Expression of transforming growth factor beta(1), beta(3), and basic fibroblast growth factor in full-thickness skin wounds of equine limbs and thorax.

This study investigates the behavior of transforming growth factor (TGF)-beta(1), TGF-beta(3), and basic fibroblast growth factor (bFGF) in the full-thickness skin wounds of horses, noting differences in their expression between wounds in the limbs and thorax, to gain insights into the development of excessive granulation tissue.

Background and Aim

• The research focuses on uncovering the role and pattern of expression of TGF-beta(1), TGF-beta(3), and bFGF in the full-thickness skin wounds of horses.
• It delves into whether these expressions vary depending on the location of the wound—whether on limbs or thorax.
• The objective is to comprehend the cause of exuberant granulation tissue, a common issue in wound healing in horses.

Methods

• Using four 2 to 4-year-old horses, six wounds were created on one lateral metacarpal area and one midthoracic area of each horse.
• These wounds were analyzed both visibly and histologically at different postoperative milestones: 12 and 24 hours, and 2, 5, 10, and 14 days.
• Enzyme-Linked Immunosorbent Assays (ELISAs) were employed to measure the concentration of growth factors in wound biopsies obtained at these times.

Findings

• The study identifies that TGF-beta(1) shows a peak at 24 hours in both the locations and returns back to its baseline in thoracic wounds by the end of 14 days, but continually stays elevated in limb wounds.
• TGF-beta(3) manifestation over time demonstrates a gradual increase, with a slight inclination towards reaching a higher and earlier peak in thoracic wounds when compared to limb wounds.
• Although bFGF expression shows a trend similar to that of TGF-beta(1), there was no statistically significant difference observed between wounds on the limb or thorax.

Conclusions

• The researchers conclude that during the regular process of wound repair in horses, expression of growth factors is ramped up.
• Between TGF-beta(1) and TGF-beta(3), a reciprocal temporal regulation pattern is observed.
• Significant differences exist in TGF-beta(1) expression between limb and thoracic wounds, which might play a role in the occurrence of exuberant granulation tissue in the leg wounds as TGF-beta(1) is profibrotic.