Redox regulation of the immune response

Therapeutic potency of kaempferol against Naja haje venom induced neurotoxicity, inflammation, biological activities, and antioxidant system damage: a pre-clinical antivenom evaluation

Naja haje envenoming manifests organ system disorders leading to severe fatalities due to the venom's toxins. The neutralizing capacity of kaempferol has been reported against some medically significant snake venoms with exception of N. haje venom (NhV). This current study assessed the neutralizing profile of kaempferol against toxicities induced by NhV using in vitro and in vivo methods. In in vitro, NhV induced wide spectrum of toxic biological activities with substantial increase in hemorrhagic, anticoagulating, and hemolytic effects. Likewise in the in vivo study, the venom caused hematological disorders by inducing acute anemia, thrombocytopenia, and leucopenia in envenomed rats. Also, the venom caused detrimental effect on the antioxidant defense system of the brain through significant (P < 0.05) elevation of malondialdehyde (MDA), nitrite (NIT), and suppression of reduce glutathione (GSH) antioxidant, superoxide dismutase (SOD), catalase (CAT), and glutathione transferase (GST) enzymes. Additionally, the levels of neurotoxicity biomarkers, monoamine oxidase (MAO) and acetylcholinesterase (AChE), and pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), were significantly (P < 0.0.5) enhanced by NhV in the brain of envenomed rats. Severe pathohistological effects were observed in brain tissues of the envenomed rats. However, kaempferol substantially (P < 0.05) inhibited the NhV-induced biological activities, normalized the hematological disorders, enhanced antioxidants system functions, and significantly (P < 0.05) suppressed the levels of neurotoxicity biomarkers and pro-inflammatory cytokines. Severe structural alterations observed in the brain tissues were ameliorated after kaempferol treatment. Further exploration of kaempferol could lead to the development of an alternative therapy for treatment of N. haje envenoming.

Redox Regulation of cAMP-Dependent Protein Kinase and Its Role in Health and Disease

Protein kinase A (PKA) is a key regulator of cellular signaling that regulates key physiological processes such as metabolism, cell proliferation, and neuronal function. While its activation by the second messenger 3',5'-cyclic adenosine triphosphate (cAMP) is well characterized, recent research highlights additional regulatory mechanisms, particularly oxidative post-translational modifications, that influence PKA's structure, activity, and substrate specificity. Both the regulatory and catalytic subunits of PKA are susceptible to redox modifications, which have been shown to play important roles in the regulation of key cellular functions, including cardiac contractility, lipid metabolism, and the immune response. Likewise, redox-dependent modulation of PKA signaling has been implicated in numerous diseases, including cardiovascular disorders, diabetes, and neurodegenerative conditions, making it a potential therapeutic target. However, the mechanisms of crosstalk between redox- and PKA-dependent signaling remain poorly understood. This review examines the structural and functional regulation of PKA, with a focus on redox-dependent modifications and their impact on PKA-dependent signaling. A deeper understanding of these mechanisms may provide new strategies for targeting oxidative stress in disease and restoring balanced PKA signaling in cells.

Immunomodulatory effects of photobiomodulation: a comprehensive review

Photobiomodulation, also known as low-level light therapy (LLLT), has emerged as a promising non-invasive treatment modality with significant immunomodulatory effects. This comprehensive review examines the mechanisms underlying photobiomodulation-induced immunomodulation, its effects on specific immune cells, and its clinical applications in immune-related conditions. We explore the cellular and molecular pathways affected by photobiomodulation, including mitochondrial function, reactive oxygen species production, and key signaling cascades. The impact of photobiomodulation on macrophages, T cells, and dendritic cells is discussed, along with its potential in managing autoimmune diseases, inflammatory conditions, and wound healing. Safety considerations, optimal treatment parameters, and future directions in the field are also addressed. This review highlights the growing body of evidence supporting photobiomodulation as a valuable tool in immunomodulation and its potential to revolutionize the treatment of various immune-mediated disorders.

The active roles of Rhodotorula mucilaginosa ZTHY2 in regulating antioxidant capacity and immune function of Leizhou black ducks

Previous studies in mice have demonstrated that Rhodotorula mucilaginosa ZTHY2 can promote animal growth, enhance antioxidant and immune functions, and regulate intestinal flora in our laboratory. This study focuses on the Leizhou black duck, a local breed in Zhanjiang, to evaluate the effects of Rhodotorula mucilaginosa ZTHY2 on its growth, antioxidant capacity, and immune function. A total of 150 1-day-old male Leizhou black ducks, of similar size and healthy, were selected for this study and randomly assigned to five treatment groups. Each group contained three replicates with ten birds each. The control group (Control) was given a standard basal diet, while the RM group received a diet supplemented with ZTHY2 at concentrations of 2 × 107 (RM1), 2 × 108(RM2), or 2 × 109(RM3) CFU/kg, respectively. The LA group was supplemented with 2 × 109 CFU/kg of Lactobacillus acidophilus in addition to the basal diet. The feeding trial lasted 42 days. The analysis revealed significant improvements in the average body weight for the RM2 and RM3 groups, which were significantly higher than that of the control group (p < 0.05 and p < 0.01). Treatment with ZTHY2 induced a dose-dependent elevation in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and SOD activities, and a reduction in malondialdehyde (MDA) content in the serum at 42 days. The serum levels of complement components C3 and C4, immunoglobulin IgG, and cytokines IFN-γ, IL-2, IL-4, IL-6, and TNF-α were significantly increased in Leizhou black ducks treated with ZTHY2 at 42-days post-treatment, with the therapeutic effect becoming more pronounced as the duration of the experiment prolonged. The greatest impact was observed at a dosage of 2 × 109 CFU/kg of ZTHY2. Moreover, ZTHY2 modulated the mRNA expression profiles of these cytokines in the thymus, spleen, and bursa, thereby sustaining the balance of immune dynamics. In summary, the supplementation of Rhodotorula mucilaginosa ZTHY2 at a dosage of 2 × 109 CFU/kg had been found to most effectively enhance the growth performance of Leizhou black ducks by optimizing their immune function and antioxidant capacity.

Exploring the interplay between inflammation and male fertility

Male fertility results from a complex interplay of physiological, environmental, and genetic factors. It is conditioned by the properly developed anatomy of the reproductive system, hormonal regulation balance, and the interplay between different cell populations that sustain an appropriate and functional environment in the testes. Unfortunately, the mechanisms sustaining male fertility are not flawless and their perturbation can lead to infertility. Inflammation is one of the factors that contribute to male infertility. In the testes, it can be brought on by varicocele, obesity, gonadal infections, leukocytospermia, physical obstructions or traumas, and consumption of toxic substances. As a result of prolonged or untreated inflammation, the testicular resident cells that sustain spermatogenesis can suffer DNA damage, lipid and protein oxidation, and mitochondrial dysfunction consequently leading to loss of function in affected Sertoli cells (SCs) and Leydig cells (LCs), and the formation of morphologically abnormal dysfunctional sperm cells that lay in the basis of male infertility and subfertility. This is due mainly to the production and secretion of pro-inflammatory mediators, including cytokines, chemokines, and reactive oxygen species (ROS) by local immune cells (macrophages, lymphocytes T, mast cells) and tissue-specific cells [SCs, LCs, peritubular myoid cells (PMCs) and germ cells (GCs)]. Depending on the location, duration, and intensity of inflammation, these mediators can exert their toxic effect on different elements of the testes. In this review, we discuss the most prevalent inflammatory factors that negatively affect male fertility and describe the different ways inflammation can impair male reproductive function.

Oligodeoxynucleotides containing CpG motifs upregulate bactericidal activities of heterophils and enhance immunoprotection of neonatal broiler chickens against Salmonella Typhimurium septicemia

In the past, we demonstrated that oligodeoxynucleotides containing CpG motifs (CpG-ODN) mimicking bacterial DNA, stimulate the innate immune system of neonatal broiler chickens and protect them against Escherichia coli and Salmonella Typhimurium (S. Typhimurium) septicemia. The first line of innate immune defense mechanism is formed by heterophils and plays a critical protective role against bacterial septicemia in avian species. Therefore, the objectives of this study were 1) to explore the kinetics of CpG-ODN mediated antibacterial mechanisms of heterophils following single or twice administration of CpG-ODN in neonatal broiler chickens and 2) to investigate the kinetics of the immunoprotective efficacy of single versus twice administration of CpG-ODN against S. Typhimurium septicemia. In this study, we successfully developed and optimized flow cytometry-based assays to measure phagocytosis, oxidative burst, and degranulation activity of heterophils. Birds that received CpG-ODN had significantly increased (p < 0.05) phagocytosis, oxidative burst, and degranulation activity of heterophils as early as 24 h following CpG-ODN administration. Twice administration of CpG-ODN significantly increased the phagocytosis activity of heterophils. In addition, our newly developed CD107a based flow cytometry assay demonstrated a significantly higher degranulation activity of heterophils following twice than single administration of CpG-ODN. However, the oxidative burst activity of heterophils was not significantly different between birds that received CpG-ODN only once or twice. Furthermore, delivery of CpG-ODN twice increased immunoprotection against S. Typhimurium septicemia compared to once but the difference was not statistically significant. In conclusion, we demonstrated enhanced bactericidal activity of heterophils after administration of CpG-ODN to neonatal broiler chickens. Further investigations will be required to identify other activated innate immune cells and the specific molecular pathways associated with the CpG-ODN mediated activation of heterophils.

