Redox modifications of protein-thiols: emerging roles in cell signaling

The assessment of thiol-disulfide homeostasis and ıschemia-modified albumin levels in patients with acromegaly

PURPOSE

Data regarding the relationship between acromegaly and oxidative stress (OS) remain limited. Dynamic thiol-disulfide homeostasis (TDH) is vital for antioxidant protection, and ischemia-modified albumin (IMA) serves as a marker of OS. This study aimed to measure serum TDH parameters and IMA levels in acromegaly patients, comparing them with healthy controls.

METHODS

This cross-sectional study consecutively included 81 patients and 55 controls, matched for age, gender, and body mass index. Serum levels of native thiol, total thiol, and disulfide (TDH parameters) were measured using the automated spectrophotometric method developed by Erel and Neselioglu, along with serum IMA levels.

RESULTS

In patients, serum native and total thiol levels were significantly lower (p = 0.005 and p = 0.007), while serum IMA levels were significantly higher (p = 0.001). Disulfide levels were similar. Patients with active disease (N = 32), patients in remission (N = 49), and controls (N = 55) were compared. In post-hoc analyses; serum TDH parameters and IMA levels were similar in remission and active disease patients. Native and total thiol levels were significantly lower in patients in remission compared to controls (p = 0.01 and p = 0.04). IMA levels were significantly higher in patients in remission compared to controls (p = 0.04). Serum thiol levels positively correlated with serum insulin-like growth factor-1 levels and negatively with age and disease duration, while age independently exerted a negative impact on serum thiol levels.

CONCLUSION

Our findings may indicate increased OS in the acromegalic process, which may contribute to the development of acromegaly and its related complications and comorbidities.

Thiol/Disulfide Homeostasis in Pericardial Fluid and Plasma of Patients Undergoing Coronary Artery Bypass Surgery

INTRODUCTION

On-pump coronary artery bypass grafting (CABG) method affect almost allbiochemicalreactions by disrupting the patient's redox homeostasis. Detection of systemic redox hemostasis in the patient is critical for the CABG method's success and the prognosis of the disease. In this study, thiol/disulfide parameters, which are indicators of redox homeostasis, and ischemia-modified albumin levels in the plasma and pericardial fluid of patients who underwent CABG were investigated.

METHODS

Sixty patients who underwent an on-pump CABG operation with the cardiopulmonary bypass method were included in this study. Blood samples were taken from the patients before and after cardiopulmonary bypass. Pericardia fluid samples were taken before cardiopulmonary bypass. Then, thiol/disulfide homeostasis, albumin, and ischemia-modified albumin levels in the pericardial fluid and the patients' plasma levels were compared.

RESULTS

Albumin and ischemia-modified albumin levels were significantly higher in the postoperative period compared to the preoperative one (P<0.001). Thiol/disulfide parameters were higher and statistically significant in preoperative than in postoperative examinations (P<0.001). A negative correlation was found between pericardial fluid ischemia-modified albumin and thiol-disulfide parameters (P<0.001).

CONCLUSION

Changes in thiol/disulfide homeostasis, albumin, and ischemia-modified albumin levels at different times during the on-pump CABG may be caused by foreign non-endothelial surfaces, filters, the reperfusion process, and pharmacological effects in the extracorporeal circulation. Thiol/disulfide homeostasis, albumin, and ischemia-modified albumin levels should be monitored during the on-pump CABG and should be intervened with appropriate therapeutic strategies. In this way, secondary pathologies can be avoided by preventing cellular damage and excessive inflammatory responses.

The role of oxidative post-translational modifications in type 1 diabetes pathogenesis

The pathogenesis of type 1 diabetes (T1D) involves a complex interplay of genetic predisposition, immune processes, and environmental factors, leading to the selective destruction of pancreatic beta-cells by the immune system. Emerging evidence suggests that intrinsic beta-cell factors, including oxidative stress and post-translational modifications (PTM) of beta-cell antigens, may also contribute to their immunogenicity, shedding new light on the multifaceted pathogenesis of T1D. Over the past 30 years, neoepitopes generated by PTMs have been hypothesized to play a role in T1D pathogenesis, but their involvement has only been systematically investigated in recent years. In this review, we explored the interplay between oxidative PTMs, neoepitopes, and T1D, highlighting oxidative stress as a pivotal factor in immune system dysfunction, beta-cell vulnerability, and disease onset.

The Effect of Preoperative Carbohydrate-containing Fluid Consumption on Maternal Oxidative Stress Markers During Elective Cesarean Delivery

PURPOSE

The purpose of this study was to evaluate the effect of carbohydrate loading prior to the cesarean surgery under spinal anesthesia on thiols and ischemia-modified albumin (IMA) levels.

DESIGN

Prospective, randomized placebo-controlled study.

METHODS

Seventy-nine pregnant women planned for cesarean sections under spinal anesthesia at Karaman Training and Research Hospital were randomized into a control group (group C) (n = 42), and an oral carbohydrate preloading group (group OCH) (n = 37). OCH loading requires consuming 400 mL the night before surgery and 200 mL up to 2 hours before anesthesia. Group OCH consumed an oral carbohydrate-rich beverage (Nutricia-Fantomalt), and group C consumed an equal volume of water. This study investigated thiol-disulfide homeostasis after preoperative carbohydrate consumption. Preoperative gastric fluid, volume, antral cross-sectional area, hypotension following the birth, and fetal blood gas parameters were compared across groups.

FINDINGS

Thiols and IMA levels did not differ across groups before and after surgery (P > .05). Gastric ultrasonography showed similar antral cross-sectional area and stomach volume between groups (P = .172, P = .128, respectively). When surgery caused hypotension, group OCH received more ephedrine for surgery-induced hypotension, although this difference is not statistically significant (P = .704). A clustered error bar (95% confidence interval) plot with an interpolation line was used for a time-based comparison of mean differences in heart rate and mean arterial pressure between the groups.

CONCLUSIONS

This study supports that mothers' thiols and IMA levels were unaffected by preoperative OCH loading before cesarean surgery. We did not examine thiol and its derivatives in umbilical cord blood; hence, we can not comment on thiol/disulfide homeostasis levels in neonates.

Protective effects of lemon nanovesicles: evidence of the Nrf2/HO-1 pathway contribution from in vitro hepatocytes and in vivo high-fat diet-fed rats

The cross-talk between plant-derived nanovesicles (PDNVs) and mammalian cells has been explored by several investigations, underlining the capability of these natural nanovesicles to regulate several molecular pathways. Additionally, PDNVs possess biological proprieties that make them applicable against pathological conditions, such as hepatic diseases. In this study we explored the antioxidant properties of lemon-derived nanovesicles, isolated at laboratory (LNVs) and industrial scale (iLNVs) in human healthy hepatocytes (THLE-2) and in metabolic syndrome induced by a high-fat diet (HFD) in the rat. Our findings demonstrate that in THLE-2 cells, LNVs and iLNVs decrease ROS production and upregulate the expression of antioxidant mediators, Nrf2 and HO-1. Furthermore, the in vivo assessment reveals that the oral administration of iLNVs improves glucose tolerance and lipid dysmetabolism, ameliorates biometric parameters and systemic redox homeostasis, and upregulates Nrf2/HO-1 signaling in HFD rat liver. Consequently, we believe LNVs/iLNVs might be a promising approach for managing hepatic and dysmetabolic disorders.

Investigating the effects of cysteine-118 oxidation on G12D KRas structure and dynamics: insights from MD simulations

Mutations of Ras proteins are believed to be among the most prominent causes of cancer. There is increasing evidence that the activity of Ras may be controlled by the redox state of cysteine residues located within the NKCD motif. This redox signaling is critical to both physiological and pathological processes and occurs when C118 is oxidized in a reversible manner. In this study, we used atomistic molecular dynamics simulations and Markov state models to investigate the structural and conformational effects of C118 oxidation on the oncogenic mutant KRas(G12D). While both mutants share common features and exhibit some distinct conformational states and fluctuations, we have found that the oxidized variant KRas(G12D/C118SOH) is more dynamic than the unoxidized counterpart, particularly in the switch II region. Additionally, C118 oxidation is found to alter the structure of the nucleotide-binding site and the switch regions as well as perturb the conformational equilibrium between Ras active and inactive states. These conformational preferences may alter the affinity to different effectors, resulting in selective downstream activation. Our results are anticipated to help future drug development efforts aimed at KRAS-related anticancer treatment.Communicated by Ramaswamy H. Sarma.

