Antioxidant peptides, the guardian of life from oxidative stress.

Reactive oxygen species (ROS) are produced during oxidative metabolism in aerobic organisms. Under normal conditions, ROS production and elimination are in a relatively balanced state. However, under internal or external environmental stress, such as high glucose levels or UV radiation, ROS production can increase significantly, leading to oxidative stress. Excess ROS production not only damages biomolecules but is also closely associated with the pathogenesis of many diseases, such as skin photoaging, diabetes, and cancer. Antioxidant peptides (AOPs) are naturally occurring or artificially designed peptides that can reduce the levels of ROS and other pro-oxidants, thus showing great potential in the treatment of oxidative stress-related diseases. In this review, we discussed ROS production and its role in inducing oxidative stress-related diseases in humans. Additionally, we discussed the sources, mechanism of action, and evaluation methods of AOPs and provided directions for future studies on AOPs.

Aldehyde Dehydrogenase 2 as a Therapeutic Target in Oxidative Stress-Related Diseases: Post-Translational Modifications Deserve More Attention.

Aldehyde dehydrogenase 2 (ALDH2) has both dehydrogenase and esterase activity; its dehydrogenase activity is closely related to the metabolism of aldehydes produced under oxidative stress (OS). In this review, we recapitulate the enzyme activity of ALDH2 in combination with its protein structure, summarize and show the main mechanisms of ALDH2 participating in metabolism of aldehydes in vivo as comprehensively as possible; we also integrate the key regulatory mechanisms of ALDH2 participating in a variety of physiological and pathological processes related to OS, including tissue and organ fibrosis, apoptosis, aging, and nerve injury-related diseases. On this basis, the regulatory effects and application prospects of activators, inhibitors, and protein post-translational modifications (PTMs, such as phosphorylation, acetylation, S-nitrosylation, nitration, ubiquitination, and glycosylation) on ALDH2 are discussed and prospected. Herein, we aimed to lay a foundation for further research into the mechanism of ALDH2 in oxidative stress-related disease and provide a basis for better use of the ALDH2 function in research and the clinic.

[Stress Medicine and Human Health].

Stress is an nonspecific adaptive response to endogenous or exogenous stimuli, which is commonly applied by organisms to maintain their internal homeostasis and normal physiological functions. When the extent of stress response surpasses the threshold that the organism can adjust to, a variety of physiological or psychological diseases can be induced by stress response. Stress medicine focuses on investigating the mechanisms underlying the development and progression of the diseases induced by stress response, aiming to find ways to prevent and treat stress-related diseases. Here, we will start with an introduction of stress response, then review the recent advances of stress medicine by discussing the latest research advances in the regulatory mechanisms and biological functions of stress response under various physiological or pathological conditions.

Nanomedicines Targeting Ferroptosis to Treat Stress-Related Diseases.

Ferroptosis, a unique form of regulated cell death driven by iron-dependent lethal lipid peroxidation, is implicated in various stress-related diseases like neurodegeneration, vasculopathy, and metabolic disturbance. Stress-related diseases encompass widespread medical disorders that are influenced or exacerbated by stress. These stressors can manifest in various organ or tissue systems and have significant implications for human overall health. Understanding ferroptosis in these diseases offers insights for therapeutic strategies targeting relevant pathways. This review explores ferroptosis mechanisms, its role in pathophysiology, its connection to stress-related diseases, and the potential of ferroptosis-targeted nanomedicines in treating conditions. This monograph also delves into the engineering of ferroptosis-targeted nanomedicines for tackling stress-related diseases, including cancer, cardia-cerebrovascular, neurodegenerative, metabolic and inflammatory diseases. Anyhow, nanotherapy targeting ferroptosis holds promise by both promoting and suppressing ferroptosis for managing stress-related diseases.

Antioxidant Hydrogels: Antioxidant Mechanisms, Design Strategies, and Applications in the Treatment of Oxidative Stress-Related Diseases.

