• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2023년도 임시총회 및 춘계학술대회
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• pp.45-45
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• 2023

Autophagy contributes to enhancing the immune system (innate and adaptive immune system) against foreign pathogens. Autophagy of macrophages is used as a major indicator for developing vaccine adjuvants to increase the adaptive immune response. In this study, RAL increased the production of immunostimulatory mediators and phagocytotic activity in RAW264.7 cells. RAL increased p62/SQSTM1 expression. Inhibition of TLR4, JNK, and PI3K/AKT blocked RAL-mediated increase of p62/SQSTM1. RAL activated JNK and PI3K/AKT signaling. RAL-mediated activation of JNK and PI3K/AKT signaling was reversed by TLR4 inhibition. Taken together, it is believed that RAL-mediated autophagy may be dependent on activating via TLR4-dependent activation of JNK and PI3K/AKT signaling in macrophages.

• 한국환경성돌연변이발암원학회지
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• 제24권2호
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• pp.51-66
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• 2004

Retinoids, better known as vitamin A, have been reported to inhibit the growth of several breast cancer cell lines in culture and to reduce breast tumor growth in animal models. Furthermore, retinoids can augment the action of other breast cancer cell growth inhibitors both in vitro and in vivo. Clinically, interest has increased in the potential use of retinoids for the prevention and treatment of human breast cancer. We have examine the effect of all-trans retinoic acid(tRA) and 9-cis retinoic acid(9-cis RA) on human breast cancer cell(MCF-10A, T47-D, MCF-7) proliferation using MTT assay and cell cycle analysis(FACS). Overexpression of cyclin D1 protein is observed in the majority of breast cancers, suggesting that dysregulated expression of cyclin D1 might be a critical event in breast cancer carcinogenesis. We investigated whether tRA and 9-cis RA might affect expression of cyclin D1 on human breast cancer cells(MCF-10A, T47-D, MCF-7) using RT-PCR and west-ern bolt. In MCF-10A cells, either tRA or 9-cis RA treatment did not affect the cell proliferation. In T47-D cells and MCF-7 cells, either tRA or 9-cis RA treatment showed the inhibition of the cell proliferation over control cells and also inhibit the estrogen stimulated cell proliferation when it was given together with estrogen. The effect of retinoids was dose- and time- dependent. T47-D cells treated with 1.0 $\muM$ tRA undergo G0/G1-phase arrest by Day 5. MCF-7 cells treated with 1.0 $\muM$ tRA undergo S-phase arrest by Day 5. All-trans retinoic acid(tRA) and 9-cis retinoic acid(9-cis RA) inhibited the cyelin D1 mRNA and protein expression levels of human MCF-7 and T47-D breast carcinoma cells in vitro. The data indicate that retinoids can reduce cyclin D1 expression levels in a variety of breast cell lines in vitro and result in inhibition of cell proliferation. tRA-mediated growth inhibition and cyclin D1 expression inhibition is more potent than 9-cis RA mediated that. tRA-mediated inhibition effect is more potent on T47-D cells than on MCF-7 cells. Our data suggest that retinoids activity is different according to property of cell lines. Future chemoprevention of breast cancer studies using retinoids will be necessary to determine the mechanism of the retinoids-mediated growth inhibition.

• The Korean Journal of Physiology and Pharmacology
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• 제27권1호
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• pp.21-29
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• 2023

The poor outcome of advanced ovarian cancer under conventional therapy necessitates new strategies to improve therapeutic efficacy. β-glucosidase (encoded by GBA) is a lysosomal enzyme and is involved in sphingolipids metabolism. Recent studies revealed that β-glucosidase plays a role in cancer development and chemoresistance. In this work, we systematically evaluated the expression and role of GBA in ovarian cancer. Our work demonstrates that inhibition of β-glucosidase has therapeutic potential for ovarian cancer. Gene Expression Profiling Interactive Analysis database, western blot and immunohistochemistry analyses of patient samples demonstrated that GBA mRNA and protein expression levels were significantly increased in ovarian cancer compared to normal tissues. Functional studies using gainof-function and loss-of-function approaches demonstrated that GBA overexpression did not affect growth and migration but alleviated cisplatin's efficacy in ovarian cancer cells. In addition, GBA depletion resulted in growth inhibition, apoptosis induction, and enhancement of cisplatin's efficacy. Of note, we found that GBA inhibition specifically decreased receptor tyrosine kinase AXL level, leading to the suppression of AXL-mediated signaling pathways. Our data suggest that GBA represents a promising target to inhibit AXL signaling and overcome cisplatin resistance in ovarian cancer.

• Journal of Photoscience
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• 제6권4호
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• pp.187-191
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• 1999

Using fluorescent probe fura-2 acetoxymethyl ester, we studied effects of N-Methyl-D-aspartate (NMDA) on free intracellular $Ca^{2+}$ concentration ([$Ca^{2+}$]$_{i}$) and interaction of ethanol with NMDA-mediated response in freshly dissociated brain cells from newborn rats. Twenty five micromolar NMDA significantly increased ($Ca^{2+}$), and this increasing effect could be prevented or reversed by the NMDA antagonists $Mg^{2}$(1.0 mM) and 2-amino-5-phosphonovalerate (AP5, 100 ${\mu}$M). Ethanol at concentrations from 2.5 to 100 mM inhibited NMDA-mediated calcium current in a concentration-dependent manner. Maximal inhibition of NMDA-mediated calcium current by ethanol was 82% at 50 mM. The ethanol inhibition at 100 mM was not significantly different from the inhibition at 50 mM.

