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Sample records for pi3k-akt signaling blocks

  1. Roxarsone induces angiogenesis via PI3K/Akt signaling

    OpenAIRE

    2016-01-01

    Background 3-Nitro-4-hydroxy phenyl arsenic acid, roxarsone, is widely used as an organic arsenic feed additive for livestock and poultry, which may increase the level of arsenic in the environment and the risk of exposure to arsenic in human. Little information is focused on the angiogenesis roxarsone-induced and its mechanism at present. This paper aims to study the role of PI3K/Akt signaling in roxarsone-induced angiogenesis in rat vascular endothelial cells and a mouse B16–F10 melanoma xe...

  2. Activation of Robo1 signaling of breast cancer cells by Slit2 from stromal fibroblast restrains tumorigenesis via blocking PI3K/Akt/β-catenin pathway.

    Science.gov (United States)

    Chang, Po-Hao; Hwang-Verslues, Wendy W; Chang, Yi-Cheng; Chen, Chun-Chin; Hsiao, Michael; Jeng, Yung-Ming; Chang, King-Jen; Lee, Eva Y-H P; Shew, Jin-Yuh; Lee, Wen-Hwa

    2012-09-15

    Tumor microenvironment plays a critical role in regulating tumor progression by secreting factors that mediate cancer cell growth. Stromal fibroblasts can promote tumor growth through paracrine factors; however, restraint of malignant carcinoma progression by the microenvironment also has been observed. The mechanisms that underlie this paradox remain unknown. Here, we report that the tumorigenic potential of breast cancer cells is determined by an interaction between the Robo1 receptor and its ligand Slit2, which is secreted by stromal fibroblasts. The presence of an active Slit2/Robo1 signal blocks the translocation of β-catenin into nucleus, leading to downregulation of c-myc and cyclin D1 via the phosphoinositide 3-kinase (PI3K)/Akt pathway. Clinically, high Robo1 expression in the breast cancer cells correlates with increased survival in patients with breast cancer, and low Slit2 expression in the stromal fibroblasts is associated with lymph node metastasis. Together, our findings explain how a specific tumor microenvironment can restrain a given type of cancer cell from progression and show that both stromal fibroblasts and tumor cell heterogeneity affect breast cancer outcomes.

  3. PI3K/Akt signaling mediated Hexokinase-2 expression inhibits cell apoptosis and promotes tumor growth in pediatric osteosarcoma

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    Zhuo, Baobiao; Li, Yuan; Li, Zhengwei; Qin, Haihui; Sun, Qingzeng; Zhang, Fengfei; Shen, Yang; Shi, Yingchun [Department of Surgery, The Children' s Hospital of Xuzhou, Xuzhou, Jiangsu Province 221006 (China); Wang, Rong, E-mail: wangrong2008163@163.com [Department of Ultrasonography, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu Province 221006 (China)

    2015-08-21

    Accumulating evidence has shown that PI3K/Akt pathway is frequently hyperactivated in osteosarcoma (OS) and contributes to tumor initiation and progression. Altered phenotype of glucose metabolism is a key hallmark of cancer cells including OS. However, the relationship between PI3K/Akt pathway and glucose metabolism in OS remains largely unexplored. In this study, we showed that elevated Hexokinase-2 (HK2) expression, which catalyzes the first essential step of glucose metabolism by conversion of glucose into glucose-6-phosphate, was induced by activated PI3K/Akt signaling. Immunohistochemical analysis showed that HK2 was overexpressed in 83.3% (25/30) specimens detected and was closely correlated with Ki67, a cell proliferation index. Silencing of endogenous HK2 resulted in decreased aerobic glycolysis as demonstrated by reduced glucose consumption and lactate production. Inhibition of PI3K/Akt signaling also suppressed aerobic glycolysis and this effect can be reversed by reintroduction of HK2. Furthermore, knockdown of HK2 led to increased cell apoptosis and reduced ability of colony formation; meanwhile, these effects were blocked by 2-Deoxy-D-glucose (2-DG), a glycolysis inhibitor through its actions on hexokinase, indicating that HK2 functions in cell apoptosis and growth were mediated by altered aerobic glycolysis. Taken together, our study reveals a novel relationship between PI3K/Akt signaling and aerobic glycolysis and indicates that PI3K/Akt/HK2 might be potential therapeutic approaches for OS. - Highlights: • PI3K/Akt signaling contributes to elevated expression of HK2 in osteosarcoma. • HK2 inhibits cell apoptosis and promotes tumor growth through enhanced Warburg effect. • Inhibition of glycolysis blocks the oncogenic activity of HK2.

  4. Salidroside attenuates myocardial ischemia-reperfusion injury via PI3K/Akt signaling pathway.

    Science.gov (United States)

    Xu, Mao-Chun; Shi, Hai-Ming; Gao, Xiu-Fang; Wang, Hao

    2013-01-01

    To investigate the cardioprotective effects of salidroside on myocardial ischemia-reperfusion injury (IRI) in rabbits and the underlying action mechanisms in PI3K/Akt signaling pathway, a rabbit ischemia/reperfusion model was created by ligating the left anterior descending coronary arterial branch for 30 min and by releasing the ligature to allow reperfusion for 120 min. Salidroside or salidroside+PI3K inhibitor (LY294002) was administered via intracoronary injections at the onset of reperfusion. Apoptosis of cardiomyocytes was assessed by terminal dUTP nick-end labeling assay, and the expression of apoptosis-related proteins was observed by immunohistochemistry. The expressions of total Akt and phosphorylated Akt (p-Akt) were detected by western blot analysis. The results showed that intracoronary injection of salidroside at the onset of reperfusion markedly reduced the apoptosis of cardiomyocytes, significantly increasing Bcl-2 and p-Akt proteins expressions and decreasing Bax and caspase-3 expressions in the hearts subjected to ischemia followed by 120-min reperfusion. However, the anti-apoptotic effect induced by salidroside was inhibited by LY294002, which blocked the activation of Akt. These results suggested that intracoronary administration of salidroside at the onset of reperfusion could significantly reduce the IRI-induced apoptosis of cardiomyocytes, and this protective mechanism seemed to be mediated by the PI3K-Akt signaling pathway.

  5. The Role of PI3K/Akt/mTOR Signaling in Gastric Carcinoma

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    Matsuoka, Tasuku [Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585 (Japan); Yashiro, Masakazu, E-mail: m9312510@med.osaka-cu.ac.jp [Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585 (Japan); Oncology Institute of Geriatrics and Medical Science, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585 (Japan)

    2014-07-07

    The phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is one of the key signaling pathways induced by various receptor-tyrosine kinases. Accumulating evidence shows that this pathway is an important promoter of cell growth, metabolism, survival, metastasis, and resistance to chemotherapy. Genetic alterations in the PI3K/Akt/mTOR pathway in gastric carcinoma have often been demonstrated. Many kinds of molecular targeting therapies are currently undergoing clinical testing in patients with solid tumors. However, with the exception of the ErbB2-targeting antibody, targeting agents, including PI3K/Akt/mTOR inhibitors, have not been approved for treatment of patients with gastric carcinoma. This review summarizes the current knowledge on PI3K/Akt/mTOR signaling in the pathogenesis of gastric carcinoma and the possible therapeutic targets for gastric carcinoma. Improved knowledge of the PI3K/Akt/mTOR pathway in gastric carcinoma will be useful in understanding the mechanisms of tumor development and for identifying ideal targets of anticancer therapy for gastric carcinoma.

  6. The Role of PI3K/Akt/mTOR Signaling in Gastric Carcinoma

    Science.gov (United States)

    Matsuoka, Tasuku; Yashiro, Masakazu

    2014-01-01

    The phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is one of the key signaling pathways induced by various receptor-tyrosine kinases. Accumulating evidence shows that this pathway is an important promoter of cell growth, metabolism, survival, metastasis, and resistance to chemotherapy. Genetic alterations in the PI3K/Akt/mTOR pathway in gastric carcinoma have often been demonstrated. Many kinds of molecular targeting therapies are currently undergoing clinical testing in patients with solid tumors. However, with the exception of the ErbB2-targeting antibody, targeting agents, including PI3K/Akt/mTOR inhibitors, have not been approved for treatment of patients with gastric carcinoma. This review summarizes the current knowledge on PI3K/Akt/mTOR signaling in the pathogenesis of gastric carcinoma and the possible therapeutic targets for gastric carcinoma. Improved knowledge of the PI3K/Akt/mTOR pathway in gastric carcinoma will be useful in understanding the mechanisms of tumor development and for identifying ideal targets of anticancer therapy for gastric carcinoma. PMID:25003395

  7. Egr-1 decreases adipocyte insulin sensitivity by tilting PI3K/Akt and MAPK signal balance in mice

    Science.gov (United States)

    Yu, Xiao; Shen, Ning; Zhang, Ming-Liang; Pan, Fei-Yan; Wang, Chen; Jia, Wei-Ping; Liu, Chang; Gao, Qian; Gao, Xiang; Xue, Bin; Li, Chao-Jun

    2011-01-01

    It is well known that insulin can activate both PI3K/Akt pathway, which is responsible for glucose uptake, and MAPK pathway, which is crucial for insulin resistance formation. But, it is unclear exactly how the two pathways coordinate to regulate insulin sensitivity upon hyperinsulinism stress of type 2 diabetes mellitus (T2DM). Here, we show that an early response transcription factor Egr-1 could tilt the signalling balance by blocking PI3K/Akt signalling through PTEN and augmenting Erk/MAPK signalling through GGPPS, resulting in insulin resistance in adipocytes. Egr-1, PTEN and GGPPS are upregulated in the fat tissue of T2DM patients and db/db mice. Egr-1 overexpression in epididymal fat induced systematic insulin resistance in wild-type mice, and loss of Egr-1 function improved whole-body insulin sensitivity in diabetic mice, which is mediated by Egr-1 controlled PI3K/Akt and Erk/MAPK signalling balance. Therefore, we have revealed, for the first time, the mechanism by which Egr-1 induces insulin resistance under hyperinsulinism stress, which provides an ideal pharmacological target since inhibiting Egr-1 can simultaneously block MAPK and augment PI3K/Akt activation during insulin stimulation. PMID:21829168

  8. PI3K / Akt signaling regulates epithelialmesenchymal transition of peritoneal mesothelial cells in peritoneal dialysis

    Institute of Scientific and Technical Information of China (English)

    彭翔

    2014-01-01

    Objective To investigate the role of PI3K/Akt signaling in the regulation of epithelial-mesenchymal transition(EMT)of peritoneal mesothelial cells(PMCs)in peritoneal dialysis in vitro and in vivo.Methods The level of phosphorylated serine/threonine kinase Akt and the expression of EMT associated gene and protein,including ZO-1,Vimentin and FN,were measured in mice EMT model.In vitro study,phosphorylation level and

  9. AKTivation of the PI3K/AKT/mTOR signaling pathway by KSHV

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    Aadra P Bhatt

    2013-01-01

    Full Text Available As an obligate intracellular parasite, the Kaposi sarcoma-associated herpesvirus (KSHV relies on host cell machinery to meet its needs for survival, viral replication, production, and dissemination of progeny virions. KSHV is a ɣ-herpesvirus that is associated with three different malignancies: Kaposi sarcoma (KS, and two B cell lymphoproliferative disorders, primary effusion lymphoma (PEL and multicentric Castleman disease (MCD. KSHV viral proteins modulate cellular phosphatidylinositol-3-kinase (PI3K/AKT/mammalian target of rapamycin (mTOR signaling pathway, which is a ubiquitous pathway that also controls B lymphocyte proliferation and development. We review the mechanisms by which KSHV manipulates the PI3K/AKT/mTOR pathway, with a specific focus on B cells.

  10. PI3K-AKT-mTOR signaling in prostate cancer progression and androgen deprivation therapy resistance

    Institute of Scientific and Technical Information of China (English)

    Merritt P Edlind; Andrew C Hsieh

    2014-01-01

    Prostate cancer (PCa) is the second most common malignancy among men in the world. Castration-resistant prostate cancer (CRPC) is the lethal form of the disease, which develops upon resistance to ifrst line androgen deprivation therapy (ADT). Emerging evidence demonstrates a key role for the PI3K-AKT-mTOR signaling axis in the development and maintenance of CRPC. This pathway, which is deregulated in the majority of advanced PCas, serves as a critical nexus for the integration of growth signals with downstream cellular processes such as protein synthesis, proliferation, survival, metabolism and differentiation, thus providing mechanisms for cancer cells to overcome the stress associated with androgen deprivation. Furthermore, preclinical studies have elucidated a direct connection between the PI3K-AKT-mTOR and androgen receptor (AR) signaling axes, revealing a dynamic interplay between these pathways during the development of ADT resistance. Thus, there is a clear rationale for the continued clinical development of a number of novel inhibitors of the PI3K pathway, which offer the potential of blocking CRPC growth and survival. In this review, we will explore the relevance of the PI3K-AKT-mTOR pathway in PCa progression and castration resistance in order to inform the clinical development of speciifc pathway inhibitors in advanced PCa. In addition, we will highlight current deifciencies in our clinical knowledge, most notably the need for biomarkers that can accurately predict for response to PI3K pathway inhibitors.

  11. Adiponectin Induces Oncostatin M Expression in Osteoblasts through the PI3K/Akt Signaling Pathway

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    Chen-Ming Su

    2015-12-01

    Full Text Available Rheumatoid arthritis (RA, a common autoimmune disorder, is associated with a chronic inflammatory response and unbalanced bone metabolism within the articular microenvironment. Adiponectin, an adipokine secreted by adipocytes, is involved in multiple functions, including lipid metabolism and pro-inflammatory activity. However, the mechanism of adiponectin performance within arthritic inflammation remains unclear. In this study, we observed the effect of adiponectin on the expression of oncostatin M (OSM, a pro-inflammatory cytokine, in human osteoblastic cells. Pretreatment of cells with inhibitors of phosphatidylinositol 3-kinase (PI3K, Akt, and nuclear factor (NF-κB reduced the adiponectin-induced OSM expression in osteoblasts. Stimulation of the cells with adiponectin increased phosphorylation of PI3K, Akt, and p65. Adiponectin treatment of osteoblasts increased OSM-luciferase activity and p65 binding to NF-κB on the OSM promoter. Our results indicate that adiponectin increased OSM expression via the PI3K, Akt, and NF-κB signaling pathways in osteoblastic cells, suggesting that adiponectin is a novel target for arthritis treatment.

  12. Exendin-4 Promotes Beta Cell Proliferation via PI3k/Akt Signalling Pathway

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    Chaoxun Wang

    2015-04-01

    Full Text Available Background/Aims: Prevention of diabetes requires maintenance of a functional beta-cell mass, the postnatal growth of which depends on beta cell proliferation. Past studies have shown evidence of an effect of an incretin analogue, Exendin-4, in promoting beta cell proliferation, whereas the underlying molecular mechanisms are not completely understood. Methods: Here we studied the effects of Exendin-4 on beta cell proliferation in vitro and in vivo through analysing BrdU-incorporated beta cells. We also analysed the effects of Exendin-4 on beta cell mass in vivo, and on beta cell number in vitro. Then, we applied specific inhibitors of different signalling pathways and analysed their effects on Exendin-4-induced beta cell proliferation. Results: Exendin-4 increased beta cell proliferation in vitro and in vivo, resulting in significant increases in beta cell mass and beta cell number, respectively. Inhibition of PI3K/Akt signalling, but not inhibition of either ERK/MAPK pathway, or JNK pathway, significantly abolished the effects of Exendin-4 in promoting beta cell proliferation. Conclusion: Exendin-4 promotes beta cell proliferation via PI3k/Akt signaling pathway.

  13. Salvianolic Acid B Inhibits Hydrogen Peroxide-Induced Endothelial Cell Apoptosis through Regulating PI3K/Akt Signaling

    Science.gov (United States)

    Liu, Chen-Li; Xie, Li-Xia; Li, Min; Durairajan, Siva Sundara Kumar; Goto, Shinya; Huang, Jian-Dong

    2007-01-01

    Background Salvianolic acid B (Sal B) is one of the most bioactive components of Salvia miltiorrhiza, a traditional Chinese herbal medicine that has been commonly used for prevention and treatment of cerebrovascular disorders. However, the mechanism responsible for such protective effects remains largely unknown. It has been considered that cerebral endothelium apoptosis caused by reactive oxygen species including hydrogen peroxide (H2O2) is implicated in the pathogenesis of cerebrovascular disorders. Methodology and Principal Findings By examining the effect of Sal B on H2O2-induced apoptosis in rat cerebral microvascular endothelial cells (rCMECs), we found that Sal B pretreatment significantly attenuated H2O2-induced apoptosis in rCMECs. We next examined the signaling cascade(s) involved in Sal B-mediated anti-apoptotic effects. We showed that H2O2 induces rCMECs apoptosis mainly through the PI3K/ERK pathway, since a PI3K inhibitor (LY294002) blocked ERK activation caused by H2O2 and a specific inhibitor of MEK (U0126) protected cells from apoptosis. On the other hand, blockage of the PI3K/Akt pathway abrogated the protective effect conferred by Sal B and potentated H2O2-induced apoptosis, suggesting that Sal B prevents H2O2-induced apoptosis predominantly through the PI3K/Akt (upstream of ERK) pathway. Significance Our findings provide the first evidence that H2O2 induces rCMECs apoptosis via the PI3K/MEK/ERK pathway and that Sal B protects rCMECs against H2O2-induced apoptosis through the PI3K/Akt/Raf/MEK/ERK pathway. PMID:18091994

  14. Salvianolic acid B inhibits hydrogen peroxide-induced endothelial cell apoptosis through regulating PI3K/Akt signaling.

    Directory of Open Access Journals (Sweden)

    Chen-Li Liu

    Full Text Available BACKGROUND: Salvianolic acid B (Sal B is one of the most bioactive components of Salvia miltiorrhiza, a traditional Chinese herbal medicine that has been commonly used for prevention and treatment of cerebrovascular disorders. However, the mechanism responsible for such protective effects remains largely unknown. It has been considered that cerebral endothelium apoptosis caused by reactive oxygen species including hydrogen peroxide (H(2O(2 is implicated in the pathogenesis of cerebrovascular disorders. METHODOLOGY AND PRINCIPAL FINDINGS: By examining the effect of Sal B on H(2O(2-induced apoptosis in rat cerebral microvascular endothelial cells (rCMECs, we found that Sal B pretreatment significantly attenuated H(2O(2-induced apoptosis in rCMECs. We next examined the signaling cascade(s involved in Sal B-mediated anti-apoptotic effects. We showed that H(2O(2 induces rCMECs apoptosis mainly through the PI3K/ERK pathway, since a PI3K inhibitor (LY294002 blocked ERK activation caused by H(2O(2 and a specific inhibitor of MEK (U0126 protected cells from apoptosis. On the other hand, blockage of the PI3K/Akt pathway abrogated the protective effect conferred by Sal B and potentated H(2O(2-induced apoptosis, suggesting that Sal B prevents H(2O(2-induced apoptosis predominantly through the PI3K/Akt (upstream of ERK pathway. SIGNIFICANCE: Our findings provide the first evidence that H(2O(2 induces rCMECs apoptosis via the PI3K/MEK/ERK pathway and that Sal B protects rCMECs against H(2O(2-induced apoptosis through the PI3K/Akt/Raf/MEK/ERK pathway.

  15. Francisella subverts innate immune signaling: Focus on PI3K/Akt

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    Thomas John Cremer

    2011-02-01

    Full Text Available Intracellular bacterial pathogens exploit host cells as a part of their lifecycle, and they do so by manipulating host cell signaling events. Many such bacteria are known to produce effector proteins that promote cell invasion, alter membrane trafficking and disrupt signaling cascades. This review highlights recent advances in our understanding of signaling pathways involved in host cell responses to Francisella tularensis, a facultative Gram-negative intracellular pathogen that causes tularemia. We highlight several key pathways that are targeted by Francisella, with a focus on the PI3K/Akt pathway. Lastly, we discuss the emerging role of microRNAs, specifically miR-155, as a key regulator of host signaling and defense.

  16. PI3K/AKT Signaling Pathway Is Essential for Survival of Induced Pluripotent Stem Cells.

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    Amir M Hossini

    Full Text Available Apoptosis is a highly conserved biochemical mechanism which is tightly controlled in cells. It contributes to maintenance of tissue homeostasis and normally eliminates highly proliferative cells with malignant properties. Induced pluripotent stem cells (iPSCs have recently been described with significant functional and morphological similarities to embryonic stem cells. Human iPSCs are of great hope for regenerative medicine due to their broad potential to differentiate into specialized cell types in culture. They may be useful for exploring disease mechanisms and may provide the basis for future cell-based replacement therapies. However, there is only poor insight into iPSCs cell signaling as the regulation of apoptosis. In this study, we focused our attention on the apoptotic response of Alzheimer fibroblast-derived iPSCs and two other Alzheimer free iPSCs to five biologically relevant kinase inhibitors as well as to the death ligand TRAIL. To our knowledge, we are the first to report that the relatively high basal apoptotic rate of iPSCs is strongly suppressed by the pancaspase inhibitor QVD-Oph, thus underlining the dependency on proapoptotic caspase cascades. Furthermore, wortmannin, an inhibitor of phosphoinositid-3 kinase / Akt signaling (PI3K-AKT, dramatically and rapidly induced apoptosis in iPSCs. In contrast, parental fibroblasts as well as iPSC-derived neuronal cells were not responsive. The resulting condensation and fragmentation of DNA and decrease of the membrane potential are typical features of apoptosis. Comparable effects were observed with an AKT inhibitor (MK-2206. Wortmannin resulted in disappearance of phosphorylated AKT and activation of the main effector caspase-3 in iPSCs. These results clearly demonstrate for the first time that PI3K-AKT represents a highly essential survival signaling pathway in iPSCs. The findings provide improved understanding on the underlying mechanisms of apoptosis regulation in iPSCs.

  17. Anger Emotional Stress Influences VEGF/VEGFR2 and Its Induced PI3K/AKT/mTOR Signaling Pathway

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    Peng Sun

    2016-01-01

    Full Text Available Objective. We discuss the influence of anger emotional stress upon VEGF/VEGFR2 and its induced PI3K/AKT/mTOR signal pathway. Methods. We created a rat model of induced anger (anger-out and anger-in emotional response using social isolation and resident-intruder paradigms and assessed changes in hippocampus’ VEGF content, neuroplasticity, and the PI3K/AKT/mTOR signaling pathway. Results. The resident-intruder method successfully generated anger-out and anger-in models that differed significantly in composite aggression score, aggression incubation, open field behavior, sucrose preference, and weight gain. Anger emotional stress decreased synaptic connections and VEGFR2 expression. Anger emotional stress led to abnormal expression of VEGF/VEGFR2 mRNA and protein and disorderly expression of key factors in the PI3K/AKT/mTOR signal pathway. Fluoxetine administration ameliorated behavioral abnormalities and damage to hippocampal neurons caused by anger emotional stress, as well as abnormal expression of some proteins in VEGF/VEGFR2 and its induced PI3K/AKT/mTOR signal pathway. Conclusion. This research provides a detailed classification of anger emotion and verifies its influence upon VEGF and the VEGF-induced signaling pathway, thus providing circumstantial evidence of mechanisms by which anger emotion damages neurogenesis. As VEGFR2 can promote neurogenesis and vasculogenesis in the hippocampus and frontal lobe, these results suggest that anger emotional stress can result in decreased neurogenesis.

  18. Intestinal trefoil factor activates the PI3K/Akt signaling pathway to protect gastric mucosal epithelium from damage.

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    Sun, Zhaorui; Liu, Hongmei; Yang, Zhizhou; Shao, Danbing; Zhang, Wei; Ren, Yi; Sun, Baodi; Lin, Jinfeng; Xu, Min; Nie, Shinan

    2014-09-01

    Intestinal trefoil factor (ITF, also named as trefoil factor 3, TFF3) is a member of the TFF-domain peptide family, which plays an essential role in the regulation of cell survival, cell migration and maintains mucosal epithelial integrity in the gastrointestinal tract. However, the underlying mechanisms and associated molecules remain unclear. The aim of this study was to explore the protective effects of ITF on gastric mucosal epithelium injury and its possible molecular mechanisms of action. In the present study, we show that ITF was able to promote the proliferation and migration of GES-1 cells via a mechanism that involves the PI3K/Akt signaling pathway. Western blot results indicated that ITF induced a dose- and time-dependent increase in the Akt signaling pathway. ITF also plays an essential role in the restitution of GES-1 cell damage induced by lipopolysaccharide (LPS). LPS induced the apoptosis of GES-1 cells, decreased cell viability significantly (Pinhibition of the PI3K/Akt pathway. Taken together, our results demonstrate that ITF promotes the proliferation and migration of gastric mucosal epithelial cells and preserves gastric mucosal epithelial integrity after damage is mediated by activation of the PI3K/Akt signaling pathway. This study suggested that the PI3K/Akt pathway could act as a key intracellular pathway in the gastric mucosal epithelium that may serve as a therapeutic target to preserve epithelial integrity during injury.

  19. Omentin-1 Stimulates Human Osteoblast Proliferation through PI3K/Akt Signal Pathway

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    Shan-Shan Wu

    2013-01-01

    Full Text Available It has been presumed that adipokines deriving from adipose tissue may play important roles in bone metabolism. Omentin-1, a novel adipokine, which is selectively expressed in visceral adipose tissue, has been reported to stimulate proliferation and inhibit differentiation of mouse osteoblast. However, little information refers to the effect of omentin-1 on human osteoblast (hOB proliferation. The current study examined the potential effects of omentin-1 on proliferation in hOB and the signal pathway involved. Omentin-1 promoted hOB proliferation in a dose-dependent manner as determined by [3H]thymidine incorporation. Western blot analysis revealed that omentin-1 induced activation of Akt (phosphatidylinositol-3 kinase downstream effector and such effect was impeded by transfection of hOB with Akt-siRNA. Furthermore, LY294002 (a selective PI3K inhibitor and HIMO (a selective Akt inhibitor abolished the omentin-1-induced hOB proliferation. These findings indicate that omentin-1 induces hOB proliferation via the PI3K/Akt signaling pathway and suggest that osteoblast is a direct target of omentin-1.

  20. K-ras/PI3K-Akt signaling is essential for zebrafish hematopoiesis and angiogenesis.

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    Lihui Liu

    Full Text Available The RAS small GTPases orchestrate multiple cellular processes. Studies on knock-out mice showed the essential and sufficient role of K-RAS, but not N-RAS and H-RAS in embryonic development. However, many physiological functions of K-RAS in vivo remain unclear. Using wild-type and fli1:GFP transgenic zebrafish, we showed that K-ras-knockdown resulted in specific hematopoietic and angiogenic defects, including the impaired expression of erythroid-specific gene gata1 and sse3-hemoglobin, reduced blood circulation and disorganized blood vessels. Expression of either K-rasC40 that links to phosphoinositide 3-kinase (PI3K activation, or Akt2 that acts downstream of PI3K, could rescue both hematopoietic and angiogenic defects in the K-ras knockdown. Consistently, the functional rescue by k-ras mRNA was significantly suppressed by wortmannin, a PI3K-specific inhibitor. Our results provide direct evidence that PI3K-Akt plays a crucial role in mediating K-ras signaling during hematopoiesis and angiogenesis in vivo, thus offering new targets and alternative vertebrate model for studying these processes and their related diseases.

  1. Mechanical Stress Regulates Osteogenesis and Adipogenesis of Rat Mesenchymal Stem Cells through PI3K/Akt/GSK-3β/β-Catenin Signaling Pathway

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    Fanglong Song

    2017-01-01

    Full Text Available Osteogenesis and adipogenesis of bone marrow mesenchymal stem cells (BMSCs are regarded as being of great importance in the regulation of bone remodeling. In this study, rat BMSCs were exposed to different levels of cyclic mechanical stress generated by liquid drops and cultured in general medium or adipogenic medium. Markers of osteogenic (Runx2 and Collagen I and adipogenic (C/EBPα, PPARγ, and lipid droplets differentiation were detected using Western blot and histological staining. The protein levels of members of the phosphatidylinositol 3-kinase (PI3K/Akt/glycogen synthase kinase 3β (GSK-3β/β-catenin signaling pathway were also examined. Results showed that small-magnitude stress significantly upregulated Runx2 and Collagen I and downregulated PPARγ and C/EBPα expression in BMSCs cultured in adipogenic medium, while large-magnitude stress reversed the effect when compared with unloading groups. The PI3K/Akt signaling pathway could be strongly activated by mechanical stimulation; however, large-magnitude stress led to decreased activation of the signaling pathway when compared with small-magnitude stress. Activation of β-catenin with LiCl led to increased expression of Runx2 and Collagen I and reduction of C/EBPα and PPARγ expression in BMSCs. Inhibition of PI3K/Akt signaling partially blocked the expression of β-catenin. Taken together, our results indicate that mechanical stress-regulated osteogenesis and adipogenesis of rat BMSCs are mediated, at least in part, by the PI3K/Akt/GSK-3β/β-catenin signaling pathway.

  2. Icaritin requires Phosphatidylinositol 3 kinase (PI3K)/Akt signaling to counteract skeletal muscle atrophy following mechanical unloading

    OpenAIRE

    ZHANG, Zong-Kang; Li, Jie; Liu, Jin; Baosheng GUO; Leung, Albert; Zhang, Ge; Zhang, Bao-Ting

    2016-01-01

    Counteracting muscle atrophy induced by mechanical unloading/inactivity is of great clinical need and challenge. A therapeutic agent that could counteract muscle atrophy following mechanical unloading in safety is desired. This study showed that natural product Icaritin (ICT) could increase the phosphorylation level of Phosphatidylinositol 3 kinase (PI3K) at p110 catalytic subunit and promote PI3K/Akt signaling markers in C2C12 cells. This study further showed that the high dose ICT treatment...

  3. Roles of PI3K/AKT/GSK3/mTOR Pathway in Cell Signaling of Mental Illnesses

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    Yasuko Kitagishi

    2012-01-01

    Full Text Available Several pharmacological agents acting on monoamine neurotransmission are used for the management of mental illnesses. Regulation of PI3K/AKT and GSK3 pathways may constitute an important signaling center in the subcellular integration of the synaptic neurotransmission. The pathways also modulate neuronal cell proliferation, migration, and plasticity. There are evidences to suggest that inflammation of neuron contributes to the pathology of depression. Inflammatory activation of neuron contributes to the loss of glial elements, which are consistent with pathological findings characterizing the depression. A mechanism of anti-inflammatory reactions from antidepressant medications has been found to be associated with an enhancement of heme oxygenase-1 expression. This induction in brain is also important in neuroprotection and neuroplasticity. As enzymes involved in cell survival and neuroplasticity are relevant to neurotrophic factor dysregulation, the PI3K/AKT/GSK3 may provide an important signaling for the neuroprotection in depression. In this paper, we summarize advances on the involvement of the PI3K/AKT/GSK3 pathways in cell signaling of neuronal cells in mental illnesses.

  4. MicroRNA-21 accelerates hepatocyte proliferation in vitro via PI3K/Akt signaling by targeting PTEN

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    Yan-nan, Bai [Department of Hepato-Biliary-Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province (China); Department of Hepatobiliary Surgery, Fujian Provincial Hospital, Provincial Clinical College of Fujian Medical University, Fuzhou 350001, Fujian Province (China); Zhao-yan, Yu; Li-xi, Luo; Jiang, Yi [Department of Hepato-Biliary-Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province (China); Qing-jie, Xia [Translational Neuroscience Center, West China Hospital/West China Medical School of Sichuan University, Chengdu 610041, Sichuan Province (China); Yong, Zeng, E-mail: yongzengmd@gmail.com [Department of Hepato-Biliary-Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province (China)

    2014-01-17

    Highlights: •miRNAs-expression patterns of primary hepatocytes under proliferative status. •miR-21 expression level peaked at 12 h after stimulated by EGF. •miR-21 drive rapid S phase entry of primary hepatocytes. •PI3K/Akt signaling was modulated via targeting PTEN by miR-21. -- Abstract: MicroRNAs (miRNAs) are involved in controlling hepatocyte proliferation during liver regeneration. In this study, we established the miRNAs-expression patterns of primary hepatocytes in vitro under stimulation of epidermal growth factor (EGF), and found that microRNA-21 (miR-21) was appreciably up-regulated and peaked at 12 h. In addition, we further presented evidences indicating that miR-21 promotes primary hepatocyte proliferation through in vitro transfecting with miR-21 mimics or inhibitor. We further demonstrated that phosphatidylinositol 3′-OH kinase (PI3K)/Akt signaling was altered accordingly, it is, by targeting phosphatase and tensin homologue deleted on chromosome 10, PI3K/Akt signaling is activated by miR-21 to accelerate hepatocyte rapid S-phase entry and proliferation in vitro.

  5. PI3K-Akt signaling pathway upregulates hepatitis C virus RNA translation through the activation of SREBPs.

    Science.gov (United States)

    Shi, Qing; Hoffman, Brett; Liu, Qiang

    2016-03-01

    Hepatitis C virus (HCV) activates PI3K-Akt signaling to enhance entry and replication. Here, we found that this pathway also increased HCV translation. Knocking down the three Akt isoforms significantly decreased, whereas ectopic expression increased HCV translation. HCV translation upregulation by Akt required their kinase activities because Akt kinase-dead mutants downregulated HCV translation; and was dependent on PI3K activity since it was sensitive to PI3K inhibitor wortmannin. The viral 3'UTR was not involved in translation upregulation by Akt. HCV NS5A increased Akt phosphorylation/activity and HCV translation in the absence of the viral 3'UTR. Sterol regulatory element-binding proteins (SREBPs) were the downstream effectors of the PI3K-Akt pathway in regulating HCV translation because Akt1 and Akt2 activated both SREBP-1 and SREBP-2, whereas Akt3 upregulated SREBP-1. Knocking down SREBPs significantly decreased, while ectopic expression of SREBPs increased HCV translation. Taken together, we showed that the PI3K-Akt signaling pathway positively regulates HCV translation through SREBPs.

  6. Leptin regulates proliferation and apoptosis of colorectal carcinoma through PI3K/Akt/mTOR signalling pathway

    Indian Academy of Sciences (India)

    Di Wang; Jian Chen; Hui Chen; Zhi Duan; Qimei Xu; Meiyan Wei; Lianghua Wang; Meizuo Zhong

    2012-03-01

    Epidemiological studies have indicated that obesity is associated with colorectal cancer. The obesity hormone leptin is considered as a key mediator for cancer development and progression. The present study aims to investigate regulatory effects of leptin on colorectal carcinoma. The expression of leptin and its receptor Ob-R was examined by immunohistochemistry in 108 Chinese patients with colorectal carcinoma. The results showed that leptin/Ob-R expression was significantly associated with T stage, TNM stage, lymph node metastasis, distant metastasis, differentiation and expression of p-mTOR, p-70S6 kinase, and p-Akt. Furthermore, the effects of leptin on proliferation and apoptosis of HCT-116 colon carcinoma cells were determined. The results showed that leptin could stimulate the proliferation and inhibit the apoptosis of HCT-116 colon cells through the PI3K/Akt/mTOR pathway. Ly294002 (a PI3K inhibitor) and rapamycin (an mTOR inhibitor) could prevent the regulatory effects of leptin on the proliferation and apoptosis of HCT-116 cells via abrogating leptin-mediated PI3K/Akt/mTOR pathway. All these results indicated that leptin could regulate proliferation and apoptosis of colorectal carcinoma through the PI3K/Akt/mTOR signalling pathway.

  7. Quercetin suppresses HeLa cells by blocking PI3K/Akt pathway.

    Science.gov (United States)

    Xiang, Tao; Fang, Yong; Wang, Shi-Xuan

    2014-10-01

    To explore the effect of quercetin on the proliferation and apoptosis of HeLa cells, HeLa cells were incubated with quercetin at different concentrations. Cell viability was evaluated by MTT assay, cell apoptosis was detected by Annexin-V/PI double labeled cytometry and DNA ladder assay. Cell cycle was flow cytometrically determined and the morphological changes of the cells were observed under a fluorescence microscope after Hoechst 33258 staining and the apoptosis-related proteins in the HeLa cells were assessed by Western blotting. The results showed that quercetin significantly inhibited the growth of HeLa cells and induced obvious apoptosis in vitro in a time- and dose-dependent manner. Moreover, quercetin induced apoptosis of HeLa cells in cell cycle-dependent manner because quercetin could induce arrest of HeLa cells at G0/G1 phase. Quercetin treatment down-regulated the expression of the PI3K and p-Akt. In addition, quercetin could down-regulate expression of bcl-2, up-regulate Bax, but exerted no effect on the overall expression of Akt. We are led to conclude that quercetin induces apoptosis via PI3k/Akt pathways, and quercetin has potential to be used as an anti-tumor agent against human cervix cancer.

