Accelerated flexor tendon repair in superhealer mice reflects alterations in TGFB1 regulated expression programs linked to inflammatory, fibrosis and cell cycle control

Purpose: The goal of this study is to compare transcriptional profiles of flexor tendon healing in wild-type (WT, C57Bl/6J) to superhealer (MRL/MpJ) miceto gain insights in the biological drivers of the tendon injury response between the C57 and MRL mice. Methods: RNA was isolated from patially lacerated or uninjured flexor tendon 7 days post-injury. Results: Transcriptional analysis of biological drivers showed positive enrichment of TGFB1 in both C57 and MRL healing tendons. only MRL tendons exhibited downstream transcriptional effects of cell cycle regulatory genes, with negative enrichment of the cell senescence-related regulators, compared to the positively-enriched inflammatory and ECM organization pathways in the C57 tendons. Conclusions: There is altered TGFB1 regulated inflammatory, fibrosis, and cell cycle pathways in flexor tendon repair. Tendon mRNA profiles of 7 days post-injury with C57Bl/6J and MRL/MpJ mice