• Journal of Microbiology and Biotechnology
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• 제29권1호
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• pp.151-159
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• 2019

Lipoteichoic acid isolated from Lactobacillus plantarum K8 (pLTA) alleviates lipopolysaccharide (LPS)-induced excessive inflammation through inhibition of $TNF-{\alpha}$ and interleukin (IL)-6. In addition, pLTA increases the survival rate of mice in a septic shock model. In the current study, we have found that pLTA contributes to homeostasis through regulation of pro- and anti-inflammatory cytokine production. In detail, pLTA decreased the production of IL-10 by phorbol-12-myristate-13-acetate (PMA)-differentiated THP-1 cells stimulated with prostaglandin E2 (PGE-2) and LPS. However, $TNF-{\alpha}$ production which was inhibited by PGE-2+LPS increased by pLTA treatment. The regulatory effects of IL-10 and $TNF-{\alpha}$ induced by PGE-2 and LPS in PMA-differentiated THP-1 cells were mediated by pLTA, but not by other LTAs isolated from either Staphylococcus aureus (aLTA) or L. sakei (sLTA). Further studies revealed that pLTA-mediated IL-10 inhibition and $TNF-{\alpha}$ induction in PGE-2+LPS-stimulated PMA-differentiated THP-1 cells were mediated by dephosphorylation of p38 and phosphorylation of c-Jun N-terminal kinase (JNK), respectively. Reduction of pLTA-mediated IL-10 inhibited the metastasis of breast cancer cells (MDA-MB-231), which was induced by IL-10 or conditioned media prepared from PGE-2+LPS-stimulated PMA-differentiated THP-1 cells. Taken together, our data suggest that pLTA contributes to inflammatory homeostasis through induction of repressed pro-inflammatory cytokines as well as inhibition of excessive anti-inflammatory cytokines.

• Journal of Microbiology and Biotechnology
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• 제32권4호
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• pp.493-503
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• 2022

Forkhead transcription factor 3a (Foxo3a) is believed to be a tumor suppressor as its inactivation leads to cell transformation and tumor development. However, further investigation is required regarding the involvement of the activating transcription factor 3 (ATF3)-mediated Tat-interactive protein 60 (Tip60)/Foxo3a pathway in cancer cell apoptosis. This study demonstrated that Chelidonium majus upregulated the expression of ATF3 and Tip60 and promoted Foxo3a nuclear translocation, ultimately increasing the level of Bcl-2-associated X protein (Bax) protein. ATF3 overexpression stimulated Tip60 expression, while ATF3 inhibition by siRNA repressed Tip60 expression. Furthermore, siRNA-mediated Tip60 inhibition significantly promoted Foxo3a phosphorylation, leading to blockade of Foxo3a translocation into the nucleus. Thus, we were able to deduce that ATF3 mediates the regulation of Foxo3a by Tip60. Moreover, siRNA-mediated Foxo3a inhibition suppressed the expression of Bax and subsequent apoptosis. Taken together, our data demonstrate that Chelidonium majus induces SKOV-3 cell death by increasing ATF3 levels and its downstream proteins Tip60 and Foxo3a. This suggests a potential therapeutic role of Chelidonium majus against ovarian cancer.

• Molecules and Cells
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• 제46권8호
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• pp.496-512
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• 2023

A fructose-enriched diet is thought to contribute to hepatic injury in developing non-alcoholic steatohepatitis (NASH). However, the cellular mechanism of fructose-induced hepatic damage remains poorly understood. This study aimed to determine whether fructose induces cell death in primary hepatocytes, and if so, to establish the underlying cellular mechanisms. Our results revealed that treatment with high fructose concentrations for 48 h induced mitochondria-mediated apoptotic death in mouse primary hepatocytes (MPHs). Endoplasmic reticulum stress responses were involved in fructose-induced death as the levels of phosho-eIF2α, phospho-C-Jun-N-terminal kinase (JNK), and C/EBP homologous protein (CHOP) increased, and a chemical chaperone tauroursodeoxycholic acid (TUDCA) prevented cell death. The impaired oxidation metabolism of fatty acids was also possibly involved in the fructose-induced toxicity as treatment with an AMP-activated kinase (AMPK) activator and a PPAR-α agonist significantly protected against fructose-induced death, while carnitine palmitoyl transferase I inhibitor exacerbated the toxicity. However, uric acid-mediated toxicity was not involved in fructose-induced death as uric acid was not toxic to MPHs, and the inhibition of xanthine oxidase (a key enzyme in uric acid synthesis) did not affect cell death. On the other hand, treatment with inhibitors of the nicotinamide adenine dinucleotide (NAD)⁺-consuming enzyme CD38 or CD38 gene knockdown significantly protected against fructose-induced toxicity in MPHs, and fructose treatment increased CD38 levels. These data suggest that CD38 upregulation plays a role in hepatic injury in the fructose-enriched diet-mediated NASH. Thus, CD38 inhibition may be a promising therapeutic strategy to prevent fructose-enriched diet-mediated NASH.