Oxidative stress is a biochemical process that disrupts the redox balance due to an excess of oxidized substances within the cell. Oxidative stress is closely associated with a multitude of diseases and health issues, including cancer, diabetes, cardiovascular diseases, neurodegenerative disorders, inflammatory conditions, and aging. Therefore, the developing of antioxidant treatment strategies has emerged as a pivotal area of medical research. Hydrogels have garnered considerable attention due to their exceptional biocompatibility, adjustable physicochemical properties, and capabilities for drug delivery. Numerous antioxidant hydrogels have been developed and proven effective in alleviating oxidative stress. In the pursuit of more effective treatments for oxidative stress-related diseases, there is an urgent need for advanced strategies for the fabrication of multifunctional antioxidant hydrogels. Consequently, the authors' focus will be on hydrogels that possess exceptional reactive oxygen species and reactive nitrogen species scavenging capabilities, and their role in oxidative stress therapy will be evaluated. Herein, the antioxidant mechanisms and the design strategies of antioxidant hydrogels and their applications in oxidative stress-related diseases are discussed systematically in order to provide critical insights for further advancements in the field.

Understanding Psychological Symptoms of Endometriosis from a Research Domain Criteria Perspective.

Endometriosis is currently the second most common gynecological disease and is associated with severe pain, vegetative impairment, and infertility. In association, there are considerable psychological symptoms that limit the quality of life of those affected. In this narrative review, the Research Domain Criteria (RDoC) framework was utilized to display the different transdiagnostic processes involved in disease progression and maintenance in regard to psychosocial functioning. Using the RDoC framework, it becomes clear that immune/endocrinological dysregulation is interlocked with (pelvic) pain chronification processes and psychological symptoms such as depressive mood, loss of control, higher vigilance toward the onset or worsening of symptoms, social isolation, and catastrophizing. This paper will discuss and identify promising treatment approaches, in addition to medical care, as well as further research implications. Endometriosis can come with substantial psychosomatic and social burden, requiring more research to understand the interdependence of different factors involved in its chronic development pathway. However, it is already clear that standard care should be extended with multifaceted treatments addressing pain, as well as the psychological and social burden, in order to halt the cycle of aggravation of symptoms and to improve quality of life for patients.

Contrasting Hygiene-Related Gastrointestinal Infections and Stress-Related Diseases at a Primary Health Care Facility within a Sub-Saharan African City: Before and during the COVID-19 Pandemic.

BACKGROUND: With the advent of the COVID-19 pandemic caused by SARS-CoV-2, protocols such as social distancing and upscaling of hygiene practices were implemented to limit the spread of the disease. Meanwhile, along with COVID-19 came stress due to restrictions on movement, trade and transport, and closure of schools, among others. AIM: This study compared the prevalence of hygiene-related gastrointestinal infections and stress-related diseases before (March 2019-February 2020) and during (March 2020-February 2021) the COVID-19 pandemic. METHODOLOGY: This was a retrospective single-center review of deidentified patient data from the Korle Bu Polyclinic, Accra, Ghana. RESULTS: Comparing the pre-COVID-19 era to the COVID-19 era, there was a statistically nonsignificant change in the number of cases and prevalence of gastroenteritis and enteric fever (p = 0.084 and 0.081, respectively), although for gastroenteritis, the prevalence was higher for the pre-COVID-19 era compared to during COVID-19 by 1.8 per 1000 cases, while that of enteric fever was higher during the COVID-19 era compared to the pre-COVID-19 era by 1.0 per 1000 cases. Of the stress-related diseases, statistically significant increases in the prevalence of anxiety disorders (p = 0.028), insomnia (p = 0.001), and headache (p = 0.010), were noted, with 2.3, 5.5, and 2.4 per 1000 cases, respectively. There were more female cases than male cases recorded for depression (p = 0.001), headache (p = 0.010), and hypertension (p = 0.001) during the pandemic, and these were statistically significant. CONCLUSION: During the pandemic, a significant increase in the prevalence of stress-related diseases was observed. However, a statistically nonsignificant change was recorded for gastrointestinal infections, with females reporting more of these disorders. Consequently, it is important to strengthen the capacity for managing stress-related conditions alongside diseases that cause pandemics when they arise.

