• BMB Reports
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• v.55 no.6
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• pp.299-304
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• 2022

Chloride channel-5 (ClC-5), an important branch of the ClC family, is involved in the regulation of the proliferation and cell-fate of a variety of cells, including tumor cells. However, its function in cholangiocarcinoma (CCA) cells remains enigmatic. Here, we discovered that ClC-5 was up-regulated in CCA tissues and CCA cell lines, while ClC-5 silencing inhibited CCA cell proliferation and induced apoptosis. Further mechanism studies revealed that ClC-5 inhibition could inhibit Wnt/β-catenin signaling activity and further activate the mitochondria apoptotic pathway in CCA cells. Furthermore, rescuing Wnt/β-catenin signaling activation eliminated the anti-tumor function of ClC-5 knockdown. Together, our research findings illustrated that ClC-5 inhibition plays an anti-tumor role in CCA cells via inhibiting the activity of the Wnt/β-catenin pathway, which in turn activates the mitochondrial apoptotic pathway.

• Korean Journal of Poultry Science
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• v.44 no.3
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• pp.199-209
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• 2017

Mitogen-activated protein kinase (MAPK) signaling pathways play a key role in innate immunity, inflammation, cell proliferation, cell differentiation, and cell death. The main objective of this study was to investigate the expression level of candidate MAPK pathway genes in the intestinal mucosal layer 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). Using high-throughput RNA sequencing, we investigated 178 MAPK signaling pathway related genes that were significantly and differentially expressed between the intestinal mucosal layers of the NE-afflicted and control chickens. In total, 15 MAPK pathway genes were further measured by quantitative real-time PCR(qRT-PCR) and the results were consistent with the RNA-sequencing data. All 178 identified genes were annotated through Gene Ontology and mapped onto the KEGG chicken MAPK signaling pathway. Several key genes of the MAPK pathway, ERK1/2, JNK1-3, p38 MAPK, MAP2K1-4, $NF-{\kappa}B1/2$, c-Fos, AP-1, Jun-D, and Jun, were differentially expressed in the two chicken lines. Therefore, we believe that RNA sequencing and qRT-PCR analysis provide resourceful information for future studies on MAPK signaling of genetically disparate chicken lines in response to pathogens.

• BMB Reports
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• v.42 no.8
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• pp.516-522
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• 2009

SH2D4A, comprising a single SH2 domain, is a novel protein of the SH2 signaling protein family. We have previously demonstrated SH2D4A is expressed ubiquitously in various tissues and is located in the cytoplasm. In this study we investigated the function of SH2D4A in human embryonic kidney (HEK) 293 cells using interaction analysis, cell proliferation assays, and kinase activity detection. SH2D4A was found to directly bind to estrogen receptor $\alpha$ (ER$\alpha$), and prevent the recruitment of phospholipase C-$\gamma$ (PLC-$\gamma$) to ER$\alpha$. Moreover, we observed its inhibitory effects on estrogen-induced cell proliferation, involving the protein kinase C (PKC) signaling pathway. Together, these findings suggested that SH2D4A inhibited cell proliferation by suppression of the ER$\alpha$/PLC-$\gamma$/PKC signaling pathway. SH2D4A may be useful for the development of a new anti-cancer drug acting as an ER signaling modulator.

• Herbal Formula Science
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• v.31 no.1
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• pp.41-51
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• 2023

Objectives : Raphani Semen (Raphanus sativus L.) is known for the various beneficial effects in Korean medicine. This study aimed to investigate the effect of Raphani Semen extract (RSE) against arachidonic acid (AA)+iron-induced oxidative stress in cells. Methods : Ingredients, their target information, oxidative stress liver injury-related proteins was obtained from various network pharmacology databases and software. A hypergeometric test and enrichment analysis were conducted to evaluate associations between protein targets of RSE. The cell viability was assessed by MTT assay, and immunoblot analysis was used to confirm the molecular mechanisms. Results : A compound-target network of RSE was constructed, which consisted of 336 edges between 18 ingredients and 123 protein targets. PI3K-Akt signaling pathway, ErbB signaling pathway, HIF-1 signaling pathway, PPAR signaling pathway, and AMPK signaling pathway was significantly associated with protein targets of RSE. RSE protected HepG2 cells against AA+iron-induced oxidative stress as mediated with AMPK signaling. Conclusion : RSE was found to protect the cells against oxidative stress via the AMPK signaling pathway.

• Mycobiology
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• v.51 no.3
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• pp.178-185
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• 2023

The cell wall integrity (CWI) signaling pathway plays important roles in the dissemination and infection of several plant pathogenic fungi. However, its roles in the pepper fruit anthracnose fungus Colletotrichum scovillei remain uninvestigated. In this study, the major components of the CWI signaling pathway-CsMCK1 (MAPKKK), CsMKK1 (MAPKK), and CsMPS1 (MAPK)-were functionally characterized in C. scovillei via homology-dependent gene replacement. The ΔCsmck1, DCsmkk1, and ΔCsmps1 mutants showed impairments in fungal growth, conidiation, and tolerance to CWI and salt stresses. Moreover, ΔCsmck1, ΔCsmkk1, and ΔCsmps1 failed to develop anthracnose disease on pepper fruits due to defects in appressorium formation and invasive hyphae growth. These results suggest that CsMCK1, CsMKK1, and CsMPS1 play important roles in mycelial growth, conidiation, appressorium formation, plant infection, and stress adaption of C. scovillei. These findings will contribute to a better understanding of the roles of the CWI signaling pathway in the development of pepper fruit anthracnose disease.

