• Title/Summary/Keyword: signal transduction mechanism

Search Result 184, Processing Time 0.036 seconds

Effects of lycopene on number and function of human peripheral blood endothelial progenitor cells cultivated with high glucose

  • Zeng, Yao-Chi;Mu, Gui-Ping;Huang, Shu-Fen;Zeng, Xue-Hui;Cheng, Hong;Li, Zhong-Xin
    • Nutrition Research and Practice
    • /
    • v.8 no.4
    • /
    • pp.368-376
    • /
    • 2014
  • BACKGROUND/OBJECTIVES: The objectives of this study were to investigate the effects of lycopene on the migration, adhesion, tube formation capacity, and p38 mitogen-activated protein kinase (p38 MAPK) activity of endothelial progenitor cells (EPCs) cultivated with high glucose (HG) and as well as explore the mechanism behind the protective effects of lycopene on peripheral blood EPCs. MATERIALS/METHODS: Mononuclear cells were isolated from human peripheral blood by Ficoll density gradient centrifugation. EPCs were identified after induction of cellular differentiation. Third generation EPCs were incubated with HG (33 mmol/L) or 10, 30, and $50{\mu}g/mL$ of lycopene plus HG. MTT assay and flow cytometry were performed to assess proliferation and apoptosis of EPCs. EPC migration was assessed by MTT assay with a modified boyden chamber. Adhesion assay was performed by replating EPCs on fibronectin-coated dishes, after which adherent cells were counted. In vitro vasculogenesis activity was assayed by Madrigal network formation assay. Western blotting was performed to analyze protein expression of both phosphorylated and non-phosphorylated p38 MAPK. RESULTS: The proliferation, migration, adhesion, and in vitro vasculogenesis capacity of EPCs treated with 10, 30, and $50{\mu}g/mL$ of lycopene plus HG were all significantly higher comapred to the HG group (P < 0.05). Rates of apoptosis were also significantly lower than that of the HG group. Moreover, lycopene blocked phosphorylation of p38 MAPK in EPCs (P < 0.05). To confirm the causal relationship between MAPK inhibition and the protective effects of lycopene against HG-induced cellular injury, we treated cells with SB203580, a phosphorylation inhibitor. The inhibitor significantly inhibited HG-induced EPC injury. CONCLUSIONS: Lycopene promotes proliferation, migration, adhesion, and in vitro vasculogenesis capacity as well as reduces apoptosis of EPCs. Further, the underlying molecular mechanism of the protective effects of lycopene against HG-induced EPC injury may involve the p38 MAPK signal transduction pathway. Specifically, lycopene was shown to inhibit HG-induced EPC injury by inhibiting p38 MAPKs.

The Suppressive Effect on Th2 Cytokines Expression and the Signal Transduction Mechanism in MC/9 Mast Cells by PRAL (MC/9 비만세포에서 행인(杏仁) 추출물의 Th2 cytokine 발현 억제 효과 및 신호전달 기전 연구)

