title: Switching on a transient endogenous ROS production in mammalian cells and tissues.
abstract: There is a growing interest in the physiological roles of reactive oxygen species (ROS) as essential components of molecular mechanisms regulating key cellular processes, including proliferation, differentiation and apoptosis. This interest has fostered the development of new molecular tools to localize and quantify ROS production in cultured cells and in whole living organisms. An equally important but often neglected aspect in the study of ROS biology is the development of accurate procedures to introduce a ROS source in the biological system under study. At present, this experimental requirement is solved in most cases by an external and systemic administration of ROS, usually hydrogen peroxide. We have previously shown that a photodynamic treatment based on the endogenous photosensitizer protoporphyrin IX and further irradiation of the target with adequate light source can be used to transiently switch on an in situ ROS production in human cultured keratinocytes and in mouse skin in vivo. Using this approach we reported that qualitatively low levels of ROS can activate cell proliferation in cultured cells and promote a transient and reversible hyperproliferative response in the skin, particularly, in the hair follicle stem cell niche, promoting physiological responses like acceleration of hair growth and supporting the notion that a local and transient ROS production can regulate stem cell function and tissue homeostasis in a whole organism. Our principal aim here is to provide a detailed description of this experimental methodology as a useful tool to investigate physiological roles for ROS in vivo in different experimental systems.
authors: Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain; Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, Madrid, Spain; Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors: Elisa
authors: E
authors: Carrasco
authors: Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark.
authors: Alfonso
authors: A
authors: Blázquez-Castro
authors: Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain; Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, Madrid, Spain; Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors: María I
authors: MI
authors: Calvo
authors: Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain. Electronic address: angeles.juarranz@uam.es.
authors: Ángeles
authors: Á
authors: Juarranz
authors: Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain; Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, Madrid, Spain; Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain; Laboratorio de Bionanotecnologia, Universidad Bernardo O'Higgins, Santiago, Chile. Electronic address: jespada@iib.uam.es.
authors: Jesús
authors: J
authors: Espada
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects* / Q000528:radiation effects; D002478:Cells, Cultured / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D008027:Light; D051379:Mice; D008967:Molecular Biology / Q000379:methods*; D011524:Protoporphyrins / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000737:chemistry / Q000302:isolation & purification*; D012867:Skin / Q000187:drug effects / Q000528:radiation effects
chemical_list: D011524:Protoporphyrins; D017382:Reactive Oxygen Species; C028025:protoporphyrin IX
keywords: 5-Aminolevulinic acid (5-ALA); Cell proliferation; Hair follicle; Photodynamic therapy; Protoporphyrin IX (PpIX); Reactive oxygen species (ROS); Skin stem cells; Src kinase