Dysregulated expression of genes involved in ER stress and chondrocyte differentiation.

<p><i>(A)</i> Immunofluorescent analysis for ATF4 in tibial epiphyseal cryosections from 2 week wildtype (<i>Wt</i>), <i>Xbp1</i>^{<i>CartΔEx2</i>}, <i>ColX</i>^<i>N617K</i> and <i>C/X</i> mice; B—Bone; HZ—Hypertrophic Zone; PZ—Proliferative Zone. <i>(B-H)</i> qPCR with primers specific for <i>(B) Chop</i>, <i>(C) Cebpb</i>, <i>(D) p57</i>^<i>Kip2</i>, <i>(E) Gadd45b</i>, <i>(F) Runx2</i>, <i>(G) Col10a1</i>, and <i>(H) Mmp13</i> on cDNA derived from <i>Wt</i>, <i>Xbp1</i>^{<i>CartΔEx2</i>}, <i>ColX</i>^<i>N617K</i> and <i>C/X</i> hypertrophic zone aRNA. Plots depict mean fold differences with standard deviation from the mean; N = 3; statistical analysis performed using Student’s <i>t</i> test, * <i>p</i> < 0.05, ** <i>p</i> < 0.01, *** <i>p</i> < 0.001, **** <i>p</i> < 0.0001. <i>(I)</i> Schematic diagram of proposed model to explain the molecular pathology of MCDS. Blue boxes depict genes. Red boxes depict biological processes. Green arrows depict activation or up-regulation. Red arrows depict inactivation or down-regulation. Green lines depict increased interaction between proteins. Red lines depict decreased interaction between proteins.