Influence of global DNA-methylation on chondrogenic fate during digit development

Abstract Precise regulation of gene expression is of utmost importance during cell fate specification. DNA methylation is a key epigenetic mechanism that plays a significant role in gene expression regulation that recruits proteins involved in gene repression or inhibits the binding of transcription factors to DNA during cell commitment to regulate cell fate. Limb development is a well-established model for understanding cell fate decisions, and the formation of skeletal elements is coordinated through a sequence of events that control chondrogenesis spatiotemporally. It has been established that epigenetic control plays a crucial role in cartilage maturation. However, further investigation is required to determine its position in the earliest stages that direct cells to the chondrocyte lineage. This study investigates how the global DNA methylation environment affects cell fate divergence during the early chondrogenic events of the chondrocyte lineage. Our research has shown for the first time that inhibiting global DNA methylation in interdigital tissue with 5-azacytidine results in the formation of an ectopic digit. This discovery suggested that DNA methylation and demethylation dynamics could change the fate of cells that were supposed to die and redirect them toward chondrogenesis induction. Our vitro findings indicate that global DNA methylation is integral in regulating precartilage condensation formation by controlling cell proliferation, cell adhesion, and proapoptotic genes. As a result, the dynamics of methylation and demethylation are crucial in governing the development of chondrogenesis and cell death during digit formation.