Browsing by Author "Tabe, Yoko"

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    Carvedilol suppresses ryanodine receptor-dependent Ca2+ bursts in human neurons bearing PSEN1 variants found in early onset Alzheimer's disease
    (Public Library of Science, 2024-08-22) Hori, Atsushi; Inaba, Haruka; Hato, Takashi; Tanaka, Kimie; Sato, Shoichi; Okamoto, Mizuho; Horiuchi, Yuna; Paran, Faith Jessica; Tabe, Yoko; Mori, Shusuke; Rosales, Corina; Akamatsu, Wado; Murayama, Takashi; Kurebayashi, Nagomi; Sakurai, Takashi; Ai, Tomohiko; Miida, Takashi; Medicine, School of Medicine
    Seizures are increasingly being recognized as the hallmark of Alzheimer's disease (AD). Neuronal hyperactivity can be a consequence of neuronal damage caused by abnormal amyloid β (Aß) depositions. However, it can also be a cell-autonomous phenomenon causing AD by Aß-independent mechanisms. Various studies using animal models have shown that Ca2+ is released from the endoplasmic reticulum (ER) via type 1 inositol triphosphate receptors (InsP3R1s) and ryanodine receptors (RyRs). To investigate which is the main pathophysiological mechanism in human neurons, we measured Ca2+ signaling in neural cells derived from three early-onset AD patients harboring Presenilin-1 variants (PSEN1 p.A246E, p.L286V, and p.M146L). Of these, it has been reported that PSEN1 p.A246E and p.L286V did not produce a significant amount of abnormal Aß. We found all PSEN1-mutant neurons, but not wild-type, caused abnormal Ca2+-bursts in a manner dependent on the calcium channel, Ryanodine Receptor 2 (RyR2). Indeed, carvedilol, an RyR2 inhibitor, and VK-II-86, an analog of carvedilol without the β-blocking effects, sufficiently eliminated the abnormal Ca2+ bursts. In contrast, Dantrolene, an inhibitor of RyR1 and RyR3, and Xestospongin c, an IP3R inhibitor, did not attenuate the Ca2+-bursts. The Western blotting showed that RyR2 expression was not affected by PSEN1 p.A246E, suggesting that the variant may activate the RyR2. The RNA-Seq data revealed that ER-stress responsive genes were increased, and mitochondrial Ca2+-transporter genes were decreased in PSEN1A246E cells compared to the WT neurons. Thus, we propose that aberrant Ca2+ signaling is a key link between human pathogenic PSEN1 variants and cell-intrinsic hyperactivity prior to deposition of abnormal Aß, offering prospects for the development of targeted prevention strategies for at-risk individuals.
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    Comparison of the clinical performance and usefulness of five SARS-CoV-2 antibody tests
    (PloS, 2021) Wakita, Mitsuru; Idei, Mayumi; Saito, Kaori; Horiuchi, Yuki; Yamatani, Kotoko; Ishikawa, Suzuka; Yamamoto, Takamasa; Igawa, Gene; Hinata, Masanobu; Kadota, Katsuhiko; Kurosawa, Taro; Takahashi, Sho; Saito, Takumi; Misawa, Shigeki; Akazawa, Chihiro; Naito, Toshio; Milda, Takashi; Takahashi, Kazuhisa; Ai, Tomohiko; Tabe, Yoko; Medicine, School of Medicine
    We examined the usefulness of five COVID-19 antibody detection tests using 114 serum samples at various time points from 34 Japanese COVID-19 patients. We examined Elecsys Anti-SARS-CoV-2 from Roche, and four immunochromatography tests from Hangzhou Laihe Biotech, Artron Laboratories, Chil, and Nadal. In the first week after onset, Elecsys had 40% positivity in Group S (severe cases) but was negative in Group M (mild-moderate cases). The immunochromatography kits showed 40–60% and 0–8% positivity in Groups S and M, respectively. In the second week, Elecsys showed 75% and 50% positivity, and the immunochromatography tests showed 5–80% and 50–75% positivity in Groups S and M, respectively. After the third week, Elecsys showed 100% positivity in both groups. The immunochromatography kits showed 100% positivity in Group S. In Group M, positivity decreased to 50% for Chil and 75–89% for Artron and Lyher. Elecsys and immunochromatography kits had 91–100% specificity. Elecsys had comparable chronological change of cut-off index values in the two groups from the second week to the sixth week. The current SARS-CoV-2 antibody detection tests do not provide meaningful interpretation of severity and infection status. Its use might be limited to short-term epidemiological studies.
