The aim of this thesis was to better understand the cellular origin of cholesteryl ester transfer protein (CETP) and to investigate the effects of the CETP inhibitor anacetrapib on the... Show moreThe aim of this thesis was to better understand the cellular origin of cholesteryl ester transfer protein (CETP) and to investigate the effects of the CETP inhibitor anacetrapib on the development of atherosclerosis. First, we investigated the specific characteristics of hepatic macrophages that express CETP. Our data clearly indicated that in the liver, CETP is exclusively expressed by F4/80+Ly6C-Clec4f+Vsig4+ macrophages that represent resident, rather than immature macrophages. Next, we showed that the HDL response to the inflammatory stimulus lipopolysaccharide is mediated by hepatic macrophages via down regulation of CETP expression in the liver that causes an increase in the level of HDL-C. In the second part of this thesis, we examined the effects and mechanism of pharmacological inhibition of CETP by anacetrapib on the development of atherosclerosis. We concluded that anacetrapib mainly decreases atherosclerotic lesion development via a reduction of non-HDL-C. Finally, we concluded that anacetrapib reduces (V)LDL-C by increasing hepatic remnant clearance via two mechanisms: 1) inhibition of CETP activity, resulting in remodelled VLDL particles that are more susceptible to hepatic clearance, and 2) a CETP-independent reduction in plasma PCSK9 level that has the potential to increase LDL receptor-mediated hepatic remnant clearance. Show less
Cardiovascular disease (CVD) is the leading cause of death worldwide despite the successful development of several pharmaceutical interventions of which statin therapy is the dominating lipid... Show moreCardiovascular disease (CVD) is the leading cause of death worldwide despite the successful development of several pharmaceutical interventions of which statin therapy is the dominating lipid-lowering treatment option. Atherosclerosis, a chronic inflammatory disease of multifactorial origin, is a dominant contributor to the development of CVD. The research described in this thesis provides evidence for anti-atherogenic effects of several innovative pharmaceutical interventions that are currently being investigated in clinical trials, targeting hypertension and hypercholesterolemia, more specifically high low-density lipoprotein-cholesterol (LDL-C) and low high-density lipoprotein-cholesterol (HDL-C), as risk factors for CVD. Our results further support additional benefit of these treatment strategies in combination with statin treatment which is currently the __gold standard__ therapy for the treatment of CVD. Most of these lipid-modifying treatment strategies affect both LDL-C and HDL-C and we demonstrate that the beneficial effects of these treatment strategies predominantly derive from their non-HDL-C/LDL-C-lowering abilities. Nonetheless, results from preclinical studies and clinical trials support the notion that treatment strategies aimed at improving HDL function and raising apolipoprotein A-I may also inhibit the development of atherosclerosis and reduce the prevalence of CVD. Show less
