Amyloid Protein AA Research Articles

Amyloid in the Lung.

Amyloidosis is the term given to abnormal deposition of misfolded precursor proteins at single or multiple sites, leading to organ dysfunction or clinical signs and symptoms. Pulmonary manifestations are nonspecific and may be associated with several amyloid protein subtypes, commonly AL (light chain) and AA (autoimmune) amyloids. Signs or symptoms of amyloid disease may often involve more of the clinical abnormalities of other affected organs than the lungs themselves. Radiologic pulmonary findings include septal and parenchymal ground glass or nodular infiltrates, multiple nodules, cysts, and focal tracheobronchial abnormalities. Lymphadenopathy with or without calcification and pleural effusions has also been reported. Directed therapy is initiated in response to clinical signs or symptoms often as a result of systemic or secondary diseases or conditions. Long-term prognosis is more dependent on the extent of organ involvement where morbidity is often the highest in those with multisystemic disease.

Noncerebral Amyloidoses: Aspects on Seeding, Cross-Seeding, and Transmission.

More than 30 proteins form amyloid in humans, most of them outside of the brain. Deposition of amyloid in extracerebral tissues is very common and seems inevitable for an aging person. Most deposits are localized, small, and probably without consequence, but in some instances, they are associated with diseases such as type 2 diabetes. Other extracerebral amyloidoses are systemic, with life-threatening effects on the heart, kidneys, and other organs. Here, we review how amyloid may spread through seeding and whether transmission of amyloid diseases may occur between humans. We also discuss whether cross-seeding is important in the development of amyloidosis, focusing specifically on the amyloid proteins AA, transthyretin, and islet amyloid polypeptide (IAPP).

Experimental AA-amyloidosis in mice is inhibited by treatment with the anti-rheumatic drug tenidap.

In a mouse model for induction of experimental AA-amyloidosis, treatment with tenidap was shown to inhibit the development of amyloidosis. Studies have shown that the drug inhibits the cytokines interleukin (IL)-6, IL-1 and tumour necrosis factor alpha (TNF-alpha) which are known to stimulate hepatocytes to synthesize acute phase proteins (APPs). The APP serum amyloid protein (SAA) is the precursor for amyloid protein AA and tenidap treatment reduces the serum levels of SAA in mouse and humans. It is suggested that reduction of SAA levels reduces the risk of AA fibril formation and thus the development of amyloidosis.

Sequence analysis of amyloid protein AA from a Turkish patient with familial Mediterranean fever: Documentation of its SAA1αderivation

This is the first amino acid sequence analysis of an amyloid fibril protein from a Turkish patient with AA anyloidosis secondary to familial Mediterranean fever. Amyloid fibrils were isolated from spleen tissue and purified by gel filtration. The major protein constituent was fnurul to be an 8 kD amyloid protein AA. Amino acid sequence analysis indicated that the Turkish AA protein is the product of apoSAA1α gene with Val at position 52, Ala at position 57, Asp at position 60, and Phe Phe at positions 68 and 69. Two other analyses of AA amyloid from individuals with familial Mediterranean fever have been reported. One is consistent with products of both apoSAA1α and apoSAA1γ genes, while the other is consistent with a product of apoSAA2β gene.

Spheroidal Keratopathy Associated with Subepithelial Corneal Amyloidosis: A Clinicopathologic Case Report and a Proposed New Classification for Spheroidal Keratopathy

An unusual case of primary spheroidal degeneration associated with subepithelial corneal amyloidosis is described clinically and histopathologically, and a new classification for spheroidal keratopathy is proposed. The corneal button obtained by lamellar keratoplasty was examined by light and transmission electron microscopy. Amyloid deposits were evaluated further by means of the thioflavin T fluorescence technique, the potassium permanganate reaction, and immunohistochemical studies using antibodies against immunoglobulin light chains and proteins AA and AP. Spheroidal droplets were observed in basement membrane, Bowman's layer, and anterior stroma, and exhibited characteristic staining with Verhoeff's iron hematoxylin. Amyloid deposits were found beneath the epithelium, almost exclusively in the central area of the corneal button. The deposits showed no immunohistochemical staining with antibodies to amyloid proteins AA and AP or kappa and lambda light chains. The histochemical properties of the spheroidal droplets in this case were similar to those observed by other authors and suggested a sulfur-rich protein other than keratin. The combination of clinical and pathologic findings permitted the differential diagnosis of subepithelial amyloidosis and distinguished this condition from that of gelatinous drop-like dystrophy. To the authors' knowledge, this is the first description of primary spheroidal keratopathy associated with secondary subepithelial corneal amyloidosis in an eye that had not undergone previous keratoplasty.

