齋藤 邦明

Abstract Stressful life events contribute to the onset of major depressive disorder (MDD). We recently demonstrated abnormalities in ubiquitination in the pathophysiology of MDD. However, the underlying molecular mechanisms remain unclear. We investigated the involvement of the ubiquitination system‐mediated glutamatergic dysfunction in social impairment induced by chronic social defeat stress (CSDS). Adult C57BL/6J mice were exposed to aggressor ICR male mice for 10 consecutive days. Social impairment was induced by CSDS in the social interaction test 1 days after the last stress exposure. In terms of brain microdialysis, CSDS reduced depolarization‐evoked glutamate release in the prefrontal cortex (PFC), which was reversed by a glutamate transporter 1 (GLT‐1) inhibitor. Interestingly, the expression of ubiquitinated, but not total GLT‐1, was decreased in the PFC of mice exposed to CSDS. The expression of neural precursor cells expressing developmentally downregulated gene 4‐like (Nedd4L: E3 ligase for GLT‐1), and ubiquitin‐conjugating enzyme E2D2 (Ube2d2: E2 ubiquitin‐conjugating enzyme for Nedd4L) was also reduced in CSDS mice. Furthermore, the downregulation of the Nedd4L‐GLT‐1 ubiquitination pathway decreased SIT ratio, but up‐regulation increased it even in non‐CSDS mice. Taken together, the decrease in GLT‐1 ubiquitination may reduce the release of extracellular glutamate induced by high‐potassium stimulation, which may lead to social impairment, while we could not find differences in GLT‐1 ubiquitination between susceptible and resistant CSDS mice. In conclusion, GLT‐1 ubiquitination could play a crucial role in the pathophysiology of MDD and is an attractive target for the development of novel antidepressants.

Indoleamine 2,3-dioxygenase 2 (IDO2) is an enzyme of the tryptophan-kynurenine pathway that is constitutively expressed in the brain. To provide insight into the physiological role of IDO2 in the brain, behavioral and neurochemical analyses in IDO2 knockout (KO) mice were performed. IDO2 KO mice showed stereotyped behavior, restricted interest and social deficits, traits that are associated with behavioral endophenotypes of autism spectrum disorder (ASD). IDO2 was colocalized immunohistochemically with tyrosine-hydroxylase-positive cells in dopaminergic neurons. In the striatum and amygdala of IDO2 KO mice, decreased dopamine turnover was associated with increased α-synuclein level. Correspondingly, levels of downstream dopamine D1 receptor signaling molecules such as brain-derived neurotrophic factor and c-Fos positive proteins were decreased. Furthermore, decreased abundance of ramified-type microglia resulted in increased dendritic spine density in the striatum of IDO2 KO mice. Both chemogenetic activation of dopaminergic neurons and treatment with methylphenidate, a dopamine reuptake inhibitor, ameliorated the ASD-like behavior of IDO2 KO mice. Sequencing analysis of exon regions in IDO2 from 309 ASD samples identified a rare canonical splice site variant in one ASD case. These results suggest that the IDO2 gene is, at least in part, a factor closely related to the development of psychiatric disorders.

Objective The objective of this study was to estimate the humoral immune response evaluated by immunoglobulin G (IgG) against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike receptor-binding domain (RBD-IgG) following the third mRNA COVID-19 vaccination in patients with kidney disease who received immunosuppressive treatment. Methods The primary outcome was RBD-IgG levels after the third SARS-CoV-2 vaccination. The primary comparison was the RBD-IgG levels between patients with kidney disease who received immunosuppressive treatment (n=124) and those who did not (n=33). Results The RBD-IgG levels were significantly lower in the patients with kidney disease who received immunosuppressive treatment than in those who did not receive immunosuppressive treatment. The RBD-IgG levels were lower in patients treated with glucocorticoid monotherapy than in those who did not receive immunosuppressive treatment. Even in patients who received ≤ 5 mg prednisolone, the RBD-IgG levels were significantly lower. Nine of the 10 patients who received rituximab within one year before the first vaccination did not experience seroconversion after the third vaccination. Meanwhile, all nine patients who received rituximab only after the second vaccination experienced seroconversion, even if B cell recovery was insufficient. Patients treated with mycophenolate mofetil plus glucocorticoid plus belimumab had significantly lower RBD-IgG levels than those treated with mycophenolate mofetil plus glucocorticoid. Conclusions The RBD-IgG levels were lower in patients with kidney disease who received immunosuppressive treatment than in those who did not receive immunosuppressive treatment. Low-dose glucocorticoid monotherapy affected the humoral immune response following the third mRNA COVID-19 vaccination.