  8. Isoorientin induces apoptosis through mitochondrial dysfunction and inhibition of PI3K/Akt signaling pathway in HepG2 cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Li; Wang, Jing; Xiao, Haifang; Xiao, Chunxia; Wang, Yutang; Liu, Xuebo, E-mail: xueboliu@yahoo.com.cn

    2012-11-15

    Isoorientin (ISO) is a flavonoid compound that can be extracted from several plant species, such as Phyllostachys pubescens, Patrinia, and Drosophyllum lusitanicum; however, its biological activity remains poorly understood. The present study investigated the effects and putative mechanism of apoptosis induced by ISO in human hepatoblastoma cancer (HepG2) cells. The results showed that ISO induced cell death in a dose-dependent manner in HepG2 cells, but no toxicity in human liver cells (HL-7702) and buffalo rat liver cells (BRL-3A) treated with ISO at the indicated concentrations. ISO-induced cell death included apoptosis which characterized by the appearance of nuclear shrinkage, the cleavage of poly (ADP-ribose) polymerase (PARP) and DNA fragmentation. ISO significantly (p < 0.01) increased the Bax/Bcl-2 ratio, disrupted the mitochondrial membrane potential (MMP), increased the release of cytochrome c, activated caspase-3, and enhanced intracellular levels of reactive oxygen species (ROS) and nitric oxide (NO). In addition, ISO effectively inhibited the phosphorylation of Akt and increased FoxO4 expression. The PI3K/Akt inhibitor LY294002 enhanced the apoptosis-inducing effect of ISO. However, LY294002 markedly quenched ROS and NO generation and diminished the protein expression of heme peroxidase enzyme (HO-1) and inducible nitric oxide synthase (iNOS). Furthermore, the addition of a ROS inhibitor (N-acetyl cysteine, NAC) or iNOS inhibitor (N-[3-(aminomethyl) benzyl] acetamidine, dihydrochloride, 1400W) significantly diminished the apoptosis induced by ISO and also blocked the phosphorylation of Akt. These results demonstrated for the first time that ISO induces apoptosis in HepG2 cells and indicate that this apoptosis might be mediated through mitochondrial dysfunction and PI3K/Akt signaling pathway, and has no toxicity in normal liver cells, suggesting that ISO may have good potential as a therapeutic and chemopreventive agent for liver cancer. Highlights:

  9. Targeting the PI3K-AKT-mTOR signaling network in cancer

    Institute of Scientific and Technical Information of China (English)

    Khurum H.Khan; Timothy A.Yap; Li Yan; David Cunningham

    2013-01-01

    The phosphoinositide 3-kinase-AKT-mammalian target of rapamycin (PI3K-AKT-mTOR) pathway is a frequently hyperactivated pathway in cancer and is important for tumor cell growth and survival.The development of targeted therapies against mTOR,a vital substrate along this pathway,led to the approval of allosteric inhibitors,including everolimus and temsirolimus,for the treatment of breast,renal,and pancreatic cancers.However,the suboptimal duration of response in unselected patients remains an unresolved issue.Numerous novel therapies against critical nodes of this pathway are therefore being actively investigated in the clinic in multiple tumour types.In this review,we focus on the progress of these agents in clinical development along with their biological rationale,the need of predictive biomarkers and various combination strategies,which will be useful in counteracting the mechanisms of resistance to this class of drugs.

  10. Cyclic mechanical strain maintains Nanog expression through PI3K/Akt signaling in mouse embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Horiuchi, Rie [Division of Regenerative Medical Engineering, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Akimoto, Takayuki, E-mail: akimoto@m.u-tokyo.ac.jp [Division of Regenerative Medical Engineering, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Institute for Biomedical Engineering, Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, 513 Waseda-tsurumaki, Shinjuku, Tokyo 162-0041 (Japan); Hong, Zhang [Institute for Biomedical Engineering, Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, 513 Waseda-tsurumaki, Shinjuku, Tokyo 162-0041 (Japan); Ushida, Takashi [Division of Regenerative Medical Engineering, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan)

    2012-08-15

    Mechanical strain has been reported to affect the proliferation/differentiation of many cell types; however, the effects of mechanotransduction on self-renewal as well as pluripotency of embryonic stem (ES) cells remains unknown. To investigate the effects of mechanical strain on mouse ES cell fate, we examined the expression of Nanog, which is an essential regulator of self-renewal and pluripotency as well as Nanog-associated intracellular signaling during uniaxial cyclic mechanical strain. The mouse ES cell line, CCE was plated onto elastic membranes, and we applied 10% strain at 0.17 Hz. The expression of Nanog was reduced during ES cell differentiation in response to the withdrawal of leukemia inhibitory factor (LIF); however, two days of cyclic mechanical strain attenuated this reduction of Nanog expression. On the other hand, the cyclic mechanical strain promoted PI3K-Akt signaling, which is reported as an upstream of Nanog transcription. The cyclic mechanical strain-induced Akt phosphorylation was blunted by the PI3K inhibitor wortmannin. Furthermore, cytochalasin D, an inhibitor of actin polymerization, also inhibited the mechanical strain-induced increase in phospho-Akt. These findings imply that mechanical force plays a role in regulating Nanog expression in ES cells through the actin cytoskeleton-PI3K-Akt signaling. -- Highlights: Black-Right-Pointing-Pointer The expression of Nanog, which is an essential regulator of 'stemness' was reduced during embryonic stem (ES) cell differentiation. Black-Right-Pointing-Pointer Cyclic mechanical strain attenuated the reduction of Nanog expression. Black-Right-Pointing-Pointer Cyclic mechanical strain promoted PI3K-Akt signaling and mechanical strain-induced Akt phosphorylation was blunted by the PI3K inhibitor and an inhibitor of actin polymerization.

  11. Photoactivation of GLUT4 translocation promotes glucose uptake via PI3-K/Akt2 signaling in 3T3-L1 adipocytes

    Directory of Open Access Journals (Sweden)

    Lei Huang

    2014-05-01

    Full Text Available Insulin resistance is a hallmark of the metabolic syndrome and type 2 diabetes. Dysfunction of PI-3K/Akt signaling was involved in insulin resistance. Glucose transporter 4 (GLUT4 is a key factor for glucose uptake in muscle and adipose tissues, which is closely regulated by PI-3K/Akt signaling in response to insulin treatment. Low-power laser irradiation (LPLI has been shown to regulate various physiological processes and induce the synthesis or release of multiple molecules such as growth factors, which (especially red and near infrared light is mainly through the activation of mitochondrial respiratory chain and the initiation of intracellular signaling pathways. Nevertheless, it is unclear whether LPLI could promote glucose uptake through activation of PI-3K/Akt/GLUT4 signaling in 3T3L-1 adipocytes. In this study, we investigated how LPLI promoted glucose uptake through activation of PI-3K/Akt/GLUT4 signaling pathway. Here, we showed that GLUT4 was localized to the Golgi apparatus and translocated from cytoplasm to cytomembrane upon LPLI treatment in 3T3L-1 adipocytes, which enhanced glucose uptake. Moreover, we found that glucose uptake was mediated by the PI3-K/Akt2 signaling, but not Akt1 upon LPLI treatment with Akt isoforms gene silence and PI3-K/Akt inhibitors. Collectively, our results indicate that PI3-K/Akt2/GLUT4 signaling act as the key regulators for improvement of glucose uptake under LPLI treatment in 3T3L-1 adipocytes. More importantly, our findings suggest that activation of PI3-K/Akt2/GLUT4 signaling by LPLI may provide guidance in practical applications for promotion of glucose uptake in insulin-resistant adipose tissue.

  12. Zinc promotes proliferation and activation of myogenic cells via the PI3K/Akt and ERK signaling cascade

    Energy Technology Data Exchange (ETDEWEB)

    Ohashi, Kazuya, E-mail: asuno10k@yahoo.co.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Wada, Eiji, E-mail: gacchu1@yahoo.co.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Zammit, Peter S., E-mail: peter.zammit@kcl.ac.uk [Randall Division of Cell and Molecular Biophysics, King' s College London, London SE1 1UL (United Kingdom); Shiozuka, Masataka, E-mail: cmuscle@mail.ecc.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Matsuda, Ryoichi, E-mail: cmatsuda@mail.ecc.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan)

    2015-05-01

    Skeletal muscle stem cells named muscle satellite cells are normally quiescent but are activated in response to various stimuli, such as injury and overload. Activated satellite cells enter the cell cycle and proliferate to produce a large number of myogenic progenitor cells, and these cells then differentiate and fuse to form myofibers. Zinc is one of the essential elements in the human body, and has multiple roles, including cell growth and DNA synthesis. However, the role of zinc in myogenic cells is not well understood, and is the focus of this study. We first examined the effects of zinc on differentiation of murine C2C12 myoblasts and found that zinc promoted proliferation, with an increased number of cells incorporating EdU, but inhibited differentiation with reduced myogenin expression and myotube formation. Furthermore, we used the C2C12 reserve cell model of myogenic quiescence to investigate the role of zinc on activation of myogenic cells. The number of reserve cells incorporating BrdU was increased by zinc in a dose dependent manner, with the number dramatically further increased using a combination of zinc and insulin. Akt and extracellular signal-regulated kinase (ERK) are downstream of insulin signaling, and both were phosphorylated after zinc treatment. The zinc/insulin combination-induced activation involved the phosphoinositide 3-kinase (PI3K)/Akt and ERK cascade. We conclude that zinc promotes activation and proliferation of myogenic cells, and this activation requires phosphorylation of PI3K/Akt and ERK as part of the signaling cascade. - Highlights: • Zinc has roles for promoting proliferation and inhibition differentiation of C2C12. • Zinc promotes activation of reserve cells. • Insulin and zinc synergize activation of reserve cells. • PI3K/Akt and ERK cascade affect zinc/insulin-mediated activation of reserve cells.

  13. The Effect of Tianmai Xiaoke Pian on Insulin Resistance through PI3-K/AKT Signal Pathway

    Directory of Open Access Journals (Sweden)

    Nana Wang

    2016-01-01

    Full Text Available In the clinical setting, given the potential adverse effects of thiazolidinediones and biguanides, we often have difficulty in treatment that no other insulin sensitizers are available for use in type 2 diabetic mellitus (T2DM patients. Tianmai Xiaoke Pian (TMXKP is a traditional Chinese medicine tablet, which is comprised of chromium picolinate, Tianhuafen, Maidong, and Wuweizi. To understand its mechanism of action on insulin resistance, TMXKP (50 mg/kg orally was tested in T2DM rats (induced by a high-fat diet and streptozotocin. Eight weeks later, fasting blood glucose (FBG and oral glucose tolerance tests (OGTT were performed. Area under the curve (AUC and homeostatic model assessment of insulin resistance (HOMA-IR were calculated, and PI3-K/AKT signal pathway-related genes and proteins were tested by reverse transcription-polymerase chain reaction (RT-PCR and western blot analysis in muscle, adipose, and liver tissues, respectively. TMXKP significantly reduced FBG, OGTT, AUC, and HOMA-IR in diabetic rats P<0.05. Furthermore, we also observed that TMXKP could significantly decrease IRS-1, IRS-2, PI3-K p85α, and AKT2 gene expression and also IRS-1, IRS-2, PI3-K, AKT2, and p-AKT2 protein expression levels P<0.05 in diabetic rats. These findings confirm that TMXKP can alleviate insulin resistance in T2DM rats through the PI3K/AKT pathway. Thus TMXKP appears to be a promising insulin sensitizer.

  14. CHRNA7 inhibits cell invasion and metastasis of LoVo human colorectal cancer cells through PI3K/Akt signaling.

    Science.gov (United States)

    Xiang, Tao; Yu, Feng; Fei, Rushan; Qian, Jing; Chen, Wenbin

    2016-02-01

    The α7 neuronal nicotinic receptor gene (CHRNA7) is widely expressed in both the brain and periphery whereas its encoding protein of α7 neuronal acetylcholine receptor (α7nAChR) belongs to the nicotinic acetylcholine receptor family. Considerable evidence suggests that α7nAChR plays an important role in chronic inflammatory and neuropathic pain signaling and thus has been proposed as a potential target for treating cognitive deficits in patients with schizophrenia, attention deficit hyperactivity disorder (ADHD) and Alzheimer's disease. The aim of the present study was to determine the role of endogenous α7nAChR signaling in human colorectal cancer growth and metastasis. pLVX‑CHRNA7 encoding the full length of CHRNA7 was constructed and transfected into LoVo human colorectal cancer cells. Cell proliferation was measured by Cell Counting Kit‑8 (CCK‑8), and cell migration and invasion were detected by Transwell chamber assays. Expression and activity of metastasis‑related metalloproteinases (MMPs) were analyzed by western blotting and gelatin zymography, respectively. Activation of metastasis-related signaling molecules was detected by western blotting. LY294002 was used to specifically block the phosphatidylinositol 3‑kinase/v‑akt murine thymoma viral oncogene homologue (PI3K/Akt) pathway. We showed that concomitantly with an increase in α7nAChR expression after transfection, LoVo cells presented reduced abilities for migration and invasion, which was accompanied by reduced expression levels of MMP‑1 and MMP‑9 as well as activation of the PI3K/Akt signaling pathway. The application of LY294002 restored the migration and invasion abilities of the LoVo cells bearing CHRNA7. Collectively, we conclude that overexpression of CHRNA7 negatively controls colorectal cancer LoVo cell invasion and metastasis via PI3K/Akt pathway activation and may serve as either a diagnostic marker or a therapeutic target for colorectal cancer metastasis.

  15. Effects of AFP-activated PI3K/Akt signaling pathway on cell proliferation of liver cancer.

    Science.gov (United States)

    Zheng, Lu; Gong, Wei; Liang, Ping; Huang, XiaoBing; You, Nan; Han, Ke Qiang; Li, Yu Ming; Li, Jing

    2014-05-01

    This study aims to investigate effects of alpha-fetoprotein (AFP)-activated phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway on hepatocellular carcinoma cell proliferation. Active cirrhosis patients after hepatitis B infection (n = 20) and viral hepatitis patients with hepatocellular carcinoma (HCC) (n = 20) were selected as the subjects of the present study. Another 20 healthy subjects were selected as the control group. The serum AFP expression and liver tissue PI3K and Akt gene mRNA expression were detected. The hepatoma cell model HepG2 which had a stable expression of AFP gene was used. Real-time quantitative PCR and Western blot and other methods were used to analyze the intracellular PI3K and Akt protein levels. Compared with control group and cirrhosis group, the serum AFP levels in HCC group significantly increased, and the tissue PI3K and Akt mRNA expression also significantly increased. HepG2 cells were intervened using AFP, in which the PIK and Akt protein expression significantly increased. After intervention by use of AFP monoclonal antibodies or LY294002 inhibitor, the PIK and Akt protein expression in HepG2 cell was significantly decreased (P AFP can promote the proliferation of hepatoma cells via activation of PI3K/Akt signaling pathway.

  16. Id-1 promotes osteosarcoma cell growth and inhibits cell apoptosis via PI3K/AKT signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Liang; Liao, Qi; Tang, Qiang [Department of Orthopaedic Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang 300006 (China); Deng, Huan [Department of Pathology, The Fourth Affiliated Hospital of Nanchang University, Nanchang 330006 (China); Chen, Lu, E-mail: chenlu0578@163.com [Department of Orthopaedic Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang 300006 (China)

    2016-02-12

    Accumulating evidence reveals that Id-1 is upregulated and functions as a potential tumor promoter in several human cancer types. However, the role of Id-1 in osteosarcoma (OS) is unknown. In present study, we found that Id-1 expression was elevated in OS tissues than adjacent normal bone tissues. More importantly, we demonstrated that overexpression of Id-1 is significantly correlated with tumor progression and poor survival in OS patients. Furthermore, increased expression of Id-1 was observed in OS cell lines and ectopic expression of Id-1 significantly enhanced in vitro cell proliferation and promoted in vivo tumor growth, whereas knockdown of Id-1 suppressed OS cells growth. Moreover, our experimental data revealed that Id-1 promotes cell proliferation by facilitating cell cycle progression and inhibits cell apoptosis. Mechanistically, the effects of Id-1 in OS cells is at least partly through activation of PI3K/Akt signaling pathway. Therefore, we identified a tumorigenic role of Id-1 in OS and suggested a potential therapeutic target for OS patients. - Highlights: • Id-1 expression is positively correlated in OS patients with poor prognosis. • Overexpression of Id-1 promotes OS cell growth in vitro and in vivo. • Id-1induces cell cycle progression and inhibits cell apoptosis. • PI3K/Akt signaling pathway contributed to the oncogenic effects of Id-1 in OS cells.

  17. Beauvericin ameliorates experimental colitis by inhibiting activated T cells via downregulation of the PI3K/Akt signaling pathway.

    Directory of Open Access Journals (Sweden)

    Xue-Feng Wu

    Full Text Available Crohn's disease is a common, chronic inflammatory bowel condition characterized by remission and relapse. Accumulating evidence indicates that activated T cells play an important role in this disease. In the present study, we aimed to examine the effect of beauvericin, a natural cyclic peptide, on 2,4,6-trinitrobenzene sulfonic acid (TNBS-induced colitis in mice, which mimics Crohn's disease. Beauvericin significantly reduced weight loss, diarrhea and mortality, accompanied with notable alleviation of macroscopic and microscopic signs. In addition, this compound decreased serum levels of tumor necrosis factor (TNF-α and interferon (IFN-γ in a concentration-dependent manner in mice with experimental colitis. These effects of beauvericin are attributed to its inhibition on activated T cells. Flow cytometry and immunoblot assay data showed that beauvericin suppressed T-cell proliferation, activation and IFN-γ-STAT1-T-bet signaling and subsequently led to apoptosis of activated T cells by suppressing Bcl-2 and phosphorylated Bad as well as increasing cleavage of caspase-3, -9, -12 and PARP. Furthermore, inhibition of PI3K/Akt signaling, which was an upstream regulator of cell activation and survival in activated T cells, contributed to the effect of beauvericin. Overall, these results supported beauvericin as a novel drug candidate for the treatment of colonic inflammation mainly by targeting PI3K/Akt in activated T cells.

  18. Salidroside Inhibits Inflammation Through PI3K/Akt/HIF Signaling After Focal Cerebral Ischemia in Rats.

    Science.gov (United States)

    Wei, Yicong; Hong, Haimian; Zhang, Xiaoqin; Lai, Wenfang; Wang, Yingzheng; Chu, Kedan; Brown, John; Hong, Guizhu; Chen, Lidian

    2017-08-01

    Salidroside is being investigated for its therapeutic potential in stroke because it is neuroprotective over an extended therapeutic window of time. In the present study, we investigated the mechanisms underlying the anti-inflammatory effects of salidroside (50 mg/kg intraperitoneally) in rats, given 1 h after reperfusion of a middle cerebral artery that had been occluded for 2 h. After 24 h, we found that salidroside increased the neuronal nuclear protein NeuN and reduced the marker of microglia and macrophages CD11b in the peri-infarct area of the brain. Salidroside also decreased IL-6, IL-1β, TNF-α, CD14, CD44, and iNOs mRNAs. At the same time, salidroside increased the ratio of phosphorylated protein kinase B (p-Akt) to total Akt. The phosphoinositide 3-kinase (PI3K) inhibitor LY294002 prevented this increase in p-Akt and reversed the inhibitory effects of salidroside on CD11b and inflammatory mediators. Salidroside also elevated the protein levels of hypoxia-inducible factor (HIF) subunits HIF1α, HIF2α, HIF3α, and of erythropoietin (EPO). The stimulatory effects of salidroside on HIFα subunits were blocked by LY294002. Moreover, YC-1, a HIF inhibitor, abolished salidroside-mediated increase of HIF1α and prevented the inhibitory effects of salidroside on CD11b and inflammatory mediators. Taken together, our results provide evidence for the first time that all three HIFα subunits and EPO can be regulated by PI3K/Akt in cerebral tissue, and that salidroside entrains this signaling pathway to induce production of HIFα subunits and EPO, one or more of which mediate the anti-inflammatory effects of salidroside after cerebral IRI.

  19. INPP4B reverses docetaxel resistance and epithelial-to-mesenchymal transition via the PI3K/Akt signaling pathway in prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Haiwen; Li, Hongliang, E-mail: honglianglity@sina.com; Chen, Qi

    2016-08-26

    Docetaxel efficiency in the therapy of prostate cancer (PCa) patients is limited due to the development of chemoresistance. Recent studies have implied a role of INPP4B in tumor chemoresistance, while the effects of INPP4B on docetaxel resistance in PCa have not been elucidated. In the present study, the docetaxel-resistant human PCa cell lines PC3-DR and DU-145-DR were established from the parental cell lines PC3 and DU-145, and the expression and role of INPP4B in docetaxel-resistant PCa cells were investigated. The results demonstrated that INPP4B expression was significantly downregulated in docetaxel-resistant cells. Overexpression of INPP4B increased the sensitivity to docetaxel and promoted cell apoptosis in PC3-DR and DU-145-DR cells. In addition, INPP4B overexpression downregulated the expression of the mesenchymal markers fibronectin, N-cadherin, and vimentin, and upregulated the expression level of the epithelial maker E-cadherin. Furthermore, INPP4B overexpression markedly inhibited the PI3K/Akt pathway. We also found that IGF-1, the inhibitor of PI3K/Akt, markedly blocked the change in EMT markers induced by overexpression of INPP4B, and reversed the resistance of PC3-DR and DU-145-DR cells to docetaxel, which is sensitized by Flag-INPP4B. In summary, the presented data indicate that INPP4B is crucial for docetaxel-resistant PCa cell survival, potentially by regulating EMT through the PI3K/Akt signaling pathway. - Highlights: • INPP4B is downregulated in docetaxel-resistant PCa cells. • INPP4B inhibits cell proliferation. • INPP4B induces cell apoptosis. • INPP4B inhibits PCa cell EMT.

  20. Correlation between PTEN Expression and PI3K/Akt Signal Pathway in Endometrial Carcinoma

    Institute of Scientific and Technical Information of China (English)

    Qinglei GAO; Fei YE; Xi XIA; Hui XING; Yunping LU; Jianfeng ZHOU; Ding MA

    2009-01-01

    In order to investigate the role of the PTEN expression in carcinogenesis and develop-ment of endometrial carcinoma and clarify whether and how PTEN and PI3K/Akt pathway relate to endometrial carcinoma,the expression of PTEN and phospho-Akt was detected by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) methods and Western-blot from 24 cases of endomctrial carcinoma,10 cases of endometrial atypical hyperplasia,10 cases of endometrial hy-perplasia,and 10 cases of normal endometrium.SP immunohistochemical methods were used to measure levels of PTEN protein expression in following 5 study groups:31 cases of endometrium in proliferative phase,30 cases of endometrium in secretory phase,71 cases of endometrial hyperplasia,25 cases of atypical hyperplasia and 73 cases of endometrial carcinoma.Immunostaining score of PTEN was 3.39±0.15 in proliferative phase,1.90±0.21 in secretory phase,3.34~0.29 in endometrial hyperplasia,0.624±0.11 in atypical hyperplasia,and 0.74±0.19 in endometrial carcinoma,respectively.PTEN mRNA relative value in normal endometrium,endometrial hyperplasia,endometrial atypical hyperplasia,and endometrial carcinoma was 2.45±0.51,2.32±0.32,0.46±0.11,and 0.35±0.13 respec-tively.The expression levels of PTEN mRNA and protein in patients with endometrial carcinoma and atypical hyperplasia were significantly lower than in those of proliferative phase and with endo-metrial hyperplasia.The level of PTEN expression in patients with endometrial carcinoma was sig-nificantly related to tissue type (P0.05).Western blot analysis revealed that Phospho-Akt level in PTEN negative cases was significantly higher,and there was a negative correlation between PTEN and phospho-Akt (r=- 0.8973,P<0.0001).It was suggested that loss of PTEN expression was an early event in endometrial tumorigenesis.The phosphorylation of Akt induced by the loss of PTEN took part in the tumorigenesis and development of endometrial carcinoma.

  1. Arctigenin, a Natural Lignan Compound, Induces Apoptotic Death of Hepatocellular Carcinoma Cells via Suppression of PI3-K/Akt Signaling.

    Science.gov (United States)

    Jiang, Xiaoxin; Zeng, Leping; Huang, Jufang; Zhou, Hui; Liu, Yubin

    2015-04-28

    In this study, we explored the cytotoxic effects of arctigenin, a natural lignan compound, on human hepatocellular carcinoma (HCC) cells and check the involvement of phosphatidylinositol 3-kinase (PI3-K)/Akt signaling. HCC cells were treated with different concentrations of arctigenin and cell viability and apoptosis were assessed. Manipulating Akt signaling was used to determine its role in the action of arctigenin. Arctigenin significantly inhibited the viability of HCC cells in a concentration-dependent manner. Arctigenin induced apoptosis and activation of caspase-9 and -3. Overexpression of a constitutively active Akt mutant blocked arctigenin-induced apoptosis. Combinational treatment with arctigenin and the PI3-K inhibitor LY294002 significantly enhanced apoptosis. Arctigenin reduced the expression of Bcl-xL, Mcl-1, and survivin and the phosphorylation of mTOR and S6K, which were significantly reversed by overexpression of constitutively active Akt. This is the first report about the anticancer activity of arctigenin in HCC cells, which is mediated by inactivation of PI3-K/Akt signaling.

  2. MicroRNA-130b targets PTEN to mediate drug resistance and proliferation of breast cancer cells via the PI3K/Akt signaling pathway

    Science.gov (United States)

    Miao, Yuan; Zheng, Wei; Li, Nana; Su, Zhen; Zhao, Lifen; Zhou, Huimin; Jia, Li

    2017-01-01

    Multidrug resistance (MDR) correlates with treatment failure and poor prognosis among breast cancer patients. This study was aimed to investigate the possible mechanism by which microRNA-130b-3p (miR-130b) mediates the chemoresistance and proliferation of breast cancer. MiR-130b was found to be up-regulated in tumor tissues versus adjacent tissues of breast cancer, as well as in adriamycin (ADR) resistant breast cancer cell line (MCF-7/ADR) versus its parental line (MCF-7) and the non-malignant breast epithelial cell line (MCF-10A), demonstrating its crucial relevance for breast cancer biology. We identified that PTEN was a direct target of miR-130b and inversely correlated with miR-130b expression in breast cancer. Moreover, over-expression of miR-130b promoted drug resistance, proliferation and decreased apoptosis of MCF-7 cells, while suppression of miR-130b enhanced drug cytotoxicity and apoptosis, as well as reduced proliferation of MCF-7/ADR cells in vitro and in vivo. Particularly, miR-130b mediated the activity of phosphoinositide-3 kinase (PI3K)/Akt signaling pathway as well as the chemoresistance and proliferation of breast cancer cell lines, which was partially blocked following knockdown of PTEN. Altogether, miR-130b targets PTEN to induce MDR, proliferation, and apoptosis via PI3K/Akt signaling pathway. This provides a novel promising candidate for breast cancer therapy. PMID:28165066

  3. Isorhamnetin protects against cardiac hypertrophy through blocking PI3K-AKT pathway.

    Science.gov (United States)

    Gao, Lu; Yao, Rui; Liu, Yuzhou; Wang, Zheng; Huang, Zhen; Du, Binbin; Zhang, Dianhong; Wu, Leiming; Xiao, Lili; Zhang, Yanzhou

    2017-05-01

    Isorhamnetin, a flavonoid compound extracted from the Chinese herb Hippophae rhamnoides L., is well known for its anti-inflammatory, anti-oxidative, anti-adipogenic, anti-proliferative, and anti-tumor activities. However, the role of isorhamnetin in cardiac hypertrophy has not been reported. The aims of the present study were to find whether isorhamnetin could alleviate cardiac hypertrophy and to define the underlying molecular mechanisms. Here, we investigated the effects of isorhamnetin (100 mg/kg/day) on cardiac hypertrophy induced by aortic banding in mice. Cardiac hypertrophy was evaluated by echocardiographic, hemodynamic, pathological, and molecular analyses. Our data demonstrated that isorhamnetin could inhibit cardiac hypertrophy and fibrosis 8 weeks after aortic banding. The results further revealed that the effect of isorhamnetin on cardiac hypertrophy was mediated by blocking the activation of phosphatidylinositol 3-kinase-AKT signaling pathway. In vitro studies performed in neonatal rat cardiomyocytes confirmed that isorhamnetin could attenuate cardiomyocyte hypertrophy induced by angiotensin II, which was associated with phosphatidylinositol 3-kinase-AKT signaling pathway. In conclusion, these data indicate for the first time that isorhamnetin has protective potential for targeting cardiac hypertrophy by blocking the phosphatidylinositol 3-kinase-AKT signaling pathway. Thus, our study suggests that isorhamnetin may represent a potential therapeutic strategy for the treatment of cardiac hypertrophy and heart failure.

  4. Plant food anthocyanins inhibit platelet granule secretion in hypercholesterolaemia: Involving the signalling pathway of PI3K-Akt.

    Science.gov (United States)

    Song, Fenglin; Zhu, Yanna; Shi, Zhenyin; Tian, Jinju; Deng, Xiujuan; Ren, Jing; Andrews, Marc C; Ni, Heyu; Ling, Wenhua; Yang, Yan

    2014-11-01

    Controlling platelet granule secretion has been considered an effective strategy to dampen thrombosis and prevent atherosclerosis. Anthocyanins are natural plant pigments and possess a wide range of biological activities, including cardiovascular protective activity. In the present study we explored the effects and the potential mechanisms of anthocyanins on platelet granule secretion in hypercholesterolemia. In a randomised, double-blind clinical trial, 150 hypercholesterolaemic individuals were treated with purified anthocyanins (320 mg/day) or placebo for 24 weeks. Anthocyanins consumption significantly reduced plasma levels of β-thromboglobulin (β-TG), soluble P-selectin, and of Regulated on Activation Normal T cell Expressed and Secreted (RANTES) as compared with the placebo. A minor reduction in platelet factor 4 (PF4) and transforming growth factor β1 (TGF-β1) levels were also observed. In in vitro experiments, we observed that puriӿed anthocyanin mixture, as well as its two main anthocyanin components, delphinidin-3-glucoside (Dp-3-g) and cyanidin-3-glucoside (Cy-3g) directly inhibited platelet á-granule, dense granule, and lysosome secretion evaluated by P-selectin, RANTES, β-TG, PF4, TGF-β1, serotonin, ATP, and CD63 release. Further, anthocyanins inhibited platelet PI3K/Akt activation and consequently attenuated eNOS phosphorylation and cGMP production, thus interrupting MAPK activation. LY294002, a PI3K inhibitor, did not cause additional inhibitory efficacy, indicating that anthocyanin-induced effects may be involved in inhibition of the PI3K/Akt signalling pathway. These results provide evidence that by inhibiting platelet granule secretion, anthocyanins may be a potent cardioprotective agent.

  5. Transient Acidosis during Early Reperfusion Attenuates Myocardium Ischemia Reperfusion Injury via PI3k-Akt-eNOS Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Xin Qiao

    2013-01-01

    Full Text Available In this paper, we concluded that transient acidosis reperfusion conferred cardioprotection against myocardial ischemia reperfusion injury in isolated rat hearts through activating PI3K-Akt-eNOS pathway.

  6. The effect of Liuwei Dihuang decoction on PI3K/Akt signaling pathway in liver of type 2 diabetes mellitus (T2DM) rats with insulin resistance.

    Science.gov (United States)

    Dai, Bing; Wu, Qinxuan; Zeng, Chengxi; Zhang, Jiani; Cao, Luting; Xiao, Zizeng; Yang, Menglin

    2016-11-04

    Liuwei Dihaung decoction (LWDHT) is a well-known classic traditional Chinese medicine formula, consists of six herbs including Rehmannia glutinosa Libosch.(family: Scrophulariaceae), Cornus officinalis Sieb.(family: Cornaceae), Dioscorea opposite Thunb.(family: Dioscoreaceae), Alisma orientale(G. Samuelsson) Juz (family: Alismataceae), Poria cocos (Schw.) Wolf (family: Polyporaceae) and Paeonia suffruticosa Andrews (family: Paeoniaceae). It has been used in the treatment of many types of diseases with signs of deficiency of Yin in the kidneys in China clinically. This study is aimed at investigating the effect of Liuwei dihuang decoction on PI3K/Akt signaling pathway in liver of T2DM rats with insulin resistance. T2DM model was induced in male Sprague-Dawley (SD) rats by high sugar and high fat diets combined with small dose of streptozocin (STZ) injection. The successful T2DM rats were randomly allocated three group--vehicle group, positive control group and Liuwei Dihuang decoction group. After 12-weeks treatment with distilled water, rosiglitazone and LWDHT by intragastric administration respectively, the rats were put to death in batches. The variance of fasting blood glucose (FBG) and fasting insulin (FINS) in serum were determined, the pathological changes of each rats' liver were observed by hematoxylin-eosin (HE) staining, the expression of insulin receptor substrate 2(IRS2), phosphatidylinositol 3-kinase (PI3K) and protein kinas B (Akt) involving the canonical PI3K/Akt signaling pathway were detected by Real-time fluorescent quantitative PCR (RT-PCR), and the expression level of IRS2, PI3K, Akt protein and phosphorylated IRS2, PI3K, Akt protein were evaluated by Western Blot. All the data were analyzed by SPSS 17.0. Four weeks of treatment with LWDHT could significantly decrease the level of FBG and FINS in serum, improve the cellular morphology of liver, kidney, pancreas tissue, and the expression of IRS2, PI3K, Akt mRNA and phosphorylated IRS2, PI3K, Akt

  7. [PI 3 K/Akt signaling pathway contributed to the protective effect of acupuncture intervention on epileptic seizure-induced injury of hippocampal pyramidal cells in epilepsy rats].

    Science.gov (United States)

    Yang, Fan; Ang, Wen-Ping; Shen, De-Kai; Liu, Xiang-Guo; Yang, Yong-Qing; Ma, Yun

    2013-02-01

    294002 group, but relatively lighter in the acupuncture group. These results suggested an elimination of the acupuncture effect after blocking the PI 3 K/Akt signaling pathway by lateral ventricular injection of LY 294002 in epilepsy rats. Acupuncture intervention has a protective effect on pyramidal cells of hippocampal CA 1 and CA 3 regions in epilepsy rats, which is associated with the normal function of intracellular PI 3 K/Akt signaling pathway.

  8. TDRG1 functions in testicular seminoma are dependent on the PI3K/Akt/mTOR signaling pathway

    Directory of Open Access Journals (Sweden)

    Wang Y

    2016-01-01

    (mTOR; Ser2448. Except for PI3K/p110, TDRG1 overexpression had the opposite effects on phosphorylation levels. Phosphorylated mTOR at Ser2481 and Thr2446 was not affected by TDRG1 or PI3K in our tests. Thus, these results indicate that TDRG1 promotes the development and migration of seminoma cells via the regulation of the PI3K/Akt/mTOR signaling pathway; this contributes to an understanding of the precise mechanisms underlying the development and migration of seminomas and lays a theoretical foundation for the development of appropriate therapies.Keywords: TDRG1, testicular seminoma, PI3K, Akt, mTOR

  9. [Effects of acupuncture on PI3K/Akt/mTOR signaling pathway in rats with premature ovarian failure].

    Science.gov (United States)

    Zhang, Yimin; Yu, Bin; Chen, Jia; Zhao, Zhisheng; Wang Jiali; Huang, Fasen; Lin, Yuee; Wang, Mengwei; Zhang, Yupei; Wei, Bo

    2015-01-01

    To explore the effects of acupuncture and medication on PI3K/Akt/mTOR signaling pathway in rats with premature ovarian failure. Ten of fifty SPF-grade female SD rats were randomly selected into a normal group, and the remaining 40 rats were treated with intraperitoneal injection of cyclophospha mide (30 mg/kg) for consecutive 5 days to establish rat model of premature ovarian failure. Thirty five successful rat models were randomly divided into a model group (9 cases), a medication group (9 cases), an acupuncture group A (9 cases) and an acupuncture group B (8 cases). The rats in the model group and normal group did not receive any treatment. The rats in the medication group were treated with intragastric administration of diethylstil bestrol, once a day. The rats in the acupuncture group A and acupuncture group B were respectively treated with acupuncture at different acupoints, twice a day. All the treatment was given for 4 weeks. After the treatment, enzyme-linked immunosorbent assay (ELISA) was applied to test the levels of estradiol (E2), progesterone (P), follicle stimulating hormone (FSH) and luteotropic hormone (LH). The ovarian tissue sample was processed with hematoxylin eosin (HE) staining as well as RNA and protein extraction to test the mRNA expression of estrogen receptor alpha (ERalpha), estrogen receptor beta (ERP), phosphatidylinositol 3-kinase/serine/threonine kinase (PI3K), protein kinase B (Akt) and mammalian target of rapamycin (mTOR). High-dose short-term in- tervention of cyclophosphamide could establish rat model of premature ovarian failure with a successful rate of 87.5%. Compared with the normal group, the vaginal smear in the model group was featured with signs of estro gen deficiency, early-follicle reduction, structural damage to the follicle, and reducing number of mature follicles; the level of E2 was significantly reduced (Pacupuncture groups, the levels of E2 was obviously increased (all Pacupuncture groups and medication group

  10. PI3K/Akt1 signalling specifies foregut precursors by generating regionalized extra-cellular matrix

    DEFF Research Database (Denmark)

    Villegas, S Nahuel; Rothová, Michaela; Barrios-Llerena, Martin E

    2013-01-01

    During embryonic development signalling pathways act repeatedly in different contexts to pattern the emerging germ layers. Understanding how these different responses are regulated is a central question for developmental biology. In this study, we used mouse embryonic stem cell (mESC) differentia......During embryonic development signalling pathways act repeatedly in different contexts to pattern the emerging germ layers. Understanding how these different responses are regulated is a central question for developmental biology. In this study, we used mouse embryonic stem cell (m......ESC) differentiation to uncover a new mechanism for PI3K signalling that is required for endoderm specification. We found that PI3K signalling promotes the transition from naïve endoderm precursors into committed anterior endoderm. PI3K promoted commitment via an atypical activity that delimited epithelial......-to-mesenchymal transition (EMT). Akt1 transduced this activity via modifications to the extracellular matrix (ECM) and appropriate ECM could itself induce anterior endodermal identity in the absence of PI3K signalling. PI3K/Akt1-modified ECM contained low levels of Fibronectin (Fn1) and we found that Fn1 dose was key...

