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Gewählte Publikation:

SHR Neuro Krebs Kardio Lipid

Radović, B; Vujić, N; Leopold, C; Schlager, S; Goeritzer, M; Patankar, JV; Korbelius, M; Kolb, D; Reindl, J; Wegscheider, M; Tomin, T; Birner-Gruenberger, R; Schittmayer, M; Groschner, L; Magnes, C; Diwoky, C; Frank, S; Steyrer, E; Du, H; Graier, WF; Madl, T; Kratky, D.
Lysosomal acid lipase regulates VLDL synthesis and insulin sensitivity in mice.
Diabetologia. 2016; 59(8):1743-1752 [OPEN ACCESS]
Web of Science PubMed PUBMED Central FullText FullText_MUG

 

Autor/innen der Med Uni Graz:
Birner-Grünberger Ruth
Frank Saša
Göritzer Madeleine
Graier Wolfgang
Groschner Lukas
Kolb-Lenz Dagmar
Korbelius Melanie
Kratky Dagmar
Leopold Christina
Madl Tobias
Radovic Branislav
Schittmayer-Schantl Matthias
Schlager Stefanie
Steyrer Ernst
Tomin Tamara
Vujic Nemanja
Wegscheider Martin
Gendermonitor:
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Number of Figures: 8
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Abstract:
Lysosomal acid lipase (LAL) hydrolyses cholesteryl esters and triacylglycerols (TG) within lysosomes to mobilise NEFA and cholesterol. Since LAL-deficient (Lal (-/-) ) mice suffer from progressive loss of adipose tissue and severe accumulation of lipids in hepatic lysosomes, we hypothesised that LAL deficiency triggers alternative energy pathway(s). We studied metabolic adaptations in Lal (-/-) mice. Despite loss of adipose tissue, Lal (-/-) mice show enhanced glucose clearance during insulin and glucose tolerance tests and have increased uptake of [(3)H]2-deoxy-D-glucose into skeletal muscle compared with wild-type mice. In agreement, fasted Lal (-/-) mice exhibit reduced glucose and glycogen levels in skeletal muscle. We observed 84% decreased plasma leptin levels and significantly reduced hepatic ATP, glucose, glycogen and glutamine concentrations in fed Lal (-/-) mice. Markedly reduced hepatic acyl-CoA concentrations decrease the expression of peroxisome proliferator-activated receptor α (PPARα) target genes. However, treatment of Lal (-/-) mice with the PPARα agonist fenofibrate further decreased plasma TG (and hepatic glucose and glycogen) concentrations in Lal (-/-) mice. Depletion of hepatic nuclear factor 4α and forkhead box protein a2 in fasted Lal (-/-) mice might be responsible for reduced expression of microsomal TG transfer protein, defective VLDL synthesis and drastically reduced plasma TG levels. Our findings indicate that neither activation nor inactivation of PPARα per se but rather the availability of hepatic acyl-CoA concentrations regulates VLDL synthesis and subsequent metabolic adaptations in Lal (-/-) mice. We conclude that decreased plasma VLDL production enhances glucose uptake into skeletal muscle to compensate for the lack of energy supply.

Find related publications in this database (Keywords)
Glucose tolerance
Lipolysis
Lysosomes
VLDL
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