Cisplatin is a chemotherapeutic agent used to treat many types of malignant tumors. However, irrespective of its potent anticancer properties and efficacy, nephrotoxicity is the dose-limiting factor of cisplatin treatment. Cisplatin infiltrates renal tubular cells in the kidneys and is metabolized by cysteine conjugate-beta lyase 1 (CCBL1) to form highly reactive thiol-cisplatin; this may mediate cisplatin's nephrotoxicity. Therefore, CCBL1 inhibition may prevent cisplatin-induced nephrotoxicity. Using a high-throughput screening assay, we identified 2',4',6'-trihydroxyacetophenone (THA) as an inhibitor of CCBL1. THA inhibited human CCBL1 β-elimination activity in a concentration-dependent manner. We further investigated the preventive effect of THA on cisplatin-induced nephrotoxicity. THA attenuated the effect of cisplatin on the viability of confluent renal tubular cells (LLC-PK1 cells) but had no effect on cisplatin-induced reduction of proliferation in the tumor cell lines (LLC and MDA-MB-231). THA pretreatment significantly attenuated cisplatin-induced increases in blood urea nitrogen, creatinine, cell damage score, and apoptosis of renal tubular cells in mice in a dose-dependent manner. Furthermore, THA pretreatment attenuated cisplatin-induced nephrotoxicity without compromising its antitumor activities in mice bearing subcutaneous syngeneic LLC tumors. THA could help prevent cisplatin-induced nephrotoxicity and may provide a new strategy for cisplatin-inclusive cancer treatments.

Cisplatin is a chemotherapeutic agent used to treat many types of malignant tumors. However, irrespective of its potent anticancer properties and efficacy, nephrotoxicity is the dose-limiting factor of cisplatin treatment. Cisplatin infiltrates renal tubular cells in the kidneys and is metabolized by cysteine conjugate-beta lyase 1 (CCBL1) to form highly reactive thiol-cisplatin; this may mediate cisplatin's nephrotoxicity. Therefore, CCBL1 inhibition may prevent cisplatin-induced nephrotoxicity. Using a high-throughput screening assay, we identified 2',4',6'-trihydroxyacetophenone (THA) as an inhibitor of CCBL1. THA inhibited human CCBL1 beta-elimination activity in a concentration-dependent manner. We further investigated the preventive effect of THA on cisplatin-induced nephrotoxicity. THA attenuated the effect of cisplatin on the viability of confluent renal tubular cells (LLC-PK1 cells) but had no effect on cisplatin-induced reduction of proliferation in the tumor cell lines (LLC and MDA-MB-231). THA pre-treatment significantly attenuated cisplatin-induced increases in blood urea nitrogen, creatinine, cell damage score, and apoptosis of renal tubular cells in mice in a dose-dependent manner. Furthermore, THA pre-treatment attenuated cisplatin-induced nephrotoxicity without compromising its anti-tumor activities in mice bearing subcutaneous syngeneic LLC tumors. THA could help prevent cisplatin-induced nephrotoxicity and may provide a new strategy for cisplatin-inclusive cancer treatments.

Sepsis is a systemic inflammatory disease caused by a bacterial infection that leads to severe mortality, especially in elderly patients, because of an excessive immune response and impaired regulatory functions. Antibiotic treatment is widely accepted as the first-line therapy for sepsis; however, its excessive use has led to the emergence of multidrug-resistant bacteria in patients with sepsis. Therefore, immunotherapy may be effective in treating sepsis. Although CD8+ regulatory T cells (Tregs) are known to have immunomodulatory effects in various inflammatory diseases, their role during sepsis remains unclear. In this study, we investigated the role of CD8+ Tregs in an LPS-induced endotoxic shock model in young (8-12 wk old) and aged (18-20 mo old) mice. The adoptive transfer of CD8+ Tregs into LPS-treated young mice improved the survival rate of LPS-induced endotoxic shock. Moreover, the number of CD8+ Tregs in LPS-treated young mice increased through the induction of IL-15 produced by CD11c+ cells. In contrast, LPS-treated aged mice showed a reduced induction of CD8+ Tregs owing to the limited production of IL-15. Furthermore, CD8+ Tregs induced by treatment with the rIL-15/IL-15Rα complex prevented LPS-induced body wight loss and tissue injury in aged mice. In this study, to our knowledge, the induction of CD8+ Tregs as novel immunotherapy or adjuvant therapy for endotoxic shock might reduce the uncontrolled immune response and ultimately improve the outcomes of endotoxic shock.

