• The Korean Journal of Physiology and Pharmacology
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• 제26권6호
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• pp.469-478
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• 2022

WNT signaling plays an important role in cardiac development, but abnormal activity is often associated with cardiac hypertrophy, myocardial infarction, remodeling, and heart failure. The effect of WNT signaling on regulation of atrial natriuretic peptide (ANP) secretion is unclear. Therefore, the purpose of this study was to investigate the effect of Wnt agonist 1 (Wnta1) on ANP secretion and mechanical dynamics in beating rat atria. Wnta1 treatment significantly increased atrial ANP secretion and pulse pressure; these effects were blocked by U73122, an antagonist of phospholipase C. U73122 also abolished the effects of Wnta1-mediated upregulation of protein kinase C (PKC) β and γ expression, and the PKC antagonist Go 6983 eliminated Wnta1-induced secretion of ANP. In addition, Wnta1 upregulated levels of phospho-transforming growth factor-β activated kinase 1 (p-TAK1), TAK1 banding 1 (TAB1) and phospho-activating transcription factor 2 (p-ATF2); these effects were blocked by both U73122 and Go 6983. Wnta1-induced ATF2 was abrogated by inhibition of TAK1. Furthermore, Wnta1 upregulated the expression of T cell factor (TCF) 3, TCF4, and lymphoid enhancer factor 1 (LEF1), and these effects were blocked by U73122 and Go 6983. Tak1 inhibition abolished the Wnta1-induced expression of TCF3, TCF4, and LEF1 and Wnta1-mediated ANP secretion and changes in mechanical dynamics. These results suggest that Wnta1 increased the secretion of ANP and mechanical dynamics in beating rat atria by activation of PKC-TAK1-ATF2-TCF3/LEF1 and TCF4/LEF1 signaling mainly via the WNT/Ca²⁺ pathway. It is also suggested that WNT-ANP signaling is implicated in cardiac physiology and pathophysiology.

• Animal cells and systems
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• 제2권3호
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• pp.403-410
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• 1998

The Tcf-1 (T cell specific factor-1) is a transcription factor uniquely expressed in T-lineage cells. Its expression is developmentally regulated, which is high in the specific stage of immature thymocytes, but is much lower in mature T cells. We cloned the Tcf-1 gene by subtractive hybridization and found it to be highly expressed in the thymus compared to the mRNA level in the spleen as expected. Since apoptosis occurs enormously in the thymus, we were interested in whether Tcf-1 gene expression could be regulated by such a high level of apoptotic assault. By using T cell hybridoma 70.7 cells, we induced apoptosis by incubating cells with anti-CD3 antibody in vitro. After apoptosis induction, Tcf-1 mRNA level was found to be significantly reduced compared to normal cells. Since Tcf-1 is a transcription factor for the CD3-e gene, we tested how CD3-e expression is regulated in apoptotic cells. The surface level of CD3-e protein is also down-regulated after apoptosis induction. Such a down-modulation of CD3-e protein would reduce the TCR/CD3 complex on the cell surface, which would be an important regulator for T cell apoptosis.

• 대한한의학회지
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• 제32권3호
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• pp.35-43
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• 2011

