Fibroblast growth factor 10 protects against particulate matter-induced lung injury by inhibiting oxidative stress-mediated pyroptosis via the PI3K/Akt/Nrf2 signaling pathway.

Particulate matter (PM) is a major environmental contaminant that causes and worsens respiratory diseases. Fibroblast growth factor 10 (FGF10), a paracrine fibroblast growth factor that specifically stimulates repair and regeneration after injury, has been shown to protect against PM-induced lung injury. However, the underlying mechanisms are still unclear. In this study, the protective effects of FGF10 were investigated using a PM-induced lung injury mouse model in vivo and BEAS-2B cells in vitro. According to the findings, FGF10 treatment alleviated PM-induced oxidative damage and pyroptosis in vivo and in vitro. Mechanistically, FGF10 activated antioxidative Nrf2 signaling. Inhibition of PI3K signaling with LY294002 or Nrf2 signaling with ML385 revealed that FGF10-mediated lung protection was mediated by the PI3K/Akt/Nrf2 pathway. These results collectively indicate that FGF10 inhibits oxidative stress-mediated pyroptosis via the PI3K/Akt/Nrf2 pathway, suggesting a possible therapy for PM-induced lung injury.

Metformin-ROS-Nrf2 connection in the host defense mechanism against oxidative stress, apoptosis, cancers, and ageing.

Reactive oxygen species (ROS) acts as a second messenger to trigger biological responses in low concentrations, while it is implicated to be toxic to biomolecules in high concentrations. Mild inhibition of respiratory chain Complex I by metformin at physiologically relevant concentrations stimulates production of low-level mitochondrial ROS. The ROS seems to induce anti-oxidative stress response via activation of nuclear factor erythroid 2-related factor 2 (Nrf2) and glutathione peroxidase (GPx), which results in not only elimination of ROS but also activation of cellular responses including resistance to apoptosis, metabolic changes, cell proliferation, senescence prevention, lifespan extension, and immune T cell activation against cancers, regardless of its effect controlling blood glucose level and T2DM. Although metformin's effect against T2DM, cancers, and ageing, are believed mostly attributed to the activation of AMP-activated protein kinase (AMPK), the cellular responses involving metformin-ROS-Nrf2 axis might be another natural asset to improve healthspan and lifespan.

The Effect of Cutibacterium acnes Infection on Nerve Penetration in the Annulus Fibrosus of Lumbar Intervertebral Discs via Suppressing Oxidative Stress.

Modic changes (MCs) and low back pain are highly correlated and an economic burden to the society. Previous studies have shown that Cutibacterium acnes (C. acnes) infection can lead to MCs. The purpose of this study was to clarify whether and how C. acnes contributes to oxidative stress and nerve growth that potentially leads to low back pain. Neurons from the hippocampus or dorsal root ganglion (DRG) of Sprague-Dawley (SD) rats were cocultured with annulus fibrosus cells (AFCs) with or without the presence of the C. acnes supernatant in vitro. Cell viability, neurite length, oxidative stress, and neuro-related gene expression were examined. Furthermore, samples from the patients with MCs and SD rat model of MCs were used to validate the nerve growth results. Neurons from both the hippocampus and DRG showed neurites when cocultured with AFCs in the environment with/without the C. acnes supernatant. The average neurite length was significantly longer when exposed to the C. acnes supernatant in the hippocampal neuron (217.1 ± 90.0 µm versus 150.1 ± 68.1 µm in the control group) and in the DRG neuron (229.1 ± 91.3 µm versus 149.2 ± 64.8 µm in the control group). Hippocampal neurons showed upregulated expression levels of NeuN, Map2, and Psd95, while upregulation was only seen in Tuj-1 in DRG neurons. Suppressed oxidative stress could be observed using axon growth symbols. Degenerated disc structures and abnormal bone remodelling were found in animal models and clinical samples of MCs, with astrocytes, microglia, and neurons in the disc. Therefore, C. acnes infection was found to cause back pain in the presence of MCs by promoting nerve penetration into the annulus fibrosus by suppressing oxidative stress.