BACKGROUND AND PURPOSE: High salt (HS) intake has been associated with hypertension and cognitive impairment. It is well-known that angiotensin II (Ang II)-AT1 and prostaglandin E2 (PGE2)-EP1 systems are involved in hypertension and neurotoxicity. However, the involvement of these systems in HS-mediated hypertension and emotional and cognitive impairments remains unclear. EXPERIMENTAL APPROACH: Mice were loaded with HS solution (2% NaCl drinking water) for 12 weeks and blood pressure was monitored. Subsequently, effects of HS intake on emotional and cognitive function and tau phosphorylation in the prefrontal cortex (PFC) and hippocampus (HIP) were investigated. The involvement of Ang II-AT1 and PGE2-EP1 systems in HS-induced hypertension and neuronal and behavioral impairments was examined by treatment with losartan, an AT1 receptor blocker (ARB), or EP1 gene knockout. KEY RESULTS: We demonstrated that hypertension and impaired social behavior and object recognition memory following HS intake could be associated with tau hyperphosphorylation, decreased phosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaMKII), and postsynaptic density protein 95 (PSD95) expression in the PFC and HIP of mice. These changes were blocked by pharmacological treatment with losartan or EP1 gene knockout. CONCLUSIONS AND IMPLICATIONS: Our findings suggest that the interaction of Ang II-AT1 and PGE2-EP1 systems could be novel therapeutic targets for hypertension-induced cognitive impairment.

The monoamine hypothesis has been common hypotheses for the pathophysiology of major depressive disorder (MDD). Since mainstream antidepressants are selective serotonin (5-HT) reuptake inhibitors, hypo-serotonergic function has been implicated in the MDD. However, one-third of patients are refractory to the treatment with antidepressants. Tryptophan (TRP) is metabolized via the kynurenine (KYN) and 5-HT pathways. Indoleamine 2,3-dioxygenase 1 (IDO1) is the first metabolizing enzyme in the TRP-KYN pathway which is inducible by pro-inflammatory cytokines, involved depression-like behavior via 5-HT depletion due to decreased level of TRP in the 5-HT pathway. Kynurenine 3-monooxygenase (KMO) is the enzyme in the metabolism of KYN to 3-hydroxykynurenine. KMO deficiency increases level of kynurenic acid (KA), a KYN metabolite by kynurenine aminotransferases (KATs) and induces depression-like behavior. Interestingly, Chronic unpredictable mild stress (CUMS) is associated with a disruption of the hypothalamus-pituitary-adrenocortical (HPA) system and increases KA level with decreased KMO expression in the prefrontal cortex. The decrease of KMO may be related to the reduction in expression of microglia, since KMO is mainly found in microglia in the nervous system. CUMS increases KA level via alternation of enzymes from KMO to KAT. KA is α7 nicotinic acetylcholine receptor (α7nAChR) antagonist. Activation of α7nAChR by nicotine or galantamine attenuates CUMS-induced depression-like behaviors. Taken together, depletion of 5-HT by induction of IDO1 and α7nAChR antagonism by KA via decreased KMO expression cause depression-like behavior, suggesting that metabolic alterations in TRP-KYN pathway are highly involved in the pathophysiology of MDD. Therefore, TRP-KYN pathway is expected to be an attractive target for the development of novel diagnosis of MDD and antidepressants.

The partial loss of liver due to liver transplantation or acute liver failure induces rapid liver regeneration. Recently, we reported that the selective inhibition of indoleamine 2,3‑dioxygenase (Ido) 1 promotes early liver regeneration. However, the role of Ido2 in liver regeneration remains unclear. Wild‑type (WT) and Ido2‑deficient (Ido2‑KO) mice were subjected to 70% partial hepatectomy (PHx). Hepatocyte growth was measured using immunostaining. The mRNA expression of inflammatory cytokines and production of kynurenine in intrahepatic mononuclear cells (MNCs) were analyzed using reverse transcription‑quantitative PCR and high‑performance liquid chromatography. The activation of NF‑κB was determined by both immunocytochemistry and western blotting analysis. The ratio of liver to body weight and the frequency of proliferation cells after PHx were significantly higher in Ido2‑KO mice compared with in WT mice. The expression of IL‑6 and TNF‑α in MNCs were transiently increased in Ido2‑KO mice. The nuclear transport of NF‑κB was significantly higher in peritoneal macrophages of Ido2‑KO mice compared with WT mice. These results suggested that Ido2 deficiency resulted in transiently increased production of inflammatory cytokines through the activation of NF‑kB, thereby promoting liver regeneration. Therefore, the regulation of Ido2 expression in MNCs may play a therapeutic role in liver regeneration under injury and disease conditions.

