Oxidative Stress and Cerebral Vascular Tone: The Role of Reactive Oxygen and Nitrogen Species.

The brain's unique characteristics make it exceptionally susceptible to oxidative stress, which arises from an imbalance between reactive oxygen species (ROS) production, reactive nitrogen species (RNS) production, and antioxidant defense mechanisms. This review explores the factors contributing to the brain's vascular tone's vulnerability in the presence of oxidative damage, which can be of clinical interest in critically ill patients or those presenting acute brain injuries. The brain's high metabolic rate and inefficient electron transport chain in mitochondria lead to significant ROS generation. Moreover, non-replicating neuronal cells and low repair capacity increase susceptibility to oxidative insult. ROS can influence cerebral vascular tone and permeability, potentially impacting cerebral autoregulation. Different ROS species, including superoxide and hydrogen peroxide, exhibit vasodilatory or vasoconstrictive effects on cerebral blood vessels. RNS, particularly NO and peroxynitrite, also exert vasoactive effects. This review further investigates the neuroprotective effects of antioxidants, including superoxide dismutase (SOD), vitamin C, vitamin E, and the glutathione redox system. Various studies suggest that these antioxidants could be used as adjunct therapies to protect the cerebral vascular tone under conditions of high oxidative stress. Nevertheless, more extensive research is required to comprehensively grasp the relationship between oxidative stress and cerebrovascular tone, and explore the potential benefits of antioxidants as adjunctive therapies in critical illnesses and acute brain injuries.

REVIEW: Evidence supporting the 'preparation for oxidative stress' (POS) strategy in animals in their natural environment.

Hypometabolism is a common strategy employed by resilient species to withstand environmental stressors that would be life-threatening for other organisms. Under conditions such as hypoxia/anoxia, temperature and salinity stress, or seasonal changes (e.g. hibernation, estivation), stress-tolerant species down-regulate pathways to decrease energy expenditures until the return of less challenging conditions. However, it is with the return of these more favorable conditions and the reactivation of basal metabolic rates that a strong increase of reactive oxygen and nitrogen species (RONS) occurs, leading to oxidative stress. Over the last few decades, cases of species capable of enhancing antioxidant defenses during hypometabolic states have been reported across taxa and in response to a variety of stressors. Interpreted as an adaptive mechanism to counteract RONS formation during tissue hypometabolism and reactivation, this strategy was coined "Preparation for Oxidative Stress" (POS). Laboratory experiments have confirmed that over 100 species, spanning 9 animal phyla, apply this strategy to endure harsh environments. However, the challenge remains to confirm its occurrence in the natural environment and its wide applicability as a key survival element, through controlled experimentation in field and in natural conditions. Under such conditions, numerous confounding factors may complicate data interpretation, but this remains the only approach to provide an integrative look at the evolutionary aspects of ecophysiological adaptations. In this review, we provide an overview of representative cases where the POS strategy has been demonstrated among diverse species in natural environmental conditions, discussing the strengths and weaknesses of these results and conclusions.

Collaborative Optimization Design of Self-Powered Sterilizer with Highly Efficient Synergistic Antibacterial Effect.

The development of self-powered sterilizers has garnered significant attention in the scientific and engineering fields. However, there remains an urgent need to improve their sterilization efficiency. In this study, we present a self-powered sterilizer with superior antibacterial capability by maximizing the utilization of breakdown discharge generated by a soft-contact freestanding rotary triboelectric nanogenerator (FR-TENG). To achieve this, a collaborative optimization strategy is proposed, encompassing the structural design of the FR-TENG, the implementation of double voltage rectification, and manipulation of the gaseous phase. Through a comprehensive analysis of antibacterial rates and microscopic images, the effectiveness of the self-powered sterilizer against various types of bacteria, including Gram-positive and Gram-negative species, as well as mixed bacteria in natural seawater, is demonstrated. Further investigations into bacterial morphologies and solution compositions reveal that the synergistic effect between electroporation and the generation of reactive oxygen/nitrogen species contributes to efficient sterilization. Additionally, controlled trials and molecular dynamics simulations are conducted to quantitatively elucidate the synergistic antibacterial effect between electroporation and reactive oxygen/nitrogen species. This study highlights the effectiveness of the collaborative optimization strategy in enhancing the sterilization efficiency of self-powered sterilizers while providing valuable insights into the synergistic antibacterial mechanisms of physical and chemical sterilization.