Multifaceted Proteome Analysis at Solubility, Redox, and Expression Dimensions for Target Identification

Multifaceted interrogation of the proteome deepens the system-wide understanding of biological systems; however, mapping the redox changes in the proteome has so far been significantly more challenging than expression and solubility/stability analyses. Here, the first high-throughput redox proteomics approach integrated with expression analysis (REX) is devised and combined with the Proteome Integral Solubility Alteration (PISA) assay. The whole PISA-REX experiment with up to four biological replicates can be multiplexed into a single tandem mass tag TMTpro set. For benchmarking this compact tool, HCT116 cells treated with auranofin are analyzed, showing great improvement compared with previous studies. PISA-REX is then applied to study proteome remodeling upon stimulation of human monocytes by interferon α (IFN-α). Applying this tool to study the proteome changes in plasmacytoid dendritic cells (pDCs) isolated from wild-type versus Ncf1-mutant mice treated with interferon α, shows that NCF1 deficiency enhances the STAT1 pathway and modulates the expression, solubility, and redox state of interferon-induced proteins. Providing comprehensive multifaceted information on the proteome, the compact PISA-REX has the potential to become an industry standard in proteomics and to open new windows into the biology of health and disease.

Gut redox and microbiome: charting the roadmap to T-cell regulation

The gastrointestinal (GI) tract redox environment, influenced by commensal microbiota and bacterial-derived metabolites, is crucial in shaping T-cell responses. Specifically, metabolites from gut microbiota (GM) exhibit robust anti-inflammatory effects, fostering the differentiation and regulation of CD8+ tissue-resident memory (TRM) cells, mucosal-associated invariant T (MAIT) cells, and stabilizing gut-resident Treg cells. Nitric oxide (NO), a pivotal redox mediator, emerges as a central regulator of T-cell functions and gut inflammation. NO impacts the composition of the gut microbiome, driving the differentiation of pro-inflammatory Th17 cells and exacerbating intestinal inflammation, and supports Treg expansion, showcasing its dual role in immune homeostasis. This review delves into the complex interplay between GI redox balance and GM metabolites, elucidating their profound impact on T-cell regulation. Additionally, it comprehensively emphasizes the critical role of GI redox, particularly reactive oxygen species (ROS) and NO, in shaping T-cell phenotype and functions. These insights offer valuable perspectives on disease mechanisms and potential therapeutic strategies for conditions associated with oxidative stress. Understanding the complex cross-talk between GI redox, GM metabolites, and T-cell responses provides valuable insights into potential therapeutic avenues for immune-mediated diseases, underscoring the significance of maintaining GI redox balance for optimal immune health.

Extracellular DNA traps in a ctenophore demonstrate immune cell behaviors in a non-bilaterian

The formation of extracellular DNA traps (ETosis) is a first response mechanism by specific immune cells following exposure to microbes. Initially characterized in vertebrate neutrophils, cells capable of ETosis have been discovered recently in diverse non-vertebrate taxa. To assess the conservation of ETosis between evolutionarily distant non-vertebrate phyla, we observed and quantified ETosis using the model ctenophore Mnemiopsis leidyi and the oyster Crassostrea gigas. Here we report that ctenophores - thought to have diverged very early from the metazoan stem lineage - possess immune-like cells capable of phagocytosis and ETosis. We demonstrate that both Mnemiopsis and Crassostrea immune cells undergo ETosis after exposure to diverse microbes and chemical agents that stimulate ion flux. We thus propose that ETosis is an evolutionarily conserved metazoan defense against pathogens.

ROS signaling in innate immunity via oxidative protein modifications

The innate immune response represents the first-line of defense against invading pathogens. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) have been implicated in various aspects of innate immune function, which involves respiratory bursts and inflammasome activation. These reactive species widely distributed within the cellular environment are short-lived intermediates that play a vital role in cellular signaling and proliferation and are likely to depend on their subcellular site of formation. NADPH oxidase complex of phagocytes is known to generate superoxide anion radical (O2 •-) that functions as a precursor for antimicrobial hydrogen peroxide (H2O2) production, and H2O2 is utilized by myeloperoxidase (MPO) to generate hypochlorous acid (HOCl) that mediates pathogen killing. H2O2 modulates the expression of redox-responsive transcriptional factors, namely NF-kB, NRF2, and HIF-1, thereby mediating redox-based epigenetic modification. Survival and function of immune cells are under redox control and depend on intracellular and extracellular levels of ROS/RNS. The current review focuses on redox factors involved in the activation of immune response and the role of ROS in oxidative modification of proteins in macrophage polarization and neutrophil function.

Serum Neopterin, Biopterin, Tryptophan, and Kynurenine Levels in Patients with Fabry Disease

Background

Fabry disease is characterized by the accumulation of globotriaosylceramide. Substrate accumulation in lysosomes is thought to trigger an inflammatory response and is responsible for progressive organ damage through the induction of autoimmunity. The levels of pteridine and kynurenine pathway metabolites increase when immune activation is observed and are employed to monitor several diseases and determine prognosis.

Aims

To elucidate the effects of immune activation on the pathophysiology of Fabry disease and to investigate the potential utility of pteridine and kynurenine metabolites.

Study Design

A prospective case-control study.

Methods

In this study, 33 patients with Fabry disease and 33 age-and sex-matched healthy controls were included. Blood pteridine and kynurenine metabolites were studied in both groups. Organ involvement in Fabry disease and its correlation with the pteridine and kynurenine pathways were also investigated.

Results

The patients’ neopterin and biopterin levels and the tryptophan/kynurenine ratio were statistically higher than those of the healthy control group (p < 0.05). A statistically significant association was found between neopterin levels and hypertrophic cardiomyopathy, cardiac arrhythmias, and GFR values (p = 0.044, p = 0.021, and p = 0.030, respectively), tryptophan and corneal verticillate, hearing loss and tinnitus (p = 0.010, p = 0.009 and p = 0.046, respectively), and kynurenine levels and valvular heart disease (p = 0.020).

Conclusion

From the onset of the disease, patients with Fabry disease exhibited elevated levels of inflammation and immune activation. Furthermore, inflammation and immune activation markers can be used as early disease biomarkers.

A Curcumin-Decorated Nanozyme with ROS Scavenging and Anti-Inflammatory Properties for Neuroprotection

Disordered reactive oxygen/nitrogen species are a common occurrence in various diseases, which usually cause cellular oxidative damage and inflammation. Despite the wide range of applications for biomimetic nanoparticles with antioxidant or anti-inflammatory properties, designs that seamlessly integrate these two abilities with a synergistic effect in a simple manner are seldom reported. In this study, we developed a novel PEI-Mn composite nanoparticle (PM NP) using a chelation method, and the curcumin was loaded onto PM NPs via metal-phenol coordination to form PEI-Mn@curcumin nanoparticles (PMC NPs). PMC NPs possessed excellent dispersibility and cytocompatibility, was engineered to serve as an effective nanozyme, and exhibited specific SOD-like and CAT-like activities. In addition, the incorporation of curcumin granted PMC NPs the ability to effectively suppress the expression of inflammatory cytokines in microglia induced by LPS. As curcumin also has antioxidant properties, it further amplified the synergistic efficiency of ROS scavenging. Significantly, PMC NPs effectively scavenged ROS triggered by H2O2 in SIM-A9 microglia cells and Neuro-2a cells. PMC NPs also considerably mitigated DNA and lipid oxidation in Neuro-2a cells and demonstrated an increase in cell viability under various H2O2 concentrations. These properties suggest that PMC NPs have significant potential in addressing excessive ROS and inflammation related to neural diseases.

