1
|
Ocular Involvement in Hereditary Amyloidosis. Genes (Basel) 2021; 12:955. [PMID: 34206500 PMCID: PMC8304974 DOI: 10.3390/genes12070955] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 06/06/2021] [Accepted: 06/18/2021] [Indexed: 12/27/2022] Open
Abstract
The term amyloidosis describes a group of rare diseases caused by protein conformation abnormalities resulting in extracellular deposition and accumulation of insoluble fibrillar aggregates. So far, 36 amyloid precursor proteins have been identified, and each one is responsible for a specific disease entity. Transthyretin amyloidosis (ATTRv) is one of the most common forms of systemic and ocular amyloidosis, due to the deposition of transthyretin (TTR), which is a transport protein mainly synthesized in the liver but also in the retinal pigment epithelial cells. ATTRv amyloidosis may be misdiagnosed with several other conditions, resulting in a significant diagnostic delay. Gelsolin and keratoepithelin are other proteins that, when mutated, are responsible for a systemic amyloid disease with significant ocular manifestations that not infrequently appear before systemic involvement. The main signs of ocular amyloid deposition are in the cornea, irido-corneal angle and vitreous, causing complications related to vasculopathy and neuropathy at the local level. This review aims at describing the main biochemical, histopathological and clinical features of systemic amyloidosis associated with eye involvement, with particular emphasis on the inherited forms. We discuss currently available treatments, focusing on ocular involvement and specific ophthalmologic management and highlighting the importance of a prompt treatment for the potential sight-threatening complications derived from amyloid deposition in ocular tissues.
Collapse
|
2
|
Regression of cardiac amyloid load documented by cardiovascular magnetic resonance in a patient with hereditary amyloidosis. Clin Res Cardiol 2020; 109:949-956. [PMID: 32048001 PMCID: PMC7308258 DOI: 10.1007/s00392-020-01611-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/29/2020] [Indexed: 01/17/2023]
|
3
|
Lattice Corneal Dystrophy Type II: Clinical, Pathologic, and Molecular Study in a Spanish Family. Eur J Ophthalmol 2018; 17:424-9. [PMID: 17534828 DOI: 10.1177/112067210701700326] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To report a family with lattice corneal dystrophy type II (LCD II) associated with systemic amyloidosis type V. METHODS A 69-year-old woman presented a LCD II and marked dermachalasis. A lower blepharoplasty was performed. Two years later a penetrating keratoplasty was performed in her left eye. Three children of the patient were studied. Subtle manifestations of LCD were identified in two of them. Pathologic study of the excised skin and corneal button was made. DNA from peripheral blood was obtained, and was subjected to amplification of exon 5 of the gelsolin. RESULTS Pathologic examination of the skin of blepharoplasty specimen demonstrated the presence of amyloid. Microscopic examination of the corneal button showed the presence of amyloid deposits beneath the normal-appearing Bowman layer and also within the stroma. Immunostaining for S-100 protein did not demonstrate a significant relationship between amyloid deposits and corneal nerves. Electron microscopic evaluation demonstrated the presence of amyloid fibrils. No clear relationship was found between amyloid deposits and corneal nerves. These findings confirm LCD type II or Meretoja syndrome. A mutation analysis of the gelsolin gene demonstrated the presence of G to A transition at nucleotide 654. Two children with manifestations of LCD also showed the identical mutation in gelsolin gene. CONCLUSIONS A new family with Meretoja syndrome is reported. This is the first documented family with Meretoja syndrome in Spain and in the Mediterranean countries. The molecular study shows the same mutation of reported families from Finland, Japan, the United States, and the United Kingdom.
Collapse
|
4
|
Abstract
RATIONALE Apolipoprotein A-1 (ApoA-1)-related amyloidosis is characterized by the deposition of ApoA-1 in various organs and can be either hereditary or nonhereditary. It is rare and easily misdiagnosed. Renal involvement is common in hereditary ApoA-1 amyloidosis, but rare in the nonhereditary form. PATIENT CONCERNS We reported two cases with ApoA-1 amyloidosis, a 64-year-old man suffering from nephrotic syndrome and a 40-year-old man with nephrotic syndrome and splenomegaly. Renal biopsies revealed glomerular, interstitial and vascular amyloid deposits and positive phospholipase A2 receptor staining in the glomerular capillary loop in case 1, and mesangial amyloid deposits in case 2. DIAGNOSES After immunostaining failed to determine the specific amyloid protein, proteomic analysis of amyloid deposits by mass spectrometry was performed and demonstrated the ApoA-1 origin of the amyloid. Genetic testing revealed no mutation of the APOA1 gene in case 1 but a heterozygous mutation, Trp74Arg, in case 2. Case 1 was thus diagnosed as nonhereditary ApoA-1 associated renal amyloidosis with membranous nephropathy, and case 2 as hereditary ApoA-1 amyloidosis with multiorgan injuries (kidney and spleen) and a positive family history. INTERVENTIONS Case 1 was treated with glucocorticoid combined with cyclosporine. Case 2 was treated with calcitriol and angiotensin converting enzyme inhibitors. OUTCOMES Two cases were followed up for 5 months and 2 years, respectively; and case 1 was found to have attenuated proteinuria while case 2 had an elevation of cholestasis indices along with renal insufficiency. LESSONS Proteomic analysis by mass spectrometry of the amyloid deposits combined with genetic analysis can provide accurate diagnosis of ApoA-1 amyloidosis. Besides, these 2 cases expand our knowledge of ApoA-1-related renal amyloidosis.
