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

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.

Amyloid deposition is delayed in mice with targeted deletion of the serum amyloid P component gene

1997 ◽  
Vol 3 (8) ◽  
pp. 855-859 ◽  
Author(s):  
Marina Botto ◽  
Philip N. Hawkins ◽  
Maria C.M. Bickerstaff ◽  
Jeff Herbert ◽  
Anne E. Bygrave ◽  
...  
Keyword(s):  
Amyloid Deposition ◽  
Serum Amyloid ◽  
Targeted Deletion ◽  
Amyloid P Component ◽  
Serum Amyloid P ◽  
Serum Amyloid P Component ◽  
Amyloid P ◽  
Component Gene

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).

scholarly journals Pharmacological removal of serum amyloid P component from intracerebral plaques and cerebrovascular Aβ amyloid deposits in vivo

Open Biology ◽  
2016 ◽  
Vol 6 (2) ◽  
pp. 150202 ◽  
Author(s):  
Raya Al-Shawi ◽  
Glenys A. Tennent ◽  
David J. Millar ◽  
Angela Richard-Londt ◽  
Sebastian Brandner ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Serum Amyloid ◽  
Amyloid P Component ◽  
Serum Amyloid P ◽  
Serum Amyloid P Component ◽  
Amyloid Deposits ◽  
Amyloid P ◽  
Cerebrovascular Amyloid

Human amyloid deposits always contain the normal plasma protein serum amyloid P component (SAP), owing to its avid but reversible binding to all amyloid fibrils, including the amyloid β (Aβ) fibrils in the cerebral parenchyma plaques and cerebrovascular amyloid deposits of Alzheimer's disease (AD) and cerebral amyloid angiopathy (CAA). SAP promotes amyloid fibril formation in vitro , contributes to persistence of amyloid in vivo and is also itself directly toxic to cerebral neurons. We therefore developed (R)-1-[6-[(R)-2-carboxy-pyrrolidin-1-yl]-6-oxo-hexanoyl]pyrrolidine-2-carboxylic acid (CPHPC), a drug that removes SAP from the blood, and thereby also from the cerebrospinal fluid (CSF), in patients with AD. Here we report that, after introduction of transgenic human SAP expression in the TASTPM double transgenic mouse model of AD, all the amyloid deposits contained human SAP. Depletion of circulating human SAP by CPHPC administration in these mice removed all detectable human SAP from both the intracerebral and cerebrovascular amyloid. The demonstration that removal of SAP from the blood and CSF also removes it from these amyloid deposits crucially validates the strategy of the forthcoming ‘Depletion of serum amyloid P component in Alzheimer's disease (DESPIAD)’ clinical trial of CPHPC. The results also strongly support clinical testing of CPHPC in patients with CAA.

scholarly journals Investigating interactions of the pentraxins serum amyloid P component and C-reactive protein by mass spectrometry

2003 ◽  
Vol 375 (2) ◽  
pp. 323-328 ◽  
Author(s):  
J. Andrew AQUILINA ◽  
Carol V. ROBINSON
Keyword(s):  
Protein A ◽  
Serum Amyloid ◽  
C Reactive Protein ◽  
Oligomeric State ◽  
Amyloid P Component ◽  
Reactive Protein ◽  
Serum Amyloid P ◽  
Serum Amyloid P Component ◽  
Amyloid P

The oligomeric state of human SAP (serum amyloid P component) in the absence and presence of known ligands has been investigated using nanoelectrospray ionization MS. At pH 8.0, in the absence of Ca2+, SAP has been shown to consist of pentameric and decameric forms. In the presence of physiological levels of Ca2+, SAP was observed to exist primarily as a pentamer, reflecting its in vivo state. dAMP was shown not only to promote decamerization, but also to lead to decamer stacking involving up to 30 monomers. A mechanism for this finding is proposed. CRP (C-reactive protein), a pentraxin closely related to SAP, exists as a pentamer in the presence or absence of Ca2+. Pentamers of CRP and SAP were shown to form mixed decamers in Ca2+-free buffer; however, in the presence of Ca2+, this interaction was not observed. Furthermore, no exchange of monomeric subunits was observed between the SAP and CRP oligomers, suggesting a remarkable stability of the individual pentameric complexes.

scholarly journals Specific localization and imaging of amyloid deposits in vivo using 123I-labeled serum amyloid P component.

1988 ◽  
Vol 167 (3) ◽  
pp. 903-913 ◽  
Author(s):  
P N Hawkins ◽  
M J Myers ◽  
A A Epenetos ◽  
D Caspi ◽  
M B Pepys
Keyword(s):  
Serum Amyloid ◽  
C Reactive Protein ◽  
Amyloid P Component ◽  
Reactive Protein ◽  
Amyloid A ◽  
Serum Amyloid P ◽  
Serum Amyloid P Component ◽  
Amyloid Deposits ◽  
Amyloid P

Highly specific, high-resolution scintigraphic images of amyloid-laden organs in mice with experimentally induced amyloid A protein (AA) amyloidosis were obtained after intravenous injection of 123I-labeled serum amyloid P component (SAP). Interestingly, a much higher proportion (up to 40%) of the injected dose of heterologous human SAP localized to amyloid and was retained there than was the case with isologous mouse SAP, indicating that human SAP binds more avidly to mouse AA fibrils than does mouse SAP. Specificity of SAP localization was established by the failure of the related proteins, human C-reactive protein and Limulus C-reactive protein, to deposit significantly in amyloid and by the absence of human SAP deposition in nonamyloidotic organs. However, only partial correlations were observed between the quantity of SAP localized and two independent estimates, histology and RIA for AA of the amount of amyloid in particular organs. It is not clear which of the three methods used reflects better the extent or clinical significance of the amyloid deposits but in vivo localization of radiolabeled SAP, detectable and quantifiable by gamma camera imaging, is apparently extremely sensitive. These findings establish the use of labeled SAP as a noninvasive in vivo diagnostic probe in experimental amyloidosis, potentially capable of revealing the natural history of the condition, and suggest that it may also be applicable generally as a specific targeting agent for diagnostic and even therapeutic purposes in clinical amyloidosis.

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