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.

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 Adenoviral expression of murine serum amyloid A proteins to study amyloid fibrillogenesis

1998 ◽  
Vol 332 (3) ◽  
pp. 721-728 ◽  
Author(s):  
Mark S. KINDY ◽  
Amy R. KING ◽  
Jin YU ◽  
Connie GERARDOT ◽  
Joel WHITLEY ◽  
...  
Keyword(s):  
Acute Phase ◽  
Half Life ◽  
Serum Amyloid A ◽  
Amyloid Fibrils ◽  
Serum Amyloid ◽  
Vector System ◽  
High Density Lipoproteins ◽  
Secondary Amyloidosis ◽  
Amyloid A ◽  
J Protein

Serum amyloid A (SAA) proteins are one of the most inducible acute-phase reactants and are precursors of secondary amyloidosis. In the mouse, SAA1 and SAA2 are induced in approximately equal quantities in response to amyloid induction models. These two isotypes differ in only 9 of 103 amino acid residues; however, only SAA2 is selectively deposited into amyloid fibrils. SAA expression in the CE/J mouse species is an exception in that gene duplication did not occur and the CE/J variant is a hybrid molecule sharing features of SAA1 and SAA2. However, even though it is more closely related to SAA2 it is not deposited as amyloid fibrils. We have developed an adenoviral vector system to overexpress SAA proteins in cell culture to determine the ability of these proteins to form amyloid fibrils, and to study the structural features in relation to amyloid formation. Both the SAA2 and CE/J SAA proteins were synthesized in large quantities and purified to homogeneity. Electron microscopic analysis of the SAA proteins revealed that the SAA2 protein was capable of forming amyloid fibrils, whereas the CE/J SAA was incapable. Radiolabelled SAAs were associated with normal or acute-phase high-density lipoproteins (HDLs); we examined them for their clearance from the circulation. In normal mice, SAA2 had a half-life of 70 min and CE/J SAA had a half-life of 120 min; however, in amyloid mice 50% of the SAA2 cleared in 55 min, compared with 135 min for the CE/J protein. When the SAA proteins were associated with acute-phase HDLs, SAA2 clearance was decreased to 60 min in normal mice compared with 30 min in amyloidogenic mice. Both normal and acute-phase HDLs were capable of depositing SAA2 into preformed amyloid fibrils, whereas the CE/J protein did not become associated with amyloid fibrils. This established approach opens the doors for large-scale SAA production and for the examination of specific amino acids involved in the fibrillogenic capability of the SAA2 molecule in vitro and in vivo.

scholarly journals Heparan Sulfate Dissociates Serum Amyloid A (SAA) from Acute-phase High-density Lipoprotein, Promoting SAA Aggregation

2012 ◽  
Vol 287 (30) ◽  
pp. 25669-25677 ◽  
Author(s):  
Fredrik Noborn ◽  
John B. Ancsin ◽  
Wimal Ubhayasekera ◽  
Robert Kisilevsky ◽  
Jin-Ping Li
Keyword(s):  
High Density Lipoprotein ◽  
Heparan Sulfate ◽  
Acute Phase ◽  
Serum Amyloid A ◽  
Density Lipoprotein ◽  
High Density ◽  
Serum Amyloid ◽  
Amyloid A

scholarly journals Heterogeneity of human serum amyloid A proteins.

1980 ◽  
Vol 152 (3) ◽  
pp. 641-656 ◽  
Author(s):  
L L Bausserman ◽  
P N Herbert ◽  
K P McAdam
Keyword(s):  
Amino Acid ◽  
Serum Amyloid A ◽  
Polyacrylamide Gel ◽  
Serum Amyloid ◽  
High Density Lipoproteins ◽  
Systemic Lupus Erythematosis ◽  
Secondary Amyloidosis ◽  
Single Chain ◽  
Amino Acid Compositions ◽  
Amyloid A

Serum amyloid A proteins (SAA), presumed precursors of the tissue amyloid A proteins (AA) characteristic of secondary amyloidosis, have been isolated from the plasma high-density lipoproteins (HDL) of normals after etiocholanolone-induced inflammation and from patients with Wegener's granulomatosis, systemic lupus erythematosis, juvenile rheumatoid arthritis, Waldenström's macroglobulinemia, and Goodpasture's syndrome. At least six polymorphic forms of SAA wer identified among the low molecular weight proteins of HDL, and these comprosed up to 27% of the total HDL protein. Gel and ion-exchange chromatography permitted isolation of the SAA polymorphs in homogeneous form. Their amino acid compositions were very similar, they were indistinguishable in cationic and sodium dodecyl sulfate-polyacrylamide gel electrophoresis systems, and each had the terminal sequency COOH-Tyr-Lys-Phe-. Charge heterogeneity in anionic-urea polyacrylamide gel electropherograms was unaffected by neuaminidase treatment, and none of the SAA protein bands stained with the periodate-Schiff reagent. The two major SAA polymorphs, designated SAA4 and SAA5 according to their order of elution from DEAE-cellulose, had different NH2-terminal sequences. Manual Edman degradation demonstrated NH2-arg-ser-phe-phe- for SAA4 and NH2-ser-phe-phe- for SAA5. This NH2-terminal heterogeneity corresponds to that most frequently reported for AA and suggests that microheterogeneity in SAA may underlie that already documented in AA. Sufficient quantitites of the other SAA polymorphs were not available for similar analyses, but the amino acid compositions do not indicate that NH2-terminal heterogeneity accounts for all of the observed polymorphism. Artifactual polymorphism also appears unlikely, and the heterogeneiy of SAA may reflect origin from more than one cell type with or without posttranslational modificaton. We calculate from quantitative COOH-terminal analyses that SAA is of 11,000-11,900 mol wt. Primary structure studies have shown AA t be a single chain protein of 76 residues, and SAA, therefore, appears to contain a peptide of 33 amino acids that is missing from AA.

