αB-crystallin Expression is Regulated by Histone Deacetylase Inhibitor in Human Fetal Retinal Pigment Epithelial Cells

Abstract

Purpose: : αB-crystallin belongs to the small heat shock protein family and plays a role as a chaperon for VEGF in angiogenesis. The aim of the present study is to investigate whether the inhibition of histone deacetylation is involved in the regulation of αB-crystallin in human fetal retinal pigment epithelial (RPE) cells.

Methods: : Early passage, confluent, cultured fetal human RPE cells were used for the study. RPE cells were switched to serum free medium for 16 h and were then exposed to histone deacetylase inhibitor, trichostatin A (TSA) at various concentrations (0.1 µM to 1.0 µM) for 24 h. αB-crystallin mRNA expression was determined by RT-PCR. The expression of αB-crystallin, acetylated histone H2B, acetylated histone H4 and GRP78 in cell lysate were examined by western blot.

Results: : The highest expression of αB-crystallin mRNA was at the 0.3 µM concentration of TSA. TSA significantly down-regulated the expression of αB-crystallin in TSA concentration dependent manner, however, TSA didn’t change the expression of acetylated histone H4 and GRP78. The expression of acetylated histone H2B was not detected.

Conclusions: : The result shows that αB-crystallin is regulated by histone deacetylase inhibitor. Our data suggest that histone deacetylase inhibitor have potential as a therapeutic strategy.

Keywords: chaperones • retinal pigment epithelium • crystallins