膵管細胞におけるArid1aおよびPtenの欠失により、YAP/TAZ経路を介して膵管内管状乳頭状腫瘍（ITPN）が発生する

京都大学新制・課程博士博士(医学)甲第24791号医博第4983号新制||医||1066(附属図書館)京都大学大学院医学研究科医学専攻(主査)教授 川口 義弥, 教授 小林 恭, 教授 小濱 和貴学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDFA

Epithelial EP4 plays an essential role in maintaining homeostasis in colon

Colonic epithelial cells comprise the mucosal barrier, and their dysfunction promotes microbial invasion from the gut lumen and induces the development of intestinal inflammation. The EP4 receptor is known to mediate the protective effect of prostaglandin (PG) E2 in the gastrointestinal tract; however, the exact role of epithelial EP4 in intestinal pathophysiology remains unknown. In the present study, we aimed to investigate the role of epithelial EP4 in maintaining colonic homeostasis by characterizing the intestinal epithelial cell-specific EP4 knockout (EP4 cKO) mice. Mice harboring the epithelial EP4 deletion showed significantly lower colonic crypt depth and lower numbers of secretory cell lineages, as well as impaired epithelial cells in the colon. Interestingly, EP4-deficient colon epithelia showed a higher number of apoptotic cells. Consistent with the defect in mucosal barrier function of colonic epithelia and secretory cell lineages, EP4 cKO colon stroma showed enhanced immune cell infiltration, which was accompanied by increased production of inflammatory cytokines. Furthermore, EP4-deficient colons were susceptible to dextran sulfate sodium (DSS)-induced colitis. Our study is the first to demonstrate that epithelial EP4 loss resulted in potential "inflammatory" status under physiological conditions. These findings provided insights into the crucial role of epithelial PGE2/EP4 axis in maintaining intestinal homeostasis

Magnetic design for an electrodeless discharged lamp

We proposed an analysis method for plasma in an electrodeless discharged lamp light-emitting by inductively-coupled plasma, and a design of a power coupler was investigated by focusing on the electric power from the exciting coil to the plasma. We found that the power of the plasma was increased and of an Al stage was decreased with moving the core upward. This result suggests that the moving of the core upward is effective to reduce wasted power loss by eddy current and improves the lamp efficiency. In order to verify the result, we changed the position of the power coupler in the commercial lamp. Resultantly, the luminous flux of the lamp was increased by approximately 150 lm (lumen), when the power coupler was moved upward by 25 mm compared with the position of a commercial lamp. Therefore, we can conclude that our proposed method is applicable to the design of the lamp and suitable design is important to obtain high lamp efficiency

JNK pathway plays a critical role for expansion of human colorectal cancer in the context of BRG1 suppression

Tumor stem cells (TSCs), capable of self-renewal and continuous production of progeny cells, could be potential therapeutic targets. We have recently reported that chromatin remodeling regulator Brg1 is required for maintenance of murine intestinal TSCs and stemness feature of human colorectal cancer (CRC) cells by inhibiting apoptosis. However, it is still unclear how BRG1 suppression changes the underlying intracellular mechanisms of human CRC cells. We found that Brg1 suppression resulted in upregulation of the JNK signaling pathway in human CRC cells and murine intestinal TSCs. Simultaneous suppression of BRG1 and the JNK pathway, either by pharmacological inhibition or silencing of c-JUN, resulted in even stronger inhibition of the expansion of human CRC cells compared to Brg1 suppression alone. Consistently, high c-JUN expression correlated with worse prognosis for survival in human CRC patients with low BRG1 expression. Therefore, the JNK pathway plays a critical role for expansion and stemness of human CRC cells in the context of BRG1 suppression, and thus a combined blockade of BRG1 and the JNK pathway could be a novel therapeutic approach against human CRC

Pancreatic RECK inactivation promotes cancer formation, epithelial-mesenchymal transition, and metastasis

膵癌悪性化の分子機構解明 --RECK発現の低下が膵癌の浸潤・転移を引き起こす--. 京都大学プレスリリース. 2023-09-19.RECK is downregulated in various human cancers; however, how RECK inactivation affects carcinogenesis remains unclear. We addressed this issue in a pancreatic ductal adenocarcinoma (PDAC) mouse model and found that pancreatic Reck deletion dramatically augmented the spontaneous development of PDAC with a mesenchymal phenotype, which was accompanied by increased liver metastases and decreased survival. Lineage tracing revealed that pancreatic Reck deletion induced epithelial-mesenchymal transition (EMT) in PDAC cells, giving rise to inflammatory cancer-associated fibroblast–like cells in mice. Splenic transplantation of Reck-null PDAC cells resulted in numerous liver metastases with a mesenchymal phenotype, whereas reexpression of RECK markedly reduced metastases and changed the PDAC tumor phenotype into an epithelial one. Consistently, low RECK expression correlated with low E-cadherin expression, poor differentiation, metastasis, and poor prognosis in human PDAC. RECK reexpression in the PDAC cells was found to downregulate MMP2 and MMP3, with a concomitant increase in E-cadherin and decrease in EMT-promoting transcription factors. An MMP inhibitor recapitulated the effects of RECK on the expression of E-cadherin and EMT-promoting transcription factors and invasive activity. These results establish the authenticity of RECK as a pancreatic tumor suppressor, provide insights into its underlying mechanisms, and support the idea that RECK could be an important therapeutic effector against human PDAC

