多成分自己集合による液晶性超分子錯体の構築

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 加藤 隆史, 東京大学教授 藤田 誠, 東京大学教授 野崎 京子, 東京大学准教授 北條 博彦, 物質・材料研究機構主幹研究員 吉尾 正史University of Tokyo(東京大学

Association Between SLFN11 and Antitumor Activity of Trabectedin

Background/Aim: Trabectedin is a DNA-damaging agent and has been approved for the treatment of patients with advanced soft tissue sarcoma. Schlafen 11 (SLFN11) was identified as a dominant determinant of the response to DNA-damaging agents. The aim of the study was to clarify the association between SLFN11 expression and the antitumor activity of trabectedin. Materials and Methods: The antitumor activity of trabectedin was evaluated under different expression levels of SLFN11 regulated by RNA interference and CRISPR-Cas9 systems, and the combined antitumor activity of ataxia telangiectasia and Rad3-related protein kinase (ATR) inhibitor and trabectedin in sarcoma cell lines using in vitro a cell viability assay and in vivo xenograft models. Results: SLFN11-knockdown cell lines had a lower sensitivity to trabectedin, compared to parental cells. ATR inhibitor enhanced the antitumor activity of trabectedin in SLFN11-knockdown cells and in a SLFN11-knockout xenograft model. Conclusion: SLFN11 expression might be a key factor in the antitumor activity of trabectedin

Load carrying behavior of concrete reinforced with bundled BFRP bars by using DIC

Recently, basalt fiber-reinforced polymer (BFRP) has gained attention in the construction industry because of its worldwide availability and eco-friendly nature. Different from conventional steel bars, BFRP bar do not corrode being an ideal reinforcing material in structures surrounding magnetic fields and marine environments, given its chemical stability. This study investigated the load carrying behavior of concrete beams reinforced with conventional deformed steel bars and seven-bundled BFRP bars through four-point flexural test. For each case, two beams were pre-pared; one beam was designed with a low reinforcement ratio and another with a high rein-forcement ratio in order to obtain a load carrying capacity of around 330-368 kN and 483-519 kN, respectively. Deflection, crack width evolution, and strain behavior of each beam were comparatively analyzed using a digital image correlation (DIC) based technique. The DIC analysis results showed that the neutral axis of bundled BFRP reinforced cases move to the upper end in an early loading stage, with larger cracks width, and the deflection is larger in BFRP cases than in those of steel-reinforced beams with the respective reinforcement ratio. However, the four-point flexural test results revealed that bundled BFRP bars can be used as an alternative to conventional steel bars. The load carrying capacities were obtained similarly to designed values, around 364 and 551 kN for low and high reinforcement ratio cases, respectively

The lectin‐like domain of thrombomodulin is a drug candidate for both prophylaxis and treatment of liver ischemia and reperfusion injury in mice

Ischemia and reperfusion injury (IRI) can occur in any tissue or organ. With respect to liver transplantation, the liver grafts from donors by definition experience transient ischemia and subsequent blood reflow. IRI is a problem not only in organ transplantation but also in cases of thrombosis or circulatory disorders such as mesenteric ischemia, myocardial, or cerebral infarction. We have reported that recombinant human soluble thrombomodulin (rTM), which is currently used in Japan to treat disseminated intravascular coagulation (DIC), has a protective effect and suppresses liver IRI in mice. However, rTM may not be fully safe to use in humans because of its inherent anticoagulant activity. In the present study, we used a mouse liver IRI model to explore the possibility that the isolated lectin-like domain of rTM (rTMD1), which has no anticoagulant activity, could be effective as a therapeutic modality for IRI. Our results indicated that rTMD1 could suppress ischemia and reperfusion-induced liver damage in a dose-dependent manner without concern of associated hemorrhage. Surprisingly, rTMD1 suppressed the liver damage even after IR insult had occurred. Taken together, we conclude that rTMD1 may be a candidate drug for prevention of and therapy for human liver IRI without the possible risk of hemorrhage

A novel interplay between the Fanconi anemia core complex and ATR-ATRIP kinase during DNA cross-link repair.

When DNA replication is stalled at sites of DNA damage, a cascade of responses is activated in the cell to halt cell cycle progression and promote DNA repair. A pathway initiated by the kinase Ataxia teleangiectasia and Rad3 related (ATR) and its partner ATR interacting protein (ATRIP) plays an important role in this response. The Fanconi anemia (FA) pathway is also activated following genomic stress, and defects in this pathway cause a cancer-prone hematologic disorder in humans. Little is known about how these two pathways are coordinated. We report here that following cellular exposure to DNA cross-linking damage, the FA core complex enhances binding and localization of ATRIP within damaged chromatin. In cells lacking the core complex, ATR-mediated phosphorylation of two functional response targets, ATRIP and FANCI, is defective. We also provide evidence that the canonical ATR activation pathway involving RAD17 and TOPBP1 is largely dispensable for the FA pathway activation. Indeed DT40 mutant cells lacking both RAD17 and FANCD2 were synergistically more sensitive to cisplatin compared with either single mutant. Collectively, these data reveal new aspects of the interplay between regulation of ATR-ATRIP kinase and activation of the FA pathway

Hepatomegaly Associated with Non-Obstructive Sinusoidal Dilation in Experimental Visceral Leishmaniasis.

Visceral leishmaniasis (VL) is the most severe form of leishmaniasis caused by protozoan parasites of the genus Leishmania. Hepatomegaly is one of the most frequent clinical manifestations of VL, whereas immunopathology of the symptom has not been well investigated. Using our chronic model of experimental VL, we examined the influence of Leishmania donovani infection on the liver by clinical, histological, and biochemical analyses. The infected mice showed increased liver weight 24 weeks post-infection. Although an increase in serum ALT and inflammatory cell accumulation were observed in the livers of infected mice, no apparent parenchymal necrosis or fibrosis was observed. Tissue water content analyses demonstrated that increased liver weight was predominantly due to an increase in water weight. Together with the finding of hepatic sinusoidal dilation, these results suggested that edema associated with sinusoidal dilation causes hepatomegaly in L. donovani infection. Immunostaining of platelets and erythrocytes showed no thrombus formation or damage to the sinusoidal endothelium in the liver of infected mice. Taken together, these results suggest that hepatomegaly during experimental VL is caused by non-obstructive sinusoidal dilation