  11. Down-regulation of ubiquitin ligase Cbl induced by twist haploinsufficiency in Saethre-Chotzen syndrome results in increased PI3K/Akt signaling and osteoblast proliferation.

    Science.gov (United States)

    Guenou, Hind; Kaabeche, Karim; Dufour, Cécilie; Miraoui, Hichem; Marie, Pierre J

    2006-10-01

    Genetic mutations of Twist, a basic helix-loop-helix transcription factor, induce premature fusion of cranial sutures in Saethre-Chotzen syndrome (SCS). We report here a previously undescribed mechanism involved in the altered osteoblastogenesis in SCS. Cranial osteoblasts from an SCS patient with a Twist mutation causing basic helix-loop-helix deletion exhibited decreased expression of E3 ubiquitin ligase Cbl compared with wild-type osteoblasts. This was associated with decreased ubiquitin-mediated degradation of phosphatidyl inositol 3 kinase (PI3K) and increased PI3K expression and PI3K/Akt signaling. Increased PI3K immunoreactivity was also found in osteoblasts in histological sections of affected cranial sutures from SCS patients. Transfection with Twist or Cbl abolished the increased PI3K/Akt signaling in Twist mutant osteoblasts. Forced overexpression of Cbl did not correct the altered expression of osteoblast differentiation markers in Twist mutant cells. In contrast, pharmacological inhibition of PI3K/Akt, but not ERK signaling, corrected the increased cell growth in Twist mutant osteoblasts. The results show that Twist haploinsufficiency results in decreased Cbl-mediated PI3K degradation in osteoblasts, causing PI3K accumulation and activation of PI3K/Akt-dependent osteoblast growth. This provides genetic and biochemical evidence for a role for Cbl-mediated PI3K signaling in the altered osteoblast phenotype induced by Twist haploinsufficiency in SCS.

  12. Carvacrol Alleviates Prostate Cancer Cell Proliferation, Migration, and Invasion through Regulation of PI3K/Akt and MAPK Signaling Pathways

    Science.gov (United States)

    Luo, Yun; Wu, Jie-Ying; Lu, Min-Hua; Shi, Zhi

    2016-01-01

    TRPM7 is a potential therapeutic target for treatment of prostate cancer. In this study, we investigated the effects of nonselective TRPM7 inhibitor carvacrol on cell proliferation, migration, and invasion of prostate cancer PC-3 and DU145 cells. Our results showed that carvacrol blocked TRPM7-like currents in PC-3 and DU145 cells and reduced their proliferation, migration, and invasion. Moreover, carvacrol treatment significantly decreased MMP-2, p-Akt, and p-ERK1/2 protein expression and inhibited F-actin reorganization. Furthermore, consistently, TRPM7 knockdown reduced prostate cancer cell proliferation, migration, and invasion as well. Our study suggests that carvacrol may have therapeutic potential for the treatment of prostate cancer through its inhibition of TRPM7 channels and suppression of PI3K/Akt and MAPK signaling pathways. PMID:27803760

  13. Lack of SIRPα phosphorylation and concomitantly reduced SHP-2-PI3K-Akt2 signaling decrease osteoblast differentiation.

    Science.gov (United States)

    Holm, Cecilia Koskinen; Engman, Sara; Sulniute, Rima; Matozaki, Takashi; Oldenborg, Per-Arne; Lundberg, Pernilla

    2016-09-09

    Normal differentiation of bone forming osteoblasts is a prerequisite for maintenance of skeletal health and is dependent on intricate cellular signaling pathways, including the essential transcription factor Runx2. The cell surface glycoprotein CD47 and its receptor signal regulatory protein alpha (SIRPα) have both been suggested to regulate bone cell differentiation. Here we investigated osteoblastic differentiation of bone marrow stromal cells from SIRPα mutant mice lacking the cytoplasmic signaling domain of SIRPα. An impaired osteoblastogenesis in SIRPα-mutant cell cultures was demonstrated by lower alkaline phosphatase activity and less mineral formation compared to wild-type cultures. This reduced osteoblastic differentiation potential in SIRPα-mutant stromal cells was associated with a significantly reduced expression of Runx2, osterix, osteocalcin, and alkaline phosphatase mRNA, as well as a reduced phosphorylation of SHP-2 and Akt2, as compared with that in wild-type stromal cells. Addition of a PI3K-inhibitor to wild-type stromal cells could mimic the impaired osteoblastogenesis seen in SIRPα-mutant cells. In conclusion, our data suggest that SIRPα signaling through SHP-2-PI3K-Akt2 strongly influences osteoblast differentiation from bone marrow stromal cells.

  14. ApoA-IV improves insulin sensitivity and glucose uptake in mouse adipocytes via PI3K-Akt Signaling

    Science.gov (United States)

    Li, Xiaoming; Wang, Fei; Xu, Min; Howles, Philip; Tso, Patrick

    2017-01-01

    Insulin resistance is a risk factor for type 2 diabetes mellitus. We investigated the effect of ApoA-IV on glucose uptake in the adipose and muscle tissues of mice and cultured 3T3-L1 adipocytes. We found that treatment with ApoA-IV lowered fasting blood glucose in both WT and diabetic KKAy mice by increasing glucose uptake in cardiac muscle, white adipose tissue, and brown adipose tissue through a mechanism that was partially insulin independent. Cell culture experiments showed that ApoA-IV improved glucose uptake in adipocytes in the absence of insulin by upregulating GLUT4 translocation by PI3K mediated activation of Akt signaling pathways. Considering our previous finding that ApoA-IV treatment enhanced pancreatic insulin secretion, these results suggests that ApoA-IV acts directly upon adipose tissue to improve glucose uptake and indirectly via insulin signaling. Our findings warrant future studies to identify the receptor for ApoA-IV and the downstream targets of PI3K-Akt signaling that regulate glucose uptake in adipocytes as potential therapeutic targets for treating insulin resistance. PMID:28117404

  15. Curcumin inhibited HGF-induced EMT and angiogenesis through regulating c-Met dependent PI3K/Akt/mTOR signaling pathways in lung cancer

    Directory of Open Access Journals (Sweden)

    Demin Jiao

    2016-01-01

    Full Text Available The epithelial-mesenchymal transition (EMT and angiogenesis have emerged as two pivotal events in cancer progression. Curcumin has been extensively studied in preclinical models and clinical trials of cancer prevention due to its favorable toxicity profile. However, the possible involvement of curcumin in the EMT and angiogenesis in lung cancer remains unclear. This study found that curcumin inhibited hepatocyte growth factor (HGF-induced migration and EMT-related morphological changes in A549 and PC-9 cells. Moreover, pretreatment with curcumin blocked HGF-induced c-Met phosphorylation and downstream activation of Akt, mTOR, and S6. These effects mimicked that of c-Met inhibitor SU11274 or PI3 kinase inhibitor LY294002 or mTOR inhibitor rapamycin treatment. c-Met gene overexpression analysis further demonstrated that curcumin suppressed lung cancer cell EMT by inhibiting c-Met/Akt/mTOR signaling pathways. In human umbilical vein endothelial cells (HUVECs, we found that curcumin also significantly inhibited PI3K/Akt/mTOR signaling and induced apoptosis and reduced migration and tube formation of HGF-treated HUVEC. Finally, in the experimental mouse model, we showed that curcumin inhibited HGF-stimulated tumor growth and induced an increase in E-cadherin expression and a decrease in vimentin, CD34, and vascular endothelial growth factor (VEGF expression. Collectively, these findings indicated that curcumin could inhibit HGF-promoted EMT and angiogenesis by targeting c-Met and blocking PI3K/Akt/mTOR pathways.

  16. CXCL8 promotes the invasion of human osteosarcoma cells by regulation of PI3K/Akt signaling pathway.

    Science.gov (United States)

    Jiang, Hai; Wang, Xiaowei; Miao, Wusheng; Wang, Bing; Qiu, Yusheng

    2017-09-01

    Chemokine cysteine-X-cysteine motif ligand 8 (CXCL8) is up-regulated in many malignancies, indicating that CXCL8 takes part in tumor progression. However, the expression and function of CXCL8 in osteosarcoma remained not fully elucidated. In this study, expressions of 12 cytokines and chemokines were measured in the serum from 12 of normal controls (NCs) and 25 of osteosarcoma patients. The human osteosarcoma cell line MG-63 was stimulated by recombinant CXCL8 to further analyze invasion, proliferation, apoptosis, cell cycles, cytokine secretions, and signaling pathways. We found that serum concentrations of CXCL8 and vascular endothelial growth factor were elevated in osteosarcoma patients in comparison with those in NCs. CXCL8 stimulation led to enhancement of invasion and suppression of late stage apoptosis in MG-63 cells. Moreover, secretions of MMPs by MG-63 cells were also increased upon stimulation. However, early stage apoptosis, proliferation, and cell cycles were not affected by CXCL8 treatment. Furthermore, CXCL8 stimulation induced elevations of phosphorylated PI3K and Akt, but not PKC or FAK. In conclusion, our findings suggested that CXCL8 enhanced the invasion and suppressed late stage apoptosis of osteosarcoma cells probably via influencing PI3K/Akt signaling pathway and elevating the expression of MMPs. CXCL8 may promote disease progression of osteosarcoma as a protumorigenic molecule, and may be served as a new therapeutic target for osteosarcoma. © 2017 APMIS. Published by John Wiley & Sons Ltd.

  17. Arctigenin Increases Hemeoxygenase-1 Gene Expression by Modulating PI3K/AKT Signaling Pathway in Rat Primary Astrocytes.

    Science.gov (United States)

    Jeong, Yeon-Hui; Park, Jin-Sun; Kim, Dong-Hyun; Kim, Hee-Sun

    2014-11-01

    In the present study, we found that the natural compound arctigenin inhibited hydrogen peroxide-induced reactive oxygen species (ROS) production in rat primary astrocytes. Since hemeoxygenase-1 (HO-1) plays a critical role as an antioxidant defense factor in the brain, we examined the effect of arctigenin on HO-1 expression in rat primary astrocytes. We found that arctigenin increased HO-1 mRNA and protein levels. Arctigenin also increases the nuclear translocation and DNA binding of Nrf2/c-Jun to the antioxidant response element (ARE) on HO-1 promoter. In addition, arctigenin increased ARE-mediated transcriptional activities in rat primary astrocytes. Further mechanistic studies revealed that arctigenin increased the phosphorylation of AKT, a downstream substrate of phosphatidylinositol 3-kinase (PI3K). Treatment of cells with a PI3K-specific inhibitor, LY294002, suppressed the HO-1 expression, Nrf2 DNA binding and ARE-mediated transcriptional activities in arctigenin-treated astrocyte cells. The results collectively suggest that PI3K/AKT signaling pathway is at least partly involved in HO-1 expression by arctigenin via modulation of Nrf2/ARE axis in rat primary astrocytes.

  18. Tramadol regulates proliferation, migration and invasion via PTEN/PI3K/AKT signaling in lung adenocarcinoma cells.

    Science.gov (United States)

    Xia, M; Tong, J-H; Ji, N-N; Duan, M-L; Tan, Y-H; Xu, J-G

    2016-06-01

    Tramadol is used mainly for the treatment of moderate to severe chronic cancer pain. However, the effect of tramadol on lung cancer remains unclear. Therefore, it is important to explore the mechanism accounting for the function of tramadol on lung cancer. We investigated the effects of tramadol on the proliferation, migration and invasion in human lung adenocarcinoma cells in vitro by CCK-8 assay, wound healing assay and Transwell assay, respectively. We also explored the potential mechanism of tramadol on lung cancer cells by Western blotting. A549 and PC-9 cells were incubated with 2 µM tramadol for different time (0, 7, 14 and 28 d). The in vitro experiments showed that tramadol treatment significantly inhibited cell proliferation, migration and invasion in a time-dependent manner. Moreover, administration of tramadol suppressed tumor growth in vivo. The data also revealed that tramadol could up-regulate the protein expression level of PTEN and consistently inhibit the phosphorylation level of PI3K and Akt, whereas the total level of PI3K and Akt remain unchanged. These findings indicated that tramadol inhibited proliferation, migration and invasion of human lung adenocarcinoma cells through elevation of PTEN and inactivation of PI3K/Akt signaling.

  19. Anti-tumor effects of progesterone in human glioblastoma multiforme: role of PI3K/Akt/mTOR signaling.

    Science.gov (United States)

    Atif, Fahim; Yousuf, Seema; Stein, Donald G

    2015-02-01

    Glioblastoma multiforme (GBM) is an aggressive primary brain tumor with a mean patient survival of 13-15 months despite surgical resection, radiation therapy and standard-of-care chemotherapy. We investigated the chemotherapeutic effects of the hormone progesterone (P4) on the growth of human GBM in four genetically different cell lines (U87MG, U87dEGFR, U118MG, LN-229) in vitro and in a U87MG subcutaneous xenograft mouse model. At high concentrations (20, 40, and 80 μM), P4 significantly (Pmatrix metalloproteinase-9. Apoptosis in tumor tissue was detected by the expression of cleaved caspase-3, BCl-2, BAD and p53 proteins and confirmed by TUNEL assay. P4 treatment also suppressed PI3K/Akt/mTOR signaling, which regulates tumor growth, as demonstrated by the suppression of proliferating cell nuclear antigen. Our data can be interpreted to suggest that P4 suppresses the growth of human GBM cells both in vitro and in vivo and enhances survival time in mice without any demonstrable side effects. This article is part of a Special Issue entitled 'Sex steroids and brain disorders'.

  20. β-Caryophyllene Pretreatment Alleviates Focal Cerebral Ischemia-Reperfusion Injury by Activating PI3K/Akt Signaling Pathway.

    Science.gov (United States)

    Zhang, Qian; An, Ruidi; Tian, Xiaocui; Yang, Mei; Li, Minghang; Lou, Jie; Xu, Lu; Dong, Zhi

    2017-02-24

    β-Caryophyllene (BCP) has been reported to be protective against focal cerebral ischemia-reperfusion (I/R) injury by its anti-oxidative and anti-inflammatory features. Recent study demonstrates that the BCP exhibits potential neuroprotection against I/R injury induced apoptosis, however, the mechanism remains unknown. Therefore, we investigate the underlying anti-apoptotic mechanism of BCP pretreatment in I/R injury. Sprague-Dawley rats (pretreated with BCP suspensions or solvent orally for 7 days) were subjected to transient Middle Cerebral Artery Occlusion (MCAO) for 90 min, followed by 24 h reperfusion. Results showed that BCP pretreatment improved the neurologic deficit score, lowered the infarct volume and decreased number of apoptotic cells in the hippocampus. Moreover, in western blot and RT-qPCR detections, BCP pretreatment down-regulated the expressions of Bax and p53, up-regulated the expression of Bcl-2, and enhanced the phosphorylation of Akt on Ser473. Blockage of PI3K activity by wortmannin not only abolished the BCP-induced decreases in infarct volume and neurologic deficit score, but also dramatically abrogated the enhancement of AKt phosphorylation. Our results suggested that BCP pre-treatment protects against I/R injury partly by suppressing apoptosis via PI3K/AKt signaling pathway activation.

  1. miR-218 inhibits the invasion and migration of colon cancer cells by targeting the PI3K/Akt/mTOR signaling pathway.

    Science.gov (United States)

    Zhang, Xiangliang; Shi, Huijuan; Tang, Hongsheng; Fang, Zhiyuan; Wang, Jiping; Cui, Shuzhong

    2015-05-01

    Colon cancer is one of the most common and lethal malignancies worldwide. Despite major advances in the treatment of colon cancer, the prognosis remains very poor. Thus, novel and effective therapies for colon cancer are urgently needed. In the present study, the expression status of miR-218 and the role of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway were investigated in colon cancer samples. Firstly, we observed that miR-218 expression was significantly reduced, while PI3K/Akt/mTOR pathway activity was enhanced. The overexpression of miR-218 suppressed the proliferation, migration and invasion of LoVo colon cancer cells, whereas the inhibition of miR-218 promoted these processes. Furthermore, the PI3K/Akt/mTOR signaling pathway was identified as a direct target of miR-218. The upregulation of miR-218 inhibited the activation of the PI3K/Akt/mTOR signaling pathway, as well as the expression of matrix metalloproteinase (MMP)9. The downregulation of miR-218 activated the PI3K/Akt/mTOR signaling pathway and promoted MMP9 expression. Taken together, our results demonstrate that miR-218 suppresses the proliferation, migration and invasion of LoVo colon cancer cells by targeting the PI3K/Akt/mTOR signaling pathway and MMP9. Our data indicate that miR-218 is a potential target in the treatment of colon cancer.

  2. Signaling through the PI 3-K, Akt and SGK Pathway in Breast Cancer Progression

    Science.gov (United States)

    2013-12-01

    EGF (R&D Systems; Minneapolis, MN), and 100 ng/ml cholera 120 toxin (List Biological Labs; Campbell, CA); T47D and ZR-75-30 in RPMI 1640 121...Tween 20) containing 5% (w/ v ) non-fat dry milk for 30 min and then incubated with the 216 specific primary antibody diluted in blocking buffer at 4...Kinase AKT pathway in human 519 cancer. Nat. Rev. Cancer. 2002;2:489–501. 520 5. Rodon J, Dienstmann R, Serra V , Tabernero J. Development of PI3K

  3. Cell type-specific dependency on the PI3K/Akt signaling pathway for the endogenous Epo and VEGF induction by baicalein in neurons versus astrocytes.

    Directory of Open Access Journals (Sweden)

    Yu-Yo Sun

    Full Text Available The neuroprotective effect of baicalein is generally attributed to inhibition of 12/15-lipoxygenase (12/15-LOX and suppression of oxidative stress, but recent studies showed that baicalein also activates hypoxia-inducible factor-α (HIF1α through inhibition of prolyl hydrolase 2 (PHD2 and activation of the phosphatidylinositide-3 kinase (PI3K/Akt signaling pathway. Yet, the significance and regulation of prosurvival cytokines erythropoietin (Epo and vascular endothelial growth factor (VEGF, two transcriptional targets of HIF1α, in baicalein-mediated neuroprotection in neurons and astrocytes remains unknown. Here we investigated the causal relationship between the PI3K/Akt signaling pathway and Epo/VEGF expression in baicalein-mediated neuroprotection in primary rat cortical neurons and astrocytes. Our results show that baicalein induced Epo and VEGF expression in a HIF1α- and PI3K/Akt-dependent manner in neurons. Baicalein also protected neurons against excitotoxicity in a PI3K- and Epo/VEGF-dependent manner without affecting neuronal excitability. In contrast, at least a 10-fold higher concentration of baicalein was needed to induce Epo/VEGF production and PI3K/Akt activity in astrocytes for protection of neurons. Moreover, only baicalein-induced astrocytic VEGF, but not Epo expression requires HIF1α, while PI3K/Akt signaling had little role in baicalein-induced astrocytic Epo/VEGF expression. These results suggest distinct mechanisms of baicalein-mediated Epo/VEGF production in neurons and astrocytes for neuroprotection, and provide new insights into the mechanisms and potential of baicalein in treating brain injury in vivo.

  4. Cell type-specific dependency on the PI3K/Akt signaling pathway for the endogenous Epo and VEGF induction by baicalein in neurons versus astrocytes.

    Science.gov (United States)

    Sun, Yu-Yo; Lin, Shang-Hsuan; Lin, Hung-Cheng; Hung, Chia-Chi; Wang, Chen-Yu; Lin, Yen-Chu; Hung, Kuo-Sheng; Lien, Cheng-Chang; Kuan, Chia-Yi; Lee, Yi-Hsuan

    2013-01-01

    The neuroprotective effect of baicalein is generally attributed to inhibition of 12/15-lipoxygenase (12/15-LOX) and suppression of oxidative stress, but recent studies showed that baicalein also activates hypoxia-inducible factor-α (HIF1α) through inhibition of prolyl hydrolase 2 (PHD2) and activation of the phosphatidylinositide-3 kinase (PI3K)/Akt signaling pathway. Yet, the significance and regulation of prosurvival cytokines erythropoietin (Epo) and vascular endothelial growth factor (VEGF), two transcriptional targets of HIF1α, in baicalein-mediated neuroprotection in neurons and astrocytes remains unknown. Here we investigated the causal relationship between the PI3K/Akt signaling pathway and Epo/VEGF expression in baicalein-mediated neuroprotection in primary rat cortical neurons and astrocytes. Our results show that baicalein induced Epo and VEGF expression in a HIF1α- and PI3K/Akt-dependent manner in neurons. Baicalein also protected neurons against excitotoxicity in a PI3K- and Epo/VEGF-dependent manner without affecting neuronal excitability. In contrast, at least a 10-fold higher concentration of baicalein was needed to induce Epo/VEGF production and PI3K/Akt activity in astrocytes for protection of neurons. Moreover, only baicalein-induced astrocytic VEGF, but not Epo expression requires HIF1α, while PI3K/Akt signaling had little role in baicalein-induced astrocytic Epo/VEGF expression. These results suggest distinct mechanisms of baicalein-mediated Epo/VEGF production in neurons and astrocytes for neuroprotection, and provide new insights into the mechanisms and potential of baicalein in treating brain injury in vivo.

  5. Berberine protects endothelial progenitor cell from damage of TNF-α via the PI3K/AKT/eNOS signaling pathway.

    Science.gov (United States)

    Xiao, Min; Men, Li Na; Xu, Ming Guo; Wang, Guo Bing; Lv, Hai Tao; Liu, Cong

    2014-11-15

    Endothelial progenitor cells (EPCs) dysfunction is closely correlated with the coronary artery injury induced by Kawasaki disease (KD). The level of tumor necrosis factor-α (TNF-α) elevated significantly in acute phase of KD which can damage the functions of EPCs. The aim of this study was to investigate whether berberine (BBR) can protect EPCs from the inhibition caused by TNF-α via the PI3K (Phosphatidyl Inositol 3-kinase) /AKT (Serine/threonine protein kinase B) /eNOS (endothelial Nitric Oxide synthase) signaling pathway. The cell proliferative ability of EPCs was determined by MTT (methyl thiazolyl tetrazolium) assays. Nitric oxide (NO) level was determined in supernatants. The mRNA level of eNOS, PI3K and AKT were measured by Real Time-Polymerase Chain Reaction (RT-PCR), and the protein levels of eNOS, phospho-eNOS (p-eNOS), Akt, phospho-Akt (p-Akt) and PI3K were analyzed using Western-blot. The results demonstrated that TNF-α inhibits the proliferative ability of EPCs. However, BBR improves the proliferative activity of EPCs inhibited by TNF-α. Blockade of PI3K by 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (Ly294002) and blockade of eNOS by l-NAME (NG-Nitroarginine Methyl Ester) attenuates the effect of BBR. BBR can increase the level of PI3K/Akt/eNOS mRNA and the protein level of PI3K, p-Akt, eNOS and p-eNOS, which can be blocked by PI3K inhibitor (LY294002) and eNOS inhibitor (l-NAME). Therefore, we concluded that impaired EPCs proliferation could be reversed by BBR via the PI3K/AKT/eNOS signaling pathway.

  6. Apoptosis Induction of Human Prostate Carcinoma DU145 Cells by Diallyl Disulfide via Modulation of JNK and PI3K/AKT Signaling Pathways

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    Young Hyun Yoo

    2012-11-01

    Full Text Available Diallyl disulfide (DADS, a sulfur compound derived from garlic, has various biological properties, such as anticancer, antiangiogenic and anti-inflammatory effects. However, the mechanisms of action underlying the compound's anticancer activity have not been fully elucidated. In this study, the apoptotic effects of DADS were investigated in DU145 human prostate carcinoma cells. Our results showed that DADS markedly inhibited the growth of the DU145 cells by induction of apoptosis. Apoptosis was accompanied by modulation of Bcl-2 and inhibitor of apoptosis protein (IAP family proteins, depolarization of the mitochondrial membrane potential (MMP, ΔΨm and proteolytic activation of caspases. We also found that the expression of death-receptor 4 (DR4 and Fas ligand (FasL proteins was increased and that the level of intact Bid proteins was down-regulated by DADS. Moreover, treatment with DADS induced phosphorylation of mitogen-activated protein kinases (MAPKs, including extracellular-signal regulating kinase (ERK, p38 MAPK and c-Jun N-terminal kinase (JNK. A specific JNK inhibitor, SP600125, significantly blocked DADS-induced-apoptosis, whereas inhibitors of the ERK (PD98059 and p38 MAPK (SB203580 had no effect. The induction of apoptosis was also accompanied by inactivation of phosphatidylinositol 3-kinase (PI3K/Akt and the PI3K inhibitor LY29004 significantly increased DADS-induced cell death. These findings provide evidence demonstrating that the proapoptotic effect of DADS is mediated through the activation of JNK and the inhibition of the PI3K/Akt signaling pathway in DU145 cells.

  7. Tripeptide SQL Inhibits Platelet Aggregation and Thrombus Formation by Affecting PI3K/Akt Signaling.

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    Su, Xing-li; Su, Wen; He, Zhi-long; Ming, Xin; Kong, Yi

    2015-09-01

    Centipede has been prescribed for the treatment of cardiovascular diseases in Asian countries for several hundred years. Previously, a new antiplatelet tripeptide SQL (H-Ser-Gln-Leu-OH) was isolated and characterized from centipede. In this study, we investigated its antithrombotic activities in vivo and underlying mechanism. It was found that SQL inhibited platelet aggregation induced by adenosine diphosphate, thrombin, epinephrine, and collagen and attenuated thrombus formation in both the ferric chloride-induced arterial thrombosis model and arteriovenous shunt thrombosis model in rats. It did not prolong the bleeding time in mice even at the dose of 10 mg/kg that showed potent antithrombosis effects. Molecular docking revealed that SQL binds PI3Kβ with the binding free energy of -24.341 kcal/mol, which is close to that of cocrystallized ligand (-24.220 kcal/mol). Additionally, SQL displayed inhibition on the late (180 seconds) but did not influence the early (60 seconds) Akt Ser473 phosphorylation in the immunoblot assay. These results suggest that SQL inhibits thrombus formation in vivo and that SQL inhibits PI3K-mediated signaling or even the PI3K itself in platelets. This study may help elucidate the mechanism for centipede treating cardiovascular diseases.

  8. Isoorientin induces apoptosis through mitochondrial dysfunction and inhibition of PI3K/Akt signaling pathway in HepG2 cancer cells.

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    Yuan, Li; Wang, Jing; Xiao, Haifang; Xiao, Chunxia; Wang, Yutang; Liu, Xuebo

    2012-11-15

    Isoorientin (ISO) is a flavonoid compound that can be extracted from several plant species, such as Phyllostachys pubescens, Patrinia, and Drosophyllum lusitanicum; however, its biological activity remains poorly understood. The present study investigated the effects and putative mechanism of apoptosis induced by ISO in human hepatoblastoma cancer (HepG2) cells. The results showed that ISO induced cell death in a dose-dependent manner in HepG2 cells, but no toxicity in human liver cells (HL-7702) and buffalo rat liver cells (BRL-3A) treated with ISO at the indicated concentrations. ISO-induced cell death included apoptosis which characterized by the appearance of nuclear shrinkage, the cleavage of poly (ADP-ribose) polymerase (PARP) and DNA fragmentation. ISO significantly (p<0.01) increased the Bax/Bcl-2 ratio, disrupted the mitochondrial membrane potential (MMP), increased the release of cytochrome c, activated caspase-3, and enhanced intracellular levels of reactive oxygen species (ROS) and nitric oxide (NO). In addition, ISO effectively inhibited the phosphorylation of Akt and increased FoxO4 expression. The PI3K/Akt inhibitor LY294002 enhanced the apoptosis-inducing effect of ISO. However, LY294002 markedly quenched ROS and NO generation and diminished the protein expression of heme peroxidase enzyme (HO-1) and inducible nitric oxide synthase (iNOS). Furthermore, the addition of a ROS inhibitor (N-acetyl cysteine, NAC) or iNOS inhibitor (N-[3-(aminomethyl) benzyl] acetamidine, dihydrochloride, 1400W) significantly diminished the apoptosis induced by ISO and also blocked the phosphorylation of Akt. These results demonstrated for the first time that ISO induces apoptosis in HepG2 cells and indicate that this apoptosis might be mediated through mitochondrial dysfunction and PI3K/Akt signaling pathway, and has no toxicity in normal liver cells, suggesting that ISO may have good potential as a therapeutic and chemopreventive agent for liver cancer.

  9. BDE-99 (2,2',4,4',5-pentabromodiphenyl ether) triggers epithelial-mesenchymal transition in colorectal cancer cells via PI3K/Akt/Snail signaling pathway.

    Science.gov (United States)

    Wang, Fei; Ruan, Xin-Jian; Zhang, Hong-Yan

    2015-01-01

    The gut is in direct contact with BDE-99 (2,2',4,4',5-pentabromodiphenyl ether), one of the most abundant PBDE congeners in the environment and in human tissues. The objective of the present study was to investigate the effects of BDE-99 on colorectal cancer (CRC) cells. The effects of BDE-99 on cell proliferation were measured by CCK-8 assay in the CRC cell line HCT-116. Wound healing and transwell migration/invasion assays were used to test the migration and invasion of CRC cells. Factors related to epithelial-to-mesenchymal transition (EMT) were measured by real-time PCR and Western blot analysis for mRNA and protein levels, respectively. BDE-99 was found to increase migration and invasion and trigger EMT in HCT-116 cells; EMT was characterized by cells acquiring mesenchymal spindle-like morphology and by increased expression of N-cadherin with a concomitant decrease in E-cadherin. BDE-99 treatment also increased the protein and mRNA levels of the transcription factor Snail, but not Slug, Twist, and ZEB1. Knockdown of Snail by siRNA significantly attenuated BDE-99-induced EMT in HCT-116 cells, suggesting that Snail plays a crucial role in BDE-99-induced EMT. The PI3K/Akt inhibitor LY294002 completely blocked BDE-99-induced Snail and invasion of HCT-116 cells. Our results revealed that BDE-99 can trigger the EMT of colon cancer cells via the PI3K/AKT/Snail signaling pathway. This study provides new insight into the tumorigenesis and metastasis of CRC stimulated by BDE-99 and possibly other PBDE congeners.

  10. PI3K/Akt/mTOR signaling & its regulator tumour suppressor genes PTEN & LKB1 in human uterine leiomyomas

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    Annu Makker

    2016-01-01

    Interpretation & conclusions: Upregulation of PTEN and LKB1 in concert with negative or low levels of activated Akt, mTOR and S6 indicates that PI3K/Akt/mTOR pathway may not play a significant role in pathogenesis of leiomyoma.

  11. Notch2 regulates matrix metallopeptidase 9 via PI3K/AKT signaling in human gastric carcinoma cell MKN-45

    Institute of Scientific and Technical Information of China (English)

    Ling-Yun Guo; Yu-Min Li; Liang Qiao; Tao Liu; Yuan-Yuan Du; Jun-Qiang Zhang; Wen-Ting He

    2012-01-01

    AIM:To clarify the role of activated Notch2 in the invasiveness of gastric cancer.METHODS:To investigate the invasiveness of silencing Notch2 gene expression,we established a Notch2 small interfering RNA (siRNA) transfected cell line using the MKN-45 gastric cancer cell line.After the successful transfection confirmed by real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting,migration and invasion assays were employed to evaluate the aggressiveness of the gastric cancer.RT-PCR and Western blottings were employed to confirm the down-regulation of Notch2 and to evaluate the expression of epithelial mesenchymal transition-related gene matrix metallopeptidase 9 (MMPg),Akt,p-Akt.To confirm the relationship between PI3K-Akt and MMP9,the PI3K inhibitor LY294002 was used to treat MKN-45 cells.RESULTS:Notch2 expression was dramatically decreased after Notch2 siRNA transfection (100.00% ±9.74% vs 11.61% ± 3.85%,P < 0.01 by qRT-PCR).There was also a marked reduction of Notch target gene Hes1 (100.00% ± 4.74% vs 61.61% ± 3.58%,P < 0.05)at the mRNA,indicating an inhibition of Notch signaling.Inhibition of Notch signaling was also confirmed by the marked reduction of Notch2 intracellular domain at the protein levels (100.00% ± 9.74% vs 65.61% ± 7.58%,P < 0.05).Down-regulation of Notch2 by siRNA enhanced tumor cell invasion (100.00% ± 21.64% vs 162.22% ± 16.84%,P < 0.05) and expression of MMP9 (1.56 fold,P < 0.05),and activated the pro-MMP9 protein to its active form (1.48 fold,P < 0.05).There was no significant difference in the protein levels of Akt between the two groups (100.00% ± 10.87% vs 96.61% ± 7.33%,P > 0.05),while down-regulation of Notch2 elevated p-Akt expression (100.00% ± 9.87% vs 154.61% ± 13.10%,P < 0.05).Furthermore,p-Akt and MMP9 was down-regulated in response to the inhibitor LY294002 (p-Akt 100.00% ± 8.87% vs 58.27% ± 5.01%,P < 0.05; MMP9

  12. Gas6 Delays Senescence in Vascular Smooth Muscle Cells through the PI3K/ Akt/FoxO Signaling Pathway

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    Cheng-wei Jin

    2015-02-01

    Full Text Available Background/Aims: Growth arrest-specific protein 6 (Gas6 is a cytokine that can be synthesized by a variety of cell types and secreted into the extracellular matrix. Previous studies have confirmed that Gas6 is involved in certain pathophysiological processes of the cardiovascular system through binding to its receptor, Axl. In the present study, we investigated the role of Gas6 in cellular senescence and explored the mechanisms underlying its activity. Methods: We used vascular smooth muscle cells (VSMCs to create two cellular senescence models, one for replicative senescence (RS and one for induced senescence (IS, to test the hypothesis that Gas6 delays senescence. Results: Gas6-treated cells appear relatively younger compared with non-Gas6-treated cells. In particular, Gas6-treated cells displayed decreased staining for SA-β-Gal, fewer G1 phase cells, and decreased levels of p16INK4a and p21Cip1 expression; conversely, Gas6-treated cells displayed more S phase cells and significantly increased proliferation indexes. Furthermore, in both the IS and RS models with Gas6 treatment, the levels of PI3K, p-Akt, and p-FoxO3a decreased following Axl inhibition by R428; similarly, the levels of p-Akt and p-FoxO3a also decreased following PI3K inhibition by LY294002. Conclusion: Gas6/Axl signaling is essential for delaying the cellular senescence process regulated by the PI3K/Akt/FoxO signaling pathway.

  13. PI3K/Akt signal pathway involved in the cognitive impairment caused by chronic cerebral hypoperfusion in rats.

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    Yi Shu

    Full Text Available Chronic cerebral hypoperfusion (CCH is a common pathophysiological state that usually occurs in conditions such as vascular dementia and Alzheimer's disease, both of which are characterized by cognitive impairment. In previous studies we found that learning capacity and memory were gradually impaired with CCH, which altered the expression of synaptophysin, microtubule associated protein-2, growth associated protein-43, brain-derived neurotrophic factor, nerve growth factor, N-methyl-D-aspartate receptor subunit 1, cAMP response element-binding protein and tau hyperphosphorylation in the hippocampus. However, the molecular basis of cognitive impairment in CCH remains obscure. Here we explore the hypothesis that the phosphoinositide 3-kinase (PI3K/protein kinase B (Akt signal pathway is involved in this type of cognitive impairment. In order to determine if the expression of PI3K, Akt and phosphorylated Akt (p-Akt proteins are altered at different stages of CCH with differing levels of cognitive impairment. we performed permanent, bilateral occlusion of the common carotid arteries (2-VO to induce CCH. Adult male SD rats were randomly divided into sham-operated group, 2-VO 1 week group, 2-VO 4 weeks group and 2-VO 8 weeks group. Behavior tests were utilized to assess cognitive abilities, while western blots were utilized to evaluate protein expression. Rats in the 2-VO groups spent less time exploring novel objects than those in the sham-operated group, and the discrimination ratio of the 2-VO 8 weeks group and the sham-operated group were higher than chance (0.50. Escape latencies in the Morris water maze task in the 2-VO 1 week group were longer than those in the sham-operated group on day 4 and day 5, while escape latencies in the 2-VO 4 weeks group were longer than those in the sham-operated group from day 3 to day 5. Escape latencies in 2-VO 8 weeks group were longer than those in the sham-operated group from day 2 to day 5. NE (northeast

  14. Endothelium-Dependent Relaxation Effect of Apocynum venetum Leaf Extract via Src/PI3K/Akt Signalling Pathway

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    Yeh Siang Lau

    2015-06-01

    Full Text Available Botanical herbs are consumed globally not only as an essential diet but also as medicines or as functional/recreational food supplements. The extract of the Apocynum venetum leaves (AVLE, also known as Luobuma, exerts its antihypertensive effect via dilating the blood vessels in an endothelium- and concentration-dependent manner with optimal effect seen at as low as 10 µg/mL. A commercial Luoboma “antihypertensive tea” is available commercially in the western province of China. The present study seeks to investigate the underlying cellular mechanisms of the nitric oxide (NO-releasing property of AVLE in rat aortas and human umbilical vein endothelial cells (HUVECs. Endothelium-dependent relaxation induced by AVLE was assessed in organ chambers in the presence or absence of polyethyleneglycol catalase (PP2, 20 µM; inhibitor of Src kinase, wortmannin (30 nM and LY294002 (20 µM; PI3 (phosphatidylinositol3-Kinase inhibitor, NG-nitro-l-arginine (L-NAME, 100 µM; endothelial NO synthase inhibitor (eNOS and ODQ (1 µM; soluble guanylyl cyclase inhibitor. Total nitrite and nitrate (NOx level and protein expression of p-Akt and p-eNOS were measured. AVLE-induced endothelium-dependent relaxation was reduced by PP2, wortmannin and LY294002 and abolished by L-NAME and ODQ. AVLE significantly increased total NOx level in rat aortas and in HUVECs compared to control. It also instigated phosphorylation of Akt and eNOS in cultured HUVECs in a concentration-dependent manner and this was markedly suppressed by PP2, wortmannin and LY294002. AVLE also inhibited superoxide generated from both NADPH oxidase and xanthine/xanthine oxidase system. Taken together, AVLE causes endothelium-dependent NO mediated relaxations of rat aortas through Src/PI3K/Akt dependent NO signalling pathway and possesses superoxide scavenging activity.

