Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01889 (ankylosing spondylitis)
 5,717 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Abundantly expressed serum amyloid A (SAA) protein under chronic inflammatory conditions gives rise to insoluble aggregates of SAA derivatives in multiple organs resulting in reactive amyloid A (AA) amyloidosis, a consequence of rheumatoid arthritis, Crohn's disease, ankylosing spondylitis, familial Mediterranean fever, and Castleman's disease. An inflammation-responsive transcription factor, SAF (for SAA activating factor), has been implicated in the sustained expression of amyloidogenic SAA under chronic inflammatory conditions. However, its role in the pathogenesis of AA amyloidosis has thus far remained obscure. In this paper we have shown that SAF-1, a major member of the SAF family, is abundantly present in human AA amyloidosis patients. To assess whether SAF-1 is directly linked to the pathogenesis of AA amyloidosis, we have developed a SAF-1 transgenic mouse model. SAF-1-overexpressing mice spontaneously developed AA amyloidosis at the age of 14 mo or older. Immunohistochemical analysis confirmed the nature of the amyloid deposits as an AA type derived from amyloidogenic SAA1. Furthermore, SAF-1 transgenic mice rapidly developed severe AA amyloidosis in response to azocasein injection, indicating increased susceptibility to inflammation. Also, during inflammation SAF-1 transgenic mice exhibited a prolonged acute phase response, leading to an extended period of SAA synthesis. Together, these results provide direct evidence that SAF-1 plays a key role in the development of AA amyloidosis, a consequence of chronic inflammation.
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PMID:Inflammation-responsive transcription factor SAF-1 activity is linked to the development of amyloid A amyloidosis. 1688 22

Systemic AA amyloidosis is a long-term complication of several chronic inflammatory disorders, including rheumatoid arthritis, ankylosing spondylitis, autoinflammatory syndromes, Crohn's disease, malignancies and conditions predisposing to recurrent infections. Organ damage results from the extracellular deposition of proteolytic fragments of the acute-phase reactant serum amyloid A (SAA) as amyloid fibrils. A sustained high concentration of SAA is the prerequisite for developing AA amyloidosis. However, only a minority of patients with long-standing inflammation actually presents with this complication, pointing to the existence of disease-modifying factors, the best characterised of which being SAA1 genotype. The kidneys, liver and spleen are the main target organs of AA amyloid deposits. In more than 90% of patients proteinuria, nephrotic syndrome and/or renal dysfunction dominate the clinical picture at onset. If not effectively treated, this disease invariably leads to end stage kidney disease and renal replacement therapy, that are still associated with a poor outcome. Although the incidence of AA in rheumatoid arthritis and other chronic arthritides has continuously decreased over the past ten years, thanks to the increasing availability of more effective anti-inflammatory and immunosuppressive therapies, AA remains a life-threatening disease with several areas of uncertainty and unmet needs, deserving continuous efforts at prevention and effective treatment. The deeper understanding of the molecular mechanisms of amyloid formation and regression is now driving the development of novel treatments targeting different steps in the amyloidogenic cascade. These therapies will hopefully improve the quality of life and outcome of these patients in a near future.
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PMID:AA amyloidosis: basic knowledge, unmet needs and future treatments. 2265 7

A relationship between the presence of amyloidosis and SAA1 genotype has been shown in recent studies of (principally) familial Mediterranean fever patients. We found that the SAA1 rs12218 polymorphism was significantly more prevalent in ankylosing spondylitis patients with amyloidosis.
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PMID:The rate and significance of type 1/type 2 serum amyloid A protein gene polymorphisms in patients with ankylosing spondylitis and amyloidosis. 2630 Jan 8