Transcriptional regulation of endothelial arginase 2 by histone deacetylase 2.
OBJECTIVE
Arginase 2 (Arg2) is a critical target in atherosclerosis because it controls endothelial nitric oxide, proliferation, fibrosis, and inflammation. Regulators of Arg2 transcription in the endothelium have not been characterized. The goal of the current study is to determine the role of specific histone deacetylases (HDACs) in the regulation of endothelial Arg2 transcription and endothelial function.


RESULTS
The HDAC inhibitor trichostatin A increased levels of Arg2 mRNA, protein, and activity in both human aortic endothelial cells and mouse aortic rings. These changes occurred in both time- and dose-dependent patterns and resulted in Arg2-dependent endothelial dysfunction. Trichostatin A and the atherogenic stimulus oxidized low-density lipoprotein enhanced the activity of common promoter regions of Arg2. HDAC inhibition with trichostatin A also decreased endothelial nitric oxide, and these effects were blunted by arginase inhibition. Nonselective class I HDAC inhibitors enhanced Arg2 expression, whereas the only selective inhibitor that increased Arg2 expression was mocetinostat, a selective inhibitor of HDACs 1 and 2. Additionally, mouse aortic rings preincubated with mocetinostat exhibited dysfunctional relaxation. Overexpression of HDAC2 (but not HDAC 1, 3, or 8) cDNA in human aortic endothelial cells suppressed Arg2 expression in a concentration-dependent manner, and siRNA knockdown of HDAC2 enhanced Arg2 expression. Chromatin immunoprecipitation indicated direct binding of HDAC2 to the Arg2 promoter, and HDAC2 overexpression in human aortic endothelial cells blocked oxidized low-density lipoprotein-mediated activation of the Arg2 promoter. Finally, overexpression of HDAC2 blocked oxidized low-density lipoprotein-mediated vascular dysfunction.


CONCLUSIONS
HDAC2 is a critical regulator of Arg2 expression and thereby endothelial nitric oxide and endothelial function. Overexpression or activation of HDAC2 represents a novel therapy for endothelial dysfunction and atherosclerosis.
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21287-4904.
Deepesh
D
Pandey
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21287-4904.
Gautam
G
Sikka
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21287-4904.
Yehudit
Y
Bergman
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21287-4904.
Jae Hyung
JH
Kim
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21287-4904.
Sungwoo
S
Ryoo
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21287-4904.|Department of Cell Biology, Johns Hopkins Medical Institutions, Baltimore, MD 21287-4904.|Department of Biomedical Engineering, Johns Hopkins Medical Institutions, Baltimore, MD 21287-4904.|Pediatrics, and the Center for Cell Dynamics, Johns Hopkins Medical Institutions, Baltimore, MD 21287-4904.
Lewis
L
Romer
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21287-4904.|Department of Biomedical Engineering, Johns Hopkins Medical Institutions, Baltimore, MD 21287-4904.
Dan
D
Berkowitz
D000818:Animals; D001119:Arginase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology* / Q000503:physiopathology; D015971:Gene Expression Regulation, Enzymologic; D057809:HEK293 Cells; D056464:Histone Deacetylase 2 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009569:Nitric Oxide / Q000378:metabolism; D011401:Promoter Regions, Genetic; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection; D014664:Vasodilation; D014665:Vasodilator Agents / Q000494:pharmacology
D056572:Histone Deacetylase Inhibitors; D008077:Lipoproteins, LDL; D012333:RNA, Messenger; D014665:Vasodilator Agents; C099252:oxidized low density lipoprotein; D009569:Nitric Oxide; C533423:HDAC2 protein, human; C533424:Hdac2 protein, mouse; D056464:Histone Deacetylase 2; C477631:ARG2 protein, human; C481673:Arg2 protein, mouse; D001119:Arginase
endothelial cells; epigenomics