9px7

ATTR cardiac amyloid fibrils apex2

spinqualitylabelsall models 9px7, resolution 3.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 9px7 is a 6 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 3.4Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Disease TTHY_HUMAN Defects in TTR are the cause of amyloidosis transthyretin-related (AMYL-TTR) [MIM:105210. A hereditary generalized amyloidosis due to transthyretin amyloid deposition. Protein fibrils can form in different tissues leading to amyloid polyneuropathies, amyloidotic cardiomyopathy, carpal tunnel syndrome, systemic senile amyloidosis. The disease includes leptomeningeal amyloidosis that is characterized by primary involvement of the central nervous system. Neuropathologic examination shows amyloid in the walls of leptomeningeal vessels, in pia arachnoid, and subpial deposits. Some patients also develop vitreous amyloid deposition that leads to visual impairment (oculoleptomeningeal amyloidosis). Clinical features include seizures, stroke-like episodes, dementia, psychomotor deterioration, variable amyloid deposition in the vitreous humor. Defects in TTR are a cause of hyperthyroxinemia dystransthyretinemic euthyroidal (HTDE) [MIM:145680. It is a condition characterized by elevation of total and free thyroxine in healthy, euthyroid persons without detectable binding protein abnormalities. Defects in TTR are a cause of carpal tunnel syndrome type 1 (CTS1) [MIM:115430. It is a condition characterized by entrapment of the median nerve within the carpal tunnel. Symptoms include burning pain and paresthesias involving the ventral surface of the hand and fingers which may radiate proximally. Impairment of sensation in the distribution of the median nerve and thenar muscle atrophy may occur. This condition may be associated with repetitive occupational trauma, wrist injuries, amyloid neuropathies, rheumatoid arthritis. Function TTHY_HUMAN Thyroid hormone-binding protein. Probably transports thyroxine from the bloodstream to the brain. Publication Abstract from PubMed BACKGROUND: Transthyretin amyloidosis (ATTR) is a degenerative disease affecting the heart and other organs. Transthyretin (TTR) aggregation is a driver of ATTR pathology, but the mechanism is poorly understood. We used proteomics and tissue clearing technology on wild-type (WT) human cardiac (WT/WT) and V122I human cardiac (V122I/WT) tissue to better understand TTR cardiomyopathy. METHODS: Flash-frozen cardiac tissue slices from human subjects with end-stage WT-TTR cardiomyopathy, end-stage V122I TTR cardiomyopathy, and an age-matched control were used. Fibrils and tissue proteomes were extracted and assessed by bottom-up proteomics. Tissue clearing was performed using a lauryl sulfate-based lipid removal strategy. Slices were stained using indirect immunofluorescence against targets identified by proteomics. TTR deposits were imaged by antibody and AmyTracker 480 staining. Structures of ATTR fibrils were characterized using cryogenic electron microscopy. RESULTS: Proteomic analysis revealed high abundance of TTR, proteins associated with amyloid fibrils, as well as angiogenic, hemostatic, and complement cascade-associated proteins. Three-dimensional imaging revealed loss of normal microvascular architecture, regions of hypervascularization and hypovascularization, and microvascular obstruction by capillary thrombosis. ATTR fibrils adopted the spearhead fold and were decorated with collagen VI, an extracellular matrix component. CONCLUSIONS: Based on our imaging and proteomic data, we hypothesize that ATTR cardiomyopathy is a microangiopathy driven by capillary bed thromboinflammation and dysregulated angiogenic revascularization. In this model, increased capillary permeability exposes components of the vascular basement membrane to misfolded TTR. These components promote aggregation and stabilize amyloid fibrils. Congestion of the vascular basement membrane prevents appropriate revascularization, reducing cardiac exertional capacity over time, leading to heart failure. Three-Dimensional Visualization and Proteomic Analysis of Human Cardiac Transthyretin Amyloidosis Tissue Reveals Microangiopathy and Capillary Occlusion.,Donnelly JP, Schafer JH, Yoon L, Massey LA, Ash C, Gao Z, Nugroho K, Jager M, Pang Z, O'Neill RT, Maurer MS, Powers ET, Lander GC, Ye L, Kelly JW J Am Heart Assoc. 2026 May 6:e042248. doi: 10.1161/JAHA.125.042248. PMID:42089154 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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