Neutrophils and redox stress in the pathogenesis of autoimmune disease

Neutrophil-to-Lymphocyte Ratio as a Prognostic Biomarker for Long-Term Survival in Older Adults at a Mental Health Care Center: A Historical Cohort Analysis

Background/Objectives: Identifying reliable biomarkers for healthy aging and longevity is a fundamental challenge in aging research and medical sciences. The neutrophil-to-lymphocyte ratio (NLR) is a readily measurable indicator of immune balance that reflects the interplay between innate immune activation and adaptive immune suppression. Methods: This study examined NLR values in 204 physically healthy residents (98 men and 106 women) stratified into four lifespan categories based on death certificates. Page's test and ordinal regression (Cumulative Link Model) were used to assess trends with longevity. Results: In men, a downward trend in NLR values was observed. In women, a significant age-related decline in NLR was identified, with longer-lived individuals showing notably lower NLR values compared to their shorter-lived counterparts. The findings suggest that lower NLR is associated with longer survival, particularly in older women, reflecting superior immune regulation and reduced systemic inflammation. Conversely, elevated NLR may indicate immune dysfunction and heightened inflammatory burden. Conclusions: The results of this study complement existing findings, reinforcing the critical importance of immune balance in supporting healthy aging and longevity. These findings also underscore the potential of NLR as a robust biomarker for evaluating immune function and anticipating resilience to age-related decline, offering a practical tool for assessing immune health in the aging population.

Influence of sodium ferulate on neutrophil extracellular traps-platelet activation-mediated endothelial dysfunction in immune small vasculitis

Objective

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is an autoimmune disease that is challenging to treat. This study aimed to identify the effect of sodium ferulate on endothelial dysfunction mediated by neutrophil extracellular trap (NET)-platelet activation in AAV to provide potential strategies for AAV treatment.

Material and Methods

An animal model of myeloperoxidase (MPO)-AAV passive immune vasculitis was established using anti-MPO immunoglobulin G and Rag2 knockout mice. The efficacy and mechanism of action of sodium ferulate in AAV were explored in cultured and isolated endothelial progenitor cells (EPCs), and messenger ribonucleic acid gene expression, relative protein expression, and protein fluorescence intensity were determined through quantitative polymerase chain reaction, Western blotting, and immunofluorescence, respectively. Serum antibody concentrations were determined by enzyme-linked immunosorbent assay, and flow cytometry was used in determining the expression levels of platelet-selectin (CD62p) and procaspase-activating compound-1 (PAC-1) on the surfaces of the platelets. The EPCs' ultramicroscopic structure was observed through transmission electron microscopy.

Results

The expression levels of ANCA, histone H3 citrullinated, and MPO protein fluorescence intensity in MPO-AAV mice were inhibited by sodium ferulate, and the expression levels of CD62p and PAC-1 on the cell surface were reduced. The relative expression levels of β-trace protein (β-TG), soluble thrombomodulin, inducible nitric oxide synthase (iNOS), and tumor necrosis factor α decreased. We found that sodium ferulate inhibited NETs' free DNA and mitigated damage in EPCs. In addition, relative expression levels of von Willebrand Factor, β-TG, and iNOS and serum concentrations of PAC-1, β-TG, and iNOS were inhibited.

Conclusion

Sodium ferulate can treat AAV by inhibiting NET release and platelet activation and reducing endothelial cell damage.

Neutrophil extracellular traps and oxidative stress in systemic lupus erythematosus patients with and without renal involvement

OBJECTIVES

To investigate the levels of plasma neutrophil extracellular traps (NETs) and free thiols, the latter reflecting systemic oxidative stress (OS), and to explore the relationship between NETs and OS in quiescent systemic lupus erythematosus (SLE) patients with and without renal involvement.

METHODS

Plasma levels of NETs and free thiols were measured cross-sectionally in 100 SLE patients with low disease activity (SLEDAI < 5), of whom 73 patients had no renal involvement (non-LN) and 27 patients had lupus nephritis (LN). Additionally, 22 healthy controls (HCs) were included. NETs were measured using a myeloperoxidase-DNA complex ELISA and free thiols were measured using a thiol assay kit.

RESULTS

NETs levels were significantly higher in both non-LN and LN patients compared to HCs (p < 0.001, p = 0.013), with no difference between the two patient groups (p = 0.799). Free thiol levels were not significantly different between groups. Interestingly, NETs were negatively correlated with free thiols in all 100 SLE patients (rho = -0.32) and non-LN patients (rho = -0.38), but not in LN patients. Levels of free thiols were significantly lower in subgroups of patients with estimated glomerular filtration rate (eGFR) < 60, serum creatinine (sCr) ≥ 90, C reactive protein (CRP) levels ≥ 5 and body mass index (BMI) ≥ 30. In multivariable regression, disease duration, NETs levels, and eGFR were independently associated with free thiol levels.

CONCLUSIONS

Levels of NETs were increased in quiescent SLE patients. Although free thiol levels did not differ among the groups. The levels of NETs and free thiols were independently associated in SLE patients, suggesting a potential role of OS in NETs formation. Therefore, reducing OS might be an additional therapeutic target for SLE treatment.

Neutrophil diversity and function in health and disease

Neutrophils, the most abundant type of granulocyte, are widely recognized as one of the pivotal contributors to the acute inflammatory response. Initially, neutrophils were considered the mobile infantry of the innate immune system, tasked with the immediate response to invading pathogens. However, recent studies have demonstrated that neutrophils are versatile cells, capable of regulating various biological processes and impacting both human health and disease. Cytokines and other active mediators regulate the functional activity of neutrophils by activating multiple receptors on these cells, thereby initiating downstream signal transduction pathways. Dysfunctions in neutrophils and disruptions in neutrophil homeostasis have been implicated in the pathogenesis of numerous diseases, including cancer and inflammatory disorders, often due to aberrant intracellular signaling. This review provides a comprehensive synthesis of neutrophil biological functions, integrating recent advancements in this field. Moreover, it examines the biological roles of receptors on neutrophils and downstream signaling pathways involved in the regulation of neutrophil activity. The pathophysiology of neutrophils in numerous human diseases and emerging therapeutic approaches targeting them are also elaborated. This review also addresses the current limitations within the field of neutrophil research, highlighting critical gaps in knowledge that warrant further investigation. In summary, this review seeks to establish a comprehensive and multidimensional model of neutrophil regulation, providing new perspectives for potential clinical applications and further research.

Proteomic Profile Regulated by the Immunomodulatory Jusvinza Drug in Neutrophils Isolated from Rheumatoid Arthritis Patients

Jusvinza is an immunomodulatory drug composed of an altered peptide ligand (APL) designed from a novel CD4+ T cell epitope of human heat shock protein 60 (HSP60), an autoantigen involved in the pathogenesis of rheumatoid arthritis (RA). The peptide induces regulatory T cells and decreases levels of TNF-α and IL-17; pre-clinical and phase I clinical studies support its use for the treatment of RA. This peptide was repositioned for the treatment of COVID-19 patients with signs of hyperinflammation. Neutrophils play a pathogenic role in both RA and severe forms of COVID-19. To add novel evidence about the mechanism of action of Jusvinza, the proteomic profile regulated by this peptide of neutrophils isolated from four RA patients was investigated using LC-MS/MS and bioinformatics analysis. A total of 149 proteins were found to be differentially modulated in neutrophils treated with Jusvinza. The proteomic profile regulated by Jusvinza is characterized by the presence of proteins related to RNA splicing, phagocytosis, endocytosis, and immune functions. In response to Jusvinza treatment, several proteins that regulate the NF-κB signaling pathway were differentially modulated, supporting the peptide's anti-inflammatory effect. Proteins related to metabolic pathways that supply ATP for cellular functions or lipid metabolites with immunoregulatory properties were also identified. Additionally, several structural components of neutrophil extracellular traps (NETs) were decreased in Jusvinza-treated cells, supporting its impairment of this biological process. Of note, these findings were validated by in vitro experiments which confirmed that Jusvinza decreased NET formation. Such results provide evidence of the molecular mechanism of action and support the therapeutic potentialities of Jusvinza to treat other diseases characterized by hyperinflammation besides RA and COVID-19.

