Serum IF1 concentration is independently associated to HDL levels and to coronary heart disease: the GENES study

Abstract

HDL is strongly inversely related to cardiovascular risk. Hepatic HDL uptake is controlled by ecto-F1-ATPase activity, and potentially inhibited by mitochondrial inhibitor factor 1 (IF1). We recently found that IF1 is present in serum and correlates with HDL-cholesterol (HDL-C). Here, we have evaluated the relationship between circulating IF1 and plasma lipoproteins, and we determined whether IF1 concentration is associated with the risk of coronary heart disease (CHD). Serum IF1 was measured in 648 coronary patients ages 45–74 and in 669 matched male controls, in the context of a cross-sectional study on CHD. Cardiovascular risk factors were documented for each participant, including life-style habits and biological and clinical markers. In controls, multivariate analysis demonstrated that IF1 was independently positively associated with HDL-C and apoA-I (r= 0.27 and 0.28, respectively, P < 0.001) and negatively with triglycerides (r=−0.23, P < 0.001). Mean IF1 concentration was lower in CHD patients than in controls (0.43 mg/l and 0.53 mg/l, respectively, P < 0.001). In multivariate analyses, following adjustments on cardiovascular risk factors or markers, IF1 was negatively related to CHD (P < 0.001). This relationship was maintained after adjustment for HDL-C or apoA-I. This study identifies IF1 as a new determinant of HDL-C that is inversely associated with CHD. HDL is strongly inversely related to cardiovascular risk. Hepatic HDL uptake is controlled by ecto-F1-ATPase activity, and potentially inhibited by mitochondrial inhibitor factor 1 (IF1). We recently found that IF1 is present in serum and correlates with HDL-cholesterol (HDL-C). Here, we have evaluated the relationship between circulating IF1 and plasma lipoproteins, and we determined whether IF1 concentration is associated with the risk of coronary heart disease (CHD). Serum IF1 was measured in 648 coronary patients ages 45–74 and in 669 matched male controls, in the context of a cross-sectional study on CHD. Cardiovascular risk factors were documented for each participant, including life-style habits and biological and clinical markers. In controls, multivariate analysis demonstrated that IF1 was independently positively associated with HDL-C and apoA-I (r= 0.27 and 0.28, respectively, P < 0.001) and negatively with triglycerides (r=−0.23, P < 0.001). Mean IF1 concentration was lower in CHD patients than in controls (0.43 mg/l and 0.53 mg/l, respectively, P < 0.001). In multivariate analyses, following adjustments on cardiovascular risk factors or markers, IF1 was negatively related to CHD (P < 0.001). This relationship was maintained after adjustment for HDL-C or apoA-I. This study identifies IF1 as a new determinant of HDL-C that is inversely associated with CHD. Despite considerable advances in the treatment of cardiovascular diseases, they remain among the leading causes of death in developed countries. Several large-scale prospective studies evidenced an independent inverse association of HDL-cholesterol (HDL-C) levels with risk of coronary heart disease (CHD) (1Navab M. Reddy S.T. Van Lenten B.J. Fogelman A.M. HDL and cardiovascular disease: atherogenic and atheroprotective mechanisms.Nat. Rev. Cardiol. 2011; 8: 222-232Crossref PubMed Scopus (456) Google Scholar). Accordingly, studies in genetically modified animals, and in patients with rare disorders of HDL metabolism, support a causal relationship between low HDL and development of atherosclerotic vascular disease (1Navab M. Reddy S.T. Van Lenten B.J. Fogelman A.M. HDL and cardiovascular disease: atherogenic and atheroprotective mechanisms.Nat. Rev. Cardiol. 