TY - JOUR
T1 - Endothelin-2-Mediated Protection of Mutant Photoreceptors in Inherited Photoreceptor Degeneration
AU - Bramall, Alexa N.
AU - Szego, Michael J.
AU - Pacione, Laura R.
AU - Chang, Inik
AU - Diez, Eduardo
AU - D'Orleans-Juste, Pedro
AU - Stewart, Duncan J.
AU - Hauswirth, William W.
AU - Yanagisawa, Masashi
AU - McInnes, Roderick R.
PY - 2013/2/28
Y1 - 2013/2/28
N2 - Expression of the Endothelin-2 (Edn2) mRNA is greatly increased in the photoreceptors (PRs) of mouse models of inherited PR degeneration (IPD). To examine the role of Edn2 in mutant PR survival, we generated Edn2-/- mice carrying homozygous Pde6brd1 alleles or the Tg(RHO P347S) transgene. In the Edn2-/- background, PR survival increased 110% in Pde6brd1/rd1 mice at post-natal (PN) day 15, and 60% in Tg(RHO P347S) mice at PN40. In contrast, PR survival was not increased in retinal explants of Pde6brd1/rd1; Edn2-/- mice. This finding, together with systemic abnormalities in Edn2-/- mice, suggested that the increased survival of mutant PRs in the Edn2-/- background resulted at least partly from the systemic EDN2 loss of function. To examine directly the role of EDN2 in mutant PRs, we used a scAAV5-Edn2 cDNA vector to restore Edn2 expression in Pde6brd1/rd1; Edn2-/- PRs and observed an 18% increase in PR survival at PN14. Importantly, PR survival was also increased after injection of scAAV5-Edn2 into Pde6brd1/rd1 retinas, by 31% at PN15. Together, these findings suggest that increased Edn2 expression is protective to mutant PRs. To begin to elucidate Edn2-mediated mechanisms that contribute to PR survival, we used microarray analysis and identified a cohort of 20 genes with >4-fold increased expression in Tg(RHO P347S) retinas, including Fgf2. Notably, increased expression of the FGF2 protein in Tg(RHO P347S) PRs was ablated in Tg(RHO P347S); Edn2-/- retinas. Our findings indicate that the increased expression of PR Edn2 increases PR survival, and suggest that the Edn2-dependent increase in PR expression of FGF2 may contribute to the augmented survival.
AB - Expression of the Endothelin-2 (Edn2) mRNA is greatly increased in the photoreceptors (PRs) of mouse models of inherited PR degeneration (IPD). To examine the role of Edn2 in mutant PR survival, we generated Edn2-/- mice carrying homozygous Pde6brd1 alleles or the Tg(RHO P347S) transgene. In the Edn2-/- background, PR survival increased 110% in Pde6brd1/rd1 mice at post-natal (PN) day 15, and 60% in Tg(RHO P347S) mice at PN40. In contrast, PR survival was not increased in retinal explants of Pde6brd1/rd1; Edn2-/- mice. This finding, together with systemic abnormalities in Edn2-/- mice, suggested that the increased survival of mutant PRs in the Edn2-/- background resulted at least partly from the systemic EDN2 loss of function. To examine directly the role of EDN2 in mutant PRs, we used a scAAV5-Edn2 cDNA vector to restore Edn2 expression in Pde6brd1/rd1; Edn2-/- PRs and observed an 18% increase in PR survival at PN14. Importantly, PR survival was also increased after injection of scAAV5-Edn2 into Pde6brd1/rd1 retinas, by 31% at PN15. Together, these findings suggest that increased Edn2 expression is protective to mutant PRs. To begin to elucidate Edn2-mediated mechanisms that contribute to PR survival, we used microarray analysis and identified a cohort of 20 genes with >4-fold increased expression in Tg(RHO P347S) retinas, including Fgf2. Notably, increased expression of the FGF2 protein in Tg(RHO P347S) PRs was ablated in Tg(RHO P347S); Edn2-/- retinas. Our findings indicate that the increased expression of PR Edn2 increases PR survival, and suggest that the Edn2-dependent increase in PR expression of FGF2 may contribute to the augmented survival.
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U2 - 10.1371/journal.pone.0058023
DO - 10.1371/journal.pone.0058023
M3 - Article
C2 - 23469133
AN - SCOPUS:84874564133
SN - 1932-6203
VL - 8
JO - PloS one
JF - PloS one
IS - 2
M1 - e58023
ER -