title: Transplantation of bone marrow-derived mesenchymal stem cells rescue photoreceptor cells in the dystrophic retina of the rhodopsin knockout mouse.
abstract: BACKGROUND
  Retinitis pigmentosa belongs to a large group of degenerative diseases of the retina with a hereditary background. It involves loss of retinal photoreceptor cells and consequently peripheral vision. At present there are no satisfactory therapeutic options for this disease. Just recently the use of mesenchymal stem cells has been discussed as one therapeutical option for retinal degeneration, as they have been shown to differentiate into various cell types, including photoreceptor cells. In this article we wanted to investigate the potency of mesenchymal stem cells to induce rescue effects in an animal model for retinitis pigmentosa, the rhodopsin knockout mouse.
  
  
  METHODS
  For the experiments, three experimental groups of 10 animals each were formed. The first group consisted of untreated rhodopsin knockout (rho(-/-)) animals used as controls. The second group consisted of rho(-/-) mice that had received an injection of mouse mesenchymal stem cells, which were transduced using an adenoviral vector containing the sequence for the green fluorescent protein (GFP) prior to transplantation. In the third sham group, animals received an injection of medium only. Thirty-five days after transplantation, GFP-expressing cells were detected in whole-mount preparations of the retinas as well as in cryostat sections. For the detection of rescue effects, semi-thin sections of eyes derived from all experimental groups were produced. Furthermore, rescue effects were also analysed ultrastructurally in ultrathin sections.
  
  
  RESULTS
  Histological analysis revealed that after transplantation, cells morphologically integrated not only into the retinal pigment epithelium but also into layers of the neuroretina displaying neuronal and glial morphologies. Furthermore, significant rescue effects, as demonstrated by the occurrence of preserved photoreceptor cells, were detected.
  
  
  CONCLUSIONS
  Our data indicate that mesenchymal stem cells can prolong photoreceptor survival in the rhodopsin knockout mouse, also providing evidence of a therapeutical benefit in retinitis pigmentosa.
authors.affiliation: Department of Anatomy I, University of Cologne, Joseph-Stelzmann Strasse 9, Cologne, Germany. stefan.arnhold@uni-koeln.de
authors.forename: S
authors.initials: S
authors.lastname: Arnhold
authors.forename: Y
authors.initials: Y
authors.lastname: Absenger
authors.forename: H
authors.initials: H
authors.lastname: Klein
authors.forename: K
authors.initials: K
authors.lastname: Addicks
authors.forename: U
authors.initials: U
authors.lastname: Schraermeyer
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology*; D002470:Cell Survival; D004195:Disease Models, Animal; D019084:Fluorescent Antibody Technique, Indirect; D020868:Gene Silencing / Q000502:physiology; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D051379:Mice; D018345:Mice, Knockout; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology* / Q000648:ultrastructure; D012174:Retinitis Pigmentosa / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D012243:Rhodopsin / Q000235:genetics*; D014162:Transfection
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D012243:Rhodopsin