scholarly journals Dementia in the older population is associated with neocortex content of serum amyloid P component

2021 ◽  
Author(s):  
Stephan Ellmerich ◽  
Graham W Taylor ◽  
Connor D Richardson ◽  
Thais Minett ◽  
A Floriaan Schmidt ◽  
...  
Keyword(s):  
Large Scale ◽  
Amyloid Β ◽  
High Serum ◽  
Serum Amyloid ◽  
Amyloid P Component ◽  
Serum Amyloid P ◽  
Serum Amyloid P Component ◽  
Amyloid P

Abstract Despite many reported associations, the direct cause of neurodegeneration responsible for cognitive loss in Alzheimer’s disease and some other common dementias is not known. The normal human plasma protein, serum amyloid P component, a constituent of all human fibrillar amyloid deposits and present on most neurofibrillary tangles, is cytotoxic for cerebral neurones in vitro and in experimental animals in vivo. The neocortical content of serum amyloid P component was immunoassayed in 157 subjects aged 65 or more with known dementia status at death, in the large scale, population-representative, brain donor cohort of the Cognitive Function and Ageing Study, which avoids the biases inherent in studies of predefined clinico-pathological groups. The serum amyloid P component values were significantly higher in individuals with dementia, independent of serum albumin content measured as a control for plasma in the cortex samples. The odds ratio for dementia at death in the high serum amyloid P component tertile was 5.24 (95% CI 1.79–15.29) and was independent of Braak tangle stages and Thal amyloid-β phases of neuropathological severity. The strong and specific association of higher brain content of serum amyloid P component with dementia, independent of neuropathology, is consistent with a pathogenetic role in dementia.

Studies with Radiolabelled Serum Amyloid P Component Provide Evidence for Turnover and Regression of Amyloid Deposits In Vivo

1994 ◽  
Vol 87 (3) ◽  
pp. 289-295 ◽  
Author(s):  
Philip N. Hawkins
Keyword(s):  
Amyloid Fibrils ◽  
Specific Binding ◽  
Serum Amyloid ◽  
Poor Correlation ◽  
Amyloid P Component ◽  
Serum Amyloid P ◽  
Serum Amyloid P Component ◽  
Amyloid Deposits ◽  
Amyloid P

1. Quantitative scintigraphic and turnover studies, utilizing the specific binding affinity of serum amyloid P component for amyloid fibrils, have been developed as a tool for evaluating amyloid deposits in vivo. 2. Serial studies in over 300 patients have shown characteristic, diagnostic tissue distributions of amyloid in different types of amyloidosis. There is generally a poor correlation between quantity of amyloid and associated organ dysfunction. 3. Contrary to previous expectations, regression of amyloid has been demonstrated systematically for the first time: AA, AL and variant transthyretin-associated amyloid deposits often regress rapidly, and sometimes completely, if the supply of fibril protein precursors is substantially reduced.

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.

Serum amyloid P component inhibits influenza A virus infections: in vitro and in vivo studies

2001 ◽  
Vol 52 (1) ◽  
pp. 43-53 ◽  
Author(s):  
A Horváth ◽  
I Andersen ◽  
K Junker ◽  
B Lyck Fogh-Schultz ◽  
E Holm Nielsen ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
In Vivo Studies ◽  
Virus Infections ◽  
Amyloid P Component ◽  
Serum Amyloid P ◽  
Serum Amyloid P Component ◽  
Amyloid P

Amyloidosis

2020 ◽  
pp. 2218-2234
Author(s):  
Mark B. Pepys ◽  
Philip N. Hawkins
Keyword(s):  
Amyloid Fibrils ◽  
Amyloid Fibril ◽  
Polarized Light ◽  
Serum Amyloid ◽  
Amyloid P Component ◽  
Serum Amyloid P ◽  
Serum Amyloid P Component ◽  
Amyloid Deposits ◽  
Amyloid P

