Regulatory effect of prostaglandin E2 on protein expression in bovine retinae, ex vivo

Abstract

We have evidence that prostaglandin (PG)E2 reduces endogenous bovine retinal amino acid neurotransmitter levels, ex vivo [Zhao et al, Methods and Findings, In press]. It is, however, unclear if these changes in neurotransmitter levels involve an effect on protein expression. Freshly isolated bovine eyeballs were injected, intravitreally with PGE2 and retinae were isolated and prepared for determination of protein expression using the 2DE‐DIGE approach. Protein spots exhibiting statistically significant changes (P<0.05) were selected and identified using LC‐MS/MS and analyzed by bioinformatics. PGE2 (10 uM) increased the expression of three proteins while five were decreased. The structural proteins, albumin and tubulin alpha‐1D chain and the cellular defense protein, heat shock 70 kDa protein 1B were up‐regulated. In contrast, peroxiredoxin 2 (a scavenger for peroxides) and aldehyde dehydrogenase 9 family, member A1 (an enzyme that breaks down alcohol) were down‐regulated. Furthermore, the GDP dissociation inhibitor 2, a signal transduction protein, recoverin, a calcium‐binding protein in photoreceptor cells and CNDP dipeptidase 2 were also down‐regulated. In conclusion, PGE2 altered the expression of both structural proteins and those involved in cellular defense and signal transduction pathways in bovine retina, ex vivo.