• BMB Reports
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• 제38권3호
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• pp.314-319
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• 2005

Adenosine, as a ubiquitous metabolite, mediates many physiological functions via activation of plasma membrane receptors. Mechanisms of most of its physiological roles have been studied extensively, but research on adenosine-induced apoptosis (AIA) has only started recently. In this study we demonstrate that adenosine dose-dependently triggered apoptosis of cultured baby hamster kidney (BHK) cells. Adenosine-induced apoptotic cell death was characterized by DNA laddering, changes in nuclear chromatin morphology and phosphatidylserine staining. Apoptosis was also quantified by flow cytometry. Results suggest the involvement of adenosine $A_1$ and $A_3$ receptors as well as equilibrative nucleoside transporters in apoptosis induced by adenosine. These results indicate a receptor-transporter co-signaling mechanism in AIA in BHK cells. The involvement of $A_1$ and $A_3$ receptors also implies a possible apoptotic pathway mediated by G protein-coupled receptors.

• Journal of Ginseng Research
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• 제39권1호
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• pp.69-75
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• 2015

Background: Ginseng has been shown to exert antistress effects both in vitro and in vivo. However, the effects of ginseng on stress in brain cells are not well understood. This study investigated how Korean Red Ginseng (KRG) controls hydrogen peroxide-induced apoptosis via regulation of phosphatidylinositol-3 kinase (PI3K)/Akt and estrogen receptor (ER)-${\beta}$ signaling. Methods: Human neuroblastoma SK-N-SH cells were pretreated with KRG and subsequently exposed to $H_2O_2$. The ability of KRG to inhibit oxidative stress-induced apoptosis was assessed in MTT cytotoxicity assays. Apoptotic protein expression was examined byWestern blot analysis. The roles of ER-${\beta}$, PI3K, and p-Akt signaling in KRG regulation of apoptosis were studied using small interfering RNAs and/or target antagonists. Results: Pretreating SK-N-SH cells with KRG decreased expression of the proapoptotic proteins p-p53 and caspase-3, but increased expression of the antiapoptotic protein BCL2. KRG pretreatment was also associated with increased ER-${\beta}$, PI3K, and p-Akt expression. Conversely, ER-${\beta}$ inhibition with small interfering RNA or inhibitor treatment increased p-p53 and caspase-3 levels, but decreased BCL2, PI3K, and p-Akt expression. Moreover, inhibition of PI3K/Akt signaling diminished p-p53 and caspase-3 levels, but increased BCL2 expression. Conclusion: Collectively, the data indicate that KRG represses oxidative stress-induced apoptosis by enhancing PI3K/Akt signaling via upregulation of ER-${\beta}$ expression.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2005년도 제48차 춘계 학술대회
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• pp.111-111
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• 2005

• 한국식품영양과학회지
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• 제45권12호
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• pp.1708-1716
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• 2016

Akt 및 mTOR는 세포 생존에 필수적인 경로로 세포 성장과 증식 등에서 중요한 역할을 하는 것으로 알려져 있다. 본 연구에서는 항암 및 항균 효과가 있는 것으로 알려진 개똥쑥(Artemisia annua L.)에 의한 HepG2 간암세포의 apoptosis 유도 효과를 확인하였다. 본 연구 결과에 의하면 개똥쑥 추출물의 처리 농도가 증가함에 따라 HepG2 세포의 생존율은 억제되었으며, 이는 apoptosis 유도 효과에 의한 것임을 세포의 형태적 변화와 flow cytometry를 통해 확인하였다. 그리고 mitopotential assay와 caspase-3/7 activity assay, western blotting으로 Bcl-2 family 단백질을 확인함으로써 apoptosis 경로 중 내인성 경로(intrinsic pathway)에 의해 apoptosis가 일어남을 알 수 있었다. 이러한 효과는 Akt/mTOR의 활성 저해와 연관이 있었으며 Akt/mTOR의 저해제인 LY294002/rapamycin을 개똥쑥 추출물과 병행처리하였을 경우 개똥쑥 추출물에 의한 apoptosis 효과를 더욱 증대시켰다. 따라서 Akt/mTOR의 저해는 개똥쑥 추출물의 apoptosis 효과를 상승시켰으며 이에 따라 미토콘드리아의 기능 손상과 caspase 활성의 증가를 통해 이루어짐을 확인하였다.

