• The Journal of Internal Korean Medicine
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• v.21 no.2
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• pp.235-241
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• 2000

호도(胡桃)(Juglandis semen)가 치매에 미치는 영향을 알아보기 위하여 치매(Alzheimer's disease) 유발물질로 알려진 amyloid-{$\beta}(A{\beta})$ 25-35를 흰쥐의 뇌 신경세포의 일종인 astrocyte에 처리한 후 뇌의 신경세포에 대한 독성 및 세포막에서의 지질 과산화에 미치는 영향을 검토하였다. 호도(胡桃)는 $A{\beta})$ 25-35로 인한 신경세포의 파괴를 억제하는 것으로 나타나 신경세포의 손상을 예방하고 보호하는 효과가 있었다. 그리고, 지질의 과산화 지표인 malondialdehyde 생성은 $A{\beta})$ 25-35 처리로 크게 증가하였으나, 호도(胡桃)의 전처리와 후처리로 크게 감소되어 호도(胡桃)가 세포막 파괴로 인한 뇌세포의 손상을 방지하는 것으로 나타났다. 이러한 결과들을 볼 때, 호도(胡桃)는 신경세포의 하나인 astrocyte에 대한 보호효과와 세포막에서 지질의 과산화를 저해 및 $A{\beta})$ 25-35 처리와 같은 치매 유발 독성에 대한 적응능력 향상을 통하여 뇌 신경세포를 보호하는 효과가 있음을 보여주는 것으로 노인성 치매 등의 임상적 응용에 그 효과가 기대된다.

• Journal of Korean Neurosurgical Society
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• v.49 no.2
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• pp.83-91
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• 2011

Objective : Minocycline, a second-generation tetracycline-class antibiotic, has been well established to exert a neuroprotective effect in animal models and neurodegenerative disease through the inhibition of microglia. Here, we investigated the effects of minocycline on motor recovery and neuropathic pain in a rat model of spinal cord injury. Methods : To simulate spinal cord injury, the rats' spinal cords were hemisected at the 10th thoracic level (T10). Minocycline was injected intraperitoneally, and was administered 30 minutes prior surgery and every second postoperative day until sacrifice 28 days after surgery. Motor recovery was assessed via the Basso-Beattie-Bresnahan test Mechanical hyperalgesia was measured throughout the 28-day post -operative course via the von Frey test Microglial and astrocyte activation was assessed by immunohistochemical staining for ionized calcium binding adaptor molecule 1 (lba1) and glial fibrillary acidic protein (GFAP) at two sites: at the level of hemisection and at the 5th lumbar level (L5). Results : In rats, spinal cord hemisection reduced locomotor function and induced a mechanical hyperalgesia of the ipsilateral hind limb. The expression of lba1 and GFAP was also increased in the dorsal and ventral horns of the spinal cord at the site of hemisection and at the L5 level. Intraperitoneal injection of minocycline facilitated overall motor recovery and attenuated mechanical hyperalgesia. The expression of lba1 and GFAP in the spinal cord was also reduced in rats treated with minocycline. Conclusion : By inhibiting microglia and astrocyte activation, minocycline may facilitate motor recovery and attenuate mechanical hyperalgesia in individuals with spinal cord injuries.

• Molecules and Cells
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• v.37 no.12
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• pp.857-864
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• 2014

Astrocyte elevated gene-1 (AEG-1) is a recently discovered oncogene that has been reported to be highly expressed in various types of malignant tumors, including renal cell carcinoma. However, the precise role of AEG-1 in renal cancer cell proliferation and apoptosis has not been clarified. In this study, we transfected the renal cancer cell line Caki-1 with a plasmid expressing AEG-1 short hairpin RNA (shRNA) and obtained cell colonies with stable knockdown of AEG-1. We found that AEG-1 down-regulation inhibited cell proliferation and colony formation and arrested cell cycle progression at the sub-G1 and G0/G1 phase. Western blot analysis indicated that the expression of proliferating cell nuclear antigen (PCNA), cyclin D1 and cyclin E were significantly reduced following AEG-1 down-regulation. In addition, AEG-1 knockdown led to the appearance of apoptotic bodies in renal cancer cells, and the ratio of apoptotic cells significantly increased. Expression of the antiapoptotic factor Bcl-2 was dramatically reduced, whereas the pro-apoptotic factors Bax, caspase-3 and poly (ADPribose) polymerase (PARP) were significantly activated. Finally, AEG-1 knockdown in Caki-1 cells remarkably suppressed cell proliferation and enhanced cell apoptosis in response to 5-fluorouracil (5-FU) treatment, suggesting that AEG-1 inhibition sensitizes Caki-1 cells to 5-FU. Taken together, our data suggest that AEG-1 plays an important role in renal cancer formation and development and may be a potential target for future gene therapy for renal cell carcinoma.