  • Kang, Ki Yeon;Han, Jae Kyung;Kim, Yun Hee
    • The Journal of Pediatrics of Korean Medicine
    • /
    • v.28 no.2
    • /
    • pp.23-39
    • /
    • 2014
  • Objectives PRAL (Prunus armniaca Linne Var) is a herbal formula in Oriental Medicine, known for its anti-inflammatory and anti-allergenic properties. However, its mechanism of action and the cellular targets have not yet been found enough. The purpose of this study is to investigate the effects of PRAL on Th2 cytokines expression in MC/9 mast cells. Methods The effect of PRAL was analyzed by ELISA, Real-time PCR, Western blot in MC/9 mast cells. mRNA levels of GM-CSF, IL-4, IL-5, IL-6, IL-13, TNF-${\alpha}$ were analyzed with Real-time PCR. Levels of IL-13, MIP-$1{\alpha}$ were measured using enzyme-linked immunosorbent assays (ELISA). NFAT, AP-1 and NF-${\kappa}B$ p65 were examined by Western blot analysis. Results PRAL inhibited GM-CSF, IL-4, IL-5, IL-6, IL-13, TNF-${\alpha}$ mRNA expression in a dose dependent manner. GM-CSF, IL-4, IL-5 mRNA expression were inhibited significantly in comparison to DNP-IgE control group at concentration of 100 ${\mu}g/ml$ and IL-6, IL-13, TNF-${\alpha}$ mRNA expression were inhibited at concentration of 50 ${\mu}g/ml$, 100 ${\mu}g/ml$. PRAL also inhibited the IL-13, MIP-$1{\alpha}$ production significantly in comparison to DNP-IgE control group in a dose dependent manner. IL-13 production was inhibited at a concentration of 200 ${\mu}g/ml$, 400 ${\mu}g/ml$ and MIP-$1{\alpha}$ was inhibited at a concentration of 100 ${\mu}g/ml$, 200 ${\mu}g/ml$, 400 ${\mu}g/ml$. Western blot analysis of transcription factors involving Th2 cytokines expression revealed prominent decrease of the mast cell specific transcription factors including NFAT-1, c-Jun as well as NF-${\kappa}B$ p65 but not NFAT-2 and c-Fos. Conclusion These results indicate that PRAL has the effect of suppressing Th2 cytokines production in the MC/9 mast cells. These data represent that PRAL potentiates therapeutic activities to the allergic disease by regulating Th2 cytokines in the MC/9 mast cells.

Artesunate inhibits collagen-induced human platelets aggregation through regulation of PI3K/Akt and MAPK pathway (PI3K/Akt 및 MAPK 기전 조절을 통한 Artesunate의 콜라겐 유도의 사람 혈소판 응집 억제효과)

  • Lee, Dong-Ha
    • Journal of Applied Biological Chemistry
    • /
    • v.65 no.1
    • /
    • pp.57-62
    • /
    • 2022
  • Excessive activation and aggregation of platelets is a major cause of cardiovascular disease. Therefore, inhibition of platelet activation and aggregation is considered an attractive therapeutic target in preventing and treating cardiovascular diseases. In particular, strong platelet activation and aggregation by collagen secreted from the vascular endothelium are characteristic of vascular diseases. Artesunate is a compound extracted from the plant roots of Artemisia or Scopolia species, and has been reported to be effective in anticancer and Alzheimer's disease fields. However, the effect and mechanism of artesunate on collagen-induced platelet activation and aggregation have not been elucidated. In this study, the effect of artesunate on collagen-induced human platelet aggregation was confirmed and the mechanism of action of artesunate was clarified. Artesunate inhibited the phosphorylation of PI3K/Akt and Mitogen-activated protein kinases, which are phosphoproteins that are known to act in the signal transduction process when platelets are activated. In addition, artesunate decreased TXA2 production and decreased granule secretion in platelets such as ATP and serotonin release. As a result, artesunate strongly inhibited platelet aggregation induced by collagen, a strong aggregation inducer secreted from vascular endothelial cells, with an IC50 of 106.41 µM. These results suggest that artesunate has value as an effective antithrombotic agent for inhibiting the activation and aggregation of human platelets through vascular injury.

Fulvestrant Does Not Have Antagonistic Effect on 17β-estradiol's Anti-proliferative Action in Cultured Chinese Hamster Ovarian Cell Line (17β-Estradiol의 CHO 세포 항 증식작용에 대한 fulvestrant의 효과)

