Publications by authors named "Yukiko Miyatake"
Article Synopsis
- - The study presents a new molecule, RA, which can sense and generate singlet oxygen (O) and has various functions depending on the wavelength of light used.
- - RA behaves like a traditional O sensor when exposed to UV-visible light, similar to a commercial product called SOSG, and can also operate as a delayed O sensor under longer wavelengths (~700 nm).
- - Additionally, RA effectively generates O when exposed to green light, showing potential as a therapeutic agent against pancreatic cancer by targeting the cells specifically.
Article Synopsis
- A new in vitro imaging technique using micro-patterned plates allows for real-time observation of pancreatic ductal adenocarcinoma (PDAC) microtumours, overcoming limitations of traditional diagnostic methods.
- PDAC cells self-organize into non-spheroidal microtumours on the plates, particularly on small-diameter rough microislands, indicating specific growth conditions are necessary for this process.
- Time-lapse imaging reveals that PDAC microtumours exhibit active behaviors, like stretching to capture dead cell debris, hinting at their complex survival strategies and the potential for developing new therapies.
Article Synopsis
- Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer, and researchers are studying the behavior of its cells in coculture with epithelial-like feeder cells.* -
- PDAC cells formed structures called anchorage-dependent multicellular aggregates (Ad-MCAs) when cocultured with HEK293T cells, gaining traits like resistance to the chemotherapy drug gemcitabine and increased expression of cancer stem cell markers.* -
- The research suggests that these Ad-MCAs may resemble early metastatic behaviors in PDAC cells, potentially helping to understand the cancer's progression and the changes in gene expression that occur in patients.*
Article Synopsis
- Dendritic epidermal T cells, mostly found in mouse skin, are essential for immune defense and are generated in the fetal thymus, relying on the Skint1 gene for proper development.
- Humans and chimpanzees possess a mutated version of the Skint1 gene (SKINT1L) that seems non-functional, while Old World monkeys have a seemingly active SKINT1L.
- Research shows that while macaques have T cells resembling the functions of dendritic epidermal T cells, they differ from those in rodents, indicating that true dendritic epidermal T cells might be unique to rodent species.
Article Synopsis
- * The study found that pancreatic cancer cells with an epithelial characteristic increase the expression of CD44 variant 9 (CD44v9) during cell division phases, indicating a link to cancer stem cell behavior.
- * Cells that were initially negative for CD44v9 regain its expression when they enter mitosis, and those expressing high levels of CD44v9 also show levels of a protein linked to drug resistance, suggesting a connection to the cancer's tough nature and growth.
Article Synopsis
- * ATL cells can form structures called anchorage-dependent multicellular aggregates (Ad-MCAs) when grown on epithelial-like feeder cells, with some cells exhibiting cancer stem cell-like traits (high CD44 expression).
- * Blocking the NF-κB pathway and disrupting the vimentin cytoskeleton hindered the formation of Ad-MCAs, indicating these pathways play key roles in ATL cell adhesion and behavior similar to metastatic processes.
Article Synopsis
- Infiltrating macrophages convert into foam cells in fatty streak lesions, contributing to atherosclerotic plaque formation.
- The role of NKG2D-positive lymphocytes in inflammatory mechanisms related to plaque formation has been studied, but the NKG2D system itself is not well understood.
- Recent findings indicate that the NKG2D receptor-ligand interaction exacerbates plaque formation in both mouse models and potentially in humans, as NKG2D ligands MICA/B were found in advanced atherosclerotic lesions.
Adult T-cell leukemia/lymphoma (ATL) is a highly invasive and intractable T-cell malignancy caused by human T-cell leukemia virus-1 infection. We demonstrate herein that normal tissue-derived epithelial cells (NECs) exert protective effects on the survival of leukemic cells, which may partially account for high resistance to antileukemic therapies in patients with ATL. Viral gene-silenced, ATL-derived cell lines (ATL cells) dramatically escaped from histone deacetylase inhibitor-induced apoptosis by direct co-culture with NECs.
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- The proteasome is an enzyme complex that breaks down both normal and damaged proteins, but its activity declines with age, potentially leading to age-related diseases.
- Researchers created a transgenic mouse model with reduced proteasomal activity, which resulted in shorter lifespans and the development of age-related traits like obesity and liver fat accumulation when fed a high-fat diet.
- The study suggests that decreased proteasomal activity has a significant impact on longevity and heightens age-related metabolic disorders, offering new insights into how these processes might relate to aging.
Article Synopsis
- * Researchers focused on cyclic AMP response element-binding protein (CREB), which is highly present in RA synovial cells and may regulate IL-6 expression, but its exact role was unclear.
