Ageing enhances cellular immunity to myeloperoxidase and experimental anti-myeloperoxidase glomerulonephritis

Myeloperoxidase-specific antineutrophil cytoplasmic antibody-associated vasculitis

Myeloperoxidase (MPO)-specific antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (MPO-ANCA-associated vasculitis) is one of two major ANCA-associated vasculitis variants characterised by systemic necrotising vasculitis with few or no immune deposits. MPO-ANCA-associated vasculitis predominantly affects small blood vessels and, in contrast to its counterpart proteinase 3-ANCA-associated vasculitis, is generally not associated with granulomatous inflammation. The kidneys and lungs are the most commonly affected organs. The pathogenesis of MPO-ANCA-associated vasculitis is characterised by loss of tolerance to the neutrophil enzyme MPO. This loss of tolerance leads to a chronic immunopathological response where neutrophils become both the target and effector of autoimmunity. MPO-ANCA drives neutrophil activation, leading in turn to tissue and organ damage. Clinical trials have improved the therapeutic approach to MPO-ANCA-associated vasculitis. However, there remains substantial unmet need regarding relapse frequency, toxicity of current treatment, and long-term morbidity. In this Series paper, we present the current state of research regarding pathogenesis, diagnosis, and treatment of MPO-ANCA-associated vasculitis.

Eternal Youth: A Comprehensive Exploration of Gene, Cellular, and Pharmacological Anti-Aging Strategies

The improvement of human living conditions has led to an increase in average life expectancy, creating a new social and medical problem-aging, which diminishes the overall quality of human life. The aging process of the body begins with the activation of effector signaling pathways of aging in cells, resulting in the loss of their normal functions and deleterious effects on the microenvironment. This, in turn, leads to chronic inflammation and similar transformations in neighboring cells. The cumulative retention of these senescent cells over a prolonged period results in the deterioration of tissues and organs, ultimately leading to a reduced quality of life and an elevated risk of mortality. Among the most promising methods for addressing aging and age-related illnesses are pharmacological, genetic, and cellular therapies. Elevating the activity of aging-suppressing genes, employing specific groups of native and genetically modified cells, and utilizing senolytic medications may offer the potential to delay aging and age-related ailments over the long term. This review explores strategies and advancements in the field of anti-aging therapies currently under investigation, with a particular emphasis on gene therapy involving adeno-associated vectors and cell-based therapeutic approaches.

Animal models for anti-neutrophil cytoplasmic antibody-associated vasculitis: Are current models good enough?

Antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) is a rare and severe systemic autoimmune disease characterized by pauci-immune necrotizing inflammation of small blood vessels. AAV involves multiple organ systems throughout the body. Our knowledge of the pathogenesis of AAV has increased considerably in recent years, involving cellular, molecular and genetic factors. Because of the controlled environment with no other confounding factors, animal models are beneficial for studying the mechanistic details of disease development and for providing novel therapeutic targets with fewer toxic side effects. However, the complexity and heterogeneity of AAV make it very difficult to establish a single animal model that can fully represent the entire clinical spectrum found in patients. The aim of this review is to overview the current status of animal models for AAV, outline the pros and cons of methods, and propose potential directions for future research.

Hypochlorous Acid Chemistry in Mammalian Cells—Influence on Infection and Role in Various Pathologies

This review discusses the formation of hypochlorous acid HOCl and the role of reactive chlorinated species (RCS), which are catalysed by the enzyme myeloperoxidase MPO, mainly located in leukocytes and which in turn contribute to cellular oxidative stress. The reactions of RCS with various organic molecules such as amines, amino acids, proteins, lipids, carbohydrates, nucleic acids, and DNA are described, and an attempt is made to explain the chemical mechanisms of the formation of the various chlorinated derivatives and the data available so far on the effects of MPO, RCS and halogenative stress. Their presence in numerous pathologies such as atherosclerosis, arthritis, neurological and renal diseases, diabetes, and obesity is reviewed and were found to be a feature of debilitating diseases.

Identification of Hub Biomarkers and Immune-Related Pathways Participating in the Progression of Antineutrophil Cytoplasmic Antibody-Associated Glomerulonephritis

Background

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a systemic autoimmune disease that generally induces the progression of rapidly progressive glomerulonephritis (GN). The purpose of this study was to identify key biomarkers and immune-related pathways involved in the progression of ANCA-associated GN (ANCA-GN) and their relationship with immune cell infiltration.

Methods

Gene microarray data were downloaded from the Gene Expression Omnibus (GEO). Hub markers for ANCA-GN were mined based on differential expression analysis, weighted gene co-expression network analysis (WGCNA) and lasso regression, followed by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Set Enrichment Analysis (GSEA) of the differential genes. The infiltration levels of 28 immune cells in the expression profile and their relationship to hub gene markers were analysed using single-sample GSEA (ssGSEA). In addition, the accuracy of the hub markers in diagnosing ANCA-GN was subsequently evaluated using the receiver operating characteristic curve (ROC).

Results

A total of 651 differential genes were screened. Twelve co-expression modules were obtained via WGCNA; of which, one hub module (black module) had the highest correlation with ANCA-GN. A total of 66 intersecting genes were acquired by combining differential genes. Five hub genes were subsequently obtained by lasso analysis as potential biomarkers for ANCA-GN. The immune infiltration results revealed the most significant relationship among monocytes, CD4⁺ T cells and CD8⁺ T cells. ROC curve analysis demonstrated a prime diagnostic value of the five hub genes. According to the functional enrichment analysis of the differential genes, hub genes were mainly enhanced in immune- and inflammation-related pathways.

Conclusion

B cells and monocytes were closely associated with the pathogenesis of ANCA-GN. Hub genes (CYP3A5, SLC12A3, BGN, TAPBP and TMEM184B) may be involved in the progression of ANCA-GN through immune-related signal pathways.

Animal models of vasculitis

PURPOSE OF REVIEW

Vasculitis describes a wide spectrum of rare, inflammatory, multisystem disorders. These heterogenous diseases all have inflammation of blood vessels as a central feature. However, they differ in terms of their genetic and environmental risk factors, disease pathogenesis, clinical presentations and treatment strategies. Many animal models of vasculitis exist, each resembling a different human clinical phenotype. This review provides an overview of recently published findings from experimental animal models of vasculitis.

RECENT FINDINGS

Several new animal models have been described during the review period. New insights gleaned from existing animal models regarding cause, disease effector mechanisms and novel treatments identified in established animal models are discussed.

SUMMARY

Animal models continue to be an important tool for understanding disease pathogenesis, especially in rare and complex diseases such as vasculitis. They also provide an invaluable platform for development and preclinical testing of new treatments.