  • Kim, Hyun Hee;Park, Hyeong Cheol;Min, Gyesik
    • Journal of Life Science
    • /
    • v.24 no.2
    • /
    • pp.173-180
    • /
    • 2014
  • Estrogen can promote or inhibit cellular proliferation depending on tissue cell types and physiological condition and acts through the signal transduction pathways mediated primarily by estrogen receptors. This study examined the effects of fulvestrant (Ful), a well-known antagonist for the estrogen receptor, on the action of $17{\beta}$-estradiol (E2) with respect to the proliferation and apoptosis of Chinese hamster ovarian (CHO) cells. We used different concentrations of E2, Ful, and E2 plus Ful during different treatment durations. Treatment with 15-40 ${\mu}M$ E2 significantly inhibited proliferation in a time-dependent manner, although it had no influence in concentrations up to 1 ${\mu}M$. Interestingly, Ful at 10-40 ${\mu}M$ also inhibited cellular proliferation in both a concentration- and time-dependent manner. In addition, Ful enhanced rather than decreased the inhibitory effect on cellular proliferation by E2 in combined treatment for 10 days. Thus, Ful does not appear to have an antagonistic effect on estrogen's anti-proliferative action in CHO cells. In TUNEL assays to confirm DNA fragmentation by E2 and/or Ful, CHO cells treated with 20 ${\mu}M$ E2 showed a TUNEL-positive reaction in most DAPI-stained nuclei, and cells treated with either 40 ${\mu}M$ Ful or 40 ${\mu}M$ Ful plus 20 ${\mu}M$ E2 also exhibited a TUNEL-positive reaction but at a lower rate compared to the E2-treated cells. These results indicate that Ful does not have an antagonistic effect on estrogen's anti-proliferative action in CHO cells, suggesting that the anti-proliferative and apoptosis-related mechanism(s) through DNA fragmentation by E2 and Ful may be mediated by different signal transduction pathways.

THE EFFECT OF BMP REGULATED SMAD PROTEIN ON ALKALINE PHOSPHATASE GENE EXPRESSION (Smad에 의한 alkaline phosphatase 유전자의 발현 조절기전)

  • Kim, Nan-Jin;Ryoo, Hyun-Mo;Kim, Hyun-Jung;Kim, Young-Jin;Nam, Soon-Hyeun
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.28 no.2
    • /
    • pp.238-246
    • /
    • 2001
  • Bone morphogenetic proteins(BMPs), members of the transforming growth factor $\beta$(TGF-$\beta$) superfamily were first identified as the factors that induce ectopic bone formation in vivo, when implanted into muscular tissue. Especially BMP-2 inhibits terminal differentiation of C2C12 myoblasts and converts them into osteoblast lineage cells. In the molecular mechanism of the signal transduction of TGF-$\beta$ and related factors, intracellular signaling proteins were identified as Smad. In previous study, it has been reported that Smad 1 and Smad 5, which belong to the R-Smad family mediate BMP signaling, were involved in the induction of osteoblast differentiation in C2C12 cells. To understnad the role of Smads involved in osteogenic transdifferentiation in C2C12 cell, in present study, after we stably transfected C2C12 cells with each. Smad(Smad 1,Smad 5) expression vector, cultured for 3 days and stained for alkaline phophatase activity. ALP activity positive cells appeared in the Smad 1, Smad 5 stably transfected cell even in the abscence of BMP. After transiently co-transfected C2C12 cells with each Smad expression vector and ALP promoter, it was examined that Smad 1 and Smad 5 expression vector had increased about 2 fold ALP promoter activity in the abscence of BMP. These result suggested that both Smad 1 and Smad 5 were involved in the intracellular BMP signals which induce osteoblast differentiation in C2C12 cells. The effect of BMP on C2C12 cells with Smad 1, Smad 5 transfected were studied by using northern blot analysis. the treatment of BMP upregulated ALP mRNA level in three groups, especially upregulation of ALP was larger in Smad 1, Smad 5 transfected cell than control group. Pretreatment with cycloheximide($10{\mu}g/ml$), a protein synthesis inhibitor resulted in blocking the ALP gene expression even in BMP(100ng/ml) treated cell. These results suggested that Smad increased the level of ALP mRNA via the synthesis of a certain transcriptional regulatory protein.

