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Factor XI localization in human deep venous thrombus and function of activated factor XI on venous thrombus formation and hemostasis

Background Novel anticoagulants targeting coagulation factor (F)XI/activated FXI (FXIa) are currently under development. However, whether FXI is present in human deep vein thrombosis (DVT) and whether FXIa and activated FX (FXa) play different roles in venous thrombus formation and hemostasis remain unclear. Objectives To determine the presence of FXI in DVT and the effects of direct oral FXIa and FXa inhibitors on venous thrombus formation and hemostasis in rabbits and on in vitro thrombus formation. Methods We immunohistochemically assessed FXI localization in human-aspirated DVT (n = 15). Additionally, we compared thrombus formation induced by endothelial denudation and stenosis or stasis in the jugular vein and skin bleeding time and volume between rabbits treated with direct FXIa inhibitors (ONO-1600586) and FXa inhibitors (rivaroxaban). Ex vivo rabbit and human blood were perfused in a flow chamber under low-shear rates (70/s). Results FXI was localized in all DVT, predominantly in fibrin-rich areas. The FXI immunopositive area in the nonorganizing area was greater than that in the organizing area. Although FXIa and FXa inhibitors comparably inhibited venous thrombus formation, FXIa inhibitors did not affect bleeding time or volume in rabbits. FXIa or FXa inhibitors mildly or strongly inhibited fibrin formation at low-shear rates, respectively. Furthermore, the FXIa inhibitor suppressed human FXIa activity, thrombin generation, and fibrin formation during perfusion. Conclusion The pathologic findings of human DVT suggest FXI’s role in human DVT. FXIa inhibitors may inhibit less fibrin formation than FXa inhibitors and may explain the minor role of FXIa in hemostasis.Citation: Nobuyuki Oguri, Toshihiro Gi, Eriko Nakamura, Kazunari Maekawa, Eiji Furukoji, Hoshimi Okawa, Sho Kouyama, Saki Horiuchi, Akira Sawaguchi, Tatefumi Sakae, Minako Azuma, Yujiro Asada, Atsushi Yamashita, Factor XI localization in human deep venous thrombus and function of activated factor XI on venous thrombus formation and hemostasis, Research and Practice in Thrombosis and Haemostasis, 9(2), 102720-102720, 2025-02, https://doi.org/10.1016/j.rpth.2025.10272

Studies of CP Violation in B→J/ψK* Decays

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Paracrine factors of vascular endothelial cells facilitate cardiomyocyte differentiation of mouse embryonic stem cells

For myocardial regeneration therapy, the low differentiation capability of functional cardiomyocytes sufficient to replace the damaged myocardial tissue is one of the major difficulties. Using Nkx2.5-GFP knock-in ES cells, we show a new efficient method to obtain cardiomyocytes from embryonic stem (ES) cells. The proportion of GFP-positive cells was significantly increased when ES cells were cultured with a conditioned medium from aortic endothelial cells (ECs), accompanied by upregulation of cardiac-specific genes as well as other mesodermal genes. The promotion was more prominent when EC-conditioned medium was added at an early stage of ES cell differentiation culture (Day 0–3). Inhibitors of bone morphogenic protein (BMP), cyclooxygenase (COX), and nitric oxide synthetase (NO) prevented the promotion of cardiomyogenesis by EC-conditioned medium. These results suggest that supplementation of EC-conditioned medium enables cardiomyocytes to be obtained efficiently through promotion of mesoderm induction, which is regulated by BMP, COX, and NOS.journal articl

Control of protein function through oxidation and reduction of persulfidated states

Irreversible oxidation of Cys residues to sulfinic/sulfonic forms typically impairs protein function. We found that persulfidation (CysSSH) protects Cys from irreversible oxidative loss of function by the formation of CysSSO1-3H derivatives that can subsequently be reduced back to native thiols. Reductive reactivation of oxidized persulfides by the thioredoxin system was demonstrated in albumin, Prx2, and PTP1B. In cells, this mechanism protects and regulates key proteins of signaling pathways, including Prx2, PTEN, PTP1B, HSP90, and KEAP1. Using quantitative mass spectrometry, we show that (i) CysSSH and CysSSO3H species are abundant in mouse liver and enzymatically regulated by the glutathione and thioredoxin systems and (ii) deletion of the thioredoxin-related protein TRP14 in mice altered CysSSH levels on a subset of proteins, predicting a role for TRP14 in persulfide signaling. Furthermore, selenium supplementation, polysulfide treatment, or knockdown of TRP14 mediated cellular responses to EGF, suggesting a role for TrxR1/TRP14-regulated oxidative persulfidation in growth factor responsiveness.journal articl

高Aｌ組成AｌＧAＮのエピタキシャル成長と欠陥制御技術

application/pdf本研究では、サファイア上のAlNエピタキシャル結晶上へのAlN及び高Al組成AlGaNの低欠陥密度結晶を作製する技術を確立し、高品質高Al組成AlGaN、無極性AlGaN、クラックフリーAlN基板を得ることができた。また、サファイア上のAlNエピタキシャル結晶上への高Al組成AlGaNを用いた電子線励起によるUV-Cの深紫外光源を作製し、強い紫外線発光を得るためのデバイス構造に関する知見を得ることができた。In this research, the studies on obtaining high quality AlN and AlGaN with high AlN molar fraction are carried out. High quality AlGaN with high AlN, nonpolar AlGaN and crack-free AlN substrate can be obtained. Furthermore by using these materials, the UV-C light source excited by electron beam is fabricated. The structures which we can obtain strong UV emission are found.平成18~22年度科学研究費補助金(特定領域研究)研究成果報告書18069006research repor

