• The Korea Journal of Herbology
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• v.39 no.1
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• pp.23-29
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• 2024

Objectives : Polyporus umbellatus is a medicinal mushroom that has been used for over thousands years in Chinese medicine as a powerful diuretic to relieve fluid retention and edema. Dermal papilla is located at the bottom of the hair follicle and connected to the blood vessels where it gets the nutrients and oxygen to nurture hair follicle. This study examined the mechanism through which the ethanol extract of Polyporus umbellatus (EPU) promoted the proliferation of human dermal papilla cells (HHDPCs). Methods : To estimate the proliferative effects of EPU on HHDPCs, cell viability was estimated by thiazolyl blue tetrazolium bromide (MTT) assay. Western blotting was used to investgate the activation of ERK, phosphoinositide 3-kinase (PI3K)/Akt, β-catenin, GSK-3β and heme oxygenase-1 (HO-1). Cells were treated with inhibitors of ERK and Akt prior to EPU treatment. Results : EPU promoted the proliferation of HHDPCs and the phosphorylation of ERK and Akt in dose dependent manner. However, the proliferative effect of EPU on HHDPCs was inhibited by pre-treatment of ERK inhibitor (PD98059) and Akt inhibitor (LY294002). Furthermore, EPU respectively stimulated the protein expression of β-catenin and phosphorylated GSK-3β. EPU significantly increased the protein expression levels of proliferation and cytoprotection related genes such as Bcl-2, SIRT-1, and HO-1 in cells. Conclusion : This results suggest that EPU promoted the proliferation of HHDPCs via activating PI3K/Akt and Wnt/β-catenin signaling pathway in HHDPCs.

• Journal of Microbiology and Biotechnology
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• v.31 no.11
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• pp.1559-1567
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• 2021

The root bark of Morus alba L. has cytotoxic activity against several types of cancer cells. However, little is known about its chemopreventive mechanisms and bioactive metabolites. In this study, we showed that M. alba L. root bark extracts (MRBE) suppressed β-catenin response transcription (CRT), which is aberrantly activated in various cancers, by promoting the degradation of β-catenin. In addition, MRBE repressed the expression of the β-catenin/T-cell factor (TCF)-dependent genes, c-myc and cyclin D1, thus inhibiting the proliferation of RPMI-8226 multiple myeloma (MM) cells. MRBE induced apoptosis in MM cells, as evidenced by the increase in the population of annexin VFITC-positive cells and caspase-3/7 activity. We identified ursolic acid in MRBE through LC/mass spectrum (MS) and observed that it also decreased intracellular β-catenin, c-myc, and cyclin D1 levels. Furthermore, it suppressed the proliferation of RPMI-8226 cells by stimulating cell cycle arrest and apoptosis. These findings suggest that MRBE and its active ingredient, ursolic acid, exert antiproliferative activity by promoting the degradation of β-catenin and may have significant chemopreventive potential against MM.

• BMB Reports
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• v.53 no.8
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• pp.425-430
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• 2020

Tumor necrosis factor-inducible gene 6 protein (TSG-6) is a cytokine secreted by mesenchymal stem cells (MSCs) and regulates MSC stemness. We previously reported that TSG-6 changes primary human hepatic stellate cells (pHSCs) into stem-like cells by activating yes-associated protein-1 (YAP-1). However, the molecular mechanism behind the reprogramming action of TSG-6 in pHSCs remains unknown. Cluster of differentiation 44 (CD44) is a transmembrane protein that has multiple functions depending on the ligand it is binding, and it is involved in various signaling pathways, including the Wnt/β-catenin pathway. Given that β-catenin influences stemness and acts downstream of CD44, we hypothesized that TSG-6 interacts with the CD44 receptor and stimulates β-catenin to activate YAP-1 during TSG-6-mediated transdifferentiation of HSCs. Immunoprecipitation assays showed the interaction of TSG-6 with CD44, and immunofluorescence staining analyses revealed the colocalization of TSG-6 and CD44 at the plasma membrane of TSG-6-treated pHSCs. In addition, TSG-6 treatment upregulated the inactive form of phosphorylated glycogen synthase kinase (GSK)-3β, which is a negative regulator of β-catenin, and promoted nuclear accumulation of active/nonphosphorylated β-catenin, eventually leading to the activation of YAP-1. However, CD44 suppression in pHSCs following CD44 siRNA treatment blocked the activation of β-catenin and YAP-1, which inhibited the transition of TSG-6-treated HSCs into stem-like cells. Therefore, these findings demonstrate that TSG-6 interacts with CD44 and activates β-catenin and YAP-1 during the conversion of TSG-6-treated pHSCs into stem-like cells, suggesting that this novel pathway is an effective therapeutic target for controlling liver disease.

