Pulmonary hypertension (PH) is a condition of increased blood pressure within the arteries of the lung (mPAP > 20mmHg) which affects approximately 1% of the global population. Chronic... Show morePulmonary hypertension (PH) is a condition of increased blood pressure within the arteries of the lung (mPAP > 20mmHg) which affects approximately 1% of the global population. Chronic thromboembolic pulmonary hypertension (CTEPH), group 4 PH, is characterized by unresolved pulmonary emboli and pulmonary vascular remodeling of both occluded and non-occluded vessels. The general aim of this thesis was to improve the understanding of CTEPH pathophysiology by focusing on patient endothelial cell (EC) behaviour and function. For this purpose, we isolated ECs from vascular material collected at pulmonary endarterectomy in patients with CTEPH (referred to as CTEPH-EC) and validated them as an in vitro model for studying endothelial pathology in CTEPH. In conclusion, we identified several abnormalities in CTEPH-EC that could play a role in pathological mechanisms driving CTEPH-specific vascular changes. We described alterations in key processes such as angiogenesis and migration, oxidative stress, metabolism and inflammation. Each of these processes may represent targets for novel therapies or biomarkers. Show less
Marques, M.L.; Ramiro, S.; Machado, P.M.; Heijde, D. van der; Gaalen, F.A. van 2020
Objective To investigate if in radiographic axial Spondyloarthritis (r-axSpA) low vertebral bone mineral density (BMD) is associated with development of new syndesmophytes at the same vertebral... Show moreObjective To investigate if in radiographic axial Spondyloarthritis (r-axSpA) low vertebral bone mineral density (BMD) is associated with development of new syndesmophytes at the same vertebral level. Methods In a post-hoc analysis from the ASSERT trial (infliximab vs placebo), dual-energy X-ray absorptiometry was used to measure baseline BMD (g/cm(2)) of the lumbar spine L1 to L4. Syndesmophyte formation was assessed in the same vertebrae on conventional radiographs defined as an increase in modified Stoke Ankylosing Spondylitis Spine Score from 0 or 1 to 2 or 3 after 2 years. Radiographs were scored by two readers. Generalised estimating equations (GEE) adjusted for within-patient correlation across multiple vertebrae, taking potential confounders into account. Results We analysed 599 vertebrae in 165 r-axSpA patients (78% male, mean (SD) age 38 (10) years, 67% with at least one syndesmophyte anywhere in the spine). In total, 24 to 74 new syndesmophytes developed in 9 (5%) to 30 (18%) patients and 13 (2%) to 39 (7%) vertebrae, if either a syndesmophyte was seen by both or only one of the readers (ie, specific and sensitive definitions) respectively. In multivariable analyses, no association was found between baseline local vertebral BMD and new syndesmophyte formation after 2 years: adjOR (95% CI): 0.56 (0.01, 44.45) (specific definition) and 0.26 (0.03, 2.63) (sensitive definition). Conclusion In patients with active and established r-axSpA, with an observed low incidence of lumbar spine syndesmophyte formation over 2 years, no relationship was found between baseline BMD and new radiographic syndesmophyte formation at the same vertebra. Show less
In this thesis we have pursued innovative analytical solutions for some of the most challenging questions in the field of SpA. We have gained better insights into the concept of axSpA by studying... Show moreIn this thesis we have pursued innovative analytical solutions for some of the most challenging questions in the field of SpA. We have gained better insights into the concept of axSpA by studying it independently of the rheumatologist’s opinion. Our findings likely add knowledge to what axSpA really is. Future studies will learn us how much of these insights will translate into a better recognition of the disease in clinical practice and in better classifying them for research purposes. Since SpA is a slowly progressing disease, several years are needed to see meaningful changes in imaging abnormalities of the axial skeleton, which poses methodological challenges. We have shown that thoughtful analytical approaches, that make best use of imaging data, are helpful in better estimating progression, in unravelling its determinants and in clarify which outcomes are best to monitor disease. Efforts are made to further improve outcome measurement in axSpA, including the development of new imaging techniques, which can benefit from our proposed solutions to long-term imaging scoring. Show less
