The tendon interfascicular basement membrane provides a vascular niche for CD146+cell subpopulations

Marr, Neil, Zamboulis, Danae EE ORCID: 0000-0003-2839-7620, Werling, Dirk, Felder, Alessandro AA, Dudhia, Jayesh, Pitsillides, Andrew AA and Thorpe, Chavaunne TT (2023) The tendon interfascicular basement membrane provides a vascular niche for CD146+cell subpopulations. FRONTIERS IN CELL AND DEVELOPMENTAL BIOLOGY, 10. 1094124-.

Access the full-text of this item by clicking on the Open Access link.

Official URL: http://dx.doi.org/10.3389/fcell.2022.1094124

Abstract

Introduction: The interfascicular matrix (IFM; also known as the endotenon) is critical to the mechanical adaptations and response to load in energy-storing tendons, such as the human Achilles and equine superficial digital flexor tendon (SDFT). We hypothesized that the IFM is a tendon progenitor cell niche housing an exclusive cell subpopulation. Methods: Immunolabelling of equine superficial digital flexor tendon was used to identify the interfascicular matrix niche, localising expression patterns of CD31 (endothelial cells), Desmin (smooth muscle cells and pericytes), CD146 (interfascicular matrix cells) and LAMA4 (interfascicular matrix basement membrane marker). Magnetic-activated cell sorting was employed to isolate and compare in vitro properties of CD146+ and CD146- subpopulations. Results: Labelling for CD146 using standard histological and 3D imaging of large intact 3D segments revealed an exclusive interfascicular cell subpopulation that resides in proximity to a basal lamina which forms extensive, interconnected vascular networks. Isolated CD146+ cells exhibited limited mineralisation (osteogenesis) and lipid production (adipogenesis). Discussion: This study demonstrates that the interfascicular matrix is a unique tendon cell niche, containing a vascular-rich network of basement membrane, CD31+ endothelial cells, Desmin+ mural cells, and CD146+ cell populations that are likely essential to tendon structure and/or function. Contrary to our hypothesis, interfascicular CD146+ subpopulations did not exhibit stem cell-like phenotypes. Instead, our results indicate CD146 as a pan-vascular marker within the tendon interfascicular matrix. Together with previous work demonstrating that endogenous tendon CD146+ cells migrate to sites of injury, our data suggest that their mobilisation to promote intrinsic repair involves changes in their relationships with local interfascicular matrix vascular and basement membrane constituents.

Item Type:	Article
Uncontrolled Keywords:	basement membrane, CD146, interfascicular matrix, tendon, tendon progenitors
Divisions:	Faculty of Health and Life Sciences Faculty of Health and Life Sciences > Institute of Life Courses and Medical Sciences
Depositing User:	Symplectic Admin
Date Deposited:	14 Feb 2024 11:20
Last Modified:	14 Feb 2024 11:21
DOI:	10.3389/fcell.2022.1094124
Open Access URL:	https://doi.org/10.3389/fcell.2022.1094124
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3178648