• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.211-226
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• 2019

Pig CD45, the leukocyte common antigen, is encoded by the PTPRC gene and CD45 is a T cell-type specific tyrosine phosphatase with alternative splicing of its exons. The CD45 is a coordinated regulator of T cell antigen receptor (TCR) signal transduction achieved by dephosphorylating the phosphotyrosine of its substances, including $CD3{\zeta}$ chain of TCR, Lck, Fyn, and Zap-70 kinase. A dysregulation of CD45 is associated with a multitude of immune disease and has been a target for immuno-drug discovery. To characterize its key structural features with the effects of regulating TCR signaling, this study predicted the unknown structure of pig CD45RO (the smallest isoform) and the complex structure bound to the ITAM (REEpYDV) of $CD3{\zeta}$ chain via homology modeling and docking the peptide, based on the known human CD45 structures. These features were integrated into the structural plasticity of extracellular domains and functional KNRY and PTP signature motifs (the role of a narrow entrance into ITAM binding site) of the tyrosine phosphatase domains in a cytoplasmic region from pig CD45RO. This contributes to the selective recognition of phosphotyrosine from its substrates by adjusting the structural stability and binding affinity of the complex. The characterized features of pigCD45RO can be applied in virtual screening of the T-cell specific immunomodulator.

• Prospectives of Industrial Chemistry
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• v.24 no.6
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• pp.32-40
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• 2021

세포 투과성 펩타이드(cell penetrating peptide; CPP)는 강력한 세포막 투과성을 보유하고 있어 난투과성 중거대분자 약물의 세포 내 전달체 개발에 있어 중요한 요소 기술로 부각되고 있다. 하지만 대부분의 세포 투과성 펩타이드는 타겟 세포에 대한 선택성 없이 투과하므로, 전신 투여시 심각한 부작용이 발생할 수 있다. 이 글에서는 선택적 세포 투과성 펩타이드를 개발하는 최근 연구 전략 중, 타겟 세포 표면에 존재하는 수용체에 결합하는 리간드를 이용한 전략과, 타겟 세포 주변의 물리, 화학, 생물학적 신호 변화를 이용하는 전략에 대해 소개한다. 특히, 최근 논문에 발표된, 어피버디(affibody)와 세포 투과성 펩타이드 결합체를 이용하여 HER2 수용체를 지닌 유방암 세포에 선택적 투과성을 부여하는 방법과, 암세포 주변의 작은 pH 변화를 감지하여 양전하성을 조절함으로써 수용체가 없는 유방암 세포에도 선택적으로 투과성을 보이는 방법에 대해 자세하게 소개한다.

• Radiation Oncology Journal
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• v.21 no.3
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• pp.227-237
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• 2003

Purpose: The human chronic myelogenous leukemia cell line, K562, expresses the chimeric bcr-abl oncoprotein, whose deregulated protein tyrosine kinase activity antagonizes via DNA damaging agents. Previous experiments have shown that nanomolar concentrations of herbimycin A (HWA) coupled with X-irradiation have a synergistic effect in inducing apoptosis in the Ph-positive K562 leukemia cell line, but genistein, a PTK inhibitor, is non selective for the radiation-induced apoptosils on $p210^{bcr/abl}$ protected K562 cells. In these experiments, the cytoplasmic signal transduction pathways, the Induction on a number of transcription factors and the differential gene expression in this model were investigated. Materials and Methids: K562 cells in the exponential growth phase were used in this study. The cells were irradiated with 0.5-12 Gy, using a 6 Mev Linac (Clinac 1800, Varian, USA). Immediately after irradiation, the cells were treated with $0.25/muM$ of HMA and $25/muM$ of genistein, and the expressions and the activities of abl kinase, MAPK family, NF- kB, c-fos, c-myc, and thymidine kinase1 (TK1) were examined. The differential gene expressions induced by PTK inhibitors were also investigated. Results: The modulating effects of herbimycin A and genistein on the radiosensitivity of K562 cells were not related to the bcr-abl kinase activity. The signaling responses through the MAPK family of proteins, were not involved either in association with the radiation-induced apoptosis, which is accelerated by HMA, the expression of c-myc was increased. The combined treatment of genistein, with irradiation, enhanced NF- kB activity and the TK1 expression and activity. Conclusion: The effects of HMA and genistein on the radiosensitivity on the K562 cells were not related to the bcr-abl kinase activity in this study, another signaling pathway, besides the WAPK family responses to radiation to K562 cells, was found. Further evaluation using this model will provide valuable information for the optional radiosensitization or radioprotection.

