• Title/Summary/Keyword: Akt Signaling Pathway

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Anti-oxidative Activity of Lycopene Via the Induction of HO-1 Expression by MAPK/Nrf2 Signaling Pathway in RAW 264.7 Cells (RAW 264.7 세포에서 Lycopene의 MAPK/Nrf2/HO-1 신호 전달 체계를 통한 항산화 효과)

  • Chung-Mu Park;Hyun An;Hyun-Seo Yoon
    • Journal of The Korean Society of Integrative Medicine
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    • v.12 no.1
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    • pp.1-10
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    • 2024
  • Purpose: Lycopene is abundantly contained in Tomatoes and is known for diverse biological activities such as antioxidant, anti-inflammatory, and anticancer effects. In this study, the antioxidative potential of lycopene was investigated through the induction of hemeoxygenase (HO)-1 by nuclear factor-erythroid 2 p45-related factor2 (Nrf2) and upstream signaling molecules, mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Aktin RAW 264.7 cells. Methods: The antioxidative potential of lycopene against oxidative stress and its molecular mechanisms were determined by the cell viability assay, intracellular reactive oxygen species (ROS) formation assay, and Western blot analysis in RAW 264.7 cells. Results: Lycopene treatment significantly attenuated tert-butyl hydroperoxide (t-BHP) induced intracellular ROS formation in a dose-dependent manner without any cytotoxicity. In addition, 50 µM of lycopene for 6 h treatment induced potent HO-1 expression and its transcription factor, Nrf2. MAPK and PI3K/Aktwere also analyzed due to their critical roles in the regulation of cellular redox homeostasis against oxidative damage. As a result, phosphorylation of extracellular regulated kinase (ERK) was significantly induced by lycopene treatment while the activated status of c-Jun NH2-terminal kinase (JNK), p38, and Akt, were not given any effect. To confirm the antioxidative mechanism of HO-1 mediated by ERK activation, each selective inhibitor was employed in a protection assay, in which oxidative damage occurred by t-BHP. Lycopene, SnPP, and CoPP treatments reflected accelerated HO-1 expression could be a protective role against oxidative damage-initiated cell death. A selective inhibitor for ERK significantly inhibited the lycopene-induced cytoprotective effect but selective inhibitors for other signaling molecules did not attenuate the rate of t-BHP-induced cell death. Conclusion: In conclusion, lycopene potently scavenged intracellular ROS formation and enhanced the HO-1 mediated antioxidative potential through the modulation of Nrf2, MAPK signaling pathway in RAW 264.7 cells.

Cytoprotective Effect of Lespedeza Cuneata Extract on Glucose Toxicity (야관문(夜關門)의 포도당 독성에 대한 세포 보호 효과)

  • Choi, Jeong-Sik;Cho, Chung-Sik;Kim, Cheol-Jung
    • The Journal of Korean Medicine
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    • v.31 no.4
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    • pp.79-100
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    • 2010
  • Objective: Production of ROS from glucose toxicity results in injury of pancreatic $\beta$-cells in diabetes models. This study was undertaken to examine the influence of Lespedeza Cuneata extract (LCE) on cytoprotective effects on glucose toxicity, insulin secretion and gene expression in RIN-m5F cells. Methods: First, we measured LCE's antioxidant activity by DPPH free radical-scavenging activity and SOD activity. After the various concentrations of LCE were added to the RIN-m5F cells, we measured cell viability with glucose stimulation by MTT assay and glucose-stimulated insulin secretion. We analyzed gene expression with Agilent whole mouse genome 44K oligo DNA microarray and searched for related pathways in KEGG (Kyoto Encyclopedia of Genes and Genomes). Lastly we measured INS-1, INS-2, INS-R, IRS-1, IRS-2, IRS-3, GLP-1R, and GLP-2R mRNA expression by real time RT-PCR. Results: Free radical-scavenging activity, SOD activity and insulin secretion increased dependent on LCE concentration, but LCE did not show considerable cytoprotective effect on RIN-m5F cells. More than twice expressed gene was 6362 in Oligo DNA chip. In KEGG, the most related pathway was the metabolic pathway. In the insulin signaling pathway, up expressed genes were Irs1, Mapk8, Akt1, and Lipe and down expressed genes were Rhoq, Fbp2, Prkar2b, Gck, and Prkag1. In real time RT-PCR, IRS-2, and IRS-3 expression increased significantly compared to the control group on LCE $12{\mu}g/m{\ell}$ concentration and GCK expression decreased significantly compared to the control group. Conclusions: These results show that LCE encourages insulin secretion and insulin metabolism by complicated gene mechanisms. Further mechanism study and clinical study seem to be necessary about Lespedeza Cuneata.

