The Glutathione System: A New Drug Target in Neuroimmune Disorders

Ribose-cysteine and levodopa abrogate Parkinsonism via the regulation of neurochemical and redox activities in alpha-synuclein transgenic Drosophila melanogaster models

Parkinson's disease (PD), the most prevalent type of parkinsonism, is a progressive neurodegenerative condition marked by several non-motor and motor symptoms. PD is thought to have a complex aetiology that includes a combination of age, genetic predisposition, and environmental factors. Increased expression of α-synuclein (α-Syn) protein is central to the evolvement of neuropathology in this devastating disorder, but the potential of ribose-cysteine and levodopa in abating pathophysiologic changes in PD model is unknown. Crosses were set up between flies conditionally expressing a pathological variant of human α-Syn (UAS-α-Syn) and those expressing GAL4 in neurons (elav-GAL4) to generate offspring referred to as PD flies. Flies were randomly assigned to five groups (n = 40) from the total population of flies, with each group having five replicates. Groups of PD flies were treated with either 500 mg/kg ribose-cysteine diet, 250 mg/kg levodopa diet, or a combination of the two compounds for 21 days, whereas the control group (w1118) and the PD group were exposed to a diet without ribose-cysteine or levodopa. In addition to various biochemical and neurochemical assays, longevity, larval motility, and gravitaxis assays were carried out. Locomotive capability, lifespan, fecundity, antioxidant state, and neurotransmitter systems were all significantly (p < 0.05) compromised by overexpression of α-Syn. However, flies treated both ribose cysteine and levodopa showed an overall marked improvement in motor functions, lifespan, fecundity, antioxidant status, and neurotransmitter system functions. In conclusion, ribose-cysteine and levodopa, both singly and in combination, potentiated a therapeutic effect on alpha-synuclein transgenic Drosophila melanogaster models of Parkinsonism.

Biomarkers and Target-Specific Small-Molecule Drugs in Alzheimer's Diagnostic and Therapeutic Research: From Amyloidosis to Tauopathy

Alzheimer's disease (AD) is the most common type of human dementia and is responsible for over 60% of diagnosed dementia cases worldwide. Abnormal deposition of β-amyloid and the accumulation of neurofibrillary tangles have been recognised as the two pathological hallmarks targeted by AD diagnostic imaging as well as therapeutics. With the progression of pathological studies, the two hallmarks and their related pathways have remained the focus of researchers who seek for AD diagnostic and therapeutic strategies in the past decades. In this work, we reviewed the development of the AD biomarkers and their corresponding target-specific small molecule drugs for both diagnostic and therapeutic applications, underlining their success, failure, and future possibilities.

Understanding the molecular basis of anti-fibrotic potential of intranasal curcumin and its association with mitochondrial homeostasis in silica-exposed mice

Silicosis is an occupational disease of the lungs brought in by repeated silica dust exposures. Inhalation of crystalline silica leads to persistent lung inflammation characterized by lung lesions due to granuloma formation. The specific molecular mechanism has not yet been identified, though. The Present study investigated the impact of silica-exposed lung fibrosis and probable molecular mechanisms. Here, Curcumin, derived from Curcuma longa shown to be an effective anti-inflammatory and anti-fibrotic molecule has been taken to investigate its therapeutic efficacy in silica-induced lung fibrosis. An experimental model of silicosis was established in mice where curcumin was administered an hour before intranasal silica exposure every alternate day for 35 days. Intranasal Curcumin treatment reduced silica-induced oxidative stress, inflammation marked by inflammatory cell recruitment, and prominent granuloma nodules along with aberrant collagen repair. Its protective benefits were confirmed by reduced MMP9 activities along with EMT markers (Vimentin and α-SMA). It has restored autophagy and suppressed the deposition of damaged mitochondria after silica exposure. Intranasal Curcumin also inhibited oxidative stress by boosting antioxidant enzyme activities and enhanced Nrf2-Keap1 expressions. Higher levels of PINK1, PARKIN, Cyt-c, P62/SQSTM, and damaged mitochondria in the silicosis group were significantly lowered after curcumin and dexamethasone treatments. Curcumin-induced autophagy resulted in reduced silica-induced mitochondria-dependent apoptosis. We report that intranasal curcumin treatment showed protective properties on pathological features prompted by silica particles, suggesting that the compound may constitute a promising strategy for the treatment of silicosis in the near future.

Gut redox and microbiome: charting the roadmap to T-cell regulation

The gastrointestinal (GI) tract redox environment, influenced by commensal microbiota and bacterial-derived metabolites, is crucial in shaping T-cell responses. Specifically, metabolites from gut microbiota (GM) exhibit robust anti-inflammatory effects, fostering the differentiation and regulation of CD8+ tissue-resident memory (TRM) cells, mucosal-associated invariant T (MAIT) cells, and stabilizing gut-resident Treg cells. Nitric oxide (NO), a pivotal redox mediator, emerges as a central regulator of T-cell functions and gut inflammation. NO impacts the composition of the gut microbiome, driving the differentiation of pro-inflammatory Th17 cells and exacerbating intestinal inflammation, and supports Treg expansion, showcasing its dual role in immune homeostasis. This review delves into the complex interplay between GI redox balance and GM metabolites, elucidating their profound impact on T-cell regulation. Additionally, it comprehensively emphasizes the critical role of GI redox, particularly reactive oxygen species (ROS) and NO, in shaping T-cell phenotype and functions. These insights offer valuable perspectives on disease mechanisms and potential therapeutic strategies for conditions associated with oxidative stress. Understanding the complex cross-talk between GI redox, GM metabolites, and T-cell responses provides valuable insights into potential therapeutic avenues for immune-mediated diseases, underscoring the significance of maintaining GI redox balance for optimal immune health.

Targeted Reprogramming of Pathogenic Fibroblast Genes at the 3'-Untranslated Regions by DNA Nanorobots for Periodontitis

Periodontitis, with its persistent nature, causes significant distress for most sufferers. Current treatments, such as mechanical cleaning and surgery, often fail to fully address the underlying overactivation of fibroblasts that drives this degradation. Targeting the post-transcriptional regulation of fibroblasts, particularly at the 3'-untranslated regions (3'UTR) of pathogenic genes, offers a therapeutic strategy for periodontitis. Herein, we developed a DNA nanorobot for this purpose. This system uses a dynamic DNA nanoframework to incorporate therapeutic microRNAs through molecular recognition and covalent bonds, facilitated by DNA monomers modified with disulfide bonds. The assembled-DNA nanoframework is encapsulated in a cell membrane embedded with a fibroblast-targeting peptide. By analyzing the 3'UTR regions of pathogenic fibroblast genes FOSB and JUND, we identified the therapeutic microRNA as miR-1-3p and integrated it into this system. As expected, the DNA nanorobot delivered the internal components to fibroblasts by the targeting peptide and outer membrane that responsively releases miR-1-3p under intracellular glutathione. It resulted in a precise reduction of mRNA and suppression of protein function in pathogenic genes, effectively reprogramming fibroblast behavior. Our results confirm that this approach not only mitigates the inflammation but also promotes tissue regeneration in periodontal models, offering a promising therapeutic avenue for periodontitis.

Glutathione-mediated redox regulation in Cryptococcus neoformans impacts virulence

The fungal pathogen Cryptococcus neoformans is well adapted to its host environment. It has several defence mechanisms to evade oxidative and nitrosative agents released by phagocytic host cells during infection. Among them, melanin production is linked to both fungal virulence and defence against harmful free radicals that facilitate host innate immunity. How C. neoformans manipulates its redox environment to facilitate melanin formation and virulence is unclear. Here we show that the antioxidant glutathione is inextricably linked to redox-active processes that facilitate melanin and titan cell production, as well as survival in macrophages and virulence in a murine model of cryptococcosis. Comparative metabolomics revealed that disruption of glutathione biosynthesis leads to accumulation of reducing and acidic compounds in the extracellular environment of mutant cells. Overall, these findings highlight the importance of redox homeostasis and metabolic compensation in pathogen adaptation to the host environment and suggest new avenues for antifungal drug development.

GSH and Ferroptosis: Side-by-Side Partners in the Fight against Tumors

Glutathione (GSH), a prominent antioxidant in organisms, exhibits diverse biological functions and is crucial in safeguarding cells against oxidative harm and upholding a stable redox milieu. The metabolism of GSH is implicated in numerous diseases, particularly in the progression of malignant tumors. Consequently, therapeutic strategies targeting the regulation of GSH synthesis and metabolism to modulate GSH levels represent a promising avenue for future research. This study aimed to elucidate the intricate relationship between GSH metabolism and ferroptosis, highlighting how modulation of GSH metabolism can impact cellular susceptibility to ferroptosis and consequently influence the development of tumors and other diseases. The paper provides a comprehensive overview of the physiological functions of GSH, including its structural characteristics, physicochemical properties, sources, and metabolic pathways, as well as investigate the molecular mechanisms underlying GSH regulation of ferroptosis and potential therapeutic interventions. Unraveling the biological role of GSH holds promise for individuals afflicted with tumors.

Seeing beyond words: Visualizing autism spectrum disorder biomarker insights

Objective

This study employs bibliometric and visual analysis to elucidate global research trends in Autism Spectrum Disorder (ASD) biomarkers, identify critical research focal points, and discuss the potential integration of diverse biomarker modalities for precise ASD assessment.