  15. Inhibitory effect of oxymatrine on hepatocyte apoptosis via TLR4/PI3K/Akt/GSK-3β signaling pathway.

    Science.gov (United States)

    Zhang, Xian; Jiang, Wei; Zhou, Ai-Ling; Zhao, Min; Jiang, Dao-Rong

    2017-06-07

    To evaluate the effect of oxymatrine (OMT) on hepatocyte apoptosis in rats with lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced acute liver failure (ALF). LPS/D-GalN was used to establish a model of ALF in rats. To evaluate the effect of OMT, we assessed apoptosis by transmission electron microscopy, and the pathological changes in the liver by light microscopy with hematoxylin and eosin staining. An automated biochemical analyzer was used to measure serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Enzyme-linked immunosorbent assay was used to determine the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1β. Western blotting was used to detect protein levels in liver tissues. Streptavidin peroxidase immunohistochemistry was used to observe expression of Toll-like receptor (TLR)4, active caspase-3, Bax and Bcl-2. All rats in the normal control and OMT-pretreated groups survived. The mortality rate in the model group was 30%. OMT preconditioning down-regulated apoptosis of hepatocytes and ameliorated pathological changes in liver tissue. The levels of AST, ALT, TNF-α and IL-1β in the model group increased significantly, and were significantly reduced by OMT pretreatment. OMT pretreatment down-regulated expression of TLR4 and active caspase-3 and the Bax/Bcl-2 ratio, and up-regulated expression of P-Akt(Ser473) (Akt phosphorylated at serine 473) and P-GSK3β(Ser9) (glycogen synthase kinase 3β phosphorylated at serine 9) induced by LPS/D-GalN. OMT inhibits hepatocyte apoptosis by suppressing the TLR4/PI3K/Akt/GSK-3β signaling pathway, which suggests that OMT is an effective candidate for ameliorating acute liver failure.

  16. Breast Cancer Invasion and Metastasis by mPRα Through the PI3K/Akt Signaling Pathway.

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    Wu, Xiaojuan; Sun, Limin; Wang, Xiao; Su, Peng; Li, Zhishuang; Zhang, Chunyan; Wang, Yan; Gao, Peng; Ma, Rong

    2016-07-01

    Invasive breast cancer is the most common type of malignancy in women worldwide. However, the mechanism responsible for breast cancer metastasis is still unclear and needs further illustration. It has been proven that matrix metallopeptidase 9 (MMP-9) promotes metastasis of the cancer cells. However, the interaction between mPRα and MMP-9 has not been studied. Therefore, in the present research, the effect of MMP-9 on the malignant progression of invasive breast cancer promoted by membrane progesterone receptorα (mPRα) was investigated. The results showed that the protein expression of mPRα, p-Akt and MMP-9 increased in the cancerous tissues compared to that of the noncancerous breast tissue. Furthermore, a positive correlation was found between mPRα and C-erbB-2, as well as the number of involved local lymph nodes. On the other hand, a negative correlation was observed between mPRα and estrogen receptors (ER) along with progesterone receptors (PR). Similarly, a positive association was found between MMP-9 and the number of involved local lymph nodes. Besides, the high expression of MMP-9 also had a positive correlation with the tumor size. However, the high level of MMP-9 had a negative correlation with ER and PR. In addition, there was a positive correlation between mPRα and p-Akt together with MMP-9. The results confirm that mPRα was a major marker of harmful prognosis and it promoted the expression of MMP-9 during invasion to the local lymph nodes through the pathway of PI3K/Akt. The present study provided a novel therapeutic strategy to inhibit breast cancer growth by preventing mPRα signaling pathway.

  17. Wortmannin, PI3K/Akt signaling pathway inhibitor, attenuates thyroid injury associated with severe acute pancreatitis in rats.

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    Abliz, Ablikim; Deng, Wenhong; Sun, Rongze; Guo, Wenyi; Zhao, Liang; Wang, Weixing

    2015-01-01

    Increasing evidences suggest that PI3K/AKT pathway plays an important role in the pathogenesis of inflammatory diseases such as acute pancreatitis. However, the exact effect of PI3K/AKT on thyroid injury associated with acute pancreatitis has not been investigated. This study aimed to investigate the protective effects of wortmannin, PI3K/AKT inhibitor, on thyroid injury in a rat model of severe acute pancreatitis (SAP). Sixty male SD rats were randomly divided into four groups: sham operating group (SO), SAP group, wortmannin treatment (WOR) group and drug control (WOR-CON) group. Serum amylase (AMY), lipase (LIP) and thyroid hormone levels were evaluated. The morphological change of thyroid tissue was analyzed under the light and transmission electron microscopy. AKT, P38MAPK and NF-κB expression in the thyroid tissue was evaluated by immunohistochemical staining. Oxidative stress and inflammatory cytokines were detected. Results showed that wortmannin attenuated the following: (1) serum AMY, LIP and thyroid hormone (2) pancreatic and thyroid pathological injuries (3) thyroid MDA, (4) thyroid ultrastructural change, (5) serum TNF-α, IL-6 and IL-1β (6) AKT, MAPKP38 and NF-κB expression in thyroid tissues. These results suggested that wortmannin attenuates thyroid injury in SAP rats, presumably because of its role on prevent ROS generation and inhibits the activation of P38MAPK, NF-κB pathway. Our findings provide new therapeutic targets for thyroid injury associated with SAP.

  18. PI3K-Akt-mTOR and MAPK signaling pathways in polycystic ovarian syndrome, uterine leiomyomas and endometriosis: an update.

    Science.gov (United States)

    Makker, Annu; Goel, Madhu Mati; Das, Vinita; Agarwal, Anjoo

    2012-03-01

    PI3K-Akt-mTOR and MAP kinase are two important cell signaling pathways that are activated by steroid hormones and growth factors leading to cellular events including gene expression, cell proliferation and survival. These pathways are considered as an attractive target for the development of novel anticancer molecules, and selective inhibitors specifically targeting different components of these cascades have been developed. This review summarizes the current available knowledge on the PI3K-Akt-mTOR and MAPK pathways and their targeting in estrogen-dependent benign gynecological disorders viz. polycystic ovarian syndrome, uterine leiomyomas and endometriosis, which are a significant cause of high morbidity in women of reproductive age group. Increasing knowledge about the role of the two growth regulatory pathways in the pathogenesis of these disorders may give the opportunity to use specific signal transduction inhibitors for management of these patients in future.

  19. The PI3K/Akt Signaling Pathway Mediates the High Glucose-Induced Expression of Extracellular Matrix Molecules in Human Retinal Pigment Epithelial Cells

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    Dong Qin

    2015-01-01

    Full Text Available Prolonged hyperglycemia is an important risk factor of the pathogenesis of diabetic retinopathy (DR. Extracellular matrix molecules, such as fibronectin, collagen IV, and laminin, are associated with fibrotic membranes. In this study, we investigated the expression of fibronectin, collagen IV, and laminin in RPE cells under high glucose conditions. Furthermore, we also detected the phosphorylation of protein kinase B (Akt under high glucose conditions in RPE cells. Our results showed that high glucose upregulated fibronectin, collagen IV, and laminin expression, and activated Akt in RPE cells. We also found that pretreatment with LY294002 (an inhibitor of phosphatidylinositol 3-kinase abolished high glucose-induced expression of fibronectin, collagen IV, and laminin in RPE cells. Thus, high glucose induced the expression of fibronectin, collagen IV, and laminin through PI3K/Akt signaling pathway in RPE cells, and the PI3K/Akt signaling pathway may contribute to the formation of fibrotic membrane during the development of DR.

  20. DUAL INHIBITION OF PI3K/AKT AND mTOR SIGNALING IN HUMAN NON-SMALL CELL LUNG CANCER CELLS BY A DIETARY FLAVONOID FISETIN

    Science.gov (United States)

    Khan, Naghma; Afaq, Farrukh; Khusro, Fatima H.; Adhami, Vaqar Mustafa; Suh, Yewseok; Mukhtar, Hasan

    2011-01-01

    Lung cancer is one of the most commonly occurring malignancies. It has been reported that mTOR is phosphorylated in lung cancer and its activation was more frequent in tumors with over-expression of PI3K/Akt. Therefore, dual inhibitors of PI3K/Akt and mTOR signaling could be valuable agents for treating lung cancer. In the present study, we show that fisetin, a dietary tetrahydroxyflavone inhibits cell-growth with the concomitant suppression of PI3K/Akt and mTOR signaling in human non-small cell lung cancer (NSCLC) cells. Using autodock 4, we found that fisetin physically interacts with the mTOR complex at two sites. Fisetin treatment was also found to reduce the formation of A549 cell colonies in a dose-dependent manner. Treatment of cells with fisetin caused decrease in the protein expression of PI3K (p85 and p110), inhibition of phosphorylation of Akt, mTOR, p70S6K1, eIF-4E and 4E-BP1. Fisetin-treated cells also exhibited dose-dependent inhibition of the constituents of mTOR signaling complex like Rictor, Raptor, GβL and PRAS40. There was increase in the phosphorylation of AMPKα and decrease in the phosphorylation of TSC2 on treatment of cells with fisetin. We also found that treatment of cells with mTOR inhibitor rapamycin and mTOR-siRNA caused decrease in phosphorylation of mTOR and its target proteins which were further downregulated on treatment with fisetin, suggesting that these effects are mediated in part, through mTOR signaling. Our results show that fisetin suppressed PI3K/Akt and mTOR signaling in NSCLC cells and thus, could be developed as a chemotherapeutic agent against human lung cancer. PMID:21618507

  1. Panaxatriol Saponins Attenuated Oxygen-Glucose Deprivation Injury in PC12 Cells via Activation of PI3K/Akt and Nrf2 Signaling Pathway

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    Yongliang Huang

    2014-01-01

    Full Text Available Panaxatriol saponins (PTS, the main components extracted from Panax notoginseng, have been shown to be efficacious in the prevention and treatment of cerebrovascular diseases in China. NF-E2-related factor 2 (Nrf2, a transcription factor regulating antioxidant and cytoprotective responses to oxidative stress, has received particular attention as a molecular target for pharmacological intervention of ischemic diseases. The aim of this study was to characterize the effect of PTS on the activation of Nrf2 signaling pathway and the potential role in its protective effect. We found that PTS induced heme oxygenase-1 (HO-1 expression in PC12 cells via activating Nrf2 signaling pathway. Phosphatidylinositol 3-kinase (PI3K/Akt kinase was involved in the upstream of this PTS activated pathway. Moreover, combination of the main components in PTS significantly enhanced the expression of Nrf2 mediated phase II enzymes. Importantly, the protective effect of PTS against oxygen-glucose deprivation-reperfusion (OGD-Rep induced cell death was significantly attenuated by PI3K inhibitor and antioxidant response element (ARE decoy oligonucleotides, suggesting that both PI3K/Akt and Nrf2 signaling pathway are essential during this protective process. Taken together, our results suggest that PTS may activate endogenous cytoprotective mechanism against OGD-Rep induced oxidative injury via the activation of PI3K/Akt and Nrf2 signaling pathway.

  2. Fucoidan Induces ROS-Dependent Apoptosis in 5637 Human Bladder Cancer Cells by Downregulating Telomerase Activity via Inactivation of the PI3K/Akt Signaling Pathway.

    Science.gov (United States)

    Han, Min Ho; Lee, Dae-Sung; Jeong, Jin-Woo; Hong, Su-Hyun; Choi, Il-Whan; Cha, Hee-Jae; Kim, Suhkmann; Kim, Heui-Soo; Park, Cheol; Kim, Gi-Young; Moon, Sung-Kwon; Kim, Wun-Jae; Hyun Choi, Yung

    2017-02-01

    Preclinical Research Fucoidan, a sulfated polysaccharide, is a compound found in various species of seaweed that has anti-viral, anti-bacterial, anti-oxidant, anti-inflammatory, and immunomodulatory activities; however, the underlying relationship between apoptosis and anti-telomerase activity has not been investigated. Here, we report that fucoidan-induced apoptosis in 5637 human bladder cancer cells was associated with an increase in the Bax/Bcl-2 ratio, the dissipation of the mitochondrial membrane potential (MMP, Δψm), and cytosolic release of cytochrome c from the mitochondria. Under the same experimental conditions, fucoidan-treatment decreased hTERT (human telomerase reverse transcriptase) expression and the transcription factors, c-myc and Sp1. This was accompanied by decreased telomerase activity. Fucoidan-treatment also suppressed activation of the PI3K/Akt signaling pathway. Inhibition of PI3K/Akt signaling enhanced fucoidan-induced apoptosis and anti-telomerase activity. Meanwhile, fucoidan treatment increased the generation of intracellular ROS, whereas the over-elimination of ROS by N-acetylcysteine, an anti-oxidant, attenuated fucoidan-induced apoptosis, inhibition of hTERT, c-myc, and Sp1 expression, and reversed fucoidan-induced inactivation of the PI3K/Akt signaling pathway. Collectively, these data indicate that the induction of apoptosis and the inhibition of telomerase activity by fucoidan are mediated via ROS-dependent inactivation of the PI3K/Akt pathway. Drug Dev Res 78 : 37-48, 2017.   © 2016 Wiley Periodicals, Inc.

  3. JNK/PI3K/Akt signaling pathway is involved in myocardial ischemia/reperfusion injury in diabetic rats: effects of salvianolic acid A intervention.

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    Chen, Qiuping; Xu, Tongda; Li, Dongye; Pan, Defeng; Wu, Pei; Luo, Yuanyuan; Ma, Yanfeng; Liu, Yang

    2016-01-01

    Recent studies have demonstrated that diabetes impairs the phosphatidylinositol 3-kinase/Akt (PI3K/Akt) pathway, while insulin resistance syndrome has been associated with alterations of this pathway in diabetic rats after ischemia/reperfusion (I/R), and activation of C-jun N-terminal kinase (JNK) is involved. The present study was designed to investigate whether inhibiting JNK activity would partially restore the PI3K/Akt signaling pathway and protect against myocardial I/R injury in diabetic rats, and to explore the effect of intervention with salvianolic acid A (Sal A). The inhibitor of JNK (SP600125) and Sal A were used in type 2 diabetic (T2D) rats, outcome measures included heart hemodynamic data, myocardial infarct size, the release of lactate dehydrogenase (LDH), SERCA2a activity, cardiomyocyte apotosis, expression levels of Bcl-2, Bax and cleaved caspase-3, and the phosphorylation status of Akt and JNK. The p-Akt levels were increased after myocardial I/R in non-diabetic rats, while there was no change in diabetic rats. Pretreatment with the SP600125 and Sal A decreased the p-JNK levels and increased the p-Akt levels in diabetic rats with I/R, and heart hemodynamic data improved, infarct size and LDH release decreased, SERCA2a activity increased, Bax and cleaved caspase-3 expression levels decreased, and the expression of Bcl-2 and the Bcl-2/Bax ratio increased. Our results suggest that the JNK/PI3K/Akt signaling pathway is involved in myocardial I/R injury in diabetic rats and Sal A exerts an anti-apoptotic effect and improves cardiac function following I/R injury through the JNK/PI3K/Akt signaling pathway in this model.

  4. PTEN/PI3K/Akt/VEGF signaling and the cross talk to KRIT1, CCM2, and PDCD10 proteins in cerebral cavernous malformations.

    Science.gov (United States)

    Kar, Souvik; Samii, Amir; Bertalanffy, Helmut

    2015-04-01

    Cerebral cavernous malformations (CCM) are common vascular malformation of the brain and are associated with abnormal angiogenesis. Although the exact etiology and the underlying molecular mechanism are still under investigation, recent advances in the identification of the mutations in three genes and their interactions with different signaling pathways have shed light on our understanding of CCM pathogenesis. The phosphatidylinositol 3-kinase (PI3K)/Akt pathway is known to play a major role in angiogenesis. Studies have shown that the phosphatase and tensin homologue deleted on chromosome ten (PTEN), a tumor suppressor, is an antagonist regulator of the PI3K/Akt pathway and mediates angiogenesis by activating vascular endothelial growth factor (VEGF) expression. Here, we provide an update literature review on the current knowledge of the PTEN/PI3K/Akt/VEGF signaling in angiogenesis, more importantly in CCM pathogenesis. In addition to reviewing the current literatures, this article will also focus on the structural domain of the three CCM proteins and their interacting partners. Understanding the biology of these proteins with respect to their signaling counterpart will help to guide future research towards new therapeutic targets applicable for CCM treatment.

  5. Over-expression of PDGFR-β promotes PDGF-induced proliferation, migration, and angiogenesis of EPCs through PI3K/Akt signaling pathway.

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    Hang Wang

    Full Text Available The proliferation, migration, and angiogenesis of endothelial progenitor cells (EPCs play critical roles in postnatal neovascularization and re-endothelialization following vascular injury. Here we evaluated whether the over-expression of platelet-derived growth factor receptor-β (PDGFR-β can enhance the PDGF-BB-stimulated biological functions of EPCs through the PDGFR-β/phosphoinositide 3-kinase (PI3K/Akt signaling pathway. We first confirmed the expression of endogenous PDGFR-β and its plasma membrane localization in spleen-derived EPCs. We then demonstrated that the PDGFR-β over-expression in EPCs enhanced the PDGF-BB-induced proliferation, migration, and angiogenesis of EPCs. Using AG1295 (a PDGFR kinase inhibitor, LY294002 (a PI3K inhibitor, and sc-221226 (an Akt inhibitor, we further showed that the PI3K/Akt signaling pathway participates in the PDGF-BB-induced proliferation, migration, and angiogenesis of EPCs. In addition, the PI3K/Akt signaling pathway is required for PDGFR-β over-expression to enhance these PDGF-BB-induced phenotypes.

  6. Over-Expression of PDGFR-β Promotes PDGF-Induced Proliferation, Migration, and Angiogenesis of EPCs through PI3K/Akt Signaling Pathway

    Science.gov (United States)

    Li, Wei; Zhao, Xiaohui; Yu, Yang; Zhu, Jinkun; Qin, Zhexue; Wang, Qiang; Wang, Kui; Lu, Wei; Liu, Jie; Huang, Lan

    2012-01-01

    The proliferation, migration, and angiogenesis of endothelial progenitor cells (EPCs) play critical roles in postnatal neovascularization and re-endothelialization following vascular injury. Here we evaluated whether the over-expression of platelet-derived growth factor receptor-β (PDGFR-β) can enhance the PDGF-BB-stimulated biological functions of EPCs through the PDGFR-β/phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. We first confirmed the expression of endogenous PDGFR-β and its plasma membrane localization in spleen-derived EPCs. We then demonstrated that the PDGFR-β over-expression in EPCs enhanced the PDGF-BB-induced proliferation, migration, and angiogenesis of EPCs. Using AG1295 (a PDGFR kinase inhibitor), LY294002 (a PI3K inhibitor), and sc-221226 (an Akt inhibitor), we further showed that the PI3K/Akt signaling pathway participates in the PDGF-BB-induced proliferation, migration, and angiogenesis of EPCs. In addition, the PI3K/Akt signaling pathway is required for PDGFR-β over-expression to enhance these PDGF-BB-induced phenotypes. PMID:22355314

  7. MiR-20a Induces Cell Radioresistance by Activating the PTEN/PI3K/Akt Signaling Pathway in Hepatocellular Carcinoma

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    Zhang, Yuqin [Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province (China); Zheng, Lin [Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province (China); Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province (China); Ding, Yi [Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province (China); Li, Qi [Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province (China); Wang, Rong [Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province (China); Liu, Tongxin; Sun, Quanquan [Department of Radiation Oncology, Cancer Hospital, Hangzhou, Zhejiang Province (China); Yang, Hua [Department of Radiation Oncology, Nanhai Hospital, Southern Medical University, Guangzhou, Guangdong Province (China); Peng, Shunli [Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province (China); Wang, Wei, E-mail: wangwei9500@hotmail.com [Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province (China); Chen, Longhua, E-mail: chenlhsmu@126.com [Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province (China)

    2015-08-01

    Purpose: To investigate the role of miR-20a in hepatocellular carcinoma (HCC) cell radioresistance, which may reveal potential strategies to improve treatment. Methods and Materials: The expression of miR-20a and PTEN were detected in HCC cell lines and paired primary tissues by quantitative real-time polymerase chain reaction. Cell radiation combined with colony formation assays was administrated to discover the effect of miR-20a on radiosensitivity. Bioinformatics prediction and luciferase assay were used to identify the target of miR-20a. The phosphatidylinositol 3-kinase inhibitor LY294002 was used to inhibit phosphorylation of Akt, to verify whether miR-20a affects HCC cell radioresistance through activating the PTEN/PI3K/Akt pathway. Results: MiR-20a levels were increased in HCC cell lines and tissues, whereas PTEN was inversely correlated with it. Overexpression of miR-20a in Bel-7402 and SMMC-7721 cells enhances their resistance to the effect of ionizing radiation, and the inhibition of miR-20a in HCCLM3 and QGY-7701 cells sensitizes them to it. PTEN was identified as a direct functional target of miR-20a for the induction of radioresistance. Overexpression of miR-20a activated the PTEN/PI3K/Akt signaling pathway. Additionally, the kinase inhibitor LY294002 could reverse the effect of miR-20a–induced radioresistance. Conclusion: MiR-20a induces HCC cell radioresistance by activating the PTEN/PI3K/Akt pathway, which suggests that miR-20a/PTEN/PI3K/Akt might represent a target of investigation for developing effective therapeutic strategies against HCC.

  8. PI3K/Akt/FoxO3a signaling mediates cardioprotection of FGF-2 against hydrogen peroxide-induced apoptosis in H9c2 cells.

    Science.gov (United States)

    Liu, Mi-Hua; Li, Guo-Hua; Peng, Li-Jun; Qu, Shun-Lin; Zhang, Yuan; Peng, Juan; Luo, Xin-Yuan; Hu, Heng-Jing; Ren, Zhong; Liu, Yao; Tang, Hui; Liu, Lu-Shan; Tang, Zhi-Han; Jiang, Zhi-Sheng

    2016-03-01

    Cardiovascular disease is a growing major global public health problem. Oxidative stress is regarded as one of the key regulators of pathological physiology, which eventually leads to cardiovascular disease. However, mechanisms by which FGF-2 rescues cells from oxidative stress damage in cardiovascular disease is not fully elucidated. Herein this study was designed to investigate the protective effects of FGF-2 in H2O2-induced apoptosis of H9c2 cardiomyocytes, as well as the possible signaling pathway involved. Apoptosis of H9c2 cardiomyocytes was induced by H2O2 and assessed using methyl thiazolyl tetrazolium assay, Hoechst, and TUNEL staining. Cells were pretreated with PI3K/Akt inhibitor LY294002 to investigate the possible PI3K/Akt pathways involved in the protection of FGF-2. The levels of p-Akt, p-FoxO3a, and Bim were detected by immunoblotting. Stimulation with H2O2 decreased the phosphorylation of Akt and FoxO3a, and induced nuclear localization of FoxO3a and apoptosis of H9c2 cells. These effects of H2O2 were abrogated by pretreatment with FGF-2. Furthermore, the protective effects of FGF-2 were abolished by PI3K/Akt inhibitor LY294002. In conclusion, our data suggest that FGF-2 protects against H2O2-induced apoptosis of H9c2 cardiomyocytes via activation of the PI3K/Akt/FoxO3a pathway.

  9. PI3K/Akt/mTOR通路与急性早幼粒细胞白血病关系的研究进展%Advances on PI3K/Akt/mTOR Signaling Network in Acute Promyelocytic Leukemia

    Institute of Scientific and Technical Information of China (English)

    刘梅

    2011-01-01

    Phosphatidylinositol 3-kinase ( PI3 K )/Akt/mammalian target of rapamycin ( mTOR ) signaling axis is an important intracellular signal transduction pathway and plays a central role in cell proliferation,growth,and survival under physiological conditions. Aberrant activation of PI3 K/Akt/mTOR signaling due to genetic dysfunction and abnormal magnification of upstream regulatory signal results in the imbalance between cell viability and apoptosis and malignant transformation. It has been shown that the constitutive activation of PI3 K/Akt/mTOR signaling network in acute promyelocytic leukemia plays a vital role in survival, proliferation, differentiation, apoptosis, and drug-resistance of leukemic cells. This article reviews recent progress on PI3 K/Akt/mTOR signaling axis in acute promyelocytic leukemia.%PI3K/Akt/mTOR信号途径作为细胞内重要信号转导通路之一,在维持细胞增殖、存活和凋亡中发挥关键作用.当PI3K/Akt/mTOR通路分子的基因功能失常、上游调控信号异常放大时使该信号通路异常激活,细胞生存与凋亡失衡,正常细胞发生恶性转化.研究表明,PI3K/Akt/mTOR信号通路在急性早幼粒细胞白血病存在异常激活,对肿瘤细胞的生存、增殖、分化、凋亡和耐药性中起重要作用.现就近年来在PI3K/Akt/mTOR信号通路与急性早幼粒细胞白血病关系研究领域的进展予以简要综述.

  10. TDRG1 functions in testicular seminoma are dependent on the PI3K/Akt/mTOR signaling pathway

    Science.gov (United States)

    Wang, Yong; Gan, Yu; Tan, Zhengyu; Zhou, Jun; Kitazawa, Riko; Jiang, Xianzhen; Tang, Yuxin; Yang, Jianfu

    2016-01-01

    Human testis development-related gene 1 (TDRG1) is a recently identified gene that is expressed exclusively in the testes and promotes the development of testicular germ cell tumors. In this study, the role of TDRG1 in the development of testicular seminoma, which is the most common testicular germ cell tumor, was further investigated. Based on polymerase chain reaction, Western blotting, and immunohistochemistry tests, both gene and protein expression levels of TDRG1 were significantly upregulated in testicular seminoma tissues compared with normal testicular tissues. Additionally, the levels of phosphoinositide-3 kinase (PI3K)/p110 and Akt phosphorylation were dramatically upregulated in testicular seminoma tissues. Accordingly, in our cell experiment, seminoma TCam-2 cells were subjected to different treatments: the TDRG1 knockout, TDRG1 overexpression, PI3K inhibition (LY294002 administration), or PI3K activation (insulin-like growth factor-1 administration). Cell proliferation, the proliferation index, apoptosis rate, cell adhesive capacity, and cell invasion capability were assessed. Cells with both TDRG1 knockout and PI3K inhibition exhibited decreased cell proliferation, proliferation indexes, cell adhesion capacity, and cell invasion capability and increased apoptosis rates. Most of these effects were reversed by TDRG1 overexpression or PI3K activation, indicating that both TDRG1- and PI3K-mediated signaling promote proliferation and invasion of testicular seminoma cells. The knockout of TDRG1 significantly decreased the phosphorylation levels of PI3K/p85, PI3K/p110, Akt, and mammalian target of rapamycin (mTOR; Ser2448). Except for PI3K/p110, TDRG1 overexpression had the opposite effects on phosphorylation levels. Phosphorylated mTOR at Ser2481 and Thr2446 was not affected by TDRG1 or PI3K in our tests. Thus, these results indicate that TDRG1 promotes the development and migration of seminoma cells via the regulation of the PI3K/Akt/mTOR signaling pathway

  11. The pyrrolidinoindoline alkaloid Psm2 inhibits platelet aggregation and thrombus formation by affecting PI3K/Akt signaling

    Science.gov (United States)

    Su, Xing-li; Su, Wen; Wang, Ying; Wang, Yue-hu; Ming, Xin; Kong, Yi

    2016-01-01

    Aim: Psm2, one of the pyrrolidinoindoline alkaloids isolated from whole Selaginella moellendorffii plants, has shown a potent antiplatelet activity. In this study, we further evaluated the antiplatelet effects of Psm2, and elucidated the underlying mechanisms. Methods: Human platelet aggregation in vitro and rat platelet aggregation ex vivo were investigated. Agonist-induced platelet aggregation was measured using a light transmission aggregometer. The antithrombotic effects of Psm2 were evaluated in arteriovenous shunt thrombosis model in rats. To elucidate the mechanisms underlying the antiplatelet activity of Psm2, ELISAs, Western blotting and molecular docking were performed. The bleeding risk of Psm2 administration was assessed in a mouse tail cutting model, and the cytotoxicity of Psm2 was measured with MTT assay in EA.hy926 cells. Results: Psm2 dose-dependently inhibited human platelet aggregation induced by ADP, U4619, thrombin and collagen with IC50 values of 0.64, 0.37, 0.35 and 0.87 mg/mL, respectively. Psm2 (1, 3, 10 mg/kg) administered to rats significantly inhibited platelet aggregation ex vivo induced by ADP. Psm2 (1, 3, 10 mg/mL, iv) administered to rats with the A–V shunt dose-dependently decreased the thrombus formation. Psm2 inhibited platelet adhesion to fibrinogen and collagen with IC50 values of 84.5 and 96.5 mg/mL, respectively, but did not affect the binding of fibrinogen to GPIIb/IIIa. Furthermore, Psm2 inhibited AktSer473 phosphorylation, but did not affect MAPK signaling and Src kinase activation. Molecular docking showed that Psm2 bound to phosphatidylinositol 3-kinase β (PI3Kβ) with a binding free energy of −13.265 kcal/mol. In addition, Psm2 did not cause toxicity in EA.hy926 cells and produced only slight bleeding in a mouse tail cutting model. Conclusion: Psm2 inhibits platelet aggregation and thrombus formation by affecting PI3K/Akt signaling. Psm2 may be a lead compound or drug candidate that could be developed for the

  12. Analysis of miRNA profiles identified miR-196a as a crucial mediator of aberrant PI3K/AKT signaling in lung cancer cells.

    Science.gov (United States)

    Guerriero, Ilaria; D'Angelo, Daniela; Pallante, Pierlorenzo; Santos, Mafalda; Scrima, Marianna; Malanga, Donatella; De Marco, Carmela; Ravo, Maria; Weisz, Alessandro; Laudanna, Carmelo; Ceccarelli, Michele; Falco, Geppino; Rizzuto, Antonia; Viglietto, Giuseppe

    2016-11-17

    Hyperactivation of the PI3K/AKT pathway is observed in most human cancer including lung carcinomas. Here we have investigated the role of miRNAs as downstream targets of activated PI3K/AKT signaling in Non Small Cell Lung Cancer (NSCLC). To this aim, miRNA profiling was performed in human lung epithelial cells (BEAS-2B) expressing active AKT1 (BEAS-AKT1-E17K), active PI3KCA (BEAS-PIK3CA-E545K) or with silenced PTEN (BEAS-shPTEN).Twenty-four differentially expressed miRNAs common to BEAS-AKT1-E17K, BEAS-PIK3CA-E545K and BEAS-shPTEN cells were identified through this analysis, with miR-196a being the most consistently up-regulated miRNA. Interestingly, miR-196a was significantly overexpressed also in human NSCLC-derived cell lines (n=11) and primary lung cancer samples (n=28).By manipulating the expression of miR-196a in BEAS-2B and NCI-H460 cells, we obtained compelling evidence that this miRNA acts downstream the PI3K/AKT pathway, mediating some of the proliferative, pro-migratory and tumorigenic activity that this pathway exerts in lung epithelial cells, possibly through the regulation of FoxO1, CDKN1B (hereafter p27) and HOXA9.

  13. Protective Effect of Tempol on Acute Kidney Injury Through PI3K/Akt/Nrf2 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Gensheng Zhang

    2016-02-01

    Full Text Available Background/Aims: Tempol is a protective antioxidant against ischemic injury in many animal models. The molecular mechanisms are not well understood. Nuclear factor erythroid 2-related factor (Nrf2 is a master transcription factor during oxidative stress, which is enhanced by activation of protein kinase C (PKC pathway. Another factor, tubular epithelial apoptosis, is mediated by activation of phosphoinositide 3-kinase (PI3K/protein kinase B (PKB, Akt signaling pathway during renal ischemic injury. We tested the hypothesis that tempol activates PKC or PI3K/Akt/Nrf2 pathways to transcribe many genes that coordinate endogenous antioxidant defense. Methods: The right renal pedicle was clamped for 45 minutes and the left kidney was removed to study renal ischemia/reperfusion (I/R injury in C57BL/6 mice. The response was assessed from serum parameters, renal morphology and renal expression of PKC, phosphorylated-PKC (p-PKC, Nrf2, heme oxygenase-1 (HO-1, Akt, phosphorylated-Akt (p-Akt, pro-caspase-3 and cleaved caspase-3 in groups of sham and I/R mice given vehicle, or tempol (50 or 100 mg/kg, intraperitoneal injection. Results: The serum malondialdehyde (MDA, marker of reactive oxygen species doubled and the BUN and creatinine increased 5- to 10-fold after I/R injury. Tempol (50 or 100 mg/kg prevented the increases in MDA but only tempol (50 mg/kg lessened the increases in BUN and creatinine and moderated the acute tubular necrosis. I/R did not change expression of PKC or p-PKC but reduced renal expression of Nrf2, p-Akt, HO-1 and pro-caspase-3 and increased cleaved caspase-3. Tempol (50 mg/kg prevented these changes produced by I/R whereas tempol (100 mg/kg had lesser or inconsistent effects. Conclusion: Tempol (50 mg/kg prevents lipid peroxidation and attenuates renal damage after I/R injury. The beneficial pathway apparently is not dependent on upregulation or phosphorylation of PKC, at lower tempol doses, does implicate upregulation of Akt with

  14. SMND-309 promotes neuron survival through the activation of the PI3K/Akt/CREB-signalling pathway.

    Science.gov (United States)

    Wang, Youlei; Zhang, Jinjin; Han, Meng; Liu, Bo; Gao, Yulin; Ma, Peng; Zhang, Songzi; Zheng, Qingyin; Song, Xiaodong

    2016-10-01

    Context In clinical practice, the promotion of neuron survival is necessary to recover neurological functions after the onset of stroke. Objective This study aimed to investigate the post-ischaemic neuroprotective effect of SMND-309, a novel metabolite of salvianolic acid, on differentiated SH-SY5Y cells. Materials and methods SH-SY5Y cells were differentiated by pre-treating with 5 μM all-trans-retinoic acid for 6 d. The differentiated SH-SY5Y cells were exposed to oxygen-glucose deprivation (OGD) for 2 h and reperfusion (R) for 24 h to induce OGD/R injury. After OGD injury, differentiated SH-SY5Y cells were treated with or without SMND-309 (5, 10, 20 μM) for another 24 h. Cell viability was detected through Cell counting kit-8 assay and lactate dehydrogenase leakage assay. Apoptosis was evaluated through flow cytometry, caspase-3 activity assay. Changes in protein levels were assessed through Western blot. Results SMND-309 ameliorated the degree of injury in the differentiated SH-SY5Y cells by increasing cell viabilities (5 μM, 65.4% ± 4.1%; 10 μM, 69.8% ± 3.7%; 20 μM, 75.3% ± 5.1%) and by reducing LDH activity (20 μM, 2.5 fold) upon OGD/R stimulation. Annexin V-fluorescein isothiocyanate/propidium iodide staining results suggested that apoptotic rate of differentiated SH-SY5Y cells decreased from 43.8% induced by OGD/R injury to 19.2% when the cells were treated with 20 μM SMND-309. SMND-309 significantly increased the Bcl-2 level of the injured differentiated SH-SY5Y cells but decreased the caspase-3 activity of these cells by 1.6-fold. In contrast, SMND-309 did not affect the Bax level of these cells. SMND-309 evidently increased the protein expression of BDNF when Akt and CREB were activated. This function was antagonized by the addition of LY294002. Conclusion SMND-309 can prevent neuronal cell death in vitro. This process may be related to the activation of the PI3K/Akt/CREB-signalling pathway.

