Evaluation of the Relationship Between Cognitive Impairment, Glycometabolism, and Nicotinic Acetylcholine Receptor Deficits in a Mouse Model of Alzheimer's Disease

PURPOSE: In patients with Alzheimer's disease (AD), the loss of cerebral nicotinic acetylcholine receptors (nAChRs) that are implicated in higher brain functions has been reported. However, it is unclear if nAChR deficits occur in association with cognitive impairments. The purpose of this study was to assess the relationship between nAChR deficits and cognitive impairments in a mouse model of AD (APP/PS2 mice). PROCEDURES: The cognitive abilities of APP/PS2 and wild-type mice (aged 2-16 months) were evaluated using the novel object recognition test. Double-tracer autoradiography analyses with 5-[125I]iodo-A-85380 ([125I]5IA: α4β2 nAChR imaging probe) and 2-deoxy-2-[18F]fluoro-D-glucose were performed in both mice of different ages. [123I]5IA-single-photon emission tomography (SPECT) imaging was also performed in both mice at 12 months of age. Furthermore, each age cohort was investigated for changes in cognitive ability and expression levels of α7 nAChRs and N-methyl-D-aspartate receptors (NMDARs). RESULTS: No significant difference was found between the APP/PS2 and wild-type mice at 2-6 months of age in terms of novel object recognition memory; subsequently, however, APP/PS2 mice showed a clear cognitive deficit at 12 months of age. [125I]5IA accumulation decreased in the brains of 12-month-old APP/PS2 mice, i.e., at the age at which cognitive impairments were first observed; this result was supported by a reduction in the protein levels of α4 nAChRs using Western blotting. nAChR deficits could be noninvasively detected by [123I]5IA-SPECT in vivo. In contrast, no significant changes in glycometabolism, expression levels of α7 nAChRs, or NMDARs were associated with cognitive impairments in APP/PS2 mice. CONCLUSION: A decrease in cerebral α4β2 nAChR density could act as a biomarker reflecting cognitive impairments associated with AD pathology

Essential Role of the Zinc Transporter ZIP9/SLC39A9 in Regulating the Activations of Akt and Erk in B-Cell Receptor Signaling Pathway in DT40 Cells

The essential trace element zinc is important for all living organisms. Zinc functions not only as a nutritional factor, but also as a second messenger. However, the effects of intracellular zinc on the B cell-receptor (BCR) signaling pathway remain poorly understood. Here, we present data indicating that the increase in intracellular zinc level induced by ZIP9/SLC39A9 (a ZIP Zrt-/Irt-like protein) plays an important role in the activation of Akt and Erk in response to BCR activation. In DT40 cells, the enhancement of Akt and Erk phosphorylation following BCR activation requires intracellular zinc. To clarify this event, we used chicken ZnT5/6/7-gene-triple-knockout DT40 (TKO) cells and chicken Zip9-knockout DT40 (cZip9KO) cells. The levels of Akt and ERK phosphorylation significantly decreased in cZip9KO cells. In addition, the enzymatic activity of protein tyrosine phosphatase (PTPase) increased in cZip9KO cells. These biochemical events were restored by overexpressing the human Zip9 (hZip9) gene. Moreover, we found that the increase in intracellular zinc level depends on the expression of ZIP9. This observation is in agreement with the increased levels of Akt and Erk phosphorylation and the inhibition of total PTPase activity. We concluded that ZIP9 regulates cytosolic zinc level, resulting in the enhancement of Akt and Erk phosphorylation. Our observations provide new mechanistic insights into the BCR signaling pathway underlying the regulation of intracellular zinc level by ZIP9 in response to the BCR activation

Development and characterization of a 68Ga-labeled A20FMDV2 peptide probe for the PET imaging of αvβ6 integrin-positive pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is known to be one of the most lethal cancers. Since the majority of patients are diagnosed at an advanced stage, development of a detection method for PDAC at an earlier stage of disease progression is strongly desirable. Integrin αVβ6 is a promising target for early PDAC detection because its expression increases during precancerous changes. The present study aimed to develop an imaging probe for positron emission tomography (PET) which targets αVβ6 integrin-positive PDAC. We selected A20FMDV2 peptide, which binds specifically to αvβ6 integrin, as a probe scaffold, and 68Ga as a radioisotope. A20FMDV2 peptide has not been previously labeled with 68Ga. A cysteine residue was introduced to the N-terminus of the probe at a site-specific conjugation of maleimide-NOTA (mal-NOTA) chelate. Different numbers of glycine residues were also introduced between cysteine and the A20FMDV2 sequence as a spacer in order to reduce the steric hindrance of the mal-NOTA on the binding probe to αVβ6 integrin. In vitro, the competitive binding assay revealed that probes containing a 6-glycine linker ([natGa]CG6 and [natGa]Ac-CG6) showed high affinity to αVβ6 integrin. Both probes could be labeled by 67/68Ga with high radiochemical yield (>50%) and purity (>98%). On biodistribution analysis, [67Ga]Ac-CG6 showed higher tumor accumulation, faster blood clearance, and lower accumulation in the surrounding organs of pancreas than did [67Ga]CG6. The αVβ6 integrin-positive xenografts were clearly visualized by PET imaging with [68Ga]Ac-CG6. The intratumoral distribution of [68Ga]Ac-CG6 coincided with the αVβ6 integrin-positive regions detected by immunohistochemistry. Thus, [68Ga]Ac-CG6 is a useful peptide probe for the imaging of αVβ6 integrin in PDAC

