Nuclear envelope-localized torsinA-LAP1 complex regulates hepatic VLDL secretion and steatosis.
J Clin Invest
; 129(11): 4885-4900, 2019 08 13.
Article
em En
| MEDLINE
| ID: mdl-31408437
ABSTRACT
Deciphering novel pathways regulating liver lipid content has profound implications for understanding the pathophysiology of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis. Recent evidence suggests that the nuclear envelope is a site of regulation of lipid metabolism but there is limited appreciation of the responsible mechanisms and molecular components within this organelle. We showed that conditional hepatocyte deletion of the inner nuclear membrane protein lamina-associated polypeptide 1 (LAP1) caused defective VLDL secretion and steatosis, including intranuclear lipid accumulation. LAP1 binds to and activates torsinA, an AAA+ ATPase that resides in the perinuclear space and continuous main ER. Deletion of torsinA from mouse hepatocytes caused even greater reductions in VLDL secretion and profound steatosis. Both of these mutant mouse lines developed hepatic steatosis and subsequent steatohepatitis on a regular chow diet in the absence of whole-body insulin resistance or obesity. Our results establish an essential role for the nuclear envelope-localized torsinA-LAP1 complex in hepatic VLDL secretion and suggest that the torsinA pathway participates in the pathophysiology of nonalcoholic fatty liver disease.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Transporte
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Chaperonas Moleculares
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Hepatócitos
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Hepatopatia Gordurosa não Alcoólica
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Lipoproteínas VLDL
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Proteínas de Membrana
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Membrana Nuclear
Limite:
Animals
Idioma:
En
Revista:
J Clin Invest
Ano de publicação:
2019
Tipo de documento:
Article