  15. Silica nanoparticles induce autophagy and endothelial dysfunction via the PI3K/Akt/mTOR signaling pathway

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    Duan J

    2014-11-01

    Full Text Available Junchao Duan,1,2 Yongbo Yu,1,2 Yang Yu,1,2 Yang Li,1,2 Ji Wang,1,2 Weijia Geng,1,2 Lizhen Jiang,1,2 Qiuling Li,1,2 Xianqing Zhou,1,2 Zhiwei Sun1,2 1School of Public Health, Capital Medical University, Beijing, 2Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, People’s Republic of China Abstract: Although nanoparticles have a great potential for biomedical applications, there is still a lack of a correlative safety evaluation on the cardiovascular system. This study is aimed to clarify the biological behavior and influence of silica nanoparticles (Nano-SiO2 on endothelial cell function. The results showed that the Nano-SiO2 were internalized into endothelial cells in a dose-dependent manner. Monodansylcadaverine staining, autophagic ultrastructural observation, and LC3-I/LC3-II conversion were employed to verify autophagy activation induced by Nano-SiO2, and the whole autophagic process was also observed in endothelial cells. In addition, the level of nitric oxide (NO, the activities of NO synthase (NOS and endothelial (eNOS were significantly decreased in a dose-dependent way, while the activity of inducible (iNOS was markedly increased. The expression of C-reactive protein, as well as the production of proinflammatory cytokines (tumor necrosis factor α, interleukin [IL]-1β, and IL-6 were significantly elevated. Moreover, Nano-SiO2 had an inhibitory effect on the phosphoinositide 3-kinase (PI3K/protein kinase B (Akt/mammalian target of rapamycin (mTOR signaling pathway. Our findings demonstrated that Nano-SiO2 could disturb the NO/NOS system, induce inflammatory response, activate autophagy, and eventually lead to endothelial dysfunction via the PI3K/Akt/mTOR pathway. This indicates that exposure to Nano-SiO2 is a potential risk factor for cardiovascular diseases. Keywords: silica nanoparticles, endothelial dysfunction, autophagy, nitric oxide, inflammation

  16. The roles of PI3K/Akt signaling pathway in regulating MC3T3-E1 preosteoblast proliferation and differentiation on SLA and SLActive titanium surfaces.

    Science.gov (United States)

    Gu, Ying-Xin; Du, Juan; Si, Mi-Si; Mo, Jia-Ji; Qiao, Shi-Chong; Lai, Hong-Chang

    2013-03-01

    Chemical modification to produce a hydrophilic microrough titanium (Ti) implant surface has been shown to increase osseointegration compared with microrough topography alone. This study aimed to investigate the roles of PI3K/Akt signaling pathway in regulating proliferation and differentiation of osteoblasts in response to surface microroughness and hydrophilicity. Ti disks were manufactured to present different surface morphologies: a smooth pretreatment surface (PT), a rough hydrophobic surface that was sand-blasted, large-grit, acid-etched (SLA), and an SLA surface with the same roughness that was chemically modified to possess high wettability/hydrophilicity (SLActive/modSLA). MC3T3-E1 cells were cultured on these substrates with or without LY294002, a PI3K inhibitor, and their behaviors, including cell viability (MTT colorimetric assay), alkaline phosphatase (ALP) activity, and osteogenic genes expression of osteopontin (OPN) and osteocalcin (OCN) were measured. Western blot was applied to detect the expression of PI3K/Akt signal pathway proteins. The results showed that a decrease in osteoblast proliferation associated with the Ti surfaces (SLActive > SLA > PT) correlated with an increase in activity of the osteogenic differentiation markers ALP. The peak of ALP activity appeared earlier at 7 days for the SLActive surfaces compared with the SLA and PT surfaces. Osteoblast proliferation, as well as the level of p-Akt, was significantly inhibited by LY294002 in all three Ti surfaces. The top value of ALP activity was increased with the inhibition of PI3K/Akt signaling pathway while the time of the peak appeared was not advanced. The expression levels of OPN and OCN were upregulated by the effect of surface roughness and hydrophilicity, which were further enhanced by LY294002. In conclusion, osteogenic responses to SLActive surface were moderately better than the SLA surface and protein expression studies indicated that PI3K/Akt signaling activation may be

  17. Shikonin promotes autophagy in BXPC-3 human pancreatic cancer cells through the PI3K/Akt signaling pathway

    OpenAIRE

    SHI, SHUQING; CAO, HAIMEI

    2014-01-01

    The present study aimed to investigate the effect of shikonin on autophagy in BXPC-3 human pancreatic cancer cells and its underlying mechanism. Cell viability was assessed using the Cell Counting Kit-8 assay and the expression of light chain (LC) 3, p62, phosphoinositide 3-kinase (PI3K), Akt, phosphorylated (p)-PI3K and p-Akt was analyzed using western blot analysis. Following treatment with 1 μmol/l shikonin for 48 h and 2.5 and 5 μmol/l shikonin for 24 and 48 h, the viability of the BXPC-3...

  18. Gomisin N Inhibits Melanogenesis through Regulating the PI3K/Akt and MAPK/ERK Signaling Pathways in Melanocytes.

    Science.gov (United States)

    Chae, Jae Kyoung; Subedi, Lalita; Jeong, Minsun; Park, Yong Un; Kim, Chul Young; Kim, Hakwon; Kim, Sun Yeou

    2017-02-22

    Gomisin N, one of the lignan compounds found in Schisandra chinensis has been shown to possess anti-oxidative, anti-tumorigenic, and anti-inflammatory activities in various studies. Here we report, for the first time, the anti-melenogenic efficacy of Gomisin N in mammalian cells as well as in zebrafish embryos. Gomisin N significantly reduced the melanin content without cellular toxicity. Although it was not capable of modulating the catalytic activity of mushroom tyrosinase in vitro, Gomisin N downregulated the expression levels of key proteins that function in melanogenesis. Gomisin N downregulated melanocortin 1 receptor (MC1R), adenylyl cyclase 2, microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2). In addition, Gomisin N-treated Melan-A cells exhibited increased p-Akt and p-ERK levels, which implies that the activation of the PI3K/Akt and MAPK/ERK pathways may function to inhibit melanogenesis. We also validated that Gomisin N reduced melanin production by repressing the expression of MITF, tyrosinase, TRP-1, and TRP-2 in mouse and human cells as well as in developing zebrafish embryos. Collectively, we conclude that Gomisin N inhibits melanin synthesis by repressing the expression of MITF and melanogenic enzymes, probably through modulating the PI3K/Akt and MAPK/ERK pathways.

  19. Gomisin N Inhibits Melanogenesis through Regulating the PI3K/Akt and MAPK/ERK Signaling Pathways in Melanocytes

    Science.gov (United States)

    Chae, Jae Kyoung; Subedi, Lalita; Jeong, Minsun; Park, Yong Un; Kim, Chul Young; Kim, Hakwon; Kim, Sun Yeou

    2017-01-01

    Gomisin N, one of the lignan compounds found in Schisandra chinensis has been shown to possess anti-oxidative, anti-tumorigenic, and anti-inflammatory activities in various studies. Here we report, for the first time, the anti-melenogenic efficacy of Gomisin N in mammalian cells as well as in zebrafish embryos. Gomisin N significantly reduced the melanin content without cellular toxicity. Although it was not capable of modulating the catalytic activity of mushroom tyrosinase in vitro, Gomisin N downregulated the expression levels of key proteins that function in melanogenesis. Gomisin N downregulated melanocortin 1 receptor (MC1R), adenylyl cyclase 2, microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2). In addition, Gomisin N-treated Melan-A cells exhibited increased p-Akt and p-ERK levels, which implies that the activation of the PI3K/Akt and MAPK/ERK pathways may function to inhibit melanogenesis. We also validated that Gomisin N reduced melanin production by repressing the expression of MITF, tyrosinase, TRP-1, and TRP-2 in mouse and human cells as well as in developing zebrafish embryos. Collectively, we conclude that Gomisin N inhibits melanin synthesis by repressing the expression of MITF and melanogenic enzymes, probably through modulating the PI3K/Akt and MAPK/ERK pathways. PMID:28241436

  20. Gomisin N Inhibits Melanogenesis through Regulating the PI3K/Akt and MAPK/ERK Signaling Pathways in Melanocytes

    Directory of Open Access Journals (Sweden)

    Jae Kyoung Chae

    2017-02-01

    Full Text Available Gomisin N, one of the lignan compounds found in Schisandra chinensis has been shown to possess anti-oxidative, anti-tumorigenic, and anti-inflammatory activities in various studies. Here we report, for the first time, the anti-melenogenic efficacy of Gomisin N in mammalian cells as well as in zebrafish embryos. Gomisin N significantly reduced the melanin content without cellular toxicity. Although it was not capable of modulating the catalytic activity of mushroom tyrosinase in vitro, Gomisin N downregulated the expression levels of key proteins that function in melanogenesis. Gomisin N downregulated melanocortin 1 receptor (MC1R, adenylyl cyclase 2, microphthalmia-associated transcription factor (MITF, tyrosinase, tyrosinase-related protein-1 (TRP-1, and tyrosinase-related protein-2 (TRP-2. In addition, Gomisin N-treated Melan-A cells exhibited increased p-Akt and p-ERK levels, which implies that the activation of the PI3K/Akt and MAPK/ERK pathways may function to inhibit melanogenesis. We also validated that Gomisin N reduced melanin production by repressing the expression of MITF, tyrosinase, TRP-1, and TRP-2 in mouse and human cells as well as in developing zebrafish embryos. Collectively, we conclude that Gomisin N inhibits melanin synthesis by repressing the expression of MITF and melanogenic enzymes, probably through modulating the PI3K/Akt and MAPK/ERK pathways.

  1. E2/ER β Enhances Calcineurin Protein Degradation and PI3K/Akt/MDM2 Signal Transduction to Inhibit ISO-Induced Myocardial Cell Apoptosis

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    Kuan-Ho Lin

    2017-04-01

    Full Text Available Secretion of multifunctional estrogen and its receptor has been widely considered as the reason for markedly higher frequency of heart disease in men than in women. 17β-Estradiol (E2, for instance, has been reported to prevent development of cardiac apoptosis via activation of estrogen receptors (ERs. In addition, protein phosphatase such as protein phosphatase 1 (PP1 and calcineurin (PP2B are also involved in cardiac hypertrophy and cell apoptosis signaling. However, the mechanism by which E2/ERβ suppresses apoptosis is not fully understood, and the role of protein phosphatase in E2/ERβ action also needs further investigation. In this study, we observed that E2/ERβ inhibited isoproterenol (ISO-induced myocardial cell apoptosis, cytochrome c release and downstream apoptotic markers. Moreover, we found that E2/ERβ blocks ISO-induced apoptosis in H9c2 cells through the enhancement of calcineurin protein degradation through PI3K/Akt/MDM2 signaling pathway. Our results suggest that supplementation with estrogen and/or overexpression of estrogen receptor β gene may prove to be effective means to treat stress-induced myocardial damage.

  2. Inhibition of fatty acid synthase suppresses U-2 OS cell invasion and migration via downregulating the activity of HER2/PI3K/AKT signaling pathway in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tao Fang; Wang, Heng [Department of Orthopedics, First Affiliated Hospital of Nanchang University, Jiangxi (China); Peng, Ai Fen [Jiangxi University of Traditional Chinese Medicine, Jiangxi (China); Luo, Qing Feng [Department of Pathology, Cancer Hospital of Jiangxi Province, Jiangxi (China); Liu, Zhi Li, E-mail: zgm7977@163.com [Department of Orthopedics, First Affiliated Hospital of Nanchang University, Jiangxi (China); Zhou, Rong Ping [Department of Orthopedics, Second Affiliated Hospital of Nanchang University, Jiangxi (China); Gao, Song; Zhou, Yang; Chen, Wen Zhao [Department of Orthopedics, First Affiliated Hospital of Nanchang University, Jiangxi (China)

    2013-10-18

    Highlights: •We investigate the relationship between FASN and HER2 or p-HER2 by IHC in OS tissues. •We construct FASN-specific RNAi plasmid. •Inhibiting FASN down-regulates HER2/PI3K/AKT cell signaling in U-2 OS. •Inhibiting FASN blocks U-2 OS cell invasion and migration. -- Abstract: FASN plays an important role in the malignant phenotype of various tumors. Our previous studies show that inhibition FASN could induce apoptosis and inhibit proliferation in human osteosarcoma (OS) cell in vivo and vitro. The aim in this study was to investigate the effect of inhibition FASN on the activity of HER2/PI3K/AKT axis and invasion and migration of OS cell. The expression of FASN, HER2 and p-HER2(Y1248) proteins was detected by immunohistochemistry in OS tissues from 24 patients with pulmonary metastatic disease, and the relationship between FASN and p-HER2 as well as HER2 was investigated. The results showed that there was a positive correlation between FASN and HER2 as well as p-HER2 protein expression. The U-2 OS cells were transfected with either the FASN specific RNAi plasmid or the negative control RNAi plasmid. FASN mRNA was measured by RT-PCR. Western blot assays was performed to examine the protein expression of FASN, HER2, p-HER2(Y1248), PI3K, Akt and p-Akt (Ser473). Migration and invasion of cells were investigated by wound healing and transwell invasion assays. The results showed that the activity of HER2/PI3K/AKT signaling pathway was suppressed by inhibiting FASN. Meanwhile, the U-2OS cells migration and invasion were also impaired by inhibiting the activity of FASN/HER2/PI3K/AKT. Our results indicated that inhibition of FASN suppresses OS cell invasion and migration via down-regulation of the “HER2/PI3K/AKT” axis in vitro. FASN blocker may be a new therapeutic strategy in OS management.

  3. The research progress of PI3K/Akt/mTOR signaling pathway and mTOR inhibitors for the treatment of tumor%PI3K/Akt/mTOR信号通路及mTOR抑制剂治疗肿瘤的研究进展

    Institute of Scientific and Technical Information of China (English)

    姜玮嘉; 孙国平

    2016-01-01

    At present, the specificity of small molecule inhibitors targeting killing tumor cells has become a hot research topic. PI3K/Akt/mTOR inhibitors as a proven is influence tumor occurrence, development, migration and invasion of signaling pathways, mTOR is one of the key targets. At home and abroad in recent years,this paper reviewed the PI3K/Akt/mTOR signaling pathways and the mechanism of mTOR inhibitors for cancer research.%目前,特异性的小分子抑制剂靶向杀伤肿瘤细胞已成为研究热点。PI3K/Akt/mTOR作为一个已被证实影响肿瘤发生、发展、迁移、侵袭的信号通路,mTOR是其中一个关键的靶点。本文探讨了近年来国内外对于PI3K/Akt/mTOR信号通路的机制和以及mTOR抑制剂对于肿瘤治疗的研究。

  4. Over-expression of NYGGF4 (PID1) inhibits glucose transport in skeletal myotubes by blocking the IRS1/PI3K/AKT insulin pathway.

    Science.gov (United States)

    Wu, W L; Gan, W H; Tong, M L; Li, X L; Dai, J Z; Zhang, C M; Guo, X R

    2011-03-01

    Defects in insulin-stimulated glucose uptake in muscle are the important early events in the pathogenesis of insulin resistance. NYGGF4 (also named PID1) is a recently discovered gene which is suggested to be associated with obesity-associated insulin resistance. In this study, we aimed to investigate the effects of NYGGF4 on glucose uptake and insulin signaling in rat skeletal muscle cells. Rat L6 myoblasts were transfected with either an empty vector or an NYGGF4-expressing vector and induced to differentiate into mature L6 skeletal myotubes. Glucose uptake was determined by measuring uptake of 2-deoxy-d-[(3)H] glucose. Immunoblotting was performed to detect the translocation of insulin-sensitive glucose transporter 4 (GLUT4). Immunoblotting was also used to measure phosphorylation and total protein levels of the insulin signaling proteins including insulin receptor (IR), insulin receptor substrate 1 (IRS1), Akt, extracellular signal-regulated kinase 1 and 2 (ERK1/2), p38, and c-Jun-N-terminal kinase (JNK). NYGGF4 over-expression in L6 skeletal myotubes reduced insulin-stimulated glucose uptake and impaired insulin-stimulated GLUT4 translocation. It also diminished insulin-stimulated tyrosine phosphorylation of IRS1 and serine phosphorylation of Akt without affecting the phosphorylation of IR, ERK1/2, p38, or JNK. Over-expression of NYGGF4 inhibits glucose transport in skeletal myotubes by blocking the IRS1/PI3K/AKT insulin pathway. These observations highlight the potential role of NYGGF4 in glucose homeostasis and the development of insulin resistance in obesity. Copyright © 2010 Elsevier Inc. All rights reserved.

  5. Oxidant Stress and Signal Transduction in the Nervous System with the PI 3-K, Akt, and mTOR Cascade

    Directory of Open Access Journals (Sweden)

    Yan Chen Shang

    2012-10-01

    Full Text Available Oxidative stress impacts multiple systems of the body and can lead to some of the most devastating consequences in the nervous system especially during aging. Both acute and chronic neurodegenerative disorders such as diabetes mellitus, cerebral ischemia, trauma, Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and tuberous sclerosis through programmed cell death pathways of apoptosis and autophagy can be the result of oxidant stress. Novel therapeutic avenues that focus upon the phosphoinositide 3-kinase (PI 3-K, Akt (protein kinase B, and the mammalian target of rapamycin (mTOR cascade and related pathways offer exciting prospects to address the onset and potential reversal of neurodegenerative disorders. Effective clinical translation of these pathways into robust therapeutic strategies requires intimate knowledge of the complexity of these pathways and the ability of this cascade to influence biological outcome that can vary among disorders of the nervous system.

  6. ALDH1B1 Is Crucial for Colon Tumorigenesis by Modulating Wnt/β-Catenin, Notch and PI3K/Akt Signaling Pathways.

    Directory of Open Access Journals (Sweden)

    Surendra Singh

    Full Text Available In the normal human colon, aldehyde dehydrogenase 1B1 (ALDH1B1 is expressed only at the crypt base, along with stem cells. It is also highly expressed in the human colonic adenocarcinomas. This pattern of expression corresponds closely to that observed for Wnt/β-catenin signaling activity. The present study examines the role of ALDH1B1 in colon tumorigenesis and signalling pathways mediating its effects. In a 3-dimensional spheroid growth model and a nude mouse xenograft tumor model, shRNA-induced suppression of ALDH1B1 expression decreased the number and size of spheroids formed in vitro and the size of xenograft tumors formed in vivo by SW 480 cells. Six binding elements for Wnt/β-catenin signalling transcription factor binding elements (T-cell factor/lymphoid enhancing factor were identified in the human ALDH1B1 gene promoter (3 kb but shown by dual luciferase reporter assay to not be necessary for ALDH1B1 mRNA expression in colon adenocarcinoma cell lines. We examined Wnt-reporter activity and protein/mRNA expression for Wnt, Notch and PI3K/Akt signaling pathways. Wnt/β-catenin, Notch and PI3K/Akt-signaling pathways were down-regulated in SW 480 cells in which ALDH1B1 expression had been suppressed. In summary, our data demonstrate that ALDH1B1 may promote colon cancer tumorigenesis by modulating the Wnt/β-catenin, Notch and PI3K/Akt signaling pathways. Selective targeting of ALDH1B1 may represent a novel means to prevent or treat colon cancer.

  7. Kushenin induces the apoptosis of HCV-infected cells by blocking the PI3K-Akt-mTOR pathway via inhibiting NS5A.

    Science.gov (United States)

    Zhou, Yi; Chen, Na; Liu, Xiaojing; Lin, Shumei; Luo, Wenjuan; Liu, Min

    2016-07-01

    With the increased burden induced by HCV, there is an urgent need to develop better-tolerated agents with good safety. In this study, we evaluated the anti-HCV capability of kushenin, as well as the possible mechanism to Huh7.5-HCV cells. The results demonstrated that kushenin significantly inhibited the HCV-RNA level. Similarly, the expression of HCV-specific protein NS5A was also decreased. Molecular docking results displayed that kushenin bonded well to the active pockets of HCV NS5A, further confirming the effects of kushenin on HCV replication. Coimmunoprecipitation assay determined that kushenin suppressed the interaction between PI3K and NS5A in HCV-replicon cells. Furthermore, kushenin exerted an obviously induced function on HCV-replicon cells apoptosis by inhibiting PI3K-Akt-mTOR pathway, which could be ameliorated by the specific activator IGF-1 addition. Taken together, kushenin possesses the ability to inhibit HCV replication, and contributes to the increased apoptosis of HCV-infected cells by blocking the PI3K-Akt-mTOR pathway via inhibiting NS5A. Our results provide important evidence for a better understanding of the pathogenesis of HCV infection, and suggest that kushenin has the potential to treat HCV disease.

  8. TDRG1 regulates chemosensitivity of seminoma TCam-2 cells to cisplatin via PI3K/Akt/mTOR signaling pathway and mitochondria-mediated apoptotic pathway.

    Science.gov (United States)

    Gan, Yu; Wang, Yong; Tan, Zhengyu; Zhou, Jun; Kitazawa, Riko; Jiang, Xianzhen; Tang, Yuxin; Yang, Jianfu

    2016-07-02

    We previously identified TDRG1 (testis developmental related gene 1), a novel gene with exclusive expression in testis, promoted the proliferation and progression of cultured human seminoma cells through PI3K/Akt/mTOR signaling. As increasing evidence reveal that aberrant activation of this signaling is involved in cisplatin resistance. Then, in this study, we further explored whether TDRG1 regulated the chemosensitivity of seminoma TCam-2 cells to cisplatin. Our researches showed TDRG1 could regulate the viability of TCam-2 cells following cisplatin treatment in vitro through control of both cell apoptosis and cell cycle. Mechanistically, we observed TDRG1 positively regulated the expression levels of the key elements in PI3K/Akt/mTOR pathway including p-PI3K, p-Akt and p-mTOR and also affected the translocation of nuclear p-Akt in TCam-2 cells during cisplatin treatment. Meanwhile, the levels of Bad, cytochrome c, caspase-9 ratio (activated/total), caspase-3 ratio (activated/total) and cleaved-PARP were negatively modulated by TDRG1, which meant the involvement of mitochondria-mediated apoptotic pathway. Furthermore, we found the effect of TDRG1 knockdown or TDRG1 overexpression could be reversed by IGF-1, a PI3K signaling activator, or LY294002, a inhibitor of this pathway, respectively. Similar effects of TDRG1 on cisplatin chemosensitivity and associated molecular mechanism were also confirmed in vivo by employing xenograft assays. In addition, the positive correlation between TDRG1 and p-PI3K, or p-Akt, was found in tumor tissues from seminoma patients. In conclusion, we uncover that TDRG1 regulates chemosensitivity of TCam-2 cells to cisplatin through PI3K/Akt/mTOR signaling and mitochondria-mediated apoptotic pathway both in vitro and in vivo.

  9. PI3K/Akt/mTOR signaling pathway and targeting therapy of skin cancer%PI3K/Akt/mTOR信号通路与皮肤肿瘤靶向治疗

    Institute of Scientific and Technical Information of China (English)

    李金超; 许爱娥

    2009-01-01

    P13K/AkdmTOR信号转导通路是促存活通路,在很多肿瘤中组成性激活.该通路激活的机制是肿瘤抑制基PTEN功能缺失、P13K扩增或突变、Akt扩增或突变.近年研究发现,该通路失常可促进肿瘤细胞的存活和生长,持续活化在皮肤肿瘤发病中起着重要的作用,已经发现抑制该通路中的信号分子可以治疗多种肿瘤,目前,针对该通路的抑制药物也在研究中,主要集中于mTOR抑制剂.%The PI3K/Akt/mTOR pathway is a prototypic survival pathway that is constitutively activated in various types of cancer. This pathway may be activated by function loss of tumor suppressor gene PTEN, amplification or mutation of PI3K and Akt genes. Recent studies have shown that the abnormality of PI3K/Akt/mTOR pathway may promote the survival and development of tumor cells, and continuous activation of this pathway is associated with the development of cutaneous tumors. It has been found that many tumors can be treated by inhibition of this pathway. Multiple inhibitors of this pathway have been developed and are being evaluated in laboratory and clinical trials, with much attention focused on mTOR inhibition.

  10. Salidroside improves behavioral and histological outcomes and reduces apoptosis via PI3K/Akt signaling after experimental traumatic brain injury.

    Science.gov (United States)

    Chen, Szu-Fu; Tsai, Hsin-Ju; Hung, Tai-Ho; Chen, Chien-Cheng; Lee, Chao Yu; Wu, Chun-Hu; Wang, Pei-Yi; Liao, Nien-Chieh

    2012-01-01

    Traumatic brain injury (TBI) induces a complex sequence of apopototic cascades that contribute to secondary tissue damage. The aim of this study was to investigate the effects of salidroside, a phenolic glycoside with potent anti-apoptotic properties, on behavioral and histological outcomes, brain edema, and apoptosis following experimental TBI and the possible involvement of the phosphoinositide 3-kinase/protein kinase B (PI3K)/Akt signaling pathway. Mice subjected to controlled cortical impact injury received intraperitoneal salidroside (20, or 50 mg/kg) or vehicle injection 10 min after injury. Behavioral studies, histology analysis and brain water content assessment were performed. Levels of PI3K/Akt signaling-related molecules, apoptosis-related proteins, cytochrome C (CytoC), and Smac/DIABLO were also analyzed. LY294002, a PI3K inhibitor, was administered to examine the mechanism of protection. The protective effect of salidroside was also investigated in primary cultured neurons subjected to stretch injury. Treatment with 20 mg/kg salidroside significantly improved functional recovery and reduced brain tissue damage up to post-injury day 28. Salidroside also significantly reduced neuronal death, apoptosis, and brain edema at day 1. These changes were associated with significant decreases in cleaved caspase-3, CytoC, and Smac/DIABLO at days 1 and 3. Salidroside increased phosphorylation of Akt on Ser473 and the mitochondrial Bcl-2/Bax ratio at day 1, and enhanced phosphorylation of Akt on Thr308 at day 3. This beneficial effect was abolished by pre-injection of LY294002. Moreover, delayed administration of salidroside at 3 or 6 h post-injury reduced neuronal damage at day 1. Salidroside treatment also decreased neuronal vulnerability to stretch-induced injury in vitro. Post-injury salidroside improved long-term behavioral and histological outcomes and reduced brain edema and apoptosis following TBI, at least partially via the PI3K/Akt signaling pathway.

  11. Selective inhibition of PI3K/Akt/mTOR signaling pathway regulates autophagy of macrophage and vulnerability of atherosclerotic plaque.

    Directory of Open Access Journals (Sweden)

    Chungang Zhai

    Full Text Available Macrophage infiltration contributes to the instability of atherosclerotic plaques. In the present study, we investigated whether selective inhibition of PI3K/Akt/mTOR signaling pathway can enhance the stability of atherosclerotic plaques by activation of macrophage autophagy. In vitro study, selective inhibitors or siRNA of PI3K/Akt/mTOR pathways were used to treat the rabbit's peritoneal primary macrophage cells. Inflammation related cytokines secreted by macrophages were measured. Ultrastructure changes of macrophages were examined by transmission electron microscope. mRNA or protein expression levels of autophagy related gene Beclin 1, protein 1 light chain 3 II dots (LC3-II or Atg5-Atg12 conjugation were assayed by quantitative RT-PCR or Western blot. In vivo study, vulnerable plaque models were established in 40 New Zealand White rabbits and then drugs or siRNA were given for 8 weeks to inhibit the PI3K/Akt/mTOR signaling pathway. Intravascular ultrasound (IVUS was performed to observe the plaque imaging. The ultrastructure of the abdominal aortic atherosclerosis lesions were analyzed with histopathology. RT-PCR or Western blot methods were used to measure the expression levels of corresponding autophagy related molecules. We found that macrophage autophagy was induced in the presence of Akt inhibitor, mTOR inhibitor and mTOR-siRNA in vitro study, while PI3K inhibitor had the opposite role. In vivo study, we found that macrophage autophagy increased significantly and the rabbits had lower plaque rupture incidence, lower plaque burden and decreased vulnerability index in the inhibitors or siRNA treated groups. We made a conclusion that selective inhibition of the Akt/mTOR signal pathway can reduce macrophages and stabilize the vulnerable atherosclerotic plaques by promoting macrophage autophagy.

  12. Reactive oxygen species mediate Cr(VI)-induced carcinogenesis through PI3K/AKT-dependent activation of GSK-3β/β-catenin signaling

    Energy Technology Data Exchange (ETDEWEB)

    Son, Young-Ok; Pratheeshkumar, Poyil; Wang, Lei; Wang, Xin; Fan, Jia; Kim, Dong-Hern; Lee, Ju-Yeon; Zhang, Zhuo [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Lee, Jeong-Chae [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); School of Dentistry and Institute of Oral Biosciences, Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin, E-mail: xshi5@email.uky.edu [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States)

    2013-09-01

    Cr(VI) compounds are known human carcinogens that primarily target the lungs. Cr(VI) produces reactive oxygen species (ROS), but the exact effects of ROS on the signaling molecules involved in Cr(VI)-induced carcinogenesis have not been extensively studied. Chronic exposure of human bronchial epithelial cells to Cr(VI) at nanomolar concentrations (10–100 nM) for 3 months not only induced cell transformation, but also increased the potential of these cells to invade and migrate. Injection of Cr(VI)-stimulated cells into nude mice resulted in the formation of tumors. Chronic exposure to Cr(VI) increased levels of intracellular ROS and antiapoptotic proteins. Transfection with catalase or superoxide dismutase (SOD) prevented Cr(VI)-mediated increases in colony formation, cell invasion, migration, and xenograft tumors. While chronic Cr(VI) exposure led to activation of signaling cascades involving PI3K/AKT/GSK-3β/β-catenin and PI3K/AKT/mTOR, transfection with catalase or SOD markedly inhibited Cr(VI)-mediated activation of these signaling proteins. Inhibitors specific for AKT or β-catenin almost completely suppressed the Cr(VI)-mediated increase in total and active β-catenin proteins and colony formation. In particular, Cr(VI) suppressed autophagy of epithelial cells under nutrition deprivation. Furthermore, there was a marked induction of AKT, GSK-3β, β-catenin, mTOR, and carcinogenic markers in tumor tissues formed in mice after injection with Cr(VI)-stimulated cells. Collectively, our findings suggest that ROS is a key mediator of Cr(VI)-induced carcinogenesis through the activation of PI3K/AKT-dependent GSK-3β/β-catenin signaling and the promotion of cell survival mechanisms via the inhibition of apoptosis and autophagy. - Highlights: • Chronic exposure to Cr(VI) induces carcinogenic properties in BEAS-2B cells. • ROS play an important role in Cr(VI)-induced tumorigenicity of BEAS-2B cells. • PI3K/AKT/GSK-3β/β-catenin signaling involved in Cr

  13. Hyperbaric oxygen protects mandibular condylar chondrocytes from interleukin-1β-induced apoptosis via the PI3K/AKT signaling pathway

    Science.gov (United States)

    Chen, Hang; Wu, Gaoyi; Sun, Qi; Dong, Yabing; Zhao, Huaqiang

    2016-01-01

    Objectives: Mandibular condylar chondrocyte apoptosis is mainly responsible for the development and progression of temporomandibular joint osteoarthritis (TMJ-OA). Interleukin-1β (IL-1β) generally serves an agent that induces chondrocyte apoptosis. Hyperbaric oxygen (HBO) treatment increases proteoglycan synthesis in vivo. We explore the protective effect of HBO on IL-1β-induced mandibular condylar chondrocyte apoptosis in rats and the potential molecular mechanisms. Methods: Chondrocytes were isolated from the TMJ of 3-4-week old Sprague-Dawley rats. The Cell Counting Kit-8 (CCK-8) assay was used to determine cell viability. The phosphorylated phosphoinositide-3 kinase (p-PI3K), phosphorylated AKT (p-Akt), type II collagen (COL2), and aggrecan (AGG) content was detected by immunofluorescence, immunocytochemistry and western blotting. The expression of Pi3k, Akt, Col2 and Agg mRNA was measured using real-time quantitative polymerase chain reaction (RT-qPCR). Results: HBO inhibited the cytotoxicity and apoptosis induced by IL-1β (10 ng/mL) in the mandibular condylar chondrocytes. HBO also decreased the IL-1β activity that decreased p-PI3K and p-AKT levels, and increased COL2 and AGG expression, with the net effect of suppressing extracellular matrix degradation. Conclusions: These data suggest that HBO may protect mandibular condylar chondrocytes against IL-1β-induced apoptosis via the PI3K/AKT signaling pathway, and that it may promote the expression of mandibular condylar chondrocyte extracellular matrix through the PI3K/AKT signaling pathway. PMID:27904712

  14. Inhibition of phospholipaseD2 increases hypoxia-induced human colon cancer cell apoptosis through inactivating of the PI3K/AKT signaling pathway.

    Science.gov (United States)

    Liu, Maoxi; Fu, Zhongxue; Wu, Xingye; Du, Kunli; Zhang, Shouru; Zeng, Li

    2016-05-01

    Hypoxia is a common feature of solid tumor, and is a direct stress that triggers apoptosis in many human cell types. As one of solid cancer, hypoxia exists in the whole course of colon cancer occurrence and progression. Our previous studies shown that hypoxia induce high expression of phospholipase D2 (PLD2) and survivin in colon cancer cells. However, the correlation between PLD2 and survivin in hypoxic colon cancer cells remains unknown. In this study, we observed significantly elevated PLD2 and survivin expression levels in colon cancer tissues and cells. This is a positive correlation between of them, and co-expression of PLD2 and survivin has a positive correlation with the clinicpatholic features including tumor size, TNM stage, and lymph node metastasis. We also found that hypoxia induced the activity of PLD increased significant mainly caused by PLD2 in colon cancer cells. However, inhibition the activity of PLD2 induced by hypoxia promotes the apoptosis of human colon cancer cells, as well as decreased the expression of apoptosis markers including survivin and bcl2. Moreover, the pharmacological inhibition of PI3K/AKT supported the hypothesis that promotes the apoptosis of hypoxic colon cancer cells by PLD2 activity inhibition may through inactivation of the PI3K/AKT signaling pathway. Furthermore, interference the PLD2 gene expression leaded to the apoptosis of hypoxic colon cancer cells increased and also decreased the expression level of survivin and bcl2 may through inactivation of PI3K/AKT signaling pathway. These results indicated that PLD2 play antiapoptotic role in colon cancer under hypoxic conditions, inhibition of the activity, or interference of PLD2 gene expression will benefit for the treatment of colon cancer patients.

  15. Pro-inflammatory cytokine-driven PI3K/Akt/Sp1 signalling and H2S production facilitates the pathogenesis of severe acute pancreatitis.

    Science.gov (United States)

    Liu, Ying; Liao, Ribin; Qiang, Zhanrong; Zhang, Cheng

    2017-04-30

    Severe acute pancreatitis (SAP) is a disease usually associated with systemic organ dysfunction or pancreatic necrosis. Most patients with SAP suffer from defective intestinal motility in the early phase of the disease. Additionally, SAP-induced inflammation produces hydrogen sulphide (H2S) that impairs the gastrointestinal (GI) system. However, the exact mechanism of H2S in the regulation of SAP is yet to be elucidated. In the present paper, we used a rat model of SAP to evaluate the role of H2S on intestinal motility by counting the number of bowel movements and investigating the effect of H2S on inflammation. We treated colonic muscle cells (CMCs) with SAP plasma, tumour necrosis factor-α (TNF-α) or interleukin-6 (IL-6) and measured the expressions of H2S-producing enzymes cystathionine-γ-lyase (CSE), cystathionine-β-synthase (CBS) and Sp1 and PI3K/Akt by using quantitative PCR, Western blotting and immunohistochemical detection. We used the PI3K inhibitor LY294002 and the siRNA si-Sp1 to suppress the activity of the PI3K/Akt/Sp1 signalling pathway. We found that, in the SAP rat model, H2S facilitated an inhibitory effect on intestinal motility and enhanced the inflammatory response caused by SAP (PH2S plays a vital role in the pathogenesis of SAP and that SAP is modulated by inflammation driven by the PI3K/Akt/Sp1 signalling pathway. © 2017 The Author(s).

  16. Twist promotes reprogramming of glucose metabolism in breast cancer cells through PI3K/AKT and p53 signaling pathways.

    Science.gov (United States)

    Yang, Li; Hou, Yixuan; Yuan, Jie; Tang, Shifu; Zhang, Hailong; Zhu, Qing; Du, Yan-e; Zhou, Mingli; Wen, Siyang; Xu, Liyun; Tang, Xi; Cui, Xiaojiang; Liu, Manran

    2015-09-22

    Twist, a key regulator of epithelial-mesenchymal transition (EMT), plays an important role in the development of a tumorigenic phenotype. Energy metabolism reprogramming (EMR), a newly discovered hallmark of cancer cells, potentiates cancer cell proliferation, survival, and invasion. Currently little is known about the effects of Twist on tumor EMR. In this study, we found that glucose consumption and lactate production were increased and mitochondrial mass was decreased in Twist-overexpressing MCF10A mammary epithelial cells compared with vector-expressing MCF10A cells. Moreover, these Twist-induced phenotypic changes were augmented by hypoxia. The expression of some glucose metabolism-related genes such as PKM2, LDHA, and G6PD was also found to be upregulated. Mechanistically, activated β1-integrin/FAK/PI3K/AKT/mTOR and suppressed P53 signaling were responsible for the observed EMR. Knockdown of Twist reversed the effects of Twist on EMR in Twist-overexpressing MCF10A cells and Twist-positive breast cancer cells. Furthermore, blockage of the β1-integrin/FAK/PI3K/AKT/mTOR pathway by siRNA or specific chemical inhibitors, or rescue of p53 activation can partially reverse the switch of glucose metabolism and inhibit the migration of Twist-overexpressing MCF10A cells and Twist-positive breast cancer cells. Thus, our data suggest that Twist promotes reprogramming of glucose metabolism in MCF10A-Twist cells and Twist-positive breast cancer cells via activation of the β1-integrin/FAK/PI3K/AKT/mTOR pathway and inhibition of the p53 pathway. Our study provides new insight into EMR.

