• Journal of Microbiology and Biotechnology
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• 제34권4호
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• pp.812-827
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• 2024

Phloroglucinol (PG) is one of the abundant isomeric benzenetriols in brown algae. Due to its polyphenolic structure, PG exhibits various biological activities. However, the impact of PG on anagen signaling and oxidative stress in human dermal papilla cells (HDPCs) is unknown. In this study, we investigated the therapeutic potential of PG for improving hair loss. A non-cytotoxic concentration of PG increased anagen-inductive genes and transcriptional activities of β-Catenin. Since several anagen-inductive genes are regulated by β-Catenin, further experiments were performed to elucidate the molecular mechanism by which PG upregulates anagen signaling. Various biochemical analyses revealed that PG upregulated β-Catenin signaling without affecting the expression of Wnt. In particular, PG elevated the phosphorylation of protein kinase B (AKT), leading to an increase in the inhibitory phosphorylation of glycogen synthase kinase 3 beta (GSK3β) at serine 9. Treatment with the selective phosphoinositide 3-kinase/AKT inhibitor, LY294002, restored the increased AKT/GSK3β/β-Catenin signaling and anagen-inductive proteins induced by PG. Moreover, conditioned medium from PG-treated HDPCs promoted the proliferation and migration of human epidermal keratinocytes via the AKT signaling pathway. Subsequently, we assessed the antioxidant activities of PG. PG ameliorated the elevated oxidative stress markers and improved the decreased anagen signaling in hydrogen peroxide (H₂O₂)-induced HDPCs. The senescence-associated β-galactosidase staining assay also demonstrated that the antioxidant abilities of PG effectively mitigated H₂O₂-induced senescence. Overall, these results indicate that PG potentially enhances anagen signaling and improves oxidative stress-induced cellular damage in HDPCs. Therefore, PG can be employed as a novel therapeutic component to ameliorate hair loss symptoms.

• 생명과학회지
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• 제33권11호
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• pp.859-867
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• 2023

루페올은 5환성 트리테르펜의 일종으로 많은 질병에 치료 효과가 있는 것으로 보고되었으나, 인슐린 저항성에 미치는 영향은 명확하지 않다. 본 연구에서는 3T3-L1 지방세포에서 루페올의 IRS-1 인산화 억제능을 통해 인슐린 저항성 개선효과를 조사하였다. 3T3-L1 세포를 배양하고 TNF-α를 24시간 동안 처리하여 인슐린 저항성을 유도하였다. 서로 다른 농도의 루페올(15, 30 μM) 또는 100 nM의 rosiglitazone을 처리한 세포를 배양한 후, 용해된 세포를 이용하여 western blotting을 시행하였다. 실험결과 루페올은 지방세포에서 TNF-α에 의해 유발되는 인슐린 신호전달의 음성 조절자와 염증 활성화 단백질 kinase에 대한 개선 효과를 나타냈다. 인슐린 신호전달의 음성 조절자인 PTP-1B와 JNK의 활성 및 IKK와 염증활성화 단백질키나아제의 활성을 억제하였다. 또한, 루페올은 IRS-1의 serine 인산화는 하향 조절하고 tyrosine 인산화는 상향 조절하였다. 그 후, 하향 조절된 PI3K/AKT 경로가 활성화되고, GLUT 4의 세포막 전위가 자극되어, 결과적으로 인슐린 저항성이 유도된 3T3-L1 지방세포에서에서 세포내 포도당 흡수가 증가하였다. 본 연구결과, 루페올은 3T3-L1 지방세포에서 인슐린 신호전달 및 염증 활성화 단백질 kinsase들의 음성 조절인자를 억제하여, IRS-1의 serine 인산화를 하향 조절함으로써 TNF-α 유발 인슐린 저항성을 개선할 수 있을 것으로 사료된다.

• BMB Reports
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• 제43권2호
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• pp.127-132
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• 2010

Phosphatidylinositol (3,4,5)-triphosphate ($PIP_3$) is a lipid second messenger that employs a wide range of downstream effector proteins for the regulation of cellular processes, including cell survival, polarization and proliferation. One of the most well characterized cytoplasmic targets of $PIP_3$, serine/threonine protein kinase B (PKB)/Akt, promotes cell survival by directly interacting with nucleophosmin (NPM)/B23, the nuclear target of $PIP_3$. Here, we report that nuclear $PIP_3$ competes with Akt to preferentially bind B23 in the nucleoplasm. Mutation of Arg23 and Arg25 in the PH domain of Akt prevents binding to $PIP_3$, but does not disrupt the Akt/B23 interaction. However, treatment with phosphatases PTEN or SHIP abrogates the association between Akt and B23, indicating that nuclear $PIP_3$ regulates the Akt/B23 interaction by controlling the concentration and subcellular dynamics of these two proteins.

