• 생명과학회지
• /
• 제28권9호
• /
• pp.1016-1021
• /
• 2018

C. difficile 톡신A에 의한 대장상피세포 자살과정은 위막성대장염(Pseudomembranous colitis)의 주요 원인으로 고려되고 있다. 톡신A는 활성산소 를 증가시켜 세포자살 신호를 유도한다. 또한 톡신A는 미세섬유나 미세소관과 같은 세포골격계 형성을 저해함으로써 자살을 유도한다고 알려져 있다. 하지만 톡신A가 야기하는 소화기 상피세포 자살경로는 아직 불분명하다. 본 연구에서는 소화관 상피세포의 성장과 분화 그리고 기능에 중요하다고 알려져 온 Wnt 신호경로에 대한 톡신A의 영향을 확인해보았다. 이를 위해 비암화-인간대장세포주(NCM460)에 톡신A를 처치하고 Wnt 신호 분자들의 변화를 추적하였다. 또한 톡신A를 주입한 생쥐의 회장 상피세포 속 Wnt 신호경로 변화도 평가하였다. 인간 대장상피세포에서 톡신A는 Wnt 경로의 핵심 신호분자인 ${\beta}$-catenin 단백질의 양을 빠르게 감소시켰다. 이 현상은 생쥐 회장 상피세포에서도 동일하게 확인되었다. 연구자 등은 톡신A가 $GSK3{\beta}$ 활성형 인산화(Thr390)를 증가시킴도 확인하였다. 이는 톡신A가 $GSK3{\beta}$의 활성을 높여서 ${\beta}$-catenin의 인산화시키고 이를 통해 단백질 분해 과정이 촉진되었음을 보여준다. 이 결과들을 종합하면, 톡신A에 의한 소화관 상피세포 자살과정이 상피세포의 성장과 자살을 조절하는 Wnt 신호경로 차단과 밀접하게 연관되어 있음을 보여준다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권12호
• /
• pp.6197-6201
• /
• 2012

Although enhancer of zeste homolog 2 (EZH2) has been reported as an independent prognostic factor in renal cell carcinoma (RCC), little is known about the exact mechanism of EZH2 in promoting the genesis of RCC. However, several studies have shown that dysregulation of the Wnt/${\beta}$-catenin signaling pathway plays a crucial role. Therefore, we determined whether EZH2 could affect ACHN human RCC cell proliferation and invasion via the Wnt/${\beta}$-catenin pathway. In the present study, we investigated the effects of short interfering RNA (siRNA)-mediated EZH2 gene silencing on Wnt/${\beta}$-catenin signaling in ACHN cells. EZH2-siRNA markedly inhibited the proliferation and invasion capabilities of ACHN, while also reducing the expression of EZH2, Wnt3a and ${\beta}$-catenin. In contrast, cellular expression of GSK-$3{\beta}$ (glycogen synthase kinase-$3{\beta}$), an inhibitor of the Wnt/${\beta}$-catenin pathway, was conspicuously higher after transfection of EZH2 siRNA. These preliminary findings suggest EZH2 may promote proliferation and invasion of ACHN cells via action on the Wnt/${\beta}$-catenin signaling pathway.

