title: microRNA miR-34a regulates cytodifferentiation and targets multi-signaling pathways in human dental papilla cells.
abstract: Odontogenesis relies on the reciprocal signaling interactions between dental epithelium and neural crest-derived mesenchyme, which is regulated by several signaling pathways. Subtle changes in the activity of these major signaling pathways can have dramatic effects on tooth development. An important regulator of such subtle changes is the fine tuning function of microRNAs (miRNAs). However, the underlying mechanism by which miRNAs regulate tooth development remains elusive. This study determined the expression of miRNAs during cytodifferentiation in the human tooth germ and studied miR-34a as a regulator of dental papilla cell differentiation. Using microarrays, miRNA expression profiles were established at selected times during development (early bell stage or late bell stage) of the human fetal tooth germ. We identified 29 differentially expressed miRNAs from early bell stage/late bell stage comparisons. Out of 6 miRNAs selected for validation by qPCR, all transcripts were confirmed to be differentially expressed. miR-34a was selected for further investigation because it has been previously reported to regulate organogenesis. miR-34a mimics and inhibitors were transfected into human fetal dental papilla cells, mRNA levels of predicted target genes were detected by quantitative real-time PCR, and levels of putative target proteins were examined by western blotting. ALP and DSPP expression were also tested by qPCR, western blotting, and immunofluorescence. Findings from these studies suggested that miR-34a may play important roles in dental papilla cell differentiation during human tooth development by targeting NOTCH and TGF-beta signaling.
authors.affiliation: State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Mian
authors.initials: M
authors.lastname: Wan
authors.forename: Bo
authors.initials: B
authors.lastname: Gao
authors.forename: Feifei
authors.initials: F
authors.lastname: Sun
authors.forename: Yin
authors.initials: Y
authors.lastname: Tang
authors.forename: Ling
authors.initials: L
authors.lastname: Ye
authors.forename: Yi
authors.initials: Y
authors.lastname: Fan
authors.forename: Ophir D
authors.initials: OD
authors.lastname: Klein
authors.forename: Xuedong
authors.initials: X
authors.lastname: Zhou
authors.forename: Liwei
authors.initials: L
authors.lastname: Zheng
mesh_terms: D037881:Aborted Fetus; D015153:Blotting, Western; D002454:Cell Differentiation; D054425:Chemokine CCL27 / Q000235:genetics / Q000378:metabolism; D003771:Dental Papilla / Q000166:cytology / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism*; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009805:Odontogenesis / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism; D012795:Sialoglycoproteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics*; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism; D000099311:Dentin Sialophosphoprotein
chemical_list: D054425:Chemokine CCL27; D016326:Extracellular Matrix Proteins; D035683:MicroRNAs; D010750:Phosphoproteins; D012333:RNA, Messenger; D051880:Receptors, Notch; D012795:Sialoglycoproteins; D016212:Transforming Growth Factor beta; D000099311:Dentin Sialophosphoprotein; C492276:CCL27 protein, human; C522425:MIRN34 microRNA, human