• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.743-746
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• 2003

The major pathological lesion in Parkinson's disease(PD) is selective degeneration and loss of pigmented dopaminergic neurons in substantia nigra (SN). Although the initial cause and subsequent molecular signaling mechanisms leading to the dopaminergic cell death underlying the PD process is elusive, the potent neurotrophic factors (NTFs), brain derived neurotrophic factor (BDNF) and glial cell line derived neurotrophic factor (GDNF), are known to exert dopaminergic neuroprotection both in vivo and in vitro models of PD employing the neurotoxin, MPTP. BDNF and its receptor, trkB are expressed in SN dopaminergic neurons and their innervation target. Thus, neurotrophins may have autocrine, paracrine and retrograde transport effects on the SN dopaminergic neurons. This study determined the BDNF secretion from SN dopaminergic neurons by ELISA. Regulation of BDNF synthesis/release and changes in signaling pathways are monitored in the presence of free radical donor, NO donor and mitochondrial inhibitors. Also, this study shows that BDNF is able to promote survival and phenotypic differentiation of SN dopaminergic neurons in culture and protect them against MPTP-induced neurotoxicity via MAP kinase pathway.

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.283-297
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• 2000

Seeds are an ideal repository for recombinant proteins in molecular farming applications. However, in order to use plant seeds efficiently for the production of such proteins, it is necessary to understand a number of fundamental biological properties of seeds. This includes a full understanding of promoters which function in a seed-specific manner, the subcellular targeting of the desired polypeptide and the final form in which a protein is stored. Once a biologically active protein has been deposited in a seed, it is also critical that the protein can be extracted and purified efficiently. In this review, these issues are examined critically to provide a number of approaches which may be adopted for production of recombinant proteins in plants. Particular attention is paid to the relationship between subcellular localization and protein extraction and purification. The robustness and flexibility of seed-based production is illustrated by examples close to or already in commercial production.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.339-345
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• 2020

Euchrestaflavanone A (EFA) is a flavonoid found in the root bark of Cudrania tricuspidata. C. tricuspidata extract, widely used throughout Asia in traditional medicine, has been investigated phytochemically and biologically and is known to have anti-obesity, anti-inflammatory, and anti-tumor effects. It has been reported that C. tricuspidata extract also possesses anti-platelet effects; however, the mechanism of its anti-platelet and anti-thrombotic activities is yet to be elucidated. In this study, we investigated the effects of EFA on the modulation of platelet function using collagen-induced human platelets. Our results showed that EFA markedly inhibited platelet aggregation. Furthermore, it downregulated glycoprotein IIb/IIIa (αIIb/β3)-mediated signaling events, including platelet adhesion, granule secretion, thromboxane A2 production, and clot retraction, but upregulated the cyclic adenosine monophosphate-dependent pathway. Taken together, EFA possesses strong anti-platelet and anti-thrombotic properties and is a potential therapeutic drug candidate to prevent platelet-related thrombosis and cardiovascular disease.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.73-73
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• 2020

Toona sinensis (TS) leaf is known to antinociceptive, antioxidative stress and skin moisturizing effects. Acnes vulgaris is a chronic skin disease with various symptoms including itchiness, pain and interruption of normal skin function. Propionibacterium acnes (P. acnes) is a major factor in the occurrence of inflammatory acnes. This study evaluated the antioxidant and anti-inflammation effects by TS extract from adventitious shoots. TS extract showed anti-inflammatory activities by suppression of pro-inflammation mediators (iNOS and COX-2) in LPS-stimulated RAW264.7 cells. TS extract also has anti-inflammatory activities by inhibiting the secretion of pro-inflammatory cytokines on P. acnes-stimulated HaCaT cells. These effects were regulated by MAPK signaling pathway. Therefore, we suggest that TS extract from adventitious shoots might have applications as a medicine for treating P. acnes-induced skin diseases.

