The Laboratory of Food Nutrition and Functional Factors, Food Science and Technology, Jiangnan University, Wuxi 214122, China.
The Laboratory of Food Nutrition and Functional Factors, Food Science and Technology, Jiangnan University, Wuxi 214122, China; The State Key Laboratory of Food Science and Technology, Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Food Chem Toxicol. 2014 Feb;64:86-93. doi: 10.1016/j.fct.2013.10.039. Epub 2013 Nov 4.
Oxidized protein products (OPPs) can be easily found in meat and milk during processing and storage. Evidence supports that accumulation of endogenous OPPs plays a negative role in physiological metabolism. However, the impacts of dietary OPPs and the mechanisms have not been elucidated yet. The present study evaluated whether oral oxidized casein would destruct the antioxidant defense system and cause potential oxidized injury in mice liver and kidney.
We performed oxidized casein (modified respectively by H2O2-Cu and HClO) feeding experiments using KM mice (20-22 g). A 10-weeks feeding of oxidized casein as basal protein caused oxidative stress by increasing protein carbonylation (PC), advanced oxidation protein products (AOPPs), dityrosine (Dityr), lipid peroxidation and ROS levels in mice liver, kidney and blood (P<0.05). In mice liver and kidney, the mRNA expression of Nrf2, γ-GCS, HO-1, GPX-3, and GPX-4 up-regulated, the protein level of Nrf2 in nucleus increased. However, activities of anti-oxidant enzymes (CAT, SOD, and GPX) decreased (P<0.05). Moreover, histopathological examination displayed the formation of fibrous septa in mice liver and kidney after oxidized casein feeding.
Oxidized casein impairs antioxidant defense system and induces hepatic and renal fibrosis.
在加工和储存过程中，肉类和牛奶中很容易发现氧化蛋白产物（OPPs）。有证据表明，内源性 OPPs 的积累对生理代谢起着负面作用。然而，膳食 OPPs 的影响及其机制尚未阐明。本研究评估了口服氧化酪蛋白是否会破坏抗氧化防御系统，并导致小鼠肝、肾潜在的氧化损伤。
我们使用 KM 小鼠（20-22g）进行了氧化酪蛋白（分别用 H2O2-Cu 和 HClO 修饰）喂养实验。10 周的氧化酪蛋白作为基础蛋白喂养会通过增加蛋白质羰基化（PC）、高级氧化蛋白产物（AOPPs）、二酪氨酸（Dityr）、脂质过氧化和 ROS 水平来导致氧化应激在小鼠的肝、肾和血液中（P<0.05）。在小鼠的肝和肾中，Nrf2、γ-GCS、HO-1、GPX-3 和 GPX-4 的 mRNA 表达上调，核内 Nrf2 蛋白水平增加。然而，抗氧化酶（CAT、SOD 和 GPX）的活性降低（P<0.05）。此外，组织病理学检查显示，氧化酪蛋白喂养后小鼠肝、肾中出现纤维性隔室。
氧化酪蛋白破坏抗氧化防御系统并诱导肝、肾纤维化。
