title: Effect of cellular senescence on the albumin permeability of blood-derived endothelial cells.
abstract: In this study, we tested the hypotheses that endothelial cells (ECs) derived from human umbilical cord blood (hCB-ECs) exhibit low permeability, which increases as hCB-ECs age and undergo senescence, and that the change in the permeability of hCB-ECs is due to changes in tight junction protein localization and the activity of exchange protein activated by cAMP (Epac)1. Albumin permeability across low-passage hCB-EC monolayers on Transwell membranes was 10 times lower than for human aortic ECs (HAECs) (P < 0.01) but similar to in vivo values in arteries. Expression of the tight junction protein occludin and tyrosine phosphorylation of occludin were less in hCB-ECs than in HAECs (P < 0.05). More hCB-ECs than HAECs underwent mitosis (P < 0.01). hCB-ECs that underwent >44 population doublings since isolation had a significantly higher permeability than hCB-ECs that underwent <31 population doublings (P < 0.05). This age-related increase in hCB-EC permeability was associated with an increase in tyrosine phosphorylation of occludin (P < 0.01); permeability and occludin phosphorylation were reduced by treatment with 2 μM resveratrol. Tyrosine phosphorylation of occludin and cell age influence the permeability of hCB-ECs, whereas levels of EC proliferation and expression of tight junction proteins did not explain the differences between hCB-EC and HAEC permeability. The elevated permeability in late passage hCB-ECs was reduced by 25-40% by elevation of membrane-associated cAMP and activation of the Epac1 pathway. Given the similarity to in vivo permeability to albumin and the high proliferation potential, hCB-ECs may be a suitable in vitro model to study transport-related pathologies and cell aging.
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.
authors.forename: Tracy M
authors.initials: TM
authors.lastname: Cheung
authors.forename: Mansi P
authors.initials: MP
authors.lastname: Ganatra
authors.forename: Erica B
authors.initials: EB
authors.lastname: Peters
authors.forename: George A
authors.initials: GA
authors.lastname: Truskey
mesh_terms: D000418:Albumins / Q000378:metabolism*; D001011:Aorta / Q000166:cytology*; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000502:physiology*; D000242:Cyclic AMP / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism*; D005312:Fetal Blood / Q000166:cytology*; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D062793:Occludin / Q000378:metabolism; D010766:Phosphorylation; D000077185:Resveratrol; D015398:Signal Transduction / Q000502:physiology; D056564:Sirtuin 1 / Q000378:metabolism; D013267:Stilbenes / Q000494:pharmacology; D062725:Tight Junction Proteins / Q000378:metabolism
chemical_list: D000418:Albumins; D020662:Guanine Nucleotide Exchange Factors; D062793:Occludin; C116122:RAPGEF3 protein, human; D013267:Stilbenes; D062725:Tight Junction Proteins; D000242:Cyclic AMP; C447939:SIRT1 protein, human; D056564:Sirtuin 1; D000077185:Resveratrol