Human CD29+/CD56+ myogenic progenitors display tenogenic differentiation potential and facilitate tendon regeneration

Tendon injury occurs at high frequency and is difficult to repair. Identification of human stem cells being able to regenerate tendon will greatly facilitate the development of regenerative medicine for tendon injury. We identified human CD29+/CD56+ myogenic progenitors having tendon differentiation potential both in vitro and in vivo. Transplantation of human CD29+/CD56+ myogenic progenitors contributes to injured tendon repair and thus improves locomotor function. Interestingly, the tendon differentiation potential in mouse muscle stem cells is minimal and the higher TGFβ signaling level may be the key for the distinct feature of human CD29+/CD56+ myogenic progenitors. These findings reveal that human CD29+/CD56+ myogenic progenitors are bi-potential adult stem cells and can serve as a new source for tendon regeneration.