Effects of platelet-activating factor, tumor necrosis factor, and interleukin-1alpha on the expression of apolipoprotein M in HepG2 cells.
Författare
Summary, in English
Apolipoprotein M (apoM) is a recently discovered human apolipoprotein predominantly present in high-density lipoprotein (HDL) in plasma, exclusively expressed in liver and in kidney. The function of apoM is yet unknown. The human apoM gene is located in the major histocompatibility complex class III region on chromosome 6. Because many genes located in this region are related to the immune response, we have investigated whether apoM might also be involved in the host inflammatory response. In this study we examined effects of the platelet-activating factor (PAF), tumor necrosis factor (TNF-alpha), and interleukin-1alpha (IL-1alpha) on apoM expression in a hepatoblastoma cell line, HepG2 cells. PAF significantly enhanced the apoM mRNA levels and the secretion of apoM in HepG2 cell cultures. The enhancement of apoM secretion is seen at a low concentration of PAF (2 ng/ml), whereas a high concentration of PAF increases both the apoM mRNA levels and apoM secretion. Neither TNF-alpha nor IL-1alpha influenced apoM mRNA level and secretion. Furthermore, Lexipafant, a PAF-receptor (PAF-R) antagonist significantly suppressed the mRNA level and the secretion of apoM in HepG2 cells in a dose-dependent manner. Neither PAF nor Lexipafant influenced the mRNA levels and the secretion of apoA-I, apoB and apoE in HepG2 cells, indicating that the effects of PAF or Lexipafant on the apoM production on hepatic cells are selective for apoM. The cellular mechanism of the effects of PAF or Lexipafant on apoM metabolism requires further investigations.
Avdelning/ar
Publiceringsår
2002
Språk
Engelska
Sidor
944-950
Publikation/Tidskrift/Serie
Biochemical and Biophysical Research Communications
Volym
292
Issue
4
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Biological Sciences
Nyckelord
- Apolipoproteins B : metabolism
- Apolipoproteins B : genetics
- Apolipoproteins : metabolism
- Apolipoproteins : genetics
- Apolipoprotein A-I : metabolism
- Apolipoprotein A-I : genetics
- Interleukin-1 : pharmacology
- Leucine : analogs & derivatives
- Leucine : pharmacology
- Liver Neoplasms : drug therapy
- Tumor Necrosis Factor : pharmacology
- Cultured
- Tumor Cells
- Non-U.S. Gov't
- Support
- Messenger : metabolism
- RNA
- Platelet Activating Factor : pharmacology
- Liver Neoplasms : metabolism
- Platelet Activating Factor : antagonists & inhibitors
- Apolipoproteins E : genetics
- Apolipoproteins E : metabolism
- Dose-Response Relationship
- Drug
- Gene Expression : drug effects
- Hepatoblastoma : drug therapy
- Hepatoblastoma : metabolism
- Human
- Imidazoles : pharmacology
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1090-2104