• Journal of Ginseng Research
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• v.40 no.3
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• pp.211-219
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• 2016

Background: Panax ginseng root is used in traditional oriental medicine for human health. Its main active components such as saponins and polysaccharides have been widely evaluated for treating diseases, but secondary active components such as oligosaccharides have been rarely studied. This study aimed to assess the impact of water-soluble ginseng oligosaccharides (WGOS), which were isolated from the warm-water extract of Panax ginseng root, on scopolamine-induced cognitive impairment in mice and its antineuroinflammatory mechanisms. Methods: We investigated the impact of WGOS on scopolamine-induced cognitive impairment in mice by using Morris water maze and novel object recognition task. We also analyzed the impact of WGOS on scopolamine-induced inflammatory response (e.g., the hyperexpression of proinflammatory cytokines IL-$1{\beta}$ and IL-6 and astrocyte activation) by quantitative real-time polymerase chain reaction and glial fibrillary acid protein (GFAP) immunohistochemical staining. Results: WGOS pretreatment protected against scopolamine-induced learning and memory deficits in the Morris water maze and in the novel object recognition task. Furthermore, WGOS pretreatment downregulated scopolamine-induced hyperexpression of proinflammatory cytokines interleukin (IL)-$1{\beta}$ and IL-6 mRNA and astrocyte activation in the hippocampus. These results indicate that WGOS can protect against scopolamine-induced alterations in learning and memory and inflammatory response. Conclusion: Our data suggest that WGOS may be beneficial as a medicine or functional food supplement to treat disorders with cognitive deficits and increased inflammation.

• Journal of Ginseng Research
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• v.44 no.4
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• pp.603-610
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• 2020

Background: Depression is a common neuropsychiatric disease that shows astrocyte pathology. Ginsenoside Rf (G-Rf) is a saponin found in Panax ginseng which has been used to treat neuropsychiatric diseases. We aimed to investigate antidepressant properties of G-Rf when introduced into the L-alphaaminoadipic acid (L-AAA)-infused mice model which is representative of a major depressive disorder that features diminished astrocytes in the brain. Methods: L-AAA was infused into the prefrontal cortex (PFC) of mice to induce decrease of astrocytes. Mice were orally administered G-Rf (20 mg/kg) as well as vehicle only or imipramine (20 mg/kg) as controls. Depression-like behavior of mice was evaluated using forced swimming test (FST) and tail suspension test (TST). We observed recovery of astroglial impairment and increased proliferative cells in the PFC and its accompanied change in the hippocampus by Western blot and immunohistochemistry to assess the effect of G-Rf. Results: After injection of L-AAA into the PFC, mice showed increased immobility time in FST and TST and loss of astrocytes without significant neuronal change in the PFC. G-Rf-treated mice displayed significantly more decreased immobility time in FST and TST than did vehicle-treated mice, and their immobility time almost recovered to those of the sham mice and imipramine-treated mice. G-Rf upregulated glial fibrillary acidic protein (GFAP) expression and Ki-67 expression in the PFC reduced by L-AAA and also alleviated astroglial change in the hippocampus. Conclusion: G-Rf markedly reversed depression-like behavioral changes and exhibited protective effect against the astrocyte ablation in the PFC induced by L-AAA. These protective properties suggest that G-Rf might be a therapeutic agent for major depressive disorders.

• Molecules and Cells
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• v.37 no.4
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• pp.345-355
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• 2014

Mitigating secondary delayed neuronal injury has been a therapeutic strategy for minimizing neurological symptoms after several types of brain injury. Interestingly, secondary neuronal loss appeared to be closely related to functional loss and/or death of astrocytes. In the brain damage induced by agonists of two glutamate receptors, N-ethyl-D-aspartic acid (NMDA) and kainic acid (KA), NMDA induced neuronal death within 3 h, but did not increase further thereafter. However, in the KA-injected brain, neuronal death was not obviously detectable even at injection sites at 3 h, but extensively increased to encompass the entire hemisphere at 7 days. Brain inflammation, a possible cause of secondary neuronal damage, showed little differences between the two models. Importantly, however, astrocyte behavior was completely different. In the NMDA-injected cortex, the loss of glial fibrillary acidic protein-expressing ($GFAP^+$) astrocytes was confined to the injection site until 7 days after the injection, and astrocytes around the damage sites showed extensive gliosis and appeared to isolate the damage sites. In contrast, in the KA-injected brain, $GFAP^+$ astrocytes, like neurons, slowly, but progressively, disappeared across the entire hemisphere. Other markers of astrocytes, including $S100{\beta}$, glutamate transporter EAAT2, the potassium channel Kir4.1 and glutamine synthase, showed patterns similar to that of GFAP in both NMDA- and KA-injected cortexes. More importantly, astrocyte disappearance and/or functional loss preceded neuronal death in the KA-injected brain. Taken together, these results suggest that loss of astrocyte support to neurons may be a critical cause of delayed neuronal death in the injured brain.

