Neuroprotective Effect of Protease-Activated Receptor-2 in the Hypoxia-Induced Apoptosis of Rat RGC-5 Cells
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Hypoxia-induced apoptosis of retinal ganglion cells (RGCs) is regarded as a pivotal pathological process in various ocular diseases. Protease-activated receptor-2 (PAR-2) is involved in the regulation of cell inflammation, differentiation, and apoptosis in many cell types and tissues, but the role of PAR-2 in RGCs under pathological conditions remains unknown. The purpose of this study was to investigate the role of PAR-2 in the apoptosis of RGCs under hypoxic stress. An immortalized rat RGC line (RGC-5) was exposed to hypoxia (5 % O2). The expression and location of PAR-2 in RGC-5 cells under hypoxia stress were investigated using real-time PCR, western blotting and immunocytochemistry. Cell viability was determined using the Cell Counting Kit-8 assay. Apoptosis was detected using Hoechst 33342 staining and AnnexinV-FITC/PI assays. The role of Bcl-2, Bax, and the active subunit of caspase-3 was also investigated. The results showed that PAR-2 was functionally expressed in RGC-5 cells and up-regulated at both mRNA and protein levels under hypoxic stress. The PAR-2 selective agonist, SLIGRL, rescued RGC-5 cells from hypoxia-induced apoptosis through up-regulation of the Bcl-2/Bax ratio and down-regulation of caspase-3 activation. This study provides the first evidence that PAR-2 has a protective effect against the hypoxia-induced apoptosis of RGC-5 cells.
KeywordsProtease-activated receptor-2 RGC-5 cells Hypoxia Apoptosis Caspase-3 Bcl-2/Bax ratio
- Lakhani SA, Masud A, Kuida K et al (2006) Caspases 3 and 7: key mediators of mitochondrial events of apoptosis. Sci STKE 311:847–851Google Scholar
- Linsenmeier RA, Braun RD, McRipley MA et al (1998) Retinal hypoxia in long-term diabetic cats. Investig Ophthalmol Vis Sci 39:1647–1657Google Scholar
- Menzel-Severing J, Siekmann U, Weinberger A, Roessler G, Walter P, Mazinani B (2012) Early hyperbaric oxygen treatment for nonarteritic central retinal artery obstruction. Am J Ophthalmol 454–459Google Scholar