Role of MTH1 in oxidative stress and therapeutic targeting of cancer

Cancer cells maintain high levels of reactive oxygen species (ROS) to drive their growth, but ROS can trigger cell death through oxidative stress and DNA damage. To survive enhanced ROS levels, cancer cells activate their antioxidant defenses. One such defense is MTH1, an enzyme that prevents the incorporation of oxidized nucleotides into DNA, thus preventing DNA damage and allowing cancer to proliferate. MTH1 levels are often elevated in many cancers, and thus, inhibiting MTH1 is an attractive strategy for suppressing tumor growth and metastasis. Targeted MTH1 inhibition can induce DNA damage in cancer cells, exploiting their vulnerability to oxidative stress and selectively targeting them for destruction. Targeting MTH1 is promising for cancer treatment because normal cells have lower ROS levels and are less dependent on these pathways, making the approach both effective and specific to cancer. This review aims to investigate the potential of MTH1 as a therapeutic target, especially in cancer treatment, offering detailed insights into its structure, function, and role in disease progression. We also discussed various MTH1 inhibitors that have been developed to selectively induce oxidative damage in cancer cells, though their effectiveness varies. In addition, this review provide deeper mechanistic insights into the role of MTH1 in cancer prevention and oxidative stress management in various diseases.

Preparation, pungency and bioactivity transduction of piperine from black pepper (Piper nigrum L.): A comprehensive review

Piperine, derived from black pepper (Piper nigrum L.), is responsible for the pungent sensation. The diverse bioactivities of piperine underscores its promising potential as a functional food ingredient. This review presents a comprehensive overview of the research progress in extraction, synthesis, pungency transduction mechanism and bioactivities of piperine. Piperine can be extracted through various methods, such as traditional, modern, and innovative extraction techniques. Its synthesis mainly included both chemical and biosynthetic approaches. It exhibits a diverse range of bioactivities, including anticancer, anticonvulsant, antidepressant, anti-inflammatory, antioxidant, immunomodulatory, anti-obesity, neuroprotective, antidiabetic, hepatoprotective, and cardiovascular protective activities. Piperine can bind to TRPV1 receptor to elicit pungent sensation. Overall, the present review can provide a theoretical reference for advancing the potential application of piperine in the field of food science.

Phenotypes and functions of "aged" neutrophils in cardiovascular diseases

Neutrophils are important effector cells of innate immunity and undergo several phenotypic changes after release from the bone marrow. Neutrophils with a late life cycle phenotype are often referred to as "aged" neutrophils. These neutrophils undergo functional changes that accompany stimuli of inflammation, tissue senescence and injury, inducing their maturation and senescence in the circulation and locally in damaged tissues, forming a unique late-life neutrophil phenotype. "Aged" neutrophils, although attenuated in antibacterial capacity, are more active in aging and age-related diseases, exhibit high levels of mitochondrial ROS and mitochondrial DNA leakage, promote senescence of neighboring cells, and exacerbate cardiac and vascular tissue damage, including vascular inflammation, myocardial infarction, atherosclerosis, stroke, abdominal aortic aneurysm, and SARS-CoV-2 myocarditis. In this review, we outline the phenotypic changes of "aged" neutrophils characterized by CXCR4high/CD62Llow, investigate the mechanisms driving neutrophil aging and functional transformation, and analyze the damage caused by "aged" neutrophils to various types of heart and blood vessels. Tissue injury and senescence promote neutrophil infiltration and induce neutrophil aging both in the circulation and locally in damaged tissues, resulting in an "aged" neutrophil phenotype characterized by CXCR4high/CD62Llow. We also discuss the effects of certain agents, such as neutralizing mitochondrial ROS, scavenging IsoLGs, blocking VDAC oligomers and mPTP channel activity, activating Nrf2 activity, and inhibiting neutrophil PAD4 activity, to inhibit neutrophil NET formation and ameliorate age-associated cardiovascular disease, providing a new perspective for anti-aging therapy in cardiovascular disease.

Targeted serum proteome profiling reveals nicotinamide adenine dinucleotide phosphate (NADPH)-related biomarkers to discriminate linear IgA bullous disorder from dermatitis herpetiformis

Linear IgA bullous dermatosis (LABD) and dermatitis herpetiformis (DH) represent the major subtypes of IgA mediated autoimmune bullous disorders. We sought to understand the disease etiology by using serum proteomics. We assessed 92 organ damage biomarkers in LABD, DH, and healthy controls using the Olink high-throughput proteomics. The positive proteomic serum biomarkers were used to correlate with clinical features and HLA type. Targeted proteomic analysis of IgA deposition bullous disorders vs. controls showed elevated biomarkers. Further clustering and enrichment analyses identified distinct clusters between LABD and DH, highlighting the involvement of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Comparative analysis revealed biomarkers with distinction between LABD and DH and validated in the skin lesion. Finally, qualitative correlation analysis with DEPs suggested six biomarkers (NBN, NCF2, CAPG, FES, BID, and PXN) have better prognosis in DH patients. These findings provide potential biomarkers to differentiate the disease subtype of IgA deposition bullous disease.

Drug repurposing of cyclin-dependent kinase inhibitors for neutrophilic acute respiratory distress syndrome and psoriasis

BACKGROUND

Neutrophilic inflammation, characterized by dysregulated neutrophil activation, triggers a variety of inflammatory responses such as chemotactic infiltration, oxidative bursts, degranulation, neutrophil extracellular traps (NETs) formation, and delayed turnover. This type of inflammation is pivotal in the pathogenesis of acute respiratory distress syndrome (ARDS) and psoriasis. Despite current treatments, managing neutrophil-associated inflammatory symptoms remains a significant challenge.

AIM OF REVIEW

This review emphasizes the role of cyclin-dependent kinases (CDKs) in neutrophil activation and inflammation. It aims to highlight the therapeutic potential of repurposing CDK inhibitors to manage neutrophilic inflammation, particularly in ARDS and psoriasis. Additionally, it discusses the necessary precautions for the clinical application of these inhibitors due to potential off-target effects and the need for dose optimization.

KEY SCIENTIFIC CONCEPTS OF REVIEW

CDKs regulate key neutrophilic functions, including chemotactic responses, degranulation, NET formation, and apoptosis. Repurposing CDK inhibitors, originally developed for cancer treatment, shows promise in controlling neutrophilic inflammation. Clinical anticancer drugs, palbociclib and ribociclib, have demonstrated efficacy in treating neutrophilic ARDS and psoriasis by targeting off-label pathways, phosphoinositide 3-kinase (PI3K) and phosphodiesterase 4 (PDE4), respectively. While CDK inhibitors offer promising therapeutic benefits, their clinical repurposing requires careful consideration of off-target effects and dose optimization. Further exploration and clinical trials are necessary to ensure their safety and efficacy in treating inflammatory conditions.

The role of oxidative stress biomarkers in the development of peri-implant disease: A systematic review and meta-analysis

OBJECTIVES

To analyze the role of oxidative stress (OS) biomarkers in peri‑implant diseases using a systematic review and meta-analysis approach. DATE: The review incorporated cross-sectional studies, randomized controlled trials, and case-control trials to evaluate the differences in OS biomarkers of peri‑implant disease.

SOURCES

A comprehensive literature search was conducted in electronic databases such as PubMed, Scopus, Embase, Web of Science, and CNKI, and no restrictions were applied during the search process.

STUDY SELECTION

A total of 452 studies were identified, of which 18 were eligible for inclusion. Risk of bias and sensitivity analysis were assessed using Egger's test and funnel plots.