Collapse
|
5
|
Chameleon 'aggregation-prone' segments of apoA-I: A model of amyloid fibrils formed in apoA-I amyloidosis. Int J Biol Macromol 2015; 79:711-8. [PMID: 26049118 DOI: 10.1016/j.ijbiomac.2015.05.032] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 05/20/2015] [Accepted: 05/22/2015] [Indexed: 11/18/2022]
Abstract
Apolipoprotein A-I (apoA-I) is the major component of high density lipoproteins and plays a vital role in reverse cholesterol transport. Lipid-free apoA-I is the main constituent of amyloid deposits found in atherosclerotic plaques, an acquired type of amyloidosis, whereas its N-terminal fragments have been associated with a hereditary form, known as familial apoA-I amyloidosis. Here, we identified and verified four "aggregation-prone" segments of apoA-I with amyloidogenic properties, utilizing electron microscopy, X-ray fiber diffraction, ATR FT-IR spectroscopy and polarized light microscopy. These segments may act as conformational switches, possibly controlling the transition of the α-helical apoA-I content into the "cross-β" architecture of amyloid fibrils. A structural model illuminating the structure of amyloid fibrils formed by the N-terminal fragments of apoA-I is proposed, indicating that two of the identified chameleon segments may play a vital part in the formation of amyloid fibrils in familial apoA-I amyloidosis.
Collapse
|
6
|
Establishment of a human conjunctival epithelial cell line lacking the functional TACSTD2 gene (an American Ophthalmological Society thesis). TRANSACTIONS OF THE AMERICAN OPHTHALMOLOGICAL SOCIETY 2012; 110:166-177. [PMID: 23818740 PMCID: PMC3671362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
PURPOSE To report the establishment of a human conjunctival epithelial cell line lacking the functional tumor-associated calcium signal transducer 2 (TACSTD2) gene to be used as an in vitro model of gelatinous drop-like corneal dystrophy (GDLD), a rare disease in which the corneal epithelial barrier function is significantly compromized by the loss of function mutation of the TACSTD2 gene. METHODS A small piece of conjunctival tissue was obtained from a GDLD patient. The conjunctival epithelial cells were enzymatically separated and dissociated from the tissue and immortalized by the lentiviral introduction of the SV40 large T antigen and human telomerase reverse transcriptase (hTERT) genes. Population doubling, protein expression, and transepithelial resistance (TER) analyses were performed to assess the appropriateness of the established cell line as an in vitro model for GDLD. RESULTS The life span of the established cell line was found to be significantly elongated compared to nontransfected conjunctival epithelial cells. The SV40 large T antigen and hTERT genes were stably expressed in the established cell line. The protein expression level of the tight junction-related proteins was significantly low compared to the immortalized normal conjunctival epithelial cell line. TER of the established cell line was found to be significantly low compared to the immortalized normal conjunctival epithelial cell line. CONCLUSIONS Our conjunctival epithelial cell line was successfully immortalized and well mimicked several features of GDLD corneas. This cell line may be useful for the elucidation of the pathogenesis of GDLD and for the development of novel treatments for GDLD.
Collapse
MESH Headings
- Amyloidosis, Familial/genetics
- Amyloidosis, Familial/metabolism
- Amyloidosis, Familial/pathology
- Antigens, Neoplasm/genetics
- Antigens, Neoplasm/metabolism
- Blotting, Western
- Cell Adhesion Molecules/genetics
- Cell Adhesion Molecules/metabolism
- Cell Line/pathology
- Corneal Dystrophies, Hereditary/genetics
- Corneal Dystrophies, Hereditary/metabolism
- Corneal Dystrophies, Hereditary/pathology
- Electric Impedance
- Epithelium, Corneal/metabolism
- Epithelium, Corneal/pathology
- Gene Expression Regulation
- Humans
- Tight Junction Proteins/metabolism
Collapse
|
7
|
Analysis of the native structure, stability and aggregation of biotinylated human lysozyme. PLoS One 2012; 7:e50192. [PMID: 23166837 PMCID: PMC3500338 DOI: 10.1371/journal.pone.0050192] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 10/22/2012] [Indexed: 11/29/2022] Open
Abstract
Fibril formation by mutational variants of human lysozyme is associated with a fatal form of hereditary non-neuropathic systemic amyloidosis. Defining the mechanistic details of lysozyme aggregation is of crucial importance for understanding the origin and progression of this disease and related misfolding conditions. In this study, we show that a biotin moiety can be introduced site-specifically at Lys33 of human lysozyme. We demonstrate, using biophysical techniques, that the structure and stability of the native-state of the protein are not detectably altered by this modification, and that the ability to form amyloid fibrils is unchanged. By taking advantage of biotin-avidin interactions, we show that super-resolution fluorescence microscopy can generate detailed images of the mature fibrils. This methodology can readily enable the introduction of additional probes into the protein, thereby providing the means through which to understand, in detail, the nature of the aggregation process of lysozyme and its variants under a variety of conditions.
