Daily rhythms of catalase and glutathione peroxidase expression and activity are endogenously driven in the hippocampus and are modified by a vitamin A-free diet

Gender-specific association of SLC19A1 and MTHFR genetic polymorphism with oxidative stress biomarkers and plasma folate levels in older adults

BACKGROUND

Plasma folate levels are closely related to antioxidant capacity and are regulated by folate pathway gene polymorphism. However, few studies have explored the gender-specific association of folate pathway gene polymorphism with oxidative stress biomarkers. The present study was designed to explore the gender-specific independent and combined impacts of solute carrier family 19 member 1 (SLC19A1) and methylenetetrahydrofolate reductase (MTHFR) genetic polymorphisms on oxidative stress biomarkers in older adults.

METHODS

A total of 401 subjects were recruited, including 145 males and 256 females. Demographic characteristics of the participants were collected by using a self-administered questionnaire. Fasting venous blood samples were taken for folate pathway gene genotyping, circulating lipids parameters and erythrocyte oxidative stress biomarkers measurement. The difference of genotype distribution and the Hardy-Weinberg equilibrium was calculated by the Chi-square test. The general linear model was applied to compare the plasma folate levels and erythrocyte oxidative stress biomarkers. Multiple linear regression was used to explore the correlation between genetic risk scores and oxidative stress biomarkers. Logistic regression was used to explore the association of genetic risk scores of folate pathway gene with folate deficiency.

RESULTS

The male subjects have lower plasma folate and HDL-C levels than the female ones, and the male carrying MTHFR rs1801133 (CC) or MTHFR rs2274976 (GA) genotypes have higher erythrocyte SOD activity. The plasma folate levels, erythrocyte SOD and GSH-PX activities were negatively correlated with genetic risk scores in the male subjects. A positive correlation between the genetic risk scores and folate deficiency was observed in the male subjects.

CONCLUSIONS

There was association between folate pathway gene polymorphism of Solute Carrier Family 19 Member 1 (SLC19A1) and Methylenetetrahydrofolate Reductase (MTHFR) with erythrocyte SOD and GSH-PX activities, and folate levels in male but not in female aging subjects. Genetic variant of genes involved in folate metabolism has strong impact on plasma folate levels in the male aging subjects. Our data demonstrated that there was a potential interaction of gender and its genetic background in affecting the body's antioxidant capacity and the risk of folate deficiency in aging subjects.

Antioxidant Defense and Pseudoexfoliation Syndrome: An Updated Review

Oxidative stress (OS) affects the anterior ocular tissues, rendering them susceptible to several eye diseases. On the other hand, protection of the eye from harmful factors is achieved by unique defense mechanisms, including enzymatic and non-enzymatic antioxidants. The imbalance between oxidants and antioxidants could be the cause of pseudoexfoliation syndrome (PEXS), a condition of defective extracellular matrix (ECM) remodeling. A systematic English-language literature review was conducted from May 2022 to June 2022. The main antioxidant enzymes protecting the eye from reactive oxygen species (ROS) are superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), which catalyze the reduction of specific types of ROS. Similarly, non-enzymatic antioxidants such as vitamins A, E and C, carotenoids and glutathione (GSH) are involved in removing ROS from the cells. PEXS is a genetic disease, however, environmental and dietary factors also influence its development. Additionally, many OS products disrupting the ECM remodeling process and modifying the antioxidative defense status could lead to PEXS. This review discusses the antioxidative defense of the eye in association with PEXS, and the intricate link between OS and PEXS. Understanding the pathways of PEXS evolution, and developing new methods to reduce OS, are crucial to control and treat this disease. However, further studies are required to elucidate the molecular pathogenesis of PEXS.

Cognitive Impairment and Psychopathology Are Related to Plasma Oxidative Stress in Long Term Hospitalized Patients With Chronic Schizophrenia

BACKGROUND

The present study aimed to examine whether plasma oxidative stress is associated with cognitive impairment in long term hospitalized patients with chronic schizophrenia.

METHOD

Ninety-six chronic schizophrenia patients and 94 healthy unaffected subjects were enrolled. Plasma markers of oxidative stress, including malondialdehyde (MDA), manganese superoxide dismutase (MnSOD), catalase (CAT), and glutathione peroxidase (GSH-Px), were measured. Psychiatric symptoms and cognitive function were assessed with the Positive and Negative Syndrome Scale (PANSS) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), respectively.

RESULTS

Plasma MDA levels and MnSOD and GSH-Px activities were significantly lower in schizophrenia patients than in healthy controls (P < 0.001), while plasma CAT activity was higher than in healthy controls (P < 0.005). Cognitive scores on the RBANS and all of its five subscales (all P < 0.001) were significantly lower in schizophrenia patients than in healthy unaffected subjects. CAT and GSH-Px activities were positively correlated with the cognitive function scores corresponding to Visuospatial/Constructional abilities in the patient group (r = 0.298, 0.213, respectively, P < 0.05). Also, the multiple regression analysis revealed that CAT and GSH-Px activities were independent and separate contributors to the Visuospatial/Constructional index of the RBANS. Meanwhile, CAT activity was negatively correlated with general pathological symptoms (r = -0.307, Bonferroni corrected P = 0.008) and the total score of the PANSS domains (r = -0.299, Bonferroni corrected P = 0.012).

CONCLUSION

Our results that the reduced of MDA level and the increased CAT activity in plasma in male patients with chronic schizophrenia suggest that redox imbalance may be associated with the pathophysiology of schizophrenia, and it can induce impaired cognition and psychiatric symptoms.

