Podcasts about notch3

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.04.26.538393v1?rss=1 Authors: Zhang, W., Zhao, X., Qi, X., Kimber, S. J., Hooper, N., Wang, T. Abstract: Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is the most common genetic small vessel disease caused by variants in the NOTCH3 gene. Patients with CADASIL experience recurrent strokes, developing into cognitive defect and vascular dementia. CADASIL is a late-onset vascular condition, but migraine and brain MRI lesions appear in CADASIL patients as early as their teens and twenties, suggesting an abnormal neurovascular interaction at the neurovascular unit (NVU) where microvessels meet the brain parenchyma. To understand the molecular mechanisms of CADASIL, we established induced pluripotent stem cell (iPSC) models from CADASIL patients and differentiated the iPSCs into the major NVU cell types including brain microvascular endothelial-like cells (BMECs), vascular mural cells (MCs), astrocytes and cortical projection neurons. We then built an in vitro NVU model by co-culturing different neurovascular cell types in Transwells and evaluated the blood brain barrier (BBB) function by measuring transendothelial electrical resistance (TEER). Results showed that, while the wild-type MCs, astrocytes and neurons could all independently and significantly enhance TEER values of the iPSC-BMECs, such capability of MCs from iPSCs of CADASIL patients was significantly impeded. Additionally, the barrier function of the BMECs from CADASIL iPSCs was significantly impaired, accompanied with disorganised tight junctions in iPSC-BMECs, which could not be effectively rescued by the wild-type MCs, astrocytes and neurons. Our findings provide new insight into early disease pathologies on the neurovascular interaction and BBB function at the molecular and cellular levels for CADASIL, which helps inform future therapeutic development. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Author: Sam Killian, MD Educational Pearls: Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) occurs in 1:100000 individuals The disease is caused by a defect in the NOTCH3 gene on chromosome 19 It is an important cause of stroke in young patients Features include ischemia, cognitive deficits, migraines, psychiatric disease, coma, and seizure, all of which is worse with pregnancy Migraine with aura is often the first presenting symptom with onset by age 30 Strokes typically can occur by age 50 Diagnosis is with MRI for characteristic lesions Unfortunately there is no cure, and treatment is focused on stroke prevention with aspirin and statins References: Chabriat H, Joutel A, Dichgans M, Tournier-Lasserve E, Bousser MG. Cadasil. Lancet Neurol. 2009 Jul;8(7):643-53. doi: 10.1016/S1474-4422(09)70127-9. Review. PubMed PMID: 19539236. Summarized by Will Dewispelaere, MS3 | Edited by Erik Verzemnieks, MD  

CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) represents the most prevalent hereditary form of cerebral small vessel disease (SVD) resulting in early-onset stroke and vascular dementia. It is caused by stereotyped missense mutations in the transmembrane receptor Notch3, which alter the number of cysteine residues in the extracellular domain (ECD). This leads to the abnormal multimerization and extracellular deposition of mutant Notch3-ECD at the plasma membrane of smooth muscle cells in small blood vessels. Notch3-ECD-containing aggregates are the earliest manifestation of the disease and excess Notch3-ECD is believed to recruit functionally important extracellular matrix proteins resulting in brain vessel dysfunction. Biochemical and histological approaches on post-mortem brain tissue from CADASIL patients and control subjects as well as in vitro assays were used to study the consequences of Notch3-ECD deposition on the ECM components thrombospondin-2, fibrillin-1 and fibronectin and members of the latent transforming growth factor-β (TGF-β) binding protein (LTBP) family. It is demonstrated that the structural matrix components fibrillin-1 and fibronectin are enriched and contribute to the prominent thickening of CADASIL vessel walls without co-localizing with Notch3-ECD deposits, likely as a result of fibrotic adaptation secondary to aggregate formation. For LTBP-1, a key regulator of the TGF-β signaling pathway, an accumulation as well as a striking co-localization with Notch3-ECD deposits is shown suggesting specific recruitment into aggregates. Furthermore, increased levels of the TGF-β pro-domain (also known as latency-associated peptide, LAP) were found implying dysregulation of the TGF-β pathway in CADASIL development. Finally, a direct interaction of LTBP-1 with Notch3-ECD is demonstrated and evidence for a co aggregation with mutant Notch3 in vitro is provided. Conclusively, I propose LTBP-1 as a novel component of Notch3 deposits with a role in CADASIL pathogenesis.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) represents the most common hereditary form of cerebral small vessel disease characterized by early-onset stroke and premature dementia. It is caused by mutations in the transmembrane receptor Notch3, which promote the aggregation and accumulation of the Notch3 extracellular domain (Notch3-ECD) within blood vessel walls. This process is believed to mediate the abnormal recruitment and dysregulation of additional factors including extracellular matrix (ECM) proteins resulting in brain vessel dysfunction. Based on recent evidence indicating a role for the transforming growth factor-β (TGF-β) pathway in sporadic and familial small vessel disease we studied fibronectin, fibrillin-1 and latent TGF-β binding protein 1 (LTBP-1), three ECM constituents involved in the regulation of TGF-β bioavailability, in post-mortem brain tissue from CADASIL patients and control subjects.