Nanotechnology and Cancer Bioelectricity: Bridging the Gap Between Biology and Translational Medicine

Bioelectricity is the electrical activity that occurs within living cells and tissues. This activity is critical for regulating homeostatic cellular function and communication, and disruptions of the same can lead to a variety of conditions, including cancer. Cancer cells are known to exhibit abnormal electrical properties compared to their healthy counterparts, and this has driven researchers to investigate the potential of harnessing bioelectricity as a tool in cancer diagnosis, prognosis, and treatment. In parallel, bioelectricity represents one of the means to gain fundamental insights on how electrical signals and charges play a role in cancer insurgence, growth, and progression. This review provides a comprehensive analysis of the literature in this field, addressing the fundamentals of bioelectricity in single cancer cells, cancer cell cohorts, and cancerous tissues. The emerging role of bioelectricity in cancer proliferation and metastasis is introduced. Based on the acknowledgement that this biological information is still hard to access due to the existing gap between biological findings and translational medicine, the latest advancements in the field of nanotechnologies for cellular electrophysiology are examined, as well as the most recent developments in micro- and nano-devices for cancer diagnostics and therapy targeting bioelectricity.

Broadening Horizons: Exploring mtDAMPs as a Mechanism and Potential Intervention Target in Cardiovascular Diseases

Cardiovascular diseases (CVDs) have been recognized as the leading cause of premature mortality and morbidity worldwide despite significant advances in therapeutics. Inflammation is a key factor in CVD progression. Once stress stimulates cells, they release cellular compartments known as damage-associated molecular patterns (DAMPs). Mitochondria can release mitochondrial DAMPs (mtDAMPs) to initiate an immune response when stimulated with cellular stress. Investigating the molecular mechanisms underlying the DAMPs that regulate CVD progression is crucial for improving CVDs. Herein, we discuss the composition and mechanism of DAMPs, the significance of mtDAMPs in cellular inflammation, the presence of mtDAMPs in different types of cells, and the main signaling pathways associated with mtDAMPs. Based on this, we determined the role of DAMPs in CVDs and the effects of mtDAMP intervention on CVD progression. By offering a fresh perspective and comprehensive insights into the molecular mechanisms of DAMPs, this review seeks to provide important theoretical foundations for developing drugs targeting CVDs.

Hydrogen peroxide-dependent oxidation of ERK2 within its D-recruitment site alters its substrate selection

Extracellular signal-regulated kinases 1 and 2 (ERK1/2) are dysregulated in many pervasive diseases. Recently, we discovered that ERK1/2 is oxidized by signal-generated hydrogen peroxide in various cell types. Since the putative sites of oxidation lie within or near ERK1/2's ligand-binding surfaces, we investigated how oxidation of ERK2 regulates interactions with the model substrates Sub-D and Sub-F. These studies revealed that ERK2 undergoes sulfenylation at C159 on its D-recruitment site surface and that this modification modulates ERK2 activity differentially between substrates. Integrated biochemical, computational, and mutational analyses suggest a plausible mechanism for peroxide-dependent changes in ERK2-substrate interactions. Interestingly, oxidation decreased ERK2's affinity for some D-site ligands while increasing its affinity for others. Finally, oxidation by signal-generated peroxide enhanced ERK1/2's ability to phosphorylate ribosomal S6 kinase A1 (RSK1) in HeLa cells. Together, these studies lay the foundation for examining crosstalk between redox- and phosphorylation-dependent signaling at the level of kinase-substrate selection.

Heterochromatic silencing of immune-related genes in glia is required for BBB integrity and normal lifespan in drosophila

Glia and neurons face different challenges in aging and may engage different mechanisms to maintain their morphology and functionality. Here, we report that adult-onset downregulation of a Drosophila gene CG32529/GLAD led to shortened lifespan and age-dependent brain degeneration. This regulation exhibited cell type and subtype-specificity, involving mainly surface glia (comprising the BBB) and cortex glia (wrapping neuronal soma) in flies. In accordance, pan-glial knockdown of GLAD disrupted BBB integrity and the glial meshwork. GLAD expression in fly heads decreased with age, and the RNA-seq analysis revealed that the most affected transcriptional changes by RNAi-GLAD were associated with upregulation of immune-related genes. Furthermore, we conducted a series of lifespan rescue experiments and the results indicated that the profound upregulation of immune and related pathways was not the consequence but cause of the degenerative phenotypes of the RNAi-GLAD flies. Finally, we showed that GLAD encoded a heterochromatin-associating protein that bound to the promoters of an array of immune-related genes and kept them silenced during the cell cycle. Together, our findings demonstrate a previously unappreciated role of heterochromatic gene silencing in repressing immunity in fly glia, which is required for maintaining BBB and brain integrity as well as normal lifespan.

Toxicity of the spike protein of COVID-19 is a redox shift phenomenon: A novel therapeutic approach

We previously demonstrated that most diseases display a form of anabolism due to mitochondrial impairment: in cancer, a daughter cell is formed; in Alzheimer's disease, amyloid plaques; in inflammation cytokines and lymphokines. The infection by Covid-19 follows a similar pattern. Long-term effects include redox shift and cellular anabolism as a result of the Warburg effect and mitochondrial dysfunction. This unrelenting anabolism leads to the cytokine storm, chronic fatigue, chronic inflammation or neurodegenerative diseases. Drugs such as Lipoic acid and Methylene Blue have been shown to enhance the mitochondrial activity, relieve the Warburg effect and increase catabolism. Similarly, coMeBining Methylene Blue, Chlorine dioxide and Lipoic acid may help reduce long-term Covid-19 effects by stimulating the catabolism.

Production of Reactive Oxygen (ROS) and Nitrogen (RNS) Species in Macrophages J774A.1 Activated by the Interaction between Two Escherichia coli Pathotypes and Two Probiotic Commercial Strains

Probiotics play an important role against infectious pathogens, such as Escherichia coli (E. coli), mainly through the production of antimicrobial compounds and their immunomodulatory effect. This protection can be detected both on the live probiotic microorganisms and in their inactive forms (paraprobiotics). Probiotics may affect different cells involved in immunity, such as macrophages. Macrophages are activated through contact with microorganisms or their products (lipopolysaccharides, endotoxins or cell walls). The aim of this work was the evaluation of the effect of two probiotic bacteria (Escherichia coli Nissle 1917 and Bifidobacterium animalis subsp. lactis HN019 on macrophage cell line J774A.1 when challenged with two pathogenic strains of E. coli. Macrophage activation was revealed through the detection of reactive oxygen (ROS) and nitrogen (RNS) species by flow cytometry. The effect varied depending on the kind of probiotic preparation (immunobiotic, paraprobiotic or postbiotic) and on the strain of E. coli (enterohemorrhagic or enteropathogenic). A clear immunomodulatory effect was observed in all cases. A higher production of ROS compared with RNS was also observed.

Crosstalk between regulated cell death and immunity in redox dyshomeostasis for pancreatic cancer

The insidious clinical symptoms of pancreatic cancer (PACA), extensive tolerance to radiotherapy and chemotherapy, and insensitivity to immunotherapy result in an inferior prognosis. Redox dyshomeostasis could trigger programmed cell death and contribute to functional changes in immune cells, which is strongly associated with tumorigenesis and tumor development. Therefore, it is warranted to decipher the crosstalk between regulated cell death and immunity in the context of redox dyshomeostasis for PACA. Herein, four redox-related subtypes of PACA were identified: C1 and C2 displayed malignant phenotypes with dismal clinical outcomes, conspicuous enrichment in cell death pathways, high redox score, low immune activation, and "immune-desert" tumor immune microenvironment (TIME); C3, an immune-rejection/excluded subtype, with abundant immune cells, high co-stimulatory, co-inhibitory, and MHC molecules, and potential response to immunotherapy; C4, with the best prognosis, low redox pattern, high level of autophagy, low enrichment of most cell death-related pathways, and "immune-hot" TIME. Overall, this study found an attractive platform from the perspective of redox-related pathways, which would propose insights into the intricate and elaborate molecular mechanisms of PACA and offer more effective and tailored intervention protocols.

