Apolipoprotein M induces inhibition of inflammatory responses via the S1PR1 and DHCR24 pathways.
Mol Med Rep
; 19(2): 1272-1283, 2019 02.
Article
in En
| MEDLINE
| ID: mdl-30569161
ABSTRACT
Apolipoprotein M (ApoM) is a type of apolipoprotein. It is well known that highdensity lipoprotein (HDL) decreases inflammatory responses via the apoMsphingosine1phosphate (S1P) pathway. The present study further investigated the importance of ApoM in the inhibitory effects of HDL on inflammation. Mice with an apoM gene deficiency (apoM/) were employed to investigate the effects of ApoM on the expression of interleukin1ß (IL1ß), monocyte chemotactic protein1 (MCP1), S1P receptor1 (S1PR1) and 3ßhydroxysterol Δ24reductase (DHCR24), as compared with in wildtype mice (apoM+/+). Furthermore, cell culture experiments were performed using a permanent human hybrid endothelial cell line (EA.hy926). Cells were cultured in the presence of recombinant human apoM (recapoM) or were induced to overexpress apoM (apoMTg); subsequently, cells were treated with tumor necrosis factorα (TNFα), in order to investigate the effects of ApoM on IL1ß and MCP1. The results demonstrated that the mRNA expression levels of IL1ß and MCP1 were significantly higher in the liver following administration of lipopolysaccharide in apoM/ mice compared with in apoM+/+ mice. In cell culture experiments, when cells were precultured with recapoM or were engineered to overexpress apoM (apoMTg), they exhibited decreased expression levels of IL1ß and MCP1 following TNFα treatment compared with in normal apoMexpressing cells (apoMTgN). Furthermore, the mRNA expression levels of IL1ß and MCP1 were significantly elevated following addition of the S1PR1 inhibitor W146, but not by the scavenger receptor class B type I inhibitor, block lipid transport1 (BLT1), in apoMTg cells prior to TNFα treatment. Conversely, there were no differences in these inflammatory biomarkers under the same conditions in apoMTgN cells. The mRNA expression levels of DHCR24 were significantly reduced by the addition of BLT1 prior to TNFα treatment in apoMTg cells; however, there was no difference in the expression of this inflammatory biomarker in apoMTgN cells. In conclusion, ApoM displayed inhibitory effects against the inflammatory response in vivo and in vitro; these effects may be induced via the S1PR1 and DHCR24 pathways.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Signal Transduction
/
Oxidoreductases Acting on CH-CH Group Donors
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Receptors, Lysosphingolipid
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Apolipoproteins M
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Inflammation
/
Nerve Tissue Proteins
Limits:
Animals
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Humans
/
Male
Language:
En
Journal:
Mol Med Rep
Year:
2019
Document type:
Article