• Journal of Life Science
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• v.26 no.3
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• pp.325-330
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• 2016

In this study, we evaluated the antidiabetic effect of submerged culture of Ceriporia lacerata mycelium (CL01) on glucose uptake and the expression of mRNA and protein of major signal markers of insulin signaling pathway in 3T3-L1 adipocytes. After 3T3-L1 adipocytes were pre-treated by CL01 (0, 2, 10 mg/ml) for 8 hours, followed with treatment of insulin, the glucose uptake levels significantly increased by more 55.1%, 94.4% than negative control respectively (p<0.01, 0.001) in a dose-dependent manner. However, in case of CL01 pre-treatment without insulin, the glucose uptake did not increase compared with insulin-treated 3T3-L1. Also we demonstrated that the protein expression levels of pIR β, pAkt, pPI3K and pAMPK and the mRNA expression levels of GLUT4 in adipocytes inducing insulin resistance increased in CL01-treated group compared with negative control. These results demonstrated that CL01 affected glucose metabolism and the protein and gene expression through insulin signaling pathway, and increased glucose uptake levels effectively. More than 90% of those who have suffered for type 2 diabetes are more likely to have from hyperinsulinemia, hypertension, obesity and etc. because of altered insulin signaling pathway. So, it is probably considered that intake of CL01 may treat type 2 diabetes by normalization of insulin signaling pathway, and it will provide useful evidences regarding a mechanism for cure of type 2 diabetes.

• Radiation Oncology Journal
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• v.15 no.2
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• pp.79-95
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• 1997

Purpose : Phospholipase C(PLC) isozymes play significant roles in signal transduction mechanism. $PLC-\gamma$ 1 is one of the key regulatory enzymes in signal transduction for cellular proliferation and differentiation. Ras oncoprotein, EGFR, and PKC are also known to be involved in cell growth. The exact mechanisms of these signal transduction following irradiation, however, were not clearly documented Thus, this study was Planned to determine the biological significance of PLC, ras oncoprotein, EGFR, and PKC in damage and regeneration of rat intestinal mucosa following irradiation. Material and Method : Sixty Sprague-Dawley rats were irradiated to entire body with a single dose of 8Gy. The rats were divided into S groups according to the sacrifice days after irradiation. The expression of PLC, ras oncoprotein, EGFR and PKC in each group were examined by the immunoblotting and immunohistochemistry. The histopathologic findings were observed using H&I stain, and the mitoses for the evidence of regeneration were counted using the light microscopy & PCNA kit. The Phosphoinositide(PI) hydrolyzing activity assay was also done for the indirect evaluation of $PLC-\gamma$ 1 activity. Results: In the immunohistochemistry , the expression of $PLC-{\beta}$ was negative for all grøups. The expression of $PLC-{\gamma}1$ was highest in the group III followed by group II in the proliferative zone of mucosa. The expression of $PKC-{\delta}1$ was strongly positive in group 1 followed by group II in the damaged surface epithelium. The above findings were also confirttled in the immunoblotting study. In the immunoblotting study, the expressions of $PLC-{\beta}$, $PLC-{\gamma}1$, and $PKC-{\delta}1$ were the same as the results of immunohis-tochemistry. The expression of ras oncoprctein was weakly positive in groups II, III and IV. The of EGFR was the highest in the group II, III, follwed by group IV and the expression of PKC was weakly positive in the group II and III. Conclusion: $PLC-{\gamma}1$ mediated signal transduction including ras oncoprotein, EGFR, and PKC play a significant role in mucosal regeneration after irradiation. $PLC-{\delta}1$ mediated signal transduction might have an important role in mucosal damage after irradiation. Further studies will be necessary to confirm the signal transduction mediating the $PKC-{\delta}1$.

