scholarly journals AA-amyloidosis in autoinflammatory diseases

2021 ◽  
Vol 31 (4) ◽  
pp. 52-61
Author(s):  
V. Rameev ◽  
S. Moiseev ◽  
L. Lysenko (Kozlovskaya)

AA amyloidosis complicates various chronic inflammatory disorders and is characterized by the accumulation of amyloid fibrils composed of serum amyloid A protein, an acute phase reactant. In recent decades, the role of chronic infections and rheumatoid arthritis in the ethiology of AA amyloidosis have decreased significantly as a result of their treatment improvement, whereas both monogenic (familial Meditarranean fever, cryopirin-associated periodic syndrome, etc.) or polygenic (ankylosing spondilitis, psoriatic arthritis, adult onset Still’s disease, etc) autoinflammatory diseases more frequently account for AA-amyloidosis today. Autoinflammatory diseases are a consequence of innate immunity disorders although the latter can contribute to the pathogenesis of autoimmune diseases as well. In patients with autoinflammatory diseases, the suppression of inflammation, even subclinical, is essential to prevent development or progression of AA amyloidosis. The choice of inflammatory agents that can be used to achieve this aim depends on the pathogenesis of autoinflammation, e.g. key mediators that are involved in the activation of inflammatory cascade.

2021 ◽  
Vol 22 (3) ◽  
pp. 1036
Author(s):  
Xuguang Lin ◽  
Kenichi Watanabe ◽  
Masahiro Kuragano ◽  
Kiyotaka Tokuraku

Amyloid A (AA) amyloidosis is a condition in which amyloid fibrils characterized by a linear morphology and a cross-β structure accumulate and are deposited extracellularly in organs, resulting in chronic inflammatory diseases and infections. The incidence of AA amyloidosis is high in humans and several animal species. Serum amyloid A (SAA) is one of the most important precursor amyloid proteins and plays a vital step in AA amyloidosis. Amyloid enhancing factor (AEF) serves as a seed for fibril formation and shortens the onset of AA amyloidosis sharply. In this study, we examined whether AEFs extracted and purified from five animal species (camel, cat, cattle, goat, and mouse) could promote mouse SAA (mSAA) protein aggregation in vitro using quantum-dot (QD) nanoprobes to visualize the aggregation. The results showed that AEFs shortened and promoted mSAA aggregation. In addition, mouse and cat AEFs showed higher mSAA aggregation-promoting activity than the camel, cattle, and goat AEFs. Interestingly, homology analysis of SAA in these five animal species revealed a more similar amino acid sequence homology between mouse and cat than between other animal species. Furthermore, a detailed comparison of amino acid sequences suggested that it was important to mSAA aggregation-promoting activity that the 48th amino acid was a basic residue (Lys) and the 125th amino acid was an acidic residue (Asp or Glu). These data imply that AA amyloidosis exhibits higher transmission activity among animals carrying genetically homologous SAA gene, and may provide a new understanding of the pathogenesis of amyloidosis.


2021 ◽  
Vol 49 (2) ◽  
pp. 977-985
Author(s):  
Marcus Fändrich ◽  
Matthias Schmidt

Systemic amyloidosis is defined as a protein misfolding disease in which the amyloid is not necessarily deposited within the same organ that produces the fibril precursor protein. There are different types of systemic amyloidosis, depending on the protein constructing the fibrils. This review will focus on recent advances made in the understanding of the structural basis of three major forms of systemic amyloidosis: systemic AA, AL and ATTR amyloidosis. The three diseases arise from the misfolding of serum amyloid A protein, immunoglobulin light chains or transthyretin. The presented advances in understanding were enabled by recent progress in the methodology available to study amyloid structures and protein misfolding, in particular concerning cryo-electron microscopy (cryo-EM) and nuclear magnetic resonance (NMR) spectroscopy. An important observation made with these techniques is that the structures of previously described in vitro formed amyloid fibrils did not correlate with the structures of amyloid fibrils extracted from diseased tissue, and that in vitro fibrils were typically more protease sensitive. It is thus possible that ex vivo fibrils were selected in vivo by their proteolytic stability.