うつ病の病態にはモノアミン仮説が提唱されており，抗うつ薬の主流が選択的セロトニン（5-HT）再取り込み阻害薬であることから，特に5-HT神経系の機能低下が広く受け入れられている．しかし，患者の約1/3は既存の抗うつ薬に対して難治性であるため，新しい創薬ターゲットに対する新規抗うつ薬の開発が求められている．トリプトファン（TRP）は5-HT経路だけでなくキヌレニン（KYN）経路においても代謝される．インドールアミン2,3-ジオキシゲナーゼ1（IDO1）は，TRP-KYN経路の代謝を行う最初の律速酵素である．IDO1は炎症性サイトカインによって強く誘導され，TRPを代謝し，5-HT経路で代謝されるTRPレベルを低下させ，その結果，5-HT合成を抑制し，うつ様行動を惹起する．下流のキヌレニン-3-モノオキシゲナーゼ（KMO）は，KYNを3-ヒドロキシキヌレニンに代謝する重要な酵素である．KMOが欠損すると，キヌレニンアミノトランスフェラーゼ（KAT）によりKYNが代謝され，キヌレン酸（KA）が増加し，うつ様行動が惹起される．一方，慢性予測不能軽度ストレス（CUMS）は視床下部－下垂体－副腎皮質（HPA）系を破綻させ，前頭前野におけるKMOの発現が低下し，KAを増加させる．これにはCUMSによるKMOを主に発現するミクログリアの減少を伴っている．KAはα7ニコチン性アセチルコリン受容体（α7nAChR）アンタゴニスト作用を有する．ニコチンやガランタミンによるα7nAChRの活性化により，CUMS誘発のうつ病様行動が減弱される．IDO1の誘導による5-HT合成抑制と，KMO発現低下を介したKAレベルの増加によるα7nAChR拮抗作用はうつ様行動を引き起こすことから，TRP-KYN経路の代謝的変化がうつ病の病態に深く関与していると考えられる．TRP-KYN経路は，うつ病の新規診断方法や抗うつ薬の開発に向けた魅力的なターゲットになることが期待される．

Interstitial pneumonia of uncertain cause is referred to as idiopathic interstitial pneumonia (IIP). Among the various types of IIPs, the prognosis of cases of idiopathic pulmonary fibrosis (IPF) is extremely poor, and accurate differentiation between IPF and non-IPF pneumonia is critical. In this study, we consider deep learning (DL) methods owing to their excellent image classification capabilities. Although DL models require large quantities of training data, collecting a large number of pathological specimens is difficult for rare diseases. In this study, we propose an end-to-end scheme to automatically classify IIPs using a convolutional neural network (CNN) model. To compensate for the lack of data on rare diseases, we introduce a two-step training method to generate pathological images of IIPs using a generative adversarial network (GAN). Tissue specimens from 24 patients with IIPs were scanned using a whole slide scanner, and the resulting images were divided into patch images with a size of 224 × 224 pixels. A progressive growth GAN (PGGAN) model was trained using 23,142 IPF images and 7817 non-IPF images to generate 10,000 images for each of the two categories. The images generated by the PGGAN were used along with real images to train the CNN model. An evaluation of the images generated by the PGGAN showed that cells and their locations were well-expressed. We also obtained the best classification performance with a detection sensitivity of 97.2% and a specificity of 69.4% for IPF using DenseNet. The classification performance was also improved by using PGGAN-generated images. These results indicate that the proposed method may be considered effective for the diagnosis of IPF.

Abstract Artificial intelligence (AI) applications in medical imaging continue facing the difficulty in collecting and using large datasets. One method proposed for solving this problem is data augmentation using fictitious images generated by generative adversarial networks (GANs). However, applying a GAN as a data augmentation technique has not been explored, owing to the quality and diversity of the generated images. To promote such applications by generating diverse images, this study aims to generate free-form lesion images from tumor sketches using a pix2pix-based model, which is an image-to-image translation model derived from GAN. As pix2pix, which assumes one-to-one image generation, is unsuitable for data augmentation, we propose StylePix2pix, which is independently improved to allow one-to-many image generation. The proposed model introduces a mapping network and style blocks from StyleGAN. Image generation results based on 20 tumor sketches created by a physician demonstrated that the proposed method can reproduce tumors with complex shapes. Additionally, the one-to-many image generation of StylePix2pix suggests effectiveness in data-augmentation applications.