Methods

A comprehensive bibliometric analysis was conducted using data from the Web of Science Core Collection database until December 31, 2022. Visualization tools, including R, VOSviewer, CiteSpace, and gCLUTO, were utilized to examine collaborative networks, co-citation patterns, and keyword associations among countries, institutions, authors, journals, documents, and keywords.

Results

ASD biomarker research emerged in 2004, accumulating a corpus of 4348 documents by December 31, 2022. The United States, with 1574 publications and an H-index of 213, emerged as the most prolific and influential country. The University of California, Davis, contributed significantly with 346 publications and an H-index of 69, making it the leading institution. Concerning journals, the Journal of Autism and Developmental Disorders, Autism Research, and PLOS ONE were the top three publishers of ASD biomarker-related articles among a total of 1140 academic journals. Co-citation and keyword analyses revealed research hotspots in genetics, imaging, oxidative stress, neuroinflammation, gut microbiota, and eye tracking. Emerging topics included "DNA methylation," "eye tracking," "metabolomics," and "resting-state fMRI."

Conclusion

The field of ASD biomarker research is dynamically evolving. Future endeavors should prioritize individual stratification, methodological standardization, the harmonious integration of biomarker modalities, and longitudinal studies to advance the precision of ASD diagnosis and treatment.

Effect of oil contaminants on antioxidant responses and antioxidant properties of Pleurotus florida (P. Kumm)

This research investigated the antioxidant responses of Pleurotus florida at different concentrations of gas oil [0% (control), 2.5%, 5%, and 10% (v:v)] for 30 days. The activities of superoxide dismutase and catalase enzymes decreased in responses to the gas oil presence by an average of 83% and 49%, respectively. In contrast, the activities of the ascorbate peroxidase and glutathione peroxidase enzymes displayed an upward trend in the groups cultured in oil-contaminated media. The gas oil contaminant increased total phenol and flavonoid accumulation, reflecting the variation in secondary metabolism. According to the 1,2-diphenyl-2-picrylhydrazyl radical scavenging, the 2.5% gas oil treatment resulted in the highest antioxidant activity (48 μg mL-1). The highest scavenging activity of nitric oxide radicals (IC50 = 272 μg mL-1) was observed in the treatment with the highest gas oil concentration (10%). Also, this treatment showed an excellent ability to chelate Fe+2 ions (IC50 = 205 μg mL-1). The IC50 values of methanolic extract for nitric oxide scavenging activity and metal chelating ability were significantly reduced by increasing gas oil concentration in the treatments. With increasing the gas oil concentration, malondialdehyde content as a criterion measure of lipid peroxidation level showed significant reduction. These results show that P. florida is resistant to and a compatible mushroom with oil pollutants. Also, the activity of glutathione peroxidase and the ascorbate-glutathione cycle detoxify nitric oxide radicals and products of reactive oxygen species-induced lipid peroxidation in the gas oil treatments.

In Vivo Intracerebral Administration of α-Ketoisocaproic Acid to Neonate Rats Disrupts Brain Redox Homeostasis and Promotes Neuronal Death, Glial Reactivity, and Myelination Injury

Maple syrup urine disease (MSUD) is caused by severe deficiency of branched-chain α-keto acid dehydrogenase complex activity, resulting in tissue accumulation of branched-chain α-keto acids and amino acids, particularly α-ketoisocaproic acid (KIC) and leucine. Affected patients regularly manifest with acute episodes of encephalopathy including seizures, coma, and potentially fatal brain edema during the newborn period. The present work investigated the ex vivo effects of a single intracerebroventricular injection of KIC to neonate rats on redox homeostasis and neurochemical markers of neuronal viability (neuronal nuclear protein (NeuN)), astrogliosis (glial fibrillary acidic protein (GFAP)), and myelination (myelin basic protein (MBP) and 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase)) in the cerebral cortex and striatum. KIC significantly disturbed redox homeostasis in these brain structures 6 h after injection, as observed by increased 2',7'-dichlorofluorescein oxidation (reactive oxygen species generation), malondialdehyde levels (lipid oxidative damage), and carbonyl formation (protein oxidative damage), besides impairing the antioxidant defenses (diminished levels of reduced glutathione and altered glutathione peroxidase, glutathione reductase, and superoxide dismutase activities) in both cerebral structures. Noteworthy, the antioxidants N-acetylcysteine and melatonin attenuated or normalized most of the KIC-induced effects on redox homeostasis. Furthermore, a reduction of NeuN, MBP, and CNPase, and an increase of GFAP levels were observed at postnatal day 15, suggesting neuronal loss, myelination injury, and astrocyte reactivity, respectively. Our data indicate that disruption of redox homeostasis, associated with neural damage caused by acute intracerebral accumulation of KIC in the neonatal period may contribute to the neuropathology characteristic of MSUD patients.

Diet with optimal glutathione supplement improves growth, nonspecific immunity, intestinal microbiota, and antioxidant ability in Micropterus salmoides

In this study, Micropterus salmoides were fed with dietary glutathione (GSH, 0, 100, 300, and 500 mg/kg) for 56 days to investigate its effects on growth performance, serum nonspecific immunity, liver antioxidant capacity, tissue morphology, and intestinal microbiota. The results showed that the survival rate, weight gain rate, and specific growth rate and condition factor increased, whereas the feed conversion ratio, hepato-somatic index, and viscerosomatic index decreased in the GSH groups. Compared with the control group, the serum total protein content significantly increased, whereas the triglyceride and total cholesterol significantly decreased in the 300-mg/kg dietary GSH group. The activities of lysozyme, alkaline phosphatase, and acid phosphatase were significantly higher in GSH-supplemented groups, peaking at 300-mg/kg GSH. GSH supplementation significantly increased total antioxidant capacity and decreased malondialdehyde content, with the most pronounced effects at 300-mg/kg GSH. Further antioxidant indicators showed that a dietary supplement of 300-mg/kg GSH significantly increased the activities of superoxide dismutase, glutathione transferase, endogenous glutathione, glutathione reductase, and catalase. At 300-mg/kg GSH, the liver exhibited improved characteristics with alleviated vacuolation and hepatocyte nuclear shift, and intestine showed enhanced structure with increased villus height and intestinal wall thickness. Additionally, a 300-mg/kg GSH supplementation improved the diversity of intestinal microbiota, increased the abundance of probiotics such as Bacillus, and inhibited the development of pathogenic bacteria such as Plesiomonas. Overall, the results suggest that the effect of GSH addition on improving growth performance, nonspecific immunity, antioxidant capacity, and intestinal microbiota of M. salmoides is best in the 300-mg/kg addition group. Based on second-degree polynomial regression analysis of weight gain, the optimum requirement of dietary GSH in M. salmoides is a 336.84-mg/kg diet.

Systemic and strict regulation of the glutathione redox state in mitochondria and cytosol is needed for zebrafish ontogeny

BACKGROUND

Redox control seems to be indispensable for proper embryonic development. The ratio between glutathione (GSH) and its oxidized disulfide (GSSG) is the most abundant cellular redox circuit.

METHODS

We used zebrafish harboring the glutaredoxin 1-redox sensitive green fluorescent protein (Grx1-roGFP) probe either in mitochondria or cytosol to test the hypothesis that the GSH:GSSG ratio is strictly regulated through zebrafish embryogenesis to sustain the different developmental processes of the embryo.

RESULTS

Following the GSSG:GSH ratio as a proxy for the GSH-dependent reduction potential (EhGSH) revealed increasing mitochondrial and cytosolic EhGSH during cleavage and gastrulation. During organogenesis, cytosolic EhGSH decreased, while that of mitochondria remained high. The similarity between EhGSH in brain and muscle suggests a central regulation. Modulation of GSH metabolism had only modest effects on the GSSG:GSH ratios of newly hatched larvae. However, inhibition of GSH reductase directly after fertilization led to dead embryos already 10 h later. Exposure to the emerging environmental pollutant Perfluorooctane Sulfonate (PFOS) disturbed the apparent regulated EhGSH as well.

CONCLUSIONS

Mitochondrial and cytosolic GSSG:GSH ratios are almost identical in different organs during zebrafish development indicating that the EhGSH might follow H2O2 levels and rather indirectly affect specific enzymatic activities needed for proper embryogenesis.

GENERAL SIGNIFICANCE

Our data confirm that vertebrate embryogenesis depends on strictly regulated redox homeostasis. Disturbance of the GSSG:GSH circuit, e.g. induced by environmental pollution, leads to malformation and death.

Evaluation of Antidepressant Activity of Capsaicin Nanoemulsion in Nicotine Withdrawal-Induced Depression in Mice

Depression is a low-energy condition that has an impact on a person's thoughts, actions, propensities, emotional state, and sense of wellbeing. According to the World Health Organization (WHO), 5% of adults are depressed. Individuals who are depressed are commonly prescribed antidepressants, and sometimes, individuals may have other psychiatric conditions that share overlapping symptoms with depression. These cooccurring conditions can complicate the diagnostic process, leading to a misdiagnosis and the prescription of antidepressants. Capsaicin (CAP) is a known antidepressant. Hence, this study aimed to assess the antidepressant activity of CAP nanoemulsion in nicotine (NC) withdrawal-induced depression in mice. Mice treated with CAP (3 mg/kg) showed reduced immobility in the forced swimming test (FST), tail-suspension test (TST), and open field test (OFT). During the OFT, the animals treated with nanoemulsion (CAP 3 mg/kg) spent less time in the corners than the control animals. Biochemical parameters, such as superoxide dismutase (SOD) and glutathione (GSH), were observed in reduced quantities in the NC withdrawal model (NWM), where they were slightly increased in the high-dose nanoemulsion (CAP 3 mg/kg) compared to the low-dose nanoemulsion (CAP 1 mg/kg). These results suggest that CAP caused antidepressant activity in the NWM via the nanoemulsion.