Benefits of Combining Antiepileptic Drugs with Vitamin B12 on Redox Balance: Penicillin-Induced Experimental Epilepsy Model

Purpose

A combination of antiepileptic drugs and antioxidants may be an effective treatment by restoring the disrupted redox balance and reducing oxidative stress exposure to neurons. This study aims to evaluate the effects of valproate and vitamin B12 on oxidative stress in an experimental epilepsy model induced by penicillin when administered alone or in combination.

Patients and Methods

35 male Wistar rats were used in this study. The rats were divided into five groups, which were saline group, 1 mg/kg, 2 mg/kg Vit B12 groups and Sodium valproate group Sodium valproate + Vit B12 group. The epileptic activity was induced by 500 IU of penicillin injection. Sodium valproate and Vitamin B12 were administered 30 min after penicillin administration. Electrocorticogram recordings were taken for 2 hours post-treatment and serum parameters were assessed for oxidative stress markers using spectrophotometric method.

Results

There is statistically significant difference between the groups in total antioxidant status, total oxidant status, and oxidative stress index value (p=0.013; p˂0.001; p˂0.001, respectively). The valproate+vitamin B12 group showed elevated total thiol and native thiol levels, along with reduced disulphide levels, resulting in the lowest OSI value.

Conclusion

These findings suggest the combined treatment effectively reduces oxidative stress. This study provides valuable insights into the antioxidant properties of valproate and vitamin B12, positioning them as potential agents for managing epilepsy. Understanding the efficacy and reliability of antioxidant strategies in epilepsy management could contribute significantly to advancements in epilepsy therapeutics.

Redox active plant phenolic, acetosyringone, for electrogenetic signaling

Redox is a unique, programmable modality capable of bridging communication between biology and electronics. Previous studies have shown that the E. coli redox-responsive OxyRS regulon can be re-wired to accept electrochemically generated hydrogen peroxide (H2O2) as an inducer of gene expression. Here we report that the redox-active phenolic plant signaling molecule acetosyringone (AS) can also induce gene expression from the OxyRS regulon. AS must be oxidized, however, as the reduced state present under normal conditions cannot induce gene expression. Thus, AS serves as a "pro-signaling molecule" that can be activated by its oxidation-in our case by application of oxidizing potential to an electrode. We show that the OxyRS regulon is not induced electrochemically if the imposed electrode potential is in the mid-physiological range. Electronically sliding the applied potential to either oxidative or reductive extremes induces this regulon but through different mechanisms: reduction of O2 to form H2O2 or oxidation of AS. Fundamentally, this work reinforces the emerging concept that redox signaling depends more on molecular activities than molecular structure. From an applications perspective, the creation of an electronically programmed "pro-signal" dramatically expands the toolbox for electronic control of biological responses in microbes, including in complex environments, cell-based materials, and biomanufacturing.

Novel disulfidptosis-derived gene blueprint stratifying patients with breast cancer

INTRODUCTION

Breast cancer remains the predominant cancer among females, accounting for about 24.2% of all cancer cases. Alarmingly, it is the primary cause of cancer-related mortality in women under 45.

METHODS

This research analyzed RNA sequencing data from 1082 TCGA-BRCA and 107 GSE58812 breast cancer patients. Single-cell RNA data from five patients in the GSE118389 data set were also studied. Using Random forest and COX regression, we developed a prognostic model. Pathway analysis employed GSVA and GO, while immune profiles were assessed via ssGSEA and MCPcounter. Mutation patterns utilized maftools, and drug sensitivity scores were derived from the GDSC database with oncoPredict.

RESULTS

Analysis of the GSE118389 data set identified three distinct cell types: immune, epithelial, and stromal. P53 and VEGF were notably enriched. Five key genes (TMEM251, ADAMTSL2, CDC123, PSMD1, TLE1) were pinpointed for their prognostic significance. We introduced a disulfidptosis-associated score as a novel risk factor for breast cancer prognosis. Survival outcomes varied significantly between training and validation sets. Comprehensive immune profiling revealed no difference in activated CD8-positive T cells between risk groups, but a positive correlation of NK cells, neutrophils, cytotoxic lymphocytes, and monocytic cells with the riskscore was noted. Importantly, a negative association between the drug Nelarabine and riskscore was identified.

CONCLUSION

This research underscores the significance of a disulfidptosis-associated gene signature in breast cancer prognosis.

Comprehensive intratumoral heterogeneity landscaping of liver hepatocellular carcinoma and discerning of APLP2 in cancer progression

INTRODUCTION

As the sixth most common type of cancer worldwide, liver hepatocellular carcinoma (LIHC) emerges as grave public health danger owing to its chemotherapy-resistant feature. Disulfidoptosis is a newly discovered programmed cell death process affecting the normal actin cytoskeleton structure.

METHODS

Single-cell RNA (scRNA)-seq data were procured from GSE149614 and GSE202642 datasets. We utilized uniform manifold approximation and projection and clustering algorithm Louvian for dimensionality reduction and FindAllMarkers function for determining the differentially expressed genes (DEGs). Monocle2 and SCENIC were utilized to perform pseudo-time series and transcription factor analysis for selected subgroups. A series of in vitro experiments, including colony formation assay (CFA), flow cytometry targeting apoptosis and cell cycle, was applied to investigate how APLP2 regulated the LIHC progression. Two cell lines of LIHC cells, HepG2, and Huh7, were used for si-APLP2 transfection.

RESULTS

Tumor heterogeneity landscape of LIHC was depicted by detailed subgroup analysis. We found T and B cells were enriched with POU2F1 and HES1 activity. Inflammatory cancer-associated fibroblasts interacted with the cancer cells, uniquely through COL1A1/SDC1, COL1A2/SDC1 and LUM/ITGB1 pathways. The transformation from normal hepatocytes to malignant cells was displayed by cell trajectory analysis. State4, which was determined as malignant cells, was enriched in PI3K, hypoxia, and Epidermal growth factor receptor pathway, and enriched with Nuclear Receptor Subfamily 2 Group F Member 1 transcription factor activity. We observed an intense communication from the cancer cells to endothelial cells, mainly through the Vitronectin (VTN) to Kinase Insert Domain Receptor (KDR) pathway. A prognostic model targeting LIHC was constructed based on the disulfidoptosis-based DEGs, namely APLP2, PDIA6, YBX1, SPP1, whose accuracy was validated in multiple cohorts. Knockdown of APLP2 significantly increased the apoptosis and delayed cell cycle progression of LIHC cell line.

CONCLUSION

A prognostic model targeting LIHC was constructed based on the disulfidoptosis-related DEGs, which displayed high stability and accuracy in multiple cohorts. APLP2 played an active role in the carcinogenesis of LIHC by regulating the apoptosis and cell cycle.

Evaluation of the dynamic thiol/disulfide homeostasis in patients with chronic venous insufficiency

OBJECTIVE

There is no study in the literature evaluating the dynamic thiol/disulfide homeostasis in patients with chronic venous insufficiency. Thus, we designed this study to evaluate the dynamic thiol/disulfide homeostasis as a novel indicator of oxidative stress in patients with chronic venous insufficiency.

METHODS

This was a prospective case-control study performed at the department of cardiovascular surgery of a tertiary referral hospital in Turkey. A total of 80 (CEAP C3-C6) patients with lower extremity chronic venous insufficiency (as the study group) and 80 healthy subjects (as the control group) were enrolled to the study. The participants' basic demographic and clinical characteristics as well as serum levels of some laboratory parameters including albumin, ferroxidase, myeloperoxidase, native thiol, total thiol, disulphide, native thiol/total thiol, disulphide/native thiol, and disulphide/total thiol were determined, and then compared between the groups.

RESULTS

In terms of basic demographic and clinical characteristics, both groups were statistically similar, and there were no significant differences between the groups. When the laboratory parameters were considered, serum ferroxidase and myeloperoxidase levels were detected to be significantly higher, whereas albumin, native thiol, total thiol, and disulphide levels were detected to be significantly lower in the study group than in the control group.

