Hart- en vaatziekten zijn wereldwijd de belangrijkste doodsoorzaak, waarvan het grootste deel kan worden toegeschreven aan coronairlijden. De belangrijkste veroorzaker hiervan is atherosclerose... Show moreHart- en vaatziekten zijn wereldwijd de belangrijkste doodsoorzaak, waarvan het grootste deel kan worden toegeschreven aan coronairlijden. De belangrijkste veroorzaker hiervan is atherosclerose ofwel aderverkalking, wat een op zichzelf staande complexe lipide-gedreven chronische inflammatoire ontstekingsziekte is. Na een hartinfarct is tijdige reperfusie door een acute dotterbehandeling het belangrijkste doel om verdere schade aan de hartspier te beperken. Echter, het herstel van de coronaire perfusie zelf induceert myocardiale reperfusieschade. Gedurende vele jaren heeft translationeel onderzoek zicht gericht op immunomodulatie van deze post-ischemische inflammatierespons. Dit proefschrift omvat pre-klinisch onderzoek waarin gunstige modulatie van de post-ischemische inflammatierespons door farmacologische interventies met annexine A5 en phosphorylcholine antilichamen wordt aangetoond. Remming van bijvoorbeeld cytokine IL-6 en afweercellen als monocyten, macrofagen en leukocyten, resulteert na een hartinfarct in minder schade aan de hartspier met een verbetering van de resterende hartfunctie. Daarnaast werd onderzocht hoe een pre-klinisch experimenteel onderzoeksmodel kan worden geoptimaliseerd door rekening te houden met zowel ischemie-reperfusie schade als hypercholesterolemie, een belangrijke risicofactor voor hart- en vaatziekten. Door gebruik te maken van klinisch relevantere onderzoeksmodellen kunnen in de toekomst hopelijk meer veelbelovende pre-klinische onderzoeksresultaten succesvol worden vertaald naar de dagelijkse klinische praktijk. Ter introductie worden deze onderzoeksresultaten voorafgegaan door een state-of-the-art review waarin een overzicht wordt gegeven van alle fases die deze post-ischemische inflammatierespons omvat. Hierbij worden de meest toonaangevende onderzoeksresultaten betreffende modulatie van deze inflammatierespons beschreven. Na recente succesvolle grote klinische trials, zal in de toekomst een belangrijke rol zijn weggelegd voor modulatie van deze afweerreactie bij zowel atherosclerose als na een hartinfarct. Show less
Background and aims: Neuroimmune guidance cues have been shown to play a role in atherosclerosis, but their exact role in human pathophysiology is largely unknown. In the current study, we... Show moreBackground and aims: Neuroimmune guidance cues have been shown to play a role in atherosclerosis, but their exact role in human pathophysiology is largely unknown. In the current study, we investigated the role of a c.1769G > T variant in Netrin-1 in (premature) atherosclerosis.Methods: To determine the effect of the genetic variation, purified Netrin-1, either wild type (wtNetrin-1) or the patient observed variation (mutNetrin-1), was used for migration, adhesion, endothelial barrier function and bindings assays. Expression of adhesion molecules and transcription proteins was analyzed by RT-PCR, Western blot or ELISA. To further delineate how mutNetrin-1 mediates its effect on cell migration, lenti-viral knockdown of UNC5B or DCC was used.Results: Bindings assays revealed a decreased binding capacity of mutNetrin-1 to the receptors UNC5B, DCC and beta 3-integrin and an increased binding capacity to neogenin, heparin and heparan sulfate compared to wtNetrin-1. Exposure of endothelial cells to mutNetrin-1 resulted in enhanced monocyte adhesion and expression of IL-6, CCL2 and ICAM-1 compared to wtNetrin-1. In addition, mutNetrin-1 lacks the inhibitory effect on the NF-kappa B pathway that is observed for wtNetrin-1. Moreover, the presence of mutNetrin-1 diminished migration of macrophages and smooth muscle cells. Importantly, UNC5B or DCC specific knockdown showed that mutNetrin-1 is unable to act through DCC resulting in enhanced inhibition of migration.Conclusions: Our data demonstrates that mutNetrin-1 fails to exert anti-inflammatory effects on endothelial cells and more strongly blocks macrophage migration compared to wtNetrin-1, suggesting that the carriers of this genetic molecular variant may well be at risk for premature atherosclerosis. Show less
Meeuwsen, J.A.L.; Vries, J.J. de; Duijvenvoorde, A. van; Velden, S. van der; Laan, S.W. van der; Koeverden, I.D. van; ... ; Jager, S.C.A. de 2019
future AbstractMouse studies have established distinct monocyte subtypes that participate in the process of atherosclerotic lesion formation. The pro-inflammatory Ly6Chigh monocyte subtype actively... Show morefuture AbstractMouse studies have established distinct monocyte subtypes that participate in the process of atherosclerotic lesion formation. The pro-inflammatory Ly6Chigh monocyte subtype actively contributes to murineplaque progression and destabilization. Also in humans, different peripheral monocyte subtypes have been identified, of which the CD14+CD16− classical monocyte is suggested to display similar pro-atherosclerotic properties as the murine Ly6Chigh subtype. We aimed to investigate if circulating CD14+CD16− classical monocytes associate with characteristics of a vulnerable carotid atherosclerotic plaque and if they associate with the risk of secondary adverse manifestations of atherosclerotic disease.We enrolled 175 carotid endarterectomy patients of the Athero-Express biobank in our study. Just prior to surgical procedure, blood was collected and peripheral blood mononuclear cells were isolated. Characterization of monocyte subsets was performed by flow cytometry. Plaque characteristics were semi-quantitatively scored for the presence of fat, collagen, intraplaque hemorrhage and calcification. Vessel density, smooth muscle cells and macrophages were assessed quantitatively on a continuous scale. All features of a vulnerable plaque phenotype, including low amounts of collagen and smooth muscle cells, and increased fat content, vessel density, intraplaque hemorrhage and plaque macrophages were not significantly associated with differential levels of peripheral classical CD14+CD16− monocytes or other monocyte subsets. Using Cox regression models to evaluate the prognostic value of circulating monocyte subtypes, we found that total counts of peripheral monocytes, as well as CD14+CD16− classical and other monocyte subtypes were not associated with the risk of secondary cardiovascular events during 3 years follow-up.Circulating classical CD14+CD16− monocytes do not associate with specific vulnerable plaque characteristics. In addition, they do not predict secondary adverse manifestations. This suggests that in patients with established carotid artery disease, the circulating monocytes do not reflect plaque characteristics and have no value in identifying patients at risk for future cardiovascular events. Show less
