BackgroundTo evaluate the potential of cerebrospinal fluid (CSF) levels of matrix metalloproteinases and tissue-type inhibitors (MMP; TIMP), and ratios of MMPs to TIMPs, to function as biomarkers... Show moreBackgroundTo evaluate the potential of cerebrospinal fluid (CSF) levels of matrix metalloproteinases and tissue-type inhibitors (MMP; TIMP), and ratios of MMPs to TIMPs, to function as biomarkers for sporadic or hereditary cerebral amyloid angiopathy (CAA).MethodsCSF concentrations of the matrix metalloproteinases MMP-2, MMP-9 and MMP-14, as well as the tissue inhibitors of metalloproteinases TIMP-1, TIMP-2 and TIMP-3, were determined using immunoassays. These assays were applied to two, independent study groups of sporadic CAA (sCAA) (n = 28/43) and control subjects (n = 40/40), as well as to groups of pre-symptomatic (n = 11) and symptomatic hereditary Dutch-CAA (D-CAA) patients (n = 12), and age-matched controls (n = 22/28, respectively).ResultsIn the sCAA/control cohorts, inconsistent differences were found for individual MMPs and TIMPs, but MMP-2/TIMP-2 (discovery/validation: p = 0.004; p = 0.02) and MMP-14/TIMP-2 ratios (discovery/validation: p < 0.001; p = 0.04) were consistently decreased in sCAA, compared to controls. Moreover, MMP-14 was decreased in symptomatic D-CAA (p = 0.03), compared to controls. The MMP-14/TIMP-1 (p = 0.03) and MMP-14/TIMP-2 (p = 0.04) ratios were decreased in symptomatic D-CAA compared to controls and also compared to pre-symptomatic D-CAA (p = 0.004; p = 0.005, respectively).ConclusionCSF MMP-2/TIMP-2 and MMP-14/TIMP-2 were consistently decreased in sCAA, compared to controls. Additionally, MMP-14/TIMP-2 levels were also decreased in symptomatic D-CAA, compared to both pre-symptomatic D-CAA and controls, and can therefore be considered a biomarker for sporadic and late-stage hereditary forms of CAA. Show less
Jansen, A.F.M.; Schoffelen, T.; Textoris, J.; Mege, J.L.; Bleeker-Rovers, C.P.; Roest, H.I.J.; ... ; Deuren, M. van 2017
Chimerism after orthotopic liver transplantation (OLT) is the main focus of the studies described in this thesis. The first study showed that chimerism of different cell lineages within the liver... Show moreChimerism after orthotopic liver transplantation (OLT) is the main focus of the studies described in this thesis. The first study showed that chimerism of different cell lineages within the liver graft does occur after OLT. Subsequently, in allogeneic blood stem cell recipients, chimerism was demonstrated in liver tissue, providing evidence that circulating progenitor cells can indeed differentiate into parenchymal liver cells.The secondary focus of this thesis is on matrix metalloproteinases (MMPs). These proteolytic enzymes are involved in a wide variety of physiological and disease-related matrix remodeling processes. MMP-2 and MMP-9 gene promotor polymorphisms were assessed of OLT donors and recipients in relation to ischemia/reperfusion injury, acute rejection and non-anastomotic biliary strictures after transplantation. We performed a side study, in which we evaluated the value of serum liver chemistry profile and abdominal ultrasound for detecting clinically relevant biliary strictures using time-dependent multivariate regression analysis. The two main themes, chimerism and MMPs, merge in the final chapter of this thesis. In liver transplant recipients with donor/recipient mismatches for MMP gene polymorphisms chimerism was studied, in both liver biopsies as in peripheral blood after OLT. Show less
This thesis describes the design, synthesis and application of chemical tools for the activity-based protein profiling of proteases, with the main focus on matrix metalloproteinases (MMPs) and the... Show moreThis thesis describes the design, synthesis and application of chemical tools for the activity-based protein profiling of proteases, with the main focus on matrix metalloproteinases (MMPs) and the proteasome. The use of photoaffinity labeling is described and the thesis starts with an extensive outline of the three most often used photoreactive groups and their application in (recently published) protein profiling studies. Targeting MMPs is performed by application of photoaffinity probes, while the proteasome is commonly targeted by so-called suicide inhibitors. The last experimental chapter deals with the creation of a novel chemoselective cleavable linker and its use in the pull-down of active proteasome subunits. Show less
