Transcriptional control of chondrocyte fate and differentiation

Chondrogenesis is an essential process in vertebrates. It leads to the formation of cartilage growth plates, which drive body growth and have primary roles in endochondral ossification. It also leads to the formation of permanent cartilaginous tissues that provide major structural support in the articular joints and respiratory and auditory tracts throughout life. Defects in chondrogenesis cause chondrodysostoses and chondrodysplasias. These skeletal malformation diseases account for a significant proportion of birth defects in humans and can dramatically affect a person's expectancy and quality of life. Chondrogenesis occurs when pluripotent mesenchymal cells commit to the chondrocyte lineage, and through a series of differentiation steps build and eventually remodel cartilage. This review summarizes and discusses our current knowledge and lack of knowledge about the chondrocyte differentiation pathway, from mesenchymal cells to growth plate and articular chondrocytes, with a main focus on how it is controlled by tissue patterning and cell differentiation transcription factors, such as, but not limited to, Pax1 and Pax9, Nkx3.1 and Nkx3.2, Sox9, Sox5 and Sox6, Runx2 and Runx3, and c-Maf.