Systemic Redox Imbalance in Patients with Chronic Granulomatous Disease

The interplay between oxidative stress and inflammation supports autistic-related behaviors in Cntnap2 knockout mice

Autism Spectrum Disorder (ASD) is a highly prevalent neurodevelopmental condition characterized by social communication deficits and repetitive/restricted behaviors. Several studies showed that oxidative stress and inflammation may contribute to ASD. Indeed, increased levels of oxygen radicals and pro-inflammatory molecules were described in the brain and peripheral blood of persons with ASD and mouse models. Despite this, a potential direct connection between oxidative stress and inflammation within specific brain areas and ASD-related behaviors has not been investigated in detail yet. Here, we used RT-qPCR, RNA sequencing, metabolomics, immunohistochemistry, and flow cytometry to show that pro-inflammatory molecules were increased in the cerebellum and periphery of mice lacking Cntnap2, a robust model of ASD. In parallel, oxidative stress was present in the cerebellum of mutant animals. Systemic treatment with N-acetyl-cysteine (NAC) rescued cerebellar oxidative stress, inflammation, as well as motor and social impairments in Cntnap2-/- mice, concomitant with enhanced function of microglia cells in NAC-treated mutants. Intriguingly, social deficits, cerebellar inflammation, and microglia dysfunction were induced by NAC in Cntnap2+/+ animals. Our findings suggest that the interplay between oxidative stress and inflammation accompanied by genetic vulnerability may underlie ASD-related behaviors in Cntnap2 mutant mice.

Redox Status Response of Physical Exercise Training in Women with Breast Cancer during Trastuzumab Therapy

Trastuzumab is indicated in the adjuvant setting for the early and intermediate stages of breast cancer (BC) positive for epidermal growth factor receptor 2 (HER2). Although HER2 in BC patients tends to disrupt pro-oxidant and inflammatory signaling, the influence of trastuzumab in modulating this process remains unknown. Due to the absence of any chemotherapeutic or chemoprophylactic agents for trastuzumab-induced side effects, this study investigated the potential role of regular physical exercise in modulating the antioxidant defenses, oxidative stress, and nitrosative damage in BC patients during trastuzumab treatment.

AIM

The study aimed to analyze the relationship between regular physical activity and the redox status in women with BC during trastuzumab therapy.

MATERIALS AND METHODS

We observed 50 BC patients during trastuzumab therapy in two groups: one that undertook moderately intensive supervised physical exercises, and a second that performed physical activity according to the recommendations for cancer patients, along with a third (control) group of healthy women.

RESULTS

The antioxidant enzyme and non-enzymatic antioxidant activities were significantly higher in the exercised group compared with the other participants. The concentrations of lipid and protein oxidative damage and nitrosative stress products were significantly higher in both BC groups than in the healthy controls.

CONCLUSIONS

Trastuzumab treatment stimulates a redox response in BC patients. The results highlight the oxidative imbalance in parallel with regular physical training in women with BC during trastuzumab therapy. Further studies are needed to analyze different intensities and levels of physical training in women with BC during trastuzumab treatment.

The Multiple Faces of Nitric Oxide in Chronic Granulomatous Disease: A Comprehensive Update

Nitric oxide (NO), a signaling molecule, regulates multiple biological functions, including a variety of physiological and pathological processes. In this regard, NO participates in cutaneous inflammations, modulation of mitochondrial functions, vascular diseases, COVID-19, neurologic diseases, and obesity. It also mediates changes in the skeletal muscle function. Chronic granulomatous disease (CGD) is a primary immunodeficiency disorder characterized by the malfunction of phagocytes caused by mutations in some of the genes encoding subunits of the superoxide-generating phagocyte NADPH (NOX). The literature consulted shows that there is a relationship between the production of NO and the NADPH oxidase system, which regulates the persistence of NO in the medium. Nevertheless, the underlying mechanisms of the effects of NO on CGD remain unknown. In this paper, we briefly review the regulatory role of NO in CGD and its potential underlying mechanisms.

Mitochondrial Reactive Oxygen Species Regulate Immune Responses of Macrophages to Aspergillus fumigatus

Reactive Oxygen Species (ROS) are highly reactive molecules that can induce oxidative stress. For instance, the oxidative burst of immune cells is well known for its ability to inhibit the growth of invading pathogens. However, ROS also mediate redox signalling, which is important for the regulation of antimicrobial immunity. Here, we report a crucial role of mitochondrial ROS (mitoROS) in antifungal responses of macrophages. We show that mitoROS production rises in murine macrophages exposed to swollen conidia of the fungal pathogen Aspergillus fumigatus compared to untreated macrophages, or those treated with resting conidia. Furthermore, the exposure of macrophages to swollen conidia increases the activity of complex II of the respiratory chain and raises mitochondrial membrane potential. These alterations in mitochondria of infected macrophages suggest that mitoROS are produced via reverse electron transport (RET). Significantly, preventing mitoROS generation via RET by treatment with rotenone, or a suppressor of site IQ electron leak, S1QEL1.1, lowers the production of pro-inflammatory cytokines TNF-α and IL-1β in macrophages exposed to swollen conidia of A. fumigatus. Rotenone and S1QEL1.1 also reduces the fungicidal activity of macrophages against swollen conidia. Moreover, we have established that elevated recruitment of NADPH oxidase 2 (NOX2, also called gp91phox) to the phagosomal membrane occurs prior to the increase in mitoROS generation. Using macrophages from gp91phox-/- mice, we have further demonstrated that NOX2 is required to regulate cytokine secretion by RET-associated mitoROS in response to infection with swollen conidia. Taken together, these observations demonstrate the importance of RET-mediated mitoROS production in macrophages infected with A. fumigatus.

