Taurine protects against Retinal Ganglion Cell Degeneration

Incredible edible egg!!

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042017

Taurine Provides Neuroprotection against Retinal Ganglion Cell Degeneration
Abstract <http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042017#top>

Retinal ganglion cell (RGC) degeneration occurs in numerous retinal
diseases leading to blindness, either as a primary process like in
glaucoma, or secondary to photoreceptor loss. However, no commercial drug
is yet directly targeting RGCs for their neuroprotection. In the 70s,
taurine, a small sulfonic acid provided by nutrition, was found to be
essential for the survival of photoreceptors, but this dependence was not
related to any retinal disease. More recently, taurine deprivation was
incriminated in the retinal toxicity of an antiepileptic drug. We
demonstrate here that taurine can improve RGC survival in culture or in
different animal models of RGC degeneration. Taurine effect on RGC survival
was assessed *in vitro* on primary pure RCG cultures under
serum-deprivation conditions, and on NMDA-treated retinal explants from
adult rats. *In vivo*, taurine was administered through the drinking water
in two glaucomatous animal models (DBA/2J mice and rats with vein
occlusion) and in a model of *Retinitis pigmentosa* with secondary RGC
degeneration (P23H rats). After a 6-day incubation, 1 mM taurine
significantly enhanced RGCs survival (+68%), whereas control RGCs were
cultured in a taurine-free medium, containing all natural amino-acids. This
effect was found to rely on taurine-uptake by RGCs. Furthermore taurine (1
mM) partly prevented NMDA-induced RGC excitotoxicity. Finally, taurine
supplementation increased RGC densities both in DBA/2J mice, in rats with
vein occlusion and in P23H rats by contrast to controls drinking
taurine-free water. This study indicates that enriched taurine nutrition
can directly promote RGC survival through RGC intracellular pathways. It
provides evidence that taurine can positively interfere with retinal
degenerative diseases.
*Citation: *Froger N, Cadetti L, Lorach H, Martins J, Bemelmans A-P, et al.
(2012) Taurine Provides




*Figure 5.
<http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042017?imageURI=info:doi/10.1371/journal.pone.0042017.g005>
Taurine
supplementation prevents RGC degeneration in glaucomatous Long-Evans rats
following episcleral vein occlusion.*


**


Taurine Reduces the Secondary RGC Degeneration Following Photoreceptor Loss
in P23H Rats


*Taurine was previously reported to prevent glutamate excitotoxicity in
embryonic cultured cerebellar neurons
[11]<http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042017#pone.0042017-ElIdrissi1>or
mixed brain neurons
[10]<http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042017#pone.0042017-Wu1>.
Our present study extends this conclusion to adult RGCs in NMDA-treated
retinal explants. *The intracellular effects of taurine discussed above
could explain this prevention of RGC glutamate excitotoxicity in
NMDA-treated retinal explants. Especially, the taurine-induced reduction of
intracellular Ca2+ levels, as described in brain neurons
[10]<http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042017#pone.0042017-Wu1>,
[11]<http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042017#pone.0042017-ElIdrissi1>and
in immortalized RGCs under hypoxia
[20]<http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042017#pone.0042017-Chen1>,
could limit the toxic Ca2+ overload resulting from the prolonged activation
of the Ca2+-permeable NMDA receptors. The taurine-mediated reduction in
glutamate excitotoxicity could also be attributed to the taurine effect on
glutamate uptake
[31]<http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042017#pone.0042017-Chen2>.
Despite the negative conclusion of the clinical trial with memantine, a
blocker of NMDA receptors
[32]<http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042017#pone.0042017-DaneshMeyer1>,
glutamate excitotoxicity is considered as an important molecular mechanism
in RGC degeneration during glaucoma and other retinal diseases with an
ischemic contribution
[21]<http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042017#pone.0042017-Seki1>.
Therefore, the protective effect of taurine on pure RGC cultures and on RGC
glutamate excitotoxicity could explain the *in vivo* RGC rescue in glaucoma
animal models.


[Non-text portions of this message have been removed]

well its an extra can of red bull for me today then !
 
puk
 
 
In a message dated 19/11/2012 04:39:45 GMT Standard Time,  
[hidden email] writes:

 
 
 
Incredible edible egg!!