Photocleavable Visible Light-Triggered Anthraquinone-Derived Water-Soluble Block Copolymer for Peroxynitrite Generation in Cancer Therapy.

We report a facile stimuli-responsive strategy to generate reactive oxygen and nitrogen species (ROS and RNS) in the biological milieu from a photocleavable water-soluble block copolymer under visible light irradiation (427 nm, 2.25 mW/cm2). An anthraquinone-based water-soluble polymeric nitric oxide (NO) donor (BCPx-NO) is synthesized, which exhibits NO release in the range of 40-65 µM within 10 h of photoirradiation with a half-life of 30-103 min. Additionally, BCPx-NO produces peroxynitrite (ONOO-) and singlet oxygen (1O2) under photoirradiation. To understand the mechanism of NO release and photolysis of the functional group under blue light, we prepared a small-molecule anthraquinone-based N-nitrosamine (NOD). The cellular investigation of the effect of spatiotemporally controlled ONOO- and 1O2 generation from the NO donor polymeric nanoparticles in a triple negative breast adenocarcinoma (MDA-MB-231) under visible light irradiation (white light, 5.83 mW/cm2; total dose 31.5 J/cm2) showed an IC50 of 0.6 mg/mL. The stimuli-responsive strategy using a photolabile water-soluble block copolymer employed to generate ROS and RNS in a biological setting widens the horizon for their potential in cancer therapy.

Tannic acid and zinc ion coordination of nanase for the treatment of inflammatory bowel disease by promoting mucosal repair and removing reactive oxygen and nitrogen species.

Colon mucosal overexpression of reactive oxygen and nitrogen species (RONS) accelerates the development of inflammatory bowel disease (IBD) and destroys the mucosa and its barrier. IBD can be alleviated by removing RONS from the inflamed colon. The preparation of strong and efficient nanoantioxidants remains a challenge despite the development of numerous nanoantioxidants. In this paper, Zn-TA nanoparticles with fine hollow microstructure (HZn-TA) were successfully prepared and could be effectively used to treat IBD. In the first step, ZIF-8 nanoparticles were synthesized by a one-pot method. On this basis, HZn-TA nanoparticles were etched by TA, and a multifunctional nanase was developed for the treatment of IBD. RONS, including reactive oxygen species (ROS) and nitric oxide (NO), can be eliminated to increase cell survival following Hydrogen peroxide (H2O2) stimulation, including reactive oxygen species (ROS) and nitric oxide (NO with hydrogen peroxide (H2O2). In a model for preventing and delaying acute colitis, clearance of RONS has been shown to reduce intestinal inflammation in mice by reducing colon damage, proinflammatory cytokine levels, the spleen index, and body weight. Intestinal mucosal healing can be promoted by HZn-TA nanoparticles, which can upregulate zonula occludens protein 1 (ZO-1) and claudin-1 expression. Based on the results of this study, HZn-TA nanoparticles were able to effectively treat IBD with minimal adverse effects by being biocompatible, multienzyme active, and capable of scavenging RONS. Therefore, we pioneered the application of HZn-TA nanoparticles for the treatment of IBD, which are capable of clearing RONS without significant adverse effects. STATEMENT OF SIGNIFICANCE: ➢ HZn-TA nanoparticles were successfully prepared and could be effectively used to treat IBD. ➢ Intestinal mucosal healing can be promoted by HZn-TA nanoparticles, which can upregulate ZO-1 and claudin-1 expression. ➢ HZn-TA nanoparticles were able to effectively treat IBD with minimal adverse effects by being biocompatible, multienzyme active, and capable of scavenging RONS.

