Objective: To examine DNA methylation in mouse hemopoiesis before and after in vivo exposure to a leukemogenic dose of x-rays, and address whether methylation levels are associated with the relative radiosensitivity of tissues in vivo.
Methods: The methylation status of control CBA/H and C57BL/6 mouse tissues before and after exposure to 3-Gy x-rays, and myeloid and lymphoid leukemias and lymphomas, was assessed by the direct analysis of the 5-methylcytosine (5-(Me)C) content of DNA, and by Southern blot analysis of genomic repeat sequences.
Results: The DNA 5-(Me)C content of bone marrow is 15% lower than spleen. Together with the analyses of stem (myeloid) and progenitor (lymphoid) leukemias and lymphomas, we found a trend of increasing methylation during hemopoietic differentiation. Exposure to x-rays induced greater cell death in the hypomethylated bone marrow (>80%) than spleen (50%) in vivo, supporting the observed correlation found between methylation status and radiosensitivity of other high-turnover hierarchical tissues. Furthermore, there was an 8% DNA 5-(Me)C content decrease in bone marrow after in vivo exposure to 3-Gy x-rays, but this was genotype dependent, being observed in AML-susceptible (CBA/H) but not AML-resistant (C57BL/6) inbred mice.
Conclusion: Together these data suggest that methylation status may be related to the relative radiosensitivity of high-turnover hierarchical tissues such as bone marrow and that radiation-induced DNA hypomethylation has a role in radiation leukemogenesis.
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http://dx.doi.org/10.1016/j.exphem.2006.06.008 | DOI Listing |
Anal Chem
January 2025
Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou, Fujian 350117, China.
Multiple myeloma is a hematologic malignancy characterized by the proliferation of abnormal plasma cells in the bone marrow. Despite therapeutic advancements, there remains a critical need for reliable, noninvasive methods to monitor multiple myeloma. Circulating plasma cells (CPCs) in peripheral blood are robust and independent prognostic markers, but their detection is challenging due to their low abundance.
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Division of Immunology and Allergy, Children's Hospital of Philadelphia; Department of Pediatrics, Perelman School of Medicine; Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States.
Leukopoiesis is lethally arrested in mice lacking the master transcriptional regulator PU.1. Depending on the animal model, subtotal PU.
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Irving Institute for Cancer Dynamics, Columbia University, New York, NY 10027, USA.
Understanding how intratumoral immune populations coordinate antitumor responses after therapy can guide treatment prioritization. We systematically analyzed an established immunotherapy, donor lymphocyte infusion (DLI), by assessing 348,905 single-cell transcriptomes from 74 longitudinal bone marrow samples of 25 patients with relapsed leukemia; a subset was evaluated by both protein- and transcriptome-based spatial analysis. In acute myeloid leukemia (AML) DLI responders, we identified clonally expanded CD8 cytotoxic T lymphocytes with in vitro specificity for patient-matched AML.
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January 2025
Department of Surgical Pathology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Immunologic bile duct destruction is a pathogenic condition associated with vanishing bile duct syndrome (VBDS) after liver transplantation and hematopoietic stem-cell transplantation. As the bile acid receptor sphingosine 1-phosphate receptor 2 (S1PR2) plays a critical role in recruitment of bone marrow-derived monocytes/macrophages to sites of cholestatic liver injury, S1PR2 expression was examined using cultured macrophages and patient tissues. Bile canaliculi destruction precedes intrahepatic ductopenia; therefore, we focused on hepatocyte S1PR2 and the downstream RhoA/Rho kinase 1 (ROCK1) signaling pathway and bile canaliculi alterations using three-dimensional hepatocyte culture models that form obvious bile canaliculus-like networks.
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January 2025
School of Clinical Medicine, Guizhou Medical University, Guiyang, China.
Legg-Calvé-Perthes disease (LCPD) involves femoral head osteonecrosis caused by disrupted blood supply, leading to joint deformity and early osteoarthritis. This study investigates the role of miRNA-223-5p in regulating hypoxia-induced apoptosis and enhancing osteogenesis in bone marrow mesenchymal stem cells (BMSCs). Utilizing a juvenile New Zealand white rabbit model of LCPD established through femoral neck ligation, we transfected BMSCs with miR-223-5p mimics, inhibitors, and controls, followed by hypoxic exposure.
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