title: Rapid tissue regeneration induced by intracellular ATP delivery-A preliminary mechanistic study.
abstract: We have reported a new phenomenon in acute wound healing following the use of intracellular ATP delivery-extremely rapid tissue regeneration, which starts less than 24 h after surgery, and is accompanied by massive macrophage trafficking, in situ proliferation, and direct collagen production. This unusual process bypasses the formation of the traditional provisional extracellular matrix and significantly shortens the wound healing process. Although macrophages/monocytes are known to play a critical role in the initiation and progression of wound healing, their in situ proliferation and direct collagen production in wound healing have never been reported previously. We have explored these two very specific pathways during wound healing, while excluding confounding factors in the in vivo environment by analyzing wound samples and performing in vitro studies. The use of immunohistochemical studies enabled the detection of in situ macrophage proliferation in ATP-vesicle treated wounds. Primary human macrophages and Raw 264.7 cells were used for an in vitro study involving treatment with ATP vesicles, free Mg-ATP alone, lipid vesicles alone, Regranex, or culture medium. Collagen type 1α 1, MCP-1, IL-6, and IL-10 levels were determined by ELISA of the culture supernatant. The intracellular collagen type 1α1 localization was determined with immunocytochemistry. ATP-vesicle treated wounds showed high immunoreactivity towards BrdU and PCNA antigens, indicating in situ proliferation. Most of the cultured macrophages treated with ATP-vesicles maintained their classic phenotype and expressed high levels of collagen type 1α1 for a longer duration than was observed with cells treated with Regranex. These studies provide the first clear evidence of in situ macrophage proliferation and direct collagen production during wound healing. These findings provide part of the explanation for the extremely rapid tissue regeneration, and this treatment may hold promise for acute and chronic wound care.
authors.affiliation: Department of Surgery, University of Louisville, Louisville, Kentucky, United States of America.
authors.forename: Harshini
authors.identifier: http://orcid.org/0000-0002-3103-9712
authors.initials: H
authors.lastname: Sarojini
authors.affiliation: Department of Surgery, University of Louisville, Louisville, Kentucky, United States of America.
authors.forename: Adrian T
authors.initials: AT
authors.lastname: Billeter
authors.affiliation: Department of Surgery, University of Louisville, Louisville, Kentucky, United States of America.
authors.forename: Sarah
authors.initials: S
authors.lastname: Eichenberger
authors.affiliation: Department of Surgery, University of Louisville, Louisville, Kentucky, United States of America.
authors.forename: Devin
authors.initials: D
authors.lastname: Druen
authors.affiliation: Department of Surgery, University of Louisville, Louisville, Kentucky, United States of America.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Barnett
authors.affiliation: Department of Surgery, University of Louisville, Louisville, Kentucky, United States of America.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Gardner
authors.affiliation: Department of Surgery, University of Louisville, Louisville, Kentucky, United States of America.
authors.forename: Norman J
authors.initials: NJ
authors.lastname: Galbraith
authors.affiliation: Department of Surgery, University of Louisville, Louisville, Kentucky, United States of America.
authors.forename: Hiram C
authors.initials: HC
authors.lastname: Polk
authors.affiliation: Department of Surgery, University of Louisville, Louisville, Kentucky, United States of America.
authors.forename: Sufan
authors.initials: S
authors.lastname: Chien
mesh_terms: D000255:Adenosine Triphosphate / Q000008:administration & dosage / Q000627:therapeutic use*; D000818:Animals; D018932:Chemokine CCL2 / Q000378:metabolism; D024042:Collagen Type I / Q000378:metabolism; D000090602:Collagen Type I, alpha 1 Chain; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008081:Liposomes; D008264:Macrophages / Q000187:drug effects / Q000502:physiology; D051379:Mice; D000067996:RAW 264.7 Cells / Q000187:drug effects / Q000502:physiology; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D018932:Chemokine CCL2; D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D015850:Interleukin-6; D008081:Liposomes; D016753:Interleukin-10; D000255:Adenosine Triphosphate