The effect of heat treatment on colostral and newborn calf redox status and oxylipid biomarkers

Newborn calves experience altered redox balance upon transition to extrauterine life. In addition to its nutritional value, colostrum is rich in bioactive factors, including pro- and antioxidants. The objective was to investigate differences in pro- and antioxidants as well as oxidative markers in raw and heat-treated (HT) colostrum and in the blood of calves fed either raw or HT colostrum. Eleven colostrum samples (≥8 L) of Holstein cows were each divided into a raw or HT (60°C, 60 min) portion. Both treatments were stored for <24 h at 4°C and tube-fed in a randomized-paired design at 8.5% of body weight to 22 newborn female Holstein calves within 1 h after birth. Colostrum samples were obtained before feeding, and calf blood samples were taken immediately before feeding (0 h) and at 4, 8, and 24 h after feeding. All samples were analyzed for reactive oxygen and nitrogen species (RONS) and antioxidant potential (AOP), from which the oxidant status index (OSi) was calculated. In 0-, 4-, and 8-h plasma samples, targeted fatty acids (FA) were analyzed using liquid chromatography-mass spectrometry, and oxylipids and isoprostanes (IsoP) using liquid chromatography-tandem mass spectrometry. Results for RONS, AOP, and OSi were analyzed by mixed-effects ANOVA or mixed-effects repeated-measures ANOVA, for colostrum and calf blood samples, respectively, whereas FA, oxylipid, and IsoP were analyzed using false discovery rate-adjusted analysis of paired data. Compared with control, HT colostrum showed lower RONS [least squares means (LSM) 189, 95% confidence interval (95% CI): 159-219 vs. 262, 95% CI: 232-292) relative fluorescence units] and OSi (7.2, 95% CI: 6.0-8.3 vs. 10.0, 95% CI: 8.9-11.1), but AOP remained unchanged (26.7, 95% CI: 24.4-29.0 vs. 26.4, 95% CI: 24.1-28.7 Trolox equivalents/µL). Changes in colostrum oxidative markers due to heat treatment were minor. No changes in RONS, AOP, OSi, or oxidative markers were detected in calf plasma. In both groups of calves, plasma RONS activity declined considerably at all postfeeding time points compared with precolostral values, and AOP reached its maximum 8 to 24 h after feeding. Generally, oxylipid and IsoP plasma abundance reached nadirs at 8 h post-colostrum in both groups. Overall, effects due to heat treatment on redox balance of colostrum and newborn calves and on oxidative biomarkers were minimal. In this study, heat treatment of colostrum reduced RONS activity but did not lead to detectable changes in calf oxidative status overall. This indicates that there were only minor changes in colostral bioactive components that could alter newborn redox balance and markers of oxidative damage.

Radiotherapy Induces Innate Immune Responses in Patients Treated for Prostate Cancers

PURPOSE

Radiotherapy is a curative therapeutic modality used to treat cancers as a single agent or in combination with surgery and chemotherapy. Advanced radiotherapy technologies enable treatment with large fractions and highly conformal radiation doses to effect free-radical damage to cellular DNA leading to cell-cycle arrest, cell death, and innate immune response (IIR) stimulation.

EXPERIMENTAL DESIGN

To understand systemic clinical responses after radiation exposure, proteomic and metabolomic analyses were performed on plasma obtained from patients with cancer at intervals after prostate stereotactic body radiotherapy. Pathway and multivariate analyses were used to delineate molecular alterations following radiotherapy and its correlation with clinical outcomes.

RESULTS

DNA damage response increased within the first hour after treatment and returned to baseline by 1 month. IIR signaling also increased within 1 hour of treatment but persisted for up to 3 months thereafter. Furthermore, robust IIR and metabolite elevations, consistent with an early proinflammatory M1-mediated innate immune activation, were observed in patients in remission, whereas patients experiencing prostate serum antigen-determined disease progression demonstrated less robust immune responses and M2-mediated metabolite elevations.

CONCLUSIONS

To our knowledge, these data are the first report of longitudinal proteomic and metabolomic molecular responses in patients after radiotherapy for cancers. The data supports innate immune activation as a critical clinical response of patients receiving radiotherapy for prostate cancer. Furthermore, we propose that the observed IIR may be generalized to the treatment of other cancer types, potentially informing multidisciplinary therapeutic strategies for cancer treatment.

The advent of phyllobilins as bioactive phytochemicals – natural compounds derived from chlorophyll in medicinal plants and food with immunomodulatory activities

The degradation of the green plant pigment chlorophyll has fascinated chemists and biologists alike over the last few decades. Bioactivities of the compounds formed in this biochemical degradation pathway, however, have only come to light recently. These natural compounds that are formed from chlorophyll during plant senescence are now called phyllobilins. In this review, we shortly discuss chlorophyll degradation and outline the so-far known bioactivities of selected phyllobilins (phylloleucobilin, dioxobilin-type phylloleucobilin, and phylloxanthobilin), and we also highlight the recently discovered immunomodulatory effects of a yellow phylloxanthobilin.

Maternal Immune Response to ZIKV Triggers High-Inflammatory Profile in Congenital Zika Syndrome

The immunological mechanisms involved in the development of congenital Zika syndrome (CZS) have yet to be fully clarified. This study aims to assess the immuno-inflammatory profile of mothers and their children who have been diagnosed with CZS. Blood samples, which were confirmed clinically using the plaque reduction neutralization test (PRNT), were collected from children with CZS and their mothers (CZS+ group). Samples were also collected from children who did not develop CZS and had a negative PRNT result and from their mothers (CZS- group). The data demonstrated a correlation between the leukocyte profile of CZS+ children and their mothers, more evident in monocytes. Monocytes from mothers of CZS+ children showed low expression of HLA and elevated hydrogen peroxide production. CZS+ children presented standard HLA expression and a higher hydrogen peroxide concentration than CZS- children. Monocyte superoxide dismutase activity remained functional. Moreover, when assessing the monocyte polarization, it was observed that there was no difference in nitrite concentrations; however, there was a decrease in arginase activity in CZS+ children. These data suggest that ZIKV infection induces a maternal immuno-inflammatory background related to the child's inflammatory response after birth, possibly affecting the development and progression of congenital Zika syndrome.

Aldehyde Dehydrogenase 2 Ameliorates LPS-Induced Acute Kidney Injury through Detoxification of 4-HNE and Suppression of the MAPK Pathway

Lipopolysaccharide (LPS)-induced septic acute kidney injury (AKI) is determined as a devastating organ dysfunction elicited by an inappropriate response to infection with high morbidity and mortality rates. Previous evidence has illustrated an indispensable role of mitochondrial aldehyde dehydrogenase 2 (ALDH2) in the pathogenesis of sepsis-induced multiorgan abnormalities. Specifically, this study investigated the potential role of ALDH2 in sepsis-induced AKI. After LPS administration, we observed a significant decline in renal function, increased inflammatory cytokines, oxidative stress, 4-hydroxy-2-nonenal (4-HNE) accumulation, and apoptosis via MAPK activation in ALDH2^-/- mice; in contrast, pretreatment with Alda-1 (an ALDH2 activator) alleviated the LPS-induced dysfunctions in mice. Moreover, in vitro analysis revealed that ALDH2 overexpression in mouse tubular epithelial cells (mTECs) improved the inflammatory response, oxidative stress, 4-HNE accumulation, and apoptosis via MAPK inhibition, whereas ALDH2 knockdown in mTECs aggravated these parameters via MAPK activation. Therefore, ALDH2 may protect against LPS-induced septic AKI by suppressing 4-HNE/MAPK pathway.

Receptor-Mediated Redox Imbalance: An Emerging Clinical Avenue against Aggressive Cancers

Cancer cells are more vulnerable to abnormal redox fluctuations due to their imbalanced antioxidant system, where cell surface receptors sense stress and trigger intracellular signal relay. As canonical targets of many targeted therapies, cell receptors sensitize the cells to specific drugs. On the other hand, cell target mutations are commonly associated with drug resistance. Thus, exploring effective therapeutics targeting diverse cell receptors may open new clinical avenues against aggressive cancers. This paper uses focused case studies to reveal the intrinsic relationship between the cell receptors of different categories and the primary cancer hallmarks that are associated with the responses to external or internal redox perturbations. Cold atmospheric plasma (CAP) is examined as a promising redox modulation medium and highly selective anti-cancer therapeutic modality featuring dynamically varying receptor targets and minimized drug resistance against aggressive cancers.

Relation between redox potential and natural antibody levels in goat kid serum

The redox potential and the natural antibody (NAb) levels are parameters commonly tested to verify the physiological response to stressful situations determined by farming conditions or research needs. In this paper, the redox potential, assessed by different spectrophotometric methods, was related to NAb levels together with total immunoglobulin (tot-Ig) levels in goat kid serum. Reactive oxygen metabolites (ROMs) and ceruloplasmin (CP) oxidase activity were significantly associated with NAb-IgG and NAb-IgM. Nitric oxide metabolites (NOx) and total thiol levels (TTLs) were significantly related to NAb-IgM and tot-IgM, and with NAb-IgG, respectively. A tendency was shown between ROMs and tot-IgM, and between CP and tot-IgM, where, however, the significance levels were above the cut-off values. Total oxidant status (TOS), total antioxidant activity (TAA), determined by the ABTS-based method, the ferric reducing ability of plasma (FRAP), and free radical scavenging activity (FRSA) were associated with neither NAb nor tot-Ig. The obtained results are discussed in light of the possible linkage between the (anti)oxidant status and the innate immune system in goats.

