Glutathione Peroxidase-1 Knockout Facilitates Memory Impairment Induced by β-Amyloid (1-42) in Mice via Inhibition of PKC βII-Mediated ERK Signaling; Application with Glutathione Peroxidase-1 Gene-Encoded Adenovirus Vector.

Abstract

A growing body evidence suggests that selenium (Se) deficiency is associated with an increased risk of developing Alzheimer's disease (AD). Se-dependent glutathione peroxidase-1 (GPx-1) of a major antioxidant enzyme, and the most abundant isoform of GPx in the brain. In the present study, we investigated whether GPx-1 is protective against memory impairments induced by beta-amyloid (Aβ) (1-42) in mice. As the alteration of protein kinase C (PKC)-mediated ERK activation was recognized in the early stage of AD, we examined whether the GPx-1 gene modulates Aβ (1-42)-induced changes in PKC and ERK levels. We observed that Aβ (1-42) treatment (400 pmol, i.c.v.) significantly decreased PKC βII expression in the hippocampus of mice. Aβ (1-42)-induced neurotoxic changes [i.e., oxidative stress (i.e., reactive oxygen species, 4-hydroxy-2-noneal, and protein carbonyl), reduced PKC βII and phospho-ERK expressions, and memory impairment under Y-maze and passive avoidance test] were more pronounced in GPx-1 knockout than in wild type mice. Importantly, exposure to a GPx-1 gene-encoded adenovirus vector (Adv-GPx-1) significantly increased GPx-1 mRNA and GPx activity in the hippocampus of GPx-1 knockout mice. Adv-GPx-1 exposure also significantly blocked the neurotoxic changes induced by Aβ (1-42) in GPx-1 knockout mice. Treatment with ERK inhibitor U0126 did not significantly change Adv-GPx-1-mediated attenuation in PKC βII expression. In contrast, treatment with PKC inhibitor chelerythrine (CHE) reversed Adv-GPx-1-mediated attenuation in ERK phosphorylation, suggesting that PKC βII-mediated ERK signaling is important for Adv-GPx-1-mediated potentials against Aβ (1-42) insult. Our results suggest that treatment with the antioxidant gene GPx-1 rescues Aβ (1-42)-induced memory impairment via activating PKC βII-mediated ERK signaling.

• Authors: Eun-Joo Shin, Yoon Hee Chung, Naveen Sharma, Bao Trong Nguyen, Sung Hoon Lee, Sang Won Kang, Seung-Yeol Nah, Myung Bok Wie, Toshitaka Nabeshima, Ji Hoon Jeong, Hyoung-Chun Kim
• Journal: Neurochemical research (Neurochem Res) Vol. 45 Issue 12 Pg. 2991-3002 (Dec 2020) ISSN: 1573-6903 [Electronic] United States
• PMID: 33064252 (Publication Type: Journal Article)

Chemical References

• Amyloid beta-Peptides
• Peptide Fragments
• amyloid beta-protein (1-42)
• Glutathione Peroxidase
• Protein Kinase C beta
• Glutathione Peroxidase GPX1

Topics

• Adenoviridae (genetics)
• Amyloid beta-Peptides
• Animals
• Gene Expression (drug effects)
• Genetic Therapy
• Glutathione Peroxidase (deficiency, genetics, pharmacology)
• Hippocampus (enzymology, metabolism)
• MAP Kinase Signaling System (drug effects)
• Male
• Memory (drug effects)
• Memory Disorders (chemically induced, enzymology, genetics, therapy)
• Mice, Inbred C57BL
• Mice, Knockout
• Peptide Fragments
• Protein Kinase C beta (metabolism)
• Glutathione Peroxidase GPX1