title: Endotoxin-induced vascular endothelial cell migration is dependent on TLR4/NF-κB pathway, NAD(P)H oxidase activation, and transient receptor potential melastatin 7 calcium channel activity.
abstract: Endothelial dysfunction is decisive and leads to the development of several inflammatory diseases. Endotoxemia-derived sepsis syndrome exhibits a broad inflammation-induced endothelial dysfunction. We reported previously that the endotoxin, lipopolysaccharide (LPS), induces the conversion of endothelial cells (ECs) into activated fibroblasts, showing a myofibroblast-like protein expression profile. Enhanced migration is a hallmark of myofibroblast function. However, the mechanism involved in LPS-induced EC migration is no totally understood. Some studies have shown that the transient receptor potential melastatin 7 (TRPM7) ion channel is involved in fibroblast and tumor cell migration through the regulation of calcium influx. Furthermore, LPS modulates TRPM7 expression. However, whether TRPM7 is involved in LPS-induced EC migration remains unknown. Here, we study the participation of LPS as an inducer of EC migration and study the mechanism underlying evaluating the participation of the TRPM7 ion channel. Our results demonstrate that LPS induced EC migration in a dose-dependent manner. Furthermore, this migratory process was mediated by the TLR-4/NF-κB pathway and the generation of ROS through the PKC-activated NAD(P)H oxidase. In addition, LPS increased the intracellular calcium level and the number of focal adhesion kinase (FAK)-positive focal adhesions in EC. Finally, we demonstrate that using TRPM7 blockers or suppressing TRPM7 expression through siRNA successfully inhibits the calcium influx and the LPS-induced EC migration. These results point out TRPM7 as a new target in the drug design for several inflammatory diseases that impair vascular endothelium function.
authors.affiliation: Laboratorio de Fisiopatología Integrativa, Departamento de Ciencias Biologicas, Facultad de Ciencias Biologicas and Facultad de Medicina, Universidad Andres Bello, Avenida Republica 239, Santiago, Chile.
authors.forename: Daniela
authors.initials: D
authors.lastname: Sarmiento
authors.affiliation: Laboratorio de Fisiopatología Integrativa, Departamento de Ciencias Biologicas, Facultad de Ciencias Biologicas and Facultad de Medicina, Universidad Andres Bello, Avenida Republica 239, Santiago, Chile.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Montorfano
authors.affiliation: Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Independencia 1027, Santiago, Chile.
authors.forename: Mónica
authors.initials: M
authors.lastname: Cáceres
authors.affiliation: Laboratorio de Fisiopatología Integrativa, Departamento de Ciencias Biologicas, Facultad de Ciencias Biologicas and Facultad de Medicina, Universidad Andres Bello, Avenida Republica 239, Santiago, Chile; Laboratorio de Bionanotecnología, Universidad Bernardo O'Higgins, General Gana 1780, Santiago, Chile.
authors.forename: César
authors.initials: C
authors.lastname: Echeverría
authors.affiliation: Laboratorio de Fisiología, Departamento de Ciencias Biologicas, Facultad de Ciencias Biologicas and Facultad de Medicina, Universidad Andres Bello, Avenida Republica 239, Santiago, Chile.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Fernández
authors.affiliation: Laboratorio de Biología y Fisiopatología Molecular, Departamento de Ciencias Biologicas, Facultad de Ciencias Biologicas and Facultad de Medicina, Universidad Andres Bello, Avenida Republica 239, Santiago, Chile.
authors.forename: Claudio
authors.initials: C
authors.lastname: Cabello-Verrugio
authors.affiliation: Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Independencia 1027, Santiago, Chile.
authors.forename: Oscar
authors.initials: O
authors.lastname: Cerda
authors.affiliation: Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 367, Santiago, Chile.
authors.forename: Pablo
authors.initials: P
authors.lastname: Tapia
authors.affiliation: Laboratorio de Fisiopatología Integrativa, Departamento de Ciencias Biologicas, Facultad de Ciencias Biologicas and Facultad de Medicina, Universidad Andres Bello, Avenida Republica 239, Santiago, Chile; Millennium Institute on Immunology and Immunotherapy, Santiago, Chile. Electronic address: fsimon@unab.cl.
authors.forename: Felipe
authors.initials: F
authors.lastname: Simon
mesh_terms: D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008954:Models, Biological; D019255:NADPH Oxidases / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D050053:TRPM Cation Channels / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D051197:Toll-Like Receptor 4 / Q000378:metabolism*
chemical_list: D008070:Lipopolysaccharides; D016328:NF-kappa B; D017382:Reactive Oxygen Species; C495345:TLR4 protein, human; D050053:TRPM Cation Channels; D051197:Toll-Like Receptor 4; D019255:NADPH Oxidases; D017346:Protein Serine-Threonine Kinases; C486583:TRPM7 protein, human; D011493:Protein Kinase C; D002118:Calcium
keywords: Endothelial cell migration; Endothelial dysfunction; Inflammation; Lipopolysaccharide; TRPM7.