Altered expression of exosomal miRNAs from primary human trabecular meshwork cells induced by transforming growth factor-β2

Background Primary open-angle glaucoma (POAG) is tightly related with extracellular matrix (ECM) remodeling of human trabecular meshwork cells (HTMCs). Transforming growth factor-β2 (TGF-β2) can induce ECM remodeling. MicroRNAs (miRNAs) serve as a potential therapeutic target in influencing the development of glaucoma by regulating TGF-β2. Recent studies also have found that exosomes may be involved in the regulation of intraocular pressure in patients of glaucoma. Therefore, the aim of the current study was to investigate the exosomal miRNAs expression changes derived from HTMCs treated with TGF-β2. Methods Exosomes were isolated from HTMCs supernatant cultured for 24 h with TGF-β2. The morphology of exosome pellets was examined by transmission electron microscopy. Nanoparticle tracking analysis used to demonstrate the particle size distribution. Total exosomal RNAs were extracted for subsequent miRNA gene chip analysis to investigate differentially expressed miRNAs between the control cells and treatment cells. Gene Ontology (GO) annotation, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were used to predict potential target and validate possible functions of the exosomal miRNAs. Results There were 23 miRNAs up-regulated and 3 miRNAs down-regulated. Go annotation and KEGG pathway enrichment analysis revealed that 469,102 and 94 GO terms involved in biological processes, cellular components and molecular function for the possible functions of the 26 miRNAs. Conclusions These findings indicate that TGF-β2 may alter exosomal miRNAs expression to participate in the pathogenesis of POAG in which multiple molecular functions and pathways are involved. They may provide significant information for potential biomarkers for POAG diagnosis, clinical treatment and potential prognosis.