The COVID-19 vaccine will be safe and effective in solid organ transplant recipients (SOTs). However, the blunted antibody responses were also of concern. Few studies have reported prolonged serologic follow-up after 2 doses of BNT162b2 vaccine in SOTs. We performed a single-center, prospective observational study of 78 SOTs who received 2 doses of BNT162b2 vaccine. We identified the trajectory of antibody titers after vaccination among SOTs with or without mycophenolate mofetil (MMF) or withdrawn from MMF. We found low seroconversion rates (29/42: 69%) and low antibody titers in SOTs treated with MMF. An inverse linear relationship between neutralizing antibody titers and MMF concentration was confirmed in restricted cubic spline plots (P for effect < .01, P for nonlinearity = .08). For the trajectory of antibody responses, seroconversion and improved antibody titers were observed after withdrawal from MMF in SOTs who showed seronegative or low antibody titers at the first visit after 2 doses of vaccine (P for effect < .01, P for nonlinearity < .05, and P for interaction < .01). We identified increased B-cell counts after withdrawal from MMF (P < .01). The recovery of antibody responses was seen in SOTs withdrawn from MMF. The trajectories of antibody responses were modified by MMF administration.

OBJECTIVES: High concentrations of low-density lipoprotein cholesterol (LDL-C) are a risk factor for cardiovascular disease. We validated the efficacy of the Martin method is useful in the estimation of LDL-C concentrations was validated in Japanese populations and derived a modified Martin method for easy laboratory information system applications. METHODS: We created 3 subject groups, including 2664 health check-up participants registered with the Resource Center for Health Science, 29,806 clinical patients (A) in the Gifu University Hospital, and 113,716 clinical patients (B) in the Fujita Health University Hospital. Each method to estimate serum LDL-C concentrations (Friedewald formula, Martin method and modified Martin method) was validated by correlation analysis with serum LDL-C concentrations measured using a direct method. RESULTS: The correlation coefficients with the direct method in terms of the Friedewald formula, Martin method, and modified Martin method were 0.963, 0.972 and 0.970 in the health check-up participants; 0.946, 0.962 and 0.961 in clinical patients A; and 0.961, 0.979 and 0.978 in clinical patients B, respectively. Concordance ratios with using the direct method in the Friedewald formula, Martin method and modified Martin method were 82.8%, 85.5% and 85.3% in the health check-up participants; 76.4%, 80.5% and 80.2% in clinical patients A; and 76.1%, 82.6% and 82.6% in clinical patients B, respectively. CONCLUSION: Our results show that the Martin and modified Martin methods display good performance in terms of the estimation of LDL-C concentrations among triglyceride concentrations of a wide range, and they may thus be useful for estimating LDL-C concentrations.

LPSは炎症の成立に重要な役割を果たしている。LPSはLPS結合蛋白(LBP)と結合し、さらにCD14が結合することで炎症シグナルを細胞内に誘導する。今回、我々は長期療養(5年以上)のRA患者を対象に、高感度法によるLBPの定量とACPA抗体の変動を調査した。また炎症の指標とされているCRPおよびIL-6の測定を同時に行いバイオマーカーとしてのLBPの臨床的意義について検討を行った。血中LBP値(Mean±SD)は健常者3.69±1.26μg/mL、OA群6.05±2.40μg/mL、RA群11.10±5.16μg/mLであり、RA群で最も有意に高値を示した(p<0.0001)。さらにstage、classの亢進に伴いLBPが増加した。また、ACPAとは相関(r=0.410)を認め、陽性群と陰性群での比較では陽性例が有意(p<0.002)に高値であった。このことから高感度法によるLBPの測定はRAの新たな病態解析の指標の一つになる可能性が有るものと考える。(著者抄録)

ADVIAシリーズ用に開発されたIL-6測定試薬をCentaur XPTを用いてその有用性について検討した。併行精度(%)2.2〜7.7,室内再現精度(%)2.9〜6.8で精度について問題ないと考えられる。また従来法のELISA法(r=0.966),CLEIA法(r=0.977)との相関は良好であった。健常者(1.35±0.70pg/mL),不明関節炎患者(3.49±6.29pg/mL)と関節リウマチ患者(17.56±31.28pg/mL)の比較において関節リウマチ患者が有意(p<0.001)に高値であった。さらに操作性については,既に検査室に設置されている装置を用いるため操作手順を大きく変更することはなく日常検査項目と同時測定が可能である。今後,炎症性疾患や感染症などの早期診断バイオマーカーとして臨床の場における新たな診断価値が提唱されるものと考えている。(著者抄録)

LPSは炎症の成立に重要な役割を果たしている。LPSはLPS結合蛋白(LBP)と結合し、さらにCD14が結合することで炎症シグナルを細胞内に誘導する。今回、我々は長期療養(5年以上)のRA患者を対象に、高感度法によるLBPの定量とACPA抗体の変動を調査した。また炎症の指標とされているCRPおよびIL-6の測定を同時に行いバイオマーカーとしてのLBPの臨床的意義について検討を行った。血中LBP値(Mean±SD)は健常者3.69±1.26μg/mL、OA群6.05±2.40μg/mL、RA群11.10±5.16μg/mLであり、RA群で最も有意に高値を示した(p<0.0001)。さらにstage、classの亢進に伴いLBPが増加した。また、ACPAとは相関(r=0.410)を認め、陽性群と陰性群での比較では陽性例が有意(p<0.002)に高値であった。このことから高感度法によるLBPの測定はRAの新たな病態解析の指標の一つになる可能性が有るものと考える。(著者抄録)

