Long pentraxin 3, a key component of innate immunity, is modulated by high-density lipoproteins in endothelial cells.
OBJECTIVE
High-density lipoproteins (HDL) are endowed with cardiovascular protective activities. In addition to their role in reverse cholesterol transport, HDL exert several beneficial effects on endothelial cells, including the induction of endothelial nitric oxide synthase and prostacyclin release, and the control of the immune and inflammatory response.


RESULTS
To identify possible mechanisms involved in these effects we investigated the modulation of the expression of acute phase proteins of the pentraxin superfamily, such as C-reactive protein (CRP), serum amyloid P component protein (SAP), and the long pentraxin 3 (PTX3) by HDL in human endothelial cells. HDL induced PTX3 mRNA expression and protein release, whereas no effect was observed on CRP and SAP expression. This effect was mainly dependent on the activation of the lysosphingolipids receptors-PI3K/Akt axis and was mimicked by sphingosine 1 phosphate and other S1P mimetics. This observation was confirmed in vivo; indeed an increased expression of PTX3 mRNA was detected in the aorta of transgenic mice overexpressing human apoA-I, compared to apoA-I knock-out mice. Furthermore, plasma levels of PTX3 significantly increased in C57BL/6 mice injected with HDL.


CONCLUSIONS
These data suggest that part of the atheroprotective effects of HDL could result from the modulation of molecules that act as sensors of the immunoinflammatory balance in the vascular wall.
Norata
Giuseppe Danilo
GD
Department of Pharmacological Sciences, University of Milan, Via Balzaretti 9, 20133, Milan, Italy. Danilo.Norata@unimi.it
Marchesi
Patrizia
P
Pirillo
Angela
A
Uboldi
Patrizia
P
Chiesa
Giulia
G
Maina
Virginia
V
Garlanda
Cecilia
C
Mantovani
Alberto
A
Catapano
Alberico Luigi
AL
D000209:Acute-Phase Proteins / Q000378:metabolism; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D016632:Apolipoprotein A-I / Q000235:genetics / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism*; D008076:Cholesterol, HDL / Q000494:pharmacology; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007113:Immunity, Innate / Q000502:physiology*; D008075:Lipoproteins, HDL / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D000683:Serum Amyloid P-Component / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D000099153:Pentraxins
D000209:Acute-Phase Proteins; D016632:Apolipoprotein A-I; D002097:C-Reactive Protein; D008076:Cholesterol, HDL; D008075:Lipoproteins, HDL; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D012333:RNA, Messenger; D000683:Serum Amyloid P-Component; D000099153:Pentraxins