PKCδ-dependent p47phox activation mediates methamphetamine-induced dopaminergic neurotoxicity

• Published in: Free radical biology & medicine 2018-02, Vol.115, p.318-337
• Main Authors: Dang, Duy-Khanh, Shin, Eun-Joo, Kim, Dae-Joong, Tran, Hai-Quyen, Jeong, Ji Hoon, Jang, Choon-Gon, Ottersen, Ole Petter, Nah, Seung-Yeol, Hong, Jau-Shyong, Nabeshima, Toshitaka, Kim, Hyoung-Chun
• Format: Article
• Language: English
• Subjects: 47phox antisense oligonucleotide; Acetophenones - pharmacology; Animals; Apoptosis - drug effects; Benzopyrans - pharmacology; Cells, Cultured; Dopamine; Dopaminergic Neurons - physiology; Gene Expression Regulation; Glutathione-immunoreactivity; Methamphetamine; Methamphetamine - administration & dosage; Mice; Mice, Inbred C57BL; Mice, Knockout; Microglia; Microglia - drug effects; Microglia - metabolism; Microglia - pathology; NADPH Oxidases - genetics; NADPH Oxidases - metabolism; NF-E2-Related Factor 2 - metabolism; Nrf2-transcription factor; Oligonucleotides, Antisense - genetics; Oxidative Stress - drug effects; p47phox knockout mice; PKCδ antisense oligonucleotide; PKCδ knockout mice; Pro-apoptosis; Protein Kinase C-delta - antagonists & inhibitors; Protein Kinase C-delta - genetics; Protein Kinase C-delta - metabolism; Protein Transport; Reactive Oxygen Species - metabolism; Striatum
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/j.freeradbiomed.2017.12.018

Protein kinase C (PKC) has been recognized to activate NADPH oxidase (PHOX). However, the interaction between PKC and PHOX in vivo remains elusive. Treatment with methamphetamine (MA) resulted in a selective increase in PKCδ expression out of PKC isoforms. PKCδ co-immunoprecipitated with p47phox, and facilitated phosphorylation and membrane translocation of p47phox. MA-induced increases in PHOX activity and reactive oxygen species were attenuated by knockout of p47phox or PKCδ. In addition, MA-induced impairments in the Nrf-2-related glutathione synthetic system were also mitigated by knockout of p47phox or PKCδ. Glutathione-immunoreactivity was co-localized in Iba-1-labeled microglial cells and in NeuN-labeled neurons, but not in GFAP-labeled astrocytes, reflecting the necessity for self-protection against oxidative stress by mainly microglia. Buthionine-sulfoximine, an inhibitor of glutathione biosynthesis, potentiated microglial activation and pro-apoptotic changes, leading to dopaminergic losses. These neurotoxic processes were attenuated by rottlerin, a pharmacological inhibitor of PKCδ, genetic inhibitions of PKCδ [i.e., PKCδ knockout mice (KO) and PKCδ antisense oligonucleotide (ASO)], or genetic inhibition of p47phox (i.e., p47phox KO or p47phox ASO). Rottlerin did not exhibit any additive effects against the protective activity offered by genetic inhibition of p47phox. Therefore, we suggest that PKCδ is a critical regulator for p47phox activation induced by MA, and that Nrf-2-dependent GSH induction via inhibition of PKCδ or p47phox, is important for dopaminergic protection against MA insult. [Display omitted] •Interplay between PKC and PHOX in vivo in the neurotoxic condition remains unclear.•PKCδ co-immunoprecipitated with p47phox and facilitated the potential of p47phox.•Methamphetamine-induced Nrf-2 system was mitigated by inhibition of p47phox or PKCδ.•BSO potentiated microgliosis and apoptotic changes, leading to dopaminergic losses.•PKCδ is a critical regulator for p47phox activation induced by methamphetamine.