Cardiovascular diseases are the leading cause of death worldwide, with atherosclerosis as most common underlying pathology. Atherosclerosis is characterized by arterial narrowing due to cholesterol... Show moreCardiovascular diseases are the leading cause of death worldwide, with atherosclerosis as most common underlying pathology. Atherosclerosis is characterized by arterial narrowing due to cholesterol and lipid accumulation. Despite available effective cholesterol lowering medication, considerable risk for recurrent vascular events remains. This residual risk is at least in part explained by high blood lipid levels. The research described in this thesis revealed novel therapeutic strategies that improve lipid metabolism and reduce atherosclerosis development in mice. Inhibition of the endocannabinoid system was found to be an effective strategy, as well as concomitant activation of two incretin hormone receptors, namely those for GIP and GLP1. For combined GIP/GLP1 receptor agonism we additionally showed strongly attenuated hepatic steatosis. We were also able to identify additional targets to attenuate hyperlipidemia by studying the mechanisms underlying the strong day-night rhythm of brown adipose tissue, which is a lipid combusting tissue. In this thesis, I also stress the importance of the choice in animal model when studying lipid-modifying interventions, and describe the development of the software tool RandoMice which can be used to improve the quality of preclinical studies by creating well-balanced experimental groups. Show less
Throughout evolution, humans have lived in synchrony with the natural light-dark cycle. Our bodies were used to going to sleep a few hours after dark, and waking up just before dawn. However, in... Show moreThroughout evolution, humans have lived in synchrony with the natural light-dark cycle. Our bodies were used to going to sleep a few hours after dark, and waking up just before dawn. However, in modern society the unambiguous availability of artificial light has desynchronized our biological clock from the naturally occurring day and night, with large consequences for metabolic health. This thesis sheds light on the negative health consequences of a disturbed biological clock, and elucidates novel approaches to prevent disease associated with chronic rhythm disruption, as occurs in shift work. We have identified important mechanisms through which rhythm disruption contributes to (cardio)metabolic disease, namely by exacerbating vascular inflammation and by deregulating rhythm in glucocorticoid hormone, thereby affecting the metabolic activity of tissues such as brown fat and bone. We continued by investigating two main approaches to prevent diseases associated with circadian disturbances: (1) by limiting disruption of the circadian timing system, and (2) by directly targeting the affected tissues. We found that timed feeding (1) and stimulation of the metabolic activity of brown fat (2) are both promising strategies to prevent and/or reduce (cardio)metabolic disease risk in the ever-increasing population of individuals who suffer from circadian disturbances. Show less
