Biology subjects

Asada, Y.

Publications and source records attributed to Asada, Y..

3 recordsLinked to original sources

bioRxiv2024

Neutrophil extracellular traps formation and deposition of fibrin and von Willebrand factor during human coronary atherogenesis

Background and aimsNeutrophil extracellular traps (NETs), fibrin, and the von Willebrand factor (VWF) are present in acute coronary thrombotic plaques. However, the presence and extent of NETs, fibrin, and VWF in early-to-unstable coronary atherosclerotic lesions remain unclear. This study aims to determine the presence and extent of neutrophils, NETs, fibrin, and VWF formation during human coronary atherogenesis. MethodsCoronary sections from autopsy patients with non-cardiac death (n=5, 37 sections) and ischemic heart diseases (n= 11, 65 sections) were classified by atherosclerosis classification: diffuse intimal thickening, pathological intimal thickening, fibrous cap atheroma, fibrocalcified plaque, thin-cap fibroatheroma, ruptured plaque, and intraplaque hemorrhage. We immunohistochemically assessed the expression of CD66b (neutrophils), citrullinated histone H3 (Cit-H3, a marker of NETs), fibrin, and VWF. ResultsNeutrophil and Cit-H3 expression were rarely observed, except in thin-cap fibroatheromas and ruptured plaques. Fibrin deposition was observed in pathological intimal thickening and necrotic cores of atheromas, and it was abundant in thin-cap fibroatheroma and ruptured plaques. VWF deposition was observed in the necrotic core of the atheromas and was abundant in ruptured plaques. In non-ruptured plaques, the immunopositive areas for Cit-H3 and fibrin were larger in hemorrhagic plaques than in non-hemorrhagic plaques. ConclusionsThese results suggest that NET formation is rare in stable coronary plaques, and fibrin formation begins in stable lesions and increases with plaque destabilization in the coronary artery. Intraplaque hemorrhage may promote NET formation and fibrin deposition in non-ruptured plaques. The abundance of neutrophilic infiltrates and VWF deposition may be a response to plaque rupture.

pathology↗

bioRxiv2023

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

BackgroundNovel anticoagulants targeting coagulation factor XI (FXI)/activated FXI (FXIa) are under development. However, whether FXI is present in human deep vein thrombosis (DVT) and whether FXIa and activated factor X (FXa) play different roles in venous thrombus formation and hemostasis remain unclear. This study aimed 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 mural thrombus formation in flow chamber system. MethodsWe immunohistochemically assessed FXI localization in human aspirated DVT (n=15). Additionally, we compared thrombus formation induced by endothelial denudation and stenosis in 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 on a flow chamber under low shear rates (70/s). ResultFXI was localized in all DVT, predominantly in fibrin-rich areas. The FXI-immunopositive area in the non-organizing 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. ConclusionThe pathological findings of human DVT suggest FXIs role in human DVT. FXIa inhibitors may inhibit less fibrin formation than FXa inhibitors, and may explain the minor role of FXIa in hemostasis. EssentialO_LIPresence of factor XI (FXI) in venous thrombus and less bleeding in its inhibition are unclear. C_LIO_LIWe assessed FXI localization in deep vein thrombosis (DVT) and function of FXIa in rabbit. C_LIO_LIFXI localized in human DVT that provide a rationale for FXI inhibition in human DVT. C_LIO_LIFXIa inhibitor inhibited less fibrin formation than factor Xa inhibitor under low-shear rate. C_LI

pathology↗

bioRxiv2021

Chromosome counting in the mouse and human zygote using low-invasive super-resolution live-cell imaging

In preimplantation embryos, an abnormal chromosome number causes developmental failure and a reduction in the pregnancy rate. Conventional chromosome testing methods requiring biopsy reduce the risk of associated genetic diseases; nevertheless, the reduction in cell number also reduces the pregnancy rate. Therefore, we attempted to count the chromosomes in mouse (Slc:ICR) embryos using super-resolution live-cell imaging as a new method of chromosome counting that does not reduce the cell number or viability. We counted the forty chromosomes at the first mitosis by injecting embryos with histone H2B-mCherry mRNA under conditions by which pups could be obtained; however, the results were often an underestimation of chromosome number and varied by embryo and time point. Therefore, we developed a method to count the chromosomes via CRISPR/dCas-mediated live-cell fluorescence in situ hybridization targeting the sequence of the centromere region, enabling us to count the chromosomes more accurately in mouse embryos. The methodology presented here may provide useful information for assisted reproductive technologies, such as those used in livestock animals/humans, as a technique for assessing the chromosomal integrity of embryos prior to transfer. Impact StatementLow-toxic super-resolution observation enables chromosome counting in preimplantation embryos without cell collection.

developmental biology↗