The studies described in this thesis focus on gene therapeutic strategies to target pathological vascular wall remodeling after PT(C)A or bypass surgery. Inflammatory processes and extracellular... Show moreThe studies described in this thesis focus on gene therapeutic strategies to target pathological vascular wall remodeling after PT(C)A or bypass surgery. Inflammatory processes and extracellular proteases, both activated by mechanical and vascular injury caused by these interventions, are thought to contribute largely to the development of post-angioplasty restenosis and vein graft disease. Therefore, viral and non-viral gene therapy techniques were used in these studies to deliver genes encoding protective as well as inhibiting proteins in order to modulate the inflammatory cascade (i.e. IL-10 and the MCP-1/CCR-2 pathway) in the first part of this thesis and the plasminogen activator and MMP-system in the second part. Finally, the expression of several involving genes was blocked locally by RNA interference techniques in the last part of this thesis. The possibilities and effects of these gene therapy applications were studied in cell cultures, in a human saphenous vein organ culture model and in two mouse models of restenosis and vein graft disease. Altogether, these studies provided more insight into the pathophysiology of post-interventional remodeling and several potential therapeutic strategies were assessed. Show less
Identification of translational and/or post-translational modifications of cardiac proteins after acute myocardial infarction (AMI) or during the progression to congestive heart failure (CHF) is... Show moreIdentification of translational and/or post-translational modifications of cardiac proteins after acute myocardial infarction (AMI) or during the progression to congestive heart failure (CHF) is relevant to gain insight into the pathological mechanisms. Characterization of the release kinetics of these cardiac proteins from the reversibly or irreversibly injured myocardium into the circulation may lead to new diagnostic biomarkers. Although cardiac Troponin I (cTnI) is a well-known biomarker of irreversible myocardial damage in acute myocardial infarction, we demonstrated that the release of cTnI also occurs from viable cardiomyocytes by a stretch-related mechanism, mediated by integrin stimulation. This finding may explain why in several pathological conditions, such as CHF, plasma cTnI levels are elevated in the absence of myocardial necrosis. In addition, we investigated the role of Tenascin-C re-expression during the development of heart failure and the relevance of TNC as a biomarker of ventricular remodeling. In animals with pressure-overload induced ventricle dilatation, TNC gene expression was upregulated, resulting in re-expression of myocardial TNC protein levels and elevated TNC plasma levels, correlating with cardiac function. Plasma TNC levels in patients with CHF declined during cardiac resynchronization therapy. This study indicates that serial plasma TNC levels can be used as a marker of adverse or reverse ventricular remodeling. Show less
The studies in this thesis describe the clinical impact of several matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in H. pylori-induced gastritis and gastric... Show moreThe studies in this thesis describe the clinical impact of several matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in H. pylori-induced gastritis and gastric cancer. In patients with H. pylori-induced gastritis, significantly increased mucosal MMP-9 levels were found. By successful H. pylori eradication, active and chronic inflammation decreased, accompanied by a significant decrease of mucosal MMP-9. MMP-2, MMP-7, MMP-8 and MMP-9, lipocalin-2, MMP-9/lipocalin-2 and TIMP-1 were significantly increased in tumour tissue of gastric cancer patients compared to normal gastric mucosa whereas only enhanced levels of MMP-2 and MMP-9/lipocalin-2 complexes were independently related to worse prognosis. Subsequently the genotype distribution of single-nucleotide polymorphisms (SNPs) of MMPs and TIMPs in gastric cancer was studied. The genotype distribution of MMP-7-181A>G was associated with H. pylori status and tumour-related survival of the patients. Single-nucleotide polymorphism TIMP-2-303C>T correlated significantly with tumour-related survival. First-order dendrogram cluster analysis combined with Cox analysis identified the MMP-7-181A>G and TIMP-2-303C>T polymorphism combination to have a major impact on patients survival outcome. Show less