  • PDF

IP-10 Decreases TNF-α Induced MUC5AC Expression in Human Airway Epithelial Cells: a Possible Relation with Little Sputum Production in Idiopathic Pulmonary Fibrosis (IP-10에 의한 기도상피세포에서의 TNF-α 유도 MUC5AC발현 억제: 특발성폐섬유증 환자의 적은 객담과의 연관성)

  • Kim, Seung Joon;Kang, Chun Mi;You, Moon Bin;Yoon, Hyung Kyu;Kim, Young Kyoon;Kim, Kwan Hyoung;Moon, Hwa Sik;Park, Sung Hak;Song, Jeong Sup
    • Tuberculosis and Respiratory Diseases
    • /
    • v.64 no.5
    • /
    • pp.347-355
    • /
    • 2008
  • Background: IPF is characterized by chronic, fibrosing inflammatory lung disease of unknown etiology. Typical symptoms of IPF are exertional dyspnea with nonproductive cough. Why patients with typical IPF have dry cough rather than productive cough, is unknown. IP-10 plays an important regulatory role in leukocyte trafficking into the lung. The present study investigated the effect of IP-10 in the pathogenesis of dry cough rather than productive cough in IPF patients. Methods: IP-10 concentration was measured by ELISA from BALF of IPF patients. To evaluate the role of IP-10 in mucin expression, the expression of the MUC5AC mucin gene was measured in NCI-H292 cells, a human pulmonary mucoepidermoid carcinoma cell line, after stimulation by TNF-${\alpha}$ with or without IP-10 pretreatment. EGFR-MAPK expression was also examined as a possible mechanism. Results: IP-10 levels were significantly higher in the BALF of IPF patients compared to healthy controls. IP-10 pretreatment reduced TNF-${\alpha}$ induced MUC5AC mucin expression by inhibiting the EGFR-MAPK signal transduction pathway in NCI-H292 cells. Conclusion: These findings suggest that little mucus production in IPF patients might be attributable to IP-10 overproduction, which inhibits the EGFR-MAPK signal transduction pathway required for MUC5AC mucin gene expression.

Gene Expression Profiles in Cervical Cancer with Radiation Therapy Alone and Chemo-radiation Therapy (자궁경부암의 방사선치료 및 방사선항암화학 병용치료에 따른 유전자발현 조절양상)

  • Lee Kyu Chan;Kim Meyoung-kon;Kim Jooyoung;Hwang You Jin;Choi Myung Sun;Kim Chul Yong
    • Radiation Oncology Journal
    • /
    • v.21 no.1
    • /
    • pp.54-65
    • /
    • 2003
  • Purpose : To analyze the gene expression Profiles of uterine ceulcal cancer, and its variation after radiation therapy, with or without concurrent chemotherapy, using a CDNA microarray. Materials and Methods :Sixteen patients, 8 with squamous ceil carcinomas of the uterine cervix, who were treated with radiation alone, and the other 8 treated w14h concurrent chemo-radiation, were Included in the study. Before the starling of the treatment, tumor biopsies were carried out, and the second time biopsies were peformed after a radiation dose of 16.2$\~$27 Gy. Three normal cervix tissues were used as a control group. The microarray experiments were peformed with 5 groups of the total RNAs extracted individually and then admixed as control, pre-radiation therapy alone, during-radiation therapy alone, pre-chemoradiation therapy, and during-chemoradlation therapy. The 33P-iabeled CDNAS were synthesized from the total RNAs of each group, by reverse transcription, and then they were hybridized to the CDNA microarray membrane. The gene expression of each microarrays was captured by the intensity of each spot produced by the radioactive isotopes. The pixels per spot were counted with an Arrayguage, and were exported to Microsoft Excel The data were normalized by the Z transformation, and the comparisons were peformed on the Z-ratio values calculated. Results : The expressions of 15 genes, including integrin linked kinase (ILK), CDC28 protein kinase 2, Spry 2, and ERK 3, were increased with the Z-ratio values of over 2.0 for the cervix cancer tissues compared to those for the normal controls. Those genes were involved In cell growth and proliferation, cell cycle control, or signal transduction. The expressions of the other 6 genes, Including G protein coupled receptor kinase 5, were decreased with the Z-ratio values of below -2.0. After the radiation thorapy, most of the genes, with a previously Increase expressions, represented the decreased expression profiles, and the genes, with the Z-ratio values of over 2.0, were cyclic nucleotlde gated channel and 3 Expressed sequence tags (EST). In the concurrent chemo-radiation group, the genes involved in cell growth and proliferation, cell cycle control, and signal transduction were shown to have increased expressions compared to the radiation therapy alone group. The expressions of genes involved in anglogenesis (angiopoietln-2), immune reactions (formyl peptide receptor-iike 1), and DNA repair (CAMP phosphodiesterase) were increased, however, the expression of gene involved In apoptosls (death associated protein kinase) was decreased. Conclusion : The different kinds of genes involved in the development and progression of cervical cancer were identified with the CDNA microarray, and the proposed theory is that the proliferation signal stalls with ILK, and is amplified with Spry 2 and MAPK signaling, and the cellular mitoses are Increased with the increased expression oi Cdc 2 and cell division kinases. After the radiation therapy, the expression profiles demonstrated 4he evidence of the decreased cancer cell proliferation. There was no sigificant difference in the morphological findings of cell death between the radiation therapy aione and the chemo-radiation groups In the second time biopsy specimen, however, the gene expression profiles were markedly different, and the mechanism at the molecular level needs further study.

