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.

Lamin B1 overexpression increases nuclear rigidity in autosomal dominant leukodystrophy fibroblasts / D. Ferrera, C. Canale, R. Marotta, N. Mazzaro, M. Gritti, M. Mazzanti, S. Capellari, P. Cortelli, L. Gasparini. - In: THE FASEB JOURNAL. - ISSN 0892-6638. - 28:9(2014), pp. 3906-3918. [10.1096/fj.13-247635]

Lamin B1 overexpression increases nuclear rigidity in autosomal dominant leukodystrophy fibroblasts

R. Marotta;M. Gritti;M. Mazzanti;
2014

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.
ADLD; Atomic force microscopy; Human fibroblasts; Nuclear lamina; Nucleus; Adult; Animals; Blotting, Western; Case-Control Studies; Cell Membrane Permeability; Cell Nucleus; Cell Proliferation; Cells, Cultured; Embryo, Mammalian; Female; Fibroblasts; Flow Cytometry; Fluorescent Antibody Technique; Humans; Lamin Type B; Male; Mice; Middle Aged; Patch-Clamp Techniques; Pelizaeus-Merzbacher Disease; Phenotype; RNA, Small Interfering; Skin; Biotechnology; Biochemistry; Molecular Biology; Genetics
Settore BIO/09 - Fisiologia
Settore BIO/11 - Biologia Molecolare
Settore BIO/17 - Istologia
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/551157
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