Background: Childhood trauma (CT) is a risk factor for depressive and anxiety disorders. Although dysregulated biological stress systems may underlie the enduring effect of CT, the relation between... Show moreBackground: Childhood trauma (CT) is a risk factor for depressive and anxiety disorders. Although dysregulated biological stress systems may underlie the enduring effect of CT, the relation between CT and separate and cumulative activity of the major stress systems, namely, the hypothalamic-pituitary-adrenal (HPA)-axis, the immune-inflammatory system, and the autonomic nervous system (ANS), remains inconclusive.Methods: In the Netherlands Study of Depression and Anxiety (NESDA, n = 2778), we determined whether self-reported CT (as assessed by the Childhood Trauma Interview) was associated with separate and cumulative markers of the HPA-axis (cortisol awakening response, evening cortisol, dexamethasone suppression test cortisol), the immune-inflammatory system (C-reactive protein, interleukin-6, tumor necrosis factor-alpha), and the ANS (heart rate, respiratory sinus arrhythmia, pre-ejection period) in adulthood.Results: Almost all individuals with CT (n = 1330) had either current or remitted depressive and/or anxiety disorder (88.6%). Total-sample analyses showed little evidence for CT being significantly associated with the separate or cumulative stress systems' activity in adulthood. These findings were true for individuals with and without depressive and/or anxiety disorders. To maximize contrast, individuals with severe CT were compared to healthy controls without CT. This yielded slight, but significantly higher levels of cortisol awakening response (AUCg, beta =.088, p =.007; AUCi, beta =.084, p =.010), cumulative HPA-axis markers (beta =.115, p =.001), Creactive protein (beta =.055, p =.032), interleukin-6 (beta =.053, p =.038), cumulative inflammation (beta =.060, p =.020), and cumulative markers across all systems (beta =.125, p =.0003) for those with severe CT, partially explained by higher rates of smoking, body mass index, and chronic diseases.Conclusion: While our findings do not provide conclusive evidence on CT directly dysregulating stress systems, individuals with severe CT showed slight indications of dysregulations, partially explained by an unhealthy lifestyle and poorer health. Show less
The aim of this thesis was to unravel a selection of a multitude of potential causal pathways that may underlie the association between excess body fat and cardiovascular disease, such as... Show moreThe aim of this thesis was to unravel a selection of a multitude of potential causal pathways that may underlie the association between excess body fat and cardiovascular disease, such as adipokines, inflammation, HDL-cholesterol and postprandial triglyceride response, and cholesteryl ester transfer protein (CETP). We showed that hs-CRP and GlycA as measures of inflammation, adiponectin, and leptin are not associated with clinical and subclinical cardiovascular disease in the general population. However, all may be relevant markers of disease risk. Also, postprandial triglyceride excursions, genetically-determined CETP and HDL-cholesterol, while not related with subclinical atherosclerosis in the general population, may be interesting targets to pursue in women and men separately, and in subgroups of individuals at high-cardiovascular risk. Show less
During my PhD we have investigated different approaches to block intraplaque angiogenesis in atherosclerosis. Intraplaque angiogenesis is a physiological response to the increased oxygen demand in... Show moreDuring my PhD we have investigated different approaches to block intraplaque angiogenesis in atherosclerosis. Intraplaque angiogenesis is a physiological response to the increased oxygen demand in the plaque but also has adverse effects by facilitating intraplaque hemorrhage and influx of inflammatory mediators, resulting in plaque instability and consequent rupture. To study this phenomenon we used in vitro assays as well as the accelerated atherosclerosis vein graft model in ApoE3*Leiden mice, a unique model in which the formed plaque shows characteristics that highly resemble human atherosclerotic lesions, including intraplaque angiogenesis and hemorrhage and a high inflammatory cell content. We focused on different approaches to restore plaque stability via improving intraplaque oxygen levels as well as via blocking different growth factors signaling. Moreover we studied the effects of our treatments on the interaction between angiogenesis and inflammation both in vitro and in vivo. Show less
This thesis focuses on the role of chemokine receptors CXCR3 and CCR2 in the inflammatory process and infection control using the zebrafish model. It describes the regulatory interplay between an... Show moreThis thesis focuses on the role of chemokine receptors CXCR3 and CCR2 in the inflammatory process and infection control using the zebrafish model. It describes the regulatory interplay between an atypical and a conventional chemokine receptor during chemotaxis in macrophages, the role of chemotactic signaling in cell polarization and explores an in vivo screening workflow for human anti-inflammatory drugs using zebrafish. Show less
