Browsing by Subject "NOTCH3"

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    Broad phenotype of cysteine-altering NOTCH3 variants in UK Biobank
    (Wolters Kluwer, 2020-09-29) Rutten, Julie W.; Hack, Remco J.; Duering, Marco; Gravesteijn, Gido; Dauwerse, Johannes G.; Overzier, Maurice; van den Akker, Erik B.; Slagboom, Eline; Holstege, Henne; Nho, Kwangsik; Saykin, Andrew; Dichgans, Martin; Malik, Rainer; Lesnik Oberstein, Saskia A.J.; BioHealth Informatics, School of Informatics and Computing
    Objective To determine the small vessel disease spectrum associated with cysteine-altering NOTCH3 variants in community-dwelling individuals by analyzing the clinical and neuroimaging features of UK Biobank participants harboring such variants. Methods The exome and genome sequencing datasets of the UK Biobank (n = 50,000) and cohorts of cognitively healthy elderly (n = 751) were queried for cysteine-altering NOTCH3 variants. Brain MRIs of individuals harboring such variants were scored according to Standards for Reporting Vascular Changes on Neuroimaging criteria, and clinical information was extracted with ICD-10 codes. Clinical and neuroimaging data were compared to age- and sex-matched UK Biobank controls and clinically diagnosed patients from the Dutch cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) registry. Results We identified 108 individuals harboring a cysteine-altering NOTCH3 variant (2.2 of 1,000), of whom 75% have a variant that has previously been reported in CADASIL pedigrees. Almost all variants were located in 1 of the NOTCH3 protein epidermal growth factor–like repeat domains 7 to 34. White matter hyperintensity lesion load was higher in individuals with NOTCH3 variants than in controls (p = 0.006) but lower than in patients with CADASIL with the same variants (p < 0.001). Almost half of the 24 individuals with brain MRI had a Fazekas score of 0 or 1 up to age 70 years. There was no increased risk of stroke. Conclusions Although community-dwelling individuals harboring a cysteine-altering NOTCH3 variant have a higher small vessel disease MRI burden than controls, almost half have no MRI abnormalities up to age 70 years. This shows that NOTCH3 cysteine altering variants are associated with an extremely broad phenotypic spectrum, ranging from CADASIL to nonpenetrance.
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    Latent NOTCH3 epitopes unmasked in CADASIL and regulated by protein redox state
    (Elsevier, 2014-10-02) Zhang, Xiaojie; Lee, Soo Jung; Young, Kelly Z.; Josephson, David A.; Geschwind, Michael D.; Wang, Michael M.; Department of Neurology, IU School of Medicine
    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy CADASIL is caused by more than a hundred NOTCH3 mutations. Virtually all encoded mutant proteins contain an odd number of cysteines. As such, structural changes in NOTCH3 may be the primary molecular abnormality in CADASIL. Thus, we sought evidence for structurally altered NOTCH3 protein in CADASIL tissue. Four antibodies were raised in rabbits against two non-overlapping N-terminal NOTCH3 sequences. These reagents were used in immunohistochemical experiments to detect epitopes in post-mortem CADASIL brains (n=8), control brains, and cells overexpressing NOTCH3. To determine the biochemical nature of NOTCH3 epitopes, we used these antibodies to probe pure NOTCH3-Fc fusion proteins treated with acid, urea, guanidinium, ionic detergents, acrylamide, and thiol- and phosphorus-based reductants. All antibodies avidly stained arteries in 8 of 8 CADASIL brain samples. The most prominent staining was in degenerating media of leptomeningeal arteries and sclerotic penetrating vessels. Normal appearing vessels from control brains were not reactive. Antibodies did not react with cultured cells overexpressing NOTCH3 or with purified NOTCH3-Fc protein. Furthermore, treatment of pure protein with acid, chaotropic denaturants, alkylators, and detergents failed to unmask N-terminal NOTCH3 epitopes. Antibodies, however, recognized novel N-terminal epitopes in purified NOTCH3-Fc protein treated with three different reductants (DTT, beta-mercaptoethanol, and TCEP). We conclude that CADASIL arteries feature latent N-terminal NOTCH3 epitopes, suggesting the first evidence in vivo of NOTCH3 structural alterations.
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    ZIP4 Is a Novel Cancer Stem Cell Marker in High-Grade Serous Ovarian Cancer
    (MDPI, 2020-12-09) Fan, Qipeng; Zhang, Wen; Emerson, Robert E.; Xu, Yan; Obstetrics and Gynecology, School of Medicine
    High-grade serous ovarian cancer (HGSOC) is one of the most deadly and heterogenic cancers. We have recently shown that ZIP4 (gene name SLC39A4), a zinc transporter, is functionally involved in cancer stem cell (CSC)-related cellular activities in HGSOC. Here, we identified ZIP4 as a novel CSC marker in HGSOC. Fluorescence-activated cell sorter (FACS)-sorted ZIP4+, but not ZIP4- cells, formed spheroids and displayed self-renewing and differentiation abilities. Over-expression of ZIP4 conferred drug resistance properties in vitro. ZIP4+, but not ZIP4- cells, formed tumors/ascites in vivo. We conducted limiting dilution experiments and showed that 100-200 ZIP4+ cells from both PE04 and PEA2 cells formed larger tumors than those from 100-200 ALDH+ cells in mice. Mechanistically, we found that ZIP4 was an upstream regulator of another CSC-marker, NOTCH3, in HGSOC cells. NOTCH3 was functionally involved in spheroid formation in vitro and tumorigenesis in vivo in HGSOC. Genetic compensation studies showed that NOTCH3, but not NOTCH1, was a critical downstream mediator of ZIP4. Furthermore, NOTCH3, but not NOTCH1, physically bound to ZIP4. Collectively, our data suggest that ZIP4 is a novel CSC marker and the new ZIP4-NOTCH3 axis represents important therapeutic targets in HGSOC.