• Korean Journal of Poultry Science
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• v.50 no.4
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• pp.283-291
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• 2023

Long-chain fatty acids (LCFAs) are vital in cellular compartments, primarily regulating lipid metabolism. Fatty Acid-Binding Proteins (FABPs) facilitate LCFA transport, lipid synthesis, storage, and act as signaling molecules influencing various pathways, including inflammation. FABP4, in particular, is linked to vascular and cardio-related diseases, and it plays a role in macrophage-mediated inflammatory responses. Previous studies have identified FABP4 as not only a representative biomarker for lipogenesis but also as having correlations with immune responses. This study aims to investigate the regulation of the chicken FABP4 (chFABP4) gene by toll-like receptor 3 (TLR3) activation and determine the signaling pathways that are involved in chFABP4 transcriptional regulation. We analyzed the transcriptional regulation of chFABP4 in TLR3-stimulated DF-1 cells. The results showed that chFABP4 was up-regulated upon stimulation with polyinosinic-polycytidylic acid (PIC), a TLR3 ligand. Notably, chFABP4 transcription was independently regulated in the NF-κB signaling pathway. It was up-regulated in p38 inhibition, demonstrating that the p38 signaling pathway might suppress the transcription of chFABP4 within TLR3-activated DF-1 cells. In contrast, chFABP4 expression was down-regulated in JNK signaling pathway inhibition, suggesting the positive regulation of JNK signaling pathway for chFABP4 transcription in DF-1 cells in response to TLR3 activation, consistent with findings in macrophages. MEK pathway inhibition resulted in a similar regulation to NF-κB signaling. These results suggest that each MAPK contributes differentially to the transcriptional regulation of chFABP4 by in DF-1 cells in response to TLR3 activation.

• Applied Chemistry for Engineering
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• v.32 no.6
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• pp.647-652
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• 2021

In this study, Saussurea Lappa roots were extracted using ethanol and n-hexane, and also the effects on proliferation of human hair dermal papilla cells and fibroblast and related signaling pathway were evaluated. 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromide (MTT) assay was conducted for cell proliferation effect of Saussurea Lappa root extract, and extracellular signal-related kinase (ERK), serine/threonine protein kinase (Akt), wingless-related integration site (Wnt)/𝛽-catenin signaling pathway, and 5𝛼-reductase expression through western blot analysis were measured. Saussurea Lappa root extract significantly increased human hair dermal papilla cells and propagation of fibroblast, promoted phosphorylation of ERK and Akt that get involved in cell proliferation. Additionally, Saussurea Lappa root extract significantly decreased promotion of Akt phosphorylation and cell proliferation by MEK/ERK inhibitor PD98059 and PI3K/Akt inhibitor LY294002. Also, Saussurea Lappa root extract induced intranuclear 𝛽-catenin accumulation by promoting phosphorylation of 𝛽-catenin (Ser552, 675) through phosphorylation of GSK-3𝛽 (Ser9), and suppressed activation of 5𝛼-reductase type I and II. Overall, Saussurea Lappa root induces cell proliferation through vitalization of ERK and Akt route of human hair dermal papilla cells and fibroblast and apoptosis defense mechanism, and can be helpful in hair loss prevention and hair growth by vitalizing the 𝛽-catenin signaling pathway and inhibiting activation of 5𝛼-reductase, which can be used as a potential hair care products.

• Tuberculosis and Respiratory Diseases
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• v.49 no.3
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• pp.310-322
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• 2000

