Peptide RL-QN15 promotes wound healing of diabetic foot ulcers through p38 mitogen-activated protein kinase and smad3/miR-4482-3p/vascular endothelial growth factor B axis

Dandan Sun; Kun Guo; Naixin Liu; Yilin Li; Yuansheng Li; Yan Hu; Shanshan Li; Zhe Fu; Yinglei Wang; Yutong Wu; Yingxuan Zhang; Jiayi Li; Chao Li; Zhuo Wang; Zijian Kang; Jun Sun; Ying Wang; Xinwang Yang

doi:10.1093/burnst/tkad035

Peptide RL-QN15 promotes wound healing of diabetic foot ulcers through p38 mitogen-activated protein kinase and smad3/miR-4482-3p/vascular endothelial growth factor B axis

Burns Trauma. 2023 Nov 15:11:tkad035. doi: 10.1093/burnst/tkad035. eCollection 2023.

Authors

Dandan Sun¹, Kun Guo¹, Naixin Liu¹, Yilin Li¹, Yuansheng Li¹, Yan Hu¹, Shanshan Li¹, Zhe Fu¹, Yinglei Wang¹, Yutong Wu¹, Yingxuan Zhang¹, Jiayi Li¹, Chao Li², Zhuo Wang², Zijian Kang¹, Jun Sun¹, Ying Wang³, Xinwang Yang¹

Affiliations

¹ Department of Anatomy and Histology and & Embryology, Faculty of Basic Medical Science, Kunming Medical University, No. 1168 Chunrong West Road, Chenggong District, Kunming, 650500, Yunnan, China.
² Department of Biochemistry and Molecular Biology, Faculty of Basic Medical Science, Kunming Medical University, No. 1168 Chunrong West Road, Chenggong District, Kunming, 650500, Yunnan, China.
³ Key Laboratory of Chemistry in Ethnic Medicinal Resources & Key Laboratory of Natural Products Synthetic Biology of Ethnic Medicinal Endophytes, State Ethnic Affairs Commission & Ministry of Education, School of Ethnic Medicine, Yunnan MinZu University, No. 2929 Yuehua Street, Chenggong District, Kunming, 650504, Yunnan, China.

Abstract

Background: Wound management of diabetic foot ulcers (DFUs) is a complex and challenging task, and existing strategies fail to meet clinical needs. Therefore, it is important to develop novel drug candidates and discover new therapeutic targets. However, reports on peptides as molecular probes for resolving issues related to DFUs remain rare. This study utilized peptide RL-QN15 as an exogenous molecular probe to investigate the underlying mechanism of endogenous non-coding RNA in DFU wound healing. The aim was to generate novel insights for the clinical management of DFUs and identify potential drug targets.

Methods: We investigated the wound-healing efficiency of peptide RL-QN15 under diabetic conditions using in vitro and in vivo experimental models. RNA sequencing, in vitro transfection, quantitative real-time polymerase chain reaction, western blotting, dual luciferase reporter gene detection, in vitro cell scratches, and cell proliferation and migration assays were performed to explore the potential mechanism underlying the promoting effects of RL-QN15 on DFU repair.

Results: Peptide RL-QN15 enhanced the migration and proliferation of human immortalized keratinocytes (HaCaT cells) in a high-glucose environment and accelerated wound healing in a DFU rat model. Based on results from RNA sequencing, we defined a new microRNA (miR-4482-3p) related to the promotion of wound healing. The bioactivity of miR-4482-3p was verified by inhibiting and overexpressing miR-4482-3p. Inhibition of miR-4482-3p enhanced the migration and proliferation ability of HaCaT cells as well as the expression of vascular endothelial growth factor B (VEGFB). RL-QN15 also promoted the migration and proliferation ability of HaCaT cells, and VEGFB expression was mediated via inhibition of miR-4482-3p expression by the p38 mitogen-activated protein kinase (p38MAPK) and smad3 signaling pathways.

Conclusions: RL-QN15 is an effective molecule for the treatment of DFUs, with the underlying mechanism related to the inhibition of miR-4482-3p expression via the p38MAPK and smad3 signaling pathways, ultimately promoting re-epithelialization, angiogenesis and wound healing. This study provides a theoretical basis for the clinical application of RL-QN15 as a molecular probe in promoting DFU wound healing.

Keywords: Diabetic foot ulcer; Mitogen-activated protein kinase; Peptide; RL-QN15; Vascular endothelial growth factor B; Wound healing; miR-4482-3p.