• 생명과학회지
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• 제25권11호
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• pp.1255-1264
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• 2015

천궁(C. officinale)은 예로부터 민간처방 약재로 사용되었으며, 항염증, 항산화, 항암 및 신생혈관억제 등의 효능을 가지는 것으로 알려져 있다. 하지만 혈구암세포에서 apoptosis 유발과 관련된 분자생물학적 기전에 대해서는 명확히 밝혀져 있지 않다. 본 연구에서는 인체 혈구암세포인 U937 세포에서 천궁의 열수, 에탄올 및 메탄올 추출물(WECO, EECO 및 MECO)이 유발하는 항암효과 및 항암기전을 조사하였다. 먼저 WECO, EECO 및 MECO가 유발하는 증식억제 정도를 조사한 결과 EECO가 가장 뛰어난 효능을 가진다는 것을 알 수 있었으며, 이러한 현상이 apoptosis 유발에 의한 것임을 annexin-V 염색, apoptotic body 형성, DNA 단편화 및 MMP 소실 등을 통하여 확인하였다. EECO 처리에 의한 apoptosis 유발에는 DR4의 발현 증가와 함께 cIAP-1, Bcl-2 및 total Bid의 발현감소가 관여하였으며, caspases-3, -8 및 -9의 활성화와 함께 caspases-3의 기질 단백질인 PARP, β-catenin 및 PLC γ1의 단편화도 관찰되었다. 또한 EECO는 AMPK signaling pathway를 활성화시키는 것으로 나타났으며, AMPK 억제제인 compound C를 이용하여 AMPK의 활성을 억제하였을 경우 EECO에 의하여 유발되었던 apoptosis가 현저하게 감소되는 것으로 나타났다. 이상의 결과를 살펴볼 때 인체 혈구암세포인 U937 세포에서 EECO에 의하여 유발되는 apoptosis는 AMPK가 중요한 조절자로서 작용하는 것으로 생각된다.

• 생명과학회지
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• 제23권7호
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• pp.926-932
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• 2013

글루타민과 혈청은 세포의 생존과 증식에 기본적으로 요구되지만, 그들의 양적 변화에 따른 내피세포 반응에 관한 신호전달 관련 연구는 거의 이루어지지 않았다. 본 연구에서는 인체 재대정맥 내피세포(human umbilical vein endothelial cells, HUVECs)의 증식에 미치는 글루타민과 혈청의 결핍에 관한 영향을 조사하였다. 본 연구의 결과에 의하면 글루타민 및 혈청이 결핍된 조건에서 배양된 HUVECs의 증식 억제는 apoptosis 유발과 연관성이 있었음을 DAPI staining에 의한 핵의 형태 변화와 유세포 분석을 통하여 확인하였다. 비록 혈청이 결핍된 조건보다 글루타민 결핍에 의한 apoptosis 유발 정도가 더 높게 나타났으나, 두 현상에 의한 apoptosis의 유발은 anti-apoptotic Bcl-2 및 Bcl-xL의 발현 저하와 pro-apoptotic Bax의 발현 증가, IAP family 단백질의 발현 감소, caspase의 활성 증가에 따른 PARP 단백질의 단편화와 연관성이 있었다. 또한 이러한 조건에서 HUVECs의 Bid 발현의 감소 또는 tBid 발현의 증가 현상이 관찰되어, 글루타민 또는 혈청 결핍에 의한 HUVECs의 apoptosis 유발은 세포막 수용체 및 미토콘드리아 활성 경로를 동시에 통하여 이루어지고 있음을 알 수 있었다. 그러나 글루타민과 혈청이 동시에 결핍된 조건에서 배양된 HUVECs의 증식 억제 현상은 각각의 조건에 비하여 증가되었으나 apoptosis는 유발되지 않았다.

• Natural Product Sciences
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• 제19권2호
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• pp.155-159
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• 2013

Honokiol, a naturally occurring neolignan mainly found in Magnolia species, has exhibited a potential anti-proliferative activity in human cancer cells. However, the growth inhibitory activity against hepatocellular carcinoma cells and the underlying molecular mechanisms has been poorly determined. The present study was designed to examine the anti-proliferative effect of honokiol in SK-HEP-1 human hepatocellular cancer cells. Honokiol exerted anti-proliferative activity with cell-cycle arrest at the G0/G1 phase and sequential induction of apoptotic cell death. The cell-cycle arrest was well correlated with the down-regulation of checkpoint proteins including cyclin D1, cyclin A, cyclin E, CDK4, PCNA, retinoblastoma protein (Rb), and c-Myc. The increase of sub-G1 peak by the higher concentration of honokiol ($75{\mu}M$) was closely related to the induction of apoptosis, which was evidenced by decreased expression of Bcl-2, Bid, and caspase-9. Hohokiol was also found to attenuate the activation of signaling proteins in the Akt/mTOR and ERK pathways. These findings suggest that the anti-proliferative effect of honokiol was associated in part with the induction of cell-cycle arrest, apoptosis, and dow-nregulation of Akt/mTOR signaling pathways in human hepatocellular cancer cells.

