Polyamines are involved in murine kidney development controlling expression of c-ret, E-cadherin, and Pax2/8 genes.
Polyamines play an important role in cell growth and differentiation. We studied changes in morphogenesis and the expression of the developmental control genes in the embryonic mouse kidney in response to polyamine depletion, using a kidney organ culture approach and reducing the polyamine pools with alpha-difluoromethylornithine (DFMO), an irreversible suicide inhibitor of ornithine decarboxylase (ODC). We found that inhibition of ODC results in a systematic kidney organogenesis phenotype, in that the DFMO-treated kidney specimens were of smaller size, had less epithelial ureteric bud branches, and their mesenchymal-derived tubule formation was retarded. These dysmorphologies were shown to be associated with changes in cell proliferation. Whole-mount in situ experiments revealed that inhibition of ODC causes increases in epithelial c-ret and E-cadherin and a decrease in mesenchymal Pax-8 expression, whereas levels of epithelial Wnt-11, mesenchymal GDNF, FoxD1, and Pax-2 transcripts remain unchanged. We studied regulation of the Pax-2 gene by analyzing a mouse line in which lacZ was driven by an 8.5 kb Pax-2 enhancer in the epithelial ureteric bud, and found that Pax-2 expression, as indicated by lacZ expression, increased after DFMO treatment. Transient transfection experiments in HEK 293 cells with the minimal Pax-2 promoter showed enhanced transcription upon reduction of the polyamine pools. We propose that ODC and polyamines have an important role in kidney organogenesis, being involved in the regulation of the expression of genes implicated in epithelial-mesenchymal tissue interactions.
Loikkanen
Ildikó
I
Department of Biochemistry, University of Oulu, PO Box 3000, FIN-90014 Oulu, Finland.
Lin
Yanfeng
Y
Railo
Antti
A
Pajunen
Antti
A
Vainio
Seppo
S
D000818:Animals; D015820:Cadherins / Q000235:genetics; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics; D000518:Eflornithine / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D007668:Kidney / Q000166:cytology / Q000196:embryology* / Q000201:enzymology; D051379:Mice; D009687:Nuclear Proteins / Q000235:genetics; D038081:Organogenesis / Q000187:drug effects / Q000235:genetics; D009955:Ornithine Decarboxylase / Q000235:genetics; D065108:Ornithine Decarboxylase Inhibitors; D051762:PAX2 Transcription Factor; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors; D011073:Polyamines / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000187:drug effects; D011518:Proto-Oncogene Proteins / Q000235:genetics; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic / Q000187:drug effects
D015820:Cadherins; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D009687:Nuclear Proteins; D065108:Ornithine Decarboxylase Inhibitors; D051762:PAX2 Transcription Factor; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors; C497319:Pax2 protein, mouse; C499496:Pax8 protein, mouse; D011073:Polyamines; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C494999:Ret protein, mouse; D009955:Ornithine Decarboxylase; D000518:Eflornithine