• Journal of Ginseng Research
• /
• 제44권3호
• /
• pp.475-482
• /
• 2020

Background: Active natural ingredients, especially small molecules, have recently received wide attention as modifiers used to treat neurodegenerative disease by promoting neurogenic regeneration of neural stem cell (NSC) in situ. 20(S)-protopanaxadiol (PPD), one of the bioactive ingredients in ginseng, possesses neuroprotective properties. However, the effect of PPD on NSC proliferation and differentiation and its mechanism of action are incompletely understood. Methods: In this study, we investigated the impact of PPD on NSC proliferation and neuronal lineage differentiation through activation of the Wnt/glycogen synthase kinase (GSK)-3β/β-catenin pathway. NSC migration and proliferation were investigated by neurosphere assay, Cell Counting Kit-8 assay, and EdU assay. NSC differentiation was analyzed by Western blot and immunofluorescence staining. Involvement of the Wnt/GSK3β/β-catenin pathway was examined by molecular simulation and Western blot and verified using gene transfection. Results: PPD significantly promoted neural migration and induced a significant increase in NSC proliferation in a time- and dose-dependent manner. Furthermore, a remarkable increase in anti-microtubule-associated protein 2 expression and decrease in nestin protein expression were induced by PPD. During the differentiation process, PPD targeted and stimulated the phosphorylation of GSK-3β at Ser9 and the active forms of β-catenin, resulting in activation of the Wnt/GSK-3β/β-catenin pathway. Transfection of NSCs with a constitutively active GSK-3β mutant at S9A significantly hampered the proliferation and neural differentiation mediated by PPD. Conclusion: PPD promotes NSC proliferation and neural differentiation in vitro via activation of the Wnt/GSK-3β/β-catenin pathway by targeting GSK-3β, potentially having great significance for the treatment of neurodegenerative diseases.

• International Journal of Oral Biology
• /
• 제34권2호
• /
• pp.53-59
• /
• 2009

Periodontal ligament (PDL) tissue is a connective tissue that is interposed between the roots of the teeth and the inner wall of the alveolar bone socket. PDL is always exposed to physiologic mechanical force such as masticatory force and PDL cells play important roles during orthodontic tooth movement by synthesizing and secreting different mediators involved in bone remodeling. The Wnt/${\beta}$-catenin signaling pathway was recently shown to play a significant role in the control of bone formation. In the present study, we applied cyclic tensile stress of 20% elongation to cultured human PDL cells and assessed its impact after six days upon components of the Wnt/${\beta}$-catenin signaling pathway. RTPCR analysis showed that Wnt1a, Wnt3a, Wnt10b and the Wnt receptor LRP5 were down-regulated, whereas the Wnt inhibitor DKK1 was up-regulated in response to these stress conditions. In contrast, little change was detected in the mRNA expression of Wnt5a, Wnt7b, Fz1, and LRP6. By western blotting we found decreased expression of the ${\beta}$-catenin and p-GSK-3${\beta}$ proteins. Our results thus show that mechanical stress suppresses the canonical Wnt/${\beta}$-catenin signaling pathway in PDL cells.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권16호
• /
• pp.7277-7284
• /
• 2015

Background: The Wnt/${\beta}$-catenin signaling pathway is an important regulator of cellular functions such as proliferation, survival and cell adhesion. Wnt/${\beta}$-catenin signaling is associated with tumor initiation and progression; ${\beta}$-catenin mutations explain only 30% of aberrant signaling found in breast cancer, indicating that other components and/or regulation of the Wnt/${\beta}$-catenin pathway may be involved. Objective: We evaluated AXIN2 rs2240308 and rs151279728 polymorphisms, and expression profiles of ${\beta}$-catenin destruction complex genes in breast cancer patients. Materials and Methods: We collected peripheral blood samples from 102 breast cancer and 102 healthy subjects. The identification of the genetic variation was performed using PCR-RFLPs and DNA sequencing. RT-qPCR was used to determine expression profiles. Results: We found significant association of AXIN2 rs151279728 and rs2240308 polymorphisms with breast cancer risk. Significant increase was observed in AXIN2 level expression in breast cancer patients. Further analyses showed APC, ${\beta}$-catenin, CK1${\alpha}$, GSK3${\beta}$ and PP2A gene expression to be associated to clinic-pathological characteristics. Conclusions: The present study demonstrated, for the first time, that AXIN2 genetic defects and disturbance of ${\beta}$-catenin destruction complex expression may be found in breast cancer patients, providing additional support for roles of Wnt/${\beta}$-catenin pathway dysfunction in breast cancer tumorigenesis. However, the functional consequences of the genetic alterations remain to be determined.