Kay, J.; Harigai, M.; Rancourt, J.; Dickson, C.; Melby, T.; Issa, M.; ... ; Kremer, J.M. 2020
Objective To characterise changes in selected haematological parameters following once-daily oral baricitinib dosing.Methods Data were pooled from eight randomised clinical trials (four phase 3,... Show moreObjective To characterise changes in selected haematological parameters following once-daily oral baricitinib dosing.Methods Data were pooled from eight randomised clinical trials (four phase 3, three phase 2, one phase 1b) and one long-term extension. Changes in haematological parameters were evaluated up to 128 weeks (N=2387); overall safety of baricitinib was assessed up to 6 years (N=3492).Results Mean absolute neutrophil counts decreased (-1.36x10(9)/L) within 1 month, followed by stabilisation within the normal reference range through week 128. The incidence of serious infections was not elevated in patients with neutropenia during the 24-week placebo-controlled period. Mean lymphocyte counts increased (+0.30x10(9)/L) within 1 month, then decreased to baseline (weeks 12-24). Mean platelet counts increased at week 2 (+51x10(9)/L), then decreased towards baseline. Overall, mean haemoglobin concentrations decreased (-0.12 mmol/L), then returned to baseline; however, reduced baseline haemoglobin concentrations observed in the highest baseline high-sensitivity C reactive protein quartile increased over time. Permanent drug discontinuation occurred due to laboratory abnormalities related to neutrophil count in 8 (0.2%), lymphocyte counts in 6 (0.2%), platelet counts in 8 (0.2%), and haemoglobin levels in 16 (0.5%) of all baricitinib-treated patients (N=3492 with 7993 total person-years of exposure).Conclusions Moderate decreases in neutrophils were seen during baricitinib treatment; however, serious infection was uncommon in patients with neutropenia. Transient increases were observed in lymphocytes and platelets, which returned to baseline over time. Changes in haemoglobin concentration were generally small. Haematological abnormalities seldom led to drug discontinuation. Show less
The major hallmark of Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the formation of many fluid-filled cysts in the kidneys, which ultimately impairs the normal renal structure and... Show moreThe major hallmark of Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the formation of many fluid-filled cysts in the kidneys, which ultimately impairs the normal renal structure and function, leading to end-stage renal disease (ESRD). A large body of evidence suggests that injury-repair mechanisms are part of ADPKD progression. Once cysts have been formed, proliferation and fluid secretion contribute to the cyst size increase, which eventually causes stress on the surrounding tissue resulting in local injury and fibrosis. In addition, renal injury can cause or accelerate cyst formation.In this review, we will describe the various mechanisms activated during renal injury and tissue repair and show how they largely overlap with the molecular mechanisms activated during PKD progression. In particular, we will discuss molecular mechanisms such as proliferation, inflammation, cell differentiation, cytokines and growth factors secretion, which are activated following the renal injury to allow the remodelling of the tissue and a proper organ repair. We will also underline how, in a context of PKD-related gene mutations, aberrant or chronic activation of these developmental pathways and repair/remodelling mechanisms results in exacerbation of the disease. Show less
Background: Major depressive disorder (MDD) is linked to higher cardio-metabolic comorbidity that may in part be due to the low-grade inflammation and poorer metabolic health observed in MDD.... Show moreBackground: Major depressive disorder (MDD) is linked to higher cardio-metabolic comorbidity that may in part be due to the low-grade inflammation and poorer metabolic health observed in MDD. Heterogeneity of MDD is however large, and immune-inflammatory and metabolic dysregulation is present in only part of the MDD cases. We examined the associations of four depression dimensional profilers (atypical energy-related symptom dimension, melancholic symptom dimension, childhood trauma severity, and anxious distress symptom dimension) with immuno-metabolic outcomes, both cross-sectionally and longitudinally.Methods: Three waves covering a 6-year follow-up (>7000 observations) of the Netherlands Study of Depression and Anxiety (NESDA) were used. Depression profilers were based on the Inventory of Depressive Symptomatology, the Beck Anxiety Inventory, and the Childhood Trauma index. An inflammatory index (based on IL-6 and CRP), a metabolic syndrome index (based on the five metabolic syndrome components), and a combination of