Institute for Atherosclerosis Research

Crohn's disease (CD) is a chronic inflammatory bowel disease characterized by transmural inflammation that can affect any part of the gastrointestinal tract. Early and accurate diagnosis remains challenging due to the heterogeneous nature of the disease and overlapping symptoms with other gastrointestinal disorders. Current diagnostic approaches rely on a combination of clinical presentation, endoscopic findings, histological examination, and imaging studies, which can be invasive and time-consuming. The identification of reliable biomarkers could significantly improve diagnostic accuracy and reduce the need for invasive procedures. This review examines currently used biomarkers, including C-reactive protein, fecal calprotectin, and anti-Saccharomyces cerevisiae antibodies, while exploring emerging potential biomarkers such as microRNA panels, metabolomic signatures, and novel inflammatory mediators. Recent advances in genomics, proteomics, and metabolomics have revealed promising biomarker candidates that could enhance diagnostic precision and enable personalized treatment approaches. Understanding the performance characteristics and clinical utility of these biomarkers is crucial for their implementation in routine clinical practice and improved patient outcomes.

ABSTRACTIn this study, we aim to validate the analytical Cramer‐Rao lower bound (CRLB) equation for determining attenuation coefficients using a 1310 nm Optical Coherence Tomography (OCT) system. Our experimental results successfully confirm the validity of the equation, achieving unprecedented precision with a standard deviation below 0.01 mm−1 for intralipid samples. Furthermore, we introduce a systematic framework for attaining high precision in OCT attenuation measurements.

This review offers an in-depth analysis of mitochondrial DNA (mtDNA) mutations in colorectal cancer stem cells (CSCs), emphasizing their significant impact on tumor dynamics and potential therapeutic strategies. CSCs are a special subpopulation due to their unique capabilities for self-renewal, differentiation, and resistance to conventional therapies. Given that CSCs significantly differ from other tumor cell subpopulations, particularly in their metabolic properties, and considering that colorectal cancer is a malignancy characterized by mitochondrial dysfunction, this review aims to put together existing data on the differences in the mitochondrial genome of CSCs compared to other colorectal tumor cell subpopulations. Additionally, the review seeks to explore the potential roles of these differences and to identify new ideas for therapeutic strategies. Key topics include the identification and properties of CSCs in colorectal cancer, the distinctive features of the mitochondrial genome, and the functional consequences of mtDNA mutations. The review hypothesizes that CSCs rely on well-functioning mitochondria for crucial aspects like energy production; yet, mtDNA mutations can lead to mitochondrial dysfunction, altering CSC characteristics and influencing cancer progression. The article discusses emerging therapeutic approaches targeting mitochondrial function in colorectal CSCs and highlights the need for advanced research, including the development of preclinical models and exploration of targeted therapies, to improve the understanding and treatment of colorectal cancer.

BACKGROUND:The microbiota-derived short chain fatty acid butyrate has been shown to lower blood pressure (BP) in rodent studies. Nonetheless, the net effect of butyrate on hypertension in humans remains uncovered. In this study, for the first time, we aimed to determine the effect of oral butyrate on BP in patients with hypertension.METHODS:We performed a double-blind randomized placebo-controlled trial including 23 patients with hypertension. Antihypertensive medication was discontinued for the duration of the study with a washout period of 4 weeks before starting the intervention. Participants received daily oral capsules containing either sodium butyrate or placebo with an equivalent dosage of sodium chloride for 4 weeks. The primary outcome was daytime 24-hour systolic BP. Differences between groups over time were assessed using linear mixed models (group-by-time interaction).RESULTS:Study participants (59.0±3.7 years; 56.5% female) had an average baseline office systolic BP of 143.5±14.6 mm Hg and diastolic BP of 93.0±8.3 mm Hg. Daytime 24-hour systolic and diastolic BP significantly increased over the intervention period in the butyrate compared with the placebo group, with an increase of +9.63 (95% CI, 2.02–17.20) mm Hg in daytime 24-hour systolic BP and +5.08 (95% CI, 1.34–8.78) mm Hg in diastolic BP over 4 weeks. Butyrate levels significantly increased in plasma, but not in feces, upon butyrate intake, underscoring its absorption.CONCLUSIONS:Four-week treatment with oral butyrate increased daytime systolic and diastolic BP in subjects with hypertension. Our findings implicate that butyrate does not have beneficial effects on human hypertension, which warrants caution in future butyrate intervention studies.REGISTRATION:URL: https://onderzoekmetmensen.nl/; Unique identifier: NL8924.

