287 results match your criteria: "Graduate School and Faculty of Medicine[Affiliation]"

We report two cases of eyebrow granulomas in patients who underwent a permanent eye makeup procedure. A rash was observed 16 months after the procedure in Case 1, and 10 years after the procedure in Case 2. Histopathologically, both patients exhibited noncaseating epithelioid cell granulomas.

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Organ tropism of metastatic cells is not well understood. To determine the key factors involved in the selection of a specific organ upon metastasis, we established metastatic cell lines and analyzed their homing to specific tissues. Toward this, 143B osteosarcoma cells were injected intracardially until the kidney-metastasizing sub-cell line Bkid was established, which significantly differed from the parental 143B cells.

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-Derived Circulating Immune Complexes in Sarcoidosis Patients.

Microorganisms

October 2021

Department of Human Pathology, Graduate School and Faculty of Medicine, Tokyo Medical and Dental University, Tokyo 113-8510, Japan.

is a potential etiologic agent of sarcoidosis and a dysregulated immune response to the commensal bacterium is suspected to cause granuloma formation. -derived insoluble immune complexes were recently demonstrated in sinus macrophages of sarcoidosis lymph nodes, suggesting local proliferation of the bacterium in affected organs. In the present study, we developed a method for detecting -derived immune complexes in human blood by measuring the concentration of -specific lipoteichoic acid (PLTA) detectable after an antigen retrieval pretreatment of plasma samples.

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Seeds of dicotyledonous plants store proteins in dedicated membrane-bounded organelles called protein storage vacuoles (PSVs). Formed during seed development through morphological and functional reconfiguration of lytic vacuoles in embryos [M. Feeney , 177, 241-254 (2018)], PSVs undergo division during the later stages of seed maturation.

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is implicated in the pathogenesis of sarcoidosis. We investigated the usefulness of immunohistochemistry (IHC) with a commercially available -specific monoclonal antibody (PAB antibody) for differentiating sarcoidosis from other granulomatous diseases. Formalin-fixed paraffin-embedded tissue samples from 94 sarcoidosis patients and 30 control patients with other granulomatous diseases were examined by the original manual IHC method.

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Protein-rich droplets, such as stress granules, P-bodies, and the nucleolus, perform diverse and specialized cellular functions. Recent evidence has shown the droplets, which are also known as biomolecular condensates or membrane-less compartments, form by phase separation. Many droplets also contact membrane-bound organelles, thereby functioning in development, intracellular degradation, and organization.

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Stem cell spreading dynamics intrinsically differentiate acral melanomas from nevi.

Cell Rep

August 2021

Department of Stem Cell Biology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan; Division of Aging and Regeneration, Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan. Electronic address:

Early differential diagnosis between malignant and benign tumors and their underlying intrinsic differences are the most critical issues for life-threatening cancers. To study whether human acral melanomas, deadly cancers that occur on non-hair-bearing skin, have distinct origins that underlie their invasive capability, we develop fate-tracing technologies of melanocyte stem cells in sweat glands (glandular McSCs) and in melanoma models in mice and compare the cellular dynamics with human melanoma. Herein, we report that glandular McSCs self-renew to expand their migratory progeny in response to genotoxic stress and trauma to generate invasive melanomas in mice that mimic human acral melanomas.

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Systemic and local inflammation associated with therapeutic intervention of primary tumor occasionally promotes metastatic recurrence in mouse and human. However, it remains unclear what types of immune cells are involved in this process. Here, we found that the tissue-repair-promoting Ym1Ly6C monocyte subset expanded as a result of systemic and local inflammation induced by intravenous injection of lipopolysaccharide or resection of primary tumor and promoted lung metastasis originating from circulating tumor cells (CTCs).

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Genome-wide CRISPR screening reveals nucleotide synthesis negatively regulates autophagy.

J Biol Chem

August 2021

Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address:

Macroautophagy (hereafter, autophagy) is a process that directs the degradation of cytoplasmic material in lysosomes. In addition to its homeostatic roles, autophagy undergoes dynamic positive and negative regulation in response to multiple forms of cellular stress, thus enabling the survival of cells. However, the precise mechanisms of autophagy regulation are not fully understood.

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Organelle degradation in the lens by PLAAT phospholipases.

Nature

April 2021

Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo, Japan.

The eye lens of vertebrates is composed of fibre cells in which all membrane-bound organelles undergo degradation during terminal differentiation to form an organelle-free zone. The mechanism that underlies this large-scale organelle degradation remains largely unknown, although it has previously been shown to be independent of macroautophagy. Here we report that phospholipases in the PLAAT (phospholipase A/acyltransferase, also known as HRASLS) family-Plaat1 (also known as Hrasls) in zebrafish and PLAAT3 (also known as HRASLS3, PLA2G16, H-rev107 or AdPLA) in mice-are essential for the degradation of lens organelles such as mitochondria, the endoplasmic reticulum and lysosomes.

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Sarcoidosis may have more than a single causative agent, including infectious and non-infectious agents. Among the potential infectious causes of sarcoidosis, and are the most likely microorganisms. Potential latent infection by both microorganisms complicates the findings of molecular and immunologic studies.

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Reconciling Flux Experiments for Quantitative Modeling of Normal and Malignant Hematopoietic Stem/Progenitor Dynamics.

