Methylsulfonylmethane (MSM) enhances growth hormone (GH) signaling via Jak2/STAT5b activation in osteoblast-like cells.

<p>(A) Jak2 was immunoprecipitated with anti-Jak2 antibody from whole cell extracts of UMR 106 cells left untreated or pretreated with 30 nM GH for 2 h followed by MSM for 24 h. Jak2 precipitation and the phosphorylation status of Jak2 were analyzed by Western blotting with anti-Jak2 and anti-phosphotyrosine (4G10) antibodies. (B) The relative levels of Jak2 phosphorylation were determined using densitometric analysis and normalized to the amount of Jak2. (C) UMR-106 cells were incubated with 50 µM AG490 for 4 h, then left untreated or pretreated with 30 nM GH for 2 h followed by MSM for 24 h. STAT5b precipitation and the phosphorylation status of the precipitated STAT5b were analyzed by Western blot with anti-STAT5b and 4G10 antibodies. This picture is representative of three independent experiments. Data shown are representative of three independent experiments. Asterisks indicate a statistically significant increase by t-test (***p<0.001).