Rational design of an iminocoumarin-based fluorescence probe for peroxynitrite with high signal-to-noise ratio.

As a high reactive oxygen species (ROS) and a reactive nitrogen species (RNS), peroxynitrite anion (ONOO- ) is widely present in organisms and plays influential roles in physiological and pathological processes. It is of great significance to develop effective fluorescent probes for imaging peroxynitrite variation in living systems. Herein we present a novel fluorescent probe TQC0 for monitoring ONOO- based on the iminocoumarin platform, and this probe was synthesized by the knoevenagel condensation between a dihydropyridine-salicylaldehyde derivative and 2-benzothiazole-acetonitrile, and subsequently masked with the boronate moiety. The obtained probe TQC0 exhibited a high signal-to-noise ratio (206-fold) and a quick 'turn-on' response (about 10 min) with great selectivity and sensitivity. Furthermore, the probe TQC0 was successfully applied for imaging ONOO- in living cells with low cytotoxicity.

Reactive oxygen/nitrogen species scavenging and inflammatory regulation by renal-targeted bio-inspired rhodium nanozymes for acute kidney injury theranostics.

Acute kidney injury (AKI) results from the rapid deterioration of renal function, which is mainly treated by transplantation and dialysis, and has a high mortality rate. Inflammation induced by excess reactive oxygen/nitrogen species (RONS) plays a crucial role in AKI. Although small molecule antioxidants have been utilized to alleviate AKI, low bioavailability and side-effect of these drugs tremendously limit their clinical use. Hence, we successfully construct ultra-small (2-4 nm) rhodium nanoparticles modified with l-serine (denoted as Rh-Ser). Our results show that Rh-Ser with multiple enzyme-mimicking activities, allows remove various RONS to protect damaged kidney cells. Additionally, the ultrasmall size of Rh-Ser is conducive to enrichment in the renal tubules, and the modification of l-serine enables Rh-Ser to bind to kidney injury molecule-1, which is highly expressed on the surface of damaged renal cells, thereby targeting the damaged kidney and increasing the retention time. Moreover, Rh-Ser allows the production of oxygen at the inflammatory site, thus further improving hypoxia and inhibiting pro-inflammatory macrophages to relieve inflammation, and increasing the survival rate of AKI mice from 0 to 80%, which exhibits a better therapeutic effect than that of small molecule drug. Photoacoustic and fluorescence imaging can effectively monitor and evaluate the enrichment and therapeutic effect of Rh-Ser. Our study provides a promising strategy for the targeted treatment of AKI via RONS scavenging and inflammatory regulation.

Olfaction in the Anthropocene: NO3 negatively affects floral scent and nocturnal pollination.

There is growing concern about sensory pollutants affecting ecological communities. Anthropogenically enhanced oxidants [ozone (O3) and nitrate radicals (NO3)] rapidly degrade floral scents, potentially reducing pollinator attraction to flowers. However, the physiological and behavioral impacts on pollinators and plant fitness are unknown. Using a nocturnal flower-moth system, we found that atmospherically relevant concentrations of NO3 eliminate flower visitation by moths, and the reaction of NO3 with a subset of monoterpenes is what reduces the scent's attractiveness. Global atmospheric models of floral scent oxidation reveal that pollinators in certain urban areas may have a reduced ability to perceive and navigate to flowers. These results illustrate the impact of anthropogenic pollutants on an animal's olfactory ability and indicate that such pollutants may be critical regulators of global pollination.

Biomarkers of Oxidative and Radical Stress.

Reactive oxygen and nitrogen species (ROS/RNS) are generated as a result of normal intracellular metabolism [...].

Effect of reactive oxygen, nitrogen, and sulfur species on signaling pathways in atherosclerosis.