these two indices were constructed. Mixed models were used for cross-sectional and longitudinal models, controlling for covariates.Results: Of the four depression profilers, only the atypical, energy-related symptom dimension showed robust associations with higher scores on the inflammatory, metabolic syndrome and combined inflammatory-metabolic indexes cross-sectionally, as well as at follow-up. The melancholic symptom dimension was associated with lower scores on the metabolic syndrome index both cross-sectionally and longitudinally.Conclusion: The atypical energy-related symptom dimension was linked to poorer immune-inflammatory and metabolic health, while the melancholic symptom dimension was linked to relatively better metabolic health. Persons with high atypical energy-related symptom burden, representing an immuno-metabolic depression, may be the most important group to target in prevention programs for cardiometabolic disease, and may benefit most from treatments targeting immuno-metabolic pathways. Show less
Atherosclerosis is the main pathology behind most cardiovascular diseases. It is a chronic inflammatory disease characterized by the formation of lipid-rich plaques in arteries. Atherosclerotic... Show moreAtherosclerosis is the main pathology behind most cardiovascular diseases. It is a chronic inflammatory disease characterized by the formation of lipid-rich plaques in arteries. Atherosclerotic plaques are initiated by the deposition of cholesterol-rich LDL particles in the arterial walls leading to the activation of innate and adaptive immune responses. Current treatments focus on the reduction of LDL blood levels using statins, however the critical components of inflammation and autoimmunity have been mostly ignored as therapeutic targets. The restoration of immune tolerance towards atherosclerosis-relevant antigens can arrest lesion development as shown in pre-clinical models. In this review, we evaluate the clinical development of similar strategies for the treatment of inflammatory and autoimmune diseases like rheumatoid arthritis, type 1 diabetes or multiple sclerosis and analyse the potential of tolerogenic vaccines for atherosclerosis and the challenges that need to be overcome to bring this therapy to patients. Show less
Noordam, R.; Boersma, V.; Verkouter, I.; Cessie, S. le; Christen, T.; Lamb, H.J.; ... ; Mutsert, R. de 2020
Background and aims: In the present study, we assessed the extent of mediation by low-grade systemic inflammation and adipokines in the association between abdominal adiposity and insulin... Show moreBackground and aims: In the present study, we assessed the extent of mediation by low-grade systemic inflammation and adipokines in the association between abdominal adiposity and insulin resistance.Methods and results: In this cross-sectional analysis of baseline measurements of the Netherlands Epidemiology of Obesity study, total body fat (TBF) was measured in all (n = 5772) participants who did not have missing data and neither used glucose-lowering medication, and abdominal subcutaneous adipose tissue (aSAT) and visceral adipose tissue (VAT) were assessed by MRI in a random subgroup (n = 2448). C-reactive protein (CRP), adiponectin, and leptin were considered as potential mediators, and insulin resistance was assessed by Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). Mediation by CRP, adiponectin, and leptin was studied by including the mediators to the fully adjusted linear regression model. Participants had a mean (SD) age of 56 (6) years, TBF of 36 (9) %, VAT of 119 (61) cm2 and aSAT of 300 (111) cm2. Per SD of TBF, VAT and aSAT, HOMA-IR was 64% (95% confidence interval [CI]: 59-70), 33% (95% CI: 28-42) and 20% (95%CI: 14-26) higher, respectively. The association between aSAT and HOMA-IR fully disappeared after adjustment for leptin; the association between VAT and HOMA-IR attenuated after adjustment for leptin (22%) and adiponectin (15%). No mediation was observed by CRP, and mediation estimates were similar in men and women.Conclusion: Where leptin fully explained the aSAT-HOMA-IR association, the VAT-HOMA-IR association was only partly explained by leptin and adiponectin similarly in men and women. (C) 2020 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved. Show less
Rafiq, R.; Haddaoui, H. el; Mutsert, R. de; Rosendaal, F.R.; Hiemstra, P.S.; Cobbaert, C.M.; ... ; Jongh, R.T. de 2020