Collapse
|
8
|
Tissue transglutaminase colocalizes with extracellular matrix proteins in cerebral amyloid angiopathy. Neurobiol Aging 2012; 34:1159-69. [PMID: 23122413 DOI: 10.1016/j.neurobiolaging.2012.10.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 09/27/2012] [Accepted: 10/07/2012] [Indexed: 11/20/2022]
Abstract
Cerebral amyloid angiopathy (CAA) is a key histopathological hallmark of Alzheimer's disease (AD) and hereditary cerebral hemorrhage with amyloidosis of the Dutch type (HCHWA-D). CAA is characterized by amyloid-beta (Aβ) depositions and remodeling of the extracellular matrix (ECM) in brain vessels and plays an important role in the development and progression of both AD and HCHWA-D. Tissue transglutaminase (tTG) modulates the ECM by molecular cross-linking of ECM proteins. Here, we investigated the distribution pattern, cellular source, and activity of tTG in CAA in control, AD, and HCHWA-D cases. We observed increased tTG immunoreactivity and colocalization with Aβ in the vessel wall in early stage CAA, whereas in later CAA stages, tTG and its cross-links were present in halos enclosing the Aβ deposition. In CAA, tTG and its cross-links at the abluminal side of the vessel were demonstrated to be either of astrocytic origin in parenchymal vessels, of fibroblastic origin in leptomeningeal vessels, and of endothelial origin at the luminal side of the deposited Aβ. Furthermore, the ECM proteins fibronectin and laminin colocalized with the tTG-positive halos surrounding the deposited Aβ in CAA. However, we observed that in situ tTG activity was present throughout the vessel wall in late stage CAA. Together, our data suggest that tTG and its activity might play a differential role in the development and progression of CAA, possibly evolving from direct modulation of Aβ aggregation to cross-linking of ECM proteins resulting in ECM restructuring.
Collapse
|
9
|
Direct tissue evaluation via immunofluorescence: in the diagnosis of hereditary transthyretin cardiac amyloidosis. Tex Heart Inst J 2012; 39:71-75. [PMID: 22412233 PMCID: PMC3298917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Multiple precursor proteins have been shown to cause cardiac amyloidosis. The most common forms are due either to immunoglobulin light chains or to transthyretin proteins (either wild-type or mutant forms). Correct subclassification of the amyloid is paramount because treatment differs in accordance with the type of amyloidosis. Indirect diagnostic methods, including serologic analysis, can lead to misdiagnosis. Definitive diagnosis often requires analysis of amyloid in the tissue. We present a case of a woman who was diagnosed with hereditary transthyretin cardiac amyloidosis by means of immunofluorescence and genetic analysis. This case highlights the importance-in the diagnostic algorithm of cardiac amyloidosis-of direct evaluation of the tissue with immunofluorescence and of genetic testing.
Collapse
|
10
|
|
11
|
Abstract
A 68-year-old Italian woman who had a clinical history of thyroidectomy in 2002 presented with slowly progressing renal insufficiency and non-nephrotic proteinurea in 2004. A renal biopsy showed the occurrence of amyloid; the thyroid biopsy previously taken also revealed amyloid infiltration. Other amyloid-containing tissues included bone marrow and heart. The plasma cell level in the bone marrow was found to be less than 5% and both serum and urine samples were positive for a monoclonal kappa light chain band. DNA analysis unexpectedly revealed the presence of a novel transthyretin (TTR) mutation, ATTR Asn124Ser. Histologically, amyloid deposits in the thyroid had a homogeneous appearance with moderate Congophilia. In immunohistochemistry, a kappa light chain antiserum showed positive immunoreactivity with amyloid deposits in the thyroid. Furthermore, a TTR antiserum, anti-TTR50-127, also recognized a number of amyloid deposits stained positive with the kappa light chain antiserum. Overall, the kappa light chain antiserum reacted with most of the amyloid deposits in the thyroid, whereas TTR immunoreactivity was scarcer, with a scattered appearance. In contrast, only the anti-TTR50-127 antiserum labeled amyloid in the kidney, albeit not all deposits. In this study, we report a patient having a novel TTR variant, ATTR Asn124Ser, with co-localization of kappa light chains in the amyloid deposits in the thyroid tissue.
Collapse
|
12
|
Abstract
Familial amyloid polyneuropathy type I (FAP-I) is caused by a mutant transthyretin (TTR V30M) produced by liver, and orthotopic liver transplantation (OLT) is a widely accepted treatment for stopping the major production of TTR V30M. Anemia affects 24.8% of symptomatic FAP-I patients with low erythropoietin (Epo) levels, suggesting a blockage of Epo-producing cells by local or circulating factors. To evaluate the putative toxicity effect of the mutant protein on Epo-producing cells and consequent Epo production, clinical and laboratory parameters of 20 FAP patients were collected before and after liver transplantation, analyzed and compared. Following OLT, the prevalence of anemia increased, with a significant decrease in transferrin saturation, but without significant change in ferritin. Serum Epo levels remained low after OLT and the observed to expected (O/E) Epo level ratio decreased even further after OLT (O/E < 0.8 rose to 70%). Despite the decrease in creatinine clearance (95.1 to 66.9 ml/min, p < 0.001), a similar median O/E Epo level was observed, independently of the presence of renal failure, excluding an important impact of renal failure on Epo production. The increase of anemia after OLT and the maintenance of a defective endogenous Epo production after liver transplantation excluded an inhibitory effect of the circulating TTR V30M on the Epo-producing cells.
