1. Glutathione peroxidase-1 knockout potentiates behavioral sensitization induced by cocaine in mice via σ-1 receptor-mediated ERK signaling: A comparison with the case of glutathione peroxidase-1 overexpressing transgenic mice.
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Mai, Huynh Nhu, Pham, Duc Toan, Chung, Yoon Hee, Sharma, Naveen, Cheong, Jae Hoon, Yun, Jaesuk, Nah, Seung-Yeol, Jeong, Ji Hoon, Gen Lei, Xin, Shin, Eun-Joo, Nabeshima, Toshitaka, and Kim, Hyoung-Chun
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COCAINE , *COCAINE-induced disorders , *SIGMA receptors , *TRANSGENIC mice , *GLUTATHIONE , *GENETIC overexpression , *MICE , *DRUG addiction - Abstract
• Genetic depletion of GPx-1 potentiates cocaine-induced behavioral sensitization. • Signaling of σ-1 receptor-ERK-oxidative burden mediates the behavioral sensitization. • GPx-1 gene inhibits this signaling, and induces Nrf-2-related GSH system. We demonstrated that the gene of glutathione peroxidase-1 (GPx-1), a major antioxidant enzyme, is a potential protectant against the neurotoxicity and conditioned place preference induced by cocaine. Because the sigma (σ)-1 receptor is implicated in cocaine-induced drug dependence, we investigated whether the GPx-1 gene modulates the σ-1 receptor in the behavioral sensitization induced by cocaine. Cocaine-induced behavioral sensitization was more pronounced in GPx-1 knockout (KO) than wild-type (WT) mice and was less pronounced in GPx-1 overexpressing transgenic (GPx-1 TG) than non-TG mice. Cocaine treatment significantly enhanced the oxidative burden and reduced the GSH levels in the striatum of WT, GPx-1 KO, and non-TG mice but not in that of GPx-1 TG mice. In addition, cocaine significantly increased the nuclear translocation, its DNA binding activity of nuclear factor erythroid-2-related factor 2 (Nrf2) as well as the mRNA expression of γ-glutamylcysteine (GCL). The genetic depletion of GPx-1 inhibited the Nrf2-related glutathione system, whereas the genetic overexpression of GPx-1 activated this system against behavioral sensitization. BD1047, a σ-1 receptor antagonist, and U0126, an ERK inhibitor significantly induced the Nrf2-related antioxidant potential against behavioral sensitization. Unlike BD1047, U0126 did not affect the cocaine-induced σ-1 receptor immunoreactivity, suggesting that the σ-1 receptor is an upstream molecule for ERK signaling. Importantly, BD1047 and U0126 failed to affect the σ-1 receptor immunoreactivity and ERK phosphorylation induced by cocaine in GPx-1 TG mice. Our results suggest that GPx-1 is a critical mediator for the attenuation of cocaine-induced behavioral sensitization via modulating σ-1 receptor-mediated ERK activation by the induction of the Nrf2-related system. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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