Phosphatidylcholine deficiency upregulates enzymes of triacylglycerol metabolism in CHO cells

We studied the regulation of triacylglycerol (TAG) metabolism by phosphatidylcholine (PC) in CHO MT58 cells, which are deficient in PC synthesis because of a temperature-sensitive CTP:phosphocholine cytidylyltransferase. At the permissive growth temperature (34°C), these cells contained 49% less TAG...

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Autores principales: Caviglia, Jorge Matías, Tacconi de Gómez Dumm, Irma Nelva, Coleman, Rosalind A., Igal, Rubén Ariel
Formato: Articulo
Lenguaje:Inglés
Publicado: 2004
Materias:
Ciencias Médicas
Diacylglycerol acyltransferase
Lipase
Lipolysis
Phosphatidylcholine metabolism
Triacylglycerol synthesis
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83356
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-83356
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Médicas
Diacylglycerol acyltransferase
Lipase
Lipolysis
Phosphatidylcholine metabolism
Triacylglycerol synthesis
spellingShingle Ciencias Médicas
Diacylglycerol acyltransferase
Lipase
Lipolysis
Phosphatidylcholine metabolism
Triacylglycerol synthesis
Caviglia, Jorge Matías
Tacconi de Gómez Dumm, Irma Nelva
Coleman, Rosalind A.
Igal, Rubén Ariel
Phosphatidylcholine deficiency upregulates enzymes of triacylglycerol metabolism in CHO cells
topic_facet Ciencias Médicas
Diacylglycerol acyltransferase
Lipase
Lipolysis
Phosphatidylcholine metabolism
Triacylglycerol synthesis
description We studied the regulation of triacylglycerol (TAG) metabolism by phosphatidylcholine (PC) in CHO MT58 cells, which are deficient in PC synthesis because of a temperature-sensitive CTP:phosphocholine cytidylyltransferase. At the permissive growth temperature (34°C), these cells contained 49% less TAG and 30% less PC than wild-type CHO K1 cells. Treatment with dipalmitoylphosphatidylcholine normalized both the PC and TAG levels. Despite low TAG levels, the incorporation of [14C] oleate into TAG was increased in CHO MT58 cells. The in vitro de novo synthesis of TAG and the activity of diacylglycerol acyltransferase were 90% and 34% higher, respectively. Two other key enzyme activities in TAG synthesis, acyl-CoA synthetase and mitochondrial glycerol-3-phosphate acyltransferase (GPAT), increased by 48% and 2-fold, respectively, and mitochondrial GPAT mRNA increased by ∼4-fold. Additionally, TAG hydrolysis was accelerated in CHO MT58 cells, and in vitro lipolytic activity increased by 68%. These studies suggest that a homeostatic mechanism increases TAG synthesis and recycling in response to PC deficiency. TAG recycling produces diacylglycerol and fatty acids that can be substrates for de novo PC synthesis and for lysophosphatidylcholine (lysoPC) acylation. In CHO MT58 cells, in which de novo PC synthesis is blocked, lysoPC acylation with fatty acid originating from TAG may represent the main pathway for generating PC.
format Articulo
Articulo
author Caviglia, Jorge Matías
Tacconi de Gómez Dumm, Irma Nelva
Coleman, Rosalind A.
Igal, Rubén Ariel
author_facet Caviglia, Jorge Matías
Tacconi de Gómez Dumm, Irma Nelva
Coleman, Rosalind A.
Igal, Rubén Ariel
author_sort Caviglia, Jorge Matías
title Phosphatidylcholine deficiency upregulates enzymes of triacylglycerol metabolism in CHO cells
title_short Phosphatidylcholine deficiency upregulates enzymes of triacylglycerol metabolism in CHO cells
title_full Phosphatidylcholine deficiency upregulates enzymes of triacylglycerol metabolism in CHO cells
title_fullStr Phosphatidylcholine deficiency upregulates enzymes of triacylglycerol metabolism in CHO cells
title_full_unstemmed Phosphatidylcholine deficiency upregulates enzymes of triacylglycerol metabolism in CHO cells
title_sort phosphatidylcholine deficiency upregulates enzymes of triacylglycerol metabolism in cho cells
publishDate 2004
url http://sedici.unlp.edu.ar/handle/10915/83356
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AT colemanrosalinda phosphatidylcholinedeficiencyupregulatesenzymesoftriacylglycerolmetabolisminchocells
AT igalrubenariel phosphatidylcholinedeficiencyupregulatesenzymesoftriacylglycerolmetabolisminchocells
bdutipo_str Repositorios
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