Thu, 2 Feb 2012 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/13969/ https://edoc.ub.uni-muenchen.de/13969/1/Zechmeister_Martin.pdf Zechmeister, Martin

Purpose: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a cerebral small vessel disease caused by mutations of the NOTCH3 gene. Marked variations in disease severity have raised the hypothesis that non-genetic factors may modulate the expressivity of the phenotype. The aim of the current study was to evaluate whether atherosclerosis, assessed by carotid duplex ultrasonography, is associated with variations in the clinical and MRI phenotype of CADASIL. Methods: Data from 144 consecutive patients enrolled in an ongoing prospective cohort study were collected. Degree of disability was assessed by the modified Rankin Scale, that of cognitive impairment by the Mattis Dementia Rating Scale (MDRS). The total volume of the brain, of lacunar lesions and of white matter hyperintensities, the number of cerebral microhemorrhages, and parameters derived from histograms of apparent diffusion coefficient were measured on cerebral MRI. Atherosclerosis was evaluated by B-mode ultrasonography of carotid arteries. Both the carotid intima-media thickness cIMT) and the presence of carotid plaques or stenosis were recorded. Results: Higher cIMT was found to be independently associated with lower MDRS scores when this score was less than the quartile limit (p = 0.02). Only a trend for a positive association was detected between cIMT and the Rankin score (p = 0.06). There was no significant association between carotid markers and the occurrence of stroke or MRI parameters except for diffusion data. The mean and peak values of MRI diffusion histograms were found positively associated with the presence of plaques (p < 0.01). Conclusion: The results suggest that the severity of atherosclerosis may relate to cognitive decline in CADASIL and that this effect is possibly related to the degree of microstructural cerebral tissue lesions. Longitudinal studies are needed to confirm these results. Copyright (C) 2010 S. Karger AG, Basel

Summary CADASIL (cerebral autosomal arteriopathy with subcortical infarcts and eukoencephalopathy) is a autosomal dominant disease,which lead among other things to migraen headache and early stroke. Shortly before beginning of this work Notch3 was identified as responsible gene. Notch3 coded for a large transmembranereceptor with 34 extracellularly located,epidermal growth factor (EGF) similar domains. In this work 70 related families (70 index patients and 13 relatives) with bioptisch secured diagnosis in substantial two Exons (3 and 4) were examined, since within this range the mutations accumulate. By sequencing of Exon 3 and Exon 4 mutations in 70 % of the cases were identified. Three types of mutations were found: Point mutations ((n = 50), Dinukleotid mutation (n = 1) and Deletionen (n= 2). In addition numerous Polymorphismen was identified (n =43). Seven of the mutated nucleotides mutations arose frequently, whereby transitions of cytosine to thymine occure. All mutations including the Deletionen led either to an acquisition or a loss of a Cystein. Therefore it is to be accepted obviously that the change of a Cystein in a EGF similar domain of Notch3 represents the crucial mutation mechanical which is responsible for CADASIL. With the Polymorphismen no changes of the Cystein arose. Genotyp/Phaenotyp correlations could not be proven. This stands in the agreement with the uniformity of the mutations. Due to the results of this work an improvement in the procedure results for the existing diagnostics. Scinbiopsie and MRT photographs can be supplemented by the sequencing of Exon 3 and 4. Thus 2/3 of the mutations are already discovered. If no mutations are found there, still the remaining 22 Exons of the extracellular domain can be sequenzed, whereby here first on Exon 6 (and 12) the emphasis should be put. This procedure is used meanwhile as standard technique for the diagnostics. In this work as the further supplementing diagnostic method the analysis with mutation-specific restriction enzymes was developed. Under consultation of the theoretically computed restriction enzymes of the 7 most frequent mutations one receives 52% (amount of = 37) of the mutations with 70 index patients (74% of the found mutations). In families, in which a mutation already admits is, further family members with this method let themselves be examined faster and more economically, than by sequencing. In this work it could be shown that forecasts of mutation effects make the development of protein models possible on the protein structure. As possible working hypothesis a Conformationchange ore a Surfacechange can be accepted, the one effect on the connection partner be had can and possibly the function affected. An incorrect dismantling of the Notch3 of receptor leads to the fact that truncated receptor fragments collect in the Media of the vessels in the proximity of osmiophilen deposits. Because of the stereotyped mutations with those frequently so-called CpG (modulators of the Epigenetic)is present further possible mutations can be predicted.

Mutations in Notch3 are the cause of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), an inherited small vessel disease leading to subcortical strokes and vascular dementia. The phenotypic presentation is variable but remarkable for a high frequency of migraine with aura. Magnetic resonance images show a microangiopathic pattern of lesions. Prominent involvement of the temporopolar white matter and involvement of the temporopolar arcuate fibers are conspicuous findings seen in many patients, The underlying angiopathy is characterized by a unique type of ultrastructural basal lamina deposits and by degeneration of vascular smooth muscle cells which are the major source of Notch3 expression. In line with these findings there is evidence for a functional impairment of vascular smooth muscle cells. CADASIL has opened a new perspective in studying basic mechanisms of vessel wall degeneration and ischemic tissue damage related to small vessel disease. Copyright (C) 2002 S. Karger AG, Basel.