Deleting myeloid IL-10 receptor signalling attenuates atherosclerosis in LDLR^-/- mice by altering intestinal cholesterol fluxes

Summary

Inflammatory responses and cholesterol homeostasis are interconnected in atherogenesis. Interleukin (IL)-10 is an important anti-inflammatory cytokine, known to suppress atherosclerosis development. However, the specific cell types responsible for the atheroprotective effects of IL-10 remain to be defined and knowledge on the actions of IL-10 in cholesterol homeostasis is scarce. Here we investigated the functional involvement of myeloid IL-10-mediated atheroprotection. To do so, bone marrow from IL-10 receptor 1 (IL-10R1) wild-type and myeloid IL-10R1-deficient mice was transplanted to lethally irradiated female LDLR^-/- mice. Hereafter, mice were given a high cholesterol diet for 10 weeks after which atherosclerosis development and cholesterol metabolism were investigated. In vitro, myeloid IL-10R1 deficiency resulted in a pro-inflammatory macrophage phenotype. However, in vivo significantly reduced lesion size and severity was observed. This phenotype was associated with lower myeloid cell accumulation and more apoptosis in the lesions. Additionally, a profound reduction in plasma and liver cholesterol was observed upon myeloid IL-10R1 deficiency, which was reflected in plaque lipid content. This decreased hypercholesterolaemia was associated with lowered very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) levels, likely as a response to decreased intestinal cholesterol absorption. In addition, IL-10R1 deficient mice demonstrated substantially higher faecal sterol loss caused by increased non-biliary cholesterol efflux. The induction of this process was linked to impaired ACAT2-mediated esterification of liver and plasma cholesterol. Overall, myeloid cells do not contribute to IL-10-mediated atheroprotection. In addition, this study demonstrates a novel connection between IL-10-mediated inflammation and cholesterol homeostasis in atherosclerosis. These findings make us reconsider IL-10 as a beneficial influence on atherosclerosis.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Keywords

Interleukin-10 - myeloid cells - atherosclerosis - cholesterol - TICE

^* These authors contributed equally.