Oxidative Stress-Related Mechanisms in SARS-CoV-2 Infections.

The COVID-19 pandemic caused relatively high mortality in patients, especially in those with concomitant diseases (i.e., diabetes, hypertension, and chronic obstructive pulmonary disease (COPD)). In most of aforementioned comorbidities, the oxidative stress appears to be an important player in their pathogenesis. The direct cause of death in critically ill patients with COVID-19 is still far from being elucidated. Although some preliminary data suggests that the lung vasculature injury and the loss of the functioning part of pulmonary alveolar population are crucial, the precise mechanism is still unclear. On the other hand, at least two classes of medications used with some clinical benefits in COVID-19 treatment seem to have a major influence on ROS (reactive oxygen species) and RNS (reactive nitrogen species) production. However, oxidative stress is one of the important mechanisms in the antiviral immune response and innate immunity. Therefore, it would be of interest to summarize the data regarding the oxidative stress in severe COVID-19. In this review, we discuss the role of oxidative and antioxidant mechanisms in severe COVID-19 based on available studies. We also present the role of ROS and RNS in other viral infections in humans and in animal models. Although reactive oxygen and nitrogen species play an important role in the innate antiviral immune response, in some situations, they might have a deleterious effect, e.g., in some coronaviral infections. The understanding of the redox mechanisms in severe COVID-19 disease may have an impact on its treatment.

Correlation of Blood Biochemical Markers with Tardive Dyskinesia in Schizophrenic Patients.

Objective: Oxidative stress factors and proinflammatory cytokines had been found to be involved in the pathogenesis of patients with tardive dyskinesia (TD). This study assumes that blood biochemical markers would have a link with TD in schizophrenia patients. To explore the correlation between blood biochemical markers and tardive dyskinesia in patients with schizophrenia (SCH). Methods: From January 2010 to August 2021, the inpatients who met the diagnostic criteria of schizophrenia in the Chinese Classification and Diagnosis Criteria of Mental Disorders (DSM-4) and the American Diagnostic and Statistical Manual of Mental Disorders (DSM-4) were followed up in the psychiatric outpatient department of Jinxia Street Community Health Service Center, Longhu District, Shantou City. The diagnostic criteria of Abnormal Involuntary Movement Scale (AIMS) used in the TD study of Schooler and Kane were used to screen the patients. Patients were divided into the schizophrenia (SCH group) and the schizophrenia with TD groups (TD group). Oxidative stress factors including Superoxide Dismutase1 (SOD1), Glutathione Peroxidase1 (GPX1), Malondialdehyde1 (MDA1), Catalase Activity1 (CAT1), and brain-derived neurotrophic factor 1 (BDNF1) and some inflammatory cytokines including interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-8 (IL-8), serum tumor necrosis factor (TNF-α), prolactin, estrogen, and cortisol were measured in 121 schizophrenic patients with tardive dyskinesia and 118 schizophrenic patients. The correlation analysis was conducted on the data. Results: Age and female were immutable risk factors for the development of TD, and there were significant differences in blood biochemical indices GPX1, MDA1, CAT1, and TNF-α in schizophrenic patients with and without TD. Conclusion: This study supports that oxidative stress and immune disorders are associated with TD patients. Blood biochemical markers GPX1, MDA1, CAT1, and TNF-α may play an important role in the pathogenesis of schizophrenia combined with TD patients, and they may be useful in the diagnosis of schizophrenia with tardive dyskinesia.

Streptococcus lutetiensis Induces Autophagy via Oxidative Stress in Bovine Mammary Epithelial Cells.