CONCLUSIONS

Dynamic thiol/disulphide homeostasis could be considered as an indicator reflecting the oxidative stress status in patients with chronic venous insufficiency.

Investigating the prognostic role of lncRNAs associated with disulfidptosis-related genes in clear cell renal cell carcinoma

INTRODUCTION

Renal cell carcinoma (RCC) is a grave malignancy that poses a significant global health burden with over 400,000 new cases annually. Disulfidptosis, a newly discovered programmed cell death process, is linked to the actin cytoskeleton, which plays a vital role in maintaining cell shape and survival. The role of disulfidptosis is poorly depicted in the clear cell histologic variant of RCC (ccRCC).

METHODS

Three sets of ccRCC cohorts, ICGC_RECA-EU (n = 91), GSE76207 (n = 32) and TCGA-KIRC (n = 607), were included in our study, the batch effect of which was removed using the "combat" function. Correlation was calculated using the "rcorr" function of the "Hmisc" package for Pearson analysis, which was visualized using the "pheatmap" package. Principal component analysis was performed by the "vegan" package, visualized using the "scatterplot3d" package. Long non-coding RNAs (lncRNAs) associated with disulfidptosis were screened out using least absolute shrinkage and selection operator (LASSO) and COX analysis. Tumor mutation, immune landscaping and immunotherapy prediction were performed for further characterization of two risk groups.

RESULTS

A total of 1822 disulfidptosis-related lncRNAs was selected, among which 308 lncRNAs were found to be significantly associated with the clinical outcome of ccRCC patients. We retained 11 disulfidptosis-related lncRNAs, namely, AP000439.3, RP11-417E7.1, RP11-119D9.1, LINC01510, SNHG3, AC156455.1, RP11-291B21.2, EMX2OS, AC093850.2, HAGLR and RP11-389C8.2, through LASSO and COX analysis for prognosis model construction, which displayed satisfactory accuracy (area under the curve, AUC, values all above 0.6 in multiple cohorts) in stratification of ccRCC prognosis. A nomogram model was constructed by integrating clinical factors with risk score, which further enhanced the prediction efficacy (AUC values all above 0.7 in multiple cohorts). We found that patients of male gender, higher clinical stages and advanced pathological T stage were inclined to have higher risk score values. Dactinomycin_1911, Vinblastine_1004, Daporinad_1248 and Vinorelbine_2048 were identified as promising candidate drugs for treating ccRCC patients of higher risk score value. Moreover, patients of higher risk value were prone to be resistant to immunotherapy.

CONCLUSION

We developed a prognosis predicting model based on 11 selected disulfidptosis-related lncRNAs, the efficacy of which was verified in different cohorts. Furthermore, we delineated an intricate portrait of tumor mutation, immune topography and pharmacosensitivity evaluations within disparate risk stratifications.

Oxidant and antioxidant balance in children with bacteremia

BACKGROUND

There is a crucial balance between oxidant and antioxidant defense mechanisms. We aimed to evaluate the role of the balance of these systems in children with bloodstream infection.

METHODS

We analyzed prospectively oxidant and antioxidant stress parameters from serum samples of children with BSI besides demographic and clinical data of children. Serum levels of the total antioxidant status (TAS), total oxidant status (TOS), albumin, plasma thiol, disulphide, catalase (CAT), myeloperoxidase (MPO), ischemia-modified albumin (IMA) levels, ferroxidase and arylesterase (ARES) activity were evaluated in both patients and healthy controls.

RESULTS

A total of 113 children were evaluated, 50 of them had bacteremia and the remaining 63 were healthy subjects. The median TOS values were 18.5 µmol H2O2/L and 13.1 µmol H2O2/L in patient and control groups, respectively with a statistically significant difference between groups. The mean serum IMA levels were 0.8±0.1 absorbance unit (ABSU) in patients and 0.5±0.09 ABSU in control, the difference between groups was statistically significant. The native thiol, total thiol levels and the disulphide levels were significantly lower in the patient group as compared with the control group. The myeloperoxidase level was 136 U/L in patients and 107 in controls with a statistically significant difference between groups.

CONCLUSIONS

TOS, IMA, MPO, and particularly plasma thiols seem good candidates for accurate diagnosis of bacteremia in children.

Binding of Selected Aroma Compounds to Myofibrillar Protein, Sarcoplasmic Protein, and Collagen during Thermal Treatment: Role of Conformational Changes and Degradation of Proteins

To investigate the effects of conformational changes and thermal degradation of myofibrillar protein (MP), sarcoplasmic protein (SP), and collagen (CO) on the binding ability for aroma compounds during heating. Using SDS-PAGE, HPLC, and LC-MS/MS, a consistent rise in the total concentration of peptides and free amino acids formed by the thermal degradation of proteins was observed. The surface hydrophobicity, total sulfhydryl content, particle size, and secondary structure content of proteins changed significantly over time. Furthermore, the aroma binding ability of proteins was determined by gas chromatography-mass spectrometry. The results revealed an increase in binding ability during 5 or 10 min of heating due to protein unfolding and the accumulation of degradation products. However, the binding ability decreased due to protein aggregation with prolonged heating. Notably, all proteins exhibited strong affinity toward (E)-2-octenal, (E,E)-2,4-decadienal, 2-methyl-3-furanthiol, and dimethyl trisulfide. The binding ability of MP and SP was similar but differed significantly from that of CO, which had lower binding ability for hexanal, (E)-2-octenal, (E,E)-2,4-decadienal, and dimethyl trisulfide compared to MP and SP.

Evaluation of Oxidative Stress Levels and Dynamic Thiol-disulfide Balance in Patients with Retinopathy of Prematurity

PURPOSE

The aim of this study is to evaluate both dynamic thiol-disulfide homeostasis and oxidative stress (OS) levels in patients with retinopathy of prematurity (ROP).

METHODS

A total of 129 infants of <34 weeks gestational age were enrolled in the present study. The thiol-disulfide homeostasis was determined by using the new, cost-effective and fully automated colorimetric method. Total antioxidant status (TAS), Total oxidant status (TOS) and Oxidative stress index (OSI) levels were evaluated.

RESULTS

We found serum TAS levels were lower while serum TOS and OSI levels were significantly higher in patients with ROP compare to the without ROP group (p < .05). However, native, total and disulfide values were not statistically significant between the groups (p > .05). In addition, we also evaluated the native, total and disulfide levels in patients with ROP according to grades and no statistically significant results were found (p > .05). Low birth weight (p = .001), gestational age (p = .001) and 5-min Apgar score were significantly lower in the ROP group.

CONCLUSION

This study revealed that dynamic thiol-disulfide homeostasis was changed in patients with ROP. Increased TOS and decreased TAS levels may be associated with functional reduction of the antioxidant system due to increased OS. This indicate that ROP patients are highly sensitive to OS. The dynamic thiol-disulfide homeostasis may conduce to the pathophysiological mechanism and disease follow-up in patients with ROP. The results of this study show that ROP patients are highly sensitive to oxidative stress.

