European Journal of Clinical Investigation (2006) 36, 552–559 © 2006 The Authors. Journal Compilation © 2006 Blackwell Publishing Ltd Blackwell Publishing Ltd Comparison of different cellular models measuring in vitro the whole human serum cholesterol efflux capacity S. Mweva * , J. L. Paul *† , M. Cambillau * , D. Goudouneche † , P. Beaune * , A. Simon ‡ and N. Fournier *† * Hôpital Européen Georges Pompidou, Paris, † Faculté des Sciences Pharmaceutiques et Biologiques, Châtenay-Malabry, ‡ Hôpital Broussais, Paris, France Abstract Background Fu5AH rat hepatoma cells and cAMP (cyclic AMP)-pretreated J774 mouse macrophages are commonly used as models for SR-BI (scavenger receptor class B type I) and ABCA1 (ATP binding cassette transporter 1)-mediated free cholesterol efflux to whole serum, respectively. However, the responsiveness of Fu5AH, control or cAMP pretreated J774 cells to the various lipids and HDL (high-density lipoprotein)-parameters from both normo- and dyslipidaemic subjects has never been compared within the same study. Materials and methods Fifty-eight men were classified into four groups: type IIa hyper- cholesterolaemic (n = 12), type IIb dyslipidaemic (n = 13), type IV hypertriglyceridaemic (n = 18) and normolipidaemic (n = 15) were recruited. A complete lipid profile including preβ-HDL was performed. Cholesterol efflux from Fu5AH cells as well as from control or cAMP pretreated J774 cells were measured; the difference between these two latter values being taken as the ABCA1-mediated efflux. Results The Fu5AH and the control J774 cells delivered cholesterol to mature HDLs, especially to phospholipid (PL)-rich HDL. Using cAMP pretreated cells, the ABCA1- dependent efflux was highly sensitive to preβ-HDL, which appeared to be a factor in determining the efflux. Consistent with the dependence of the SR-BI-mediated efflux on HDL-PL levels, which are not different between groups, all sera displayed similar efflux capacities from the Fu5AH cells. Conversely, in accordance with their high preβ-HDL levels, the ABCA1-dependent efflux highlighted the efficiency of type IV sera. Conclusion Two complementary cellular models providing SR-BI and ABCA1-dependent efflux should be used to measure the capacity of a biological fluid which contains a wide variety of components to promote cholesterol efflux. Keywords ATP binding cassette transporter 1, cholesterol efflux, Fu5AH rat hepatoma cells, J774 mouse macrophages, preβ-HDL, scavenger receptor BI. Eur J Clin Invest 2006; 36 (8): 552–559 Introduction One proposed mechanism by which high-density lipoprotein (HDL) protects against atherosclerosis [1] is reverse cholesterol transport; the first step of which is the efflux of cellular free cholesterol (FC) [2]. The HDL includes a wide variety of particles and the capacity of a given HDL subpopulation to promote efflux may differ depending on the mechanism of efflux. To date, there are at least three known mechanisms by which HDL and/or its apolipoproteins (apo) can remove FC from cells [3–5]. Aqueous diffusion is a relatively inefficient efflux mechanism that operates in all cell types [6].Recently, two proteins have been reported that mediate efficient cholesterol efflux. The scavenger Service de Biochimie, Hôpital Européen Georges Pompidou, Paris (S. Mweva, J. L. Paul, M. Cambillau, N. Fournier); Laboratoire de Biochimie Appliquée, Faculté des Sciences Pharmaceutiques et Biologiques, Châtenay-Malabry (J. L. Paul, D. Goudouneche, N. Fournier); Hôpital Broussais, Centre de Médecine Préventive Cardio Vasculaire, Paris (A. Simon), France. Correspondence to: Natalie Fournier, Laboratoire de Biochimie Appliquée, EA 3543, Faculté des Sciences Pharmaceutiques, 5 rue JB Clément, 92296 Châtenay-Malabry, France. Tel.: +33 (1) 46 83 57 23; fax: +33 (1) 46 83 56 95; e-mail: natalie_fournier@yahoo.fr Received 20 February 2006; accepted 25 May 2006