Streptococcus lutetiensis, an emerging pathogen causing bovine mastitis, has not been well characterized. We reported that S. lutetiensis was pathogenic both in vivo and in vitro and caused inflammatory reactions in the mammary gland. However, roles of autophagy and oxidative stress in the pathogenesis of S. lutetiensis-induced mastitis are unclear. In this study, an autophagy model of S. lutetiensis-infected bovine mammary epithelial cells (bMECs) was used to assess oxidative stress and autophagy flux. Expressions of Beclin1, light chain 3II, and Sequestosome 1/p62 were elevated in bMECs after S. lutetiensis infection. In addition, autophagosome and lysosome formation confirmed autophagy occurred. Based on LysoTracker Red and acridine orange, lysosome degradation was blocked, and lower expressions of lysosomal-associated membrane protein 2, cathepsins D, and cathepsins L confirmed lysosomal damage. Concurrently, the nuclear factor erythroid 2-related factor 2 (Nrf2), kelch-like ECH-associated protein 1 (Keap1), heme oxygenase 1 (HO1), and NAD (P)H: quinone oxidoreductase 1 (NQO1), and basilic proteins associated with the Nrf2/Keap1 signaling pathway, were detected. Decreased keap1 and increased Nrf2, HO1, NQO1, and reactive oxygen species (ROS) indicated increased oxidative stress. Treatment with N-Acetyl-L-cysteine (NAC), an ROS inhibitor, decreased both oxidative stress and autophagy. Therefore, we concluded that S. lutetiensis caused intracellular oxidative stress and autophagy in bMECs. In addition, crosstalk between autophagy and oxidative stress affected the autophagic flux and blocked downstream autophagy. The Nrf2-keap1-p62 pathway participated in this process, with ROS acting upstream of these effects, interfering with normal cell functions.

Oxidative stress and inflammatory markers in patients with COVID-19: Potential role of RAGE, HMGB1, GFAP and COX-2 in disease severity.

BACKGROUND: SARS-CoV-2 infection can lead to the abnormal induction of cytokines and a dysregulated hyperinflammatory state that is implicated in disease severity and risk of death. There are several molecules present in blood associated with immune cellular response, inflammation, and oxidative stress that could be used as severity markers in respiratory viral infections such as COVID-19. However, there is a lack of clinical studies evaluating the role of oxidative stress-related molecules including glial fibrillary acidic protein (GFAP), the receptor for advanced glycation end products (RAGE), high mobility group box-1 protein (HMGB1) and cyclo-oxygenase-2 (COX-2) in COVID-19 pathogenesis. AIM: To evaluate the role of oxidative stress-related molecules in COVID-19. METHOD: An observational study with 93 Brazilian participants from September 2020 to April 2021, comprising 23 patients with COVID-19 admitted to intensive care unit (ICU), 19 outpatients with COVID-19 with mild to moderate symptoms, 17 individuals reporting a COVID-19 history, and 34 healthy controls. Blood samples were taken from all participants and western blot assay was used to determine the RAGE, HMGB1, GFAP, and COX-2 immunocontent. RESULTS: We found that GFAP levels were higher in patients with severe or critical COVID-19 compared to outpatients (p = 0.030) and controls (p < 0.001). A significant increase in immunocontents of RAGE (p < 0.001) and HMGB1 (p < 0.001) were also found among patients admitted to the ICU compared to healthy controls, as well as an overexpression of the inducible COX-2 (p < 0.001). In addition, we found a moderate to strong correlation between RAGE, GFAP and HMGB1 proteins. CONCLUSION: SARS-CoV-2 infection induces the upregulation of GFAP, RAGE, HMGB1, and COX-2 in patients with the most severe forms of COVID-19.

Implications of Oxidative Stress in the Pathogenesis and Treatment of Hyperpigmentation Disorders.

Oxidative stress represents an imbalance between the generation of reactive oxygen and nitrogen species and the ability of antioxidant systems to decompose those products. Oxidative stress is implicated in the pathogenesis of hyperpigmentation, hypopigmentation, melanoma, and other skin diseases. Regulatory networks involving oxidative stress and related pathways are widely represented in hypopigmentation diseases, particularly vitiligo. However, there is no complete review into the role of oxidative stress in the pathogenesis of hyperpigmentation disorders, especially regarding associations involving oxidative stress and cellular signaling pathways. Here, we review oxidative and antioxidant systems, oxidative stress-induced signal transduction mechanisms, and effects of antioxidant drugs used in preclinical and clinical settings in hyperpigmentation disorders.

