S Ricciardi1, A Miluzio1, D Brina1, K Clarke2, M Bonomo2, R Aiolfi3, L G Guidotti3, F Falciani2, S Biffo1. 1. Molecular Histology and Cell Growth Unit, National Institute of Molecular Genetics - INGM, 'Romeo ed Enrica Invernizzi', Milan, Italy. 2. Centre for Computational Biology and Modeling, Institute of Integrative Biology, University of Liverpool, Liverpool, UK. 3. Immunopathology Unit, San Raffaele Scientific Institute, Milan, Italy.
Abstract
BACKGROUND: Ribosomopathies constitute a class of inherited disorders characterized by defects in ribosome biogenesis and function. Classically, bone marrow (BM) failure is a clinical symptom shared between these syndromes, including Shwachman-Bodian-Diamond syndrome (SBDS). Eukaryotic translation initiation factor 6 (eIF6) is a critical translation factor that rescues the quasilethal effect of the loss of the SBDS protein. OBJECTIVES: To determine whether eIF6 activity is necessary for BM development. METHODS: We used eIF6(+/-) mice and primary BM megakaryocytes to investigate the involvement of eIF6 in the regulation of hematopoiesis. RESULTS: We provide evidence that reduced eIF6 expression negatively impacts on megakaryopoiesis. We show that inhibition of eIF6 leads to a reduction in cell size and mean ploidy level of megakaryocytes and a delay in megakaryocyte maturation by blocking the G1 /S transition. Consistent with this phenotype, only few megakaryocyte-forming proplatelets were found in eIF6(+/-) cells. We also discovered that, in eIF6(+/-) cells, the steady-state abundance of mitochondrial respiratory chain complex I-encoding mRNAs is decreased, resulting in decreased reactive oxygen species (ROS) production. Intriguingly, connectivity map analysis showed that eIF6-mediated changes overlap with specific translational inhibitors. eIF6 is a translation factor acting downstream of insulin/phorbol 12-myristate 13-acetate (PMA) stimulation. PMA treatment significantly restored eIF6(+/-) megakaryocyte maturation, indicating that activation of eIF6 is essential for the rescue of the phenotype. CONCLUSIONS: Taken together, our results show a role for eIF6-driven translation in megakaryocyte development, and unveil the novel connection between translational control and ROS production in this cell subset.
BACKGROUND: Ribosomopathies constitute a class of inherited disorders characterized by defects in ribosome biogenesis and function. Classically, bone marrow (BM) failure is a clinical symptom shared between these syndromes, including Shwachman-Bodian-Diamond syndrome (SBDS). Eukaryotic translation initiation factor 6 (eIF6) is a critical translation factor that rescues the quasilethal effect of the loss of the SBDS protein. OBJECTIVES: To determine whether eIF6 activity is necessary for BM development. METHODS: We used eIF6(+/-) mice and primary BM megakaryocytes to investigate the involvement of eIF6 in the regulation of hematopoiesis. RESULTS: We provide evidence that reduced eIF6 expression negatively impacts on megakaryopoiesis. We show that inhibition of eIF6 leads to a reduction in cell size and mean ploidy level of megakaryocytes and a delay in megakaryocyte maturation by blocking the G1 /S transition. Consistent with this phenotype, only few megakaryocyte-forming proplatelets were found in eIF6(+/-) cells. We also discovered that, in eIF6(+/-) cells, the steady-state abundance of mitochondrial respiratory chain complex I-encoding mRNAs is decreased, resulting in decreased reactive oxygen species (ROS) production. Intriguingly, connectivity map analysis showed that eIF6-mediated changes overlap with specific translational inhibitors. eIF6 is a translation factor acting downstream of insulin/phorbol 12-myristate 13-acetate (PMA) stimulation. PMA treatment significantly restored eIF6(+/-) megakaryocyte maturation, indicating that activation of eIF6 is essential for the rescue of the phenotype. CONCLUSIONS: Taken together, our results show a role for eIF6-driven translation in megakaryocyte development, and unveil the novel connection between translational control and ROS production in this cell subset.
Authors: Julia Barbara Kral; Waltraud Cornelia Schrottmaier; Manuel Salzmann; Alice Assinger Journal: Transfus Med Hemother Date: 2016-03-09 Impact factor: 3.747
Authors: Thomas C J Tan; John Knight; Thomas Sbarrato; Kate Dudek; Anne E Willis; Rose Zamoyska Journal: Proc Natl Acad Sci U S A Date: 2017-07-10 Impact factor: 11.205
Authors: Marion Mussbacher; Manuel Salzmann; Christine Brostjan; Bastian Hoesel; Christian Schoergenhofer; Hannes Datler; Philipp Hohensinner; José Basílio; Peter Petzelbauer; Alice Assinger; Johannes A Schmid Journal: Front Immunol Date: 2019-02-04 Impact factor: 7.561
Authors: Kim Clarke; Sara Ricciardi; Tim Pearson; Izwan Bharudin; Peter K Davidsen; Michela Bonomo; Daniela Brina; Alessandra Scagliola; Deborah M Simpson; Robert J Beynon; Farhat Khanim; John Ankers; Mark A Sarzynski; Sujoy Ghosh; Addolorata Pisconti; Jan Rozman; Martin Hrabe de Angelis; Chris Bunce; Claire Stewart; Stuart Egginton; Mark Caddick; Malcolm Jackson; Claude Bouchard; Stefano Biffo; Francesco Falciani Journal: Cell Rep Date: 2017-11-07 Impact factor: 9.423