Histopathologic and Immunohistochemical Findings in Gelatinous Drop-Like Corneal Dystrophy

A cornea with gelatinous drop-like corneal dystrophy was examined by histochemical and immunohistochemical techniques. Pretreatment of the sections with potassium permanganate did not decrease the staining with Congo red dye. Immunohistochemically, amyloid deposits in the cornea with this disease almost did not stain with antibodies to amyloid protein AA and AA-3. However, the corneal epithelium reacted distinctly with antibodies to amyloid protein AA and AA-3. Cross-reactivity with antibodies to protein AA and serum precursor of protein AA has been reported and protein AA-3 is the synthesized peptide corresponding to the amino acid sequence 37-47 of the human amyloid protein AA molecule. The present study suggests at least that corneal epithelial cells with gelatinous drop-like corneal dystrophy may produce a precursor of amyloid related to protein AA-3.

Massive vascular AA-amyloidosis: a histologically and biochemically distinctive subtype of reactive systemic amyloidosis.

Amyloid protein AA consists of several subspecies which mainly arise through proteolytic cleavage at various sites of the precursor, serum protein AA. The most common protein AA subspecies (the protein AA prototype) contains 76 amino-acid residues. In previous studies we have shown that distinctive patterns of amyloid infiltration occur in AA-amyloidosis. The amyloid in different patterns of infiltration seems to consist of distinctive protein AA subspecies. In the present study we have analysed protein AA in three patients with a form of AA-amyloidosis with heavy vascular infiltration and show that the amyloid fibrils contain two groups of protein AA subspecies. One, quantitatively predominating, group contains large subspecies of up to 94 amino-acid residues and a second group of protein AA-molecules contains around 50 amino-acid residues. The AA molecules lack the N-terminal arginine residue. It is concluded that AA-amyloidosis with massive vascular infiltration is a distinctive subform with typical clinical and histological appearance and with fibrils containing characteristic protein AA subspecies.

Amino acid sequence variations in protein AA of cats with high and low incidences of AA amyloidosis

1. 1. Amyloid isolated from the liver of a domestic short-haired (DSH) cat was dissolved and purified by gel filtration for amino acid sequence analysis. 2. 2. Sequences of two major peptides corresponding to positions 18–23 and 25–75 of human amyloid protein AA were obtained when cyanogen bromide-cleaved protein was applied to an amino acid sequenator. 3. 3. Comparison of these regions of amyloid protein from the Abyssinian cat (high incidence of AA amyloidosis) and DSH cat (low incidence of AA amyloidosis) revealed three amino acid differences, two of which occurred within regions that are completely conserved in the Abyssinian cat and all other species. 4. 4. Secondary prediction plots showed less potential for amyloidogenicity (i.e., less beta-sheet conformation) in protein AA of the DSH cat as compared to the Abyssinian cat and other animal species. 5. 5. These differences in protein AA of the DSH cat may, therefore, be linked to the comparatively uncommon occurrence of AA amyloidosis in the DSH cat as compared to the Abyssinian cat and other animals species.

The pathogenesis of reactive systemic amyloidosis.

The diagnosis of amyloidosis is based on the presence of extracellular tissue deposits of proteinaceous material that demonstrate a characteristic green color when stained with Congo red and viewed under polarized light. Several different proteins are amyloidogenic but, in domestic animals, spontaneously occurring systemic amyloidosis is reactive in nature and characterized by the presence of amyloid protein AA. This type of systemic amyloidosis may occur secondary to chronic inflammatory or neoplastic disease, but in many instances no predisposing disease is found. A sustained increase in the serum concentration of serum amyloid A protein (SAA) is necessary but not sufficient for the development of reactive amyloidosis. Other inherited and acquired host-related factors are likely to be important in the development of reactive amyloidosis because this condition develops in few patients with chronic inflammatory disease. The tissue tropism of amyloid deposits varies with the amyloid protein itself and species affected. The consequences of amyloidosis for the host depend upon the tissues involved and the response of these tissues to the presence of the amyloid deposits. In domestic animals, reactive systemic amyloidosis is nephropathic, leading to end-stage renal disease, and the clinical presentation is that of uremia.

