Endocannabinoids, a class of lipid messengers, have emerged as crucial regulators of synaptic communication in the central nervous system (CNS). Dysregulation of these compounds has been... Show moreEndocannabinoids, a class of lipid messengers, have emerged as crucial regulators of synaptic communication in the central nervous system (CNS). Dysregulation of these compounds has been implicated in many brain disorders. Although some studies have identified and quantified a limited number of target compounds, a method that provides comprehensive quantitative information on endocannabinoids and related N-acylethanolamines (NAEs) in CSF is currently lacking as measurements are challenging due to low concentrations under normal physiological conditions. Here we developed and validated a high-throughput nano liquid chromatography-electrospray ionization mass spectrometry (nano LC-ESI-MS/MS) platform for the simultaneous quantification of endocannabinoids (anandamide (AEA), 2-arachidonoyl glycerol (2-AG)), ten related NAEs and eight additional putatively annotated NAEs in human CSF. Requiring only 200 μL of CSF our method has limits of detection from 0.28 to 61.2 pM with precisions of RSD <15% for most compounds. We applied our method to CSF from 45 healthy humans and demonstrated potential age and gender effects on concentrations of endocannabinoids and NAEs. Notably, our results show that docosahexaenoyl ethanolamide (DHEA) concentrations increase with age in males. Our method may offer new opportunities to gain insight into regulatory functions of endocannabinoids in the context of (ab)normal brain function. Show less
Lysophosphatidic acid (LPA), a bioactive lysophospholipid, accumulates in the atherosclerotic plaque. It has the capacity to activate mast cells, which potentially exacerbates plaque progression.... Show moreLysophosphatidic acid (LPA), a bioactive lysophospholipid, accumulates in the atherosclerotic plaque. It has the capacity to activate mast cells, which potentially exacerbates plaque progression. In this study, we thus aimed to investigate whether LPA contributes to plaque destabilization by modulating mast cell function. We here show by an imaging mass spectrometry approach that several LPA species are present in atherosclerotic plaques. Subsequently, we demonstrate that LPA is a potent mast cell activator which, unlike other triggers, favors release of tryptase. Local perivascular administration of LPA to an atherosclerotic carotid artery segment increases the activation status of perivascular mast cells and promotes intraplaque hemorrhage and macrophage recruitment without impacting plaque cell apoptosis. The mast cell stabilizer cromolyn could prevent intraplaque hemorrhage elicited by LPA-mediated mast cell activation. Finally, the involvement of mast cells in these events was further emphasized by the lack of effect of perivascular LPA administration in mast cell deficient animals. We demonstrate that increased accumulation of LPA in plaques induces perivascular mast cell activation and in this way contributes to plaque destabilization in vivo. This study points to local LPA availability as an important factor in atherosclerotic plaque stability. Show less
Proprotein convertase subtilisin-like/kexin type 9 (PCSK9) is a protein involved in LDL-cholesterol metabolism. The single-nucleotide polymorphism (SNP) rs11591147 has been associated with lower... Show moreProprotein convertase subtilisin-like/kexin type 9 (PCSK9) is a protein involved in LDL-cholesterol metabolism. The single-nucleotide polymorphism (SNP) rs11591147 has been associated with lower LDL-cholesterol and a lower risk of coronary heart disease. Because PCSK9 has high affinity to the LDL receptor, inhibiting PCSK9 is a testable therapeutic target for lipid-lowering therapy. Currently, several approaches to inhibit PCSK9 are under development, but it is unknown what the effects of those inhibitors will be on cognition or noncardiovascular clinical events. In this study, we assessed the association between rs11591147 and cognitive performance, activities of daily living (ADL), and noncardiovascular clinical events within 5,777 participants of the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER). Rs11591147 was associated with 10% to 16% lower LDL cholesterol levels (P = 3.62 × 10(-12)), but was not associated with cognitive performance, ADL, or noncardiovascular clinical events in the PROSPER study. Our findings suggest that lower cholesterol levels due to genetic variation in the PCSK9 gene are not associated with cognitive performance, functional status, or noncardiovascular clinical events. Show less
Diepen, J.A. van; Stienstra, R.; Vroegrijk, I.O.C.M.; Berg, S.A.A. van den; Salvatori, D.; Hooiveld, G.J.; ... ; Rensen, P.C.N. 2013