Increasing glutathione levels by a novel posttranslational mechanism inhibits neuronal hyperexcitability

Glutathione (GSH) depletion, and impaired redox homeostasis have been observed in experimental animal models and patients with epilepsy. Pleiotropic strategies that elevate GSH levels via transcriptional regulation have been shown to significantly decrease oxidative stress and seizure frequency, increase seizure threshold, and rescue certain cognitive deficits. Whether elevation of GSH per se alters neuronal hyperexcitability remains unanswered. We previously showed that thiols such as dimercaprol (DMP) elevate GSH via post-translational activation of glutamate cysteine ligase (GCL), the rate limiting GSH biosynthetic enzyme. Here, we asked if elevation of cellular GSH by DMP altered neuronal hyperexcitability in-vitro and in-vivo. Treatment of primary neuronal-glial cerebrocortical cultures with DMP elevated GSH and inhibited a voltage-gated potassium channel blocker (4-aminopyridine, 4AP) induced neuronal hyperexcitability. DMP increased GSH in wildtype (WT) zebrafish larvae and significantly attenuated convulsant pentylenetetrazol (PTZ)-induced acute 'seizure-like' swim behavior. DMP treatment increased GSH and inhibited convulsive, spontaneous 'seizure-like' swim behavior in the Dravet Syndrome (DS) zebrafish larvae (scn1Lab). Furthermore, DMP treatment significantly decreased spontaneous electrographic seizures and associated seizure parameters in scn1Lab zebrafish larvae. We investigated the role of the redox-sensitive mammalian target of rapamycin (mTOR) pathway due to the presence of several cysteine-rich proteins and their involvement in regulating neuronal excitability. Treatment of primary neuronal-glial cerebrocortical cultures with 4AP or l-buthionine-(S,R)-sulfoximine (BSO), an irreversible inhibitor of GSH biosynthesis, significantly increased mTOR complex I (mTORC1) activity which was rescued by pre-treatment with DMP. Furthermore, BSO-mediated GSH depletion oxidatively modified the tuberous sclerosis protein complex (TSC) consisting of hamartin (TSC1), tuberin (TSC2), and TBC1 domain family member 7 (TBC1D7) which are critical negative regulators of mTORC1. In summary, our results suggest that DMP-mediated GSH elevation by a novel post-translational mechanism can inhibit neuronal hyperexcitability both in-vitro and in-vivo and a plausible link is the redox sensitive mTORC1 pathway.

Are Thiol/Disulfide and 8-OHdG Levels in the Blood of Patients with Diabetic Foot a Risk Factor for Amputation?

OBJECTIVE

As diabetic patients live longer and there are more effective treatments available, the incidence of diabetes and its complications is increasing. The effects of oxidative stress and antioxidant processes on diabetes behavior, especially diabetic foot, are really direct. The goal of this research is to investigate the effects of oxidative stress and antioxidant mechanism on the outcome of amputation by examining the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and thiol/disulfide in the blood of patients diagnosed with diabetic foot.

METHODS

The research consisted of 76 patients with type 2 diabetes with associated diabetic foot, ages 40-65 (51 men, 25 women). Patients with diabetic foot wounds and accompanying peripheral artery disease were not included in the study. After a mean follow-up of 9.6 months, 28 patients resulted in amputation. Between patients who required amputation and those who did not, the levels of 8-OHdG, native thiol, total thiol, disulfide, native thiol/total thiol ratio, disulfide/native thiol ratio, and disulfide/total thiol ratio were compared. Additionally, the age, sex, Wagner stage, and amputation outcome of these 2 patient groups were compared.

RESULTS

The outcomes of amputation in diabetic foot patients were not related to the levels of native thiol, total thiol, disulfide, native thiol/total thiol ratio, disulfide/native thiol ratio, total thiol/disulfide ratio, or 8-OHdG (P > .05). However, patients with diabetic foot who were male, older, and at a more advanced Wagner stage had a higher rate of amputations (P < .05).

CONCLUSION

Oxidative stress and antioxidant mechanism are effective on diabetes complications. However, since there are many factors affecting the outcome of amputation, they are not directly effective in terms of resulting amputation in patients with diabetic foot ulcer.

Addressing the gaps in homeostatic mechanisms of copper and copper dithiocarbamate complexes in cancer therapy: a shift from classical platinum-drug mechanisms

The platinum drug, cisplatin, is considered as among the most successful medications in cancer treatment. However, due to its inherent toxicity and resistance limitations, research into other metal-based non-platinum anticancer medications with diverse mechanisms of action remains an active field. In this regard, copper complexes feature among non-platinum compounds which have shown promising potential as effective anticancer drugs. Moreover, the interesting discovery that cancer cells can alter their copper homeostatic processes to develop resistance to platinum-based treatments leads to suggestions that some copper compounds can indeed re-sensitize cancer cells to these drugs. In this work, we review copper and copper complexes bearing dithiocarbamate ligands which have shown promising results as anticancer agents. Dithiocarbamate ligands act as effective ionophores to convey the complexes of interest into cells thereby influencing the metal homeostatic balance and inducing apoptosis through various mechanisms. We focus on copper homeostasis in mammalian cells and on our current understanding of copper dysregulation in cancer and recent therapeutic breakthroughs using copper coordination complexes as anticancer drugs. We also discuss the molecular foundation of the mechanisms underlying their anticancer action. The opportunities that exist in research for these compounds and their potential as anticancer agents, especially when coupled with ligands such as dithiocarbamates, are also reviewed.

Nitric oxide-driven modifications of lipoic arm inhibit α-ketoacid dehydrogenases

Pyruvate dehydrogenase complex (PDHC) and oxoglutarate dehydrogenase complex (OGDC), which belong to the mitochondrial α-ketoacid dehydrogenase family, play crucial roles in cellular metabolism. These multi-subunit enzyme complexes use lipoic arms covalently attached to their E2 subunits to transfer an acyl group to coenzyme A (CoA). Here, we report a novel mechanism capable of substantially inhibiting PDHC and OGDC: reactive nitrogen species (RNS) can covalently modify the thiols on their lipoic arms, generating a series of adducts that block catalytic activity. S-Nitroso-CoA, a product between RNS and the E2 subunit's natural substrate, CoA, can efficiently deliver these modifications onto the lipoic arm. We found RNS-mediated inhibition of PDHC and OGDC occurs during classical macrophage activation, driving significant rewiring of cellular metabolism over time. This work provides a new mechanistic link between RNS and mitochondrial metabolism with potential relevance for numerous physiological and pathological conditions in which RNS accumulate.

Reactive oxygen species as mediators of disease progression and therapeutic response in colorectal cancer

Significance Reactive oxygen species (ROS) are critical to normal cellular function with redox homeostasis achieved by balancing ROS production with removal through detoxification mechanisms. Many of the conventional chemotherapies used to treat colorectal cancer (CRC) derive a proportion of their cytotoxicity from ROS generation and resistance to chemotherapy is associated with elevated detoxification mechanisms. Furthermore, cancer stem cells demonstrate elevated detoxification mechanisms making definitive treatment with existing chemotherapy challenging. In this article we review the roles of ROS in normal and malignant colonic cell biology and how existing and emerging therapies might harness ROS for therapeutic benefit. Recent advances Recent publications have elucidated the contribution of ROS to the cytotoxicity of conventional chemotherapy alongside the emerging approaches of photodynamic therapy (PDT), sonodynamic therapy (SDT) and radiodynamic therapy (RDT) in which ROS are generated in response to excitatory light, sound or X-ray stimuli to promote cancer cell apoptosis. Critical issues The majority of patients with metastatic CRC have a very poor prognosis with 5-year survival of approximately 13% making the need for new or more effective treatments an imperative. Future Directions Modulation of ROS through a combination of new and emerging therapies may improve the efficacy of current chemotherapy providing novel approaches to treat otherwise resistant disease.

Hyperglycemia enhances the generation of ROS and RNS that impair antioxidant power and cause oxidative damage in human erythrocytes

Hyperglycemia is a state in which excess glucose circulates in blood. Erythrocytes are in direct contact with this high glucose concentration and are greatly affected by it. We have examined the effect of hyperglycemic condition on isolated human erythrocytes under in vitro conditions. Erythrocytes were incubated with different concentrations of glucose (5, 15, 30, 45 mmol/L) for 24 h, and several biochemical parameters were determined. Treatment with high glucose concentrations increased heme degradation and methemoglobin level, while methemoglobin reductase activity was decreased. A significant increase in protein oxidation and lipid hydroperoxides with a decrease in total sulfhydryl content was seen. This suggested the generation of oxidative stress, which was confirmed by an enhanced production of reactive oxygen and nitrogen species. Hyperglycemia led to a significant decline in the antioxidant power of erythrocytes, lowering their ability to quench free radicals and reduce metal ions to lower oxidation states. The plasma membrane redox system was upregulated, while ascorbate free radical reductase activity was lowered. Glucose exposure inhibited the enzymes of glycolysis and hexose monophosphate shunt. Electron microscopy showed morphological changes resulting in the formation of echinocytes. Thus, the hyperglycemic condition generates reactive species that oxidize proteins, hemoglobin, and lipids; impair the total antioxidant capacity; and alter morphology in human erythrocytes.

