Severe Glutathione Deficiency, Oxidative Stress and Oxidant Damage in Adults Hospitalized with COVID-19: Implications for GlyNAC (Glycine and N-Acetylcysteine) Supplementation

Humanity is battling a respiratory pandemic pneumonia named COVID-19 which has resulted in millions of hospitalizations and deaths. COVID-19 exacerbations occur in waves that continually challenge healthcare systems globally. Therefore, there is an urgent need to understand all mechanisms by which COVID-19 results in health deterioration to facilitate the development of protective strategies. Oxidative stress (OxS) is a harmful condition caused by excess reactive-oxygen species (ROS) and is normally neutralized by antioxidants among which Glutathione (GSH) is the most abundant. GSH deficiency results in amplified OxS due to compromised antioxidant defenses. Because little is known about GSH or OxS in COVID-19 infection, we measured GSH, TBARS (a marker of OxS) and F2-isoprostane (marker of oxidant damage) concentrations in 60 adult patients hospitalized with COVID-19. Compared to uninfected controls, COVID-19 patients of all age groups had severe GSH deficiency, increased OxS and elevated oxidant damage which worsened with advancing age. These defects were also present in younger age groups, where they do not normally occur. Because GlyNAC (combination of glycine and N-acetylcysteine) supplementation has been shown in clinical trials to rapidly improve GSH deficiency, OxS and oxidant damage, GlyNAC supplementation has implications for combating these defects in COVID-19 infected patients and warrants urgent investigation.

Stability of the Glutathione Supplementation into Parenteral Nutrition to Protect Very Preterm Babies from Oxidative Stress

Most very premature newborns (< 32 weeks of gestation) receive parenteral nutrition (PN) that is inherently contaminated with peroxides. Oxidative stress induced by PN is associated with bronchopulmonary dysplasia, a main pathological complication in these babies who have weak antioxidant capacity to detoxify peroxides because of their glutathione deficiency. In animals, glutathione supplementation of PN prevented oxidative stress and alveolar loss (the main characteristic of bronchopulmonary dysplasia). Of its two forms - disulfide (GSSG) and free thiol (GSH) - GSSG was used because of its better stability in PN. However, a 30% loss of GSSG in PN is observed. The potentially high therapeutic benefits of GSSG supplementation on the health of very premature babies makes the study of its stability highly important. Thus, GSSG was incubated in combination with the following components of PN: dextrose, multivitamins, Primene, Travasol, as well as with cysteine, cystine and peroxides for 24h. Total glutathione in these solutions was measured 0-24h after the addition of GSSG. The combination of cysteine and multivitamins caused the maximum loss of glutathione. Removing the cysteine prevented the degradation of glutathione. GSSG reacts with cysteine to form cysteine-glutathione disulfide, another suitable glutathione substrate for preterm neonates.

Oxidative Stress-Related Mechanisms in Schizophrenia Pathogenesis and New Treatment Perspectives

Schizophrenia is recognized to be a highly heterogeneous disease at various levels, from genetics to clinical manifestations and treatment sensitivity. This heterogeneity is also reflected in the variety of oxidative stress-related mechanisms contributing to the phenotypic realization and manifestation of schizophrenia. At the molecular level, these mechanisms are supposed to include genetic causes that increase the susceptibility of individuals to oxidative stress and lead to gene expression dysregulation caused by abnormal regulation of redox-sensitive transcriptional factors, noncoding RNAs, and epigenetic mechanisms favored by environmental insults. These changes form the basis of the prooxidant state and lead to altered redox signaling related to glutathione deficiency and impaired expression and function of redox-sensitive transcriptional factors (Nrf2, NF-κB, FoxO, etc.). At the cellular level, these changes lead to mitochondrial dysfunction and metabolic abnormalities that contribute to aberrant neuronal development, abnormal myelination, neurotransmitter anomalies, and dysfunction of parvalbumin-positive interneurons. Immune dysfunction also contributes to redox imbalance. At the whole-organism level, all these mechanisms ultimately contribute to the manifestation and development of schizophrenia. In this review, we consider oxidative stress-related mechanisms and new treatment perspectives associated with the correction of redox imbalance in schizophrenia. We suggest that not only antioxidants but also redox-regulated transcription factor-targeting drugs (including Nrf2 and FoxO activators or NF-κB inhibitors) have great promise in schizophrenia. But it is necessary to develop the stratification criteria of schizophrenia patients based on oxidative stress-related markers for the administration of redox-correcting treatment.

