Fibroblast reticular cells engineer a blastema extracellular network during digit tip regeneration in mice

ECM network associated with different tissues and represent a subset of loose connective tissue fibroblasts. During blastema formation there is an upregulation of matrix production that returns to its pre-existing level and anatomical pattern in the endpoint regenerate. Co-localization studies demonstrate a strong spatial correlation between the ER-TR7 antigen and collagen type III (COL3) in histological sections. ER-TR7 and COL3 are co-induced in cultured digit fibroblasts following treatment with tumor necrosis factor alpha and a lymphotoxin beta receptor agonist. These results provide an initial characterization of the ECM during digit regeneration and identify a subpopulation of fibroblasts involved in producing the blastema provisional matrix that is remodeled during the regeneration response.