Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Zimmermann, R; Haemmerle, G; Wagner, EM; Strauss, JG; Kratky, D; Zechner, R.
Decreased fatty acid esterification compensates for the reduced lipolytic activity in hormone-sensitive lipase-deficient white adipose tissue.
J Lipid Res. 2003; 44(11):2089-2099
Doi: 10.1194/jlr.M300190-JLR200
[OPEN ACCESS]
Web of Science
PubMed
FullText
FullText_MUG
- Co-Autor*innen der Med Uni Graz
- Kratky Dagmar
- Altmetrics:
- Dimensions Citations:
- Plum Analytics:
- Scite (citation analytics):
- Abstract:
- It has been observed previously that hormone-sensitive lipase-deficient (HSL-ko) mice have reduced white adipose tissue (WAT) stores compared to control mice. These findings contradict the expectation that the decreased lipolytic activity in WAT of HSL-ko mice would cause accumulation of triglycerides (TGs) in that tissue. Here we demonstrate that the cellular TG synthesis in HSL-deficient WAT is markedly reduced due to downregulation of the enzymatic activities of glycerophosphate acyltransferase, dihydroxyacetonphosphate acyltransferase, lysophosphatidate acyltransferase, and diacylglycerol acyltransferase. Fatty acid de novo synthesis is also decreased due to reduced cellular glucose uptake, reduced glucose incorporation into adipose tissue lipids, and reduced activities of acetyl:CoA carboxylase and fatty acid synthase. Finally, the activities of phosphoenolpyruvate carboxykinase (PEPCK), acyl:CoA synthetase (ACS), and glucose 6-phosphate dehydrogenase, the enzymes that provide glycerol-3-phosphate, acyl-CoA, and NADPH for TG synthesis, respectively, are decreased in HSL-ko mice. The reduced expression of the peroxisome proliferator-activated receptor gamma (PPAR gamma) target genes PEPCK, ACS, and aP2, as well as reduced mRNA levels of PPAR gamma itself, suggest the involvement of this transcription factor in the downregulation of lipogenesis. Taken together, these results establish that in the absence of HSL, the reduced NEFA production is counteracted by a drastic reduction of NEFA reesterification that provides sufficient quantities of NEFA for release into the circulation. These metabolic adaptations result in decreased fat mass in HSL-ko mice.
- Find related publications in this database (using NLM MeSH Indexing)
- Acyltransferases - genetics
- Adipose Tissue - chemistry
- Animals - chemistry
- Body Weight - chemistry
- CCAAT-Enhancer-Binding Proteins - genetics
- Cholesterol Esterase - deficiency
- DNA-Binding Proteins - genetics
- Esterification - genetics
- Fatty Acids - biosynthesis
- Fatty Acids, Nonesterified - biosynthesis
- Glucose - metabolism
- Lipolysis - metabolism
- Male - metabolism
- Mice - metabolism
- Mice, Knockout - metabolism
- RNA, Messenger - genetics
- Receptors, Cytoplasmic and Nuclear - genetics
- Sterol Regulatory Element Binding Protein 1 - genetics
- Transcription Factors - genetics
- Find related publications in this database (Keywords)
- triglyceride synthesis
- fatty acid synthesis
- peroxisome proliferator-activated receptor gamma