C5a enhances Vδ1 T cells recruitment via the CCL2-CCR2 axis in IgA nephropathy

Inflammation in glomerular diseases

The structural and functional integrity of glomerular cells is critical for maintaining normal kidney function. Glomerular diseases, which involve chronic histological damage to the kidney, are related to injury to glomerular cells such as endothelial cells, mesangial cells (MCs), and podocytes. When faced with pathogenic conditions, these cells release pro-inflammatory cytokines such as chemokines, inflammatory factors, and adhesion factors. These substances interact with glomerular cells through specific inflammatory pathways, resulting in damage to the structure and function of the glomeruli, ultimately causing glomerular disease. Although the role of inflammation in chronic kidney diseases is well known, the specific molecular pathways that result in glomerular diseases remain largely unclear. For a long time, it has been believed that only immune cells can secrete inflammatory factors. Therefore, targeted therapies against immune cells were considered the first choice for treating inflammation in glomerular disease. However, emerging research indicates that non-immune cells such as glomerular endothelial cells, MCs, and podocytes can also play a role in renal inflammation by releasing inflammatory factors. Similarly, targeted therapies against glomerular cells should be considered. This review aims to uncover glomerular diseases related to inflammation and pathways in glomerular inflammation, and for the first time summarized that non-immune cells in the glomerulus can participate in glomerular inflammatory damage by secreting inflammatory factors, providing valuable references for future strategies to prevent and treat glomerular diseases. More importantly, we emphasized targeted glomerular cell therapy, which may be a key direction for the future treatment of glomerular diseases.

Research progress on V delta 1+ T cells and their effect on pathogen infection

The ongoing high occurrence of harmful infectious diseases significantly threatens human health. Existing methods used to control such diseases primarily involve targeting the pathogens, usually neglecting the vital role of host factors in disease advancement. Gamma delta (γδ) T cells act as a bridge between innate and adaptive immunity, playing a crucial role in combating pathogen invasion. Among these γδT cell subsets, which are categorized based on T cell receptor delta variable expression patterns, V delta (δ) 1+ T cells possess unique recognition abilities and regulatory characteristics and actively engage in various immune responses. The differentiation, development, and immune reactivity of Vδ1+ T cells are closely associated with the initial and progressive stages of infectious diseases. This article provides an overview of the classification, distribution, differentiation, and development of Vδ1+ T cells and their mechanisms in combating pathogenic infections, offering new insights for disease diagnosis and treatment.

Unveiling the genetic link and pathogenesis between psoriasis and IgA nephropathy based on Mendelian randomization and transcriptome data analyses

It has been reported that many people with psoriasis have been diagnosed with secondary IgA nephropathy (IgAN). However, the mechanisms behind the association between psoriasis and IgAN have not been well clarified. The connection between psoriasis and IgAN deserves deeper exploration. Mendelian randomization (MR) analysis would be employed to explore the link of causality between IgAN and psoriasis, psoriasis vulgaris, other and unspecified psoriasis, guttate psoriasis, and arthropathic psoriasis. Transcriptomic analyses were carried out against the Gene Expression Omnibus databases. We identified crosstalk genes through the analysis of Differentially expressed genes and weight gene co-expression network analysis. Functional annotations were enriched for these crosstalk genes. Subsequently, we established a protein-protein interaction network, and candidate genes would be discovered through the utilization of the MCODE and CytoHubba plug-in applications. Lastly, the predictive efficacy of these genes was examined via creating receiver operating characteristic curves. The MR analysis suggested that psoriasis vulgaris patients were at a higher risk for IgAN. [OR = 1.040, 95%CI (1.005,1.076), p = 0.026 < 0.05]. Additionally, arthropathic psoriasis may augment the incidence of IgAN [OR = 1.081, 95%CI (1.040-1.124), p < 0.01] in the European population. Through the analysis of DEGs and WGCNA, we identified 12 significant genes (NETO2, RRM2, SLAMF7, GBP1, KIF20A, CCL4, MMP1, IL1β, NDC80, CXCL9, C15orf48, GSTA3), which may be potential crosstalk genes between the two diseases. Then, the functional annotation results indicated that the crosstalk genes seemed primarily involved in immune and inflammatory responses. By establishing the PPI network, we further discovered that CXCL9, IL1β, CCL4, and MMP1 play a vital part in psoriasis and IgAN, and all have good diagnostic values. Our MR analysis provided evidence that genetic vulnerability to IgAN may be associated with an elevated risk of psoriasis vulgaris and arthropathic psoriasis respectively among Europeans. Doctors should be aware of these associations when patients with psoriasis present with renal dysfunction, especially those with psoriasis vulgaris and arthropathic psoriasis. Chronic inflammation, drug effects, and immunity may contribute to the generation and development of both diseases. IL1β, CXCL9, CCL4, and MMP1 may be core biomarkers for psoriasis and IgAN.

C5a Induces Inflammatory Signaling and Apoptosis in PC12 Cells through C5aR-Dependent Signaling: A Potential Mechanism for Adrenal Damage in Sepsis

The complement system is critically involved in the pathogenesis of sepsis. In particular, complement anaphylatoxin C5a is generated in excess during sepsis, leading to cellular dysfunction. Recent studies have shown that excessive C5a impairs adrenomedullary catecholamine production release and induces apoptosis in adrenomedullary cells. Currently, the mechanisms by which C5a impacts adrenal cell function are poorly understood. The PC12 cell model was used to examine the cellular effects following treatment with recombinant rat C5a. The levels of caspase activation and cell death, protein kinase signaling pathway activation, and changes in inflammatory protein expression were examined following treatment with C5a. There was an increase in apoptosis of PC12 cells following treatment with high-dose C5a. Ten inflammatory proteins, primarily involved in apoptosis, cell survival, and cell proliferation, were upregulated following treatment with high-dose C5a. Five inflammatory proteins, involved primarily in chemotaxis and anti-inflammatory functions, were downregulated. The ERK/MAPK, p38/MAPK, JNK/MAPK, and AKT protein kinase signaling pathways were upregulated in a C5aR-dependent manner. These results demonstrate an apoptotic effect and cellular signaling effect of high-dose C5a. Taken together, the overall data suggest that high levels of C5a may play a role in C5aR-dependent apoptosis of adrenal medullary cells in sepsis.

Role of MCP-1 as an inflammatory biomarker in nephropathy

The Monocyte chemoattractant protein-1 (MCP-1), also referred to as chemokine ligand 2 (CCL2), belongs to the extensive chemokine family and serves as a crucial mediator of innate immunity and tissue inflammation. It has a notable impact on inflammatory conditions affecting the kidneys. Upon binding to its receptor, MCP-1 can induce lymphocytes and NK cells' homing, migration, activation, differentiation, and development while promoting monocytes' and macrophages' infiltration, thereby facilitating kidney disease-related inflammation. As a biomarker for kidney disease, MCP-1 has made notable advancements in primary kidney diseases such as crescentic glomerulonephritis, chronic glomerulonephritis, primary glomerulopathy, idiopathic proteinuria glomerulopathy, acute kidney injury; secondary kidney diseases like diabetic nephropathy and lupus nephritis; hereditary kidney diseases including autosomal dominant polycystic kidney disease and sickle cell kidney disease. MCP-1 not only predicts the occurrence, progression, prognosis of the disease but is also closely associated with the severity and stage of nephropathy. When renal tissue is stimulated or experiences significant damage, the expression of MCP-1 increases, demonstrating a direct correlation with the severity of renal injury.