Publications by authors named "Satoko Okayama"

Article Synopsis
  • Heterochromatin is crucial for gene expression and stability in eukaryotic cells, forming dense, inactive regions in the nucleus.
  • This study investigates how specific modifications of histone proteins (H3K9me3 and H3K27me3) impact the organization of heterochromatin by using mutant cells and a dual inhibitor.
  • Findings indicate that loss of H3K9 methylation leads to a redistribution of H3K27me3, and when both modifications are lost, it disrupts the structural organization of heterochromatin, highlighting the protective role of H3K27me3.
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Article Synopsis
  • Motile cilia in epithelial cells beat in sync to move fluid across organ surfaces, but their microtubule structure's formation is not fully understood.
  • Researchers found that the protein CAMSAP3 is crucial for the stability and formation of the cilium's structure, specifically concentrating at the transition zone where cilia are formed.
  • Dysfunction of CAMSAP3 leads to loss of key microtubules and uncoordinated cilia movement, highlighting its importance in cilia function in airway epithelial cells.*
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The calyx of Held, a large glutamatergic presynaptic terminal in the auditory brainstem undergoes developmental changes to support the high action-potential firing rates required for auditory information encoding. In addition, calyx terminals are morphologically diverse, which impacts vesicle release properties and synaptic plasticity. Mitochondria influence synaptic plasticity through calcium buffering and are crucial for providing the energy required for synaptic transmission.

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Targeted temperature management (TTM), or therapeutic hypothermia, is one of the most potent neuroprotective approaches after ischemic and traumatic brain injuries. TTM has been applied clinically with various methods, but effective achievement and maintenance of the target temperature remain challenging. Furthermore, timing of cooling and target body and brain temperature to optimize effectiveness for neuroprotection and to minimize side effects are yet to be standardized.

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Background And Objective: The periodontal ligament (PDL) is an essential tissue for tooth function. However, the 3-dimensional ultrastructure of these PDL collagen bundles on a mesoscale is not clear. We investigated the 3-dimensional ultrastructure of these collagen bundles and quantitatively analyzed their histomorphometry using focused ion beam/scanning electron microscope (FIB/SEM) tomography.

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Rett syndrome (RTT) is a neurodevelopmental disorder mainly caused by mutations in the gene encoding the transcriptional regulator Methyl-CpG-binding protein 2 (MeCP2), located on the X chromosome. Many RTT patients have breathing abnormalities, such as apnea and breathing irregularity, and respiratory infection is the most common cause of death in these individuals. Previous studies showed that MeCP2 is highly expressed in the lung, but its role in pulmonary function remains unknown.

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The accurate comprehension of normal tissue provides essential data to analyse abnormalities such as disease and regenerative processes. In addition, understanding the proper structure of the target tissue and its microenvironment may facilitate successful novel treatment strategies. Many studies have examined the nature and structure of periodontal ligaments (PDLs); however, the three-dimensional (3D) structure of cells in normal PDLs remains poorly understood.

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Endocrine and endothelial cells of the anterior pituitary gland frequently make close appositions or contacts, and the secretory granules of each endocrine cell tend to accumulate at the perivascular regions, which is generally considered to facilitate secretory functions of these cells. However, three-dimensional relationships between the localization pattern of secretory granules and blood vessels are not fully understood. To define and characterize these spatial relationships, we used scanning electron microscopy (SEM) three-dimensional reconstruction method based on focused ion-beam slicing and scanning electron microscopy (FIB/SEM).

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An important consideration in regeneration therapy is the fact that the tissue surrounding an organ supports its function. Understanding the structure of the periosteum can contribute to more effective bone regeneration therapy. As a cellular source, the periosteum also assists bone growth and fracture healing; this further necessitates its direct contact with the bone.

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Methyl-CpG-binding protein 2 (MeCP2) is an epigenetic regulator of gene expression that is essential for normal brain development. Mutations in MeCP2 lead to disrupted neuronal function and can cause Rett syndrome (RTT), a neurodevelopmental disorder. Previous studies reported cardiac dysfunction, including arrhythmias in both RTT patients and animal models of RTT.

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IntroductionMitochondrial fission and fusion events are fundamental mechanisms for quality control of mitochondrial functions. Mitochondrial DNA (mtDNA) usually divides in offspring mitochondria after fission and mtDNA dynamics are thought to be coordinated with mitochondrial turnover. Recently, several candidate mechanisms for the relationship between mtDNA division and mitochondrial fission have been suggested ([1], 2012).

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The endoplasmic reticulum (ER) and mitochondria associate at multiple contact sites to form specific domains known as mitochondria-ER associated membranes (MAMs) that play a role in the regulation of various cellular processes such as Ca2+ transfer, autophagy, and inflammation. Recently, it has been suggested that MAMs are also involved in mitochondrial dynamics, especially fission events. Cytological analysis showed that ER tubules were frequently located close to each other in mitochondrial fission sites that accumulate fission-related proteins.

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In mammals, definitive erythropoiesis first occurs in fetal liver (FL), although little is known about how the process is regulated. FL consists of hepatoblasts, sinusoid endothelial cells and hematopoietic cells. To determine niche cells for fetal liver erythropoiesis, we isolated each FL component by flow cytometry.

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Induced pluripotent stem cells (iPSCs) are a promising tool for regenerative medicine. Use of iPSC lines for future hematotherapy will require examination of their hematopoietic potential. Adult skin fibroblast somatic cells constitute a source of iPSCs that can be accessed clinically without ethical issues.

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