title: Bone morphogenetic protein 3 controls insulin gene expression and is down-regulated in INS-1 cells inducibly expressing a hepatocyte nuclear factor 1A-maturity-onset diabetes of the young mutation.
abstract: Inactivating mutations in the transcription factor hepatocyte nuclear factor (HNF) 1A cause HNF1A-maturity-onset diabetes of the young (HNF1A-MODY), the most common monogenic form of diabetes. To examine HNF1A-MODY-induced defects in gene expression, we performed a microarray analysis of the transcriptome of rat INS-1 cells inducibly expressing the common hot spot HNF1A frameshift mutation, Pro291fsinsC-HNF1A. Real-time quantitative PCR (qPCR), Western blotting, immunohistochemistry, reporter assays, and chromatin immunoprecipitation (ChIP) were used to validate alterations in gene expression and to explore biological activities of target genes. Twenty-four hours after induction of the mutant HNF1A protein, we identified a prominent down-regulation of the bone morphogenetic protein 3 gene (Bmp-3) mRNA expression. Reporter assays, qPCR, and Western blot analysis validated these results. In contrast, inducible expression of wild-type HNF1A led to a time-dependent increase in Bmp-3 mRNA and protein levels. Moreover, reduced protein levels of BMP-3 and insulin were detected in islets of transgenic HNF1A-MODY mice. Interestingly, treatment of naïve INS-1 cells or murine organotypic islet cultures with recombinant human BMP-3 potently increased their insulin levels and restored the decrease in SMAD2 phosphorylation and insulin gene expression induced by the HNF1A frameshift mutation. Our study suggests a critical link between HNF1A-MODY-induced alterations in Bmp-3 expression and insulin gene levels in INS-1 cells and indicates that the reduced expression of growth factors involved in tissue differentiation may play an important role in the pathophysiology of HNF1A-MODY.
authors.affiliation: Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin 2, Ireland.
authors.forename: Caroline
authors.initials: C
authors.lastname: Bonner
authors.forename: Angela M
authors.initials: AM
authors.lastname: Farrelly
authors.forename: Caoimhín G
authors.initials: CG
authors.lastname: Concannon
authors.forename: Heiko
authors.initials: H
authors.lastname: Dussmann
authors.forename: Mathurin
authors.initials: M
authors.lastname: Baquié
authors.forename: Isabelle
authors.initials: I
authors.lastname: Virard
authors.forename: Hella
authors.initials: H
authors.lastname: Wobser
authors.forename: Donat
authors.initials: D
authors.lastname: Kögel
authors.forename: Claes B
authors.initials: CB
authors.lastname: Wollheim
authors.forename: Marjan
authors.initials: M
authors.lastname: Rupnik
authors.forename: Maria M
authors.initials: MM
authors.lastname: Byrne
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: König
authors.forename: Jochen H M
authors.initials: JH
authors.lastname: Prehn
mesh_terms: D000818:Animals; D055398:Bone Morphogenetic Protein 3 / Q000494:pharmacology*; D045744:Cell Line, Tumor; D015536:Down-Regulation / Q000187:drug effects* / Q000235:genetics; D016368:Frameshift Mutation / Q000187:drug effects*; D020869:Gene Expression Profiling; D051538:Hepatocyte Nuclear Factor 1-alpha / Q000235:genetics*; D006801:Humans; D007328:Insulin / Q000235:genetics*; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic / Q000235:genetics; D051381:Rats
chemical_list: D055398:Bone Morphogenetic Protein 3; D051538:Hepatocyte Nuclear Factor 1-alpha; D007328:Insulin