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Proteomics reveals lowering oxygen alters cytoskeletal and endoplasmatic stress proteins in human endothelial cells
Author(s) -
Østergaard Louise,
Simonsen Ulf,
EskildsenHelmond Yvonne,
Vorum Henrik,
Uldbjerg Niels,
Honoré Bent,
Mulvany Michael J.
Publication year - 2009
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.200800130
Subject(s) - downregulation and upregulation , cofilin , microbiology and biotechnology , cytoskeleton , unfolded protein response , actin , biology , apoptosis , chemistry , actin cytoskeleton , biochemistry , cell , endoplasmic reticulum , gene
Abstract A proteomic approach was applied to explore the signalling pathways elicited by lowering O 2 in endothelial cells. Endothelial cells isolated from native umbilical cords were subjected to 21, 5, or 1% O 2 for 24 h. 2‐D PAGE was performed and candidate proteins were identified using LC‐MS/MS. Lowering of O 2 from 21 to 5% induced upregulation of cofilin‐1, cyclophilin A, tubulin and tubulin fragments, a fragment of glucose‐regulated protein 78 (Grp78) and calmodulin. The upregulation of Grp78 suggested that ER stress proteins were altered and indeed Grp94 and caspase 12 expression were increased in cells exposed to 5% O 2 . The presence of ER stress is also supported by findings of blunted caffeine‐evoked ER calcium release in cells exposed to 5 and 1% O 2 . Exposure to 1% O 2 caused increases in cofilin‐1, cyclophilin A, and caspase 12 as well as a decrease of β‐actin, but it did not alter the expression of calmodulin, tubulin, Grp78, and Grp94. Incubation with CoCl 2 , a stabilizer of the hypoxia‐inducible factor, increased the expression of several of the proteins. The present investigations reveal that lowering O 2 , probably in part through hypoxia‐inducible factor, alter the expression of a series of proteins mainly involved in cytoskeletal changes ( e.g . cofilin‐1, tubulin, and β‐actin) and in ER stress/apoptosis ( e.g . Grp78/94, caspase 12, and cyclophilin A).