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Mitsuharu Ueda

Publications and source records attributed to Mitsuharu Ueda.

14 recordsLinked to original sources

Osteogenesis imperfecta, intellectual disability and recurrent infections in a male with a pathogenic SASH3 variant.

Src Homology 3 Domain-containing Adaptor Protein 3 (SASH3) deficiency is an X-linked immune disorder. Here we identified a male case with a pathogenic SASH3 variant (c.1039C>T [p.Arg347Cys]) who presented with osteogenesis imperfecta, intellectual disability and recurrent infections. While immunological features in this case were characterized, further studies are needed to determine the association between the SASH3 variant and the skeletal or neurological manifestations.

Journal Article↗

A transgenic rat with the human ATTR V30M: a novel tool for analyses of ATTR metabolisms.

Amyloidogenic transthyretin (ATTR) is the pathogenic protein of familial amyloidotic polyneuropathy (FAP). To establish a tool for analyses of ATTR metabolisms including after liver transplantations, we developed a transgenic rat model expressing human ATTR V30M and confirmed expressions of human ATTR V30M in various tissues. Mass spectrometry for purified TTR revealed that rat intrinsic TTR and human ATTR V30M formed tetramers. Congo red staining and immunohistochemistry revealed that nonfibrillar deposits of human ATTR V30M, but not amyloid deposits, were detected in the gastrointestinal tracts of the transgenic rats. At 24h after liver transplantation, serum human ATTR V30M levels in transgenic rats that received livers from normal rats became lower than detectable levels. These results thus suggest that this transgenic rat may be a useful animal model which analyzes the metabolism of human ATTR V30M including liver transplantation studies.

Amyloid Neuropathies, Familial↗

FK506 inhibits murine AA amyloidosis: possible involvement of T cells in amyloidogenesis.

OBJECTIVE: To determine the possibility that T cells represent a potential target for therapy in AA amyloidosis. METHODS: AA amyloidosis was induced in C3H/HeN mice by concomitant administration of AgNO3 and amyloid-enhancing factor (AEF). Mice injected with AgNO3 and AEF received intraperitoneal injections of FK506 (2-200 microg/day). The degree of splenic amyloid deposition was determined by Congo red staining. Serum amyloid A (SAA), interleukin 1beta (IL-1beta), IL-6, and tumor necrosis factor-a concentrations were measured by ELISA. AA amyloidosis was also induced in ICR mice by injection of Freund's complete adjuvant (FCA) and Mycobacterium butyricum without AEF. ICR mice injected with FCA and M. butyricum also received intraperitoneal injections of FK506 (200 microg/day) to eliminate the possibility that FK506 action might depend upon AEF activity in the amyloid formation. Amyloid deposition was also induced with and without AEF in severe combined immunodeficient (SCID) mice and nude mice to clarify the role of T cells in the mechanism of amyloid formation in AA amyloidosis. RESULTS: FK506 treatment significantly reduced the amount of amyloid deposition and incidence of amyloidosis without reducing serum SAA and proinflammatory cytokine levels in the murine AA amyloidosis models with and without AEF. SCID mice and nude mice showed resistance to development of AA amyloidosis. CONCLUSION: Our findings may provide a new therapeutic strategy for amyloidosis. The results suggested that T cells may play an important role in the mechanism of amyloid formation in AA amyloidosis.

Amyloidosis↗

Lipid droplets are present in amyloid deposits in familial amyloidotic polyneuropathy and dialysis related amyloidosis.

