• IMMUNE NETWORK
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• v.9 no.6
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• pp.248-254
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• 2009

[ $TGF-{\beta}1$ ]is well known to induce Ig germ-line ${\alpha}$ ($GL{\alpha}$) transcription and subsequent IgA isotype class switching recombination (CSR). Homeodomain protein TG-interacting factor (TGIF) and E3-ubiquitin ligases TGIF interacting ubiquitin ligase 1 (Tiul1) are implicated in the negative regulation of $TGF-{\beta}$ signaling. In the present study, we investigated the roles of Tiul1 and TGIF in $TGF{\beta}1$-induced IgA CSR. We found that over-expression of Tiul1 decreased $TGF{\beta}1$-induced $GL{\alpha}$ promoter activity and strengthened the inhibitory effect of Smad7 on the promoter activity. Likewise, overexpression of TGIF also diminished $GL{\alpha}$ promoter activity and further strengthened the inhibitory effect of Tiul1, suggesting that Tiul1 and TGIF can down-regulate $TGF{\beta}1$-induced $GL{\alpha}$ expression. In parallel, overexpression of Tiul1 decreased the expression of endogenous IgA CSR-predicitive transcripts ($GLT_{\alpha},\;PST_{\alpha},\;and\;CT_{\alpha}$) and $TGF{\beta}1$-induced IgA secretion, but not $GLT_{\gamma3}$ and IgG3 secretion. Here, over-expressed TGIF further strengthened the inhibitory effect of Tiul1. These results suggest that Tiul1 and TGIF act as negatively regulators in $TGF{\beta}1$-induced IgA isotype expression.

• Nutrition Research and Practice
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• v.11 no.3
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• pp.190-197
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• 2017

BACKGROUND/OBJECTIVES: Gallus gallus domesticus (GD) is a natural mutant breed of chicken in Korea with an atypical characterization of melanin in its tissue. This study investigated the effects of melanin extracts of GD on osteoblast differentiation and inhibition of osteoclast formation. MATERIALS/METHODS: The effects of the melanin extract of GD on human osteoblast MG-63 cell differentiation were examined by evaluating cell viability, osteoblast differentiation, and expression of osteoblast-specific transcription factors such as bone morphogenetic protein 2 (BMP-2), small mothers against decapentaplegic homologs 5 (SMAD5), runt-related transcription factor 2 (RUNX2), osteocalcin and type 1 collagen (COL-1) by reverse transcription-polymerase chain reaction and western blotting analysis. We investigated the inhibitory effect of melanin on the osteoclasts formation through tartrate-resistant acid phosphatase (TRAP) activity and TRAP stains in Raw 264.7 cell. RESULTS: The melanin extract of GD was not cytotoxic to MG-63 cells at concentrations of $50-250{\mu}g/mL$. Alkaline phosphatase (ALP) activity and bone mineralization of melanin extract-treated cells increased in a dose-dependent manner from 50 to $250{\mu}g/mL$ and were 149% and 129% at $250{\mu}g/mL$ concentration, respectively (P < 0.05). The levels of BMP-2, osteocalcin, and COL-1 gene expression were significantly upregulated by 1.72-, 4.44-, and 2.12-fold in melanin-treated cells than in the control cells (P < 0.05). The levels of RUNX2 and SMAD5 proteins were higher in melanin-treated cells than in control vehicle-treated cells. The melanin extract attenuated the formation of receptor activator of nuclear factor kappa-B ligand-induced TRAP-positive multinucleated RAW 264.7 cells by 22%, and was 77% cytotoxic to RAW 264.7 macrophages at a concentration of $500{\mu}g/mL$. CONCLUSIONS: This study provides evidence that the melanin extract promoted osteoblast differentiation by activating BMP/SMADs/RUNX2 signaling and regulating transcription of osteogenic genes such as ALP, type I collagen, and osteocalcin. These results suggest that the effective osteoblastic differentiation induced by melanin extract from GD makes it potentially useful in maintaining bone health.

• Molecules and Cells
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• v.22 no.2
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• pp.133-140
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• 2006

Jun activation domain-binding protein 1 (Jab1) is involved in various cellular mechanisms including development in Drosophila and mouse, cell cycle control and signal transduction pathways. Recent studies also determined that Jab1 functions as a nuclear exporter and inducer of cytoplasmic degradation for several proteins including p53, p27, capsid of West Nile virus, and Smad4/7 proteins. In particular, p53 is shown to bind to and to be exported into the cytoplasm by Jab1, which helps to maintain low levels of p53 under normal conditions. This review was undertaken in an effort to understand the biological significance of the homeostasis of p53 as maintained in the presence of Jab1. Based on our observations, we have provided potential mechanistic hypotheses for the nuclear export of p53 in coordination with Jab1 and the role of other factors in these processes.

