The Variation of Disulfides in the Progression of Type 2 Diabetes Mellitus

Physical frailty is related to oxidative stress through thiol/disulfide homeostasis parameters

AIM

To evaluate relationship between frailty and oxidative stress through thiol/disulfide homeostasis parameters [Native thiol (NT), total thiol (TT), and disulfide levels (D), disulfide-native thiol (D/NT), disulfide-total thiol (D/TT), native thiol-total thiol (NT/TT) ratios, and ischemia-modified albumin levels (IMA)].

MATERIALS AND METHODS

In total, 139 community-dwelling older adults were included. The frailty status, defined by the FRIED frailty index (FFI) and Clinical Frailty Scale (CFS), and comprehensive geriatric assessment results compared with thiol/disulfide homeostasis parameters and ischemia-modified albumin levels.

RESULTS

NT and TT levels were significantly lower in the frail group (respectively; p = 0.014, p = 0.020). The FFI scores were correlated with the levels of NT, TT, D/NT, D/TT, and NT/TT (respectively; r = - 0.25, r = - 0.24, r = 0.17, r = 0.17, r = - 0.17). The significant correlation could not be retained with the CFS scores. In ROC analysis, the AUC for NT was calculated as 0.639 in diagnosing frailty according to the FFI (95% CI 0.542-0.737), AUC was 0.638 for TT (95% CI 0.540-0.735), and AUC was 0.610 for NT/TT (95% CI 0.511-0.780). The AUC was calculated as 0.610 for both D/NT and D/TT in diagnosing physical frailty (95% CI 0.511-0.708).

CONCLUSION

Thiol/disulfide homeostasis parameters can be a potential biomarker in diagnosing physical frailty. However, further studies are needed for diagnosing frailty defined with cumulative deficit models.

Oxidative Stress Levels and Dynamic Thiol-Disulfide Balance in Preterm Newborns with Bronchopulmonary Dysplasia

OBJECTIVE

The aim of this study was to assess the oxidative stress (OS) levels and dynamic thiol-disulfide balance in preterm newborns with bronchopulmonary dysplasia (BPD).

METHODS

This prospective study included newborns separated into 2 groups, those with BPD (case) or without BPD (control). The 2 groups were compared by clinical and laboratory findings. The OS parameters total oxidant status (TOS), total antioxidant status (TAS), OS index (OSI), native thiol (NT), and total thiol were measured within the first day after birth. Oxygen requirements were measured using the fraction of inspired oxygen (FIO2) recorded in the first hour after birth/admission and the average FIO2 within 28 days of the birth.

RESULTS

Infants diagnosed with BPD had a significantly lower gestational age and birth weight and a lower 5-min Apgar score (P < .05). Infants with BPD also had a higher rate of respiratory distress syndrome, rate of use of surfactant therapy, duration of ventilation therapy, and duration of hospital stay compared with control (P = .001, P = .001, P = .001, and P = .001, respectively). Plasma TAS and NT levels of newborns with BPD were significantly lower than newborns without BPD (P < .05). In the BPD group, plasma TOS and OSI levels were significantly higher than in the control group.

CONCLUSION

We found that OS was increased in newborns with BPD. The clinical significance of this study will provide the clinician with a different perspective on BPD by determining the dynamic thiol disulfide balance.

Reactive Sulfur Species in Human Diseases

Significance: Reactive sulfur species (RSS) have been recently recognized as redox molecules no less important than reactive oxygen species or reactive nitrogen species. They possess regulatory and protective properties and are involved in various metabolic processes, thereby contributing to the maintenance of human health. It has been documented that many disorders, including neurological, cardiovascular, and respiratory diseases, diabetes mellitus (DM), and cancer, are related to the disruption of RSS homeostasis. Recent Advances: There is still a growing interest in the role of RSS in human diseases. Since a decrease in hydrogen sulfide or other RSS has been reported in many disorders, safe and efficient RSS donors have been developed and tested under in vitro conditions or on animal models. Critical Issues: Cardiovascular diseases and DM are currently the most common chronic diseases worldwide due to stressful and unhealthy lifestyles. In addition, because of high prevalence and aging of the population, neurological disorders including Parkinson's disease and Alzheimer's disease as well as respiratory diseases are a formidable challenge for health care systems. From this point of view, the knowledge of the role of RSS in these disorders and RSS modulation options are important and could be useful in therapeutic strategies. Future Directions: Improvement and standardization of analytical methods used for RSS estimation are crucial for the use of RSS as diagnostic biomarkers. Finding good, safe RSS donors applicable for therapeutic purposes could be useful as primary or adjunctive therapy in many common diseases. Antioxid. Redox Signal. 39, 1000-1023.

