MicroRNA ‐379‐5p targets MAP3K2 to reduce autophagy and alleviate neuronal injury following cerebral ischemia via the JNK / c‐Jun signaling pathway

A reproducible model of global cerebral ischemia in mice is essential for elucidating the molecular mechanism of ischemic neuronal injury. Such a model is particularly important in the mouse because many genetically engineered mutant animals are available. In C57BL/6 and SV129/EMS mice, we evaluated a three-vessel occlusion model. Occlusion of the basilar artery with a miniature clip was followed by bilateral carotid occlusion. The mean cortical cerebral blood flow was reduced to less than 10% of the preischemic value, and the mean anoxic depolarization was attained within 1 minute. In C57BL/6 mice, there was CA1 hippocampal neuronal degeneration 4 days after ischemia. Neuronal damage depended upon ischemic duration: the surviving neuronal count was 78.5 ± 8.5% after 8-minute ischemia and 8.4 ± 12.7% after 14-minute ischemia. In SV129/EMS mice, similar neuronal degeneration was not observed after 14-minute ischemia. The global ischemia model in C57BL/6 mice showed high reproducibility and consistent neuronal injury in the CA1 sector, indicating that comparison of ischemic outcome between wild-type and mutant mice could provide meaningful data using the C57BL/6 genetic background. Strain differences in this study highlight the need for consideration of genetic background when evaluating ischemia experiments in mice.

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Cerebral microdialysis monitoring: determination of normal and ischemic cerebral metabolisms in patients with aneurysmal subarachnoid hemorrhage

Journal of Neurosurgery ◽

10.3171/jns.2000.93.5.0808 ◽

2000 ◽

Vol 93 (5) ◽

pp. 808-814 ◽

Cited By ~ 144

Author(s):

Mette K. Schulz ◽

Lars Peter Wang ◽

Mogens Tange ◽

Per Bjerre

Keyword(s):

Subarachnoid Hemorrhage ◽

Cerebral Ischemia ◽

Delayed Cerebral Ischemia ◽

Neuronal Injury ◽

Low Flow ◽

Cerebral Microdialysis ◽

Intracerebral Microdialysis ◽

Content Type ◽

Wide Range ◽

Fine Print

Object. The success of treatment for delayed cerebral ischemia is time dependent, and neuronal monitoring methods that can detect early subclinical levels of cerebral ischemia may improve overall treatment results. Cerebral microdialysis may represent such a method. The authors' goal was to characterize patterns of markers of energy metabolism (glucose, pyruvate, and lactate) and neuronal injury (glutamate and glycerol) in patients with subarachnoid hemorrhage (SAH), in whom ischemia was or was not suspected.Methods. By using low-flow intracerebral microdialysis monitoring, central nervous system extracellular fluid concentrations of glucose, pyruvate, lactate, glutamate, and glycerol were determined in 46 patients suffering from poor-grade SAH. The results in two subgroups were analyzed: those patients with no clinical or radiological signs of cerebral ischemia (14 patients) and those who succumbed to brain death (five patients).Significantly lower levels of energy substrates and significantly higher levels of lactate and neuronal injury markers were observed in patients with severe and complete ischemia when compared with patients without symptoms of ischemia (glucose 0 compared with 2.12 ± 0.15 mmol/L; pyruvate 0 compared with 151 ± 11.5 µmol; lactate 6.57 ± 1.07 compared with 3.06 ± 0.32 mmol/L; glycerol 639 ± 91 compared with 81.6 ± 12.4 µmol; and glutamate 339 ± 53.4 compared with 14 ± 3.33 µmol). Immediately after catheter placement, glutamate concentrations declined over the first 4 to 6 hours to reach stable values. The remaining parameters exhibited stable values after 1 to 2 hours.Conclusions. The results confirm that intracerebral microdialysis monitoring of patients with SAH can be used to detect patterns of cerebral ischemia. The wide range from normal to severe ischemic values calls for additional studies to characterize further incomplete and possible subclinical levels of ischemia.

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