Atherosclerosis is a chronic inflammatory disease in which fats, lipids, cholesterol, calcium, proliferating smooth muscle cells, and immune cells accumulate in the intima of the large arteries, forming atherosclerotic plaques. A complex interplay of various vascular and immune cells takes place during the initiation and progression of atherosclerosis. Multiple reports indicate that tight control of reactive oxygen species (ROS), reactive nitrogen species (RNS), and reactive sulfur species (RSS) production is critical for maintaining vascular health. Unrestricted ROS and RNS generation may lead to activation of various inflammatory signaling pathways, facilitating atherosclerosis. Given these deleterious consequences, it is important to understand how ROS and RNS affect the signaling processes involved in atherogenesis. Conversely, RSS appears to exhibit an atheroprotective potential and can alleviate the deleterious effects of ROS and RNS. Herein, we review the literature describing the effects of ROS, RNS, and RSS on vascular smooth muscle cells, endothelial cells, and macrophages and focus on how changes in their production affect the initiation and progression of atherosclerosis. This review also discusses the contribution of ROS, RNS, and RSS in mediating various post-translational modifications, such as oxidation, nitrosylation, and sulfation, of the molecules involved in inflammatory signaling.

Gut microbiome, short-chain fatty acids, alpha-synuclein, neuroinflammation, and ROS/RNS: Relevance to Parkinson's disease and therapeutic implications.

In this review, we explore how short-chain fatty acids (SCFAs) produced by the gut microbiome affect Parkinson's disease (PD) through their modulatory interactions with alpha-synuclein, neuroinflammation, and oxidative stress mediated by reactive oxygen and nitrogen species (ROS/RNS). In particular, SCFAs-such as acetate, propionate, and butyrate-are involved in gut-brain communication and can modulate alpha-synuclein aggregation, a hallmark of PD. The gut microbiome of patients with PD has lower levels of SCFAs than healthy individuals. Probiotics may be a potential strategy to restore SCFAs and alleviate PD symptoms, but the underlying mechanisms are not fully understood. Also in this review, we discuss how alpha-synuclein, present in the guts and brains of patients with PD, may induce neuroinflammation and oxidative stress via ROS/RNS. Alpha-synuclein is considered an early biomarker for PD and may link the gut-brain axis to the disease pathogenesis. Therefore, elucidating the role of SCFAs in the gut microbiome and their impact on alpha-synuclein-induced neuroinflammation in microglia and on ROS/RNS is crucial in PD pathogenesis and treatment.

Reactive nitrogen species-mediated cell proliferation during tail regeneration and retinoic acid as a putative modulator of tissue regeneration in the geckos.

Reactive nitrogen species (RNS), a mediator of nitrosative stress, plays a vital role during wound healing but its role during tissue regeneration is poorly understood. In the present study, the role of RNS was investigated post-tail autotomy and limb amputation in a gecko species, Hemidactylus murrayi Gleadow, 1887. Tail autotomy led to an increased expression of iNOS and nitrosative stress leading to protein S-nitrosylation that probably restricted the acute inflammatory response caused by wounding. Increased nitrosative stress was also associated with proliferation of the wound epithelium and the tail blastema. Nitric oxide synthase inhibitor (L-NAME) caused retarded growth and structural abnormalities in the regenerating tail while peroxynitrite inhibitor (FeTmPyp) arrested tail regeneration. Spermine NONOate and retinoic acid, used as NO donors generated small outgrowths post-amputation of limbs with an increased number of proliferating cells and s-nitrosylation indicating the role of nitric oxide signalling in cell proliferation during regeneration. Additionally, retinoic acid treatment caused regeneration of nerve, muscle and adipose tissue in the regenerated limb structure 105 days post-amputation suggesting it to be a putative modulator of tissue regeneration in the non-regenerating limbs.

Ultrasmall Cu2O@His Nanozymes with RONS Scavenging Capability for Anti-inflammatory Therapy.