Role of SLC4 and SLC26 solute carriers during oxidative stress.

Bicarbonate is one of the major anions in mammalian tissues and fluids, is utilized by various exchangers to transport other ions and organic substrates across cell membranes and plays a critical role in cell and systemic pH homoeostasis. Chloride/bicarbonate (Cl- /HCO3- ) exchangers are abundantly expressed in erythrocytes and epithelial cells and, as a consequence, are particularly exposed to oxidants in the systemic circulation and at the interface with the external environment. Here, we review the physiological functions and pathophysiological alterations of Cl- /HCO3- exchangers belonging to the solute carriers SLC4 and SLC26 superfamilies in relation to oxidative stress. Particularly well studied is the impact of oxidative stress on the red blood cell SLC4A1/AE1 (Band 3 protein), of which the function seems to be directly affected by oxidative stress and possibly involves oxidation of the transporter itself or its interacting proteins, with detrimental consequences in oxidative stress-related diseases including inflammation, metabolic dysfunctions and ageing. The effect of oxidative stress on SLC26 members was less extensively explored. Indirect evidence suggests that SLC26 transporters can be target as well as determinants of oxidative stress, especially when their expression is abolished or dysregulated.

Injectable reactive oxygen and nitrogen species-controlling hydrogels for tissue regeneration: current status and future perspectives.

The dual role of reactive oxygen and nitrogen species (RONS) in physiological and pathological processes in biological systems has been widely reported. It has been recently suggested that the regulation of RONS levels under physiological and pathological conditions is a potential therapy to promote health and treat diseases, respectively. Injectable hydrogels have been emerging as promising biomaterials for RONS-related biomedical applications owing to their excellent biocompatibility, three-dimensional and extracellular matrix-mimicking structures, tunable properties and easy functionalization. These hydrogels have been developed as advanced injectable platforms for locally generating or scavenging RONS, depending on the specific conditions of the target disease. In this review article, the design principles and mechanism by which RONS are generated/scavenged from hydrogels are outlined alongside a discussion of their in vitro and in vivo evaluations. Additionally, we highlight the advantages and recent developments of these injectable RONS-controlling hydrogels for regenerative medicines and tissue engineering applications.

Molecular characterization of the stress network in individuals at risk for schizophrenia.

The biological mechanisms underlying inter-individual differences in human stress reactivity remain poorly understood. We aimed to identify the molecular underpinning of aberrant neural stress sensitivity in individuals at risk for schizophrenia. Linking mRNA expression data from the Allen Human Brain Atlas to task-based fMRI revealed 201 differentially expressed genes in cortex-specific brain regions differentially activated by stress in individuals with low (healthy siblings of schizophrenia patients) or high (healthy controls) stress sensitivity. These genes are associated with stress-related psychiatric disorders (e.g. schizophrenia and anxiety) and include markers for specific neuronal populations (e.g. ADCYAP1, GABRB1, SSTR1, and TNFRSF12A), neurotransmitter receptors (e.g. GRIN3A, SSTR1, GABRB1, and HTR1E), and signaling factors that interact with the corticosteroid receptor and hypothalamic-pituitary-adrenal axis (e.g. ADCYAP1, IGSF11, and PKIA). Overall, the identified genes potentially underlie altered stress reactivity in individuals at risk for schizophrenia and other psychiatric disorders and play a role in mounting an adaptive stress response in at-risk individuals, making them potentially druggable targets for stress-related diseases.

Extracellular Vesicles under Oxidative Stress Conditions: Biological Properties and Physiological Roles.