Collapse
|
13
|
Insights into the Conformational Changes of Several Human Lysozyme Variants Associated with Hereditary Systemic Amyloidosis. Biotechnol Prog 2007; 23:246-54. [PMID: 17269695 DOI: 10.1021/bp060264a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this study, various ethanol- and temperature-induced molecular dynamics simulations were conducted to investigate the conformational changes of several human lysozyme variants (I56T, D67H, and T70N) associated with hereditary systemic amyloidosis. The results show that these variants are all more sensitive to conditions affecting the structural integrity of this protein. The structural analyses of these variants reveal a high population of more unstable beta-domain and distorted hydrophobic core compared to the wild-type human lysozyme, particularly for the two natural amyloidogenic variants D67H and I56T. For the D67H variant, the distance between the mass centers of residues 54 and 67 was found to elongate as a result of the destruction of the hydrogen-bonding network stabilizing the two long loops in the beta-domain. It further accelerates the unfolding of this variant, starting from the hydrophobic core between the alpha- and beta-domains. For the I56T variant, the introduction of a hydrophilic residue in the hydrophobic core directly destroys the native contacts in the alpha-beta interface, leading to fast unfolding. The present results are consistent with the previous hypothesis suggesting that the distortion of the hydrophobic core at the alpha-beta interface putatively results in the formation of the initial "seed" for amyloid fibrils.
Collapse
|
14
|
|
15
|
Abstract
PURPOSE To determine whether primary, polymorphic, corneal amyloid deposition is associated with a mutation of the TGFBI gene. METHODS Interventional case series of 8 patients. Slit lamp examination of all patients and photodocumentation of 5 patients were performed. Genomic DNA was isolated from buccal mucosal swabs obtained from all patients and all 17 exons of the TGFBI gene were amplified and sequenced. RESULTS Multiple polymorphic, refractile deposits were noted throughout the central corneal stroma in all patients. The deposits appeared gray-white on direct illumination and translucent on retroillumination, characteristic of amyloid. In 2 patients, linear, branching opacities, reminiscent of lattice corneal dystrophy, were identified. Histopathologic examination confirmed the presence of stromal amyloid in the cornea of 1 patient who required corneal transplantation for pseudophakic corneal edema. Screening of the entire coding region of the TGFBI gene revealed 4 previously described synonymous substitutions, Leu217Leu, Val327Val, Leu472Leu, and Phe540Phe. A previously unreported missense change, Asp299Asn, was identified in one affected patient but not in her affected sister. No pathogenic mutations, including the Ala546Asp missense mutation previously associated with polymorphic corneal amyloidosis, were identified in any of the patients. CONCLUSIONS TGFBI gene mutations were not identified in a series of patients with polymorphic corneal amyloid deposition. As bilateral, discrete stromal amyloid deposits may be dystrophic or degenerative, differentiation between these phenotypically similar conditions is facilitated with the use of molecular genetic analysis.
Collapse
|
16
|
Diagnostic performance of 123I-labeled serum amyloid P component scintigraphy in patients with amyloidosis. Am J Med 2006; 119:355.e15-24. [PMID: 16564782 DOI: 10.1016/j.amjmed.2005.08.043] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Accepted: 08/25/2005] [Indexed: 01/02/2023]
Abstract
PURPOSE To assess the diagnostic accuracy and additional information provided by 123I-labeled serum amyloid P component (SAP) scintigraphy in patients with systemic and localized amyloidosis. SUBJECTS AND METHODS 123I-labeled human SAP was injected intravenously into 20 controls and 189 consecutive patients with histologically proven amyloidosis: of AA type in 60 cases, AL type in 80, hereditary ATTR type in 27, and localized amyloidosis in 22 cases. SAP scintigrams were obtained 24 hours after tracer injection and were analyzed for abnormal patterns of uptake. Sensitivity and specificity were determined, and scintigraphic findings were compared with clinical data. RESULTS Diagnostic sensitivity of SAP scintigraphy for systemic AA, AL, and ATTR amyloidosis was 90%, 90%, and 48% respectively, and specificity was 93%. The distribution of amyloid was less diverse in AA than in AL type. Myocardial uptake was not visualized in any patient. Splenic amyloid was very frequent (80%) in AA and AL type but rarely detected clinically (14%). Abnormal tracer uptake in the liver and kidneys correlated with disturbed liver function and proteinuria, respectively. Bone marrow uptake was specific for AL (21%) and was more frequent in AL kappa than AL lambda. Localized amyloid deposits were not imaged. CONCLUSION SAP scintigraphy is diagnostic of amyloid in most patients with AA and AL type but fewer with hereditary ATTR type, relating to differing distributions and burdens of amyloid in these disorders. It usually reveals more widespread organ involvement than is identified clinically, and certain distributions of amyloid are characteristic of particular fibril types.
Collapse
|
17
|
Abstract
Trafficking and proteolytic processing of amyloid precursor protein (APP) have been the focus of numerous investigations in the past two decades, since the identification of Abeta as the principal component of brain senile plaques and the cloning of APP cDNA. Tremendous progress has been made in the recent past toward the characterization of beta- and gamma-secretases. Here, we review the salient features of Alzheimer disease amyloidogenesis, and discuss the current knowledge on APP trafficking and amyloidogenic processing of APP in intracellular membrane compartments and microdomains.
