Benign intracranial hypertension and leukoencephalopathy due to venous sinus stenosis in an SLE patient

The final, definitive version of this article has been published in the Journal, LUPUS, 16/10, 2007, © SAGE Publications Ltd, 2007 by SAGE Publications Ltd at the LUPUS page: http://lup.sagepub.com/ on SAGE Journals Online: http://online.sagepub.com/ArticleLUPUS. 16(10): 839-840 (2007)journal articl

p.E66Q mutation in the GLA gene is associated with a high risk of cerebral small-vessel occlusion in elderly Japanese males

Background and purposeGLA is the causative gene of Fabry disease, an X-linked lysosomal storage disorder resulting from -galactosidase A (-GAL) deficiency. Stroke is an important manifestation of Fabry disease, and recent epidemiological studies have indicated that up to 4.9% of young male cryptogenic stroke patients have GLA mutations. To determine the importance of GLA mutations in the general stroke population, the frequency of GLA mutations in Japanese male ischaemic stroke (IS) patients with various risk factors and ages was measured. MethodsA total of 475 male IS patients (mean age 69.712.5years), were enrolled in this study. A blood sample was obtained to produce blood spots for measurement of -GAL activity. Blood samples with decreased enzymatic activity were reassayed and the entire GLA gene was analyzed by direct DNA sequencing if -Gal A activity was consistently low. Results-Gal A activity was decreased in 10 men, five of whom (1.1%) had the GLA gene mutation, p.E66Q. All IS patients with p.E66Q mutation had substantial residual -Gal A activity, in contrast to patients with classic-type Fabry disease. Clinically, all patients with p.E66Q mutation were >50years old and had multiple small-vessel occlusions (lacunar infarctions). Statistical analysis using Fisher's exact test showed the allele frequency of GLA p.E66Q in patients with small-vessel occlusion to be significantly higher than that in the general Japanese population [odds ratio (OR)=3.34, P=0.025). ConclusionsGLA p.E66Q mutation is a genetic risk factor for cerebral small-vessel occlusion in elderly Japanese males.ArticleEUROPEAN JOURNAL OF NEUROLOGY. 21(1):49-56 (2014)journal articl

Follow-up nationwide survey on predictive genetic testing for late-onset hereditary neurological diseases in Japan

A follow-up nationwide survey on predictive genetic testing for late-onset neurological diseases in Japan was conducted. A questionnaire was sent to 89 institutional members of the Japan's National Liaison Council for Clinical Sections of Medical Genetics, and was returned by 60 (67.4%). A total of 301 clients with an interest in predictive testing were accumulated from April 2006 to March 2011. The greatest interest was shown for spinocerebellar degeneration (SCD, n = 110), followed by myotonic dystrophy type 1 (DM1, n = 69), Huntington's disease (HD, n = 52) and familial amyloid polyneuropathy (FAP, n = 35). The ratios of clients who actually underwent predictive testing were: SCD, 21.8%; DM1, 39.1%; HD, 26.9%; and FAP, 74.3%, indicating that predictive testing was conducted very cautiously for untreatable neurological diseases in Japan. Clinical geneticists were predominantly involved in genetic counseling, whereas the participation of non-medical doctor (non-MD) staff, including nurses, clinical psychologists and genetic counselors, was not common. Lack of non-MD counseling staff was one of the most serious issues in conducting predictive testing, which has not been improved since the previous survey performed in 2006. Institutional arrangements, such as revision of medical insurance system regarding genetic testing and counseling, might be necessary to resolve this issue.ArticleJOURNAL OF HUMAN GENETICS. 58(8):560-563 (2013)journal articl

Protein C Mutation (A267T) Results in ER Retention and Unfolded Protein Response Activation

BACKGROUND: Protein C (PC) deficiency is associated with a high risk of venous thrombosis. Recently, we identified the PC-A267T mutation in a patient with PC deficiency and revealed by in vitro studies decreased intracellular and secreted levels of the mutant. The aim of the present study was to characterize the underlying mechanism(s). METHODOLOGY/PRINCIPAL FINDINGS: CHO-K1 cells stably expressing the wild-type (PC-wt) or the PC mutant were generated. In order to examine whether the PC mutant was subjected to increased intracellular degradation, the cells were treated with several inhibitors of various degradation pathways and pulse-chase experiments were performed. Protein-chaperone complexes were analyzed by treating the cells with a cross-linker followed by Western blotting (WB). Expression levels of the immunoglobulin-binding protein (BiP) and the phosphorylated eukaryotic initiation factor 2α (P-eIF2α), both common ER stress markers, were determined by WB to examine if the mutation induced ER stress and unfolded protein response (UPR) activation. We found no major differences in the intracellular degradation between the PC variants. The PC mutant was retained in the endoplasmic reticulum (ER) and had increased association with the Grp-94 and calreticulin chaperones. Retention of the PC-A267T in ER resulted in UPR activation demonstrated by increased expression levels of the ER stress markers BiP and P-eIF2α and caused also increased apoptotic activity in CHO-K1 cells as evidenced by elevated levels of DNA fragmentation. CONCLUSIONS/SIGNIFICANCE: The reduced intracellular level and impaired secretion of the PC mutant were due to retention in ER. In contrast to other PC mutations, retention of the PC-A267T in ER resulted in minor increased proteasomal degradation, rather it induced ER stress, UPR activation and apoptosis