Thiol disulfide homeostasis in psychiatric disorders: A comprehensive review

Thiol-disulfide couple maintains an intracellular redox status. Dynamic thiol-disulfide homeostasis acts crucial parts in metabolic processes involving signal mechanisms, inflammation, antioxidant defense. Thiol-disulfide homeostasis have been implicated in numerous diseases. In this comprehensive review we identified the studies that examined the thiol-disulfide homeostasis in psychiatric disorders. Most cases demonstrated alterations in thiol-disulfide homeostasis and in most of them the thiol-disulfide balance tended to change direction to the disulfide side, that is, to the oxidative side. Currently, the fact that N-acetylcysteine, a thiol-containing compound, is of great interest as a new treatment approach in psychiatric disorders and the role of glutathione, the most abundant thiol, in the brain highlights the importance of evaluating the thiol-disulfide balance in psychiatric disorders.

The role of protein oxidation in the development of diabetic microvascular complications

OBJECTIVE

The role of protein oxidation in the development of diabetic microvascular complications was investigated.

METHODS

In total, 266 participants were split into five groups: Group 1; diabetes mellitus for at least 10 years without any complications, Group 2; diabetic nephropathy, Group 3; diabetic neuropathy, Group 4; diabetic retinopathy, and Group 5; control group. Thiol, disulfide, ferroxidase, and ischemia-modified albumin (IMA) levels were analyzed in the serum.

RESULTS

Native thiol, total thiol, and native thiol/total thiol were lower in Group 4 than Groups 1, 3, and 5 (p<0.001). However, disulfide/native thiol and disulfide/total thiol were higher in Group 4 than all other groups (p<0.001). IMA was higher in Groups 3 and 4 than all other groups (p<0.001). Ferroxidase was lower in Groups 3 and 4 than Group 2 (p<0.001).

CONCLUSION

Thiol-disulfide homeostasis impairment in favor of disulfide may have a function in the progress of diabetic retinopathy. Furthermore, the disruptions of IMA and ferroxidase levels involve in the development of diabetic retinopathy and neuropathy.

Total thiol can contribute to differentiating prostate cancer from BPH: Prostate Thiol Index as a new player

To assess the distinctiveness of serum native thiol (NT), total thiol (TT) and disulfide (SS) levels in PCa patients, we created a new parameter, prostate thiol index (PTI) [tPSA (TTxPVxAge) ^-1/2 ]. We determined the performance of the PTI on PCa diagnosis. A total of 107 male patients (PCa:65; BPH:42) who were separated according to their Gleason scores, ISUP grades and EAU risk groups and 20 healthy subjects were included. The performances of the tests were determined. The PCa and BPH groups had lower NT and TT levels and higher SS levels than the control group. PCa patients had higher PTI, tPSA, fPSA, PSAD levels, lower fPSA%, PV and PSA-AV levels than BPH patients. TT, PTI, tPSA, fPSA, fPSA%, PSA-AV, PSAD and PV had significant diagnostic performances. PTI had the highest AUC value and accuracy, PSA-AV had the highest specificity, and fPSA had the lowest sensitivity. The performance of the PTI was the best in distinguishing PCa from BPH. PTI, tPSA and PSAD positively and PSA-AV negatively correlated with ISUP grades and EAU groups. TT can contribute to the discrimination of PCa from BPH and PTI may decrease unnecessary biopsies in clinical practice.

Does plasma thiol and disulphide be a new marker for prostate cancer in prostate-specific antigen level between 10 and 20 ng/ml?

INTRODUCTION

We aimed to evaluate plasma thiol and disulphide levels as an additional marker to prostate specific antigen (PSA) in the diagnosis of prostate cancer (PCa).

METHODS

Between March 2017 and January 2018 prospective study was conducted among patients with PSA levels of 2.5-20 ng/mL without suspicion of malignancy in rectal examination and who underwent prostate needle biopsy. Patients were divided into two groups according to PSA level as 2.5-10 ng/mL (Group 1) and 10.01-20 ng/mL (Group 2). Diagnostic efficacy of thiol, disulphide and PSA levels were measured by ROC analysis.

RESULTS

A total of 76 patients were included in the study. There were 49 patients in group 1 and 27 patients in group 2. There was no significant difference between two groups in terms of PSA density and prostate size. In Group 1, area under curve (AUC) was higher in PSA than other parameters with statistically significant difference (p<.05). In group 2, AUC of native and total thiol was higher than PSA but there was no statistically significant difference for AUC in parameters.

CONCLUSIONS

We think that plasma thiol test may be used in diagnosis of prostate cancer while PSA levels between 10 to 20 ng/mL. However, further studies are required.