EphA2 Receptor Signaling Mediates Inflammatory Responses in Lipopolysaccharide-Induced Lung Injury

  • Hong, Ji Young;Shin, Mi Hwa;Chung, Kyung Soo;Kim, Eun Young;Jung, Ji Ye;Kang, Young Ae;Kim, Young Sam;Kim, Se Kyu;Chang, Joon;Park, Moo Suk
    • Tuberculosis and Respiratory Diseases
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    • v.78 no.3
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    • pp.218-226
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    • 2015
  • Background: Eph receptors and ephrin ligands have several functions including angiogenesis, cell migration, axon guidance, fluid homeostasis, oncogenesis, inflammation and injury repair. The EphA2 receptor potentially mediates the regulation of vascular permeability and inflammation in response to lung injury. Methods: Mice were divided into 3 experimental groups to study the role of EphA2 signaling in the lipopolysaccharide (LPS)-induced lung injury model i.e., IgG+phosphate-buffered saline (PBS) group (IgG instillation before PBS exposure), IgG+LPS group (IgG instillation before LPS exposure) and EphA2 monoclonal antibody (mAb)+LPS group (EphA2 mAb pretreatment before LPS exposure). Results: EphA2 and ephrinA1 were upregulated in LPS-induced lung injury. The lung injury score of the EphA2 mAb+LPS group was lower than that of the IgG+LPS group ($4.30{\pm}2.93$ vs. $11.45{\pm}1.20$, respectively; p=0.004). Cell counts (EphA2 mAb+LPS: $11.33{\times}10^4{\pm}8.84{\times}10^4$ vs. IgG+LPS: $208.0{\times}10^4{\pm}122.6{\times}10^4$; p=0.018) and total protein concentrations (EphA2 mAb+LPS: $0.52{\pm}0.41mg/mL$ vs. IgG+LPS: $1.38{\pm}1.08mg/mL$; p=0.192) were decreased in EphA2 mAb+LPS group, as compared to the IgG+LPS group. In addition, EphA2 antagonism reduced the expression of phospho-p85, phosphoinositide 3-kinase $110{\gamma}$, phospho-Akt, nuclear factor ${\kappa}B$, and proinflammatory cytokines. Conclusion: This results of the study indicated a role for EphA2-ephrinA1 signaling in the pathogenesis of LPS-induced lung injury. Furthermore, EphA2 antagonism inhibits the phosphoinositide 3-kinase-Akt pathway and attenuates inflammation.

Actin-binding LIM protein 1 regulates receptor activator of NF-κB ligand-mediated osteoclast differentiation and motility