• Journal of Ginseng Research
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• v.42 no.2
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• pp.199-207
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• 2018

Background: Ginseng is a well-known traditional Chinese medicine that has been widely used in a range of therapeutic and healthcare applications in East Asian countries. Microbial transformation is regarded as an effective and useful technology in modification of nature products for finding new chemical derivatives with potent bioactivities. In this study, three minor derivatives of ginsenoside compound K were isolated and the inducing effects in the Wingless-type MMTV integration site (Wnt) signaling pathway were also investigated. Methods: New compounds were purified from scale-up fermentation of ginsenoside Rb1 by Paecilomyces bainier sp. 229 through repeated silica gel column chromatography and high pressure liquid chromatography. Their structures were determined based on spectral data and X-ray diffraction. The inductive activities of these compounds on the Wnt signaling pathway were conducted on MC3T3-E1 cells by quantitative real-time polymerase chain reaction analysis. Results: The structures of a known 3-keto derivative and two new dehydrogenated metabolites were elucidated. The crystal structure of the 3-keto derivative was reported for the first time and its conformation was compared with that of ginsenoside compound K. The inductive effects of these compounds on osteogenic differentiation by activating the Wnt/b-catenin signaling pathway were explained for the first time. Conclusion: This study may provide a new insight into the metabolic pathway of ginsenoside by microbial transformation. In addition, the results might provide a reasonable explanation for the activity of ginseng in treating osteoporosis and supply good monomer ginsenoside resources for nutraceutical or pharmaceutical development.

• Natural Product Sciences
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• v.29 no.1
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• pp.31-37
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• 2023

In this study, we investigated the efficacy of Celtis choseniana Nakai (C. choseniana) as complementary herbal medicine to ameliorate androgenic alopecia (AGA). The effects of C. choseniana on AGA were evaluated using testosterone propionate-induced AGA mouse model and dihydrotestosterone-treated human hair follicle dermal papilla cells. In vivo, C. choseniana treatment deactivated androgen signaling by reducing the concentration of serum dihydrotestosterone level and expressions of 5α-reductase 2 and androgen receptor. Next, C. choseniana treatment increased the hair regrowth rate. Histological studies demonstrated that C. choseniana induced the anagen phase in testosterone propionate-induced AGA mouse model. Cellular proliferation was promoted by C. choseniana treatment via increasing the expression of proliferation factors, such as proliferating cell nuclear antigen and cyclin D1. Furthermore, C. choseniana treatment increased the expression of proteins related to the Wnt/β-catenin signaling pathway. In addition, dickkopf-1, a Wnt inhibitor, was downregulated with C. choseniana treatment. Likewise, C. choseniana treatment promoted cellular proliferation in vitro. This study demonstrated the inhibitory effect of C. choseniana on androgen-induced AGA. Moreover, C. choseniana induced activation of Wnt/β-catenin signaling, resulting in prolonged anagen and cellular proliferation. Therefore, we suggest that C. choseniana can be used as a therapeutic agent to alleviate AGA.

• Molecules and Cells
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• v.46 no.7
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• pp.441-450
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• 2023

β-Catenin (Ctnnb1) has been shown to play critical roles in the development and maintenance of epithelial cells, including the retinal pigment epithelium (RPE). Ctnnb1 is not only a component of intercellular junctions in the epithelium, it also functions as a transcriptional regulator in the Wnt signaling pathway. To identify which of its functional modalities is critically involved in mouse RPE development and maintenance, we varied Ctnnb1 gene content and activity in mouse RPE lineage cells and tested their impacts on mouse eye development. We found that a Ctnnb1 double mutant (Ctnnb1^dm), which exhibits impaired transcriptional activity, could not replace Ctnnb1 in the RPE, whereas Ctnnb1^Y654E, which has reduced affinity for the junctions, could do so. Expression of the constitutively active Ctnnb1^∆ex3 mutant also suppressed the development of RPE, instead facilitating a ciliary cell fate. However, the post-mitotic or mature RPE was insensitive to the loss, inactivation, or constitutive activation of Ctnnb1. Collectively, our results suggest that Ctnnb1 should be maintained within an optimal range to specify RPE through transcriptional regulation of Wnt target genes in the optic neuroepithelium.