2011; 8: 222-232Crossref PubMed Scopus (456) Google Scholar, 2Francis G.A. The complexity of HDL.Biochim. Biophys. Acta. 2010; 1801: 1286-1293Crossref PubMed Scopus (57) Google Scholar). A low level of HDL-C (generally considered as <40 mg/dl in men and <50 mg/dl in women) remains predictive of future cardiovascular risk, even when the concentration of LDL-cholesterol (LDL-C) has reached low levels upon treatment with statins (3Barter P. Gotto A.M. LaRosa J.C. Maroni J. Szarek M. Grundy S.M. Kastelein J.J.P. Bittner V. Fruchart J-C. HDL cholesterol, very low levels of LDL cholesterol, and cardiovascular events.N. Engl. J. Med. 2007; 357: 1301-1310Crossref PubMed Scopus (1295) Google Scholar). Research to understand the protective effects of HDL against coronary artery disease (CAD) has yielded a large number of likely beneficial actions of HDL particles and their components, such as antiinflammatory, antithrombotic, antioxidative, and cytoprotective effects (1Navab M. Reddy S.T. Van Lenten B.J. Fogelman A.M. HDL and cardiovascular disease: atherogenic and atheroprotective mechanisms.Nat. Rev. Cardiol. 2011; 8: 222-232Crossref PubMed Scopus (456) Google Scholar). However, the best-characterized protective action of HDL is their central contribution in a process called reverse cholesterol transport (RCT), a process whereby cholesterol is transported from peripheral cells to the liver for further excretion into bile and feces. Thus, these pleiotropic cardioprotective functions of HDL, supported by epidemiological studies, led to the idea that therapies aiming at enhancing plasma HDL levels would be antiatherogenic and protective against cardiovascular events. However, this issue was revived with recent results from large clinical trials showing that some mechanisms that enhance HDL levels are not necessarily beneficial toward atherosclerosis (4Boden W.E. Probstfield J.L. Anderson T. Chaitman B.R. Desvignes-Nickens P. Koprowicz K. McBride R. Teo K. Weintraub W. Niacin in patients with low HDL cholesterol levels receiving intensive statin therapy.N. Engl. J. Med. 2011; 365: 2255-2267Crossref PubMed Scopus (2267) Google Scholar, 5Schwartz G.G. Olsson A.G. Abt M. Ballantyne C.M. Barter P.J. Brumm J. Chaitman B.R. Holme I.M. Kallend D. Leiter L.a. et al.Effects of dalcetrapib in patients with a recent acute coronary syndrome.N. Engl. J. Med. 2012; 367: 2089-2099Crossref PubMed Scopus (1554) Google Scholar). HDL is highly heterogeneous with subclasses that differ in composition and physical properties, and display different antiatherogenic properties (6Camont L. Chapman M.J. Kontush A. Biological activities of HDL subpopulations and their relevance to cardiovascular disease.Trends Mol. Med. 2011; 17: 594-603Abstract Full Text Full Text PDF PubMed Scopus (317) Google Scholar). Moreover, several environmental factors, such as tobacco and alcohol consumption, physical activity, or inflammation, are known to influence plasma HDL levels and functions (1Navab M. Reddy S.T. Van Lenten B.J. Fogelman A.M. HDL and cardiovascular disease: atherogenic and atheroprotective mechanisms.Nat. Rev. Cardiol. 2011; 8: 222-232Crossref PubMed Scopus (456) Google Scholar). Given the complexity of the HDL system, it has emerged that a single measurement of HDL-C level often fails to provide a reliable prediction of HDL biological activities (7Calabresi L. Gomaraschi M. Franceschini G. High-density lipoprotein quantity or quality for cardiovascular prevention?.Curr. Pharm. Des. 2010; 16: 1494-1503Crossref PubMed Scopus (31) Google Scholar). Therefore, new biological markers reflecting metabolic or vascular activities of HDL lipoproteins are needed to better evaluate patients’ cardiovascular risk or to evaluate their responsiveness to emergent HDL-related therapies (2Francis G.A. The complexity of HDL.Biochim. Biophys. Acta. 2010; 1801: 1286-1293Crossref PubMed Scopus (57) Google Scholar). In this context, we previously demonstrated the presence of a protein complex, related to mitochondrial ATP-synthase, on the surface of human hepatocytes, behaving as a high-affinity receptor for HDL apolipoprotein A-I (apoA-I). ApoA-I binds to cell surface ATP-synthase (namely, ecto-F1-ATPase), stimulating extracellular ATP hydrolysis into ADP (8Martinez L.O. Jacquet S. Esteve J.P. Rolland C. Cabezon E. Champagne E. Pineau T. Georgeaud V. Walker J.E. Terce F. et al.Ectopic beta-chain of ATP synthase is an apolipoprotein A-I receptor in hepatic HDL endocytosis.Nature. 