Salivary Gland Dysfunction in Stroke Patients Is Associated with Increased Protein Glycoxidation and Nitrosative Stress

Stroke is one of the leading causes of disability and death worldwide. Despite intensive medical care, many of the complaints directly threatening the patient's life marginalize their dental needs after the stroke. Recent studies indicate reduced saliva secretion in stroke patients in addition to the increased incidence of caries and periodontal disease. Since oxidative stress plays a vital role in the pathogenesis of salivary gland hypofunction and neurodegenerative disorders (including stroke), this is the first to evaluate the relationship between salivary gland activity and protein glycoxidation and nitrosative damage. The content of glycation and protein oxidation products and nitrosative stress was assessed in nonstimulated (NWS) and stimulated (SWS) whole saliva of stroke patients with normal salivary secretion and hyposalivation (reduced saliva production). The study included 30 patients in the stroke's subacute phase and 30 healthy controls matched by age and sex. We have shown that stroke patients with hyposalivation show increased contents of protein glycation (↑Amadori products and ↑advanced glycation end products), glycoxidation (↑dityrosine), and nitration (↑nitrotyrosine) products compared to stroke cases with normal salivary secretion and control group. Interestingly, higher oxidative/nitrosative stress was found in NWS, which strongly correlates with salivary flow rate, total protein content, and salivary amylase activity. Such relationships were not observed in the control group. Summarizing, oxidative and nitrosative stress may be one of the mechanisms responsible for the impairment of saliva secretion in stroke patients. However, extraglandular sources of salivary oxidative stress in stroke patients cannot be excluded. Further studies to assess salivary gland hypofunction in stroke cases are necessary.

High-Sugar Diet Disrupts Hypothalamic but Not Cerebral Cortex Redox Homeostasis

Despite several reports on the relationship between metabolic and neurodegenerative diseases, the effect of a high-sugar diet (HSD) on brain function is still unknown. Given the crucial role of oxidative stress in the pathogenesis of these disorders, this study was the first to compare the effect of an HSD on the activity of prooxidative enzymes, enzymatic and non-enzymatic antioxidants, and protein oxidative damage in the brain structures regulating energy metabolism (hypothalamus) and cognitive functions (cerebral cortex). Male Wistar rats were randomly divided into two groups (n = 10)-control diet (CD) and high-sugar diet (HSD)-for 8 weeks. We showed a decrease in glutathione peroxidase and superoxide dismutase activity and an increase in catalase activity in the hypothalamus of HSD rats compared to controls. The activity of xanthine oxidase and NADPH oxidase and the contents of oxidation (protein carbonyls), glycoxidation (dityrosine, kynurenine and N-formylkynurenine) and protein glycation products (advanced glycation end products and Amadori products) were significantly higher only in the hypothalamus of the study group. The HSD was also responsible for the disruption of antioxidant systems and oxidative damage to blood proteins, but we did not show any correlation between systemic redox homeostasis and the brain levels. In summary, HSD is responsible for disorders of enzymatic antioxidant defenses only at the central (plasma/serum) and hypothalamic levels but does not affect the cerebral cortex. The hypothalamus is much more sensitive to oxidative damage caused by an HSD than the cerebral cortex.

A New Insight into Meloxicam: Assessment of Antioxidant and Anti-Glycating Activity in In Vitro Studies

Meloxicam is a non-steroidal anti-inflammatory drug, which has a preferential inhibitory effect to cyclooxyganase-2 (COX-2). Although the drug inhibits prostaglandin synthesis, the exact mechanism of meloxicam is still unknown. This is the first study to assess the effect of meloxicam on protein glyco-oxidation as well as antioxidant activity. For this purpose, we used an in vitro model of oxidized bovine serum albumin (BSA). Glucose, fructose, ribose, glyoxal and methylglyoxal were used as glycating agents, while chloramine T was used as an oxidant. We evaluated the antioxidant properties of albumin (2,2-di-phenyl-1-picrylhydrazyl radical scavenging capacity, total antioxidant capacity and ferric reducing antioxidant power), the intensity of protein glycation (Amadori products, advanced glycation end products) and glyco-oxidation (dityrosine, kynurenine, N-formylkynurenine, tryptophan and amyloid-β) as well as the content of protein oxidation products (advanced oxidation protein products, carbonyl groups and thiol groups). We have demonstrated that meloxicam enhances the antioxidant properties of albumin and prevents the protein oxidation and glycation under the influence of various factors such as sugars, aldehydes and oxidants. Importantly, the antioxidant and anti-glycating activity is similar to that of routinely used antioxidants such as captopril, Trolox, reduced glutathione and lipoic acid as well as protein glycation inhibitors (aminoguanidine). Pleiotropic action of meloxicam may increase the effectiveness of anti-inflammatory treatment in diseases with oxidative stress etiology.