RESULTS

We found that the levels of glutathione peroxidase (GSH-Px) in the peri‑implant sulcus fluid (PISF) of patients with peri‑implant diseases were significantly reduced (SMD = -1.40; 95 % CI = 1.70, -1.11; p < 0.001), while the levels of total myeloperoxidase (MPO) and malondialdehyde (MDA) were significantly increased (SMD = 0.46; 95 % CI = 0.12, 0.80; p = 0.008; SMD = 0.28; 95 % CI = 0.01, 0.56; p = 0.043). However, there were no significant differences of MPO concentration (SMD = 0.38; 95 % CI = -0.39, 1.15; p = 0.331) and superoxide dismutase (SOD)(SMD = -0.43; 95 % CI = -1.94, 1.07; p = 0.572) in PISF between peri‑implant disease group and control group. Similarly, salivary MPO did not show significant differences (SMD = 1.62; 95 % CI = -1.01, 4.24; p = 0.227).

CONCLUSIONS

Our results supported that the level of local OS biomarkers was closely related to peri‑implant diseases. GSH-Px, total MPO and MDA may be PISF biomarkers with good capability to monitor the development of peri‑implant disease.

CLINICAL SIGNIFICANCE

This study found significant differences in the levels of local OS biomarkers (GSH-Px, total MPO, and MDA) between patients with peri‑implant diseases and healthy subjects, which may be ideal candidate biomarkers for predicting and diagnosing peri‑implant diseases.

Bioactives of Melipona rufiventris Propolis: Exploring its Antimicrobial, Anti-Inflammatory, and Antioxidant Activities

This study explores the potential of propolis, a resinous substance produced by bees, from Melipona rufiventris species. With its composition encompassing resin, wax, pollen, and soil, propolis holds historical significance in traditional medicine within tropical regions. This research is driven by the scarcity of information surrounding M. rufiventris propolis, prompting an investigation into its chemical constituents, in vivo toxicity, and antimicrobial, antioxidant, and anti-inflammatory properties. This exploration could potentially uncover novel applications for this natural product, bolstering both meliponiculture practices and the preservation of native bee populations. The propolis was sampled in Cabo Verde-MG and underwent ethanolic extraction to yield an extract (EEP) for analysis. Chemical assessments (Folin-Ciocalteau, and UHPLC-HRMS) revealed the presence of polyphenols, including flavonoids. The EEP demonstrated higher antimicrobial activity against Gram-positive bacteria and exhibited efficacy against multiresistant strains isolated from complex wounds. Synergistic interactions with commercial antibiotics were also observed. Furthermore, anti-inflammatory evaluations showcased the EEP's potential in reducing NF-kB activation and TNF-α release at non-toxic concentrations. Despite these promising biological activities, the EEP exhibited no antiproliferative effects and demonstrated safety in both the MTS assay and the G. mellonella model. Collectively, these findings highlight the M. rufiventris propolis extract as a valuable reservoir of bioactive compounds with multifaceted potential.

Agonistic anti-DCIR antibody inhibits ITAM-mediated inflammatory signaling and promotes immune resolution

DC inhibitory receptor (DCIR) is a C-type lectin receptor selectively expressed on myeloid cells, including monocytes, macrophages, DCs, and neutrophils. Its role in immune regulation has been implicated in murine models and human genome-wide association studies, suggesting defective DCIR function associates with increased susceptibility to autoimmune diseases such as rheumatoid arthritis, lupus, and Sjögren's syndrome. However, little is known about the mechanisms underlying DCIR activation to dampen inflammation. Here, we developed anti-DCIR agonistic antibodies that promote phosphorylation on DCIR's immunoreceptor tyrosine-based inhibitory motifs and recruitment of SH2 containing protein tyrosine phosphatase-2 for reducing inflammation. We also explored the inflammation resolution by depleting DCIR+ cells with antibodies. Utilizing a human DCIR-knock-in mouse model, we validated the antiinflammatory properties of the agonistic anti-DCIR antibody in experimental peritonitis and colitis. These findings provide critical evidence for targeting DCIR to develop transformative therapies for inflammatory diseases.

Decoding Behcet's Uveitis: an In-depth review of pathogenesis and therapeutic advances

Behcet's disease (BD) is a rare but globally distributed vasculitis that primarily affects populations in the Mediterranean and Asian regions. Behcet's uveitis (BU) is a common manifestation of BD, occurring in over two-thirds of the patients. BU is characterized by bilateral, chronic, recurrent, non-granulomatous uveitis in association with complications such as retinal ischemia and atrophy, optic atrophy, macular ischemia, macular edema, and further neovascular complications (vitreous hemorrhage, neovascular glaucoma). Although the etiology and pathogenesis of BU remain unclear, numerous studies reveal that genetic factors (such as HLA-B51), dysregulated immune responses of both the innate and adaptive immune systems, infections (such as streptococcus), and environmental factors (such as GDP) are all involved in its development. Innate immunity, including hyperactivity of neutrophils and γδT cells and elevated NK1/NK2 ratios, has been shown to play an essential role in this disease. Adaptive immune system disturbance, including homeostatic perturbations, Th1, Th17 overaction, and Treg cell dysfunction, is thought to be involved in BU pathogenesis. Treatment of BU requires a tailored approach based on the location, severity of inflammation, and systemic manifestations. The therapy aims to achieve rapid inflammation suppression, preservation of vision, and prevention of recurrence. Systemic corticosteroids combined with other immunosuppressive agents have been widely used to treat BU, and beneficial effects are observed in most patients. Recently, biologics have been shown to be effective in treating refractory BU cases. Novel therapeutic targets for treating BU include the LCK gene, Th17/Treg balance, JAK pathway inhibition, and cytokines such as IL-17 and RORγt. This article summarizes the recent studies on BU, especially in terms of pathogenesis, diagnostic criteria and classification, auxiliary examination, and treatment options. A better understanding of the significance of microbiome composition, genetic basis, and persistent immune mechanisms, as well as advancements in identifying new biomarkers and implementing objective quantitative detection of BU, may greatly contribute to improving the adequate management of BU patients.

Review: A Contemporary, Multifaced Insight into Psoriasis Pathogenesis

Psoriasis is a chronic recurrent inflammatory autoimmune pathology with a significant genetic component and several interferences of immunological cells and their cytokines. The complex orchestration of psoriasis pathogenesis is related to the synergic effect of immune cells, polygenic alterations, autoantigens, and several other external factors. The major act of the IL-23/IL-17 axis, strongly influencing the inflammatory pattern established during the disease activity, is visible as a continuous perpetuation of the pro-inflammatory response and keratinocyte activation and proliferation, leading to the development of psoriatic lesions. Genome-wide association studies (GWASs) offer a better view of psoriasis pathogenic pathways, with approximately one-third of psoriasis's genetic impact on psoriasis development associated with the MHC region, with genetic loci located on chromosome 6. The most eloquent genetic factor of psoriasis, PSORS1, was identified in the MHC I site. Among the several factors involved in its complex etiology, dysbiosis, due to genetic or external stimulus, induces a burst of pro-inflammatory consequences; both the cutaneous and gut microbiome get involved in the psoriasis pathogenic process. Cutting-edge research studies and comprehensive insights into psoriasis pathogenesis, fostering novel genetic, epigenetic, and immunological factors, have generated a spectacular improvement over the past decades, securing the path toward a specific and targeted immunotherapeutic approach and delayed progression to inflammatory arthritis. This review aimed to offer insight into various domains that underline the pathogenesis of psoriasis and how they influence disease development and evolution. The pathogenesis mechanism of psoriasis is multifaceted and involves an interplay of cellular and humoral immunity, which affects susceptible microbiota and the genetic background. An in-depth understanding of the role of pathogenic factors forms the basis for developing novel and individualized therapeutic targets that can improve disease management.

Histone H3 posttranslational modified enzymes defined neutrophil plasticity and their vulnerability to IL-10 in the course of the inflammation

BACKGROUND

Neutrophils are a heterogeneous population capable of antimicrobial functions associated with pre-activation/activation and tissue regeneration. The specific polarisation of immune cells is mediated by the modification of 'chromatin landscapes', which enables differentiated access and activity of regulatory elements that guarantee their plasticity during inflammation No specific pattern within histone posttranslational modifications (PTMs) controlling this plasticity has been identified.

