• Biomolecules & Therapeutics
• /
• 제18권1호
• /
• pp.39-47
• /
• 2010

Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor involved in neuronal differentiation, plasticity, survival and regeneration. BDNF draws massive attention mainly due to the potential as a therapeutic target in neurological diseases such as depression and Alzheimer's disease. In a primary screening for the natural compounds enhancing BDNF release from cultured rat primary cortical neuron, we found that compounds such as baicalein, tanshinone IIa, cinnamic acid, epiberberine, genistein and wogonin among many others increased BDNF release. All the compounds at $0.1{\mu}M$ of concentration barely showed stimulatory effect on BDNF induction, however, their combination (mixture 1; baicalein, tanshinone IIa and cinnamic acid, mixture 2; epiberberine, genistein and wogonin) showed synergistic increase in BDNF release as well as mRNA and protein expression. The level of BDNF expression was comparable to the maximum BDNF stimulation attainable by a positive control oroxylin A ($20{\mu}M$) without cell toxicity as determined by MTT analysis. Both mixtures synergistically increased the phosphorylation of extracellular signal-regulated kinase (ERK) as well as cAMP response element binding protein (CREB), an immediate and essential regulator of BDNF expression. Similar to these results, mixture of these compounds synergistically inhibited the up-regulation of inducible nitric oxide synthase (iNOS) induced by lipopolysaccharide treatments in rat primary astrocytes. These results suggest that the combinatorial treatment of natural compounds in lower concentration might be a useful strategy to obtain sufficient BDNF stimulation in neurological disease condition such as depression, while minimizing potential side effects and toxicity of higher concentration of a single compound.

• BMB Reports
• /
• 제50권2호
• /
• pp.60-70
• /
• 2017

Glaucoma is characterized by a slow and progressive degeneration of the optic nerve, including retinal ganglion cell (RGC) axons in the optic nerve head (ONH), leading to visual impairment. Despite its high prevalence, the biological basis of glaucoma pathogenesis still is not yet fully understood, and the factors contributing to its progression are currently not well characterized. Intraocular pressure (IOP) is the only modifiable risk factor, and reduction of IOP is the standard treatment for glaucoma. However, lowering IOP itself is not always effective for preserving visual function in patients with primary open-angle glaucoma. The second messenger cyclic adenosine 3',5'-monophosphate (cAMP) regulates numerous biological processes in the central nervous system including the retina and the optic nerve. Although recent studies revealed that cAMP generated by adenylyl cyclases (ACs) is important in regulating aqueous humor dynamics in ocular tissues, such as the ciliary body and trabecular meshwork, as well as cell death and growth in the retina and optic nerve, the functional role and significance of cAMP in glaucoma remain to be elucidated. In this review, we will discuss the functional role of cAMP in aqueous humor dynamics and IOP regulation, and review the current medications, which are related to the cAMP signaling pathway, for glaucoma treatment. Also, we will further focus on cAMP signaling in RGC growth and regeneration by soluble AC as well as ONH astrocytes by transmembrane ACs to understand its potential role in the pathogenesis of glaucoma neurodegeneration.

• Journal of Microbiology and Biotechnology
• /
• 제27권1호
• /
• pp.161-170
• /
• 2017

Meningitis caused by Streptococcus suis serotype 2 (S. suis 2) is a great threat to the pig industry and human health. Virulence factors associated with the pathogenesis of meningitis have yet to be clearly defined, even though many potential S. suis 2 virulence factors have been identified. This greatly hinders the progress of S. suis 2 meningitis pathogenesis research. In this study, a co-culture blood-brain barrier (BBB) model was established using primary porcine brain microvascular endothelial cells and astrocytes, and the whole genome library of S. suis 2 was constructed using phage display technology. Finally, a total of 14 potential virulence factors contributing to S. suis 2 adherence to and invasion of the BBB were selected by analyzing the interactions between the phage library and the co-culture model. Twelve of these factors have not been previously reported in meningitis-related research. The data provide valuable insight into the pathogenesis of S. suis 2 meningitis and potential targets for the development of drug therapies.

• Biomolecules & Therapeutics
• /
• 제22권5호
• /
• pp.445-452
• /
• 2014

The purpose of this study was to investigate the therapeutic effects of DA-9801, an optimized extract of Dioscorea species, on diabetic peripheral neuropathy in a type 2 diabetic animal model. In this study, db/db mice were treated with DA-9801 (30 and 100 mg/kg, daily, p.o.) for 12 weeks. DA-9801 reduced the blood glucose levels and increased the withdrawal latencies in hot plate tests. Moreover, it prevented nerve damage based on increased nerve conduction velocity and ultrastructural changes. Decrease of nerve growth factor (NGF) may have a detrimental effect on diabetic neuropathy. We previously reported NGF regulatory properties of the Dioscorea genus. In this study, DA-9801 induced NGF production in rat primary astrocytes. In addition, it increased NGF levels in the sciatic nerve and the plasma of type 2 diabetic animals. DA-9801 also increased neurite outgrowth and mRNA expression of Tieg1/Klf10, an NGF target gene, in PC12 cells. These results demonstrated the attenuation of diabetic peripheral neuropathy by oral treatment with DA-9801 via NGF regulation. DA-9801 is currently being evaluated in a phase II clinical study.

