| 1. |
- Maas, Coen, et al.
(författare)
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Misfolded proteins activate Factor XII in humans, leading to kallikrein formation without initiating coagulation
- 2008
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Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 118:9, s. 3208-3218
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Tidskriftsartikel (refereegranskat)abstract
- When blood is exposed to negatively charged surface materials such as glass, an enzymatic cascade known as the contact system becomes activated. This cascade is initiated by autoactivation of Factor XII and leads to both coagulation (via Factor XI) and an inflammatory response (via the kallikrein-kinin system). However, while Factor XII is important for coagulation in vitro, it is not important for physiological hemostasis, so the physiological role of the contact system remains elusive. Using patient blood samples and isolated proteins, we identified a novel class of Factor XII activators. Factor XII was activated by misfolded protein aggregates that formed by denaturation or by surface adsorption, which specifically led to the activation of the kallikreinkinin system without inducing coagulation. Consistent with this, we found that Factor XII, but not Factor XI, was activated and kallikrein was formed in blood from patients with systemic amyloidosis, a disease marked by the accumulation and deposition of misfolded plasma proteins. These results show that the kallikrein-kinin system can be activated by Factor XII, in a process separate from the coagulation cascade, and point to a protective role for Factor XII following activation by misfolded protein aggregates.
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| 2. |
- Adams, David, et al.
(författare)
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First European consensus for diagnosis, management, and treatment of transthyretin familial amyloid polyneuropathy
- 2016
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Ingår i: Current Opinion in Neurology. - : Lippincott Williams & Wilkins. - 1350-7540 .- 1473-6551. ; 29, s. S14-S26
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Tidskriftsartikel (refereegranskat)abstract
- Purpose of review Early and accurate diagnosis of transthyretin familial amyloid polyneuropathy (TTR-FAP) represents one of the major challenges faced by physicians when caring for patients with idiopathic progressive neuropathy. There is little consensus in diagnostic and management approaches across Europe. Recent findings The low prevalence of TTR-FAP across Europe and the high variation in both genotype and phenotypic expression of the disease means that recognizing symptoms can be difficult outside of a specialized diagnostic environment. The resulting delay in diagnosis and the possibility of misdiagnosis can misguide clinical decision-making and negatively impact subsequent treatment approaches and outcomes. Summary This review summarizes the findings from two meetings of the European Network for TTR-FAP (ATTReuNET). This is an emerging group comprising representatives from 10 European countries with expertise in the diagnosis and management of TTR-FAP, including nine National Reference Centres. The current review presents management strategies and a consensus on the gold standard for diagnosis of TTR-FAP as well as a structured approach to ongoing multidisciplinary care for the patient. Greater communication, not just between members of an individual patient's treatment team, but also between regional and national centres of expertise, is the key to the effective management of TTR-FAP.
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| 3. |
- Banerjee, Sambhasan, et al.
(författare)
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Amyloid fibril structure from the vascular variant of systemic AA amyloidosis
- 2022
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Systemic AA amyloidosis is a debilitating protein misfolding disease in humans and animals. In humans, it occurs in two variants that are called 'vascular' and 'glomerular', depending on the main amyloid deposition site in the kidneys. Using cryo electron microscopy, we here show the amyloid fibril structure underlying the vascular disease variant. Fibrils purified from the tissue of such patients are mainly left-hand twisted and contain two non-equal stacks of fibril proteins. They contrast in these properties to the fibrils from the glomerular disease variant which are right-hand twisted and consist of two structurally equal stacks of fibril proteins. Our data demonstrate that the different disease variants in systemic AA amyloidosis are associated with different fibril morphologies.
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| 4. |
- Benson, Merrill D., et al.
(författare)
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Tissue biopsy for the diagnosis of amyloidosis : experience from some centres
- 2022
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Ingår i: Amyloid. - : Informa UK Limited. - 1350-6129 .- 1744-2818. ; 29:1, s. 8-13
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Tidskriftsartikel (refereegranskat)abstract
- A reliable diagnosis of amyloidosis is usually based on a tissue biopsy. With increasing options for specific treatments of the different amyloid diseases, an exact and valid diagnosis including determination of the biochemical fibril nature is imperative. Biopsy sites as well as amyloid typing principles vary and this paper describes methods employed at some laboratories specialised in amyloidosis in Europe, Japan and USA.
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| 5. |
- Liberta, Falk, et al.
(författare)
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Cryo-EM fibril structures from systemic AA amyloidosis reveal the species complementarity of pathological amyloids
- 2019
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Ingår i: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Systemic AA amyloidosis is a worldwide occurring protein misfolding disease of humans and animals. It arises from the formation of amyloid fibrils from the acute phase protein serum amyloid A. Here, we report the purification and electron cryo-microscopy analysis of amyloid fibrils from a mouse and a human patient with systemic AA amyloidosis. The obtained resolutions are 3.0 angstrom and 2.7 angstrom for the murine and human fibril, respectively. The two fibrils differ in fundamental properties, such as presence of right-hand or left-hand twisted cross-beta sheets and overall fold of the fibril proteins. Yet, both proteins adopt highly similar beta-arch conformations within the N-terminal similar to 21 residues. Our data demonstrate the importance of the fibril protein N-terminus for the stability of the analyzed amyloid fibril morphologies and suggest strategies of combating this disease by interfering with specific fibril polymorphs.
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| 6. |
- Sjölander, Daniel, et al.
(författare)
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Sensitive and rapid assessment of amyloid by oligothiophene fluorescence in subcutaneous fat tissue
- 2015
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Ingår i: Amyloid. - : Informa Healthcare. - 1350-6129 .- 1744-2818. ; 22:1, s. 19-25
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Tidskriftsartikel (refereegranskat)abstract
- Systemic amyloidosis (SA) is often diagnosed late. Combining clinical and biochemical biomarkers is necessary for raising suspicion of disease. Fine needle aspiration (FNA) of subcutaneous fat enables SA detection by Congo red staining. The luminescent conjugated probe heptameric formic thiophene acetic acid (h-FTAA) is a sensitive alternative to Congo red-staining of tissue samples. Our objective was to compare h-FTAA fluorescence with the Congo red stain for amyloid detection in FNA-obtained fat tissue. Herein, we studied samples from 57 patients with established SA (19 with AA, 20 with AL, and 18 with ATTR) and 17 age-matched controls (34–75 years). Positivity for h-FTAA was graded according to a Congo red-based grading scale ranging from 0 to 4+. Amyloid grading by both methods correlated strongly (r = 0.87). Here h-FTAA was positive in 53 of 54 Congo red-positive cases (sensitivity 98%) and h-FTAA was negative in 7 of 17 Congo red-negative controls (specificity 41%), but was also positive for 3 Congo red-negative SA cases. We conclude that h-FTAA fluorescence is more sensitive than Congo red staining in this small exploratory study of fat tissue samples, implicating potential sensitivity for prodromal amyloidosis, but is less specific for clinical amyloidosis defined by Congo red positivity. Given its simplicity h-FTAA staining may therefore be the most appropriate method for rapid screening of fat tissue samples but should presently treat grade 1+ as only suggestive, whereas 2+ or higher as positive for amyloidosis. Parallel assessment of h-FTAA and Congo red staining appears highly promising for clinical applications.
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