Recombinant human interleukin-1 suppresses lipoprotein lipase activity, but not expression of lipoprotein lipase mRNA in mesenchymal rat heart cell cultures.
The effect of human recombinant interleukin-1 (IL-1) on the regulation of lipoprotein lipase (LPL) was studied in rat heart mesenchymal cell cultures. A time-dependent reduction in enzyme activity occurred with a 30% fall after 1 h. The suppression of enzyme activity was accompanied by a commensurate reduction in enzyme mass. The reduction in LPL activity was most prominent in the heparin releasable pool; IL-1 treatment resulted in a 7.2-8.3-fold decrease in the functional compartment and a 2.5-2.8-fold decrease in residual cellular activity. The effect of IL-1 could be prevented by the addition of the IL-1 inhibitor. However, in contradistinction to the effect of tumor necrosis factor (TNF), there was no change in LPL mRNA in cultures treated with IL-1. The present results show that the regulation of LPL in mesenchymal heart cell cultures by IL-1 occurs posttranscriptionally, as has been shown in 3T3 cells. The more pronounced effect on LPL activity in the functional pool suggests that IL-1 treatment might have influenced also the processing and/or transport of the enzyme to the cell surface.
Friedman
G
G
Department of Medicine B, Hadassah University Hospital, Jerusalem, Israel.
Barak
V
V
Chajek-Shaul
T
T
Etienne
J
J
Treves
A J
AJ
Stein
O
O
Stein
Y
Y
D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D004586:Electrophoresis; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D015151:Immunoblotting; D007375:Interleukin-1 / Q000494:pharmacology*; D008071:Lipoprotein Lipase / Q000037:antagonists & inhibitors* / Q000235:genetics; D008648:Mesoderm / Q000187:drug effects / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology*; D012333:RNA, Messenger / Q000187:drug effects; D051381:Rats; D011994:Recombinant Proteins / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D007375:Interleukin-1; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D008071:Lipoprotein Lipase