Equine adult, fetal and ESC-tenocytes have differential migratory, proliferative and gene expression responses to factors upregulated in the injured tendon.

The research article focuses on how adult, fetal, and embryonic stem cell-derived tenocytes (tendon cells) from horses respond differently to various factors that increase after a tendon injury. Using 2-dimensional and 3-dimensional models, the study examines cellular reaction to these factors to understand their role in either repairing or regenerating the tendon. This understanding could then inform the development of cell-based therapies for improved tendon healing and regeneration.

Investigation of Tendon Cells Response to Injury Factors

• The study involved determining the reactions of adult, fetal, and embryonic stem cell (ESC)-derived tenocytes from horses to different factors (cytokines, chemokines, and growth factors) that increase after a tendon injury.
• This was achieved through 2-dimensional (2D) and 3-dimensional (3D) in vitro wound models, which simulated the environment and conditions of a real injury.

Proliferation and Migration in 2D Models

• Using 2D proliferation assays, the study demonstrated that the reactions of fetal and adult tenocytes to the tested factors were more similar to each other and drastically different from the reactions of embryonic stem cell-derived tenocytes.
• However, 2D migration assays suggested a certain level of similarity between fetal, adult, and ESC-derived tenocytes in terms of movement and spread in response to injury factors.

Response in 3D Wound Closure Assays

• In 3D wound closure assays also, the response of fetal tenocytes appeared to be intermediary, demonstrating characteristics between adult and embryonic stem cell-derived tenocytes.
• The study further showed that TGFβ3, one of the studied factors, enhances 3D gel contraction and wound healing in adult and fetal tenocytes, while FGF2 inhibits these processes in adult cells.

Implications of the Research

• The findings from this research suggest that the difference in cellular responses to the upregulated factors following a tendon injury may determine whether the tendon gets repaired or regenerated.
• The observed differential response of tenocytes thus needs further investigation and understanding, as it can inform the development of cell-based therapies for tendon regeneration, potentially improving the treatment and prognosis of tendon injuries in both horses and humans.