• 동의생리병리학회지
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• 제17권2호
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• pp.451-456
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• 2003

We investigated the effects of Sabaek-san (SBS) water extract on the growth of human lung carcinoma A549 cells. Upon treatment with SBS extract, a concentration-dependent inhibition of cell viability was observed and cells developed many of the hallmark features of apoptosis. including condensation of chromatin. Flow cytometry analysis confirmed that SBS treatment increased populations of apoptotic-sub G1 phase. In addition. proteolytic cleavages of poly(ADP-ribose) polymerase and β-catenin protein were observed after treatment of SBS extract. These apoptotic effects of SBS in A549 cells were associated with marked inhibition of Bcl-2 and Bel-xL mRNA in a dose-dependent manner. however the levels of Bax expression were not affected, SBS treatment also induced a proteolytic activation of caspase-3. which is believed to play a central role In the apoptotic signaling pathway. The previous and present results indicated that SBS-induced inhibition of lung cancer cell proliferation is associated with the blockage of G1/S progression and the induction of apoptosis.

• Biomolecules & Therapeutics
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• 제20권3호
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• pp.273-279
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• 2012

Hesperidin, a flavanone present in citrus fruits, has been studied as potential therapeutic agents that have anti-tumor activity and apoptotic effects in several cancers, but there is no report about the apoptotic effect of hesperidin in human malignant pleural mesothelioma through the specificity protein 1 (Sp1) protein. We investigated whether hesperidin inhibited cell growth and regulated Sp1 target proteins by suppressing the levels of Sp1 protein in MSTO-211H cells. The $IC_{50}$ value of hesperidin was determined to be 152.3 ${\mu}M$ in MSTO-211H cells for 48 h. Our results suggested that hesperidin (0-160 ${\mu}M$) decreased cell viability, and induced apoptotic cell death. Hesperidin increased Sub-$G_1$ population in MSTO-211H cells. Hesperidin significantly suppressed mRNA/protein level of Sp1 and modulated the expression level of the Sp1 regulatory protein such as p27, p21, cyclin D1, Mcl-1, and survivin in mesothelioma cells. Also, hesperidin induced apoptotic signaling including: cleavages of Bid, caspase-3, and PARP, upregulation of Bax, and down-regulation of Bcl-$_{xl}$ in mesothelioma cells. These results show that hesperidin suppressed mesothelioma cell growth through inhibition of Sp1. In this study, we demonstrated that Sp1 acts as a novel molecular target of hesperidin in human malignant pleural mesothelioma.

• Journal of Ginseng Research
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• 제42권2호
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• pp.123-132
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• 2018

Ginseng has gained its popularity as an adaptogen since ancient days because of its triterpenoid saponins, known as ginsenosides. These triterpenoid saponins are unique and classified as protopanaxatriol and protopanaxadiol saponins based on their glycosylation patterns. They play many protective roles in humans and are under intense research as various groups continue to study their efficacy at the molecular level in various disorders. Ginsenosides Rb1 and Rg1 are the most abundant ginsenosides present in ginseng roots, and they confer the pharmacological properties of the plant, whereas ginsenoside Rg3 is abundantly present in Korean Red Ginseng preparation, which is highly known for its anticancer effects. These ginsenosides have a unique mode of action in modulating various signaling cascades and networks in different tissues. Their effect depends on the bioavailability and the physiological status of the cell. Mostly they amplify the response by stimulating phosphotidylinositol-4,5-bisphosphate 3-kinase/protein kinase B pathway, caspase-3/caspase-9-mediated apoptotic pathway, adenosine monophosphate-activated protein kinase, and nuclear factor kappa-light-chain-enhancer of activated B cells signaling. Furthermore, they trigger receptors such as estrogen receptor, glucocorticoid receptor, and N-methyl-$\text\tiny{D}$-aspartate receptor. This review critically evaluates the signaling pathways attenuated by ginsenosides Rb1, Rg1, and Rg3 in various tissues with emphasis on cancer, diabetes, cardiovascular diseases, and neurodegenerative disorders.