Collapse
|
18
|
Abstract
Although aging is closely related with the onset of senile systemic amyloidosis (SSA) caused by wild-type transthyretin (TTR), the effect of aging on amyloid formation has remained unclear in familial amyloidotic polyneuropathy (FAP), caused by variant- and wild-type TTR. The aim of this study was to elucidate the effects of aging and/or other factors in FAP on amyloid formation in the lung, one of the most important target organs of amyloid deposition in SSA. Pulmonary amyloid distribution was determined using 19 autopsied lung samples from patients with FAP amyloidogenic TTR (ATTR) V30M, the most common type of FAP. Amyloid deposition was observed around the walls of the bronchi/ bronchioles, the pulmonary arteries, and the pulmonary veins, while no amyloid deposits could be found around the lymphatics. In addition, amyloid deposition in the alveolar regions was a characteristic finding in aged patients with FAP ATTR V30M (average ages of the patients with amyloid positive vs. negative: 50.55 +/- 8.75 vs. 39.75 +/- 4.17 years old, p < 0.005), similar to the finding in one SSA patient. These results suggest that aging could play an important role in the progression of pulmonary amyloid formation in FAP ATTR V30M.
Collapse
|
19
|
Hereditary Lattice Corneal Dystrophy Is Associated with Corneal Amyloid Deposits Enclosing C-Terminal Fragments of Keratoepithelin. ACTA ACUST UNITED AC 2005; 46:1133-9. [PMID: 15790870 DOI: 10.1167/iovs.04-1319] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
PURPOSE To investigate the molecular basis of hereditary lattice corneal dystrophy (LCD) type IIIA associated with corneal amyloid deposits afflicting several members of a four-generation family. METHODS Histologic, immunohistochemical and biochemical studies were performed on corneal tissue samples obtained after perforating keratoplasty. DNA was extracted from peripheral blood leukocytes. All exons of the keratoepithelin-encoding TGFBI gene were amplified and sequenced. The presence of a mutation was confirmed by digestion of the isolated PCR product with the restriction enzyme AlwNI. RESULTS The cornea of the index patient (II-1) contained large patchy deposits of amyloid, which were immunoreactive for the C terminus of keratoepithelin. Western blot analysis of the polypeptide chains extracted from the amyloid deposits of paraffin-embedded tissue revealed that these represented mainly fragments of the full-length protein. The smallest fragments were 6.5 and 6.9 kDa. DNA analyses of the TGFBI gene revealed a heterozygous T-->C transition at the second position of codon 540 in exon 12, indicating that replacement of phenylalanine by serine (Phe540Ser) leads to dominant disease. The mutation creates a new restriction site for the enzyme AlwNI. Five of the examined family members carried this mutation. Three of them (aged >/=41 years) had the disease, two family members (aged <20 years) do not yet show any clinical symptoms. An additional inconsequential single-nucleotide polymorphism (T1667C) was found at the third position of the same codon (Phe540Phe) in three unaffected family members. CONCLUSIONS This is the first report of a single-nucleotide mutation at codon 540 of TGFBI leading to LCD, and the first to demonstrate that the amyloid deposits in LCD contain proteolytic fragments of keratoepithelin.
Collapse
|
20
|
Abstract
Cytoskeletal rearrangement occurs in a variety of cellular processes and involves a wide spectrum of proteins. Among these, the gelsolin superfamily proteins control actin organization by severing filaments, capping filament ends and nucleating actin assembly [1]. Gelsolin is the founding member of this family, which now contains at least another six members: villin, adseverin, capG, advillin, supervillin and flightless I. In addition to their respective role in actin filament remodeling, these proteins have some specific and apparently non-overlapping particular roles in several cellular processes, including cell motility, control of apoptosis and regulation of phagocytosis (summarized in table 1). Evidence suggests that proteins belonging to the gelsolin superfamily may be involved in other processes, including gene expression regulation. This review will focus on some of the known functions of the gelsolin superfamily proteins, thus providing a basis for reflection on other possible and as yet incompletely understood roles for these proteins.
Collapse
|
21
|
Abstract
A middle age Portuguese woman was investigated for renal amyloidosis. She presented with progressive renal failure, proteinuria, hypertension, and sensory symptoms in the feet. Clinical and neurophysiological evaluation disclosed sensory-autonomic neuropathy. Cardiovascular tests and 123-MIBG investigation showed parasympathetic dysfunction and decrease of myocardial innervation, in accordance with small fiber neuropathy, as usually observed in amyloidosis. Immunohistochemical studies revealed AFib amyloidosis and genetic studies the amino acid exchange Glu526Val of the fibrinogen Aalpha-chain mutation, which was also present in one of her sons. The mutant gene in this patient was associated with the same haplotype as all other reported cases of Glu526Val mutations. This is the first reported AFibamyloidosis in Portugal, and the first case of AFib in which sensory and autonomic nerve fiber dysfunction is described, indicating that small nerve fiber lesion can occur in the fibrinogen Aalpha chain mutation. This can be important for prognosis, in particular when liver transplantation is considered for treatment.
Collapse
|
22
|
Two different types of amyloid deposits--apolipoprotein A-IV and transthyretin--in a patient with systemic amyloidosis. J Transl Med 2004; 84:981-8. [PMID: 15146166 DOI: 10.1038/labinvest.3700124] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Certain forms of systemic amyloidosis have been associated with the pathologic deposition as fibrils of three different apolipoprotein-related proteins--apolipoprotein A-I, apolipoprotein A-II, and serum amyloid A. We have previously reported (Bergström et al, Biochem Biophys Res Commun 2001;285:903-908) that amyloid fibrils extracted from the heart of an elderly male with senile systemic amyloidosis contained, in addition to wild-type transthyretin-related molecules, an N-terminal fragment of yet a fourth apolipoprotein--apolipoprotein A-IV (apoA-IV). We now provide the results of our studies that have established the complete amino-acid sequence of this approximately 70-residue component and, additionally, have shown this protein to be the product of an unmutated apoA-IV gene. Notably, the apoA-IV and transthyretin fibrils were not codeposited but, rather, had anatomically distinct patterns of distribution within the heart and other organs, as evidenced immunohistochemically, by variation in the ultra structural morphology and by differences in the intensity of Congo red birefringence. These findings provide the first conclusive evidence that two separate forms of amyloid, each derived from a wild-type amyloidogenic precursor protein, were present in a patient with systemic amyloidosis.