Glutathione and glutathione-dependent enzymes: From biochemistry to gerontology and successful aging

The tripeptide glutathione (GSH), namely γ-L-glutamyl-L-cysteinyl-glycine, is an ubiquitous low-molecular weight thiol nucleophile and reductant of utmost importance, representing the central redox agent of most aerobic organisms. GSH has vital functions involving also antioxidant protection, detoxification, redox homeostasis, cell signaling, iron metabolism/homeostasis, DNA synthesis, gene expression, cysteine/protein metabolism, and cell proliferation/differentiation or death including apoptosis and ferroptosis. Various functions of GSH are exerted in concert with GSH-dependent enzymes. Indeed, although GSH has direct scavenging antioxidant effects, its antioxidant function is substantially accomplished by glutathione peroxidase-catalyzed reactions with reductive removal of H2O2, organic peroxides such as lipid hydroperoxides, and peroxynitrite; to this antioxidant activity also contribute peroxiredoxins, enzymes further involved in redox signaling and chaperone activity. Moreover, the detoxifying function of GSH is basically exerted in conjunction with glutathione transferases, which have also antioxidant properties. GSH is synthesized in the cytosol by the ATP-dependent enzymes glutamate cysteine ligase (GCL), which catalyzes ligation of cysteine and glutamate forming γ-glutamylcysteine (γ-GC), and glutathione synthase, which adds glycine to γ-GC resulting in GSH formation; GCL is rate-limiting for GSH synthesis, as is the precursor amino acid cysteine, which may be supplemented as N-acetylcysteine (NAC), a therapeutically available compound. After its cell export, GSH is degraded extracellularly by the membrane-anchored ectoenzyme γ-glutamyl transferase, a process occurring, as GSH synthesis and export, in the γ-glutamyl cycle. GSH degradation occurs also intracellularly by the cytoplasmic enzymatic ChaC family of γ-glutamyl cyclotransferase. Synthesis and degradation of GSH, together with its export, translocation to cell organelles, utilization for multiple essential functions, and regeneration from glutathione disulfide by glutathione reductase, are relevant to GSH homeostasis and metabolism. Notably, GSH levels decline during aging, an alteration generally related to impaired GSH biosynthesis and leading to cell dysfunction. However, there is evidence of enhanced GSH levels in elderly subjects with excellent physical and mental health status, suggesting that heightened GSH may be a marker and even a causative factor of increased healthspan and lifespan. Such aspects, and much more including GSH-boosting substances administrable to humans, are considered in this state-of-the-art review, which deals with GSH and GSH-dependent enzymes from biochemistry to gerontology, focusing attention also on lifespan/healthspan extension and successful aging; the significance of GSH levels in aging is considered also in relation to therapeutic possibilities and supplementation strategies, based on the use of various compounds including NAC-glycine, aimed at increasing GSH and related defenses to improve health status and counteract aging processes in humans.

Pathogenesis and treatment of depression: Role of diet in prevention and therapy

In recent years, there has been a significant increase in depression, which is related to, among other things, the COVID-19 pandemic. Depression can be fatal if not treated or if treated inappropriately. Depression is the leading cause of suicide attempts. The disease is multifactorial, and pharmacotherapy often fails to bring satisfactory results. Therefore, increasingly more importance is attached to the natural healing substances and nutrients in food, which can significantly affect the therapy process and prevention of depressive disorders. A proper diet is vital to preventing depression and can be a valuable addition to psychological and pharmacologic treatment. An inadequate diet may reduce the effectiveness of antidepressants or increase their side effects, leading to life-threatening symptoms. This study aimed to review the literature on the pathogenesis of the development and treatment of depression, with particular emphasis on dietary supplements and the role of nutrition in the prevention and treatment of depressive disorders.

Nutritional Support During Long COVID: A Systematic Scoping Review

Introduction: Long COVID is a term that encompasses a range of signs, symptoms, and sequalae that continue or develop after an acute COVID-19 infection. The lack of early recognition of the condition contributed to delays in identifying factors that may contribute toward its development and prevention. The aim of this study was to scope the available literature to identify potential nutritional interventions to support people with symptoms associated with long COVID. Methods: This study was designed as a systematic scoping review of the literature (registration PROSPERO CRD42022306051). Studies with participants aged 18 years or older, with long COVID and who underwent a nutritional intervention were included in the review. Results: A total of 285 citations were initially identified, with five papers eligible for inclusion: two were pilot studies of nutritional supplements in the community, and three were nutritional interventions as part of inpatient or outpatient multidisciplinary rehabilitation programs. There were two broad categories of interventions: those that focused on compositions of nutrients (including micronutrients such as vitamin and mineral supplements) and those that were incorporated as part of multidisciplinary rehabilitation programs. Nutrients included in more than one study were multiple B group vitamins, vitamin C, vitamin D, and acetyl-l-carnitine. Discussion: Two studies trialed nutritional supplements for long COVID in community samples. Although these initial reports were positive, they are based on poorly designed studies and therefore cannot provide conclusive evidence. Nutritional rehabilitation was an important aspect of recovery from severe inflammation, malnutrition, and sarcopenia in hospital rehabilitation programs. Current gaps in the literature include a potential role for anti-inflammatory nutrients such as the omega 3 fatty acids, which are currently undergoing clinical trials, glutathione-boosting treatments such as N-acetylcysteine, alpha-lipoic acid, or liposomal glutathione in long COVID, and a possible adjunctive role for anti-inflammatory dietary interventions. This review provides preliminary evidence that nutritional interventions may be an important part of a rehabilitation program for people with severe long COVID symptomatology, including severe inflammation, malnutrition, and sarcopenia. For those in the general population with long COVID symptoms, the role of specific nutrients has not yet been studied well enough to recommend any particular nutrient or dietary intervention as a treatment or adjunctive treatment. Clinical trials of single nutrients are currently being conducted, and future systematic reviews could focus on single nutrient or dietary interventions to identify their nuanced mechanisms of action. Further clinical studies incorporating complex nutritional interventions are also warranted to strengthen the evidence base for using nutrition as a useful adjunctive treatment for people living with long COVID.

Methionine: An Indispensable Amino Acid in Cellular Metabolism and Health of Atlantic Salmon

Methionine is an indispensable amino acid with an important role as the main methyl donor in cellular metabolism for both fish and mammals. Metabolization of methionine to the methyl donor S-adenosylmethionine (SAM) has consequence for polyamine, carnitine, phospholipid, and creatine synthesis as well as epigenetic modifications such as DNA- and histone tail methylation. Methionine can also be converted to cysteine and contributes as a precursor for taurine and glutathione synthesis. Moreover, methionine is the start codon for every protein being synthetized and thereby serves an important role in initiating translation. Modern salmon feed is dominated by plant ingredients containing less taurine, carnitine, and creatine than animal-based ingredients. This shift results in competition for SAM due to an increasing need to endogenously synthesize associated metabolites. The availability of methionine has profound implications for various metabolic pathways including allosteric regulation. This necessitates a higher nutritional need to meet the requirement as a methyl donor, surpassing the quantities for protein synthesis and growth. This comprehensive review provides an overview of the key metabolic pathways in which methionine plays a central role as methyl donor and unfolds the implications for methylation capacity, metabolism, and overall health particularly emphasizing the development of fatty liver, oxidation, and inflammation when methionine abundance is insufficient focusing on nutrition for Atlantic salmon (Salmo salar).

The effects of a highly bioavailable curcumin PhytosomeTM preparation on the retinal architecture and glial reactivity in the GFAP-IL6 mice

Uncontrolled, chronic inflammation in the retina can disturb retinal structure and function leading to impaired visual function. For the first time, in a mouse model of chronic neuroinflammation (GFAP-IL6), we investigated the impact of chronic glial activation on the retinal microglia population and structure. In addition, we tested a curcumin PhytosomeTM preparation with enhanced bioavailability to investigate the effects of a cytokine-suppressing anti-inflammatory drug on retinal architecture. Curcumin PhytosomeTM was fed to 3-month old GFAP-IL6 mice for 4 weeks and compared to their untreated GFAP-IL6 counterparts as well as wild type mice on control diet. Microglial numbers and morphology together with neuronal numbers were characterized using immunohistochemistry and cell reconstruction in the retina, using retinal wholemount and slices. GFAP-IL6 mice showed a significant increase in Iba1-labelled mononuclear phagocytes, including microglia, and displayed altered glial morphology. This resulted in a reduction in cone density and a thinning of the retinal layers compared to wild type mice. Curcumin PhytosomeTM treatment contributed to decreased microglial density, significantly decreasing both soma and cell size compared to control diet, as well as preventing the thinning of the retinal layers. This study is the first to characterize the impact of chronic retinal inflammation in the GFAP-IL6 mouse and the therapeutic benefit of enhanced bioavailable curcumin PhytosomeTM to significantly reduce microglia density and prevent neuronal loss. These data suggest that curcumin could be used as a complementary therapy alongside traditional treatments to reduce associated retinal inflammation in a variety of retinal diseases.

