Author: Giacomo Cafaro
Borrego-Yaniz et al (OP0102) performed a genome-wide association study in a cohort of 3,498 giant cell arteritis patients and identified three new loci associated with the disease: MFGE8 (lactadherin), VTN (vitronectin), and CCDC25 (receptor for neutrophil extracellular traps). Additionally, drug repurposing analysis identified the vitronectin antagonist abciximab as a potential drug to be tested.
Bruckner et al (POS1031) created a chimeric human/mouse model by implanting a piece of human cartilage surrounded by rheumatoid arthritis (RA) synovial fibroblasts (RASF) on SCID mice and found that injection of human mesenchymal stem cells derived from gingival tissue or their exosomes was able to reduce the invasiveness and migration of RASF, representing a potential treatment for RA.
Jara et al (POS0819) investigated the concentration of the primary miRNA (pri-miRNA)-145-5p in salivary gland tissue of Sjogren’s syndrome patients and found increased levels, suggesting accumulation due to deficient processing. Its levels correlated with interferon I score, representing an area for additional investigation to understand a potential pathogenic role in the disease.
Li et al (POS0329) performed single-cell RNA sequencing on hand articular cartilage from patients with osteoarthritis (OA) and healthy controls. 13 cellular sub-populations were identified. They found significant enrichment of ferroptosis pathways in two cell subpopulations from OA tissue compared to controls, with higher expression of the gene FHT1. These data suggest iron metabolism may be a potential target for new drug investigation.
Tzemach et al (OP0110) investigated myeloid cells in psoriatic arthritis (PsA) synovial fluid and found, among other results, an enrichment of a cluster of conventional dendritic cells (cDC)2 in patients non responding to bDMARDs, along with a cluster of cDC1 cells expressing inhibitory genes, typical of severely refractory patients.
Raimondo et al (OP0106) employed a transgenic IL-23 overexpression mouse model of psoriasis expressing a photoconvertible fluorescent reporter, to evaluate cell trafficking from skin to other tissues and found CD2+ MCHII+ monocytes as the main cells escaping skin tissue and invading synovium. Their fate, however, could either be towards pro-inflammatory or anti-inflammatory macrophages, depending on the synovial mileu, further supporting the concept of tissue-directed inflammation.
Natoli et al (OP0100) investigated the DNA methylation pattern of peripheral blood CD4+ T cells from patients with PsA, psoriasis and heatlhy controls. They were able to accurately tell the three conditions apart solely by the characteristics of the DNA methylation signatures, suggesting a potential application in terms of patient stratification and prediction of disease evolution.
ABOUT THE AUTHOR
Giacomo is Assistant Professor and Consultant Rheumatologist at the Rheumatology Unit of the University of Perugia, Italy.
He was PARTNER fellow at the Institute of Infection, Immunity and Inflammation at the University of Glasgow, working on stromal immunology in tendinopathy and PsA.
His main research interests are T cell biology in autoimmune diseases, psoriatic arthritis, Sjögren’s syndrome and ultrasound in rheumatology. Giacomo is a member of the Newsletter sub-committee