Maintaining Redox Homeostasis Research Articles

A CC-Type Glutaredoxins GRX480 Functions in Cadmium Tolerance by Maintaining Redox Homeostasis in Arabidopsis

Cadmium (Cd) toxicity causes oxidative stress damage in plant cells. Glutaredoxins (GRXs), a type of small oxidoreductase, play a crucial role in modulating thiol redox states. However, whether GRXs act in Cd stress remains to be identified. Here, we reveal that Arabidopsis GRX480, a member of the CC-type family, enhances plant Cd stress tolerance. The GRX480 mutants exhibit enhanced sensitivity to Cd stress, manifested by shortened root, reduced biomass, lower chlorophyll and proline levels, and decreased photosynthetic efficiency compared with the wild type. The Cd concentration in GRX480 mutants is higher than the wild type, resulting from the inhibition of Cd efflux and transport genes transcription. Lower levels of GSH were detected in Cd-treated GRX480 mutants than in the wild type, indicating that GRX480 regulates plant Cd tolerance by influencing the balance between GSH and GSSG. Furthermore, the hyperaccumulation of reactive oxygen species (ROS) is associated with decreased expression of H2O2 scavenging genes in Cd-treated GRX480 mutants. Additionally, more toxic reactive carbonyl species (RCS), produced during oxidative stress, accumulate in Cd-treated GRX480 mutants than in wild type. Overall, our study establishes a critical role of GRX480 in response to Cd stress, highlighting its multifaceted contributions to detoxification and the maintenance of redox homeostasis.

7447 Rare KSR2 Variants: The Effect of Glycine and N-acetylcysteine (GlyNAC) Supplementation

Abstract Disclosure: J. Youn: None. Y. Carcamo-Bahena: None. E. Lartigue: None. S. Sisley: None. Kinase suppressor of ras 2 (KSR2) is an intracellular scaffolding protein involved in multiple signaling pathways. Of note, disruption of the kinase domain of KSR2 in humans and mice causes obesity by reducing metabolic rate, suggesting its important role in energy homeostasis. In the present study, we identified two variants (P189L, T290A) with mutations located in the proximal CA2 region from children with severe, early-onset obesity. Since variants in this region have not been confirmed to cause obesity, we generated plasmid constructs containing these KSR2 mutations by site directed mutagenesis. The HEK293 cells transfected with KSR2 plasmid construct containing P189L or T290A had reduced binding affinity with AMPK and phosphorylation of AMPK without affecting KSR2 protein integrity. These variants also significantly reduced cellular metabolic rates measured by Seahorse analysis in C2C12 cells, suggesting that KSR2 variants in the proximal CA2 region can result in impaired KSR2 function, subsequently leading to a decrease in cellular metabolic rate. In addition, these KSR2 variants decreased protein levels of NRF-2, a transcription factor of cytoprotective genes regulating the antioxidant glutathione (GSH) pathway compared to wild type KSR2 which augmented NRF2 levels. We also observed lower levels of total GSH and GSH/Glutathione disulfide (GSSG) ratio and higher levels of thiobarbituric acid reactive substances (TBARS), an indicator of oxidative stress, indicating an imbalance of antioxidant and oxidant with proximal KSR2 variants. However, treatment of cells with Glycine and N-acetylcysteine (GlyNAC) reversed the detrimental effects of KSR2 variants by normalizing protein expression levels of NRF-2, GSH/GSSG ratios and TBARS levels. Taken together, we show strong evidence that two new KSR2 variants, P189L and T290A, cause disruption of KSR2 function. Additionally, we also report a novel role of KSR2 in maintaining redox homeostasis suggesting that increased oxidative stress following GSH deficiency may play an important role in the development of obesity from KSR2 variants. Presentation: 6/1/2024

Androgen Receptor Mediates Dopamine Agonist Resistance by Regulating Intracellular reactive oxygen species (ROS) in Prolactin-secreting Pituitary Adenoma.