A Chlorophyll-Derived Phylloxanthobilin Is a Potent Antioxidant That Modulates Immunometabolism in Human PBMC

Phyllobilins are natural products derived from the degradation of chlorophyll, which proceeds via a common and strictly controlled pathway in higher plants. The resulting tetrapyrrolic catabolites—the phyllobilins—are ubiquitous in nature; despite their high abundance, there is still a lack of knowledge about their physiological properties. Phyllobilins are part of human nutrition and were shown to be potent antioxidants accounting with interesting physiological properties. Three different naturally occurring types of phyllobilins—a phylloleucobilin, a dioxobilin-type phylloleucobilin and a phylloxanthobilin (PxB)—were compared regarding potential antioxidative properties in a cell-free and in a cell-based antioxidant activity test system, demonstrating the strongest effect for the PxB. Moreover, the PxB was investigated for its capacity to interfere with immunoregulatory metabolic pathways of tryptophan breakdown in human blood peripheral mononuclear cells. A dose-dependent inhibition of tryptophan catabolism to kynurenine was observed, suggesting a suppressive effect on pathways of cellular immune activation. Although the exact mechanisms of immunomodulatory effects are yet unknown, these prominent bioactivities point towards health-relevant effects, which warrant further mechanistic investigations and the assessment of the in vivo extrapolatability of results. Thus, phyllobilins are a still surprisingly unexplored family of natural products that merit further investigation.

Opportunities for Nitric Oxide in Potentiating Cancer Immunotherapy

Despite nearly 30 years of development and recent highlights of nitric oxide (NO) donors and NO delivery systems in anticancer therapy, the limited understanding of exogenous NO's effects on the immune system has prevented their advancement into clinical use. In particular, the effects of exogenously delivered NO differing from that of endogenous NO has obscured how the potential and functions of NO in anticancer therapy may be estimated and exploited despite the accumulating evidence of NO's cancer therapy-potentiating effects on the immune system. After introducing their fundamentals and characteristics, this review discusses the current mechanistic understanding of NO donors and delivery systems in modulating the immunogenicity of cancer cells as well as the differentiation and functions of innate and adaptive immune cells. Lastly, the potential for the complex modulatory effects of NO with the immune system to be leveraged for therapeutic applications is discussed in the context of recent advancements in the implementation of NO delivery systems for anticancer immunotherapy applications. SIGNIFICANCE STATEMENT: Despite a 30-year history and recent highlights of nitric oxide (NO) donors and delivery systems as anticancer therapeutics, their clinical translation has been limited. Increasing evidence of the complex interactions between NO and the immune system has revealed both the potential and hurdles in their clinical translation. This review summarizes the effects of exogenous NO on cancer and immune cells in vitro and elaborates these effects in the context of recent reports exploiting NO delivery systems in vivo in cancer therapy applications.

Exosome from indoleamine 2,3-dioxygenase-overexpressing bone marrow mesenchymal stem cells accelerates repair process of ischemia/reperfusion-induced acute kidney injury by regulating macrophages polarization

BACKGROUND

Ischemia-reperfusion injury (IRI)-induced acute kidney injury (AKI) can repair itself completely. However, most moderate and severe patients undergoing IRI-AKI progress to chronic kidney disease due to incomplete repair. The present study is aimed to investigate the role of bone marrow mesenchymal stem cell-derived exosomes (MSC-Exo) with indoleamine 2,3-dioxygenase (IDO) overexpression on incomplete repair in mice after IRI.

METHODS

IRI mice was established by clamping the unilateral renal pedicles and challenged with MSC-Exo. Blood biochemical indexes and inflammation factors contents were measured by ELISA assay. Histopathological examinations were monitored by HE, Masson, Immunohistochemical and TUNEL staining. Immunofluorescence, flow cytometry and immunoblotting were used to detect the polarization of macrophages, respectively.

RESULTS

As compared to sham operation mice, IRI mice showed high contents of serum BUN and Scr, and more severe damaged kidney tissues on days 1 and 3, which all gradually declined over time, showing the lowest level on day 7 after injury. Once treated with MSCs-Exo that could directly transfer to kidney tubular cells, the restoration of kidney functions significantly accelerated by contrast to IRI mice, and the promotive effects were more obvious in IDO-overexpressed MSCs-Exo (MSCs-Exo-IDO)-treated IRI mice. Furthermore, MSCs-Exo-IDO administration also accelerated renal tubular cells proliferation, restrained tubular cells apoptosis, fibrosis and inflammation factor secretions during self-repair process compared to IRI mice, whose effects were higher than MSCs-Exo-NC-challenged IRI mice and IDO overexpressing plasmid-injected IRI mice. Mechanistically, MSCs-Exo-NC and MSCs-Exo-IDO exposure promoted the polarization from M1 macrophage to M2 macrophage, leading to more anti-inflammatory factors production, and subsequently altered the inflammatory microenvironment of renal tubular cells, which facilitated the self-repair process in mice after IRI.

CONCLUSION

MSCs-derived exosome accelerated renal self-repair in IRI mice by activating M2 macrophages polarization, which effects were amplified by IDO overexpression in MSCs. Potentially, genetically modified MSCs-Exo is an effective approach to improve renal self-repair in IRI-AKI mice.

Mitochondrial trafficking and redox/phosphorylation signaling supporting cell migration phenotypes

Regulation of cell signaling cascades is critical in making sure the response is activated spatially and for a desired duration. Cell signaling cascades are spatially and temporally controlled through local protein phosphorylation events which are determined by the activation of specific kinases and/or inactivation of phosphatases to elicit a complete and thorough response. For example, A-kinase-anchoring proteins (AKAPs) contribute to the local regulated activity protein kinase A (PKA). The activity of kinases and phosphatases can also be regulated through redox-dependent cysteine modifications that mediate the activity of these proteins. A primary example of this is the activation of the epidermal growth factor receptor (EGFR) and the inactivation of the phosphatase and tensin homologue (PTEN) phosphatase by reactive oxygen species (ROS). Therefore, the local redox environment must play a critical role in the timing and magnitude of these events. Mitochondria are a primary source of ROS and energy (ATP) that contributes to redox-dependent signaling and ATP-dependent phosphorylation events, respectively. The strategic positioning of mitochondria within cells contributes to intracellular gradients of ROS and ATP, which have been shown to correlate with changes to protein redox and phosphorylation status driving downstream cellular processes. In this review, we will discuss the relationship between subcellular mitochondrial positioning and intracellular ROS and ATP gradients that support dynamic oxidation and phosphorylation signaling and resulting cellular effects, specifically associated with cell migration signaling.

Immunomodulatory Effect of Hispolon on LPS-Induced RAW264.7 Cells and Mitogen/Alloantigen-Stimulated Spleen Lymphocytes of Mice

Hispolon is a potent anticancer, anti-inflammatory, antioxidant, and antidiabetic agent isolated from Phellinus linteus, an oriental medicinal mushroom. However, the immunomodulatory mechanisms by which hispolon affects macrophages and lymphocytes remain poorly characterized. We investigated the immunomodulatory effects of hispolon on oxidative stress, inflammatory responses, and lymphocyte proliferation using lipopolysaccharide (LPS)-treated RAW264.7 macrophages or mitogen/alloantigen-treated mouse splenocytes. Hispolon inhibited LPS-induced reactive oxygen and nitrogen species (ROS/RNS) generation and decreased total sulfhydryl (SH) levels in a cell-free system and RAW264.7 cells. Hispolon exerted significant anti-inflammatory effects by inhibiting production of the proinflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) and activation of nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3) in LPS-treated RAW264.7 cells. Hispolon also modulated NF-κB and STAT3 activation by suppressing the NF-κB p65 interaction with phospho-IκBα and the STAT3 interaction with JAK1, as determined via coimmunoprecipitation analysis. Additionally, hispolon significantly decreased lymphocyte proliferation, T cell responses and T helper type 1 (Th1)/type 2 (Th2) cytokines production in mitogen/alloantigen-treated splenocytes. We conclude that hispolon exerts immunomodulatory effects on LPS-treated macrophages or mitogen/alloantigen-treated splenocytes through antioxidant, anti-inflammatory, and antiproliferative activities. Thus, hispolon may be a therapeutic agent for treating immune-mediated inflammatory diseases.

The Variable Nature of Vitamin C—Does It Help When Dealing with Coronavirus?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still spreading worldwide. For this reason, new treatment methods are constantly being researched. Consequently, new and already-known preparations are being investigated to potentially reduce the severe course of coronavirus disease 2019 (COVID-19). SARS-CoV-2 infection induces the production of pro-inflammatory cytokines and acute serum biomarkers in the host organism. In addition to antiviral drugs, there are other substances being used in the treatment of COVID-19, e.g., those with antioxidant properties, such as vitamin C (VC). Exciting aspects of the use of VC in antiviral therapy are its antioxidant and pro-oxidative abilities. In this review, we summarized both the positive effects of using VC in treating infections caused by SARS-CoV-2 in the light of the available research. We have tried to answer the question as to whether the use of high doses of VC brings the expected benefits in the treatment of COVID-19 and whether such treatment is the correct therapeutic choice. Each case requires individual assessment to determine whether the positives outweigh the negatives, especially in the light of populational studies concerning the genetic differentiation of genes encoding the solute carriers responsible forVC adsorption. Few data are available on the influence of VC on the course of SARS-CoV-2 infection. Deducing from already-published data, high-dose intravenous vitamin C (HDIVC) does not significantly lower the mortality or length of hospitalization. However, some data prove, among other things, its impact on the serum levels of inflammatory markers. Finally, the non-positive effect of VC administration is mainly neutral, but the negative effect is that it can result in urinary stones or nephropathies.

