Rzheshevsky A V
Center for Rehabilitation Medicine, Dnepropetrovsk, 49000, Ukraine.
Biochemistry (Mosc). 2014 Oct;79(10):1056-68. doi: 10.1134/S0006297914100071.
Metabolic syndrome is extremely prevalent in the world and can be considered as one of main factors leading to accelerated aging and premature death. This syndrome may be closely linked with age-related disruptions in hypothalamic-pituitary system function, which perhaps represent a trigger mechanism of development of endocrine and cardiovascular pathologies. Age-related elevation of the sensitivity threshold of the hypothalamus to regulatory signals in association with low mobility and excessive diet trigger a cascade of biochemical reactions that might be used for activation of programmed death of the organism - phenoptosis. Accumulation of fatty acids in a cell and resulting lipotoxicity include resistance to insulin and leptin, endoplasmic reticulum stress, uncoupling of oxidation and phosphorylation, and dysfunction of biological membranes. Decrease in ATP synthesis is correlated with accumulation of calcium ions in cells, dysfunction of mitochondria, and increasing apoptotic activity. Age-related activation of mTOR (which is greatly influenced by excess energy substrates) has deleterious impact on one of the main mechanisms of cell defense by which defective mitochondria are replaced: mitophagy and biogenesis of mitochondria will be suppressed, and this will increase in greater degree mitochondrial dysfunction and oxidative stress. Fatty acid-induced inflammation will increase activity of nuclear factor NF-κB, the well-known stimulator of age-related pathologies. The final stage of phenoptosis can be represented by endothelium dysfunction related with oxidative stress, insulin resistance, and the most prevalent cardiovascular pathologies.
代谢综合征在全球极为普遍,可被视为导致加速衰老和过早死亡的主要因素之一。该综合征可能与下丘脑 - 垂体系统功能随年龄增长出现的紊乱密切相关,这或许是内分泌和心血管疾病发展的触发机制。下丘脑对调节信号的敏感性阈值随年龄增长而升高,再加上低运动量和过度饮食,引发一系列生化反应,这些反应可能会激活生物体的程序性死亡——自然凋亡。细胞内脂肪酸的积累以及由此产生的脂毒性包括对胰岛素和瘦素的抵抗、内质网应激、氧化与磷酸化的解偶联以及生物膜功能障碍。ATP合成的减少与细胞内钙离子的积累、线粒体功能障碍以及凋亡活性增加相关。mTOR的与年龄相关的激活(其受过量能量底物的影响很大)对细胞防御的主要机制之一产生有害影响,即替换有缺陷的线粒体:线粒体自噬和线粒体生物合成将受到抑制,这将在更大程度上增加线粒体功能障碍和氧化应激。脂肪酸诱导的炎症会增加核因子NF-κB的活性,NF-κB是与年龄相关疾病的著名刺激因子。自然凋亡的最后阶段可能表现为与氧化应激、胰岛素抵抗以及最常见的心血管疾病相关的内皮功能障碍。