The Effect of Prednisone on Atherogenesis as Studied in the Macrophage Foam Cell Formation Model System.

Summary

Glucocorticoids (GCs) are a class of endogenous steroid hormones produced by the adrenal glands and controlled by the hypothalamic-pituitary-adrenal axis (HPA). One of the mechanisms of their action is achieved through ligand-receptor attachment to a class of cytosolic steroid hormone receptors termed Glucocorticoid Receptors (GRs). The formed ligand-receptor complex is a transcription factor involved in gene activation of anti-inflammatory products or repression of pro-inflammatory products \[1\]. Synthetic forms of GCs are a group of anti-inflammatory and immunosuppressive medications (e.g. Prednisone) that are widely used in clinical practice to treat inflammatory diseases (e.g. Rheumatoid Arthritis, Vasculitis, Asthma). The effectiveness of this class of drugs is limited by numerous adverse effects that include, but not limited to, insulin resistance, glucose intolerance, dyslipidemia, and hypertension, all of which are well known risk factors for cardiovascular diseases (CVD) \[2,3\]. Furthermore, recent research suggest that inflammation has a key role in development of CVD and can predict prognosis \[4\]. Inflammatory cells have an important role in the development of atherosclerotic lesion in the arteries. Blood monocyte-derived macrophages are involved in this process, and they infiltrate the lesion where they take up various forms of lipids (cholesterol - rich LDL, and oxidized LDL) as well as triglycerides - rich VLDL), followed by the formation of lipid-laden foam cells, the hallmark of early atherogenesis. Inflammatory cells and molecules as well as proteolytic enzymes secreted from inflammatory cells in the atherosclerotic lesion, have a central role in destabilizing the plaque (vulnerable plaque) leading to its rupture, which, in turn, induces thrombosis, and initiating acute coronary events \[4,5\]. Based on our understanding of the involvement of inflammation in the early development of atherosclerotic lesion, and our experience with the anti-inflammatory effects of synthetic GCs, a hypothesis emerged suggesting this class of drugs as a way to inhibit early atherosclerotic plaque formation, and to attenuate CVDs \[6\]. Research results in this field are surprising because while glucocorticoids treatment in humans increase the risk of CVDs \[6,7,8,9\], animal models shows the opposite, atheroprotection was shown in rabbits \[10,11,12\] and mice \[13,14,15\]. This paradox may be explained partially by the fact that clinical studies in this field are mainly conducted in patients with predisposing factors to develop CVD, either because of pre-existing traditional risk factors like Diabetes and Hyperlipidemia, or because of the pre-existing medical condition they are being treated for with GCs (e.g. Rheumatoid Arthritis). Mechanism based research to study the effects of GCs on atherogenesis, without confounding factors, is lacking. Only few studies were performed on GCs in healthy subjects but none of them explored their effects on foam cell formation \[16,17\]. Our study thus aims to further our understanding of the role of specific glucocorticoid, prednisone, in the process of atherogenesis. In order to achieve that we plan to study the following: 1. The effects of five days of treatment with prednisone on serum lipid concentration and oxidative stress. 2. an Ex-vivo study is planned where the serum of healthy human subjects treated with Prednisone, will be introduced to J774A.1 murine macrophage-like cell line, a well-studied macrophage foam cell formation model.

