• Title/Summary/Keyword: neuronal

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Different Effects of Dopamine on Differential Rotational Mobility between Inner and Outer Monolayer of Synaptosomal Plasma Membrane Vesicles Isolated from Bovine Brain

  • Kim, Hyun-Gang;Choi, Chang-Hwa;Kim, Inn-Se;Chung, In-Kyo;Cho, Goon-Jae;Jang, Hye-Ock;Yun, Il
    • The Korean Journal of Physiology and Pharmacology
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    • v.4 no.5
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    • pp.409-415
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    • 2000
  • Fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) was used to evaluate the effects of dopamine HCl on the range of the rotatioanl mobility of bulk bilayer structure of the synaptosomal plasma membrane vesicles (SPMV) isolated from whole bovine brain. In a dose-dependent manner, dopamine decreased the anisotropy $({\gamma}),$ limiting anisotropy $({\gamma}{infty})$ and order parameter (S) of DPH in the membranes. These indicate that dopamine increased the rotational mobility of the probe in the neuronal membranes. Cationic 1-[4-(trimethylammonio)-phenyl]-6-phenylhexa-1,3,5-hexatriene (TMA-DPH) and anionic 3-[p-(6-phenyl)-1,3,5-hexatrienyl]-phenylpropionic acid (PRO-DPH) were utilized to examine the range of transbilayer asymmetric rotational mobility of the neuronal membranes. Dopamine had a greater increasing effect on the mobility of the inner monolayer as compared to the outer monolayer of the neuronal membranes. It has been proven that dopamine exhibits a selective rather than nonselective fluidizing effect within the transbilayer domains of the SPMV.

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Sildenafil Ameliorates Advanced Glycation End Products-Induced Mitochondrial Dysfunction in HT-22 Hippocampal Neuronal Cells

  • Sung, Soon Ki;Woo, Jae Suk;Kim, Young Ha;Son, Dong Wuk;Lee, Sang Weon;Song, Geun Sung
    • Journal of Korean Neurosurgical Society
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    • v.59 no.3
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    • pp.259-268
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    • 2016
  • Objective : Accumulation of advanced glycation end-products (AGE) and mitochondrial glycation is importantly implicated in the pathological changes of the brain associated with diabetic complications, Alzheimer disease, and aging. The present study was undertaken to determine whether sildenafil, a type 5 phosphodiesterase type (PDE-5) inhibitor, has beneficial effect on neuronal cells challenged with AGE-induced oxidative stress to preserve their mitochondrial functional integrity. Methods : HT-22 hippocampal neuronal cells were exposed to AGE and changes in the mitochondrial functional parameters were determined. Pretreatment of cells with sildenafil effectively ameliorated these AGE-induced deterioration of mitochondrial functional integrity. Results : AGE-treated cells lost their mitochondrial functional integrity which was estimated by their MTT reduction ability and intracellular ATP concentration. These cells exhibited stimulated generation of reactive oxygen species (ROS), disruption of mitochondrial membrane potential, induction of mitochondrial permeability transition, and release of the cytochrome C, activation of the caspase-3 accompanied by apoptosis. Western blot analyses and qRT-PCR demonstrated that sildenafil increased the expression level of the heme oxygenase-1 (HO-1). CoPP and bilirubin, an inducer of HO-1 and a metabolic product of HO-1, respectively, provided a similar protective effects. On the contrary, the HO-1 inhibitor ZnPP IX blocked the effect of sildenafil. Transfection with HO-1 siRNA significantly reduced the protective effect of sildenafil on the loss of MTT reduction ability and MPT induction in AGE-treated cells. Conclusion : Taken together, our results suggested that sildenafil provides beneficial effect to protect the HT-22 hippocampal neuronal cells against AGE-induced deterioration of mitochondrial integrity, and upregulation of HO-1 is involved in the underlying mechanism.

Cilostazol attenuates kainic acid-induced hippocampal cell death

  • Park, Young-Seop;Jin, Zhen;Jeong, Eun Ae;Yi, Chin-ok;Lee, Jong Youl;Park, In Sung;Roh, Gu Seob
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.1
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    • pp.63-70
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    • 2018
  • Cilostazol is a selective inhibitor of type 3 phosphodiesterase (PDE3) and has been widely used as an antiplatelet agent. Cilostazol mediates this activity through effects on the cyclic adenosine monophosphate (cAMP) signaling cascade. Recently, it has attracted attention as a neuroprotective agent. However, little is known about cilostazol's effect on excitotoxicity induced neuronal cell death. Therefore, this study evaluated the neuroprotective effect of cilostazol treatment against hippocampal neuronal damage in a mouse model of kainic acid (KA)-induced neuronal loss. Cilostazol pretreatment reduced KA-induced seizure scores and hippocampal neuron death. In addition, cilostazol pretreatment increased cAMP response element-binding protein (CREB) phosphorylation and decreased neuroinflammation. These observations suggest that cilostazol may have beneficial therapeutic effects on seizure activity and other neurological diseases associated with excitotoxicity.

