Microarray profile of p62P392L-regulated gene expression in RANKL and M-CSF stimulated normal human bone marrow derived non-adherent cells

Paget’s disease of bone (PDB) is a chronic focal skeletal disorder that affects 2-3% of the population over the age of 60. PDB is inherited as an autosomal dominant trait with genetic heterogeneity. SQSTM1/p62 UBA domain mutation (p62P392L) is widely identified in PDB and has been shown to increase osteoclastogenesis. Further, environmental factors such as paramyxovirus are implicated in PDB and MVNP has been shown to induce Pagetic phenotype in osteoclasts. However, the molecular mechanisms underlying p62P392L and MVNP stimulation of osteoclast differentiation in PDB are unclear. We therefore determined p62P392L regulated gene expression profiling during osteoclast differentiation. We identified 9.7% genes were upregulated (> 4-fold) in p62P392L transduced cells. P62P392L mutant increased Integrin β3 (185 fold), integrin β5 (26 fold), IL-1α (11 fold), IL-6R (8 fold), CXCL-2 (7.5 fold), CXCL-3 (5 fold) compared to p62WT transduced cells. Furthermore, bone marrow mononuclear cells derived from patients with PDB showed high levels of SIRPβ1 mRNA expression compared to normal subjects. Thus, p62P392L mutant regulated gene expression profiling during osteoclast differentiation provides new insights into molecular mechanisms and therapeutic targets to control elevated osteoclast activity in PDB. Total RNA isolated from normal human bone marrow mononuclear cells transduced with p62EV, p62WT, p62P392L retroviral expression vectors and stimulated with M-CSF and RANKL for 48 h were subjected to Agilent microarray (~26,000 genes) analysis. One replicate per treatment was hybridized.