Serum TNF-α Level Is Associated with Disease Severity in Adult Patients with Immunoglobulin A Vasculitis Nephritis

Effect of vitamin D3 and a stinging nettle extract on the gastric tissue of rats administered with trinitrobenzene sulfonic acid

In this study, the effects of vitamin D3 (Vit. D) and a stinging nettle [Urtica dioica L. (UD)] extract were examined using histopathological and immunohistochemical methods in the stomach tissues of an experimentally created rat model of Crohn's disease (CD). The CD model was created using trinitrobenzene sulfonic acid (TNBS). The animals in the study were divided into control, TNBS, TNBS+Vit. D, and TNBS+UD groups. At the end of the experiment, the animals were euthanised and their stomach tissues were evaluated for necrosis, degeneration, apoptosis, and inflammation. Additionally, an immunohistochemical method was applied to determine the somatostatin (SSTR), aquaporin-1 (AQP-1), caspase-3, and tumour necrosis factor-alpha (TNF-α) immunoreactivity in the gastric tissues. In the evaluations, degenerative and necrotic changes and mononuclear cell infiltration areas were observed in the TNBS group, but such changes could be improved with Vit. D and UD applications. The results suggest that the combination of the Vit. D and UD extract may have a protective and therapeutic role in mitigating TNBS-induced damage to the gastric tissues, potentially through the regulation of SSTR, AQP-1, caspase-3, and TNF-α expression. This indicates a promising avenue for further research and the exploration of these compounds in the context of gastrointestinal health.

IL-4-secreting CD40L+ MAIT cells support antibody production in the peripheral blood of Heonch-Schönlein purpura patients

OBJECTIVE

Here, we explored the phenotype and function of MAIT cells in the peripheral blood of patients with HSP.

METHODS

Blood samples from HSP patients and HDs were assessed by flow cytometry and single-cell RNA sequencing to analyze the proportion, phenotype, and function of MAIT cells. Th-cytokines in the serum of HSP patients were analyzed by CBA. IgA in cocultured supernatant was detected by CBA to analyze antibody production by B cells.

RESULTS

The percentage of MAIT cells in HSP patients was significantly reduced compared with that in HDs. Genes related to T cell activation and effector were up-regulated in HSP MAIT cells, indicating a more activated phenotype. In addition, HSP MAIT cells displayed a Th2-like profile with the capacity to produce more IL-4 and IL-5, and IL-4 was correlated with IgA levels in the serum of HSP patients. Furthermore, CD40L was up-regulated in HSP MAIT cells, and CD40L+ MAIT cells showed an increased ability to produce IL-4 and to enhance IgA production by B cells.

CONCLUSION

Our data demonstrate that MAIT cells in HSP patients exhibit an activated phenotype. The enhanced IL-4 production and CD40L expression of MAIT cells in HSP patients could take part in the pathogenesis of HSP.

Exploring the potential mechanisms of Shiwei Hezi pill against nephritis based on the method of network pharmacology

Objective: We aimed to reveal the potential active ingredients, targets and pathways of Shiwei Hezi pill (SHP) in the treatment of nephritis based on systematic network pharmacology. Methods: The online database was used to screen the common targets of SHP and nephritis, and the interaction between targets was analyzed. Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed using the Bioinformatics website. Molecular docking was carried out to verify the correlation between core ingredients and key targets. Cytoscape 3.6.1 was applied to perform protein-protein interactions (PPT) network construction and data visualization. Results: A total of 82 active ingredients in SHP were screened, and 140 common targets of SHP and nephritis were obtained. Our results demonstrated that TNF, AKT1 and PTGS2 might be the key targets of SHP in the treatment of nephritis. GO enrichment analysis yielded 2163 GO entries (p < 0.05), including 2,014 entries of the biological process (BP) category, 61 entries of the cell composition (CC) category and 143 entries of the molecular function (MF) category. KEGG pathway enrichment analysis produced 186 signaling pathways (p < 0.05), involving the AGE-RAGE, IL-17and TNF signaling pathways. The results of molecular docking showed that three active ingredients in SHP (quercetin, kaempferol and luteolin) could effectively bind to the TNF, AKT1 and PTGS2 targets. Conclusion: The effective active ingredients in SHP may regulate multiple signaling pathways through multiple targets, thereby exhibiting a therapeutic effect on nephritis.