• Korean Journal of Poultry Science
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• v.44 no.3
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• pp.211-223
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• 2017

Transforming growth factor beta ($TGF-{\beta}$) signaling pathways are involved in the regulation of proliferation, differentiation, immunity, survival, and apoptosis of many cells. The aim of this study was to investigate the differential expression of $TGF-{\beta}$-related genes, and their interactions and regulators in the spleen of two genetically disparate chicken lines (Marek's disease resistant line 6.3 and Marek's disease-susceptible line 7.2) induced with necrotic enteritis (NE) by Eimeria maxima and Clostridium perfringens infection. By using high-throughput RNA-sequencing, we investigated 76 $TGF-{\beta}$-related genes that were significantly and differentially expressed in the spleens of the chickens. Approximately 20 $TGF-{\beta}$ pathway genes were further verified by qRT-PCR, and the results were consistent with our RNA sequencing data. All 76 identified genes were analyzed through Gene Ontology and mapped onto the KEGG chicken $TGF-{\beta}$ pathway. Our results demonstrated that several key genes, including $TGF-{\beta}$1-3, bone morphogenetic proteins (BMP)1-7, inhibitor of differentiation (ID) proteins ID1-3, SMAD1-9, and Jun, showed a markedly differential expression between the two chicken lines, relative to their respective controls. We then further predicted 24 known miRNAs that targeted BMP7 mRNA from 139 known miRNAs in the two chicken lines. Among these, six miRNAs were measured by qRT-PCR. In conclusion, this study is the first to analyze most of the genes, interactions, and regulators of the $TGF-{\beta}$ pathway in the innate immune responses of NE afflicted chickens.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.2
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• pp.157-167
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• 2022

In this study, we investigated the effects of heptapeptide on cellular activation and inhibition of cellular damage induced by photoaging condition in NIH3T3 fibroblasts. Cell proliferation and extracellular matrix (ECM) expression were induced by heptapeptide. The reduced cell viability under photoaging condition through ultraviolet A (UVA) irradiation was increased by heptapeptide. And UVA-induced apoptosis, matrix metalloproteinases-1 (MMP-1) expression, and reactive oxygen species (ROS) level were decreased by heptapeptide. In addition, the inhibition of transforming growth factor-β (TGF-β)/smad signaling under UVA irradiation which resulting in reduction of ECM expression was also recovered by heptapeptide. We also tested the effect of heptapeptide under another photoaging condition through heat shock, and pre-treatment of heptapeptide prevented the phosphorylation of mitogen-activated protein kinase (MAPK) and MMP-1 expression induced by heat shock. From these results, it has been shown that the heptapeptide has protective effects on fibroblasts through the up-regulation of cellular activity and through the decreasing of intracellular ROS level induced by UVA irradiation or heat shock. It is expected that the dermal protection effect of heptapeptide can be applied as a new cosmetic material in the future.

• BMB Reports
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• v.55 no.11
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• pp.565-570
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• 2022

Pulmonary arterial hypertension (PAH) is a progressive and devastating disease whose pathogenesis is associated with a phenotypic switch of pulmonary arterial vascular smooth muscle cells (PASMCs). Bone morphogenetic protein (BMP) signaling and potassium two pore domain channel subfamily K member 3 (KCNK3) play crucial roles in PAH pathogenesis. However, the relationship between BMP signaling and KCNK3 expression in the PASMC phenotypic switching process has not been studied. In this study, we explored the effect of BMPs on KCNK3 expression and the role of KCNK3 in the BMP-mediated PASMC phenotypic switch. Expression levels of BMP receptor 2 (BMPR2) and KCNK3 were downregulated in PASMCs of rats with PAH compared to those in normal controls, implying a possible association between BMP/BMPR2 signaling and KCNK3 expression in the pulmonary vasculature. Treatment with BMP2, BMP4, and BMP7 significantly increased KCNK3 expression in primary human PASMCs (HPASMCs). BMPR2 knockdown and treatment with Smad1/5 signaling inhibitor substantially abrogated the BMP-induced increase in KCNK3 expression, suggesting that KCNK3 expression in HPASMCs is regulated by the canonical BMP-BMPR2-Smad1/5 signaling pathway. Furthermore, KCNK3 knockdown and treatment with a KCNK3 channel blocker completely blocked BMP-mediated anti-proliferation and expression of contractile marker genes in HPAMSCs, suggesting that the expression and functional activity of KCNK3 are required for BMP-mediated acquisition of the quiescent PASMC phenotype. Overall, our findings show a crosstalk between BMP signaling and KCNK3 in regulating the PASMC phenotype, wherein BMPs upregulate KCNK3 expression and KCNK3 then mediates BMP-induced phenotypic switching of PASMCs. Our results indicate that the dysfunction and/or downregulation of BMPR2 and KCNK3 observed in PAH work together to induce aberrant changes in the PASMC phenotype, providing insights into the complex molecular pathogenesis of PAH.

