Desipramine induces eryptosis in human erythrocytes, an effect blunted by nitric oxide donor sodium nitroprusside and N-acetyl-L-cysteine but enhanced by Calcium depletion.

Desipramine a representative of tricyclic antidepressants (TCAs) promotes recovery of depressed patients by inhibition of reuptake of neurotransmitters serotonin (SER) and norepinephrine (NE) in the presynaptic membrane by directly blocking their respective transporters SERT and NET. To study the effect of desipramine on programmed erythrocyte death (eryptosis) and explore the underlying mechanisms. Phosphatidylserine (PS) exposure on the cell surface as marker of cell death was estimated from annexin-V-binding, cell volume from forward scatter in flow cytometry.

How to Increase Cellular Glutathione.

Glutathione (GSH) has special antioxidant properties due to its high intracellular concentration, ubiquity, and high reactivity towards electrophiles of the sulfhydryl group of its cysteine moiety. In most diseases where oxidative stress is thought to play a pathogenic role, GSH concentration is significantly reduced, making cells more susceptible to oxidative damage. Therefore, there is a growing interest in determining the best method(s) to increase cellular glutathione for both disease prevention and treatment.

Effects of Physiological and Pathological Urea Concentrations on Human Microvascular Endothelial Cells.

Urea is the uremic toxin accumulating with the highest concentration in the plasma of chronic kidney disease (CKD) patients, not being completely cleared by dialysis. Urea accumulation is reported to exert direct and indirect side effects on the gastrointestinal tract, kidneys, adipocytes, and cardiovascular system (CVS), although its pathogenicity is still questioned since studies evaluating its side effects lack homogeneity. Here, we investigated the effects of physiological and pathological urea concentrations on a human endothelial cell line from the microcirculation (Human Microvascular Endothelial Cells-1, HMEC-1).

Effects of Nitisinone on Oxidative and Inflammatory Markers in Alkaptonuria: Results from SONIA1 and SONIA2 Studies.

Nitisinone (NTBC) was recently approved to treat alkaptonuria (AKU), but there is no information on its impact on oxidative stress and inflammation, which are observed in AKU. Therefore, serum samples collected during the clinical studies SONIA1 (40 AKU patients) and SONIA2 (138 AKU patients) were tested for Serum Amyloid A (SAA), CRP and IL-8 by ELISA; Advanced Oxidation Protein Products (AOPP) by spectrophotometry; and protein carbonyls by Western blot. Our results show that NTBC had no significant effects on the tested markers except for a slight but statistically significant effect for NTBC, but not for the combination of time and NTBC, on SAA levels in SONIA2 patients.

How Aging and Oxidative Stress Influence the Cytopathic and Inflammatory Effects of SARS-CoV-2 Infection: The Role of Cellular Glutathione and Cysteine Metabolism.

SARS-CoV-2 infection can cause a severe respiratory distress syndrome with inflammatory and thrombotic complications, the severity of which increases with patients' age and presence of comorbidity. The reasons for an age-dependent increase in the risk of severe COVID-19 could be many. These include defects in the homeostatic processes that control the cellular redox and its pivotal role in sustaining the immuno-inflammatory response to the host and the protection against oxidative stress and tissue degeneration.

Effects of the uremic toxin indoxyl sulphate on human microvascular endothelial cells.

Indoxyl sulphate (IS) is a uremic toxin accumulating in the plasma of chronic kidney disease (CKD) patients. IS accumulation induces side effects in the kidneys, bones and cardiovascular system. Most studies assessed IS effects on cell lines by testing higher concentrations than those measured in CKD patients.

Melatonin modulates Nrf2 activity to protect porcine pre-pubertal Sertoli cells from the abnormal H O generation and reductive stress effects of cadmium.

Melatonin (MLT) is a cytoprotective agent holding potential to prevent cadmium (Cd) toxicity and its impact in testicular function and fertility. In this study, we explored such potential in porcine pre-pubertal Sertoli cells (SCs). Cd toxicity resulted in impaired SC viability and function, abnormal cellular H O generation and efflux, and induction of reductive stress by the upregulation of Nrf2 expression and activity, cystine uptake and glutathione biosynthesis, glutathione-S-transferase P (GSTP) expression, and protein glutathionylation inhibition.

Blood Thiol Redox State in Chronic Kidney Disease.

Thiols (sulfhydryl groups) are effective antioxidants that can preserve the correct structure of proteins, and can protect cells and tissues from damage induced by oxidative stress. Abnormal levels of thiols have been measured in the blood of patients with moderate-to-severe chronic kidney disease (CKD) compared to healthy subjects, as well as in end-stage renal disease (ESRD) patients on haemodialysis or peritoneal dialysis. The levels of protein thiols (a measure of the endogenous antioxidant capacity inversely related to protein oxidation) and -thiolated proteins (mixed disulphides of protein thiols and low molecular mass thiols), and the protein thiolation index (the molar ratio of the -thiolated proteins to free protein thiols in plasma) have been investigated in the plasma or red blood cells of CKD and ESRD patients as possible biomarkers of oxidative stress.

