Background: To determine whether extremely mild small vessel disease (SVD) phenotypes can occur in NOTCH3 variant carriers from Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts... Show moreBackground: To determine whether extremely mild small vessel disease (SVD) phenotypes can occur in NOTCH3 variant carriers from Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) pedigrees using clinical, genetic, neuroimaging, and skin biopsy findings. Methods: Individuals from CADASIL pedigrees fulfilling criteria for extremely mild NOTCH3-associated SVD (mSVD(NOTCH3)) were selected from the cross-sectional Dutch CADASIL cohort (n=200), enrolled between 2017 and 2020. Brain magnetic resonance imaging were quantitatively assessed for SVD imaging markers. Immunohistochemistry and electron microscopy was used to quantitatively assess and compare NOTCH3 ectodomain (NOTCH3(ECD)) aggregation and granular osmiophilic material deposits in the skin vasculature of mSVD(NOTCH3) cases and symptomatic CADASIL patients. Results: Seven cases were identified that fulfilled the mSVD(NOTCH3) criteria, with a mean age of 56.6 years (range, 50-72). All of these individuals harbored a NOTCH3 variant located in one of EGFr domains 7-34 and had a normal brain magnetic resonance imaging, except the oldest individual, aged 72, who had beginning confluence of WMH (Fazekas score 2) and 1 cerebral microbleed. mSVD(NOTCH3) cases had very low levels of NOTCH3(ECD) aggregation in skin vasculature, which was significantly less than in symptomatic EGFr 7-34 CADASIL patients (P=0.01). Six mSVD(NOTCH3) cases had absence of granular osmiophilic material deposits. Conclusions: Our findings demonstrate that extremely mild SVD phenotypes can occur in individuals from CADASIL pedigrees harboring NOTCH3 EGFr 7-34 variants with normal brain magnetic resonance imaging up to age 58 years. Our study has important implications for CADASIL diagnosis, disease prediction, and the counseling of individuals from EGFr 7-34 CADASIL pedigrees. Show less
Pericytes (PCs) have been reported to contribute to the mechanoregulation of the capillary diameter and blood flow in health and disease. How this is realized remains poorly understood. We designed... Show morePericytes (PCs) have been reported to contribute to the mechanoregulation of the capillary diameter and blood flow in health and disease. How this is realized remains poorly understood. We designed several models representing basement membrane (BM) in between PCs and endothelial cells (ECs). These models captured a unique protein organization with micron-sized FN patches surrounded by laminin (LM) and allowed to obtain quantitative information on PC morphology and contractility. Using human induced pluripotent stem cell-derived PCs, we could address mechanical aspects of mid-capillary PC behavior in vitro. Our results showed that PCs strongly prefer FN patches over LM for adhesion formation, have an optimal stiffness for spreading in the range of EC rigidity, and react in a non-canonical way with increased traction forces and reduced spreading on other stiffness then the optimal. Our approach opens possibilities to further study PC force regulation under well-controlled conditions. Show less
