Immortalized Human Rheumatoid Arthritis Fibroblast-Like Synoviocytes-hTERT

Constructing A 3D Co-Culture In Vitro Synovial Tissue Model for Rheumatoid Arthritis Research

The development and exploration of highly effective drugs for rheumatoid arthritis remains urgent. However, existing disease research models are unable to meet the rapid development needs of high-throughput drug screening. In this study, bacterial cellulose (BC) simulating the structure of extracellular matrix was used as a 3D culture platform, and THP-1-derived M1 macrophages, representing the inflammatory component, human umbilical vein endothelial cells (HUVECs), simulating the vascular component, and rheumatoid arthritis fibroblast-like synoviocytes (RA-FLSs), embodying the synovial pathology, were co-cultured to simulate the pathological microenvironment in RA synovial tissues, and synovial organoids were constructed.

Compared to planar cultures and 2D co-cultures, 3D synovial organoids not only exhibit a broader range of transcriptomic features characteristic of rheumatoid arthritis but also demonstrate increased drug resistance, likely due to the more complex and physiologically relevant cell-cell and cell-matrix interactions present in 3D environments. This model offers a promising path for personalized treatment, accelerating precision medicine in rheumatology.

Hsa-miR-21-5p Affects Multiple Pathogenic Factors Associated With Fibroblast-Like Synoviocytes in Rheumatoid Arthritis

Fibroblast-like synoviocytes (FLS) contribute significantly to the pathogenesis of rheumatoid arthritis (RA), particularly through their roles in synovitis and joint destruction. The microRNAs (miRNAs) are short non-coding RNA that regulate gene expression post-transcriptionally. Although more than 2000 human miRNAs are registered, comprehensive analyses of miRNA expression in FLS are limited. Herein, we investigated the relationship between miRNAs and FLS.

Next-generation sequencing (small RNA-seq) was performed on primary cultured FLS derived from patients with RA to analyze the mature miRNA expression pattern. MiRNA mimics were transfected into FLS and an immortalized synovial fibroblast cell line, and validated using conventional RNA-seq. Out of 2861 mature miRNAs, 297 mature miRNAs were detected and intronic miRNAs were predominated. Notably, hsa-miR-21-5p was abundantly expressed and its expression was enhanced by IL-6 stimulation. MiR-21-5p mimic led to enhanced cell proliferation. These data suggest that hsa-miR-21-5p in FLS may exacerbate the pathophysiology of rheumatoid synovitis by promoting FLS proliferation, highlighting its potential as a therapeutic target in RA.