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Neuroprotective effects of FK506 against excitotoxicity in organotypic hippocampal slice culture
Lee, Kyung Hee,Won, Ran,Kim, Un Jeng,Kim, Ga Min,Chung, Myung-Ae,Sohn, Jin-Hun,Lee, Bae Hwan Elsevier 2010 Neuroscience Letters Vol.474 No.3
<P><B>Abstract</B></P> <P>FK506 has been originally classified as an immunosuppressant and is known to exhibit neurotrophic actions <I>in vitro</I> and protective effects on some neurological conditions. We investigated the neuroprotective effects of FK506 on kainic acid (KA)-induced neuronal death in organotypic hippocampal slice cultures (OHSCs). After an 18h KA (5μM) treatment, significantly neuronal death was detected in the CA3 region using propidium iodide staining. However, neuronal death was significantly prevented at 24 and 48h after treatment with 0.1μM FK506. Using cresyl violet staining, we also observed that an increased number of CA3 neurons survived in the 0.1μM FK506 group compared to the KA only group. Based on the results of the Western blot analysis, the expressions of 5-lipoxygenase and caspase-3 were reduced 24h after 0.1μM FK506 treatment. The levels of superoxide dismutase (SOD) and phospho-Akt expression were increased by treatment with 0.1μM FK506. These results suggest that FK506 may have a positive role in protecting neurons against cell death in the KA injury model of OHSCs.</P>
Antioxidant Effects on Neuronal Cell Death in Memory and Cognition Area
( Un Jeng Kim ),( Bae Hwan Lee ),( Kyung Hee Lee ) 한국감성과학회 2015 추계학술대회 Vol.2015 No.-
Hippocampus is a part of brain which plays an important role in memory and recognition. Despite of its important role, hippocampus is very sensitive to global reduction in oxygen level. Oxidative stress and mitochondrial dysfunction are known to be primary factors in the progression of various neurodegenerative disorders. Tyrosine phosphatase shows to regulate the various proteins involving in fundamental cellular processes and survival signals. We investigated that the protein tyrosine phosphatase inhibitor, Sodium orthovanadate (SOV), affects neuronal cell survival and neuroprotective signals in hippocampus after oxidative injury. Hippocampal slices were prepared from 6-7 day-old rats using a tissue chopper and placed on a membrane insert. Neuronal cell death, as assessed by propidium iodide (PI) uptake, was significantly reduced by SOV treatment (10 and 25 uM). The SOV-treated group exhibited increased expression of SOD2 which indicates the level of ROS compared with the KA-only group. Furthermore, the phospho-AKT/AKT ratio showed that the level of phospho-AKT was significantly increased in the 25uM SOV-treated group. These results suggest that SOV may protect hippocampal neurons against oxidative stress (NRF-2013R1A1A4A01009332).
The neuronal activity changes by oxidative injury in OHSC using optical imaging system
( Un Jeng Kim ),( Bae Hwan Lee ),( Kyung Hee Lee ) 한국감성과학회 2017 한국감성과학회 국제학술대회(ICES) Vol.2017 No.-
Oxidative stress produces neurotoxicity often related with various CNS disorders. Ascorbic acid (AA) have been shown to have protective effects as anti-oxidants in experimental neurological disorder models such as stroke, ischemia, and epileptic seizures. The present study was conducted to examine the protective effects of AA on kainic acid (KA) neurotoxicity using organotypic hippocampal slice cultures. AA may enhance the protection effect and benefit to improve neuronal plasticity in post-injury. Thus, we investigated that the antioxidant affects neuroprotective signaling and neuroplastic changes in hippocampus after oxidative injury. Electrophysiological and biochemical assays were used to observe changes in synaptic efficacy following electrical and/or pharmacological manipulation of synaptic function. Neuronal cell death, as assessed by propidium iodide (PI) uptake, was reduced by AA treatment compared with KA treatment. AA significantly prevented cell death and inhibited reactive oxygen species (ROS) level, and mitochondrial dysfunction. Optical imaging revealed that KA treatment tended to delay the latency of electrical stimulation and decrease the amplitude of optical signals of synaptic activity. These results suggest that AA may protect hippocampal neurons against oxidative stress and the survived neurons may functional to synaptic plasticity changes. This work was supported by the Basic Science Research Program through NRF of Korea, which is funded by the MEST (2016R1D1A3B02008194) and the Ministry of Science, ICT, and Future Planning (2014R1A2A2A04004407).
Un Jeng Kim,Yongho Kwak,Jeongsoo Han,Jin-Hun Sohn,Shigeki Watanuki,Bae Hwan Lee 대한인간공학회 2014 대한인간공학회 학술대회논문집 Vol.2014 No.5
The information on the spatial differences in the active regions of the nucleus of the solitary tract (NST) may be essential to understand the effect of salts. In the present study, we aimed to investigate the spatial distribution patterns of cation-specific active regions in the NST. For this purpose, the anterior part of the tongue of urethane-anesthetized Sprague-Dawley rats (n = 25) was stimulated with artificial saliva (Control), 0.5 M and 1.0 M NaCl, 0.5 M KCl, and 0.3 M NH4Cl. The 3D-position of c-Fos-like immunoreactive (cFLI) cells in the NST was determined. The cFLI cells were observed throughout the NST, irrespective of the stimulus; however, the intermediate-medial-central regions of the NST had a higher number of cFLI cells than the other regions after all taste stimulations. The analysis of images revealed that the activated regions in the NST were significantly different depending on the cations. Therefore, these results suggest that there are cation-specific regions in the NST.
( Un Jeng Kim ),( Yongho Kwak ),( Jeongsoo Han ),( Jin Hun Sohn ),( Shigeki Watanuki ),( Bae Hwan Lee ) 한국감성과학회 2014 춘계학술대회 Vol.2014 No.-
This study aims to explore and identify semantics of emotions evoked in the cognitive process of human beings when they are stimulated by different physical signals presented on information displays. To do this, we compared emotion maps driven from two independent experimental setups. Kansei engineering approaches using semantic differential method were adopted to draw the emotion maps. In each experimental setup, different set of subjects were asked to evaluate levels of semantic associations between physical stimuli and delivering information. The information to deliver was defined using sets of adjectives that are useful to describe various states of process in or out of control. Distinctive earcons and hapticons with different design parameters were given as the physical stimuli in each experiment. Factor analysis was applied to determine the dimensions, locations of adjectives and stimuli on each emotion map. The results showed that people`s emotions corresponding to given physical stimuli can be abstracted into 2 dimensions when they are expressed using the set of adjectives in the experiments.
Neuroprotective effects of dehydroascorbic acid
( Bae Hwan Lee ),( Se Jung Jung ),( Eun Shin Kim ),( Kyung Hee Lee ),( Un Jeng Kim ) 한국감성과학회 2004 추계학술대회 Vol.2004 No.-
Ascorbic acid (AA), a well-known antioxidant, may play a significant role to protect neuronal cells against oxidative stress. Dehydroascorbic acid (DHA) is regenerated into AA at the expense of reduced GSH within the cells. The present study examined the effects of AA and DHA on functional recovery from spinal cord injury (SCI) in rats. AA or DHA was injected intravenously in the SCI rat model. The rats injected with DHA showed effective behavioral recovery compared with the saline-treated group. However, there was no significant difference between the AA treated group and the saline treated group. These results suggest that DHA may improve functional recovery from spinal cord injury and may provide an insight into a therapeutic approach on neurodegenerative disorders.