Collapse
|
23
|
Structure of the N-terminal half of gelsolin bound to actin: roles in severing, apoptosis and FAF. EMBO J 2004; 23:2713-22. [PMID: 15215896 PMCID: PMC514944 DOI: 10.1038/sj.emboj.7600280] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2004] [Accepted: 05/26/2004] [Indexed: 11/08/2022] Open
Abstract
The actin filament-severing functionality of gelsolin resides in its N-terminal three domains (G1-G3). We have determined the structure of this fragment in complex with an actin monomer. The structure reveals the dramatic domain rearrangements that activate G1-G3, which include the replacement of interdomain interactions observed in the inactive, calcium-free protein by new contacts to actin, and by a novel G2-G3 interface. Together, these conformational changes are critical for actin filament severing, and we suggest that their absence leads to the disease Finnish-type familial amyloidosis. Furthermore, we propose that association with actin drives the calcium-independent activation of isolated G1-G3 during apoptosis, and that a similar mechanism operates to activate native gelsolin at micromolar levels of calcium. This is the first structure of a filament-binding protein bound to actin and it sets stringent, high-resolution limitations on the arrangement of actin protomers within the filament.
Collapse
|
24
|
Abstract
Transthyretin (TTR) is a transport protein for thyroid hormones and vitamin A and might have an important role in the nervous system. However, TTR can undergo a conformational change and form amyloid fibrils, in both acquired and hereditary forms of systemic amyloidosis. More than 80 TTR mutations have been associated with autosomal dominant amyloidosis, usually presenting with peripheral and autonomic neuropathy and/or cardiomyopathy. Major areas of research in TTR amyloidosis include: molecular mechanisms leading to fibril formation; mechanisms of fibril-induced cell death; modulators of phenotypic expression of the disease; and therapeutic strategies.
Collapse
|
25
|
|
26
|
Abstract
Amyloidogenesis has historically been associated with pathology in a class of neurodegenerative diseases known as amyloid diseases. Recent studies have shown that proteolysis by furin during secretion initiates both variant gelsolin amyloidogenesis, associated with the disease familial amyloidosis of Finnish type, and Pmel17 fiber formation, which is necessary for the functional biogenesis of melanosomes. Proteolysis combined with organelle-dependent environment changes orchestrate amyloidogenesis associated with both pathological processes and a functional pathway.
Collapse
|
27
|
Identification of S-sulfonation and S-thiolation of a novel transthyretin Phe33Cys variant from a patient diagnosed with familial transthyretin amyloidosis. Protein Sci 2003; 12:1775-85. [PMID: 12876326 PMCID: PMC2323963 DOI: 10.1110/ps.0349703] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Familial transthyretin amyloidosis (ATTR) is an autosomal dominant disorder associated with a variant form of the plasma carrier protein transthyretin (TTR). Amyloid fibrils consisting of variant TTR, wild-type TTR, and TTR fragments deposit in tissues and organs. The diagnosis of ATTR relies on the identification of pathologic TTR variants in plasma of symptomatic individuals who have biopsy proven amyloid disease. Previously, we have developed a mass spectrometry-based approach, in combination with direct DNA sequence analysis, to fully identify TTR variants. Our methodology uses immunoprecipitation to isolate TTR from serum, and electrospray ionization and matrix-assisted laser desorption/ionization mass spectrometry (MS) peptide mapping to identify TTR variants and posttranslational modifications. Unambiguous identification of the amino acid substitution is performed using tandem MS (MS/MS) analysis and confirmed by direct DNA sequence analysis. The MS and MS/MS analyses also yield information about posttranslational modifications. Using this approach, we have recently identified a novel pathologic TTR variant. This variant has an amino acid substitution (Phe --> Cys) at position 33. In addition, like the Cys10 present in the wild type and in this variant, the Cys33 residue was both S-sulfonated and S-thiolated (conjugated to cysteine, cysteinylglycine, and glutathione). These adducts may play a role in the TTR fibrillogenesis.
