title: MicroRNA modulation of megakaryoblast fate involves cholinergic signaling.
abstract: MicroRNAs (miRNAs) are abundant small regulatory RNAs with multiple roles in cell fate determination. The processes regulating cellular miRNA levels are still unclear and experimental oligonucleotide tools to readily mimic their effects are not yet available. Here, we report that thapsigargin-induced intracellular Ca(++) release suppressed pre-miR-181a levels in human promegakaryotic Meg-01 cells, induced differentiation-associated nuclear endoreduplication and caspase-3 activation and replaced the acetylcholinesterase 3' splice variant AChE-S with AChE-R. AChE, PKC and PKA inhibitors all attenuated the pre-miR-181a decline and the induced differentiation. AChmiON, a synthetic 23-mer 2'-oxymethylated oligonucleotide mimicking the miR-181a sequence, blocked the calcium-induced differentiation while elevating cellular pre-miR-181a levels and inducing DNA fragmentation and cell death. Moreover, when added to RW 264.7 macrophages, AChmiON at 100 nM induced nitric oxide production with efficiency close to that of bacterial endotoxin, demonstrating physiologically relevant activities also in blood-born monocytes/macrophages. The stress-induced modulation of hematopoietic miR-181a levels through AChE, PKC and PKA cascade(s) suggests using miRNA mimics for diverting the fate of hematopoietic tumor cells towards differentiation and/or apoptosis.
authors.affiliation: Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Edmond Safra Campus, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Cinthya
authors.initials: C
authors.lastname: Guimaraes-Sternberg
authors.forename: Ari
authors.initials: A
authors.lastname: Meerson
authors.forename: Iftach
authors.initials: I
authors.lastname: Shaked
authors.forename: Hermona
authors.initials: H
authors.lastname: Soreq
mesh_terms: D000110:Acetylcholinesterase / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D053148:Caspase 3; D020169:Caspases / Q000187:drug effects / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D008264:Macrophages / Q000187:drug effects; D008533:Megakaryocytes / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D035683:MicroRNAs / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000494:pharmacology*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D019284:Thapsigargin / Q000037:antagonists & inhibitors / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D035683:MicroRNAs; D009841:Oligonucleotides; D009569:Nitric Oxide; D019284:Thapsigargin; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D000110:Acetylcholinesterase; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases; D002118:Calcium