Identity of tendon stem cells--how much do we know?

Area of Science:

• Regenerative Medicine
• Stem Cell Biology
• Musculoskeletal Research

Background:

• Tendon stem cells (TDSCs) are multipotent adult stem cells with significant differentiation potential for tendon repair.
• While characterized in vitro, their in vivo identity, niche, and functions remain less understood, leading to controversy.
• Differences exist among mesenchymal stem cells (MSCs) from various origins, impacting their properties and functions.

Purpose of the Study:

• To review current evidence on the anatomical locations of TDSCs in vivo.
• To identify niche signals regulating TDSC functions within the tendon.
• To discuss the roles of TDSCs in tendon healing and non-healing processes.

Main Methods:

• Literature review of studies characterizing TDSCs in vitro and in vivo.
• Analysis of evidence regarding TDSC niche and anatomical distribution.
• Synthesis of findings on TDSC roles in tendon repair and pathology.

Main Results:

• TDSCs exhibit plasticity, making them important for cell-based tendon therapies.
• In vitro characterization is extensive, but in vivo identity and niche regulation require further investigation.
• Evidence suggests tissue origin influences stem cell properties and functions.

Conclusions:

• Understanding the in vivo identity and niche of TDSCs is critical for advancing tendon regenerative medicine.
• Further research is needed to elucidate TDSC roles in tendon healing and non-healing.
• Developing strategies to identify and manipulate TDSCs in vivo holds therapeutic promise.