Publications by authors named "Mayuko Takezaki"

8 Publications

  • Page 1 of 1

NRF2 mediates γ-globin gene regulation through epigenetic modifications in a β-YAC transgenic mouse model.

Exp Biol Med (Maywood) 2020 09 26;245(15):1308-1318. Epub 2020 Jul 26.

Division of Hematology/Oncology, Department of Pediatrics, Augusta University, Augusta, GA 30912, USA.

Impact Statement: Sickle cell disease is an inherited hemoglobin disorder that affects over 100,000 people in the United States causing high morbidity and early mortality. Although new treatments were recently approved by the FDA, only one drug Hydroxyurea induces fetal hemoglobin expression to inhibit sickle hemoglobin polymerization in red blood cells. Our laboratory previously demonstrated the ability of the NRF2 activator, dimethyl fumarate to induce fetal hemoglobin in the sickle cell mouse model. In this study, we investigated molecular mechanisms of γ-globin gene activation by NRF2. We observed the ability of NRF2 to modulate chromatin structure in the human β-like globin gene locus of β-YAC transgenic mice during development. Furthermore, an NRF2/TET3 interaction regulates γ-globin gene DNA methylation. These findings provide potential new molecular targets for small molecule drug developed for treating sickle cell disease.
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http://dx.doi.org/10.1177/1535370220945305DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7441346PMC
September 2020

MIR-144-mediated NRF2 gene silencing inhibits fetal hemoglobin expression in sickle cell disease.

Exp Hematol 2019 02 6;70:85-96.e5. Epub 2018 Nov 6.

Department of Pediatrics, Augusta University, Augusta, GA, USA; Department of Biochemistry and Molecular Biology, Augusta University, Augusta, GA, USA. Electronic address:

Inherited genetic modifiers and pharmacologic agents that enhance fetal hemoglobin (HbF) expression reverse the clinical severity of sickle cell disease (SCD). Recent efforts to develop novel strategies of HbF induction include discovery of molecular targets that regulate γ-globin gene transcription and translation. The purpose of this study was to perform genome-wide microRNA (miRNA) analysis to identify genes associated with HbF expression in patients with SCD. We isolated RNA from purified reticulocytes for microarray-based miRNA expression profiling. Using samples from patients with contrasting HbF levels, we observed an eightfold upregulation of miR-144-3p (miR-144) and miR-144-5p in the low-HbF group compared with those with high HbF. Additional analysis by reverse transcription quantitative polymerase chain reaction confirmed individual miR-144 expression levels of subjects in the two groups. Subsequent functional studies in normal and sickle erythroid progenitors showed NRF2 gene silencing by miR-144 and concomitant repression of γ-globin transcription; by contrast, treatment with miR-144 antagomir reversed its silencing effects in a dose-dependent manner. Because NRF2 regulates reactive oxygen species levels, additional studies investigated mechanisms of HbF regulation using a hemin-induced oxidative stress model. Treatment of KU812 cells with hemin produced an increase in NRF2 expression and HbF induction that reversed with miR-144 pretreatment. Chromatin immunoprecipitation assay confirmed NRF2 binding to the γ-globin antioxidant response element, which was inhibited by miR-144 mimic treatment. The genome-wide miRNA microarray and primary erythroid progenitor data support a miR-144/NRF2-mediated mechanism of γ-globin gene regulation in SCD.
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http://dx.doi.org/10.1016/j.exphem.2018.11.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6748328PMC
February 2019

Constitutively CD40-activated B cells regulate CD8 T cell inflammatory response by IL-10 induction.

J Immunol 2013 Apr 25;190(7):3189-96. Epub 2013 Feb 25.

Department of Medicine, Georgia Regents University, Augusta, GA 30912, USA.

B cells are exposed to high levels of CD40 ligand (CD40L, CD154) in chronic inflammatory diseases. In addition, B cells expressing both CD40 and CD40L have been identified in human diseases such as autoimmune diseases and lymphoma. However, how such constitutively CD40-activated B cells under inflammation may impact on T cell response remains unknown. Using a mouse model in which B cells express a CD40L transgene (CD40LTg) and receive autocrine CD40/CD40L signaling, we show that CD40LTg B cells stimulated memory-like CD4 and CD8 T cells to express IL-10. This IL-10 expression by CD8 T cells was dependent on IFN-I and programmed cell death protein 1, and was critical for CD8 T cells to counterregulate their overactivation. Furthermore, adoptive transfer of naive CD8 T cells in RAG-1(-/-) mice normally induces colitis in association with IL-17 and IFN-γ cytokine production. Using this model, we show that adoptive cotransfer of CD40LTg B cells, but not wild-type B cells, significantly reduced IL-17 response and regulated colitis in association with IL-10 induction in CD8 T cells. Thus, B cells expressing CD40L can be a therapeutic goal to regulate inflammatory CD8 T cell response by IL-10 induction.
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http://dx.doi.org/10.4049/jimmunol.1203364DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3608804PMC
April 2013

CD4(+)CD25(+) regulatory T cells resist a novel form of CD28- and Fas-dependent p53-induced T cell apoptosis.

J Immunol 2010 Jan 30;184(1):94-104. Epub 2009 Nov 30.

Immunotherapy Center, Medical College of Georgia, Augusta, GA 30912, USA.