Objective: The role of adiposity in the relationship between vitamin D and inflammation is unknown. Our aim was therefore to assess the association of serum 25-hydroxyvitamin D (25(OH)D) with C... Show moreObjective: The role of adiposity in the relationship between vitamin D and inflammation is unknown. Our aim was therefore to assess the association of serum 25-hydroxyvitamin D (25(OH)D) with C-reactive protein (CRP), leptin and adiponectin and the role of adiposity in this relationship.Methods: This is a cross-sectional analysis of The Netherlands Epidemiology of Obesity Study (NEO), a population-based cohort study in men and women aged 45 to 65 years. Main outcome measures were CRP, leptin and adiponectin. In the linear regression analyses we adjusted for age, sex, ethnicity, creatinine, education, alcohol use, smoking status, physical activity, number of chronic diseases, season, total body fat and waist circumference.Results: Of the 6287 participants, 21% were vitamin D deficient (serum 25(OH)D < 50 nmol/L). Mean (SD) age and BMI were 56 (6) years and 26.3 (4.4) kg/m(2), respectively. Although after adjustment for most examined potential confounders, each 10 nmol/L increase in serum 25(OH)D was associated with 2.3% (95%CI: -4.0 to -0.5) lower CRP, 3.5% (-4.7 to -2.2) lower leptin, and 0.13 ng/mL (0.04-0.21) higher adiponectin, most of these associations seemed to largely stem from an additional potential confounder - adiposity - as they either disappeared (leptin and CRP) or were largely diminished (adiponectin) upon further adjustment for adiposity indices (total body fat and waist circumference).Conclusion: We found that measures of adiposity largely explained the negative association of serum 25(OH)D with the pro-inflammatory CRP and leptin, and the positive association with the anti-inflammatory adiponectin. These results suggest that future studies should take the effect of adiposity into account. Show less
A prominent feature of severe streptococcal infections is the profound inflammatory response that contributes to systemic toxicity. In sepsis the dysregulated host response involves both... Show moreA prominent feature of severe streptococcal infections is the profound inflammatory response that contributes to systemic toxicity. In sepsis the dysregulated host response involves both immunological and nonimmunological pathways. Here, we report a fatal case of an immunocompetent healthy female presenting with toxic shock and purpura fulminans caused by group B streptococcus (GBS; serotype III, CC19). The strain (LUMC16) was pigmented and hyperhemolytic. Stimulation of human primary cells with hyperhemolytic LUMC16 and STSS/NF-HH strains and pigment toxin resulted in a release of proinflammatory mediators, including tumor necrosis factor, interleukin (IL)-1 beta, and IL-6. In addition, LUMC16 induced blood clotting and showed factor XII activity on its surface, which was linked to the presence of the pigment. The expression of pigment was not linked to a mutation within the CovR/S region. In conclusion, our study shows that the hemolytic lipid toxin contributes to the ability of GBS to cause systemic hyperinflammation and interferes with the coagulation system. Show less
Purpose Sciatic symptoms due to lumbar disc herniation are likely to be caused not solely by mechanical compression of the nerve root, but also by pain-inducing elements from inflammatory processes... Show morePurpose Sciatic symptoms due to lumbar disc herniation are likely to be caused not solely by mechanical compression of the nerve root, but also by pain-inducing elements from inflammatory processes. Key components in the inflammatory reaction are M1 and M2 macrophages, with the M1 type being associated with pro-inflammatory processes and M2 with anti-inflammatory-processes. Method The present systematic review summarizes all studies on associations between M1 and M2 macrophages and their related inflammation factors and pain symptoms in lumbar disc herniations. Literature search was performed using an optimally sensitive search string. Studies were selected for inclusion by means of predefined inclusion and exclusion criteria and subsequently graded for risk of bias. A total of 14 studies were included. Overall risk of bias was moderate (8/14), and three studies had high risk of bias and three has low risk of bias. Results Regarding M1-related cytokines, high levels of TNF-alpha, TNFR1, IL-6, IL-8, and IFN-gamma were all associated high VAS scores. In contrast, high levels of TNFR2 were associated with lower VAS scores. Moreover, no associations were found for IL-1a and IL-1 beta. Results regarding M2-related cytokines revealed the opposite: high levels of both IL-4 and IL-10 were associated with lower VAS scores. No associations were established for TGF-beta. Moreover, the presence of macrophages (CD68) was negatively associated with VAS scores. Conclusion While M1-related pro-inflammatory cytokines worsen pain symptoms, M2-related anti-inflammatory cytokines alleviate pain symptoms. Nevertheless, the present evidence is limited, and further research on the underlying pathophysiological mechanism in sciatica is required. Graphic abstract These slides can be retrieved under Electronic Supplementary Material. Show less
Park, Y.J.; Gherghe, A.M.; Heijde, D. van der 2020