Dopamine agonists (DA) are the first-line treatment for patients with prolactin-secreting pituitary adenoma (PRL adenoma). However, a subset of individuals exhibits poor responses, known as DA resistance. Previous studies have reported that DA resistance is more prevalent in male patients. This study aims to investigate the relationship between androgen receptor (AR) expression and DA resistance, as well as to explore underlying mechanisms of AR-mediated DA resistance. Our results demonstrated that patients with higher AR expression exhibit greater resistance to DA in our cohort of DA-resistant PRL adenoma. Furthermore, AR was found to be involved in cell proliferation, PRL secretion, and resistance to BRC both in vitro and in vivo. Mechanistically, we demonstrated that intracellular ROS function as upstream mediators of apoptosis and ferroptosis following BRC treatment. As a ligand-dependent transcription factor, AR could translocate to the nucleus and transcriptionally promote NRF2 expression, which regulates intracellular ROS levels, thereby enhancing cell viability, and conferring DA resistance to PA cells. Finally, AR targeting agents were used to inhibit AR signaling, downregulate NRF2 transcription, and sensitize PA cells to BRC treatment. Conclusion and innovation: We demonstrated that AR plays a crucial role in mediating DA resistance in PRL-adenoma. Mechanistically, AR promotes cell proliferation and PRL secretion and confers drug resistance by transcriptionally regulating NRF2 expression to maintain redox homeostasis in PA cells. Finally, combining AR targeting agents with BRC shows promise as a therapeutic strategy for treating PRL adenomas.

Thiourea and arginine synergistically preserve redox homeostasis and ionic balance for alleviating salinity stress in wheat

Plant growth regulators are cost-effective and efficient methods for enhancing plant defenses under stress conditions. This study investigates the ability of two plant growth-regulating substances, thiourea (TU) and arginine (Arg), to mitigate salinity stress in wheat. The results show that both TU and Arg, particularly when used together, modify plant growth under salinity stress. Their application significantly increases the activities of antioxidant enzymes while decreasing the levels of reactive oxygen species (ROS), malondialdehyde (MDA), and relative electrolyte leakage (REL) in wheat seedlings. Additionally, these treatments significantly reduce the concentrations of Na+ and Ca2+ and the Na+/K+ ratio, while significantly increasing K+ levels, thereby preserving ionic osmotic balance. Importantly, TU and Arg markedly enhance the chlorophyll content, net photosynthetic rate, and gas exchange rate in wheat seedlings under salinity stress. The use of TU and Arg, either individually or in combination, results in a 9.03–47.45% increase in dry matter accumulation, with the maximum increase observed when both are used together. Overall, this study highlights that maintaining redox homeostasis and ionic balance are crucial for enhancing plant tolerance to salinity stress. Furthermore, TU and Arg are recommended as potential plant growth regulators to boost wheat productivity under such conditions, especially when applied together.

Dose rate dependent genotoxic and metabolic effects predict onset of impaired development and mortality in Atlantic salmon (S. salar) embryos exposed to chronic gamma radiation

Release of radionuclides to the environment from either nuclear weapon and fuel cycles or from naturally occurring radionuclides (NORM) may cause long term contamination of aquatic ecosystems and chronic exposure of living organisms to ionizing radiation, which in turn could lead to adverse effects compromising the sustainability of populations. To address the effects of chronic ionizing radiation on the development of fish, Atlantic salmon embryos were exposed from fertilization until hatching (88 days, 550 day-degree) to dose rates from 1 to 30 mGy·h−1 gamma radiation (60Co). The lowest adopted dose rate was similar to the highest doses measured in some water bodies right after the Chernobyl accident (1 mGy·h−1), however, well above current environmentally realistic scenarios (20 μGy·h−1), or the threshold assumed for significant effects on fish population (40 μGy·h−1). Dose dependent effects were observed on survival, hatching, morbidity, DNA damage, antioxidant defenses, and metabolic status. Histopathological analysis showed dose rate dependent impairment of eye and brain tissues development and establishment of epidermal mucus cell layers accompanied by increased DNA damage at doses ≥1.3 Gy (dose rates ≥1 mGy·h−1).At ≥32.8 Gy (dose rates ≥20 mGy·h−1) deformities and developmental growth defects resulted in respective 46 and 95 % pre-hatch mortality. The 10 mGy·h−1 exposure (≥ 12 Gy total dose) caused significantly increased DNA damage, impaired eye development, and both premature and delayed hatching, while no deformities or effect on survival were observed. We observed a dose rate dependent reduction from dose rate ≥ 20 mGy·h−1 (≥ 27 Gy total dose) on antioxidant SOD, catalase and glutathione reductase enzyme activities. The reduction of antioxidant enzyme activities was in line with observed developmental delay and disturbance to time of hatching. Metabolomic profiles showed a clear shift at dose rates ≥10 mGy·h−1 (≥ 12 Gy total dose) in pathways related to oxidative stress, detoxification, DNA damage and repair. Due to gamma radiation exposure, a switch of central metabolism from glycolysis, citric acid cycle and lactate production towards pentose phosphate pathway indicated a rewiring mechanism for increased production of reductive equivalents to maintain redox homeostasis at the expense of energy output and thus embryonic development.