The beneficial effects of virgin olive oil against oxidative stress induced by hypercholesterolemia in rats

Cardiovascular disease(CVD) remains the major cause of mortality in the world, typically claiming a third of all deaths. The primary cause of CVD is atherosclerosis. Therefore, timely prevention and therapy of atherosclerosis are able to reduce the risk of the development of its clinical manifestations. Anti-atherosclerotic activity of medicinal plants mainly appears in their multiple effects.This study was carried out to evaluate the hypolipidemic activity of virgin olive oil in experimentally induced hyperlipemic Wistar. A total of 24 rats were randomly allocated to 4 equal groups and treated as follows for 50 days: (1) Normal control (NC); that were fed with a standart diet; (2) High Cholesterol Diet Control (HCD); which received high cholesterol diet for 50 days; (3) Animals receiving high cholesterol diet for 50 days, after this period the animals are fed for eight days by the standard foodand receiving by gavage virgin olive oil (HCD+VOO) and(4) Animals fed for eight days with the standard food and receiving by gavage olive oil (VOO). High Cholesterol Diet containing yolk egg and coconut oil. Results showed that olive oil caused a significant (p < 0.01) reduction in serum levels of Total Cholesterol (TC), Triglycerides (TG), Low­Density Lipoprotein Cholesterol (LDL) and Atherogenic Index Serum (AIS). The results also demonstrated a significant (p < 0.01) increase in High­Density Lipoprotein Cholesterol (HDL). Moreover, virgin olive oil induced a significant reduction in liver lipid content. On the other hand, a High cholesterol diet induced oxidative stress was measured by estimating reduced glutathione level and amount of thiobarbituric acid reactive substances (TBARS) formed as an index of lipid peroxidation in a liver and a heart. Virgin olive oil supplementation attenuated all these variations. Our observations of the study indicate that the virgin olive oil has a significant antihyperlipidemic potential.

Expression of TRX1 optimizes the antitumor functions of human CAR T cells and confers resistance to a pro-oxidative tumor microenvironment.

Use of chimeric antigen receptor (CAR) T cells to treat B cell lymphoma and leukemia has been remarkably successful. Unfortunately, the therapeutic efficacy of CAR T cells against solid tumors is very limited, with immunosuppression by the pro-oxidative tumor microenvironment (TME) a major contributing factor. High levels of reactive oxygen species are well-tolerated by tumor cells due to their elevated expression of antioxidant proteins; however, this is not the case for T cells, which consequently become hypo-responsive. The aim of this study was to improve CAR T cell efficacy in solid tumors by empowering the antioxidant capacity of CAR T cells against the pro-oxidative TME. To this end, HER2-specific human CAR T cells stably expressing two antioxidant systems: thioredoxin-1 (TRX1), and glutaredoxin-1 (GRX1) were generated and characterized. Thereafter, antitumor functions of CAR T cells were evaluated under control or pro-oxidative conditions. To provide insights into the role of antioxidant systems, gene expression profiles as well as global protein oxidation were analyzed. Our results highlight that TRX1 is pivotal for T cell redox homeostasis. TRX1 expression allows CAR T cells to retain their cytolytic immune synapse formation, cytokine release, proliferation, and tumor cell-killing properties under pro-oxidative conditions. Evaluation of differentially expressed genes and the first comprehensive redoxosome analysis of T cells by mass spectrometry further clarified the underlying mechanisms. Taken together, enhancement of the key antioxidant TRX1 in human T cells opens possibilities to increase the efficacy of CAR T cell treatment against solid tumors.

Oxidative Stress and Inflammation Are Associated With Age-Related Endothelial Dysfunction in Men With Low Testosterone.

