Role of Hox genes in stem cell differentiation
摘要
Hox genes are an evolutionary highly conserved genefamily. They determine the anterior-posterior body axisin bilateral organisms and influence the developmentalfate of cells. Embryonic stem cells are usually devoidof any Hox gene expression, but these transcriptionfactors are activated in varying spatial and temporalpatterns defining the development of various bodyregions. In the adult body, Hox genes are among othersresponsible for driving the differentiation of tissuestem cells towards their respective lineages in order torepair and maintain the correct function of tissues andorgans. Due to their involvement in the embryonic andadult body, they have been suggested to be useable forimproving stem cell differentiations in vitro and in vivo .In many studies Hox genes have been found as drivingfactors in stem cell differentiation towards adipogenesis,in lineages involved in bone and joint formation, mainlychondrogenesis and osteogenesis, in cardiovascularlineages including endothelial and smooth muscle celldifferentiations, and in neurogenesis. As life expectancyis rising, the demand for tissue reconstruction continuesto increase. Stem cells have become an increasinglypopular choice for creating therapies in regenerativemedicine due to their self-renewal and differentiationpotential. Especially mesenchymal stem cells are usedmore and more frequently due to their easy handlingand accessibility, combined with a low tumorgenicityand little ethical concerns. This review therefore intendsto summarize to date known correlations betweennatural Hox gene expression patterns in body tissuesand during the differentiation of various stem cellstowards their respective lineages with a major focus onmesenchymal stem cell differentiations. This overviewshall help to understand the complex interactions of Hoxgenes and differentiation processes all over the bodyas well as in vitro for further improvement of stem celltreatments in future regenerative medicine approaches.