Stem Cell Reports

April 2021

Wellcome and MRC Cambridge Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, Cambridge CB2 0AW, UK. Electronic address:

Hematopoiesis serves as a paradigm for how homeostasis is maintained within hierarchically organized cell populations. However, important questions remain as to the contribution of hematopoietic stem cells (HSCs) toward maintaining steady state hematopoiesis. A number of in vivo lineage labeling and propagation studies have given rise to contradictory interpretations, leaving key properties of stem cell function unresolved.

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Phase-separated droplets with liquid-like properties can be degraded by macroautophagy/autophagy, but the mechanism underlying this degradation is poorly understood. We have recently derived a physical model to investigate the interaction between autophagic membranes and such droplets, uncovering that intrinsic wetting interactions underlie droplet-membrane contacts. We found that the competition between droplet surface tension and the increasing tendency of growing membrane sheets to bend determines whether a droplet is completely engulfed or isolated in a piecemeal fashion, a process we term fluidophagy.

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Autophagosome maturation stymied by SARS-CoV-2.

Dev Cell

February 2021

Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan. Electronic address:

Many pathogens are capable of disrupting autophagy within host cells. In this issue of Developmental Cell, Miao et al. discover that the SARS-CoV-2 protein ORF3a inhibits autophagosome-lysosome fusion by dysregulating the HOPS complex.

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Glutathione transferase Omega 1 confers protection against azoxymethane-induced colorectal tumour formation.

Carcinogenesis

June 2021

ACRF Department of Cancer Biology and Therapeutics, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia.

Inflammatory bowel disease (IBD) is characterized by multiple alterations in cytokine expression and is a risk factor for colon cancer. The Omega class glutathione transferase GSTO1-1 regulates the release of the pro-inflammatory cytokines interleukin 1β (IL-1β) and interleukin 18 (IL-18) by deglutathionylating NEK7 in the NLRP3 inflammasome. When treated with azoxymethane and dextran sodium sulphate (AOM/DSS) as a model of IBD, Gsto1-/- mice were highly sensitive to colitis and showed a significant increase in the size and number of colon tumours compared with wild-type (WT) mice.

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Compartmentalization of cellular material in droplet-like structures is a hallmark of liquid-liquid phase separation, but the mechanisms of droplet removal are poorly understood. Evidence suggests that droplets can be degraded by autophagy, a highly conserved degradation system in which membrane sheets bend to isolate portions of the cytoplasm within double-membrane autophagosomes. Here we examine how autophagosomes sequester droplets that contain the protein p62 (also known as SQSTM1) in living cells, and demonstrate that double-membrane, autophagosome-like vesicles form at the surface of protein-free droplets in vitro through partial wetting.

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Article Synopsis
  • The study examines the long-term motor outcomes and disability levels in children affected by acute flaccid myelitis (AFM) linked to the 2015 enterovirus D68 outbreak.
  • A nationwide follow-up assessed motor function and daily living activities at various stages (acute, recovery, chronic) in 33 pediatric patients.
  • Despite many showing persistent motor deficits, overall disability levels improved significantly over three years, with better outcomes for non-motor neurological symptoms.
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Autophagy in Human Diseases.

N Engl J Med

October 2020

From the Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, University of Tokyo, Tokyo (N.M.); and the Center for Autophagy Research, Department of Internal Medicine and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas (B.L.).

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Using single-molecule imaging with enhanced time resolutions down to 5 ms, we found that CD59 cluster rafts and GM1 cluster rafts were stably induced in the outer leaflet of the plasma membrane (PM), which triggered the activation of Lyn, H-Ras, and ERK and continually recruited Lyn and H-Ras right beneath them in the inner leaflet with dwell lifetimes <0.1 s. The detection was possible due to the enhanced time resolutions employed here.

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The ESCRT-III membrane fission machinery maintains the integrity of the nuclear envelope. Although primary nuclei resealing takes minutes, micronuclear envelope ruptures seem to be irreversible. Instead, micronuclear ruptures result in catastrophic membrane collapse and are associated with chromosome fragmentation and chromothripsis, complex chromosome rearrangements thought to be a major driving force in cancer development.

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Background: Acute flaccid myelitis is a recently defined clinically distinct syndrome of polio-like acute flaccid paralysis. Acute flaccid myelitis cases show characteristic neuroradiological features of longitudinal spinal cord lesions with predominant gray matter involvement. Current evidence suggests injury to the anterior horn neurons as the underlying mechanism.

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Nucleomorphs are relic endosymbiont nuclei so far found only in two algal groups, cryptophytes and chlorarachniophytes, which have been studied to model the evolutionary process of integrating an endosymbiont alga into a host-governed plastid (organellogenesis). However, past studies suggest that DNA transfer from the endosymbiont to host nuclei had already ceased in both cryptophytes and chlorarachniophytes, implying that the organellogenesis at the genetic level has been completed in the two systems. Moreover, we have yet to pinpoint the closest free-living relative of the endosymbiotic alga engulfed by the ancestral chlorarachniophyte or cryptophyte, making it difficult to infer how organellogenesis altered the endosymbiont genome.

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Lysosome biology in autophagy.

Cell Discov

February 2020

Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033 Japan.

Autophagy is a major intracellular degradation system that derives its degradative abilities from the lysosome. The most well-studied form of autophagy is macroautophagy, which delivers cytoplasmic material to lysosomes via the double-membraned autophagosome. Other forms of autophagy, namely chaperone-mediated autophagy and microautophagy, occur directly on the lysosome.

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