Anterior cruciate ligament-derived mesenchymal stromal cells have a propensity to differentiate into the ligament lineage

Yusuke Ogata; Yo Mabuchi; Kosuke Shinoda; Yuta Horiike; Mitsuru Mizuno; Koji Otabe; Eriko Grace Suto; Nobuharu Suzuki; Ichiro Sekiya; Chihiro Akazawa

doi:10.1016/j.reth.2017.12.001

Anterior cruciate ligament-derived mesenchymal stromal cells have a propensity to differentiate into the ligament lineage

Regen Ther. 2018 Jan 23:8:20-28. doi: 10.1016/j.reth.2017.12.001. eCollection 2018 Jun.

Authors

Affiliations

¹ Department of Biochemistry and Biophysics, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
² Center for Stem Cell and Regenerative Medicine, Tokyo Medical and Dental University, Tokyo, Japan.

Abstract

Introduction: The anterior cruciate ligament (ACL) consists of various components, such as collagen, elastin fibres, and fibroblasts. Because ACL has a poor regenerative ability, ACL reconstruction need require the use of autologous tendons. In recent years, tissue-resident stem cells have been studied to promote ACL regeneration as an alternatively method. However, the existence of stem cells in ligaments has not been clearly defined. Here, we prospectively isolated stem cells from ACLs and characterized their properties.

Methods: ACLs from 11 donors and bone marrows (BM) from 8 donors were obtained with total knee arthroplasty. We used flow cytometry to screen the cell surface markers on ACL cells. Frozen sections were prepared from patient ACL tissues and stained with specific antibodies. Cultured ACL-derived and BM-derived cells at passage 3 were differentiated into adipocytes, osteoblasts and tendon/ligament cells.

Results: ACL-derived mesenchymal stem/stromal cells (ACL-MSCs) expressed high levels of CD73 and CD90. Immunohistochemical analyses revealed that ACL-MSCs were located on the inner surface of ACL sinusoids. Furthermore, the expression of cell surface antigens was clearly different between ACL-MSCs and bone marrow (BM)-derived MSCs (BM-MSCs) at the time of isolation, but the two cell populations became indistinguishable after long-term culture. Interestingly, ACL-MSCs are markedly different from BM-MSCs in their differentiation ability and have a high propensity to differentiate into ligament-committed cells.

Conclusions: Our findings suggest that ACL-MSCs express CD90 and CD73 markers, and their differentiation capacity is maintained even through culture. The cell population having tissue-specific properties is an important research target for investigating the ligament therapies.

Keywords: ACL, anterior cruciate ligament; Anterior cruciate ligament; BM, bone marrow; BMP, bone morphogenic protein; Bone marrow; Cell surface marker; Differentiation; FACS, fluorescence-activated cell sorting; MKX, transcription factor Mohawk; MSC, mesenchymal stem/stromal cell; Mesenchymal stem/stromal cell; Regeneration therapy.