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    Inhibition of BCL2A1 by STAT5 inactivation overcomes resistance to targeted therapies of FLT3-ITD/D835 mutant AML
    (Elsevier, 2022) Yamatani, Kotoko; Ai, Tomohiko; Saito, Kaori; Suzuki, Koya; Hori, Atsushi; Kinjo, Sonoko; Ikeo, Kazuho; Ruvolo, Vivian; Zhang, Weiguo; Mak, Po Yee; Kaczkowski, Bogumil; Harada, Hironori; Katayama, Kazuhiro; Sugimoto, Yoshikazu; Myslinski, Jered; Hato, Takashi; Miida, Takashi; Konopleva, Marina; Hayashizaki, Yoshihide; Carter, Bing Z.; Tabe, Yoko; Andreeff, Michael; Medicine, School of Medicine
    Tyrosine kinase inhibitors (TKIs) are established drugs in the therapy of FLT3-ITD mutated acute myeloid leukemia (AML). However, acquired mutations, such as D835 in the tyrosine kinase domain (FLT3-ITD/D835), can induce resistance to TKIs. A cap analysis gene expression (CAGE) technology revealed that the gene expression of BCL2A1 transcription start sites was increased in primary AML cells bearing FLT3-ITD/D835 compared to FLT3-ITD. Overexpression of BCL2A1 attenuated the sensitivity to quizartinib, a type II TKI, and venetoclax, a selective BCL2 inhibitor, in AML cell lines. However, a type I TKI, gilteritinib, inhibited the expression of BCL2A1 through inactivation of STAT5 and alleviated TKI resistance of FLT3-ITD/D835. The combination of gilteritinib and venetoclax showed synergistic effects in the FLT3-ITD/D835 positive AML cells. The promoter region of BCL2A1 contains a BRD4 binding site. Thus, the blockade of BRD4 with a BET inhibitor (CPI-0610) downregulated BCL2A1 in FLT3-mutated AML cells and extended profound suppression of FLT3-ITD/D835 mutant cells. Therefore, we propose that BCL2A1 has the potential to be a novel therapeutic target in treating FLT3-ITD/D835 mutated AML.
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    Novel Variants in the CLCN1, RYR2, and DCTN1 Found in Elderly Japanese Dementia Patients: A Case Series
    (MDPI, 2021-02-07) Hori, Atsushi; Ai, Tomohiko; Isshiki, Miwa; Motoi, Yumiko; Yano, Kouji; Tabe, Yoko; Hattori, Nobutaka; Miida, Takashi; Medicine, School of Medicine
    Dementia has an enormous impact on medical and financial resources in aging societies like Japan. Diagnosis of dementia can be made by physical and mental examinations, imaging tests, and findings of high abnormal proteins in cerebrospinal fluids. In addition, genetic tests can be performed in neurodegenerative diseases such as Alzheimer's disease (AD), frontotemporal dementia (FTD), and Parkinson's disease (PD). In this case series, we presented three cases of dementia with unknown causes who carry novel variants in the genes associated with neurodegenerative diseases. Three patients (Patients 1, 2, and 6) were found by screening 18 dementia patients using a gene panel including 63 genes. The age of onset for Patient 1 was 74 years old, and his father had PD and mother had AD. The age of onset for Patient 2 was 75 years old, and her mother had AD. The age of onset for Patient 6 was 83 years old, and her father, two sisters, and daughter had dementia. The Mini-Mental State Examination produced results of 20, 15, and 22, respectively. The suspected diagnosis by neurological examinations and imaging studies for Patients 1 and 2 was AD, and for Patient 6 was FTD. Patient 1 was treated with donepezil; Patient 2 was treated with donepezil and memantine; and Patient 6 was treated with donepezil, galantamine, and rivastigmine. The three rare variants identified were: CLCN1, encoding a chloride channel, c.2848G>A:p.Glu950Lys (Patient 1); RYR2, encoding a calcium releasing ryanodine receptor, c.13175A>G:p.Lys4392Arg (Patient 2); and DCTN1, encoding a subunit of dynactin, c. 3209G>A:p.Arg1070Gln (Patient 6). The detected variants were interpreted according to the American College of Medical Genetics (ACMG) guidelines. The minor allele frequency for each variant was 0.025%, 0.023%, and 0.0004% in East Asians, respectively. The DCTN1 variant found in Patient 6 might be associated with FTD. Although none of them were previously reported in dementia patients, all variants were classified as variants of unknown significance (VUS). Our report suggests that results of genetic tests in elderly patients with dementia need to be carefully interpreted. Further data accumulation of genotype-phenotype relationships and development of appropriate functional models are warranted.