A synthetic tryptophan metabolite reduces hemorrhagic area and inflammation after pulmonary radiofrequency ablation in rabbit nonneoplastic lungs

Purpose The purpose of this study was to determine the effect of a synthetic tryptophan metabolite, tranilast [N-（3,4-dimethoxycinnamoyl）-anthranilic acid], on inflammatory and hemorrhagic areas after pulmonary radiofrequency ablation （RFA） in rabbits. Materials and methods Percutaneous RFA using a 17-gauge LeVeen electrode was performed in normal rabbit lungs. The rabbits were divided into tranilast-treated （300 mg/kg/day, orally） and control groups （n = 24/group）. The effects of tranilast were evaluated using multidetector-row computed tomography （CT）, histology, and immunohistochemistry immediately after RFA on days 1, 7, 14, and 28. Results Oral administration of tranilast significantly reduced the size of ablated lesions assessed using CT and histology on days 7 and 14. Furthermore, it reduced the hemorrhagic areas on day 7 and inflammatory areas on day 14, but did not affect the areas of coagulation necrosis on days 1, 7, 14, and 28. Immunohistochemical analysis showed an increase in the ratio of CD163-positive macrophage areas to rabbit macrophage （RAM11）-positive pan-macrophage areas and a decrease in the number of nuclear factor-κB-positive nuclei and CD31-positive microvessels in the tranilast group on days 7 and/or 14. Conclusions The results suggest that tranilast modulates the repair process after pulmonary RFA through macrophage accumulation, suppression of inflammation, and angiogenesis

Elevated plasma levels of factor VIII enhance arterial thrombus formation on erosive smooth muscle cell-rich neointima but not normal intima in rabbits

Background Plaque erosion, a type of coronary atherothrombosis, involves superficial injury to smooth muscle cell (SMC)-rich plaques. Elevated levels of coagulation factor VIII (FVIII) correlate with an increased ischemic heart disease risk. FVIII may contribute to thrombus formation on eroded plaques. Aims We aimed to elucidate the role of elevated FVIII in arterial thrombus formation within SMC-rich neointima in rabbits. Methods and results We assessed the effect of recombinant human FVIII (rFVIII) on blood coagulation in vitro and platelet aggregation ex vivo. An SMC-rich neointima was induced through balloon injury to the unilateral femoral artery. Three weeks after the first balloon injury, superficial erosive injury and thrombus formation were initiated with a second balloon injury of the bilateral femoral arteries 45 min after the administration of rFVIII (100 IU/kg) or saline. The thrombus area and contents were histologically measured 15 min after the second balloon injury. rFVIII administration reduced the activated partial thromboplastin time and augmented botrocetin-induced, but not collagen- or adenosine 5′-diphosphate-induced, platelet aggregation. While rFVIII did not influence platelet-thrombus formation in normal intima, it increased thrombus formation on SMC-rich neointima post-superficial erosive injury. Enhanced immunopositivity for glycoprotein IIb/IIIa and fibrin was observed in rFVIII-administered SMC-rich neointima. Neutrophil count in the arterial thrombus on the SMC-rich neointima correlated positively with thrombus size in the control group, unlike the rFVIII group. Conclusions Increased FVIII contributes to thrombus propagation within erosive SMC-rich neointima, highlighting FVIII's potential role in plaque erosion-related atherothrombosis.Citation: Sugita C, Maekawa K, Gi T, Oguri N, Nakamura E, Furukoji E, Azuma M, Asada Y, Yamashita A. Elevated plasma levels of factor VIII enhance arterial thrombus formation on erosive smooth muscle cell-rich neointima but not normal intima in rabbits. Thromb Res. 2024 Jun;238:185-196. doi: 10.1016/j.thromres.2024.04.025. Epub 2024 May 6. PMID: 38729030

Expression of fibroblast activation protein-α in human deep vein thrombosis

Background Fibroblast activation protein-α (FAP), a type-II transmembrane serine protease, is associated with wound healing, cancer-associated fibroblasts, and chronic fibrosing diseases. However, its expression in deep vein thrombosis (DVT) remains unclear. Therefore, this study investigated FAP expression and localization in DVT. Methods We performed pathological analyses of the aspirated thrombi of patients with DVT (n = 14), classifying thrombotic areas in terms of fresh, cellular lysis, and organizing reaction components. The organizing reaction included endothelialization and fibroblastic reaction. We immunohistochemically examined FAP-expressed areas and cells, and finally analyzed FAP expression in cultured dermal fibroblasts. Results All the aspirated thrombi showed a heterogeneous mixture of at least two of the three thrombotic areas. Specifically, 83 % of aspirated thrombi showed fresh and organizing reaction components. Immunohistochemical expression of FAP was restricted to the organizing area. Double immunofluorescence staining showed that FAP in the thrombi was mainly expressed in vimentin-positive or α-smooth muscle actin-positive fibroblasts. Some CD163-positive macrophages expressed FAP. FAP mRNA and protein levels were higher in fibroblasts with low-proliferative activity cultured under 0.1 % fetal bovine serum (FBS) than that under 10 % FBS. Fibroblasts cultured in 10 % FBS showed a significant decrease in FAP mRNA levels following supplementation with hemin, but not with thrombin. Conclusions The heterogeneous composition of venous thrombi suggests a multistep thrombus formation process in human DVT. Further, fibroblasts or myofibroblasts may express FAP during the organizing process. FAP expression may be higher in fibroblasts with low proliferative activity