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Modulation of muscle redox and protein aggregation rescues lethality caused by mutant lamins
Journal article   Open access   Peer reviewed

Modulation of muscle redox and protein aggregation rescues lethality caused by mutant lamins

Gary S. Coombs, Jose L. Rios-Monterrosa, Shuping Lai, Qiang Dai, Ashley C. Goll, Margaret R. Ketterer, Maria F. Valdes, Nnamdi Uche, Ivor J. Benjamin and Lori L. Wallrath
Redox biology, Vol.48, pp.102196-102196
12/2021
DOI: 10.1016/j.redox.2021.102196
PMCID: PMC8646998
PMID: 34872044
url
https://doi.org/10.1016/j.redox.2021.102196View
Published (Version of record) Open Access

Abstract

Mutations in the human LMNA gene cause a collection of diseases called laminopathies, which includes muscular dystrophy and dilated cardiomyopathy. The LMNA gene encodes lamins, filamentous proteins that form a meshwork on the inner side of the nuclear envelope. How mutant lamins cause muscle disease is not well understood, and treatment options are currently limited. To understand the pathological functions of mutant lamins so that therapies can be developed, we generated new Drosophila models and human iPS cell-derived cardiomyocytes. In the Drosophila models, muscle-specific expression of the mutant lamins caused nuclear envelope defects, cytoplasmic protein aggregation, activation of the Nrf2/Keap1 redox pathway, and reductive stress. These defects reduced larval motility and caused death at the pupal stage. Patient-derived cardiomyocytes expressing mutant lamins showed nuclear envelope deformations. The Drosophila models allowed for genetic and pharmacological manipulations at the organismal level. Genetic interventions to increase autophagy, decrease Nrf2/Keap1 signaling, or lower reducing equivalents partially suppressed the lethality caused by mutant lamins. Moreover, treatment of flies with pamoic acid, a compound that inhibits the NADPH-producing malic enzyme, partially suppressed lethality. Taken together, these studies have identified multiple new factors as potential therapeutic targets for LMNA-associated muscular dystrophy. •Drosophila models of LMNA muscular dystrophy exhibited redox imbalance.•Amino acid substitutions in all three domains of lamins caused reductive stress.•iPS cell-derived cardiomyocytes showed an altered response to NAC treatment.•Genetic manipulation of autophagy regulators suppressed lethality caused by mutant lamins.•Pamoic acid, a malic enzyme inhibitor, suppressed lethality caused by mutant lamins.
Drosophila Lamins Muscular dystrophy Nuclear envelope Reductive stress

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