ADVIAシリーズ用に開発されたIL-6測定試薬をCentaur XPTを用いてその有用性について検討した。併行精度(%)2.2〜7.7,室内再現精度(%)2.9〜6.8で精度について問題ないと考えられる。また従来法のELISA法(r=0.966),CLEIA法(r=0.977)との相関は良好であった。健常者(1.35±0.70pg/mL),不明関節炎患者(3.49±6.29pg/mL)と関節リウマチ患者(17.56±31.28pg/mL)の比較において関節リウマチ患者が有意(p<0.001)に高値であった。さらに操作性については,既に検査室に設置されている装置を用いるため操作手順を大きく変更することはなく日常検査項目と同時測定が可能である。今後,炎症性疾患や感染症などの早期診断バイオマーカーとして臨床の場における新たな診断価値が提唱されるものと考えている。(著者抄録)

Various cancer cells require massive amounts of glucose as an energy source for their dysregulated growth. Although D‑allose, a rare sugar, inhibits tumor cell growth via inhibition of glucose uptake, a few cells can survive after treatment. However, the mechanism by which D‑allose‑resistant cells are generated remains unclear. Here, we investigated the properties of D‑allose‑resistant cells and evaluated the efficacy of combined treatment with this rare sugar and antitumor drugs. To this end, we established a D‑allose‑resistant tumor cell line and prepared a C57BL/6J mouse tumor xenograft model using Lewis lung carcinoma (LLC) cells. Xenograft‑bearing mice were treated with D‑allose (9 g/kg) and/or hydroxychloroquine (HCQ, 60 mg/kg), an autophagy inhibitor, for two weeks. Although D‑allose inhibited LLC cell growth in a dose‑dependent manner, a few cells survived. The upregulation of LC3‑II, a classical autophagy marker, and the downregulation of mTOR and its downstream molecule Beclin1 were observed in established D‑allose‑resistant LLC cells, which were more sensitive to cell death induced by HCQ. Similarly, in the tumor xenograft model, the tumor volume in mice co‑treated with D‑allose and HCQ was considerably smaller than that in untreated or HCQ‑treated mice. Importantly, the administration of D‑allose induced autophagy selectively at the tumor site of the xenograft‑bearing mice. These results provide a new therapeutic strategy targeting autophagy which is induced in tumor cells by D‑allose administration, and may be used to improve therapies for lung cancer.

汎用生化学自動分析装置を用いたSARS-CoV-2抗体定量の有用性について基礎的検討を行った。陰性検体としてSARS-CoV-2流行以前に健康診断を受診した300名から得られた300検体の血清を用い、新型コロナワクチンを2回接種した本学教職員30名から経時的に得られた血清150検体を用いた。異なる2種類の精度管理血清(血清1:陰性域、血清2:陽性域)を20回連続測定した。その結果、血清1と血清2の測定値はそれぞれ1.69±0.58、31.70±0.89、変動係数はそれぞれ34.5%と2.8%であった。期待値を大きく外れるポイントは認められず良好な希釈直線性が得られ、理論値3000BAU/mLの検体を2n倍希釈し測定した。その結果、300BAU/mLから400BAU/mL付近においてフッキング現象が観察され、プロゾーンの存在が示された。本試薬は多くの検査室が所有する汎用自動分析装置で使用できると考えられた。

BACKGROUND: Coronavirus disease 2019 (COVID-19) is known to cause not only respiratory but also neuropsychiatric symptoms, which are assumed to be derived from a cytokine storm and its effects on the central nervous systems. Patients with COVID-19 who develop severe respiratory symptoms are known to show severe neuropsychiatric symptoms such as cerebrovascular disease and encephalopathy. However, the detailed clinical courses of patients with neuropsychiatric symptoms caused by mild or asymptomatic COVID-19 remain poorly understood. Here, we present a case of COVID-19 who presented with severe and prolonged neuropsychiatric symptoms subsequent to mild respiratory symptoms. CASE PRESENTATION: A 55-year-old female with COVID-19 accompanied by mild respiratory symptoms showed delusion, psychomotor excitement, and poor communication ability during quarantine outside the hospital. Considering her diminished respiratory symptoms, her neuropsychiatric symptoms were initially regarded as psychogenic reactions. However, as she showed progressive disturbance of consciousness accompanied by an abnormal electroencephalogram, she was diagnosed with post-COVID-19 encephalopathy. Although her impaired consciousness and elevated cytokine level improved after steroid pulse therapy, several neuropsychiatric symptoms, including a loss of concentration, unsteadiness while walking, and fatigue, remained. CONCLUSIONS: This case suggests the importance of both recognizing that even apparently mild COVID-19-related respiratory symptoms can lead to severe and persistent neuropsychiatric symptoms, and elucidating the mechanisms, treatment, and long-term course of COVID-19-related neuropsychiatric symptoms in the future.