It has been well documented that transthyretin (TTR) shows an affinity for lipoproteins and amyloid is deposited around adipocytes in patients with familial amyloidotic polyneuropathy (FAP). We examined the involvement of lipids in amyloid fibrils in the tissues by histopathologic methods. Sudan black B staining for frozen tissues of autopsied FAP patients and biospied dialysis related amyloidosis (DRA) patients revealed colocalization of lipids in the tissue sections where Congo red staining was positive, while no such positive staining was observed in paraffin embedded tissues. Immunohistochemical study using lipoprotein antibodies revealed that only anti-high density lipoprotein (HDL) antibody showed immunoreactivity in both types of amyloid specimens where Congo red was positively stained. Measurement of the components of lipids in the frozen cardiac samples from an FAP patient and an amyotrophic lateral sclerosis (ALS) patient revealed that concentrations of triglyceride and cholesterol in each lipoprotein, except for HDL-triglyceride, were markedly elevated in the FAP patient's material, compared to that of the ALS patient. These results suggest that interaction of amyloid fibrils with HDL may play an important role in amyloid formation in FAP.

Adult↗

Aging and transthyretin-related amyloidosis: pathologic examinations in pulmonary amyloidosis.

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.

Adult↗

Analysis of amyloid fibrils in the cheetah (Acinonyx jubatus).

Recently, a high prevalence of amyloid A (AA) amyloidosis has been documented among captive cheetahs worldwide. Biochemical analysis of amyloid fibrils extracted from the liver of a Japanese captive cheetah unequivocally showed that protein AA was the main fibril constituent. Further characterization of the AA fibril components by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis revealed three main protein AA bands with approximate molecular weights of 8, 10 and 12 kDa. Mass spectrometry analysis of the 12-kDa component observed in SDS-PAGE and Western blotting confirmed the molecular weight of a 12,381-Da peak. Our finding of a 12-kDa protein AA component provides evidence that the cheetah SAA sequence is longer than the previously reported 90 amino acid residues (approximately 10 kDa), and hence SAA is part of the amyloid fibril.

Acinonyx↗

Effect of tacrolimus and partial hepatectomy on transthyretin metabolism in rats.

Liver transplantation, which serves as treatment of familial amyloidotic polyneuropathy (FAP), and domino liver transplantation, which utilizes resected livers from patients with FAP for treatment of liver diseases, may induce changes in transthyretin (TTR), a pathogenic FAP-related protein. To evaluate this possibility, we performed a 70% hepatectomy or administered tacrolimus to Dark Agouti (DA) rats for 7 days and then measured changes in liver TTR mRNA levels and changes in serum TTR concentrations. After hepatectomy, TTR mRNA levels decreased by 77%; at day 3, they returned to preoperative levels. Except for slightly elevated serum TTR concentrations 12 h after operation, serum TTR levels remained unchanged. Thus, partial hepatectomy did not influence serum TTR concentrations. After tacrolimus administration, TTR mRNA declined by 56% 12 h after the experiment started; however, after day 3, a rebound phenomenon occurred until day 7. Tacrolimus may facilitate serum TTR degradation, although production of TTR in the liver also increased. This finding -- that TTR, the source of FAP-inducing amyloid, did not increase after transplantation -- may help post-transplantation treatment of patients who have FAP and other liver diseases.

Animals↗

[Application to transthyretin analysis].

Transthyretin (TTR) is the precursor protein of familial amyloidotic polyneuropathy (FAP) and senile systemic amyloidosis (SSA). TTR-related FAP is a hereditary amyloidosis induced by mutated TTR. The most common type of FAP is FAP amyloidogenic TTR (ATTR) Val30Met: TTR substitution of methionine for valine at position 30 of the TTR sequence. In this type of FAP, amyloid deposition causes organ failure including peripheral neuropathy, autonomic disorders, gastrointestinal symptoms, and cardiac and renal failure. In Japan, it is well known that Kumamoto and Nagano are the two major foci of FAP, but recently, FAP has been found throughout Japan. In addition, various different types of mutations in the TTR gene and phenotypes of FAP have also been documented. Medical care for FAP is becoming more important. Detection of mutant TTR is indispensable to diagnose the disease in order to treat FAP. We have developed a method for detecting mutant TTR in serum and cerebrospinal fluid by means of mass spectrometry to screen for variant TTR in FAP patients. In this article, we reviewed the general characteristics of TTR and clinical features of FAP, and described the identification of mutant TTR using surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry (MS). In addition, we analyzed TTR modifications and protein profiles in serum samples of Japanese and Swedish patients using SELDI-TOF-MS to look for a key protein(s) as a trigger of FAP.

