• 한국식품영양과학회지
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• 제45권6호
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• pp.835-842
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• 2016

PI3K/Akt 신호계는 세포 생존의 조절에 필수적인 경로로 대부분 암세포에서 활성이 증대되어 있다. 본 연구에서는 동충하초의 주요 생리활성 물질인 cordycepin에 의한 AGS 인체 위암 세포의 apoptosis 유도에 미치는 PI3K/Akt 신호계의 역할을 조사하였다. 본 연구의 결과에 의하면 cordycepin의 처리 농도의 증가에 따라 AGS 세포의 생존율은 억제되었으며, 이는 apoptosis 유도와 밀접한 관계가 있음을 핵의 형태적 변화와 flow cytometry 분석을 통하여 확인 하였다. 이러한 cordycepin의 apoptosis 유도 효과는 PI3K/Akt 신호계의 활성 저하와 연관성이 있었으며, 세포독성을 나타내지 않는 범위의 PI3K/Akt 신호계 저해제인 LY294002를 cordycepin과 동시 처리하였을 경우, cordycepin에 의한 apoptosis 유발을 더욱 증대시켰다. 그리고 cordycepin에 대한 LY294002의 apoptosis 유발 증대는 caspases (caspase-3, -8 및 -9)의 활성 증가와 poly(ADP-ribose) polymerase 단백질의 분해 증가를 촉진했다. 또한 cordycepin이 처리된 AGS 세포에서 LY294002는 apoptosis 유도에 관여하는 Bax의 발현을 증가시켰고 apoptosis 억제에 관여하는 Bcl-2의 발현은 감소시켰으며, 이는 미토콘드리아 기능 손상과 미토콘드리아에서 세포질로의 cytochrome c 유리를 증대시켰다. 따라서 PI3K/Akt 신호계의 활성 차단은 cordycepin의 항암 활성을 더욱 상승시켰으며, 이는 미토콘드리아 기능 손상과 caspase의 활성 증대를 통하여 이루어짐을 알 수 있었다.

• 생명과학회지
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• 제21권1호
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• pp.89-95
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• 2011

식품에서 추출한 파이토케미컬은 여러 암종에서 암세포의 증식억제와 apoptosis를 유도한다. 최근에 이러한 파이토케미컬의 세포 내 신호전달 기작에 관한 관심이 높아지고 있으며, 본 연구에서는 파이토케미컬의 일종인 커큐민과 EGCG를 HCT116 대장암세포에 처리함으로써 암세포의 증식억제와 apoptosis 유도 효과를 알아보고, 암세포의 증식에 관여하는 Akt의 활성과 종양 억제유전자인 p53의 신호경로를 규명하고자 하였다. 그 결과, 커큐민과 EGCG를 처리했을 때 HCT116 세포의 증식이 억제되었고, 암세포에서 apoptosis 효과가 나타남을 확인하였다. 동일한 조건에서 Western blotting을 실시했을 때 Akt의 활성은 감소하였으며 p53의 발현은 증가하였다. 또한 Akt의 저해제인 LY294002를 처리했을 때 암세포의 증식이 더욱 강하게 억제되었으며, p53의 발현은 더욱 강하게 증가하는 것으로 나타났다. 따라서 HCT116 세포에서 커큐민과 EGCG 처리에 의한 암세포의 증식 억제 및 apoptosis는 p53의 발현이 증가함에 따라 유도되며, 이러한 p53의 발현 증가는 Akt 신호경로를 저해함으로써 일어난다는 것을 확인하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권4호
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• pp.1119-1124
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• 2012