NADPH Oxidases Connecting Fatty Liver Disease, Insulin Resistance and Type 2 Diabetes: Current Knowledge and Therapeutic Outlook

Nonalcoholic fatty liver disease (NAFLD), characterized by ectopic fat accumulation in hepatocytes, is closely linked to insulin resistance and is the most frequent complication of type 2 diabetes mellitus (T2DM). One of the features connecting NAFLD, insulin resistance and T2DM is cellular oxidative stress. Oxidative stress refers to a redox imbalance due to an inequity between the capacity of production and the elimination of reactive oxygen species (ROS). One of the major cellular ROS sources is NADPH oxidase enzymes (NOX-es). In physiological conditions, NOX-es produce ROS purposefully in a timely and spatially regulated manner and are crucial regulators of various cellular events linked to metabolism, receptor signal transmission, proliferation and apoptosis. In contrast, dysregulated NOX-derived ROS production is related to the onset of diverse pathologies. This review provides a synopsis of current knowledge concerning NOX enzymes as connective elements between NAFLD, insulin resistance and T2DM and weighs their potential relevance as pharmacological targets to alleviate fatty liver disease.

Redox Homeostasis and Immune Alterations in Coronavirus Disease-19

The global Coronavirus Disease 2019 (COVID-19) pandemic is characterized by a wide variety of clinical features, from no or moderate symptoms to severe illness. COVID-19 is caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that first affects the respiratory tract. Other than being limited to lungs, SARS-CoV-2 may lead to a multisystem disease that can even be durable (long COVID). The clinical spectrum of COVID-19 depends on variability in the immune regulation. Indeed, disease progression is consequent to failure in the immune regulation, characterized by an intensification of the pro-inflammatory response. Disturbance of systemic and organ-related redox balance may be a further mechanism underlying variability in COVID-19 severity. Other than being determinant for SARS-CoV-2 entry and fusion to the host cell, reactive species and redox signaling are deeply involved in the immune response. This review sums up the present knowledge on the role of redox balance in the regulation of susceptibility to SARS-CoV-2 infection and related immune response, debating the effectiveness of antioxidant compounds in the management of COVID-19.

Promising Strategies in Plant-Derived Treatments of Psoriasis-Update of In Vitro, In Vivo, and Clinical Trials Studies

Psoriasis is a common, chronic systemic inflammatory disease affecting 125 million people worldwide. It is associated with several important conditions, including psoriatic arthritis, cardiometabolic syndrome, and depression, leading to a significant reduction in patients’ quality of life. Current treatments only reduce symptoms, not cure. This review discusses the mechanisms involved in the initiation and development of the disease, the role of oxidative stress in this autoimmune disease, as well as potential therapeutic options with substances of natural origin. The main aim of the study is intended to offer a review of the literature to present plants and phytochemicals that can represent potential remedies in the fight against psoriasis. We identified many in vitro, in vivo, and clinical trials studies that evaluated the relationship between chosen natural substances and immune system response in the course of psoriasis. We sought to find articles about the efficacy of potential natural-derived drugs in controlling symptoms and their ability to maintain long-term disease inactivity without side effects, and the result of our work is a review, which highlights the effectiveness of plant-derived drugs in controlling the inflammatory burden on psoriatic patients by decreasing the oxidative stress conditions.

Tryptophan Metabolism in Bipolar Disorder in a Longitudinal Setting

Immune-mediated inflammatory processes and oxidative stress are involved in the aetiopathogenesis of bipolar disorder (BD) and weight-associated comorbidities. Tryptophan breakdown via indoleamine 2,3-dioxygenase-1 (IDO-1) along the kynurenine axis concomitant with a pro-inflammatory state was found to be more active in BD, and associated with overweight/obesity. This study aimed to investigate tryptophan metabolism in BD compared to controls (C), stratified by weight classes, in a longitudinal setting, dependent on the incidence of BD episodes. Peripheral tryptophan, kynurenine, and neopterin were assessed in the serum of 226 BD individuals and 142 C. Three samples in a longitudinal assessment were used for 75 BD individuals. Results showed a higher kynurenine/tryptophan in both BD compared to C and overweight compared to normal weight persons. Levels remained stable over time. In the longitudinal course, no differences were found between individuals who were constantly euthymic or not, or who had an illness episode or had none. Findings indicate that tryptophan, kynurenine, and IDO-1 activity may play a role in pathophysiology in BD but are not necessarily associated with clinical manifestations. Accelerated tryptophan breakdown along the kynurenine axis may be facilitated by being overweight. This may increase the risk of accumulation of neurotoxic metabolites, impacting BD symptomatology, cognition, and somatic comorbidities.

The impact of environmental injustice and social determinants of health on the role of air pollution in asthma and allergic disease in the United States

There is clear evidence that exposure to environmental air pollution is associated with immune dysregulation, asthma, and other allergic diseases. However, the burden of air pollution exposure is not equally distributed across the United States. Many social and environmental factors place communities of color and people who are in poverty at increased risk of exposure to pollution and morbidity from asthma and allergies. Here, we review the evidence that supports the relationship between air pollution and asthma, while considering the social determinants of health that contribute to disparities in exposures and outcomes.

Effects of Clostridium butyricum and a Bacteriophage Cocktail on Growth Performance, Serum Biochemistry, Digestive Enzyme Activities, Intestinal Morphology, Immune Responses, and the Intestinal Microbiota in Rabbits

The objective of this study was to assess the effects of dietary supplementation with Clostridium butyricum (CB) and a bacteriophage cocktail (BP) on growth performance, serum biochemical parameters, intestinal digestive and oxidase enzymes, intestinal morphology, immune responses, and the cecum microbiota in rabbits. In total, 108 New Zealand rabbits (5 weeks old) were randomly and equally allotted into three dietary treatment groups (four replicates per treatment, n = 36/treatment): (1) the control (CN) group-rabbits fed the basal diet; (2) CB group-rabbits fed the basal diet supplemented with 100 mg/kg diet Clostridium butyricum; and (3) BP group-rabbits fed the basal diet supplemented with 200 mg/kg diet BP cocktail, respectively, for 6 weeks. Compared with the CN diet, dietary CB and BP inclusion increased the average daily gain (ADG) and average daily feed intake (ADFI) and decreased the feed/gain (F/G) ratio of rabbits. Furthermore, CB increased the digestive enzyme activity (α-amylase and trypsin in the ileum); the chymotrypsin activity was also significantly increased in the duodenum and jejunum. Supplementation with CB significantly enhanced antioxidant capacity (SOD and GSH-Px) in the jejunum and ileum and reduced MDA levels. Additionally, rabbits fed CB had significantly elevated villus height (V) and (V/C) ratios but reduced crypt depth (C). Moreover, dietary CB supplementation markedly increased the ileal expression of tight junction proteins (occludin, ZO-1, and claudin-1) and increased secretory immunoglobulin A (sIgA) production. High-throughput sequencing indicated that the microbiota in the rabbit intestine was altered by CB and BP. Venn diagrams and heatmap plots revealed that the gut microbial community composition varied obviously among rabbits fed different diets. Specifically, CB increased the relative abundance of beneficial bacteria to maintain intestinal barrier homeostasis, whereas BP decreased the relative abundance of Gammaproteobacteria, which included a plenty of pathogenic bacteria.

Integrated analysis of lncRNA and mRNA in liver of Megalobrama amblycephala post Aeromonas hydrophila infection

Background

As non-coding RNA molecules of more than 200 bp in length, long non-coding RNAs (lncRNAs) play a variety of roles in biological processes, including regulating the immune responses to bacterial infections. In recent years, there have been many in-depth studies on mammalian lncRNAs, but the relevant studies in fish are very limited. Meanwhile, since lncRNAs are not conserved among species, it is difficult to apply the existing results directly to unstudied species.

Results

To obtain the information of lncRNAs in Megalobrama amblycephala, one of the most economically important freshwater fish in China, also to better understand the biological significance of lncRNAs in the immunity system, the fish liver at 0, 4, 12, 24, and 72 h post Aeromonas hydrophila infection (hpi) were obtained for lncRNA-sequencing (lncRNA-seq). A total of 14,849 lncRNAs were identified, and 2196 lncRNAs showed significant differences at different time points post A. hydrophila infection. Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed that the target genes of the differentially expressed lncRNAs were enriched in several pathways related to immune such as apoptosis, inflammation, and immune response. Time-specific modules were then identified, using weighted correlation network analysis (WGCNA), and 28 modules significantly correlated with different time point after infection were found. Furthermore, four immune-related genes and six lncRNAs in the time-specific modules were subsequently verified by RT-qPCR.

