• 공업화학
• /
• 제32권6호
• /
• pp.647-652
• /
• 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.

• Molecules and Cells
• /
• 제40권7호
• /
• pp.457-465
• /
• 2017

Streptozotocin (STZ)-induced murine models of type 1 diabetes have been used to examine ER stress during pancreatic ${\beta}$-cell apoptosis, as this ER stress plays important roles in the pathogenesis and development of the disease. However, the mechanisms linking type 1 diabetes to the ER stress-modulating anti-diabetic signaling pathway remain to be addressed, though it was recently established that ERK5 (Extracellular-signal-regulated kinase 5) contributes to the pathogeneses of diabetic complications. This study was undertaken to explore the mechanism whereby ERK5 inhibition instigates pancreatic ${\beta}$-cell apoptosis via an ER stress-dependent signaling pathway. STZ-induced diabetic WT and CHOP deficient mice were i.p. injected every 2 days for 6 days under BIX02189 (a specific ERK5 inhibitor) treatment in order to evaluate the role of ERK5. Hyperglycemia was exacerbated by co-treating C57BL/6J mice with STZ and BIX02189 as compared with mice administered with STZ alone. In addition, immunoblotting data revealed that ERK5 inhibition activated the unfolded protein response pathway accompanying apoptotic events, such as, PARP-1 and caspase-3 cleavage. Interestingly, ERK5 inhibition-induced exacerbation of pancreatic ${\beta}$-cell apoptosis was inhibited in CHOP deficient mice. Moreover, transduction of adenovirus encoding an active mutant form of $MEK5{\alpha}$, an upstream kinase of ERK5, inhibited STZ-induced unfolded protein responses and ${\beta}$-cell apoptosis. These results suggest that ERK5 protects against STZ-induced pancreatic ${\beta}$-cell apoptosis and hyperglycemia by interrupting the ER stress-mediated apoptotic pathway.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권4호
• /
• pp.1183-1186
• /
• 2012

Objective: To observe the effect of insulin-like growth factor-1 (IGF-1) on bone morphogenetic protein (BMP)-2 expression in hepatocellular carcinoma SMMC7721 cells. Methods: Cells were divided into blank control, IGF-1, IGF-1 + SB203580, and SB203580 groups. SB203580 was used to block the p38 MAPK signaling pathway. Changes in the expression of BMP-2, p38 MAPK, and phosphorylated p38, MERK, ERK and JNK were determined using reverse transcription polymerase chain reactions (RT-PCR) and Western blot analysis. Results: Protein expression of phosphorylated BMP-2, MERK, ERK, and JNK was significantly up-regulated by IGF-1 compared with the control group ($1.138{\pm}0.065$ vs. $0.606{\pm}0.013$, $0.292{\pm}0.005$ vs. $0.150{\pm}0.081$, $0.378{\pm}0.006$ vs. $0.606{\pm}0.013$, and $0.299{\pm}0.015$ vs. $0.196{\pm}0.017$, respectively; P<0.05). Levels of BMP-2 and phosphorylated MERK and JNK were significantly reduced after blocking of the p38MAPK signaling pathway ($0.494{\pm}0.052$ vs. $0.165{\pm}0.017$, $0.073{\pm}0.07$ vs. $0.150{\pm}0.081$, and $0.018{\pm}0.008$ vs. $0.196{\pm}0.017$, respectively; P<0.05), but such a significant difference was not observed for phosphorylated ERK protein expression ($0.173{\pm}0.07$ vs. $0.150{\pm}0.081$, P>0.05). Conclusion: IGF-1 can up-regulate BMP-2 expression, and p38 MAPK signaling pathway blockage can noticeably reduce the up-regulated expression. We can conclude that the up-regulatory effect of IGF-1 on BMP-2 expression is realized through the p38 MAPK signaling pathway.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
• /
• pp.152.2-153
• /
• 2003

${\beta}Although$ it has been demonstrated that $p2l^{WAFl/Cip1}$, a well known cell cycle inhibitor, could be induced by $TGF-{\beta}$ in a p53-independent manner, the detailed signal transduction pathways still remain poorly understood. In this study, we show that ERK is required for $TGF-{\beta}$ induction of $p21^{WAF1/Cip1}$, but JNK or p38 MAPK is not. ERK activation by $TGF-{\beta}$ significantly attenuated by treatment with ROS scavenger such as NAC or catalase, indicating that ROS, mainly $H_2O_2$, generation by $TGF-{\beta}$ might stimulate ERK signaling pathway to require the induction of $p21^{WAF1/Cip1}$. (omitted)

