As indicated by its name, the CXXC5 plays a role as a transcription factor in the nucleus of cells, and involved in myelopoiesis, endothelial differentiation, vessel formation, and oligodendrocyte differentiation.[9][10][7]
The CXXC5 is also characterized as a negative feedback regulator of the Wnt/β-catenin signaling pathway functioning by direct interaction with the Dishevelled (Dvl) protein in the cytosol.[6][9][11][12][13] The cytosolic overexpression of CXXC5 was induced by several pathophysiological conditions, such as osteoporosis, alopecia, senescence of growth plate, cutaneous wound, and restoration of the suppressed Wnt/β-catenin signaling by blockade of its Dvl binding function improved the pathological features as observed in Cxxc5-/- mice.[9][12][13][14] These results indicate that the Dvl binding with cytosolic CXXC5 could be a target for the development of agents for treating alopecia, acute wound, and short stature in childhood and adolescence, which exhibit suppressed Wnt/β-catenin signaling by cytosolic CXXC5 overexpression of the responsible tissue cells.[11][13][15] The CXXC5-Dvl protein-protein interaction (PPI) as a target for development of agents in hair loss or acute wound was also confirmed by construction and testing the function of PTD-DBM, a peptide inhibiting the CXXC5-Dvl PPIl.[11][13]
The improvement of abnormalities by the CXXC5-Dvl PPI inhibitor is attributed to restoration of damaged tissues by activating the stem cells through restorative activation of the suppressed Wnt/β-catenin signaling and its target genes involving regeneration.
