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Knockout of PARG110 confers resistance to cGMP-induced toxicity in mammalian photoreceptors.

Sahaboglu, A; Tanimoto, N; Bolz, S; Garrido, M G; Ueffing, M; Seeliger, M W; Löwenheim, H; Ekström, Per LU and Paquet-Durand, Francois LU (2014) In Cell Death & Disease 5(May 22).
Abstract
Hereditary retinal degeneration (RD) relates to a heterogeneous group of blinding human diseases in which the light sensitive neurons of the retina, the photoreceptors, die. RD is currently untreatable and the underlying cellular mechanisms remain poorly understood. However, the activity of the enzyme poly-ADP-ribose polymerase-1 (PARP1) and excessive generation of poly-ADP-ribose (PAR) polymers in photoreceptor nuclei have been shown to be causally involved in RD. The activity of PARP1 is to a large extent governed by its functional antagonist, poly-ADP-glycohydrolase (PARG), which thus also may have a role in RD. To investigate this, we analyzed PARG expression in the retina of wild-type (wt) mice and in the rd1 mouse model for human RD,... (More)
Hereditary retinal degeneration (RD) relates to a heterogeneous group of blinding human diseases in which the light sensitive neurons of the retina, the photoreceptors, die. RD is currently untreatable and the underlying cellular mechanisms remain poorly understood. However, the activity of the enzyme poly-ADP-ribose polymerase-1 (PARP1) and excessive generation of poly-ADP-ribose (PAR) polymers in photoreceptor nuclei have been shown to be causally involved in RD. The activity of PARP1 is to a large extent governed by its functional antagonist, poly-ADP-glycohydrolase (PARG), which thus also may have a role in RD. To investigate this, we analyzed PARG expression in the retina of wild-type (wt) mice and in the rd1 mouse model for human RD, and detected increased PARG protein in a subset of degenerating rd1 photoreceptors. Knockout (KO) animals lacking the 110 kDa nuclear PARG isoform were furthermore analyzed, and their retinal morphology and function were indistinguishable from wild-type animals. Organotypic wt retinal explants can be experimentally treated to induce rd1-like photoreceptor death, but PARG110 KO retinal explants were unexpectedly highly resistant to such treatment. The resistance was associated with decreased PAR accumulation and low PARP activity, indicating that PARG110 may positively regulate PARP1, an event that therefore is absent in PARG110 KO tissue. Our study demonstrates a causal involvement of PARG110 in the process of photoreceptor degeneration. Contrasting its anticipated role as a functional antagonist, absence of PARG110 correlated with low PARP activity, suggesting that PARG110 and PARP1 act in a positive feedback loop, which is especially active under pathologic conditions. This in turn highlights both PARG110 and PARP1 as potential targets for neuroprotective treatments for RD. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Cell Death & Disease
volume
5
issue
May 22
publisher
Nature Publishing Group
external identifiers
  • pmid:24853412
  • wos:000337229300034
  • scopus:84907960469
ISSN
2041-4889
DOI
10.1038/cddis.2014.208
language
English
LU publication?
yes
id
cc146dcf-8ecc-4f7e-bcb8-737f780b1df7 (old id 4452699)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/24853412?dopt=Abstract
date added to LUP
2014-06-06 20:04:02
date last changed
2017-01-25 12:57:25
@article{cc146dcf-8ecc-4f7e-bcb8-737f780b1df7,
  abstract     = {Hereditary retinal degeneration (RD) relates to a heterogeneous group of blinding human diseases in which the light sensitive neurons of the retina, the photoreceptors, die. RD is currently untreatable and the underlying cellular mechanisms remain poorly understood. However, the activity of the enzyme poly-ADP-ribose polymerase-1 (PARP1) and excessive generation of poly-ADP-ribose (PAR) polymers in photoreceptor nuclei have been shown to be causally involved in RD. The activity of PARP1 is to a large extent governed by its functional antagonist, poly-ADP-glycohydrolase (PARG), which thus also may have a role in RD. To investigate this, we analyzed PARG expression in the retina of wild-type (wt) mice and in the rd1 mouse model for human RD, and detected increased PARG protein in a subset of degenerating rd1 photoreceptors. Knockout (KO) animals lacking the 110 kDa nuclear PARG isoform were furthermore analyzed, and their retinal morphology and function were indistinguishable from wild-type animals. Organotypic wt retinal explants can be experimentally treated to induce rd1-like photoreceptor death, but PARG110 KO retinal explants were unexpectedly highly resistant to such treatment. The resistance was associated with decreased PAR accumulation and low PARP activity, indicating that PARG110 may positively regulate PARP1, an event that therefore is absent in PARG110 KO tissue. Our study demonstrates a causal involvement of PARG110 in the process of photoreceptor degeneration. Contrasting its anticipated role as a functional antagonist, absence of PARG110 correlated with low PARP activity, suggesting that PARG110 and PARP1 act in a positive feedback loop, which is especially active under pathologic conditions. This in turn highlights both PARG110 and PARP1 as potential targets for neuroprotective treatments for RD.},
  articleno    = {e1234},
  author       = {Sahaboglu, A and Tanimoto, N and Bolz, S and Garrido, M G and Ueffing, M and Seeliger, M W and Löwenheim, H and Ekström, Per and Paquet-Durand, Francois},
  issn         = {2041-4889},
  language     = {eng},
  number       = {May 22},
  publisher    = {Nature Publishing Group},
  series       = {Cell Death & Disease},
  title        = {Knockout of PARG110 confers resistance to cGMP-induced toxicity in mammalian photoreceptors.},
  url          = {http://dx.doi.org/10.1038/cddis.2014.208},
  volume       = {5},
  year         = {2014},
}