1.Hippocampus-dependent Task Improves the Cognitive Function after Ovariectomy in Rats.
Osong Public Health and Research Perspectives 2017;8(3):227-234
OBJECTIVES: Estrogen is an important hormone for cell growth, development, and differentiation by transcriptional regulation and modulation of intracellular signaling via second messengers. The reduction in the estrogen level after ovariectomy may lead to cognitive impairments associated with morphological changes in areas of the brain mediate memory. The aim of the present study was to find out the effect of tasks on the cognitive function after ovariectomy in rats. METHODS: The animals used in the experiment were 50 Sprague-Dawley female rats. This study applied a hippocampus-independent task (wheel running) and a hippocampus-dependent task (Morris water maze) after ovariectomy in rats and measured the cognitive performance (object-recognition and object-location test) and growth-associated protein 43 (GAP-43) and neurotrophin 3 (NT-3) expression in the hippocampus, which is an important center for memory and learning. RESULTS: There were meaningful differences between the hippocampus-independent and hippocampus-dependent task groups for the object-location test and GAP-43 and NT-3 expression in the hippocampus, but not the object-recognition test. However, the hippocampus-independent task group showed a significant improvement in the object-recognition test, compared to the control group. CONCLUSION: These results suggest that hippocampus-dependent task training after ovariectomy enhances the hippocampus-related memory and cognitive function that are associated with morphological and functional changes in the cells of the hippocampus.
Animals
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Brain
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Cognition Disorders
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Cognition*
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Estrogens
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Female
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GAP-43 Protein
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Hippocampus
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Humans
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Learning
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Memory
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Neurotrophin 3
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Ovariectomy*
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Rats*
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Rats, Sprague-Dawley
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Second Messenger Systems
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Water
2.MPTP-induced vulnerability of dopamine neurons in A53T α-synuclein overexpressed mice with the potential involvement of DJ-1 downregulation.
Seongmi LEE ; Seung Tack OH ; Ha Jin JEONG ; Sok Cheon PAK ; Hi Joon PARK ; Jongpil KIM ; Hyun Seok CHO ; Songhee JEON
The Korean Journal of Physiology and Pharmacology 2017;21(6):625-632
Familial Parkinson's disease (PD) has been linked to point mutations and duplication of the α-synuclein (α-syn) gene. Mutant α-syn expression increases the vulnerability of neurons to exogenous insults. In this study, we developed a new PD model in the transgenic mice expressing mutant hemizygous (hemi) or homozygous (homo) A53T α-synuclein (α-syn Tg) and their wildtype (WT) littermates by treatment with sub-toxic (10 mg/kg, i.p., daily for 5 days) or toxic (30 mg/kg, i.p., daily for 5 days) dose of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Tyrosine hydroxylase and Bcl-2 levels were reduced in the α-syn Tg but not WT mice by sub-toxic MPTP injection. In the adhesive removal test, time to remove paper was significantly increased only in the homo α-syn Tg mice. In the challenging beam test, the hemi and homo α-syn Tg mice spent significantly longer time to traverse as compared to that of WT group. In order to find out responsible proteins related with vulnerability of mutant α-syn expressed neurons, DJ-1 and ubiquitin enzyme expressions were examined. In the SN, DJ-1 and ubiquitin conjugating enzyme, UBE2N, levels were significantly decreased in the α-syn Tg mice. Moreover, A53T α-syn overexpression decreased DJ-1 expression in SH-SY5Y cells. These findings suggest that the vulnerability to oxidative injury such as MPTP of A53T α-syn mice can be explained by downregulation of DJ-1.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine
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Adhesives
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Animals
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Apoptosis
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Dopamine*
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Dopaminergic Neurons*
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Down-Regulation*
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Hominidae
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Humans
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Mice*
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Mice, Transgenic
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Neurons
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Parkinson Disease
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Point Mutation
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Synucleins
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Tyrosine 3-Monooxygenase
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Ubiquitin
3.Decursin induces apoptosis in glioblastoma cells, but not in glial cells via a mitochondria-related caspase pathway.
Seung Tack OH ; Seongmi LEE ; Cai HUA ; Byung Soo KOO ; Sok Cheon PAK ; Dong Il KIM ; Songhee JEON ; Boo Ahn SHIN
The Korean Journal of Physiology and Pharmacology 2019;23(1):29-35
Decursin is a major biological active component of Angelica gigas Nakai and is known to induce apoptosis of metastatic prostatic cancer cells. Recently, other reports have been commissioned to examine the anticancer activities of this plant. In this study, we evaluated the inhibitory activity and related mechanism of action of decursin against glioblastoma cell line. Decursin demonstrated cytotoxic effects on U87 and C6 glioma cells in a dose-dependent manner but not in primary glial cells. Additionally, decursin increased apoptotic bodies and phosphorylated JNK and p38 in U87 cells. Decursin also down-regulated Bcl-2 as well as cell cycle dependent proteins, CDK-4 and cyclin D1. Furthermore, decursin-induced apoptosis was dependent on the caspase activation in U87 cells. Taken together, our data provide the evidence that decursin induces apoptosis in glioblastoma cells, making it a potential candidate as a chemotherapeutic drug against brain tumor.
Angelica
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Apoptosis*
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Brain Neoplasms
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Cell Cycle
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Cell Cycle Checkpoints
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Cell Line
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Cyclin D1
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Extracellular Vesicles
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Glioblastoma*
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Glioma
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Neuroglia*
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Plants
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Prostatic Neoplasms