High concentrations of reactive oxygen and nitrogen species (RONS) are key characteristics of inflammatory sites. Scavenging RONS at the site of inflammation is an effective therapeutic strategy. This study introduces ultrasmall Cu2O@His nanoparticles with RONS-scavenging ability for the treatment of inflammatory bowel disease (IBD) in mice. The strong coordination between the nitrogen atom in histidine (His) and copper enhances the dispersion and stability of Cu2O@His. Due to their small size and large surface area, Cu2O@His exhibits outstanding RONS-clearing ability. Importantly, Cu2O@His can target mitochondrial sites and repair damaged mitochondria. With excellent dispersion and scavenging RONS ability, Cu2O@His demonstrates good efficacy in treating mouse IBD. This work provides a new paradigm for developing nanozymes with an ultrasmall size and multiple scavenging RONS abilities.

Plasma-Activated Media Produced by a Microwave-Excited Atmospheric Pressure Plasma Jet Is Effective against Cisplatin-Resistant Human Bladder Cancer Cells In Vitro.

Media exposed to atmospheric pressure plasma (APP) produce reactive oxygen and nitrogen species (RONS), with hydrogen peroxide (H2O2), nitrite (NO2-), and nitrate (NO3-) being among the most detected species due to their relatively long lifetime. In this study, a standardized microwave-excited (ME) APP jet (APPJ) source was employed to produce gaseous RONS to treat liquid samples. The source was a commercially available plasma jet, which generated argon plasma utilizing a coaxial transmission line resonator at the operating frequency of 2.45 GHz. An ultraviolet-visible spectrophotometer was used to measure the concentrations of H2O2 and NO3- in plasma-activated media (PAM). Three different types of media (deionized water, Hank's balanced salt solution, and cell culture solution Dulbecco's modified eagles medium [DMEM]) were utilized as liquid samples. Among these media, the plasma-treated DMEM was observed to have the highest levels of H2O2 and NO3-. Subsequently, the feasibility of using argon ME-APPJ-activated DMEM (PAM) as an adjuvant to enhance the therapeutic effects of cisplatin on human bladder cancer cells (T-24) was investigated. Various cancer cell lines, including T-24 cells, treated with PAM were observed in vitro for changes in cell viability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. A viability reduction was detected in the various cancer cells after incubation in PAM. Furthermore, the study's results revealed that PAM was effective against cisplatin-resistant T-24 cells in vitro. In addition, a possible connection between HER expression and cell viability was sketched.

Closing Dichloramine Decomposition Nitrogen and Oxygen Mass Balances: Relative Importance of End-Products from the Reactive Nitrogen Species Pathway.

In drinking water chloramination, monochloramine autodecomposition occurs in the presence of excess free ammonia through dichloramine, the decay of which was implicated in N-nitrosodimethylamine (NDMA) formation by (i) dichloramine hydrolysis to nitroxyl which reacts with itself to nitrous oxide (N2O), (ii) nitroxyl reaction with dissolved oxygen (DO) to peroxynitrite or mono/dichloramine to nitrogen gas (N2), and (iii) peroxynitrite reaction with total dimethylamine (TOTDMA) to NDMA or decomposition to nitrite/nitrate. Here, the yields of nitrogen and oxygen-containing end-products were quantified at pH 9 from NHCl2 decomposition at 200, 400, or 800 µeq Cl2·L-1 with and without 10 µM-N TOTDMA under ambient DO (∼500 µM-O) and, to limit peroxynitrite formation, low DO (≤40 µM-O). Without TOTDMA, the sum of free ammonia, monochloramine, dichloramine, N2, N2O, nitrite, and nitrate indicated nitrogen recoveries ±95% confidence intervals were not significantly different under ambient (90 ± 6%) and low (93 ± 7%) DO. With TOTDMA, nitrogen recoveries were less under ambient (82 ± 5%) than low (97 ± 7%) DO. Oxygen recoveries under ambient DO were 88-97%, and the so-called unidentified product of dichloramine decomposition formed at about three-fold greater concentration under ambient compared to low DO, like NDMA, consistent with a DO limitation. Unidentified product formation stemmed from peroxynitrite decomposition products reacting with mono/dichloramine. For a 2:2:1 nitrogen/oxygen/chlorine atom ratio and its estimated molar absorptivity, unidentified product inclusion with uncertainty may close oxygen recoveries and increase nitrogen recoveries to 98% (ambient DO) and 100% (low DO).