Systematic review of the human health hazards of propylene dichloride

Propylene dichloride (PDC) is a chlorinated substance used primarily as an intermediate in basic organic chemical manufacturing. The United States Environmental Protection Agency (EPA) is currently evaluating PDC as a high-priority substance under the Toxic Substances Control Act (TSCA). We conducted a systematic review of the non-cancer and cancer hazards of PDC using the EPA TSCA and Integrated Risk Information System (IRIS) frameworks. We identified 12 epidemiological, 16 toxicokinetic, 34 experimental animal, and 49 mechanistic studies. Point-of-contact respiratory effects are the most sensitive non-cancer effects after inhalation exposure, and PDC is neither a reproductive nor a developmental toxicant. PDC is not mutagenic in vivo, and while in vitro evidence is mixed, DNA strand breaks consistently occur. Nasal tumors in rats and lung tumors in mice occurred after lifetime high-level inhalation exposure. Cholangiocarcinoma (CCA) was observed in Japanese print workers exposed to high concentrations of PDC. However, co-exposures, as well as liver parasites, hepatitis, and other risk factors, may also have contributed. The cancer mode of action (MOA) analysis revealed that PDC may act through multiple biological pathways occurring sequentially and/or simultaneously, although chronic tissue damage and inflammation likely dominate. Critically, health benchmarks protective of non-cancer effects are expected to protect against cancer in humans.

Mode of action assessment for propylene dichloride as a human carcinogen

As part of a systematic review of the non-cancer and cancer hazards of propylene dichloride (PDC), with a focus on potential carcinogenicity in workers following inhalation exposures, we determined that a mode of action (MOA)-centric framing of cancer effects was warranted. In our MOA analysis, we systematically reviewed the available mechanistic evidence for PDC-induced carcinogenesis, and we mapped biologically plausible MOA pathways and key events (KEs), as guided by the International Programme on Chemical Safety (IPCS)-MOA framework. For the identified pathways and KEs, biological concordance, essentiality of KEs, concordance of empirical observations among KEs, consistency, and analogy were evaluated. The results of this analysis indicate that multiple biologically plausible pathways may contribute to the cancer MOA for PDC, but that the relevant pathways vary by exposure route and level, tissue type, and species; further, more than one pathway may occur concurrently at high exposure levels. While several important data gaps exist, evidence from in vitro mechanistic studies, in vivo experimental animal studies, and ex vivo human tumor tissue analyses indicates that the predominant MOA pathway likely involves saturation of cytochrome p450 2E1 (CYP2E1)-glutathione (GSH) detoxification (molecular initiating event; MIE), accumulation of CYP2E1-oxidative metabolites, cytotoxicity, chronic tissue damage and inflammation, and ultimately tumor formation. Tumors may occur through several subsets of inflammatory KEs, including inflammation-induced aberrant expression of activation-induced cytidine deaminase (AID), which causes DNA strand breaks and mutations and can lead to tumors with a characteristic mutational signature found in occupational cholangiocarcinoma. Dose concordance analysis showed that low-dose mutagenicity (from any pathway) is not a driving MOA, and that prevention of target tissue damage and inflammation (associated with saturation of CYP2E1-GSH detoxification) is expected to also prevent the cascade of processes responsible for tumor formation.

Differential Impacts of Endogenous Antioxidants on Clinical Symptoms and Cognitive Function in Acute and Chronic Schizophrenia Patients

BACKGROUND

Impaired antioxidant defense is implicated in the pathophysiology of schizophrenia, and superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) are 3 first-line endogenous antioxidants. Various cognitive functions decline differently during the schizophrenia course. The characteristic roles of the 3 antioxidants in clinical and cognitive profiles in acute and chronic phases of schizophrenia require study.

METHODS

We recruited 311 patients with schizophrenia, including 92 acutely exacerbated patients who had been off antipsychotics for at least 2 weeks and 219 chronic patients who had been stable on medication for at least 2 months. Blood SOD, CAT, and GSH levels; clinical symptoms; and 9 cognitive test scores were measured.

RESULTS

Blood CAT levels were higher in the acute patients than in the chronic patients, whereas SOD and GSH levels were similar to one another. Higher CAT levels were correlated with less positive symptoms, better working memory and problem solving in the acute phase, and less negative symptoms, less general psychopathology, better global assessment of function, and better cognitive function (in speed of processing, attention, problem solving) in the chronic period. Higher SOD levels were correlated with better global assessment of function in the acute phase and better speed of processing, working memory, and verbal learning and memory in the chronic period. GSH influenced neither clinical nor cognitive manifestations.

CONCLUSIONS

This study showed that blood CAT affected different clinical and cognitive domains between acute and chronic stages of schizophrenia, SOD influenced cognitive functions in chronic state, but GSH affected none. Further studies are needed to explore the underlying mechanisms.

Differential relationships of NMDAR hypofunction and oxidative stress with cognitive decline

NMDAR hypofunction and oxidative stress are implicated in the pathogenesis of Alzheimer's disease. D-amino acid oxidase (DAO) regulates NMDAR function. Glutathione, superoxide dismutase, and catalase are three first-line endogenous antioxidants. This study explored the associations of these potential biomarkers with mild cognitive impairment. Cognitive function and blood levels of DAO, glutathione, superoxide dismutase, and catalase were measured in 63 mild cognitive impairment patients and 24 healthy individuals every 6 months for 2 years. Among the patients, DAO and glutathione levels at baseline contributed to the cognitive decline 2 years later. Among the healthy individuals, only glutathione levels were associated with cognitive change. The four biomarkers differed in change directions (upward vs. downward) in the patients and in the healthy individuals. Among patients, glutathione levels were negatively correlated with superoxide dismutase and positively correlated with catalase, and DAO levels were negatively correlated with superoxide dismutase. To our knowledge, this is the first study to demonstrate the differential associations of NMDAR hypofunction and oxidative stress with cognitive change between the mild cognitive impairment patients and healthy people. Glutathione may be regarded as an aging marker for both mild cognitive impairment and normal aging; and DAO, a biomarker exclusively for mild cognitive impairment.

Mancozeb-induced cytotoxicity in human erythrocytes: enhanced generation of reactive species, hemoglobin oxidation, diminished antioxidant power, membrane damage and morphological changes

Mancozeb is an ethylene bis-dithiocarbamate fungicide extensively used in agriculture to safeguard crops from various fungal diseases. The general population is exposed to mancozeb through consumption of contaminated food or water. Here, we have investigated the effect of mancozeb on isolated human erythrocytes under in vitro conditions. Erythrocytes were treated with different concentrations of mancozeb (0, 5, 10, 25, 50, 100 μM) and incubated for 24 h at 37 °C. Analysis of biochemical parameters and cell morphology showed dose-dependent toxicity of mancozeb in human erythrocytes. Mancozeb treatment caused hemoglobin oxidation and heme degradation. Protein and lipid oxidation were enhanced, while a significant decrease was seen in reduced glutathione and total sulfhydryl content. A significant increase in the generation of reactive oxygen and nitrogen species was detected in mancozeb-treated erythrocytes. The antioxidant capacity and the activity of key antioxidant enzymes were greatly diminished, while crucial metabolic pathways were inhibited in erythrocytes. Damage to the erythrocyte membrane on mancozeb treatment was apparent from increased cell lysis and osmotic fragility, along with the impairment of the plasma membrane redox system. Mancozeb also caused morphological alterations and transformed the normal discoid-shaped erythrocytes into echinocytes and stomatocytes. Thus, mancozeb induces oxidative stress in human erythrocytes, impairs the antioxidant defense system, oxidizes cellular components, that will adversely affect erythrocyte structure and function.

Reactive oxygen species formation and its effect on CD4+ T cell-mediated inflammation

Reactive oxygen species (ROS) are produced both enzymatically and non-enzymatically in vivo. Physiological concentrations of ROS act as signaling molecules that participate in various physiological and pathophysiological activities and play an important role in basic metabolic functions. Diseases related to metabolic disorders may be affected by changes in redox balance. This review details the common generation pathways of intracellular ROS and discusses the damage to physiological functions when the ROS concentration is too high to reach an oxidative stress state. We also summarize the main features and energy metabolism of CD4+ T-cell activation and differentiation and the effects of ROS produced during the oxidative metabolism of CD4+ T cells. Because the current treatment for autoimmune diseases damages other immune responses and functional cells in the body, inhibiting the activation and differentiation of autoreactive T cells by targeting oxidative metabolism or ROS production without damaging systemic immune function is a promising treatment option. Therefore, exploring the relationship between T-cell energy metabolism and ROS and the T-cell differentiation process provides theoretical support for discovering effective treatments for T cell-mediated autoimmune diseases.