Molecular basis of the interactions between the disordered Neh4 and Neh5 domains of Nrf2 and CBP/p300 in oxidative stress response.

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a major transcription factor that functions in maintaining redox homeostasis in cells. It mediates the transcription of cytoprotective genes in response to environmental and endogenous stresses to prevent oxidative damage. Thus, Nrf2 plays a significant role in chemoprevention. However, aberrant activation of Nrf2 has been shown to protect cancer cells from apoptosis and contribute to their chemoresistance. The interaction between Nrf2 and CBP is critical for the gene transcription activation. CBP and its homologue p300 interact with two transactivation domains in Nrf2, Neh4, and Neh5 domains through their TAZ1 and TAZ2 domains. To date, the molecular basis of this crucial interaction is not known, hindering a more detailed understanding of the regulation of Nrf2. To close this knowledge gap, we have used a set of biophysical experiments to dissect the Nrf2-CBP/p300 interactions. Structural properties of Neh4 and Neh5 and their binding with the TAZ1 and TAZ2 domains of CBP/p300 were characterized. Our results show that the Neh4 and Neh5 domains of Nrf2 are intrinsically disordered, and they both can bind the TAZ1 and TAZ2 domains of CBP/p300 with micromolar affinities. The findings provide molecular insight into the regulation of Nrf2 by CBP/p300 through multi-domain interactions.

Plant peptide hormone phytosulfokine promotes embryo development of mass in Pinus massoniana

Pinus massoniana is a critical afforestation and ecological tree species in China. However, the continued existence of this pine is severely threatened by pine wilt disease. Somatic embryogenesis serves as a highly efficient clonal propagation approach. Although significant progress has been made in somatic embryogensis research on P. massoniana, resulting in the successful regeneration of plants, the limited embryogenic potential of improved cell lines and loss of embryogenic properties resulting from prolonged proliferation have posed obstacles to the industrialization of SE production. In this study, we investigated the effect of phytosulfokine on embryo development of cell lines from P. massoniana which lead to a cascade of physicochemical changes. Eight embryogenic cell lines of P. massoniana were used to observe phenotype and cytological changes. Physiological factors and the contents of nutrients and endogenous hormones were measured before and after phytosulfokine addition. We found that PSK promoted a change in the embryogenic mass of P. massoniana, leading to their development from pro-embryogenic mass (PEM)I to PEMII or PEMIII stages of pro-embryos. In addition, PSK accumulated soluble sugar, protein, and starch, and maintained redox homeostasis during cell line proliferation by reducing H2O2 levels. Our findings increase our understanding of how PSK affects somatic embryogensis in P. massoniana, thereby providing a valuable tool for establishing efficient somatic embryogensis systems in conifer species.

Systematic analysis of the global characteristics and reciprocal effects of S-nitrosylation and S-persulfidation in the human proteome

Gasotransmitter-mediated cysteine post-translational modifications, including S-nitrosylation (SNO) and S-persulfidation (SSH), play crucial roles and interact in various biological processes. However, there has been a delay in appreciating the interactional rules between SNO and SSH. Here, all human S-nitrosylated and S-persulfidated proteomic data were curated, and comprehensive analyses from multiple perspectives, including sequence, structure, function, and exact protein impacts (e.g., up-/down-regulation), were performed. Although these two modifications collectively regulated a wide array of proteins to jointly maintain redox homeostasis, they also exhibited intriguing differences. First, SNO tended to be more accessible and functionally clustered in pathways associated with cell damage repair and other protein modifications, such as phosphorylation and ubiquitination. Second, SSH preferentially targeted cysteines in disulfide bonds and modulated tissue development and immune-related pathways. Finally, regardless of whether SNO and SSH occupied the same position of a given protein, their combined effect tended to be suppressive when acting synergistically; otherwise, SNO likely inhibited while SSH activated the target protein. Indeed, a side-by-side comparison of SNO and SSH shed light on their globally reciprocal effects and provided a reference for further research on gasotransmitter-mediated biological effects.