2003; 421: 75-79Crossref PubMed Scopus (388) Google Scholar). ADP further activates the nucleotide receptor P2Y13, resulting in HDL endocytosis (9Jacquet S. Malaval C. Martinez L.O. Sak K. Rolland C. Perez C. Nauze M. Champagne E. Terce F. Gachet C. et al.The nucleotide receptor P2Y13 is a key regulator of hepatic high-density lipoprotein (HDL) endocytosis.Cell. Mol. Life Sci. 2005; 62: 2508-2515Crossref PubMed Scopus (94) Google Scholar). We and others (10Fabre A.C. Malaval C. Ben Addi A. Verdier C. Pons V. Serhan N. Lichtenstein L. Combes G. Huby T. Briand F. et al.P2Y13 receptor is critical for reverse cholesterol transport.Hepatology. 2010; 52: 1477-1483Crossref PubMed Scopus (88) Google Scholar, 11Blom D. Yamin T.T. Champy M. E. E. L. S. R. J. et lipoprotein in Biophys. Acta. 2010; 1801: PubMed Scopus Google that HDL hepatic and HDL levels were maintained or the that serum HDL levels not necessarily the of HDL to High-density lipoprotein and in reverse cholesterol 2010; PubMed Scopus Google Scholar). factor 1 is a mitochondrial protein of that the of the mitochondrial synthase A inhibitor of mitochondrial Full Text PDF PubMed Google Scholar). human and we previously demonstrated that IF1 HDL uptake (8Martinez L.O. Jacquet S. Esteve J.P. Rolland C. Cabezon E. Champagne E. Pineau T. Georgeaud V. Walker J.E. Terce F. et al.Ectopic beta-chain of ATP synthase is an apolipoprotein A-I receptor in hepatic HDL endocytosis.Nature. 2003; 421: 75-79Crossref PubMed Scopus (388) Google Scholar). In we recently the presence of IF1 in human and we developed a for this A. Pons V. C. F. Combes G. Rolland C. N. F. et factor 1 is present in human serum and is positively with 2011; PubMed Scopus Google Scholar). in have a association of IF1 level with HDL-C A. Pons V. C. F. Combes G. Rolland C. N. F. et factor 1 is present in human serum and is positively with 2011; PubMed Scopus Google Scholar). In the present IF1 were in the of a study on CHD. The results in of IF1 a new determinant of HDL levels and a of cardiovascular risk. IF1 be for CHD risk in with low HDL The et study is a study to the of and environmental in the of CHD. an The study was by the A biological has as to the of Research and to the previously were CHD ages in the and from to after to the for cardiovascular and for and of their CHD F. V. S. D. J. D. M. M. J. of clinical and peripheral disease in men with coronary heart J. Cardiol. 2012; Full Text Full Text PDF PubMed Scopus Google Scholar, S. M. V. F. Verdier C. C. A. D. M. et and in coronary artery disease and PubMed Scopus Google Scholar). CHD was by a of acute coronary a of coronary artery a documented a or the presence at coronary of a coronary of or an acute coronary the were not in the they were considered the male controls, ages were from the into was to the of the with and CHD. with and CHD were in the after an with CHD were in the of the and a coronary were in the The with by a this and on the of the study and a a was from each for level of at alcohol consumption, physical activity, on cardiovascular risk factors, and and The was with and clinical was as for at the and was as the number of was was into for a for a and for at a or In this was considered and as a or a of or was from the In with their at was and and heart were measured with an was measured and the was were after a were for serum cholesterol, triglycerides and protein with on an and lipoprotein were with an on an was the with as as concentration was of the concentration of lipoprotein cholesterol in of the PubMed Scopus Google Scholar). and or were by a A was developed to IF1 in human as previously A. Pons V. C. F. Combes G. Rolland C. N. F. et factor 1 is present in human serum and is positively with 2011; PubMed Scopus Google Scholar). the and a of of was measured in to and was on different with a between to of IF1 with HDL markers, with A-I and in this In the of and apoA-I with clinical and biological markers were of IF1 with HDL-C and apoA-I were a multivariate of HDL-C on IF1 and apoA-I on IF1 were of IF1 on HDL-C or apoA-I and lipoprotein were A was to for The for a to be in the to be at P < were further maintained in the when the was at P < However, with were not as an risk was in each were with to for with of for IF1 and HDL-C or apoA-I was by the factors in the between IF1 and were The contribution to the for each was In the are as for and as with for The was to the of between and The of were by was to the of of