title: High levels of oncomiR-21 contribute to the senescence-induced growth arrest in normal human cells and its knock-down increases the replicative lifespan.
abstract: Cellular senescence of normal human cells has by now far exceeded its initial role as a model system for aging research. Many reports show the accumulation of senescent cells in vivo, their effect on their microenvironment and its double-edged role as tumour suppressor and promoter. Importantly, removal of senescent cells delays the onset of age-associated diseases in mouse model systems. To characterize the role of miRNAs in cellular senescence of endothelial cells, we performed miRNA arrays from HUVECs of five different donors. Twelve miRNAs, comprising hsa-miR-23a, hsa-miR-23b, hsa-miR-24, hsa-miR-27a, hsa-miR-29a, hsa-miR-31, hsa-miR-100, hsa-miR-193a, hsa-miR-221, hsa-miR-222 and hsa-let-7i are consistently up-regulated in replicatively senescent cells. Surprisingly, also miR-21 was found up-regulated by replicative and stress-induced senescence, despite being described as oncogenic. Transfection of early passage endothelial cells with miR-21 resulted in lower angiogenesis, and less cell proliferation mirrored by up-regulation of p21(CIP1) and down-regulation of CDK2. These two cell-cycle regulators are indirectly regulated by miR-21 via its validated direct targets NFIB (Nuclear factor 1 B-type), a transcriptional inhibitor of p21(CIP) (1) , and CDC25A, which regulates CDK2 activity by dephosphorylation. Knock-down of either NFIB or CDC25A shows a phenocopy of over-expressing miR-21 in regard to cell-cycle arrest. Finally, miR-21 over-epxression reduces the replicative lifespan, while stable knock-down by sponges extends the replicative lifespan of endothelial cells. Therefore, we propose that miR-21 is the first miRNA that upon its knock-down extends the replicative lifespan of normal human cells.
authors.affiliation: Department of Biotechnology, BOKU-VIBT University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190, Vienna, Austria.
authors.forename: Hanna
authors.initials: H
authors.lastname: Dellago
authors.forename: Barbara
authors.initials: B
authors.lastname: Preschitz-Kammerhofer
authors.forename: Lucia
authors.initials: L
authors.lastname: Terlecki-Zaniewicz
authors.forename: Carina
authors.initials: C
authors.lastname: Schreiner
authors.forename: Klaus
authors.initials: K
authors.lastname: Fortschegger
authors.forename: Martina W-F
authors.initials: MW
authors.lastname: Chang
authors.forename: Matthias
authors.initials: M
authors.lastname: Hackl
authors.forename: Rossella
authors.initials: R
authors.lastname: Monteforte
authors.forename: Harald
authors.initials: H
authors.lastname: Kühnel
authors.forename: Markus
authors.initials: M
authors.lastname: Schosserer
authors.forename: Florian
authors.initials: F
authors.lastname: Gruber
authors.forename: Erwin
authors.initials: E
authors.lastname: Tschachler
authors.forename: Marcel
authors.initials: M
authors.lastname: Scheideler
authors.forename: Regina
authors.initials: R
authors.lastname: Grillari-Voglauer
authors.forename: Johannes
authors.initials: J
authors.lastname: Grillari
authors.forename: Matthias
authors.initials: M
authors.lastname: Wieser
mesh_terms: D017209:Apoptosis; D049109:Cell Proliferation; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000235:genetics*; D051357:Cyclin-Dependent Kinase 2 / Q000096:biosynthesis / Q000378:metabolism*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism; D006801:Humans; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism*; D051839:NFI Transcription Factors / Q000235:genetics / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000235:genetics; D034622:RNA Interference; D034741:RNA, Small Interfering; D014162:Transfection; D015854:Up-Regulation; D020687:cdc25 Phosphatases / Q000235:genetics
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D051839:NFI Transcription Factors; D034741:RNA, Small Interfering; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2; C517004:CDC25A protein, human; D020687:cdc25 Phosphatases