title: MiR-17/20/93/106 promote hematopoietic cell expansion by targeting sequestosome 1-regulated pathways in mice.
abstract: MicroRNAs (miRNAs) are pivotal for regulation of hematopoiesis but their critical targets remain largely unknown. Here, we show that ectopic expression of miR-17, -20,-93 and -106, all AAAGUGC seed-containing miRNAs, increases proliferation, colony outgrowth and replating capacity of myeloid progenitors and results in enhanced P-ERK levels. We found that these miRNAs are endogenously and abundantly expressed in myeloid progenitors and down-regulated in mature neutrophils. Quantitative proteomics identified sequestosome 1 (SQSTM1), an ubiquitin-binding protein and regulator of autophagy-mediated protein degradation, as a major target for these miRNAs in myeloid progenitors. In addition, we found increased expression of Sqstm1 transcripts during CSF3-induced neutrophil differentiation of 32D-CSF3R cells and an inverse correlation of SQSTM1 protein levels and miR-106 expression in AML samples. ShRNA-mediated silencing of Sqstm1 phenocopied the effects of ectopic miR-17/20/93/106 expression in hematopoietic progenitors in vitro and in mice. Further, SQSTM1 binds to the ligand-activated colony-stimulating factor 3 receptor (CSF3R) mainly in the late endosomal compartment, but not in LC3 positive autophagosomes. SQSTM1 regulates CSF3R stability and ligand-induced mitogen-activated protein kinase signaling. We demonstrate that AAAGUGC seed-containing miRNAs promote cell expansion, replating capacity and signaling in hematopoietic cells by interference with SQSTM1-regulated pathways.
authors.affiliation: Department of Hematology, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Annemarie
authors.initials: A
authors.lastname: Meenhuis
authors.forename: Peter A
authors.initials: PA
authors.lastname: van Veelen
authors.forename: Hans
authors.initials: H
authors.lastname: de Looper
authors.forename: Nicole
authors.initials: N
authors.lastname: van Boxtel
authors.forename: Iris J
authors.initials: IJ
authors.lastname: van den Berge
authors.forename: Su M
authors.initials: SM
authors.lastname: Sun
authors.forename: Erdogan
authors.initials: E
authors.lastname: Taskesen
authors.forename: Patrick
authors.initials: P
authors.lastname: Stern
authors.forename: Arnoud H
authors.initials: AH
authors.lastname: de Ru
authors.forename: Arjan J
authors.initials: AJ
authors.lastname: van Adrichem
authors.forename: Jeroen
authors.initials: J
authors.lastname: Demmers
authors.forename: Mojca
authors.initials: M
authors.lastname: Jongen-Lavrencic
authors.forename: Bob
authors.initials: B
authors.lastname: Löwenberg
authors.forename: Ivo P
authors.initials: IP
authors.lastname: Touw
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Sharp
authors.forename: Stefan J
authors.initials: SJ
authors.lastname: Erkeland
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation / Q000235:genetics; D049109:Cell Proliferation; D015870:Gene Expression; D020869:Gene Expression Profiling; D006360:Heat-Shock Proteins / Q000235:genetics*; D006410:Hematopoiesis / Q000235:genetics*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics; D051379:Mice; D035683:MicroRNAs / Q000235:genetics*; D008969:Molecular Sequence Data; D040901:Proteomics / Q000379:methods; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000071456:Sequestosome-1 Protein; D015398:Signal Transduction / Q000235:genetics
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D006360:Heat-Shock Proteins; D035683:MicroRNAs; C099718:SQSTM1 protein, human; D000071456:Sequestosome-1 Protein; C101343:Sqstm1 protein, mouse