Conclusions

The above findings reveal the discovery of widespread differentially expressed lncRNAs in the M. amblycephala liver post A. hydrophila infection, suggesting that lncRNAs might participate in the regulation of host response to bacterial infection, enriching the information of lncRNAs in teleost and providing a resources basis for further studies on the immune function of lncRNAs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07969-5.

Selenium Regulation of the Immune Function of Dendritic Cells in Mice Through the ERK, Akt and RhoA/ROCK Pathways

Selenium levels can regulate the function of T cells, macrophages, B cells, natural killer cells and other immune cells. However, the effect of selenium on the immune function of dendritic cells (DCs) isolated from selenium-supplemented mice is unknown. In this study, C57BL/6J mice were randomly divided into three groups and fed diets containing low (0.08 ppm), medium (0.25 ppm) or high (1 ppm) selenium levels for 8 weeks. Immature (imDCs) and mature (mDCs) dendritic cells were then isolated from the bone marrow. Next, the migration, phagocytic capacity and mixed lymphocyte reaction (MLR) for imDCs and mDCs were detected by transwell and flow cytometry. The levels of C-C chemokine receptor type 7 (CCR7), major histocompatibility complex II (MHCII) and reactive oxygen species (ROS) were assayed by flow cytometry. F-actin and superoxide dismutase (SOD) activity was detected by fluorescence microscopy and SOD assay kit, respectively. In addition, the extracellular signal-regulated kinase (ERK), Akt, Ras homolog gene family member A/Rho-associated protein kinase (RhoA/ROCK) signalling, selenoprotein K (SELENOK) and glutathione peroxidase 1 (GPX1) levels were measured by western blot analysis. The results indicated that selenium deficiency enhanced the migration of imDCs by ROS and SELENOK-mediated ERK, Akt and RhoA/ROCK pathways but impaired the antigen uptake of imDCs. Although a high selenium level inhibited the migration of imDCs, it had no effect on phagocytic capacity. For mDCs, low selenium levels impaired free migration, and high levels inhibited the chemotactic migration involved in F-actin and CCR7, respectively. Low and high selenium levels impaired the MLR by inhibiting MHCII surface localisation, which might be related to ROS- and SELENOK-mediated ERK, Akt and RhoA/ROCK signalling pathways. In summary, selenium may regulate the immune function of mouse DCs through the ROS- and SELENOK-mediated ERK, Akt and RhoA/ROCK signalling.

Wan-Nian-Qing, a Herbal Composite Prescription, Suppresses the Progression of Liver Cancer in Mice by Regulating Immune Response

The Wan-Nian-Qing prescription (WNQP), an herbal composite containing Ornithogalum caudatum, has been used in China for several years for cancer treatment. However, the mechanism of its pharmacological action against liver cancer is not clear. This study aimed to investigate the role of WNQP in inhibiting tumor growth in hepatocellular carcinoma model mice and determine its mechanism of action. We established HepG2- and SMMC-7721-xenografted tumor models in nude mice and BALB/c mice. The mice were administered WNQP for 2 weeks. The bodyweight of each mouse was monitored every day, and the tumor size was measured using vernier caliper before each round of WNQP administration. After the last dose, mice were sacrificed. The tumors were removed, lysed, and subjected to proteome profiling, enzyme-linked immunosorbent assay, and western blotting. The liver, spleen, and kidney were collected for histopathological examination. The effects of WNQP against liver cancer were first systematically confirmed in HepG2- and SMMC-7721-xenografted nude mice and BALB/c mice models. WNQP inhibited tumor growth, but failed to affect bodyweight and organ structures (liver and spleen), confirming that it was safe to use in mice. In BALB/c mice, WNQP regulated immune function, inferred from the modulation of immune-related cytokines such as interleukins, interferon, tumor necrosis factors, and chemokines. Further results confirmed that this regulation occurred via the regulatory effects of WNQP on Nrf2 signaling. WNQP can inhibit the growth of HepG2- and SMMC-7721-xenografted tumors in nude mice and BALB/c mice. This effect manifests at least partially through immunomodulation mediated apoptosis.

Hijacked Immune Cells in the Tumor Microenvironment: Molecular Mechanisms of Immunosuppression and Cues to Improve T Cell-Based Immunotherapy of Solid Tumors

The understanding of the tumor microenvironment (TME) has been expanding in recent years in the context of interactions among different cell types, through direct cell–cell communication as well as through soluble factors. It has become evident that the development of a successful antitumor response depends on several TME factors. In this context, the number, type, and subsets of immune cells, as well as the functionality, memory, and exhaustion state of leukocytes are key factors of the TME. Both the presence and functionality of immune cells, in particular T cells, are regulated by cellular and soluble factors of the TME. In this regard, one fundamental reason for failure of antitumor responses is hijacked immune cells, which contribute to the immunosuppressive TME in multiple ways. Specifically, reactive oxygen species (ROS), metabolites, and anti-inflammatory cytokines have central roles in generating an immunosuppressive TME. In this review, we focused on recent developments in the immune cell constituents of the TME, and the micromilieu control of antitumor responses. Furthermore, we highlighted the current challenges of T cell-based immunotherapies and potential future strategies to consider for strengthening their effectiveness.

Aryl hydrocarbon receptor engagement during redox alteration determines the fate of CD4+ T cells in C57BL/6 mice

The preservation of the redox homeostasis is critical for cell survival and functionality. Redox imbalance is an essential inducer of several pathological states. CD4⁺ /helper T cells are highly dependent on the redox state of their surrounding milieu. The potential of the aryl hydrocarbon receptor (AhR) engagement in controlling CD4⁺ T-cell fate during redox alteration is still challenging. C57BL/6 mice were treated with AhR agonist 6-formylindolo[3,2-b]carbazole (FICZ), AhR antagonist CH223191, an inhibitor of glutathione biosynthesis buthionine sulfoximine (BSO), and the antioxidant N-acetylcysteine (NAC) alone or in combination. Six days later, splenocytes were evaluated for the expression of the redox-related genes and the possible changes in T-cell subsets. FICZ like BSO significantly elevated the expression of HMOX1, GCLC, and GCLM genes but it failed to increase the expression of the Nrf2 gene. Moreover, FICZ + BSO increased while FICZ + CH223191 or NAC decreased the expression of these genes. FICZ also significantly increased Th1 cell numbers but decreased Tregs in a dose-dependent manner. Furthermore, a high dose of FICZ + CH223191 + NAC significantly enhanced Th1, Th17, and Treg cells but its low dose in such a situation increased Th2 and Th17 while decreased Treg cells. AhR engagement during redox alteration can determine the fate of CD4 + T cells, so, AhR agonists or antagonists might be useful in assessing immune responses. However, these results need further verifications in vitro and in animal models of various diseases.

Alleviation of Oxidative Stress in Dental Pulp Cells Following 4-Hexylresorcinol Administration in a Rat Model

Damaged dental pulp undergoes oxidative stress and 4-hexylresorcinol (4HR) is a well-known antioxidant. In this study, we aimed to evaluate the therapeutic effects of a 4HR ointment on damaged dental pulp. Pulp cells from rat mandibular incisor were cultured and treated with 4HR or resveratrol (1–100 μM). These treatments (10–100 μM) exerted a protective effect during subsequent hydrogen peroxide treatments. The total antioxidant capacity and glutathione peroxidase activity were significantly increased following 4HR or resveratrol treatment (p < 0.05), while the expression levels of TNF-α and IL1β were decreased following the exposure to 4HR pre-treatment in an in vitro model. Additionally, the application of 4HR ointment in an exposed dental pulp model significantly reduced the expression of TNF-α and IL1β (p < 0.05). Conclusively, 4HR exerted protective effects against oxidative stress in dental pulp tissues through downregulating TNF-α and IL1β.