  • Jin, Su Hyun;Kim, Hyunsoo;Gu, Dong Ryun;Park, Keun Ha;Lee, Young Rae;Choi, Yongwon;Lee, Seoung Hoon
    • BMB Reports
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    • v.51 no.7
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    • pp.356-361
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    • 2018
  • Actin-binding LIM protein 1 (ABLIM1), a member of the LIM-domain protein family, mediates interactions between actin filaments and cytoplasmic targets. However, the role of ABLIM1 in osteoclast and bone metabolism has not been reported. In the present study, we investigated the role of ABLIM1 in the receptor activator of $NF-{\kappa}B$ ligand (RANKL)-mediated osteoclastogenesis. ABLIM1 expression was induced by RANKL treatment and knockdown of ABLIM1 by retrovirus infection containing Ablim1-specific short hairpin RNA (shAblim1) decreased mature osteoclast formation and bone resorption activity in a RANKL-dose dependent manner. Coincident with the downregulated expression of osteoclast differentiation marker genes, the expression levels of c-Fos and the nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), critical transcription factors of osteoclastogenesis, were also decreased in shAblim1-infected osteoclasts during RANKL-mediated osteoclast differentiation. In addition, the motility of preosteoclast was reduced by ABLIM1 knockdown via modulation of the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/Akt/Rac1 signaling pathway, suggesting another regulatory mechanism of ABLIM1 in osteoclast formation. These data demonstrated that ABLIM1 is a positive regulator of RANKL-mediated osteoclast formation via the modulation of the differentiation and PI3K/Akt/Rac1-dependent motility.

Treatment of Vemurafenib-Resistant SKMEL-28 Melanoma Cells with Paclitaxel

  • Nguyen, Dinh Thang;Phan, Tuan Nghia;Kumasaka, Mayuko Y.;Yajima, Ichiro;Kato, Masashi
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.2
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    • pp.699-705
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    • 2015
  • Vemurafenib has recently been used as drug for treatment of melanomas with $BRAF^{V600E}$ mutation. Unfortunately, treatment with only vemurafenib has not been sufficiently effective, with recurrence after a short period. In this study, three vemurafenib-resistant $BRAF^{V600E}$ melanoma cell lines, $A375P^R$, $A375M^R$ and SKMEL-$28^R$, were established from the original A375P, A375M and SKMEL-28 cell lines. Examination of the molecular mechanisms showed that the phosphorylation levels of MEK and ERK, which play key roles in the RAS/RAF/MEK/ERK signaling pathway, were reduced in these three cell lines, with increased phosphorylation levels of pAKTs limited to SKMEL-$28^R$ cells. Treatment of SKMEL-$28^R$ cells with 100 nM paclitaxel resulted in increased apoptosis and decreased cellular proliferation, invasion and colony formation via reduction of expression levels of EGFR and pAKTs. Moreover, vemurafenib-induced pAKTs in SKMEL-$28^R$ were decreased by treatment with an AKT inhibitor, MK-2206. Taken together, our results revealed that resistance mechanisms of $BRAF^{V600E}$-mutation melanoma cells to vemurafenib depended on the cell type. Our results suggested that paclitaxel should be considered as a drug in combination with vemurafenib to treat melanoma cells.

Lisophosphatidic Acid Inhibits Melanocyte Proliferation via Cell Cycle Arrest

  • Kim, Dong-Seok;Park, Seo-Hyoung;Kim, Sung-Eun;Kwon, Sun-Bang;Park, Eun-Sang;Youn, Sang-Woong;Park, Kyoung-Chan
    • Archives of Pharmacal Research
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    • v.26 no.12
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    • pp.1055-1060
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    • 2003
  • Lysophosphatidic acid (LPA) is a well-known mitogen in various cell types. However, we found that LPA inhibits melanocyte proliferation. Thus, we further investigated the possible signaling pathways involved in melanocyte growth inhibition. We first examined the regulation of the three major subfamilies of mitogen-activated protein (MAP) kinases and of the Akt pathway by LPA. The activations of extracellular signal-regulated protein kinase (ERK) and c-Jun N-terminal kinase (JNK) were observed in concert with the inhibition of melanocyte proliferation by LPA, whereas p38 MAP kinase and Akt were not influenced by LPA. However, the specific inhibition of the ERK or JNK pathways by PD98059 or D-JNKI1, respectively, did not restore the antiproliferative effect. We next examined changes in the expression of cell cycle related proteins. LPA decreased cyclin $D_1 and cyclin D_2$ levels but increased $p21^{WAF1/CIP1}$ (p21) and $p27^{KIP1}$ (p27) levels, which are known inhibitors of cyclin-dependent kinase. Flow cytometric analysis showed the inhibition of DNA synthesis by a reduction in the S phase and an increase in the $G_0/G_1$ phase of the cell cycle. Our results suggest that LPA induces cell cycle arrest by regulating the expressions of cell cycle related proteins.