2021 ◽  
Vol 8 ◽  
Author(s):  
Per Eriksson ◽  
Johan Mölne ◽  
Lina Wirestam ◽  
Christopher Sjöwall

Historically, secondary amyloidosis has been a feared complication of chronic inflammatory conditions. The fibril protein AA derives from the acute phase reactant serum amyloid A (SAA). Long-term elevation of SAA levels remains a major risk factor for the development of AA amyloidosis in rheumatic diseases, and the prognosis may be unpredictable. Nowadays, with increased availability of effective biological agents, the incidence of AA amyloidosis seems to be declining. Still, genetically predisposed subjects with slowly progressive disease and mild symptoms combined with ongoing systemic inflammation may be at risk. Interleukin-6 (IL-6) is one of the drivers of SAA release and effectiveness of the humanized anti-IL-6 receptor antibody tocilizumab (TCZ) for the treatment of AA amyloidosis has been observed in some rheumatic conditions. Herein, we report two male subjects with longstanding ankylosing spondylitis (AS) complicated by renal amyloidosis who received TCZ with rapid and beneficial effects regarding inflammation and proteinuria. To the best of our knowledge, the use of TCZ in AS patients with this extra-articular manifestation has not previously been described. The paper includes histopathology, clinical follow-up, and longitudinal data of the two cases along with a comprehensive review of relevant literature. Mechanisms behind amyloid-mediated tissue damage and organ dysfunction are discussed. Altogether, our data highlight that blocking IL-6 signaling may represent a promising therapeutic option in patients with renal AA amyloidosis.


Author(s):  
Syed Wali Peeran ◽  
Ahmed Elhassan ◽  
Mohammed Zameer ◽  
Syed Nahid Basheer ◽  
Mohammed Mustafa ◽  
...  

Serum Amyloid A (SAA) is an Acute-Phase Protein (APP) produced as an innate nonspecific response to any tissue damage. Hence, it plays a significant role in chronic inflammatory diseases. In particular, SAA levels increase dramatically in chronic periodontitis and chronic apical periodontitis. Recent studies suggest this role of SAA in the pathogenesis of various diseases, including chronic periodontitis and chronic apical periodontitis. Thus, the focus of this review is to sum up the current understanding of the role of SAA in health and disease and to elaborate on possible mechanisms by which SAA could play a role in the pathogenesis of chronic periodontitis and chronic apical periodontitis.


2009 ◽  
Vol 36 (11) ◽  
pp. 2409-2415 ◽  
Author(s):  
TAKESHI KURODA ◽  
YOKO WADA ◽  
DAISUKE KOBAYASHI ◽  
SHUICHI MURAKAMI ◽  
TAKEHITO SAKAI ◽  
...  

Objective.To examine the effect of anti-tumor necrosis factor-α (anti-TNF) therapy in patients with reactive AA amyloidosis associated with rheumatoid arthritis (RA).Methods.Fourteen patients with reactive AA amyloidosis associated with RA were prospectively evaluated. Four patients were treated with infliximab and 10 with etanercept. The mean period of anti-TNF therapy was 20.1 ± 13.8 months. Laboratory findings and renal function were examined before and after initiation of anti-TNF therapy. In 9 patients the area of amyloid deposits in serial gastroduodenal mucosal biopsy specimens was examined and image analysis was performed.Results.C-reactive protein and serum amyloid A protein levels were significantly reduced after initiation of anti-TNF therapy. Twenty-four hour creatinine clearance improved in 4 patients, did not change in 5, and deteriorated in 3. Twenty-four hour urinary protein excretion was significantly decreased in 3 patients, not exacerbated in 6, and increased in 3 after initiation of anti-TNF therapy. The biopsy specimens from the 9 patients who underwent serial gastroduodenal biopsies showed significant decreases in the area of amyloid deposits, from 8.8% ± 6.4% to 1.6% ± 0.6% (p = 0.003) after initiation of anti-TNF therapy. Four patients showed a sustained decrease in the areas of amyloid deposits in their third biopsy specimens, and amyloid deposits were not detectable in 2.Conclusion.Our results indicate a striking effect of anti-TNF therapy for rapid removal and sustained disappearance of amyloid deposits in gastric mucosal tissue with amelioration of renal functions in patients with reactive amyloidosis due to RA.


1988 ◽  
Vol 255 (1) ◽  
pp. 29-34 ◽  
Author(s):  
A E Nel ◽  
M C De Beer ◽  
E G Shephard ◽  
A F Strachan ◽  
M L Vandenplas ◽  
...  

