Cardiovascular diseases (CVD), which are mainly caused by the development of atherosclerosis, are the leading cause of morbidity and mortality in Western Society. Two main risk factors for the... Show moreCardiovascular diseases (CVD), which are mainly caused by the development of atherosclerosis, are the leading cause of morbidity and mortality in Western Society. Two main risk factors for the development of atherosclerosis are hyperlipidemia and inflammation, that cause accumulation of lipids and immune cells, respectively, in the arterial wall. While activation of brown adipose tissue (BAT) is a promising strategy to alleviate hyperlipidemia, reduction of inflammation is also thought to reduce atherosclerosis progression. In this thesis, we aimed to address two key objectives: 1) to identify genetic targets in mice and men that are involved in BAT activity and evaluate their effects on lipoprotein metabolism and atherosclerosis development, and 2) to identify genetic targets in mice that are involved in modulation of the immune system and evaluate their effects on atherosclerosis development. Chapter 1 serves as a general introduction in which hyperlipidemia and inflammation are introduced as the two main causes for atherosclerosis development. More specifically, firstly the physiology and role of BAT in lipoprotein metabolism and atherosclerosis development are explained. Secondly, the contribution of pro- and anti-inflammatory cytokines as well as specific receptors on immune cells in propelling immune responses are explained in the context of atherosclerosis development. Show less
Dam, A.D. van; Boon, M.R.; Berbee, J.F.P.; Rensen, P.C.N.; Harmelen, V. van 2017
The brain is increasingly recognized as the regulator of body homeostasis and as possible treatment target for cardiovascular disease. This thesis further reveals the role of the autonomic nervous... Show moreThe brain is increasingly recognized as the regulator of body homeostasis and as possible treatment target for cardiovascular disease. This thesis further reveals the role of the autonomic nervous system (ANS) in the control of lipid metabolism and inflammation, and identified pathological consequences of disturbed regulation. Part I focuses on regulation of lipid metabolism by the ANS, with special attention for brown adipose tissue (BAT) as an emerging pharmacological target for therapy. We describe novel targets that modulate BAT, both directly (e.g. CB1R) and via the brain (e.g. MC4R, GLP-1R) to show that BAT activation improves dyslipidemia, glucose tolerance and T2D and even atherosclerosis. In addition, we identified the biological clock as an important regulator of BAT function and showed the consequences of disturbed circadian rhythmicity for lipid metabolism. Part II of this thesis describes studies on the regulation of inflammation by the ANS, with focus on the anti-inflammatory reflex. During this reflex, binding of acetylcholine to _7nAChR and subsequent intracellular signaling results in transcriptional repression of pro-inflammatory genes. We investigated the effects of hematopoietic _7nAChR deficiency and the consequences of selective parasympathetic and sympathetic denervation of the spleen for this reflex, and for inflammation and atherosclerotic plaque development. Show less
