RESUMEN
Objective@#This study investigated the effects of interleukin-1β (IL-1β) on human synovial fluid-derived mesenchymal stem cells (hSFMSCs) in the temporomandibular joint.@*Methods @#hSFMSCs from synovial fluid samples of temporomandibular disorder (TMD) patients were cultured in vitro. hSFMSCs were divided into three groups with different concentrations of rhIL-1β in complete medium (α-MEM cell culture medium + 10% FBS + 1× GlutaMAX): 0 ng/mL IL-1β group, 1 ng/mL IL-1β group and 10 ng/mL IL-1β group. Changes in the rate of colony formation, growth curve, cell cycle and apoptosis of hSFMSCs under IL-1β stimulation were evaluated. The osteogenic, adipogenic and chondrogenic potential of the cells were also determined using histochemical and real-time fluorescence quantitative PCR methods. @*Results @#No significant differences in growth or proliferation capacity were observed in any IL-1β-stimulated group in comparisons of the colony-formation rate (F = 0.665, P=0.548), growth curve (F=0.001, P=0.999), cell cycle (FG1=0.773, PG1=0.503; FS =0.636, PS =0.562) or apoptosis (F=0.196, P=0.827) of the cells. However, the multidifferentiation capacity of hSFMSCs was affected in the inflammatory environment. Mineralized nodule and lipid clusters decreased significantly, and the gene expression levels of runt-related transcription factor 2 (RUNX2), osteocalcin (OCN), peroxisomal proliferative receptor G2 (PPARG2) and lipoprotein lipase (LPL) were suppressed significantly in IL-1β-mediated induction medium (P < 0.05). In general, cartilage pellets formed in all the IL-1β-mediated chondrogenic differentiation groups. The gene levels of sex-determining region Y-related high-mobility group box-9 (SOX9) and collagen II were decreased (P < 0.05), while that of matrix metalloproteinase 13 (MMP13) was increased significantly in the presence of IL-1β (P < 0.05). @*Conclusion@# IL-1β directly affects the multidifferentiation potential of hSFMSCs but not their cell growth or proliferation ability.