Objectives: This study was performed to screen target-specific inhibitors of ${\beta}$-catenin/TCF signaling whose functional activation plays an important role in early events in carcinogenesis. Methods: To investigate the activation or suppression of ${\beta}$-catenin/TCF transcription, we established a transiently transfected cell line with a constitutively active ${\beta}$-catenin mutant gene whose product is not degraded. This cell line was also co-transfected with luciferase reporter gene constructs containing either an optimized (TOPflash) or mutant (FOPflash) TCF-binding element. We investigated cytotoxic effects using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium salt (MTS) assay. To find effective inhibitors of ${\beta}$-catenin/TCF signaling from medicinal herbs, the crude extracts of 99 types of medicinal herbs were screened using a luciferase assay system in HEK-293 and SH-SY5y cells. Results: At a concentration of $50{\mu}g$/ml, extracts of Angelica koreanae radix, Cannabis sativa semen, Ephedrae intermedia Schrenk radix, and Vitis rotundifolia fruit showed the following inhibitory effects on ${\beta}$-catenin/TCF signaling: $40{\pm}5.6%$, $23{\pm}6.1%$, $8{\pm}5.1%$, and $22{\pm}9.8%$ in ${\beta}$-catenin-activated HEK-293 cells and $9{\pm}4.7%$, $39{\pm}8.1%$, $39{\pm}6.4%$, and $42{\pm}10.1%$ in ${\beta}$-catenin-activated SH-SY5y cells, respectively. Crude extracts of E. radix were isolated by silica gel column chromatography, and two non-polar fractions of these extracts showed inhibitory effects on ${\beta}$-catenin/TCF signaling. Conclusions: In this study, we established a transiently transfected cell line as a screening system and found that various medicinal herb extracts had inhibitory effects on ${\beta}$signaling.

• IMMUNE NETWORK
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• 제16권1호
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• pp.61-74
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• 2016

Dendritic cells (DCs) are professional antigen-presenting cells that sample their environment and present antigens to naïve T lymphocytes for the subsequent antigen-specific immune responses. DCs exist in a range of distinct subpopulations including plasmacytoid DCs (pDCs) and classical DCs (cDCs), with the latter consisting of the cDC1 and cDC2 lineages. Although the roles of DC-specific transcription factors across the DC subsets have become understood, the posttranscriptional mechanisms that regulate DC development are yet to be elucidated. MicroRNAs (miRNAs) are pivotal posttranscriptional regulators of gene expression in a myriad of biological processes, but their contribution to the immune system is just beginning to surface. In this study, our in-house probe collection was screened to identify miRNAs possibly involved in DC development and function by targeting the transcripts of relevant mouse transcription factors. Examination of DC subsets from the culture of mouse bone marrow with Flt3 ligand identified high expression of miR-124 which was able to target the transcript of TCF4, a transcription factor critical for the development and homeostasis of pDCs. Further expression profiling of mouse DC subsets isolated from in vitro culture as well as via ex vivo purification demonstrated that miR-124 was outstandingly expressed in CD24⁺ cDC1 cells compared to in pDCs and CD172α⁺ cDC2 cells. These results imply that miR-124 is likely involved in the processes of DC subset development by posttranscriptional regulation of a transcription factor(s).

• Asian Pacific Journal of Cancer Prevention
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• 제15권7호
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• pp.3331-3333
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• 2014

Background: The results of previous researches that analyzed the association between genetic polymorphisms of transcription factor-7-like 2 (TCF7L2, rs7903146) and polycystic ovary syndrome (PCOS) were conflicting. Current systematic analysis was conducted to re-explore this association using updated materials. Materials and Methods: The PubMed database was used for data collection and the final search was conducted on January 3, 2014. For TCF7L2 rs7903146, a non-signficiant slight increase in risk of PCOS development was observed under three genetic models (dominant model: OR=1.06, 95%CI: 0.93-1.21, p>0.05; recessive model: OR=1.12, 95%CI: 0.87-1.43, p> 0.05; homozygous model: OR=1.14, 95%CI: 0.87-1.47, p>0.05). In the subgroup analyses in Asian group, allele susceptibility of PCOS was calculated (allele model: OR=1.00, 95%CI: 0.74-1.35, p>0.05; dominant model: OR=0.98, 95%CI: 0.71-1.35, p>0.05; recessive model: OR=1.79, 95%CI: 0.33-9.84, p>0.05; homozygous model: OR=1.78, 95%CI: 0.32-9.80, p>0.05), the differences were again not statistically significant. Conclusions: The findings of this systemic analysis suggest that the polymorphism of TCF7L2 rs7903146 may not be associated with the susceptibility to PCOS.