METHODS

Using the in vitro model of inflammation, reflecting different states of neutrophils from resting, pre-activated cells to activated and reducing tissue regeneration, we have analysed 11 different histone posttranslational modifications (PTMs), PTM enzymes associated with remodelling neutrophil chromatin, and H3K4me3 ChIP-Seq Gene Ontology analysis focusing on the processes related to histone PTMs. These findings were verified by extrapolation to adequate clinical status, using neutrophils derived from the patients with sepsis (systemic septic inflammation with LPS-stimulated neutrophils), neuromyelitis optical spectrum disorders (aseptic inflammation with pre-activated neutrophils) and periodontitis (local self-limiting septic inflammation with IL-10-positive neutrophils).

RESULTS

Physiological activation of neutrophils comprises a pre-activation characterised by histone H3K27ac and H3K4me1, which position enhancers; direct LPS exposure is induced explicitly by H3K4me3 which marked Transcription Start Site (TSS) regions and low-level of H3K9me3, H3K79me2 and H3K27me3 which, in turn, marked repressed genes. Contrary to antimicrobial action, IL-10 positively induced levels of H3S10p and negatively H3K9me3, which characterised processes related to the activation of genes within heterochromatin mediated by CHD1 and H3K9me3 specific demethylase JMJD2A. IL-10 protects changes within histone PTMs induced by TNF or LPS that affected H3K4me3-specific methyltransferase SETD1A and MLL1. Neutrophils previously exposed to inflammatory factors become unvulnerable to IL-10 because previous LPS stimulation interrupts TSS regions marked by H3K4me3 of CHD1 and JMJD2A genes. Therefore, LPS-activated neutrophils are disabled to induce CHD1/JMJD2A enzymes by IL-10, making this process irreversible. Because transcription of JMJD2A and CHD1 also depends on TSS positioning by H3K4me3, neutrophils before LPS stimulation become insensitive to IL-10.

CONCLUSION

Neutrophils, once pre-activated by TNF or directly stimulated by LPS, become insensitive to the anti-inflammatory effects of IL-10, and vice versa; IL-10 protects neutrophils against these proinflammatory stimuli. This phenomenon is responsible for disturbing the natural process of resolving inflammation and tissue regeneration.

IL-8 (CXCL8) Correlations with Psychoneuroimmunological Processes and Neuropsychiatric Conditions

Interleukin-8 (IL-8/CXCL8), an essential CXC chemokine, significantly influences psychoneuroimmunological processes and affects neurological and psychiatric health. It exerts a profound effect on immune cell activation and brain function, suggesting potential roles in both neuroprotection and neuroinflammation. IL-8 production is stimulated by several factors, including reactive oxygen species (ROS) known to promote inflammation and disease progression. Additionally, CXCL8 gene polymorphisms can alter IL-8 production, leading to potential differences in disease susceptibility, progression, and severity across populations. IL-8 levels vary among neuropsychiatric conditions, demonstrating sensitivity to psychosocial stressors and disease severity. IL-8 can be detected in blood circulation, cerebrospinal fluid (CSF), and urine, making it a promising candidate for a broad-spectrum biomarker. This review highlights the need for further research on the diverse effects of IL-8 and the associated implications for personalized medicine. A thorough understanding of its complex role could lead to the development of more effective and personalized treatment strategies for neuropsychiatric conditions.

The Role of Neutrophils in Multiple Sclerosis and Ischemic Stroke

Inflammation plays an important role in numerous central nervous system (CNS) disorders. Its role is ambiguous-it can induce detrimental effects, as well as repair and recovery. In response to injury or infection, resident CNS cells secrete numerous factors that alter blood-brain barrier (BBB) function and recruit immune cells into the brain, like neutrophils. Their role in the pathophysiology of CNS diseases, like multiple sclerosis (MS) and stroke, is highly recognized. Neutrophils alter BBB permeability and attract other immune cells into the CNS. Previously, neutrophils were considered a homogenous population. Nowadays, it is known that various subtypes of these cells exist, which reveal proinflammatory or immunosuppressive functions. The primary goal of this review was to discuss the current knowledge regarding the important role of neutrophils in MS and stroke development and progression. As the pathogenesis of these two disorders is completely different, it gives the opportunity to get insight into diverse mechanisms of neutrophil involvement in brain pathology. Our understanding of the role of neutrophils in CNS diseases is still evolving as new aspects of their activity are being unraveled. Neutrophil plasticity adds another level to their functional complexity and their importance for CNS pathophysiology.

The Immunomodulatory effect of exosomes in diabetes: a novel and attractive therapeutic tool in diabetes therapy

Exosomes carry proteins, metabolites, nucleic acids and lipids from their parent cell of origin. They are derived from cells through exocytosis, are ingested by target cells, and can transfer biological signals between local or distant cells. Therefore, exosomes are often modified in reaction to pathological processes, including infection, cancer, cardiovascular diseases and in response to metabolic perturbations such as obesity and diabetes, all of which involve a significant inflammatory aspect. Here, we discuss how immune cell-derived exosomes origin from neutrophils, T lymphocytes, macrophages impact on the immune reprogramming of diabetes and the associated complications. Besides, exosomes derived from stem cells and their immunomodulatory properties and anti-inflammation effect in diabetes are also reviewed. Moreover, As an important addition to previous reviews, we describes promising directions involving engineered exosomes as well as current challenges of clinical applications in diabetic therapy. Further research on exosomes will explore their potential in translational medicine and provide new avenues for the development of effective clinical diagnostics and therapeutic strategies for immunoregulation of diabetes.

Eugenol Inhibits Neutrophils Myeloperoxidase In Vitro and Attenuates LPS-Induced Lung Inflammation in Mice

Eugenol (Eug) is a polyphenol extracted from the essential oil of Syzygium aromaticum (L.) Merr. and Perry (Myrtaceae). The health benefits of eugenol in human diseases were proved in several studies. This work aims to evaluate the effect of eugenol on lung inflammatory disorders. For this, using human neutrophils, the antioxidant activity of eugenol was investigated in vitro. Furthermore, a model of LPS-induced lung injury in mice was used to study the anti-inflammatory effect of eugenol in vivo. Results showed that eugenol inhibits luminol-amplified chemiluminescence of resting neutrophils and after stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLF) peptide or phorbol myristate acetate (PMA). This effect was dose dependent and was significant from a low concentration of 0.1 µg/mL. Furthermore, eugenol inhibited myeloperoxidase (MPO) activity without affecting its degranulation. Eugenol has no scavenging effect on hydrogen peroxide (H2O2) and superoxide anion (O2-). Pretreatment of mice with eugenol prior to the administration of intra-tracheal LPS significantly reduced neutrophil accumulation in the bronchoalveolar lavage fluid (BALF) and decreased total proteins concentration. Moreover, eugenol clearly inhibited the activity of matrix metalloproteinases MMP-2 (21%) and MMP-9 (28%), stimulated by LPS administration. These results suggest that the anti-inflammatory effect of eugenol against the LPS-induced lung inflammation could be exerted via inhibiting myeloperoxidase and metalloproteinases activity. Thus, eugenol could be a promising molecule for the treatment of lung inflammatory diseases.

Ursolic Acid Formulations Effectively Induce Apoptosis and Limit Inflammation in the Psoriasis Models In Vitro

Psoriasis, a prevalent inflammatory skin disorder affecting a significant percentage of the global population, poses challenges in its management, necessitating the exploration of novel cost-effective and widely accessible therapeutic options. This study investigates the potential of ursolic acid (UA), a triterpenoid known for its anti-inflammatory and pro-apoptotic properties, in addressing psoriasis-related inflammation and keratinocyte hyperproliferation. The research involved in vitro models employing skin and immune cells to assess the effects of UA on psoriasis-associated inflammation. The presented research demonstrates the limiting effects of UA on IL-6 and IL-8 production in response to the inflammatory stimuli and limiting effects on the expression of psoriatic biomarkers S100A7, S100A8, and S100A9. Further, the study reveals promising outcomes, demonstrating UA's ability to mitigate inflammatory responses and hyperproliferation of keratinocytes by the induction of non-inflammatory apoptosis, as well as a lack of the negative influence on other cell types, including immune cells. Considering the limitations of UA's poor solubility, hybrid systems were designed to enhance its bioavailability and developed as hybrid nano-emulsion and bi-gel topical systems to enhance bioavailability and effectiveness of UA. One of them in particular-bi-gel-demonstrated high effectiveness in limiting the pathological response of keratinocytes to pro-psoriatic stimulation; this was even more prominent than with ursolic acid alone. Our results indicate that topical formulations of ursolic acid exhibit desirable anti-inflammatory activity in vitro and may be further employed for topical psoriasis treatment.