Ginsenoside Rg3 from Red Ginseng Prevents Damage of Neuronal Cells through the Phosphorylation of the Cell Survival Protein Akt

  • Joo, Seong-Soo;Won, Tae-Joon;Lee, Yong-Jin;Hwang, Kwang-Woo;Lee, Seon-Gu;Yoo, Yeong-Min;Lee, Do-Ik
    • Food Science and Biotechnology
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    • v.15 no.2
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    • pp.244-247
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    • 2006
  • Neuronal cell death significantly contributes to neuronal loss in neurological injury and disease. Typically, neuronal loss or destruction upon exposure to neurotoxins, oxidative stress, or DNA damage causes neurodegenerative diseases such as Alzheimer's disease. In this study, we attempted to determine whether ginsenoside Rg3 from red ginseng has a neuroprotective effect via an anti-apoptotic role induced by S-nitroso-N-acetylpenicillamine (SNAP) at the molecular level. We also investigated the antioxidant effect of Rg3 using a metal-catalyzed reaction with $Cu^{2+}/H_2O_2$. Our results showed that Rg3 ($40-100\;{\mu}g/mL$) protected SK-N-MC neuroblastoma cells under cytotoxic conditions and effectively protected DNA from fragmentation. In the signal pathway, caspase-3, and poly (ADP-ribose) polymerase (PARP) were kept at an inactivated status when pretreated with Rg3 in all ranges. In particular, the important upstream p-Akt signal pathway was increased in a dose-dependent manner, which indicates that Rg3 may contribute to cell survival. We also found that oxidative stress can be mitigated by Rg3. Therefore, we have concluded that Rg3 plays a certain role in neurodegenerative pathogenesis via an anti apoptotic, antioxidative effect.

Protection of spontaneous and glutamate-induced neuronal damages by Soeumin Sibjeundaibo-tang and Soyangin Sibimijihwang-tang in cultured mice cerebrocortical cells

  • Lee, Mi-Young;Ma, Jin-Yeul;Choo, Young-Kug;Jung, Kyu-Yong
    • Advances in Traditional Medicine
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    • v.1 no.1
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    • pp.55-63
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    • 2000
  • Soeumin Sibjeundaibo-tang (SJDBT) and Soyangin Sibimijihwang-tang (SMJHT) have been used traditionally to improve the systemic blood circulation and biological energy production in the patients with circulatory and neuronal diseases. The object of this study is to determine the protective effects of SJDBT and SMJHT extracts on the spontaneous and glutamate-induced neuronal damages in cultured cells derived from mice cerebral cortex. At 14 days after beginning the cultures, the activity of lactate dehydrogenase released into the culture media was significantly decreased by treatment of cerebroneuronal cells with SJDBT and SMJHT (0.1 mg/ml) for 7 days. By comparison with the normal cells, cerebroneuronal morphology was dramatically changed by treatment of glutamate (1 mM) for 12 hrs, and this was conspicuously recovered by pretreatment of cerebroneural cells with SJDBT and SMJHT (0.1-1.0 mg/ml) for 2 days. Moreover, glutamated-induced DNA fragmentation was also protected by pretreatment of cerebroneuronal cells with those extracts. These results suggest that naturally occurring and glutamate-induced degeneration of cultured cerebrocortical cells may be related, in part, to the process of apoptotic cell death. The pharmacological properties of SJDBT and SMJHT extracts to improve cerebroneuronal degeneration may be considered as one of useful medicines that can prevent cerebrocortical impairments resulted from age-dependent and excitotoxicity-induced neuronal degeneration in human brain.