Mitochondria are the main sites of cellular aerobic energy production through conjugation of respiration and oxidative phosphorylation. We have recently discovered mutations (genome variants) of mitochondrial DNA (mtDNA) associated with atherosclerosis. We have then investigated the possible mechanisms underlying such association and the role of mitochondrial mutations in atherogenesis. Mitochondrial dysfunction is a known component of the pathogenesis of chronic human diseases, including atherosclerosis. The aim of the study was to explore whether there is a relationship between cellular oxygen consumption and atherosclerosis-associated mitochondrial mutations. The study of mitochondrial respiration abnormalities can help to understand the role of mtDNA mutations in pathology. By using the polarographic method with Clark electrode, we tested the possibility of respiration impairment in permeabilized cells carrying the tested mtDNA variants using the cybrid (cytoplasmic hybrid) lines. Mitochondria introduced in the cybrid lines were obtained from atherosclerotic patients that differed in the profile of mtDNA mutations, which made it possible to compare the degree of mtDNA mutation load with the rate of oxygen consumption by cybrid cells. It was found that three of the studied mutations were individually associated with impaired respiration. Besides, some combinations of two specific mutations have a high probability of being associated with altered oxygen consumption. As a result, eight mutations were identified, individually or paired combinations of which were associated with high or low rates of cellular respiration, significantly different from control cells. The observed effect may be involved in the pathogenesis of atherosclerosis. The study of mtDNA mutations associated with atherosclerosis can help reveal pharmacological targets for the development of novel therapies.

Atherosclerosis is a chronic disease characterized by the increased infiltration and retention of LDL particles in arterial walls. There are several mechanisms underlying atherogenesis, with the pro-atherogenic modifications of LDL playing a significant role. One such modification of native LDL is desialylation, which is characterized by the removal of terminal sialic acid from ApoB-100 glycans that induces critical changes in the overall functionality of the LDL particle. The aim of this study was to model the desialylation of native LDL in mice, resembling a phenomenon previously observed in atherosclerotic patients. LDL desialylation was induced in C57BL/6J mice via the injection of exogenous neuraminidase. The degree of LDL desialylation and its duration were assessed. The impact of LDL desialylation on blood lipid levels was evaluated. Furthermore, the morphological alterations in the aorta during LDL desialylation in the bloodstream were examined. The control group of C57BL/6J mice received saline injections, while the experimental group underwent a single injection of IgG-conjugated Vibrio cholerae neuraminidase. The LDL sialic acid levels were assessed 1-7 days post-injection using the Warren method and normalized to total protein content measured via the Lowry method. A similar protocol was followed for the subchronic administration of the IgG-neuraminidase conjugate over a 6-week period. The blood lipid profiles were analyzed using commercial kits. The atherosclerotic plaque burden in the mouse aorta was quantified using Oil Red O and hematoxylin-eosin staining. A single administration of 20 mU IgG-neuraminidase conjugate resulted in decreased LDL sialic acid levels for 5 days, gradually recovering by days 6-7. Subchronic administration maintained reduced LDL sialic acid levels for up to 2 months. Notably, sustained LDL desialylation was associated with elevated LDL cholesterol levels. A sustained desialylation of LDL in C57BL/6J mice was achieved through subchronic administration of IgG-conjugated neuraminidase. This study provides an approach for sustained LDL desialylation in mice. Further studies using apolipoprotein E knockout mice and LDL desialylation will reveal the role of this process in the occurrence and development of atherosclerosis.

Atherosclerosis is a complex disease that has garnered significant attention from researchers studying its various aspects. Its pathogenesis involves a wide array of cellular and molecular components, as well as crucial mechanisms and processes crucial for cellular and organismal functioning. Atherosclerosis is considered a chronic inflammatory disease characterized by disrupted lipid metabolism, oxidative stress, and immune response. Apoptosis, a fundamental cellular process essential for normal cell and organismal function, has also been implicated in numerous pathological conditions. In this review, we aim to compile and present data on the role of apoptosis in various cell types during the progression of atherosclerosis. By examining the involvement of apoptosis in atherosclerosis, we hope to shed light on the intricate interplay between cell death and disease pathogenesis. Understanding the specific mechanisms and consequences of apoptosis in atherosclerosis can contribute to the development of targeted therapeutic strategies and interventions for this debilitating condition.