Appearance of serum amyloid protein in high-density lipoproteins of rabbits subjected to relatively mild stimuli

1984 ◽  
Vol 796 (3) ◽  
pp. 354-358 ◽  
Author(s):  
Elizabeth A. Moon ◽  
A.Malcolm Mackinnon ◽  
Philip J. Barter
Keyword(s):  
High Density ◽  
Serum Amyloid ◽  
High Density Lipoproteins ◽  
Amyloid Protein

Serum amyloid A and high density lipoproteins during the acute phase response

1988 ◽  
Vol 18 (6) ◽  
pp. 619-626 ◽  
Author(s):  
LINDA L. BAUSSERMAN ◽  
D. N. BERNIER ◽  
K. P. W. J. McADAM ◽  
P. N. HERBERT
Keyword(s):  
Acute Phase ◽  
Acute Phase Response ◽  
Serum Amyloid A ◽  
High Density ◽  
Phase Response ◽  
Serum Amyloid ◽  
High Density Lipoproteins ◽  
Amyloid A

scholarly journals Serum Amyloid P Component Prevents High-Density Lipoprotein-Mediated Neutralization of Lipopolysaccharide

2000 ◽  
Vol 68 (9) ◽  
pp. 4954-4960 ◽  
Author(s):  
Carla J. C. de Haas ◽  
Miriam J. J. G. Poppelier ◽  
Kok P. M. van Kessel ◽  
Jos A. G. van Strijp
Keyword(s):  
Magnetic Beads ◽  
High Density ◽  
Serum Amyloid ◽  
High Density Lipoproteins ◽  
Amyloid P Component ◽  
Serum Amyloid P ◽  
Serum Amyloid P Component ◽  
Amyloid P ◽  
Lps Binding

ABSTRACT Lipopolysaccharide (LPS) is an amphipathic macromolecule that is highly aggregated in aqueous preparations. LPS-binding protein (LBP) catalyzes the transfer of single LPS molecules, segregated from an LPS aggregate, to high-density lipoproteins (HDL), which results in the neutralization of LPS. When fluorescein isothiocyanate-labeled LPS (FITC-LPS) is used, this transfer of LPS monomers to HDL can be measured as an increase in fluorescence due to dequenching of FITC-LPS. Recently, serum amyloid P component (SAP) was shown to neutralize LPS in vitro, although only in the presence of low concentrations of LBP. In this study, we show that SAP prevented HDL-mediated dequenching of FITC-LPS, even in the presence of high concentrations of LBP. Human bactericidal/permeability-increasing protein (BPI), a very potent LPS-binding and -neutralizing protein, also prevented HDL-mediated dequenching of FITC-LPS. Furthermore, SAP inhibited HDL-mediated neutralization of both rough and smooth LPS in a chemiluminescence assay quantifying the LPS-induced priming of neutrophils in human blood. SAP bound both isolated HDL and HDL in serum. Using HDL-coated magnetic beads prebound with SAP, we demonstrated that HDL-bound SAP prevented the binding of LPS to HDL. We suggest that SAP, by preventing LPS binding to HDL, plays a regulatory role, balancing the amount of LPS that, via HDL, is directed to the adrenal glands.

scholarly journals High-Density Lipoproteins and Serum Amyloid A (SAA)

2021 ◽  
Vol 23 (2) ◽  
Author(s):  
Nancy R. Webb
Keyword(s):  
Serum Amyloid A ◽  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Density Lipoprotein ◽  
High Density ◽  
Serum Amyloid ◽  
High Density Lipoproteins ◽  
Amyloid A

Abstract Purpose of Review Serum amyloid A (SAA) is a highly sensitive acute phase reactant that has been linked to a number of chronic inflammatory diseases. During a systemic inflammatory response, liver-derived SAA is primarily found on high-density lipoprotein (HDL). The purpose of this review is to discuss recent literature addressing the pathophysiological functions of SAA and the significance of its association with HDL. Recent Findings Studies in gene-targeted mice establish that SAA contributes to atherosclerosis and some metastatic cancers. Accumulating evidence indicates that the lipidation state of SAA profoundly affects its bioactivities, with lipid-poor, but not HDL-associated, SAA capable of inducing inflammatory responses in vitro and in vivo. Factors that modulate the equilibrium between lipid-free and HDL-associated SAA have been identified. Summary HDL may serve to limit SAA’s bioactivities in vivo. Understanding the factors leading to the release of systemic SAA from HDL may provide insights into chronic disease mechanisms.

scholarly journals Serum amyloid A is a chemoattractant: induction of migration, adhesion, and tissue infiltration of monocytes and polymorphonuclear leukocytes.

1994 ◽  
Vol 180 (1) ◽  
pp. 203-209 ◽  
Author(s):  
R Badolato ◽  
J M Wang ◽  
W J Murphy ◽  
A R Lloyd ◽  
D F Michiel ◽  
...  
Keyword(s):  
Acute Phase ◽  
Polymorphonuclear Leukocytes ◽  
Serum Amyloid A ◽  
High Density ◽  
Serum Amyloid ◽  
High Density Lipoproteins ◽  
Secondary Amyloidosis ◽  
Polymorphonuclear Cells ◽  
Amyloid A ◽  
Cell Adhesion Molecule 1

Serum amyloid A (SAA) is an acute phase protein that in the blood is bound to high density lipoproteins; SAA is secreted mainly by hepatocytes, and its concentration increases in the blood up to 1000 times during an inflammatory response. At present, its biological function is unclear. Since some forms of secondary amyloidosis are caused by deposition in tissues of peptides derived from the SAA and leukocytes seem to be involved in this process, we investigated the effect of human SAA on human monocytes and polymorphonuclear cells (PMN). When recombinant human SAA (rSAA) was used at concentrations corresponding to those found during the acute phase (> 0.8 microM), it induced directional migration of monocytes and polymorphonuclear leukocytes. Preincubation of rSAA with high density lipoproteins blocked this chemoattractant activity for both monocytes and PMN. rSAA also regulated the expression of the adhesion proteins CD11b and leukocyte cell adhesion molecule 1 and induced the adhesion of PMN and monocytes to umbilical cord vein endothelial cell monolayers. When subcutaneously injected into mice, rSAA recruited PMN and monocytes at the injection site. On the basis of these data, we suggest that SAA may participate in enhancing the migration of monocytes and PMN to inflamed tissues during an acute phase response.

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