大腸癌肝転移症例におけるCD133発現の免疫組織学的検討

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 小池 和彦, 東京大学准教授 深柄 和彦, 東京大学准教授 藤城 光弘, 東京大学准教授 野村 幸世, 東京大学講師 保科 克行University of Tokyo(東京大学

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

Expression of the stem cell marker CD133 is related to tumor development in colorectal carcinogenesis

Summary: Background/Objective: CD133 is currently considered the most robust surface marker for colorectal cancer stem cells. Two meta-analysis reports have suggested that CD133 expression is significantly associated with shorter survival, and CD133 may play an important role in the progression of colorectal cancer. However, the role of CD133 in colorectal adenoma has not been fully elucidated. Methods: We used immunohistochemistry to evaluate CD133 expression in 200 endoscopically resected colorectal polyps from 200 patients and 20 normal mucosae between January 1993 and December 1996. Results: CD133 staining was positive in 17.9% of the colorectal adenomas. Moreover, CD133 expression was associated with differentiation status (p = 0.003) and tumor size (p = 0.03). Conclusion: CD133 might play an important role in tumor development. Keywords: CD133, colorectal adenoma, immunohistochemistr

Automated analysis of the serum antioxidative activities against five different reactive oxygen species by sequential injection system with a chemiluminescence detector.

BACKGROUND: There is a growing evidence that reactive oxygen species (ROS) may cause many pathologic conditions including chronic diseases, neurodegenerative disorders, cancer and aging. There are a number of methods to measure the total antioxidative activity of the serum. However, since the lifetime and oxidative activity of various types of ROS are all different, to measure simply the total antioxidative activity of the serum is not enough. Therefore, to aid the diagnosis and to improve the therapeutic strategy, it is important to develop a simple and reliable method of assaying antioxidative activity of the serum. METHODS: A method that combines sequential injection analysis (SIA) and luminol chemiluminescence (CL) detection was employed for the measurement of antioxidative activities of human serum. We collected sera from healthy subjects (n=42) and patients with diabetes (n=39) and rheumatoid arthritis (n=25) and tested the sensitivity, reproducibility and reliability of our method. RESULTS: Since the operation is automatically controlled by a personal computer, we obtained a satisfactory repeatability without the need of much manpower. The time required for obtaining the antioxidative activity against one ROS for one individual is less than 3min. Although the value of antioxidative activity varies from subject to subject, there were a certain relationship between the disease and the antioxidative values of each type of ROS. The results suggest that the measurement of antioxidative activity against different ROS may provide us with valuable information regarding the disease state. CONCLUSIONS: The evaluation of antioxidative activities against each ROS by the proposed method should be more informative to understand the antioxidative status of biological fluid

Transcription Factor YY1 Interacts with Retroviral Integrases and Facilitates Integration of Moloney Murine Leukemia Virus cDNA into the Host Chromosomes▿

Retroviral integrases associate during the early viral life cycle with preintegration complexes that catalyze the integration of reverse-transcribed viral cDNA into the host chromosomes. Several cellular and viral proteins have been reported to be incorporated in the preintegration complex. This study demonstrates that transcription factor Yin Yang 1 binds to Moloney murine leukemia virus, human immunodeficiency virus type 1, and avian sarcoma virus integrases. The results of coimmunoprecipitation and in vitro pulldown assays revealed that Yin Yang 1 interacted with the catalytic core and C-terminal domains of Moloney murine leukemia virus and human immunodeficiency virus type 1 integrases, while the transcriptional repression and DNA-binding domains of the Yin Yang 1 molecule interacted with Moloney murine leukemia virus integrase. Immunoprecipitation of the cytoplasmic fraction of virus-infected cells followed by Southern blotting and chromatin immunoprecipitation demonstrated that Yin Yang 1 associated with Moloney murine leukemia virus cDNA in virus-infected cells. Yin Yang 1 enhanced the in vitro integrase activity of Moloney murine leukemia virus, human immunodeficiency virus type 1, and avian sarcoma virus integrases. Furthermore, knockdown of Yin Yang 1 in host cells by small interfering RNA reduced Moloney murine leukemia virus cDNA integration in vivo, although viral cDNA synthesis was increased, suggesting that Yin Yang 1 facilitates integration events in vivo. Taking these results together, Yin Yang 1 appears to be involved in integration events during the early viral life cycle, possibly as an enhancer of integration