Isolation and Characterization of Mouse Testis Specific Serine/Threonine Kinase 5 Possessing Four Alternatively Spliced Variants

  • Wei, Youheng;Fu, Guolong;Hu, Hairong;Lin, Gang;Yang, Jingchun;Guo, Jinhu;Zhu, Qiquan;Yu, Long
    • BMB Reports
    • /
    • v.40 no.5
    • /
    • pp.749-756
    • /
    • 2007
  • Phosphorylation on serine/threonine or tyrosine residues of target proteins is an essential and significant regulatory mechanism in signal transduction during many cellular and life processes, including spermatogenesis, oogenesis and fertilization. In the present work, we reported the isolation and characterization of mouse testis-specific serine/threonine kinase 5 (Tssk5), which contains four alternatively spliced variants including, Tssk5$\alpha$, Tssk5$\beta$, Tssk5$\gamma$ and Tssk5$\delta$. Moreover, the locus of Tssk5 is on chromosome 14qC3 and the four variants had a similar high expression in the testis and the heart; however, had a low expression in other tissues, except for Tssk5$\alpha$ which also had comparably high expression in the spleen. Each variant of Tssk5 expression began in the testis 16 days after birth. Aside from TSSK5$\alpha$, the other isoforms have an insertion of ten amino acid residues (RLTPSLSAAG) in region VIb (HRD domain) (His-Arg-Asp). Moreover, only TSSK5$\alpha$ exhibited kinase activity and consistently, a further Luciferase Reporter Assay demonstrated that TSSK5$\beta$, TSSK5$\gamma$ and TSSK5$\delta$ cannot be stimulated at the CREB/CRE responsive pathway in comparison to TSSK5$\alpha$. These findings suggest that TSSK5$\beta$, TSSK5$\gamma$, TSSK5$\delta$ may be pseudokinases due to the insertion, which may damage the structure responsible for active kinase activity. Pull-down assay experiments indicated that TSSK5$\beta$, TSSK5 $\gamma$ and TSSK5$\delta$ can directly interact with TSSK5$\alpha$. In summary, these four isoforms with similar expression patterns may be involved in spermatogenesis through a coordinative way in testis.

