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Endothelin-2-mediated protection of mutant photoreceptors in inherited photoreceptor degeneration.

Bramall AN, Szego MJ, Pacione LR, Chang I, Diez E, D'Orleans-Juste P, Stewart DJ, Hauswirth WW, Yanagisawa M, McInnes RR - PLoS ONE (2013)

Bottom Line: Together, these findings suggest that increased Edn2 expression is protective to mutant PRs.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.

View Article: PubMed Central - PubMed

Affiliation: Program in Developmental Biology, The Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada.

ABSTRACT
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 Pde6b(rd1) alleles or the Tg(RHO P347S) transgene. In the Edn2(-/-) background, PR survival increased 110% in Pde6b(rd1/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 Pde6b(rd1/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 Pde6b(rd1/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 Pde6b(rd1/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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Identification of possible EDN2 regulated genes using microarrays.Gene expression was examined using the Mouse 430_2.0 Affymetrix array (4 arrays/genotype) and the 20 most differentially expressed mRNAs in Tg(RHO P347S); Edn2+/+ vs. Edn2+/+ retinas, and in Tg(RHO P347S); Edn2−/− vs. Edn2−/− retinas, at PN21 are shown. All differentially expressed genes in Tg(RHO P347S); Edn2+/+ retinas showed a significant reduction in expression in Tg(RHO P347S); Edn2−/− retinas, with the exception of Nuclear protein 1. The fold reduction is shown to the right of each pair of bars. The detection of Edn2 transcripts in Tg(RHO P347S); Edn2−/− retinas is due to the expression of partial Edn2 mRNAs from the Edn2−/− locus, in which part of exon 1 and all of exon 2 were replaced with the Neo cassette. n.s. =  no statistically significant increase in expression.
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pone-0058023-g006: Identification of possible EDN2 regulated genes using microarrays.Gene expression was examined using the Mouse 430_2.0 Affymetrix array (4 arrays/genotype) and the 20 most differentially expressed mRNAs in Tg(RHO P347S); Edn2+/+ vs. Edn2+/+ retinas, and in Tg(RHO P347S); Edn2−/− vs. Edn2−/− retinas, at PN21 are shown. All differentially expressed genes in Tg(RHO P347S); Edn2+/+ retinas showed a significant reduction in expression in Tg(RHO P347S); Edn2−/− retinas, with the exception of Nuclear protein 1. The fold reduction is shown to the right of each pair of bars. The detection of Edn2 transcripts in Tg(RHO P347S); Edn2−/− retinas is due to the expression of partial Edn2 mRNAs from the Edn2−/− locus, in which part of exon 1 and all of exon 2 were replaced with the Neo cassette. n.s. =  no statistically significant increase in expression.

Mentions: To identify retinal genes whose expression is directly or indirectly regulated by EDN2 in the presence of the Tg(RHO P347S) mutant allele, we identified mRNAs that were differentially expressed in Tg(RHO P347S); Edn2+/+ vs. Edn2+/+ retinas, to mRNAs that were differentially expressed between Tg(RHO P347S); Edn2−/− vs. Edn2−/− retinas (Fig. 6). This comparison was used, rather than contrasting the mRNAs of Tg(RHO P347S); Edn2+/+ vs. Tg(RHO P347S); Edn2−/− retinas, because this latter comparison would fail to distinguish between mRNA changes due the absence of EDN2 alone and indirect changes due to the absence of EDN2 in the presence of the Tg(RHO P347S) mutant allele.


Endothelin-2-mediated protection of mutant photoreceptors in inherited photoreceptor degeneration.

Bramall AN, Szego MJ, Pacione LR, Chang I, Diez E, D'Orleans-Juste P, Stewart DJ, Hauswirth WW, Yanagisawa M, McInnes RR - PLoS ONE (2013)

Identification of possible EDN2 regulated genes using microarrays.Gene expression was examined using the Mouse 430_2.0 Affymetrix array (4 arrays/genotype) and the 20 most differentially expressed mRNAs in Tg(RHO P347S); Edn2+/+ vs. Edn2+/+ retinas, and in Tg(RHO P347S); Edn2−/− vs. Edn2−/− retinas, at PN21 are shown. All differentially expressed genes in Tg(RHO P347S); Edn2+/+ retinas showed a significant reduction in expression in Tg(RHO P347S); Edn2−/− retinas, with the exception of Nuclear protein 1. The fold reduction is shown to the right of each pair of bars. The detection of Edn2 transcripts in Tg(RHO P347S); Edn2−/− retinas is due to the expression of partial Edn2 mRNAs from the Edn2−/− locus, in which part of exon 1 and all of exon 2 were replaced with the Neo cassette. n.s. =  no statistically significant increase in expression.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3585171&req=5

pone-0058023-g006: Identification of possible EDN2 regulated genes using microarrays.Gene expression was examined using the Mouse 430_2.0 Affymetrix array (4 arrays/genotype) and the 20 most differentially expressed mRNAs in Tg(RHO P347S); Edn2+/+ vs. Edn2+/+ retinas, and in Tg(RHO P347S); Edn2−/− vs. Edn2−/− retinas, at PN21 are shown. All differentially expressed genes in Tg(RHO P347S); Edn2+/+ retinas showed a significant reduction in expression in Tg(RHO P347S); Edn2−/− retinas, with the exception of Nuclear protein 1. The fold reduction is shown to the right of each pair of bars. The detection of Edn2 transcripts in Tg(RHO P347S); Edn2−/− retinas is due to the expression of partial Edn2 mRNAs from the Edn2−/− locus, in which part of exon 1 and all of exon 2 were replaced with the Neo cassette. n.s. =  no statistically significant increase in expression.
Mentions: To identify retinal genes whose expression is directly or indirectly regulated by EDN2 in the presence of the Tg(RHO P347S) mutant allele, we identified mRNAs that were differentially expressed in Tg(RHO P347S); Edn2+/+ vs. Edn2+/+ retinas, to mRNAs that were differentially expressed between Tg(RHO P347S); Edn2−/− vs. Edn2−/− retinas (Fig. 6). This comparison was used, rather than contrasting the mRNAs of Tg(RHO P347S); Edn2+/+ vs. Tg(RHO P347S); Edn2−/− retinas, because this latter comparison would fail to distinguish between mRNA changes due the absence of EDN2 alone and indirect changes due to the absence of EDN2 in the presence of the Tg(RHO P347S) mutant allele.

Bottom Line: Together, these findings suggest that increased Edn2 expression is protective to mutant PRs.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.

View Article: PubMed Central - PubMed

Affiliation: Program in Developmental Biology, The Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada.

ABSTRACT
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 Pde6b(rd1) alleles or the Tg(RHO P347S) transgene. In the Edn2(-/-) background, PR survival increased 110% in Pde6b(rd1/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 Pde6b(rd1/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 Pde6b(rd1/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 Pde6b(rd1/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.

Show MeSH
Related in: MedlinePlus