  17. PAR1- and PAR2-induced innate immune markers are negatively regulated by PI3K/Akt signaling pathway in oral keratinocytes

    Directory of Open Access Journals (Sweden)

    Dale Beverly A

    2010-10-01

    Full Text Available Abstract Background Protease-Activated Receptors (PARs, members of G-protein-coupled receptors, are activated by proteolytic activity of various proteases. Activation of PAR1 and PAR2 triggers innate immune responses in human oral keratinocytes (HOKs, but the signaling pathways downstream of PAR activation in HOKs have not been clearly defined. In this study, we aimed to determine if PAR1- and PAR2-mediated signaling differs in the induction of innate immune markers CXCL3, CXCL5 and CCL20 via ERK, p38 and PI3K/Akt. Results Our data show the induction of innate immunity by PAR1 requires both p38 and ERK MAP kinases, while PAR2 prominently signals via p38. However, inhibition of PI3K enhances expression of innate immune markers predominantly via suppressing p38 phosphorylation signaled by PAR activation. Conclusion Our data indicate that proteases mediating PAR1 and PAR2 activation differentially signal via MAP kinase cascades. In addition, the production of chemokines induced by PAR1 and PAR2 is suppressed by PI3K/Akt, thus keeping the innate immune responses of HOK in balance. The results of our study provide a novel insight into signaling pathways involved in PAR activation.

  18. DNA Synthesis during Endomitosis Is Stimulated by Insulin via the PI3K/Akt and TOR Signaling Pathways in the Silk Gland Cells of Bombyx mori

    Directory of Open Access Journals (Sweden)

    Yaofeng Li

    2015-03-01

    Full Text Available Silk gland cells undergo multiple endomitotic cell cycles during silkworm larval ontogeny. Our previous study demonstrated that feeding is required for continued endomitosis in the silk gland cells of silkworm larvae. Furthermore, the insulin signaling pathway is closely related to nutritional signals. To investigate whether the insulin signaling pathway is involved in endomitosis in silk gland cells, in this study, we initially analyzed the effects of bovine insulin on DNA synthesis in endomitotic silk gland cells using 5-bromo-2'-deoxyuridine (BrdU labeling technology, and found that bovine insulin can stimulate DNA synthesis. Insulin signal transduction is mainly mediated via phosphoinositide 3-kinase (PI3K/Akt, the target of rapamycin (TOR and the extracellular signal-regulated kinase (ERK pathways in vertebrates. We ascertained that these three pathways are involved in DNA synthesis in endomitotic silk gland cells using specific inhibitors against each pathway. Moreover, we investigated whether these three pathways are involved in insulin-stimulated DNA synthesis in endomitotic silk gland cells, and found that the PI3K/Akt and TOR pathways, but not the ERK pathway, are involved in this process. These results provide an important theoretical foundation for the further investigations of the mechanism underlying efficient endomitosis in silk gland cells.

  19. Long noncoding RNA HULC promotes cell proliferation by regulating PI3K/AKT signaling pathway in chronic myeloid leukemia.

    Science.gov (United States)

    Lu, Yinghao; Li, Yan; Chai, Xiao; Kang, Qian; Zhao, Peng; Xiong, Jie; Wang, Jishi

    2017-04-05

    Aberrant expression of long noncoding RNA (lncRNA) HULC is associated with various human cancers. However, the role of HULC in chronic myeloid leukemia (CML) is unknown. In this study, we found that HULC was remarkably overexpressed in both leukemia cell lines and primary hematopoietic cells derived from CML patients. The increase in HULC expression was positively correlated with clinical stages in CML. Moreover, the knockdown of HULC significantly inhibited CML cell proliferation and induced apoptosis by repressing c-Myc and Bcl-2. Furthermore, inhibition of HULC enhanced imatinib-induced apoptosis of CML cells. Further experiments demonstrated that HULC silencing markedly suppressed the phosphorylation of PI3K and AKT, indicating that enhancement of imatinib-induced apoptosis by HULC inhibition is related with the reduction of c-Myc expression and inhibition of PI3K/Akt pathway activity. Furthermore, HULC could modulate c-Myc and Bcl-2 by miR-200a as an endogenous sponge. Taken together, these results reveal that HULC promotes oncogenesis in CML and suggest a potential strategy for the CML treatment.

  20. Development of PI3K/AKT/mTOR signaling pathway and hypofractionated radiotherapy in non-small cell lung cancer%非小细胞肺癌大分割放疗敏感性与PI3K/AKT/mTOR信号通路研究进展*

    Institute of Scientific and Technical Information of China (English)

    刘宁波(综述); 王平(审校)

    2013-01-01

    常规分割放疗在中晚期非小细胞肺癌治疗中疗效有限,大分割放疗地位越来越重要,但仍有相当部分肿瘤细胞具有放射线抗拒,其分子机制未明。PI3K/AKT/mTOR信号通路与非小细胞肺癌常规分割放疗抗拒有关,但与大分割放疗抗拒关系尚未明确。调控PI3K/AKT/mTOR信号通路的基因表达及蛋白磷酸化水平有望增加NSCLC肿瘤细胞对大分割放疗的敏感性,并可能达到逆转放疗抗拒的效果;在PI3K/AKT/mTOR信号通路的诸多基因中,有望从临床样本中筛选获得预测NSCLC大分割放疗疗效的分子标记。%Radiotherapy is a primary treatment for lung cancer, especially for non-small cell lung cancer (NSCLC). Compared with conventional fractionated radiotherapy, hypofractionated radiotherapy (HFRT) is a powerful method in NSCLC treatment because of its convenience and excellent clinical efficacy. Although HFRT has been significantly developed for treating NSCLC, radiation resistance with an unknown molecular mechanism is still observed in tumors. The PI3K/AKT/mTOR signaling pathway significantly affects resistance to conventional fractionated radiotherapy. However, whether this pathway induces radiation resistance to HFRT remains unclear. The underlying molecular mechanisms between HFRT and the PI3K/AKT/mTOR signal pathway may be used as targets in radiation sensitivity or in the modification of radiation resistance in NSCLC patients. New predictive biomarkers can also be expected in the PI3K/AKT/mTOR signaling pathway when the clinical specimen is screened using HFRT.

  1. Si Shen Wan Regulates Phospholipase Cγ-1 and PI3K/Akt Signal in Colonic Mucosa from Rats with Colitis

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    Duan-yong Liu

    2015-01-01

    Full Text Available The present study explored the feasible pathway of Si Shen Wan (SSW in inhibiting apoptosis of intestinal epithelial cells (IECs by observing activation of phospholipase Cγ-1 (PLC-γ1 and PI3K/Akt signal in colonic mucosa from rats with colitis. Experimental colitis was induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS in the Sprague-Dawley rats. After SSW was administrated for 7 days after TNBS infusion, western blot showed an increment in levels of PI3K, p-Akt, and IL-23 and a decrement in levels of PLC-γ1 and HSP70 in colonic mucosal injury induced by TNBS. Meanwhile, assessments by ELISA revealed an increment in concentrations of IL-2, IL-6, and IL-17 and a reduction in level of TGF-β after TNBS challenge. Impressively, treatment with SSW for 7 days significantly attenuated the expressions of PI3K and p-Akt and the secretion of IL-2, IL-6, IL-17, and IL-23 and promoted the activation of PLC-γ1, HSP70, and TGF-β. Our previous studies had demonstrated that SSW restored colonic mucosal ulcers by inhibiting apoptosis of IECs. The present study demonstrated that the effect of SSW on inhibiting apoptosis of IECs was realized probably by activation of PLC-γ1 and suppression of PI3K/Akt signal pathway.

  2. Sinulariolide Suppresses Human Hepatocellular Carcinoma Cell Migration and Invasion by Inhibiting Matrix Metalloproteinase-2/-9 through MAPKs and PI3K/Akt Signaling Pathways.

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    Wu, Yu-Jen; Neoh, Choo-Aun; Tsao, Chia-Yu; Su, Jui-Hsin; Li, Hsing-Hui

    2015-07-20

    Sinulariolide is an active compound isolated from the cultured soft coral Sinularia flexibilis. In this study, we investigate the migration and invasion effects of sinulariolide in hepatocellular carcinoma cell HA22T. Sinulariolide inhibited the migration and invasion effects of hepatocellular carcinoma cells in a concentration-dependent manner. The results of zymography assay showed that sinulariolide suppressed the activities of matrix metalloproteinase (MMP)-2 and MMP-9. Moreover, protein levels of MMP-2, MMP-9, and urokinase-type plasminogen activator (uPA) were reduced by sinulariolide in a concentration-dependent manner. Sinulariolide also exerted an inhibitory effect on phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinases (ERK), phosphatidylinositol 3-kinase (PI3K), Akt, Focal adhesion kinase (FAK), growth factor receptor-bound protein 2 (GRB2). Taken together, these results demonstrated that sinulariolide could inhibit hepatocellular carcinoma cell migration and invasion and alter HA22T cell metastasis by reduction of MMP-2, MMP-9, and uPA expression through the suppression of MAPKs, PI3K/Akt, and the FAK/GRB2 signaling pathway. These findings suggest that sinulariolide merits further evaluation as a chemotherapeutic agent for human hepatocellular carcinoma.

  3. Co-Inhibition of GLUT-1 Expression and the PI3K/Akt Signaling Pathway to Enhance the Radiosensitivity of Laryngeal Carcinoma Xenografts In Vivo.

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    Luo, Xing-Mei; Xu, Bin; Zhou, Min-Li; Bao, Yang-Yang; Zhou, Shui-Hong; Fan, Jun; Lu, Zhong-Jie

    2015-01-01

    In the present study, we investigated the role of GLUT-1 and PI3K/Akt signaling in radioresistance of laryngeal carcinoma xenografts. Volume, weight, radiosensitization, and the rate of inhibition of tumor growth in the xenografts were evaluated in different groups. Apoptosis was evaluated by TUNEL assay. In addition, mRNA and protein levels of GLUT-1, p-Akt, and PI3K in the xenografts were measured. Treatment with LY294002, wortmannin, wortmannin plus GLUT-1 AS-ODN, and LY294002 plus GLUT-1 AS-ODN after X-ray irradiation significantly reduced the size and weight of the tumors, rate of tumor growth, and apoptosis in tumors compared to that observed in the 10-Gy group (pGLUT-1, p-Akt, and PI3K was downregulated. The E/O values of LY294002, LY294002 plus GLUT-1 AS-ODN, wortmannin, and wortmannin plus GLUT-1 AS-ODN were 2.7, 1.1, 1.8, and 1.8, respectively. Taken together, these data indicate that GLUT-1 AS-ODN as well as the inhibitors of PI3K/Akt signaling may act as radiosensitizers of laryngeal carcinoma in vivo.

  4. Interleukin-21 promotes osteoclastogenesis in RAW264.7 cells through the PI3K/AKT signaling pathway independently of RANKL

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    Xing, Rui; Zhang, Yingjian; Li, Changhong; Sun, Lin; Yang, Lin; Zhao, Jinxia; Liu, Xiangyuan

    2016-01-01

    Cytokines play a key role in the bone destruction of rheumatoid arthritis (RA). Interleukin-21 (IL-21) promotes osteoclastogenesis in RA in a receptor activator of nuclear factor-κB ligand (RANKL)-dependent way. Whether IL-21 is capable of promoting osteoclastogenesis directly in the absence of RANKL remains unknown. In the present study, we examined the osteoclastogenic activity of IL-21 in RAW264.7 cells in the absence of RANKL. We found that IL-21 enhanced osteoclastogenesis and this was demonstrated by increased numbers of tartrate-resistant acid phosphatase (TRAP)-positive stained, multinucleated cells compared with the negative control. Western blot analysis and immunocytochemistry showed the positive expression of calcitonin receptor (CTR) in the IL-21 group. RT-PCR and RT-qPCR also verified the increased mRNA expression of CTR and cathepsin K in the IL-21 group compared with the negative control. The scanning electronic microscope images showed a few resorption pits on the bone slices cultured with IL-21. The phosphoinositide 3-kinase (PI3K)/AKT pathway inhibitor LY294002 significantly suppressed IL-21-induced osteoclastogenesis. Taken together, these findings suggest that IL-21 has direct osteoclastogenic potential independently of RANKL. IL-21 may promote osteoclastogenesis through the PI3K/AKT signaling pathway. Therapy targeting IL-21 may be of value in preventing bone erosions in patients with RA. PMID:27599586

  5. Inhibition of c-Met activation sensitizes osteosarcoma cells to cisplatin via suppression of the PI3K-Akt signaling.

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    Wang, Kelai; Zhuang, Yan; Liu, Chunlan; Li, Yang

    2012-10-01

    Osteosarcoma is a common malignant bone tumor. Cisplatin (CDDP) achieves a high response rate in osteosarcoma. However, osteosarcoma usually exhibits cisplatin resistance. Many members of receptor tyrosine kinases (RTKs)(1) have been demonstrated to be overexpressed and constitutively activated in various tumors including osteosarcoma, resulting in malignant progression and insensitivity to chemotherapy. Hepatocyte growth factor receptor (HGFR/c-Met) also appears overexpressed and activated in osteosarcoma cells. Nevertheless, which role of c-Met activation in cisplatin efficacy against osteosarcoma cells remains still elusive. This study found that inhibition of c-Met activity by PHA-665752 or blockade of the interaction of autocrined HGF with c-Met with neutralizing anti-HGF antibody promoted cisplatin efficacy in osteosarcoma cells, while addition of recombinant human HGF (rh-HGF) counteracts cisplatin cytotoxicity. Specifically, we demonstrated that inhibition of c-Met activity led to suppression of the PI3K-Akt pathway, thus enhancing cisplatin chemosensitivity. Our study clearly suggests that inhibition of c-Met activity can effectively sensitize osteosarcoma cells to cisplatin via suppression of the PI3K-Akt signaling.

  6. Fisetin, a dietary flavonoid induces apoptosis via modulating the MAPK and PI3K/Akt signalling pathways in human osteosarcoma (U-2 OS cells

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    Jian-Ming Li

    2015-12-01

    Full Text Available Human osteosarcoma is the most prevalent primary malignant bone tumor with high frequency of invasion and metastasis. Strong resistance coupled with toxicity of the currently available chemotherapeutic drugs poses challenge in treatment. The study aimed to investigate if fisetin, a dietary flavonoid induced apoptosis in human osteosarcoma (U-2 OS cells. Fisetin at 20-100 µM effectively reduced the viability of OS cells, and induced apoptosis by significantly inducing the expression of caspases (Caspases- 3,-8 and -9 and pro-apoptotic proteins (Bax and Bad with subsequent down-regulation of Bcl-xL and Bcl-2. While fisetin inhibited PI3K/Akt pathway and ERK1/2, it caused enhanced expressions of p-JNK, p-c-Jun and p-p38. Fisetin-induced ROS generation and decrease in mitochondrial membrane potential would have also contributed to rise in apoptotic cell counts. The observations suggest that fisetin was able to effectively induce apoptosis of U-2 OS cells through ROS generation and modulation of MAPK and PI3K/Akt signalling cascades.

  7. Gedunin abrogates aldose reductase, PI3K/Akt/mToR, and NF-κB signaling pathways to inhibit angiogenesis in a hamster model of oral carcinogenesis.

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    Kishore T, Kranthi Kiran; Ganugula, Raghu; Gade, Deepak Reddy; Reddy, Geereddy Bhanuprakash; Nagini, Siddavaram

    2016-02-01

    Aberrant activation of oncogenic signaling pathways plays a central role in tumor development and progression. The aim of this present study was to investigate the chemopreventive effects of the neem limonoid gedunin in the hamster model of oral cancer based on its ability to modulate aldose reductase (AR), phosphatidyl inositol-3-kinase (PI3K)/Akt, and nuclear factor kappa B (NF-κB) pathways to block angiogenesis. Administration of gedunin suppressed the development of HBP carcinomas by inhibiting PI3K/Akt and NF-κB pathways through the inactivation of Akt and inhibitory kappa B kinase (IKK), respectively. Immunoblot and molecular docking interactions revealed that inhibition of these signaling pathways may be mediated via inactivation of AR by gedunin. Gedunin blocked angiogenesis by downregulating the expression of miR-21 and the pro-angiogenic factors vascular endothelial growth factor and hypoxia inducible factor-1 alpha (HIF-1α). In conclusion, the results of the present study provide compelling evidence that gedunin prevents progression of hamster buccal pouch (HBP) carcinomas via inhibition of the kinases Akt, IKK, and AR, and the oncogenic transcription factors NF-κB and HIF-1α to block angiogenesis.

  8. Camptothecin inhibits platelet-derived growth factor-BB-induced proliferation of rat aortic vascular smooth muscle cells through inhibition of PI3K/Akt signaling pathway

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    Park, Eun-Seok [Department of Applied Biochemistry, Division of Life Science, College of Health and Biomedical Science, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Kang, Shin-il [College of Pharmacy Medical Research Center, Chungbuk National University, Cheongju (Korea, Republic of); Yoo, Kyu-dong [Hazardous Substances Analysis Division, Gwangju Regional Food and Drug Administration, Gwangju (Korea, Republic of); Lee, Mi-Yea [Department of Nursing Kyungbok University, Pocheon (Korea, Republic of); Yoo, Hwan-Soo; Hong, Jin-Tae [College of Pharmacy Medical Research Center, Chungbuk National University, Cheongju (Korea, Republic of); Shin, Hwa-Sup [Department of Applied Biochemistry, Division of Life Science, College of Health and Biomedical Science, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Kim, Bokyung [Department of Physiology, Konkuk Medical School, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Yun, Yeo-Pyo, E-mail: ypyun@chungbuk.ac.kr [College of Pharmacy Medical Research Center, Chungbuk National University, Cheongju (Korea, Republic of)

    2013-04-15

    The abnormal proliferation of vascular smooth muscle cells (VSMCs) in arterial wall is a major cause of vascular disorders such as atherosclerosis and restenosis after angioplasty. In this study, we investigated not only the inhibitory effects of camptothecin (CPT) on PDGF-BB-induced VSMC proliferation, but also its molecular mechanism of this inhibition. CPT significantly inhibited proliferation with IC50 value of 0.58 μM and the DNA synthesis of PDGF-BB-stimulated VSMCs in a dose-dependent manner (0.5–2 μM ) without any cytotoxicity. CPT induced the cell cycle arrest at G0/G1 phase. Also, CPT decreased the expressions of G0/G1-specific regulatory proteins including cyclin-dependent kinase (CDK)2, cyclin D1 and PCNA in PDGF-BB-stimulated VSMCs. Pre-incubation of VSMCs with CPT significantly inhibited PDGF-BB-induced Akt activation, whereas CPT did not affect PDGF-receptor beta phosphorylation, extracellular signal-regulated kinase (ERK) 1/2 phosphorylation and phospholipase C (PLC)-γ1 phosphorylation in PDGF-BB signaling pathway. Our data showed that CPT pre-treatment inhibited VSMC proliferation, and that the inhibitory effect of CPT was enhanced by LY294002, a PI3K inhibitor, on PDGF-BB-induced VSMC proliferation. In addition, inhibiting the PI3K/Akt pathway by LY294002 significantly enhanced the suppression of PCNA expression and Akt activation by CPT. These results suggest that the anti-proliferative activity of CPT is mediated in part by downregulating the PI3K/Akt signaling pathway. - Highlights: ► CPT inhibits proliferation of PDGF-BB-induced VSMC without cytotoxicity. ► CPT arrests the cell cycle in G0/G1 phase by downregulation of cyclin D1 and CDK2. ► CPT significantly attenuates Akt phosphorylation in PDGF-BB signaling pathway. ► LY294002 enhanced the inhibitory effect of CPT on VSMC proliferation. ► Thus, CPT is mediated by downregulating the PI3K/Akt signaling pathway.

  9. Salidroside improves behavioral and histological outcomes and reduces apoptosis via PI3K/Akt signaling after experimental traumatic brain injury.

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    Szu-Fu Chen

    Full Text Available BACKGROUND: Traumatic brain injury (TBI induces a complex sequence of apopototic cascades that contribute to secondary tissue damage. The aim of this study was to investigate the effects of salidroside, a phenolic glycoside with potent anti-apoptotic properties, on behavioral and histological outcomes, brain edema, and apoptosis following experimental TBI and the possible involvement of the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt signaling pathway. METHODOLOGY/PRINCIPAL FINDINGS: Mice subjected to controlled cortical impact injury received intraperitoneal salidroside (20, or 50 mg/kg or vehicle injection 10 min after injury. Behavioral studies, histology analysis and brain water content assessment were performed. Levels of PI3K/Akt signaling-related molecules, apoptosis-related proteins, cytochrome C (CytoC, and Smac/DIABLO were also analyzed. LY294002, a PI3K inhibitor, was administered to examine the mechanism of protection. The protective effect of salidroside was also investigated in primary cultured neurons subjected to stretch injury. Treatment with 20 mg/kg salidroside significantly improved functional recovery and reduced brain tissue damage up to post-injury day 28. Salidroside also significantly reduced neuronal death, apoptosis, and brain edema at day 1. These changes were associated with significant decreases in cleaved caspase-3, CytoC, and Smac/DIABLO at days 1 and 3. Salidroside increased phosphorylation of Akt on Ser473 and the mitochondrial Bcl-2/Bax ratio at day 1, and enhanced phosphorylation of Akt on Thr308 at day 3. This beneficial effect was abolished by pre-injection of LY294002. Moreover, delayed administration of salidroside at 3 or 6 h post-injury reduced neuronal damage at day 1. Salidroside treatment also decreased neuronal vulnerability to stretch-induced injury in vitro. CONCLUSIONS/SIGNIFICANCE: Post-injury salidroside improved long-term behavioral and histological outcomes and reduced brain edema and

  10. Protease-activated receptor-2 promotes kidney tubular epithelial inflammation by inhibiting autophagy via the PI3K/Akt/mTOR signalling pathway.

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    Du, Chunyang; Zhang, Tao; Xiao, Xia; Shi, Yonghong; Duan, Huijun; Ren, Yunzhuo

    2017-08-02

    Protease-activated receptor-2 (PAR2), which belongs to a specific class of the G-protein-coupled receptors, is central to several inflammation processes. However, the precise molecular mechanism involved remains undefined. Autophagy has been previously shown to affect inflammation. In the present study, we examine the effect of PAR2 on kidney tubular epithelial autophagy and on autophagy-related inflammation and reveal the underlying mechanism involved. Autophagic activity and levels of autophagic marker LC3 were examined in human kidney tubular epithelial cells with PAR2 knockdown or overexpression. We administered the mammalian target of rapamycin (mTOR) inhibitor (rapamycin) or activator (MHY1485) to investigate the function of the phosphoinositide 3-kinase (PI3K)/Akt/mTOR pathway. We also used transforming growth factor-β1 (TGF-β1)-induced HK-2 cell inflammation models to investigate the role of PAR2-associated autophagy in kidney tubular epithelial inflammation. PAR2 antagonist and rapamycin were administered to mice after unilateral ureteral obstruction to detect the correlations between PAR2, autophagy, and inflammation. Our results show that PAR2 overexpression in HK-2 cells led to a greater reduction in autophagy via the PI3K/Akt/mTOR pathway activation and induces autophagy-related inflammation. Meanwhile, a knockdown of PAR2 via PAR2 RNAi transfection greatly increased autophagy and alleviated autophagy-associated inflammation. In unilateral ureteral obstruction (UUO) kidneys, PAR2 antagonist treatment greatly attenuated renal inflammation and interstitial injury by enhancing autophagy. Moreover, inhibition of mTOR, rapa, markedly increased autophagy and inhibited the UUO-induced inflammation. We conclude that PAR2 induces kidney tubular epithelial inflammation by inhibiting autophagy via the PI3K/Akt/mTOR signalling pathway. Our results are suggestive that PAR2 inhibition may play a role in the treatment of diseases with increased inflammatory

  11. Biphasic activation of PI3K/Akt and MAPK/Erk1/2 signaling pathways in bovine herpesvirus type 1 infection of MDBK cells

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    Zhu Liqian

    2011-04-01

    Full Text Available Abstract Many viruses have been known to control key cellular signaling pathways to facilitate the virus infection. The possible involvement of signaling pathways in bovine herpesvirus type 1 (BoHV-1 infection is unknown. This study indicated that infection of MDBK cells with BoHV-1 induced an early-stage transient and a late-stage sustained activation of both phosphatidylinositol 3-kinase (PI3K/Akt and mitogen activated protein kinases/extracellular signal-regulated kinase 1/2 (MAPK/Erk1/2 signaling pathways. Analysis with the stimulation of UV-irradiated virus indicated that the virus binding and/or entry process was enough to trigger the early phase activations, while the late phase activations were viral protein expression dependent. Biphasic activation of both pathways was suppressed by the selective inhibitor, Ly294002 for PI3K and U0126 for MAPK kinase (MEK1/2, respectively. Furthermore, treatment of MDBK cells with Ly294002 caused a 1.5-log reduction in virus titer, while U0126 had little effect on the virus production. In addition, the inhibition effect of Ly294002 mainly occurred at the post-entry stage of the virus replication cycle. This revealed for the first time that BoHV-1 actively induced both PI3K/Akt and MAPK/Erk1/2 signaling pathways, and the activation of PI3K was important for fully efficient replication, especially for the post-entry stage.

  12. Anti-fibrotic actions of interleukin-10 against hypertrophic scarring by activation of PI3K/AKT and STAT3 signaling pathways in scar-forming fibroblasts.

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    Jihong Shi

    inhibits fibrosis by activating AKT and STAT3 phosphorylation downstream of the IL-10 receptor, and by facilitating crosstalk between the PI3K/AKT and STAT3 signal transduction pathways.

  13. Nontranscriptional activation of PI3K/Akt signaling mediates hypotensive effect following activation of estrogen receptor β in the rostral ventrolateral medulla of rats

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    Wu Kay LH

    2012-08-01

    Full Text Available Abstract Background Estrogen acts on the rostral ventrolateral medulla (RVLM, where sympathetic premotor neurons are located, to elicit vasodepressor effects via an estrogen receptor (ERβ-dependent mechanism. We investigated in the present study nontranscriptional mechanism on cardiovascular effects following activation of ERβ in the RVLM, and delineated the involvement of phosphatidylinositol 3-kinase (PI3K/serine/threonine kinase (Akt signaling pathway in the effects. Methods In male Sprague–Dawley rats maintained under propofol anesthesia, changes in arterial pressure, heart rate and sympathetic neurogenic vasomotor tone were examined after microinjection bilaterally into RVLM of 17β-estradiol (E2β or a selective ERα or ERβ agonist. Involvement of ER subtypes and PI3K/Akt signaling pathway in the induced cardiovascular effects were studied using pharmacological tools of antagonists or inhibitors, gene manipulation with antisense oligonucleotide (ASON or adenovirus-mediated gene transfection. Results Similar to E2β (1 pmol, microinjection of ERβ agonist, diarylpropionitrile (DPN, 1, 2 or 5 pmol, into bilateral RVLM evoked dose-dependent hypotension and reduction in sympathetic neurogenic vasomotor tone. These vasodepressive effects of DPN (2 pmol were inhibited by ERβ antagonist, R,R-tetrahydrochrysene (50 pmol, ASON against ERβ mRNA (250 pmol, PI3K inhibitor LY294002 (5 pmol, or Akt inhibitor (250 pmol, but not by ERα inhibitor, methyl-piperidino-pyrazole (1 nmol, or transcription inhibitor, actinomycin D (5 or 10 nmol. Gene transfer by microinjection into bilateral RVLM of adenovirus encoding phosphatase and tensin homologues deleted on chromosome 10 (5 × 108 pfu reversed the vasodepressive effects of DPN. Conclusions Our results indicate that vasodepressive effects following activation of ERβ in RVLM are mediated by nongenomic activation of PI3K/Akt signaling pathway. This study provides new insight in the

  14. Participation of the PI-3K/Akt-NF-κB signaling pathways in hypoxia-induced mitogenic factor-stimulated Flk-1 expression in endothelial cells

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    Huang Chuanshu

    2006-07-01

    Full Text Available Abstract Background Hypoxia-induced mitogenic factor (HIMF, a lung-specific growth factor, promotes vascular tubule formation in a matrigel plug model. We initially found that HIMF enhances vascular endothelial growth factor (VEGF expression in lung epithelial cells. In present work, we tested whether HIMF modulates expression of fetal liver kinase-1 (Flk-1 in endothelial cells, and dissected the possible signaling pathways that link HIMF to Flk-1 upregulation. Methods Recombinant HIMF protein was intratracheally instilled into adult mouse lungs, Flk-1 expression was examined by immunohistochemistry and Western blot. The promoter-luciferase reporter assay and real-time RT-PCR were performed to examine the effects of HIMF on Flk-1 expression in mouse endothelial cell line SVEC 4–10. The activation of NF-kappa B (NF-κB and phosphorylation of Akt, IKK, and IκBα were examined by luciferase assay and Western blot, respectively. Results Intratracheal instillation of HIMF protein resulted in a significant increase of Flk-1 production in lung tissues. Stimulation of SVEC 4–10 cells by HIMF resulted in increased phosphorylation of IKK and IκBα, leading to activation of NF-κB. Blocking NF-κB signaling pathway by dominant-negative mutants of IKK and IκBα suppressed HIMF-induced Flk-1 upregulation. Mutation or deletion of NF-κB binding site within Flk-1 promoter also abolished HIMF-induced Flk-1 expression in SVEC 4–10 cells. Furthermore, HIMF strongly induced phosphorylation of Akt. A dominant-negative mutant of PI-3K, Δp85, as well as PI-3K inhibitor LY294002, blocked HIMF-induced NF-κB activation and attenuated Flk-1 production. Conclusion These results suggest that HIMF upregulates Flk-1 expression in endothelial cells in a PI-3K/Akt-NF-κB signaling pathway-dependent manner, and may play critical roles in pulmonary angiogenesis.

  15. Anti-diabetic effect of citrus pectin in diabetic rats and potential mechanism via PI3K/Akt signaling pathway.

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    Liu, Yanlong; Dong, Man; Yang, Ziyu; Pan, Siyi

    2016-08-01

    This study was performed to investigate the anti-diabetic effect of citrus pectin in type 2 diabetic rats and its potential mechanism of action. The results showed that fasting blood glucose levels were significantly decreased after 4 weeks of citrus pectin administration. Citrus pectin improved glucose tolerance, hepatic glycogen content and blood lipid levels (TG, TC, LDL-c and HDL-c) in diabetic rats. Citrus pectin also significantly reduced insulin resistance, which played an important role in the resulting anti-diabetic effect. Moreover, after the pectin treatment, phosphorylated Akt expression was upregulated and GSK3β expression was downregulated, indicating that the potential anti-diabetic mechanism of citrus pectin might occur through regulation of the PI3K/Akt signaling pathway. Together, these results suggested that citrus pectin could ameliorate type 2 diabetes and potentially be used as an adjuvant treatment.

  16. PI3K/Akt Signaling Pathway Activates the WNK-OSR1/SPAK-NCC Phosphorylation Cascade in Hyperinsulinemic db/db Mice

    Science.gov (United States)

    Nishida, Hidenori; Sohara, Eisei; Nomura, Naohiro; Chiga, Motoko; Alessi, Dario R; Rai, Tatemitsu; Sasaki, Sei; Uchida, Shinichi

    2013-01-01

    Metabolic syndrome patients have insulin resistance, which causes hyperinsulinemia, which in turn causes aberrant increased renal sodium reabsorption. The precise mechanisms underlying this greater salt-sensitivity of hyperinsulinemic patients remain unclear. Abnormal activation of the recently-identified WNK kinase-OSR1/SPAK kinases-NCC transporter phosphorylation cascade results in the salt-sensitive hypertension of pseudohypoaldosteronism type II. Here, we report a study of renal WNK-OSR1/SPAK-NCC cascade activation in the db/db mouse model of hyperinsulinemic metabolic syndrome. Thiazide sensitivity was increased, suggesting greater activity of NCC in db/db mice. In fact, increased phosphorylation of OSR1/SPAK and NCC was observed. In both SpakT243A/+ and Osr1T185A/+ knock-in db/db mice, which carry mutations that disrupt the signal from WNK kinases, increased phosphorylation of NCC and elevated blood pressure were completely corrected, indicating that phosphorylation of SPAK and OSR1 by WNK kinases is required for the increased activation and phosphorylation of NCC in this model. Renal phosphorylated Akt was increased in db/db mice, suggesting that increased NCC phosphorylation is regulated by the PI3K/Akt signaling cascade in the kidney in response to hyperinsulinemia. A PI3K inhibitor (NVP-BEZ235) corrected the increased OSR1/SPAK-NCC phosphorylation. Another more specific PI3K inhibitor (GDC-0941) and an Akt inhibitor (MK-2206) also inhibited increased NCC phosphorylation. These results indicate that the PI3K/Akt signaling pathway activates the WNK-OSR1/SPAK-NCC phosphorylation cascade in db/db mice. This mechanism may play a role in the pathogenesis of salt-sensitive hypertension in human hyperinsulinemic conditions such as the metabolic syndrome. PMID:22949526

  17. Roundabout4 Suppresses Glioma-Induced Endothelial Cell Proliferation, Migration and Tube Formation in Vitro by Inhibiting VEGR2-Mediated PI3K/AKT and FAK Signaling Pathways

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    Heng Cai

    2015-03-01

    Full Text Available Background and Aims: Endothelial cell (EC proliferation, migration, and tube formation are the critical steps for tumor angiogenesis, which is involved in the formation of new tumor blood vessels. Roundabout4 (Robo4, a new member of Robo proteins family, is specifically expressed in endothelial cells. This study aimed to investigate the effects of Robo4 on glioma-induced endothelial cell proliferation, migration and tube formation in vitro. Methods and Results: We found that Robo4 was endogenously expressed in Human Brain Microvascular Endothelial Cells (HBMECs, while Robo4 was significantly down-regulated in endothelial cells cultured in glioma conditioned medium. Robo4 over-expression remarkably suppressed glioma-induced endothelial cell proliferation, migration and tube formation in vitro. In addition, Robo4 influenced the glioma-induced angiogenesis via binding to its ligand Slit2. Further studies demonstrated that the knockdown of Robo4 up-regulated the phosphorylation of VEGFR2, PI3K, AKT and FAK in EC cultured in glioma conditioned medium. VEGFR2 inhibitor SU-1498, AKT inhibitor LY294002 and FAK inhibitor 14 (FAK inhibitor blocked the Robo4 knockdown-mediated alteration in glioma angiogenesis in vitro. Conclusion: Our results proved that Robo4 suppressed glioma-induced endothelial cell proliferation, migration and tube formation in vitro by inhibiting VEGR2-mediated activation of PI3K/AKT and FAK signaling pathways.

  18. miR-21 Reduces Hydrogen Peroxide-Induced Apoptosis in c-kit+ Cardiac Stem Cells In Vitro through PTEN/PI3K/Akt Signaling

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    Wang, Yan; Long, Xianping; Zhao, Ranzun; Wang, Zhenglong; Liu, Zhijiang

    2016-01-01

    The low survival rate of cardiac stem cells (CSCs) in the infarcted myocardium hampers cell therapy for ischemic cardiomyopathy. MicroRNA-21 (miR-21) and one of its target proteins, PTEN, contribute to the survival and proliferation of many cell types, but their prosurvival effects in c-kit+ CSC remain unclear. Thus, we hypothesized that miR-21 reduces hydrogen peroxide- (H2O2-) induced apoptosis in c-kit+ CSC and estimated the contribution of PTEN/PI3K/Akt signaling to this oxidative circumstance. miR-21 mimics efficiently reduced H2O2-induced apoptosis in c-kit+ CSC, as evidenced by the downregulation of the proapoptosis proteins caspase-3 and Bax and upregulation of the antiapoptotic Bcl-2. In addition, the gain of function of miR-21 in c-kit+ CSC downregulated the protein level of PTEN although its mRNA level changed slightly; in the meantime, miR-21 overexpression also increased phospho-Akt (p-Akt). The antiapoptotic effects of miR-21 were comparable with Phen (bpV), the selective inhibitor of PTEN, while miR-21 inhibitor or PI3K's inhibitor LY294002 efficiently attenuated the antiapoptotic effect of miR-21. Taken together, these results indicate that the anti-H2O2-induced apoptosis effect of miR-21 in c-kit+ CSC is contributed by PTEN/PI3K/Akt signaling. miR-21 could be a potential molecule to facilitate the c-kit+ CSC therapy in ischemic myocardium. PMID:27803763

  19. 2,2',4,4'-Tetrabromodiphenyl ether promotes human neuroblastoma SH-SY5Y cells migration via the GPER/PI3K/Akt signal pathway.

