title: Identification of novel SHOX target genes in the developing limb using a transgenic mouse model.
abstract: Deficiency of the human short stature homeobox-containing gene (SHOX) has been identified in several disorders characterized by reduced height and skeletal anomalies such as Turner syndrome, Léri-Weill dyschondrosteosis and Langer mesomelic dysplasia as well as isolated short stature. SHOX acts as a transcription factor during limb development and is expressed in chondrocytes of the growth plates. Although highly conserved in vertebrates, rodents lack a SHOX orthologue. This offers the unique opportunity to analyze the effects of human SHOX expression in transgenic mice. We have generated a mouse expressing the human SHOXa cDNA under the control of a murine Col2a1 promoter and enhancer (Tg(Col2a1-SHOX)). SHOX and marker gene expression as well as skeletal phenotypes were characterized in two transgenic lines. No significant skeletal anomalies were found in transgenic compared to wildtype mice. Quantitative and in situ hybridization analyses revealed that Tg(Col2a1-SHOX), however, affected extracellular matrix gene expression during early limb development, suggesting a role for SHOX in growth plate assembly and extracellular matrix composition during long bone development. For instance, we could show that the connective tissue growth factor gene Ctgf, a gene involved in chondrogenic and angiogenic differentiation, is transcriptionally regulated by SHOX in transgenic mice. This finding was confirmed in human NHDF and U2OS cells and chicken micromass culture, demonstrating the value of the SHOX-transgenic mouse for the characterization of SHOX-dependent genes and pathways in early limb development.
authors.affiliation: Department of Human Molecular Genetics, Heidelberg University Hospital, Heidelberg, Germany.
authors.forename: Katja U
authors.initials: KU
authors.lastname: Beiser
authors.affiliation: Department of Human Molecular Genetics, Heidelberg University Hospital, Heidelberg, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Glaser
authors.affiliation: Division of Experimental Orthopaedics, Orthopaedic University Hospital, Heidelberg, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Kleinschmidt
authors.affiliation: Department of Human Molecular Genetics, Heidelberg University Hospital, Heidelberg, Germany.
authors.forename: Isabell
authors.initials: I
authors.lastname: Scholl
authors.affiliation: Department of Human Molecular Genetics, Heidelberg University Hospital, Heidelberg, Germany.
authors.forename: Ralph
authors.initials: R
authors.lastname: Röth
authors.affiliation: Medical Research Center (ZMF), Medical Faculty Mannheim at Heidelberg University, Mannheim, Germany.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Medical Research Center (ZMF), Medical Faculty Mannheim at Heidelberg University, Mannheim, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Gretz
authors.affiliation: Institute of Pathology, Heidelberg University Hospital, Heidelberg, Germany.
authors.forename: Gunhild
authors.initials: G
authors.lastname: Mechtersheimer
authors.affiliation: Department of Developmental Bioengineering, University of Twente, Enschede, The Netherlands.
authors.forename: Marcel
authors.initials: M
authors.lastname: Karperien
authors.affiliation: Department of Human Molecular Genetics, Heidelberg University Hospital, Heidelberg, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Antonio
authors.initials: A
authors.lastname: Marchini
authors.affiliation: Division of Experimental Orthopaedics, Orthopaedic University Hospital, Heidelberg, Germany.
authors.forename: Wiltrud
authors.initials: W
authors.lastname: Richter
authors.affiliation: Department of Human Molecular Genetics, Heidelberg University Hospital, Heidelberg, Germany.
authors.forename: Gudrun A
authors.initials: GA
authors.lastname: Rappold
mesh_terms: D000818:Animals; D018076:DNA, Complementary; D024202:Electrophoretic Mobility Shift Assay; D005121:Extremities / Q000196:embryology*; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D017403:In Situ Hybridization; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D018076:DNA, Complementary