Monokine-induced hepatic secretion of serum amyloid A protein (apo-SAA), an acute-phase reactant, is followed by rapid association with high-density lipoprotein (HDL) in plasma. Plasma clearance of apo-SAA is more rapid than any of the other HDL apolipoproteins. It has been shown that, of the acute-phase HDL3 apolipoproteins, apo-SAA preferentially associates with neutrophil membranes. HDL apolipoproteins have been shown to activate protein kinase C in endothelial cells. We therefore investigated potential phosphorylation of HDL3 apolipoproteins by protein kinase C. Apo-SAA was the only apolipoprotein phosphorylated (Km = 12 mM). Phosphorylation of the apo-SAA-containing HDL3 particle was selective for the more basic isoforms of apo-SAA (pI 7.0, 7.4, 7.5 and 8.0), with more acidic isoforms being phosphorylated when delipidated acute-phase apolipoproteins were used as substrate. However, phosphorylation was not in itself responsible for the establishment of the apo-SAA isoforms.


2017 ◽  
Vol 54 (6) ◽  
pp. 912-921 ◽  
Author(s):  
Yumi Nakayama ◽  
Junichi Kamiie ◽  
Gen Watanabe ◽  
Kazuhiko Suzuki ◽  
Tomoaki Murakami

The authors describe a spontaneous case of amyloid A (AA) amyloidosis in an adult female Japanese quail ( Coturnix japonica). The bird developed AA amyloidosis secondary to chronic peritonitis caused by a Gram-negative bacillus infection. Mild amyloid deposition was also identified in the intestinal tract of apparently healthy adult individuals, suggesting that quail may develop intestinal amyloidosis with age. Based on these observations, it was hypothesized that quail can develop AA amyloidosis following inflammatory stimulation with lipopolysaccharide (LPS). Therefore, adult quail were repeatedly injected with LPS and the development of AA amyloidosis was confirmed. The amyloid deposition in this model increased when quail amyloid was intravenously injected as an amyloid-enhancing factor. The experiments were repeated with young quail, but amyloid deposits were not observed following LPS injections. However, AA amyloidosis did develop when quail amyloid was injected in addition to LPS. These results indicated that adult quail develop AA amyloidosis after inflammatory stimulation with LPS. Furthermore, quail AA amyloidosis was shown to have transmissibility regardless of age. Interestingly, the authors found that administration of chicken amyloid fibrils also induced AA amyloidosis in young quail. This is the first report of cross-species transmission of avian AA amyloidosis.


2005 ◽  
Vol 53 (2) ◽  
pp. 237-242 ◽  
Author(s):  
Naohiro Sakata ◽  
Yoshinobu Hoshii ◽  
Tomomi Nakamura ◽  
Makiko Kiyama ◽  
Hirofumi Arai ◽  
...  

Apolipoprotein AI (apoAI), a major component of high-density lipoproteins, is one of the major amyloid fibril proteins and a minor constituent of the senile plaques observed in Alzheimer's disease. We examined colocalization of apoAI in various kinds of systemic amyloidosis in this study. Forty-three of 48 formalin-fixed paraffin-embedded heart specimens with various forms of systemic amyloidosis reacted immunohistochemically with anti-human apoAI antibody. ApoAI was also detected in water-extracted amyloid material by immunoblotting. In addition, we observed colocalization of apoAI and murine amyloid A (AA) amyloidosis in human apoAI transgenic mice. This is the first report of colocalization of apoAI with amyloid deposits in various forms of human systemic amyloidosis and murine AA amyloidosis in human apoAI transgenic mice. ApoAI may not always be a major component of amyloid fibrils, even when it is present in systemic amyloid deposits.


2008 ◽  
Vol 363 (1510) ◽  
pp. 3701-3705 ◽  
Author(s):  
Per Westermark ◽  
Gunilla T Westermark

The amyloidoses comprise a heterogeneous group of diseases in which 1 out of more than 25 human proteins aggregates into characteristic beta-sheet fibrils with some unique properties. Aggregation is nucleation dependent. Among the known amyloid-forming constituents is the prion protein, well known for its ability to transmit misfolding and disease from one individual to another. There is increasing evidence that other amyloid forms also may be transmissible but only if certain prerequisites are fulfilled. One of these forms is systemic AA-amyloidosis in which an acute-phase reactant, serum AA, is over-expressed and, possibly after cleavage, aggregates into amyloid fibrils, causing disease. In a mouse model, this disorder can easily be transmitted from one animal to another both by intravenous and oral routes. Also, synthetic amyloid-like fibrils made from defined small peptides have this property, indicating a prion-like transmission mechanism. Even some fibrils occurring in the environment can transmit AA-amyloidosis in the murine model. AA-amyloidosis is particularly common in certain areas of Papua New Guinea, probably due to the endemicity of malaria and perhaps genetic predisposition. Now, when kuru is disappearing, more interest should be focused on the potentially lethal systemic AA-amyloidosis.


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