Concomitant reduction of phosphorylation of LKB1 and AMPKα in mouse knee osteoarthritic cartilages. Mouse knee sections from surgical instability-induced osteoarthritis (OA) and the sham control at 8 weeks post surgery were analyzed for phosphorylation of liver kinase B1 (LKB1) and AMP-activated protein kinase alpha (AMPKα) by immunohistochemistry as described in Materials and methods. Cellularity of each section was confirmed with hematoxylin staining. Only the cells present in the noncalcified region of femoral and tibial cartilage were subjected to analysis. Cells staining positively for LKB1 and AMPKα were presented as percentage of cells stained for hematoxylin. Data representative of two individual experiments (n = 3 animals). *P <0.05 relative to the sham control.