Collapse
MESH Headings
- Amino Acid Sequence
- Amyloidosis, Familial/blood
- Amyloidosis, Familial/diagnosis
- Amyloidosis, Familial/genetics
- Amyloidosis, Familial/metabolism
- Cysteine/genetics
- Female
- Humans
- Middle Aged
- Molecular Sequence Data
- Mutation, Missense/genetics
- Oxidative Stress
- Peptide Mapping
- Phenylalanine/genetics
- Prealbumin/chemistry
- Prealbumin/genetics
- Prealbumin/metabolism
- Protein Conformation
- Sequence Analysis, DNA
- Spectrometry, Mass, Electrospray Ionization
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
Collapse
|
28
|
Fibrillogenesis in gelsolin-related familial amyloidosis. Amyloid 2003; 10 Suppl 1:21-5. [PMID: 14640038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
To clarify the mechanisms involved in amyloid formation in Finnish-type familial amyloidosis (FAF), we have tested the in vitro fibrillogenicity of synthetic wild-type and mutated gelsolin peptide analogs and studied the fragmentation patterns of gelsolin in the circulation of FAF patients with the Asn-187 or Tyr-187 gelsolin mutation. Fibril formation of synthetic peptides having sequence homology with wild-type or mutant gelsolins was monitored by Congo-red staining and polarization microscopy, negative staining electron microscopy and quantitative thioflavine-T fluorometry. Immunoblotting with anti-gelsolin and amyloid-specific antibodies and sequence analyses were used to study the fragmentation pattern of gelsolin. Ultrastructurally amyloid-like fibrils were formed from mutant Asn-187 and Tyr-187 gelsolin peptides. Fluorometric analysis revealed highly accelerated fibril formation from the mutant peptides as compared with the corresponding wild-type peptides. Addition of mercaptoethanol alone or in combination with dithiotreitol tended to enhance fibril formation of the 9-mer and 11-mer Asn peptides. Blocking of the C-terminal carboxyl of the mutant Asn-187 gelsolin182-192 peptide by amidation increased amyloidogenicity. The Tyr-187 gelsolin mutation, corresponding to the naturally occurring mutation in the Danish subtype of FAF, required acidic conditions to form fibrils meeting the criteria of amyloid. In FAF patients, in addition to the full-sized gelsolin, a series of lower-molecular mass C-terminal fragments of gelsolin (70,000-45,000 Da) was found in the circulation. In homozygous FAF(Asn-187) the 65-kDa fragment containing the amyloid forming region and the 55-kDa fragment, devoid of that region, was the major gelsolin species in the plasma. The results indicate that the 65-kDa gelsolin fragment derived by alpha-gelsolinase cleavage at the mutation-induced novel proteolysis site Arg172-Ala173 represents the putative circulating precursor protein of tissue amyloid in FAF and that the Asp187Asn/Tyr substitution in gelsolin creates a conformation that is highly fibrillogenic.
Collapse
|
29
|
Beta2-microglobulin amyloidosis: insights from conservation analysis and fibril modelling by protein docking techniques. J Mol Biol 2003; 330:159-74. [PMID: 12818210 DOI: 10.1016/s0022-2836(03)00557-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Current data suggest that globular domains may form amyloids via different mechanisms. Nevertheless, there are indications that the initiation of the process takes place invariably in the less stable segments of a protein domain. We have studied the sequence and structural conservation of beta(2)-microglobulin that deposits into fibrils in dialysis-related amyloidosis. The dataset includes 51 high-resolution non-redundant structures of the antibody constant domain-like proteins (C1) and 132 related sequences. We describe a set of 30 conserved residues. Among them, 23 are conserved structurally, 16 are conserved sequentially and nine are conserved both sequentially and structurally. Strands A (12-18), G (91-95) and D (45-55) are the less conserved and stable segments of the domain, while strands B (22-28), C (36-41), E (62-70) and F (78-83) are the conserved and stable segments. We find that the conserved residues form a cluster with a network of interactions. The observed pattern of conservation is consistent with experimental data including H/D exchange, urea denaturation and limited proteolysis that suggest that strands A and G do not participate in the amyloid fibril. Additionally, the low conservation of strand D is consistent with the observation that this strand may acquire different conformations as seen in crystal structures of bound and isolated beta(2)-microglobulin. We used a docking technique to suggest a model for a fibril via stacking of beta(2)-microglobulin monomers. Our analysis suggests that the favored monomer building block for fibril elongation is the conformation of the isolated beta(2)-microglobulin, without the beta-bulge on strand D and without strands A and G participating in the fibril beta-sheet structure. This monomer retains all the conserved residues and their network of interactions, increasing the likelihood of its existence in solution. The inter-strand interaction between the two (monomer) building blocks forms a new continuous beta-sheet such that addition of monomers results in a fibril model that has the characteristic cross-beta structure.
Collapse
|
30
|
Abstract
Systemic amyloidosis results from the deposition of insoluble protein fibrils in various organs and tissues. To date, several different proteins have been associated with amyloid fibril formation, including immunoglobulin light chain, serum amyloid A protein, and transthyretin. Recent reports have shown that variant fibrinogen chains can form amyloid in certain kindreds. Hepatic transplantation has previously been reported in the treatment of hereditary amyloidosis associated with variant transthyretin proteins, which are mainly synthesized in the liver. This article reports the first use and long-term follow-up of combined hepatic and renal transplantation in the successful treatment of two patients with hereditary fibrinogen amyloidosis. Both patients experienced sustained improvement in renal function and nutritional status at 61/2 years and 28 months of follow-up, respectively. Orthotopic liver transplantation is effective and potentially curative treatment of hereditary fibrinogen amyloidosis.