• References

• 1 Galkina E, Ley K.. Immune and inflammatory mechanisms of atherosclerosis (*). Annu Rev Immunol 2009; 27: 165-197.
• 2 Hansson GK, Libby P.. The immune response in atherosclerosis: a double-edged sword. Nature Rev Immunol 2006; 6: 508-519.
• 3 Han X, Kitamoto S, Wang H. et al. Interleukin-10 overexpression in macrophages suppresses atherosclerosis in hyperlipidaemic mice. FASEB J 2010; 24: 2869-2880.
• 4 Mallat Z, Heymes C, Ohan J. et al. Expression of interleukin-10 in advanced human atherosclerotic plaques: relation to inducible nitric oxide synthase expression and cell death. Arterioscl Thromb Vasc Biol 1999; 19: 611-616.
• 5 Kleemann R, Zadelaar S, Kooistra T.. Cytokines and atherosclerosis: a comprehensive review of studies in mice. Cardiovasc Res 2008; 79: 360-376.
• 6 de Waal Malefyt R, Abrams J, Bennett B. et al. Interleukin 10(IL-10) inhibits cytokine synthesis by human monocytes: an autoregulatory role of IL-10 produced by monocytes. J Exp Med 1991; 174: 1209-1220.
• 7 Fiorentino DF, Zlotnik A, Mosmann TR. et al. IL-10 inhibits cytokine production by activated macrophages. J Immunol 1991; 147: 3815-3822.
• 8 Moore KW, de Waal Malefyt R, Coffman RL. et al. Interleukin-10 and the interleukin-10 receptor. Annu Rev Immunol 2001; 19: 683-765.
• 9 Han X, Kitamoto S, Lian Q. et al. Interleukin-10 facilitates both cholesterol uptake and efflux in macrophages. J Biol Chem 2009; 284: 32950-32958.
• 10 Halvorsen B, Waehre T, Scholz H. et al. Interleukin-10 enhances the oxidized LDL-induced foam cell formation of macrophages by antiapoptotic mechanisms. J Lipid Res 2005; 46: 211-219.
• 11 Namiki M, Kawashima S, Yamashita T. et al. Intramuscular gene transfer of interleukin-10 cDNA reduces atherosclerosis in apolipoprotein E-knockout mice. Atherosclerosis 2004; 172: 21-29.
• 12 Pinderski LJ, Fischbein MP, Subbanagounder G. et al. Overexpression of interleukin-10 by activated T lymphocytes inhibits atherosclerosis in LDL receptor-deficient Mice by altering lymphocyte and macrophage phenotypes. Circ Res 2002; 90: 1064-1071.
• 13 Von Der Thusen JH, Kuiper J, Fekkes ML. et al. Attenuation of atherogenesis by systemic and local adenovirus-mediated gene transfer of interleukin-10 in LDLr-/- mice. FASEB J 2001; 15: 2730-2732.
• 14 Caligiuri G, Rudling M, Ollivier V. et al. Interleukin-10 deficiency increases atherosclerosis, thrombosis, and low-density lipoproteins in apolipoprotein E knockout mice. Mol Med 2003; 9: 10-17.
• 15 Kanters E, Pasparakis M, Gijbels MJ. et al. Inhibition of NF-kappaB activation in macrophages increases atherosclerosis in LDL receptor-deficient mice. J Clin Invest 2003; 112: 1176-1185.
• 16 Potteaux S, Esposito B, van Oostrom O. et al. Leukocyte-derived interleukin 10 is required for protection against atherosclerosis in low-density lipoprotein receptor knockout mice. Arterioscl Thromb Vasc Biol 2004; 24: 1474-1478.
• 17 Kanters E, Gijbels MJ, van der Made I. et al. Hematopoietic NF-kappaB1 deficiency results in small atherosclerotic lesions with an inflammatory phenotype. Blood 2004; 103: 934-940.
• 18 Khan JA, Cao M, Kang BY. et al. AAV/hSTAT3-gene delivery lowers aortic inflammatory cell infiltration in LDLR KO mice on high cholesterol. Atherosclerosis 2010; 213: 59-66.
• 19 van der Wulp MY, Verkade HJ, Groen AK. Regulation of cholesterol homeostasis. Mol Cell Endocrinol 2013; 368: 1-16.
• 20 Cheng SH, Stanley MM.. Secretion of cholesterol by intestinal mucosa in patients with complete common bile duct obstruction. Proc Soc Exp Biol Med 1959; 101: 223-225.
• 21 Kruit JK, Plosch T, Havinga R. et al. Increased fecal neutral sterol loss upon liver X receptor activation is independent of biliary sterol secretion in mice. Gastroenterol 2005; 128: 147-156.
• 22 van der Velde AE, Brufau G, Groen AK. Transintestinal cholesterol efflux. Curr Opin Lipidol 2010; 21: 167-171.
• 23 Le May C, Berger JM, Lespine A. et al. Transintestinal cholesterol excretion is an active metabolic process modulated by PCSK9 and statin involving ABCB1. Arterioscl Thromb Vasc Biol 2013; 33: 1484-1493.
• 24 van der Velde AE, Vrins CL, van den Oever K. et al. Direct intestinal cholesterol secretion contributes significantly to total fecal neutral sterol excretion in mice. Gastroenterol 2007; 133: 967-975.
