Dexmedetomidine Protects Against Chemical Hypoxia-Induced Neurotoxicity in Differentiated PC12 Cells Via Inhibition of NADPH Oxidase 2-Mediated Oxidative Stress
- 113 Downloads
Dexmedetomidine (Dex) is a widely used sedative in anesthesia and critical care units, and it exhibits neuroprotective activity. However, the precise mechanism of Dex-exerted neuroprotection is not clear. Increased neuronal NADPH oxidase 2 (NOX2) contributes to oxidative stress and neuronal damage in various hypoxia-related neurodegenerative disorders. The present study investigated whether Dex regulated neuronal NOX2 to exert its protective effects under hypoxic conditions. Well-differentiated PC12 cells were exposed to cobalt chloride (CoCl2) to mimic a neuronal model of chemical hypoxia-mediated neurotoxicity. The data showed that Dex pretreatment of PC12 cells significantly suppressed CoCl2-induced neurotoxicity, as evidenced by the enhanced cell viability, restoration of cellular morphology, and reduction in apoptotic cells. Dex improved mitochondrial function and inhibited CoCl2-induced mitochondrial apoptotic pathways. We further demonstrated that Dex attenuated oxidative stress, downregulated NOX2 protein expression and activity, and inhibited intracellular calcium ([Ca2+]i) overload in CoCl2-treated PC12 cells. Moreover, knockdown of the NOX2 gene markedly improved mitochondrial function and attenuated apoptosis under hypoxic conditions. These results demonstrated that the protective effects of Dex against hypoxia-induced neurotoxicity in neural cells were mediated, at least partially, via inhibition of NOX2-mediated oxidative stress.
KeywordsDexmedetomidine Hypoxia· NADPH oxidase 2 Oxidative stress PC12 cells
This study was supported by the Natural Science Foundation of China (NSFC; No. 81571076).
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflicts of interest.
- Degos V, Charpentier TL, Chhor V, Brissaud O, Lebon S, Schwendimann L, Bednareck N, Passemard S, Mantz J, Gressens P (2013) Neuroprotective effects of dexmedetomidine against glutamate agonist-induced neuronal cell death are related to increased astrocyte brain-derived neurotrophic factor expression. Anesthesiology 118(5):1123–1132CrossRefGoogle Scholar
- Takizuka A, Minami K, Uezono Y, Horishita T, Yokoyama T, Shiraishi M, Sakurai T, Shigematsu A, Ueta Y (2007) Dexmedetomidine inhibits muscarinic type 3 receptors expressed in Xenopus oocytes and muscarine-induced intracellular Ca2+ elevation in cultured rat dorsal root ganglia cells. Naunyn Schmiedeberg's Arch Pharmacol 375(5):293–301CrossRefGoogle Scholar
- Wu GJ, Chen JT, Tsai HC, Chen TL, Liu SH, Chen RM (2016) Protection of dexmedetomidine against ischemia/reperfusion-induced apoptotic insults to neuronal cells occurs via an intrinsic mitochondria-dependent pathway. J Cell Biochem 118(9):2635–264Google Scholar