Cell senescence altered the miRNA expression profile in porcine angular aqueous plexus cells

PURPOSE: This study investigates the impact of aging on the miRNA expression profile in porcine angular aqueous plexus (AAP) cells, which are the porcine equivalent of human Schlemm’s canal endothelial cells. METHODS: AAP endothelial cells were isolated and cultured in physiologic (5% O(2)) or hyperoxic condition (40% O(2)) for 14 days to induce cell senescence. miRNA and protein expression profiles of control and senescent cells were analyzed with miRNA microarray and isobaric tags for relative and absolute quantification (iTRAQ), respectively. RESULTS: The miRNA microarray identified 33 differentially expressed miRNAs in senescent cells compared with controls (p<0.05), and quantitative real-time PCR (qRT-PCR) confirmed 12 of them (p<0.05). iTRAQ analysis identified 148 upregulated and 222 downregulated proteins (p<0.05, fold change>1.2). Bioinformatics analysis of miRNA microarray and proteomics data predicted that six out of seven miRNAs are associated with aqueous humor outflow by targeting integrin and the downstream pathways (Src/Rho kinase, focal adhesion kinase (FAK)/NO-cGMP), and one miRNA might influence gap junction by targeting the Inositol trisphosphate receptor (IP3R) /Protein kinase C (PKC) pathway. CONCLUSIONS: This study identified miRNAs in senescent AAP cells that might regulate aqueous humor outflow by targeting proteins involved in focal adhesion, cytoskeleton, NO-cGMP signaling, and gap junction.