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    Tian, P-C; Wang, H-L; Chen, G-H; Luo, Q; Chen, Z; Wang, Y; Liu, Y-F

    2016-02-01

    Neuroblastoma is the predominant tumor of early childhood. 2,2',4,4'-Tetrabromodiphenyl ether (BDE-47) has the highest concentration among all polybrominated diphenyl ether (PBDE) congeners in human body, particularly for children. Considering that accumulating evidences showed developmental neurotoxicity of PBDE, there is an urgent need to investigate the effects of BDE-47 on the development of neuroblastoma. This study revealed that BDE-47 had limited effects on the cytotoxicity while significantly increased the in vitro migration and invasion of human neuroblastoma SH-SY5Y cells. This was further confirmed by the results that BDE-47 treatment significantly downregulated the expression of E-cadherin and zona occludin-1 and upregulated the expression of matrix metalloproteinase-9 (MMP-9). Silencing of MMP-9 by specific small interfering RNA significantly abolished the BDE-47-induced migration and invasion of SH-SY5Y cells. Further, the signals G protein-coupled estrogen receptor 1 (GPER)/phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (Akt) mediated the BDE-47-induced upregulation of MMP-9 and in vitro migration of SH-SY5Y cells since G15 (GPER inhibitor) and LY 294002 (PI3K/Akt inhibitor) significantly abolished the effects of BDE-47. Our results revealed that BDE-47 significantly triggered the metastasis of human neuroblastoma SH-SY5Y cells via upregulation of MMP-9 by the GPER/PI3K/Akt signal pathway. This study revealed for the first time that BDE-47 can promote the migration of SH-SY5Y cells. It also provided a better understanding about the metastasis of human neuroblastoma induced by environmental endocrine disruptors.

  20. Netrin-1 induces the migration of Schwann cells via p38 MAPK and PI3K-Akt signaling pathway mediated by the UNC5B receptor

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Jianwei [General Hospital of Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin 300052 (China); Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin 300050 (China); Sun, Xiaolei; Ma, Jianxiong [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin 300050 (China); Ma, Xinlong, E-mail: gengxiao502@163.com [General Hospital of Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin 300052 (China); Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin 300050 (China); Zhang, Yang; Li, Fengbo; Li, Yanjun; Zhao, Zhihu [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin 300050 (China)

    2015-08-14

    Schwann cells (SCs) play an essentially supportive role in the regeneration of injured peripheral nerve system (PNS). As Netrin-1 is crucial for the normal development of nervous system (NS) and can direct the process of damaged PNS regeneration, our study was designed to determine the role of Netrin-1 in RSC96 Schwann cells (an immortalized rat Schwann cell line) proliferation and migration. Our studies demonstrated that Netrin-1 had no effect on RSC96 cells proliferation, while significantly promoted RSC96 cells migration. The Netrin-1-induced RSC96 cells migration was significantly attenuated by inhibition of p38 and PI3K through pretreatment with SB203580 and LY294002 respectively, but not inhibition of MEK1/2 and JNK by U0126-EtOH and SP600125 individually. Treatment with Netrin-1 enhanced the phosphorylation of p38 and Akt. QRT-PCR indicated that Netrin-1 and only its receptors Unc5a, Unc5b and Neogenin were expressed in RSC96 cells, among which Unc5b expressed the most. And UNC5B protein was significantly increased after stimulated by Netrin-1. In conclusion, we show here that Netrin-1-enhanced SCs migration is mediated by activating p38 MAPK and PI3K-Akt signal cascades via receptor UNC5B, which suggests that Netrin-1 could serve as a new therapeutic strategy and has potential application value for PNS regeneration. - Highlights: • Netrin-1 attracts RSC96 Schwann cells migration in a dose dependent manner. • Netrin-1 induced Schwann cells migration is p38 and PI3K-Akt signaling dependent. • UNC5B may be dominant receptor mediating Netrin-1′ effect on RSC96 cells motility. • Netrin-1 may promote peripheral nerve repair by enhancing Schwann cells motility.

  1. Hepatocyte growth factor promotes proliferation, invasion, and metastasis of myeloid leukemia cells through PI3K-AKT and MAPK/ERK signaling pathway

    Science.gov (United States)

    Guo, Jiang-Rui; Li, Wei; Wu, Yong; Wu, Lin-Qing; Li, Xin; Guo, Ya-Fei; Zheng, Xiao-Hui; Lian, Xiao-Lan; Huang, Hui-Fang; Chen, Yuan-Zhong

    2016-01-01

    This study aims to investigate effects of HGF expression on biological behaviors of Kasumi-1 and HL60. Expression of HGF and c-Met gene were detected using qRT-PCR. Short hairpin RNA (shRNA) was used to reduce HGF expression. Silencing effect of shRNA was verified by qRT-PCR and western blot. Cell reproductive capacity, cell clonality and cell cycle (apoptosis) were detected by CCK-8, clone formation, flow cytometry (FCM), respectively. Cell adhesion, cell invasion ability and cell proliferation were also examined. Changes of PI3K-AKT, MAPK/ERK signaling factors were detected by western blot. HGF and c-Met expression in first-vist AML group was significantly higher than in AML-relief and normal control group. HGF shRNA can inhibit cell proliferation, inhibit cloning ability. Compared with control group, apoptosis ratios of Kasumi-1 and HL60 cell in interference groups were significantly higher. After shRNA interference, the number of adherent cells and transmembrane cells were significantly decreased compared with control group. Meanwhile, shRNA also down-regulated Bad, Bcl-XL, Bcl-2, CDK1, Cyclin B, MMP2, MMP9, and up-regulated cleaved caspase9, cleaved caspase3, cleaved PARP, Bax, and P21. Moreover, phosphorylated c-Met, AKT, Erk, and mTOR were also reduced. In conclusion, HGF and c-Met gene highly expressed among first-visit AML patients, but decreased after relief treatment. HGF may promote proliferation, invasion, and metastasis of AML cells through PI3K-AKT and MAPK/ERK signaling pathway. Therefore, proliferation and invasion ability of AML cell can be inhibited by down-regulating HGF gene to retardate cell in G2/M stage. PMID:27725846

  2. Novel ferrocenyl pyrazoles inhibit breast cancer cell viability via induction of apoptosis and inhibition of PI3K/Akt and ERK1/2 signaling.

    Science.gov (United States)

    Atmaca, Harika; Özkan, Ayşe Nur; Zora, Metin

    2017-02-01

    Despite the advances in early detection and targeted therapies, chemotherapy is still of vital importance in breast cancer treatment. However, development of drug resistance and serious side effects limits their usage. Thus, there is an urgent need for safer and more effective agents against breast cancer. We have previously described the synthesis of a number of pyrazole derivatives, and in the current study, we have investigated the effects of two different ferrocenyl pyrazole (FP) derivates, 5-ferrocenyl-1-phenyl-1H-pyrazole (FP-Ph) and 5-ferrocenyl-1H-pyrazole (FP-H), on breast cancer cells. First, we investigated the effects of both FPs on cell viability and induction of cell death in breast cancer cells and benign MCF-10A cells by XTT and DNA fragmentation assays, respectively. Morphological changes in human breast cancer cells after FPs treatment were detected by both phase contrast microscope and atomic force microscopy (AFM). Then, we tested whether FPs exert their cytotoxic effect through inhibiting PI3K/Akt and/or ERK1/2 signaling pathways by using specific inhibitors. Both FPs induced cytotoxicity in a time and concentration-dependent manner in breast cancer cells; however, MCF-10A benign breast epithelial cells were much less susceptible to the cytotoxic effect of both FPs. FPs inhibited both PI3K/Akt and ERK 1/2 signaling pathways in breast cancer cells. The ultra structure images of MCF-7 cells by AFM showed that the cell surface was smooth in untreated cells, but it was rough with protrusions in treated cells. Both FPs induced apoptotic cell death in MDA-MB-231 cells; however, necrotic cell death was induced in caspase-3 lack MCF-7 cells, which implies that the synthesized FPs may induce apoptosis through caspase-3 dependent mechanism. In summary, these results suggest that FPs might be promising agents for the breast cancer therapy.

  3. HO-1 attenuates hippocampal neurons injury via the activation of BDNF-TrkB-PI3K/Akt signaling pathway in stroke.

    Science.gov (United States)

    Qi, Dashi; Ouyang, Changjie; Wang, Yulan; Zhang, Shichun; Ma, Xijuan; Song, YuanJian; Yu, HongLi; Tang, Jiali; Fu, Wei; Sheng, Lei; Yang, Lihua; Wang, Mei; Zhang, Weihao; Miao, Lei; Li, Tengteng; Huang, Xiaojing; Dong, Hongyan

    2014-08-19

    Although recent studies have found that HO-1 plays an important role in neuronal survival, little is known about the precise mechanisms occurring during cerebral ischemia/reperfusion (I/R). Therefore, the aim of this study was to investigate the neuroprotective mechanisms of HO-1 against ischemic brain injury induced by cerebral I/R and to explore whether the BDNF-TrkB-PI3K/Akt signaling pathway contributed to the protection provided by HO-1. Over-expressed HO-1 plasmids were employed to induce the overexpression of HO-1 through hippocampi CA1 injection 5 days before the cerebral I/R animal model was induced by four-vessel occlusion for 15 min transient ischemia and followed by reperfusion in Sprague-Dawley rats. Immunoblotting was carried out to examine the expression of the related proteins, and HE-staining was used to detect the percentage of living neurons in the hippocampal CA1 region. The results showed that over-expressed HO-1 could significantly protect neurons against cerebral I/R. Furthermore, the protein expression of BDNF, TrkB and p-Akt also increased in the rats treated with over-expressed HO-1 plasmids. However, treatment with tropomyosin receptor kinase B (TrkB) receptor antagonist (K252a) reversed the HO-1-induced increase in BDNF and p-Akt protein levels and decreased the level of cleaved caspase-3 protein in I/R rats. In summary, our results imply that HO-1 can decrease cell apoptosis in the I/R rat brain and that the mechanism may be related to the activation of the BDNF-TrkB-PI3K/Akt signaling pathway.

  4. Effects of SIRT1 gene knock-out via activation of SREBP2 protein-mediated PI3K/AKT signaling on osteoarthritis in mice.

    Science.gov (United States)

    Yu, Fei; Zeng, Hui; Lei, Ming; Xiao, De-Ming; Li, Wei; Yuan, Hao; Lin, Jian-Jing

    2016-10-01

    This study investigated the effects of SIRT1 gene knock-out on osteoarthritis in mice, and the possible roles of SREBP2 protein and the PI3K/AKT signaling pathway in the effects. Mice were randomly divided into a normal group and a SIRT1 gene knock-out group (6 mice in each group). In these groups, one side of the knee anterior cruciate ligament was traversed, and the ipsilateral medial meniscus was cut to establish an osteoarthritis model of knee joint. The countralateral synovial bursa was cut out, serving as controls. The knee joint specimens were then divided into four groups: SIRT1(+/+) control group (group A, n=6); SIRT1(+/+) osteoarthritis group (group B, n=6); SIRT1(-/-) control group (group C, n=6); SIRT1(-/-) osteoarthritis group (group D, n=6). HE staining, Masson staining, Safranin O-Fast Green staining and Van Gieson staining were used to observe the morphological changes in the articular cartilage of the knee. Immunohistochemical staining was employed to detect the expression of SIRT1, SREBP2, VEGF, AKT, HMGCR and type II collagen proteins. SA-β-gal staining was utilized to evaluate chondrocyte aging. The results showed clear knee joint cartilage destruction and degeneration in the SIRT1(-/-) osteoarthritis group. The tidal line was twisted and displaced anteriorly. Type II collagen was destroyed and distributed unevenly. Compared with the SIRT1(+/+) osteoarthritis group and SIRT1(-/-) control group, SIRT1 protein expression was not obviously changed in the SIRT1(-/-) osteoarthritis group (P>0.05), while the expression levels of the SREBP2, VEGF and HMGCR proteins were significantly increased (PSIRT1 gene knock-out may aggravate cartilage degeneration in osteoarthritis by activating the SREBP2 protein-mediated PI3K/AKT signalling pathway, suggesting that SIRT1 gene may play a protective role against osteoarthritis.

  5. CK2α Regulates the Metastases and Migration of Lung Adenocarcinoma 
A549 Cell Line through PI3K/Akt/GSK-3β Signal Pathway

    Directory of Open Access Journals (Sweden)

    Aibing WU

    2017-04-01

    Full Text Available Background and objective Lung cancer is the leading cancer-related death worldwide. Patients with lung cancer mainly died of tumor metastasis and invasion. Protein kinase CK2 is an ubiquitous serine/threonine protein kinase and is frequently upregulated in various human tumors. This study aims to explore the effect and molecular mechanism of the invasion and migration of lung adenocarcinoma A549 cells after knock-down of CK2α expression. Methods The pSilencerTM 4.1-siCK2α-eGFP of lentiviral-mediated shRNA was constructed. The expression of CK2α was knock-downed, and a stable A549 cell line was established. The invasion and migration of A549 cell line was detected through Transwell and Boyden chamber assays. The protein expression of the PI3K/Akt signaling pathway and mesenchymal-to-epithelial transition (EMT was evaluated using Western blot analysis. Results The invasion and migration of A549 cells were significantly inhibited after the knockdown of CK2α expression compared with that in the control group. p-PTEN, Akt, p-Akt473, p-Akt308, p-PDK1, p-c-Raf, and p-GSK-3β were significantly downregulated, whereas PTEN was upregulated. Moreover, vimentin, β-catenin, Snail, MMP2, and MMP9 were significantly downregulated after reducing the CK2α expression. Conclusion CK2α might regulate the invasion and migration of A549 cells through the PI3K/Akt/GSK-3β/Snail signaling pathway, which controls EMT in lung adenocarcinoma.

  6. Chaetominine reduces MRP1-mediated drug resistance via inhibiting PI3K/Akt/Nrf2 signaling pathway in K562/Adr human leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Jingyun; Wei, Xing [State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai (China); Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai (China); Lu, Yanhua, E-mail: luyanhua@ecust.edu.cn [State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai (China); Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai (China)

    2016-05-13

    Drug resistance limits leukemia treatment and chaetominine, a cytotoxic alkaloid that promotes apoptosis in a K562 human leukemia cell line via the mitochondrial pathway was studied with respect to chemoresistance in a K562/Adr human resistant leukemia cell line. Cytotoxicity assays indicated that K562/Adr resistance to adriamycin (ADR) did not occur in the presence of chaetominine and that chaetominine increased chemosensitivity of K562/Adr to ADR. Data show that chaetominine enhanced ADR-induced apoptosis and intracellular ADR accumulation in K562/Adr cells. Accordingly, chaetominine induced apoptosis by upregulating ROS, pro-apoptotic Bax and downregulating anti-apoptotic Bcl-2. RT-PCR and western-blot confirmed that chaetominine suppressed highly expressed MRP1 at mRNA and protein levels. But little obvious alternation of another drug transporter MDR1 mRNA was observed. Furthermore, inhibition of MRP1 by chaetominine relied on inhibiting Akt phosphorylation and nuclear Nrf2. In summary, chaetominine strongly reverses drug resistance by interfering with the PI3K/Akt/Nrf2 signaling, resulting in reduction of MRP1-mediated drug efflux and induction of Bax/Bcl-2-dependent apoptosis in an ADR-resistant K562/Adr leukemia cell line. - Highlights: • Chaetominine enhanced chemosensitivity of ADR against K562/Adr cells. • Chaetominine increased intracellular ADR levels via inhibiting MRP1. • Chaetominine induced apoptosis of K562/Adr cells through upregulation of ROS and modulation of Bax/Bcl-2. • Inhibition of MRP1 and Nrf2 by chaetominine treatment was correlative with blockade of PI3K/Akt signaling.

  7. Ozone oil promotes wound healing by increasing the migration of fibroblasts via PI3K/Akt/mTOR signaling pathway.

    Science.gov (United States)

    Xiao, Weirong; Tang, Hua; Wu, Meng; Liao, Yangying; Li, Ke; Li, Lan; Xu, Xiaopeng

    2017-09-01

    Background: Skin injury affects millions of people via the uncontrolled inflammation and infection. Many cellular components including fibroblasts and signaling pathways such as TGF-β were activated to facilitate the wound healing to repair injured tissues. Methods and Results: C57BL/6 female mice were divided into control and ozone oil treated groups. Excisional wounds were created on the dorsal skin and the fibroblasts were isolated from granulation tissues. The skin injured mouse model revealed that ozone oil could significantly decrease the wound area and accelerate wound healing compared with control group. QPCR and western blotting assays showed that ozone oil upregulated collagen I, α-SMA and TGF-β1 mRNA and protein levels in fibroblasts. Wound healing assay demonstrated that ozone oil could increase the migration of fibroblasts. Western blotting assay demonstrated that ozone oil increased the EMT process of fibroblasts via upregulating fibronectin, vimentin, N-cadherin, MMP-2, MMP-9, IGFBP-3, IGFBP5 and IGFBP6 and decreasing epithelial protein E-cadherin and cellular senescence marker p16 expression. Mechanistically, western blotting assay revealed that ozone oil increased the phosphorylation of PI3K, Akt and mTOR to regulate the EMT process, while inhibition of PI3K reversed this effect of ozone oil. At last, the results from Cytometric Bead Array demonstrated ozone oil significantly decreased the inflammation in fibroblasts. Conclusion: Our results demonstrated ozone oil facilitated the wound healing via increasing fibroblast migration and EMT process via PI3K/Akt/mTOR signaling pathway in vivo and vitro. The cellular and molecular mechanisms we found here may provide new therapeutic targets for the treatment of skin injury. ©2017 The Author(s).

  8. Rapamycin Prevents cyclophosphamide-induced Over-activation of Primordial Follicle pool through PI3K/Akt/mTOR Signaling Pathway in vivo.

    Science.gov (United States)

    Zhou, Linyan; Xie, Yanqiu; Li, Song; Liang, Yihua; Qiu, Qi; Lin, Haiyan; Zhang, Qingxue

    2017-08-16

    Primordial follicular depletion has thought to be a common adverse effect of chemotherapy especially for female of reproductive age. The study aimed to evaluate the protective effect of rapamycin on the primordial follicles and its potential mechanism for patients receiving chemotherapy. 8-week old BALB/c female mice were randomly assigned into four groups (control; rapamycin; cyclophosphamide; and rapamycin combined with cyclophosphamide). Hematoxylin staining, immunohistochemical, TUNEL, western blotting and ELISA were employed to assess inter-group differences using Student's t-test and Mann-Whitney test. Cyclophosphamide depleted the follicular reserve and induced the phosphorylation of the key proteins of PI3K/Akt/mTOR pathway in mice in a dose-dependent manner. Co-treatment with rapamycin significantly reduced primordial follicle loss at all cyclophosphamide dose groups and prevent the follicle growth wave caused by cyclophosphamide treatment (P primordial follicles in all groups and fewer apoptosis in large growing follicles were observed in ovaries from rapamycin + cyclophosphamide group compared to that received cyclophosphamide alone. Serum anti-Müllerian hormone (AMH) was significantly reduced in cyclophosphamide alone group, in contrast to the normal level in rapamycin + cyclophosphamide group. Compared to p-Akt/Akt and p-mtor/mtor, p-rps6/rps6 was significantly decreased in rapamycin + cyclophosphamide group (P primordial follicle activation induced by cyclophosphamide through PI3K/Akt/mTOR signaling pathway and thus plays a role in preserving the follicle pool. These results suggest that rapamycin may be an effective protection for ovarian function during chemotherapy, which means a new nonsurgical application for protection of ovarian reserve and prevention of POF.

  9. Afatinib resistance in non-small cell lung cancer involves the PI3K/AKT and MAPK/ERK signalling pathways and epithelial-to-mesenchymal transition.

    Science.gov (United States)

    Coco, Simona; Truini, Anna; Alama, Angela; Dal Bello, Maria Giovanna; Venè, Roberta; Garuti, Anna; Carminati, Enrico; Rijavec, Erika; Genova, Carlo; Barletta, Giulia; Sini, Claudio; Ballestrero, Alberto; Boccardo, Francesco; Grossi, Francesco

    2015-09-01

    The epidermal growth factor receptor (EGFR) signalling is one of the most deregulated pathways in non-small cell lung cancer (NSCLC). Recently, the development of novel irreversible tyrosine kinase inhibitors (TKI), such as afatinib, has significantly improved the survival of advanced NSCLC patients harbouring activated EGFR mutations. However, treatment with TKI is not always curative due to the development of resistance. In the present study, we investigated the sensitivity to afatinib in two NSCLC EGFR mutated cell lines (NCI-H1650 and NCI-H1975) by expression profile analysis of 92 genes involved in the EGF pathway. Thereafter, the established afatinib resistant clones were evaluated at different biological levels: genomic, by array comparative genomic hybridisation (aCGH) and deep sequencing; transcriptomic, by quantitative polymerase chain reaction (qPCR) and proteomic, by Western blot and immunofluorescence. The baseline gene expression of the two cell lines revealed that NCI-H1650, the less afatinib-responsive cell, showed activation of two main EGFR downstream pathways such as PI3K/AKT and PLCγ/PKC axes. Analysis of the afatinib-resistant cells showed PI3K/AKT and MAPK/ERK pathways activation together with a biological switch from an epithelial-to-mesenchymal phenotype might confer afatinib-resistant properties to this cell line. Our data suggest that the activation of EGFR-dependent downstream pathways might be involved in the occurrence of resistance to afatinib assuming that the EGFR mutational status should not be exclusively considered when selecting TKI treatments. In particular, the epithelial-to-mesenchymal transition might provide a new basis for understanding afatinib resistance.

  10. PRL-3 promotes the peritoneal metastasis of gastric cancer through the PI3K/Akt signaling pathway by regulating PTEN.

    Science.gov (United States)

    Xiong, Jianbo; Li, Zhengrong; Zhang, Yang; Li, Daojiang; Zhang, Guoyang; Luo, Xianshi; Jie, Zhigang; Liu, Yi; Cao, Yi; Le, Zhibiao; Tan, Shengxing; Zou, Wenyu; Gong, Peitao; Qiu, Lingyu; Li, Yuanyuan; Wang, Huan; Chen, Heping

    2016-10-01

    Peritoneal metastasis is the most frequent cause of death in patients with advanced gastric carcinoma (GC). The phosphatase of regenerating liver-3 (PRL-3) is recognized as an oncogene and plays an important role in GC peritoneal metastasis. However, the mechanism of how PRL-3 regulates GC invasion and metastasis is unknown. In the present study, we found that PRL-3 presented with high expression in GC with peritoneal metastasis, but phosphatase and tensin homologue (PTEN) was weakly expressed. The p-PTEN/PTEN ratio was also higher in GC with peritoneal metastasis than that in the normal gastric tissues. We also found the same phenomenon when comparing the gastric mucosa cell line with the GC cell lines. After constructing a wild-type and a mutant-type plasmid without enzyme activity and transfecting them into GC SGC7901 cells, we showed that only PRL-3 had enzyme activity to downregulate PTEN and cause PTEN phosphorylation. The results also showed that PRL-3 increased the expression levels of MMP-2/MMP-9 and promoted the migration and invasion of the SGC7901 cells. Knockdown of PRL-3 decreased the expression levels of MMP-2/MMP-9 significantly, which further inhibited the migration and invasion of the GC cells. PRL-3 also increased the expression ratio of p-Akt/Akt, which indicated that PRL-3 may mediate the PI3K/Akt pathway to promote GC metastasis. When we transfected the PTEN siRNA plasmid into the PRL-3 stable low expression GC cells, the expression of p-Akt, MMP-2 and MMP-9 was reversed. In conclusion, our results provide a bridge between PRL-3 and PTEN; PRL-3 decreased the expression of PTEN as well as increased the level of PTEN phosphorylation and inactivated it, consequently activating the PI3K/Akt signaling pathway, and upregulating MMP-2/MMP-9 expression to promote GC cell peritoneal metastasis.

  11. Quercetin attenuates high fructose feeding-induced atherosclerosis by suppressing inflammation and apoptosis via ROS-regulated PI3K/AKT signaling pathway.

    Science.gov (United States)

    Lu, Xue-Li; Zhao, Cui-Hua; Yao, Xin-Liang; Zhang, Han

    2017-01-01

    Quercetin is a dietary flavonoid compound extracted from various plants, such as apple and onions. Previous studies have revealed its anti-inflammatory, anti-cancer, antioxidant and anti-apoptotic activities. This study investigated the ability of quercetin to inhibit high fructose feeding- or LPS-induced atherosclerosis through regulating oxidative stress, apoptosis and inflammation response in vivo and in vitro experiments. 50 and 100mg/kg quercetin were used in our study, showing significant inhibitory role in high fructose-induced atherosclerosis via reducing reactive oxygen species (ROS) levels, Caspase-3 activation, inflammatory cytokines releasing, the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive cells and collagen contents as well as modulating apoptosis- and inflammation-related proteins expression. We also explored the protective effects of quercetin on atherosclerosis by phosphatidylinositide 3-kinases (PI3K)/Protein kinase B (AKT)-associated Bcl-2/Caspase-3 and nuclear factor kappa B (NF-κB) signal pathways activation, promoting AKT and Bcl-2 expression and reducing Caspase-3 and NF-κB activation. Quercetin reduced the atherosclerotic plaque size in vivo in high fructose feeding-induced mice assessed by oil red O. Also, in vitro experiments, quercetin displayed inhibitory role in LPS-induced ROS production, inflammatory response and apoptosis, which were linked with PI3K/AKT-regulated Caspase-3 and NF-κB activation. In conclusion, our results showed that quercetin inhibited atherosclerotic plaque development in high fructose feeding mice via PI3K/AKT activation regulated by ROS.

  12. WSTF promotes proliferation and invasion of lung cancer cells by inducing EMT via PI3K/Akt and IL-6/STAT3 signaling pathways.

    Science.gov (United States)

    Meng, Jin; Zhang, Xu-Tao; Liu, Xin-Li; Fan, Lei; Li, Chen; Sun, Yang; Liang, Xiao-Hua; Wang, Jian-Bo; Mei, Qi-Bing; Zhang, Feng; Zhang, Tao

    2016-11-01

    Williams syndrome transcription factor (WSTF), which is encoded by the BAZ1B gene, was first identified as a hemizygously deleted gene in patients with Williams syndrome. WSTF protein has been reported to be involved in transcription, replication, chromatin remodeling and DNA damage response, and also functions as a tyrosine protein kinase. However, the function of WSTF in cancer is not known. Here, we show that WSTF overexpression promotes proliferation, colony formation, migration and invasion of lung cancer A549 and H1299 cells. WSTF overexpression also promotes tumor growth and invasive abilities of lung cancer cells in mouse xenograft models. cDNA microarray and subsequent qRT-PCR validation revealed that WSTF overexpression significantly upregulated the expression of EMT (epithelial to mesenchymal transition) marker fibronectin (FN1) and EMT-inducing genes Fos and CEACAM6. The changes of EMT markers including downregulated E-cadherin and upregulated N-cadherin and FN1 were further confirmed at both mRNA and protein levels upon WSTF overexpression, with typical morphological changes of EMT. Furthermore, WSTF activates both PI3K/Akt and IL-6/STAT3 oncogenic signaling pathways. Treatment with PI3K inhibitor ZSTK474 or STAT3 inhibitor niclosamide reversed the effects of WSTF overexpression by inhibiting cell proliferation, migration and invasion, with decreased level of p-Akt, p-STAT3 and IL-6. ZSTK474 and niclosamide also reversed EMT markers and EMT-inducing proteins including Snail, Slug, Twist and CEACAM6 in WSTF-overexpressing A549 cells. Taken together, these results demonstrate that WSTF may act as an oncoprotein in lung cancer to accelerate tumor aggressiveness by promoting EMT via activation of PI3K/Akt and IL-6/STAT3 pathways. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. The natural secolignan peperomin E induces apoptosis of human gastric carcinoma cells via the mitochondrial and PI3K/Akt signaling pathways in vitro and in vivo.

    Science.gov (United States)

    Wang, Xin-Zhi; Cheng, Ying; Wu, Hao; Li, Na; Liu, Rui; Yang, Xiao-Lin; Qiu, Yun-Ying; Wen, Hong-Mei; Liang, Jing-Yu

    2016-07-15

    nude mice. These findings indicate that PepE can inhibit cell proliferation and induce apoptosis of gastric cancer cells through mitochondrial and PI3K/Akt signaling pathways with relative safety and may be a novel effective chemotherapeutic agent against gastric cancer. Copyright © 2016 Elsevier GmbH. All rights reserved.

  14. Blocking SIRT1 inhibits cell proliferation and promotes aging through the PI3K/AKT pathway.

    Science.gov (United States)

    Li, Hongyan; Wang, Rong

    2017-09-26

    Alzheimer's disease (AD) is the most prevalent age-related disease and the most common cause of dementia in the elderly. Its hallmark neuropathological features are the presence of amyloid-beta oligomers and neurofibrillary tangles that are composed of hyperphosphorylated tau protein. SIRT1 has been shown to have a neuroprotective effect; however, its working mechanisms are not well understood. This study aimed to address this issue. We used an in vitro neuronal SH-SY5Y cell culture model to investigate the effect of SIRT1 knockdown on cell survival, proliferation, functionality, and cytotoxicity. We also investigated how SIRT1 knockdown affected relevant signaling/regulator molecules, including AKT, CREB, and p53, to gain further mechanistic insight. We found that SIRT1 knockdown inhibited cell survival, proliferation, and functionality. These effects were associated with suppressed AKT activity and CREB activation and increased p53 expression. These results will help us to better understand the protective role of SIRT1 in AD, and they support the potential use of SIRT1 as a biomarker and drug target for the prevention, diagnosis, and treatment of AD as well as other relevant age-related diseases. Copyright © 2017. Published by Elsevier Inc.

  15. Apelin-13 upregulates Egr-1 expression in rat vascular smooth muscle cells through the PI3K/Akt and PKC signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qi-Feng [Department of Cardiology, The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); Yu, Hong-Wei [Department of Cardiology, Jinzhou Central Hospital, Jinzhou 121001 (China); Sun, Li-Li [Department of Ophthalmology, The Third Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); You, Lu; Tao, Gui-Zhou [Department of Cardiology, The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); Qu, Bao-Ze, E-mail: qubaoze1971@hotmail.com [Department of Cardiology, The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China)

    2015-12-25

    Previous studies have shown that Apelin-13 upregulates early growth response factor-1 (Egr-1) via the extracellular signal-regulated protein kinase (ERK) signaling pathway. Apelin-13 induces proliferation and migration of vascular smooth muscle cells (VSMCs) as well as the upregulation of osteopontin (OPN) via the upregulation of Egr-1. This study was designed to further explore the activity of Apelin-13 in VSMCs by investigating members of the mitogen-activated protein kinase (MAPK) family, in particular Jun kinase (JNK) and p38 mitogen-activated protein kinase (P38). We also examined whether the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) and protein kinase C (PKC) signaling pathways were involved in the regulation of Egr-1 by Apelin-13. We treated rat aortic VSMCs with Apelin-13 and examined the expression of JNK, p-JNK, P38, and p-P38 to investigate whether Apelin-13-mediated increases in Egr-1 occurred through the JNK and P38 signaling pathways. We then pretreated VSMCs with the Gi protein inhibitor pertussis toxin (PTX) and the Gq inhibitor YM254890, added Apelin-13 and looked for changes in Egr-1 expression. Finally, we pretreated with the PI3K inhibitor LY294002 and the PKC inhibitor GF109203X, and treated with Apelin-13. Our results showed that JNK and P38 did not participate in Apelin-13-mediated increase in Egr-1. Instead, Apelin-13 upregulation of Egr-1 was mediated by a PTX-sensitive Gi protein. Apelin-13 did increase ERK phosphorylation through the PI3K/Akt and PKC signaling pathways, resulting in changes in Egr-1 expression. These data provide important targets for future studies to modulate vascular remodeling. - Highlights: • Apelin-13 mediates Egr-1 upregulation in vascular smooth muscle cells via ERK1/2. • The underlying mechanisms are unknown, but exclude Jnk or p38 pathway activation. • Apelin-13 binds to Gi, activating the PI3K/Akt and PKC signaling cascades. • Consequent ERK phosphorylation results in increased Egr-1

  16. Paeonia lactiflora Pall. protects against ANIT-induced cholestasis by activating Nrf2 via PI3K/Akt signaling pathway

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    Ma X

    2015-09-01

    Full Text Available Xiao Ma,1,2 Yan-ling Zhao,2 Yun Zhu,3 Zhe Chen,1,2 Jia-bo Wang,4 Rui-yu Li,1,4 Chang Chen,1,2 Shi-zhang Wei,1,2 Jian-yu Li,3 Bing Liu,5 Rui-lin Wang,3 Yong-gang Li,3 Li-fu Wang,3 Xiao-he Xiao4 1Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu, People’s Republic of China; 2Department of Pharmacy, 302 Military Hospital of People’s Liberation Army, Beijing, People’s Republic of China; 3Department of Integrative Medical Center, 302 Military Hospital of People’s Liberation Army, Beijing, People’s Republic of China; 4China Military Institute of Chinese Medicine, 302 Military Hospital of People’s Liberation Army, Beijing, People’s Republic of China; 5School of Chinese Medicine, The University of Hong Kong, Hong Kong Background: Paeonia lactiflora Pall. (PLP, a traditional Chinese herbal medicine, has been used for hepatic disease treatment over thousands of years. In our previous study, PLP was shown to demonstrate therapeutic effect on hepatitis with severe cholestasis. The aim of this study was to evaluate the antioxidative effect of PLP on alpha-naphthylisothiocyanate (ANIT-induced cholestasis by activating NF-E2-related factor 2 (Nrf2 via phosphatidylinositol 3-kinase (PI3K/Akt signaling pathway. Materials and methods: Liquid chromatography-mass spectrometry (LC-MS was performed to identify the main compounds present in PLP. The mechanism of action of PLP and its therapeutic effect on cholestasis, induced by ANIT, were further investigated. Serum indices such as total bilirubin (TBIL, direct bilirubin (DBIL, aspartate aminotransferase (AST, alanine aminotransferase (ALT, alkaline phosphatase (ALP, γ-glutamyl transpeptidase (γ-GT, and total bile acid (TBA were measured, and histopathology of liver was also performed to determine the efficacy of treatment with PLP. Moreover, in order to illustrate the underlying signaling pathway, liver glutathione (GSH content and mRNA or protein levels of glutamate

  17. Effects of simulated microgravity on human umbilical vein endothelial cell angiogenesis and role of the PI3K-Akt-eNOS signal pathway.

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    Fei Shi

    Full Text Available Endothelial cells are very sensitive to microgravity and the morphological and functional changes in endothelial cells are believed to be at the basis of weightlessness-induced cardiovascular deconditioning. It has been shown that the proliferation, migration, and morphological differentiation of endothelial cells play critical roles in angiogenesis. However, the influence of microgravity on the ability of endothelial cells to foster angiogenesis remains to be explored in detail. In the present study, we used a clinostat to simulate microgravity, and we observed tube formation, migration, and expression of endothelial nitric oxide synthase (eNOS in human umbilical vein endothelial cells (HUVEC-C. Specific inhibitors of eNOS and phosphoinositide 3-kinase (PI3K were added to the culture medium and gravity-induced changes in the pathways that mediate angiogenesis were investigated. After 24 h of exposure to simulated microgravity, HUVEC-C tube formation and migration were significantly promoted.This was reversed by co-incubation with the specific inhibitor of N-nitro-L-arginine methyl ester hydrochloride (eNOS. Immunofluorescence assay, RT-PCR, and Western blot analysis demonstrated that eNOS expression in the HUVEC-C was significantly elevated after simulated microgravity exhibition. Ultrastructure observation via transmission electron microscope showed the number of caveolae organelles in the membrane of HUVEC-C to be significantly reduced. This was correlated with enhanced eNOS activity. Western blot analysis then showed that phosphorylation of eNOS and serine/threonine kinase (Akt were both up-regulated after exposure to simulated microgravity. However, the specific inhibitor of PI3K not only significantly downregulated the expression of phosphorylated Akt, but also downregulated the phosphorylation of eNOS. This suggested that the PI3K-Akt signal pathway might participate in modulating the activity of eNOS. In conclusion, the present study

  18. Calpain 1 regulates TGF-β1-induced epithelial-mesenchymal transition in human lung epithelial cells via PI3K/Akt signaling pathway

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    Tan, Wei-Jun; Tan, Qiu-Yue; Wang, Ting; Lian, Min; Zhang, Li; Cheng, Zhen-Shun

    2017-01-01

    Cell proliferation, transformation, and epithelial-mesenchymal transition (EMT) are key processes involved in the development of idiopathic pulmonary fibrosis (IPF). This study investigated the regulatory factors and signaling pathways that mediate EMT in the human type II alveolar epithelial A549 cell line. A549 cells were cultured in RPMI-1640 medium and allocated to the following four groups: blank control group or treated with transforming growth factor-β1 (TGF-β1), TGF-β1 + PD 150606 (a calpain 1 inhibitor), or PD 150606. We examined E-cadherin (E-cad), α-smooth muscle actin (α-SMA), and calpain 1 mRNA transcript and protein expression levels in these four groups by performing RT-PCR and western blot analyses. The results indicated that TGF-β1 treatment significantly downregulated E-cad and upregulated α-SMA expression compared with that of the blank control group (Pcells. However, TGF-β1-induced ETM was not correlated with the ERK and JNK signaling pathways. These combined results indicate that calpain 1 could regulate EMT in TGF-β1-treated A549 epithelial cells via the PI3K/Akt signaling pathway.