• 한국식물생명공학회:학술대회논문집
• /
• 한국식물생명공학회 2004년도 생명공학 실용화를 위한 비젼
• /
• pp.74-79
• /
• 2004

Little is known about the effect of epigallocatechin-3 gallate (ESCG), a major constituent of green tea, on the expression of cyclooxygenase (COX)-2. Here, we studied the role of phospholipase D (PLD) isozymes in EGCG-induced COX-2 expression. Stimulation of human astrocytoma cells (U87) with EGCG induced formation of phosphatidylbutanol, a specific product of PLD activity, and synthesis of COX-2protein and its product, prostaglandin $E_2$ ($PGE_2$). Pretreatment of cells with 1-butanol, but not 3-butanol, suppressed EGCG-induced COX-2 expression and $PGE_2$ synthesis. Furthermore, evidence that PLD was involved in EGCG-induced COX-2 expression w3s provided by the observations that COX-2 expression was stimulated by over-expression of PLD1 or PLD2 isozymes and treatment with phosphatidic acid(PA), and that prevention of PA dephosphorylation by 1-propranolol significantly potentiated COX-2expression Induced by EGCG. EGCG induced activation of p38 mitogen-activated protein kinase (p38MAPK), and specific Inhibition of p38 MAPK dramatically abolished EGCG-Induced PLD activation, COX-2 expression, and $PGE_2$ formation. Moreover, protein kinase C (PKC) inhibition suppressed EGCG-induced p38 MAPK activation, COX-2 expression, and $PGE_2$ accumulation. The same pathways as those obtained in the astrocytoma cells were active in primary rat astrocytes, suggesting the relevance of the findings. Collectively, our results demonstrate for the first time that PLD isozymes mediate EGCG-induced COX-2 expression through PKC and p38 in immortalized astroglial line and normal astrocyte cells.

• 대한의생명과학회지
• /
• 제25권2호
• /
• pp.177-184
• /
• 2019

Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common genetic cause of Parkinson's disease (PD). LRRK2 contains a functional kinase and GTPase domains. A pathogenic G2019S mutation that is the most prevalent among the LRRK2 mutations and is also found in sporadic cases, increases its kinase activity. Therefore, identification of LRRK2 kinase substrates and the development of kinase inhibitors are under intensive investigation to find PD therapeutics. Several recent studies have suggested members of Rab proteins, a branch of the GTPase superfamily, as LRRK2 kinase substrates. Rab proteins are key regulators of cellular vesicle trafficking. Among more than 60 members of human Rab proteins, Rab3, Rab5, Rab8, Rab10, Rab12, Rab29, Rab35, and Rab43 have been identified as LRRK2 kinase substrates. However, most studies have used human embryonic kidney (HEK) 293T cells overexpressing LRRK2/Rab proteins or murine embryonic fibroblast (MEF) cells which are not relevant to PD, rather than neuronal cells. In this study, we tested whether Rab proteins are phosphorylated by LRRK2 in astroglia in addition to neurons. Among the various Rab substrates, we tested phosphorylation of Rab10, because of the commercial availability and credibility of the phospho-Rab10 (pRab10) antibody, in combination with a specific LRRK2 kinase inhibitor. Based on the results of specific LRRK2 kinase inhibitor treatment, we concluded that LRRK2 phosphorylates Rab10 in the tested brain cells such as primary neurons, astrocytes and BV2 microglial cells.

• Journal of Ginseng Research
• /
• 제46권1호
• /
• pp.79-90
• /
• 2022

Background: Herbal medicines are popular approaches to capably prevent and treat obesity and its related diseases. Excessive exposure to dietary lipids causes oxidative stress and inflammation, which possibly induces cellular senescence and contribute the damaging effects in brain. The potential roles of selective enhanced ginsenoside in regulating high fat diet (HFD)-induced brain damage remain unknown. Methods: The protection function of Ginsenoside F1-enhanced mixture (SGB121) was evaluated by in vivo and in vitro experiments. Human primary astrocytes and SH-SY5Y cells were treated with palmitic acid conjugated Bovine Serum Albumin, and the effects of SGB121 were determined by MTT and lipid uptake assays. For in vivo tests, C57BL/6J mice were fed with high fat diet for 3 months with or without SGB121 administration. Thereafter, immunohistochemistry, western blot, PCR and ELISA assays were conducted with brain tissues. Results and conclusion: SGB121 selectively suppressed HFD-induced oxidative stress and cellular senescence in brain, and reduced subsequent inflammation responses manifested by abrogated secretion of IL-6, IL-1β and TNFα via NF-κB signaling pathway. Interestingly, SGB121 protects against HFD-induced damage by improving mitophagy and endoplasmic reticulum-stress associated autophagy flux and inhibiting apoptosis. In addition, SGB121 regulates lipid uptake and accumulation by FATP4 and PPARα. SGB121 significantly abates excessively phosphorylated tau protein in the cortex and GFAP activation in corpus callosum. Together, our results suggest that SGB121 is able to favor the resistance of brain to HFD-induced damage, therefore provide explicit evidence of the potential to be a functional food.