CONTEXT: Vascular aging, including endothelial dysfunction secondary to oxidative stress and inflammation, increases the risk for age-associated cardiovascular disease (CVD). Low testosterone in middle-aged/older men is associated with increased CVD risk. OBJECTIVE: We hypothesized that low testosterone contributes to age-associated endothelial dysfunction, related in part to greater oxidative stress and inflammation. METHODS: This cross-sectional study included 58 healthy, nonsmoking men categorized as young (N = 20; age 29 ± 4 years; testosterone 500 ± 58 ng/dL), middle-aged/older with higher testosterone (N = 20; age 60 ± 6 years; testosterone 512 ± 115 ng/dL), and middle-aged/older lower testosterone (N = 18; age 59 ± 8 years; testosterone 269 ± 48 ng/dL). Brachial artery flow-mediated dilation (FMDBA) was measured during acute infusion of saline (control) and vitamin C (antioxidant). Markers of oxidative stress (total antioxidant status and oxidized low-density lipoprotein cholesterol), inflammation (interleukin [IL]-6 and C-reactive protein [CRP]), and androgen deficiency symptoms were also examined. RESULTS: During saline, FMDBA was reduced in middle-aged/older compared with young, regardless of testosterone status (P < 0.001). FMDBA was reduced in middle-aged/older lower testosterone (3.7% ± 2.0%) compared with middle-aged/older higher testosterone (5.7% ± 2.2%; P = 0.021), independent of symptoms. Vitamin C increased FMDBA (to 5.3% ± 1.6%; P = 0.022) in middle-aged/older lower testosterone but had no effect in young (P = 0.992) or middle-aged/older higher testosterone (P = 0.250). FMDBA correlated with serum testosterone (r = 0.45; P < 0.001), IL-6 (r = -0.41; P = 0.002), and CRP (r = -0.28; P = 0.041). CONCLUSION: Healthy middle-aged/older men with low testosterone appear to have greater age-associated endothelial dysfunction, related in part to greater oxidative stress and inflammation. These data suggest that low testosterone concentrations may contribute to accelerated vascular aging in men.

Oxidative stress and expression of inflammatory factors in lung tissue of acute mountain sickness rats.

The aim of the present study was to investigate the changes in lung histomorphology and oxidative stress, as well as the expression of interleukin (IL)­17C and other inflammatory factors during acute mountain sickness (AMS) in male Sprague­Dawley rats and to explore the underlying mechanism. Rats were randomly divided into a control group (0 h) and three hypoxia stress groups, exposed to low­pressure oxygen storage at a simulated altitude of 6,000 m for 24, 48 and 72 h, respectively. Morphological changes in lung tissue were observed by hematoxylin and eosin staining under light microscopy and transmission electron microscopy. The expression of inflammatory factors IL­17C, nuclear factor­κB (NF­κB), IL­1ß, IL­6 and tumor necrosis factor­α (TNF­α) in lung tissue was assessed by RNA sequencing and verified by reverse transcription­quantitative PCR (RT­qPCR) and western blotting (WB). Superoxide dismutase (SOD) and glutathione peroxidase (GSH­Px) enzyme activity and malondialdehyde (MDA) expression were also measured. Experimental groups were compared to the control group following 24, 48 and 72 h of hypoxic stress. Lung tissue suffered from different degrees of injury, and the damage was the most severe after 48 h of hypoxic stress. RNA sequencing data from the lung tissue of rats from each group suggested that the expression of IL­17C, NF­κB, IL­1ß, IL­6, and TNF­α increased significantly after hypoxic stress. RT­qPCR and WB demonstrated that the expression of IL­17C and NF­κB increased significantly after hypoxia lasting 48 and 72 h. IL­1ß expression increased significantly after hypoxia stress lasting 24 and 48 h, and the expressions of TNF­α and IL­6 increased significantly after hypoxia stress lasting 24, 48 and 72 h (P<0.01). The enzyme activity of SOD and GSH­Px decreased significantly after lasting 24, 48 and 72 h of hypoxia (P<0.01), and MDA increased significantly after hypoxic stress lasting 48 and 72 h (P<0.01). In conclusion, under hypoxic stress, rats quickly initiate oxidative stress and immune responses. However, with prolonged hypoxic stress time, excessive oxidative stress can further stimulate the immune system in vivo, and release a large quantity of inflammatory factors accumulating in the body. This, in turn, may lead to the occurrence of inflammatory storms and further damage the lung tissue resulting in AMS.