- * By using a dominant negative molecule called ATF-1DN to inhibit CREB in synovial cells from a rat model of RA, the researchers found that ATF-1DN significantly lowered IL-6 production, suggesting CREB's involvement in the pathogenesis of RA.
Article Synopsis
- - The ubiquitin-proteasome pathway is crucial for degrading proteins and producing peptides important for immune response, and it involves the 20S proteasome, which has three main beta subunits.
- - A new beta subunit, beta5t, found only in cortical thymic epithelial cells in mice, is part of the thymoproteasome that plays a role in positive selection of T-cells.
- - This study reveals that human beta5t is also found exclusively in the thymic cortex, suggesting that the functional role of thymoproteasomes is similar in both humans and mice, as it forms specialized proteasomes with distinct compositions.
Article Synopsis
- H60 is a molecule that acts as a ligand for the NKG2D receptor and has been identified as a dominant minor histocompatibility antigen.
- The study discovered two new ligands, H60b and H60c, which are similar to H60 and are encoded on mouse chromosome 10, with H60b having a transmembrane region and H60c being GPI-anchored.
- Both H60b and H60c can bind to NKG2D and trigger immune responses, with their expression patterns being regulated differently, particularly in response to infections.
Article Synopsis
- High-dose steroid hormones can lead to necrosis of the femoral head, possibly through ischemic hypoxia causing apoptosis in osteocytes.
- A study used mouse cell lines to analyze gene expression in osteocytes under hypoxic conditions with and without steroid hormone exposure.
- Results showed that osteocytes exposed to high-dose steroids exhibit increased sensitivity to apoptosis in low-oxygen environments, which may help explain the causes of idiopathic bone necrosis.
Article Synopsis
- Human T-cell leukemia virus type 1 (HTLV-1) causes both adult T-cell leukemia and HAM/TSP, with chronic myelopathy (HAM rat disease) occurring specifically in WKAH rats.
- In the study, researchers found that HTLV-1 infection led to the production of interferon-gamma (IFN-gamma) in spinal cords of HAM-resistant rats, but not in WKAH rats, where neurons were the main producers.
- The WKAH rats' inability to produce IFN-gamma was linked to a defect in signaling through the interleukin-12 receptor, suggesting this impacts the progression of HAM rat disease.
[Gene expression in spinal cord of HTLV-I associated myelopathy sensitive and resistant rats].
Hokkaido Igaku Zasshi
September 2005
Article Synopsis
- A study on FW-pX rats, which possess the human T cell leukemia virus type-1 pX gene, revealed they developed severe health issues similar to chronic graft-vs.-host disease (GVHD), such as thymus atrophy and inflammatory cell infiltration in various organs.
- Following the mating of F344 transgenic rats with nontransgenic Wistar rats, neonatal FW-pX rats showed significant loss of thymic epithelial cells and a striking depletion of CD4 CD8 double-positive thymocytes.
- The findings indicate that the FW-pX rats may serve as a model for understanding chronic GVHD and other autoimmune diseases, potentially due to impaired T cell development in the thymus during early life.
Article Synopsis
- Transgenic rats with the env-pX gene from human T cell leukemia virus type-I developed autoimmune diseases due to impaired regulatory T (T-reg) cell functions.
- The main issue with T-reg cells was linked to abnormal differentiation processes, not directly due to thymus-related problems, as shown by bone marrow transfer experiments.
- Gene expression analysis revealed that env-pX T-reg cells exhibit a naive phenotype with low suppressor of cytokine signaling (SOCS) expression, potentially leading to overactive JAK/STAT signaling pathways and loss of T-reg cell function.
Article Synopsis
- The study investigates how warm ischemia affects gene expression in tissue samples from lung, liver, kidney, and spleen in rats, using cDNA array analysis and other techniques.
- Despite no visible changes in RNA quality, the cDNA array revealed significant modulation of gene expression due to warm ischemia, with variation in percentage among different tissues (e.g., 19.1% in lung).
- The research highlights that warm ischemia can lead to a differential transcriptional response in tissues and indicates that surgical tissue samples may carry the effects of ischemia, which should be considered in genetic analyses.
Article Synopsis
- * Experiments involving bone marrow cell transplantation suggest that the persistent arthritis in env-pX rats is primarily influenced by their articular tissues rather than by the transgenic bone marrow cells.
- * Elevated levels of interleukin-6 (IL-6) in synovial cells from env-pX rats before arthritis onset indicate that IL-6 plays a crucial role in the severity and persistence of arthritis in these rats.