Prediction of Antioxidant Capacity of Thiolate-Disulfide Systems Using Species-Specific Basicity Values.

The principal reactions that maintain redox homeostasis in living systems are the deprotonation of thiols, followed by the oxidative conversion of the produced thiolates into disulfides, which thus reduce the harmful oxidizing agents. The various biological thiols have different molecule-specific propensities to carry on the co-dependent deprotonation and redox processes. This study utilizes the known correlation between thiolate basicities and oxidizabilities, to quantify antioxidant or reducing capacities and pH-dependences of thiol-disulfide antioxidant systems, as a tool to find adequate molecules against oxidative stress.

Antioxidant Defenses, Oxidative Stress Responses, and Apoptosis Modulation in Spontaneous Abortion: An Immunohistochemistry Analysis of First-Trimester Chorionic Villi.

Oxidative stress (OS) and apoptosis are critical factors in placental development and function. Their interplay influences trophoblast proliferation, differentiation, and invasion, as well as vascular development. An imbalance between these processes can lead to pregnancy-related disorders such as preeclampsia, intrauterine growth restriction, and even spontaneous abortion. Our study seeks to elucidate the associations between preventive antioxidant/protective OS response factors-glutathione (GSH), MutT Homolog 1 (MTH1), and apoptotic regulation modulators-tumor protein p53 and B-cell lymphoma (Bcl-2) transcripts, in the context of spontaneous abortion (30 samples) versus elective termination of pregnancy (20 samples), using immunohistochemistry (IHC) to determine their proteomic expression in chorionic villi within abortive fetal placenta tissue samples. Herein, comparative statistical analyses revealed that both OS response factors, GSH and MTH1, were significantly under-expressed in spontaneous abortion cases as compared to elective. Conversely, for apoptotic regulators, p53 expression was significantly higher in spontaneous abortion cases, whereas Bcl-2 expression was significantly lower in spontaneous abortion cases. These findings suggest that a strong pro-apoptotic signal is prevalent within spontaneous abortion samples, alongside reduced anti-apoptotic protection, depleted antioxidant defenses and compromised oxidative DNA damage prevention/repair, as compared to elective abortion controls. Herein, our hypothesis that OS and apoptosis are closely linked processes contributing to placental dysfunction and spontaneous abortion was thus seemingly corroborated. Our results further highlight the importance of maintaining redox homeostasis and apoptotic regulation for a successful pregnancy. Understanding the mechanisms underlying this interplay is essential for developing potential therapies to manage OS, promote placentation, and avoid unwanted apoptosis, ultimately improving pregnancy outcomes. Antioxidant supplementation, modulation of p53 activity, and the enhancement of DNA repair mechanisms may represent potential approaches to mitigate OS and apoptosis in the placenta. Further research is needed to explore these strategies and their efficacy in preventing spontaneous abortion.

Drp1 depletion protects against ferroptotic cell death by preserving mitochondrial integrity and redox homeostasis

Mitochondria are highly dynamic organelles which undergo constant fusion and fission as part of the mitochondrial quality control. In genetic diseases and age-related neurodegenerative disorders, altered mitochondrial fission-fusion dynamics have been linked to impaired mitochondrial quality control, disrupted organelle integrity and function, thereby promoting neural dysfunction and death. The key enzyme regulating mitochondrial fission is the GTPase Dynamin-related Protein 1 (Drp1), which is also considered as a key player in mitochondrial pathways of regulated cell death. In particular, increasing evidence suggests a role for impaired mitochondrial dynamics and integrity in ferroptosis, which is an iron-dependent oxidative cell death pathway with relevance in neurodegeneration. In this study, we demonstrate that CRISPR/Cas9-mediated genetic depletion of Drp1 exerted protective effects against oxidative cell death by ferroptosis through preserved mitochondrial integrity and maintained redox homeostasis. Knockout of Drp1 resulted in mitochondrial elongation, attenuated ferroptosis-mediated impairment of mitochondrial membrane potential, and stabilized iron trafficking and intracellular iron storage. In addition, Drp1 deficiency exerted metabolic effects, with reduced basal and maximal mitochondrial respiration and a metabolic shift towards glycolysis. These metabolic effects further alleviated the mitochondrial contribution to detrimental ROS production thereby significantly enhancing neural cell resilience against ferroptosis. Taken together, this study highlights the key role of Drp1 in mitochondrial pathways of ferroptosis and expose the regulator of mitochondrial dynamics as a potential therapeutic target in neurological diseases involving oxidative dysregulation.