Astragalus polysaccharide ameliorated complex factor-induced chronic fatigue syndrome by modulating the gut microbiota and metabolites in mice

Chronic fatigue syndrome (CFS) is a debilitating disease with no symptomatic treatment. Astragalus polysaccharide (APS), a component derived from the traditional Chinese medicine A. membranaceus, has significant anti-fatigue activity. However, the mechanisms underlying the potential beneficial effects of APS on CFS remain poorly understood. A CFS model of 6-week-old C57BL/6 male mice was established using the multiple-factor method. These mice underwent examinations for behavior, oxidative stress and inflammatory indicators in brain and intestinal tissues, and ileum histomorphology. 16 S rDNA sequencing analysis indicated that APS regulated the abundance of gut microbiota and increased production of short chain fatty acids (SCFAs) and anti-inflammatory bacteria. In addition, APS reversed the abnormal expression of Nrf2, NF-κB, and their downstream factors in the brain-gut axis and alleviated the reduction in SCFAs in the cecal content caused by CFS. Further, APS modulated the changes in serum metabolic pathways induced by CFS. Finally, it was verified that butyrate exerted antioxidant and anti-inflammatory effects in neuronal cells. In conclusion, APS could increase the SCFAs content by regulating the gut microbiota, and SCFAs (especially butyrate) can further regulate the oxidative stress and inflammation in the brain, thus alleviating CFS. This study explored the efficacy and mechanism of APS for CFS from the perspective of gut-brain axis and provides a reference to further explore the efficacy of APS and the role of SCFAs in the central nervous system.

Critical Roles of the Cysteine-Glutathione Axis in the Production of γ-Glutamyl Peptides in the Nervous System

γ-Glutamyl moiety that is attached to the cysteine (Cys) residue in glutathione (GSH) protects it from peptidase-mediated degradation. The sulfhydryl group of the Cys residue represents most of the functions of GSH, which include electron donation to peroxidases, protection of reactive sulfhydryl in proteins via glutaredoxin, and glutathione conjugation of xenobiotics, whereas Cys-derived sulfur is also a pivotal component of some redox-responsive molecules. The amount of Cys that is available tends to restrict the capacity of GSH synthesis. In in vitro systems, cystine is the major form in the extracellular milieu, and a specific cystine transporter, xCT, is essential for survival in most lines of cells and in many primary cultivated cells as well. A reduction in the supply of Cys causes GPX4 to be inhibited due to insufficient GSH synthesis, which leads to iron-dependent necrotic cell death, ferroptosis. Cells generally cannot take up GSH without the removal of γ-glutamyl moiety by γ-glutamyl transferase (GGT) on the cell surface. Meanwhile, the Cys-GSH axis is essentially common to certain types of cells; primarily, neuronal cells that contain a unique metabolic system for intercellular communication concerning γ-glutamyl peptides. After a general description of metabolic processes concerning the Cys-GSH axis, we provide an overview and discuss the significance of GSH-related compounds in the nervous system.

Effects of cyanobacterial metabolites: Aeruginosin 98A, microginin-FR1, anabaenopeptin-A, cylindrospermopsin in binary and quadruple mixtures on the survival and oxidative stress biomarkers of Daphnia magna

The aim of our study was to determine the effects of aeruginosin 98 A (ARE-A), microginin-FR1 (MG-FR1), anabaenopeptin-A (ANA-A) cylindrospermopsin (CYL) and their binary and quadruple mixtures on the survival and the levels of oxidative stress biomarkers in Daphnia magna: total glutathione (GSH), catalase (CAT), dismutase (SOD) and malondialdehyde (MDA). The biochemical indicators were measured with ELISA kits and the interactive effects were determined by isobole and polygonal analysis with Compusyn® computer software. The study revealed that oligopeptides did not decrease daphnid survival, only CYL inhibited this parameter, with synergistic effects when it was used as a component. The single metabolites at the two highest concentrations and all the binary and quadruple mixtures at all concentrations diminished GSH level, however both in the binary and in the quadruple mixtures most of the interactions between the metabolites were antagonistic. Nearly additive effects were found only in AER-A + CYL and MG-FR1+CYL. On the other hand, CAT activity was slightly increased in daphnids exposed to the binary mixtures with antagonistic interactions, however nearly addivive effects were found in animals exposed to the mixture of AER-A + ANA-A and synergistic in the quadruple mixture. SOD was elevated in daphnids exposed to single AER-A and MG-FR1, however it was diminished in the animals exposed to ANA-A and CYL. Binary mixtures in which CYL was present as a component decreased the level of this enzyme with nearly additive interactions in ANA-A + CYL. The quadruple mixture increased SOD level, with antagonistic interactions. Both single cyanobacterial metabolites, their binary and quadruple mixtures induced lipid peroxidation measured by MDA level and most of interactions in the binary mixtures were synergistic. The study suggested that antioxidative system of Daphnia magna responded to the tested metabolites and the real exposure to mixtures of these products may lead to various interactive effects with varied total toxicity.

Exposure to ambient air pollution and elevated blood levels of gamma-glutamyl transferase in a large Austrian cohort

Gamma glutamyl transferase (GGT) is related to oxidative stress and an indicator for liver damage. We investigated the association between air pollution and GGT in a large Austrian cohort (N = 116,109) to better understand how air pollution affects human health. Data come from voluntary prevention visits that were routinely collected within the Vorarlberg Health Monitoring and Prevention Program (VHM&PP). Recruitment was ongoing from 1985 to 2005. Blood was drawn and GGT measured centralized in two laboratories. Land use regression models were applied to estimate individuals' exposure at their home address for particulate matter (PM) with a diameter of <2.5 μm (PM2.5), <10 μm (PM10), fraction between 10 μm and 2.5 μm (PMcoarse), as well as PM2.5 absorbance (PM2.5abs), NO₂, NO_x and eight components of PM. Linear regression models, adjusting for relevant individual and community-level confounders were calculated. The study population was 56 % female with a mean age of 42 years and mean GGT was 19.0 units. Individual PM2.5 and NO₂ exposures were essentially below European limit values of 25 and 40 μg/m³, respectively, with means of 13.58 μg/m³ for PM2.5 and 19.93 μg/m³ for NO₂. Positive associations were observed for PM2.5, PM10, PM2.5abs, NO₂, NO_x, and Cu, K, S in PM2.5 and PM10 fractions and Zn mainly in PM2.5 fraction. The strongest association per interquartile range observed was an increase of serum GGT concentration by 1.40 % (95 %-CI: 0.85 %; 1.95 %) per 45.7 ng/m³ S in PM2.5. Associations were robust to adjustments for other biomarkers, in two-pollutant models and the subset with a stable residential history. We found that long-term exposure to air pollution (PM2.5, PM10, PM2.5abs, NO₂, NO_x) as well as certain elements, were positively associated with baseline GGT levels. The elements associated suggest a role of traffic emissions, long range transport and wood burning.

Feasibility of Acupuncture and Exploration of Metabolomic Alterations for Psychoneurological Symptoms Among Breast Cancer Survivors

OBJECTIVE

Approximately 24-68% of breast cancer survivors report co-occurring psychoneurological symptoms of pain, fatigue, sleep disturbance, depression, and anxiety during and after cancer treatment. This study aimed to assess the feasibility and acceptability of acupuncture for the treatment of multiple psychoneurological symptoms among breast cancer survivors and explore metabolomic changes before and after acupuncture.

METHODS

We conducted a single-arm, prospective pilot study of breast cancer survivors with at least two moderate to severe psychoneurological symptoms (>3 on a 0-10 scale). Acupuncture was administered twice weekly for 5 weeks, for 30 minutes per session. Along with Patient-Reported Outcomes Measurement Information System (PROMIS) questionnaires, a fasting serum comprehensive hydrophilic metabolites panel was analyzed at baseline and after acupuncture.

RESULTS

Eight participants (mean age 52.5 ± 10.9 years; 62.5% Black) were enrolled. Feasibility was supported, with 67% recruitment, 87.5% retention, and 98% acceptability. Post intervention, PROMIS T-scores were reduced for all psychoneurological symptoms. Significant differences in serum metabolites before and after acupuncture were F-1,6/2,6-DP, glutathione disulfide, phosphorylcholine, 6-methylnicotinamide, glutathione, and putrescine (variable importance of projection values larger than 1.5 and p values <0.05). Pathway analysis indicated that glutathione metabolism (p = 0.002, q = 0.071), and arginine and proline metabolisms (p = 0.009, q = 0.166) were potentially involved in mechanisms of acupuncture.

CONCLUSIONS

Acupuncture to reduce multiple psychoneurological symptoms among breast cancer survivors was feasible and acceptable. Study findings also shed light on the metabolic pathways involved in the acupuncture response and will be tested in future studies.

Development of a fast and robust liquid chromatography-mass spectrometry-based metabolomics analysis method for neonatal dried blood spots

Dried blood spot (DBS) samples have been widely used in many fields including newborn screening, with the advantages in transportation, storage and non-invasiveness. The DBS metabolomics research of neonatal congenital diseases will greatly expand the understanding of the disease. In this study, we developed a liquid chromatography-mass spectrometry-based method for neonatal metabolomics analysis of DBS. The influences of blood volume and chromatographic effects on the filter paper on metabolite levels were studied. The levels of 11.11 % metabolites were different between 75 μL and 35 μL of blood volumes used for DBS preparation. Chromatographic effects on the filter paper occurred in DBS prepared with 75 μL whole blood and 6.67 % metabolites had different MS responses when central disks were compared with outer disks. The DBS storage stability study showed that compared with - 80 °C storage, storing at 4 °C for 1 year had obvious influences on more than half metabolites. Storing at 4 °C and - 20 °C for short term (< 14 days) and - 20 °C for longer term (1 year) had less influences on amino acids, acyl-carnitines and sphingomyelins, but greater influences on partial phospholipids. Method validation showed that this method has a good repeatability, intra-day and inter-day precision and linearity. Finally, this method was applied to investigate metabolic disruptions of congenital hypothyroidism (CH), metabolic changes of CH newborns were mainly involved in amino acid metabolism and lipid metabolism.

