A mouse strain where basal connective tissue growth factor gene expression can be switched from low to high

• Published in: PloS one 2010-09, Vol.5 (9), p.e12909
• Main Authors: Doherty, Heather E, Kim, Hyung-Suk, Hiller, Sylvia, Sulik, Kathleen K, Maeda, Nobuyo
• Format: Article
• Language: English
• Subjects: 3' Untranslated regions; Abnormalities; Alleles; Analysis; Animal models; Animal tissues; Animals; Biocompatibility; Biomedical materials; Bone cancer; c-Fos protein; Cardiovascular disease; Cattle; Connective tissue growth factor; Connective Tissue Growth Factor - genetics; Connective Tissue Growth Factor - metabolism; Connective tissues; Developmental Biology/Embryology; Disease Models, Animal; Embryos; Extracellular matrix; Female; Fibrosis; Fibrosis - embryology; Fibrosis - genetics; Fibrosis - metabolism; Fos protein; Gene expression; Gene Expression Regulation; Genes; Genetic Engineering; Genetic research; Genetics and Genomics/Animal Genetics; Genetics and Genomics/Disease Models; Genetics and Genomics/Gene Function; Growth hormone; Growth Hormone - genetics; Growth hormones; Humans; Laboratories; Lethality; Male; Mice; Mice - embryology; Mice - genetics; Mice - metabolism; Mice, Inbred C57BL; Mice, Knockout; Molecular Biology/mRNA Stability; Mutants; Nucleotide sequence; Organ Specificity; Osteosarcoma; Pathology; Peptide Fragments - genetics; Promoter Regions, Genetic; Proto-Oncogene Proteins c-fos - genetics; Proto-Oncogene Proteins c-fos - metabolism; RNA; Rodents; Sarcoma; Sequences; Signaling; Somatotropin; Stem cells; Tamoxifen; Transcription
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0012909

Connective tissue growth factor (CTGF) is a signaling molecule that primarily functions in extracellular matrix maintenance and repair. Increased Ctgf expression is associated with fibrosis in chronic organ injury. Studying the role of CTGF in fibrotic disease in vivo, however, has been hampered by perinatal lethality of the Ctgf null mice as well as the limited scope of previous mouse models of Ctgf overproduction. Here, we devised a new approach and engineered a single mutant mouse strain where the endogenous Ctgf-3' untranslated region (3'UTR) was replaced with a cassette containing two 3'UTR sequences arranged in tandem. The modified Ctgf allele uses a 3'UTR from the mouse FBJ osteosarcoma oncogene (c-Fos) and produces an unstable mRNA, resulting in 60% of normal Ctgf expression (Lo allele). Upon Cre-expression, excision of the c-Fos-3'UTR creates a transcript utilizing the more stable bovine growth hormone (bGH) 3'UTR, resulting in increased Ctgf expression (Hi allele). Using the Ctgf Lo and Hi mutants, and crosses to a Ctgf knockout or Cre-expressing mice, we have generated a series of strains with a 30-fold range of Ctgf expression. Mice with the lowest Ctgf expression, 30% of normal, appear healthy, while a global nine-fold overexpression of Ctgf causes abnormalities, including developmental delay and craniofacial defects, and embryonic death at E10-12. Overexpression of Ctgf by tamoxifen-inducible Cre in the postnatal life, on the other hand, is compatible with life. The Ctgf Lo-Hi mutant mice should prove useful in further understanding the function of CTGF in fibrotic diseases. Additionally, this method can be used for the production of mouse lines with quantitative variations in other genes, particularly with genes that are broadly expressed, have distinct functions in different tissues, or where altered gene expression is not compatible with normal development.