Expression of Tissue Remodeling- and Inflammation-Related Factors During the Wound-Healing Process in Humans

Background/Objectives: There is a growing interest in the research of wound healing mechanisms worldwide. Particular attention has been paid to the expression of tissue remodeling- and inflammation-related factors. Herein, we investigate the expression patterns of TGF-β1, IL-6, TNF-a, uPA, uPA receptors, MMP-2, and MMP-9 through the four phases of the normal wound-healing process in humans. Methods: Twenty-two individuals presenting with a first episode of pilonidal sinus underwent surgical excision and the wound was left to heal by secondary intention. Sequential biopsies were collected on day 0 (operation), day 2 (inflammatory phase), day 9 (proliferative phase), and day 14 (tissue remodeling phase). The expression levels of the proteins were evaluated using reverse transcription-quantitative PCR. Statistical analyses were performed using GraphPad Prism software. One-way analysis of variance (ANOVA) with Dunn's Multiple Comparison post hoc test was used. Results: The results showed statistically significant differences in the expressions of the factors during wound healing (p < 0.05). TGF-b1 increased on days 2 and 9. TNF-a increased on day 2 and then decreased on day 9. Il-6 was increased on day 2 and decreased on days 9 and 14. uPa mRNA increased up to day 9 but its receptor exhibited high expression throughout the observation time. Finally, MMP-2 mRNA expression increased on day 2 and declined on days 9 and 14, while MMP-9 was highly expressed until the 14th postoperative day. Conclusions: Each factor investigated in this study has an important and distinct role in the normal wound repair procedure. Further investigation is required to evaluate the tissue-specific regulation of these factors and their potential use as therapeutic targets or prognostic biomarkers in wound healing.