Under physio-pathological conditions, cells release membrane-surrounded structures named Extracellular Vesicles (EVs), which convey their molecular cargo to neighboring or distant cells influencing their metabolism. Besides their involvement in the intercellular communication, EVs might represent a tool used by cells to eliminate unnecessary/toxic material. Here, we revised the literature exploring the link between EVs and redox biology. The first proof of this link derives from evidence demonstrating that EVs from healthy cells protect target cells from oxidative insults through the transfer of antioxidants. Oxidative stress conditions influence the release and the molecular cargo of EVs that, in turn, modulate the redox status of target cells. Oxidative stress-related EVs exert both beneficial or harmful effects, as they can carry antioxidants or ROS-generating enzymes and oxidized molecules. As mediators of cell-to-cell communication, EVs are also implicated in the pathophysiology of oxidative stress-related diseases. The review found evidence that numerous studies speculated on the role of EVs in redox signaling and oxidative stress-related pathologies, but few of them unraveled molecular mechanisms behind this complex link. Thus, the purpose of this review is to report and discuss this evidence, highlighting that the analysis of the molecular content of oxidative stress-released EVs (reminiscent of the redox status of originating cells), is a starting point for the use of EVs as diagnostic and therapeutic tools in oxidative stress-related diseases.

Is Stress a Cause or a Consequence of Endometriosis?

Clinical studies clearly indicate that endometriosis is a condition associated with high levels of chronic stress. The stress intensity correlates with pain severity and disease extension. However, it is unknown whether chronic stress represents a primary cause of endometriosis and, therefore, if avoiding or treating chronic stress may reduce the risk of developing endometriosis. Repeated, uncontrolled stress either before or after experimental endometriosis induction promotes disease mechanisms and accelerates lesion growth in rodents. Furthermore, patients with endometriosis have a heightened risk of other inflammatory and immune-related diseases, many of which have also been associated with stress. Here, we review the latest evidences regarding the relationship between chronic stress and endometriosis and discuss the potential bidirectional aspect of such association. Further research may clarify if endometriosis is a cause and/or a consequence of stress and whether stress-reducing therapies are effective to mitigate symptoms and slow down the development of endometriotic lesions.

Factors associated with irritable bowel syndrome among medical students at Ain Shams University.

BACKGROUND: Irritable bowel syndrome (IBS) is one of the most common and potentially disabling gastrointestinal disorders. The pathogenesis of this disorder remains obscure. However, many etiological explanations point toward bacterial etiology. Also, several studies have documented that psychological and social factors may play a role. Medical education is among the most challenging and stressful education, and this may predispose to high rates of IBS. OBJECTIVES: The aims of this study are to estimate the frequency of IBS in a selected sample of students of Faculty of Medicine in Ain Shams University and to find out the determinants associated with this disorder. STUDY DESIGN: A cross-sectional study was carried out among medical students from October 2017 to February 2018 at Faculty of Medicine-Ain Shams University. All participants were asked to complete a confidential self-administered questionnaire. An interview questionnaire was used for diagnosis of IBS according to Rome III criteria, while morbid anxiety and depression were diagnosed by using the Arabic version of Hospital Anxiety and Depression Scale (HADS). RESULTS: Three hundred eighty-two students completed the questionnaire. The frequency of IBS was 31.7% with higher proportion among females and among students with positive family history of IBS. However, IBS was significantly less prevalent among students practicing regular exercise. Lastly, based on (HADS), there was a statistical significant relationship between IBS and anxiety (p < 0.05), but not depression. CONCLUSION: The study revealed that around 31% of the studied group was suffering from IBS. Female gender, suffering from anxiety, and positive family history of IBS were the main associated factors for IBS. Screening of all medical students in the faculty for IBS is suggested. Providing psychological and emotional support along with stress management is highly recommended.

Contaminants: a dark side of food supplements?

