title: Induction of cellular senescence by insulin-like growth factor binding protein-5 through a p53-dependent mechanism.
abstract: The insulin-like growth factor (IGF) signaling pathway plays a crucial role in the regulation of cell growth, differentiation, apoptosis, and aging. IGF-binding proteins (IGFBPs) are important members of the IGF axis. IGFBP-5 is up-regulated during cellular senescence in human dermal fibroblasts and endothelial cells, but the function of IGFBP-5 in cellular senescence is unknown. Here we show that IGFBP-5 plays important roles in the regulation of cellular senescence. Knockdown of IGFBP-5 in old human umbilical endothelial cells (HUVECs) with IGFBP-5 micro-RNA lentivirus caused partial reduction of a variety of senescent phenotypes, such as changes in cell morphology, increases in cell proliferation, and decreases in senescence-associated beta-galactosidase (SA-beta-gal) staining. In addition, treatment with IGFBP-5 protein or up-regulation of IGFBP-5 in young cells accelerates cellular senescence, as confirmed by cell proliferation and SA-beta-gal staining. Premature senescence induced by IGFBP-5 up-regulation in young cells was rescued by knockdown of p53, but not by knockdown of p16. Furthermore, atherosclerotic arteries exhibited strong IGFBP-5-positive staining along intimal plaques. These results suggest that IGFBP-5 plays a role in the regulation of cellular senescence via a p53-dependent pathway and in aging-associated vascular diseases.
authors.affiliation: Department of Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, Daegu 705-717, Republic of Korea.
authors.forename: Kwang Seok
authors.initials: KS
authors.lastname: Kim
authors.forename: Young Bae
authors.initials: YB
authors.lastname: Seu
authors.forename: Suk-Hwan
authors.initials: SH
authors.lastname: Baek
authors.forename: Mi Jin
authors.initials: MJ
authors.lastname: Kim
authors.forename: Keuk Jun
authors.initials: KJ
authors.lastname: Kim
authors.forename: Jung Hye
authors.initials: JH
authors.lastname: Kim
authors.forename: Jae-Ryong
authors.initials: JR
authors.lastname: Kim
mesh_terms: D050197:Atherosclerosis / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects / Q000502:physiology*; D004247:DNA / Q000235:genetics; D004249:DNA Damage / Q000235:genetics; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D018975:Insulin-Like Growth Factor Binding Protein 5 / Q000235:genetics / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D035683:MicroRNAs / Q000235:genetics; D011499:Protein Processing, Post-Translational; D015398:Signal Transduction; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D014470:Umbilical Cord / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects