2 处理分别使 OIECs 的细胞活力降低 44.9%和 26.5%（P＜0.05），但 ROS 浓度分别升高 34.7%和 61.8%（P＜0.05）。与 CON 和 CON+H2O2 组相比，Arg 补充使 OIECs 的 ROS 浓度分别降低 40.7%和 28.8%（P＜0.05），而线粒体膜电位、相对线粒体 DNA 含量和复合物（I-IV）活性分别升高 14.9%-49.0%和 29.3%-64.1%（P＜0.05）。与 CON 和 CON+H2O2 组相比，Arg 补充使促凋亡基因的 mRNA 丰度分别降低 33.9%-53.1%和 22.4%-49.1%（P＜0.05）。与 CON 和 CON+H2O2 组相比，Arg 补充使促凋亡、线粒体自噬和细胞质细胞色素 c 蛋白的丰度分别降低 33.0%-59.2%和 14.6%-37.7%（P＜0.05）。
Arg 的供应通过改善线粒体功能和减轻细胞凋亡和自噬来保护 OIECs 免受 H2O2 诱导的损伤。