Background : Phospholipase C(PLC) plays an important role in cellular signal transduction and is thought to be critical in cellular growth, differentiation and transformation of certain malignancies. Two second messengers produced from the enzymatic action of PLC are diacylglycerol (DAG) and inositol 1, 4, 5-trisphosphate (IP3). These two second messengers are important in down stream signal activation of protein kinase C and intracellular calcium elevation. In addition, functional domains of the PLC isozymes, such as Src homology 2 (SH2) domain, Src homology 3 (SH3) domain, and pleckstrin homology (PH) domain play crucial roles in protein translocation, lipid membrane modificailon and intracellular memrane trafficking which occur during various mitogenic processes. We have previously reported the presence of PLC-${\gamma}1$, ${\gamma}2$, ${\beta}1$, ${\beta}3$, and ${\delta}1$ isozymes in normal human lung tissue and tyrosine-kinase-independent activation of phospholipase C-${\gamma}$ isozymes by tau protein and AHNAK. We had also found that the expression of AHNAK protein was markedly increased in various mstologic types of lung can∞r tissues as compared to the normallungs. However, the report concerning expression of various PLC isozymes in lung canærs and other lung diseases is lacking. Therefore, in this study we examined the expression of PLC isozymes in the paired surgical specimens taken from lung cancer patients. Methods : Surgically resected lung cancer tissue samples taken from thirty seven patients and their paired normal control lungs from the same patients, The expression of various PLC isozymes were studied. Western blot analysis of the tissue extracts for the PLC isozymes and immunohistochemistry was performed on typical samples for localization of the isozyme. Results : In 16 of 18 squamous cell carcinomas, the expression of PLC-${\gamma}1$ was increased. PLC-${\gamma}1$ was also found to be increased in all of 15 adenocarcinoma patients. In most of the non-small cell lung cancer tissues we had examined, expression of PLC-${\delta}1$ was decreased. However, the expression of PLC-${\delta}1$ was markedly increased in 3 adenocarcinomas and 3 squamous carcinomas. Although the numbers were small, in all 4 cases of small cell lung cancer tissues, the expression of PLC-${\delta}1$ was nearly absent. Conclusion : We found increased expression of PLC-${\gamma}1$ isozyme in lung cancer tissues. Results of this study, taken together with our earlier findings of AHNAK protein-a putative PLD-${\gamma}$, activator-over-expression, and the changes observed in PLC-${\delta}1$ in primary human lung cancers may provide a possible insight into the derranged calcium-inositol signaling pathways leading to the lung malignancies.

• Journal of Life Science
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• v.28 no.9
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• pp.1100-1117
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• 2018

The Ras superfamily of small G-proteins acts as a molecular switch on the intracellular signaling pathway. Upon ligand stimulation, inactive GTPases (Ras-GDP) are activated (Ras-GTP) using guanine nucleotide exchange factor (GEF) and transmit signals to their downstream effectors. Following signal transmission, active Ras-GTP become inactive Ras-GDP and cease signaling. However, the intrinsic GTPase activity of Ras proteins is weak, requiring Ras GTPase-activating protein (RasGAP) to efficiently convert RAS-GTP to Ras-GDP. Since deregulation of the Ras pathway is found in nearly 30% of all human cancers, it might be useful to clarify the structural and physiological roles of Ras GTPases. Recently, RasGAP has emerged as a new class of tumor-suppressor protein and a potential therapeutic target for cancer. Therefore, it is important to clarify the physiological roles of the individual GAPs in human diseases. The first RasGAP discovered was RASA1, also known as p120 RasGAP. RASA1 is widely expressed, independent of cell type and tissue distribution. Subsequently, neurofibromatosis type 1 (NF1) was discovered. The remaining GAPs are affiliated with the GAP1 and synaptic GAP (SynGAP) families. There are more than 170 Ras GTPases and 14 Ras GAP members in the human genome. This review focused on the current understanding of Ras GTPase and RasGAP in human diseases, including cancers.

• Journal of Life Science
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• v.34 no.4
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• pp.279-285
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• 2024

The zonula occludens (ZO) protein serves as a scaffolding protein, providing structural support at the junctions between cells and the cytoplasmic surface. It acts as a bridge between integral membrane proteins and the cytoskeleton. Besides its structural role, it also participates in regulating cell growth and proliferation. Recent studies have highlighted the involvement of ZO protein in various diseases, including cancer. Specifically, research has indicated that ZO protein influences the cancer microenvironment surrounding cancer cells, thereby facilitating their growth and development. ZO proteins exert diverse functions in the cancer microenvironment, impacting processes such as angiogenesis, inflammatory responses, the epithelial-mesenchymal transition, and interactions with mesenchymal stem cells. The specific mechanisms vary depending on the type of cancer and environmental conditions. Recent research unveiled several signaling pathways involving ZO protein, which could potentially impede cancer progression in the tumor microenvironment. Consequently, these insights open avenues for novel treatment strategies. While the numerous physiological, structural, and morphological roles of ZO protein have been observed at the cellular and in vivo levels, understanding the signaling mechanisms it operates in vivo and how these mechanisms influence the cancer microenvironment remains a challenge. In this review, we delineate the characteristics and regulatory mechanisms of ZO protein in the context of the cancer microenvironment. Additionally, we propose leveraging the properties of ZO protein to devise defense mechanisms within the cancer cell environment and provide an overview of its in vivo role.