title: Targets of transcriptional regulation by two distinct type I receptors for transforming growth factor-beta in human umbilical vein endothelial cells.
abstract: Transforming growth factor-beta (TGF-beta) plays a crucial role in vascular development and homeostasis by regulating many transcriptional targets. Activin receptor-like kinase 5 (ALK-5) is a TGF-beta type I receptor expressed in various TGF-beta-responsive cells. In contrast, ALK-1 functions as a TGF-beta type I receptor in endothelial cells, and is responsible for human hereditary hemorrhagic telangiectasia (HHT) type II. ALK-5 and ALK-1 mediate TGF-beta signals through distinct Smad proteins, i.e., Smad2/Smad3 and Smad1/Smad5, respectively. To identify target genes of ALK-1 and ALK-5 in endothelial cells, we conducted oligonucleotide microarray analysis. Human umbilical vein endothelial cells (HUVEC) were infected with recombinant adenoviruses carrying a constitutively active form of ALK-1 or ALK-5. ALK-5 inhibited the proliferation, network formation, and tube formation of HUVEC and induced their apoptosis, whereas ALK-1 did not exhibit significant effects on HUVEC in vitro. mRNAs were extracted from HUVEC and used for hybridization of oligonucleotide arrays representing approximately 7,000 human genes. Northern blot and quantitative real-time polymerase chain reaction (PCR) analyses were also performed for some of these genes, confirming the validity of this microarray analysis. We found that ALK-1 specifically upregulated Smad6, Smad7, Id1, Id2, endoglin, STAT1, and interleukin 1 receptor-like 1. ALK-5, in contrast, upregulated PlGF, SM22alpha, connexin 37, betaIG-H3, and LTBP1. ALK-1 downregulated Smad1, CXCR4, Ephrin-A1, and plakoglobin, whereas ALK-5 downregulated claudin 5 and integrin beta(5). These results revealed some new targets of TGF-beta in endothelial cells, and differences in transcriptional regulation patterns between ALK-1 and ALK-5.
authors.affiliation: Department of Molecular Pathology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Tatsuru
authors.initials: T
authors.lastname: Ota
authors.forename: Makiko
authors.initials: M
authors.lastname: Fujii
authors.forename: Takashi
authors.initials: T
authors.lastname: Sugizaki
authors.forename: Masami
authors.initials: M
authors.lastname: Ishii
authors.forename: Keiji
authors.initials: K
authors.lastname: Miyazawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Aburatani
authors.forename: Kohei
authors.initials: K
authors.lastname: Miyazono
mesh_terms: D030201:Activin Receptors, Type I / Q000145:classification / Q000235:genetics / Q000502:physiology*; D030301:Activin Receptors, Type II; D002478:Cells, Cultured; D015536:Down-Regulation; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D020869:Gene Expression Profiling; D006801:Humans; D008954:Models, Biological; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D017346:Protein Serine-Threonine Kinases; D012333:RNA, Messenger / Q000032:analysis; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000145:classification / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D016212:Transforming Growth Factor beta / Q000502:physiology; D014471:Umbilical Veins / Q000166:cytology; D015854:Up-Regulation
chemical_list: D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D017346:Protein Serine-Threonine Kinases; C425364:ACVRL1 protein, human; D030201:Activin Receptors, Type I; D030301:Activin Receptors, Type II; D000077293:Receptor, Transforming Growth Factor-beta Type I; C000625841:TGFBR1 protein, human