Background: The effect and possible mechanism of traditional Chinese medicine, baicalin, on the PI3K/Akt signaling pathway in drug-resistant human myeloid leukemia HL-60/ADR cells have been investigated in this current study. Methods: HL-60/ADR cells were treated by 20, 40, $80\;{\mu}mol/L$ baicalin followed by cell cycle analysis at 24h. The mRNA expression level of the apoptosis related gene, Bcl-2 and bad, were measured by RT-PCR on cells treated with $80\;{\mu}mol/L$ baicalin at 12, 24 and 48hr. Western blot was performed to detect the changes in the expression of the proteins related to HL-60/ADR cell apoptosis and the signaling pathway before and after baicalin treatment, including Bcl-2, PARP, Bad, Caspase 3, Akt, p-Akt, NF-${\kappa}B$, p-NF-${\kappa}B$, mTOR and p-mTOR. Results: Sub-G1 peak of HL-60/ADR cells appeared 24 h after $20\;{\mu}mol/L$ baicalin treatment, and the ratio increased as baicalin concentration increased. Cell cycle analysis showed 44.9% G0/G1 phase cells 24 h after baicalin treatment compared to 39.6% in the control group. Cells treated with $80\;{\mu}mol/L$ baicalin displayed a trend in decreasing of Bcl-2 mRNA expression over time. Expression level of the Bcl-2 and PARP proteins decreased significantly while that of the PARP, Caspase-3, and Bad proteins gradually increased. No significant difference in Akt expression was observed between treated and the control groups. However, the expression levels of p-Akt, NF-${\kappa}B$, p-NF-${\kappa}B$, mTOR and p-mTOR decreased significantly in a time-dependent manner. Conclusions: We conclude that baicalin may induce HL-60/ADR cell apoptosis through the PI3K/AKT signaling pathway.

• 공업화학
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• 제32권6호
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• pp.647-652
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• 2021

본 연구에서는 에탄올과 노말헥산을 이용하여 당목향 뿌리 추출물을 제조하고, 인체 모유두세포의 세포증식 및 모발성장 관련 신호전달에 미치는 영향을 평가하였다. 당목향 뿌리 추출물의 세포증식 효과는 MTT assay를 실시하였으며, ERK, Akt, Wnt/𝛽-catenin 신호 경로, 5𝛼-reductase의 발현을 western blot 분석을 통해 측정하였다. 당목향 뿌리 추출물은 인체 모유두세포의 증식을 유의하게 증가시켰고, 세포증식에 관여하는 ERK와 Akt의 인산화를 촉진하였으며, 당목향 뿌리 추출물에 의해 증가된 ERK, Akt 인산화 촉진과 세포증식은 MEK/ERK 억제제 PD98059와 PI3K/Akt 억제제 LY294002에 의해 유의하게 감소되었다. 또한 당목향 뿌리 추출물은 GSK-3𝛽 (Ser9)의 인산화를 통한 𝛽-catenin(Ser552, 675)의 인산화를 촉진함으로써 핵 내의 𝛽-catenin 축적을 유도하였고, 5𝛼-reductase type I, II의 활성을 억제하였다. 종합적으로 당목향 뿌리 추출물은 모유두세포의 ERK, Akt 경로의 활성화를 통해 세포의 증식을 유도하며, 𝛽-catenin 신호 경로 활성화 및 5𝛼-reductase 활성 억제를 통해 탈모 예방 및 모발 성장 효과를 나타냄으로써 헤어케어제품의 소재로 응용가능성이 있음을 시사한다.

• The Korean Journal of Physiology and Pharmacology
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• 제21권5호
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• pp.547-554
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• 2017

Previous studies have demonstrated the role of hydroquinone (HQ), a hydroxylated benzene metabolite, in modulating various immune responses; however, its role in macrophage-mediated inflammatory responses is not fully understood. In this study, the role of HQ in inflammatory responses and the underlying molecular mechanism were explored in macrophages. HQ down-regulated the expression of interferon $(IFN)-{\beta}$ mRNA in LPS-stimulated RAW264.7 cells without any cytotoxicity and suppressed interferon regulatory factor (IRF)-3-mediated luciferase activity induced by TIR-domain-containing adapter-inducing interferon-${\beta}$ (TRIF) and TANK-binding kinase 1 (TBK1). A mechanism study revealed that HQ inhibited IRF-3 phosphorylation induced by lipopolysaccharide (LPS), TRIF, and AKT by suppressing phosphorylation of AKT, an upstream kinase of the IRF-3 signaling pathway. IRF-3 phosphorylation is highly induced by wild-type AKT and poorly induced by an AKT mutant, AKT C310A, which is mutated at an inhibitory target site of HQ. We also showed that HQ inhibited IRF-3 phosphorylation by targeting all three AKT isoforms (AKT1, AKT2, and AKT3) in RAW264.7 cells and suppressed IRF-3-mediated luciferase activities induced by AKT in HEK293 cells. Taken together, these results strongly suggest that HQ inhibits the production of a type I IFN, $IFN-{\beta}$, by targeting AKTs in the IRF-3 signaling pathway during macrophage-mediated inflammation.

