title: CADASIL mutations and shRNA silencing of NOTCH3 affect actin organization in cultured vascular smooth muscle cells.
abstract: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common hereditary vascular dementia caused by mutations in NOTCH3 gene. Pathology is manifested in small- and middle-sized arteries throughout the body, though primarily in cerebral white matter. Hemodynamics is altered in CADASIL and NOTCH3 is suggested to regulate actin filament polymerization and thereby vascular tone. We analyzed NOTCH3 expression and morphology of actin cytoskeleton in genetically genuine cultured human CADASIL vascular smooth muscle cells (VSMCs) (including a cell line homozygous for p.Arg133Cys mutation) derived from different organs, and in control VSMCs with short hairpin RNA (shRNA)-silenced NOTCH3. NOTCH3 protein level was higher in VSMCs derived from adult than newborn arteries in both CADASIL and control VSMCs. CADASIL VSMCs showed altered actin cytoskeleton including increased branching and node formation, and more numerous and smaller adhesion sites than control VSMCs. Alterations in actin cytoskeleton in shRNA-silenced VSMCs were similar as in CADASIL VSMCs. Severity of the alterations in actin filaments corresponded to NOTCH3 expression level being most severe in VSMCs derived from adult cerebral arteries. These observations suggest that hypomorphic NOTCH3 activity causes alterations in actin organization in CADASIL. Furthermore, arteries from different organs have specific characteristics, which modify the effects of the NOTCH3 mutation and which is one explanation for the exceptional susceptibility of cerebral white matter arteries.
authors.affiliation: Protein Chemistry Unit, Institute of Biomedicine/Anatomy, University of Helsinki, Helsinki, Finland.
authors.forename: Saara
authors.initials: S
authors.lastname: Tikka
authors.forename: Yan Peng
authors.initials: YP
authors.lastname: Ng
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Di Maio
authors.forename: Kati
authors.initials: K
authors.lastname: Mykkänen
authors.forename: Maija
authors.initials: M
authors.lastname: Siitonen
authors.forename: Tatiana
authors.initials: T
authors.lastname: Lepikhova
authors.forename: Minna
authors.initials: M
authors.lastname: Pöyhönen
authors.forename: Matti
authors.initials: M
authors.lastname: Viitanen
authors.forename: Ismo
authors.initials: I
authors.lastname: Virtanen
authors.forename: Hannu
authors.initials: H
authors.lastname: Kalimo
authors.forename: Marc
authors.initials: M
authors.lastname: Baumann
mesh_terms: D008841:Actin Cytoskeleton / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000199:Actins / Q000235:genetics / Q000378:metabolism; D000375:Aging / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D019943:Amino Acid Substitution; D000818:Animals; D046589:CADASIL / Q000378:metabolism* / Q000473:pathology; D002460:Cell Line; D005260:Female; D020868:Gene Silencing; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism* / Q000473:pathology; D020125:Mutation, Missense; D032389:Myocytes, Smooth Muscle / Q000378:metabolism* / Q000473:pathology; D009928:Organ Specificity / Q000235:genetics; D034741:RNA, Small Interfering / Q000096:biosynthesis* / Q000235:genetics; D000071656:Receptor, Notch3; D051880:Receptors, Notch / Q000096:biosynthesis* / Q000235:genetics; D014161:Transduction, Genetic
chemical_list: D000199:Actins; C499374:NOTCH3 protein, human; D034741:RNA, Small Interfering; D000071656:Receptor, Notch3; D051880:Receptors, Notch