• Genomics & Informatics
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• v.2 no.1
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• pp.36-44
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• 2004

Astrocytes play supportive roles for neurons in the brain. Recently, they have been accepted to have various functions in the vascular system as well as in the nervous system. We investigated the differential gene expression in rat astrocytes according to the oxygen tension, which is a crucial factor for angiogenesis. A cDNA microarray was performed to find the genes whose expression was sensitive to oxygen tension. We found 26 genes in the astrocyte were found and classified into 4 groups. In order to show the genes' relevancy to angiogenesis, seven of the 26 genes were investigated to see whether they have capabilities of interaction with angiogenesis­related factors in AngioDB. Through this investigation, we found interactions of three proteins with angiogenesis-related factors. These genes were further investigated with a new focus on the vascular endothelial growth factor (VEGF) expression in an astrocyte based on our hypothesis that astrocytes can have effects on endothelial angiogenesis via the release of VEGF. Collectively, we identified several genes whose expressions were dependent on the oxygen concentration of the astrocyte. Furthermore, the relevancy of astrocytes to angiogenesis was investigated using preexisting information of AngioDB, and suggested a possible signaling pathway for VEGF expression in the aspects of brain endothelial angiogenesis by astrocytes.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.1
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• pp.47-57
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• 2022

Stiripentol is an anti-epileptic drug for the treating of refractory status epilepticus. It has been reported that stiripentol can attenuate seizure severity and reduce seizure-induced neuronal damage in animal models of epilepsy. The objective of the present study was to investigate effects of post-treatment with stiripentol on cognitive deficit and neuronal damage in the cornu ammonis 1 (CA1) region of the hippocampus proper following transient ischemia in the forebrain of gerbils. To evaluate ischemia-induced cognitive impairments, passive avoidance test and 8-arm radial maze test were performed. It was found that post-treatment with stiripentol at 20 mg/kg, but not 10 or 15 mg/kg, reduced ischemia-induced memory impairment. Transient ischemia-induced neuronal death in the CA1 region was also significantly attenuated only by 20 mg/kg stiripentol treatment after transient ischemia. In addition, 20 mg/kg stiripentol treatment significantly decreased ischemia-induced astrocyte damage and immunoglobulin G leakage. In brief, stiripentol treatment after transient ischemia ameliorated transient ischemia-induced cognitive impairment in gerbils, showing that pyramidal neurons were protected and astrocyte damage and blood brain barrier leakage were significantly attenuated in the hippocampus. Results of this study suggest stiripentol can be developed as a candidate of therapeutic drug for ischemic stroke.

• The Journal of Internal Korean Medicine
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• v.19 no.2
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• pp.381-391
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• 1998

The present study was done to investigate the effects of Bombusae concretio Salicea (BCS) on cultured astrocyte cell system and lipid peroxidation in $A{\beta}25-35$ treatment conditions. Cell killing was significantly enhanced by addition of increasing concentrations of $A{\beta}25-35$. Pretreatment of BCS attenuated in cell killing enhanced by increasing concentrations of $A{\beta}25-35$. MDA level induced by $A{\beta}25-35$ treatment was significantly increased and the level was slightly reduced by pretreatment of BCS. The present study showed that $A{\beta}25-35$ strongly increased MDA level and the level was enhanced by addition of increasing concentrations of In conclusion, it was shown that $A{\beta}25-35$ is not only potent lipid peroxide inducer, but also cause protection of neurodegeneration induced by $A{\beta}25-35$. It can be concluded that the activation of antioxidative enzymes may be related to the inhibition of lipid peroxidative reactions. We cannot fully explain to effects of BCS at present; however, the ability of BCS to reduce cell killing and MDA level induced by $A{\beta}25-35$ suggest that BCS may be a protective agent for free radical generating compounds such as $A{\beta}25-35$.

• 한국체육학회지인문사회과학편
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• v.58 no.4
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• pp.481-492
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• 2019

The purpose of this study was to investigate the effects of treadmill exercise on cerebellar astrocyte activation and purkinje cells, neurotrophic factors expression, and motor function in aged rats. Sprague-Dawley (SD) rats were used and divided into three groups; (1) Young Control Group (YCG; 3months aged, n=10); (2) Old Control Group; (OCG; 24months aged, n=10); (3) Old Exercise Group (OEG; 24months aged, n=10). Rats were then subjected to treadmill exercise for 5 days per week for 12 weeks during which time the speed of the treadmill was gradually increased. The results revealed that in the rota-rod test, motor function was significantly increased in the OEG compared to the OCG (p<.05), and similarly YCG. Number of calbindin-positive purkinje cell expression significantly increased in the cerebellar vermis of OEG compared to the OCG (p<.05), and similarly YCG. GFAP-, NMDAR-positive cell expression significantly increased in the OEG (respectively p<.001), GFAP and GLAST protein levels were significantly increased in the cerebellum of OEG compared to the OCG (p<.05, p<.001) and similarly YCG. BDNF and NGF protein levels were highest in the YCG, increased in the OEG compared to OCG (p<.001, p<.05). These result show that regular exercise not only improved astrocyte activation, but also increased purkinje cell expression in the cerebellum and motor function by increasing the neurotrophic factors in aged rats.