• BMB Reports
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• 제44권8호
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• pp.506-511
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• 2011

Mammalian Target of Rapamycin (mTOR) is a serine/threonine kinase and that forms two multiprotein complexes known as the mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). mTOR regulates cell growth, proliferation and survival. mTORC1 is composed of the mTOR catalytic subunit and three associated proteins: raptor, mLST8/$G{\beta}L$ and PRAS40. mTORC2 contains mTOR, rictor, mLST8/$G{\beta}L$, mSin1, and protor. Here, we discuss mTOR as a promising anti-ischemic agent. It is believed that mTORC2 lies down-stream of Akt and acts as a direct activator of Akt. The different functions of mTOR can be explained by the existence of two distinct mTOR complexes containing unique interacting proteins. The loss of TSC2, which is upstream of mTOR, activates S6K1, promotes cell growth and survival, activates mTOR kinase activities, inhibits mTORC1 and mTORC2 via mTOR inhibitors, and suppresses S6K1 and Akt. Although mTOR signaling pathways are often activated in human diseases, such as cancer, mTOR signaling pathways are deactivated in ischemic diseases. From Drosophila to humans, mTOR is necessary for Ser473 phosphorylation of Akt, and the regulation of Akt-mTOR signaling pathways may have a potential role in ischemic disease. This review evaluates the potential functions of mTOR in ischemic diseases. A novel mTOR-interacting protein deregulates over-expression in ischemic disease, representing a new mechanism for controlling mTOR signaling pathways and potential therapeutic strategies for ischemic diseases.

• The Korean Journal of Physiology and Pharmacology
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• 제24권3호
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• pp.213-221
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• 2020

Salvianolic acid B (SAB) is an active phytocomponent of a popular Chinese herb called Radix Salvia militiorrhiza with numerous biological properties. The anti-psoriasis activity of SAB was examined by evaluating various psoriasis inflammatory and keratin markers against imiquimod (IMQ)-induced psoriasis on BALB/c mice. Totally 50 healthy BALB/c mice were evenly divided into 5 groups including control, drug control (SAB; 40 mg/kg), IMQ-induced psoriasis (5%), IMQ exposure and treated with SAB (40 mg/kg), or standard methotrexate (MTX; 1 mg/kg). Mice supplemented with either SAB or MTX significantly lowered the values of psoriasis area severity index (PASI), erythema, scaling, skin thickness, inflammatory markers (interleukin [IL]-22/23/17A/1β/6) and lipid peroxidation product (malondialdehyde). Also, IMQ exposed BALB/c mice treated with SAB or MTX display lesser histopathological changes with enhanced antioxidant activities (catalase, superoxide dismutase). Moreover, the protein expression of keratin markers (K16 and K17) and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signaling proteins (pAkt/Akt and pPI3K/PI3K) were significantly downregulated after administration with SAB and MTX as compared with IMQ induced mice. Taking together, SAB and MTX significantly ameliorate psoriatic changes by inhibiting psoriatic inflammatory and keratin markers through abolishing PI3K/Akt signaling pathway. However, further studies (clinical trials) are needed to confirm the anti-psoriatic property of SAB before recommending to psoriasis patients.