Incidence of gastrointestinal perforation associated with bevacizumab in combination with neoadjuvant chemotherapy as first-line treatment of advanced ovarian, fallopian tube, or peritoneal cancer: analysis of a Japanese healthcare claims database

[Objective] To assess the incidence of bevacizumab-associated gastrointestinal (GI) perforation during first-line treatment of patients with ovarian, fallopian tube, or peritoneal cancer receiving neoadjuvant chemotherapy (NAC) in Japanese real-world clinical practice. [Methods] A retrospective study was conducted using a healthcare claims database owned by Medical Data Vision Co., Ltd. (study period, 2008–2020). Patients who initiated first-line treatment of ovarian, fallopian tube, or peritoneal cancer were identified and divided into NAC and primary debulking surgery (PDS) groups. The incidence of bevacizumab-associated GI perforation was compared within the NAC group and between the groups. [Results] Paclitaxel + carboplatin (TC) was most commonly used as first-line treatment (39.5% and 59.6% in the NAC and PDS groups, respectively). TC + bevacizumab was used in 9.3% and 11.6% of patients in the NAC and PDS groups, respectively. In the NAC group receiving TC, the proportion of patients with risk factors for GI perforation was lower among patients with versus without concomitant bevacizumab. The incidence of GI perforation in the NAC group was 0.38% (1/266 patients) in patients receiving TC + bevacizumab and 0.18% (2/1, 131 patients) in patients receiving TC without bevacizumab (risk ratio=2.13; 95% confidence interval [CI]=0.19 to 23.36; risk difference=0.20; 95% CI=−0.58 to 0.97). None of the 319 patients in the PDS group receiving TC + bevacizumab had GI perforation. [Conclusion] No notable increase was observed in GI perforation associated with NAC containing bevacizumab. We conclude that bevacizumab is prescribed with sufficient care in Japan to avoid GI perforation

Noninvasive evaluation of nicotinic acetylcholine receptor availability in mouse brain using single-photon emission computed tomography with [(123)I]5IA.

INTRODUCTION: Nicotinic acetylcholine receptors (nAChRs) are of great interest because they are implicated in higher brain functions. Nuclear medical imaging is one of the useful techniques for noninvasive evaluation of physiological and pathological function in living subjects. Recent progress in nuclear medical imaging modalities enables the clear visualization of the organs of small rodents. Thus, translational research using nuclear medical imaging in transgenic mice has become possible and helps to elucidate human disease pathology. However, imaging of α4β2 nAChRs in the mouse brain has not yet been performed. The purpose of this study was to assess the feasibility of single-photon emission computed tomography (SPECT) with 5-[(123)I]iodo-3-[2(S)-azetidinylmethoxy]pyridine ([(123)I]5IA) for evaluating α4β2 nAChR availability in the mouse brain. METHODS: A 60-min dynamic SPECT imaging session of α4β2 nAChRs in the mouse brain was performed. The regional distribution of radioactivity in the SPECT images was compared to the density of α4β2 nAChRs measured in an identical mouse. Alteration of nAChR density in the brains of Tg2576 mice was also evaluated. RESULTS: The mouse brain was clearly visualized by [(123)I]5IA-SPECT and probe accumulation was significantly inhibited by pretreatment with (-)-nicotine. The regional distribution of radioactivity in SPECT images showed a significant positive correlation with α4β2 nAChR density measured in an identical mouse brain. Moreover, [(123)I]5IA-SPECT was able to detect the up-regulation of α4β2 nAChRs in the brains of Tg2576 transgenic mice. CONCLUSIONS: [(123)I]5IA-SPECT imaging would be a promising tool for evaluating α4β2 nAChR availability in the mouse brain and may be useful in translational research focused on nAChR-related diseases

Histological and Nuclear Medical Comparison of Inflammation After Hemostasis with Non-Thermal Plasma and Thermal Coagulation

The objective of this study is to examine the invasiveness of hemostasis by non-thermal plasma (NTP) compared with hemostasis by thermal coagulation (TC). The inflammation recovery process after hemostasis by TC and NTP was compared by using histological methods and nuclear medical molecular imaging. The necrotic areas in the NTP group disappeared after 5 days, whereas they remained 15 days after hemostasis in the TC group. The accumulation of 2-deoxy-2-[F-18] fluoro-D-glucopyranose (F-18-FDG), which reflects the existence of inflammatory cells, was higher in the TC group than in the NTP group on day 15. Thus, this study indicates that hemostasis by NTP is less inflammatory than TC. This report is the first to evaluate inflammation that occurred after hemostasis with medical devices noninvasively

Development of an atmospheric Cherenkov imaging camera for the CANGAROO-III experiment

A Cherenkov imaging camera for the CANGAROO-III experiment has been developed for observations of gamma-ray induced air-showers at energies from 10$^{11}$ to 10$^{14}$ eV. The camera consists of 427 pixels, arranged in a hexagonal shape at 0.17$^\circ$ intervals, each of which is a 3/4-inch diameter photomultiplier module with a Winston-cone--shaped light guide. The camera was designed to have a large dynamic range of signal linearity, a wider field of view, and an improvement in photon collection efficiency compared with the CANGAROO-II camera. The camera, and a number of the calibration experiments made to test its performance, are described in detail in this paper.Comment: 25 pages, 29 figures, elsart.cls, to appear in NIM-

The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target