Reversing Cognitive Decline in Aging: Reversible Mechanistic Defects and a Novel Nutritional Intervention

Aging is the biggest risk factor for cognitive-decline and Alzheimer’s disease (AD), but underlying mechanisms are not well-understood and interventions are lacking. Cognitive-decline in AD has been associated with deficiency of glutathione, (the most abundant, intracellular, antioxidant protein), elevated oxidative-stress, insulin-resistance and increased inflammation. We identified and reported that glutathione-deficiency and oxidative-stress in older-adults occur due to decreased availability of precursor amino-acids glycine and cysteine, and can be corrected with GlyNAC (a combination of glycine and the cysteine precursor N-acetylcysteine). We hypothesized that cognitive decline in older-adults is linked to glutathione-deficiency, mitochondrial-dysfunction, oxidative-stress, insulin-resistance, and inflammation. The first abstract discusses the rationale and findings of an open-label clinical trial: compared to young-humans, older-adults had cognitive-decline, glutathione-deficiency, mitochondrial-dysfunction, abnormal glucose-metabolism and insulin-resistance, oxidative-stress, endothelial-dysfunction and inflammation. These defects were improved/reversed by supplementing GlyNAC for 24-weeks, but benefits receded on stopping GlyNAC for 12-weeks. The second abstract presents a study in 8 young (20-weeks old) and 16 aged (90-weeks old) wild-type male C57BL/6J mice where we found that aged-mice had naturally-occurring cognitive-impairment, and brain defects in glutathione-deficiency, oxidative-stress, glucose-transport, mitochondrial glucose-oxidation, insulin-resistance, endoplasmic-reticulum stress, autophagy, mitophagy, inflammation, senescence, genomic and telomere damage. Aged-mice received either GlyNAC or isonitrogenous-placebo supplementation for 8-weeks, and only GlyNAC-fed mice improved cognition and brain defects. Collectively these data highlights the discovery of novel and reversible mechanistic defects in older-adults and aged-mice with naturally-occurring cognitive-decline, and identifies that supplementing GlyNAC can improve brain-health and cognition. These findings could have important implications for reversing cognitive-decline in older-adults, and AD.

Actions of L-Glutamine vs. COVID-19 Suggest Additional Benefit in Sickle Cell Disease