Histopathologic and Immunochemical Features of Lattice Corneal Dystrophy Type III

We examined seven corneas from five patients with a new form of lattice corneal dystrophy (designated lattice corneal dystrophy type III) by light and electron microscopy. Numerous amyloid deposits were scattered throughout the corneal stroma, some of which were much larger than those usually observed in either lattice corneal dystrophy type I or II; these were located predominantly midway between the epithelium and the endothelium. Image analysis disclosed that the cross-sectional size of the large stromal amyloid deposits was significantly greater than those in age-matched patients with lattice corneal dystrophy type I. All patients had a discontinuous band of amyloid (15 to 25 micron wide) in the superficial stroma beneath Bowman's layer, which usually had only one or two small disruptions. Descemet's membrane and the endothelium were normal. The stromal deposits, which were composed of 10-nm diameter fibrils typical of amyloid, stained positively with Congo red after the histologic sections were pretreated with dilute potassium permanganate. Immunohistochemical studies on formalin-fixed, paraffin-embedded tissue indicated that only some deposits reacted weakly with antibodies to amyloid protein AA. The deposits stained positively with antibodies to protein AP and negatively with antibodies to kappa and lambda immunoglobulin light chains.

Characterization of amyloid proteins AA and SAA as apolipoproteins of high density lipoprotein (HDL). Displacement of SAA from the HDL-SAA complex by apo AI and apo AII.

An AA-like protein with a molecular weight of 8600 complexed to high-density lipoprotein (HDL) was demonstrated in several acute-phase sera with high levels of SAA. The protein 'apo AA' (to distinguish it from tissue AA) was isolated by elution from sodium dodecyl sulphate (SDS)-polyacrylamide gel, and showed antigenic identity with purified tissue protein AA in double immunodiffusion. Normal HDL was shown to bind purified tissue AA in vitro. When the in vitro-associated HDL-AA complexes were given intravenously to mice during induction of amyloidosis, human AA was incorporated in the amyloid fibrils. Both apo AI and apo AII were shown to displace SAA from acute phase HDL when added to HDL-SAA complexes in vitro. This might be of importance in amyloidogenesis, as the liver and the small intestine, which are the main sites for AI and AII synthesis, are also sites of early amyloid deposition.

Characterization of amyloid protein AA and its serum precursor SAA in the horse.

Amyloid was extracted from the liver of a horse that had developed amyloidosis after being used for several years for the production of antibodies to bacterial antigens. The amyloid fibrils were shown to be of the AA type. Two AA proteins with molecular weights of 9000 and 11,000 and with identical partial N-terminal amino acid sequences were identified. Marked structural homology with AA from other species including man was seen, although clear species-related antigenic specificity was observed. SAA isolated from an acute phase (septic abortion) horse serum was identical to AA with respect to antigenicity and the 10 first N-terminal amino acid residues that have been studied up to now. The bulk of SAA was present in the high-density lipoprotein complex in serum. Also SAA was heterogeneous with respect to size, most molecules having a molecular weight of 11,000, and a minority 9000.

Amyloidogenesis. One serum amyloid A isotype is selectively removed from the circulation.

The deposits of fibrils found in amyloidosis of the A type are derived from only one of the three serum amyloid A (SAA) gene products, namely SAA2. In order to explore the mechanism of SAA isotype-specific amyloid protein AA deposition, the molecular kinetics of the serum amyloid proteins were examined in CBA mice during casein induction of amyloidosis. The presence of SAA mRNA in spleen was searched for; hepatic SAA1 and SAA2 mRNA levels, rates of specific protein synthesis and secretion by hepatocytes, and serum levels were measured during a 20-d period of amyloid induction. We observed the following: small amounts of amyloid substance appeared in the spleen by day 5 and increased steadily over the ensuing 15 d to occupy nearly 30% of splenic volume by day 20. No SAA mRNA was detected in spleen at any time during induction of amyloid formation. Total serum SAA levels peaked 1 d after we began casein treatment, and thereafter declined. This decline was accounted for entirely by a dramatic fall in SAA2, while SAA1 levels remained nearly constant throughout. The ratios of hepatic SAA2:SAA1 mRNA, as determined by in vitro translation, remained constant during the 20-d period, as did amounts of SAA1 and SAA2 synthesized and secreted by freshly isolated hepatocytes. These data indicate that the deposition of amyloid A protein derived from SAA2 is not due to local SAA production in spleen, nor excessive SAA2 production compared with SAA1, but involves the selective and accelerated removal of SAA2 from the circulating pool of both SAA1 and SAA2.