Collapse
|
31
|
Presence of variant transthyretin in aqueous humor of a patient with familial amyloidotic polyneuropathy after liver transplantation. Amyloid 2002; 9:247-51. [PMID: 12557753 DOI: 10.3109/13506120209114101] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
To determine the origin of transthyretin (TTR) in the aqueous humor of patients with familial amyloidotic polyneuropathy (FAP), we measured TTR levels and analyzed the TTR forms in the aqueous humor of three FAP patients (one patient; liver transplanted, and two patients; non-transplanted). The total TTR levels were almost the same as reported previously in non-transplanted patients and slightly increased in a transplanted patient. Analyses with mass spectrometry in the two non-transplanted FAP ATTR V30M patients revealed that both wild type and variant TTR forms were detected in their aqueous humor samples. Moreover, variant TTR forms could be detected in the aqueous humor of the transplanted patient while the liver produced no variant TTR. These results suggest that variant TTR in aqueous humor may be derived from retina where TTR was produced. In conclusion, TTR metabolism may occur in its own ocular cycle and variant TTR produced by the retina may play an important role in amyloid formation in the ocular tissues of FAP patients.
Collapse
|
32
|
|
33
|
Subepithelial amyloid deposits in congenital hereditary endothelial dystrophy: a histopathologic study of five cases. Cornea 2002; 21:524-9. [PMID: 12072731 DOI: 10.1097/00003226-200207000-00017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To report the clinical, histologic, ultrastructural, and immunohistochemical features of congenital hereditary endothelial dystrophy (CHED) associated with subepithelial amyloid deposits. METHODS The clinical features of seven patients and histologic characteristics of eight corneal buttons were evaluated. The corneal specimens included five cases with histologic features of CHED associated with subepithelial amyloid. The remaining three corneal buttons of CHED without amyloid were obtained from the fellow eye of an affected patient and from siblings of two affected patients. Light microscopic studies were performed on sections stained with hematoxylin and eosin, periodic acid Schiff stain, and Congo red stain with and without permanganate bleach. Immunohistochemistry with an antibody to the amyloid AA protein and lambda and kappa light chains was done on all specimens. Electron microscopy was performed on three corneal specimens. The cases were followed for 1-9 years. RESULTS The notable clinical findings included decreased vision, history of parental consanguinity (4/7 cases), and affected siblings (5/7 cases). Examination revealed nystagmus (5/7 cases) and bilateral ground-glass corneas in all patients. In addition, central subepithelial whitish opacities were noted in patients with CHED and amyloid. Three patients had associated congenital glaucoma. The patients underwent penetrating keratoplasty at a mean age of 10 years. Histologically, five corneal buttons of CHED revealed varying degrees of subepithelial amyloid deposits associated with a subepithelial fibrous pannus. Immunohistochemically, the deposits were nonreactive to anti-amyloid A antibody but were immunoreactive with an antibody to lambda light chains in two cases. Electron microscopy confirmed the presence of subepithelial amyloid. Thickening of Descemet's membrane and attenuation of corneal endothelial cells, noted in all cases, was consistent with features of CHED. The corneal buttons from the fellow eye and the siblings showed histologic features of CHED, with a subepithelial fibrous pannus without amyloid deposits. Spheroidal degeneration was noted in two corneal specimens. To date, no recurrence of the amyloid deposits has been seen in the grafts. CONCLUSIONS This study demonstrates that subepithelial amyloidosis may be rarely associated with a recessive form of congenital hereditary endothelial dystrophy. The clinical, histologic, and immunohistochemical features suggest a secondary form of amyloidosis.
Collapse
MESH Headings
- Adolescent
- Amyloid/metabolism
- Amyloidosis, Familial/genetics
- Amyloidosis, Familial/metabolism
- Amyloidosis, Familial/pathology
- Child
- Corneal Dystrophies, Hereditary/genetics
- Corneal Dystrophies, Hereditary/metabolism
- Corneal Dystrophies, Hereditary/pathology
- Endothelium, Corneal/metabolism
- Endothelium, Corneal/pathology
- Epithelium, Corneal/metabolism
- Epithelium, Corneal/ultrastructure
- Female
- Humans
- Keratoplasty, Penetrating
- Male
- Retrospective Studies
Collapse
|
34
|
Role of proprotein convertases in the pathogenic processing of the amyloidosis-associated form of secretory gelsolin. Amyloid 2002; 9:83-7. [PMID: 12440480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
Familial amyloidosis of the Finnish type (FAF) is caused by two proteolytic cleavages of mutant gelsolin leading to the accumulation of FAF amyloid in the patients' tissues. Here, we demonstrate that, in mouse pituitary corticotropic AtT20 cells, the enzyme responsible for the first cleavage of mutant secretory FAF gelsolin to FAF amyloid precursor is present in reasonable amounts. Furthermore, in At T20 cells stably expressing alpha1-PDX a potent inhibitor of most proprotein convertases, this cleavage was inhibited The present data provide strong evidence that proprotein convertases, possibly furin or PC5, are involved in the initialpathological cleavage of mutant secretory FAF gelsolin leading ultimately to the amyloid disease.
Collapse
|
35
|
Abstract
Hereditary familial amyloidosis of Finnish type (FAF) leading to amyloid in the peripheral and central nervous systems stems from deposition of a 71 residue fragment generated from the D187N/Y variants of plasma gelsolin by two sequential endoproteolytic events. We identify the protease accomplishing the first cleavage as furin, a proprotein convertase. Endoproteolysis of plasma gelsolin occurs in the trans-Golgi network due to the inability of the FAF variants to bind and be stabilized by Ca(2+). Secretion and processing of the FAF variants by furin can be uncoupled by blocking the convergence of the exocytic pathway transporting plasma gelsolin and the endocytic recycling of furin. We propose that coincidence of membrane trafficking pathways contributes to the development of proteolysis-initiated amyloid disease.
Collapse
|