Molecular Mechanisms Regulating Ocular Apoptosis in Zebrafish gdf6a Mutants

Sameer D Pant, Lindsey D March, Jakub K Famulski, Curtis R French, Ordan J Lehmann, Andrew J Waskiewicz

Research output: Contribution to journalArticle

7 Citations (Scopus)
19 Downloads (Pure)

Abstract

The role of Gdf6 in regulating apoptosis was studied using a zebrafish gdf6a−/− mutant, which encodes a truncated, nonfunctional protein. To investigate whether intrinsic or extrinsic apoptotic mechanisms were involved, morpholino antisense oligonucleotides targeting baxa, baxb, and p53 were employed. Caspase-3 immunohistochemistry (IHC) was performed to assay apoptosis. Pharmacologic inhibition (using SB203580) and IHC were used to investigate the role of p38 mitogen activated protein (MAP) kinase activation in gdf6a−/− -induced apoptosis. To assess the role of Gdf6a in transcriptional regulation of TGFβ signal transducers, in situ hybridization (ISH) was performed using probes to smad1, 5, 7, and 8.
Results.: Results indicate maximal ocular apoptosis occurs 28 hours post fertilization (hpf) in gdf6a−/− mutants that is mediated independently of p53 by intrinsic mechanisms involving Bax proteins. Also, gdf6a−/− mutants exhibit markedly increased p38 MAP kinase activation that can be inhibited to significantly reduce retinal apoptosis. A reduction in retinal smad1 expression was also noted in gdf6a−/− mutants.

Conclusions.: gdf6a−/− -induced apoptosis is characterized by the involvement of intrinsic apoptotic pathways, p38 MAP kinases, and dysregulated smad expression. Modulation of key mediators can inhibit retinal apoptosis offering potential avenues of therapy. However, the efficacy of pharmacomodulation in improvement of visual function needs to be further examined.
Original languageEnglish
Pages (from-to)5871-5879
Number of pages9
JournalInvestigative Ophthalmology & Visual Science
Volume54
Issue number8
DOIs
Publication statusPublished - 01 Aug 2013

Fingerprint

Zebrafish
Apoptosis
p38 Mitogen-Activated Protein Kinases
Immunohistochemistry
bcl-2-Associated X Protein
Morpholinos
Antisense Oligonucleotides
Transducers
Fertilization
Caspase 3
In Situ Hybridization
Proteins

Cite this

Pant, S. D., March, L. D., Famulski, J. K., French, C. R., Lehmann, O. J., & Waskiewicz, A. J. (2013). Molecular Mechanisms Regulating Ocular Apoptosis in Zebrafish gdf6a Mutants. Investigative Ophthalmology & Visual Science, 54(8), 5871-5879. https://doi.org/10.1167/iovs.12-11315
Pant, Sameer D ; March, Lindsey D ; Famulski, Jakub K ; French, Curtis R ; Lehmann, Ordan J ; Waskiewicz, Andrew J. / Molecular Mechanisms Regulating Ocular Apoptosis in Zebrafish gdf6a Mutants. In: Investigative Ophthalmology & Visual Science. 2013 ; Vol. 54, No. 8. pp. 5871-5879.
@article{9f63beceae6e47c6aa9cf9a9aa832d37,
title = "Molecular Mechanisms Regulating Ocular Apoptosis in Zebrafish gdf6a Mutants",
abstract = "The role of Gdf6 in regulating apoptosis was studied using a zebrafish gdf6a−/− mutant, which encodes a truncated, nonfunctional protein. To investigate whether intrinsic or extrinsic apoptotic mechanisms were involved, morpholino antisense oligonucleotides targeting baxa, baxb, and p53 were employed. Caspase-3 immunohistochemistry (IHC) was performed to assay apoptosis. Pharmacologic inhibition (using SB203580) and IHC were used to investigate the role of p38 mitogen activated protein (MAP) kinase activation in gdf6a−/− -induced apoptosis. To assess the role of Gdf6a in transcriptional regulation of TGFβ signal transducers, in situ hybridization (ISH) was performed using probes to smad1, 5, 7, and 8. Results.: Results indicate maximal ocular apoptosis occurs 28 hours post fertilization (hpf) in gdf6a−/− mutants that is mediated independently of p53 by intrinsic mechanisms involving Bax proteins. Also, gdf6a−/− mutants exhibit markedly increased p38 MAP kinase activation that can be inhibited to significantly reduce retinal apoptosis. A reduction in retinal smad1 expression was also noted in gdf6a−/− mutants.Conclusions.: gdf6a−/− -induced apoptosis is characterized by the involvement of intrinsic apoptotic pathways, p38 MAP kinases, and dysregulated smad expression. Modulation of key mediators can inhibit retinal apoptosis offering potential avenues of therapy. However, the efficacy of pharmacomodulation in improvement of visual function needs to be further examined.",
author = "Pant, {Sameer D} and March, {Lindsey D} and Famulski, {Jakub K} and French, {Curtis R} and Lehmann, {Ordan J} and Waskiewicz, {Andrew J}",
year = "2013",
month = "8",
day = "1",
doi = "10.1167/iovs.12-11315",
language = "English",
volume = "54",
pages = "5871--5879",
journal = "Investigative Ophthalmology",
issn = "0146-0404",
publisher = "Association for Research in Vision and Ophthalmology Inc.",
number = "8",