Proanthocyanidins: A novel approach to Henoch‑Schonlein purpura through balancing immunity and arresting oxidative stress via TLR4/MyD88/NF‑κB signaling pathway (Review)

Henoch-Schonlein purpura (HSP), a recurrent and immunoglobulin (Ig)A-mediated vasculitis, presents not only as skin lesions but also as systemic involvement that can be life-threatening. Although the etiology of HSP remains unknown, immune imbalance and oxidative stress (OS) are primary contributors to its pathogenesis, alongside the abnormal activation of Toll-like receptor (TLR)/myeloid differentiation primary response gene 88 (MyD88)/nuclear factor-κB (NF-κB) pathway. TLRs, especially TLR4, stimulate downstream signaling molecules such as NF-κB and proinflammatory cytokines, which are released when TLRs combine with the key adapter molecule MyD88. This leads to the activation of T helper (Th) cell 2/Th17 and overproduction of reactive oxygen species (ROS). The function of regulatory T (Treg) cells is suppressed in the process. Th17/Treg imbalance then produces various inflammatory cytokines to promote proliferation and differentiation of B cells and the secretion of antibodies. IgA is secreted, and it binds to vascular endothelial surface receptors where the complex induces injury of the vascular endothelial cells. Additionally, excessive ROS creates OS that leads to an inflammatory response and vascular cell apoptosis or necrosis, thereby contributing to vascular endothelial damage and HSP occurrence. Proanthocyanidins are active compounds naturally enriched in fruits, vegetables and plants. Proanthocyanidins have diverse properties, including anti-inflammatory, antioxidant, antibacterial, immunoregulatory, anticarcinogenic and vascular protective effects. Proanthocyanidins are used in the management of various diseases. Proanthocyanidins regulate T cells, equilibrate immunity and arrest OS by inhibiting the TLR4/MyD88/NF-κB signaling pathway. Considering the pathogenesis of HSP and the properties of proanthocyanidins, the present study hypothesized that these compounds may potentially lead to HSP recovery through modulating the immune equilibrium and preventing OS by inhibiting the TLR4/MyD88/NF-κB pathway. To the best of our knowledge, however, little is known about the positive effects of proanthocyanidins against HSP. The present review summarizes the potential of proanthocyanidins to treat HSP.

Deciphering prognostic value of CD22 and its contribution to suppression of proinflammatory cytokines production in patients with IgA nephropathy

BACKGROUND

CD22, mainly expressed in mature B cells, could negatively regulate the function of B cells by binding to sialic acid-positive IgG (SA-IgG). Soluble CD22 (sCD22) is generated by the cleavage of the extracellular domain of CD22 on the membrane surface. However, the role of CD22 in IgA nephropathy (IgAN) remains unknown.

METHODS

A total of 170 IgAN patients with a mean follow-up of 18 months were included in this study. The sCD22, TGF-β, IL-6 and TNF-α were detected using commercial ELISA kits. SA-IgG were purified to stimulate peripheral blood mononuclear cells (PBMCs) from IgAN patients.

RESULTS

The plasma levels of sCD22 were lower in IgAN patients in comparison with healthy control. Furthermore, CD22 mRNA levels in PBMCs from patients with IgAN were significantly lower than those of healthy controls. The plasma levels of sCD22 were positively correlated to the mRNA levels of CD22. We found that patients with higher sCD22 levels had a lower level of serum creatinine and a higher level of eGFR on the time of renal biopsy and a higher remission rate of proteinuria and a lower risk of kidney events at the end of follow-up. The logistic regression analysis showed sCD22 was associated with an increased odd of proteinuria remission after being adjusted for eGFR, proteinuria, and SBP. After adjusting for confounding variables, sCD22 was a borderline significant predictor of less kidney composite endpoint. In addition, the sCD22 levels were positively associated with SA-IgG in plasma. The experimental results in vitro showed that addition of SA-IgG enhanced the release of sCD22 in cell supernatant and the phosphorylation of CD22 in PBMCs, further inhibiting the production of IL-6, TNF-α, and TGF-β in cell supernatant in a dose-dependent manner. Pretreatment with CD22-antibody significantly increased the expression of cytokines in PBMCs.

CONCLUSIONS

This is the first study to demonstrate that lower plasma soluble CD22 in IgAN patients and high soluble CD22 levels are associated with an increased odd of proteinuria remission and a decreased odd of kidney endpoint. The interaction between CD22 and SA-IgG can inhibit proliferation and inflammation release in PBMCs from IgAN patients.

