Membrane-bound sn-1,2-diacylglycerols explain the dissociation of hepatic insulin resistance from hepatic steatosis in MTTP knockout mice

Copyright © 2020 Abulizi et al. Published by The American Society for Biochemistry and Molecular Biology, Inc..

Microsomal triglyceride transfer protein (MTTP) deficiency results in a syndrome of hypolipidemia and accelerated NAFLD. Animal models of decreased hepatic MTTP activity have revealed an unexplained dissociation between hepatic steatosis and hepatic insulin resistance. Here, we performed comprehensive metabolic phenotyping of liver-specific MTTP knockout (L-Mttp-/-) mice and age-weight matched wild-type control mice. Young (10-12-week-old) L-Mttp-/- mice exhibited hepatic steatosis and increased DAG content; however, the increase in hepatic DAG content was partitioned to the lipid droplet and was not increased in the plasma membrane. Young L-Mttp-/- mice also manifested normal hepatic insulin sensitivity, as assessed by hyperinsulinemic-euglycemic clamps, no PKCε activation, and normal hepatic insulin signaling from the insulin receptor through AKT Ser/Thr kinase. In contrast, aged (10-month-old) L-Mttp-/- mice exhibited glucose intolerance and hepatic insulin resistance along with an increase in hepatic plasma membrane sn-1,2-DAG content and PKCε activation. Treatment with a functionally liver-targeted mitochondrial uncoupler protected the aged L-Mttp-/- mice against the development of hepatic steatosis, increased plasma membrane sn-1,2-DAG content, PKCε activation, and hepatic insulin resistance. Furthermore, increased hepatic insulin sensitivity in the aged controlled-release mitochondrial protonophore-treated L-Mttp-/- mice was not associated with any reductions in hepatic ceramide content. Taken together, these data demonstrate that differences in the intracellular compartmentation of sn-1,2-DAGs in the lipid droplet versus plasma membrane explains the dissociation of NAFLD/lipid-induced hepatic insulin resistance in young L-Mttp-/- mice as well as the development of lipid-induced hepatic insulin resistance in aged L-Mttp-/- mice.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:61

Enthalten in:

Journal of lipid research - 61(2020), 12 vom: 09. Dez., Seite 1565-1576

Sprache:

Englisch

Beteiligte Personen:

Abulizi, Abudukadier [VerfasserIn]
Vatner, Daniel F [VerfasserIn]
Ye, Zhang [VerfasserIn]
Wang, Yongliang [VerfasserIn]
Camporez, Joao-Paulo [VerfasserIn]
Zhang, Dongyan [VerfasserIn]
Kahn, Mario [VerfasserIn]
Lyu, Kun [VerfasserIn]
Sirwi, Alaa [VerfasserIn]
Cline, Gary W [VerfasserIn]
Hussain, M Mahmood [VerfasserIn]
Aspichueta, Patricia [VerfasserIn]
Samuel, Varman T [VerfasserIn]
Shulman, Gerald I [VerfasserIn]

Links:

Volltext

Themen:

1,2-diacylglycerol
Carrier Proteins
Diabetes
Diglycerides
Drug therapy
Journal Article
Lipids
Liver
Liver microsomal triglyceride transfer protein
Liver-targeted mitochondrial uncoupler
Metabolic disease
Microsomal triglyceride transfer protein
Nonalcoholic fatty liver disease
Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.

Anmerkungen:

Date Completed 25.10.2021

Date Revised 08.12.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1194/jlr.RA119000586

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM314802355