title: Degenerate wave and capacitive coupling increase human MSC invasion and proliferation while reducing cytotoxicity in an in vitro wound healing model.
abstract: Non-unions pose complications in fracture management that can be treated using electrical stimulation (ES). Bone marrow mesenchymal stem cells (BMMSCs) are essential in fracture healing; however, the effect of different clinical ES waveforms on BMMSCs cellular activities remains unknown. We compared the effects of direct current (DC), capacitive coupling (CC), pulsed electromagnetic field (PEMF) and degenerate wave (DW) on cellular activities including cytotoxicity, proliferation, cell-kinetics and apoptosis by stimulating human-BMMSCs 3 hours a day, up to 5 days. In addition, migration and invasion were assessed using fluorescence microscopy and by quantifying gene and protein expression. We found that DW had the greatest proliferative and least apoptotic and cytotoxic effects compared to other waveforms. DC, DW and CC stimulations resulted in a higher number of cells in S phase and G(2)/M phase as shown by cell cycle analysis. CC and DW caused more cells to invade collagen and showed increased MMP-2 and MT1-MMP expression. DC increased cellular migration in a scratch-wound assay and all ES waveforms enhanced expression of migratory genes with DC having the greatest effect. All ES treated cells showed similar progenitor potential as determined by MSC differentiation assay. All above findings were shown to be statistically significant (p<0.05). We conclude that ES can influence BMMSCs activities, especially DW and CC, which show greater invasion and higher cell proliferation compared to other types of ES. Application of DW or CC to the fracture site may help in the recruitment of BMMSCs to the wound that may enhance rate of bone healing at the fracture site.
authors.affiliation: Plastic & Reconstructive Surgery Research, School of Translational Medicine, Manchester Interdisciplinary Biocentre, University of Manchester, Manchester, United Kingdom.
authors.forename: Michelle
authors.initials: M
authors.lastname: Griffin
authors.forename: Syed Amir
authors.initials: SA
authors.lastname: Iqbal
authors.forename: Anil
authors.initials: A
authors.lastname: Sebastian
authors.forename: James
authors.initials: J
authors.lastname: Colthurst
authors.forename: Ardeshir
authors.initials: A
authors.lastname: Bayat
mesh_terms: D000368:Aged; D017209:Apoptosis / Q000502:physiology; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism; D002453:Cell Cycle / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D004558:Electric Stimulation / Q000379:methods; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D053511:Matrix Metalloproteinase 14 / Q000235:genetics / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D008875:Middle Aged; D008954:Models, Biological; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016196:S Phase / Q000502:physiology; D014945:Wound Healing / Q000502:physiology*
chemical_list: D020778:Matrix Metalloproteinase 2; D053511:Matrix Metalloproteinase 14