Monocarboxylate Transporter 4: A Potential Therapeutic Target in Refractory Rheumatoid Arthritis (360G-Wellcome-211962_Z_18_Z)

Rheumatoid Arthritis (RA) occurs as a complex set of interactions between adaptive and innate immune cells and stromal fibroblasts. Using mouse models of RA we have previously shown that tissue fibroblasts can both promote inflammation and tissue repair. Using a combination of immunohistochemistry, multi-parameter cytometry and single cell RNAseq of both primary human biopsy material and mouse RA models we have identified three different populations of fibroblasts, inflammation lining fibroblasts, resolving sub-lining fibroblasts and pericytes. From analysis of gene expression signatures on these different tissue fibroblast populations we have identified difference in metabolic function. One of key proteins we have identified that is up regulated in inflammatory joint fibroblasts is the monocarboxylate transporter 4 (mct4) which has a key role in the export of lactate resulting from glycolysis. This receptor has been shown to a have a key role in cancer metabolism and disease progression which has lead to the development and clinical trial of high affinity inhibitors. The aim of this project will be to further characterise mct4 expression and function in rheumatoid arthritis fibroblasts using gene expression, immunohistochemistry and functional assays to determine if a mct4 inhibitor could potentially make a novel treatment for treatment refractory rheumatoid arthritis.