Investigation On The Wound Healing Effects Of Active Peptide Nigrocin-AA1 From Amolops Afghanus

Skin damage is one of the most frequently encountered problems in life,and the continued exposure of the wound to the bacteria can easily cause an infection and turn it into a chronic wound disease.Wound healing is a complex,sophisticated,dynamic process that mobilizes relevant cells and tissues in and outside of the body to co-regulate and eventually promote wound healing.Antimicrobial peptides have a broad spectrum of antibacterial activity,can kill bacteria directly or indirectly wound,wound healing to create a good environment.In recent years,a number of studies have shown that mammalian-derived peptides can regulate the immunity of the body and promote wound healing.However,there is less research on the antimicrobial peptides to promote wound healing,and the mechanism remains unclear.Here we report an antimicrobial peptide named Nigrocin-AA1 from skin secretions of Amolops afghanus that the peptide had the sequence of '“GLLSGILGAGKRIVCGLSGLC.”contained an intramolecular disulfide bridge at the C-terminus.We investigated that Nigrocin-AAl showed potent wound healing activity and low hemolysis and low or no cytotoxicity in vitro and in vivo.Nigrocin-AAl can promote the proliferation and migration of human immortalized keratinocytes,fibroblasts,macrophages,and it can promote wound healing in vivo through a mouse model with two-full thickness dermal wound.This peptide can play a role in promoting skin wound healing by mediating TGF-(3-related pathways,inhibiting the inflammatory response and regulating the phosphorylation level of downstream related receptors such as Smad2,Smad3,JNK,ERK and P38.In addition,our study found that Nigrocin-AAl can promote fibronectin fibroblast differentiation,promote the up-regulation of collagen type I(Co1 I)and collagen type III(Col III)at the gene level,and further promote the accumulation of extracellular matrix and wound healing.This study provides some information and basis for mammalian secreted polypeptides to study wound healing cells and mechanisms.Using this peptide to promote wound healing prompts us that it may serve as a new drug candidate in the treatment of wound healing.