• Molecules and Cells
• /
• 제27권3호
• /
• pp.351-357
• /
• 2009

Phytoestrogens are the natural compounds isolated from plants, which are structurally similar to animal estrogen, $17{\beta}$-estradiol. Tectoridin, a major isoflavone isolated from the rhizome of Belamcanda chinensis. Tectoridin is known as a phytoestrogen, however, the molecular mechanisms underlying its estrogenic effect are remained unclear. In this study we investigated the estrogenic signaling triggered by tectoridin as compared to a famous phytoestrogen, genistein in MCF-7 human breast cancer cells. Tectoridin scarcely binds to ER ${\alpha}$ as compared to $17{\beta}$-estradiol and genistein. Despite poor binding to ER ${\alpha}$, tectoridin induced potent estrogenic effects, namely recovery of the population of cells in the S-phase after serum starvation, transactivation of the estrogen response element, and induction of MCF-7 cell proliferation. The tectoridin-induced estrogenic effect was severely abrogated by treatment with U0126, a specific MEK1/2 inhibitor. Tectoridin promoted phosphorylation of ERK1/2, but did not affect phosphorylation of ER ${\alpha}$ at $Ser^{118}$. It also increased cellular accumulation of cAMP, a hallmark of GPR30-mediated estrogen signaling. These data imply that tectoridin exerts its estrogenic effect mainly via the GPR30 and ERK-mediated rapid nongenomic estrogen signaling pathway. This property of tectoridin sets it aside from genistein where it exerts the estrogenic effects via both an ER-dependent genomic pathway and a GPR30-dependent nongenomic pathway.

• BMB Reports
• /
• 제47권12호
• /
• pp.685-690
• /
• 2014

The Ras/Raf/MEK/Erk signaling pathway is important for regulation of cell growth, proliferation, differentiation, survival, and apoptosis in response to a variety of extracellular stimuli. Lack of Erk MAPK activation is observed in several cancer cells despite active activation of Ras. However, little is known about the modulation of Erk1/2 activity by active Ras. Here, we show that overexpression of active H-Ras (H-RasG12R) in NIH3T3 fibroblasts impaired FGF2-induced Erk1/2 phosphorylation, as compared to wild-type cells. Northern blot analysis revealed that prolonged expression of active Ras increased MAP kinase phosphatase 3 (MKP3) mRNA expression, a negative regulator of Erk MAPK. Inhibition of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway abrogated active Ras-induced up-regulation of MKP3 expression, leading to the rescue of Erk1/2 phosphorylation. Our results demonstrated that the Ras/Raf/MEK/Erk signaling cascade is negatively regulated by the PI3K/Aktdependent transcriptional activation of the MKP3 gene.

• Biomolecules & Therapeutics
• /
• 제26권6호
• /
• pp.584-590
• /
• 2018

Osteoporosis development is closely associated with oxidative stress and reactive oxygen species (ROS). Taurine has potential antioxidant effects, but its role in osteoblasts is not clearly understood. The aim of this study was to determine the protective effects and mechanisms of actions of taurine on hydrogen peroxide ($H_2O_2$)-induced oxidative stress in osteoblast cells. UMR-106 cells were treated with taurine prior to $H_2O_2$ exposure. After treatment, cell viability, apoptosis, intracellular ROS production, malondialdehyde content, and alkaline phosphate (ALP) activity were measured. We also investigated the protein levels of ${\beta}-catenin$, ERK, CHOP and NF-E2-related factor 2 (Nrf2) along with the mRNA levels of Nrf2 downstream antioxidants. The results showed that pretreatment of taurine could reverse the inhibition of cell viability and suppress the induced apoptosis in a dose-dependent manner: taurine significantly reduced $H_2O_2$-induced oxidative damage and expression of CHOP, while it induced protein expression of Nrf2 and ${\beta}-catenin$ and activated ERK phosphorylation. DKK1, a Wnt/${\beta}-catenin$ signaling inhibitor, significantly suppressed the taurine-induced Nrf2 signaling pathway and increased CHOP. Activation of ERK signaling mediated by taurine in the presence of $H_2O_2$ was significantly inhibited by DKK1. These data demonstrated that taurine protects osteoblast cells against oxidative damage via Wnt/${\beta}-catenin$-mediated activation of the ERK signaling pathway.