Annulated Heterocyclic[g]Coumarin Composites: Synthetic Approaches and Bioactive Profiling

Coumarins, widely abundant natural heterocyclic compounds, are extensively employed in creating various biologically and pharmacologically potent substances. The hybridization of heterocycles presents a key opportunity to craft innovative multicyclic compounds with enhanced biological activity. Fusing different heterocyclic rings with the coumarin structure presents an intriguing method for crafting fresh hybrid compounds possessing remarkable biological effects. In the pursuit of creating heterocyclic-fused coumarins, a wide range of annulated heterocyclic[g]coumarin composites has been introduced, displaying impressive biological potency. The influence of the linear attachment of heterocyclic rings to the coumarin structure on the biological performance of the resulting compounds has been investigated. This review centers on the synthetic methodologies, structural activity relationship investigation, and biological potentials of annulated heterocyclic[g]coumarin composites. We conducted searches across several databases, including Web of Science, Google Scholar, PubMed, and Scopus. After sieving, we ultimately identified and included 71 pertinent studies published between 2000 and the middle of 2023. This will provide valuable perspectives for medicinal chemists in the prospective design and synthesis of lead compounds with significant therapeutic effects, centered around heterocycle-fused coumarin frameworks.

Orchestration of the Adipose Tissue Immune Landscape by Adipocytes

Obesity is epidemic and of great concern because of its comorbid and costly inflammatory-driven complications. Extensive investigations in mice have elucidated highly coordinated, well-balanced interactions between adipocytes and immune cells in adipose tissue that maintain normal systemic metabolism in the lean state, while in obesity, proinflammatory changes occur in nearly all adipose tissue immune cells. Many of these changes are instigated by adipocytes. However, less is known about obesity-induced adipose-tissue immune cell alterations in humans. Upon high-fat diet feeding, the adipocyte changes its well-known function as a metabolic cell to assume the role of an immune cell, orchestrating proinflammatory changes that escalate inflammation and progress during obesity. This transformation is particularly prominent in humans. In this review, we (a) highlight a leading and early role for adipocytes in promulgating inflammation, (b) discuss immune cell changes and the time course of these changes (comparing humans and mice when possible), and (c) note how reversing proinflammatory changes in most types of immune cells, including adipocytes, rescues adipose tissue from inflammation and obese mice from insulin resistance.

Plasma-derived exosomal protein SHP2 deficiency induces neutrophil hyperactivation in Behcet's uveitis

To investigate the effect of plasma-derived exosomal proteins on neutrophil hyperactivation in Behcet's uveitis (BU), we treated neutrophils from healthy controls with plasma-derived exosomes from active BU patients, and determined the level of neutrophil activation by real-time quantitative PCR (RT-qPCR) and cytokine detection assay. The results revealed that exosomes from active BU patients could activate neutrophils as shown by increasing the expression levels of pro-inflammatory cytokines (IL-17 and IL-6), chemokines (IL-8 and MCP-1), and NETs (MPO and ELANE). Label-free quantitative proteomic analysis of plasma-derived exosomes from patients and healthy controls found a remarkably distinct protein profile and identified differentially expressed proteins (DEPs) between the two groups. The results of GO, KEGG, and GSEA enrichment analysis showed that DEPs were enriched in innate immune-mediated and neutrophil hyperactivation-related signaling pathways. The protein-protein interaction (PPI) analysis determined that SHP2 was a downregulated key hub protein in the exosomes of active BU patients. Knockdown of SHP2 in human neutrophil cell lines (NB4 cells) was shown to promote the secretion of pro-inflammatory cytokines, chemokines, and NETs. The converse effects were observed following SHP2 overexpression. In conclusion, we highlighted a pathogenic role of plasma-derived exosomal SHP2 deficiency in facilitating neutrophil activation and suggested that SHP2 might be an immunoprotective factor in BU pathologic process.

Insights into Autophagic Machinery and Lysosomal Function in Cells Involved in the Psoriatic Immune-Mediated Inflammatory Cascade

Impaired autophagy, due to the dysfunction of lysosomal organelles, contributes to maladaptive responses by pathways central to the immune system. Deciphering the immune-inflammatory ecosystem is essential, but remains a major challenge in terms of understanding the mechanisms responsible for autoimmune diseases. Accumulating evidence implicates a role that is played by a dysfunctional autophagy-lysosomal pathway (ALP) and an immune niche in psoriasis (Ps), one of the most common chronic skin diseases, characterized by the co-existence of autoimmune and autoinflammatory responses. The dysregulated autophagy associated with the defective lysosomal system is only one aspect of Ps pathogenesis. It probably cannot fully explain the pathomechanism involved in Ps, but it is likely important and should be seriously considered in Ps research. This review provides a recent update on discoveries in the field. Also, it sheds light on how the dysregulation of intracellular pathways, coming from modulated autophagy and endolysosomal trafficking, characteristic of key players of the disease, i.e., skin-resident cells, as well as circulating immune cells, may be responsible for immune impairment and the development of Ps.

Endothelial cell activation and glycocalyx shedding - potential as biomarkers in patients with lupus nephritis

Lupus nephritis (LN) is a common and severe manifestation of systemic lupus erythematosus and an important cause of acute and chronic kidney injury. Early diagnosis of LN and preventing relapses are key to preserving renal reserve. However, due to the complexity and heterogeneity of the disease, clinical management remains challenging. Kidney biopsy remains the gold standard for confirming the diagnosis of LN and subsequent assessment of kidney histopathology, but it is invasive and cannot be repeated frequently. Current clinical indicators of kidney function such as proteinuria and serum creatinine level are non-specific and do not accurately reflect histopathological changes, while anti-dsDNA antibody and C3 levels reflect immunological status but not kidney injury. Identification of novel and specific biomarkers for LN is prerequisite to improve management. Renal function deterioration is associated with changes in the endothelial glycocalyx, a delicate gel-like layer located at the interface between the endothelium and bloodstream. Inflammation induces endothelial cell activation and shedding of glycocalyx constituents into the circulation. This review discusses the potential role of soluble glycocalyx components as biomarkers of active LN, especially in patients in whom conventional serological and biochemical markers do not appear helpful.

Phytocompounds from Amazonian Plant Species against Acute Kidney Injury: Potential Nephroprotective Effects

There are several Amazonian plant species with potential pharmacological validation for the treatment of acute kidney injury, a condition in which the kidneys are unable to adequately filter the blood, resulting in the accumulation of toxins and waste in the body. Scientific production on plant compounds capable of preventing or attenuating acute kidney injury-caused by several factors, including ischemia, toxins, and inflammation-has shown promising results in animal models of acute kidney injury and some preliminary studies in humans. Despite the popular use of Amazonian plant species for kidney disorders, further pharmacological studies are needed to identify active compounds and subsequently conduct more complex preclinical trials. This article is a brief review of phytocompounds with potential nephroprotective effects against acute kidney injury (AKI). The classes of Amazonian plant compounds with significant biological activity most evident in the consulted literature were alkaloids, flavonoids, tannins, steroids, and terpenoids. An expressive phytochemical and pharmacological relevance of the studied species was identified, although with insufficiently explored potential, mainly in the face of AKI, a clinical condition with high morbidity and mortality.

Neutrophil function following treatment of psoriatic arthritis patients with secukinumab: altered cytokine signalling but no impairment of host defence

OBJECTIVES

Identifying that dysfunction of the IL-23/17 axis underlies PsA has led to the development of effective targeted therapies such as the IL-17A inhibitor secukinumab. As IL-17A stimulates the secretion of neutrophil chemoattractants, such as CXCL8 (IL-8), we examined the effect of secukinumab on neutrophil function in PsA.