Thiol-disulfide homeostasis: an integrated approach with biochemical and clinical aspects

Dynamic thiol-disulfide homeostasis (TDH) is a new area has begun to attract more scrutiny. Dynamic TDH is reversal of thiol oxidation in proteins and represents the status of thiols (-SH) and disulfides (-S-S-). Organic compounds containing the sulfhydryl group is called thiol, composed of sulfur and hydrogen atoms. Disulfides are the most important class of dynamic, redox responsive covalent bonds build in between two thiol groups. For many years, thiol levels were analyzed by several methods. During last years, measurements of disulfide levels have been analyzed by a novel automated method, developed by Erel and Neselioglu. In this method, addition to thiol (termed as native thiol) levels, disulfide levels were also measured and sum of native thiol and disulfide levels were termed as total thiol. Therefore, TDH was begun to be understood in organism. In healthy humans, TDH is maintained within a certain range. Dysregulated dynamic TDH has been implicated several disorders with unknown etiology. A growing body of evidence has demonstrated that the thiol-disulfide homeostasis is involved in variety diseases, such as diabetes mellitus, hypertension, nonsmall cell lung cancer, familial Mediterranean fever (FMF), inflammatory bowel diseases, occupational diseases, gestational diabetes mellitus and preeclampsia. These results may elucidate some pathogenic mechanism or may be a predictor indicating diagnostic clue, prognostic marker or therapeutic sign. In conclusion, protection of the thiol-disulfide homeostasis is of great importance for the human being. Evidence achieved so far has proposed that thiol-disulfide homeostasis is an important issue needs to elucidate wholly.

Relationship between diabetic polyneuropathy, serum visfatin, and oxidative stress biomarkers

BACKGROUND

Diabetic polyneuropathy is a very common complication of diabetes. Numerous studies are available in terms of pathogenesis. But examination methods with low reliability are still not standardized and generally time consuming. High-sensitive, easy-to-access methods are expected. Biochemical markers are one of the subjects of research. We aimed to discover a potential biomarker that can be used for this purpose in patients with diabetes who have not yet developed symptoms of neuropathy.

AIM

To determine the place and availability of visfatin and thiol-disulfide homeostasis in this disorder.

METHODS

A total of 392 patients with type 2 diabetes mellitus were included in the study. The polyneuropathy clinical signs were evaluated with the Subjective Peripheral Neuropathy Screen Questionnaire and Michigan Neuropathy Screening Instrument questionnaire and examination. The biochemical parameters, oxidative stress markers, visfatin, and thiol-disulfide homeostasis were analyzed and correlated with each other and clinical signs.

RESULTS

Subjective Peripheral Neuropathy Screen Questionnaire and Michigan Neuropathy Screening Instrument questionnaire with examination scores were correlated with each other and diabetes duration (P < 0.005). Neuropathy related symptoms were present in 20.7% of the patients, but neuropathy related findings were observed in 43.9% of the patients. Serum glucose, glycated hemoglobin, and visfatin were positively correlated with each other. Also, these parameters were positively correlated with the total oxidative stress index. Total and native thiol was positively correlated with total antioxidant status and negatively with oxidant status. Inversely thiol-disulfide positively correlated with higher glucose and oxidant status and negatively with total antioxidant status (P < 0.005). There was no correlation between visfatin and thiol-disulphide (P = 0.092, r = 0.086). However, a significant negative correlation was observed between visfatin and total with native thiol (P < 0.005, r = -0.338), (P < 0.005, r = -0.448).

CONCLUSION

Diagnosis of neuropathy is one of the issues studied in patients with diabetes. Visfatin and thiol-disulfide balance were analyzed for the first time in this study with inspiring results.

Dynamic thiol/disulphide homeostasis in patients with hypertrophic cardiomyopathy

BACKGROUND

In addition to the genetic complexity of hypertrophic cardiomyopathy (HCM), there must be other disease-modifying factors that contribute to its highly variable clinical and phenotypic expression. The authors aimed to investigate serum thiol/disulphide homeostasis as a proxy for oxidative stress using a novel automated assay in patients with HCM.

METHODS

This cross-sectional study was conducted on 119 patients with HCM and 52 without HCM. The methods used to measure dynamic thiol/disulphide homeostasis as calorimetric and duplex quantities were developed in 2014.

RESULTS

Median serum native thiol levels were significantly lower in patients with HCM than in those without (312.5 μmol/L [285-370 μmol/L] vs 421 μmol/L [349-469.5 μmol/L]; p < 0.001). Serum total thiol levels and disulphide levels were considerably lower than those in the control group ([844.68 ± 195.99 μmol/L vs 1158.92 ± 243.97 μmol/L; p < 0.001], [259.13 ± 65.66 μmol/L vs 375.02 ± 79.99 μmol/L; p < 0.001], respectively). Serum disulphide/native thiol ratios and disulphide/total thiol ratios were significantly lower in HCM patients than in controls (0.80 ± 0.09 vs 0.92 ± 0.05; p < 0.001 and 0.31 [0.30-0.32] vs 0.32 [0.32-0.33]; p < 0.001). Finally, reduced thiol ratios were higher and oxidized thiol ratios were significantly lower in patients with HCM than in controls.

CONCLUSIONS

Despite the fact that antioxidant capacity was impaired, the extracellular environment remained in a reducing state by keeping serum disulphide/native thiol ratios low. Therefore, the authors speculate that HCM may behave similarly to tumours with respect to serum thiol-disulphide levels.