Vitamin C supplementation for diabetes management: A comprehensive narrative review

Growing evidence suggests that vitamin C supplementation may be an effective adjunct therapy in the management of people with diabetes. This paper critically reviews the current evidence on effects of vitamin C supplementation and its potential mechanisms in diabetes management. Evidence from meta-analyses of randomized controlled trials (RCTs) show favourable effects of vitamin C on glycaemic control and blood pressure that may be clinically meaningful, and mixed effects on blood lipids and endothelial function. However, evidence is mostly of low evidence certainty. Emerging evidence is promising for effects of vitamin C supplementation on some diabetes complications, particularly diabetic foot ulcers. However, there is a notable lack of robust and well-designed studies exploring effects of vitamin C as a single compound supplement on diabetes prevention and patient-important outcomes (i.e. prevention and amelioration of diabetes complications). RCTs are also required to investigate potential preventative or ameliorative effects of vitamin C on gestational diabetes outcomes. Oral vitamin C doses of 500-1000 mg per day are potentially effective, safe, and affordable for many individuals with diabetes. However, personalisation of supplementation regimens that consider factors such as vitamin C status, disease status, current glycaemic control, vitamin C intake, redox status, and genotype is important to optimize vitamin C's therapeutic effects safely. Finally, given a high prevalence of vitamin C deficiency in patients with complications, it is recommended that plasma vitamin C concentration be measured and monitored in the clinic setting.

Correlation of Metabolic Syndrome with Redox Homeostasis Biomarkers: Evidence from High-Fat Diet Model in Wistar Rats

Metabolic Syndrome (MetS) is an extremely complex disease. A non-balanced diet such as high-fat diet (HFD) induces metabolic dysfunction that could modify redox homeostasis. We here aimed at exploring redox homeostasis in male Wistar rats, following 8 weeks of HFD, correlating the eventual modification of selected biomarkers that could be associated with the clinical manifestations of MetS. Therefore, we selected parameters relative to both the glucose tolerance and lipid altered metabolism, but also oxidative pattern. We assessed some biomarkers of oxidative stress i.e., thiols balance, lipid peroxidation and antioxidant barriers, via the use of specific biochemical assays, individuating eventual cross correlation with parameters relative to MetS through a Principal Component Analysis (PCA). The present study shows that 8 weeks of HFD induce MetS in rats, altering glucose and lipid homeostasis and increasing visceral adipose tissue, but also impairing the physiological antioxidant responses that could not counteract the oxidative stress condition. Crucially, cross-correlation analysis suggested that the assessment of specific oxidative stress parameters reported here can provide information comparable to the more widely acquired biomarkers of Mets such as glucose tolerance. Lastly, hepatic steatosis in association with the oxidative stress condition was also highlighted by histological analysis. This research will elucidate the fundamental impact of these oxidative stress parameters on MetS induced in the HFD rat model, tracing paths for developing prevention approaches.

Cineole regulates Wnt/β-catenin pathway through Nrf2/keap1/ROS to inhibit bisphenol A-induced apoptosis, autophagy inhibition and immunosuppression of grass carp hepatocytes

Bisphenol A (BPA), an environmental pollutant, can cause multiple organ tissue damage by inducing oxidative stress. Cineole (CIN) is a terpene oxide existing in a variety of plant essential oils, which has anti-inflammatory, analgesic, and antioxidant effects. This study examined the effects of 200 nM BPA and 20 μM CIN on apoptosis, autophagy, and immunology in grass carp hepatocytes (L8824). The treatments were categorized as NC, CIN, BPA + CIN, and BPA. The findings demonstrated that BPA exposure could increase ROS levels and oxidative stress-related indicators, decrease the expression of the Nrf2/keap1 pathway and the Wnt/β-catenin pathway, increase the expression of genes involved in the apoptotic pathway (Bax and Caspase3), and decrease the expression of the anti-apoptotic gene Bcl-2 by lowering mitochondrial membrane potential. BPA also reduced the expression of genes linked to autophagy (ATG5, Beclin1, LC3). Changes in immunological function after BPA exposure were also shown by changes in the amounts of antimicrobial peptides (HEPC, β-defensin, LEAP2) and cytokines (INF-γ, IL-1β, IL-2, and TNF-α). After the co-treatment of CIN and BPA, CIN can inhibit BPA-induced apoptosis and recover from autophagy and immune function to a certain extent by binding to keap1 to exert an anti-oxidative regulatory effect of Nrf2 incorporation into the nucleus. Molecular docking provides strong evidence for the interaction of CIN ligands with keap1 receptors. Therefore, these results indicated that CIN could inhibit BPA-induced apoptosis, autophagy inhibition and immunosuppression in grass carp hepatocytes by regulating the Wnt/β-catenin pathway with Nrf2/keap1/ROS. This study provided further information to the risk assessment of the neuroendocrine disruptor BPA on aquatic organisms and offered suggestions and resources for further research into the function of natural extracts in the body's detoxification process.

Nitric oxide bioavailability for red blood cell deformability in the microcirculation: A review of recent progress

The rheological properties of red blood cells (RBCs) play an important role in their microcirculation. RBCs can elastically deform in response to mechanical forces to pass through narrow vessels for effective gas exchange in peripheral tissues. Decreased RBC deformability is observed in lifestyle-related diseases such as diabetes mellitus, hypercholesterolemia, and hypertension, which are pathological conditions linked to increased oxidative stress and decreased nitric oxide (NO) bioavailability. Redox-sensitive cysteine residues on RBC cytoskeletal proteins, such as α- and β-spectrins, responsible for membrane flexibility, are affected by prolonged oxidative stress, leading to reversible and irreversible oxidative modifications and decreased RBC deformability. However, endogenously, and exogenously generated NO protects RBC membrane flexibility from further oxidative modification by shielding redox-sensitive cysteine residues with a glutathione cap. Recent studies have shown that nitrate-rich diets and moderate exercise can enhance NO production to increase RBC deformability by increasing the interplay between RBCs and vascular endothelium-mediated NO bioavailability for microcirculation. This review focuses on the molecular mechanism of RBC- and non-RBC-mediated NO generation, and how diet- and exercise-derived NO exert prophylactic effects against decreased RBC deformability in lifestyle-related diseases with vascular endothelial dysfunction.

Assessment of dynamic thiol-disulfide homeostasis in patients with lipoid proteinosis (Urbach-Wiethe syndrome)

OBJECTIVE:

Lipoid proteinosis is a rare autosomal recessive genetic dermatological disease that occurs due to the accumulation of hyaline material in the skin and mucous membranes. This study aimed to investigate whether dynamic thiol-disulfide homeostasis is a new marker of oxidative stress in patients suffering from lipoid proteinosis.

METHODS:

The study group involved 17 patients with lipoid proteinosis and 17 healthy controls with same gender and age. Native thiol, total thiol, disulfide levels, and thiol-disulfide indexes were measured with the fully automated spectrophotometric method described by Erel and Neselioglu, and the results of the two groups were statistically analyzed.

RESULTS:

Serum total thiol and native thiol levels were significantly lower in lipoid proteinosis group compared to the control group (p=0.020 and p=0.014, respectively). The disulfide levels were found to be higher in lipoid proteinosis group, but there was no significant difference between two groups.

CONCLUSIONS:

Impaired dynamic thiol-disulfide homeostasis was observed in lipoid proteinosis patients, suggesting that thiol-disulfide homeostasis may have a role in the pathogenesis of this disease.

Genetic alterations and oxidative stress in T cell lymphomas

T cell lymphomas encompass a diverse group of Non-Hodgkin lymphomas with a wide spectrum of clinical, immunological and pathological manifestations. In the last two decades there has been a progress in our understanding of the cell of origin, genetic abnormalities and their impact on behaviour in T cell lymphomas. Genetic alterations are one of the critical drivers of the pathogenesis of T cell lymphoma. Disease progression has been correlated with multiple genetic abnormalities where malignant clones arise primarily out of the host immune surveillance arsenal. There are many cellular processes involved in disease development, and some of them are T cell signaling, differentiation, epigenetic modifications, and immune regulation. Modulation of these crucial pathways via genetic mutations and chromosomal abnormalities possessing either point or copy number mutations helps tumor cells to develop a niche favourable for their growth via metabolic alterations. Several metabolic pathways especially regulation of redox homeostasis is critical in pathogenesis of lymphoma. Disruption of redox potential and induction of oxidative stress renders malignant cells vulnerable to mitochondrial damage and triggers apoptotic pathways causing cell death. Targeting genetic abnormalities and oxidative stress along with current treatment regime have the potential for improved therapeutics and presents new combination approaches towards selective treatment of T cell lymphomas.