• 대한임상검사과학회지
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• 제55권3호
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• pp.184-194
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• 2023

골격근은 대사, 열기반 온도 조절, 그리고 전반적인 체내 균형을 위해 필수적인 조직이고 근발생(myogenesis)이라는 다단계 과정을 거쳐서 근관세포를 형성한다. p-아니스알데하이드(p-anisaldehyde, PAA) (4-메톡시벤잘데하이드)는 아니스 씨에서 추출된 에센셜 오일의 주성분이지만, 골격근에서의 기능은 아직까지 알려져 있지 않다. 따라서, 우리는 마우스 C2C12 근육모세포를 이용하여 근육분화가 PAA에 의해 영향을 받는지를 연구하였다. C2C12 근육모세포의 분화를 유도하기 위해 이 세포를 분화배지에서 5일동안 배양하였고, 매일 PAA (50 또는 200 ㎍/mL)를 포함하는 새로운 배지로 교체하였다. 대조군으로서 PAA가 포함되지 않은 배지를 사용하였다. 우리는 분화시작 후 1, 3, 5일째에 근관세포의 길이와 지름을 측정함으로써 PAA가 근관 형성에 미치는 영향을 평가하였고, quantitative real-time polymerase chain reaction 분석을 통해 PAA가 근육 표지인자(myoblast determination protein 1, myogenin, myocyte enhancer factor 2C, muscle creatine kinase, 및 myosin heavy chain)와 근육위축 관련 유전자(atrogin-1과 muscle ring finger-1 [MuRF-1])의 발현에 미치는 영향을 분석하였다. 또한, 주요 근육형성 키나아제인 protein kinase B (Akt)의 인산화를 웨스턴 블롯을 이용해 관찰하였다. 그 결과 PAA가 더 작고 얇은 근관 형성을 유의하게 유발하며 근육 표지인자의 발현을 감소시킨다는 것을 확인하였다. 또한, atrogin-1과 MuRF-1의 발현이 PAA에 의해서 감소하였는데, 이는 Akt 인산화의 감소와 일치하는 결과이다. 결론적으로, 본 연구결과는 PAA가 Akt 인산화와 활성화를 감소시킴으로써 C2C12 세포에서의 근육 분화를 억제하는 역할을 한다는 것을 증명한다.

• Journal of Applied Biological Chemistry
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• 제48권3호
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• pp.120-126
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• 2005

Endothelial nitric oxide synthase (eNOS) plays a critical role in vascular biology and pathophysiology. Its activity is regulated by multiple mechanisms such as calcium/calmodulin, protein-protein interactions, sub-cellular locations and phosphorylation at various sites. Phosphorylation of eNOS-Ser1177 (based on mouse sequence) has been identified as an important mechanism of eNOS activation. However, signaling pathway leading to it phosphorylation remains controversial. The regulation of eNOS-Ser1177 phosphorylation by Src and protein kinase A (PKA) was investigated in the present study using cultured mouse aorta endothelial cells. Expression of a constitutively active Src mutant in the cells enhanced phosphorylation of eNOS and protein kinase B (Akt). The Src-stimulated phosphorylation was not attenuated by the expression of a dominant negative PKA regulatory subunit. Neither activation nor inhibition of PKA activity had any significant effect on tyrosine phosphorylation of activation or inactivation site in Src. Based on the results of this study, it is suggested that Src/Akt pathway and PKA signaling may regulate eNOS phosphorylation independently. The existence of multiple mechanisms for eNOS phosphorylation may guarantee endothelial nitric oxide production in various cellular contexts which is essential for maintenance of vascular health.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2004년도 KSOT/KEMS Fall Annual Meeting
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• pp.115-115
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• 2004

• 생명과학회지
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• 제20권11호
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• pp.1617-1624
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• 2010

$\alpha$-MSH는 세포내 cAMP를 증폭시켜 멜라닌세포의 증식과 색소 증가에 관여한다. 본 연구에서는 $\alpha$-MSH로 자극한 B16F10 세포에서 세신추출물의 hypopigmenting 효과를 조사하고 그 억제기전에 대하여 조사하였다. 세신추출물은 $\alpha$-MSH에 의해 유도된 tyrosinase 활성과 멜라닌생성을 효과적으로 억제시켰으며, 이는 tyrosinase 발현을 조절하는 전사인자인 MITF의 발현억제와 연관성이 있었다. 즉 세신추출물은 MEK/ERK와 PI3K/Akt의 활성화를 통하여 MITF를 조절함으로서 $\alpha$-MSH에 의해 유도되는 tyrosinase, TRP-1, Dct 등 멜라닌생성관련 단백질을 억제함으로서 멜라닌생성을 저해하는 것으로 사료된다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권1호
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• pp.221-225
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• 2015

