Abstract

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are not only side products of chemical reactions, but participants in various cellular processes as well. ROS and RNS are involved in the defense against pathogenic microorganisms (H₂O₂, HOCl, ONOO^–, \({\text{O}}_{2}^{{\centerdot - }},\) and OH^•), fertilization (H₂O₂), cell division \(\left( {{\text{O}}_{2}^{{\centerdot - }}} \right),\) apoptosis (H₂O₂), regeneration (H₂O₂), coordination of a direction of the cellular movement, regulation of the vascular tone (NO^•), etc. A balance between the production and the removal of ROS and RNS results in an intracellular homeostasis, whereas their overproduction causes cell damage and most probably leads to changes in the cellular metabolism. ROS and RNS can act as intracellular messengers, i.e., change the intracellular oxidative–reductive state and/or structure and function of a protein by means of a modification of amino acid residues (mainly cysteines), and the red-ox state of a number of proteins can affect the cellular metabolism. Hydrogen peroxide is the main form of ROS which participates in oxidative–reductive transduction of signals in eukaryotes. Alterations in antioxidant systems contribute to aging and a development of the age-related diseases. Primarily, aging is associated with an increased level of oxidative stress, various types of macromolecular changes, and an accumulation of DNA damage. Ageing can, to some extent, be a consequence of disorders in the proteostasis regulation and changes in the proteome functioning, because proteins are responsible for most of the cellular functions. Moreover, not all the cellular proteins can be resynthesized due to the age-related DNA damage. Thus, reactive oxygen and nitrogen species that are permanently generated in an organism are important participants in regulatory mechanisms in a cell, but also a reason for several pathological states, including cancers. ROSs are known to regulate the metabolism of signal molecules which are necessary for the cell cycle. Moreover, ROSs are able to change the activity of the iron-containing proteins. The aging that is associated with an ineffective functioning of the antioxidant defense is connected with the oxidative stress, various changes in cellular structures and macromolecules, an accumulation of metabolic products which can have a negative effect, the DNA damage (for example, owing to mistakes during a replication by DNA polymerases), and disorders in functioning of reparation systems.

中文翻译：

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活性氧：参与细胞过程和病理学进展

摘要

活性氧（ROS）和活性氮（RNS）不仅是化学反应的副产物，而且还是各种细胞过程的参与者。ROS和RNS参与对病原微生物的防御（H ₂ Ø ₂，次氯酸，ONOO ^- ，\（{\文本{Ø}} _ {2} ^ {{\ centerdot - }} \）和OH ^•） ，受精（H ₂ O ₂），细胞分裂\（\ left（{{\ text {O}} _ {2} ^ {{\\ centerdot-}}} \ right）\\细胞凋亡（H ₂ O ₂） ，再生（H ₂ O ₂），细胞运动方向的协调，血管张力的调节（否^•ROS和RNS的产生与去除之间的平衡会导致细胞内稳态，而ROS和RNS的过度产生会导致细胞损伤，最有可能导致细胞代谢发生变化。ROS和RNS可以充当细胞内的信使，即通过氨基酸残基（主要是半胱氨酸）的修饰以及许多物质的氧化还原状态来改变蛋白质的细胞内氧化还原状态和/或结构和功能蛋白质会影响细胞代谢。过氧化氢是活性氧的主要形式，它参与真核生物信号的氧化-还原转导。抗氧化剂系统的变化会导致衰老和与年龄有关的疾病的发展。首先，衰老与氧化应激水平升高有关，各种类型的大分子变化以及DNA损伤的积累。在某种程度上，老化可能是蛋白质稳态调节异常和蛋白质组功能变化的结果，因为蛋白质负责大多数细胞功能。此外，由于年龄相关的DNA损伤，并非所有的细胞蛋白都可以重新合成。因此，在生物体中永久产生的活性氧和氮物质是细胞调节机制的重要参与者，但也是多种病理状态（包括癌症）的原因。已知ROS调节细胞周期所需的信号分子的代谢。而且，ROS能够改变含铁蛋白的活性。