Activatable Probes for Ratiometric Imaging of Endogenous Biomarkers In Vivo.

Dynamic variations in the concentration and abnormal distribution of endogenous biomarkers are strongly associated with multiple physiological and pathological states. Therefore, it is crucial to design imaging systems capable of real-time detection of dynamic changes in biomarkers for the accurate diagnosis and effective treatment of diseases. Recently, ratiometric imaging has emerged as a widely used technique for sensing and imaging of biomarkers due to its advantage of circumventing the limitations inherent to conventional intensity-dependent signal readout methods while also providing built-in self-calibration for signal correction. Here, the recent progress of ratiometric probes and their applications in sensing and imaging of biomarkers are outlined. Ratiometric probes are classified according to their imaging mechanisms, and ratiometric photoacoustic imaging, ratiometric optical imaging including photoluminescence imaging and self-luminescence imaging, ratiometric magnetic resonance imaging, and dual-modal ratiometric imaging are discussed. The applications of ratiometric probes in the sensing and imaging of biomarkers such as pH, reactive oxygen species (ROS), reactive nitrogen species (RNS), glutathione (GSH), gas molecules, enzymes, metal ions, and hypoxia are discussed in detail. Additionally, this Review presents an overview of challenges faced in this field along with future research directions.

Cold atmospheric plasma (CAP) treatment increased reactive oxygen and nitrogen species (RONS) levels in tumor samples obtained from patients with low-grade glioma.

Low-grade gliomas (LGGs) are a heterogeneous group of tumors with an average 10-year survival rate of 40%-55%. Current treatment options include chemotherapy, radiotherapy, and gross total resection (GTR) of the tumor. The extent of resection (EOR) plays an important role in improving surgical outcomes. However, the major obstacle in treating low-grade gliomas is their diffused nature and the presence of residual cancer cells at the tumor margins post resection. Cold Atmospheric Plasma (CAP) has shown to be effective in targeted killing of tumor cells in various glioma cell lines without affecting non-tumor cells through Reactive Oxygen and Nitrogen Species (RONS). However, no study on the effectiveness of CAP has been carried out in LGG tissues till date. In this study, we applied helium-based CAP on tumor tissues resected from LGG patients. Our results show that CAP is effective in promoting RONS accumulation in LGG tissues when CAP jet parameters are set at 4 kV voltage, 5 min treatment time and 3 lpm gas flow rate. We also observed that CAP jet is more effective in thinner slice preparations of tumor as compared to thick tumor samples. Our results indicate that CAP could prove to be an effective adjunct therapy in glioma surgery to target residual cancer cells to improve surgical outcome of patients with low-grade glioma.

The progression of inorganic nanoparticles and natural products for inflammatory bowel disease.

There is a growing body of evidence indicating a close association between inflammatory bowel disease (IBD) and disrupted intestinal homeostasis. Excessive production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), along with an increase in M1 proinflammatory macrophage infiltration during the activation of intestinal inflammation, plays a pivotal role in disrupting intestinal homeostasis in IBD. The overabundance of ROS/RNS can cause intestinal tissue damage and the disruption of crucial gut proteins, which ultimately compromises the integrity of the intestinal barrier. The proliferation of M1 macrophages contributes to an exaggerated immune response, further compromising the intestinal immune barrier. Currently, intestinal nanomaterials have gained widespread attention in the context of IBD due to their notable characteristics, including the ability to specifically target regions of interest, clear excess ROS/RNS, and mimic biological enzymes. In this review, we initially elucidated the gut microenvironment in IBD. Subsequently, we delineate therapeutic strategies involving two distinct types of nanomedicine, namely inorganic nanoparticles and natural product nanomaterials. Finally, we present a comprehensive overview of the promising prospects associated with the application of nanomedicine in future clinical settings for the treatment of IBD (graphic abstract). Different classes of nanomedicine are used to treat IBD. This review primarily elucidates the current etiology of inflammatory bowel disease and explores two prominent nanomaterial-based therapeutic approaches. First, it aims to eliminate excessive reactive oxygen species and reactive nitrogen species. Second, they focus on modulating the polarization of inflammatory macrophages and reducing the proportion of pro-inflammatory macrophages. Additionally, this article delves into the treatment of inflammatory bowel disease using inorganic metal nanomaterials and natural product nanomaterials.