Amyloid Neuropathies, Familial↗

Effect of nitric oxide in amyloid fibril formation on transthyretin-related amyloidosis.

Although oxidative stress is said to play an important role in the amyloid formation mechanism in several types of amyloidosis, few details about this role have been described. Amyloid is commonly deposited around the vessels that are the primary site of action of nitric oxide generated from endothelial cells and smooth muscle cells, so nitric oxide may be also implicated in amyloid formation. For this study, we examined the in vitro effect of S-nitrosylation on amyloid formation induced by wild-type transthyretin, a precursor protein of senile systemic amyloidosis, and amyloidogenic transthyretin V30M, a precursor protein of amyloid deposition in familial amyloidotic polyneuropathy. S-Nitrosylation of amyloidogenic transthyretin V30M via the cysteine at position 10 was 2 times more extensive than that of wild-type transthyretin in a nitric oxide-generating solution. Both wild-type transthyretin and amyloidogenic transthyretin V30M formed amyloid fibrils under acidic conditions, and S-nitrosylated transthyretins exhibited higher amyloidogenicity than did unmodified transthyretins. Moreover, S-nitrosylated amyloidogenic transthyretin V30M formed more fibrils than did S-nitrosylated wild-type transthyretin. Structural studies revealed that S-nitrosylation of amyloidogenic transthyretin V30M induced a change in its conformation, as well as instability of the tetramer conformation. These results suggest that the nitric oxide-mediated modification of transthyretin, especially variant transthyretin, may play an important role in amyloid formation in senile systemic amyloidosis and familial amyloidotic polyneuropathy.

Amino Acid Substitution↗

Role of extracellular superoxide dismutase in patients under maintenance hemodialysis.

BACKGROUND: It has been well documented that free radical injury is involved in the progression of chronic renal failure. Extracellular superoxide dismutase (EC-SOD), localized on the endothelial cell surface, plays an important role in reducing oxidative stress especially in the vessels by binding to the endothelial cell surface via the heparin-binding domain. Although EC-SOD Arg213Gly, which cannot bind on endothelial cells, has been considered a polymorphism, the effect of EC-SOD on hemodialysis patients has not been well examined. METHODS: In 178 hemodialysis patients, the following examinations were performed. EC-SOD Arg213Gly was examined by polymerase chain reaction (PCR)-induced mutation restriction analysis (PCR-IMRA). As indexes of atherosclerosis, the annual progression in intima-media thickness (DeltaIMT), plaque score, pulse wave velocity (PWV) and plasma-oxidized low-density lipoprotein (OxLDL) values were examined. RESULTS: PCR-IMRA revealed that 20 of 178 patients possessed the mutation (11.2%), and the incidence was about twice as high as that in a previously reported Japanese population. Although there were no statistical differences in plaque score and PWV with and without EC-SOD Arg213Gly, DeltaIMT and plasma OxLDL values in patients with EC-SOD Arg213Gly were significantly higher than those in patients without the mutation. CONCLUSION: EC-SOD Arg213Gly is an accelerating factor for the progression of renal failure and atherosclerosis.

Adult↗

Muscular amyloid angiopathy with amyloidgenic transthyretin Ser50Ile and Tyr114Cys.