• Animal Bioscience
• /
• 제34권6호
• /
• pp.993-1005
• /
• 2021

Objective: Zearalenone (ZEA) has estrogen-like effects. Our previous study has shown that ZEA (0.5 to 1.5 mg/kg) could induce abnormal uterine proliferation through transforming growth factor signaling pathway. To further study the other regulatory networks of uterine hypertrophy caused by ZEA, the potential mechanism of ZEA on porcine endometrial epithelial cells (PECs) was explored by the Illumina Hiseq 2000 sequencing system. Methods: The PECs were treated with ZEA at 0 (ZEA0), 5 (ZEA5), 20 (ZEA20), and 80 (ZEA80) µmol/L for 24 h. The collected cells were subjected to cell cycle, RNA-seq, real-time quantitative polymerase chain reaction, immunofluorescence, and western blot analysis. Results: The proportion of cells in the S and G2 phases decreased (p<0.05), but the proportion of cells in the G1 phase increased (p<0.05) in the ZEA80 treatment. Data analysis revealed that the expression of Wnt pathway-related genes, estrogen-related genes, and mitogen-activated protein kinase pathway-related genes increased (p<0.05), but the expression of genetic stability genes decreased (p<0.05) with increasing ZEA concentrations. The relative mRNA and protein expression of WNT1, β-catenin, glycogen synthase kinase 3β (GSK-3β) were increased (p<0.05) with ZEA increasing, while the relative mRNA and protein expression of cyclin D1 (CCND1) was decreased (p<0.05). Moreover, our immunofluorescence results indicate that β-catenin accumulated around the nucleus from the cell membrane and cytoplasm with increasing ZEA concentrations. Conclusion: In summary, ZEA can activate the Wnt/β-catenin signaling pathway by up-regulating WNT1 and β-catenin expression, to promote the proliferation and development of PECs. At the same time, the up-regulation of GSK-3β and down-regulation of CCND1, as well as the mRNA expression of other pathway related genes indicated that other potential effects of ZEA on the uterine development need further study.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권15호
• /
• pp.6549-6556
• /
• 2015

The PI3K-Akt-mTOR, $Wnt/{\beta}$-catenin and apoptosis signaling pathways have been shown to be involved in genesis of colorectal cancer (CRC). The aim of this study was to elucidate whether combination of Gelam honey and ginger might have chemopreventive properties in HT29 colon cancer cells by modulating the mTOR, $Wnt/{\beta}$-catenin and apoptosis signaling pathways. Treatment with Gelam honey and ginger reduced the viability of the HT29 cells dose dependently with $IC_{50}$ values of 88 mg/ml and 2.15 mg/ml respectively, their while the combined treatment of 2 mg/ml of ginger with 31 mg/ml of Gelam honey inhibited growth of most HT29 cells. Gelam honey, ginger and combination induced apoptosis in a dose dependent manner with the combined treatment exhibiting the highest apoptosis rate. The combined treatment downregulated the gene expressions of Akt, mTOR, Raptor, Rictor, ${\beta}$-catenin, $Gsk3{\beta}$, Tcf4 and cyclin D1 while cytochrome C and caspase 3 genes were shown to be upregulated. In conclusion, the combination of Gelam honey and ginger may serve as a potential therapy in the treatment of colorectal cancer through inhibiton of mTOR, $Wnt/{\beta}$ catenin signaling pathways and induction of apoptosis pathway.

