SOCS1 Regulates Apoptosis and Inflammation by Inhibiting IL-4 Signaling in IL-1β-Stimulated Human Osteoarthritic Chondrocytes

Figure 2

Knockdown of SOCS1 increased cell viability and inhibited apoptosis in IL-1β-stimulated human osteoarthritic chondrocytes transfected with and without siIL-4. The expression of SOCS1 at the protein and mRNA levels was detected by Western blotting (a) and RT-PCR (b), respectively, after transfection of SOCS1 siRNA or the negative control. IL-1β: human osteoarthritic chondrocytes were stimulated with 10 ng/ml IL-1β for 24 h (); IL-1β + siCtrl: human osteoarthritic chondrocytes were transfected with the negative control siRNA after stimulation with IL-1β (); IL-1β + siSOCS1: human osteoarthritic chondrocytes were transfected with SOCS1 siRNA after stimulation with IL-1β (). versus IL-1β. Cell viability was measured using cell counting kits (c). Cell apoptosis was detected by flow cytometry using an Annexin V-FITC/PI Apoptosis Detection Kit (d). The expression levels of caspase 9 (e) and Bax/Bcl-2 (f), which are hallmarks of cell apoptosis, were detected using Western blotting. IL-1β: 10 ng/ml IL-1β stimulation for 24 h (); siSOCS1: transfection with SOCS1 siRNA (); siIL-4: transfection with IL-4 siRNA (); “−”: no added, “+”: added. versus no addition, versus no addition, versus only added IL-1β, versus only added IL-1β, .

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