• BMB Reports
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• v.56 no.7
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• pp.374-384
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• 2023

Fibrosis is a pathological condition that is characterized by an abnormal buildup of extracellular matrix (ECM) components, such as collagen, in tissues. This condition affects various organs of the body, including the liver and kidney. Early diagnosis and treatment of fibrosis are crucial, as it is a progressive and irreversible process in both organs. While there are certain similarities in the fibrosis process between the liver and kidney, there are also significant differences that must be identified to determine molecular diagnostic markers and potential therapeutic targets. Long non-coding RNAs (lncRNAs), a class of RNA molecules that do not code for proteins, are increasingly recognized as playing significant roles in gene expression regulation. Emerging evidence suggests that specific lncRNAs are involved in fibrosis development and progression by modulating signaling pathways, such as the TGF-β/Smad pathway and the β-catenin pathway. Thus, identifying the precise lncRNAs involved in fibrosis could lead to novel therapeutic approaches for fibrotic diseases. In this review, we summarize lncRNAs related to fibrosis in the liver and kidney, and propose their potential as therapeutic targets based on their functions.

• Journal of Nutrition and Health
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• v.56 no.6
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• pp.602-614
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• 2023

Purpose: The balance between synthesis and degradation of proteins plays a critical role in the maintenance of skeletal muscle mass. Mitochondrial dysfunction has been closely associated with skeletal muscle atrophy caused by aging, cancer, and chemotherapy. Polygalacin D is a saponin derivative isolated from Platycodon grandiflorum (Jacq.) A. DC. This study aimed to investigate the effects of polygalacin D on myoblast differentiation and muscle atrophy in association with mitochondrial function in in vitro and in zebrafish models in vivo. Methods: C2C12 myoblasts were cultured in differentiation media containing different concentrations of polygalacin D, followed by the immunostaining of the myotubes with myosin heavy chain (MHC). The mRNA expression of markers related to myogenesis, muscle atrophy, and mitochondrial function was determined by real-time quantitative reverse transcription polymerase chain reaction. Wild type AB^* zebrafish (Danio rerio) embryos were treated with 5-fluorouracil, leucovorin, and irinotecan (FOLFIRI) with or without polygalacin D, and immunostained to detect slow and fast types of muscle fibers. The Tg(Xla.Eef1a1:mitoEGFP) zebrafish expressing mitochondria-targeted green fluorescent protein was used to monitor mitochondrial morphology. Results: The exposure of C2C12 myotubes to 0.1 ng/mL of polygalacin D increased the formation of MHC-positive multinucleated myotubes (≥ 8 nuclei) compared with the control. Polygalacin D significantly increased the expression of MHC isoforms (Myh1, Myh2, Myh4, and Myh7) involved in myoblast differentiation while it decreased the expression of atrophic markers including muscle RING-finger protein-1 (MuRF1), mothers against decapentaplegic homolog (Smad)2, and Smad3. In addition, polygalacin D promoted peroxisome proliferator-activated receptor-gamma coactivator (Pgc1α) expression and reduced the level of mitochondrial fission regulators such as dynamin-1-like protein (Drp1) and mitochondrial fission 1 (Fis1). In a zebrafish model of FOLFIRI-induced muscle atrophy, polygalacin D improved not only mitochondrial dysfunction but also slow and fast muscle fiber atrophy. Conclusion: These results demonstrated that polygalacin D promotes myogenesis and alleviates chemotherapy-induced muscle atrophy by improving mitochondrial function. Thus, polygalacin D could be useful as nutrition support to prevent and ameliorate muscle wasting and weakness.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4249-4254
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• 2013

Background: Parafibromin is a protein encoded by the HRPT2 (hyperparathyroidism 2) oncosuppressor gene and its down-regulated expression is involved in pathogenesis of parathyroid, breast, gastric and colorectal carcinomas. This study aimed to clarify the effects of parafibromin expression on the phenotypes and relevant mechanisms of DLD-1 colon carcinoma cells. Methods: DLD-1 cells transfected with a parafibromin-expressing plasmid were subjected to examination of phenotype, including proliferation, differentiation, apoptosis, migration and invasion. Phenotype-related proteins were measured by Western blot. Parafibromin and ki-67 expression was detected by immunohistochemistry on tissue microarrays. Results: The transfectants showed higher proliferation by CCK-8, better differentiation by electron microscopy and ALP activity and more apoptotic resistance to cisplatin by DNA fragmentation than controls. There was no difference in early apoptosis by annexin V, capase-3 activity, migration and invasion between DLD-1 cells and their transfectants. Ectopic parafibromin expression resulted in down-regulated expression of smad4, MEKK, GRP94, GRP78, $GSK3{\beta}$-ser9, and Caspase-9. However, no difference was detectable in caspase-12 and -8 expression. A positive relationship was noted between parafibromin and ki-67 expression in colorectal carcinoma. Conclusions: Parafibromin overexpression could promote cell proliferation, apoptotic resistance, and differentiation of DLD-1 cells.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.357-365
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• 2022

We examined the lung anti-fibrotic properties of flavanones and flavones, which are flavonoid compounds, in bleomycin- and TGF-β1-stimulated A549 cells. Taken together, treatment with Bleomycin and TGF-β1 increased intracellular ROS by increasing the expression of various NOX families in A549 cells; further, the increased ROS levels resulted in increased fibrosis markers and induced pulmonary fibrosis. Flavonoid treatment has been demonstrated to alleviate or inhibit pulmonary fibrosis by modulating Smad-dependent and -non-dependent TGF-β mechanisms by modulating intracellular NOX expression.