Cytokine regulation of macrophage apo E secretion: opposing effects of GM-CSF and TGF-β

Acquisition of Secretion of Transforming Growth Factor-β1 Leads to Autonomous Suppression of Scavenger Receptor Activity in a Monocyte-Macrophage Cell Line, THP-1

“…TGF-␤1 is reported to decrease the expression of ScR mRNA in THP-1 cells (24) and LPL mRNA in preadipocytes (22) and to increase apoE mRNA in macrophages (20). The present results agree with the findings in previous reports and show that the TGF-␤1 secreted from sTHP-1 cells suppressed the transcript levels of ScR and LPL mRNAs and increased the level of ApoE mRNA.…”

“…The expression of ApoE is stimulated by cholesterol loading (19) and transforming growth factor-␤1 (TGF-␤1) (20), while LPL expression is inhibited by oxysterols (21), TGF-␤ (22), and lipopolysaccharides (23). Bottalico et al (24) reported that TGF-␤1 inhibits ScR activity in THP-1 cells.…”

TGF-β1 Up-Regulates Expression of ABCA1, ABCG1 and SR-BI through Liver X Receptor α Signaling Pathway in THP-1 Macrophage-Derived Foam Cells

“…In atherosclerosis, TGF-could contribute to plaque stability through the inhibition of metalloproteinase activity and increased matrix deposition 34) . TGFmight significantly increase cholesterol efflux in macrophage-derived foam cells from apoE / mice 26) , and cholesterol, alone or complex in lipoproteins, could suppress TGF-responsiveness by increasing lipid raft and/or caveolae accumulation of TGF-receptors and facilitating rapid degradation of TGF-and thus suppressing TGF--induced signaling 35) .…”

Tumor necrosis factor-alpha modulates monocyte/macrophage apoprotein E gene expression.

“…TGF,8 has been demonstrated to induce macrophage apo E expression (10). On the other hand, the monocyte colony stimulating factor (MSCF)' has been shown, in separate reports, both to inhibit and augment macrophage apo E expression ( 10,11).…”