METHODS

Nineteen patients with active PsA were treated with secukinumab. Clinical response [PsA Response Criteria (PsARC) and Psoriasis Area and Severity Index (PASI)] and peripheral blood neutrophil function (apoptosis, receptor expression, phagocytosis/killing, chemotaxis and RNA expression) were measured at 12 week intervals for 48 weeks and compared with age- and sex-matched healthy controls.

RESULTS

At 12 weeks, 12/16 (75%) patients had a PsARC response (100% at 36 weeks) and 10/14 (71%) achieved a 90% PASI response. At baseline, there were no differences in PsA neutrophil reactive oxygen species generation, constitutive or cytokine-delayed apoptosis, chemotaxis or phagocytosis of opsonized Staphylococcus aureus compared with healthy controls. Similarly, there were no differences in these functions from baseline to 12 weeks of therapy. However, surface levels of CD11b/CD18 and CD63 increased and expression of CD16 decreased during therapy. In addition, in a subgroup of early (12 week) responders to secukinumab, RNA sequencing revealed transcriptome changes predicting down-regulation of cytokine signalling and chemotaxis pathways and up-regulation of de novo gene expression pathways, including translation initiation, mRNA catabolism and translation.

CONCLUSION

Complex changes in the properties of circulating neutrophils occur with secukinumab treatment in PsA that may indicate altered responsiveness to changes in both local and systemic levels of pro-inflammatory cytokines. However, host defence processes of neutrophils were unaltered.

A Review of the Relationship between the Immune Response, Inflammation, Oxidative Stress, and the Pathogenesis of Sickle Cell Anaemia

Sickle cell anaemia (SCD) is a life-threatening haematological disorder which is predominant in sub-Saharan Africa and is triggered by a genetic mutation of the β-chain haemoglobin gene resulting in the substitution of glutamic acid with valine. This mutation leads to the production of an abnormal haemoglobin molecule called haemoglobin S (HbS). When deoxygenated, haemoglobin S (HbS) polymerises and results in a sickle-shaped red blood cell which is rigid and has a significantly shortened life span. Various reports have shown a strong link between oxidative stress, inflammation, the immune response, and the pathogenesis of sickle cell disease. The consequence of these processes leads to the development of vasculopathy (disease of the blood vessels) and several other complications. The role of the immune system, particularly the innate immune system, in the pathogenesis of SCD has become increasingly clear in recent years of research; however, little is known about the roles of the adaptive immune system in this disease. This review examines the interaction between the immune system, inflammation, oxidative stress, blood transfusion, and their effects on the pathogenesis of sickle cell anaemia.

Salivary Alterations of Myeloperoxidase in Patients with Systemic Diseases: A Systematic Review

Salivary myeloperoxidase (MPO) is a key mediator of the oral immune system, acting as an enzyme that utilises H2O2 to generate molecules with high bactericidal activity. While MPO determination in plasma is quite common, the use of saliva is still rare. Our systematic review was designed to answer the question "Are salivary levels of myeloperoxidase altered in patients with systemic diseases?". Following the inclusion and exclusion criteria, we included twenty-six studies. Altered MPO levels in saliva were most commonly found in patients with cardiovascular and gastrointestinal diseases. Most studies concerned unstimulated whole saliva, and only a few of them stimulated, mainly by chewing paraffin. Enzyme-linked immunosorbent assay (ELISA) was the most common method for determination of MPO concentrations in saliva. Increased salivary MPO levels were more often observed for inflammatory diseases, except patients with inflammatory bowel diseases who were eligible for biologic therapy. In conclusion, MPO could be altered in the saliva of patients with systematic diseases, especially cardiovascular or gastrointestinal diseases. However, further investigations are recommended to validate these outcomes.

Comparison of the oxidative profiles before and after revascularization in peripheral arterial disease: a pilot study

Reactive and highly reactive oxygen species (ROS and hROS) produced by white blood cells are essential for innate immunity; however, they may cause oxidative stress in the host. We developed systems for simultaneously monitoring ROS and hROS, i.e., superoxide radicals (O2•-) and hypochlorite ions (OCl-) secreted from stimulated white blood cells in a few microliters of whole blood. We previously reported on the evaluation of healthy volunteers' blood using the developed system; however, whether patients' blood can be assessed remains unclear. Here, we report a pilot study of 30 cases (28 patients) with peripheral arterial disease, in whom we measured the ROS and hROS levels before and approximately one month after endovascular treatment (EVT) using the system (CFL-H2200) that we developed. At approximately the same time points, physiological indices of blood vessels, oxidative stress markers, and standard clinical parameters in the blood were also monitored. The ankle-brachial index, a diagnostic tool for peripheral arterial disease, was significantly improved after EVT (p<0.001). The ROS-hROS ratio, low-density lipoprotein cholesterol, and hematocrit levels were decreased after EVT (p<0.05), while triglyceride and lymphocyte levels were increased after EVT (p<0.05). The correlations between the study parameters were also analyzed.

Amelioration of nephritis in receptor for advanced glycation end-products (RAGE)-deficient lupus-prone mice through neutrophil extracellular traps

The receptor for advanced glycation end-products (RAGE) is a pattern recognition receptor that regulates inflammation, cell migration, and cell fate. Systemic lupus erythematosus (SLE) is a chronic multiorgan autoimmune disease. To understand the function of RAGE in SLE, we generated RAGE-deficient (Ager-/-) lupus-prone mice by backcrossing MRL/MpJ-Faslpr/J (MRL-lpr) mice with Ager-/- C57BL/6 mice. In 18-week-old Ager-/- MRL-lpr, the weights of the spleen and lymph nodes, as well as the frequency of CD3+CD4-CD8- cells, were significantly decreased. Ager-/- MRL-lpr mice had significantly reduced urine albumin/creatinine ratios and markedly improved renal pathological scores. Moreover, neutrophil infiltration and neutrophil extracellular trap formation in the glomerulus were significantly reduced in Ager-/- MRL-lpr. Our study is the first to reveal that RAGE can have a pathologic role in immune cells, particularly neutrophils and T cells, in inflammatory tissues and suggests that the inhibition of RAGE may be a potential therapeutic strategy for SLE.

Neutrophil, NETs and Behçet's disease: A review

Behçet's disease (BD) is a chronic systemic vasculitis characterized by recurrent oral and genital ulcers, skin lesions, articular, neurological, vascular and sight-threatening ocular inflammation. BD is thought to share both autoimmune and autoinflammatory disease features. BD is triggered by environmental factors such as infectious agents in genetically predisposed subjects. Neutrophils seem to play an instrumental role in BD and recent works regarding the role of neutrophils extracellular traps (NETs) provides new insight in the pathophysiology of BD and the mechanisms involved in immune thrombosis. This review provides a recent overview on the role of neutrophils and NETs in the pathogenesis of BD.

Neutrophil Extracellular Traps in Airway Diseases: Pathological Roles and Therapeutic Implications

Neutrophils are important effector cells of the innate immune response that fight pathogens by phagocytosis and degranulation. Neutrophil extracellular traps (NETs) are released into the extracellular space to defend against invading pathogens. Although NETs play a defensive role against pathogens, excessive NETs can contribute to the pathogenesis of airway diseases. NETs are known to be directly cytotoxic to the lung epithelium and endothelium, highly involved in acute lung injury, and implicated in disease severity and exacerbation. This review describes the role of NET formation in airway diseases, including chronic rhinosinusitis, and suggests that targeting NETs could be a therapeutic strategy for airway diseases.