• Journal of Microbiology and Biotechnology
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• v.32 no.1
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• pp.126-140
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• 2022

Stem cells can be applied usefully in basic research and clinical field due to their differentiation and self-renewal capacity. The aim of this study was to establish an effective novel therapeutic cellular source and create its molecular expression profile map to elucidate the possible therapeutic mechanism and signaling pathway. We successfully obtained a mesenchymal stem cell population from human embryonic stem cells (hESCs) cultured on chemically defined feeder-free conditions and treated with connective tissue growth factor (CTGF) and performed the expressive proteomic approach to elucidate the molecular basis. We further selected 12 differentially expressed proteins in CTGF-induced hESC-derived mesenchymal stem cells (C-hESC-MSCs), which were found to be involved in the metabolic process, immune response, cell signaling, and cell proliferation, as compared to bone marrow derived-MSCs(BM-MSCs). Moreover, these up-regulated proteins were potentially related to the Wnt/β-catenin pathway. These results suggest that C-hESC-MSCs are a highly proliferative cell population, which can interact with the Wnt/β-catenin signaling pathway; thus, due to the upregulated cell survival ability or downregulated apoptosis effects of C-hESC-MSCs, these can be used as an unlimited cellular source in the cell therapy field for a higher therapeutic potential. Overall, the study provided valuable insights into the molecular functioning of hESC derivatives as a valuable cellular source.

• BMB Reports
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• v.51 no.3
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• pp.134-142
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• 2018

Organ growth is fundamental to animal development. One of major mechanisms for growth control is mediated by the conserved Hippo signaling pathway initially identified in Drosophila. The core of this pathway in Drosophila consists of a cascade of protein kinases Hippo and Warts that negatively regulate transcriptional coactivator Yorkie (Yki). Activation of Yki promotes cell survival and proliferation to induce organ growth. A key issue in Hippo signaling is to understand how core kinase cascade is activated. Activation of Hippo kinase cascade is regulated in the upstream by at least two transmembrane proteins Crumbs and Fat that act in parallel. These membrane proteins interact with additional factors such as FERM-domain proteins Expanded and Merlin to modulate subcellular localization and function of the Hippo kinase cascade. Hippo signaling is also influenced by cytoskeletal networks and cell tension in epithelia of developing organs. These upstream events in the regulation of Hippo signaling are only partially understood. This review focuses on our current understanding of some upstream processes involved in Hippo signaling in developing Drosophila organs.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.12
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• pp.1155-1163
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• 2004

Extracellular signal-regulated kinase (ERK) signaling pathway is one of the mitogen-activated protein kinase (MAPK) signal transduction pathways. This pathway is known as pivotal in many signaling networks that govern proliferation, differentiation and cell survival. The ERK signaling pathway comprises positive and negative feedback loops, depending on whether the terminal kinase stimulates or inhibits the activation of the initial level. In this paper, we attempt to model the ERK pathway by considering both of the positive and negative feedback mechanisms based on Michaelis-Menten kinetics. In addition, we propose a fraction ratio model based on the mass action law. We first develop a mathematical model of the ERK pathway with fraction ratios. Secondly, we analyze the dynamical properties of the fraction ratio model based on simulation studies. Furthermore, we propose a concept of an inhibitor, catalyst, and substrate (ICS) controller which regulates the inhibitor, catalyst, and substrate concentrations of the ERK signal transduction pathway. The ICS controller can be designed through dynamical analysis of the ERK signaling transduction pathway within limited concentration ranges.

• Molecular & Cellular Toxicology
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• v.4 no.3
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• pp.177-182
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• 2008

Caveolin proteins are mediators of cell death or the survival of injured cells, and they are inhibitors of various signaling pathways. The expression of caveolin-, which is involved in the protein kinase A (PKA) signaling pathway, was examined in the differentiated mouse vestibular cell line UB/UE-1 after gentamicin ototoxicity. Caveolae in the vestibular hair cell of healthy guinea pigs were observed through an electron microscope. UB/UE-1 cells were cultured at 95% $CO_2$ with 5% $O_2$ at $33^{\circ}C$ for 48 hours and at 95% $CO_2$ with 5% $O_2$ at $39^{\circ}C$ for 24 hours for differentiation. Cells were treated with 1 mM gentamicin, 0.02 mM H89 (PKA inhibitor), and then incubated for 24 hours. Caveolin-1 expression was examined by western blotting and PKA activity by a $PepTag^{(R)}$ assay. Caveolae were observed in the vestibular hair cells of healthy guinea pigs by electron microscopy. Caveolin-1 was expressed spontaneously in differentiated UB/UE-1 cells and increased after gentamicin treatment. PKA was also over-activated by gentamicin treatment. Both gentamicin-induced caveolin-1 expression and PKA over-activation were inhibited by H89. These results indicate that gentamicin-induced caveolin-1 expression is mediated by the PKA signaling pathway. We conclude that caveolae/ caveolin activity, induced via a PKA signaling pathway, may be one of the mechanisms of gentamicin-induced ototoxicity.

• BMB Reports
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• v.48 no.10
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• pp.571-576
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• 2015

SB743921 is a potent inhibitor of the spindle protein kinesin and is being investigated in ongoing clinical trials for the treatment of myeloma. However, little is known about the molecular events underlying the induction of cell death in multiple myeloma (MM) by SB743921, alone or in combination treatment. Here, we report that SB743921 induces mitochondria-mediated cell death via inhibition of the $NF-{\kappa}B$ signaling pathway, but does not cause cell cycle arrest in KMS20 MM cells. SB743921-mediated inhibition of the $NF-{\kappa}B$ pathway results in reduced expression of SOD2 and Mcl-1, leading to mitochondrial dysfunction. We also found that combination treatment with SB743921 and bortezomib induces death in bortezomib-resistant KMS20 cells. Altogether, these data suggest that treatment with SB743921 alone or in combination with bortezomib offers excellent translational potential and promises to be a novel MM therapy.