Homogentisic acid induces autophagy alterations leading to chondroptosis in human chondrocytes: Implications in Alkaptonuria.

Alkaptonuria (AKU) is an ultra-rare genetic disease caused by a deficient activity of the enzyme homogentisate 1,2-dioxygenase (HGD) leading to the accumulation of homogentisic acid (HGA) on connective tissues. Even though AKU is a multi-systemic disease, osteoarticular cartilage is the most affected system and the most damaged tissue by the disease. In chondrocytes, HGA causes oxidative stress dysfunctions, which induce a series of not fully characterized cellular responses.

SARS-CoV2 infection impairs the metabolism and redox function of cellular glutathione.

Viral infections sustain their replication cycle promoting a pro-oxidant environment in the host cell. In this context, specific alterations of the levels and homeostatic function of the tripeptide glutathione have been reported to play a causal role in the pro-oxidant and cytopathic effects (CPE) of the virus. In this study, these aspects were investigated for the first time in SARS-CoV2-infected Vero E6 cells, a reliable and well-characterized in vitro model of this infection.

Measurement of S-glutathionylated proteins by HPLC.

S-glutathionylated proteins (GSSP), i.e., protein-mixed disulfides with glutathione (GSH), are considered a suitable biomarker of oxidative stress.

The effects of 3 weeks of oral glutathione supplementation on whole body insulin sensitivity in obese males with and without type 2 diabetes: a randomized trial.

The effect of oral glutathione (GSH) supplementation was studied in obese subjects with and without type 2 diabetes (T2DM) on measures of glucose homeostasis and markers of oxidative stress. Twenty subjects (10 patients with T2DM and 10 obese subjects) were recruited for the study, and randomized in a double-blinded placebo-controlled manner to consume either 1000 mg GSH per day or placebo for 3 weeks. Before and after the 3 weeks insulin sensitivity was measured with the hyperinsulinemic-euglycemic clamp and a muscle biopsy was obtained to measure GSH and skeletal muscle mitochondrial hydrogen peroxide (HO) emission rate.

The age-dependent decline of the extracellular thiol-disulfide balance and its role in SARS-CoV-2 infection.

SARS-CoV-2 (COVID-19) infection can cause a severe respiratory distress syndrome. The risk of severe manifestations and mortality characteristically increase in the elderly and in the presence of non-COVID-19 comorbidity. We and others previously demonstrated that the low molecular weight (LMW) and protein thiol/disulfide ratio declines in human plasma with age and such decline is even more rapid in the case of inflammatory and premature aging diseases, which are also associated with the most severe complications of COVID-19 infection.

Superior Properties of N-Acetylcysteine Ethyl Ester over N-Acetyl Cysteine to Prevent Retinal Pigment Epithelial Cells Oxidative Damage.

Oxidative stress plays a key role in the pathophysiology of retinal diseases, including age-related macular degeneration (AMD) and diabetic retinopathy, which are the major causes of irreversible blindness in developed countries. An excess of reactive oxygen species (ROS) can directly cause functional and morphological impairments in retinal pigment epithelium (RPE), endothelial cells, and retinal ganglion cells. Antioxidants may represent a preventive/therapeutic strategy and reduce the risk of progression of AMD.

Plasma Protein Carbonyls as Biomarkers of Oxidative Stress in Chronic Kidney Disease, Dialysis, and Transplantation.

Accumulating evidence indicates that oxidative stress plays a role in the pathophysiology of chronic kidney disease (CKD) and its progression; during renal replacement therapy, oxidative stress-derived oxidative damage also contributes to the development of CKD systemic complications, such as cardiovascular disease, hypertension, atherosclerosis, inflammation, anaemia, and impaired host defence. The main mechanism underlying these events is the retention of uremic toxins, which act as a substrate for oxidative processes and elicit the activation of inflammatory pathways targeting endothelial and immune cells. Due to the growing worldwide spread of CKD, there is an overwhelming need to find oxidative damage biomarkers that are easy to measure in biological fluids of subjects with CKD and patients undergoing renal replacement therapy (haemodialysis, peritoneal dialysis, and kidney transplantation), in order to overcome limitations of invasive monitoring of CKD progression.

Anethole Dithiolethione Increases Glutathione in Kidney by Inhibiting -Glutamyltranspeptidase: Biochemical Interpretation and Pharmacological Consequences.

Aims: Anethole dithiolethione (ADT) is a marketed drug to treat xerostomia. Its mechanism of action is still unknown, but several preclinical studies indicate that it is able to increase intracellular glutathione (GSH) and protect against oxidative stress. Here, we investigated the molecular mechanisms behind these effects.

