title: miR-34b regulates multiciliogenesis during organ formation in zebrafish.
abstract: Multiciliated cells (MCCs) possess multiple motile cilia and are distributed throughout the vertebrate body, performing important physiological functions by regulating fluid movement in the intercellular space. Neither their function during organ development nor the molecular mechanisms underlying multiciliogenesis are well understood. Although dysregulation of members of the miR-34 family plays a key role in the progression of various cancers, the physiological function of miR-34b, especially in regulating organ formation, is largely unknown. Here, we demonstrate that miR-34b expression is enriched in kidney MCCs and the olfactory placode in zebrafish. Inhibiting miR-34b function using morpholino antisense oligonucleotides disrupted kidney proximal tubule convolution and the proper distribution of distal transporting cells and MCCs. Microarray analysis of gene expression, cilia immunostaining and a fluid flow assay revealed that miR-34b is functionally required for the multiciliogenesis of MCCs in the kidney and olfactory placode. We hypothesize that miR-34b regulates kidney morphogenesis by controlling the movement and distribution of kidney MCCs and fluid flow. We found that cmyb was genetically downstream of miR-34b and acted as a key regulator of multiciliogenesis. Elevated expression of cmyb blocked membrane docking of centrioles, whereas loss of cmyb impaired centriole multiplication, both of which resulted in defects in the formation of ciliary bundles. Thus, miR-34b serves as a guardian to maintain the proper level of cmyb expression. In summary, our studies have uncovered an essential role for miR-34b-Cmyb signaling during multiciliogenesis and kidney morphogenesis.
authors.affiliation: Key Laboratory of Stem Cell Biology and State Key Laboratory of Medical Genomics and Laboratory of Development and Diseases, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, and Shanghai Institute of Hematology, RuiJin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Cong
authors.initials: C
authors.lastname: Fu
authors.forename: Hongbo
authors.initials: H
authors.lastname: Fan
authors.forename: Tingting
authors.initials: T
authors.lastname: Du
authors.forename: Mei
authors.initials: M
authors.lastname: Dong
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.forename: Yi
authors.initials: Y
authors.lastname: Jin
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhou
authors.forename: Min
authors.initials: M
authors.lastname: Deng
authors.forename: Aihua
authors.initials: A
authors.lastname: Gu
authors.forename: Qing
authors.initials: Q
authors.lastname: Jing
authors.forename: Tingxi
authors.initials: T
authors.lastname: Liu
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000235:genetics / Q000502:physiology; D007668:Kidney / Q000196:embryology / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000502:physiology*; D016133:Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D035683:MicroRNAs; D029961:Zebrafish Proteins
keywords: Cell migration; Kidney; Multiciliogenesis; Olfactory placode; microRNA; mir34b