Effect of Superchilling (Hyo-On) Aging on the Total Bacterial Count and Concentration of Taste Components of Pork Loin

氷温を利用した肉類の長期熟成処理の有用性を評価するために、従来の熟成処理温度である4℃および氷温である−1℃で豚ロース肉の熟成処理を行い、一般生菌数、イノシン酸および遊離アミノ酸濃度に及ぼす影響を評価した。−1℃熟成処理の一般生菌数は、4℃熟成処理と比較して、熟成処理7、14および21日で有意に低下した。さらに−1℃熟成処理42日後でも、肉類が腐敗したと判断する一般生菌数である108コロニー形成単位/gには達していなかった。一方、−1℃熟成処理のイノシン酸濃度は、4℃熟成処理と比較して、緩やかな減少がみられた。腐敗の指標の1 つである一般生菌数が同等であった4℃熟成処理14日および−1℃熟成処理42日について遊離アミノ酸濃度の測定および官能評価を実施した。その結果、豚ロース肉の−1℃熟成処理42日は、4℃熟成処理14日と比較して、うま味に関わるグルタミン酸濃度の有意な上昇と嗜好型官能評価において総合的に好ましいと評価された。これらの結果より豚ロース肉の−1℃熟成処理は、4℃熟成処理よりも、一般生菌数の増殖抑制と食味性を向上させることで付加価値の向上に寄与できると考えられる。To evaluate the effects of long-term meat aging at superchilling, the total bacterial count, concentration of taste components, and palatability of pork loin were compared for samples aged at 4 °C and −1 °C. At 7, 14, and 21 days of aging, the total bacterial count of pork aged at −1℃ had significantly decreased compared to that of the sample aged at 4 ℃. Even after aging pork at −1 °C for 42 days, the total bacterial count did not reach 108 colony forming unit/g, which is generally considered to be the spoilage of meat. The concentration of inosinic acid in the pork loin aged at −1 ℃ was s decreased more slowly than that of the sample aged at 4 ℃. Free amino acid analysis and sensory evaluation were performed on the samples aged at 4 °C for 14 days and at −1 ℃ for 42 days, in which the total bacterial count was almost equivalent. Further, the glutamic acid concentration and overall palatability of pork loin sample aged at −1 ℃ for 42 days were significantly increased as compared to those of samples aged at 4 °C for 14 days. From these results, it was concluded that aging at −1 ℃ increased the added value of pork by suppressing the growth of bacteria and improving its palatability over that achieved from samples aged at 4 °C.本研究の一部は、2020年度関西大学若手研究者育成経費（個人研究）において、研究課題「熱成処理温度の違いが食肉の呈味成分の生成に関与するアミノペプチダーゼ活性に及ぼす影響」として研究費を受け、その成果を公表するものである

Prevention of hypoglycemia by intermittent-scanning continuous glucose monitoring device combined with structured education in patients with type 1 diabetes mellitus : A randomized, crossover trial

Aims: We conducted a randomized, crossover trial to compare intermittent-scanning continuous glucose monitoring (isCGM) device with structured education (Intervention) to self-monitoring of blood glucose (SMBG) (Control) in the reduction of time below range. Methods: This crossover trial involved 104 adults with type 1 diabetes mellitus (T1DM) using multiple daily injections. Participants were randomly allocated to either sequence Intervention/Control or sequence Control/Intervention. During the Intervention period which lasted 84 days, participants used the first-generation FreeStyle Libre (Abbott Diabetes Care, Alameda, CA, USA) and received structured education on how to prevent hypoglycemia based on the trend arrow and by frequent sensor scanning (≥10 times a day). Confirmatory SMBG was conducted before dosing insulin. The Control period lasted 84 days. The primary endpoint was the decrease in the time below range (TBR; <70 mg/dL). Results: The time below range was significantly reduced in the Intervention arm compared to the Control arm (2.42 ± 1.68 h/day [10.1 %±7.0 %] vs 3.10 ± 2.28 h/day [12.9 %±9.5 %], P = 0.012). The ratio of high-risk participants with low blood glucose index >5 was significantly reduced (8.6 % vs 23.7 %, P < 0.001). Conclusions: The use of isCGM combined with structured education significantly reduced the time below range in patients with T1DM

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

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