_http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042017_
 (http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042017)

Taurine  Provides Neuroprotection against Retinal Ganglion Cell  
Degeneration
Abstract
<_http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0042017#top_
(http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042017#top) >

Retinal  ganglion cell (RGC) degeneration occurs in numerous retinal
diseases  leading to blindness, either as a primary process like in
glaucoma, or  secondary to photoreceptor loss. However, no commercial drug
is yet  directly targeting RGCs for their neuroprotection. In the 70s,
taurine, a  small sulfonic acid provided by nutrition, was found to be
essential for  the survival of photoreceptors, but this dependence was not
related to any  retinal disease. More recently, taurine deprivation was
incriminated in the  retinal toxicity of an antiepileptic drug. We
demonstrate here that taurine  can improve RGC survival in culture or in
different animal models of RGC  degeneration. Taurine effect on RGC survival
was assessed *in vitro* on  primary pure RCG cultures under
serum-deprivation conditions, and on  NMDA-treated retinal explants from
adult rats. *In vivo*, taurine was  administered through the drinking water
in two glaucomatous animal models  (DBA/2J mice and rats with vein
occlusion) and in a model of *Retinitis  pigmentosa* with secondary RGC
degeneration (P23H rats). After a 6-day  incubation, 1 mM taurine
significantly enhanced RGCs survival (+68%),  whereas control RGCs were
cultured in a taurine-free medium, containing all  natural amino-acids. This
effect was found to rely on taurine-uptake by  RGCs. Furthermore taurine (1
mM) partly prevented NMDA-induced RGC  excitotoxicity. Finally, taurine
supplementation increased RGC densities  both in DBA/2J mice, in rats with
vein occlusion and in P23H rats by  contrast to controls drinking
taurine-free water. This study indicates that  enriched taurine nutrition
can directly promote RGC survival through RGC  intracellular pathways. It
provides evidence that taurine can positively  interfere with retinal
degenerative diseases.
*Citation: *Froger N,  Cadetti L, Lorach H, Martins J, Bemelmans A-P, et al.
(2012) Taurine  Provides

*Figure 5.
<_http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042017?image
URI=info:doi/10.1371/journal.pone.0042017.g005_
(http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042017?imageURI=info:doi/10.1371/journal.
pone.0042017.g005) >
Taurine
supplementation  prevents RGC degeneration in glaucomatous Long-Evans rats
following  episcleral vein occlusion.*

**

Taurine Reduces the Secondary RGC  Degeneration Following Photoreceptor Loss
in P23H Rats

*Taurine was  previously reported to prevent glutamate excitotoxicity in
embryonic  cultured cerebellar neurons
[11]<_http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.004
2017#pone.0042017-ElIdrissi1_
(http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042017#pone.0042017-ElIdrissi1) >or
mixed  brain neurons
[10]<_http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.004
2017#pone.0042017-Wu1_
(http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042017#pone.0042017-Wu1) >.
Our  present study extends this conclusion to adult RGCs in NMDA-treated
retinal  explants. *The intracellular effects of taurine discussed above
could  explain this prevention of RGC glutamate excitotoxicity in
NMDA-treated  retinal explants. Especially, the taurine-induced reduction  
of
intracellular Ca2+ levels, as described in brain neurons
[10]<_http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.004
2017#pone.0042017-Wu1_
(http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042017#pone.0042017-Wu1) >,
[11]<_http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.004
2017#pone.0042017-ElIdrissi1_
(http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042017#pone.0042017-ElIdrissi1) >and
in  immortalized RGCs under hypoxia
[20]<_http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.004
2017#pone.0042017-Chen1_
(http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042017#pone.0042017-Chen1) >,
could  limit the toxic Ca2+ overload resulting from the prolonged activation
of  the Ca2+-permeable NMDA receptors. The taurine-mediated reduction  in
glutamate excitotoxicity could also be attributed to the taurine effect  on
glutamate uptake
[31]<_http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.004
2017#pone.0042017-Chen2_
(http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042017#pone.0042017-Chen2) >.
Despite  the negative conclusion of the clinical trial with memantine, a
blocker of  NMDA receptors
[32]<_http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.004
2017#pone.0042017-DaneshMeyer1_
(http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042017#pone.0042017-DaneshMeyer1) >,
glutamate  excitotoxicity is considered as an important molecular mechanism
in RGC  degeneration during glaucoma and other retinal diseases with an
ischemic  contribution
[21]<_http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.004
2017#pone.0042017-Seki1_
(http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042017#pone.0042017-Seki1) >.
Therefore,  the protective effect of taurine on pure RGC cultures and on RGC
glutamate  excitotoxicity could explain the *in vivo* RGC rescue in glaucoma
animal  models.

[Non-text portions of this message have been  removed]






[Non-text portions of this message have been removed]