As metformin can inhibit endometrial carcinoma (EC) cell growth and the insulin growth factor (IGF) system is active in EC, the question of whether it can regulate endometrial carcinoma cell secretion of IGF-1 or expression of IGF-1 receptor (IGF-1R) is of interest. In this study, serum IGF-1 levels in EC patients were found to be comparable with that in the non EC patients (p>0.05). However, the IGF-1 level in the medium of cultured cells after treatment with metformin was decreased (p<0.05). IGF-1R was highly expressed in human endometrial carcinoma paraffin sections, but IGF-1R and phosphor-protein kinase B/protein kinase B (p-Akt/Akt) expression was down-regulated after metformin treatment (p<0.05). In summary, metformin can reduce the secretion of IGF-1 by Ishikawa and JEC EC cell lines and their expression of IGF-1R to deactivate downstream signaling involving the PI-3K/Akt pathway to inhibit endometrial carcinoma cell growth.

• Journal of Microbiology and Biotechnology
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• 제25권5호
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• pp.589-597
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• 2015

It has been reported that overexpression of MUC5AC induced by excessive inflammation leads to airway obstruction in respiratory diseases such as chronic obstructive pulmonary disease and asthma. 15-Hydroxyeicosatetraenoic acid (15-HETE) has been reported to have anti-inflammatory effects, but the role of 15-HETE in respiratory inflammation has not been determined. Therefore, the aim of this study was to investigate the effects of 15-HETE on MUC5AC expression and related pathways. In this study, phorbol-12-myristate-13-acetate (PMA) was used to stimulate NCI-H292 bronchial epithelial cells in order to examine the effects of 15-HETE. 15-HETE inhibited PMA-induced expression of MUC5AC mRNA and secretion of MUC5AC protein. Moreover, 15-HETE regulated matrix metallopeptidase 9 (MMP-9), mitogen-activated protein kinase kinase (MEK), and extracellular signal-regulated kinase (ERK). In addition, 15-HETE decreased the nuclear translocation of specificity protein-1 (Sp-1) transcription factor and nuclear factor κB (NF-κB). Furthermore, 15-HETE enhanced the transcriptional activity of peroxisome proliferator-activated receptor gamma (PPARγ) as a PPARγ agonist. This activity reduced the phosphorylation of protein kinase B (PΚB/Akt) by increasing the expression of phosphatase and tensin homolog (PTEN). In conclusion, 15-HETE regulated MUC5AC expression via modulating MMP-9, MEK/ERK/Sp-1, and PPARγ/PTEN/Akt signaling pathways in PMA-treated respiratory epithelial cells.

• Archives of Pharmacal Research
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• 제27권3호
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• pp.324-333
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• 2004

To determine whether Insulin-like growth factor (IGF-I) treatment represents a potential means of enhancing the survival of cardiac muscle cells from adriamycin (ADR)-induced cell death, the present study examined the ability of IGF-I to prevent cell death. The study was performed utilising the embryonic, rat, cardiac muscle cell line, H9C2. Incubating cardiac muscle cells in the presence of adriamycin increased cell death, as determined by MTT assay and annexin V-positive cell number. The addition of 100 ng/mL IGF-I, in the presence of adriamycin, decreased apoptosis. The effect of IGF-I on phosphorylation of PI, a substrate of phosphatidylinositol 3-kinase (PI 3-kinase) or protein kinase B (AKT), was also examined in H9C2 cardiac muscle cells. IGF-I increased the phosphorylation of ERK 1 and 2 and $PKC{\;}{\zeta}{\;}kinase$. The use of inhibitors of PI 3-kinase (LY 294002), in the cell death assay, demonstrated partial abrogation of the protective effect of IGF-I. The MEK1 inhibitor-PD098059 and the PKC inhibitor-chelerythrine exhibited no effect on IGF-1-induced cell protection. In the regulatory subunit of PI3K-p85- dominant, negative plasmid-transfected cells, the IGF-1-induced protective effect was reversed. This data demonstrates that IGF-I protects cardiac muscle cells from ADR-induced cell death. Although IGF-I activates several signaling pathways that contribute to its protective effect in other cell types, only activation of PI 3-kinase contributes to this effect in H9C2 cardiac muscle cells.