Dipeptidyl-peptidase 3 protects oxygen-glucose deprivation/reoxygenation-injured hippocampal neurons by suppressing apoptosis, oxidative stress and inflammation via modulation of Keap1/Nrf2 signaling

Dipeptidyl-peptidase 3 (DPP3) plays a key role in regulating apoptosis, oxidative stress and inflammation under various pathological conditions, however, whether DPP3 regulates apoptosis and oxidative stress in neurons undergoing cerebral ischemia/reperfusion injury has not yet been well studied. The goals of this work were to evaluate the role of DPP3 in the regulation of oxygen-glucose deprivation/reoxygenation (OGD/R)-induced apoptosis, oxidative stress and inflammation in HT22 hippocampal neurons. Here, we showed that DPP3 expression was elevated in response to OGD/R in neurons. Knockdown of DPP3 exacerbated OGD/R-induced apoptosis, oxidative stress and inflammation, whilst up-regulation of DPP3 alleviated OGD/R-induced apoptosis, oxidative stress and inflammation in HT22 neurons. Further results revealed that DPP3 enhanced the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and promoted transcriptional activity of the anti-oxidant response element (ARE). Additionally, DPP3 was shown to regulate Nrf2/ARE activation in a kelch-like ECH-associated protein 1 (Keap1)-dependent manner. Notably, inhibition of Nrf2 markedly reversed the DPP3-mediated neuroprotective effects against OGD/R injury. Taken together, these findings demonstrate that DPP3 exerts a neuroprotective role in OGD/R-injured neurons by suppressing neuronal apoptosis, oxidative stress and inflammation via modulation of Keap1/Nrf2 signaling. This work suggests DPP3 as a potential target for providing neuroprotective effects during cerebral ischemia/reperfusion injury.

Lactobacillus delbrueckii Protected Intestinal Integrity, Alleviated Intestinal Oxidative Damage, and Activated Toll-Like Receptor-Bruton's Tyrosine Kinase-Nuclear Factor Erythroid 2-Related Factor 2 Pathway in Weaned Piglets Challenged with Lipopolysaccharide

Oxidative stress is increasingly being recognized as a player in the pathogenesis of intestinal pathologies, and probiotics are becoming an attractive means of addressing it. The present study investigated the effects of dietary supplementation with Lactobacillus delbrueckii (LAB) on intestinal integrity and oxidative damage in lipopolysaccharide (LPS)-challenged piglets. A total of 36 crossbred weaned piglets (Duroc × Landrace × Large Yorkshire) were randomly divided into three groups: (1) non-challenged controls (CON), (2) LPS-challenged controls (LPS), and (3) 0.2% LAB (2.01 × 10¹⁰ CFU/g) + LPS treatment (LAB + LPS). On the 29th day of the experiment, the LPS and CON groups were injected intraperitoneally with LPS and saline at 100 ug/kg body weight, respectively. The results show that the LPS-induced elevation of the serum diamine oxidase (DAO) level and small intestinal crypt depth (CD) were reversed by the dietary addition of LAB, which also markedly increased the ileal expression of tight junction proteins (occludin, ZO-1, and claudin-1) in the LPS-challenged piglets. Furthermore, LAB supplementation normalized other LPS-induced changes, such as by decreasing malondialdehyde (MDA) in both the serum and intestinal mucosa and 8-hydroxy-2-deoxyguanosine (8-OHdG) in the jejunal mucosa, increasing glutathione reductase (GR) and glutathione peroxidase (GSH-Px) in both the serum and intestinal mucosa, and increasing glutathione (GSH) and superoxide dismutase (SOD) in the jejunal mucosa. LAB also activated Toll-like receptor (TLR)–Bruton’s tyrosine kinase (Btk)–nuclear factor erythroid 2-related factor 2(Nrf2) signaling pathways in the intestine, suggesting that it plays a vital role in the ameliorative antioxidant capacity of weaned piglets. In summary, LAB increased intestinal integrity by improving the intestinal structure and tight junctions while enhancing antioxidant functions via the activation of the TLR–Btk–Nrf2 signaling pathway.

Role of the Intestinal Microbiome, Intestinal Barrier and Psychobiotics in Depression

The intestinal microbiota plays an important role in the pathophysiology of depression. As determined, the microbiota influences the shaping and modulation of the functioning of the gut-brain axis. The intestinal microbiota has a significant impact on processes related to neurotransmitter synthesis, the myelination of neurons in the prefrontal cortex, and is also involved in the development of the amygdala and hippocampus. Intestinal bacteria are also a source of vitamins, the deficiency of which is believed to be related to the response to antidepressant therapy and may lead to exacerbation of depressive symptoms. Additionally, it is known that, in periods of excessive activation of stress reactions, the immune system also plays an important role, negatively affecting the tightness of the intestinal barrier and intestinal microflora. In this review, we have summarized the role of the gut microbiota, its metabolites, and diet in susceptibility to depression. We also describe abnormalities in the functioning of the intestinal barrier caused by increased activity of the immune system in response to stressors. Moreover, the presented study discusses the role of psychobiotics in the prevention and treatment of depression through their influence on the intestinal barrier, immune processes, and functioning of the nervous system.

Identification and validation of redox-immune based prognostic signature for hepatocellular carcinoma

The intimate interaction between redox signaling and immunity has been widely revealed. However, the clinical application of relevant therapeutic is unavailable due to the absence of validated markers that stratify patients. Here, we identified novel biomarkers for prognosis prediction in hepatocellular carcinoma (HCC). Prognostic redox-immune-related genes for predicting overall survival (OS) of HCC were identified using datasets from TCGA, LIRI-JP, and GSE14520. LASSO Cox regression was employed to construct the signature model and generate a risk score in the TCGA cohort. The signature contained CDO1, G6PD, LDHA, GPD1L, PPARG, FABP4, CCL20, SPP1, RORC, HDAC1, STC2, HDGF, EPO, and IL18RAP. Patients in the high-risk group had a poor prognosis compared to the low-risk group. Univariate and multivariate Cox regressions identified this signature as an independent factor for predicting OS. Nomogram constructed by multiple clinical parameters showed good performance for predicting OS indicated by the c-index, the calibration curve, and AUC. GSEA showed that oxidoreductase activity and peroxisome-related metabolic pathways were enriched in the low-risk group, while glycolysis activity and hypoxia were higher in the high-risk group. Furthermore, immune profiles analysis showed that the immune score and stromal score were significantly decreased in the high-risk group in the TCGA cohort. There was a considerably lower infiltration of anti-tumor immune cells while a higher proportion of pro-tumor immune cells in silico. Immune markers were distinctly expressed between the subgroups, and redox-sensitive immunoregulatory biomarkers were at higher levels in the high-risk group. Altogether, we identified a redox-immune prognostic signature. A more severe redox perturbation-driven immunosuppressive environment in the high-risk group stratified by the signature may account for poor survival. This may provide a clue to the combined therapy targeting redox and immune in HCC.

Transcriptome Analyses of Immune System Behaviors in Primary Polyp of Coral Acropora digitifera Exposed to the Bacterial Pathogen Vibrio coralliilyticus under Thermal Loading

Elevated sea surface temperature associated with global warming is a serious threat to coral reefs. Elevated temperatures directly or indirectly alter the distribution of coral-pathogen interactions and thereby exacerbate infectious coral diseases. The pathogenic bacterium Vibrio coralliilyticus is well-known as a causative agent of infectious coral disease. Rising sea surface temperature promotes the infection of corals by this bacterium, which causes several coral pathologies, such as bacterial bleaching, tissue lysis, and white syndrome. However, the effects of thermal stress on coral immune responses to the pathogen are poorly understood. To delineate the effects of thermal stress on coral immunity, we performed transcriptome analysis of aposymbiotic primary polyps of the reef-building coral Acropora digitifera exposed to V. coralliilyticus under thermal stress conditions. V. coralliilyticus infection of coral that was under thermal stress had negative effects on various molecular processes, including suppression of gene expression related to the innate immune response. In response to the pathogen, the coral mounted various responses including changes in protein metabolism, exosome release delivering signal molecules, extracellular matrix remodeling, and mitochondrial metabolism changes. Based on these results, we provide new insights into innate immunity of A. digitifera against pathogen infection under thermal stress conditions.

Redox homeostasis as a target for new antimycobacterial agents

Despite early treatment with antimycobacterial combination therapy, drug resistance continues to emerge. Maintenance of redox homeostasis is essential for Mycobacterium avium (M. avium) survival and growth. The aim of the present study was to investigate the antimycobacterial activity of two pro-glutathione (pro-GSH) drugs that are able to induce redox stress in M. avium and to modulate cytokine production by macrophages. Hence, we investigated two molecules shown to possess antiviral and immunomodulatory properties: C4-GSH, an N-butanoyl GSH derivative; and I-152, a prodrug of N-acetyl-cysteine (NAC) and β-mercaptoethylamine (MEA). Both molecules showed activity against replicating M. avium, both in the cell-free model and inside macrophages. Moreover, they were even more effective in reducing the viability of bacteria that had been kept in water for 7 days, proving to be active both against replicating and non-replicating bacteria. By regulating the macrophage redox state, I-152 modulated cytokine production. In particular, higher levels of interferon-gamma (IFN-γ), interleukin 1 beta (IL-1β), IL-18 and IL-12, which are known to be crucial for the control of intracellular pathogens, were found after I-152 treatment. Our results show that C4-GSH and I-152, by inducing perturbation of redox equilibrium, exert bacteriostatic and bactericidal activity against M. avium. Moreover, I-152 can boost the host response by inducing the production of cytokines that serve as key regulators of the Th1 response.