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•Recent advances in fluorescent and luminescent probes for ROS and RNS are discussed.•Metal-coordinated ROS- and RNS- selective probe systems are covered.•The categories of this ...review are H2O2, •OH, 1O2, O2•–, HOCl, ONOO−, NO/NO2, and HNO.
Reactive oxygen species(ROS) are chemically reactive speciescontaining oxygen, which are produced from molecular oxygen (O2) during vital processes occurring in humans and other living organisms. These species include hydrogen peroxide (H2O2), hypochlorous acid/hypochlorite (HOCl/ClO–), hydroxyl radicals (OH), superoxide anion radicals (O2–) and singlet oxygen (1O2). ROS play key roles in various signaling and pathological processes and are essential to human life, but overproduction of ROS by exogenous stimuli is harmful because ROS can induce oxidation of DNA, proteins or lipids, resulting in cell death. Therefore, unusual ROS levels can indicate ailments such as Parkinson’s and Alzheimer’s diseases, inflammation, diabetes and cancer. Reactive nitrogen species (RNS) are another group of important chemically reactive species, which can damage cells via nitrosative stress. RNS include nitric oxide (NO), nitroxyl (HNO), nitrogen dioxide (NO2) and peroxynitrite (ONOO–). Due to their importance in human life, research into fluorescent and luminescent sensing and imaging of these ROS and RNS has been very active over the last couple of decades. Metal ions play key roles in the probes as an on–off redox switch for photoinduced quenching and as a reaction site with ROS, RNS or luminescent cores. Metal coordination reports the presence of analyte by changing the fluorescence intensity, lifetime, or excitation/emission maxima. Redox-active metal ions can be trigger switches that control fluorescence quenching effects, which can be used to sense ROS or RNS. In addition, metal ions, especially lanthanide metal ions, can often be themselves a source of light emission. In this review, we cover ROS- and RNS-selective fluorescent and luminescent probes based on metal-coordinated systems. This review is organized by the target ROS or RNS, which are H2O2, HOCl/ClO–, OH, O2–, 1O2, NO, ONOO–, HNO and NO2.
Abiotic stress causes alterations in physiological, biochemical and metabolic equilibrium in the plant cells, leading to reduction in protein turn-over, change in post translational modification of ...proteins, impaired photosynthetic capability and increase in ROS production. The stress-induced ROS at higher levels can trigger oxidation of biomolecules, decomposition of membranes, inactivation of enzymes and alteration in gene expression. On the other hand, ROS is also detected by its sensors and signal transduction pathways are activated, which further transports the signal to the nucleus through redox reactions and involvement of Mitogen-activated Protein Kinase (MAPK) pathway. Consequently, change in gene expression patterns is instigated by involvement of stress-regulated cis-acting elements (ARE, CORE, W-box, GCC box, as-1 like) and stress-responsive transcription factors (NAC, MYB, WRKY, RAV, bZIP, AP2/ERF, ZAT). Finally, these gene products are transmitted back to the cell organelles to facilitate prevention from oxidative damage. Additionally, epigenetic changes play a central role in mediating cellular responses to abiotic stresses. Here, we review the recent updates on ROS-mediated signaling and monitoring of transcriptional and epigenetic changes that occur in a cell due to oxidative stress.
•During abiotic stress, a misbalance between generation and scavenging of ROS occurs and cellular homeostasis may be lost.•Thus, ROS-mediated signaling pathway and secondary messengers are activated to maintain appropriate concentration.•ROS-generated signals are transported to the nucleus, which instigates transcriptional and epigenetic reprogramming.
Oxidative stress is considered a major contributor to the etiology of both “normal” senescence and severe pathologies with serious public health implications. Several cellular sources, including ...mitochondria, are known to produce significant amounts of reactive oxygen species (ROS) that may contribute to intracellular oxidative stress. Mitochondria possess at least 10 known sites that are capable of generating ROS, but they also feature a sophisticated multilayered ROS defense system that is much less studied. This review summarizes the current knowledge about major components involved in mitochondrial ROS metabolism and factors that regulate ROS generation and removal at the level of mitochondria. An integrative systemic approach is applied to analysis of mitochondrial ROS metabolism, which is “dissected” into ROS generation, ROS emission, and ROS scavenging. The in vitro ROS‐producing capacity of several mitochondrial sites is compared in the metabolic context and the role of mitochondria in ROS‐dependent intracellular signaling is discussed.