Molecular analysis of the human cytoglobin mRNA isoforms.

Multiple functions have been proposed for the ubiquitously expressed vertebrate globin cytoglobin (Cygb), including nitric oxide (NO) metabolism, lipid peroxidation/signalling, superoxide dismutase activity, reactive oxygen/nitrogen species (RONS) scavenging, regulation of blood pressure, antifibrosis, and both tumour suppressor and oncogenic effects. Since alternative splicing can expand the biological roles of a gene, we investigated whether this mechanism contributes to the functional diversity of Cygb. By mining of cDNA data and molecular analysis, we identified five alternative mRNA isoforms for the human CYGB gene (V-1 to V-5). Comprehensive RNA-seq analyses of public datasets from human tissues and cells confirmed that the canonical CYGB V-1 isoform is the primary CYGB transcript in the majority of analysed datasets. Interestingly, we revealed that isoform V-3 represented the predominant CYGB variant in hepatoblastoma (HB) cell lines and in the majority of analysed normal and HB liver tissues. CYGB V-3 mRNA is transcribed from an alternate upstream promoter and hypothetically encodes a N-terminally truncated CYGB protein, which is not recognized by some antibodies used in published studies. Little to no transcriptional evidence was found for the other CYGB isoforms. Comparative transcriptomics and flow cytometry on CYGB+/+ and gene-edited CYGB-/- HepG2 HB cells did not unveil a knockout phenotype and, thus, a potential function for CYGB V-3. Our study reveals that the CYGB gene is transcriptionally more complex than previously described as it expresses alternative mRNA isoforms of unknown function. Additional experimental data are needed to clarify the biological meaning of those alternative CYGB transcripts.

Evaluation of a novel pyridinium cation-linked styryl-based boronate probe for the detection of selected inflammation-related oxidants.

Reactive oxygen and nitrogen species (RONS) are a range of chemical individuals produced by living cells that contribute to the proper functioning of organisms. Cells under oxidative and nitrative stress show excessive production of RONS (including hydrogen peroxide, H2O2, hypochlorous acid, HOCl, and peroxynitrite, ONOO-) which may result in a damage proteins, lipids, and genetic material. Thus, the development of probes for in vivo detection of such oxidants is an active area of research, focusing on molecular redox sensors, including boronate-caged fluorophores. Here, we report a boronate-based styryl probe with a cationic pyridinium moiety (BANEP+) for the fluorescent detection of selected biological oxidants in vitro and in vivo. We compare the chemical reactivity of the BANEP+ probe toward H2O2, HOCl, and ONOO- and examine the influence of the major intracellular non-enzymatic antioxidant molecule, glutathione (GSH). We demonstrate that, at the physiologically relevant GSH concentration, the BANEP+ probe is efficiently oxidized by peroxynitrite, forming its phenolic derivative HNEP+. GSH does not affect the fluorescence properties of the BANEP+ and HNEP+ dyes. Finally, we report the identification of a novel type of molecular marker, with the boronate moiety replaced by the iodine atom, formed from the probe in the presence of HOCl and iodide anion. We conclude that the reported chemical reactivity and structural features of the BANEP+ probe may be a basis for the development of new red fluorescent probes for in vitro and in vivo detection of ONOO-.