Biomedical applications of muscle-derived stem cells: from bench to bedside

ABSTRACT

Introduction

Skeletal muscle-derived stem cells (Sk-MDSCs) are considered promising sources of adult stem cell therapy. Skeletal muscle comprises approximately 40–50% of the total body mass with marked potential for postnatal adaptive response, such as muscle hypertrophy, hyperplasia, atrophy, and regenerative capacity. This strongly suggests that skeletal muscle contains various stem/progenitor cells related to muscle-nerve-vascular tissues, which would support the above postnatal events even in adulthood.

Area covered

The focus of this review is the therapeutic potential of the Sk-MDSCs as an adult stem cell autograft. For this purpose, the validity of cell isolation and purification, tissue reconstitution capacity in vivo after transplantation, comparison of the results of basic mouse and preclinical human studies, potential problematic and beneficial aspects, and effective usage have been discussed following the history of clinical applications.

Expert opinion

Although the clinical application of Sk-MDSCs began as a therapy for the systemic disease of Duchenne muscular dystrophy, here, through the unique local injection method, therapy for severely damaged peripheral nerves, particularly the long-gap nerve transection, has been introduced. The beneficial aspects of the use of Sk-MDSCs as the source of local tissue transplantation therapy have also been discussed.

KEYWORDS:

• Autologous cell transplantation
• adult stem cells
• local cell injection treatment
• long-gap nerve injury
• peripheral nerve therapy
• nerve bridge

Article highlights

• A short history of the detection of skeletal muscle-derived stem cells (Sk-MDSCs) and their usefulness are summarized in the first two sections, ‘Introduction’ and ‘Reasons for the use of Sk-MDSCs’.

• The importance of the in vivo differentiation potential and a comparison of its capacity between mice and humans are discussed in the sections ‘In vivo differentiation potential’ and ‘Mouse to human’ in terms of the therapeutic applications of Sk-MDSCs.

• The history of satellite cell/myoblast (one of the Sk-MDSCs) transplantation therapy for Duchenne muscular dystrophy (DMD) and the difficulty and/or possibility of a cell delivery system are described in ‘Clinical trials of myoblast transplantation in patients with Duchenne muscular dystrophy (DMD)’ and ‘Possible systemic delivery of myogenic cells’.

• Clinical applications of Sk-MDSCs other than to treat DMD, mainly through local injection methods, and their safety are introduced in ‘Other clinical trials’.

• The possible therapeutic potential of Sk-34 cells, particularly for severe peripheral nerve injury, is described in ‘Possibility of other Sk-MDSC transplantation therapies’.

• Location of Sk-34 and Sk-DN/29⁺ cells in the skeletal muscle and their cell surface antigen characteristics are explained in ‘Location and characterization of Sk-34 and Sk-DN cells’ and the outlook on practical clinical therapeutic use is described in the sections ‘How to use the human Sk-34 and Sk-DN/29⁺ cells for therapy’. This box summarizes key points contained in the article.

Declaration of interest

The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial relationships or otherwise to disclose.

Additional information

Funding

This paper is not funded.