Investigation of Thiol/Disulfide Homeostasis and Ischemia-Modified Albumin Levels in Children with Wilson Disease

BackgroundThe aim of the present study was to assess thiol/disulfide homeostasis (TDH) parameters and ischemia-modified albumin (IMA) levels in children with Wilson Disease (WD) and to compare them to healthy controls. Methods: Based on the inclusion and exclusion criteria, fifteen children with WD and twenty-nine healthy children were enrolled, and serum thiol/disulfide and IMA levels were compared between groups. Results: The mean values of native and total thiols were significantly lower in the WD group than in the control group. The mean value of disulfide was significantly higher in the WD group than in the control group. The mean percentages of disulfide/total thiol and native thiol/total thiol were higher in the WD group than in the control group. The IMA value was also higher in the WD group than in the control group. Conclusion: The present study demonstrating altered thiol/disulfide parameters indicates increased oxidative stress in children with WD.

Evaluation of dynamic thiol/disulfide homeostasis in hereditary tyrosinemia type 1 patients

BACKGROUND

Despite successful treatment with nitisinone, the pathophysiology of long-term complications, including hepatocellular carcinoma and mental decline in tyrosinemia type 1 patients, is still obscure. Oxidative stress may play a role in these complications. While increased fumarylacetoacetate and maleylacetoacetate cause oxidative stress in the liver, increased tyrosine causes oxidative stress in the brain. The aim of this study is to evaluate dynamic thiol/disulfide homeostasis as an indicator of oxidative stress in late-diagnosed tyrosinemia type 1 patients.

METHODS

Twenty-four late-diagnosed (age of diagnosis; 14.43 ± 26.35 months) tyrosinemia type 1 patients (19 under nitisinone treatment and 5 with liver transplantation) and 25 healthy subjects were enrolled in the study. Serum native thiol, total thiol, and disulfide levels were measured, and disulfide/native, disulfide/total, and native thiol/total thiol ratios were calculated from these values.

RESULTS

No significant difference was observed in native, total, and disulfide thiol levels between the groups and no increase in disulfide/native, disulfide/total, and native/total thiol ratios was detected, despite significantly higher plasma tyrosine levels in the nitisinone-treated group.

CONCLUSIONS

We suggest that providing sufficient metabolic control with good compliance to nitisinone treatment can help to prevent oxidative stress in late-diagnosed tyrosinemia type 1 patients.

IMPACT

Despite successful nitisinone (NTBC) treatment, the underlying mechanisms of long-term complications in hereditary tyrosinemia type 1 (HT1), including hepatocellular carcinoma and mental decline, are still obscure. Oxidative stress may play a role in these complications. Thiol/disulfide homeostasis, which is an indicator of oxidative stress, is not disturbed in hereditary tyrosinemia patients under NTBC treatment, despite higher plasma tyrosine levels and patients who had liver transplantation. This is the first study evaluating dynamic thiol/disulfide homeostasis as an indicator of oxidative stress in late-diagnosed HT1 patients.

Evaluation of Salivary Thiol/Disulfide Homeostasis and Oxidative Stress in Children with Severe Early Childhood Caries Using a Novel Method

Objective This study aimed to assess the role of thiol/disulfide homeostasis and oxidative stress in the saliva of children with severe early childhood caries (S-ECC).

Methods Eighty children aged 3 to 6 years were involved in this case-control study. The study consisted of two groups: the study group (S-ECC) and the control group with no caries. Thiol/disulfide homeostasis and antioxidant levels were calculated after obtaining unstimulated saliva samples from all participating children.

Results The native/total thiol and total oxidant status (TOS) levels of the study group were higher than those of the control group, though not statistically significant (p > 0.05). The oxidative stress index (OSI) value was significantly higher in the study group compared to the control group (p = 0.024).

Conclusion Our results confirmed that the thiol/disulfide homeostasis was reduced, and disulfide formation, which is rereducible to thiol, was insufficient in children with S-ECC to compensate oxidative stress compared with the control group. Also, thiol levels were inadequate to compensate for oxidative stress, and thiol/disulfide homeostasis was not an independent parameter for S-ECC. Besides, the increases in the TOS level and OSI value show that oxidative stress had significant effects on S-ECC's etiopathogenesis.

A New Biomarker in The Distinction Between Stable Coronary Artery Disease and Acute Coronary Syndrome:Thiols

Backraund; Thiols are important elements for oxidation reactions and under oxidative stress. The aim of this study was to determine thiole levels, an antioxidative marker in CAD patients with stable and acute coronary syndrome. Methods; 210 of the patients included in the study were diagnosed with acute coronary syndrome (ACS), 205 consisted of patients with stable angina pectoris (SAP). Thiol groups levels and thiol/disulphide homeostasis was measured by spectrophotometrically. Results: Native thiol and total thiol levels, disulfide/natural thiol and disulfide/total thiol ratios were decreased in the ACS groups compared to the SAP groups Conclusions: Thiol levels and thiol / disulfide ratios can be used as markers to evaluate acute coronary syndrome.

The Evaluation of Thiol/Disulfide Homeostasis and Oxidative DNA Damage in Patients with Obsessive Compulsive Disorder

Objective

In this study, we aimed to examine thiol/disulfide homeostasis and oxidative DNA damage in patients with OCD and compare them with healthy controls.

Methods

Thirty-five patients previously diagnosed with OCD in Van Yuzuncu Yil University Department of Psychiatry and thirty-three healthy volunteers were included in the study. The severity of the symptoms was measured using the Yale-Brown Obsessive-Compulsive Scale. Five μL of blood samples were taken from the patient and control groups. The samples were stored at appropriate conditions until use. Leukocyte DNA was isolated and the levels of 8-hydroxy-2-deoxyguanosine (8-OHdG) and deoxyguanosine were detected to assess the oxidative DNA damage. The level of oxidative DNA damage was expressed as 8-OHdG/10⁶dG. Total thiol/native thiol levels were measured for thiol/disulfide homeostasis. The level of disulfide was determined by subtracting the native thiol value from the total thiol value and the result was divided by two. Results were given as percentages.

Results

The total and native thiol levels in patients with OCD were significantly lower, and the disulfide levels were significantly higher in patients with OCD than healthy control subjects. In addition, 8-OHdG, an indicator of DNA damage, was significantly lower in the control group compared to the patient group.

Conclusion

Increased levels of disulfide/native thiol and disulfide/total thiol in patients with OCD show that levels of oxidative stress were elevated and therefore, higher 8-OHdG levels in patients with OCD is a marker of oxidative DNA damage.

Dynamic thiol disulfide homeostasis in painters as indices of oxidative stress

This study was designed to determine thiol-disulfide homeostasis as indices of oxidative stress in painters by using a novel and automated colorimetric measurement method. Male painters (n = 117) were separated into three groups according to duration of work; group 1 (<5 years), group 2 (5-14 years) and group 3 (≥15 years). Hippuric acid, trichloroacetic acid (TCA), and phenol in urine was determined. Catalase activity and ischemia-modified albumin (IMA) levels were also assessed. Disulfide/Native Thiol and Disulfide/Total Thiol of group 2 and group 3 were significantly higher than those of group 1 (p < 0.001). A positive correlation was observed between urinary phenol and disulfide/native thiol (r = 0.214, p = 0.035), IMA (r = 0.305, p = 0.002), disulfide (r = 0.209, p = 0.040), and duration of work (r = 0.341, p < 0.001). The newly developed automated colorimetric method used in our study proposes a promising, practical and daily applicable test for evaluating oxidative status of painters.

Proptosis is associated with thiol-disulfide in patients with Graves' ophthalmopathy

Objective

Graves' ophthalmopathy (GO) is a vision-threatening finding observed in approximately half of Graves' disease patients. The pathophysiology of GO is unclear, and one of the suspected factors is oxidative stress. In our study, we compared the relationship between proptosis and SH-SS in patients diagnosed with GO.

