25-Hydroxycholesterol impairs endothelial function and vasodilation by uncoupling and inhibiting endothelial nitric oxide synthase.
Endothelial dysfunction is a key early step in atherosclerosis. 25-Hydroxycholesterol (25-OHC) is found in atherosclerotic lesions. However, whether 25-OHC promotes atherosclerosis is unclear. Here, we hypothesized that 25-OHC, a proinflammatory lipid, can impair endothelial function, which may play an important role in atherosclerosis. Bovine aortic endothelial cells were incubated with 25-OHC. Endothelial cell proliferation, migration, and tube formation were measured. Nitric oxide (NO) production and superoxide anion generation were determined. The expression and phosphorylation of endothelial NO synthase (eNOS) and Akt as well as the association of eNOS and heat shock protein (HSP)90 were detected by immunoblot analysis and immunoprecipitation. Endothelial cell apoptosis was monitored by TUNEL staining and caspase-3 activity, and expression of Bcl-2, Bax, cleaved caspase-9, and cleaved caspase-3 were detected by immunoblot analysis. Finally, aortic rings from Sprague-Dawley rats were isolated and treated with 25-OHC, and endothelium-dependent vasodilation was evaluated. 25-OHC significantly inhibited endothelial cell proliferation, migration, and tube formation. 25-OHC markedly decreased NO production and increased superoxide anion generation. 25-OHC reduced the phosphorylation of Akt and eNOS and the association of eNOS and HSP90. 25-OHC also enhanced endothelial cell apoptosis by decreasing Bcl-2 expression and increasing cleaved caspase-9 and cleaved caspase-3 expressions as well as caspase-3 activity. 25-OHC impaired endothelium-dependent vasodilation. These data demonstrated that 25-OHC could impair endothelial function by uncoupling and inhibiting eNOS activity as well as by inducing endothelial cell apoptosis. Our findings indicate that 25-OHC may play an important role in regulating atherosclerosis.
Division of Hypertension and Vascular Diseases, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; The Key Laboratory of Assisted Circulation, Ministry of Health, Guangzhou, China; Guangdong Province Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; and.
Zhi-Jun
ZJ
Ou
Division of Hypertension and Vascular Diseases, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; The Key Laboratory of Assisted Circulation, Ministry of Health, Guangzhou, China; Guangdong Province Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; and.
Jing
J
Chen
Division of Cardiac Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; The Key Laboratory of Assisted Circulation, Ministry of Health, Guangzhou, China; Guangdong Province Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; and.
Wei-Ping
WP
Dai
Division of Cardiac Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; The Key Laboratory of Assisted Circulation, Ministry of Health, Guangzhou, China; Guangdong Province Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; and.
Xiang
X
Liu
Division of Cardiac Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; The Key Laboratory of Assisted Circulation, Ministry of Health, Guangzhou, China; Guangdong Province Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; and.
Yin-Ke
YK
Yang
Division of Cardiac Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; The Key Laboratory of Assisted Circulation, Ministry of Health, Guangzhou, China; Guangdong Province Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; and.
Yan
Y
Li
Division of Cardiac Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; The Key Laboratory of Assisted Circulation, Ministry of Health, Guangzhou, China; Guangdong Province Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; and.
Ze-Bang
ZB
Lin
Division of Cardiac Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; The Key Laboratory of Assisted Circulation, Ministry of Health, Guangzhou, China; Guangdong Province Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; and.
Tian-Tian
TT
Wang
Division of Cardiac Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; The Key Laboratory of Assisted Circulation, Ministry of Health, Guangzhou, China; Guangdong Province Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; and.
Ying-Ying
YY
Wu
Division of Cardiac Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; The Key Laboratory of Assisted Circulation, Ministry of Health, Guangzhou, China; Guangdong Province Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; and.
Dan-Hong
DH
Su
Division of Cardiac Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; The Key Laboratory of Assisted Circulation, Ministry of Health, Guangzhou, China; Guangdong Province Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; and.
Tian-Pu
TP
Cheng
Division of Cardiac Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; The Key Laboratory of Assisted Circulation, Ministry of Health, Guangzhou, China; Guangdong Province Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; and.
Zhi-Ping
ZP
Wang
Division of Hypertension and Vascular Diseases, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; The Key Laboratory of Assisted Circulation, Ministry of Health, Guangzhou, China; Guangdong Province Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; and.
Jun
J
Tao
Division of Cardiac Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China; The Key Laboratory of Assisted Circulation, Ministry of Health, Guangzhou, China; Guangdong Province Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, Guangzhou, China; and Guangdong Provincial Key Laboratory of Brain Function and Disease, Guangzhou, China oujs@mail.sysu.edu.cn oujs2000@yahoo.com.
Jing-Song
JS
Ou
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002417:Cattle; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D004727:Endothelium / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006888:Hydroxycholesterols / Q000494:pharmacology*; D066298:In Vitro Techniques; D018836:Inflammation Mediators / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013481:Superoxides / Q000378:metabolism; D014475:Uncoupling Agents / Q000494:pharmacology*; D014664:Vasodilation / Q000187:drug effects*
D004791:Enzyme Inhibitors; D006888:Hydroxycholesterols; D018836:Inflammation Mediators; D014475:Uncoupling Agents; D013481:Superoxides; D009569:Nitric Oxide; C007997:25-hydroxycholesterol; D052250:Nitric Oxide Synthase Type III
25-hydroxycholesterol; apoptosis; atherosclerosis; endothelial nitric oxide synthase; vasodilation