title: Cross-talk between miR-29 and transforming growth factor-betas in trabecular meshwork cells.
abstract: OBJECTIVE
  To investigate the interactions between microRNA-29 (miR-29), a negative regulator of extracellular matrix (ECM), and transforming growth factors (TGF)β-1 and TGFβ-2.
  
  
  METHODS
  Changes in expression of the miR-29 family were analyzed by quantitative-PCR (Q-PCR) after treatment with TGFβ1 and TGFβ2 (1 ng/mL). TGFβ1 and TGFβ2 were evaluated at gene expression and protein levels by Q-PCR and ELISA, respectively, in human trabecular meshwork (HTM) cells transfected with miR-29b or scramble control. TGFβ1 promoter activity was analyzed using an adenovirus with the reporter SEAP. The effects of miR-29b and TGFβ2 on ECM gene expression were evaluated in cells transfected with miR-29b or scramble control and treated with TGFβ2, and the expression of ECM genes was analyzed by Q-PCR.
  
  
  RESULTS
  TGFβ2 but not TGFβ1, downregulated the three members of the miR-29 family. Overexpression of miR-29b antagonized the effects of TGFβ2 on the expression of several ECM components. MiR-29b decreased the expression of TGFβ1 at the promoter, transcript, and protein levels but had only a minor effect on the expression of active TGFβ2. The inhibition of TGFβ1 by miR-29b was partially recovered after co-transfection with a plasmid-expressing bone morphogenetic protein 1.
  
  
  CONCLUSIONS
  Results showed some level of crosstalk between TGFβs and miR-29. Specifically, the downregulation of miR-29 by TGFβ2 contributed to the induction of several ECM components by this cytokine in TM cells. This observation, together with the inhibitory effects of miR-29b on the expression of TGFβ1, suggests that the miR-29 family could play an important role in modulating TGFβs on the outflow pathway.
authors.affiliation: Department of Ophthalmology, Duke University, Durham, North Carolina, USA.
authors.forename: Coralia
authors.initials: C
authors.lastname: Luna
authors.forename: Guorong
authors.initials: G
authors.lastname: Li
authors.forename: Jianming
authors.initials: J
authors.lastname: Qiu
authors.forename: David L
authors.initials: DL
authors.lastname: Epstein
authors.forename: Pedro
authors.initials: P
authors.lastname: Gonzalez
mesh_terms: D002478:Cells, Cultured; D015536:Down-Regulation; D004797:Enzyme-Linked Immunosorbent Assay; D005109:Extracellular Matrix / Q000235:genetics; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014129:Trabecular Meshwork / Q000187:drug effects / Q000378:metabolism*; D014162:Transfection; D053773:Transforming Growth Factor beta1 / Q000378:metabolism* / Q000494:pharmacology; D053781:Transforming Growth Factor beta2 / Q000378:metabolism* / Q000494:pharmacology
chemical_list: C532045:MIRN29a microRNA, human; D035683:MicroRNAs; D053773:Transforming Growth Factor beta1; D053781:Transforming Growth Factor beta2