• 대한약리학회지
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• 제29권2호
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• pp.245-252
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• 1993

Amiloride는 $Na{^+}$ channels를 선택적으로 억제하는 potassium sparing diuretic이다. 본 연구에서는 amiloride와 아데노신 수용체의 상호작용을 밝히고자, 흰쥐에서 얻은 crude adipocytic membrane fractions의 adenylyl cyclase activity를 여러 조건하에서 측정하였다. 우선 GTP가 isoproterenol-stimulated adenylyl cyclase activity에 미치는 영향을 조사함으로서 $G_i$ protein (inhibitory guanine nucleotide binding protein)의 기능을 알아보았다. 그 결과 amiloride는 높은 GTP 농도에서 isoproterenol-stimulated adenylyl cyclase의 활성을 억제하는 것을 관찰할 수 없었다. 이와는 대조적으로 amiloride 존재 하에서 2-chloroadenosine을 사용하여 아데노신 수용체를 경유한 isoproterenol-stimulated adenylyl cyclase activity가 억제되는 정도를 측정하였을 때, 2-chloroadenosine의 농도에 따라 큰 변화 없거나 오히려 억제 효과가 더욱 크게 나타났다. 그러나 위와 같은 조건하에서 propranolol에 의한 isoproterenol-stimulated adenylyl cyclase activity의 억제는 amiloride에 의해서 유의하게 변하지 않는 것으로 보아서, 수용체를 매개로 한 $G_s$ protein의 기능은 amiloride에 의해 영향을 받지 않는 것으로 생각된다. 그리고 amiloride에 의해 증가된, 2-chloroadenosine-mediated adenylyl cyclase의 억제 효과는 150mM NaCl 존재 하에서도 그대로 유지되었다. 이러한 결과로 보아 amiloride는 아데노신 수용체와 결합하여 $G_i$ proteins과의 coupling을 용이하게 할 뿐만 아니라, $G_i$ protein을 선택적으로 변화시켜 $G_i$ protein의 GTP 의존적인 adenylyl cyclase의 억제 기능을 제거하는 두 작용을 갖는 것으로 사료된다.

• 대한한의학회지
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• 제23권2호
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• pp.57-69
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• 2002

Objective: The aim of this study is to investigate the effect of Injin butanol fractions with Thin Layer Chromatography on Fas-mediated Apoptosis. Method: Injin-butanol fraction separated by TLC. MIT assay, cell cycle analysis, Caspase-3 protease assay, DNA fragmentation assay and quantitative RT-PCR were performed to evaluate the effects of TLC extraction of lnjin-butanol fraction on cell viability, cell cycle progression and apoptosis. Results: Scopoletin, luteolin, apigenin and unknown powder was isolated by TLC. Fas-mediated apoptosis analysis shows that scopoletin has inhibiting function on apoptosis. Caspase- 3 protease assay analysis shows that scopoletin inhibits activity of caspase-3. Quantitative RT-PCR analysis shows that no activity on caspase-3, but apoptosis inhibition cytokine -Bcl-2- is activated, and apoptosis activating cytokine -Bax- is unactivated. Conclusion: These results show that each fraction of Injin-butanol TLC extraction, especially scopoletin, acts as a protective function on liver cell viability, and inhibitory function on apoptosis. (J Korean Oriental Moo 2002;23(2):57-69)

• The Korean Journal of Physiology and Pharmacology
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• 제6권2호
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• pp.63-70
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• 2002

Cholinergic modulation of GABAergic spontaneous miniature inhibitory postsynaptic currents (mIPSCs) by the activation of muscarine receptors was investigated in mechanically dissociated rat nucleus basalis of the Meynert neurons using the conventional whole-cell patch recording configuration. Muscarine $(10{\mu}M)$ reversibly and concentration-dependently decreased mIPSC frequency without affecting the current amplitude distribution. Muscarine action on GABAergic mIPSCs was completely blocked by $1{\mu}M$ methoctramine, a selective $M_2$ receptor antagonist, but not by $1{\mu}M$ pirenzepine, a selective $M_1$ receptor antagonist. NEM $(10{\mu}M),$ a G-protein uncoupler, attenuated the inhibitory action of muscarine on GABAergic mIPSC frequency. Muscarine still could decrease GABAergic mIPSC frequency even in the $Ca^{2+}-free$ external solution. However, the inhibitory action of muscarine on GABAergic mIPSCs was completely occluded in the presence of forskolin. The results suggest that muscarine acts presynaptically and reduces the probability of spontaneous GABA release, and that such muscarine-induced inhibitory action seems to be mediated by G-protein-coupled $M_2$ receptors, via the reduction of cAMP production. Accordingly, $M_2$ receptor-mediated disinhibition of nBM neurons might play one of important roles in the regulation of cholinergic outputs from nBM neurons as well as the excitability of nBM neurons themselves.