Publications by authors named "Yuichiro Nakata"

Cellular senescence in stem cells compromises regenerative capacity, promotes chronic inflammation, and is implicated in aging. Hematopoietic stem and progenitor cells (HSPCs) are responsible for producing mature blood cells, however, how cellular senescence influences their function is largely unknown. Here, we show that JMJD3, a histone demethylase, activates cellular senescence by upregulating p16 in competition with Polycomb group proteins, and reprograms HSPC integrity to overcome hematopoietic defects induced by replicative and oncogenic stresses.

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Article Synopsis
  • The genome faces constant DNA damage from both internal and external sources, requiring precise regulation of repair mechanisms to maintain integrity.
  • After exposure to ionizing radiation (IR), the modification of histone H3 (H3K4me3) shows a decrease shortly after and an increase later, indicating the dynamic response of chromatin to DNA damage in both human and mouse cells.
  • PTIP, a critical component of a histone methyltransferase complex, is necessary for the upregulation of H3K4me3 and helps induce cell cycle arrest by activating the PRDM1 cell cycle inhibitor, with its reduced expression linked to acute myeloid leukemia.
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Approximately 20% of head and neck squamous cell carcinomas (HNSCCs) exhibit reduced methylation on lysine 36 of histone H3 (H3K36me) due to mutations in histone methylase NSD1 or a lysine-to-methionine mutation in histone H3 (H3K36M). Whether such alterations of H3K36me can be exploited for therapeutic interventions is still unknown. Here, we show that HNSCC models expressing H3K36M can be divided into two groups: those that display aberrant accumulation of H3K27me3 and those that maintain steady levels of H3K27me3.

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  • About 20% of head and neck squamous cell carcinomas (HNSCC) show reduced methylation on histone H3 due to mutations, affecting therapeutic options.
  • Some HNSCC models with the H3K36M mutation can be categorized by their H3K27me3 levels, which influence cell growth and sensitivity to drugs like PARP1/2 inhibitors.
  • The study suggests that maintaining a balance between H3K36 and H3K27 methylation is crucial for genome stability, as higher H3K27me3 levels can make cancer cells more vulnerable to DNA damage.
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During emergency hematopoiesis, hematopoietic stem cells (HSCs) rapidly proliferate to produce myeloid and lymphoid effector cells, a response that is critical against infection or tissue injury. If unresolved, this process leads to sustained inflammation, which can cause life-threatening diseases and cancer. Here, we identify a role of double PHD fingers 2 (DPF2) in modulating inflammation.

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Resistance to cancer treatment remains a major clinical hurdle. Here, we demonstrate that the CoREST complex is a key determinant of endocrine resistance and ER breast cancer plasticity. In endocrine-sensitive cells, CoREST is recruited to regulatory regions co-bound to ERα and FOXA1 to regulate the estrogen pathway.

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Background: Histologic tumor necrosis (TN) is a well-established independent prognostic indicator in patients treated surgically for clear cell renal cell carcinoma (ccRCC). However, the precise mechanisms by which TN alters disease progression remain unknown. The DEAD-box protein DDX41, a member of a large family of helicases, has been characterized as a pattern recognition receptor against an array of double-stranded (ds)DNA produced from bacteria, dsDNA viruses, and nearby cells that have released dsDNA fragments through necrosis.

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A contribution of the cholinergic system to immune cell function has been suggested, though the role of nicotine and its receptors in T cells, especially regulatory T (Treg) cells, is unclear. We herein investigated the expression and function of nicotinic acetylcholine receptors (nAChRs) in murine-induced Treg (iTreg) cells. Upon differentiation of naive BALB/c T cells into iTreg cells and other T-cell subsets, the effect of nicotine on cytokine production and proliferation of iTreg cells was examined.

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The majority of breast cancers express the estrogen receptor (ERα) and agents targeting this pathway represent the main treatment modality. Endocrine therapy has proven successful in the treatment of hormone-responsive breast cancer since its early adoption in the 1940s as an ablative therapy. Unfortunately, therapeutic resistance arises, leading to disease recurrence and relapse.