Characterization of amyloid deposits in biopsies of 15 with "sporadic" (non-familial or plasma cell dyscrasia amyloid polyneuropathy.

Review of the clinical and laboratory findings of 39 patients with amyloid polyneuropathy (AP) showed 12 cases to be hereditary and 12 to be associated with plasma cell dyscrasia (PCD). The remaining 15, termed "sporadic" AP, had neuropathy clinically indistinguishable from the other two groups but without a clinicopathologically identified PCD or positive family history. In an attempt to identify the type of amyloid in "sporadic" AP, the immunoreactivity of amyloid deposits was investigated using specific antisera raised against the following different chemical types of amyloid fibril proteins: variable regions of amyloid light chains kappa (A kappa) and lambda (A lambda), amyloid protein AA, and prealbumin. It was found that the amyloid in "sporadic" AP had A lambda antigenic determinants in ten cases, A kappa in one and prealbumin in three; in one case, the A lambda nature of amyloid was confirmed biochemically on the extracted amyloid fibrills. Thus, the most common type of AP in our population appears to be the "sporadic" form. In "sporadic" AP, the amyloid is most commonly of immunoglobulin light chain origin, even in the absence of overt PCD, and it can be rapidly categorized immunocytochemically to determine therapeutic directions or provide genetic guidance.

Bovine amyloid protein AA: Isolation and amino acid sequence analysis

1. 1. Amyloid-laden renal glomeruli were selectively isolated from a cow with a history of multiple organ inflammatory diseases which terminated in amyloid-induced glomerulopathy and severe proteinuria. 2. 2. Lyophilized amyloid fibrils obtained by water extraction procedures were dissolved in 6M guanidine hydrochloride and gel filtered on Sepharose CL6B and Sephacryl S-300 Superfine columns for slab gel electrophoresis, analytic isoelectric focusing, and amino acid sequence analyses. 3. 3. Electrophoresis of material from the major retarded peak of the elution profile revealed that bovine protein AA moves as one band with an apparent molecular mass of about 14,000 Daltons. 4. 4. Several distinct bands between approximately pH 4.0 and 5.0 were observed when this material was evaluated by analytic isoelectric focusing, thus having a pattern resembling that of human and dog protein AA. 5. 5. A blocked N-terminus was demonstrated when protein from the major retarded peak was subjected to amino acid sequencing, but cyanogen bromide cleavage followed by gel filtration produced 3 peptide fragments for amino acid sequence analysis. 6. 6. These peptides had a high degree of homology with positions 4–14, 18–24 and 25–49 of human protein AA. 7. 7. An apparent complete homology between bovine protein AA and protein AA from other species was apparent at positions 35–45, providing further evidence that this is a functionally significant part of the serum protein AA (SAA) molecule.

Heterogenous participation of the hepatocyte population in amyloid protein AA synthesis

Amyloid protein AA is believed to be synthesized in the liver in a form of its precursor, the acute phase reactant, SAA. To identify precisely the cell involved in SAA biosynthesis, immunohistochemical reaction to anti-mouse AA was analysed on the liver sections from CBA/J mice which had received a single casein injection and were sacrificed at predetermined times up to 48 hours. Two different primary localizations of the reaction were revealed. One was in the cytoplasm of certain hepatocytes. This reaction peaked at 6–8 hours after the casein injection in the intensity of the reaction and in the number of the cells involved. The hepatocytes with positive cytoplasmic reaction were scattered over the lobule and even at the peak did not exceed 20% of the total hepatocyte population. The other localization of the reaction covered linearly the surface of the hepatocyte cords, and peaked at 12–16 hours after the casein injection.

Colchicine inhibition of serum amyloid protein SAA and SAP synthesis in primary mouse liver cell cultures.