Scoping Review on Epigenetic Mechanisms in Primary Immune Thrombocytopenia

Immune Thrombocytopenia (ITP) is an autoimmune blood disorder that involves multiple pathways responsible for the homeostasis of the immune system. Numerous pieces of literature have proposed the potential of immune-related genes as diagnostic and prognostic biomarkers, which mostly implicate the role of B cells and T cells in the pathogenesis of ITP. However, a more in-depth understanding is required of how these immune-related genes are regulated. Thus, this scoping review aims to collate evidence and further elucidate each possible epigenetics mechanism in the regulation of immunological pathways pertinent to the pathogenesis of ITP. This encompasses DNA methylation, histone modification, and non-coding RNA. A total of 41 studies were scrutinized to further clarify how each of the epigenetics mechanisms is related to the pathogenesis of ITP. Identifying epigenetics mechanisms will provide a new paradigm that may assist in the diagnosis and treatment of immune thrombocytopenia.

Modulation of Beta-Amyloid-Activated Primary Human Neutrophils by Dietary Phenols from Virgin Olive Oil

The defense mechanism against harmful stimuli is inflammation. Indeed, neurodegenerative disorders can arise as a result of a persistent neuroinflammation. Beta-amyloid (Aβ_1-42) is an early trigger in the origination of Alzheimer's disease, leading to synaptic and cognitive impairments. Virgin olive oil (VOO) is correlated with a decreased risk of developing immune-inflammatory disorders, but the potential effects of the phenolic fraction (PF) from VOO in the modulation of neuroinflammatory processes in neutrophils remain unknown. In this study, we investigated the ability of the PF to modulate the activation of Aβ_1-42-stimulated primary human neutrophils, focusing on the expression of gene and surface markers and the release of pro-inflammatory and chemoattractant mediators. Down-regulation of pro-inflammatory cytokine gene expression in Aβ_1-42-treated neutrophils, among other changes, was reported. Furthermore, pretreatment with PF prevented neutrophil activation. The beneficial effects in the modulation of inflammatory responses show the relevance of VOO to achieve a healthier diet that can help prevent inflammatory diseases.

Discussion on the common controversies of Helicobacter pylori infection

BACKGROUND

Helicobacter pylori ( H. pylori ) can persistently colonize on the gastric mucosa after infection and cause gastritis, atrophy, metaplasia, and even gastric cancer (GC).

METHODS

Therefore, the detection and eradication of H. pylori are the prerequisite.

RESULTS

Clinically, there are some controversial issues, such as why H. pylori infection is persistent, why it translocases along with the lesser curvature of the stomach, why there is oxyntic antralization, what the immunological characteristic of gastric chronic inflammation caused by H. pylori is, whether H. pylori infection is associated with extra-gastric diseases, whether chronic atrophic gastritis (CAG) is reversible, and what the potential problems are after H. pylori eradication. What are the possible answers?

CONCLUSION

In the review, we will discuss these issues from the attachment to eradication in detail.

N-Acetylserotonin is an oxidation-responsive activator of Nrf2 ameliorating colitis in rats

N-Acetylserotonin (NAS) is an intermediate in the melatonin biosynthetic pathway. We investigated the anti-inflammatory activity of NAS by focusing on its chemical feature oxidizable to an electrophile. NAS was readily oxidized by reaction with HOCl, an oxidant produced in the inflammatory state. HOCl-reacted NAS (Oxi-NAS), but not NAS, activated the anti-inflammatory nuclear factor erythroid 2-related factor 2 (Nrf2)-heme oxygenase (HO)-1 pathway in cells. Chromatographic and mass analyses demonstrated that Oxi-NAS was the iminoquinone form of NAS and could react with N-acetylcysteine possessing a nucleophilic thiol to form a covalent adduct. Oxi-NAS bound to Kelch-like ECH-associated protein 1, resulting in Nrf2 dissociation. Moreover, rectally administered NAS increased the levels of nuclear Nrf2 and HO-1 proteins in the inflamed colon of rats. Simultaneously, NAS was converted to Oxi-NAS in the inflamed colon. Rectal NAS mitigated colonic damage and inflammation. The anticolitic effects were significantly compromised by the coadministration of an HO-1 inhibitor.

Carnosic acid inhibits reactive oxygen species-dependent neutrophil extracellular trap formation and ameliorates acute respiratory distress syndrome

AIMS

Infiltration of activated neutrophils into the lungs is a hallmark of acute respiratory distress syndrome (ARDS). Neutrophilic inflammation, particularly neutrophil extracellular traps (NETs), is proposed as a useful target for treating ARDS. Carnosic acid (CA) is a food additive; however, its anti-neutrophilic activity in the treatment of ARDS has not been well established. The hypothesis of present study is to confirm that CA alleviates ARDS by suppressing neutrophilic inflammation and oxidative damage.

MAIN METHODS

Generation of superoxide anions and reactive oxygen species (ROS), induction of elastase degranulation, and formation of NETs by human neutrophils were assayed using spectrophotometry, flow cytometry, and immunofluorescent microscopy. Immunoblotting was performed to determine the cellular mechanisms involved. Cell-free radical systems were used to test antioxidant activities. The therapeutic effect of CA was evaluated in a lipopolysaccharide (LPS)-induced ARDS mouse model.

KEY FINDINGS

CA greatly reduced superoxide anion production, ROS production, elastase release, cluster of differentiation 11b expression, and cell adhesion in activated human neutrophils. Mechanistic studies have demonstrated that CA suppresses phosphorylation of extracellular regulated kinase and c-Jun N-terminal kinase in activated neutrophils. CA effectively scavenges reactive oxygen and nitrogen species, but not superoxide anions. This is consistent with the finding that CA is effective against ROS-dependent NET formation. CA treatment significantly improved pulmonary neutrophil infiltration, oxidative damage, NET formation, and alveolar damage in LPS-induced mice.

SIGNIFICANCE

Our data suggested the potential application of CA for neutrophil-associated ARDS therapy.

The Potential Importance of CXCL1 in the Physiological State and in Noncancer Diseases of the Cardiovascular System, Respiratory System and Skin

In this paper, we present a literature review of the role of CXC motif chemokine ligand 1 (CXCL1) in physiology, and in selected major non-cancer diseases of the cardiovascular system, respiratory system and skin. CXCL1, a cytokine belonging to the CXC sub-family of chemokines with CXC motif chemokine receptor 2 (CXCR2) as its main receptor, causes the migration and infiltration of neutrophils to the sites of high expression. This implicates CXCL1 in many adverse conditions associated with inflammation and the accumulation of neutrophils. The aim of this study was to describe the significance of CXCL1 in selected diseases of the cardiovascular system (atherosclerosis, atrial fibrillation, chronic ischemic heart disease, hypertension, sepsis including sepsis-associated encephalopathy and sepsis-associated acute kidney injury), the respiratory system (asthma, chronic obstructive pulmonary disease (COPD), chronic rhinosinusitis, coronavirus disease 2019 (COVID-19), influenza, lung transplantation and ischemic-reperfusion injury and tuberculosis) and the skin (wound healing, psoriasis, sunburn and xeroderma pigmentosum). Additionally, the significance of CXCL1 is described in vascular physiology, such as the effects of CXCL1 on angiogenesis and arteriogenesis.

Pathogenesis, multi-omics research, and clinical treatment of psoriasis

Psoriasis is a common inflammatory skin disease involving interactions between keratinocytes and immune cells that significantly affects the quality of life. It is characterized by hyperproliferation and abnormal differentiation of keratinocytes and excessive infiltration of immune cells in the dermis and epidermis. The immune mechanism underlying this disease has been elucidated in the past few years. Research shows that psoriasis is regulated by the complex interactions among immune cells, such as keratinocytes, dendritic cells, T lymphocytes, neutrophils, macrophages, natural killer cells, mast cells, and other immune cells. An increasing number of signaling pathways have been found to be involved in the pathogenesis of psoriasis, which has prompted the search for new treatment targets. In the past decades, studies on the pathogenesis of psoriasis have focused on the development of targeted and highly effective therapies. In this review, we have discussed the relationship between various types of immune cells and psoriasis and summarized the major signaling pathways involved in the pathogenesis of psoriasis, including the PI3K/AKT/mTOR, JAK-STAT, JNK, and WNT pathways. In addition, we have discussed the results of the latest omics research on psoriasis and the epigenetics of the disease, which provide insights regarding its pathogenesis and therapeutic prospects; we have also summarized its treatment strategies and observations of clinical trials. In this paper, the various aspects of psoriasis are described in detail, and the limitations of the current treatment methods are emphasized. It is necessary to improve and innovate treatment methods from the molecular level of pathogenesis, and further provide new ideas for the treatment and research of psoriasis.