Amyloidosis is the clinical condition caused by extracellular deposition of amyloid in the tissues. Amyloid deposits are composed of amyloid fibrils, abnormal insoluble protein fibres formed by misfolding of their normally soluble precursors. About 30 different proteins can form clinically or pathologically significant amyloid fibrils in vivo as a result of either acquired or hereditary abnormalities. Small, focal, clinically silent amyloid deposits in the brain, heart, seminal vesicles, and joints are a universal accompaniment of ageing. Clinically important amyloid deposits usually accumulate progressively, disrupting the structure and function of affected tissues and lead inexorably to organ failure and death. There is no licensed treatment which can specifically clear amyloid deposits, but intervention which reduces the availability of the amyloid fibril precursor proteins can arrest amyloid accumulation and may lead to amyloid regression with clinical benefit. Pathology—amyloid fibrils bind Congo red dye producing pathognomonic green birefringence when viewed in high-intensity cross-polarized light, and the protein type can be identified by immunostaining or proteomic analysis. Amyloid deposits always contain a nonfibrillar plasma glycoprotein, serum amyloid P component, the universal presence of which is the basis for use of radioisotope-labelled serum amyloid P component as a diagnostic tracer. Clinicopathological correlation—amyloid may be deposited in any tissue of the body, including blood vessels walls and connective tissue matrix; clinical manifestations are correspondingly diverse. Identification of the amyloid fibril protein is always essential for appropriate clinical management. The specific types of amyloidosis covered in this chapter are reactive systemic (AA) amyloidosis, monoclonal immunoglobulin light chain (AL) amyloidosis, and hereditary systemic amyloidoses (including familial amyloid polyneuropathy).

Is Serum Amyloid P Component Required for in Vivo Amyloid Deposition?

1996 ◽  
Vol 90 (s34) ◽  
pp. 33P-33P
Author(s):  
W L Hutchinson ◽  
J Herbert ◽  
P N Hawkins ◽  
M B Pepys
Keyword(s):  
Amyloid Deposition ◽  
Serum Amyloid ◽  
Amyloid P Component ◽  
Serum Amyloid P ◽  
Serum Amyloid P Component ◽  
Amyloid P

scholarly journals Human serum amyloid P component, a circulating lectin with specificity for the cyclic 4,6-pyruvate acetal of galactose. Interactions with various bacteria

1985 ◽  
Vol 225 (1) ◽  
pp. 107-111 ◽  
Author(s):  
C R K Hind ◽  
P M Collins ◽  
M L Baltz ◽  
M B Pepys
Keyword(s):  
Xanthomonas Campestris ◽  
Group A Streptococcus ◽  
Serum Amyloid ◽  
Amyloid P Component ◽  
Serum Amyloid P ◽  
Serum Amyloid P Component ◽  
Group A ◽  
Amyloid P ◽  
Specific Ligand

Serum amyloid P component (SAP), a normal plasma glycoprotein, has recently been shown to have Ca2+-dependent binding specificity for methyl 4,6-O-(1-carboxyethylidene)-beta-D-galactopyranoside (MO beta DG) [Hind, Collins, Renn, Cook, Caspi, Baltz & Pepys (1984) J. Exp. Med. 159, 1058-1069]. SAP was found to bind in vitro to Klebsiella rhinoscleromatis, the cell wall of which is known to contain this particular cyclic pyruvate acetal of galactose. SAP also bound in similar amounts (approx. 6000 molecules per organism) to group A Streptococcus pyogenes, but very much less was taken up on Xanthomonas campestris, which contains the 4,6-cyclic pyruvate acetal of mannose. No SAP bound to Escherichia coli, which contains the 4,6-cyclic pyruvate acetal of glucose, or to Streptococcus pneumoniae type 4, which contains the 2,3-cyclic pyruvate acetal of alpha- rather than beta-galactopyranoside, or to other organisms (Streptococcus agalactiae, Staphylococcus aureus and Staphylococcus epidermidis), the carbohydrate structures of which are less well characterized. Binding of SAP to those organisms which it did recognize was completely inhibited or reversed by millimolar concentrations of free MO beta DG. SAP, a human plasma protein, thus behaves as a lectin and may be a useful probe for its particular specific ligand in the cell walls of bacteria and other organisms.

scholarly journals Multifaceted anti-amyloidogenic and pro-amyloidogenic effects of C-reactive protein and serum amyloid P component in vitro

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Daisaku Ozawa ◽  
Ryo Nomura ◽  
P. Patrizia Mangione ◽  
Kazuhiro Hasegawa ◽  
Tadakazu Okoshi ◽  
...  
Keyword(s):  
Serum Amyloid ◽  
C Reactive Protein ◽  
Amyloid P Component ◽  
Reactive Protein ◽  
Serum Amyloid P ◽  
Serum Amyloid P Component ◽  
Amyloid P
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