• IMMUNE NETWORK
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• 제11권6호
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• pp.420-423
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• 2011

Since CKD-712 has been developed as an anti-inflammatory agent, we examined the effect of CKD-712 during TLR4 signaling. Using HEK293 cells expressing TLR4, CKD-712 was pre-treated 1 hr before LPS stimulation. Activation of NF-${\kappa}B$ was assessed by promoter assay. The activation of ERK, JNK, p38, IRF3 and Akt was measured by western blotting. CKD-712 inhibited the NF-${\kappa}B$ signaling triggered by LPS. The activation of ERK, JNK, p38 or IRF3 was not inhibited by CKD-712. On the contrary the activation of these molecules was augmented slightly. The activation of Akt with stimulation of LPS was also enhanced with CKD-712 pre-treatment at lower concentration, but was inhibited at higher concentration. We suggest that during TLR4 signaling CKD-712 inhibits NF-${\kappa}B$ activation. However, CKD-712 augmented the activation of Akt as well as Map kinases. Therefore, we suggest that CKD-712 might have a role as an immunomodulator.

• The Korean Journal of Physiology and Pharmacology
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• 제27권4호
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• pp.345-356
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• 2023

This study aimed to assess the effects of exogenous hydrogen sulfide (H₂S) on abdominal aorta coarctation (AAC) induced myocardial fibrosis (MF) and autophagy in rats. Forty-four Sprague-Dawley rats were randomly divided into control group, AAC group, AAC + H₂S group, and H₂S control group. After a model of rats with AAC was built surgically, AAC + H₂S group and H₂S group were injected intraperitoneally with H₂S (100 µmol/kg) daily. The rats in the control group and the AAC group were injected with the same amount of PBS. We observed that H₂S can improve left ventricular function and the deposition of myocardial collagen fibers, inhibit pyroptosis, down-regulate the expression of P-eif2α in myocardial tissue, and inhibit cell autophagy by activating the phosphatidylinositol 3-kinase (PI3K)/AKT1 signaling pathway (p < 0.05). In addition, angiotensin II (1 µM) H9c2 cardiomyocytes were injured in vitro experiments, and it was also observed that pyroptosis was inhibited after H₂S (400 µmol/kg) intervention, the expression of P-eif2α in cardiomyocytes was significantly down-regulated, and the PI3K/AKT1 signaling pathway was activated at the same time. Therefore, increasing the expression of P-eif2α reverses the activation of the PI3K/AKT1 signaling pathway by H₂S. In conclusion, these findings suggest that exogenous H₂S can ameliorate MF in rats with AAC by inhibiting pyroptosis, and the mechanism may be associated with inhibiting the phosphorylation of eif2α and activating the PI3K/AKT1 signaling pathway to inhibit excessive cell autophagy.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 춘계학술대회
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• pp.88-88
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• 2020

Ginseng (Panax ginseng Meyer) is a very well-known traditional herbal medicine that has long been used to enhance the body's immunity. Because it is a type of ginseng, it is believed that wild simulated ginseng (WSG) also has immune-enhancing activity. However, study on the immune-enhancing activity of WSG is quite insufficient compared to ginseng. In this study, we evaluated immune-enhancing activity of WSG through macrophage activation to provide a scientific basis for the immune enhancing activity of WSG. WSG increased the production of immunomodulators such as NO, iNOS, COX-2, IL-1β, IL-6 and TNF-α and activated phagocytosis in mouse macrophages RAW264.7 cells. Inhibition of TLR2 and TLR4 reduced the production of immunomodulators induced by WSG. WSG activated MAPK, NF-κB and PI3K/AKT signaling pathways, and inhibition of such signaling activation blocked WSG-mediated production of immunomodulators. In addition, activation of MAPK, NF-κB and PI3K/AKT signaling pathways by WSG was reversed by TLR2 or TLR4 inhibition. Based on the results of this study, WSG is thought to activate macrophages through the production of immunomodulators and phagocytosis activation through TLR2/4-dependent MAPK, NF-κB and PI3K/AKT signaling pathways. Therefore, it is thought that WSG have the potential to be used as an agent for enhancing immunity.