LPS結合蛋白(LBP)はLPSを単球に提示するなど,前炎症段階における初期免疫に関与する。今回我々は化学発光免疫測定装置へ搭載可能な新規LBP測定試薬の基本性能評価を行った。再現性は4%未満であり,共存物質の影響を受けないこと,良好な希釈直線性を有することが確認された。健常対照群のLBP値はELISA法やLA法の既報よりも高値であった。また,RA患者において健常対照群よりも有意に高値であった。本試薬は良好な基本性能を有しており新たな炎症関連マーカーとしての活用が期待される。(著者抄録)

Since recognizing the location and extent of infarction is essential for diagnosis and treatment, many methods using deep learning have been reported. Generally, deep learning requires a large amount of training data. To overcome this problem, we generated pseudo patient images using CycleGAN, which performed image transformation without paired images. Then, we aimed to improve the extraction accuracy by using the generated images for the extraction of cerebral infarction regions. First, we used CycleGAN for data augmentation. Pseudo-cerebral infarction images were generated from healthy images using CycleGAN. Finally, U-Net was used to segment the cerebral infarction region using CycleGAN-generated images. Regarding the extraction accuracy, the Dice index was 0.553 for U-Net with CycleGAN, which was an improvement over U-Net without CycleGAN. Furthermore, the number of false positives per case was 3.75 for U-Net without CycleGAN and 1.23 for U-Net with CycleGAN, respectively. The number of false positives was reduced by approximately 67% by introducing the CycleGAN-generated images to training cases. These results indicate that utilizing CycleGAN-generated images was effective and facilitated the accurate extraction of the infarcted regions while maintaining the detection rate.

Maternal use of valproic acid (VPA) during pregnancy is associated with an increased risk of autism spectrum disorder (ASD) in the offspring. In the pathophysiological hypothesis of ASD, excitation/inhibition (E/I) imbalance is attracted. Dysfunction of serotonergic system is also suggested to be involved in ASD. In this study, we investigated glutamatergic-serotonergic neuronal interaction in the ASD-like behavior induced by prenatal VPA exposure in mice. Prenatal VPA exposure induced not only excessive repetitive self-grooming behavior, impairments of social behavior and object recognition memory, but also increased glutamatergic signaling (CaMKII phosphorylation) and decreased serotonin contents in the prefrontal cortex. Memantine (low-affinity NMDA antagonist) suppressed both the increase of CaMKII phosphorylation and ASD-like behaviors. Activation of serotonergic signaling via 5-HT_1A receptor by fluoxetine, tandospirone (5-HT_1A receptor agonist) and optogenetics attenuated the ASD-like behaviors in prenatal VPA-exposed mice. WAY-100635 (5-HT_1A receptor antagonist) antagonized the effect of fluoxetine on the ASD-like behaviors. These results suggest that the hyper-NMDA receptor signaling and ASD-like behaviors are associated with hypo-signaling of 5-HT_1A receptor in the prenatal VPA-exposed mice.

Chronic stress contributes to the pathogenesis of major depressive disorder (MDD). In the kynurenine pathway (KP), kynurenine is metabolized to 3-hydroxykynurenine (3-HK) by kynurenine 3-monooxygenase (KMO) and to kynurenic acid (KA) by kynurenine aminotransferase. KP alternation has been reported to be associated with the pathogenesis of MDD. We investigated the involvement of KP in the depressive-like behavior induced by chronic unpredictable mild stress (CUMS). Mice were randomly exposed to 9 kinds of mild stressors for 4 weeks. Corticosterone level in the serum and corticotropin-releasing hormone (CRH) mRNA level in the hypothalamus (HT) elevated immediately after CUMS. Further, KMO mRNA level was decreased, but KA content was increased in the prefrontal cortex (PFC). Because KA is α7 nicotinic acetylcholine receptor (α7nAChR) antagonist, we investigated the effects of nicotine (Nic) and galantamine (Gal :α7nAChR agonist) on the depressive-like behavior and dysregulation of HPA axis induced by CUMS. When Nic and Gal were administrated before exposure to each stressor during CUMS, they attenuated CUMS-induced decreased sociability. Although Nic failed to inhibit elevated corticosterone level in the serum immediately after CUMS, but suppressed that sustained elevation 1 week after CUMS. Alternation of KP from 3-HK to KA through downregulation of KMO may be involved in the depressive-like behavior and the sustained elevation of serum corticosterone 1 week after CUMS.