Background:The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection associated with coronavirus disease 2019 (COVID-19) causes a 3- to 9-fold higher age-adjusted mortality in African American and Hispanic populations, the major US racial groups affected by sickle cell disease (SCD). The Centers for Disease Control designates SCD as a condition at increased risk for severe COVID-19. An urgent need for repurposing of available and safe therapeutics has been cited for such high-risk populations until vaccines are widely available. L-glutamine (GLN) ameliorates clinical pathology of SCD related to elements of COVID-19. Multiple systemic complications of COVID-19 are increasingly attributed to oxidative damage, a target which GLN regulates. Prescription-grade L-glutamine (PGLG) (Endari®, Emmaus Medical) decreases oxidative stress by increasing the ratio of reduced nicotinamide adenine dinucleotide (NAD) to total NAD, which may increase availability of reduced glutathione. PGLG also decreases red cell endothelial adhesion in patients with SCD. Of note, additional analysis of the phase 3 trial demonstrated a 63% lower occurrence of acute chest syndrome (ACS) in PGLG-treated SCD patients compared to control, which has important relevance in the pandemic. A recent report of two computational screens of FDA-approved therapeutics, directed to protein and chemistry targets and to gene expression changes induced by SARS-CoV-2, predicts glutathione and GLN are highly likely to confer benefit in COVID-19 (Kim, J Translat Med, 2020). Methods:We therefore reviewed reports of multi-system effects of GLN in experimental respiratory distress animal models and in ICU and COVID-19 patients. We focused on contributors to cytokine storm and acute respiratory distress syndrome (ARDS), the leading causes of mortality in COVID-19 (Huang, Lancet, 2020). We also conducted a clinical trial in hospitalized COVID-19 patients on ESPEN-recommended nutrition +/- GLN. Results:In experimental ARDS, sepsis, and endotoxin-induced lung injury, GLN decreases consolidation, pulmonary edema, and neutrophil infiltration and increases lung compliance, oxygen saturation, heat shock protein activation, and survival by 2.5-fold over saline controls (Perng WC, Clin Exp Pharmacol Physiol, 2010; Singleton, Crit Care Med, 2005). Patients with severe COVID-19 have increased proinflammatory cytokines; interleukin 6 (IL-6) levels predict and contribute to severity of COVID-19 (Yuki, Clin Immunol, 2020). GLN modulates inflammatory responses by suppressing C-reactive protein, IL-6, and TNF-α release; it also reduces IL-6 in murine studies (37% decrease,p< 0.05; Chuang, BMC Pulm Med, 2014), which could benefit COVID-19 patients. Myocardial injury occurs in up to 12% of COVID-19 patients directly with viral entry through ACE-2 receptors, microvascular damage, endothelial shedding, and inflammation-mediated damage, which GLN protects against (Shi, Eur Heart J, 2020; Shi, JAMA Cardiol, 2020; Shao, Pak J Med Sci, 2015). Inflammatory states lead to GLN consumption and negative GLN balance (Santos, Amino Acids, 2019). Deficient plasma GLN (< 420 µmol/L) is a defined risk for higher mortality in ICU and COVID-19 patients (Shen, Cell, 2020). Glutathione deficiency contributes to SARS-CoV-2 oxidative lung damage and severe disease (Polonikov, ACS Infect Dis, 2020). In a recent clinical trial, patients were confirmed to have SARS-CoV-2 by RT-PCR, had positive CT scans, and were admitted from a COVID-19 clinic. Both arms received ESPEN-recommended nutrition for COVID-19 alone or with GLN (10 grams, 3 times/day; see Table). Conclusions:GLN and glutathione deficiency contribute to COVID-19 severity, and GLN has salutary biologic actions on reducing lung pathology, mediators of cytokine storm, and myocardial injury in animal models, SCD, and ICU patients. GLN reduces severity in standard risk COVID-19 patientsafterinfection has occurred. These findings, combined with computational prediction of GLN benefit vs. COVID-19, support the hypothesis that PGLG treatmentprior toSARS-CoV-2 infection mayreducethe development of severe COVID-19 in SCD and perhaps other high-risk populations. The data as a whole provides a strong rationale for a controlled clinical trial of PGLG toreducesevere COVID-19 in high-risk SCD patients and improve outcomes if infection occurs. Disclosures Cengiz: Biruni University Medical Faculty:Current Employment;Istanbul University-Cerrahpasa Medical Faculty:Ended employment in the past 24 months.Yavuzer:Istanbul University-Cerrahpasa, Cerrahpasa School of Medicine, Department of Internal Medicine, Division of Geriatrics:Current Employment.Yavuzer:Biruni University Medical Faculty:Current Employment;Istanbul University-Cerrahpasa Mediacl Faculty:Ended employment in the past 24 months.Tang:Kaiser Permanente:Current Employment.Ward:Emmaus Medical, Inc.:Current Employment.Goodrow:Emmaus Medical, Inc.:Current Employment;Emmaus Life Sciences Shareholder:Current equity holder in publicly-traded company.Ludlum:Emmaus Life Sciences, Inc.:Consultancy, Current equity holder in publicly-traded company.Stark:Emmaus Life Sciences Shareholder:Current equity holder in publicly-traded company;Emmaus Medical, Inc:Current Employment.Perrine:Cetya Inc.:Membership on an entity's Board of Directors or advisory committees;Phoenicia Bioscience:Current Employment, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees;Phoenicia Therapeutics:Membership on an entity's Board of Directors or advisory committees, Patents & Royalties;Boston University School of Medicine:Current Employment, Patents & Royalties;Viracta Therapeutics:Patents & Royalties.

A glutathione-dependent control of the indole butyric acid pathway supports Arabidopsis root system adaptation to phosphate deprivation

Root system architecture results from a highly plastic developmental process to adapt to environmental conditions. In particular, the development of lateral roots and root hair growth are constantly optimized to the rhizosphere properties, including biotic and abiotic constraints. The development of the root system is tightly controlled by auxin, the driving morphogenic hormone in plants. Glutathione, a major thiol redox regulator, is also critical for root development but its interplay with auxin is scarcely understood. Previous work showed that glutathione deficiency does not alter root responses to indole acetic acid (IAA), the main active auxin in plants. Because indole butyric acid (IBA), another endogenous auxinic compound, is an important source of IAA for the control of root development, we investigated the crosstalk between glutathione and IBA during root development. We show that glutathione deficiency alters lateral roots and root hair responses to exogenous IBA but not IAA. Detailed genetic analyses suggest that glutathione regulates IBA homeostasis or conversion to IAA in the root cap. Finally, we show that both glutathione and IBA are required to trigger the root hair response to phosphate deprivation, suggesting an important role for this glutathione-dependent regulation of the auxin pathway in plant developmental adaptation to its environment.

The Therapeutic Potential of Glutathione Supplement: A Review of Clinical Trials

Glutathione (GSH) is a tripeptide (γ-glutamyl cysteinyl glycine) involved in a variety of biological processes indispensable to sustain life and the most abundant free radical scavenger synthesized endogenously in humans. There are adverse health consequences from glutathione deficiency. The present mini –review aims to provide an extensive overview to glutathione supplement therapeutic effects in human subjects.