📋 Browse Articles

Reactive molecules, including oxygen and nitrogen species, serve dual roles in human physiology. While they function as essential signaling molecules under normal physiological conditions, they contribute to cellular dysfunction and damage when produced in excess by normal metabolism or in response to stressors. Oxidative/nitrosative stress is a pathological state, resulting from the overproduction of reactive species exceeding the antioxidant capacity of the body, which is implicated in several chronic human diseases. Antioxidant Show less

AbstractLung cancer is a common malignant tumor that occurs in the human body and poses a serious threat to human health and quality of life. The existing treatment methods mainly include surgical treatment, chemotherapy, and radiotherapy. However, due to the strong metastatic characteristics of lung cancer and the emergence of related drug resistance and radiation resistance, the overall survival rate of lung cancer patients is not ideal. There is an urgent need to develop new treatment strategies or new effective drugs to treat lung cancer. Ferroptosis, a novel type of programmed cell death, is different from the traditional cell death pathways such as apoptosis, necrosis, pyroptosis and so on. It is caused by the increase of iron-dependent reactive oxygen species due to intracellular iron overload, which leads to the accumulation of lipid peroxides, thus inducing cell membrane oxidative damage, affecting the normal life process of cells, and finally promoting the process of ferroptosis. The regulation of ferroptosis is closely related to the normal physiological process of cells, and it involves iron metabolism, lipid metabolism, and the balance between oxygen-free radical reaction and lipid peroxidation. A large number of studies have confirmed that ferroptosis is a result of the combined action of the cellular oxidation/antioxidant system and cell membrane damage/repair, which has great potential application in tumor therapy. Therefore, this review aims to explore potential therapeutic targets for ferroptosis in lung cancer by clarifying the regulatory pathway of ferroptosis. Based on the study of ferroptosis, the regulation mechanism of ferroptosis in lung cancer was understood and the existing chemical drugs and natural compounds targeting ferroptosis in lung cancer were summarized, with the aim of providing new ideas for the treatment of lung cancer. In addition, it also provides the basis for the discovery and clinical application of chemical drugs and natural compounds targeting ferroptosis to effectively treat lung cancer. Show less

Hydrogen peroxide (H2 O2 ) is an important reactive oxygen species that plays a major role in redox signaling. Although H2 O2 is known to regulate gene expression and affect multiple cellular processes, the characteristics and mechanisms of such transcriptional regulation remain to be defined. In this study, we utilized transcriptome sequencing to determine the global changes of mRNA and lncRNA transcripts induced by H2 O2 in human pancreatic normal epithelial (HPNE) and pancreatic cancer (PANC-1) cells. Promoter analysis using PROMO and TRRUST revealed that mRNAs and lncRNAs largely shared the same sets of transcription factors in response to ROS stress. Interestingly, promoters of the upregulated genes were similar to those of the downregulated transcripts, suggesting that the H2 O2 -responding promoters are conserved but they alone do not determine the levels of transcriptional outputs. We also found that H2 O2 induced significant changes in molecules involved in the pathways of RNA metabolism, processing, and transport. Detailed analyses further revealed a significant difference between pancreatic cancer and noncancer cells in their response to H2 O2 stress, especially in the transcription of genes involved in cell-cycle regulation and DNA repair. Our study provides new insights into RNA transcriptional regulation upon ROS stress in cancer and normal cells. Transcription of mRNA and lncRNA. Antioxidants 2022, 11, 495. https:// Show less

The ability to detect oxygen availability is a ubiquitous attribute of aerobic organisms. However, the mechanism(s) that transduce oxygen concentration or availability into appropriate physiological responses is less clear and often controversial. This review will make the case for oxygen-dependent metabolism of hydrogen sulfide (H2 S) and polysulfides, collectively referred to as reactive sulfur species (RSS) as a physiologically relevant O2 sensing mechanism. This hypothesis is based on observations that H2 S and RSS metabolism is inversely correlated with O2 tension, exogenous H2 S elicits physiological responses identical to those produced by hypoxia, factors that affect H2 S production or catabolism also affect tissue responses to hypoxia, and that RSS efficiently regulate downstream effectors of the hypoxic response in a manner consistent with a decrease in O2 . H2 S-mediated O2 sensing is then compared to the more generally accepted reactive oxygen species (ROS) mediated O2 sensing mechanism and a number of reasons are offered to resolve some of the confusion between the two.



 Show less

Reactive oxygen species (ROS) are considered a key factor in the heart aging process. Mitochondrial respiration is an important site of ROS generation and a potential contributor to heart functional changes with aging. We have examined the effects of aging on various parameters related to mitochondrial bioenergetics in rat heart, such as complex I activity, oxygen consumption, membrane potential, ROS production, and cardiolipin content and oxidation. A loss in complex I activity, state 3 respiration, and membrane potential was found in mitochondria with aging. The capacity of mitochondria to produce H(2)O(2) was significantly increased in aged rats. The mitochondrial content of cardiolipin, a phospholipid required for optimal activity of complex I, significantly decreased as a function of aging, whereas there was a significant increase in the level of oxidized cardiolipin. The lower complex I activity in mitochondria from aged rats could be almost completely restored to the level of young heart by exogenously added cardiolipin, but not by other phospholipids nor by peroxidized cardiolipin. It is proposed that aging causes heart mitochondrial complex I deficiency, which can be attributed to ROS-induced cardiolipin peroxidation. These results may prove useful in elucidating the mechanism underlying mitochondrial dysfunction associated with heart aging. Show less