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Cytoprotective Effects of Docosyl Cafferate against tBHP-Induced Oxidative Stress in SH-SY5Y Human Neuroblastoma Cells

  • Choi, Yong-Jun;Kwak, Eun-Bee;Lee, Jae-Won;Lee, Yong-Suk;Cheong, Il-Young;Lee, Hee-Jae;Kim, Sung-Soo;Kim, Myong-Jo;Kwon, Yong-Soo;Chun, Wan-Joo
    • Biomolecules & Therapeutics
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    • v.19 no.2
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    • pp.195-200
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    • 2011
  • Neuronal cell death is a common characteristic feature of a variety of neurodegenerative disorders including Alzheimer's disease and Parkinson's disease. However, there have been no effective drugs to successfully prevent neuronal death in those diseases. In the present study, docosyl cafferate (DC), a derivative of caffeic acid, was isolated from Rhus verniciflua and its protective effects on tBHP-induced neuronal cell death were examined in SH-SY5Y human neuroblastoma cells. Pretreatment of DC significantly attenuated tBHP-induced neuronal cell death in a concentration-dependent manner. DC also significantly suppressed tBHP-induced caspase-3 activation. In addition, DC restored tBHP-induced depletion of intracellular Bcl-2, an anti-apoptotic member of the Bcl-2 family. Furthermore, DC significantly suppressed tBHP-induced degradation of IKB, which retains $NF-{\kappa}B$ in the cytoplasm, resulting in the suppression of nuclear translocation of $NF-{\kappa}B$ and its subsequent activation. Taken together, the results clearly demonstrate that DC exerts its neuroprotective activity against tBHP-induced oxidative stress through the suppression of nuclear translocation of $NF-{\kappa}B$.

A ROCK Inhibitor Blocks the Inhibitory Effect of Chondroitin Sulfate Proteoglycan on Morphological Changes of Mesenchymal Stromal/Stem Cells into Neuron-Like Cells

  • Lim, Hee-Suk;Joe, Young Ae
    • Biomolecules & Therapeutics
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    • v.21 no.6
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    • pp.447-453
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    • 2013
  • Chondroitin sulfate proteoglycan (CSPG) inhibits neurite outgrowth of various neuronal cell types, and CSPG-associated inhibition of neurite outgrowth is mediated by the Rho/ROCK pathway. Mesenchymal stromal/stem cells (MSCs) have the potential to differentiate into neuron-like cells under specific conditions and have been shown to differentiate into neuron-like cells by co-treatment with the ROCK inhibitor Y27632 and the hypoxia condition mimicking agent $CoCl_2$. In this study, we addressed the hypothesis that a ROCK inhibitor might be beneficial to regenerate neurons during stem cell therapy by preventing transplanted MSCs from inhibition by CSPG in damaged tissues. Indeed, dose-dependent inhibition by CSPG pretreatment was observed during morphological changes of Wharton's jelly-derived MSCs (WJ-MSCs) induced by Y27632 alone. The formation of neurite-like structures was significantly inhibited when WJ-MSCs were pre-treated with CSPG before induction under Y27632 plus $CoCl_2$ conditions, and pretreatment with a protein kinase C inhibitor reversed such inhibition. However, CSPG treatment resulted in no significant inhibition of the WJ-MSC morphological changes into neuron-like cells after initiating induction by Y27632 plus $CoCl_2$. No marked changes were detected in expression levels of neuronal markers induced by Y27632 plus $CoCl_2$ upon CSPG treatment. CSPG also blocked the morphological changes of human bone marrow-derived MSCs into neuron-like cells under other neuronal induction condition without the ROCK inhibitor, and Y27632 pre-treatment blocked the inhibitory effect of CSPG. These results suggest that a ROCK inhibitor can be efficiently used in stem cell therapy for neuronal induction by avoiding hindrance from CSPG.

Intestinal Neuronal Dysplasia in Twins (쌍생아에서 발생한 Intestinal Neuronal Dysplasia)

  • Lim, In-Suk;Chung, Ju-Young;Choi, Myung-Jai;Kim, Sang-Woo;Kim, Hong-Ju;Kim, Jeong-Yeon
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.6 no.2
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    • pp.202-207
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    • 2003
  • Intestinal neuronal dysplasia (IND) is a disorder of abnormal intestinal innervation resulting in dysfunctional colonic motility. IND shares clinical features with Hirschsprung's disease but differentiated by histological findings such as hyperplasia of submucosal and myenteric plexuses, giant ganglia, ectopic ganglion cell and increased acetylcholinesterase activity in lamina propria. Although IND may exist as an isolated condition, more commonly, it occurs in association with Hirschsprung's disease. We report a case of twins affected with IND. Both children manifested with delayed passage of meconium and severe abdominal distention after birth. Barium enema in both patients showed microcolon. They underwent emergency ileostomy under the impression of total aganglionosis. But surgical biopsy specimens showed hyperganglionosis in submucosa with formation of giant ganglia. Both neonates suffers from several episodes of peudo-obstruction after the repair operation of colostomy.