The circadian rhythm gene Bmal1 ameliorates acute deoxynivalenol-induced liver damage

Deoxynivalenol (DON) is widely emerging in various grain crops, milk, and wine products, which can trigger different toxic effects on humans and animals by inhalation or ingestion. It also imposes a considerable financial loss on the agriculture and food industry each year. Previous studies have reported acute and chronic toxicity of DON in liver, and liver is not only the main detoxification organ for DON but also the circadian clock oscillator directly or indirectly regulates critical physiologically hepatic functions under different physiological and pathological conditions. However, researches on the association of circadian rhythm in DON-induced liver damage are limited. In the present study, mice were divided into four groups (CON, DON, Bmal1^OE, and Bmal1^OE + DON) and AAV8 was used to activate (Bmal1) expression in liver. Then mice were gavaged with 5 mg/kg bw/day DON or saline at different time points (ZT24 = 0, 4, 8, 12, 16, and 20 h) in 1 day and were sacrificed 30 min after oral gavage. The inflammatory cytokines, signal transducers, and activators of transcription Janus kinase/signal transducers and activator of transcription 3 (JAKs/STAT3) pathway and bile acids levels were detected by enzyme-linked immunosorbent assay (ELISA), western blotting, and target metabolomics, respectively. The DON group showed significantly elevated interleukin-1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α) levels (P < 0.05 for both) and impaired liver function with rhythm disturbances compared to the CON and Bmal1^OE groups. At the molecular level, expressions of some circadian clock proteins were significantly downregulated (P < 0.05 for both) and JAKs/STAT3 pathway was activated during DON exposure, accompanied by indicated circadian rhythm disturbance and inflammatory damage. Importantly, Bmal1 overexpression attenuated DON-induced liver damage, while related hepatic bile acids such as cholic acid (CA) showed a decreasing trend in the DON group compared with the CON group. Our study demonstrates a novel finding that Bmal1 plays a critical role in attenuating liver damage by inhibiting inflammatory levels and maintaining bile acids levels under the DON condition. Therefore, Bmal1 may also be a potential molecular target for reducing the hepatotoxic effects of DON in future studies.

Oxidative Stress as a Therapeutic Target of Cardiac Remodeling

Cardiac remodeling is defined as a group of molecular, cellular, and interstitial changes that clinically manifest as changes in the heart's size, mass, geometry, and function after different stimuli. It is important to emphasize that remodeling plays a pathophysiological role in the onset and progression of ventricular dysfunction and subsequent heart failure. Therefore, strategies to mitigate this process are critical. Different factors, including neurohormonal activation, can regulate the remodeling process and increase cell death, alterations in contractile and regulatory proteins, alterations in energy metabolism, changes in genomics, inflammation, changes in calcium transit, metalloproteases activation, fibrosis, alterations in matricellular proteins, and changes in left ventricular geometry, among other mechanisms. More recently, the role of reactive oxygen species and oxidative stress as modulators of remodeling has been gaining attention. Therefore, this review assesses the role of oxidative stress as a therapeutic target of cardiac remodeling.

Transplantation of adipose-derived mesenchymal stem cells ameliorates acute hepatic injury caused by nonsteroidal anti-inflammatory drug diclofenac sodium in female rats

BACKGROUND

Although the beneficial role of adipose-derived mesenchymal stem cells (AD-MSCs) in acute liver injury has been addressed by numerous studies employing different liver injury inducers, the role of rat AD-MSCs (rAD-MSCs) in diclofenac sodium (DIC) - induced acute liver injury has not yet been clarified.

OBJECTIVE

This study aimed to investigate whether rat adipose- rAD-MSCs injected intraperitoneal could restore the DIC-induced hepatoxicity.

METHODS

Hepatotoxicity was induced by DIC in a dose-based manner, after which intraperitoneal injection of rAD-MSCs was performed.

RESULTS

Here, the transplanted cells migrated to the injured liver, and this was evidenced by detecting the specific SRY in the liver samples. After administering DIC, a significant decrease in body weight, survival rate, serum proteins, antioxidants, anti-apoptotic gene expression, and certain growth factors, whereas hepatic-specific markers, pro-inflammatory mediators, and oxidative, pro-apoptotic, and ER-stress markers were elevated. These adverse effects were significantly recovered after engraftment with rAD-MSCs. This was evidenced by enhanced survival and body weight, improved globulin and albumin values, increased expression of SOD, GPx, BCL-2, VEGF, and FGF-basic expression, and decreased serum ALT, AST, ALP, and total bilirubin. rAD-MSCs also reduced liver cell damage by suppressing the expression of MDA, IL-1B, IL-6, BAX, JNK, GRP78/BiP, CHOP, XBP-1, and cleaved caspase 3/7. Degenerative hepatic changes and multifocal areas of fatty change within liver cells were observed in DIC-received groups. These changes were improved with the transplantation of rAD-MSCs.

CONCLUSIONS

We could conclude that targeted AD-MSCs could be applied to reduce hepatic toxicity caused by NSAIDs (DIC).

Antioxidant and neuroprotective actions of resveratrol in cerebrovascular diseases

Cerebralvascular diseases are the most common high-mortality diseases worldwide. Despite its global prevalence, effective treatments and therapies need to be explored. Given that oxidative stress is an important risk factor involved with cerebral vascular diseases, natural antioxidants and its derivatives can be served as a promising therapeutic strategy. Resveratrol (3, 5, 4′-trihydroxystilbene) is a natural polyphenolic antioxidant found in grape skins, red wine, and berries. As a phytoalexin to protect against oxidative stress, resveratrol has therapeutic value in cerebrovascular diseases mainly by inhibiting excessive reactive oxygen species production, elevating antioxidant enzyme activity, and other antioxidant molecular mechanisms. This review aims to collect novel kinds of literature regarding the protective activities of resveratrol on cerebrovascular diseases, addressing the potential mechanisms underlying the antioxidative activities and mitochondrial protection of resveratrol. We also provide new insights into the chemistry, sources, and bioavailability of resveratrol.

Redox regulation of the immune response

The immune-inflammatory response is associated with increased nitro-oxidative stress. The aim of this mechanistic review is to examine: (a) the role of redox-sensitive transcription factors and enzymes, ROS/RNS production, and the activity of cellular antioxidants in the activation and performance of macrophages, dendritic cells, neutrophils, T-cells, B-cells, and natural killer cells; (b) the involvement of high-density lipoprotein (HDL), apolipoprotein A1 (ApoA1), paraoxonase-1 (PON1), and oxidized phospholipids in regulating the immune response; and (c) the detrimental effects of hypernitrosylation and chronic nitro-oxidative stress on the immune response. The redox changes during immune-inflammatory responses are orchestrated by the actions of nuclear factor-κB, HIF1α, the mechanistic target of rapamycin, the phosphatidylinositol 3-kinase/protein kinase B signaling pathway, mitogen-activated protein kinases, 5' AMP-activated protein kinase, and peroxisome proliferator-activated receptor. The performance and survival of individual immune cells is under redox control and depends on intracellular and extracellular levels of ROS/RNS. They are heavily influenced by cellular antioxidants including the glutathione and thioredoxin systems, nuclear factor erythroid 2-related factor 2, and the HDL/ApoA1/PON1 complex. Chronic nitro-oxidative stress and hypernitrosylation inhibit the activity of those antioxidant systems, the tricarboxylic acid cycle, mitochondrial functions, and the metabolism of immune cells. In conclusion, redox-associated mechanisms modulate metabolic reprogramming of immune cells, macrophage and T helper cell polarization, phagocytosis, production of pro- versus anti-inflammatory cytokines, immune training and tolerance, chemotaxis, pathogen sensing, antiviral and antibacterial effects, Toll-like receptor activity, and endotoxin tolerance.

Bifunctional 2D/2D g-C3N4/BiO2-x nanosheets heterojunction for bacterial disinfection mechanisms under visible and near-infrared light irradiation

The efficient deployment of visible and near-infrared (NIR) light for photocatalytic disinfection is of great concern a matter. Herein, we report a specific bifunctional 2D/2D g-C₃N₄/BiO_2-x nanosheets heterojunction, prepared through a self-assembly approach. Delightfully, the obtained 2D/2D heterojunctions exhibited satisfactory photocatalytic disinfection performance towards Escherichia coli K-12 (E. coli K-12) under visible light irradiation, which was credited to the Z-scheme interfacial heterojunction facilitating the migration of photogenerated carries. The photoactivity enhancement driven by NIR light illumination was ascribed to the cooperative synergy effect of photothermal effect and "hot electrons", engineering efficient charge transfer. Intriguingly, the carboxyl groups emerged on g-C₃N₄ nanosheets contributed a vital role in establishing the enhanced photocatalytic reaction. Moreover, the disinfection mechanism was systematically described. The cell membrane was destroyed, evidenced by the generation of lipid peroxidation reaction and loss of energy metabolism. Subsequently, the damage of defense enzymes and release of intracellular constituents announced the irreversible death of E. coli K-12. Interestingly enough, considerable microbial community shifts of surface water were observed after visible and NIR light exposure, highlighting the critical feature of disinfection process in shaping microbial communities. The authors believe that this work gives a fresh light on the feasibility of heterostructures-enabled disinfection processes.