Adolescent binge drinking represents a major public health challenge and lead to persistent psychiatric disorders. However, the underlying pathogenic mechanisms remain poorly understood. Myelin abnormalities were observed in human subjects with alcohol abuse. Gray matter myelination in the prefrontal cortex and hippocampus during adolescence are vulnerable to alcohol.In the present study, we investigated whether myelin abnormalities in the gray matter are involved in behavioral abnormalities induced by adolescent binge ethanol treatment (ABET). To produce ABET, C57BL/6J mouse was given EtOH (3.0g/kg, i.e. 25% ethanol w/v) once a day during adolescence (P28-46) in an intermittent fashion. ABET persistently developed behavioral abnormalities such as anxiety-like behaviors in the marble burying test and the novelty suppressed feeding test, impaired memory function in the novel object recognition test, and impairments of social behavior in social interaction test. ABET decreased myelin-related protein and oligodendrocyte lineage cells in the prefrontal cortex and hippocampus. Clemastine, which promotes oligodendroglial differentiation and myelination, rescues the behavioral abnormalities. These findings suggest that myelin abnormalities in the gray matter may be involved in the behavioral abnormalities caused by ABET in adulthood.

Dopamine contributes to attention as a key neurotransmitter in the nervous system projecting to the forebrain. Numerous animal models have been generated to model attentional impairment with dopaminergic dysregulation. We previously generated mice lacking Shati, an N-acetyltransferase-8-like protein, on a C57BL/6J genetic background (Shati/Nat8l^−/−). Modulation of this gene leads to changes in behavioral phenotypes such as attentional impairment associated with hypodopaminergic neurotransmission in mice. In this study, the effect of Shati/Nat8l deficit in dopaminergic projections was investigated using an object-based attention test (OBAT). Shati/Nat8l^−/− mice showed attentional impairment in the OBAT, accompanied by reduced neuronal activity in the prefrontal cortex (PFC) and the hypodopaminergic function indicated by the reduced expression of tyrosine hydroxylase (dopaminergic marker) protein and dopamine-related genes in the ventral tegmental area (VTA). The activation of dopaminergic projections of the VTA-PFC by chemogenetic stimulation ameliorated the attentional impairment in Shati/Nat8l^−/− mice. These results confirm previous findings that Shati/Nat8l deficiency interrupts the dopaminergic system and contributes to novel evidence that Shati/Nat8l is implicated in the dopaminergic projections of the VTA-PFC, which play important roles in the regulation of attention in the OBAT.

Tryptophan (TRP) is metabolized via the kynurenine (KYN) pathway, which is related to the pathogenesis of major depressive disorder (MDD). Kynurenine 3-monooxygenase (KMO) is a pivotal enzyme in the metabolism of KYN to 3-hydroxykynurenine. In rodents, KMO deficiency induces a depression-like behavior and increases the levels of kynurenic acid (KA), a KYN metabolite formed by kynurenine aminotransferases (KATs). We will introduce the involvement of TRP metabolism in the depression-like behavior induced by chronic unpredictable mild stress (CUMS). Corticosterone level in the serum and corticosterone-releasing hormone (CRH) mRNA level in the hypothalamus (HT) were elevated immediately after CUMS. Associated with the dysregulation of hypothalamic-pituitary-adrenal (HPA) axis, KMO mRNA level was decreased, and KA content was increased in the prefrontal cortex (PFC). Microglia marker Iba-1 was decreased immediately after CUMS. Because KMO is mainly found in microglia in the central nervous system, these results suggests that CUMS increased KA contents via alternation of kynurenine metabolic enzyme from KMO to KATs due to the reduction of microglia. Because KA is α7 nicotinic acetylcholine receptor (α7nAChR) antagonist, we investigated the effect of nicotine and galantamine (allosteric potentiating ligand for α7nAChR ) on the depression-like behavior and dysregulation of HPA axis induced by CUMS. When nicotine and galantamine were administrated before exposure to each stressor, they attenuated CUMS-induced depression-like behaviors. Although nicotine didn&apos;t affect elevated corticosterone level in the serum immediately after CUMS, it suppressed the sustained elevation 1 week after CUMS. Increase of KA associative with downregulation of KMO in microglia was involved in the depressive-like behavior and the sustained elevation of serum corticosterone after CUMS. The ameliorating effects of nicotine and galantamine on depression-like behaviors induced by CUMS are associated with the activation of α7nAChR.