• International Journal of Oral Biology
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• v.49 no.2
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• pp.27-33
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• 2024

Diabetes, a chronic hyperglycemic condition, is caused by insufficient insulin secretion or functional impairment. Long-term inadequate regulation of blood glucose levels or hyperglycemia can lead to various complications, such as retinopathy, nephropathy, and cardiovascular disease. Recent studies have explored the molecular mechanisms linking diabetes to bone loss and an increased susceptibility to fractures. This study reviews the characteristics and molecular mechanisms of diabetes-induced bone disease. Depending on the type of diabetes, changes in bone tissue vary. The molecular mechanisms responsible for bone loss in diabetes include the accumulation of advanced glycation end products (AGEs), upregulation of inflammatory cytokines, induction of oxidative stress, and deficiencies in insulin/IGF-1. In diabetes, alveolar bone loss results from complex interactions involving oral bacterial infections, host responses, and hyperglycemic stress in periodontal tissues. Therapeutic strategies for diabetes-induced bone loss may include blocking the AGEs signaling pathway, decreasing inflammatory cytokine activity, inhibiting reactive oxygen species generation and activity, and controlling glucose levels; however, further research is warranted.

• Journal of Life Science
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• v.21 no.5
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• pp.664-670
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• 2011

Oxidative stress results in sustained release of heat shock protein 90 (HSP90) from vascular smooth muscle cells (VSMCs). We investigated whether extracellular HSP90 predisposed VSMCs to pro-inflammatory phenotype. Exposure of human aortic smooth muscle cells to HSP90 not only significantly enhanced CXCL10 secretion but also increased CXCL10 transcription. HSP90-mediated CXCL10 secretion was attenuated by OxPAPC, a TLR-2/4 inhibitor, and curcumin, a TLR-4 dimerization inhibitor. Inhibitors of diphenyleneiodium chloride and the Akt pathway also attenuated CXCL10 secretion in response to HSP90. The gene delivery of I${\kappa}$B using recombinant adenoviruses and treatment with resveratrol, which inhibit NF-${\kappa}$B activity, significantly attenuated HSP90-induced CXCL10 secretion from VSMCs. We propose that extracellular HSP90 contributes to an inflammatory reaction in the stressed vasculature by inducing CXCL10 expression of VSMCs, and that TLR-4, Akt, and NF-${\kappa}$B play active roles in the process.

• The Korean Journal of Pharmacology
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• v.31 no.3
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• pp.355-363
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• 1995

It has been well known that the intracellular calcium concentration $([Ca^{2+}]_i)$ in living cell is very sensitive to live or to survive, but the transmembrane system of calcium ion, especially mechanism of calcium ion movement in unexcitable state has been little elucidated. Though many proposed theories for calcium ion transport have been reported, it is still unclear that how could the sustained maintenance in cytosolic calcium level be done in cell. Since one of possible mechanisms of calcium transport may be related to the acetylcholine receptor-linked calcium channel, author performed experiment to elucidate this mechanism of calcium influx related to cholinergic receptor in ml muscarinic receptor-transfected RBL-2H3 cell-line. 1) The effects of carbachol both on calcium ion influx and on the secretion of hexosaminidase were respectively observed in the manner of time-related or concentration-dependent pattern in this model. 2) The effects of several metal cations on calcium transport were shown in carbachol-induced cell-line. 3) Atropine was administered to examine the relationship between cholinergic receptor and calcium ion influx in this model. 4) PMA (Phorbol 12-myristate 13-acetate) or PTx (Pertussis toxin) was respectively administered to examine the secondary mediator which involved pathway of calcium ion movement in carbachol-induced cell-line. The results of this experiments were as follows; 1) Carbachol significantly stimulated both the calcium influx and the secretion of hexosaminidase in the manner of the concentration-dependent pattern. 2) Atropine potently blocked the effects of carbachol in concentration-response manner. 3) Administered metal cations inhibited the calcium influx in carbachol-stimulated this model to the concentration-related pattern. 4) PMA did not inhibit carbachol-induced secretion of hexosaminidase, but blocked the calcium influx in this cell-line. 5) The suppression of carbachol-induced hexosaminidase secretion was shown in PTx-treated cell -line.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.9-14
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• 2016