• 한국발생생물학회지:발생과생식
• /
• 제12권1호
• /
• pp.1-8
• /
• 2008

배아줄기세포는 다양한 분화 유도 방법을 통해 신경계세포로 분화시킬 수 있을 뿐만 아니라, 보다 더 엄격한 선발조건을 적용함으로써 특정 종류의 신경세포만을 확보할 수도 있게 되었다. 세포사멸연구를 포함한 신경생리학적 연구의 대상으로써 중요한 요건은 이렇게 확보한 배아줄기세포 유래의 신경계세포들이 정상적인 신경생리학적 특성을 갖고 있어야 하며, 동시에 그런 신경생리학적 특성이 체외에서 일정기간 동안 이상 자연적인 세포사멸없이 유지되어야 한다는 것이다. 생쥐 배아줄기세포를 retinoic acid로 처리한 후, astrocytes monolayer 위에서 신경계세포로 분화시키면 장기간 생존이 가능한 다수의 신경계세포를 손쉽게 확보할 수 있을 뿐만 아니라, 면역세포화학적 방법을 통해 신경세포의 생사를 개별세포 수준에서 추적할 수 있다. 배아줄기세포 유래의 신경계세포는 glutamate agonist들에 대해 수용체 특이적 흥분성 신경독성 반응을 보이며, 이 반응은 신경계세포로의 분화가 진행될수록 더욱 뚜렷해지는 양상을 보인다. 신경계세포의 발생분화, 생존에 관여하는 Neurotrophin, GDNF 계열의 신경계 작용 성장인자들의 수용체가 배아줄기세포 유래의 신경계세포에서 발현되고 있으며, 이들에 의해 신경계세포로의 분화과정에서 세포의 생존능 및 신경독성처리에 대한 세포사멸반응이 조절될 수도 있다. 따라서 배아줄기세포 유래의 신경계세포는 신경세포의 생존과 사멸, 그리고 세포손상으로부터의 보호와 같은 신경약리학적 연구를 위한 중요한 특성을 나타내고 있기에 관련 연구를 위한 새로운 연구시스템이 될 수 있는 것이다. 특히 일반적인 신경세포는 유전적 변형이 어려워 다양한 신경약리학적 연구에 많은 제약을 받아 왔으나, 이제 유전자 변형 배아줄기세포로부터 얻은 신경세포를 활용하여 연구할 수 있게 됨으로써, 보다 복합적인 신경약리학적 기초연구도 가능하게 되었다. 특히 최근 인간 배아줄기세포 유래 신경계세포도 유사한 신경독성 반응을 보이고 있음이 확인됨으로써(Schrattenholz & Klemm, 2007), 이제 배아줄기세포는 신경약리학적 기초 연구만이 아닌, 나아가 대량의 약물 스크리닝과 같은 제약산업에도 활용될 수 있는 가능성을 제시하고 있다.

• 대한본초학회지
• /
• 제36권6호
• /
• pp.1-8
• /
• 2021

Objectives : Atractylodis rhizoma Alba has been traditionally used as a medicinal resource that is used for enhancing Qi (氣) in traditional medicine in Korea, China, and Japan. This study investigated the protective effects of Atractylodis rhizoma Alba extract (ARE) against trimethyltin (TMT), a neurotoxin that causes selective hippocampal injury, using both in vitro and in vivo models. Methods : We investigated the effects of ARE on TMT- (5mM) induced cytotoxicity in primary cultures of mouse hippocampal cells (7 days in vitro ) and on hippocampal injury in C57BL/6 mice injected with TMT (2.6 mg/kg). Results : We observed that ARE treatment (0 - 50 ㎍/mL) significantly reduced TMT-induced cytotoxicity in cultured hippocampal neurons in a dose-dependent manner, based on results of lactate dehydrogenase and 3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assays. Additionally, this study showed that orally administered ARE (5 mg/kg; between -6 and 0 days before TMT injection) significantly attenuated seizures in adult mice. Furthermore, quantitative analysis of allograft inflammatory factor-1 (Iba-1)- and glial fibrillary acidic protein (GFAP)- positive cells showed significantly reduced levels of Iba-1- and GFAP-positive cell bodies in the dentate gyrus of mice treated with ARE prior to TMT injection. These findings indicate the significant protective effects of ARE against the TMT-induced massive activation of microglia and astrocytes in the hippocampus. Conclusions : We conclude that ARE minimizes the detrimental effects of TMT-induced hippocampal neurotoxicity, both in vitro and in vivo . Our findings may serve as useful guidelines to support ARE administration as a promising pharmacotherapeutic approach to hippocampal degeneration.