Isoorientin ameliorates OVA-induced asthma in a murine model of asthma

Allergic asthma which is induced by ovalbumin (OVA) is a chronic airway inflammation disease. Isoorientin (Iso) is a natural C-glucosyl flavone with many biological properties. We aimed to evaluate the effectiveness of Iso on OVA-induced allergic asthma. A total of 30 C57BL/6 mice were randomly divided into five groups: control group, OVA group, Dex (dexamethasone, 10 mg/kg) group, low-dose Iso group (Iso-L, 25 mg/kg), and high-dose Iso group (Iso-H, 50 mg/kg). The serum and bronchoalveolar lavage fluid (BALF) were collected for biochemical parameters, the lung tissue was collected for hematoxylin-eosin (H&E) staining, immunohistochemistry (IHC), and western blot. The levels of IL-4, IL-5, IL-13, malondialdehyde (MDA), NO, and reactive oxygen species (ROS) in Iso-L and Iso-H groups were significantly lower than that in model group (p < 0.05). Simultaneously, the levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity were higher than that in model group (p < 0.05). Iso significantly ameliorated airway hyperresponsiveness. Meanwhile, H&E staining revealed that mice treated with Iso resulted in the ameliorated inflammatory cell infiltration and a reduction in interstitial thickening. The nuclear factor erythroid 2-like 2 (Nrf2) and HO-1 protein expression in Iso-L and Iso-H groups were enhanced over that in model group, while p-NF-κB-p65 and p-IκB-α protein expression was decreased (p < 0.05). Our research indicated that Iso alleviated the OVA-induced allergic asthma, and this effect can be explained by the modulation of Nrf2/HO-1 and NF-κB signaling pathway; thus, the results providing a therapeutic rationale for the treatment of Iso on allergic asthma.

NRF2/PGC-1α-mediated mitochondrial biogenesis contributes to T-2 toxin-induced toxicity in human neuroblastoma SH-SY5Y cells

The T-2 toxin is a highly toxic trichothecene mycotoxin that would cause serious toxicity in humans and animals. Recent studies suggest that the central nervous system (CNS) is susceptible to T-2 toxin, which can easily cross the blood-brain barrier, accumulate in brain tissues, and cause neurotoxicity. The growing evidence indicates that oxidative damage and mitochondrial dysfunction play a critical role in T-2 toxin-induced neurotoxicity, but the mechanisms are still poorly understood. Our present study showed that T-2 toxin decreased cell viability and increased lactate dehydrogenase leakage in human neuroblastoma SH-SY5Y cells in a concentration- and time-dependent manner. T-2 toxin elicited prominent oxidative stress and mitochondrial dysfunction, as evidenced by the promotion of cellular reactive oxygen species generation, disruption of the mitochondrial membrane potential, depletion of glutathione and reduction of the cellular ATP content. T-2 toxin impaired mitochondrial biogenesis, including decreased mitochondrial DNA copy number and affected the nuclear factor erythroid 2 related factor 2 (NRF2) / peroxisome proliferator-activated receptor γ coactivator 1 alpha (PGC-1α) pathway by upregulating NRF2 mRNA and protein expression while inhibiting the expression of PGC-1α, nuclear respiratory factor (NRF1) and mitochondrial transcription factor A (TFAM). NRF2 knockdown was found to significantly exacerbate T-2 toxin-induced cytotoxicity, oxidative stress, and mitochondrial dysfunction, as well as aggravate mitochondrial biogenesis impairment. NRF2 knockdown compromised T-2 toxin-induced upregulation of NRF2, but augmented the inhibition of PGC-1α, NRF1, and TFAM by T-2 toxin. Taken together, these findings suggest that T-2 toxin-induced oxidative stress and mitochondrial dysfunction in SH-SY5Y cells, at least in part by, NRF2/PGC-1α pathway-mediated mitochondrial biogenesis.

Emerging Promise of Phytochemicals in Ameliorating Neurological Disorders

BACKGROUND

The field of medicine and synthetic drug development have advanced rapidly over the past few decades. However, research on alternative medicine such as phytochemicals cannot be ignored. The main reason for prominent curiosity about phytochemicals stems from the belief that usage of natural compounds is safer and has lesser detrimental side effects.

OBJECTIVE

The aim of the present review was to discuss in detail with several phytochemicals that have been studied or are being studied in the context of various neurological disorders including depression, Alzheimer's disease, Huntington's disease and even neuroinflammatory disorders such as encephalitis.

METHODS

The potential role of phytochemicals in the treatment or management of symptoms associated with neurological disorders have been included in this article. All data included in this paper has been pooled from various databases including Google Scholar, PubMed, Science Direct, Springer and Wiley Online Library.

RESULTS

Phytochemicals have been widely studied for their therapeutic properties associated with neurological disorders. Using various experimental techniques for both in vivo and in vitro experiments, studies have shown that phytochemicals do have antioxidant, anti-inflammatory and neuroprotective activities which play major roles in the treatment of neurological diseases.

CONCLUSION

Even though there has been compelling evidence of the therapeutic role of phytochemicals, further research is still required to evaluate the safety and efficacy of these medicines. Using previously published papers as foundation for additional research such as preclinical studies and clinical trials, phytochemicals can become a safer alternative to synthetic drugs for treating a spectrum of neurological diseases.

Suppression of glutathione system and upregulation of caspase 3-dependent apoptosis mediate rohypnol-induced gastric injury

Objectives: This study investigated the impact of rohypnol on gastric tissue integrity.

Methods: Forty male Wistar rats were randomized into control, low dose rohypnol-treated, high dose rohypnol-treated, low dose rohypnol-treated recovery and high dose rohypnol-treated recovery groups.

Results: Rohypnol caused significant rise in gastric malondialdehyde (MDA), oxidized glutathione (GSSG), nitric oxide (NO), tumour necrotic factor-α (TNF-α), and interleukin-6 (IL-6) levels. Also, rohypnol caused reductions in gastric reduced glutathione (GSH) (as well as GSH/GSSG), and activities of superoxide dismutase (SOD), catalase, glutathione-S-transferase (GST), glutathione peroxidase (GPx), cyclo-oxygenase (COX-2). Furthermore, rohypnol upregulated caspase 3 activity and induced gastric DNA damage, evident by a rise in 8-hydroxydeoxyguanosine (8-OHdG) and DNA fragmentation index (DFI) in gastric tissue. These alterations were coupled with reduced gastric weight and distorted gastric cytoarchitecture. Cessation of rohypnol caused a significant but not complete reversal of rohypnol-induced gastric damage.

Conclusion: This study revealed that rohypnol induced gastric injury by suppressing glutathione content and COX-2 activity, and upregulating caspase 3-dependent apoptosis, which was partly reversed by rohypnol withdrawal.

Oxidative stress and antioxidant defenses in mild cognitive impairment: A systematic review and meta-analysis

This study aims to systematically review and meta-analyze the nitro-oxidative stress (O&NS)/antioxidant (ANTIOX) ratio in the peripheral blood of people with mild cognitive impairment (MCI). We searched PubMed, Scopus, Google Scholar, and Web of Science for articles published from inception until July 31, 2021. Forty-six studies on 3.798 MCI individuals and 6.063 healthy controls were included. The O&NS/ANTIOX ratio was significantly higher in MCI than in controls with a Standardized Mean Difference (SMD)= 0.378 (95% CI: 0.250; 0.506). MCI individuals showed increased lipid peroxidation (SMD=0.774, 95%CI: 4.416; 1.132) and O&NS-associated toxicity (SMD=0.621, CI: 0.377; 0.865) and reduced glutathione (GSH) defenses (SMD=0.725, 95%CI: 0.269; 1.182) as compared with controls. MCI was also accompanied by significantly increased homocysteine (SMD=0.320, CI: 0.059; 0.581), but not protein oxidation, and lowered non-vitamin (SMD=0.347, CI: 0.168; 0.527) and vitamin (SMD=0.564, CI: 0.129; 0.999) antioxidant defenses. The results show that MCI is at least in part due to increased neuro-oxidative toxicity and suggest that treatments targeting lipid peroxidation and the GSH system may be used to treat or prevent MCI.

Zhi-Zi-Chi Decoction Reverses Depressive Behaviors in CUMS Rats by Reducing Oxidative Stress Injury Via Regulating GSH/GSSG Pathway

Depression is one of the main diseases that lead to disability and loss of ability to work. As a traditional Chinese medicine, Zhi-zi-chi decoction is utilized to regulate and improve depression. However, the research on the antidepressant mechanism and efficacy material basis of Zhi-zi-chi decoction has not been reported yet. Our previous research has found that Zhi-Zi-chi decoction can reduce glutamate-induced oxidative stress damage to PC 12 cells, which can exert a neuroprotective effect, and the antidepressant effect of Zhi-Zi-chi decoction was verified in CUMS rat models. In this study, the animal model of depression was established by chronic unpredictable mild stimulation combined with feeding alone. The brain metabolic profile of depressed rats was analyzed by the method of metabolomics based on ultra-performance liquid chromatography-quadrupole/time-of-flight mass. 26 differential metabolites and six metabolic pathways related to the antidepressant of Zhi-zi-chi decoction were screened and analyzed. The targeted metabolism of the glutathione metabolic pathway was analyzed. At the same time, the levels of reactive oxygen species, superoxide dismutase, glutathione reductase, glutathione peroxidase in the brain of depressed rats were measured. Combined with our previous study, the antioxidant effect of the glutathione pathway in the antidepressant effect of Zhi-zi-chi decoction was verified from the cellular and animal levels respectively. These results indicated that Zhi-zi-chi decoction exerted a potential antidepressive effect associated with reversing the imbalance of glutathione and oxidative stress in the brain of depressed rats.

