scholarly journals Global ischemia induces lysosomal-mediated degradation of mTOR and activation of autophagy in hippocampal neurons destined to die

2016 ◽  
Vol 24 (2) ◽  
pp. 317-329 ◽  
Author(s):  
Jee-Yeon Hwang ◽  
Michael Gertner ◽  
Fabrizio Pontarelli ◽  
Brenda Court-Vazquez ◽  
Michael Vander Laan Bennett ◽  
...  
1998 ◽  
Vol 254 (2) ◽  
pp. 101-104 ◽  
Author(s):  
Moo Ho Won ◽  
Jae Chul Lee ◽  
Yung Hi Kim ◽  
Dong Keun Song ◽  
Hong Won Suh ◽  
...  

2019 ◽  
Vol 73 (10) ◽  
pp. 1208-1217 ◽  
Author(s):  
Vanessa Russo ◽  
Patrizio Candeloro ◽  
Natalia Malara ◽  
Gerardo Perozziello ◽  
Michelangelo Iannone ◽  
...  

Brain ischemia represents a leading cause of death and disability in industrialized countries. To date, therapeutic intervention is largely unsatisfactory and novel strategies are required for getting better protection of neurons injured by cerebral blood flow restriction. Recent evidence suggests that brain insulin leads to protection of neuronal population undergoing apoptotic cell death via modulation of oxidative stress and mitochondrial cytochrome c (CytC), an effect to be better clarified. In this work, we investigate on the effect of insulin given intracerebroventricular (ICV) before inducing a transient global ischemia by bilateral occlusion of the common carotid arteries (BCCO) in Mongolian gerbils (MG). The transient (3 min) global ischemia in MG is observed to produce neurodegenerative effect mainly into CA3 hippocampal region, 72 h after cerebral blood restriction. Intracerebroventricular microinfusion of insulin significantly prevents the apoptosis of CA3 hippocampal neurons. Histological observation, after hematoxylin and eosin staining, puts in evidence the neuroprotective role of insulin, but Raman microimaging provides a clearer insight in the CytC mechanism underlying the apoptotic process. Above all, CytC has been revealed to be an outstanding, innate Raman marker for monitoring the cells status, thanks to its resonant scattering at 530 nm of incident wavelength and to its crucial role in the early stages of cells apoptosis. These data support the hypothesis of an insulin-dependent neuroprotection and antiapoptotic mechanism occurring in the brain of MG undergoing transient brain ischemia. The observed effects occurred without any peripheral change on serum glucose levels, suggesting an alternative mechanism of insulin-induced neuroprotection.


2006 ◽  
Vol 3 (3) ◽  
pp. 181-186 ◽  
Author(s):  
Zhen He ◽  
James Meschia ◽  
Thomas Brott ◽  
Dennis Dickson ◽  
Michael Mckinney

2002 ◽  
Vol 22 (5) ◽  
pp. 534-546 ◽  
Author(s):  
Guodong Cao ◽  
Yumin Luo ◽  
Tetsuya Nagayama ◽  
Wei Pei ◽  
R. Anne Stetler ◽  
...  