• 25 Vrins CL, Ottenhoff R, van den Oever K. et al. Trans-intestinal cholesterol efflux is not mediated through high density lipoprotein. J Lipid Res 2012; 53: 2017-2023.
• 26 Brown JM, Bell 3rd TA, Alger HM. et al. Targeted depletion of hepatic ACAT2-driven cholesterol esterification reveals a non-biliary route for fecal neutral sterol loss. J Biol Chem 2008; 283: 10522-10534.
• 27 Pils MC, Pisano F, Fasnacht N. et al. Monocytes/macrophages and/or neutrophils are the target of IL-10 in the LPS endotoxemia model. Eur J Immunol 2010; 40: 443-448.
• 28 Clausen BE, Burkhardt C, Reith W. et al. Conditional gene targeting in macrophages and granulocytes using LysMcre mice. Transgenic Res 1999; 8: 265-277.
• 29 Brufau G, Kuipers F, Lin Y. et al. A reappraisal of the mechanism by which plant sterols promote neutral sterol loss in mice. PloS one 2011; 6: e21576.
• 30 van der Veen JN, van Dijk TH, Vrins CL. et al. Activation of the liver X receptor stimulates trans-intestinal excretion of plasma cholesterol. J Biol Chem 2009; 284: 19211-19219.
• 31 Lutjohann D, Brzezinka A, Barth E. et al. Profile of cholesterol-related sterols in aged amyloid precursor protein transgenic mouse brain. J Lipid Res 2002; 43: 1078-1085.
• 32 Sudhop T, Lutjohann D, Kodal A. et al. Inhibition of intestinal cholesterol absorption by ezetimibe in humans. Circulation 2002; 106: 1943-1948.
• 33 Tabas I.. Macrophage apoptosis in atherosclerosis: consequences on plaque progression and the role of endoplasmic reticulum stress. Antioxid Redox Signal 2009; 11: 2333-2339.
• 34 Tabas I.. Macrophage death and defective inflammation resolution in atherosclerosis. Nature Rev Immunol 2010; 10: 36-46.
• 35 Halvorsen B, Holm S, Yndestad A. et al. Interleukin-10 increases reverse cholesterol transport in macrophages through its bidirectional interaction with liver X receptor alpha. Biochem Biophys Res Commun 2014; 450: 1525-1530.
• 36 Agouridis AP, Elisaf M, Milionis HJ.. An overview of lipid abnormalities in patients with inflammatory bowel disease. Ann Gastroenterol 2011; 24: 181-187.
• 37 Shouval DS, Biswas A, Goettel JA. et al. Interleukin-10 receptor signalling in innate immune cells regulates mucosal immune tolerance and anti-inflammatory macrophage function. Immunity 2014; 40: 706-719.
• 38 Metghalchi S, Ponnuswamy P, Simon T. et al. Indoleamine 2,3-Dioxygenase Fine-Tunes Immune Homeostasis in Atherosclerosis and Colitis through Repression of Interleukin-10 Production. Cell Metabol 2015; 22: 460-471.
• 39 Zigmond E, Bernshtein B, Friedlander G. et al. Macrophage-restricted interleukin-10 receptor deficiency, but not IL-10 deficiency, causes severe spontaneous colitis. Immunity 2014; 40: 720-733.
• 40 Glocker EO, Kotlarz D, Klein C. et al. IL-10 and IL-10 receptor defects in humans. Ann NY Acad Sci 2011; 1246: 102-107.
• 41 Mahler M, Leiter EH.. Genetic and environmental context determines the course of colitis developing in IL-10-deficient mice. Inflamm Bowel Dis 2002; 8: 347-355.
• 42 Mallat Z, Besnard S, Duriez M. et al. Protective role of interleukin-10 in atherosclerosis. Circ Res 1999; 85: e17-24.
• 43 Potteaux S, Deleuze V, Merval R. et al. In vivo electrotransfer of interleukin-10 cDNA prevents endothelial upregulation of activated NF-kappaB and adhesion molecules following an atherogenic diet. European cytokine network. Eur Cytokine Netw 2006; 17: 13-18.
• 44 Zemse SM, Chiao CW, Hilgers RH. et al. Interleukin-10 inhibits the in vivo and in vitro adverse effects of TNF-alpha on the endothelium of murine aorta. Am J Physiol Heart Circ Physiol 2010; 299: H1160-1167.
• 45 Gareus R, Kotsaki E, Xanthoulea S. et al. Endothelial cell-specific NF-kappaB inhibition protects mice from atherosclerosis. Cell Metabol 2008; 8: 372-383.
• 46 Tilg H, van Montfrans C, van den Ende A. et al. Treatment of Crohn's disease with recombinant human interleukin 10 induces the proinflammatory cytokine interferon gamma. Gut 2002; 50: 191-195.
• 47 van Diepen JA, Berbee JF, Havekes LM. et al. Interactions between inflammation and lipid metabolism: relevance for efficacy of anti-inflammatory drugs in the treatment of atherosclerosis. Atherosclerosis 2013; 228: 306-315.
• 48 Eefting D, Schepers A, De Vries MR. et al. The effect of interleukin-10 knockout and overexpression on neointima formation in hypercholesterolaemic APOE*3-Leiden mice. Atherosclerosis 2007; 193: 335-342.