Inducing apoptosis by the inhibition of c-myb in oral squamous carcinoma cell line, KB cell

  • Lee, Jung-Chang;Moon, Hyun-Ju;Lee, Young-Hee;Jung, Ji-Eun;Sharma, Manju;Jhee, Eun-Jung;Yi, Ho-Keun
    • International Journal of Oral Biology
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    • v.32 no.4
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    • pp.127-133
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    • 2007
  • Oral squamous cell carcinoma (OSCC) is the most common malignancy and is a major cause of worldwide cancer mortality. The proto-oncogene c-myb plays an important role in regulation of cell growth and differentiation, and it is expressed at high levels in hematopoietic cells and many other types of cancers. However, the function of c-myb is not well known in OSCC. The present study aimed to reveal the function of c-myb and to test the alternation of cell growth and signaling by c-myb in OSCC. In this study, c-myb and dominant-negatibe myb(DNmyb) were expressed in an adenovirus-mediated gene delivery system to KB cells. The over-expressed c-myb brought increased cellular proliferation compared with control cells. However, DN-myb infected KB cells showed significant reduction of cell growth and enhanced induction of apoptosis to activate PARP and caspase 9. c-myb induced increase of IGF-I, -II and IGF-IR expressions while DN-myb down-regulated these expression. Activation of ERK and Akt/PKB pathway was shown only in c-myb transduced cells. These findings suggest that the role of c-myb in cell growth of oral cancer cells is partially mediated through the modulation of IGFs, ERK and Akt/PKB. From this results, DN-myb is strongly recommended as a curable gene for the treatment of c-myb dependent malignancies such as OSCC.

Ginseng-derived nanoparticles induce skin cell proliferation and promote wound healing

  • Song Yang;Shuyan Lu;Limei Ren;Shuai Bian;Daqing Zhao;Meichen Liu;Jiawen Wang
    • Journal of Ginseng Research
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    • v.47 no.1
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    • pp.133-143
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    • 2023
  • Background: Past studies suggested that ginseng extracts and ginseng-derived molecules exerted significant regulatory effects on skin. However, no reports have described the effects of ginseng-derived nanoparticles (GDNPs) on skin cell proliferation and wound healing. In this study, we investigated whether GDNPs regulate the proliferation of skin cells and promote wound healing in a mouse model. Methods: GDNPs were separated and purified via differential centrifugation and sucrose/D2O gradient ultracentrifugation. GDNP uptake, cell proliferation and cell cycle progression were measured by confocal microscopy, CCK-8 assay and flow cytometry, respectively. Cell migration and angiogenic effects were assessed by the wound scratch assay and tube formation assay, respectively. ELISA was used to detect extracellular matrix secretion. The relevant signaling pathway was confirmed by western blotting. The effects of GDNPs on skin wound healing were assessed by wound observation, HE staining, and western blotting. Results: GDNPs possessed the essential features of exosomes, and they were accumulated by skin cells. Treatment with GDNPs notably enhanced the proliferation of HaCaT, BJ and HUVECs. GDNPs also enhanced the migration in HaCaT cells and HUVECs and angiogenesis in HUVECs. GDNPs increased the secretion of MMP-1, fibronectin-1, elastin-1, and COL1A1 in all three cell lines. GDNPs regulated cell proliferation through the ERK and AKT/ mTOR pathways. Furthermore, GDNPs facilitated skin wound healing and decreased inflammation in a mouse skin wound model. Conclusion: GDNPs can promote skin wound healing through the ERK and AKT/mTOR pathways. GDNPs thus represent an alternative treatment for chronic skin wounds.