and to the of the of were not the were or to a multivariate were to the association of and apoA-I with CHD. were for cardiovascular risk and for physical activity, alcohol consumption, and were found associated with CHD the IF1 a further adjustment was for HDL-C or apoA-I. of and apoA-I were was mg/l for for and for to the between IF1 and HDL-C or apoA-I. The was to The of the was evaluated by analysis of the the The of the prediction was evaluated by in and and and Med. PubMed Scopus Google were and with and IF1 or or in were the or a PubMed Scopus Google Scholar). were and P < was considered to be was with and with of IF1 levels in the male controls ages demonstrated a with a at 0.53 mg/l and a of mg/l 1 and Serum IF1 was positively with HDL-C and and negatively with triglycerides and lipoproteins and HDL-C and apoA-I as a of of IF1 in the the study with male it is likely that the relationship between serum IF1 and among In a we measured IF1 among in a study in the Mean IF1 level was mg/l A with HDL-C and a with concentration were and biological of the study of on on cholesterol mg/l < for for for habits physical at a physical a or are as or on physical at a physical a or in a new between IF1 and HDL-C IF1 and apoA-I and IF1 and triglycerides in of measurement in 669 male are between and cardiovascular risk factors in cholesterol < < < in a new are as or < < < between IF1 levels and metabolic or cardiovascular risk markers were and with for HDL-C and apoA-I and were negatively with and factors, such as alcohol consumption, physical activity, and an as documented by with HDL-C or with IF1 were or in the of alcohol This that IF1 for are by environmental that are known to HDL-C or apoA-I This was supported by multivariate among we developed that IF1 as an of HDL-C or apoA-I In of HDL-C concentration was the determinant of HDL-C levels inversely by serum positively associated In of apoA-I alcohol and serum IF1 were the of apoA-I and tobacco or an was a physical was positively Serum IF1 was as the in were developed that HDL-C or apoA-I as The and respectively, of IF1 HDL-C or apoA-I were the of the by and levels as positively and to IF1 to a analysis of HDL-C and apoA-I on IF1 in the of HDL-C on IF1 of apoA-I on IF1 of of mg/l < < physical for at a physical a or of physical for at a physical a or in a new of CHD and were considered of risk factors was in CHD and and were in than in level and physical were of alcohol were not different between and However, alcohol were with a of alcohol in controls a of and in not metabolic markers, or were lower in CHD reflecting effects of in However, CHD levels of lipoproteins and and lower HDL markers. of of metabolic to the of IF1 was in CHD 0.53 mg/l in controls (P < We determined IF1 levels in and controls or not for or and we of on serum IF1 A analysis of risk factors associated with of CHD in study or and low physical A to association was for Thus, these factors were into for further were the CHD and and IF1 as following adjustments on cardiovascular risk factors and markers between the were into and with were determined A association with CHD was with levels of the effects of IF1 were and with a than with HDL-C or apoA-I. of IF1 were after a further adjustment on and of IF1 associated with a of CHD risk and adjustment was on apoA-I levels of of IF1 associated with a that results on IF1 were not by the of a coronary were after patients an acute in the were to in the was to provide a of were found when and IF1 were considered as not The of the was Thus, multivariate in of IF1 independently negatively associated with CHD. A on CHD risk, between IF1 and HDL-C or apoA-I levels and respectively, this and apoA-I were considered from of their and the were low levels of HDL-C an IF1 a of the for CHD (P < 0.001). A was in the reverse at low levels of IF1 with However, risk was P < 0.001) when markers were of IF1 and HDL-C was associated with an of than of the markers low levels of apoA-I an IF1 a risk (P < 0.001). was (P < 0.001) when markers were However, an apoA-I by a of CHD that the beneficial of IF1 in of association to CHD is at low levels of HDL-C or apoA-I were considered for were for of coronary heart disease and IF1 as for on for and on