Metabolic Dysfunctions of Intestinal Fatty Acids and Tryptophan Reveal Immuno-Inflammatory Response Activation in IgA Nephropathy

BACKGROUND

Immunoglobulin A nephropathy (IgAN) is the most common form of primary glomerulonephritis. Although an important link between intestinal metabolites and immune activity is widely established, the metabolic profile of IgAN is still poorly understood, which severely limits the mechanistic studies and therapy of IgAN.

METHODS

The diversity of intestinal flora and relative abundance of metabolites in IgAN patients and healthy subjects were measured by 16s ribosomal RNA gene sequencing combined with liquid chromatography tandem-mass spectrometry. The levels of serum Gd-IgA1, IL-6, IL-10, IL-22, and TNF-a were tested by ELISA. We employed the tryptophan-targeted UHPLC-MRM-MS approach to assess the content of tryptophan metabolites quantitatively.

RESULTS

Intestinal fatty acid levels, mainly unsaturated fatty acids, were observed to be dramatically decreased in IgAN patients. Disorders in linoleic acid and arachidonic acid metabolism, metabolic imbalances of anti-/pro- inflammatory fatty acid metabolites, and intestinal AhR signaling deficiency might reflect the damage of the intestinal mucosal barrier in IgAN patients. In addition, we found that high levels of Gd-IgA1, IL-22, and TNF-α were associated with the activity of the tryptophan-kynurenine metabolic pathway, as well as lower levels of 3-indolepropionic acid. 3-indolepropionic acid, kynurenine, and indoleacrylic acid had synergistic effects on regulating immuno-inflammatory responses in IgAN patients.

CONCLUSIONS

The metabolic characteristic of fatty acids and tryptophan in the intestinal system is disturbed in IgAN patients, leading to active immune-inflammatory reactions.

Th1 Cytokines Signature in 2 Cases of IgA Nephropathy Flare after mRNA-Based SARS-CoV-2 Vaccine: Exploring the Pathophysiology

mRNA-based vaccines have dramatically shifted the course of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. IgA nephropathy (IgAN) flare is the most reported renal adverse effect after the administration of these vaccines. Unraveling the mechanistic pathways leading to these flares is necessary to confirm a causal association. Herein, we report 2 cases of IgAN flare after SARS-CoV-2 vaccination in patients previously diagnosed with IgAN. We describe and compare the clinical and analytical features of the disease at the time of the diagnostic with the post-vaccine flare. In addition, we obtained serum and urine of these patients at the moment of the flare and determined the levels of IL-2, TNF-α, and IFNγ using a multiplex bead-based assay. As diseased controls, we included n = 13 patients diagnosed with IgAN who had available serum and urine samples at the moment of the diagnostic stored in our biobank. We also included 6 healthy controls. Compared to the first episode, postvaccination flares were more severe in terms of peak serum creatinine, albuminuria, and urinary erythrocyte count. The histological lesions found at the biopsy performed during the post-vaccine flare were similar to those found at the diagnostic. One of the patients who suffered a post-vaccine flare showed increased serum IL-2 and TNFα compared to the IgAN-diseased controls and the healthy controls. In conclusion, although several cases of post-vaccine IgAN flares have been reported, there are no mechanistic studies on the occurrence of these flares. We here suggest that hyperactivation of the Th1 pathway may be involved, but larger studies with more refined methods for numerical and functional Th1 lymphocytes evaluation are required.

Pathogenesis of IgA Vasculitis: An Up-To-Date Review

Immunoglobin A (IgA) vasculitis (IgAV), formerly called the Henoch-Schönlein purpura (HSP), is a small vessel vasculitis, characterized by IgA1-dominant immune deposition at diseased vessel walls. IgAV is the most common form of vasculitis in children; typical symptoms include palpable purpura, arthritis or arthralgia, abdominal pain, and hematuria or proteinuria. Galactose-deficient IgA1 is detected in the tissues of the kidney and skin in patients with IgAV; it forms immune complexes leading to subsequent immune reactions and injuries. This report provides the recent advances in the understanding of environmental factors, genetics, abnormal innate and acquired immunity, and the role of galactose-deficient IgA1 immunocomplexes in the pathogenesis of IgAV.