Strategies to Maintain Redox Homeostasis in Yeast Cells with Impaired Fermentation-Dependent NADPH Generation.

Redox homeostasis is the balance between oxidation and reduction reactions. Its maintenance depends on glutathione, including its reduced and oxidized form, GSH/GSSG, which is the main intracellular redox buffer, but also on the nicotinamide adenine dinucleotide phosphate, including its reduced and oxidized form, NADPH/NADP+. Under conditions that enable yeast cells to undergo fermentative metabolism, the main source of NADPH is the pentose phosphate pathway. The lack of enzymes responsible for the production of NADPH has a significant impact on yeast cells. However, cells may compensate in different ways for impairments in NADPH synthesis, and the choice of compensation strategy has several consequences for cell functioning. The present study of this issue was based on isogenic mutants: Δzwf1, Δgnd1, Δald6, and the wild strain, as well as a comprehensive panel of molecular analyses such as the level of gene expression, protein content, and enzyme activity. The obtained results indicate that yeast cells compensate for the lack of enzymes responsible for the production of cytosolic NADPH by changing the content of selected proteins and/or their enzymatic activity. In turn, the cellular strategy used to compensate for them may affect cellular efficiency, and thus, the ability to grow or sensitivity to environmental acidification.

A near-infrared ratiometric fluorescent probe for the sensing and imaging of sulfur dioxide derivatives in living systems

As a reactive sulfur species, sulfur dioxide (SO2) and its derivatives play crucial role in various physiological processes, which can maintain redox homeostasis at normal levels and lead to the occurrence of many diseases at abnormal levels. So, the development of a suitable fluorescent probe is a crucial step in advancing our understanding of the role of SO2 derivatives in living organisms. Herein, we developed a near-infrared fluorescent probe (SP) based on the ICT mechanism to monitor SO2 derivatives in living organisms in a ratiometric manner. The probe SP exhibited excellent selectivity, good sensitivity, fast response rate (within 50 s), and low detection limit (1.79 µM). In addition, the cell experiment results suggested that the SP has been successfully employed for the real-time monitoring of endogenous and exogenous SO2 derivatives with negligible cytotoxicity. Moreover, SP was effective in detecting SO2 derivatives in mice.

The Role of S-Glutathionylation in Health and Disease: A Bird's Eye View.

Protein glutathionylation is a reversible post-translational modification that involves the attachment of glutathione to cysteine residues. It plays a role in the regulation of several cellular processes and protection against oxidative damage. Glutathionylation (GS-ylation) modulates protein function, inhibits or enhances enzymatic activity, maintains redox homeostasis, and shields several proteins from irreversible oxidative stress. Aberrant GS-ylation patterns are thus implicated in various diseases, particularly those associated with oxidative stress and inflammation, such as cardiovascular diseases, neurodegenerative disorders, cancer, and many others. Research in the recent years has highlighted the potential to manipulate protein GS-ylation for therapeutic purposes with strategies that imply both its enhancement and inhibition according to different cases. Moreover, it has become increasingly evident that monitoring the GS-ylation status of selected proteins offers diagnostic potential in different diseases. In this review, we try to summarize recent research in the field with a focus on our current understanding of the molecular mechanisms related to aberrant protein GS-ylation.

AT-hook motif nuclear localized transcription factors function redundantly in promoting root growth through modulation of redox homeostasis.

Maintaining an optimal redox status is essential for plant growth and development, particularly when the plants are under stress. AT-hook motif nuclear localized (AHL) proteins are evolutionarily conserved transcription factors in plants. Much of our understanding about this gene family has been derived from studies on clade A members. To elucidate the functions of clade B genes, we first analyzed their spatial expression patterns using transgenic plants expressing a nuclear localized GFP under the control of their promoter sequences. AHL1, 2, 6, 7, and 10 were further functionally characterized owing to their high expression in the root apical meristem. Through mutant analyses and transgenic studies, we showed that these genes have the ability to promote root growth. Using yeast one-hybrid and dual luciferase assays, we demonstrated that AHL1, 2, 6, 7, and 10 are transcription regulators and this activity is required for their roles in root growth. Although mutants for these genes did not showed obvious defects in root growth, transgenic plants expressing their fusion proteins with the SRDX repressor motif exhibited a short-root phenotype. Through transcriptome analysis, histochemical staining and molecular genetics experiments, we found that AHL10 maintains redox homeostasis via direct regulation of glutathione transferase (GST) genes. When the transcript level of GSTF2, a top-ranked target of AHL10, was reduced by RNAi, the short-root phenotype in the AHL10-SRDX expressing plant was largely rescued. These results together suggest that AHL genes function redundantly in promoting root growth through direct regulation of redox homeostasis.

