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Delta-6-desaturase and delta-5-desaturase in human Hep G2 cells are both fatty acid interconversion rate limiting and are upregulated under essential fatty acid deficient conditions

Melin, T LU and Nilsson, A LU (1997) In Prostaglandins, Leukotrienes and Essential Fatty Acids 56(6). p.42-437
Abstract

Essential fatty acids are interconverted by desaturases and elongases to eicosanoid precursors. In essential fatty acid deficiency (EFAD) an increased hepatic interconversion of linoleic acid (18:2) to arachidonic acid (20:4n-6) has been demonstrated in vivo. We now cultured Hep G2 cells under EFAD conditions. 20:3n-6 appeared in EFAD cells, but also in controls. After adding 14C-18:2 to the medium, interconversion products and their distribution in different lipids were studied by HPLC. When trace amounts 18:2 were incubated, 38% were converted by the EFAD cells after 21 h, vs 6% by controls. 20% was converted to 20:4 by EFAD cells vs 14% by controls. EFAD cells preferentially distributed more 18:2 and conversion products to neutral... (More)

Essential fatty acids are interconverted by desaturases and elongases to eicosanoid precursors. In essential fatty acid deficiency (EFAD) an increased hepatic interconversion of linoleic acid (18:2) to arachidonic acid (20:4n-6) has been demonstrated in vivo. We now cultured Hep G2 cells under EFAD conditions. 20:3n-6 appeared in EFAD cells, but also in controls. After adding 14C-18:2 to the medium, interconversion products and their distribution in different lipids were studied by HPLC. When trace amounts 18:2 were incubated, 38% were converted by the EFAD cells after 21 h, vs 6% by controls. 20% was converted to 20:4 by EFAD cells vs 14% by controls. EFAD cells preferentially distributed more 18:2 and conversion products to neutral fats and to phosphatidyl ethanolamine, but less to cardiolipin than controls did, when incubated with trace amount 18:2, but not with 1 mM 18:2. A relative accumulation of radioactivity in 20:3 was observed. In conclusion; in EFAD Hep G2 cells delta-6- and delta-5-desaturase both were found to be upregulated and eicosanoid precursors were distributed more into phosphatidyl ethanolamine. Delta-5-desaturase had a rate limiting property as well as delta-6-desaturase.

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published
subject
keywords
Arachidonic Acid/metabolism, Cell Line, Fatty Acid Desaturases/metabolism, Fatty Acids/metabolism, Fatty Acids, Essential/deficiency, Humans, Kinetics, Linoleic Acid, Linoleic Acids/metabolism, Linoleoyl-CoA Desaturase, Phospholipids/metabolism, Up-Regulation
in
Prostaglandins, Leukotrienes and Essential Fatty Acids
volume
56
issue
6
pages
6 pages
publisher
Elsevier
external identifiers
  • scopus:0030923290
  • pmid:9223654
ISSN
0952-3278
DOI
10.1016/s0952-3278(97)90596-2
language
English
LU publication?
no
id
e3f58706-432d-4ed2-81ec-3c50e9185abf
date added to LUP
2019-09-24 14:42:09
date last changed
2024-01-01 21:09:10
@article{e3f58706-432d-4ed2-81ec-3c50e9185abf,
  abstract     = {{<p>Essential fatty acids are interconverted by desaturases and elongases to eicosanoid precursors. In essential fatty acid deficiency (EFAD) an increased hepatic interconversion of linoleic acid (18:2) to arachidonic acid (20:4n-6) has been demonstrated in vivo. We now cultured Hep G2 cells under EFAD conditions. 20:3n-6 appeared in EFAD cells, but also in controls. After adding 14C-18:2 to the medium, interconversion products and their distribution in different lipids were studied by HPLC. When trace amounts 18:2 were incubated, 38% were converted by the EFAD cells after 21 h, vs 6% by controls. 20% was converted to 20:4 by EFAD cells vs 14% by controls. EFAD cells preferentially distributed more 18:2 and conversion products to neutral fats and to phosphatidyl ethanolamine, but less to cardiolipin than controls did, when incubated with trace amount 18:2, but not with 1 mM 18:2. A relative accumulation of radioactivity in 20:3 was observed. In conclusion; in EFAD Hep G2 cells delta-6- and delta-5-desaturase both were found to be upregulated and eicosanoid precursors were distributed more into phosphatidyl ethanolamine. Delta-5-desaturase had a rate limiting property as well as delta-6-desaturase.</p>}},
  author       = {{Melin, T and Nilsson, A}},
  issn         = {{0952-3278}},
  keywords     = {{Arachidonic Acid/metabolism; Cell Line; Fatty Acid Desaturases/metabolism; Fatty Acids/metabolism; Fatty Acids, Essential/deficiency; Humans; Kinetics; Linoleic Acid; Linoleic Acids/metabolism; Linoleoyl-CoA Desaturase; Phospholipids/metabolism; Up-Regulation}},
  language     = {{eng}},
  number       = {{6}},
  pages        = {{42--437}},
  publisher    = {{Elsevier}},
  series       = {{Prostaglandins, Leukotrienes and Essential Fatty Acids}},
  title        = {{Delta-6-desaturase and delta-5-desaturase in human Hep G2 cells are both fatty acid interconversion rate limiting and are upregulated under essential fatty acid deficient conditions}},
  url          = {{http://dx.doi.org/10.1016/s0952-3278(97)90596-2}},
  doi          = {{10.1016/s0952-3278(97)90596-2}},
  volume       = {{56}},
  year         = {{1997}},
}