Uptake of Aggregating Transthyretin by Fat Body in a Drosophila Model for TTR-Associated Amyloidosis

Background: A functional link has been established between the severe neurodegenerative disorder Familial amyloidotic polyneuropathy and the enhanced propensity of the plasma protein transthyretin (TTR) to form aggregates in patients with single point mutations in the TTR gene. Previous work has led to the establishment of an experimental model based on transgenic expression of normal or mutant forms of human TTR in Drosophila flies. Remarkably, the severity of the phenotype was greater in flies that expressed a single copy than with two copies of the mutated gene. Methodology/Principal Findings: In this study, we analyze the distribution of normal and mutant TTR in transgenic flies, and the ultrastructure of TTR-positive tissues to clarify if aggregates and/or amyloid filaments are formed. We report the formation of intracellular aggregates of 20 nm spherules and amyloid filaments in thoracic adipose tissue and in brain glia, two tissues that do not express the transgene. The formation of aggregates of nanospherules increased with age and was more considerable in flies with two copies of mutated TTR. Treatment of human neuronal cells with protein extracts prepared from TTR flies of different age showed that the extracts from older flies were less toxic than those from younger flies. Conclusions/Significance: These findings suggest that the uptake of TTR from the circulation and its subsequent segregation into cytoplasmic quasi-crystalline arrays of nanospherules is part of a mechanism that neutralizes the toxic effect of TTR.Original Publication:Malgorzata Pokrzywa, Ingrid Dacklin, Monika Vestling, Dan Hultmark, Erik Lundgren and Rafael Cantera, Uptake of Aggregating Transthyretin by Fat Body in a Drosophila Model for TTR-Associated Amyloidosis, 2010, PLOS ONE, (5), 12.http://dx.doi.org/10.1371/journal.pone.0014343Licensee: Public Library of Science (PLoS)http://www.plos.org

Iodine Atoms: A New Molecular Feature for the Design of Potent Transthyretin Fibrillogenesis Inhibitors

The thyroid hormone and retinol transporter protein known as transthyretin (TTR) is in the origin of one of the 20 or so known amyloid diseases. TTR self assembles as a homotetramer leaving a central hydrophobic channel with two symmetrical binding sites. The aggregation pathway of TTR into amiloid fibrils is not yet well characterized but in vitro binding of thyroid hormones and other small organic molecules to TTR binding channel results in tetramer stabilization which prevents amyloid formation in an extent which is proportional to the binding constant. Up to now, TTR aggregation inhibitors have been designed looking at various structural features of this binding channel others than its ability to host iodine atoms. In the present work, greatly improved inhibitors have been designed and tested by taking into account that thyroid hormones are unique in human biochemistry owing to the presence of multiple iodine atoms in their molecules which are probed to interact with specific halogen binding domains sitting at the TTR binding channel. The new TTR fibrillogenesis inhibitors are based on the diflunisal core structure because diflunisal is a registered salicylate drug with NSAID activity now undergoing clinical trials for TTR amyloid diseases. Biochemical and biophysical evidence confirms that iodine atoms can be an important design feature in the search for candidate drugs for TTR related amyloidosis

The disruption of proteostasis in neurodegenerative diseases

Cells count on surveillance systems to monitor and protect the cellular proteome which, besides being highly heterogeneous, is constantly being challenged by intrinsic and environmental factors. In this context, the proteostasis network (PN) is essential to achieve a stable and functional proteome. Disruption of the PN is associated with aging and can lead to and/or potentiate the occurrence of many neurodegenerative diseases (ND). This not only emphasizes the importance of the PN in health span and aging but also how its modulation can be a potential target for intervention and treatment of human diseases.info:eu-repo/semantics/publishedVersio

Renal amyloidosis in children

Renal amyloidosis is a detrimental disease caused by the deposition of amyloid fibrils. A child with renal amyloidosis may present with proteinuria or nephrotic syndrome. Chronic renal failure may follow. Amyloid fibrils may deposit in other organs as well. The diagnosis is through the typical appearance on histopathology. Although chronic infections and chronic inflammatory diseases used to be the causes of secondary amyloidosis in children, the most frequent cause is now autoinflammatory diseases. Among this group of diseases, the most frequent one throughout the world is familial Mediterranean fever (FMF). FMF is typically characterized by attacks of clinical inflammation in the form of fever and serositis and high acute-phase reactants. Persisting inflammation in inadequately treated disease is associated with the development of secondary amyloidosis. The main treatment is colchicine. A number of other monogenic autoinflammatory diseases have also been identified. Among them cryopyrin-associated periodic syndrome (CAPS) is outstanding with its clinical features and the predilection to develop secondary amyloidosis in untreated cases. The treatment of secondary amyloidosis mainly depends on the treatment of the disease. However, a number of new treatments for amyloid per se are in the pipeline