Ozone priming enhanced low temperature tolerance of wheat (Triticum aestivum L.) based on physiological, biochemical and transcriptional analyses.

Low temperature significantly inhibits the plant growth in wheat (Triticum aestivum L.), prompting the exploration of effective strategies to mitigate low temperature stress. Several priming methods enhance low temperature stress tolerant, however, the role of ozone priming remains unclear in wheat. Here we found ozone priming alleviated low temperature stress in wheat. Transcriptome analysis showed that ozone priming positively modulated 'photosynthesis-antenna proteins' pathway in wheat under low temperature. Which was confirmed by the results of the ozone-primed plants had higher trapped energy flux and electron transport flux per reaction, and less damage to chloroplasts than non-primed plants under low temperature. Ozone priming also mitigated the overstimulation of glutathione metabolism and induced the accumulation of total ascorbic acid and glutathione, maintained redox homeostasis in wheat under low temperature. Moreover, gene expressions and enzyme activities in glycolysis pathways were upregulated in ozone priming comparing with non-priming after the low temperature stress. Furthermore, exogenous antibiotics significantly increased low temperature tolerance, which further proved that the inhibition of ribosome biogenesis by ozone priming was involved in low temperature tolerance in wheat. In conclusion, ozone priming enhanced wheat low temperature tolerance through promoting light-harvesting capacity, redox homeostasis, and carbohydrate metabolism, as well as inhibiting ribosome biogenesis.

Co-exposure of bisphenol A and selenium deficiency induces pyroptosis via ROS/NLRP3 pathway in chicken spleen

Bisphenol A (BPA) is widely applied in plastic products, which will produce immunotoxicity to organisms after spilling in the environment, and become a kind of endocrine disruptor. Selenium (Se) is an essential trace element and plays an important role in maintaining redox homeostasis and immune function. BPA exposure and Se deficiency often occur together in livestock and poultry farming, however, studies on the effects of joint exposure on chicken immunotoxins have not been reported. Therefore, this study established a chicken spleen and MDCC-MSB1 cell model under the combined effects of BPA exposure or/and Se deficiency. Transcriptomic analysis showed that BPA exposure and/or Se deficiency induced differential enrichment of positive regulatory pathways such as NLRP3 inflammatory complex assembly, inflammatory response and cellular oxidative stress response. In the -Se+BPA group, pathological damage was significantly increased, Se content decreased, BPA accumulation, oxidative stress and pyroptosis. Meanwhile, the roles and mechanisms of oxidative stress and pyroptosis in BPA exposure or/and Se deficiency-induced splenic tissue injury were investigated by using IF and qRT-PCR methods. The results showed that joint BPA exposure with Se deficiency resulted in more significant changes in the above outcomes than one of them. The oxidative stress inhibitor NAC effectually reduced Se deficiency and BPA-induced oxidative stress and pyroptosis, further suggests that oxidative stress mediated Se deficiency or/and BPA-induced pyroptosis. This study revealed that BPA exposure and Se deficiency induced spleen pyroptosis in chickens via the ROS/NLRP3 pathway. These results provide the theoretical basis for the toxicity of BPA in poultry and enrich the toxicological mechanism of combined exposure of Se deficiency and environmental toxins.

A Nanozyme-Boosted MOF-CRISPR Platform for Treatment of Alzheimer's Disease.

Rectifying the aberrant microenvironment of a disease through maintenance of redox homeostasis has emerged as a promising perspective with significant therapeutic potential for Alzheimer's disease (AD). Herein, we design and construct a novel nanozyme-boosted MOF-CRISPR platform (CMOPKP), which can maintain redox homeostasis and rescue the impaired microenvironment of AD. By modifying the targeted peptides KLVFFAED, CMOPKP can traverse the blood-brain barrier and deliver the CRISPR activation system for precise activation of the Nrf2 signaling pathway and downstream redox proteins in regions characterized by oxidative stress, thereby reinstating neuronal antioxidant capacity and preserving redox homeostasis. Furthermore, cerium dioxide possessing catalase enzyme-like activity can synergistically alleviate oxidative stress. Further in vivo studies demonstrate that CMOPKP can effectively alleviate cognitive impairment in 3xTg-AD mouse models. Therefore, our design presents an effective way for regulating redox homeostasis in AD, which shows promise as a therapeutic strategy for mitigating oxidative stress in AD.