Construction of Mammalian Cell Expression Vector for pAcGFP-bFLIP(L) Fusion Protein and Its Expression in Follicular Granulosa Cells

  • Yang, Run Jun;Li, Wu Feng;Li, Jun Ya;Zhang, Lu Pei;Gao, Xue;Chen, Jin Bao;Xu, Shang Zhong
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.23 no.3
    • /
    • pp.401-409
    • /
    • 2010
  • FLICE inhibitory protein (FLIP) is one of the important anti-apoptotic proteins in the Fas/FasL apoptotic path which has death effect domains, mimicking the pro-domain of procaspase-8. To reveal the intracellular signal transduction molecules involved in the process of follicular development in the bovine ovary, we cloned the c-FLIP(L) gene in bovine ovary tissue with the reverse transcription polymerase chain reaction (RT-PCR), deleted the termination codon in its cDNA, and directionally cloned the amplified c-FLIP(L) gene into eukaryotic expression vector pAcGFP-Nl, including AcGFP, and successfully constructed the fusion protein recombinant plasmid. After identifying by restrictive enzyme BglII/EcoRI and sequencing, pAcGFP-bFLIP(L) was then transfected into follicular granulosa cells, mediated by Lipofectamine 2000, the expression of AcGFP observed and the transcription and expression of c-FLIP(L) detected by RT-PCR and Western blot. The results showed that the cattle c-FLIP(L) was successfully cloned; the pAcGFPbFLIP(L) fusion protein recombinant plasmid was successfuly constructed by introducing a BglII/EcoRI cloning site at the two ends of the c-FLIP(L) open reading frame and inserting a Kozak sequence before the start codon. AcGFP expression was detected as early as 24 h after transfection. The percentage of AcGFP positive cells reached about 65% after 24 h. A 1,483 bp transcription was amplified by RT-PCR, and a 83 kD target protein was detected by Western blot. Construction of the pAcGFP-bFLIP(L) recombinant plasmid should be helpful for further understanding the mechanism of regulation of c-FLIP(L) on bovine oocyte formation and development.

Effect of Hypoxia on the Signal Transduction of Apoptosis in Osteoblasts (저산소 상태에서 조골세포 고사의 신호전달 기전)

  • Park, Young-Joo;Oh, Soh-Taek;Kang, Kyung-Hwa;Kim, Sang-Cheol
    • The korean journal of orthodontics
    • /
    • v.33 no.6 s.101
    • /
    • pp.453-463
    • /
    • 2003
  • Mammalian cell is critically dependent on a continuous supply of oxygen. Even brief periods of oxygen deprivation can result in profound cellular damage. The aim of this study was to examine the possible mechanism of apoptosis in response to hypoxia in MC3T3E1 osteoblasts. MC3T3El osteoblasts under hypoxic conditions ($2\%$ oxygen) resulted in apoptosis in a time-dependent manner, determined by DNA fragmentation assay and nuclear morphology, stained with fluorescent dye (Hoechst 33258) Pretreatment with Z-VAD-FMK, a pancaspase inhibitor, or Z-DEVD-CHO, a specific caspase-3 inhibitor, suppressed the DNA ladder in response to hypoxia in a concentration dependent manner. An increase in caspase-3-like protease (DEVDase) activity was observed during apoptosis, but no caspase-l activity (YVADase) was detected. To confirm what caspases were involved in apoptosis, western blot analysis was performed using an anticaspase-3 or 6 antibody. The 17-kDa protein, that corresponds to the active products of caspase-3 and the 20-kDa protein of the active protein of caspase-6 were generated in hypoxia-challenged lysates, in which the full length forms of caspase-3 and 6 were evident. With a time course similar to caspase-3 and 6 activation, hypoxic stress also caused the cleavage of Lamin A, typical of caspase-6 activity. In addition, the hypoxic stress elicited the release of cytochrome c into the cytosol during apoptosis. These findings suggested that the activation of caspases accompanied by a cytochrome c release in response to hypoxia was involved in apoptotic cell death in MC3T3E1 osteoblasts.