Methods

In this prospective study, 40 recently diagnosed Graves' disease patients with proptosis, 40 recently diagnosed Graves' disease patients without GO and 30 healthy individuals with similar demographic characteristics were included. Serum thiol-disulfide (SH-SS) measurements were performed. Eye examinations were performed by a single ophthalmologist to check for the presence of GO, and proptosis values were recorded with a Hertel exophthalmometer.

Results

Total SH values were lower in the group with proptosis than in the other groups (p < 0.05). Total and native SH values were lower in patients without proptosis than in the control group (p < 0.05). Total SH, native SH and SS levels were independently associated with proptosis (p < 0.05). According to this analysis, it was found that increasing SS and decreasing total and native SH levels increased the probability of proptosis by 24.4%, 32.7% and 32.4%, respectively.

Conclusion

A decrease in SH, which is a natural antioxidant that protects the body against oxidative stress, and an increase in SS are important signs of oxidative damage. Proptosis and SH-SS are closely related in GO. This may help us detect GO and proptosis in Graves' patients. It can also assist in developing new options for preventing and treating GO.

Is there a relationship between dynamic thiol/disulfide homeostasis and osteoarthritis progression?

We aim to determine serum dynamic thiol/disulphide homeostasis with novel methods in early-stage osteoarthritis and late-stage osteoarthritis patients and investigated whether it was associated with the progression of osteoarthritis risk or not. One hundred eighteen patients were included in this prospective study. Osteoarthritis patients were divided into five stages, according to the Kellgren-Lawrence scale. Dynamic thiol/disulphide homeostasis was determined with a novel spectrophotometric method. Late-stage osteoarthritis patients had significantly lower levels of native and total thiol than the patients of early-stage osteoarthritis. Disulphide, index-1, index-2 levels, and WOMAC score of late-stage osteoarthritis patients were significantly higher than the ones belonging to patients of early-stage osteoarthritis. Decreased native thiol and total thiol levels and increased WOMAC score and disulphide levels were independently associated with increased risk of late-stage osteoarthritis. We suggest that both WOMAC score and dynamic thiol/disulphide homeostasis may be implicated in the pathogenesis and progression of osteoarthritis. We also recommend that dynamic thiol/disulphide homeostasis may have clinical utility as possible markers of differential diagnosis of early-stage and late-stage osteoarthritis.

Positive Aspects of Oxidative Stress at Different Levels of the Human Body: A Review

Oxidative stress is the subject of numerous studies, most of them focusing on the negative effects exerted at both molecular and cellular levels, ignoring the possible benefits of free radicals. More and more people admit to having heard of the term "oxidative stress", but few of them understand the meaning of it. We summarized and analyzed the published literature data in order to emphasize the importance and adaptation mechanisms of basal oxidative stress. This review aims to provide an overview of the mechanisms underlying the positive effects of oxidative stress, highlighting these effects, as well as the risks for the population consuming higher doses than the recommended daily intake of antioxidants. The biological dose-response curve in oxidative stress is unpredictable as reactive species are clearly responsible for cellular degradation, whereas antioxidant therapies can alleviate senescence by maintaining redox balance; nevertheless, excessive doses of the latter can modify the redox balance of the cell, leading to a negative outcome. It can be stated that the presence of oxidative status or oxidative stress is a physiological condition with well-defined roles, yet these have been insufficiently researched and explored. The involvement of reactive oxygen species in the pathophysiology of some associated diseases is well-known and the involvement of antioxidant therapies in the processes of senescence, apoptosis, autophagy, and the maintenance of cellular homeostasis cannot be denied. All data in this review support the idea that oxidative stress is an undesirable phenomenon in high and long-term concentrations, but regular exposure is consistent with the hormetic theory.

Pediatric Carbon Monoxide Poisoning: Effects of Hyperbaric Oxygen Therapy on Thiol/Disulfide Balance

OBJECTIVES

Carbon monoxide (CO) poisoning remains the foremost cause of poisoning worldwide. This study aimed to investigate the effects of hyperbaric oxygen therapy (HBOT) and normobaric oxygen therapy (NBOT) on thiol/disulfide homeostasis in children with CO intoxication.

METHODS

Eighty-one children aged 0 to 18 years with CO intoxication were included in this cross-sectional study. No changes were made in the routine clinical evaluation and treatment practices of the patients. Thirty-two children who received HBOT and 49 children who received NBOT were compared for serum native thiol, disulfide, and total thiol levels, as well as for the changes in disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol ratios before and after treatment.

RESULTS

Antioxidant levels, such as native thiol and total thiol, were significantly decreased in patients who received HBOT and increased in those who received NBOT (P = 0.02 and P = 0.01, respectively). There was no statistically significant difference between the 2 groups concerning the change of native thiol/total thiol ratios (P = 0.07). In addition, there was no significant difference regarding changes in disulfide, disulfide/native thiol, and disulfide/total thiol levels before and after treatment (P = 0.39, P = 0.07, and P = 0.07, respectively).

CONCLUSIONS

Although thiol-disulfide balance is maintained in patients treated with HBOT, antioxidant levels decrease significantly compared with NBOT. Despite efficiency of HBOT in CO intoxication, oxidative stress and reperfusion injury due to hyperoxygenation should be considered in the treatment of HBOT.

Fructose and methylglyoxal-induced glycation alters structural and functional properties of salivary proteins, albumin and lysozyme

Glycation process refers to reactions between reduction sugars and amino acids that can lead to formation of advanced glycation end products (AGEs) which are related to changes in chemical and functional properties of biological structures that accumulate during aging and diseases. The aim of this study was to perform and analyze in vitro glycation by fructose and methylglyoxal (MGO) using salivary fluid, albumin, lysozyme, and salivary α-amylase (sAA). Glycation effect was analyzed by biochemical and spectroscopic methods. The results were obtained by fluorescence analysis, infrared spectroscopy (total attenuated reflection-Fourier transform, ATR-FTIR) followed by multivariate analysis of principal components (PCA), protein profile, immunodetection, enzymatic activity and oxidative damage to proteins. Fluorescence increased in all glycated samples, except in saliva with fructose. The ATR-FTIR spectra and PCA analysis showed structural changes related to the vibrational mode of glycation of albumin, lysozyme, and salivary proteins. Glycation increased the relative molecular mass (Mr) in protein profile of albumin and lysozyme. Saliva showed a decrease in band intensity when glycated. The analysis of sAA immunoblotting indicated a relative reduction in intensity of its correspondent Mr after sAA glycation; and a decrease in its enzymatic activity was observed. Carbonylation levels increased in all glycated samples, except for saliva with fructose. Thiol content decreased only for glycated lysozyme and saliva with MGO. Therefore, glycation of salivary fluid and sAA may have the potential to identify products derived by glycation process. This opens perspectives for further studies on the use of saliva, an easy and non-invasive collection fluid, to monitor glycated proteins in the aging process and evolution of diseases.

Evaluation of serum thiol-disulphide homeostasis parameters as oxidative stress markers in epilepsy patients

The present study focuses on the investigation of the dynamic thiol-disulphide homeostasis in patients with epilepsy and understanding the effects of antiepileptic drugs on thiol levels. A total of 148 participants, 75 of whom had epilepsy and 73 were healthy volunteers, were included in the study. Total thiol and native thiol levels of all epilepsy patients and healthy volunteers were measured. Disulphide level, disulphide/native thiol, disulphide/total thiol and native/total thiol ratios were calculated from these values. The results were compared between epilepsy patients and healthy volunteers. A statistically significant difference was found between native thiol level, total thiol level, disulphide level, disulfide/total thiol, disulphide/native thiol and native/total thiol ratios between patients with epilepsy and healthy volunteers (p = 0.002, p = 0.035, p < 0.001, p < 0.001, p < 0.001, p < 0.001, respectively). The drugs used had a significant effect on disulphide, disulphide/total thiol, native/total thiol levels (p values 0.004, 0.009, 0.009, respectively). Decreased levels of serum native, total thiol and increased disulfide levels as parameters of oxidative stress may be considered as parameters to explain the pathogenesis or consequences of epilepsy.