An overview of the emerging interface between cardiac metabolism, redox biology and the circadian clock

At various biological levels, mammals must integrate with 24-hr rhythms in their environment. Daily fluctuations in stimuli/stressors of cardiac metabolism and oxidation-reduction (redox) status have been reported over the course of the day. It is therefore not surprising that the heart exhibits dramatic oscillations in various cellular processes over the course of the day, including transcription, translation, ion homeostasis, metabolism, and redox signaling. This temporal partitioning of cardiac processes is governed by a complex interplay between intracellular (e.g., circadian clocks) and extracellular (e.g., neurohumoral factors) influences, thus ensuring appropriate responses to daily stimuli/stresses. The purpose of the current article is to review knowledge regarding control of metabolism and redox biology in the heart over the course of the day, and to highlight whether disruption of these daily rhythms contribute towards cardiac dysfunction observed in various disease states.

Real-Time Amperometric Recording of Extracellular H₂O₂ in the Brain of Immunocompromised Mice: An In Vitro, Ex Vivo and In Vivo Characterisation Study

We detail an extensive characterisation study on a previously described dual amperometric H₂O₂ biosensor consisting of H₂O₂ detection (blank) and degradation (catalase) electrodes. In vitro investigations demonstrated excellent H₂O₂ sensitivity and selectivity against the interferent, ascorbic acid. Ex vivo studies were performed to mimic physiological conditions prior to in vivo deployment. Exposure to brain tissue homogenate identified reliable sensitivity and selectivity recordings up to seven days for both blank and catalase electrodes. Furthermore, there was no compromise in pre- and post-implanted catalase electrode sensitivity in ex vivo mouse brain. In vivo investigations performed in anaesthetised mice confirmed the ability of the H₂O₂ biosensor to detect increases in amperometric current following locally perfused/infused H₂O₂ and antioxidant inhibitors mercaptosuccinic acid and sodium azide. Subsequent recordings in freely moving mice identified negligible effects of control saline and sodium ascorbate interference injections on amperometric H₂O₂ current. Furthermore, the stability of the amperometric current was confirmed over a five-day period and analysis of 24-h signal recordings identified the absence of diurnal variations in amperometric current. Collectively, these findings confirm the biosensor current responds in vivo to increasing exogenous and endogenous H₂O₂ and tentatively supports measurement of H₂O₂ dynamics in freely moving NOD SCID mice.

Humoral and mucosal defense molecules rhythmically oscillate during a light-dark cycle in permit, Trachinotus falcatus

Circadian rhythm provides organisms with an internal system to maintain temporal order in a dynamic environment. This is typified by a 24-h cycle for a number of physiological processes, including immunity. The present study characterized the humoral and mucosal defense molecules and their dynamics during a light-dark (LD) cycle in juvenile permit, Trachinotus falcatus. All studied defense molecules were constitutively identified in serum and skin mucus. Serum generally exhibited higher levels of these defenses than skin mucus, with the exception of anti-protease (ANTIPRO). The difference in ANTIPRO, lysozyme (LYZ), esterase (ESA) and catalase (CAT) levels between serum and skin mucus was not affected by the phase of the daily cycle. However, a clear phase-dependent difference was observed in protease (PRO), globulin (GLOB), myeloperoxidase (MPO), alkaline phosphatase (ALP) and glutathione peroxidase (GPX) levels. Activities of ALP and GPX displayed significant daily rhythmicity in both serum and skin mucus. Circadian profile of ALP was identical in both biofluids, but an antiphasic feature was exhibited by GPX. GLOB and MPO levels also exhibited significant daily oscillation but only in serum with acrophases registered at ZT 14.5 and 6.15, respectively. Mucus PRO and serum ANTIPRO demonstrated significant temporal variations during a daily cycle albeit not rhythmic. Cluster analysis of the defense molecules in serum and skin mucus revealed two different daily profiles suggesting a possibility of distinct circadian control between humoral and mucosal immunity. These observations indicate that LD cycle had a remarkable impact in the defense molecules characterizing the humoral and mucosal immunity in permit. Daily rhythmic patterns of these defense molecules contribute to our understanding of the barely explored interplay of immunity and circadian rhythm in teleost fish. Lastly, the results could be useful in developing aquaculture practices aiming at modifying the immune functions of permit for improved health.

Skin, reactive oxygen species, and circadian clocks

SIGNIFICANCE

Skin, a complex organ and the body's first line of defense against environmental insults, plays a critical role in maintaining homeostasis in an organism. This balance is maintained through a complex network of cellular machinery and signaling events, including those regulating oxidative stress and circadian rhythms. These regulatory mechanisms have developed integral systems to protect skin cells and to signal to the rest of the body in the event of internal and environmental stresses.

RECENT ADVANCES

Interestingly, several signaling pathways and many bioactive molecules have been found to be involved and even important in the regulation of oxidative stress and circadian rhythms, especially in the skin. It is becoming increasingly evident that these two regulatory systems may, in fact, be interconnected in the regulation of homeostasis. Important examples of molecules that connect the two systems include serotonin, melatonin, vitamin D, and vitamin A.

CRITICAL ISSUES

Excessive reactive oxygen species and/or dysregulation of antioxidant system and circadian rhythms can cause critical errors in maintaining proper barrier function and skin health, as well as overall homeostasis. Unfortunately, the modern lifestyle seems to contribute to increasing alterations in redox balance and circadian rhythms, thereby posing a critical problem for normal functioning of the living system.

FUTURE DIRECTIONS

Since the oxidative stress and circadian rhythm systems seem to have areas of overlap, future research needs to be focused on defining the interactions between these two important systems. This may be especially important in the skin where both systems play critical roles in protecting the whole body.