A Naturally-occured Homopeptidedimer From Amphibian Promote The Regeneration Of Skin Wounds By Inhibiting Inflammation Homodimer Of Peptide

Objective:Skin is an important physical barrier between the human body and the external environment,which is responsible for many and important physiological functions,but is susceptible to skin damage caused by a variety of factors(physical,mechanical,chemical and pathogenic microbial).An important prerequisite for the reconstruction of the internal environmental stability after skin damage is the rapid healing of the wound,and the process of wound healing is orderly and complex,susceptible to different factors to develop into chronic trauma or hypertrophic scar healing.There are some limitations in the existing wound-promoting drugs and treatment methods,so it is important to find new drugs to promote skin wound repair.Amphibian skin-derived peptides have shown good activity in a large number of studies to promote wound repair,In this study we identified a new type of peptide OA-GP11 dimer from the skin secretions of Yunnan Odorrana Andersanii to explore the skin-promoting wound repair capabilities and other functions of this small peptide,laying the foundation for a new potential candidate for skin wound healing.Methods:In this study,adult Yunnan skunk frogs(O.andersonii)were collected in the wild,electrical stimulation was used to collect skin secretions from stinky frogs,and a new peptide OA-GP11 dimer was identified from their skin secretions.The homologous dimer of peptide OA-GP11 was found by cDNA cloning and combined with mass spectrometry analysis results.The comparison was retrieved by the NCBI database and found that the peptide was a new peptide and named OA-GP11 dimer.We detect the antibacterial activity,hemolytic activity and acute toxicity of the peptide dimer.Through a series of in vitro cell experiments(1.The MTS experiment detected the probiotic activity of in vitro OA-GP11 dimer on mouse cells(PAM212)and mouse macrophages(Raw264.6);Dimer’s migration-promoting activity for mouse keratin cells(PAM212)and mouse macrophages(Raw264.6).The wound healing model construction experiment of the whole animal level in the body explores the healing activity and possible mechanism of wound healing of small peptides,and further explores the histological level and molecular level mechanism of the active peptide to promote the healing of trauma through pathological histological analysis,cytokine release activity detection,transcription group analysis and cell signaling pathway detection.Results:1.A new type of peptide OA-GP11 dimer was identified from the skin secretions of Yunnan skunk frogs,consisting of 22 amino acid residues,and its amino acid sequence was "GPLSGINAE(?)EANIGSLPG" with a relative molecular mass of 2180.54 Da.M M 2.OA-GP11 dimer does not have antibacterial activity against Gram-positive bacteria(Staphylococcus aureus),Gram-negative bacteria(E.coli),fungi(White candida), shrivelled spores,and no antioxidant activity for ABTS+.3.OA-GP11 dimer did not significantly promote cell proliferation activity in mouse keratin cells(PAM212)and mouse macrophages(Raw264.6),but it did not inhibit activity.Better ability to promote the migration of cells in mice was demonstrated in migration(cell scratches)and invasive(Transwell)experiments.4.OA-GP11 dimer significantly accelerates the healing of full cortex trauma and second-degree burns in mice,and promotes rapid healing and reprinted formation of wounds.5.EIIS A testing has found that OA-GP11 dimer can significantly inhibit the release of inflammatory factors(TNF-α and IL-6)in LPS stimulus-induced RAW264.7 cells.6.Through the transcription group results,it was found that there were 1010 differential expression genes in the blank control group of OA-GP11 dimer,of which 437 were raised genes and 573 were lowered genes,and the significant difference expression of NF-κB signaling pathways was found according to the gene enrichment factor size of the relevant pathway differences.And the Western blot experimental results show that OA-GP11 dimer can effectively reduce the phosphorylation of NF-κB in LPS-induced RAW264.7 cells.Conclusion(s):Yunnan skunk frog skin-derived peptide OA-GP11 dimer can effectively promote the repair of acute wound(full-cortical trauma)and chronic wound(scald)in mice,and after LPS stimulation induced mouse macrophage inflammatory response treatment,small peptide OA-GP 11 dimer can not only reduce the expression of phosphorylation of I-κB and NF-κB,but also inhibit the release of inflammatory factors,which is particularly important in the post-traumatic healing polypeptide treatment group can show good wound repair.This study has enriched the action and mechanism of skin repair peptides derived from the skin of amphibian frogs.It is the first peptide dimer with tissue regeneration activity and has shown good results in animal models with high levels of inflammation(scalds).Repair tissue regeneration activity.It has laid a certain foundation for the development of OA-GP 11 dimer as a potential drug for promoting skin wound repair.