Glutathione protects against the meiotic defects of ovine oocytes induced by arsenic exposure via the inhibition of mitochondrial dysfunctions

Accumulating evidences revealed the connections between arsenic exposure and mitochondrial dysfunctions induced reproductive toxicology. Meanwhile, production declines were found in livestock suffering from arsenic exposure. However, the connections between arsenic exposure and livestock meiotic defects remain unclear. In this study, the effects of sodium arsenite (NaAsO2) exposure during the in vitro maturation (IVM) on the meiotic potentials of ovine oocytes were analyzed. Furthermore, the effects of glutathione (GSH) supplementation on the meiotic defects of NaAsO2 exposed ovine oocytes were investigated by the assay of nuclear maturation, spindle organization, chromosome alignment, cytoskeleton assembly, cortical granule (CGs) dynamics, mitochondrial dysfunctions, reactive oxygen species (ROS) accumulation, oxidative DNA damages, cellular apoptosis, epigenetic modifications and fertilization capacities. The results showed that the meiotic defects of NaAsO2 exposed ovine oocytes were effectively ameliorated by the GSH supplementation via the inhibition of mitochondrial dysfunctions, which not only promoted the nuclear maturation, spindle organization, chromosome alignment, cytoskeleton assembly, CGs dynamic and fertilization capacities, but also inhibited the ROS accumulation, oxidative DNA damages and apoptosis of ovine MII oocytes. The abnormal expressions of 5mC, H3K4me3 and H3K9me3 in NaAsO2 exposed ovine oocytes, indicating the abnormal epimutations of DNA methylation and histone methylation, were also effectively ameliorated by the GSH supplementation. Taken together, this study confirmed the connections between arsenic exposure and meiotic defects of ovine oocytes. Meanwhile, the effects of GSH supplementation on the developmental competence of livestock oocytes, especially for these suffering from arsenic exposure were also founded, benefiting the extended researches for the GSH applications.

Glutathione in Brain Disorders and Aging

Glutathione is a remarkably functional molecule with diverse features, which include being an antioxidant, a regulator of DNA synthesis and repair, a protector of thiol groups in proteins, a stabilizer of cell membranes, and a detoxifier of xenobiotics. Glutathione exists in two states—oxidized and reduced. Under normal physiological conditions of cellular homeostasis, glutathione remains primarily in its reduced form. However, many metabolic pathways involve oxidization of glutathione, resulting in an imbalance in cellular homeostasis. Impairment of glutathione function in the brain is linked to loss of neurons during the aging process or as the result of neurological diseases such as Huntington’s disease, Parkinson’s disease, stroke, and Alzheimer’s disease. The exact mechanisms through which glutathione regulates brain metabolism are not well understood. In this review, we will highlight the common signaling cascades that regulate glutathione in neurons and glia, its functions as a neuronal regulator in homeostasis and metabolism, and finally a mechanistic recapitulation of glutathione signaling. Together, these will put glutathione’s role in normal aging and neurological disorders development into perspective.

Neurochemical abnormalities in chronic fatigue syndrome: a pilot magnetic resonance spectroscopy study at 7 Tesla

RATIONALE

Chronic fatigue syndrome (CFS) is a common and burdensome illness with a poorly understood pathophysiology, though many of the characteristic symptoms are likely to be of brain origin. The use of high-field proton magnetic resonance spectroscopy (MRS) enables the detection of a range of brain neurochemicals relevant to aetiological processes that have been linked to CFS, for example, oxidative stress and mitochondrial dysfunction.

METHODS

We studied 22 CFS patients and 13 healthy controls who underwent MRS scanning at 7 T with a voxel placed in the anterior cingulate cortex. Neurometabolite concentrations were calculated using the unsuppressed water signal as a reference.

RESULTS

Compared to controls, CFS patients had lowered levels of glutathione, total creatine and myo-inositol in anterior cingulate cortex. However, when using N-acetylaspartate as a reference metabolite, only myo-inositol levels continued to be significantly lower in CFS participants.

CONCLUSIONS

The changes in glutathione and creatine are consistent with the presence of oxidative and energetic stress in CFS patients and are potentially remediable by nutritional intervention. A reduction in myo-inositol would be consistent with glial dysfunction. However, the relationship of the neurochemical abnormalities to the causation of CFS remains to be established, and the current findings require prospective replication in a larger sample.

N-Acetylcysteine Mitigates Social Dysfunction in a Rat Model of Autism Normalizing Glutathione Imbalance and the Altered Expression of Genes Related to Synaptic Function in Specific Brain Areas

Prenatal exposure to valproic acid (VPA) is a risk factor for autism spectrum disorder (ASD) in humans and it induces autistic-like behaviors in rodents. Imbalances between GABAergic and glutamatergic neurotransmission and increased oxidative stress together with altered glutathione (GSH) metabolism have been hypothesized to play a role in both VPA-induced embriotoxicity and in human ASD. N-acetylcysteine (NAC) is an antioxidant precursor of glutathione and a modulator of glutamatergic neurotransmission that has been tested in ASD, although the clinical studies currently available provided controversial results. Here, we explored the effects of repeated NAC (150 mg/kg) administration on core autistic-like features and altered brain GSH metabolism in the VPA (500 mg/kg) rat model of ASD. Furthermore, we measured the mRNA expression of genes encoding for scaffolding and transcription regulation proteins, as well as the subunits of NMDA and AMPA receptors and metabotropic glutamate receptors mGLUR1 and mGLUR5 in brain areas that are relevant to ASD. NAC administration ameliorated the social deficit displayed by VPA-exposed rats in the three-chamber test, but not their stereotypic behavior in the hole board test. Furthermore, NAC normalized the altered GSH levels displayed by these animals in the hippocampus and nucleus accumbens, and it partially rescued the altered expression of post-synaptic terminal network genes found in VPA-exposed rats, such as NR2a, MGLUR5, GLUR1, and GLUR2 in nucleus accumbens, and CAMK2, NR1, and GLUR2 in cerebellum. These data indicate that NAC treatment selectively mitigates the social dysfunction displayed by VPA-exposed rats normalizing GSH imbalance and reestablishing the expression of genes related to synaptic function in a brain region-specific manner. Taken together, these data contribute to clarify the behavioral impact of NAC in ASD and the molecular mechanisms that underlie its effects.

Development, validation, and application of the ribosome separation and reconstitution system for protein translation in vitro

Stress-induced molecular damage to ribosomes can impact protein synthesis in cells, but cell-based assays do not provide a clear way to distinguish the effects of ribosome damage from stress responses and damage to other parts of the translation machinery. Here we describe a detailed protocol for the separation of yeast ribosomes from other translational machinery constituents, followed by reconstitution of the translation mixture in vitro. This technique, which we refer to as ribosome separation and reconstitution (RSR), allows chemical modifications of yeast ribosomes without compromising other key translational components. In addition to the characterization of stress-induced ribosome damage, RSR can be applied to a broad range of experimental problems in studies of yeast translation.

Glutathione Infusion Before and 3 Days After Primary Angioplasty Blunts Ongoing NOX2-Mediated Inflammatory Response

Background

Glutathione is a water‐soluble tripeptide with a potent oxidant scavenging activity. We hypothesized that glutathione administration immediately before and after primary angioplasty (primary percutaneous coronary intervention) could be effective in modulating immune cell activation, thereby preventing infarct expansion.

Methods and Results

One hundred consecutive patients with ST‐segment–elevation myocardial infarction, scheduled to undergo primary percutaneous coronary intervention were randomly assigned before the intervention to receive an infusion of glutathione (2500 mg/25 mL over 10 minutes), followed by drug administration at the same doses at 24, 48, and 72 hours elapsing time or placebo. Total leukocytes, NOX2 (nicotinamide adenine dinucleotide phosphate oxidase 2) activation, NO bioavailability, cTpT (serum cardiac troponin T), hsCRP (high‐sensitivity C‐reactive protein), and TNF‐α (tumor necrosis factor α) levels were measured. Left ventricular size and function were assessed within 120 minutes, 5 days, and 6 months from percutaneous coronary intervention. Following reperfusion, a significant reduction of neutrophil to lymphocyte ratio (P<0.0001), hsCRP generation (P<0.0001), NOX2 activation (P<0.0001), TNF‐α levels (P<0.001), and cTpT release (P<0.0001) were found in the glutathione group compared with placebo. In treated patients, blunted inflammatory response was linked to better left ventricular size and function at follow‐up (r=0.78, P<0.005).

Conclusions

Early and prolonged glutathione infusion seems able to protect vital myocardial components and endothelial cell function against harmful pro‐oxidant and inflammatory environments, thus preventing maladaptive cardiac repair and left ventricular adverse remodeling.

Registration

URL: https://www.clinicaltrialsregister.eu; Unique identifier: 2014‐004486‐25.