Assessing Oxidative Stress by Thiol/Disulfide Homeostasis Among Vitamin D-Deficient Patients

Objective: Thiol/disulfide (T/DS) homeostasis represents a promising new approach to evaluate oxidative stress. Therefore, we aimed to examine T/DS homeostasis in vitamin D (VitD)-deficient patients.

Methods: We enrolled 154 patients with VitD deficiency and 154 healthy control subjects in the study. For both groups, native thiol, total thiol, and disulfide values were measured. Additionally, considering the obtained 25-hydroxycholecalciferol [25(OH)D] levels, the patient group was further divided into two subgroups (Group 1: <10 ng/mL, Group 2: 10-20 ng/mL), which were compared in more depth according to the specified parameters.

Results: Values of native thiol, total thiol, and disulfide measured in the combination of Groups 1 and 2, comprising individuals with VitD deficiency, proved to be higher in comparison to the control group with statistical significance (p=0.007, p=0.028, and p<0.001, respectively). When subgroups were considered according to VitD classifications, native thiol and total thiol were again higher in Group 1 in comparison to the values obtained for control subjects (p=0.022; p<0.001). While the total thiol level of Group 2 was higher than that of controls (p<0.001), no difference with statistical significance was obtained in the comparison of disulfide levels among the indviduals of Group 1, Group 2, and the controls (p=0.081).

Conclusion: In this study, among patients with VitD deficiency, we have confirmed that values of native thiol and total thiol were increased, while the T/DS balance was found to have shifted in favor of the thiol level.

Dynamic Thiol/Disulfide Homeostasis and Oxidative DNA Damage in Adult Attention Deficit Hyperactivity Disorder

Objective

Insufficient number of oxidative stress studies have been conducted in patients with adult attention deficit hyperactivity disorder (ADHD). The objective of the current study is to examine the thiol/disulfide homeostasis as well as oxidative DNA damage levels in adult ADHD patients and to compare them with the results of healthy control subjects.

Methods

The study was inclusive of forty-nine patients who were diagnosed with adult ADHD, as well as thirty-three healthy volunteers to be used as the control group. The diagnosis of the patients was conducted according to the DSM-5 diagnostic criteria. Blood were stored under appropriate laboratory conditions. For the purpose of detecting the oxidative DNA damage level, an extraction of genomic DNA from leukocytes was carried out, and furthermore the levels of 8-hydroxy-2-deoxyguanosine (8-OHdG), apart from deoxyguanosine, were measured accordingly.

Results

Total thiol and the native thiol levels were observed to be statistically lower in adult ADHD patients as compared to the subjects in the healthy control group (p = 0.001). It was observed that the disulfide levels were higher in adult ADHD patients as compared to the healthy control subjects (p = 0.001). In addition, the levels of 8-OHdG, which are considered as a marker for assessing DNA damage, were found to be significantly lower in the control group as compared to the adult ADHD patients (p = 0.001).

Conclusion

It was observed that the thiol/disulfide homeostasis had shifted towards disulfide, and 8-OHdG levels were increased in adult ADHD patients.

Dynamic thiol/disulphide homeostasis and ischemic modified albumin levels in isolated oligohydramnios

OBJECTIVE

Oligohydramnios is defined as amniotic fluid index in ultrasonographic measurement is less than 5 percentile according to gestational age, the amniotic fluid volume is ≤ 5 cm, or if the single deepest dial is < 2 cm. The condition of oligohydramnios that not with fetal structural/chromosomal abnormalities, intrauterine growth retardation, intrauterine infection and maternal disease is described as isolated oligohydramnios (IO). The aim of this study is to examine whether oxidative stress and reactive oxygen species (ROS) have a place in the pathophysiology of IO.

MATERIALS AND METHODS

In this prospective case-control study, a total of 126 participants were included. The patient group consisted of 65 patients who were diagnosed IO, and the control group consisted of 61 healthy normal pregnants. Native thiol (-SH), total thiol (-SH + -SS), dynamic disulfide (-SS), IMA values from maternal serum were measured and compared between groups.

RESULTS

Maternal serum -SH and -SH + -SS values were significantly lower in the IO group than in the control group (409.47 ± 55.36 μmol/L vs. 437.40 ± 48.68 μmol/L, p = 0.03 and 457.40 ± 63.01 μmol/L vs. 484.59 ± 52.75 μmol/L, p = 0.01). In the IO group when -SS/-SH and -SS/-SH + -SS ratio was found to be statistically significantly higher than control group (5.84 ± 1.1 vs 5.41 ± 0.71, p = 0.01 and 5.2 ± 0.88 vs 4.8 ± 0.58, p = 0.01), -SH/-SH + -SS ratio was significantly lower (89.56 ± 1.7 vs 90.24 ± 1.16, p = 0.01). There was no significant difference in terms of -SS value (p = 0.66). IMA value was significantly higher in the IO group than control group (0.76 ± 0.10 ABSU vs 0.68 ± 0.06, p < 0.01). It is seen as a result of ROC analysis that -SH, -SH + -SS, -SS/-SH, -SS/-SH + -SS, -SH/-SH + -SS and IMA values have a diagnostic value for IO (p < 0.05).

CONCLUSION

The thiol/disulfide balance shifted towards oxidative stress in IO compared to control group. So oxidative stress and ROS have a place in the pathophysiology of IO.

Effects of Panthenol and N-Acetylcysteine on Changes in the Redox State of Brain Mitochondria under Oxidative Stress In Vitro

The glutathione system in the mitochondria of the brain plays an important role in maintaining the redox balance and thiol–disulfide homeostasis, whose violations are the important component of the biochemical shifts in neurodegenerative diseases. Mitochondrial dysfunction is known to be accompanied by the activation of free radical processes, changes in energy metabolism, and is involved in the induction of apoptotic signals. The formation of disulfide bonds is a leading factor in the folding and maintenance of the three-dimensional conformation of many specific proteins that selectively accumulate in brain structures during neurodegenerative pathology. In this study, we estimated brain mitochondria redox status and functioning during induction of oxidative damage in vitro. We have shown that the development of oxidative stress in vitro is accompanied by inhibition of energy metabolism in the brain mitochondria, a shift in the redox potential of the glutathione system to the oxidized side, and activation of S-glutathionylation of proteins. Moreover, we studied the effects of pantothenic acid derivatives—precursors of coenzyme A (CoA), primarily D-panthenol, that exhibit high neuroprotective activity in experimental models of neurodegeneration. Panthenol contributes to the significant restoration of the activity of enzymes of mitochondrial energy metabolism, normalization of the redox potential of the glutathione system, and a decrease in the level of S-glutathionylated proteins in brain mitochondria. The addition of succinate and glutathione precursor N-acetylcysteine enhances the protective effects of the drug.

Folinic Acid as Adjunctive Therapy in Treatment of Inappropriate Speech in Children with Autism: A Double-Blind and Placebo-Controlled Randomized Trial

This is a double-blind, placebo-controlled randomized trial to investigate the potential therapeutic effects of folinic acid/placebo as an adjuvant to risperidone on inappropriate speech and other behavioral symptoms of autism spectrum disorder (ASD). Fifty-five ASD children (age (mean ± standard deviation) = 13.40 ± 2.00; male/female: 35/20) were evaluated for behavioral symptoms at baseline, week 5, and week 10 using the aberrant behavior checklist-community (ABC-C). Folinic acid dosage was 2 mg/kg up to 50 mg per day for the entire course of the study. The repeated measures analysis showed significant effect for time × treatment interaction on inappropriate speech (F = 3.51; df = 1.61; P = 0.044), stereotypic behavior (F = 4.02; df = 1.37; P = 0.036), and hyperactivity/noncompliance (F = 6.79; df = 1.66; P = 0.003) subscale scores. In contrast, no significant effect for time × treatment interaction was found on lethargy/social withdrawal (F = 1.06; df = 1.57; P = 0.336) and irritability (F = 2.86; df = 1.91; P = 0.064) subscale scores. Our study provided preliminary evidence suggesting that folinic acid could be recommended as a beneficial complementary supplement for alleviating speech and behavioral symptoms in children with ASD.Clinical trial registeration: This trial was registered in the Iranian Registry of Clinical Trials ( www.irct.ir ; No. IRCT20090117001556N114).