}

Pant, SD, March, LD, Famulski, JK, French, CR, Lehmann, OJ & Waskiewicz, AJ 2013, 'Molecular Mechanisms Regulating Ocular Apoptosis in Zebrafish gdf6a Mutants', Investigative Ophthalmology & Visual Science, vol. 54, no. 8, pp. 5871-5879. https://doi.org/10.1167/iovs.12-11315

Molecular Mechanisms Regulating Ocular Apoptosis in Zebrafish gdf6a Mutants. / Pant, Sameer D; March, Lindsey D; Famulski, Jakub K; French, Curtis R; Lehmann, Ordan J; Waskiewicz, Andrew J.

In: Investigative Ophthalmology & Visual Science, Vol. 54, No. 8, 01.08.2013, p. 5871-5879.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Molecular Mechanisms Regulating Ocular Apoptosis in Zebrafish gdf6a Mutants

AU - Pant, Sameer D

AU - March, Lindsey D

AU - Famulski, Jakub K

AU - French, Curtis R

AU - Lehmann, Ordan J

AU - Waskiewicz, Andrew J

PY - 2013/8/1

Y1 - 2013/8/1

N2 - The role of Gdf6 in regulating apoptosis was studied using a zebrafish gdf6a−/− mutant, which encodes a truncated, nonfunctional protein. To investigate whether intrinsic or extrinsic apoptotic mechanisms were involved, morpholino antisense oligonucleotides targeting baxa, baxb, and p53 were employed. Caspase-3 immunohistochemistry (IHC) was performed to assay apoptosis. Pharmacologic inhibition (using SB203580) and IHC were used to investigate the role of p38 mitogen activated protein (MAP) kinase activation in gdf6a−/− -induced apoptosis. To assess the role of Gdf6a in transcriptional regulation of TGFβ signal transducers, in situ hybridization (ISH) was performed using probes to smad1, 5, 7, and 8. Results.: Results indicate maximal ocular apoptosis occurs 28 hours post fertilization (hpf) in gdf6a−/− mutants that is mediated independently of p53 by intrinsic mechanisms involving Bax proteins. Also, gdf6a−/− mutants exhibit markedly increased p38 MAP kinase activation that can be inhibited to significantly reduce retinal apoptosis. A reduction in retinal smad1 expression was also noted in gdf6a−/− mutants.Conclusions.: gdf6a−/− -induced apoptosis is characterized by the involvement of intrinsic apoptotic pathways, p38 MAP kinases, and dysregulated smad expression. Modulation of key mediators can inhibit retinal apoptosis offering potential avenues of therapy. However, the efficacy of pharmacomodulation in improvement of visual function needs to be further examined.

AB - The role of Gdf6 in regulating apoptosis was studied using a zebrafish gdf6a−/− mutant, which encodes a truncated, nonfunctional protein. To investigate whether intrinsic or extrinsic apoptotic mechanisms were involved, morpholino antisense oligonucleotides targeting baxa, baxb, and p53 were employed. Caspase-3 immunohistochemistry (IHC) was performed to assay apoptosis. Pharmacologic inhibition (using SB203580) and IHC were used to investigate the role of p38 mitogen activated protein (MAP) kinase activation in gdf6a−/− -induced apoptosis. To assess the role of Gdf6a in transcriptional regulation of TGFβ signal transducers, in situ hybridization (ISH) was performed using probes to smad1, 5, 7, and 8. Results.: Results indicate maximal ocular apoptosis occurs 28 hours post fertilization (hpf) in gdf6a−/− mutants that is mediated independently of p53 by intrinsic mechanisms involving Bax proteins. Also, gdf6a−/− mutants exhibit markedly increased p38 MAP kinase activation that can be inhibited to significantly reduce retinal apoptosis. A reduction in retinal smad1 expression was also noted in gdf6a−/− mutants.Conclusions.: gdf6a−/− -induced apoptosis is characterized by the involvement of intrinsic apoptotic pathways, p38 MAP kinases, and dysregulated smad expression. Modulation of key mediators can inhibit retinal apoptosis offering potential avenues of therapy. However, the efficacy of pharmacomodulation in improvement of visual function needs to be further examined.

U2 - 10.1167/iovs.12-11315

DO - 10.1167/iovs.12-11315

M3 - Article

C2 - 23847306

VL - 54

SP - 5871

EP - 5879

JO - Investigative Ophthalmology

JF - Investigative Ophthalmology

SN - 0146-0404

IS - 8

ER -