Among patients with familial amyloid polyneuropathy (FAP), those with transthyretin Val30Met mainly show distally predominant weakness and atrophy, whereas some FAP patients, including those with transthyretin Ser50Ile and Tyr114Cys, show muscle weakness and atrophy that is dominant proximally, simulating myopathy. To clarify the cause of proximally dominant muscular atrophy in patients with FAP transthyretin Ser50Ile and Tyr114Cys, we investigated the distinctive features of muscle specimens of patients with FAP, 3 of who had Val30Met, 2 Ser50Ile, and 2 Tyr114Cys transthyretin. All specimens showed transthyretin amyloid around blood vessels and perimysium, and neurogenic denervation patterns. The amount of amyloid around the vessels was much greater in patients with FAP Ser50Ile and Tyr114Cys than in Val30Met patients. Muscular amyloid angiopathy may contribute to motor nerve injury that, in turn, may lead to amyotropic changes in patients with FAP Ser50Ile and Tyr114Cys.

Adult↗

[Practical application of nutritional assessment protein and inflammatory marker in the nutrition support team (NST)].

Recently nutrition support team (NST) has been established for the purpose of prevention of complications which are caused by nutrition disorders and reduction of the medical expenses. Although physical examinations and blood biochemical data had been used as the indexes evaluating nutritional of patients, they were not suitable for the evaluation for the short-term in-patient. On the contrary, serum albumin (ALB) has been wildly used as a nutritional marker. However, it is impossible to evaluate nutrition state for the short-term in-patient and acute phase disease patient accurately, because the plasma half-life is 21 days and it takes long time to detect the change in nutritional state by its value. Rapid turnover proteins (RTP), whose plasma half-life is shorter, has paid attention to evaluate nutritional state for the short-term in-patients and acute phase disease patients. Although, prognostic inflammatory and nutritional index (PINI) was considered as a useful maker for evaluating inflammatory and nutritional states using the concentrations of transthyretin (TTR), a RTP, alpha1-acid glycoprotein (alpha1-AG), a chronic inflammation marker, C reactive protein (CRP), a acute inflammation marker, and ALB, However, it has several pitfalls. We newly made serum amyloid A (SAA) index using SAA instead of CRP. When we compared SAA index with PINI in many diseases, it turned out that SAA index became a more effective index which reflected the patient condition than did PINI. As for this index, it is expected to be used by NST while further alternation may be needed.

C-Reactive Protein↗

A different amyloid formation mechanism: de novo oculoleptomeningeal amyloid deposits after liver transplantation.

BACKGROUND: Liver transplantation has served as a treatment for patients with familial amyloidotic polyneuropathy (FAP) because variant transthyretin (TTR), the pathogenic protein of FAP, is predominantly produced by the liver. However, the effect on amyloid formation of TTR that is synthesised by the retina and the choroid plexus remains to be elucidated in FAP patients with liver transplants. OBJECTIVE: To investigate changes in ocular tissues and the central nervous system (CNS) of FAP patients after liver transplantation. DESIGN: Clinical study. SETTING: Graduate School of Medical Sciences, Kumamoto University, Japan. INTERVENTION: Transplantation of livers from cadaveric or living donors. MEASUREMENTS: Preoperative measures and postoperative (16-108 months) follow-up of clinical data, including routine ophthalmologic, neurologic, and laboratory evaluations. RESULTS: In 22 patients with FAP related to the amyloidogenic TTR (ATTR) Val30Met and 3 patients with FAP ATTR Tyr114Cys, after liver transplantation, 3 patients began to show evidence of de novo glaucoma, and 1 had vitreous opacity that was caused by the variant TTR. Another three patients showed new amyloid deposits in the pupillary margin, which could lead to glaucoma and vitreous opacity. As for changes in the CNS and levels of total protein and TTR in cerebrospinal fluid (CSF), after liver transplantation, two FAP ATTR Tyr114Cys patients exhibited de novo amyloid deposition in the leptomeninges, and total protein and TTR levels in CSF were significantly increased. CONCLUSIONS: Oculoleptomeningeal involvement in FAP was not prevented by liver transplantation because variant TTR produced by the retina and the choroid plexus forms amyloid fibrils in situ.

Adult↗