Leptin-induced BMP-2 mRNA expression is mediated by JAK2-ERK1/2 signaling in human primary chondrocytes.

<p>(<i>A</i>) Cells were kept as controls or treated with leptin for 10’, 30’, 1, 4, and 8 h, and the phosphorylations of JAK1/2 and ERK1/2 were determined by Western blot. (<i>B</i>-<i>D</i>) Cells were transfected with (<i>B</i>-<i>C</i>) JAK1- or JAK2-specific siRNA or (<i>D</i>) ERK1- or ERK2-specific siRNA and then kept as controls or treated with leptin for 4 h. (<i>B</i>) The phosphorylation of ERK1/2 was determined by Western blot and (<i>C</i>-<i>D</i>) the BMP-2 mRNA expression was determined by real-time PCR. Results in (<i>A</i>) and (<i>B</i>) are representative of three independent experiments with similar results. Data in (<i>C</i>) and (<i>D</i>) are mean ± SEM from three independent experiments. *, <i>P</i> < 0.05 <i>vs</i>. siCL/control or untreated cells. #, <i>P</i> < 0.05 <i>vs</i>. siCL/leptin-treated cells.