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Leptin inhibits apolipoprotein M transcription and secretion in human hepatoma cell line, HepG2 cells.

Luo, Guanghua; Hurtig, Maria; Zhang, Xiaoying; Nilsson-Ehle, Peter LU and Xu, Ning LU (2005) In Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids 1734(2). p.198-202
Abstract
Apolipoprotein M (apoM) is a novel apolipoprotein presented mostly in high-density lipoprotein (HDL) in human plasma. Previously we have reported that both leptin and leptin receptor are essential for apoM expression in vivo. The expression of apoM is lower in the leptin deficient (ob/ob) mouse and leptin receptor deficient (db/db) mouse than in the normal mouse. In the present study, however, we demonstrated that supra-physiological concentrations of recombinant leptin significantly inhibited apoM transcription and secretion in the human hepatoma cell line, HepG2 cells. Both Northern blotting and real-time RT-PCR were applied into the analyses of apoM mRNA levels, and compatible data were obtained. The inhibitory effect of leptin on apoM... (More)
Apolipoprotein M (apoM) is a novel apolipoprotein presented mostly in high-density lipoprotein (HDL) in human plasma. Previously we have reported that both leptin and leptin receptor are essential for apoM expression in vivo. The expression of apoM is lower in the leptin deficient (ob/ob) mouse and leptin receptor deficient (db/db) mouse than in the normal mouse. In the present study, however, we demonstrated that supra-physiological concentrations of recombinant leptin significantly inhibited apoM transcription and secretion in the human hepatoma cell line, HepG2 cells. Both Northern blotting and real-time RT-PCR were applied into the analyses of apoM mRNA levels, and compatible data were obtained. The inhibitory effect of leptin on apoM mRNA levels in HepG2 cells is dose dependent, i.e. 100 ng/mL of leptin decreased apoM mRNA levels by 30%, and 500 ng/mL of leptin decreased apoM mRNA levels about 50%. Even at a physiological concentration of leptin (10 ng/mL), apoM expression was decreased, and in parallel, the secretion of apoM into the medium was also decreased. Furthermore, we examined apoAI, apoB and apoE by Northern blotting analyses. The results demonstrated that leptin does not significantly influence the expressions of apoAI, apoB and apoE in HepC2 cells, suggesting that leptin has a specific regulatory effect on hepatic apoM transcription and secretion in vitro. The mechanism on the contradictory effects of leptin on apoM expression in vivo and in vitro needs further investigation. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
HepG2 cell line, lipoprotein, apolipoprotein M, leptin
in
Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids
volume
1734
issue
2
pages
198 - 202
publisher
Elsevier
external identifiers
  • pmid:15904876
  • wos:000229526700010
  • scopus:19444375752
ISSN
1388-1981
DOI
10.1016/j.bbalip.2005.02.005
language
English
LU publication?
yes
id
1f8cf95c-e1be-4a67-97b7-75559739403d (old id 137932)
date added to LUP
2007-07-05 13:23:17
date last changed
2017-08-27 05:11:17
@article{1f8cf95c-e1be-4a67-97b7-75559739403d,
  abstract     = {Apolipoprotein M (apoM) is a novel apolipoprotein presented mostly in high-density lipoprotein (HDL) in human plasma. Previously we have reported that both leptin and leptin receptor are essential for apoM expression in vivo. The expression of apoM is lower in the leptin deficient (ob/ob) mouse and leptin receptor deficient (db/db) mouse than in the normal mouse. In the present study, however, we demonstrated that supra-physiological concentrations of recombinant leptin significantly inhibited apoM transcription and secretion in the human hepatoma cell line, HepG2 cells. Both Northern blotting and real-time RT-PCR were applied into the analyses of apoM mRNA levels, and compatible data were obtained. The inhibitory effect of leptin on apoM mRNA levels in HepG2 cells is dose dependent, i.e. 100 ng/mL of leptin decreased apoM mRNA levels by 30%, and 500 ng/mL of leptin decreased apoM mRNA levels about 50%. Even at a physiological concentration of leptin (10 ng/mL), apoM expression was decreased, and in parallel, the secretion of apoM into the medium was also decreased. Furthermore, we examined apoAI, apoB and apoE by Northern blotting analyses. The results demonstrated that leptin does not significantly influence the expressions of apoAI, apoB and apoE in HepC2 cells, suggesting that leptin has a specific regulatory effect on hepatic apoM transcription and secretion in vitro. The mechanism on the contradictory effects of leptin on apoM expression in vivo and in vitro needs further investigation.},
  author       = {Luo, Guanghua and Hurtig, Maria and Zhang, Xiaoying and Nilsson-Ehle, Peter and Xu, Ning},
  issn         = {1388-1981},
  keyword      = {HepG2 cell line,lipoprotein,apolipoprotein M,leptin},
  language     = {eng},
  number       = {2},
  pages        = {198--202},
  publisher    = {Elsevier},
  series       = {Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids},
  title        = {Leptin inhibits apolipoprotein M transcription and secretion in human hepatoma cell line, HepG2 cells.},
  url          = {http://dx.doi.org/10.1016/j.bbalip.2005.02.005},
  volume       = {1734},
  year         = {2005},
}