MicroRNA-215 Regulates Fibroblast Function: Insights from a Human Fibrotic Disease

Abstract

MicroRNAs are implicated in the regulation of gene expression via various mechanisms in health and disease, including fibrotic processes. Pterygium is an ocular surface condition characterized by abnormal fibroblast proliferation and matrix deposition. We aimed to investigate the role of microRNAs in pterygium and understand the relevant cellular and molecular mechanisms. To achieve this objective, a combination of approaches using surgically excised paired human pterygium and conjunctival tissues as well as cultured primary fibroblast cells from tissue explants were evaluated. Fibroblast dysfunction has been shown to play a central role in pterygium pathology. Here we show that miR-215, among a few others, was down-regulated (2-fold) in pterygium compared to control, and this was consistent in microarray, real-time PCR and fluorescent in-situ hybridization. The effects of increased miR-215 were investigated by adding exogenous miR-215 to fibroblasts, and this showed a decrease in cell proliferation but no significant apoptosis compared to control. Further cell cycle analysis showed that miR-215 depressed progression of cells at G1/S as well as G2/M. A few cell cycle related transcripts were downregulated (2.2-4.5-fold) on addition of miR-215: Mcm3, Dicer1, Cdc25A, Ick, Trip13 and Mcm10. Theoretic binding energies were used to predict miR-215 binding targets and luciferase reporter studies confirmed Mcm10 and Cdc25A as direct targets. In summary, mir-215 could play a role in inhibiting fibroblast proliferation in ocular surface conjunctiva. Dampening of this mir-215 could result in increased fibroblast cell cycling and proliferation, with possibly increased fibroblastic production of matrix, inducing pterygium formation.

Overexpression of MCM10 promotes cell proliferation and predicts poor prognosis in prostate cancer

“…E3 ubiquitin ligase RBBP6 promoted MCM10 transcription by ubiquitinating and destabilizing the transcriptional repressor ZBTB38 . MiRNAs, such as miR‐215, were also reported as MCM10 regulators by inhibiting its expression . However, the downstream genes of MCM10 in PCa remained unknown.…”

Mcm10: A Dynamic Scaffold at Eukaryotic Replication Forks

“…Interestingly, RBBP6 (also known as PACT or P2P-R) interacts with the critical cell cycle regulators Rb and p53 to modulate cell cycle progression [ 86 , 88 , 89 ]. Furthermore, the zinc-finger transcription factor GATA-binding factor 6 (GATA6) promotes MCM10 expression in highly proliferative mouse follicle progenitor cells by stimulating Ectodysplasin-A receptor-associated adapter protein (Edaradd) and NF-κB signaling [ 90 ]. MCM10 expression levels are also controlled by microRNAs, such as miR-215, which directly regulates MCM as well as other cell cycle genes, including MCM3 and CDC25A [ 91 , 92 ].…”

MiR-199a-3p/5p participated in TGF-β and EGF induced EMT by targeting DUSP5/MAP3K11 in pterygium

“…First, we got the miRNA expression pro le of pterygium using the Affymetrix' miRNA 4.0 microarray and validated it in pterygium samples, where we rst observed the signi cant increase of miR-199a in pterygium. Although there were several researches, using microarray to screen the differentially expressed miRNAs in pterygium [2,[26][27][28], the Affymetrix' miRNA 4.0 microarray provided more complete measurements of miRNA, compared to GeneChip® miRNA 2.0 and 3.0, based on reports in Sanger miRBase 20.0 database. For instance, a larger number of miRNAs reads, reached to 6659, were discovered in our study compared to previous pterygium microarray researches, such as Silin Chen's (GSE21346), only 1380 reads.…”