Yongfei Fang

Introduction: Antimicrobial peptides (AMPs) are promising candidates for combating multidrug-resistant infections, but their clinical application is often limited by challenges such as poor selectivity and high cytotoxicity. This study aimed to optimize the therapeutic potential of brevinin-1pl, a frog-derived AMP with broad-spectrum antimicrobial and anticancer activities.Methods: Major experimental approaches encompassed antibacterial activity evaluation, hemolytic potential assessment, bactericidal rate determination via time-kill kinetics, SYTOX Green-based membrane integrity analysis, and MTT assays for anti-proliferative effects.Results: Substitutions with arginine (brevinin-1pl-2R and brevinin-1pl-5R) enhanced activity against Gram-positive bacteria but reduced efficacy against Gram-negative strains. Lysine substitution (brevinin-1pl-6K) decreased activity against Gram-positive bacteria due to reduced hydrophobicity. In contrast, histidine substitution (brevinin-1pl-3H) showed diminished activity against Gram-negative bacteria (e.g., MRSA MIC increased from 2 µM to 4 µM) but reduced hemolysis, indicating improved selectivity. Mechanistic studies using SYTOX green assays confirmed membrane disruption as a primary mode of action, while suggesting alternative mechanisms for Gram-positive Enterococcus faecium and Gram-negative Escherichia coli. The brevinin-1pl and its analogues demonstrated significant inhibitory efficacy against both MCF-7 breast cancer cells and H838 non-small cell lung cancer cells at a concentration of 10^–4 M. Notably, brevinin-1pl-3H exhibited low cytotoxicity toward normal HaCaT cells despite its high hydrophobicity, suggesting potential for dermatological applications.Conclusion: These findings demonstrate that strategic amino acid substitutions can optimize the therapeutic potential of AMPs, offering a promising approach to develop peptides with enhanced efficacy and reduced clinical side effects.

Genetics alone cannot explain most cases of rheumatoid arthritis (RA). Thus, investigating environmental factors such as the gut microbiota may provide new insights into the initiation and progression of RA. In this study, we performed 16S rRNA sequencing to characterise the gut microbiota of DBA1 mice that did or did not develop arthritis after induction with collagen. We found that divergence in the distribution of microbiota after induction was pronounced and significant. Mice susceptible to collagen-induced arthritis (CIA) showed enriched operational taxonomic units (OTUs) affiliated with the genus Lactobacillus as the dominant genus prior to arthritis onset. With disease development, the abundance of OTUs affiliated with the families Bacteroidaceae, Lachnospiraceae, and S24-7 increased significantly in CIA-susceptible mice. Notably, germ-free mice conventionalized with the microbiota from CIA-susceptible mice showed a higher frequency of arthritis induction than those conventionalized with the microbiota from CIA-resistant mice. Consistently, the concentration of the cytokine interleukin-17 in serum and the proportions of CD8+T cells and Th17 lymphocytes in the spleen were significantly higher in the former group, whereas the abundances of dendritic cells, B cells, and Treg cells in the spleen were significantly lower. Our results suggest that the gut microbiome influences arthritis susceptibility.

MicroRNA (miRNA)-mediated gene silencing at the translational level has led to novel discoveries for numerous biological processes. Recently, there has been increasing evidence to indicate that miRNAs are involved in normal immune functions and inflammation. In this review, we focus on recent advances that have elucidated the role of miRNAs in B-cell development, differentiation, apoptosis and function. While the regulatory mechanisms of miRNAs in controlling and maintaining B-cell fate remain largely uncharacterized, further studies on miRNAs and their targets will increase our understanding of B-cell development and function. Such studies may be able to provide new therapeutic strategies for treating autoimmune diseases.

To analyze the Chinese medical syndrome typing laws in rheumatoid arthritis (RA) patients of the dampness-heat impeding syndrome and the cold-dampness impeding syndrome. Clinical data and serum of 322 inpatients and outpatients were collected to perform DAS28 score. Laboratory indices including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), albumin (ALB), globulin (GLB), and blood routines (white blood cell, red blood cell, and platelet) were tested by conventional methods, and the serum levels of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta were detected by ELISA. The difference of each index was analyzed between RA patients of the dampness-heat impeding syndrome and the cold-dampness impeding syndrome. The levels of DAS28 scores, ESR, CRP, white blood cell count, and platelet of RA patients of the dampness-heat impeding syndrome were significantly higher than those of the cold-dampness impeding syndrome (P ESR >CRP >GLB > PLT >WBC (P<0.01). Compared with the cold-dampness impeding syndrome, only ALB was of diagnostic value for cold-dampness impeding syndrome and the AUC was 0.636 (P = 0.000). DAS28 score, ESR, CRP, PLT, WBC, GLB, and ALB could be used as objective index in identifying the differences between the dampness-heat impeding syndrome and the cold-dampness impeding syndrome in RA patients.

Introduction: Increasing evidence indicates that microRNAs (miRNAs) play a critical role in the pathogenesis of inflammatory diseases. The aim of the study was to investigate the expression pattern and function of miRNAs in CD4⁺ T cells from patients with rheumatoid arthritis (RA). Methods: The expression profile of miRNAs in CD4⁺ T cells from synovial fluid (SF) and peripheral blood of 33 RA patients was determined by microarray assay and validated by qRT-PCR analysis. The correlation between altered expression of miRNAs and cytokine levels was determined by linear regression analysis. The role of miR-146a overexpression in regulating T cell apoptosis was evaluated by flow cytometry. A genome-wide gene expression analysis was further performed to identify miR-146a-regulated genes in T cells. Results: miRNA expression profile analysis revealed that miR-146a expression was significantly upregulated while miR-363 and miR-498 were downregulated in CD4⁺ T cells of RA patients. The level of miR-146a expression was positively correlated with levels of tumor necrosis factor-alpha (TNF-α), and in vitro studies showed TNF-α upregulated miR-146a expression in T cells. Moreover, miR-146a overexpression was found to suppress Jurkat T cell apoptosis. Finally, transcriptome analysis of miR-146a overexpression in T cells identified Fas associated factor 1 (FAF1) as a miR-146a-regulated gene, which was critically involved in modulating T cell apoptosis. Conclusions: We have detected increased miR-146a in CD4⁺ T cells of RA patients and its close correlation with TNF-α levels. Our findings that miR-146a overexpression suppresses T cell apoptosis indicate a role of miR-146a in RA pathogenesis and provide potential novel therapeutic targets.