作者: Fang, Fang ; Page, Grier P ; Sinchar, Derek ; Kanias, Tamir ; Esparza, Orlando ; Davizon-Castillo, Pavel ; Hazegh, Kelsey ; Zuchelkowski, Benjamin E ; Wang, Ling ; Kelly, Kathleen ; Ufelle, Alexander C

p38 MAPKs are key regulators of cellular adaptation to various stress stimuli, however, their role in mediating erythrocyte cell death and hemolysis is largely unknown. We hypothesized that activation of erythrocyte p38 MAPK is a common event in the stimulation of hemolysis, and that inhibition of p38 MAPK pathways could mitigate hemolysis in hemoglobinopathies. We exposed human erythrocytes to diamide-induced oxidative stress or to hypoosmotic shock in the presence or absence of p38 MAPK inhibitors (SCIO469, SB203580, CMPD1) and used immunoblotting to determine MAPK activity and to identify possible downstream effectors of p38 MAPK. We also evaluated the impact of p38 MAPK inhibitors on stress-induced hemolysis or hypoxia-induced sickling in erythrocytes from mouse models of sickle cell disease. We found that human erythrocytes express conventional MAPKs (MKK3, p38 MAPK, MAPKAPK2) and identified differential MAPK activation pathways in each stress condition. Specifically, p38 MAPK inhibition in diamide-treated erythrocytes was associated with decreased phosphorylation of Src tyrosine kinases and Band 3 protein. Conversely, hypoosmotic shock induced MAPKAPK2 and RSK2 phosphorylation, which was inhibited by SCIO469 or CMPD1. Relevant to hemoglobinopathies, sickle cell disease was associated with increased erythrocyte MKK3, p38 MAPK, and MAPKAPK2 expression and phosphorylation as compared with erythrocytes from healthy individuals. Furthermore, p38 MAPK inhibition was associated with decreased hemolysis in response to diamide treatments or osmotic shock, and with decreased erythrocyte sickling under experimental hypoxia. These findings provided insights into MAPK-mediated signaling pathways that regulate erythrocyte function and hemolysis in response to extracellular stressors or human diseases.

2021-05-01·Cell Stem Cell1区 · 医学

iPSC modeling of stage-specific leukemogenesis reveals BAALC as a key oncogene in severe congenital neutropenia

1区 · 医学

Article

作者: Martina Konantz ; Doris Steinemann ; Thomas Moritz ; Azadeh Zahabi ; Siarhei Kandabarau ; Benjamin Dannenmann ; Karl Welte ; Malte Ritter ; Nico Lachmann ; Claudia Lengerke ; Frederic Stein ; Benedikt Oswald ; Anna Solovyeva ; Tatsuya Morishima ; Cornelia Zeidler ; Perihan Mir ; Miriam Erlacher ; Patricia Arreba-Tutusaus ; Charlotte M. Niemeyer ; Tim Ripperger ; Julia Skokowa ; Masoud Nasri ; Jehan Mardan ; Maksim Klimiankou

Severe congenital neutropenia (CN) is a pre-leukemic bone marrow failure syndrome that can evolve to acute myeloid leukemia (AML). Mutations in CSF3R and RUNX1 are frequently observed in CN patients, although how they drive the transition from CN to AML (CN/AML) is unclear. Here we establish a model of stepwise leukemogenesis in CN/AML using CRISPR-Cas9 gene editing of CN patient-derived iPSCs. We identified BAALC upregulation and resultant phosphorylation of MK2a as a key leukemogenic event. BAALC deletion or treatment with CMPD1, a selective inhibitor of MK2a phosphorylation, blocked proliferation and induced differentiation of primary CN/AML blasts and CN/AML iPSC-derived hematopoietic stem and progenitor cells (HSPCs) without affecting healthy donor or CN iPSC-derived HSPCs. Beyond detailing a useful method for future investigation of stepwise leukemogenesis, this study suggests that targeting BAALC and/or MK2a phosphorylation may prevent leukemogenic transformation or eliminate AML blasts in CN/AML and RUNX1 mutant BAALC(hi) de novo AML.

2019-07-08·Angewandte Chemie International Edition1区 · 化学

The Aminotriazole Antagonist Cmpd‐1 Stabilises a Distinct Inactive State of the Adenosine 2A Receptor

1区 · 化学

Article

作者: Crump, Matthew P. ; Mercier, Joël ; Joedicke, Lisa ; de Fabritiis, Gianni ; Lovera, Silvia ; Sands, Zara A. ; Kelm, Sebastian ; Sessions, Richard B. ; McMillan, David ; Landin, Erik J. B. ; Taylor, Richard J.

AbstractThe widely expressed G‐protein coupled receptors (GPCRs) are versatile signal transducer proteins that are attractive drug targets but structurally challenging to study. GPCRs undergo a number of conformational rearrangements when transitioning from the inactive to the active state but have so far been believed to adopt a fairly conserved inactive conformation. Using 19F NMR spectroscopy and advanced molecular dynamics simulations we describe a novel inactive state of the adenosine 2A receptor which is stabilised by the aminotriazole antagonist Cmpd‐1. We demonstrate that the ligand stabilises a unique conformation of helix V and present data on the putative binding mode of the compound involving contacts to the transmembrane bundle as well as the extracellular loop 2.

100 项与 Cmpd1(Pfizer) 相关的药物交易

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