title: Mertk geneexpression and photoreceptor outer segment phagocytosis by cultured rat bone marrow mesenchymal stem cells.
abstract: Bone marrow mesenchymal stem cells (BM-MSCs) are multipotential stem cells that have been used for a broad spectrum of indications. Several investigations have used BM-MSCs to promote photoreceptor survival and suggested that BM-MSCs are a potential source of cell replacement therapy for some forms of retinal degeneration.
  
  
  
  To investigate the expression of the MER proto-oncogene, tyrosine kinase (Mertk), involved in the disruption of RPE phagocytosis and the onset of autosomal recessive retinitis pigmentosa in rat BM-MSCs and to compare phagocytosis of the photoreceptor outer segment (POS) by BM-MSCs and RPE cells in vitro.
  
  
  
  MSCs were isolated from the bone marrow of Brown Norway rats. Reverse transcription-PCR (RT-PCR) and western blot analyses were used to examine the expression ofMertk. The phagocytized POS was detected with double fluorescent labeling, transmission electron microscopy, and scanning electron microscopy.
  
  
  
  Mertkexpression did not differ among the first three passages of BM-MSCs.Mertk geneexpression was greater in the BM-MSCs than the RPE cells. Mertk protein expression in the BM-MSCs was similar to that in the RPE cells in the primary passage and was greater than that in the RPE cells in the other two passages. BM-MSCs at the first three passages phagocytized the POS more strongly than the RPE cells. The process of BM-MSC phagocytosis was similar to that of the RPE cells.
  
  
  
  BM-MSCs may be an effective cell source for treating retinal degeneration in terms of phagocytosis of the POS.
authors.affiliation: Department of Ophthalmology, Peking University Third Hospital, Beijing, China Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, China.
authors.forename: Rong-Mei
authors.initials: RM
authors.lastname: Peng
authors.affiliation: Department of Ophthalmology, Peking University Third Hospital, Beijing, China Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Hong
authors.affiliation: Department of Ophthalmology, Peking University Third Hospital, Beijing, China Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Department of Ophthalmology, China Medical University, the First Affiliated Hospital, Shenyang, China.
authors.forename: Yu-Zhao
authors.initials: YZ
authors.lastname: Sun
authors.affiliation: Department of Ophthalmology, Peking University Third Hospital, Beijing, China Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, China.
authors.forename: Yi-Qian
authors.initials: YQ
authors.lastname: Sun
authors.affiliation: Department of Ophthalmology, Peking University Third Hospital, Beijing, China Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, China.
authors.forename: Pei
authors.initials: P
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology* / Q000648:ultrastructure; D002478:Cells, Cultured; D005786:Gene Expression Regulation; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000648:ultrastructure; D008863:Microspheres; D010587:Phagocytosis; D011914:Rats, Inbred BN; D055214:Retinal Photoreceptor Cell Outer Segment / Q000378:metabolism* / Q000648:ultrastructure; D000076202:c-Mer Tyrosine Kinase / Q000235:genetics* / Q000378:metabolism
chemical_list: C490765:Mertk protein, rat; D000076202:c-Mer Tyrosine Kinase