• Journal of dental hygiene science
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• v.16 no.6
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• pp.401-408
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• 2016

Periodontal disease is one of the major dental diseases. Currently, various methods are used for healing and successful regeneration of periodontal tissue damaged by periodontal disease. The periodontal ligament and alveolar bone have received considerable interest for use in periodontal tissue regeneration and induction. However, as the functions of the factors required for tooth attachment and key regulatory factors for periodontal tissue regeneration in the cementum have recently been identified, interest in cementum formation and regeneration has increased. Dental cementum forms in the late phase of tooth development because of the reciprocal regulatory interaction between cervical loop epithelial cells and surrounding mesenchymal cells, which is regulated by various gene signaling networks. Many attempts have been made to understand the regulatory factors and cellular and molecular mechanisms associated with new cementum formation. In this paper, we reviewed the study outcomes to date on the regulatory factors that induce cementum formation and regeneration, focusing on understanding the roles and functions of Wnt signaling in the regulation of cementum formation. In addition, we aimed to obtain information on the useful reciprocal regulatory factors that mediate cementum formation and regeneration through a series of molecular mechanisms.

• Molecules and Cells
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• v.39 no.11
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• pp.821-826
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• 2016

The ${\beta}$-catenin functions as an adhesion molecule and a component of the Wnt signaling pathway. In the absence of the Wnt ligand, ${\beta}$-catenin is constantly phosphorylated, which designates it for degradation by the APC complex. This process is one of the key regulatory mechanisms of ${\beta}$-catenin. The level of ${\beta}$-catenin is also controlled by the E3 ubiquitin protein ligase SIAH-1 via a phosphorylation-independent degradation pathway. Similar to ${\beta}$-catenin, STAT3 is responsible for various cellular processes, such as survival, proliferation, and differentiation. However, little is known about how these molecules work together to regulate diverse cellular processes. In this study, we investigated the regulatory relationship between STAT3 and ${\beta}$-catenin in HEK293T cells. To our knowledge, this is the first study to report that ${\beta}$-catenin-TCF-4 transcriptional activity was suppressed by phosphorylated STAT3; furthermore, STAT3 inactivation abolished this effect and elevated activated ${\beta}$-catenin levels. STAT3 also showed a strong interaction with SIAH-1, a regulator of active ${\beta}$-catenin via degradation, which stabilized SIAH-1 and increased its interaction with ${\beta}$-catenin. These results suggest that activated STAT3 regulates active ${\beta}$-catenin protein levels via stabilization of SIAH-1 and the subsequent ubiquitin-dependent proteasomal degradation of ${\beta}$-catenin in HEK293T cells.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6549-6556
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• 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.

• BMB Reports
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• v.50 no.1
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• pp.1-2
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• 2017

Acquiring a selective growth advantage by breaking the proliferation barrier established by gatekeeper genes is a centrally important event in tumor formation. Removal of the mammalian Hippo kinase Mst1 and Mst2 in hepatocytes leads to rapid hepatocellular carcinoma (HCC) formation, indicating that the Hippo signaling pathway is a critical gatekeeper that restrains abnormal growth in hepatocytes. By rigorous genetic approaches, we identified an interacting network of the Hippo, Wnt/${\beta}$-catenin and Notch signaling pathways that control organ size and HCC development. We found that in hepatocytes, the loss of Mst1/2 leads to the activation of Notch signaling, which forms a positive feedback loop with Yap/Taz (transcription factors controlled by Mst1/2). This positive feedback loop results in severe liver enlargement and rapid HCC formation. Blocking the Yap/Taz-Notch positive feedback loop by Notch inhibition in vivo significantly reduced the Yap/Taz activities, hepatocyte proliferation and tumor formation. Furthermore, we uncovered a surprising inhibitory role of Wnt/${\beta}$-catenin signaling to Yap/Taz activities, which are important in tumor initiation. Genetic removal of ${\beta}$-catenin in the liver of the Mst1/2 mutants significantly accelerates tumoriogenesis. Therefore, Wnt/${\beta}$-catenin signaling, known for its oncogenic property, exerts an unexpected function in restricting Yap/Taz and Notch activities in HCC initiation. The molecular interplay between the three signaling pathways identified in our study provides new insights in developing novel therapeutic strategies to treat liver tumors.