Arthritis & RheumatismVolume 27, Issue 3 p. 349-352 Brief ReportFree to Read Colchicine inhibition of serum amyloid protein saa and sap synthesis in primary mouse liver cell cultures Emiko Tatsuta MD, Emiko Tatsuta MD Visiting Scientist Arthritis and Connective Tissue Disease Section, the Thorndike Memorial Laboratory and Division of Medicine, Boston City Hospital, and Boston University School of Medicine, Arthritis Section, Boston, Massachusetts.Search for more papers by this authorJean D. Sipe PhD, Corresponding Author Jean D. Sipe PhD Associate Research Professor of Medicine and Biochemistry Arthritis and Connective Tissue Disease Section, the Thorndike Memorial Laboratory and Division of Medicine, Boston City Hospital, and Boston University School of Medicine, Arthritis Section, Boston, Massachusetts.Jean D. Sipe, PhD, Arthritis, K5, 71 East Concord Street, Boston, MA 02118Search for more papers by this authorTsuranobu Shirahama MD, Tsuranobu Shirahama MD Research Professor of Medicine Arthritis and Connective Tissue Disease Section, the Thorndike Memorial Laboratory and Division of Medicine, Boston City Hospital, and Boston University School of Medicine, Arthritis Section, Boston, Massachusetts.Search for more papers by this authorMartha Skinner MD, Martha Skinner MD Associate Professor of Medicine Arthritis and Connective Tissue Disease Section, the Thorndike Memorial Laboratory and Division of Medicine, Boston City Hospital, and Boston University School of Medicine, Arthritis Section, Boston, Massachusetts.Search for more papers by this authorAlan S. Cohen MD, Alan S. Cohen MD Conrad Wesselhoeft Professor of Medicine.Search for more papers by this author Emiko Tatsuta MD, Emiko Tatsuta MD Visiting Scientist Arthritis and Connective Tissue Disease Section, the Thorndike Memorial Laboratory and Division of Medicine, Boston City Hospital, and Boston University School of Medicine, Arthritis Section, Boston, Massachusetts.Search for more papers by this authorJean D. Sipe PhD, Corresponding Author Jean D. Sipe PhD Associate Research Professor of Medicine and Biochemistry Arthritis and Connective Tissue Disease Section, the Thorndike Memorial Laboratory and Division of Medicine, Boston City Hospital, and Boston University School of Medicine, Arthritis Section, Boston, Massachusetts.Jean D. Sipe, PhD, Arthritis, K5, 71 East Concord Street, Boston, MA 02118Search for more papers by this authorTsuranobu Shirahama MD, Tsuranobu Shirahama MD Research Professor of Medicine Arthritis and Connective Tissue Disease Section, the Thorndike Memorial Laboratory and Division of Medicine, Boston City Hospital, and Boston University School of Medicine, Arthritis Section, Boston, Massachusetts.Search for more papers by this authorMartha Skinner MD, Martha Skinner MD Associate Professor of Medicine Arthritis and Connective Tissue Disease Section, the Thorndike Memorial Laboratory and Division of Medicine, Boston City Hospital, and Boston University School of Medicine, Arthritis Section, Boston, Massachusetts.Search for more papers by this authorAlan S. Cohen MD, Alan S. Cohen MD Conrad Wesselhoeft Professor of Medicine.Search for more papers by this author First published: March 1984 https://doi.org/10.1002/art.1780270317Citations: 22AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume27, Issue3March 1984Pages 349-352 RelatedInformation

Murine tissue amyloid protein AA. NH2-terminal sequence identity with only one of two serum amyloid protein (ApoSAA) gene products.

Amyloid protein AA is the presumptive fragment of an acute phase serum apolipoprotein, apoSAA. Two major murine apoSAA isotypes (apoSAA1 and apoSAA2) have been identified. The NH2-terminal amino acid sequences of purified murine apoSAA1 and apoSAA2 have been examined and compared with that of murine amyloid protein AA. Our results indicate that apoSAA1 and apoSAA2 are separate gene products and that amyloid protein AA has NH2-terminal amino acid sequence identity with only one of these isotypes, namely apoSAA2.

Another look at serum amyloid protein SAA.

Another look at serum amyloid protein SAA.

Heterogeneity of human amyloid protein AA and its related serum protein, SAA.

The heterogeneity of the human amyloid proteins SAA and AA was studied. Both proteins could be separated into several fractions by ion-exchange chromatography. Amino acid analysis of the ion-exchange-chromatographed fractions of protein AA showed that the main difference was in the length of the polypeptide. Thus, it seems that the original AA preparation consists of a mixture of AA proteins with length ranging from 66 to 78 amino acid residues. By enzymatic degradation of three different forms of SAA with kallikrein, fragments were formed with a molecular weight very similar to that of protein AA.