Chloride channel protein ۲ prevents glutamate-induced apoptosis in retinal ganglion cells

Objective(s): The purpose of this study was to investigate the role of chloride channel protein ۲ (ClC-۲) in glutamate-induced apoptosis in the retinal ganglion cell line (RGC-۵). Materials and Methods: RGC-۵ cells were treated with ۱ mM glutamate for ۲۴ hr. The expression of ClC-۲, Bax, and Bcl-۲ was detected by western blot analysis. Cell survival and apoptosis were measured by ۳-(۴,۵-dimethylthiazol-۲-yl)-۲,۵-diphenyltetrazolium bromide (MTT) and flow cytometry assays, respectively. Caspase-۳ and -۹ activities were determined by a colorimetric assay. The roles of ClC-۲ in glutamate-induced apoptosis were examined by using ClC-۲ complementary deoxyribonucleic acid (cDNA) and small inference ribonucleic acid (RNA) transfection technology. Results: Overexpression of ClC-۲ in RGC-۵ cells significantly decreased glutamate-induced apoptosis and increased cell viability, whereas silencing of ClC-۲ with short hairpin (sh) RNA produced opposite effects. ClC-۲ overexpression increased the expression of Bcl-۲, decreased the expression of Bax, and decreased caspase-۳ and -۹ activation in RGC-۵ cells treated with glutamate, but silencing of ClC-۲ produced opposite effects. Conclusion: Our data suggest that ClC-۲ chloride channels might play a protective role in glutamate-induced apoptosis in retinal ganglion cells via the mitochondria-dependent apoptosis pathway.

Keywords:

Apoptosis , Chloride channels , Chloride channel protein ۲ Neuroprotection , Retinal ganglion cells