- Academic Editor
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†These authors contributed equally.
Background: Delayed wound healing, a common problem in
patients with diabetes mellitus (DM), is associated with impaired keratinocyte
autophagy. Epigallocatechin gallate (EGCG), a catechin, has been proven to
promote diabetic wound healing. This study aims to explore the therapeutic
mechanism of EGCG on diabetic wound healing. Methods: High glucose
(HG)-induced keratinocytes and streptozotocin (STZ)-induced DM rats were prepared
and intervened with EGCG to examine its therapeutic effects in in vivo
and in vitro settings. The AMPK inhibitor, Compound C, was
utilized to determine whether EGCG exerted its therapeutic effects through the
AMPK/ULK1 pathway. Results: In vitro, EGCG improved
HG-induced autophagy impairment in keratinocytes by increasing LC3II/LC3I,
Becline1, and ATG5 levels and decreasing p62 level. Mechanically, EGCG activated
the AMPK/ULK1 pathway, thereby promoting keratinocyte autophagy through the
phosphorylation of AMPK and ULK1. Notably, EGCG promoted the proliferation,
migration, synthesis and release of C-C motif chemokine ligand 2 (CCL2) in
HG-treated keratinocytes. Furthermore, EGCG indirectly promoted the activation of
fibroblasts, as evidenced by increased alpha-smooth muscle actin (