title: Effect of chronic uremia on the transcriptional profile of the calcified aorta analyzed by RNA sequencing.
abstract: The development of vascular calcification (VC) in chronic uremia (CU) is a tightly regulated process controlled by factors promoting and inhibiting mineralization. Next-generation high-throughput RNA sequencing (RNA-seq) is a powerful and sensitive tool for quantitative gene expression profiling and the detection of differentially expressed genes. In the present study, we, for the first time, used RNA-seq to examine rat aorta transcriptomes from CU rats compared with control rats. Severe VC was induced in CU rats, which lead to extensive changes in the transcriptional profile. Among the 10,153 genes with an expression level of >1 reads/kilobase transcript/million mapped reads, 2,663 genes were differentially expressed with 47% upregulated genes and 53% downregulated genes in uremic rats. Significantly deregulated genes were enriched for ontologies related to the extracellular matrix, response to wounding, organic substance, and ossification. The individually affected genes were of relevance to osteogenic transformation, tissue calcification, and Wnt modulation. Downregulation of the Klotho gene in uremia is believed to be involved in the development of VC, but it is debated whether the effect is caused by circulating Klotho only or if Klotho is produced locally in the vasculature. We found that Klotho was neither expressed in the normal aorta nor calcified aorta by RNA-seq. In conclusion, we demonstrated extensive changes in the transcriptional profile of the uremic calcified aorta, which were consistent with a shift in phenotype from vascular tissue toward an osteochondrocytic transcriptome profile. Moreover, neither the normal vasculature nor calcified vasculature in CU expresses Klotho.
authors.affiliation: Faculty of Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark;
authors.forename: Jakob L
authors.initials: JL
authors.lastname: Rukov
authors.affiliation: Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Nephrological Department P, Rigshospitalet, Copenhagen, Denmark;
authors.forename: Eva
authors.initials: E
authors.lastname: Gravesen
authors.affiliation: Nephrological Department P, Rigshospitalet, Copenhagen, Denmark; Nephrological Department B, Herlev Hospital, Copenhagen, Denmark;
authors.forename: Maria L
authors.initials: ML
authors.lastname: Mace
authors.affiliation: Nephrological Department P, Rigshospitalet, Copenhagen, Denmark;
authors.forename: Jacob
authors.initials: J
authors.lastname: Hofman-Bang
authors.affiliation: Faculty of Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark;
authors.forename: Jeppe
authors.initials: J
authors.lastname: Vinther
authors.affiliation: Department of Pathology, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Claus B
authors.initials: CB
authors.lastname: Andersen
authors.affiliation: Nephrological Department P, Rigshospitalet, Copenhagen, Denmark; Nephrological Department B, Herlev Hospital, Copenhagen, Denmark;
authors.forename: Ewa
authors.initials: E
authors.lastname: Lewin
authors.affiliation: Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Nephrological Department P, Rigshospitalet, Copenhagen, Denmark; olgaard@rh.dk Klaus.Oelgaard@regionh.dk.
authors.forename: Klaus
authors.initials: K
authors.lastname: Olgaard
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000378:metabolism*; D002908:Chronic Disease; D020869:Gene Expression Profiling; D063990:Gene Ontology; D005966:Glucuronidase / Q000378:metabolism; D000090265:Klotho Proteins; D008297:Male; D051381:Rats; D017423:Sequence Analysis, RNA; D014511:Uremia / Q000150:complications / Q000378:metabolism*; D061205:Vascular Calcification / Q000209:etiology / Q000378:metabolism*
chemical_list: D005966:Glucuronidase; D000090265:Klotho Proteins
keywords: Klotho; RNA-Seq; next-generation high-throughput RNA sequencing; uremia; vascular calcification