title: Molecular events underlying maggot extract promoted rat in vivo and human in vitro skin wound healing.
abstract: Maggot extracts promote wound healing, but their bioactive part(s) and molecular effects on the regenerating tissues/cells remain largely unclear. These issues are addressed here by treating rat skin wounds, human keratinocyte line/HaCat and fibroblasts with maggot secretion/excretion, and the extracts of maggots without and with secretion/excretion. The wound closure rates, cell proliferation activities, and statuses of wound healing-related signaling pathways (STAT3, Notch1, Wnt2, NF-κB, and TGF-beta/Smad3) and their downstream gene expression (c-Myc, cyclin D1, and VEGF) are evaluated by multiple approaches. The results reveal that the maggot extracts, especially the one from the maggots without secretion/excretion, show the best wound healing-promoting effects in terms of quicker wound closure rates and more rapid growth of keratinocytes and fibroblasts. Of the five signaling pathways checked, the ones mediated by TGF-beta/Smad3, and STAT3 are activated in the untreated wounds and become further enhanced by the maggot extracts, accompanied with c-Myc, VEGF, and cyclin D1 up-regulation. Our results thus show (1) that both body extract and secretion/excretion of maggots contain favorable wound healing elements and (2) that the enhancement of TGF-beta/Smad3 and STAT3 signaling activities may be the main molecular effects of maggot extracts on the wound tissues.
authors.affiliation: Department of Orthopedic Surgery, First Clinical College, Dalian Medical University, Dalian, China.
authors.forename: Pei-Nan
authors.initials: PN
authors.lastname: Li
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Li-Xia
authors.initials: LX
authors.lastname: Zhong
authors.forename: Yuan
authors.initials: Y
authors.lastname: Sun
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Yu
authors.forename: Mo-Li
authors.initials: ML
authors.lastname: Wu
authors.forename: Lin-Lin
authors.initials: LL
authors.lastname: Zhang
authors.forename: Qing-You
authors.initials: QY
authors.lastname: Kong
authors.forename: Shou-Yu
authors.initials: SY
authors.lastname: Wang
authors.forename: De-Cheng
authors.initials: DC
authors.lastname: Lv
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000502:physiology*; D002478:Cells, Cultured; D004175:Diptera / Q000166:cytology; D005347:Fibroblasts / Q000378:metabolism*; D006801:Humans; D019476:Insect Proteins / Q000302:isolation & purification*; D007814:Larva; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D012867:Skin / Q000293:injuries / Q000473:pathology*; D014945:Wound Healing / Q000502:physiology*; D014947:Wounds and Injuries / Q000473:pathology*
chemical_list: D019476:Insect Proteins; C011902:lucilin protein, Lucilia cuprina