The Mechanism of Taurine Protection Against Endoplasmic Reticulum Stress in an Animal Stroke Model of Cerebral Artery Occlusion and Stroke-Related Conditions in Primary Neuronal Cell Culture - Advances in Experimental Medicine and Biology - page 236

a b

14

12
10
8
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12
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MCAO MCAO+Taurine

MCAO MCAO+Taurine

MCAO MCAO+Taurine

MCAO MCAO+Taurine

BC12

Caspase 3

Bax

c e

d

2.5

8

**

**

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1
0

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Caspase-12

Cleaved caspase-12

1.5

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1.0

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2.0

0.5

0.0

0.0

MCAO MCAO+Taurine

MCAO MCAO+Taurine

Norm Hyp Tau+Hyp

Norm Hyp Tau+Hyp

Caspase-12
Cleaved caspase-12

CHOP

Fig. 23.4 Effect of taurine on expression of Bcl2, Bax, caspase-3, CHOP and, caspase-12 in rat
MCAO stroke model and CHOP and caspase-12 in neuronal cell cultures under hypoxia/reoxygen-
ation conditions. ( a ) Bax and Bl2 expression in the core of MCAO brain analyzed by Western blot,
the graph shows the ratio of BCl2 to Bax in the core of MCAO brain in MCAO (middle cerebral
artery occlusion for 2 h followed by 4 days reperfusion) and MCAO + taurine (middle cerebral artery
occlusion for 2 h followed by 4 days reperfusion, taurine was injected 24 h after reperfusion subcu-
taneously and injection continued for 4 days). ( b ) Caspase-3 expression in the core of MCAO brain
analyzed by Western blot in MCAO and MCAO + taurine. ( c ) CHOP expression analyzed by Western
blot in primary neuronal culture. Norm normoxia, Hyp hypoxia (0.3% O 2 ) for 20 h, reoxygenation for
20 h, Ta u + Hyp neurons were treated with 10 mM taurine for 1 h, then hypoxia for 20 h, reoxygen-
ation for 20 h. The bar graphs reflect the densitometric data from the experiment of CHOP Western
blot results with arbitrary units. ( d ) CHOP expression analyzed by Western blot in the core of the
MCAO rat brain. ( e ) Caspase-12 expression analyzed by Western blot. The bar graphs re fl ect the
densitometric data from the experiment of caspase-12 and cleaved caspase-12 Western blot results
with arbitrary units. The values in bar graph represent mean ± SEM, n = 3, ** p < 0.01 versus norm and
## p < 0.01 versus hyp or MCAO.1.3.3 Effect of TonEBP and dominant-negative TonEBP

Several protective mechanisms of taurine such as improvement in osmotic status
and calcium homeostasis in cell damage caused by hypoxia or glutamate excitotox-
icity have been suggested (Chang et al. 2004 ; El Idrissi and Trenkner 1999 ; Michalk
et al. 1997 ). We recently showed that ER stress inhibition may also be involved in
taurine's protective mechanisms under conditions of glutamate excitotoxicity and
hypoxia (Pan et al. 2010, 2011 ). However, details of the relevant signaling pathways
remain to be elucidated.