Feedback regulation of antioxidant transcription factor NFE2L1 and immunostimulatory factor 41BBL mediates the crosstalk between oxidative stress and tumor immunity.

Targeting the immune checkpoint to inhibit tumor immune escape, which is one of the fundamental causes of cancer, has become an important strategy for cancer treatment. The molecular mechanism of tumor immune escape involved in the process of spontaneous hepatocellular carcinoma after specifically knocking out NFE2L1, the core regulator of redox homeostasis, in the mouse liver is still unclear. Transcriptome data showed that the immunostimulatory TNFSF9/41BBL was significantly reduced in NFE2L1 knockdown hepatocarcinoma HepG2 cells, and this suggests that 41BBL may be an oxidative stress-responsive immune checkpoint. The results of the promoter activity experiment showed that NFE2L1 can promote 41BBL gene transcription activation through the ARE element in the promoter region. In addition, cell biology experiments have found that overexpression of 41BBL can inhibit cell proliferation and promote senescence. Importantly, reactive oxygen species in cells significantly increased after overexpression of 41BBL, whereas NFE2L1 was inhibited, indicating that 41BBL has the effect of feedback regulating oxidative stress in cells. In conclusion, in this study, the transcriptional activation effect of NFE2L1 on 41BBL and the feedback inhibition relationship of 41BBL on NFE2L1 was clarified. The NFE2L1/41BBL axis might be an important pathway that mediates the crosstalk between oxidative stress and the tumor immune response.

The effects of methanol extract of Galium verum L on cardiac redox state in hypertensive rats

Abstract The aim of this study was to assess the effects of methanol extract of G. verum on redox status of isolated heart of spontaneously hypertensive rats after ischemia. Twenty-four Wistar albino rats were divided into three groups: untreated control rats and rats that received 125 and 250 mg/kg G. verum extract for 4 weeks per os. Index of lipid peroxidation (measured as TBARS) and parameters of antioxidative defence system such as level of reduced glutathione (GSH) and activities of catalase (CAT) and superoxide dismutase (SOD) were spectrophotometrically determined in heart homogenate. The index of lipid peroxidation in heart tissue was lower in both treated groups compared to the control group. On the other hand, the activity of SOD was significantly higher after consumption of both doses, while the activity of CAT was significantly higher only after treatment with a higher dose of extract. Based on our results we might conclude that 4-week treatment with methanol extracts of G. verum has the potential to modulate myocardial redox signaling after ischemia, thus significantly alleviating cardiac oxidative stress and exerting dose-dependent antioxidant properties. Future studies are certainly necessary to fully clarify the role of this plant species in myocardial I-R injury.

An Oxidative Stress-Related Gene Pair (CCNB1/PKD1), Competitive Endogenous RNAs, and Immune-Infiltration Patterns Potentially Regulate Intervertebral Disc Degeneration Development.