• BMB Reports
• /
• 제57권5호
• /
• pp.250-255
• /
• 2024

Due to their stem-like characteristics and immunosuppressive properties, Mesenchymal stem cells (MSCs) offer remarkable potential in regenerative medicine. Much effort has been devoted to enhancing the efficacy of MSC therapy by enhancing MSC migration. In this study, we identified deubiquitinase BRCA1-associated protein 1 (BAP1) as an inhibitor of MSC migration. Using deubiquitinase siRNA library screening based on an in vitro wound healing assay, we found that silencing BAP1 significantly augmented MSC migration. Conversely, BAP1 overexpression reduced the migration and invasion capabilities of MSCs. BAP1 depletion in MSCs upregulates ERK phosphorylation, thereby increasing the expression of the migration factor, osteopontin. Further examination revealed that BAP1 interacts with phosphorylated ERK1/2, deubiquitinating their ubiquitins, and thus attenuating the ERK signaling pathway. Overall, our study highlights the critical role of BAP1 in regulating MSC migration through its deubiquitinase activity, and suggests a novel approach to improve the therapeutic potential of MSCs in regenerative medicine.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권12호
• /
• pp.6017-6022
• /
• 2012

Background: Resveratrol has been reported to have potential chemopreventive and apoptosis-inducing properties in a variety of tumor cell lines. Objective: In this study, to investigate the effects of resveratrol on protein kinase C (PKC) activity and apoptosis in human colon carcinoma cells, we used HT-29 cells and examined the $PKC{\alpha}$ and ERK1/2 signaling pathways. Methods: To test the effects of resveratrol on the growth of HT-29 cells, the cells were exposed to varying concentrations and assessed with the the MTT cell-viability assay. Fluorescence-activated cell sorter (FACS) analysis was applieded to determine the effects of resveratrol on cell apoptosis. Western blotting was performed to determine the protein levels of $PKC{\alpha}$ and ERK1/2. In inhibition experiments, HT-29 cells were treated with G$\ddot{o}$6976 or PD98059 for 30 min, followed by exposure to $200{\mu}M$ resveratrol for 72 h. Results: Resveratrol had a significant inhibitory effect on HT-29 cell growth. FACS revealed that resveratrol induced apoptosis. Western blotting showed that e phosphorylation of $PKC{\alpha}$ and ERK1/2 was significantly increased in response to resveratrol treatment. Pre-treatment with $PKC{\alpha}$ and ERK1/2 inhibitors (G$\ddot{o}$6976 and PD98059) promoted apoptosis. Conclusion: Resveratrol has significant anti-proliferative effects on the colon cancer cell line HT-29. The PKC-ERK1/2 signaling pathway can partially mediate resveratrol-induced apoptosis of HT-29 cells.

• Molecules and Cells
• /
• 제39권3호
• /
• pp.186-194
• /
• 2016

Epidemiological evidence suggests that bone is especially sensitive to oxidative stress, causing bone loss in the elderly. Previous studies indicated that human amnion-derived mesenchymal stem cells (HAMSCs), obtained from human amniotic membranes, exerted osteoprotective effects in vivo. However, the potential of HAMSCs as seed cells against oxidative stress-mediated dysfunction is unknown. In this study, we systemically investigated their antioxidative and osteogenic effects in vitro. Here, we demonstrated that HAMSCs significantly promoted the proliferation and osteoblastic differentiation of $H_2O_2$-induced human bone marrow mesenchymal stem cells (HBMSCs), and down-regulated the reactive oxygen species (ROS) level. Further, our results suggest that activation of the ERK1/2 MAPK signal transduction pathway is essential for both HAMSCs-mediated osteogenic and protective effects against oxidative stress-induced dysfunction in HBMSCs. U0126, a highly selective inhibitor of extracellular ERK1/2 MAPK signaling, significantly suppressed the antioxidative and osteogenic effects in HAMSCs. In conclusion, by modulating HBMSCs, HAMSCs show a strong potential in treating oxidative stress- mediated bone deficiency.