Amphibian-derived peptide homodimer OA-GL17d promotes skin wound regeneration through the miR-663a/TGF-β1/Smad axis

Abstract

Background Amphibian-derived peptides exhibit considerable potential in the discovery and development of new therapeutic interventions for clinically challenging chronic skin wounds. MicroRNAs (miRNAs) are also considered promising targets for the development of effective therapies against skin wounds. However, further research in this field is anticipated. This study aims to identify and provide a new peptide drug candidate, as well as to explore the underlying miRNA mechanisms and possible miRNA drug target for skin wound healing. Methods A combination of Edman degradation, mass spectrometry and cDNA cloning were adopted to determine the amino acid sequence of a peptide that was fractionated from the secretion of Odorrana andersonii frog skin using gel-filtration and reversed-phase high-performance liquid chromatography. The toxicity of the peptide was evaluated by Calcein-AM/propidium iodide (PI) double staining against human keratinocytes (HaCaT cells), hemolytic activity against mice blood cells and acute toxicity against mice. The stability of the peptide in plasma was also evaluated. The prohealing potency of the peptide was determined by MTS, scratch healing and a Transwell experiment against HaCaT cells, full-thickness injury wounds and scald wounds in the dorsal skin of mice. miRNA transcriptome sequencing analysis, enzyme-linked immunosorbent assay, real-time polymerase chain reaction and western blotting were performed to explore the molecular mechanisms. Results A novel peptide homodimer (named OA-GL17d) that contains a disulfide bond between the 16th cysteine residue of the peptide monomer and the sequence ‘GLFKWHPRCGEEQSMWT’ was identified. Analysis showed that OA-GL17d exhibited no hemolytic activity or acute toxicity, but effectively promoted keratinocyte proliferation and migration and strongly stimulated the repair of full-thickness injury wounds and scald wounds in the dorsal skin of mice. Mechanistically, OA-GL17d decreased the level of miR-663a to increase the level of transforming growth factor-β1 (TGF-β1) and activate the subsequent TGF-β1/Smad signaling pathway, thereby resulting in accelerated skin wound re-epithelialization and granular tissue formation. Conclusions Our results suggest that OA-GL17d is a new peptide drug candidate for skin wound repair. This study emphasizes the importance of exogenous peptides as molecular probes for exploring competing endogenous RNA mechanisms and indicates that miR-663a may be an effective target for promoting skin repair.

miR‐186‐5p targets TGFβR2 to inhibit RAW264.7 cell migration and proliferation during mouse skin wound healing

“…14,[38][39][40] In addition, as a novel molecular probe, OA-GL17d regulates miR-663a to target TGF-β1 and promote wound repair. 19 Therefore, peptides with skin-repair activity may help explore new mechanisms of diseases and provide novel drug targets. OA-GP11d is also from O. andersonii and promotes skin wound healing, 18 thus it may be a new probe to research prohealing drug targets.…”

PRP8-Induced CircMaml2 Facilitates the Healing of the Intestinal Mucosa via Recruiting PTBP1 and Regulating Sec62

“…One classical example affecting biogenesis is QKI, which upregulates many circRNAs during epithelial to mesenchymal transition (EMT) in humans via pre-mRNA binding. As QKI forms dimers, it was proposed that QKI may bind to two flanking introns and bring the circularized exons closer together, resulting in the increased production of circRNAs [ 51 , 52 ].…”

The Complex Bridge between Aquatic and Terrestrial Life: Skin Changes during Development of Amphibians

“…Epidermal keratinization of amphibians was vital through terrestrial adaptation among aquatic life because it provided osmo- and thermoregulatory systems and respiration as well as protection against mechanical damage. Amphibians produce peptides that were recently found to be antimicrobial or antioxidant, and this discovery led to clinical research on wound healing, regeneration, and bioactive peptide production throughout the world as a rising study topic [ 34 ].…”