Timeline

Start

2018-01-17

Primary completion

2018-07-09

Completion

2018-09-30

Publications

• Background Cohen DM, Steger DJ. Nuclear Receptor Function through Genomics: Lessons from the Glucocorticoid Receptor. Trends Endocrinol Metab. 2017 Jul;28(7):531-540. doi: 10.1016/j.tem.2017.04.001. Epub 2017 May 8.
• Background Stahn C, Buttgereit F. Genomic and nongenomic effects of glucocorticoids. Nat Clin Pract Rheumatol. 2008 Oct;4(10):525-33. doi: 10.1038/ncprheum0898. Epub 2008 Sep 2.
• Background Schacke H, Docke WD, Asadullah K. Mechanisms involved in the side effects of glucocorticoids. Pharmacol Ther. 2002 Oct;96(1):23-43. doi: 10.1016/s0163-7258(02)00297-8.
• Background Hansson GK. Inflammation, atherosclerosis, and coronary artery disease. N Engl J Med. 2005 Apr 21;352(16):1685-95. doi: 10.1056/NEJMra043430. No abstract available.
• Background Dickhout JG, Basseri S, Austin RC. Macrophage function and its impact on atherosclerotic lesion composition, progression, and stability: the good, the bad, and the ugly. Arterioscler Thromb Vasc Biol. 2008 Aug;28(8):1413-5. doi: 10.1161/ATVBAHA.108.169144. No abstract available.
• Background Walker BR. Glucocorticoids and cardiovascular disease. Eur J Endocrinol. 2007 Nov;157(5):545-59. doi: 10.1530/EJE-07-0455.
• Background del Rincon I, O'Leary DH, Haas RW, Escalante A. Effect of glucocorticoids on the arteries in rheumatoid arthritis. Arthritis Rheum. 2004 Dec;50(12):3813-22. doi: 10.1002/art.20661.
• Background del Rincon I, Battafarano DF, Restrepo JF, Erikson JM, Escalante A. Glucocorticoid dose thresholds associated with all-cause and cardiovascular mortality in rheumatoid arthritis. Arthritis Rheumatol. 2014 Feb;66(2):264-72. doi: 10.1002/art.38210.
• Background Ajeganova S, Svensson B, Hafstrom I; BARFOT Study Group. Low-dose prednisolone treatment of early rheumatoid arthritis and late cardiovascular outcome and survival: 10-year follow-up of a 2-year randomised trial. BMJ Open. 2014 Apr 7;4(4):e004259. doi: 10.1136/bmjopen-2013-004259.
• Background Cavallero C, Di Tondo U, Mingazzini PL, Nicosia R, Pericoli MN, Sarti P, Spagnoli LG, Villaschi S. Cell proliferation in the atherosclerotic plaques of cholesterol-fed rabbits. Part 3. Histological and radioautographic observations on glucocorticoids-treated rabbits. Atherosclerosis. 1976 Nov-Dec;25(2-3):145-52. doi: 10.1016/0021-9150(76)90020-4.
• Background Makheja AN, Bloom S, Muesing R, Simon T, Bailey JM. Anti-inflammatory drugs in experimental atherosclerosis. 7. Spontaneous atherosclerosis in WHHL rabbits and inhibition by cortisone acetate. Atherosclerosis. 1989 Apr;76(2-3):155-61. doi: 10.1016/0021-9150(89)90099-3.
• Background Asai K, Funaki C, Hayashi T, Yamada K, Naito M, Kuzuya M, Yoshida F, Yoshimine N, Kuzuya F. Dexamethasone-induced suppression of aortic atherosclerosis in cholesterol-fed rabbits. Possible mechanisms. Arterioscler Thromb. 1993 Jun;13(6):892-9. doi: 10.1161/01.atv.13.6.892.
• Background Auvinen HE, Wang Y, Princen H, Romijn JA, Havekes LM, Smit JW, Meijer OC, Biermasz NR, Rensen PC, Pereira AM. Both transient and continuous corticosterone excess inhibit atherosclerotic plaque formation in APOE*3-leiden.CETP mice. PLoS One. 2013 May 22;8(5):e63882. doi: 10.1371/journal.pone.0063882. Print 2013.
• Background Out C, Dikkers A, Laskewitz A, Boverhof R, van der Ley C, Kema IP, Wolters H, Havinga R, Verkade HJ, Kuipers F, Tietge UJ, Groen AK. Prednisolone increases enterohepatic cycling of bile acids by induction of Asbt and promotes reverse cholesterol transport. J Hepatol. 2014 Aug;61(2):351-7. doi: 10.1016/j.jhep.2014.03.025. Epub 2014 Mar 26.
• Background Tauchi Y, Zushida L, Chono S, Sato J, Ito K, Morimoto K. Effect of dexamethasone palmitate-low density lipoprotein complex on cholesterol ester accumulation in aorta of atherogenic model mice. Biol Pharm Bull. 2001 Aug;24(8):925-9. doi: 10.1248/bpb.24.925.
• Background Fleishaker DL, Mukherjee A, Whaley FS, Daniel S, Zeiher BG. Safety and pharmacodynamic dose response of short-term prednisone in healthy adult subjects: a dose ranging, randomized, placebo-controlled, crossover study. BMC Musculoskelet Disord. 2016 Jul 16;17:293. doi: 10.1186/s12891-016-1135-3.
• Background Kauh EA, Mixson LA, Shankar S, McCarthy J, Maridakis V, Morrow L, Heinemann L, Ruddy MK, Herman GA, Kelley DE, Hompesch M. Short-term metabolic effects of prednisone administration in healthy subjects. Diabetes Obes Metab. 2011 Nov;13(11):1001-7. doi: 10.1111/j.1463-1326.2011.01432.x.
• Background Nikitina NA, Sobenin IA, Myasoedova VA, Korennaya VV, Mel'nichenko AA, Khalilov EM, Orekhov AN. Antiatherogenic effect of grape flavonoids in an ex vivo model. Bull Exp Biol Med. 2006 Jun;141(6):712-5. doi: 10.1007/s10517-006-0260-7. English, Russian.
• Background Hamoud S, Hayek T, Volkova N, Attias J, Moscoviz D, Rosenblat M, Aviram M. Pomegranate extract (POMx) decreases the atherogenicity of serum and of human monocyte-derived macrophages (HMDM) in simvastatin-treated hypercholesterolemic patients: a double-blinded, placebo-controlled, randomized, prospective pilot study. Atherosclerosis. 2014 Jan;232(1):204-10. doi: 10.1016/j.atherosclerosis.2013.11.037. Epub 2013 Nov 19.

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Indications