•Reactive oxygen species (ROS) as biological signaling molecules.•The use of redox sensitive fluorescent probes for the measurement of ROS.•Genetic approaches for in vitro ROS measurement.•The use of ...novel nanoprobes from ROS detection in cells.
Reactive oxygen species (ROS) play an essential role in facilitating signal transduction processes within the cell. However, the precise details of the redox dynamics involved are not well understood. The generation of ROS is tightly controlled both spatially and temporally within the cell, making the study of ROS dynamics particularly difficult. In order to measure these dynamics, precise tools that can specifically examine the relevant ROS are required. Recent advancements in methodologies for ROS measurement have allowed the study of ROS biology at a level of precision previously unachievable. Here, we discuss improvements to fluorescent ROS dye technologies, genetically encoded ROS reporters, nanoparticle delivery systems, and nanotube ROS probes. These technologies improve specificity, localization and sensitivity over previously available ROS probes.
Reactive oxygen species (ROS) play a key signaling role in plant and animal cells. Among the many cellular mechanisms used to generate and transduce ROS signals, ROS-induced ROS release (RIRR) is ...emerging as an important pathway involved in different human pathologies and plant responses to environmental stress. RIRR is a process in which one cellular compartment or organelle generates or releases ROS, triggering the enhanced production or release of ROS by another compartment or organelle. It was initially described in animal cells and proposed to mediate mitochondria-to-mitochondria communication, but later expanded to include communication between mitochondria and plasma membrane-localized NADPH oxidases. In plants a process of RIRR was demonstrated to mediate long distance rapid systemic signaling in response to biotic and abiotic stress. This process is thought to involve the enhanced production of ROS by one cell that triggers the enhanced production of ROS by a neighboring cell in a process that propagates the enhanced “ROS production state” all the way from one part of the plant to another. In contrast to the intracellular nature of the RIRR process of animal cells, the plant RIRR process is therefore primarily studied at the cell-to-cell communication level. Studies on intracellular (organelle-to-organelle, or organelle-to-NADPH oxidase) RIRR pathways are very scarce in plants, whereas studies on cell-to-cell RIRR are very scarce in animals. Here we will attempt to highlight what is known in both systems and what each system can learn from the other.
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•ROS-induced ROS release (RIRR) plays a key signaling role in plant and animal cells.•In plants RIRR mediates cell-to-cell communication.•In animals RIRR mediates intracellular communication.•Could RIRR pathways mediate intercellular signaling in animals?•Could RIRR pathways mediate intracellular signaling in plants?
In recent years, there has been a growing focus on the toxicity and mortality induced by nanoplastics (NPs) in aquatic organisms. However, studies investigating mechanisms underlying oxidative stress ...(OS), apoptosis, and inflammation induced by NPs in fish remain limited. This study observed that polystyrene NPs (PS-NPs) were accumulated into zebrafish larvae and zebrafish embryonic fibroblast (ZF4 cells), accompanied by the occurrence of pathological damage both at the cellular and tissue–organ level. Additionally, the transcriptional up-regulation of NADPH oxidases (NOXs) and subsequent excessive generation of reactive oxygen species (ROS) resulted in notable changes in the relative mRNA and protein expression levels associated with antioxidant oxidase systems in larvae. Furthermore, the study identified the impact of NPs on mitochondrial ultrastructural, resulting in mitochondrial depolarization and downregulation of mRNA expression related to the electron transport chain due to excessive ROS generation. Short-term exposure to NPs also triggered apoptosis and inflammation in zebrafish larvae, evident from significant up-regulation in mRNA expressions of proapoptotic factors and NF-κB proinflammatory signaling pathway, as well as increased transcription and protein levels of pro-inflammatory factors in larvae. Inhibition of intracellular excessive ROS effectively reduced the induction of apoptosis, NF-κB P65 nuclear migration levels, and cytokine secretion, underscoring OS as a pivotal factor throughout the process of apoptosis and inflammatory responses induced by NPs. This research significantly advances our comprehension of biological effects and underlying mechanisms of NPs in freshwater fish.
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•PS-NPs translocate into ZF4 cells and cause excessive ROS.•PS-NPs cause oxidative stress and mitochondria dysfunction in larvae.•PS-NPs induce mitochondria-dependent apoptosis by triggering ROS.•PS-NPs induce inflammation through the ROS-driven NF-κB signaling pathway.
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