title: Valproic acid regulates erythro-megakaryocytic differentiation through the modulation of transcription factors and microRNA regulatory micro-networks.
abstract: Valproic acid (VPA) exhibits important pharmacological properties but has been reported to trigger side effects, notably on the hematological system. We previously reported that VPA affects hematopoietic homeostasis by inhibiting erythroid differentiation and promoting myeloid and megakaryocyte differentiation. Here, we analyzed the effect of VPA on regulatory factors involved in erythro-megakaryocytic differentiation pathways, including transcription factors and microRNAs (miRs). We demonstrate that VPA inhibited erythroid differentiation in erythropoietin (Epo)-stimulated TF1 leukemia cells and CD34(+)/hematopoietic stem cells (HSCs) and in aclacinomycin-(Acla)-treated K562 cells. Mir-144/451 gene expression was decreased in all erythroid and megakaryocyte models in correlation with GATA-1 inhibition. In Epo-stimulated CD34(+)/HSCs, VPA induced the expression of the ETS family transcription factors PU.1, ETS-1, GABP-α, Fli-1 and GATA-2, which are all known to be negative regulators of erythropoiesis, while it promoted the megakaryocytic pathway. PU.1 and ETS-1 expression were induced in correlation with miR-155 inhibition; however, the GATA-1/PU.1 interaction was promoted. Using megakaryoblastic Meg-01 cells, we demonstrated that VPA induced megakaryocyte morphological features and CD61 expression. GATA-2 and miR-27a expression were increased in correlation with a decrease in RUNX1 mRNA expression, suggesting megakaryocyte differentiation. Finally, by using valpromide and the Class I HDACi MS-275, we validated that the well-described HDACi activity of VPA is not required in the inhibitory effect on erythropoiesis. Overall, this report shows that VPA modulates the erythro-megakaryocytic differentiation program through regulatory micro-networks involving GATA and ETS transcription factors and miRNAs, notably the GATA-1/miR-144/451 axis.
authors.affiliation: Fondation Recherche Cancer et Sang, Laboratoire de Biologie Moléculaire et Cellulaire du Cancer, Hôpital Kirchberg, 9, rue Edward Steichen, L-2540 Luxembourg, Luxembourg.
authors.forename: Anne
authors.initials: A
authors.lastname: Trécul
authors.affiliation: Fondation Recherche Cancer et Sang, Laboratoire de Biologie Moléculaire et Cellulaire du Cancer, Hôpital Kirchberg, 9, rue Edward Steichen, L-2540 Luxembourg, Luxembourg.
authors.forename: Franck
authors.initials: F
authors.lastname: Morceau
authors.affiliation: Fondation Recherche Cancer et Sang, Laboratoire de Biologie Moléculaire et Cellulaire du Cancer, Hôpital Kirchberg, 9, rue Edward Steichen, L-2540 Luxembourg, Luxembourg.
authors.forename: Anthoula
authors.initials: A
authors.lastname: Gaigneaux
authors.affiliation: Fondation Recherche Cancer et Sang, Laboratoire de Biologie Moléculaire et Cellulaire du Cancer, Hôpital Kirchberg, 9, rue Edward Steichen, L-2540 Luxembourg, Luxembourg.
authors.forename: Michael
authors.initials: M
authors.lastname: Schnekenburger
authors.affiliation: Fondation Recherche Cancer et Sang, Laboratoire de Biologie Moléculaire et Cellulaire du Cancer, Hôpital Kirchberg, 9, rue Edward Steichen, L-2540 Luxembourg, Luxembourg.
authors.forename: Mario
authors.initials: M
authors.lastname: Dicato
authors.affiliation: Department of Pharmacy, College of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea. Electronic address: marcdiederich@snu.ac.kr.
authors.forename: Marc
authors.initials: M
authors.lastname: Diederich
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D041905:Erythroid Cells / Q000187:drug effects; D005312:Fetal Blood / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D020014:K562 Cells; D008533:Megakaryocytes / Q000187:drug effects / Q000502:physiology*; D035683:MicroRNAs / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*; D014635:Valproic Acid / Q000494:pharmacology*
chemical_list: D035683:MicroRNAs; D014157:Transcription Factors; D014635:Valproic Acid
keywords: GATA-1; Hematopoietic differentiation; Valproic acid; miR-144/451