title: In vitro exposure to very low-level laser modifies expression level of extracellular matrix protein RNAs and mitochondria dynamics in mouse embryonic fibroblasts.
abstract: BACKGROUND
  Low-level lasers working at 633 or 670 nm and emitting extremely low power densities (Ultra Low Level Lasers - ULLL) exert an overall effect of photobiostimulation on cellular metabolism and energy balance. In previous studies, it was demonstrated that ULLL pulsed emission mode regulates neurite elongation in vitro and exerts protective action against oxidative stress.
  
  
  METHODS
  In this study the action of ULLL supplied in both pulsed and continuous mode vs continuous LLL on fibroblast cultures (Mouse Embryonic Fibroblast-MEF) was tested, focusing on mitochondria network and the expression level of mRNA encoding for proteins involved in the cell-matrix adhesion.
  
  
  RESULTS
  It was shown that ULLL at 670 nm, at extremely low average power output (0.21 mW/ cm(2)) and dose (4.3 mJ/ cm(2)), when dispensed in pulsed mode (PW), but not in continuous mode (CW) supplied at both at very low (0.21 mW/cm(2)) and low levels (500 mW/cm(2)), modifies mitochondria network dynamics, as well as expression level of mRNA encoding for selective matrix proteins in MEF, e.g. collagen type 1α1 and integrin α5.
  
  
  CONCLUSIONS
  We suggest that pulsatility, but not energy density, is crucial in regulating expression level of collagen I and integrin α5 in fibroblasts by ULLL.
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 41/E, 40064 Ozzano Emilia, Bologna, Italy. a.giuliani@unibo.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Giuliani
authors.affiliation: Health Science and Technologies Interdepartmental Center for Industrial Research (HST-ICIR), University of Bologna, Bologna, Italy. Lucaluca.lorenzini8@unibo.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Lorenzini
authors.affiliation: Health Science and Technologies Interdepartmental Center for Industrial Research (HST-ICIR), University of Bologna, Bologna, Italy. marco.alessandri2@unibo.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Alessandri
authors.affiliation: Health Science and Technologies Interdepartmental Center for Industrial Research (HST-ICIR), University of Bologna, Bologna, Italy. roberta.torricella@studio.unibo.it.
authors.forename: Roberta
authors.initials: R
authors.lastname: Torricella
authors.affiliation: Health Science and Technologies Interdepartmental Center for Industrial Research (HST-ICIR), University of Bologna, Bologna, Italy. vito.baldassarro2@unibo.it.
authors.forename: Vito Antonio
authors.initials: VA
authors.lastname: Baldassarro
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 41/E, 40064 Ozzano Emilia, Bologna, Italy. luciana.giardino@unibo.it.|IRET Foundation, Ozzano Emilia, Bologna, Italy. luciana.giardino@unibo.it.
authors.forename: Luciana
authors.initials: L
authors.lastname: Giardino
authors.affiliation: Health Science and Technologies Interdepartmental Center for Industrial Research (HST-ICIR), University of Bologna, Bologna, Italy. laura.calza@unibo.it.|IRET Foundation, Ozzano Emilia, Bologna, Italy. laura.calza@unibo.it.
authors.forename: Laura
authors.initials: L
authors.lastname: Calzà
mesh_terms: D000818:Animals; D003094:Collagen / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism / Q000528:radiation effects*; D039482:Integrin alpha5 / Q000378:metabolism; D007834:Lasers; D008027:Light; D028022:Low-Level Light Therapy; D051379:Mice; D008928:Mitochondria / Q000378:metabolism*; D018384:Oxidative Stress; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D039482:Integrin alpha5; D012333:RNA, Messenger; D003094:Collagen