title: MiR-17-92 cluster regulates cell proliferation and collagen synthesis by targeting TGFB pathway in mouse palatal mesenchymal cells.
abstract: Elongation and elevation of palatal shelves, mainly caused by proliferation and extra-cellular matrix synthesis of palatal mesenchymal cells (PMCs), are essential for normal palatal development. Transforming growth factor beta (TGFB) pathway could induce proliferation inhibition and collagen synthesis in PMCs. Recent studies found that miRNA-17-92 (miR-17-92) cluster, including miR-17, miR-18a, miR-19a, miR-20a, miR-19b, and miR-92a, expressed in the 1st bronchial arch of mouse embryos during the period of palatal shelf elongation and elevation, and directly targeted TGFB pathway in cancer cell lines. Whether miR-17-92 cluster expresses and targets TGFB pathway in PMCs has not yet been studied. Using quantitative real-time RT-PCR, we found that miR-17-92 expressed in PMCs and decreased from embryonic day (E) 12 to E14 in palatal shelves. MTT assay and Western blot showed that miR-17-92 inhibited TGFB1 induced proliferation inhibition and collagen synthesis in PMCs by decreasing TGFBR2, SMAD2, and SMAD4 protein level. Further luciferase assay showed that miR-17 and miR-20a directly targeted 3′UTR of TGFBR2, and that miR-18a directly targeted 3′UTR of SMAD2 and SMAD4. We thus conclude that miR-17-92 cluster could inhibit TGFB pathway induced proliferation inhibition and collagen synthesis in PMCs by directly targeting TGFBR2, SMAD2, and SMAD4.
authors.affiliation: State Key Laboratory of Oral Disease, West China College of Stomatology, Sichuan University, Chengdu, PR China.
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.forename: Jia-Yu
authors.initials: JY
authors.lastname: Shi
authors.forename: Gui-Quan
authors.initials: GQ
authors.lastname: Zhu
authors.forename: Bing
authors.initials: B
authors.lastname: Shi
mesh_terms: D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D049109:Cell Proliferation; D003094:Collagen / Q000096:biosynthesis*; D017931:DNA Primers; D008648:Mesoderm / Q000166:cytology*; D051379:Mice; D035683:MicroRNAs / Q000502:physiology*; D010159:Palate / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000037:antagonists & inhibitors / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051899:Smad2 Protein / Q000037:antagonists & inhibitors / Q000378:metabolism; D051901:Smad4 Protein / Q000037:antagonists & inhibitors / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000502:physiology*
chemical_list: D017931:DNA Primers; D035683:MicroRNAs; D018125:Receptors, Transforming Growth Factor beta; D051899:Smad2 Protein; C497783:Smad2 protein, mouse; D051901:Smad4 Protein; C490810:Smad4 protein, mouse; D016212:Transforming Growth Factor beta; D003094:Collagen; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II