title: Lamin B1 overexpression increases nuclear rigidity in autosomal dominant leukodystrophy fibroblasts.
abstract: The architecture and structural mechanics of the cell nucleus are defined by the nuclear lamina, which is formed by A- and B-type lamins. Recently, gene duplication and protein overexpression of lamin B1 (LB1) have been reported in pedigrees with autosomal dominant leukodystrophy (ADLD). However, how the overexpression of LB1 affects nuclear mechanics and function and how it may result in pathology remain unexplored. Here, we report that in primary human skin fibroblasts derived from ADLD patients, LB1, but not other lamins, is overexpressed at the nuclear lamina and specifically enhances nuclear stiffness. Transient transfection of LB1 in HEK293 and neuronal N2a cells mimics the mechanical phenotype of ADLD nuclei. Notably, in ADLD fibroblasts, reducing LB1 protein levels by shRNA knockdown restores elasticity values to those indistinguishable from control fibroblasts. Moreover, isolated nuclei from ADLD fibroblasts display a reduced nuclear ion channel open probability on voltage-step application, suggesting that biophysical changes induced by LB1 overexpression may alter nuclear signaling cascades in somatic cells. Overall, the overexpression of LB1 in ADLD cells alters nuclear mechanics and is linked to changes in nuclear signaling, which could help explain the pathogenesis of this disease.
authors.affiliation: Department of Neuroscience and Brain Technologies.
authors.forename: Denise
authors.initials: D
authors.lastname: Ferrera
authors.affiliation: Department of Nanophysics, and.
authors.forename: Claudio
authors.initials: C
authors.lastname: Canale
authors.affiliation: Department of Nanochemistry, Istituto Italiano di Tecnologia, Genoa, Italy;
authors.forename: Roberto
authors.initials: R
authors.lastname: Marotta
authors.affiliation: Department of Neuroscience and Brain Technologies.
authors.forename: Nadia
authors.initials: N
authors.lastname: Mazzaro
authors.affiliation: Department of Biosciences, University of Milano, Milan, Italy;
authors.forename: Marta
authors.initials: M
authors.lastname: Gritti
authors.affiliation: Department of Biosciences, University of Milano, Milan, Italy;
authors.forename: Michele
authors.initials: M
authors.lastname: Mazzanti
authors.affiliation: Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto delle Scienze Neurologiche di Bologna, Clinica Neurologica, Ospedale Bellaria, Bologna, Italy; and Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
authors.forename: Sabina
authors.initials: S
authors.lastname: Capellari
authors.affiliation: Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto delle Scienze Neurologiche di Bologna, Clinica Neurologica, Ospedale Bellaria, Bologna, Italy; and Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Cortelli
authors.affiliation: Department of Neuroscience and Brain Technologies, laura.gasparini@iit.it.
authors.forename: Laura
authors.initials: L
authors.lastname: Gasparini
mesh_terms: D000328:Adult; D000818:Animals; D015153:Blotting, Western; D016022:Case-Control Studies; D002463:Cell Membrane Permeability; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D004622:Embryo, Mammalian / Q000166:cytology* / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D034921:Lamin Type B / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008875:Middle Aged; D018408:Patch-Clamp Techniques; D020371:Pelizaeus-Merzbacher Disease / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D010641:Phenotype; D034741:RNA, Small Interfering / Q000235:genetics; D012867:Skin / Q000166:cytology* / Q000378:metabolism
chemical_list: D034921:Lamin Type B; D034741:RNA, Small Interfering
keywords: ADLD; atomic force microscopy; human fibroblasts; nuclear lamina; nucleus