Objectives To summarise radiographic data in randomised controlled trials (RCTs) as part of the radiographic inhibition claim of disease-modifying antirheumatic drugs (DMARDs) approved for patients... Show moreObjectives To summarise radiographic data in randomised controlled trials (RCTs) as part of the radiographic inhibition claim of disease-modifying antirheumatic drugs (DMARDs) approved for patients with rheumatoid arthritis (RA).Methods A systemic literature review was performed using the Medline database from 1994 to February 2020. The results were grouped based on the scoring methods (Sharp, Genant modification, van der Heijde modification) and RA patient populations.Results One hundred sixty-eight publications were selected. After detailed assessment, 52 RCTs (7 methotrexate (MTX)-naive, 23 MTX inadequate response (IR), 9 DMARDs IR and 3 tumour necrosis factor-alpha inhibitors (TNFi) IR studies) were finally included. Information on patient population, scoring method used, reader reliability, statistical analyses and detailed radiographic data on baseline and change scores over multiple follow-up periods are presented.Conclusion The data gathered in this review serve as a repository for the design of future trials with radiographic damage as an outcome. Show less
Despite the available treatment options and sophisticated imaging technologies for monitoring lesion development, the morbidity and mortality from acute cardiovascular events remain unacceptably... Show moreDespite the available treatment options and sophisticated imaging technologies for monitoring lesion development, the morbidity and mortality from acute cardiovascular events remain unacceptably high.While cholesterol-lowering, anti-inflammatory and anti-platelet therapies benefits can increase survival as a primary or secondary prevention, they are not sufficient for plaque rupture prevention. Moreover, the most advance imaging technologies to detect high-risk atherosclerotic patients fail to visualize and explore cellular events in small preclinical models. Therefore, there is a clear need for the development of new therapies and the application of high-resolution imaging modalities.In the current thesis, we evaluated new possibilities to inhibit and image intraplaque angiogenesis. Show less
Oliveira, A.L.C.S.L. de; Santos-Silva, A.M. dos; Silva, A.A. da; Garcia, V.B.; Araujo, A.A. de; Geus-Oei, L.F. de; ... ; Araujo, R.F. de 2020
The inflammation has been identified as factor of tumor progression, which has increased the interest and use of molecules with anti-inflammatory and antioxidant activities in the cancer treatment.... Show moreThe inflammation has been identified as factor of tumor progression, which has increased the interest and use of molecules with anti-inflammatory and antioxidant activities in the cancer treatment. In this study, the antioxidant, anti-inflammatory, and antitumor potentials of carvedilol was explored in a different approach. The cholesterol (CHO) was investigated as facilitated agent in the action of carvedilol-loaded nanoparticles. Different formulations exhibited spherical and stable nanoparticle with mean diameter size < 250 nm. The cholesterol changed the copolymer-drug interactions and the encapsulation efficiency. The in vitro cancer study was performed using murine colorectal cancer cell line (CT-26) to observe the cell viability and apoptosis on MTS assay and flow cytometry, respectively. The experiments have demonstrated that cholesterol improved the performance of drug-loaded nanoparticles, which was much better than free drug. The in vivo inflammation peritonitis model revealed that carvedilol-loaded nanoparticles increased the level of glutathione and leukocyte migration mainly when the functionalized drug-loaded nanoparticles were tested, in a lower dose than the free drug. As hypothesized, the experimental data suggest that cholesterol-functionalized carvedilol-loaded PLGA nanoparticles can be a novel and promising approach in the inflammation-induced cancer therapy since showed anti-inflammatory, antioxidant, and antitumor effects.Graphical abstract 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
Cells, their fragments and secreted factors may all be transported to distant sites via the blood circulatory system and exert their action far away from the site of origin. Identification of these... Show moreCells, their fragments and secreted factors may all be transported to distant sites via the blood circulatory system and exert their action far away from the site of origin. Identification of these mediating factors and unraveling of the pathogenesis resulting in organ damage will contribute to our general understanding and may ultimately result in new treatment strategies. The studies included in this thesis focus on mechanisms of coagulopathy and other blood abnormalities in patients with cancer or inflammation. Show less
