Rac2 Modulates Atherosclerotic Calcification by Regulating Macrophage Interleukin-1β Production.
OBJECTIVE
The calcium composition of atherosclerotic plaque is thought to be associated with increased risk for cardiovascular events, but whether plaque calcium itself is predictive of worsening clinical outcomes remains highly controversial. Inflammation is likely a key mediator of vascular calcification, but immune signaling mechanisms that promote this process are minimally understood.


RESULTS
Here, we identify Rac2 as a major inflammatory regulator of signaling that directs plaque osteogenesis. In experimental atherogenesis, Rac2 prevented progressive calcification through its suppression of Rac1-dependent macrophage interleukin-1β (IL-1β) expression, which in turn is a key driver of vascular smooth muscle cell calcium deposition by its ability to promote osteogenic transcriptional programs. Calcified coronary arteries from patients revealed decreased Rac2 expression but increased IL-1β expression, and high coronary calcium burden in patients with coronary artery disease was associated with significantly increased serum IL-1β levels. Moreover, we found that elevated IL-1β was an independent predictor of cardiovascular death in those subjects with high coronary calcium burden.


CONCLUSIONS
Overall, these studies identify a novel Rac2-mediated regulation of macrophage IL-1β expression, which has the potential to serve as a powerful biomarker and therapeutic target for atherosclerosis.
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Nicolle
N
Ceneri
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Lina
L
Zhao
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Bryan D
BD
Young
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Abigail
A
Healy
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Suleyman
S
Coskun
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Hema
H
Vasavada
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Timur O
TO
Yarovinsky
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Kenneth
K
Ike
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Ruggero
R
Pardi
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Lingfen
L
Qin
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Li
L
Qin
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
George
G
Tellides
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Karen
K
Hirschi
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Judith
J
Meadows
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Robert
R
Soufer
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Hyung J
HJ
Chun
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Mehran M
MM
Sadeghi
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.).
Jeffrey R
JR
Bender
From the Department of Internal Medicine (Section of Cardiovascular Medicine), VA Connecticut Healthcare System, West Haven (N.C., L.Z., A.H., L.Q., G.T., J.M., R.S., M.M.S., A.R.M.); Department of Medicine and Division of Cardiology, Providence VA Medical Center, RI (A.H., A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT (N.C., L.Z., B.D.Y., A.H., S.C., H.V., T.O.Y., K.I., L.Q., L.Q., G.T., K.H., J.M., R.S., H.J.C., M.M.S., J.R.B, A.R.M.); Department of Internal Medicine (Section of Cardiovascular Medicine), Alpert Medical School at Brown University, Providence, RI (A.H., A.R.M.); and Department of Molecular Pathology, Universita Vita Salute School of Medicine, San Raffaele Scientific Institute, Milan, Italy (R.P.). alan_morrison@brown.edu.
Alan R
AR
Morrison
D000818:Animals; D001011:Aorta / Q000201:enzymology / Q000473:pathology; D001018:Aortic Diseases / Q000201:enzymology* / Q000235:genetics / Q000473:pathology / Q000517:prevention & control; D001057:Apolipoproteins E / Q000172:deficiency / Q000235:genetics; D050197:Atherosclerosis / Q000201:enzymology* / Q000235:genetics / Q000473:pathology / Q000517:prevention & control; D002478:Cells, Cultured; D003324:Coronary Artery Disease / Q000201:enzymology* / Q000401:mortality / Q000473:pathology; D003331:Coronary Vessels / Q000201:enzymology / Q000473:pathology; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D053590:Interleukin 1 Receptor Antagonist Protein / Q000494:pharmacology; D053583:Interleukin-1beta / Q000378:metabolism*; D008264:Macrophages / Q000201:enzymology* / Q000473:pathology; D008297:Male; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009131:Muscle, Smooth, Vascular / Q000201:enzymology / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000201:enzymology / Q000473:pathology; D009479:Neuropeptides / Q000378:metabolism; D010641:Phenotype; D058226:Plaque, Atherosclerotic; D011379:Prognosis; D015398:Signal Transduction; D014162:Transfection; D015854:Up-Regulation; D061205:Vascular Calcification / Q000201:enzymology* / Q000401:mortality / Q000473:pathology; D020744:rac GTP-Binding Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D020830:rac1 GTP-Binding Protein / Q000378:metabolism; D000097766:RAC2 GTP-Binding Protein
D001057:Apolipoproteins E; D018836:Inflammation Mediators; D053590:Interleukin 1 Receptor Antagonist Protein; D053583:Interleukin-1beta; D009479:Neuropeptides; D020744:rac GTP-Binding Proteins; D020830:rac1 GTP-Binding Protein; D000097766:RAC2 GTP-Binding Protein; C508585:IL1B protein, human; C587672:IL1B protein, mouse; C484602:Rac1 protein, mouse
atherosclerosis; biomarkers; coronary artery disease; inflammation; macrophages