Oxidative stress (OS) irreversibly affects the pathogenesis of intervertebral disc degeneration (IDD). Certain non-coding RNAs act as competitive endogenous RNAs (ceRNAs) that regulate IDD progression. Analyzing the signatures of oxidative stress-related gene (OSRG) pairs and regulatory ceRNA mechanisms and immune-infiltration patterns associated with IDD may enable researchers to distinguish IDD and reveal the underlying mechanisms. In this study, OSRGs were downloaded and identified using the Gene Expression Omnibus database. Functional-enrichment analysis revealed the involvement of oxidative stress-related pathways and processes, and a ceRNA network was generated. Differentially expressed oxidative stress-related genes (De-OSRGs) were used to construct De-OSRG pairs, which were screened, and candidate De-OSRG pairs were identified. Immune cell-related gene pairs were selected via immune-infiltration analysis. A potential long non-coding RNA-microRNA-mRNA axis was determined, and clinical values were assessed. Eighteen De-OSRGs were identified that were primarily related to intricate signal-transduction pathways, apoptosis-related biological processes, and multiple kinase-related molecular functions. A ceRNA network consisting of 653 long non-coding RNA-microRNA links and 42 mRNA-miRNA links was constructed. Three candidate De-OSRG pairs were screened out from 13 De-OSRG pairs. The abundances of resting memory CD4+ T cells, resting dendritic cells, and CD8+ T cells differed between the control and IDD groups. CD8+ T cell infiltration correlated negatively with cyclin B1 (CCNB1) expression and positively with protein kinase D1 (PKD1) expression. CCNB1-PKD1 was the only pair that was differentially expressed in IDD, was correlated with CD8+ T cells, and displayed better predictive accuracy compared to individual genes. The PKD1-miR-20b-5p-AP000797 and CCNB1-miR-212-3p-AC079834 axes may regulate IDD. Our findings indicate that the OSRG pair CCNB1-PKD1, which regulates oxidative stress during IDD development, is a robust signature for identifying IDD. This OSRG pair and increased infiltration of CD8+ T cells, which play important roles in IDD, were functionally associated. Thus, the OSRG pair CCNB1-PKD1 is promising target for treating IDD.

Recent Progress in Applicability of Exercise Immunology and Inflammation Research to Sports Nutrition.

This article focuses on how nutrition may help prevent and/or assist with recovery from the harmful effects of strenuous acute exercise and physical training (decreased immunity, organ injury, inflammation, oxidative stress, and fatigue), with a focus on nutritional supplements. First, the effects of ketogenic diets on metabolism and inflammation are considered. Second, the effects of various supplements on immune function are discussed, including antioxidant defense modulators (vitamin C, sulforaphane, taheebo), and inflammation reducers (colostrum and hyperimmunized milk). Third, how 3-hydroxy-3-methyl butyrate monohydrate (HMB) may offset muscle damage is reviewed. Fourth and finally, the relationship between exercise, nutrition and COVID-19 infection is briefly mentioned. While additional verification of the safety and efficacy of these supplements is still necessary, current evidence suggests that these supplements have potential applications for health promotion and disease prevention among athletes and more diverse populations.

Clostridium butyricum Alleviates Enterotoxigenic Escherichia coli K88-Induced Oxidative Damage Through Regulating the p62-Keap1-Nrf2 Signaling Pathway and Remodeling the Cecal Microbial Community.

Clostridium butyricum (CB) can enhance antioxidant capacity and alleviate oxidative damage, but the molecular mechanism by which this occurs remains unclear. This study used enterotoxigenic Escherichia coli (ETEC) K88 as a pathogenic model, and the p62-Keap1-Nrf2 signaling pathway and intestinal microbiota as the starting point to explore the mechanism through which CB alleviates oxidative damage. After pretreatment with CB for 15 d, mice were challenged with ETEC K88 for 24 h. The results suggest that CB pretreatment can dramatically reduce crypt depth (CD) and significantly increase villus height (VH) and VH/CD in the jejunum of ETEC K88-infected mice and relieve morphological lesions of the liver and jejunum. Additionally, compared with ETEC-infected group, pretreatment with 4.4×106 CFU/mL CB can significantly reduce malondialdehyde (MDA) level and dramatically increase superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels in the serum. This pretreatment can also greatly increase the mRNA expression levels of tight junction proteins and genes related to the p62-Keap1-Nrf2 signaling pathway in the liver and jejunum in ETEC K88-infected mice. Meanwhile, 16S rDNA amplicon sequencing revealed that Clostridium disporicum was significantly enriched after ETEC K88 challenge relative to the control group, while Lactobacillus was significantly enriched after 4.4×106 CFU/mL CB treatment. Furthermore, 4.4×106 CFU/mL CB pretreatment increased the short-chain fatty acid (SCFA) contents in the cecum of ETEC K88-infected mice. Moreover, we found that Lachnoclostridium, Roseburia, Lactobacillus, Terrisporobacter, Akkermansia, and Bacteroides are closely related to SCFA contents and oxidative indicators. Taken together, 4.4×106 CFU/mL CB pretreatment can alleviate ETEC K88-induced oxidative damage through activating the p62-Keap1-Nrf2 signaling pathway and remodeling the cecal microbiota community in mice.

