Regional transcriptomics and mechanical properties of rat Achilles tendons

The transcriptome of different tendons varies based on anatomical location and is likely influenced by the biomechanical loading environment. While differences in biologic and mechanical properties of whole tendons have been assessed, less is understood about differences within a tendon along its proximal-distal axis. Therefore, our objective was to determine the characteristics of and relationship between the transcriptomes and mechanical properties of a single tendon. Since Achilles tendon injuries are among the most frequent and debilitating tendon disorders, and rats are classically used as a small animal model to study tendon biology and injury, we selected Achilles tendons from two-month-old male Sprague-Dawley rats. We then used RNA sequencing (RNAseq) and biomechanical testing to evaluate three regions – proximal, middle, and distal – to develop a comprehensive understanding of the biologic and functional properties of tendons along their proximal-distal axis.