Crosslinking of membrane CD13 in human neutrophils mediates phagocytosis and production of reactive oxygen species, neutrophil extracellular traps and proinflammatory cytokines

Aminopeptidase N, or CD13, is a cell membrane ectopeptidase highly expressed in myeloid cells. Through its enzymatic activity, CD13 regulates the activity of several bioactive peptides, such as endorphins and enkephalins, chemotactic peptides like MCP-1 and IL-8, angiotensin III, bradikinin, etc. In recent years, it has been appreciated that independently of its peptidase activity, CD13 can activate signal transduction pathways and mediate effector functions such as phagocytosis and cytokine secretion in monocytes and macrophages. Although neutrophils are known to express CD13 on its membrane, it is currently unknown if CD13 can mediate effector functions in these cells. Here, we show that in human neutrophils CD13 can mediate phagocytosis, which is dependent on a signaling pathway that involves Syk, and PI3-K. Phagocytosis mediated by CD13 is associated with production of reactive oxygen species (ROS). The level of phagocytosis and ROS production mediated by CD13 are similar to those through FcγRIII (CD16b), a widely studied receptor of human neutrophils. Also, CD13 ligation induces the release of neutrophil extracellular traps (NETs) as well as cytokine secretion from neutrophils. These results support the hypothesis that CD13 is a membrane receptor able to activate effector functions in human neutrophils.

Regulation of Neutrophil NADPH Oxidase, NOX2: A Crucial Effector in Neutrophil Phenotype and Function

Reactive oxygen species (ROS), produced by the phagocyte NADPH oxidase, NOX2, are involved in many leukocyte functions. An excessive or inappropriate ROS production can lead to oxidative stress and tissue damage. On the other hand, an absence of ROS production due to a lack of a functional NADPH oxidase is associated with recurrent infections as well as inflammation disorders. Thus, it is clear that the enzyme NADPH oxidase must be tightly regulated. The NOX2 complex bears both membrane and cytosolic subunits. The membrane subunits constitute the flavocytochrome b₅₅₈, consisting of gp91^phox (Nox2) and p22^phox subunits. The cytosolic subunits form a complex in resting cells and are made of three subunits (p47^phox, p40^phox, p67^phox). Upon leukocyte stimulation, the cytosolic subunits and the small GTPase Rac assemble with the flavocytochrome b₅₅₈ in order to make a functional complex. Depending on the stimulus, the NADPH oxidase can assemble either at the phagosomal membrane or at the plasma membrane. Many studies have explored NOX2 activation; however, how this activation is sustained and regulated is still not completely clear. Here we review the multiple roles of NOX2 in neutrophil functions, with a focus on description of its components and their assembly mechanisms. We then explain the role of energy metabolism and phosphoinositides in regulating NADPH oxidase activity. In particular, we discuss: 1) the link between metabolic pathways and NOX2 activity regulation through neutrophil activation and the level of released ROS, and 2) the role of membrane phosphoinositides in controlling the duration of NOX2 activity.

The phytoactive constituents of Eugenia selloi B.D. Jacks (pitangatuba): Toxicity and elucidation of their anti-inflammatory mechanism(s) of action

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Purified subfraction from Eugenia selloi fruit, showed anti-inflammatory activity.

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It were identified isomers of quercetrin, vanillic acid, and coumaric acid.

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S8 reduced NF-κB, IL-1β, IL-6, IL-10, MDC and MCP-1 levels in macrophages.

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S8 reduced neutrophil migration and ICAM-1 expression in mice.

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S8 showed scavenging capacity against ROO^•, HOCl and NO^• biological radicals.

We determined the phytochemical composition, anti-inflammatory mechanism of action, ROS/RNS scavenging capacity and systemic toxicity of a purified subfraction (S8) of Eugenia selloi. The composition of S8 was assessed by LC-ESI-QTOF-MS; the anti-inflammatory activity in RAW264.7 macrophages through NF-κB activation and biomarkers by multiplex in THP-1 cells; neutrophil migration, intravital microscopy and ICAM-1 expression in mice; NETs formation and CD11b expression; S8 scavenging capacity of ROS/RNS; toxicity in Galleria mellonella larvae model. Coumaric acid, quercetrin and vanillic acid were identified. S8 decreased NF-κB activation, IL-1β, IL-6, IL-10, MDC and MCP-1 levels, reduced neutrophil migration and ICAM-1 expression in mice; S8 did not interfere NET formation and CD11b expression, exhibited high antioxidant and showed negligible toxicity. E. selloi proved to be a promising, yet underexplored source of bioactive compounds, which can be useful employed in agribusiness and in the pharmaceutical and food industry to develop new products or human health supplies.

Microglia and Neuroinflammation: Crucial Pathological Mechanisms in Traumatic Brain Injury-Induced Neurodegeneration

Traumatic brain injury (TBI) is one of the most common diseases in the central nervous system (CNS) with high mortality and morbidity. Patients with TBI usually suffer many sequelae in the life time post injury, including neurodegenerative disorders such as Alzheimer’s disease (AD) and Parkinson’s disease (PD). However, the pathological mechanisms connecting these two processes have not yet been fully elucidated. It is important to further investigate the pathophysiological mechanisms underlying TBI and TBI-induced neurodegeneration, which will promote the development of precise treatment target for these notorious neurodegenerative consequences after TBI. A growing body of evidence shows that neuroinflammation is a pivotal pathological process underlying chronic neurodegeneration following TBI. Microglia, as the immune cells in the CNS, play crucial roles in neuroinflammation and many other CNS diseases. Of interest, microglial activation and functional alteration has been proposed as key mediators in the evolution of chronic neurodegenerative pathology following TBI. Here, we review the updated studies involving phenotypical and functional alterations of microglia in neurodegeneration after injury, survey key molecules regulating the activities and functional responses of microglia in TBI pathology, and explore their potential implications to chronic neurodegeneration after injury. The work will give us a comprehensive understanding of mechanisms driving TBI-related neurodegeneration and offer novel ideas of developing corresponding prevention and treatment strategies for this disease.

Redox-Mediated Carbamylation As a Hapten Model Applied to the Origin of Antibodies to Modified Proteins in Rheumatoid Arthritis

Significance: The production of antibodies to posttranslationally modified antigens is a hallmark in rheumatoid arthritis (RA). In particular, the presence of citrullination-associated antibodies, targeting both citrullinating enzymes (the peptidylarginine deiminases [PADs]) and citrullinated antigens (anticitrullinated protein antibodies [ACPAs]), has suggested that dysregulated citrullination is relevant for disease pathogenesis. Antibodies to other protein modifications with physicochemical similarities to citrulline, such as carbamylated-lysine and acetylated-lysine, have also gained interest in RA, but their mechanistic relation to ACPAs remains unclear. Recent Advances: Recent studies using RA-derived monoclonal antibodies have found that ACPAs are cross-reactive to carbamylated and acetylated peptides, challenging our understanding of the implications of such cross-reactivity. Critical Issues: Analogous to the classic antibody response to chemically modified proteins, we examine the possibility that antibodies to modified proteins in RA are more likely to resemble antihapten antibodies rather than autoantibodies. This potential shift in the autoantibody paradigm in RA offers the opportunity to explore new mechanisms involved in the origin and cross-reactivity of pathogenic antibodies in RA. In contrast to citrullination, carbamylation is a chemical modification associated with oxidative stress, it is highly immunogenic, and is considered in the group of posttranslational modification-derived products. We discuss the possibility that carbamylated proteins are antigenic drivers of cross-reacting antihapten antibodies that further create the ACPA response, and that ACPAs may direct the production of antibodies to PAD enzymes. Future Directions: Understanding the complexity of autoantibodies in RA is critical to develop tools to clearly define their origin, identify drivers of disease propagation, and develop novel therapeutics. Antioxid. Redox Signal. 36, 389-409.