Promoting Glutathione Synthesis: A Possibility for Treating Cardiomyopathy Induced by a Maternal Western Diet.

The adverse effects of a Western diet on obesity and diabetes among reproductive-aged women pose a significant threat to the cardiovascular health of their offspring. Given the crucial role of glutathione metabolism and glutathione-related antioxidant defense systems in cardiovascular diseases through scavenging ROS and maintaining redox homeostasis, further exploration of their specific influence is imperative to develop therapeutic strategies for cardiomyopathy induced by a maternal Western diet. We developed a prenatal maternal Western diet exposure model in C57/B6 mice to investigate cardiac morphology and function through histological analysis and echocardiography. RNA sequencing and analysis were utilized to elucidate the mechanisms underlying the impact of a maternal Western diet and N-acetylcysteine treatment on cardiomyopathy. Additionally, ELISAs, transmission electron microscopy, and flow cytometry were employed to assess the antioxidant defense system and mitochondrial ROS levels in progenitor cardiomyocytes. N-acetylcysteine significantly mitigated cardiomyocyte hypertrophy, myocardial interstitial fibrosis, collagen type I accumulation, and left ventricular remodeling induced by a maternal Western diet, particularly in male offspring. Furthermore, N-acetylcysteine reversed the increase in apoptosis and the increase in the β/α-MyHC ratio in the myocardium of offspring that results from a maternal Western diet. RNA sequencing and GSEA revealed that the beneficial effects of N-acetylcysteine were linked to its ability to modulate oxidative phosphorylation pathways. Additionally, N-acetylcysteine treatment during pregnancy can markedly elevate glutathione levels, augment glutathione peroxidase (GPx) activity, and mitigate the accumulation of mitochondrial ROS caused by a maternal Western diet. N-acetylcysteine mitigated cardiomyopathy induced by a maternal Western diet by bolstering glutathione synthesis and enhancing GPx activity, thereby scavenging mitochondrial ROS and modulating oxidative phosphorylation pathways.

Nebulized Glutathione as a Key Antioxidant for the Treatment of Oxidative Stress in Neurodegenerative Conditions.

Glutathione (GSH), a tripeptide synthesized intracellularly, serves as a pivotal antioxidant, neutralizing reactive oxygen species (ROS) and reactive nitrogen species (RNS) while maintaining redox homeostasis and detoxifying xenobiotics. Its potent antioxidant properties, particularly attributed to the sulfhydryl group (-SH) in cysteine, are crucial for cellular health across various organelles. The glutathione-glutathione disulfide (GSH-GSSG) cycle is facilitated by enzymes like glutathione peroxidase (GPx) and glutathione reductase (GR), thus aiding in detoxification processes and mitigating oxidative damage and inflammation. Mitochondria, being primary sources of reactive oxygen species, benefit significantly from GSH, which regulates metal homeostasis and supports autophagy, apoptosis, and ferroptosis, playing a fundamental role in neuroprotection. The vulnerability of the brain to oxidative stress underscores the importance of GSH in neurological disorders and regenerative medicine. Nebulization of glutathione presents a novel and promising approach to delivering this antioxidant directly to the central nervous system (CNS), potentially enhancing its bioavailability and therapeutic efficacy. This method may offer significant advantages in mitigating neurodegeneration by enhancing nuclear factor erythroid 2-related factor 2 (NRF2) pathway signaling and mitochondrial function, thereby providing direct neuroprotection. By addressing oxidative stress and its detrimental effects on neuronal health, nebulized GSH could play a crucial role in managing and potentially ameliorating conditions such as Parkinson's Disease (PD) and Alzheimer's Disease (AD). Further clinical research is warranted to elucidate the therapeutic potential of nebulized GSH in preserving mitochondrial health, enhancing CNS function, and combating neurodegenerative conditions, aiming to improve outcomes for individuals affected by brain diseases characterized by oxidative stress and neuroinflammation.