Atorvastatin Attenuates Ischemia/Reperfusion-Induced Hippocampal Neurons Injury Via Akt-nNOS-JNK Signaling Pathway
Ischemia-induced brain damage leads to apoptosis like delayed neuronal death in selectively vulnerable regions, which could further result in irreversible damages. Previous studies have demonstrated that neurons in the CA1 area of hippocampus are particularly sensitive to ischemic damage. Atorvastatin (ATV) has been reported to attenuate cognitive deficits after stroke, but precise mechanism for neuroprotection remains unknown. Therefore, the aims of this study were to investigate the neuroprotective mechanisms of ATV against ischemic brain injury induced by cerebral ischemia reperfusion. In this study, four-vessel occlusion model was established in rats with cerebral ischemia. Rats were divided into five groups: sham group, I/R group, I/R+ATV group, I/R+ATV+LY, and I/R+SP600125 group. Cresyl violet staining was carried out to examine the neuronal death of hippocampal CA1 region. Immunoblotting was used to detect the expression of the related proteins. Results showed that ATV significantly protected hippocampal CA1 pyramidal neurons against cerebral I/R. ATV could increase the phosphorylation of protein kinase B (Akt1) and nNOS, diminished the phosphorylation of JNK3 and c-Jun, and further inhibited the activation of caspase-3. Whereas, all of the aforementioned effects of ATV were reversed by LY294002 (an inhibitor of Akt1). Furthermore, pretreatment with SP600125 (an inhibitor of JNK) diminished the phosphorylation of JNK3 and c-Jun, and further inhibited the activation of caspase-3 after cerebral I/R. Taken together, our results implied that Akt-mediated phosphorylation of nNOS is involved in the neuroprotection of ATV against ischemic brain injury via suppressing JNK3 signaling pathway that provide a new experimental foundation for stroke therapy.
KeywordsCerebral ischemia Akt1 nNOS JNK3 LY294002
This work was supported by Jiangsu Province Key Laboratory of Brain Disease Bioinformation (JSBL1505), Jiangsu Province Key Laboratory of Anesthesiology (KJS1502), and the National Natural Science Foundation of China (81271296).
S.S. designed the study. M.X., J.Z., X.G., G.C., L.G., L.L., and K.L. performed the experiments and collected the data. S.S. and Z.Z. analyzed and interpreted the experimental data. S.S., M.X., and J.Z. prepared the manuscript.
Compliance with Ethical Standards
Conflict of Interest
The authors declare no competing financial interests.
- Amarenco P, Bogousslavsky J, Callahan A 3rd, Goldstein LB, Hennerici M, Rudolph AE, Sillesen H, Simunovic L, Szarek M, Welch KM, Zivin JA, SPARCL (2006) High-dose atorvastatin after stroke or transient ischemic attack. N Engl J Med 355(6):549–559. doi: 10.1056/NEJMoa061894 CrossRefPubMedGoogle Scholar
- Junyent F, de Lemos L, Verdaguer E, Folch J, Ferrer I, Ortuno-Sahagun D, Beas-Zarate C, Romero R, Pallas M, Auladell C, Camins A (2011) Gene expression profile in JNK3 null mice: a novel specific activation of the PI3K/AKT pathway. J Neurochem 117(2):244–252. doi: 10.1111/j.1471-4159.2011.07195.x CrossRefPubMedGoogle Scholar
- Kong D, Zhu J, Liu Q, Jiang Y, Xu L, Luo N, Zhao Z, Zhai Q, Zhang H, Zhu M, Liu X (2016) Mesenchymal stem cells protect neurons against hypoxic-ischemic injury via inhibiting parthanatos, necroptosis, and apoptosis, but not autophagy. Cell Mol Neurobiol. doi: 10.1007/s10571-016-0370-3 PubMedGoogle Scholar
- Marz-Weiss P, Kunz D, Bimmler D, Berkemeier C, Ozbek S, Dimitriades-Schmutz B, Haybaeck J, Otten U, Graf R (2011) Expression of pancreatitis-associated protein after traumatic brain injury: a mechanism potentially contributing to neuroprotection in human brain. Cell Mol Neurobiol 31(8):1141–1149. doi: 10.1007/s10571-011-9715-0 CrossRefPubMedGoogle Scholar
- Meloni BP, Craig AJ, Milech N, Hopkins RM, Watt PM, Knuckey NW (2014) The neuroprotective efficacy of cell-penetrating peptides TAT, penetratin, Arg-9, and Pep-1 in glutamic acid, kainic acid, and in vitro ischemia injury models using primary cortical neuronal cultures. Cell Mol Neurobiol 34(2):173–181. doi: 10.1007/s10571-013-9999-3 CrossRefPubMedGoogle Scholar
- Qi D, Ouyang C, Wang Y, Zhang S, Ma X, Song Y, Yu H, Tang J, Fu W, Sheng L, Yang L, Wang M, Zhang W, Miao L, Li T, Huang X, Dong H (2014) HO-1 attenuates hippocampal neurons injury via the activation of BDNF-TrkB-PI3K/Akt signaling pathway in stroke. Brain Res 1577:69–76. doi: 10.1016/j.brainres.2014.06.031 CrossRefPubMedGoogle Scholar
- Rameau GA, Tukey DS, Garcin-Hosfield ED, Titcombe RF, Misra C, Khatri L, Getzoff ED, Ziff EB (2007) Biphasic coupling of neuronal nitric oxide synthase phosphorylation to the NMDA receptor regulates AMPA receptor trafficking and neuronal cell death. J Neurosci 27(13):3445–3455. doi: 10.1523/JNEUROSCI.4799-06.2007 CrossRefPubMedGoogle Scholar
- Watanabe Y, Song T, Sugimoto K, Horii M, Araki N, Tokumitsu H, Tezuka T, Yamamoto T, Tokuda M (2003) Post-synaptic density-95 promotes calcium/calmodulin-dependent protein kinase II-mediated Ser847 phosphorylation of neuronal nitric oxide synthase. Biochem J 372(Pt 2):465–471. doi: 10.1042/BJ20030380 CrossRefPubMedPubMedCentralGoogle Scholar