Effect of submerged culture of Ceriporia lacerata mycelium on GLUT4 protein in db/db mouse (db/db 마우스에서 Ceriporia lacerata 균사체 배양액이 GLUT4 발현에 미치는 영향)

  • Shin, Eun Ji;Kim, Ji-Eun;Kim, Ji-Hye;Park, Yong Man;Yoon, Sung Kyoon;Jang, Byeong-Churl;Lee, Sam-Pin;Kim, Byoung-Cheon
    • Food Science and Preservation
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    • v.22 no.6
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    • pp.893-900
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    • 2015
  • In this study, we evaluated the antidiabetic effect of a submerged culture of Ceriporia lacerata mycelium (CL01) on hematological indices, as well as protein and mRNA expression of the insulin-signaling pathway, in db/db mice. After CL01 was administrated for 4 weeks, blood glucose levels decreased consistently, and plasma insulin and c-peptide levels each decreased by roughly 55.8%, 40% of those in the negative control (p<0.05). With regard to HOMA-IR, an insulin resistance index, insulin resistance of the CL01-fed group improved over that of the negative control group by about 62% (p<0.05). In addition, we demonstrated that the protein expression levels of pIR, pAkt, pAMPK, and GLUT4 and the mRNA expression levels of Akt2, IRS1, and GLUT4 in the muscle cells of db/db mice increased in the CL01-fed group compared to the corresponding levels in the control group. These results demonstrate that CL01 affects glucose metabolism, upregulates protein and gene expression in the insulin-signaling pathway, and decreases blood glucose levels effectively by improving insulin sensitivity. More than 90% of those who suffer from type 2 diabetes are more likely to suffer from hyperinsulinemia, hypertension, obesity, and other comorbidities because of insulin resistance. Therefore, it is possible that CL01 intake could be used as a fundamental treatment for type 2 diabetes by lowering insulin resistance, and these results may prove be useful as basic evidence for further research into the mechanisms of a cure for type 2 diabetes.

Effect of High-Fat Diet-induced Obesity on the Incidence and Progression of Prostate Cancer in C57BL/6N Mouse (C57BL/6N 마우스에서 전립선암의 발병률 및 진행에 대한 고지방식이-유도 비만의 영향)

  • Choi, Yun Ju;Kim, Ji Eun;Lee, Su Jin;Gong, Jeong Eun;Jin, Yu Jeong;Lee, Jae Ho;Lim, Yong;Hwang, Dae Youn
    • Journal of Life Science
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    • v.32 no.7
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    • pp.532-541
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    • 2022
  • Obesity induced by high-fat diet (HFD) is verified as a strong risk factor and negative prognostic factor for prostate cancer in several genetically engineered mice although it was not examined in the normal mice. To investigate whether HFD-induced obesity can affect the development and progression of cancer in the prostate of normal mice, alterations in the weight and histological structure of the prostate as well as the expression of cancer-related proteins were analyzed in obese C57BL/6N mice fed with 60% HFD for 16 weeks. First, HFD-induced obesity, including an increase in organ weight, body weight, fat accumulation, and serum lipid profile, was successfully induced in C57BL/6N mice after HFD treatment. The total weight of the prostate significantly increased HFD-induced obesity in the model mice compared with the control group. Among the four lobes of the prostate, the weight of the ventral prostate (VP) and anterior prostate (AP) were higher in HFD-induced obesity model mice than in the control group, although the weights of the lateral prostate (DLP) and seminal vesicle (SV) were constantly maintained. In addition, the incidences of hyperplasia and non-hodgkin's lymphoma (NHL) in the histological structure were remarkably increased in HFD-induced obesity model mice, while the epithelial thickness was higher in the same group. A significant increase in the phosphorylation levels of key proteins in the AKT (protein kinase B) signaling pathway was detected in HFD-induced obesity model mice. Therefore, these results suggest that HFD-induced obesity can promote hyperplasia and NHL in the prostates of C57BL/6N mice through the activation of the AKT signaling pathway.