• Journal of Microbiology and Biotechnology
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• 제29권2호
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• pp.321-329
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• 2019

Hair loss, also known as alopecia, is a common dermatological condition of psychosocial significance; development of therapeutic candidates for the treatment of this condition is, hence, important. Silibinin, a secondary metabolite from Silybum marianum, is an effective antioxidant that also prevents various cutaneous problems. In this study, we have investigated the effect of silibinin on hair induction using three-dimensional (3D) cultured, human dermal papilla (DP) spheroids. Silibinin was found to significantly increase viability through AKT serine/threonine kinase (AKT) activation in 3D DP spheroids. This was correlated with an increase in the diameter of the 3D DP spheroids. The activation of the wingless and INT-1 (Wnt)/${\beta}$-catenin signaling pathway, which is associated with hair growth induction in the DP, was evaluated using the T cell-specific transcription factor and lymphoid enhancer-binding factor (TCF/LEF) transcription factor reporter assay; results indicated significantly increased luciferase activity. In addition, we were able to demonstrate increased expression of the target genes, WNT5a and LEF1, using quantitative real-time PCR assay. Lastly, significantly elevated expression of signature genes associated with hair induction was demonstrated in the 3D DP spheroids treated with silibinin. These results suggest that silibinin promotes proliferation and hair induction through the AKT and Wnt/${\beta}$-catenin signaling pathways in 3D DP spheroids. Silibinin can be a potential candidate to promote hair proliferation.

• Molecules and Cells
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• 제43권2호
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• pp.168-175
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• 2020

Runx2 is an essential transcription factor for skeletal development. It is expressed in multipotent mesenchymal cells, osteoblast-lineage cells, and chondrocytes. Runx2 plays a major role in chondrocyte maturation, and Runx3 is partly involved. Runx2 regulates chondrocyte proliferation by directly regulating Ihh expression. It also determines whether chondrocytes become those that form transient cartilage or permanent cartilage, and functions in the pathogenesis of osteoarthritis. Runx2 is essential for osteoblast differentiation and is required for the proliferation of osteoprogenitors. Ihh is required for Runx2 expression in osteoprogenitors, and hedgehog signaling and Runx2 induce the differentiation of osteoprogenitors to preosteoblasts in endochondral bone. Runx2 induces Sp7 expression, and Runx2, Sp7, and canonical Wnt signaling are required for the differentiation of preosteoblasts to immature osteoblasts. It also induces the proliferation of osteoprogenitors by directly regulating the expression of Fgfr2 and Fgfr3. Furthermore, Runx2 induces the proliferation of mesenchymal cells and their commitment into osteoblast-lineage cells through the induction of hedgehog (Gli1, Ptch1, Ihh), Fgf (Fgfr2, Fgfr3), Wnt (Tcf7, Wnt10b), and Pthlh (Pth1r) signaling pathway gene expression in calvaria, and more than a half-dosage of Runx2 is required for their expression. This is a major cause of cleidocranial dysplasia, which is caused by heterozygous mutation of RUNX2. Cbfb, which is a co-transcription factor that forms a heterodimer with Runx2, enhances DNA binding of Runx2 and stabilizes Runx2 protein by inhibiting its ubiquitination. Thus, Runx2/Cbfb regulates the proliferation and differentiation of chondrocytes and osteoblast-lineage cells by activating multiple signaling pathways and via their reciprocal regulation.

• 동의생리병리학회지
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• 제24권3호
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• pp.504-511
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• 2010

