[Study of the role of miRNA in mesenchymal stem cells isolated from osteoarthritis patients].

OBJECTIVE MiRNAs act as gene silencers that are involved in the regulation of essential cell functions. miR-335 is involved in regulating cell differentiation processes in progenitor cells. Mesenchymal stem cells (MSCs) are progenitor cells of chondrocytes and osteoblasts responsible for homeostatic maintenance of cartilage and bone. The aim of this study was to determine a possible relationship between the expression of miR-335 and osteoarthritis. METHODS MSCs obtained from the bone marrow of 3 osteoarthritic patients and 3 controls with no clinical signs of osteoarthritis or osteoporosis were cultured and phenotypically and functionally characterised in a 3-step culture. Expression levels of miR-335 and the mesoderm-specific transcript gene -MEST- that controls its expression were determined by quantitative PCR. RESULTS Differences in the expression levels of miR-335 and MEST (median [interquartile range]: 1.69 [0.85-1.74], and 3.85 [3.20-5.67] were detected between MSCs isolated from patients with osteoarthritis and controls. Although the differences detected did not reach statistical significance (P=.1), a clear trend towards lower expression of miR-335 in osteoarthritis MSCs was observed. CONCLUSIONS Given that miR-335 has the different genes involved in the Wnt signalling pathway as potential targets, the observed trend may help to ascertain, at least partially, some of the alterations which determine the onset or progression of osteoarthritis, and can therefore serve for the design of future therapeutic targets for the treatment of this disease.