Sugiyama Akihiko, Sun Jing
Course of Veterinary Laboratory Medicine, School of Veterinary Medicine, Faculty of Agriculture, Tottori University, Minami 4-101 m Koyama-cho, Tottori, 680-8553, Japan,
Subcell Biochem. 2014;77:115-25. doi: 10.1007/978-94-007-7920-4_10.
Polyunsaturated fatty acid (PUFA) is easily peroxidized by free radicals and enzymes. When this occurs, it results in the compromised integrity of cellular membranes and leads to lipid hydroperoxide as a major reaction product, which is decomposed into aldehyde. Lipid hydroperoxide-modified lysine is known to be an early product of the lipid peroxidation process, suggesting that it might be a PUFA-oxidative stress marker during the initial stage of oxidative stress. Lipid hydroperoxides cause or enhance ROS-mediated DNA fragmentation. The α,β-unsaturated aldehydes are end products of PUFA peroxidation. They are highly reactive and readily attack and modify the protein amino acid residues into aldehyde-modified proteins. Lipid peroxidation-derived α,β-unsaturated aldehydes are capable of inducing cellular stress-responsive processes such as cell signaling and apoptosis. The lipid hydroperoxide- and aldehyde-modified proteins have been immunohistochemically detected in diverse pathological situations such as atherosclerosis, Alzheimer's disease, Parkinson's disease, and chemical material-induced liver injury and renal tubular injury in humans and experimental animals. These findings suggest that the expression of the lipid hydroperoxide- and aldehyde-modified proteins is closely associated with the pathogenesis of these diseases in humans and experimental animals.
多不饱和脂肪酸（PUFA）很容易被自由基和酶过氧化。发生这种情况时，会导致细胞膜完整性受损，并产生脂质氢过氧化物作为主要反应产物，脂质氢过氧化物会分解成醛。脂质氢过氧化物修饰的赖氨酸是脂质过氧化过程的早期产物，这表明它可能是氧化应激初始阶段的PUFA氧化应激标志物。脂质氢过氧化物会导致或增强活性氧（ROS）介导的DNA片段化。α，β-不饱和醛是PUFA过氧化的终产物。它们具有高反应性，很容易攻击并将蛋白质氨基酸残基修饰为醛修饰的蛋白质。脂质过氧化衍生的α，β-不饱和醛能够诱导细胞应激反应过程，如细胞信号传导和细胞凋亡。脂质氢过氧化物和醛修饰的蛋白质已在多种病理情况下通过免疫组织化学检测到，如人类和实验动物的动脉粥样硬化、阿尔茨海默病、帕金森病以及化学物质诱导的肝损伤和肾小管损伤。这些发现表明，脂质氢过氧化物和醛修饰的蛋白质的表达与人类和实验动物中这些疾病的发病机制密切相关。
