title: Receptor protein tyrosine phosphatase mu expression as a marker for endothelial cell heterogeneity; analysis of RPTPmu gene expression using LacZ knock-in mice.
abstract: The receptor-like protein tyrosine phosphatase mu (RPTPmu) belongs to the subfamily of meprin, A5, RPTPmu (MAM) domain-containing RPTPs, which are thought to play an important role in cell-cell adhesion mediated processes. The current study was designed to examine the expression pattern of RPTPmu in mice. We have generated RPTPmu-LacZ knock-in mice that express the beta-galactosidase (LacZ) reporter gene under the control of the RPTPmu promoter. LacZ expression patterns were analysed in embryos and adult mice by whole mount LacZ staining. Analysis of beta-galactosidase activity of heterozygous embryos and adult tissues revealed RPTPmu expression in endothelial cells of arteries and capillaries. In contrast, expression was virtually absent in endothelial cells of veins and in fenestrated endothelial cells in the adult liver and spleen. Moreover, RPTPmu expression was found in endothelial cells from the endocardium and the aorta in embryos, but not in adult mice. In addition to heterogeneous expression in endothelial cells, RPTPmu expression was found in cardiac muscle cells but not in skeletal muscle cells or smooth muscle cells. Expression was also found in Type II pneumonocytes in the lung alveoli and in Purkinje cells and other neurons in the brain. The specific expression of RPTPmu in arterial endothelial cells and in cardiac myocytes suggests that RPTPmu may play a role in the regulation of cardiovascular functions.
authors.affiliation: Department of Medical Oncology, University Medical Centre, Utrecht, The Netherlands.
authors.forename: Elianne A
authors.initials: EA
authors.lastname: Koop
authors.forename: Susana M Chuva de Sousa
authors.initials: SM
authors.lastname: Lopes
authors.forename: Elles
authors.initials: E
authors.lastname: Feiken
authors.forename: Hans A R
authors.initials: HA
authors.lastname: Bluyssen
authors.forename: Martin
authors.initials: M
authors.lastname: van der Valk
authors.forename: Emile E
authors.initials: EE
authors.lastname: Voest
authors.forename: Christine L
authors.initials: CL
authors.lastname: Mummery
authors.forename: Wouter H
authors.initials: WH
authors.lastname: Moolenaar
authors.forename: Martijn F B G
authors.initials: MF
authors.lastname: Gebbink
mesh_terms: D000483:Alleles; D000818:Animals; D001158:Arteries / Q000378:metabolism; D015152:Blotting, Northern; D015139:Blotting, Southern; D001921:Brain / Q000378:metabolism; D002196:Capillaries / Q000378:metabolism; D002448:Cell Adhesion; D002450:Cell Communication; D018076:DNA, Complementary / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D006579:Heterozygote; D007763:Lac Operon; D008099:Liver / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D008957:Models, Genetic; D018482:Muscle, Skeletal / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D010766:Phosphorylation; D017027:Protein Tyrosine Phosphatases / Q000096:biosynthesis* / Q000235:genetics*; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2; D013154:Spleen / Q000378:metabolism; D013997:Time Factors; D014018:Tissue Distribution; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D017027:Protein Tyrosine Phosphatases; C516860:Ptprm protein, mouse; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2; D001616:beta-Galactosidase