Scleraxis is required for the growth of adult tendons in response to mechanical loading.



Gumucio, Jonathan P, Schonk, Martin M, Kharaz, Yalda A, Comerford, Eithne ORCID: 0000-0002-5244-6042 and Mendias, Christopher L
(2020) Scleraxis is required for the growth of adult tendons in response to mechanical loading. JCI insight.

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Abstract

Scleraxis is a basic helix-loop-helix transcription factor that plays a central role in promoting tenocyte proliferation and matrix synthesis during embryonic tendon development. However, the role of scleraxis in the growth and adaptation of adult tendons is not known. We hypothesized that scleraxis is required for tendon growth in response to mechanical loading, and that scleraxis promotes the specification of progenitor cells into tenocytes. We conditionally deleted scleraxis in adult mice using a tamoxifen-inducible Cre-recombinase expressed from the Rosa26 locus (ScxΔ), and then induced tendon growth in Scx+ and ScxΔ adult mice via plantaris tendon mechanical overload. Compared to the wild type Scx+ group, ScxΔ mice demonstrated blunted tendon growth. Transcriptional and proteomic analyses revealed significant reductions in cell proliferation, protein synthesis, and extracellular matrix genes and proteins. Our results indicate that scleraxis is required for mechanically-stimulated adult tendon growth by causing the commitment of CD146+ pericytes into the tenogenic lineage, and by promoting the initial expansion of newly committed tenocytes and the production of extracellular matrix proteins.

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 05 Jun 2020 10:29
Last Modified: 16 Dec 2021 15:10
DOI: 10.1172/jci.insight.138295
URI: https://livrepository.liverpool.ac.uk/id/eprint/3089565