Ag receptor stimulation of preactivated T cells causes rapid cell death in an IL-2- and Fas-dependent manner. This phenomenon, known as activation-induced cell death (AICD), plays a pivotal role in the removal of Ag-reactive T cells after initial expansion. In this study, we report a novel form of T cell apoptosis that is distinct from classic AICD. When peripheral T cells were activated with anti-CD3 and anti-CD28 Abs precoated onto plastic plates, CD4(+)CD25(-) and CD8 T cells initially expanded but underwent massive apoptosis after 4 d. Unlike classic AICD, this type of T cell apoptosis pathway requires engagement of CD28 and expression of p53, a tumor-suppressor gene. The most striking feature of this form of apoptosis was regulatory T cell resistance. Under the same stimulating conditions, CD4(+)CD25(+) T cells grew continuously beyond 4 d. Consequently, when the entire CD4 population was cultured with plate-bound anti-CD3 plus anti-CD28 Ab, CD4(+)CD25(+)FoxP3(+) regulatory T cells outgrew nonregulatory T cells and expanded >7000-fold after 11 d. The data presented herein demonstrate a novel process of Ag-induced T cell death by sustained TCR and CD28 engagement and represent a simple and efficient procedure for the expansion of regulatory T cells in vitro.
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http://dx.doi.org/10.4049/jimmunol.0900753DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4436589PMC
January 2010

Role of CD28 in fatal autoimmune disorder in scurfy mice.

Blood 2007 Aug 26;110(4):1199-206. Epub 2007 Apr 26.

Immunotherapy Center, Medical College of Georgia, Augusta, USA.

Scurfy mice develop CD4 T-cell-mediated lymphoproliferative disease leading to death within 4 weeks of age. The scurfy mutation causes loss of function of the foxp3 gene (foxp3(sf)), which is essential for development and maintenance of naturally occurring regulatory CD4 T cells (nTregs). In humans, mutations of the foxp3 gene cause immune dysregulation, polyendocrinopathy, enteropathy, and X-linked syndrome (IPEX). In most patients with IPEX and also in scurfy mice, T cells show hyperreactivity and levels of Th1- and Th2-associated cytokines are substantially elevated. We report that removal of CD28 expression rescued scurfy mice from early death. Longer-term surviving CD28-deficient scurfy mice still had lymphoproliferative disorder, but their CD4 T cells showed decreased interferon-gamma and no sign of interleukin-4 or interleukin-10 hyperproduction. Furthermore, injection of CTLA4-Ig to block CD28-B7 interactions substantially improved the survival of scurfy mice by blocking effector T-cell differentiation. These data support the hypothesis that CD28-B7 interactions play a critical role in the etiology of lethal autoimmune disease in scurfy mice by stimulating the differentiation of antigen-activated naive T cells into effector T cells.
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http://dx.doi.org/10.1182/blood-2006-10-054585DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1939901PMC
August 2007

Enrichment of regulatory CD4(+)CD25(+) T cells by inhibition of phospholipase D signaling.

Nat Methods 2006 Aug;3(8):629-36

Immunotherapy Center, Institute of Molecular Medicine and Genetics, Department of Medicine, Medical College of Georgia, 1120 15th Street, Augusta, Georgia 30912, USA.

Antigen stimulation of lymphocytes induces upregulation of phospholipase D (PLD) activity, but the biological significance of PLD-mediated signaling in T cells has not been well established. Here we demonstrate that PLD signaling is essential for proliferation of mouse CD8(+) T cells and CD4(+)CD25(-) T cells, but is not required for proliferation of CD4(+)CD25(+) regulatory T cells. We exploited this observation to develop an efficient method to enrich for regulatory T cells starting from preparations of total CD4(+) T lymphocytes. Inhibition of PLD signaling blocked effector T-cell proliferation after T cell-antigen receptor (TCR) engagement, but had no significant effect on the proliferation of CD4(+)CD25(+) T cells with regulatory functions. Consequently, cells expanded in vitro for one week by antigen receptor stimulation with PLD signal inhibition were markedly enriched for regulatory T cells.
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http://dx.doi.org/10.1038/nmeth903DOI Listing
August 2006

Coupling between B cell receptor and phospholipase C-gamma2 is essential for mature B cell development.

J Exp Med 2003 Aug 11;198(4):581-9. Epub 2003 Aug 11.

Department of Molecular Genetics, Institute for Liver Research, Kansai Medical University, Moriguchi 570-8506, Japan.

Two signaling pathways known to be essential for progression from immature to mature B cells are BAFF receptor (BAFF-R) and the B cell receptor (BCR). Here, we first show that phospholipase C (PLC)-gamma2 is required for a BAFF-R-mediated survival signal. Then, we have examined the question of whether the reduced number of mature B cells in PLC-gamma2-/- mice is caused by a defect in either BCR or BAFF-R signaling. We find that a PLC-gamma2 SH2 mutant, which inhibits coupling between BCR and PLC-gamma2, fails to restore B cell maturation, despite supporting BAFF-dependent survival. Therefore, our data suggest that the BAFF-R-mediated survival signal, provided by PLC-gamma2, is not sufficient to promote B cell maturation, and that, in addition, activation of PLC-gamma2 by BCR is required for B cell development.
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http://dx.doi.org/10.1084/jem.20030280DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2194178PMC
August 2003