The specific PKC-α inhibitor chelerythrine blunts costunolide-induced eryptosis.

Costunolide, a natural sesquiterpene lactone, has multiple pharmacological activities such as neuroprotection or induction of apoptosis and eryptosis. However, the effects of costunolide on pro-survival factors and enzymes in human erythrocytes, e.g.

Antihypertensive, cardio- and neuro-protective effects of Tenebrio molitor (Coleoptera: Tenebrionidae) defatted larvae in spontaneously hypertensive rats.

In pre-hypertension, moderate control of blood pressure (BP) can be obtained by a nutritional approach. The effects of a diet enriched with defatted larvae of the mealworm Tenebrio molitor (Coleoptera: Tenebrionidae) (TM) endowed with ACE inhibitory activity was studied in both spontaneously hypertensive rats (SHR) and in the age-matched normotensive Wistar Kyoto strain. These were fed for 4 weeks with standard laboratory rodent chow supplemented with or without TM or captopril.

Cigarette smoke and glutathione: Focus on in vitro cell models.

Cigarette smoke (CS) is one of the most important preventable risk factors for the development of respiratory diseases, cardiovascular diseases, stroke, and various types of cancer. Due to its high intracellular concentration and central role in maintaining the cellular redox state, glutathione (GSH) is one of the key players in several enzymatic and non-enzymatic reactions necessary for protecting cells against CS-induced oxidative stress. A plethora of in vitro cell models have been used over the years to assess the effects of CS on intracellular GSH and its disulphide forms, i.

Glutathione S-transferase P influences the Nrf2-dependent response of cellular thiols to seleno-compounds.

Recent findings suggest a functional interaction of the drug resistance enzyme glutathione S-transferase P (GSTP) with the transcription factor Nrf2, a master regulator of the adaptive stress response to cellular electrophiles. The effect of this interaction on the metabolism and redox of cellular thiols was investigated in this study during the exposure to alkylating Se-compounds in murine embryonic fibroblasts (MEFs). GSTP1-1 gene ablation was confirmed to upregulate Nrf2 activity and to increase Cys uptake and the de novo biosynthesis of reduced glutathione (GSH) that was readily released in the extracellular medium together with other cellular thiols.

Homogentisic acid affects human osteoblastic functionality by oxidative stress and alteration of the Wnt/β-catenin signaling pathway.

Alkaptonuria (AKU) is a rare disease correlated with deficiency of the enzyme homogentisate 1,2 dioxygenase, which causes homogentisic acid (HGA) accumulation. HGA is subjected to oxidation/polymerization reactions, leading to the production of a peculiar melanin-like pigmentation (ochronosis) after chronic inflammation, which is considered as a triggering event for the generation of oxidative stress. Clinical manifestations of AKU are urine darkening, sclera pigmentation, early severe osteoarthropathy, and cardiovascular and renal complication.

Interactive alkaptonuria database: investigating clinical data to improve patient care in a rare disease.

Alkaptonuria (AKU) is an ultrarare autosomal recessive disorder (MIM 203500) that is caused byby a complex set of mutations in homogentisate 1,2-dioxygenasegene and consequent accumulation of homogentisic acid (HGA), causing a significant protein oxidation. A secondary form of amyloidosis was identified in AKU and related to high circulating serum amyloid A (SAA) levels, which are linked with inflammation and oxidative stress and might contribute to disease progression and patients' poor quality of life. Recently, we reported that inflammatory markers (SAA and chitotriosidase) and oxidative stress markers (protein thiolation index) might be disease activity markers in AKU.

A seleno-hormetine protects bone marrow hematopoietic cells against ionizing radiation-induced toxicities.

2,2'-diselenyldibenzoic acid (DSBA) is a chemical probe produced to explore the pharmacological properties of diphenyldiselenide-derived agents with seleno-hormetic activity undergoing preclinical development. The present study was designed to verify in vivo the drug's properties and to determine mechanistically how these may mediate the protection of tissues against stress conditions, exemplified by ionizing radiation induced damage in mouse bone marrow. In murine bone marrow hematopoietic cells, the drug initiated the activation of the Nrf2 transcription factor resulting in enhanced expression of downstream stress response genes.

Membrane Skeletal Protein S-Glutathionylation in Human Red Blood Cells as Index of Oxidative Stress.

Glutathione (GSH) is one of the most well-studied biomarkers of oxidative stress. Under oxidizing conditions, GSH is transformed into its disulfide forms, glutathione disulfide (GSSG) and S-glutathionylated proteins (PSSG), which are considered to be reliable biomarkers of oxidative stress. In red blood cells (RBCs), the main targets of S-glutathionylation are hemoglobin and membrane-associated skeletal proteins, but S-glutathionylated hemoglobin (HbSSG) has been more thoroughly studied as a biomarker of oxidative stress than S-glutahionylated RBC membrane skeletal proteins.