Article

Coordinated Regulation of Extracellular Matrix Synthesis by the MicroRNA-29 Family in the Trabecular Meshwork

Department of Ophthalmology, Massachusetts Eye & Ear Infirmary, Harvard Medical School, Boston, Massachusetts 02114, USA.
Investigative ophthalmology & visual science (Impact Factor: 3.66). 02/2011; 52(6):3391-7. DOI: 10.1167/iovs.10-6165
Source: PubMed

ABSTRACT The microRNA-29 (miR-29) family has emerged, in various tissues, as a key modulator of extracellular matrix (ECM) homeostasis. In this study, the authors investigate the role of the miR-29 family in the regulation of ECM synthesis in the trabecular meshwork (TM) under basal and TGF-β2 stimulatory conditions.
Human TM cells were incubated with 2.5 ng/mL activated, recombinant human TGF-β2 for 24, 48, and 72 hours. A specific pharmacologic inhibitor was used to block SMAD3 function in the context of TGF-β2 stimulation. Changes in the expression of the miR-29 family were assessed by real-time PCR. The effect of miR-29 molecules and inhibitors on ECM levels was determined by immunoblot analysis.
All three members of the miR-29 family were expressed in cultured TM cells. Although the incubation of TM cells with TGF-β2 induced miR-29a and suppressed miR-29b levels, no significant effect was observed on miR-29c expression. Additional studies revealed that SMAD3 modulates miR-29b expression under basal and TGF-β2 conditions. Subsequent gain- and loss-of-function experiments demonstrated that the miR-29 family functions as a critical suppressor of various ECM proteins under basal and TGF-β2 stimulatory conditions.
The findings derived from this study identify the miR-29 family as a critical regulator of ECM expression in the TM and suggest that its modulation by TGF-β2 may be important in controlling ECM synthesis. Together, these data provide further insight into the complex regulatory mechanisms mediating TGF-β2 signaling and ECM production in the TM.

0 Followers
 · 
90 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Nasopharyngeal carcinoma (NPC) is a malignant tumor associated with a genetic predisposition, Epstein-Barr virus infection and chromosomal abnormalities. Recently, several miRNAs have been shown to target specific mRNAs to regulate NPC development and progression. However, the involvement of miRNAs in processes leading to NPC migration and invasion remains to be elucidated. We predicted that miR-29a/b are associated with dysregulated genes controlling NPC through an integrated interaction network of miRNAs and genes. miR-29a/b over-expression in NPC cell lines had no significant effect on proliferation, whereas miR-29b mildly increased the percentage of cells in the G1 phase with a concomitant decrease in the percentage of cells in S phase. Furthermore, we demonstrated that miR-29a/b might be responsible for increasing S18 cell migration and invasion, and only COL3A1 was identified as a direct target of miR-29b despite the fact that both SPARC and COL3A1 were inhibited by miR-29a/b over-expression. Meanwhile, SPARC proteins were increased in metastatic NPC tissue and are involved in NPC progression. Unexpectedly, we identified that miRNA-29b expression was elevated in the serum of NPC patients with a high risk of metastasis. The 5-year actuarial overall survival rates in NPC patients with high serum miR-29b expression was significantly shorter than those with low serum miR-29b expression; therefore, serum miR-29b expression could be a promising prognostic marker.
    PLoS ONE 01/2015; 10(3):e0120969. DOI:10.1371/journal.pone.0120969 · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Purpose In the present study, we aimed to investigate the changes in plasma miRNA in patients with wet age-related macular degeneration. Methods The expression profiles of 384 miRNAs in plasma from 33 patients (22 male, 11 female) who were diagnosed with wet age-related macular degeneration with fundus examination, fundus fluorescein angiography, and optical coherence tomography and 31 controls (17 male, 14 female) were evaluated using high-throughput quantitative real-time PCR. Results Our results demonstrated that the expression level of five miRNAs (miR-17-5p, miR-20a-5p, miR-24-3p, miR-106a-5p, and miR-223-3p) was significantly upregulated in patients with age-related macular degeneration when compared to the control group (p<0.05). The expression level of 11 miRNAs (miR-21-5p, miR-25-3p, miR-140-3p, miR-146b-5p, miR-192-5p, miR-335-5p, miR-342-3p, miR-374a-5p, miR-410, miR-574-3p, and miR-660-5p) was significantly downregulated in patients (p<0.05). In addition, ten miRNAs (miR-26b-5p, miR-27b-3p, miR-29a-3p, miR-139-3p, miR-212–3p, miR-324-3p, miR-324-5p, miR-532-3p, miR-744-5p, and miR-Let-7c) were expressed only in the patient group. Conclusions Our results suggest that plasma miRNA levels may change in wet age-related macular degeneration. These molecules may have an important therapeutic target in patients who are unresponsive to antivascular endothelial growth factor therapy. However, further studies must be conducted for possible effects of miRNAs in vascular disorders of eye such as age-related macular degeneration.
    Molecular vision 07/2014; 20:1057-66. · 2.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Angiotensin II (Ang II) has been proven to induce epithelial-mesenchymal transition (EMT). The aim of the present study was to determine the role of microRNA-29b (miR-29b) during Ang II-induced EMT. For this purpose, we used spontaneously hypertensive rats (SHRs) and age-matched Wistar-Kyoto (WKY) rats. The levels of Ang II and its receptor in the kidneys of the SHRs are significantly higher than those in the age-matched WKY rats. As shown by RT-qPCR, the expression of miR-29b in the renal cortex was lower in the SHRs than in the WKY rats. For in vitro experiments, NRK-52E renal tubular epithelial cells were treated with 10-7 M Ang II; we found that the expression of miR-29b was decreased in the cells treated with Ang II. In addition, transfection of the NRK-52E cells with miR-29b inhibitor led to the downregulation of miR-29b in these cells, and increased the expression of transforming growth factor (TGF)-β, α-smooth muscle actin (α-SMA) and collagen I (Col I). Similar results were observed with the induction of Ang II expression in the NRK-52E cells. By contrast, the upregulation of miR-29b by transfection with miR-29b mimics inhibited the overexpression of these genes induced by Ang II. These results suggest that miR-29b plays an important role in Ang II-induced EMT.
    International Journal of Molecular Medicine 09/2014; 34(5). DOI:10.3892/ijmm.2014.1935 · 1.88 Impact Factor

Preview

Download
9 Downloads
Available from