physical activity, and alcohol and on and for for for apoA-I. in a new of CHD for and with for P a a P < P < P < P < with for P a a P < P < P < P < with for P a a P < P < P < P < with for P a a P < P < P < P < with for P a a P < P < P < P < with for P a a P < P < P < P < for physical activity, alcohol consumption, and IF1 HDL-C IF1 apoA-I for HDL-C and apoA-I were considered from of with for P a a P < P < P < P < in a new on for and on physical activity, and alcohol and on and for for for for physical activity, alcohol consumption, and IF1 HDL-C IF1 apoA-I for HDL-C and apoA-I were considered from of further the with were cardiovascular risk factors and markers with or or cardiovascular risk factors and markers between the subpopulations and physical activity, and alcohol and and The for this was as CHD. was after to the of IF1 P < for the or HDL-C P < 0.001). in the of IF1 concentration with HDL-C with with P < A we found that an related to mitochondrial ATP-synthase, was a high-affinity receptor for leading to liver uptake of HDL particles (8Martinez L.O. Jacquet S. Esteve J.P. Rolland C. Cabezon E. Champagne E. Pineau T. Georgeaud V. Walker J.E. Terce F. et al.Ectopic beta-chain of ATP synthase is an apolipoprotein A-I receptor in hepatic HDL endocytosis.Nature. 2003; 421: 75-79Crossref PubMed Scopus (388) Google Scholar). we the presence in human serum of the inhibitor of mitochondrial and we developed a for serum IF1 A. Pons V. C. F. Combes G. Rolland C. N. F. et factor 1 is present in human serum and is positively with 2011; PubMed Scopus Google Scholar). In the present for the large-scale of serum IF1 were in the context of a study on CHD. In from the we found between serum IF1 and and on a of patients A. Pons V. C. F. Combes G. Rolland C. N. F. et factor 1 is present in human serum and is positively with 2011; PubMed Scopus Google Scholar). Moreover, adjustments to that IF1 is an independent and of HDL-C or apoA-I in the that HDL-related markers are the of IF1 IF1 not be in human HDL not and as previously A. Pons V. C. F. Combes G. Rolland C. N. F. et factor 1 is present in human serum and is positively with 2011; PubMed Scopus Google Scholar). Accordingly, IF1 has to be associated with HDL in studies and such as and in studies, IF1 is not likely associated with HDL T. of and 2012; PubMed Scopus Google Scholar, The of of in transport and J. of Scholar). IF1 is circulating as an and protein further However, that IF1 be from serum into of each A. Pons V. C. F. Combes G. Rolland C. N. F. et factor 1 is present in human serum and is positively with 2011; PubMed Scopus Google Scholar). this to a of is the of IF1 the E. P. G. Walker J.E. of by the inhibitor Full Text Full Text PDF PubMed Scopus Google we that the some or of IF1 or that circulating IF1 is associated with serum The between circulating IF1 and HDL levels support to the in this new is in HDL be to this IF1 is a mitochondrial to the ATP of mitochondrial ATP-synthase E. A.G. Walker J.E. The of in with protein 2003; PubMed Scopus Google Scholar). of this complex, and of the have found present at the surface of including P. C. Lichtenstein L. Pons V. Champagne E. Martinez L.O. a protein and an apoA-I J. 2010; 16: Google Scholar). We have that apoA-I binds to cell surface and ATP activity, P2Y13 and a further to the uptake by of protein and of the HDL a process called endocytosis (8Martinez L.O. Jacquet S. Esteve J.P. Rolland C. Cabezon E. Champagne E. Pineau T. Georgeaud V. Walker J.E. Terce F. et al.Ectopic beta-chain of ATP synthase is an apolipoprotein A-I receptor in hepatic HDL endocytosis.Nature. 2003; 421: 75-79Crossref PubMed Scopus (388) Google Scholar). This endocytosis for HDL is from the HDL cholesterol uptake by the receptor a by cholesterol is the protein of the HDL are not A. M. The of the high-density lipoprotein receptor in cholesterol PubMed Scopus Google Scholar). of IF1 was to HDL uptake by human and likely by (8Martinez L.O. Jacquet S. Esteve J.P. Rolland C. Cabezon E. Champagne E. Pineau T. Georgeaud V. Walker J.E. Terce F. et al.Ectopic beta-chain of ATP synthase is an apolipoprotein A-I receptor in hepatic HDL endocytosis.Nature. 