While diabetes mellitus has been identified by the research as a risk factor for knee osteoarthritis, still the primary mechanisms have not been understood fully. It is suggested by studies that Toll-like receptor 4 expressions are raised in osteoarthritic lesions of osteoarthritis patients & in target tissues of insulin resistance like adipose tissue & skeletal muscle in patients with diabetes mellitus. The toll-like receptor is linked with inflammation & catabolic response through regulation of matrix metalloproteases. We hypothesized that Toll-like receptor 4 and matrix metalloprotease expression might be raised in the synovial tissue of knee osteoarthritis patients with diabetic pathology. Hence we investigated Toll-like receptor 4 and matrix metalloproteases expression in the synovial tissue of knee osteoarthritis patients with & without high hemoglobin A1C concentrations.
For the research, A total of 171 patients radiographically diagnosed with knee osteoarthritis were grouped based on their Hemoglobin A1C concentration (HbA1c <6.5 and HbA1c ≥6.5). We employed real-time polymerase chain reaction to make a comparison of the expression of TLRs (TLR2, TLR4) & MMPs (MMP2, MMP3, MMP9, and MMP13) in patients’ synovial tissue between the 2 groups. MMP13 regulation by the Toll-like receptor 4 ligands, lipopolysaccharide, in synovial tissue cells was examined in culture by stimulating synovial tissue cells with lipopolysaccharide or vehicle as a culture medium for 24 hours.
The expression of Toll-like receptor 4 & MMP13 in the HbA1c ≥6.5 group was considerably raised as compared to that in the HbA1c <6.5 group. On the contrary, TLR2, MMP2, MMP3 & MMP9 expression levels were similar between the groups.
Hence it can be concluded that Toll-like receptor 4 & MMP13 expression were raised in the synovium of osteoarthritis patients with high Hemoglobin A1c concentrations. Our results might provide insight into the pathology of osteoarthritis patients with diabetes mellitus.