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.

Evaluation of goose serum amyloid a acute phase response by enzyme-linked immunosorbent assay

2007 ◽  
Vol 55 (3) ◽  
pp. 349-357 ◽  
Author(s):  
Beáta Kovács ◽  
Mathilda Toussaint ◽  
E. Gruys ◽  
Ibolya Fábián ◽  
L. Szilágyi ◽  
...  
Keyword(s):  
Acute Phase ◽  
Pasteurella Multocida ◽  
Serum Amyloid A ◽  
Serum Amyloid ◽  
Enzyme Linked Immunosorbent Assay ◽  
Common Disease ◽  
Post Inoculation ◽  
Secondary Amyloidosis ◽  
Phase Reaction ◽  
Amyloid A

Serum amyloid A (SAA) is of interest as the circulating precursor of amyloid A protein, the fibrillar component of AA (secondary) amyloid deposits, and also as an extremely sensitive and rapid major acute phase protein. Serum concentrations of acute phase proteins (APPs) provide valuable information about the diagnosis and prognosis of various diseases, and thus the relevance of APPs for monitoring the health status of domestic animals is widely accepted. More importantly, the measurement of SAA concentration assists in assessing the prognosis in secondary amyloidosis, which is a common disease of geese, affecting an increasing number of animals. In the present study we introduce a highly sensitive goose-specific ELISA method for measuring SAA concentration in goose serum or plasma samples. Samples were taken from geese of the Landes Grey and Hungarian White breeds, which were stimulated for an acute phase reaction by administration of a commercially available fowl cholera vaccine containing inactivated Pasteurella multocida . Strong and characteristically rapid acute phase responses were measured in both breeds, peaking at approximately 24 h after inoculation. The maximum SAA concentration was 1200 μg/ml. At 72 h post-inoculation, the concentrations returned to pre-inoculation values. There was significantly (p = 0.004) less intense response in the control groups; however, a very mild increase of SAA levels was detected due to the stress inevitably caused by the sampling procedure.

scholarly journals The role of serum amyloid A and sphingosine-1-phosphate on high-density lipoprotein functionality

2015 ◽  
Vol 396 (6-7) ◽  
pp. 573-583 ◽  
Author(s):  
Nicole Prüfer ◽  
Burkhard Kleuser ◽  
Markus van der Giet
Keyword(s):  
High Density Lipoprotein ◽  
Acute Phase ◽  
Serum Amyloid A ◽  
Biological Activities ◽  
Density Lipoprotein ◽  
High Density ◽  
Serum Amyloid ◽  
Amyloid A ◽  
Hdl Function ◽  
Sphingosine 1 Phosphate

Abstract The high-density lipoprotein (HDL) is one of the most important endogenous cardiovascular protective markers. HDL is an attractive target in the search for new pharmaceutical therapies and in the prevention of cardiovascular events. Some of HDL’s anti-atherogenic properties are related to the signaling molecule sphingosine-1-phosphate (S1P), which plays an important role in vascular homeostasis. However, for different patient populations it seems more complicated. Significant changes in HDL’s protective potency are reduced under pathologic conditions and HDL might even serve as a proatherogenic particle. Under uremic conditions especially there is a change in the compounds associated with HDL. S1P is reduced and acute phase proteins such as serum amyloid A (SAA) are found to be elevated in HDL. The conversion of HDL in inflammation changes the functional properties of HDL. High amounts of SAA are associated with the occurrence of cardiovascular diseases such as atherosclerosis. SAA has potent pro-atherogenic properties, which may have impact on HDL’s biological functions, including cholesterol efflux capacity, antioxidative and anti-inflammatory activities. This review focuses on two molecules that affect the functionality of HDL. The balance between functional and dysfunctional HDL is disturbed after the loss of the protective sphingolipid molecule S1P and the accumulation of the acute-phase protein SAA. This review also summarizes the biological activities of lipid-free and lipid-bound SAA and its impact on HDL function.

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