2003; 421: 75-79Crossref PubMed Scopus (388) Google Scholar). Thus, serum IF1 HDL hepatic the of HDL in IF1 were negatively to levels of The inverse relationship between of HDL and lipoproteins is by and lipoprotein Thus, as IF1 concentration is related to inverse with markers the metabolic However, in multivariate were independent of we a of on the of lipoproteins or an on and V. D. M. of in human PubMed Scopus Google Scholar). ecto-F1-ATPase has at the surface of N. T. T. synthase as a for 2007; PubMed Scopus Google Scholar). IF1 concentration was found lower in CHD than in the lower IF1 level in the was not related to treatment for or multivariate demonstrated an independent inverse association of serum IF1 levels with CHD. even serum IF1 is highly related to IF1 negatively associated to CHD following adjustments on risk factors or markers, including of CHD risk yielded as of IF1 even after HDL-C was in the that association with HDL, IF1 concentration would be negatively related to CHD In as we have of the of IF1 on HDL However, we have the of circulating a IF1 is with a mitochondrial it is likely serum IF1 from the mitochondrial toward the plasma to be the This is supported by of IF1 in from human cells and are cell previously to IF1 at their cell surface P. L. A. A. A. The inhibitor protein of the synthase is associated to the surface of Biophys. 2005; PubMed Scopus Google V. E. R. S. G. The ATP synthase of liver is in acute by the inhibitor protein 2010; PubMed Scopus Google Scholar). The of IF1 has not However, it has that the protein IF1 on the plasma of hepatocytes, that the IF1 on S. M. S. G. in cells in to and 2007; PubMed Scopus Google Scholar). acute by bile in the level of IF1 was found at the liver plasma that the be by cholesterol V. E. R. S. G. The ATP synthase of liver is in acute by the inhibitor protein 2010; PubMed Scopus Google Scholar). Moreover, of mitochondrial IF1 in in to has previously K. A. of in and of PubMed Google Scholar, C. P. R. F. G. D. D. M. G. ATP synthase is by coronary and after in the J. PubMed Scopus Google serum IF1 concentration a between and on the cell environmental factors, are known to HDL or influence on IF1 that factors and serum IF1 were evidenced between IF1 and HDL-C or apoA-I their association to CHD. in with low HDL-C or apoA-I a IF1 was associated with a in the for CHD. The was in with In this that HDL liver be beneficial in patients have low levels of circulating This the of HDL be beneficial against a of HDL is central in HDL particles by pleiotropic effects on vascular and enhancing by of and of A. M. L. of the and biological actions of 2005; 8: PubMed Scopus Google Scholar, C. and actions of PubMed Scopus Google Scholar). be that HDL would of HDL to pleiotropic beneficial This not have a on the process of in the not HDL-C uptake A. M. The of the high-density lipoprotein receptor in cholesterol PubMed Scopus Google or endocytosis ecto-F1-ATPase (8Martinez L.O. Jacquet S. Esteve J.P. Rolland C. Cabezon E. Champagne E. Pineau T. Georgeaud V. Walker J.E. Terce F. et al.Ectopic beta-chain of ATP synthase is an apolipoprotein A-I receptor in hepatic HDL endocytosis.Nature. 2003; 421: 75-79Crossref PubMed Scopus (388) Google LDL uptake following between lipoproteins HDL is it a Engl. J. Med. 2007; 357: PubMed Scopus Google Scholar). it has that the of HDL particles is in to a in HDL plasma This HDL potentially HDL vascular was by E. S. L. P. L. in Full Text Full Text PDF PubMed Scopus Google Scholar). Thus, IF1 and that the hepatic of HDL, M. L. M. T. of of the of by the HDL receptor Sci. PubMed Scopus Google Scholar, D. M. M. HDL cholesterol and apoA-I in and with a PubMed Scopus Google or Niacin surface of ATP synthase in for Full Text Full Text PDF PubMed Scopus Google beneficial effects the of HDL particles in their effects on the vascular the study a in several and causal relationship be Therefore, further are the of a large prospective to the predictive of IF1 In serum IF1 in the of CHD risk with risk factors, including be in have low levels of studies be needed to in different The the and CHD for their in the The for in and with the coronary artery disease coronary heart disease protein HDL-cholesterol inhibitor factor 1 LDL-cholesterol reverse cholesterol transport receptor