• Biomolecules & Therapeutics
• /
• 제24권6호
• /
• pp.623-629
• /
• 2016

(1S,2S,3E,7E,11E)-3,7,11,15-cembratetraen-17,2-olide (LS-1), a marine cembrenolide diterpene, has anticancer activity against colon cancer cells such as HT-29, SNU-C5/5-FU (fluorouracil-resistant SNU-C5) and SNU-C5. However, the action mechanism of LS-1 on SNU-C5 human colon cancer cells has not been fully elucidated. In this study, we investigated whether the anticancer effect of LS-1could result from apoptosis via the modulation of $Wnt/{\beta}$-catenin and the TGF-${\beta}$ pathways. When treated with the LS-1, we could observe the apoptotic characteristics such as apoptotic bodies and the increase of sub-G1 hypodiploid cell population, increase of Bax level, decrease of Bcl-2 expression, cleavage of procaspase-3 and cleavage of poly (ADP-ribose) polymerase in SNU-C5 cells. Furthermore, the apoptosis induction of SNU-C5 cells upon LS-1 treatment was also accompanied by the down-regulation of $Wnt/{\beta}$-catenin signaling pathway via the decrease of GSK-$3{\beta}$ phosphorylation followed by the decrease of ${\beta}$-catenin level. In addition, the LS-1 induced the activation of TGF-${\beta}$ signaling pathway with the decrease of carcinoembryonic antigen which leads to decrease of c-Myc, an oncoprotein. These data suggest that the LS-1 could induce the apoptosis via the down-regulation of $Wnt/{\beta}$-catenin pathway and the activation of TGF-${\beta}$ pathway in SNU-C5 human colon cancer cells. The results support that the LS-1 might have potential for the treatment of human colon cancer.

• 생약학회지
• /
• 제47권2호
• /
• pp.143-149
• /
• 2016

Grateloupia elliptica has been reported to have the proliferation effect of dermal papilla cells (DPCs), which play important roles in the regulation of hair cycle. In the present study, we examined in vitro and in vivo hair growth-promoting effect of Grateloupia elliptica. When isolated rat vibrissa follicles were treated with extract of G. elliptica, the hair-fiber lengths of the vibrissa follicles significantly increased. Furthermore, the G. elliptica extract accelerated the telogen-angen transition in C57BL/6 mice. To investigate the molecular mechanisms of the G. elliptica extract on the proliferation of DPCs, we examined the activation of $wnt/{\beta}$-catenin signaling which is known to regulate hair follicle development, differentiation and hair growth. The G. elliptica extract activated $wnt/{\beta}$-catenin signaling via the increase of ${\beta}$-catenin and phospho-$GSK3{\beta}$. In addition, the G. elliptica extract increased the level of cyclin E and CDK2, while the level of $p27^{kip1}$ was decreased. These results suggest that the the G. elliptica extract may induce hair growth by proliferation of DPCs via cell-cycle progression and the activation of $Wnt/{\beta}$-catenin signaling.

• 생약학회지
• /
• 제45권4호
• /
• pp.288-293
• /
• 2014

The present study was conducted to evaluate the hair growth-promoting effect of Clitocybin A from mushroom Clitocybe aurantiaca with dermal papilla cells (DPCs), which play important roles in the regulation of hair cycle. Clitocybin A significantly increased the proliferation of immortalized rat vibrissa DPCs. Flow cytometry analysis revealed that Clitocybin A promoted cell-cycle progression through G0/G1 to S phase in immortalized rat vibrissa DPCs. In addition, Clitocybin A increased the level of cell cycle proteins such as cyclin D1, phospho-pRB, and phospho-CDK2. To elucidate the molecular mechanisms of Clitocybin A on the proliferation of DPCs, we examined the activation of wnt/${\beta}$-catenin signaling which is known to regulate hair follicle development, differentiation and hair growth. Clitocybin A activated wnt/${\beta}$-catenin signaling via the increase of phospho(ser552)-${\beta}$-catenin, phospho(ser675)-${\beta}$-catenin and phospho(ser9)-$GSK3{\beta}$. Furthermore, Clitocybin A markedly increased the activation of extracellular signal-regulated kinase (ERK). These results suggest that the Clitocybin A may induce hair growth by proliferation of DPCs via cell-cycle progression as well as the activation of Wnt/${\beta}$-catenin signaling and ERK pathway.