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Epigenetic regulation is essential for the maintenance of the hematopoietic system, and its deregulation is implicated in hematopoietic disorders. In this study, UTX, a demethylase for lysine 27 on histone H3 (H3K27) and a component of COMPASS-like and SWI/SNF complexes, played an essential role in the hematopoietic system by globally regulating aging-associated genes. Utx-deficient (UtxΔ/Δ) mice exhibited myeloid skewing with dysplasia, extramedullary hematopoiesis, impaired hematopoietic reconstituting ability, and increased susceptibility to leukemia, which are the hallmarks of hematopoietic aging.

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  • Epigenetic deregulation, specifically through mutations in KDM6A, plays a crucial role in bladder cancer development, but the underlying mechanisms remain poorly understood.
  • Researchers created genetically modified mice to study the effects of KDM6A deficiency in conjunction with the tumor-promoting agent BBN, analyzing various molecular and cellular aspects of bladder cancer.
  • Their results showed that KDM6A deficiency activates inflammatory pathways and promotes cancer characteristics, suggesting that targeted therapies against specific molecules could be effective for treating bladder cancer linked to KDM6A dysfunction.
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Chronic myelomonocytic leukemia (CMML) is a hematological malignancy characterized by uncontrolled proliferation of dysplastic myelomonocytes and frequent progression to acute myeloid leukemia (AML). We identified mutations in the gene, which encodes a negative regulator of cytokine signaling, in a subset of CMML patients. To investigate the contribution of mutant in CMML pathogenesis, we generated conditional knockin mice for that express wild-type in a steady state and inducibly express , a CMML-associated mutant.

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Polycomb repressive complex 2 (PRC2) catalyzes the monomethylation, dimethylation, and trimethylation of histone H3 Lys27 (H3K27) and acts as a central epigenetic regulator that marks the repressive chromatin domain. Embryonic ectoderm development (EED), an essential component of PRC2, interacts with trimethylated H3K27 (H3K27me3) through the aromatic cage structure composed of its three aromatic amino acids, Phe97, Trp364, and Tyr365. This interaction allosterically activates the histone methyltransferase activity of PRC2 and thereby propagates repressive histone marks.

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Polycomb repressive complex 2 (PRC2) participates in transcriptional repression through methylation of histone H3K27. The WD-repeat protein embryonic ectoderm development (EED) is a non-catalytic but an essential component of PRC2 and its mutations were identified in hematopoietic malignancies. To clarify the role(s) of EED in adult hematopoiesis and leukemogenesis, we generated Eed conditional knockout (Eed(Δ/Δ)) mice.

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We previously reported that deficiency for Samd9L, which was cloned as a candidate gene for -7/7q- syndrome, accelerated leukemia cooperatively with enhanced expression of a histone demethylase: F-box and leucine-rich repeat protein 10 (Fbxl10, also known as Jhdm1b, Kdm2b, and Ndy1). To further investigate the role of Fbxl10 in leukemogenesis, we generated transgenic (Tg) mice that overexpress Fbxl10 in hematopoietic stem cells (HSCs). Interestingly, Fbxl10 Tg mice developed myeloid or B-lymphoid leukemia with complete penetrance.

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A20 is a negative regulator of NF-κB, and mutational loss of A20 expression is involved in the pathogenesis of autoimmune diseases and B-cell lymphomas. To clarify the role of A20 in adult hematopoiesis, we generated conditional A20 knockout mice (A20(flox/flox) ) and crossed them with Mx-1Cre (MxCre (+)) and ERT2Cre (ERT2Cre (+)) transgenic mice in which Cre is inducibly activated by endogenous interferon and exogenous tamoxifen, respectively. A20(flox/flox) MxCre (+) (A20Mx) mice spontaneously exhibited myeloid proliferation, B cell apoptosis, and anemia with overproduction of pro-inflammatory cytokines.

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  • Ortho-Phenylphenol is used in treating citrus fruits post-harvest, but its toxicity to immune organs is unclear despite known cancer risks in rats.
  • In female BALB/c mice, the substance causes thymic atrophy and alters thymocyte populations, indicating its negative impact on immune cell development.
  • The compound is metabolized to phenylhydroquinone in thymocytes, which disrupts the cell cycle, promotes apoptosis through p53 activation, and increases expression of the cytochrome P450 1A1 gene.
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