Food supplements (FS) are often consumed as one of the strategies to fight ageing-associated pathologies, especially in the case of oxidative stress-related diseases. Despite the popularity of FS, some concerns about their quality and safety have been raised, especially regarding the presence of contaminants. This paper reviews and discusses the occurrence of contaminants in marketed samples of FS in the last two decades, considering both scientific literature and notifications registered on RASFF portal. The most relevant classes of contaminants were included namely metals, toxins, pesticides, dioxins and PCBs, as well as pharmacologically active ingredients. Variable amounts of contaminants were reported in a significant number of commercially available FS. Although the presence of contaminants does not necessarily mean that their levels exceed the regulatory limits or that the FS intake constitutes a risk to human health, it alerts for the need to further monitor FS safety. The evaluation of the risk associated to the consumption of FS, especially in the elderly population, is particularly challenging due to the frequent exposure to multiple toxicants and to different exposure sources, as well as due to possible pre-existing diseases and respective therapeutics. Therefore, improved quality control procedures and monitoring programs should be pursued in order to avoid undesirable products and assure the safety of FS.

Microbiota Modulate Anxiety-Like Behavior and Endocrine Abnormalities in Hypothalamic-Pituitary-Adrenal Axis.

Intestinal microbes are an important system in the human body, with significant effects on behavior. An increasing body of research indicates that intestinal microbes affect brain function and neurogenesis, including sensitivity to stress. To investigate the effects of microbial colonization on behavior, we examined behavioral changes associated with hormones and hormone receptors in the hypothalamic-pituitary-adrenal (HPA) axis under stress. We tested germ-free (GF) mice and specific pathogen-free (SPF) mice, divided into four groups. A chronic restraint stress (CRS) protocol was utilized to induce external pressure in two stress groups by restraining mice in a conical centrifuge tube for 4 h per day for 21 days. After CRS, Initially, GF restraint-stressed mice explored more time than SPF restraint-stressed mice in the center and total distance of the OFT. Moreover, the CRH, ACTH, CORT, and ALD levels in HPA axis of GF restraint-stressed mice exhibited a significantly greater increase than those of SPF restraint-stressed mice. Finally, the Crhr1 mRNA levels of GF CRS mice were increased compared with SPF CRS mice. However, the Nr3c2 mRNA levels of GF CRS mice were decreased compared with SPF CRS mice. All results revealed that SPF mice exhibited more anxiety-like behavior than GF mice under the same external stress. Moreover, we also found that GF mice exhibited significant differences in, hormones, and hormone receptors compared with SPF mice. In conclusion, Imbalances of the HPA axis caused by intestinal microbes could affect the neuroendocrine system in the brain, resulting in an anxiety-like behavioral phenotype. This study suggested that intervention into intestinal microflora may provide a new approach for treating stress-related diseases.

Neural control of chronic stress adaptation.

Stress initiates adaptive processes that allow the organism to physiologically cope with prolonged or intermittent exposure to real or perceived threats. A major component of this response is repeated activation of glucocorticoid secretion by the hypothalamo-pituitary-adrenocortical (HPA) axis, which promotes redistribution of energy in a wide range of organ systems, including the brain. Prolonged or cumulative increases in glucocorticoid secretion can reduce benefits afforded by enhanced stress reactivity and eventually become maladaptive. The long-term impact of stress is kept in check by the process of habituation, which reduces HPA axis responses upon repeated exposure to homotypic stressors and likely limits deleterious actions of prolonged glucocorticoid secretion. Habituation is regulated by limbic stress-regulatory sites, and is at least in part glucocorticoid feedback-dependent. Chronic stress also sensitizes reactivity to new stimuli. While sensitization may be important in maintaining response flexibility in response to new threats, it may also add to the cumulative impact of glucocorticoids on the brain and body. Finally, unpredictable or severe stress exposure may cause long-term and lasting dysregulation of the HPA axis, likely due to altered limbic control of stress effector pathways. Stress-related disorders, such as depression and PTSD, are accompanied by glucocorticoid imbalances and structural/ functional alterations in limbic circuits that resemble those seen following chronic stress, suggesting that inappropriate processing of stressful information may be part of the pathological process.