Adenosine 3',5'-cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the $Na^+-K^+$-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain ($3.0{\mu}mol/L$) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabain-increased atrial dynamics was blocked by KB-R7943 ($3.0{\mu}mol/L$), an inhibitor for reverse mode of $Na^+-Ca^{2+}$ exchangers (NCX), but did not by L-type $Ca^{2+}$ channel blocker nifedipine ($1.0{\mu}mol/L$) or protein kinase A (PKA) selective inhibitor H-89 ($3.0{\mu}mol/L$). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline ($100.0{\mu}mol/L$), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP ($0.5{\mu}mol/L$) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 ($30{\mu}mol/L$), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.

• Biomolecules & Therapeutics
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• v.19 no.3
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• pp.348-356
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• 2011

Liriope platyphylla is a medical herb that has long been used in Korea and China to treat cough, sputum, neurodigenerative disorders, obesity and diabetes. The aims of this study were to study the antidiabetic effects of the aqueous extract of L. platyphylla (AEtLP) through pancreatic and extrapancreatic actions. AEtLP were orally administrated to ICR mice once a day for 7 days. Of three different concentrations of AEtLP, only 10% AEtLP were low toxic to liver, based on body weight and serum biochemical analyses. However, 10% AEtLP-treated mice displayed signifi cant reduction of the glucose concentration and increased insulin concentration; no changes were noted using 5% and 15% AEtLP. Also, the increase of glucose transporter (Glut)-1 expression in liver was dependent on the concentration of AEtLP, and was regulated by the phosphorylation of Akt. The lowest expression of Glut-3 was observed in 15% AEtLP treated mice, followed by 10% AEtLP- and 5% AEtLP-treated mice. This pattern of Glut-3 expression was roughly in accord with the phosphorylation of c-Jun N-teminal kinase (JNK) in the mitogen-activated protein kinase (MAPK) pathway. Furthermore, a signifi cant rise of the superoxide dismutase activity (SOD) was detected in AEtLP-treated mice. The fi ndings suggest that AEtLP should be considered as a diabetes therapeutic candidate to induce insulin secretion from pancreatic ${\beta}$-cells and glucose uptake in liver cells.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.2
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• pp.141-149
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• 2015

"G protein-coupled receptor 40" (GPR40), a receptor for long-chain fatty acids, mediates the stimulation of glucose-induced insulin secretion. We examined the profiles of differential gene expression in GPR40-activated cells treated with linoleic acid, and finally predicted the integral pathways of the cellular mechanism of GPR40-mediated insulinotropic effects. After constructing a GPR40-overexpressing stable cell line (RIN-40) from the rat pancreatic ${\beta}$-cell line RIN-5f, we determined the gene expression profiles of RIN-5f and RIN-40. In total, 1004 genes, the expression of which was altered at least twofold, were selected in RIN-5f versus RIN-40. Moreover, the differential genetic profiles were investigated in RIN-40 cells treated with $30{\mu}M$ linoleic acid, which resulted in selection of 93 genes in RIN-40 versus RIN-40 treated with linoleic acid. Based on the Kyoto Encyclopedia of Genes and Genomes Pathway (KEGG, http://www.genome.jp/kegg/), sets of genes induced differentially by treatment with linoleic acid in RIN-40 cells were found to be related to mitogen-activated protein (MAP) kinase- and neuroactive ligand-receptor interaction pathways. A gene ontology (GO) study revealed that more than 30% of the genes were associated with signal transduction and cell proliferation. Thus, this study elucidated a gene expression pattern relevant to the signal pathways that are regulated by GPR40 activation during the acute period. Together, these findings increase our mechanistic understanding of endogenous molecules associated with GPR40 function, and provide information useful for identification of a target for the management of type 2 diabetes mellitus.