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Neuroprotective effects of erythropoietin against hypoxic injury via modulation of the mitogen-activated protein kinase pathway and apoptosis

  • Jeong, Ji Eun;Park, Jae Hyun;Kim, Chun Soo;Lee, Sang Lak;Chung, Hai Lee;Kim, Woo Taek;Lee, Eun Joo
    • Clinical and Experimental Pediatrics
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    • v.60 no.6
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    • pp.181-188
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    • 2017
  • Purpose: Hypoxic-ischemic encephalopathy is a significant cause of neonatal morbidity and mortality. Erythropoietin (EPO) is emerging as a therapeutic candidate for neuroprotection. Therefore, this study was designed to determine the neuroprotective role of recombinant human EPO (rHuEPO) and the possible mechanisms by which mitogen-activated protein kinase (MAPK) signaling pathway including extracellular signal-regulated kinase (ERK1/2), JNK, and p38 MAPK is modulated in cultured cortical neuronal cells and astrocytes. Methods: Primary neuronal cells and astrocytes were prepared from cortices of ICR mouse embryos and divided into the normoxic, hypoxia (H), and hypoxia-pretreated with EPO (H+EPO) groups. The phosphorylation of MAPK pathway was quantified using western blot, and the apoptosis was assessed by caspase-3 measurement and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Results: All MAPK pathway signals were activated by hypoxia in the neuronal cells and astrocytes (P<0.05). In the neuronal cells, phosphorylation of ERK-1/-2 and apoptosis were significantly decreased in the H+EPO group at 15 hours after hypoxia (P<0.05). In the astrocytes, phosphorylation of ERK-1/-2, p38 MAPK, and apoptosis was reduced in the H+EPO group at 15 hours after hypoxia (P<0.05). Conclusion: Pretreatment with rHuEPO exerts neuroprotective effects against hypoxic injury reducing apoptosis by caspase-dependent mechanisms. Pathologic, persistent ERK activation after hypoxic injury may be attenuateed by pretreatment with EPO supporting that EPO may regulate apoptosis by affecting ERK pathways.

Effects of Electrical Stimulation of the Vestibular System on Neuronal Activity of the Ipsilateral Medial Vestibular Nuclei Following Unilateral Labyrinthectomy in Rats (일측 전정기관 손상 흰쥐에서 동측의 내측 전정신경핵 활동성에 대한 전정기관의 전기자극 효과)

  • Lee Moon-Yong;Kim Min-Sun;Park Byung-Rim
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.3
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    • pp.263-273
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    • 1997
  • The purpose of this study was to evaluate the effects of electrical stimulation on vestibular compensation following ULX in rats. Electrical stimulation (ES) with square pulse ($100{\sim}300uA$, 1.0 ms, 100 Hz) was applied to ampullary portion bilaterally for 6 and 24 hours in rats receiving ULX. After ES, animals that showed the recovery of vestibular symptoms by counting and comparing the number of spontaneous nystagmus were selected for recording resting activity of type I, II neurons in the medial vestibular nuclei (MVN) of the lesioned side. And then the dynamic neuronal activities were recorded during sinusoidal rotation at a frequency of 0.1 Hz and 0.2 Hz. The number of spontaneous nystagmus was significantly different 24 hours (p<0.01, n=10), but not 6 hours after ULX+ES. As reported by others, the great reduction of resting activity only in the type I neurons ipsilateral to lesioned side was observed 6, 24 hours after ULX compared to that of intact labyrinthine animal. However, the significant elevation (p<0.01) of type I and reduction (p<0.01) of type II neuronal activity were seen 24 hours after ULX+ES. Interestingly, gain, expressed as maximum neuronal activity(spikes/sec)/maximum rotational velocity(deg/sec), was increased in type I cells and decreased in type II cells 24 hours after ULX+ES in response to sinusoidal rotation at frequencies of both 0.1 Hz and 0.2 Hz. This result suggests that accompanying the behavioral recovery, the electrical stimulation after ULX has beneficial effects on vestibular compensation, especially static symptoms (spontaneous nystagmus), by enhancing resting activity of type I neurons and reducing that of type II neurons.

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