Delayed hippocampal neurodegeneration after transient global ischemia is mediated, at least in part, through the activation of terminal caspases, particularly caspase-3, and the subsequent proteolytic degradation of critical cellular proteins. Caspase-3 may be activated by the membrane receptor-initiated caspase-8–dependent extrinsic pathway and the mitochondria-initiated caspase-9–dependent intrinsic pathway; however, the precise role of these deduced apoptosis-signaling pathways in activating caspase-3 in ischemic neurons remains elusive. The authors cloned the caspase-9 gene from the rat brain and investigated its potential role in mediating ischemic neuronal death in a rat model of transient global ischemia. Caspase-9 gene expression and protease activity were extremely low in the adult brain, whereas they were developmentally upregulated in newborn rats, especially at postnatal 12 weeks, a finding consistent with the theory of an essential role for caspase-9 in neuronal apoptosis during brain development. After 15-minute transient global ischemia, caspase-9 was overexpressed and proteolytically activated in the hippocampal CA1 neurons at 8 to 72 hours of reperfusion. The temporal profile of caspase-9 activation coincided with that of cytochrome c release and caspase-3 activation, but preceded CA1 neuronal death. Immunoprecipitation experiments revealed that there was enhanced formation of Apaf-1/caspase-9 complex in the hippocampus 8 and 24 hours after ischemia. Furthermore, intracerebral ventricular infusion of the relatively specific caspase-9 inhibitor N-benzyloxycarbonyl-Leu-Glu-His-Asp-fluoro-methylketone before ischemia attenuated caspase-3–like activity and significantly enhanced neuronal survival in the CA1 sector. In contrast, inhibition of caspase-8 activity had no significant effect on caspase-3 activation or neuronal survival. These results suggest that the caspase-9–dependent intrinsic pathway may be the primary mechanism responsible for the activation of caspase-3 in ischemic hippocampal neurons.


2005 ◽  
Vol 102 (34) ◽  
pp. 12230-12235 ◽  
Author(s):  
K.-M. Noh ◽  
H. Yokota ◽  
T. Mashiko ◽  
P. E. Castillo ◽  
R. S. Zukin ◽  
...  

Stroke ◽  
1996 ◽  
Vol 27 (9) ◽  
pp. 1609-1615 ◽  
Author(s):  
P. Henrich-Noack ◽  
J.H.M. Prehn ◽  
J. Krieglstein

1996 ◽  
Vol 16 (6) ◽  
pp. 1137-1142 ◽  
Author(s):  
Toshiho Ohtsuki ◽  
Christi A. Ruetzler ◽  
Kaoru Tasaki ◽  
John M. Hallenbeck

A series of experiments was performed to determine the role of interleukin (IL)-1 in the induction of tolerance to global ischemia in Mongolian gerbils. In Group I, a 2-min “preconditioning” ischemia protected CA1 hippocampal neurons in gerbils subjected to 3.5 min ischemia 3 days later. CA1 neuronal density was: sham, 171 ± 3/mm; 3.5 min ischemia, 30 ± 30/mm; 2 and 3.5 min ischemia 162 ± 6/mm. Experiments in Group II addressed the role of IL-1 in the induction of tolerance by sublethal ischemia. Arterial IL-1α and IL-Iβ became elevated between 1 and 3 days after a 2-min ischemic exposure. IL-1α was: sham, 6.4 ± 0.6 ng/ml; and 2-day, 10.2 ± 1.2 ng/ml. IL-1β was: sham, 6.4 ± 0.5 ng/ml; and 2-day, 17.3 ± 2 ng/ml. Recombinant human IL-1 receptor antagonist (IL-1ra) i.p. blocked ischemic tolerance induction by 2-min preconditioning ischemia: 2-min ischemia + vehicle, 162 ± 6/mm; and 2-min ischemia + IL-1ra, 67 ± 17/mm. Experiments in Group III assessed the capacity of IL-1 to induce tolerance to brain ischemia. IL-1α i.p. (0, 10, 20 μg/kg) for 3 days prior to 3.5-min forebrain ischemia provided significant CA1 neuroprotection in a dose-dependent manner: 2 ± 2, 68 ± 83, and 129 ± 42/mm, respectively. IL-1β (15 μg/kg) in combination with either IL-1ra (100 mg/kg) or IL-1ra vehicle i.p. on the same schedule demonstrated a significant CA1 neuroprotection that could be nullified by IL-1ra: IL-1β + IL-1ra vehicle, 153 ± 16/mm; and IL-1β + IL-1ra, 67 ± 36/mm. Recognition that tolerance arises from stimulation of a known receptor (IL-1RI) permits molecular analysis of the intracellular signaling that is critical for production of that state.


Neuroreport ◽  
1998 ◽  
Vol 9 (5) ◽  
pp. 819-824 ◽  
Author(s):  
Eugene V. Golanov ◽  
Fang Liu ◽  
Donald J. Reis

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