A lipodystrophy-causing lamin A mutant alters conformation and epigenetic regulation of the anti-adipogenic MIR335 locus

A Oldenburg, N Briand, AL Sørensen, I Cahyani… - Journal of Cell …, 2017 - rupress.org
A Oldenburg, N Briand, AL Sørensen, I Cahyani, A Shah, JØ Moskaug, P Collas
Journal of Cell Biology, 2017rupress.org
Mutations in the Lamin A/C (LMNA) gene-encoding nuclear LMNA cause laminopathies,
which include partial lipodystrophies associated with metabolic syndromes. The
lipodystrophy-associated LMNA p. R482W mutation is known to impair adipogenic
differentiation, but the mechanisms involved are unclear. We show in this study that the
lamin A p. R482W hot spot mutation prevents adipogenic gene expression by epigenetically
deregulating long-range enhancers of the anti-adipogenic MIR335 microRNA gene in …
Mutations in the Lamin A/C (LMNA) gene-encoding nuclear LMNA cause laminopathies, which include partial lipodystrophies associated with metabolic syndromes. The lipodystrophy-associated LMNA p.R482W mutation is known to impair adipogenic differentiation, but the mechanisms involved are unclear. We show in this study that the lamin A p.R482W hot spot mutation prevents adipogenic gene expression by epigenetically deregulating long-range enhancers of the anti-adipogenic MIR335 microRNA gene in human adipocyte progenitor cells. The R482W mutation results in a loss of function of differentiation-dependent lamin A binding to the MIR335 locus. This impairs H3K27 methylation and instead favors H3K27 acetylation on MIR335 enhancers. The lamin A mutation further promotes spatial clustering of MIR335 enhancer and promoter elements along with overexpression of the MIR355 gene after adipogenic induction. Our results link a laminopathy-causing lamin A mutation to an unsuspected deregulation of chromatin states and spatial conformation of an miRNA locus critical for adipose progenitor cell fate.
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