Dynamic changes of autophagy during hypertrophic scar formation and the role of autophagy intervention

Abstract

Background: The role of autophagy in the formation of hypertrophic scars (HS) remains unclear. This study aimed to explore the role and potential mechanism of autophagy during the development of HS. Methods: RNA and protein expression levels of Beclin-1, p62, and LC3II in normal skin tissues and HS specimens from different patients were examined. Autophagy inducers and inhibitors were used to cure established HS in rabbit ears, and the expression of Beclin-1, p62, and LC3II at the RNA and protein level was determined. Lastly, the effects of autophagy inducers and inhibitors on HS development were analyzed. Results: Compared to normal skin tissues, the expression of LC3Ⅱ and Beclin-1 was higher (P<0.05), while that of p62 was lower (P<0.05) in HS tissues. In addition, the LC3II/LC3I ratio was increased during HS formation, and the altered expression of the three proteins stabilized after one year. Administration of autophagy inducers enhanced the formation of HS as well as the expression levels of LC3II and Beclin-1 but decreased p62 expression. Meanwhile, administration of autophagy inhibitors increased the expression of LC3II, Beclin-1, and p62, along with reduced HS formation. Conclusion: Autophagic activity increased during HS initiation and subsequent stabilization. In addition, autophagy inhibitors were able to inhibit HS formation by suppressing autophagy, whereas autophagy inducers promoted scar hyperplasia by enhancing autophagy.

Keywords

• Hypertrophic scar
• Rabbit ear hypertrophic scar model
• Autophagy
• Beclin-1
• LC3
• p62