Oral administration of cystine and theanine attenuates 5-fluorouracil-induced intestinal mucositis and diarrhea by suppressing both glutathione level decrease and ROS production in the small intestine of mucositis mouse model.

BACKGROUND: Chemotherapy is frequently used in cancer treatment; however, it may cause adverse events, which must be managed. Reactive oxygen species (ROS) have been reported to be involved in the induction of intestinal mucositis and diarrhea, which are common side effects of treatment with fluoropyrimidine 5-fluorouracil (5-FU). Our previous studies have shown that oral administration of cystine and theanine (CT) increases glutathione (GSH) production in vivo. In the present study, we hypothesized that CT might inhibit oxidative stress, including the overproduction of ROS, and attenuate 5-FU-induced mucositis and diarrhea. METHODS: We investigated the inhibitory effect of CT administration on mucositis and diarrhea, as well as its mechanism, using a mouse model of 5-FU-induced intestinal mucositis. RESULTS: CT administration suppressed 5-FU-induced diarrhea and weight loss in the studied mice. After 5-FU administration, the GSH level and the GSH/GSSG ratio in the small intestine mucosal tissue decreased compared to normal control group; but CT administration improved the GSH/GSSG ratio to normal control levels. 5-FU induced ROS production in the basal region of the crypt of the small intestine mucosal tissue, which was inhibited by CT. CT did not affect the antitumor effect of 5-FU. CONCLUSIONS: CT administration suppressed intestinal mucositis and diarrhea in a mouse model. This finding might be associated with the antioxidant characteristics of CT, including the improved rate of GSH redox and the reduced rate of ROS production in the small intestine mucosal tissue. CT might be a suitable candidate for the treatment of gastrointestinal mucositis associated with chemotherapy.

Ferroportin-mediated ferroptosis involved in new-onset atrial fibrillation with LPS-induced endotoxemia.

Sepsis is a known risk factor for new-onset atrial fibrillation (AF), and previous studies have demonstrated that ferroptosis participates in sepsis-induced organ injury development. Nevertheless, the role of ferroptosis in new-onset AF with sepsis remains largely unknown. This study aims to investigate the underlying mechanisms linking ferroptosis and AF caused by sepsis. LPS-induced endotoxemia is often used to model the acute inflammatory response associated with sepsis. Herein, we reported that ferroptosis was significantly activated in LPS-induced endotoxemia rat model. We also observed that ferroportin (Fpn), the only identified mammalian non-heme iron exporter, was downregulated in the atrium of endotoxemia model. Vulnerability to AF was also significantly increased in a endotoxemia rat model. Additionally, Fpn knockdown by shFpn further increased intracellular iron concentration and oxidative stress and exaggerated the AF vulnerability, which was alleviated by ferroptosis inhibition. Mechanistically, silencing Fpn worsened the alterations in calcium handling proteins expression in a endotoxemia rat model. These findings suggest that Fpn-mediated ferroptosis is involved in the new-onset AF with LPS-induced endotoxemia via worsening the calcium handling proteins dysregulation and provides a novel and promising strategy for preventing AF development in sepsis.

MTS1338 in Mycobacterium tuberculosis promotes detoxification of reactive oxygen species under oxidative stress.

Diverse mechanisms exist in Mycobacterium tuberculosis for adaptation to stresses leading to its persistence in the hostile environment of macrophages. Small RNA (sRNA)-mediated regulatory mechanisms have been scarcely explored in M. tuberculosis. MTS1338, a sRNA present only in pathogenic mycobacteria, was discovered to be highly abundant during infection and significantly contributes to host-pathogen interaction. A variety of stresses have been implicated for its accumulation. Herein, we showed that MTS1338 is an oxidative stress induced sRNA, which promotes the detoxification of reactive oxygen species (ROS) under oxidative stress. Current study identified a new role of MTS1338 in M. tuberculosis under oxidative stress.