Diabetes is a disease that contains a high concentration of glucose in blood and due to defects in either insulin secretion or insulin action. Although the distinctive causes and factors of diabetes have not been clarified, the genetic factors are suggested as a main susceptibility until now. SNP (Single Nucleotide Polymorphism), as the most common genetic variation, has an influence on personal susceptibility for diseases. A nonsynonymous SNP, which changes the amino acid of the protein and its function, is especially important. Therefore, this study hypothesized that there are associations between specific SNPs of the targeted genes. Transcription factor 7-like 2 (TCF7L2) and fat mass and obesity associated (FTO) genes were selected as target genes from the results of genome-wide association and other related research studies. Second, four nonsynonymous SNPs (three in TCF7L2 and one in FTO gene) were selected as target SNPs by using public database of NCBI (National Center for Biotechnology Information). The recruited personnel was classified into three subgroups of diabetes, impaired fasting glucose (IFG) and normal groups. The individual genotypes of each group were analyzed by resequencing. None of genetic variations at four targeted SNP sites was revealed in all samples of this study. However, this study found two new SNPs that were not reported in TCF7L2 gene. One is synonymous SNP, which is heterozygous of C/T and no amino acid change of asparagine/asparagines, was located at c1641 and found in one normal person. Another is nonsynonymous SNP, which is heterozygous of G/A, was located at c1501 and found in two samples. This new discovered nonsynonymous SNP induce the amino acid change from alanine to threonine. Moreover, this new nonsynonymous SNP was found among two persons, one of whom was a diabetes patient and the other one was a person at boundary between IFG and normal, suggesting that this variant might be associated with IFG or diabetes. Even if there is a limitation of sample number for statistical power, this study has an importance due to the discovery of new SNPs. In the future study, a large sample number of diabetes cohort will be needed to investigate the frequency and association with new discovered SNP.

• Journal of Microbiology and Biotechnology
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• 제33권9호
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• pp.1206-1212
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• 2023

The Wnt/β-catenin pathway plays essential roles in regulating various cellular behaviors, including proliferation, survival, and differentiation [1-3]. The intracellular β-catenin level, which is regulated by a proteasomal degradation pathway, is critical to Wnt/β-catenin pathway control [4]. Normally, casein kinase 1 (CK1) and glycogen synthase kinase-3β (GSK-3β), which form a complex with the scaffolding protein Axin and the tumor suppressor protein adenomatous polyposis coli (APC), phosphorylate β-catenin at Ser45, Thr41, Ser37, and Ser33 [5, 6]. Phosphorylated β-catenin is ubiquitinated by the β-transducin repeat-containing protein (β-TrCP), an F-box E3 ubiquitin ligase complex, and ubiquitinated β-catenin is degraded via a proteasome pathway [7, 8]. Colorectal cancer is a significant cause of cancer-related deaths worldwide. Abnormal up-regulation of the Wnt/β-catenin pathway is a major pathological event in intestinal epithelial cells during human colorectal cancer oncogenesis [9]. Genetic mutations in the APC gene are observed in familial adenomatous polyposis coli (FAP) and sporadic colorectal cancers [10]. In addition, mutations in the N-terminal phosphorylation motif of the β-catenin gene were found in patients with colorectal cancer [11]. These mutations cause β-catenin to accumulate in the nucleus, where it forms complexes with transcription factors of the T-cell factor/lymphocyte enhancer factor (TCF/LEF) family to stimulate the expression of β-catenin responsive genes, such as c-Myc and cyclin D1, which leads to colorectal tumorigenesis [12-14]. Therefore, downregulating β-catenin response transcription (CRT) is a potential strategy for preventing and treating colorectal cancer. Plant cytokinins are N⁶-substituted purine derivatives; they promote cell division in plants and regulate developmental pathways. Natural cytokinins are classified as isoprenoid (isopentenyladenine, zeatin, and dihydrozeatin), aromatic (benzyladenine, topolin, and methoxytopolin), or furfural (kinetin and kinetin riboside), depending on their structure [15, 16]. Kinetin riboside was identified in coconut water and is a naturally produced cytokinin that induces apoptosis and exhibits antiproliferative activity in several human cancer cell lines [17]. However, little attention has been paid to kinetin riboside's mode of action. In this study, we show that kinetin riboside exerts its cytotoxic activity against colon cancer cells by suppressing the Wnt/β-catenin pathway and promoting intracellular β-catenin degradation.

• Journal of Microbiology and Biotechnology
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• 제31권11호
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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.