  19. Fisetin inhibits UVB-induced cutaneous inflammation and activation of PI3K/AKT/NFκB signaling pathways in SKH-1 hairless mice†

    Science.gov (United States)

    Pal, Harish Chandra; Athar, Mohammad; Elmets, Craig A.; Afaq, Farrukh

    2014-01-01

    Solar ultraviolet B (UVB) radiation has been shown to induce inflammation, DNA damage, p53 mutations, and alterations in signaling pathways eventually leading to skin cancer. In the present study, we investigated whether fisetin reduces inflammatory responses and modulates PI3K/AKT/NFκB cell survival signaling pathways in UVB exposed SKH-1 hairless mouse skin. Mice were exposed to 180 mJ/cm2 of UVB radiation on alternate days for a total of seven exposures, and fisetin (250 and 500 nmol) was applied topically after 15 min of each UVB exposure. Fisetin treatment to UVB exposed mice resulted in decreased hyperplasia and reduced infiltration of inflammatory cells. Fisetin treatment also reduced inflammatory mediators such as COX-2, PGE2 as well as its receptors (EP1- EP4), and MPO activity. Furthermore, fisetin reduced the level of inflammatory cytokines TNFα, IL-1β and IL-6 in UVB exposed skin. Fisetin treatment also reduced cell proliferation markers as well as DNA damage as evidenced by increased expression of p53 and p21 proteins. Further studies revealed that fisetin inhibited UVB-induced expression of PI3K, phosphorylation of AKT, and activation of the NFκB signaling pathway in mouse skin. Overall, these data suggest that fisetin may be useful against UVB-induced cutaneous inflammation and DNA damage. PMID:25169110

  20. Fisetin inhibits UVB-induced cutaneous inflammation and activation of PI3K/AKT/NFκB signaling pathways in SKH-1 hairless mice.

    Science.gov (United States)

    Pal, Harish Chandra; Athar, Mohammad; Elmets, Craig A; Afaq, Farrukh

    2015-01-01

    Solar ultraviolet B (UVB) radiation has been shown to induce inflammation, DNA damage, p53 mutations and alterations in signaling pathways eventually leading to skin cancer. In this study, we investigated whether fisetin reduces inflammatory responses and modulates PI3K/AKT/NFκB cell survival signaling pathways in UVB-exposed SKH-1 hairless mouse skin. Mice were exposed to 180 mJ cm(-2) of UVB radiation on alternate days for a total of seven exposures, and fisetin (250 and 500 nmol) was applied topically after 15 min of each UVB exposure. Fisetin treatment to UVB-exposed mice resulted in decreased hyperplasia and reduced infiltration of inflammatory cells. Fisetin treatment also reduced inflammatory mediators such as COX-2, PGE2 as well as its receptors (EP1-EP4) and MPO activity. Furthermore, fisetin reduced the level of inflammatory cytokines TNFα, IL-1β and IL-6 in UVB-exposed skin. Fisetin treatment also reduced cell proliferation markers as well as DNA damage as evidenced by increased expression of p53 and p21 proteins. Further studies revealed that fisetin inhibited UVB-induced expression of PI3K, phosphorylation of AKT and activation of the NFκB signaling pathway in mouse skin. Overall, these data suggest that fisetin may be useful against UVB-induced cutaneous inflammation and DNA damage. © 2014 The American Society of Photobiology.

  1. Effects of streptozotocin-induced type 1 maternal diabetes on PI3K/AKT signaling pathway in the hippocampus of rat neonates.

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    Hami, Javad; Kerachian, Mohammad-Amin; Karimi, Razieh; Haghir, Hossein; Sadr-Nabavi, Ariane

    2016-01-01

    Diabetes in pregnancy impairs hippocampus development in offspring, leading to behavioral problems and learning deficits. Phosphatidylinositol 3-kinase/protein kinase B (PKB/Akt) signaling pathway plays a pivotal role in the regulation of neuronal proliferation, survival and death. The present study was designed to examine the effects of maternal diabetes on PKB/Akt expression and phosphorylation in the developing rat hippocampus. Wistar female rats were maintained diabetic from a week before pregnancy through parturition and male offspring was killed at first postnatal day (P1). The hippocampal expression and phosphorylation level of PKB/Akt, one of the key molecules in PI3K/AKT signaling pathway, was evaluated using real-time polymerase chain reaction (PCR) and western blot analysis. We found a significant bilateral downregulation of AKT1 gene expression in the hippocampus of pups born to diabetic mothers (p diabetic and insulin-treated groups compared with control (p diabetic group. These results represent that diabetes during pregnancy strongly influences the regulation of PKB/AKT in the developing rat hippocampus. Furthermore, although the control of glycemia by insulin administration is not sufficient to prevent the alterations in PKB/Akt expression, it modulates the phosphorylation process, thus ultimately resulting in a situation comparable to that found in the normal condition.

  2. Targeting of cell metabolism in human acute myeloid leukemia--more than targeting of isocitrate dehydrogenase mutations and PI3K/AKT/mTOR signaling?

    Science.gov (United States)

    Hauge, Michelle; Bruserud, Øystein; Hatfield, Kimberley Joanne

    2016-03-01

    Targeting of cellular metabolism has emerged as a possible strategy in the treatment of human malignancies, and several experimental studies suggest that this therapeutic approach should also be considered in acute myeloid leukemia (AML). Clinical studies of metabolic intervention in AML patients with isocitrate dehydrogenase mutations have shown promising results. Moreover, metabolic targeting of the PI3K/AKT/mTOR signaling pathway as an anticancer strategy has been extensively studied. In this review, we focus on other emerging therapeutic alternatives for metabolic inhibition in human AML, in particular targeting of glycolysis and the AMP kinase signaling pathway. Pharmacological drugs for these metabolic interventions are already available and they seem to have an acceptable toxicity, even when used in combination with conventional chemotherapy. Future clinical studies of these therapeutic strategies should focus on the following: (i) heterogeneity of patients and the possibility that this treatment is most effective only for certain subsets of patients, (ii) toxic effects in AML patients with an existing disease-induced bone marrow failure prior to treatment, and (iii) whether this strategy should be used as part of a potentially curative treatment and/or as disease-stabilizing treatment to prolong survival in elderly or unfit patients.

  3. Inhibition of the PI3K/Akt/mTOR signaling pathway in diffuse large B-cell lymphoma: current knowledge and clinical significance.

    Science.gov (United States)

    Majchrzak, Agata; Witkowska, Magdalena; Smolewski, Piotr

    2014-09-11

    Diffuse large B-cell lymphoma (DLBCL) is one of the most common non-Hodgkin lymphomas in adults. The disease is very heterogeneous in its presentation, that is DLBCL patients may differ from each other not only in regard to histology of tissue infiltration, clinical course or response to treatment, but also in respect to diversity in gene expression profiling. A growing body of knowledge on the biology of DLBCL, including abnormalities in intracellular signaling, has allowed the development of new treatment strategies, specifically directed against lymphoma cells. The phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway plays an important role in controlling proliferation and survival of tumor cells in various types of malignancies, including DLBCL, and therefore it may be a promising target for therapeutic intervention. Currently, novel anticancer drugs are undergoing assessment in different phases of clinical trials in aggressive lymphomas, with promising outcomes. In this review we present a state of art review on various classes of small molecule inhibitors selectively involving PI3K/Akt/mTOR pathway and their clinical potential in this disease.

  4. ROLE OF PI3K-AKT-mTOR AND Wnt SIGNALING PATHWAYS IN G1-S TRANSITION OF CELL CYCLE IN CANCER CELLS

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    LAKSHMIPATHI eVADLAKONDA

    2013-04-01

    Full Text Available The PI3K–Akt pathway together with one of its downstream targets, the mechanistic target of rapamycin (mTOR is a highly deregulated pathway in cancers. There is a reciprocal relation between the Akt phosphorylation and mTOR complexes. Akt phosphorylated at T308 activates mTORC1 by inhibition of the tuberous sclerosis complex (TSC1/2, where as mTORC2 is recognized as the kinase that phosphorylates Akt at S473. Recent developments in the research on regulatory mechanisms of autophagy places mTORC1 mediated inhibition of autophagy at the central position in activation of proliferation and survival pathways in cells. Autophagy is a negative regulator of Wnt signaling pathway and the downstream effectors of Wnt signaling pathway, cyclin D1 and the c-Myc, are the key players in initiation of cell cycle and regulation of the G1-S transition in cancer cells. Production of reaction oxygen species (ROS, a common feature of a cancer cell metabolism, activates several downstream targets like the transcription factors FoxO, which play key roles in promoting the progression of cell cycle. A model is presented on the role of PI3K -Akt - mTOR and Wnt pathways in regulation of the progression of cell cycle through Go-G1-and S phases.

  5. Inhibition of the PI3K/Akt/mTOR Signaling Pathway in Diffuse Large B-Cell Lymphoma: Current Knowledge and Clinical Significance

    Directory of Open Access Journals (Sweden)

    Agata Majchrzak

    2014-09-01

    Full Text Available Diffuse large B-cell lymphoma (DLBCL is one of the most common non-Hodgkin lymphomas in adults. The disease is very heterogeneous in its presentation, that is DLBCL patients may differ from each other not only in regard to histology of tissue infiltration, clinical course or response to treatment, but also in respect to diversity in gene expression profiling. A growing body of knowledge on the biology of DLBCL, including abnormalities in intracellular signaling, has allowed the development of new treatment strategies, specifically directed against lymphoma cells. The phosphoinositide 3-kinase (PI3K/protein kinase B (Akt/mammalian target of rapamycin (mTOR signaling pathway plays an important role in controlling proliferation and survival of tumor cells in various types of malignancies, including DLBCL, and therefore it may be a promising target for therapeutic intervention. Currently, novel anticancer drugs are undergoing assessment in different phases of clinical trials in aggressive lymphomas, with promising outcomes. In this review we present a state of art review on various classes of small molecule inhibitors selectively involving PI3K/Akt/mTOR pathway and their clinical potential in this disease.

  6. EPO-dependent activation of PI3K/Akt/FoxO3a signalling mediates neuroprotection in in vitro and in vivo models of Parkinson's disease.

    Science.gov (United States)

    Jia, Yu; Mo, Shi-Jing; Feng, Qi-Qi; Zhan, Ma-Li; OuYang, Li-Si; Chen, Jia-Chang; Ma, Yu-Xin; Wu, Jia-Jia; Lei, Wan-Long

    2014-05-01

    Erythropoietin (EPO) may become a potential therapeutic candidate for the treatment of the neurodegenerative disorder -- Parkinson's disease (PD), since EPO has been found to prevent neuron apoptosis through the activation of cell survival signalling. However, the underlying mechanisms of how EPO exerts its neuroprotective effect are not fully elucidated. Here we investigated the mechanism by which EPO suppressed 6-hydroxydopamine (6-OHDA)-induced neuron death in in vitro and in vivo models of PD. EPO knockdown conferred 6-OHDA-induced cytotoxicity. This effect was reversed by EPO administration. Treatment of PC12 cells with EPO greatly diminished the toxicity induced by 6-OHDA in a dose- and time-dependent manner. EPO effectively reduced apoptosis of striatal neurons and induced a significant improvement on the neurological function score in the rat models of PD. Furthermore, EPO increased the expression of phosphorylated Akt and phosphorylated FoxO3a, and abrogated the 6-OHDA-induced dysregulation of Bcl-2, Bax and Caspase-3 in PC12 cells and in striatal neurons. Meanwhile, the EPO-dependent neuroprotection was notably reversed by pretreatment with LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K). Our data suggest that PI3K/Akt/FoxO3a signalling pathway may be a possible mechanism involved in the neuroprotective effect of EPO in PD.

  7. Resveratrol Inhibits the Invasion of Glioblastoma-Initiating Cells via Down-Regulation of the PI3K/Akt/NF-κB Signaling Pathway

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    Yuming Jiao

    2015-06-01

    Full Text Available Invasion and metastasis of glioblastoma-initiating cells (GICs are thought to be responsible for the progression and recurrence of glioblastoma multiforme (GBM. A safe drug that can be applied during the rest period of temozolomide (TMZ maintenance cycles would greatly improve the prognosis of GBM patients by inhibiting GIC invasion. Resveratrol (RES is a natural compound that exhibits anti-invasion properties in multiple tumor cell lines. The current study aimed to evaluate whether RES can inhibit GIC invasion in vitro and in vivo. GICs were identified using CD133 and Nestin immunofluorescence staining and tumorigenesis in non-obese diabetic severe combined immunodeficient (NOD/SCID mice. Invasive behaviors, including the adhesion, invasion and migration of GICs, were determined by tumor invasive assays in vitro and in vivo. The activity of matrix metalloproteinases (MMPs was measured by the gelatin zymography assay. Western blotting analysis and immunofluorescence staining were used to determine the expression of signaling effectors in GICs. We demonstrated that RES suppressed the adhesion, invasion and migration of GICs in vitro and in vivo. Moreover, we proved that RES inhibited the invasion of GICs via the inhibition of PI3K/Akt/NF-κB signal transduction and the subsequent suppression of MMP-2 expression.

  8. Marine Cyclotripeptide X-13 Promotes Angiogenesis in Zebrafish and Human Endothelial Cells via PI3K/Akt/eNOS Signaling Pathways

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    Zhong Pei

    2012-06-01

    Full Text Available Cyclotripeptide X-13 is a core of novel marine compound xyloallenoide A isolated from mangrove fungus Xylaria sp. (no. 2508. We found that X-13 dose-dependently induced angiogenesis in zebrafish embryos and in human endothelial cells, which was accompanied by increased phosphorylation of eNOS and Akt and NO release. Inhibition of PI3K/Akt/eNOS by LY294002 or l-NAME suppressed X-13-induced angiogenesis. The present work demonstrates that X-13 promotes angiogenesis via PI3K/Akt/eNOS pathways.

  9. An Integrative Analysis of the InR/PI3K/Akt Network Identifies the Dynamic Response to Insulin Signaling

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    Arunachalam Vinayagam

    2016-09-01

    Full Text Available Insulin regulates an essential conserved signaling pathway affecting growth, proliferation, and metabolism. To expand our understanding of the insulin pathway, we combine biochemical, genetic, and computational approaches to build a comprehensive Drosophila InR/PI3K/Akt network. First, we map the dynamic protein-protein interaction network surrounding the insulin core pathway using bait-prey interactions connecting 566 proteins. Combining RNAi screening and phospho-specific antibodies, we find that 47% of interacting proteins affect pathway activity, and, using quantitative phosphoproteomics, we demonstrate that ∼10% of interacting proteins are regulated by insulin stimulation at the level of phosphorylation. Next, we integrate these orthogonal datasets to characterize the structure and dynamics of the insulin network at the level of protein complexes and validate our method by identifying regulatory roles for the Protein Phosphatase 2A (PP2A and Reptin-Pontin chromatin-remodeling complexes as negative and positive regulators of ribosome biogenesis, respectively. Altogether, our study represents a comprehensive resource for the study of the evolutionary conserved insulin network.

  10. The silence of p66(Shc) in HCT8 cells inhibits the viability via PI3K/AKT/Mdm-2/p53 signaling pathway.

    Science.gov (United States)

    Zhang, Ling; Zhu, Shengtao; Shi, Xuesen; Sha, Weihong

    2015-01-01

    Colon cancer is the second most common cause of cancer-related death, indicating that some of its cancer cells are not eradicated by current therapies. The previous studies demonstrated that p66(Shc) protein, a member of Shc family, is highly expressed in colon cancer cells, but the role of p66(Shc) in the progress of colon cancer still unknown. In this study, we found that p66(Shc) highly expressed in colon cancer tissue and colon cancer cell line SW620 cells, HCT8 cells, HCT116 cells and CaCO2 cells. The silence of p66(Shc) in HCT8 cells reduced the proliferation and accelerated the apoptosis, in addition, the expression of pro-apoptotic proteins caspase-3, caspase-9, Bax was enhanced and the expression of anti-apoptotic protein Bcl-2 was declined. Moreover, the cell cycle arrest in G0/G1 phase after HCT8 cells treated with p66(Shc) siRNA. Furthermore, after HCT8 cells treated with p66(Shc) siRNA, the phosphorylation of PI3K and AKT was significantly suppressed, and the expression of Mdm-2, a downstream of AKT, was obviously prohibited, while the expression of p53 was enhanced. These results indicate that the silence of p66(Shc) in HCT8 cells inhibits the viability via PI3K/AKT/Mdm-2/p53 signaling pathway, it may provide a promising approach to prevent the progress of colon cancer cell.

  11. The silence of p66Shc in HCT8 cells inhibits the viability via PI3K/AKT/Mdm-2/p53 signaling pathway

    Science.gov (United States)

    Zhang, Ling; Zhu, Shengtao; Shi, Xuesen; Sha, Weihong

    2015-01-01

    Colon cancer is the second most common cause of cancer-related death, indicating that some of its cancer cells are not eradicated by current therapies. The previous studies demonstrated that p66Shc protein, a member of Shc family, is highly expressed in colon cancer cells, but the role of p66Shc in the progress of colon cancer still unknown. In this study, we found that p66Shc highly expressed in colon cancer tissue and colon cancer cell line SW620 cells, HCT8 cells, HCT116 cells and CaCO2 cells. The silence of p66Shc in HCT8 cells reduced the proliferation and accelerated the apoptosis, in addition, the expression of pro-apoptotic proteins caspase-3, caspase-9, Bax was enhanced and the expression of anti-apoptotic protein Bcl-2 was declined. Moreover, the cell cycle arrest in G0/G1 phase after HCT8 cells treated with p66Shc siRNA. Furthermore, after HCT8 cells treated with p66Shc siRNA, the phosphorylation of PI3K and AKT was significantly suppressed, and the expression of Mdm-2, a downstream of AKT, was obviously prohibited, while the expression of p53 was enhanced. These results indicate that the silence of p66Shc in HCT8 cells inhibits the viability via PI3K/AKT/Mdm-2/p53 signaling pathway, it may provide a promising approach to prevent the progress of colon cancer cell. PMID:26464652

  12. The CLC-2 Chloride Channel Modulates ECM Synthesis, Differentiation, and Migration of Human Conjunctival Fibroblasts via the PI3K/Akt Signaling Pathway.

    Science.gov (United States)

    Sun, Lixia; Dong, Yaru; Zhao, Jing; Yin, Yuan; Zheng, Yajuan

    2016-06-09

    Recent evidence suggests that chloride channels are critical for cell proliferation, migration, and differentiation. We examined the effects of transforming growth factor (TGF)-β1 on chloride channel expression and associations with human conjunctival fibroblast (HConF) biology. To investigate the potential role of chloride channel (CLC)-2 in migration, transition to myofibroblasts and extracellular matrix (ECM) synthesis of HconF, a small interfering RNA (siRNA) approach was applied. TGF-β1-induced migration and transition of fibroblasts to myofibroblasts characterized by α-smooth muscle actin (α-SMA) expression, supported by increased endogenous expression of CLC-2 protein and mRNA transcripts. ECM (collagen I and fibronectin) synthesis in HConF was enhanced by TGF-β1. CLC-2 siRNA treatment reduced TGF-β1-induced cell migration, transition of fibroblasts to myofibroblasts, and ECM synthesis of HConF. CLC-2 siRNA treatment in the presence of TGF-β1 inhibited phosphorylation of PI3K and Akt in HConF. These findings demonstrate that CLC-2 chloride channels are important for TGF-β1-induced migration, differentiation, and ECM synthesis via PI3K/Akt signaling in HConF.

  13. Ganoderma tsugae Extract Inhibits Growth of HER2-Overexpressing Cancer Cells via Modulation of HER2/PI3K/Akt Signaling Pathway

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    Han-Peng Kuo

    2013-01-01

    Full Text Available Ganoderma, also known as Lingzhi or Reishi, has been used for medicinal purposes in Asian countries for centuries. It is a medicinal fungus with a variety of biological properties including immunomodulatory and antitumor activities. In this study, we investigated the molecular mechanisms by which Ganoderma tsugae (GT, one of the most common species of Ganoderma, inhibits the proliferation of HER2-overexpressing cancer cells. Here, we show that a quality assured extract of GT (GTE inhibited the growth of HER2-overexpressing cancer cells in vitro and in vivo and enhanced the growth-inhibitory effect of antitumor drugs (e.g., taxol and cisplatin in these cells. We also demonstrate that GTE induced cell cycle arrest by interfering with the HER2/PI3K/Akt signaling pathway. Furthermore, GTE curtailed the expression of the HER2 protein by modulating the transcriptional activity of the HER2 gene and the stability/degradation of the HER2 protein. In conclusion, this study suggests that GTE may be a useful adjuvant therapeutic agent in the treatment of cancer cells that highly express HER2.

  14. RSC96 Schwann Cell Proliferation and Survival Induced by Dilong through PI3K/Akt Signaling Mediated by IGF-I

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    Yung-Ming Chang

    2011-01-01

    Full Text Available Schwann cell proliferation is critical for the regeneration of injured nerves. Dilongs are widely used in Chinese herbal medicine to remove stasis and stimulate wound-healing functions. Exactly how this Chinese herbal medicine promotes tissue survival remains unclear. The aim of the present study was to investigate the molecular mechanisms by which Dilong promote neuron regeneration. Our results show that treatment with extract of Dilong induces the phosphorylation of the insulin-like growth factor-I (IGF-I-mediated phosphatidylinositol 3-kinase/serine-threonine kinase (PI3K/Akt pathway, and activates protein expression of cell nuclear antigen (PCNA in a time-dependent manner. Cell cycle analysis showed that G1 transits into the S phase in 12–16 h, and S transits into the G2 phase 20 h after exposure to earthworm extract. Strong expression of cyclin D1, cyclin E and cyclin A occurs in a time-dependent manner. Small interfering RNA (siRNA-mediated knockdown of PI3K significantly reduced PI3K protein expression levels, resulting in Bcl2 survival factor reduction and a marked blockage of G1 to S transition in proliferating cells. These results demonstrate that Dilong promotes the proliferation and survival of RSC96 cells via IGF-I signaling. The mechanism is mainly dependent on the PI3K protein.

  15. Adenosine triphosphate-sensitive potassium channel opener protects PC12 cells against hypoxia-induced apoptosis through PI3K/Akt and Bcl-2 signaling pathways

    Institute of Scientific and Technical Information of China (English)

    Hong Zhang; Chunhong Jia; Danyang Zhao; Yang Lu; Runling Wang; Jia Li

    2010-01-01

    Although previous studies have shown the neuroprotective effects of the adenosine triphosphate (ATP)-sensitive potassium (KATP) channel opener against ischemic neuronal damage, little is known about the mechanisms involved. Phosphatidylinositol-3 kinase (PI3K)/v-akt murine thy-moma viral oncogene homolog (Akt) and Bcl-2 are thought to be important factors that mediate neuroprotection. The present study investigated the effects of KATP openers on hypoxia-induced PC12 cell apoptosis, as well as mRNA and protein expression of Akt and Bcl-2. Results demon-strated that pretreatment of PC12 cells with pinacidil, a KATP opener, resulted in decreased PC12 cell apoptosis following hypoxia, as detected by Annexin-V fluorescein isothiocyanate/ propidium iodide double staining flow cytometry. In addition, mRNA and protein expression of phosphorylated Akt (p-Akt) and Bcl-2 increased, as detected by immunofluorescence, Western blot analysis, and reverse-transcription polymerase chain reaction. The protective effect of this preconditioning was attenuated by glipizide, a selective KATP blocker. These results demonstrate for the first time that the protective mechanisms of KATP openers on PC12 cell apoptosis following hypoxia could result from activation of the PI3K/Akt signaling pathway, which further activates expression of the downstream Bcl-2 gene.

  16. Polyphenols isolated from Allium cepa L. induces apoptosis by suppressing IAP-1 through inhibiting PI3K/Akt signaling pathways in human leukemic cells.

    Science.gov (United States)

    Han, Min Ho; Lee, Won Sup; Jung, Ji Hyun; Jeong, Jae-Hun; Park, Cheol; Kim, Hye Jung; Kim, GonSup; Jung, Jin-Myung; Kwon, Taeg Kyu; Kim, Gi-Young; Ryu, Chung Ho; Shin, Sung Chul; Hong, Soon Chan; Choi, Yung Hyun

    2013-12-01

    Allium cepa Linn is commonly used as supplementary folk remedy for cancer therapy. Evidence suggests that Allium extracts have anti-cancer properties. However, the mechanisms of the anti-cancer activity of A. cepa Linn are not fully elucidated in human cancer cells. In this study, we investigated anti-cancer effects of polyphenols extracted from lyophilized A. cepa Linn (PEAL) in human leukemia cells and their mechanisms. PEAL inhibited cancer cell growth by inducing caspase-dependent apoptosis. The apoptosis was suppressed by caspase 8 and 9 inhibitors. PEAL also up-regulated TNF-related apoptosis-inducing ligand (TRAIL) receptor DR5 and down-regulated survivin and cellular inhibitor of apoptosis 1 (cIAP-1). We confirmed these findings in other leukemic cells (THP-1, K562 cells). In addition, PEAL suppressed Akt activity and the PEAL-induced apoptosis was significantly attenuated in Akt-overexpressing U937 cells. In conclusion, our data suggested that PEAL induced caspase-dependent apoptosis in several human leukemic cells including U937 cells. The apoptosis was triggered through extrinsic pathway by up-regulating DR5 modulating as well as through intrinsic pathway by modulating IAP family members. In addition, PEAL induces caspase-dependent apoptosis at least in part through the inhibition of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. This study provides evidence that PEAL might be useful for the treatment of leukemia.

  17. The Apoptotic Effect of Ursolic Acid on SK-Hep-1 Cells is Regulated by the PI3K/Akt, p38 and JNK MAPK Signaling Pathways.

    Science.gov (United States)

    Chuang, Wan-Ling; Lin, Ping-Yi; Lin, Hui-Chuan; Chen, Yao-Li

    2016-01-01

    Ursolic acid (UA) is a pentacyclic triterpene acid that is present in a wide variety of medicinal herbs and edible plants. This study investigated the effect of UA on apoptosis and proliferation of hepatocellular carcinoma SK-Hep-1 cells. After treatment of SK-Hep-1 cells with different concentrations of UA, we observed that cell viability was reduced in a dose- and time-dependent manner. Furthermore, there was a dose-dependent increase in the percentage of cells in the sub-G1 and G2/M phases, with cells treated with 60 μM showing the highest percentages of cells in those phases. UA-induced chromatin condensation of nuclei was observed by using DAPI staining. The western blot results revealed that exposure to UA was associated with decreased expression of the anti-apoptotic proteins Mcl-1, Bcl-xL, Bcl-2, and TCTP and increased expression of apoptosis-related proteins TNF-α, Fas, FADD, Bax, cleaved caspase-3, caspase-8, caspase-9, and PARP. Immunocytochemistry staining showed that treatment with UA resulted in increased expression of caspase-3. Moreover, exposure to UA resulted in the inhibition of the PI3K/Akt and p38 MAPK signaling pathways. These findings suggest that UA inhibits the proliferation of SK-Hep-1 cells and induces apoptosis.

  18. Hypaphorine Attenuates Lipopolysaccharide-Induced Endothelial Inflammation via Regulation of TLR4 and PPAR-γ Dependent on PI3K/Akt/mTOR Signal Pathway.

    Science.gov (United States)

    Sun, Haijian; Zhu, Xuexue; Cai, Weiwei; Qiu, Liying

    2017-04-17

    Endothelial lesion response to injurious stimuli is a necessary step for initiating inflammatory cascades in blood vessels. Hypaphorine (Hy) from different marine sources is shown to exhibit anti-inflammatory properties. However, the potential roles and possible molecular mechanisms of Hy in endothelial inflammation have yet to be fully clarified. We showed that Hy significantly inhibited the positive effects of lipopolysaccharide (LPS) on pro-inflammatory cytokines expressions, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), monocyte chemoattractant protein 1 (MCP-1) and vascular cellular adhesion molecule-1 (VCAM-1), as well as induction of the phosphorylation of Akt and mTOR in HMEC-1 cells. The downregulated peroxisome proliferator-activated receptor γ (PPAR-γ) and upregulated toll-like receptor 4 (TLR4) expressions in LPS-challenged endothelial cells were prevented by Hy. Inhibition of both PI3K and mTOR reversed LPS-stimulated increases in TLR4 expressions and decreases in PPAR-γ levels. Genetic silencing of TLR4 or PPAR-γ agonist pioglitazone obviously abrogated the levels of pro-inflammatory cytokines in LPS-treated HMEC-1 cells. These results suggest that Hy may exert anti-inflammatory actions through the regulation of TLR4 and PPAR-γ dependent on PI3K/Akt/mTOR signal pathways. Hy may be considered as a therapeutic agent that can potentially relieve or ameliorate endothelial inflammation-associated diseases.

  19. Protection afforded by quercetin against H2O2-induced apoptosis on PC12 cells via activating PI3K/Akt signal pathway.

    Science.gov (United States)

    Chen, Liang; Sun, Lejin; Liu, Zhene; Wang, Hongxia; Xu, Cunli

    2016-01-01

    Cell damage and apoptosis induced by oxidative stress have been involved in various neurodegenerative diseases. This study aims to explore the neuro-protective effects of quercetin on PC12 cells apoptosis induced by hydrogen peroxide (H(2)O(2)) and the underlying mechanisms. The cell viability was detected, as well as the production of reactive oxygen species (ROS), lactate dehydrogenase (LDH) leakage, and the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and malondialdehyde (MDA) of the cells in control, H(2)O(2) and quercetin groups. It finally turned out that quercetin might protect PC12 cells against the negative effect of H(2)O(2) by decreasing of LDH release, ROS concentration and MDA level and regaining the GSH-Px and SOD activities. To investigate the mechanism, LY294002 was introduced, the phosphatidylinositol-3-kinase (PI3K) inhibitor. Bax/Bcl-2 ratio and Akt phosphorylation (p-Akt) were examined by Western blot analysis. The data showed that LY294002 almost had the same effects with H(2)O(2), which was also significantly reversed by quercetin could enhance Bax/Bcl-2 ratio and adjust the p-Akt expression, which indicated quercetin might protect PC12 cells against the negative effect of H(2)O(2) via activating the PI3K/Akt signal pathway.

  20. PI3K/Akt signaling pathway involved in regulation of T lymphocyte activation and apoptosis mediated by CD3e

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To study the expression and kinase activity of phosphatidylinositol 3′-kinase (PI3K) and protein kinase B (PKB or Akt) during activation and apoptosis of human Jurkat T lymphocytes (TJK) with stable expression of CD8e chimera fused human CD8a extracellular and transmembra-ne domains to intracellular domain of mouse CD3e, Western blot, kinase activities detection and immunoprecipitation were carried out. It was shown that Jurkat cells with expres-sion of wild type chimera CD8e died by apoptosis after con-tinuous stimulation of anti-CD8 monoclonal antibody. The expressions of PI3K and Akt, and the kinase activity of Akt remarkably increased during the process. However, this phenomenon did not occur in the Jurkat cells (T1JK) with expression of the mutant of CD8e chimera (Y170F), sug-gesting that PI3K/Akt signaling pathway is involved in acti-vation and apoptosis of T lymphocyte mediated by CD3e.

  1. Tenuigenin Prevents IL-1β-induced Inflammation in Human Osteoarthritis Chondrocytes by Suppressing PI3K/AKT/NF-κB Signaling Pathway.

    Science.gov (United States)

    Wang, Chunlei; Zeng, Lihong; Zhang, Tao; Liu, Jiakun; Wang, Wenbo

    2016-04-01

    Tenuigenin (TEN), the main active component of Polygala tenuifolia, has been reported to have anti-inflammatory effects. However, the effects of TEN on IL-1β-stimulated osteoarthritis chondrocytes have not been reported. The purpose of this study was to investigate the anti-inflammatory effects and mechanism of TEN on IL-1β-stimulated human osteoarthritis chondrocytes. Human osteoarthritis chondrocytes were pretreated with or without TEN for 1 h and then stimulated with IL-1β. The production of NO and PGE2 were detected by the Griess reagent and ELISA. The expression of NF-κB and MAPKs (p38, JNK, ERK) were measured by Western blot analysis. The production of MMP-1, MMP3, and MMP13 were measured by ELISA. The results showed that treatment of TEN significantly inhibited IL-1β-induced NO and PGE2 production. TEN also suppressed IL-1β-induced MMP-1, MMP3, and MMP13 expression. Furthermore, TEN was found to inhibit IL-1β-induced NF-κB activation, PI3K, and AKT phosphorylation. In conclusion, these results suggest that TEN inhibits IL-1β-induced inflammation in human osteoarthritis chondrocytes by inhibiting PI3K/AKT/NF-κB signaling pathway.

  2. MicroRNA Dysregulation in Liver and Pancreas of CMP-Neu5Ac Hydroxylase Null Mice Disrupts Insulin/PI3K-AKT Signaling

    Directory of Open Access Journals (Sweden)

    Deug-Nam Kwon

    2014-01-01

    Full Text Available CMP-Neu5Ac hydroxylase (Cmah-null mice fed with a high-fat diet develop fasting hyperglycemia, glucose intolerance, and pancreatic β-cell dysfunction and ultimately develop characteristics of type 2 diabetes. The precise metabolic role of the Cmah gene remains poorly understood. This study was designed to investigate the molecular mechanisms through which microRNAs (miRNAs regulate type 2 diabetes. Expression profiles of miRNAs in Cmah-null mouse livers were compared to those of control mouse livers. Liver miFinder miRNA PCR arrays (n=6 showed that eight miRNA genes were differentially expressed between the two groups. Compared with controls, seven miRNAs were upregulated and one miRNA was downregulated in Cmah-null mice. Specifically, miR-155-5p, miR-425-5p, miR-15a-5p, miR-503-5p, miR-16-5p, miR-29a-3p, and miR-29b-3p were significantly upregulated in the liver and pancreas of Cmah-null mice. These target miRNAs are closely associated with dysregulation of insulin/PI3K-AKT signaling, suggesting that the Cmah-null mice could be a useful model for studying diabetes.

  3. PI3K/Akt1 signalling specifies foregut precursors by generating regionalized extra-cellular matrix

    DEFF Research Database (Denmark)

    Villegas, S Nahuel; Rothová, Michaela; Barrios-Llerena, Martin E;

    2013-01-01

    During embryonic development signalling pathways act repeatedly in different contexts to pattern the emerging germ layers. Understanding how these different responses are regulated is a central question for developmental biology. In this study, we used mouse embryonic stem cell (mESC) differentia...

  4. Role of PI3K/AKT/mTOR signaling in the cell cycle progression of human prostate cancer.

    Science.gov (United States)

    Gao, Ning; Zhang, Zhuo; Jiang, Bing-Hua; Shi, Xianglin

    2003-10-31

    Prostate cancer is one of the most common cancers among men. Recent studies demonstrated that PI3K signaling is an important intracellular mediator which is involved in multiple cellular functions including proliferation, differentiation, anti-apoptosis, tumorigenesis, and angiogenesis. In the present study, we demonstrate that the inhibition of PI3K activity by LY294002, inhibited prostate cancer cell proliferation and induced the G(1) cell cycle arrest. This effect was accompanied by the decreased expression of G(1)-associated proteins including cyclin D1, CDK4, and Rb phosphorylation at Ser780, Ser795, and Ser807/811, whereas expression of CDK6 and beta-actin was not affected by LY294002. The expression of cyclin kinase inhibitor, p21(CIP1/WAF1), was induced by LY294002, while levels of p16(INK4) were decreased in the same experiment. The inhibition of PI3K activity also inhibited the phosphorylation and p70(S6K), but not MAPK. PI3K regulates cell cycle through AKT, mTOR to p70(S6K). The mTOR inhibitor rapamycin has similar inhibitory effects on G(1) cell cycle progression and expression of cyclin D1, CDK4, and Rb phosphorylation. These results suggest that PI3K mediates G(1) cell cycle progression and cyclin expression through the activation of AKT/mTOR/p70(S6K) signaling pathway in the prostate cancer cells.

  5. Inhibiting GLUT-1 expression and PI3K/Akt signaling using apigenin improves the radiosensitivity of laryngeal carcinoma in vivo.

    Science.gov (United States)

    Bao, Yang-Yang; Zhou, Shui-Hong; Lu, Zhong-Jie; Fan, Jun; Huang, Ya-Ping

    2015-10-01

    Hypoxia is an important factor in radioresistance of laryngeal carcinoma. Glucose transporter-1 (GLUT-1) is an important hypoxic marker in malignant tumors, including laryngeal carcinoma. Apigenin is a natural phytoestrogen flavonoid that has potential anticancer effects. Various studies have reported that the effects of apigenin on lowering GLUT-1 expression were involved in downregulation of the PI3K/Akt pathway. Thus, apigenin may improve the radiosensitivity of laryngeal carcinoma by suppressing the expression of GLUT-1 via the PI3K/Akt pathway. The effect of GLUT-1 and PI3K/Akt pathway-related factor expressions by apigenin or antisense oligonucleotides (AS-ODNs) on the radiosensitivity of laryngeal carcinoma in vivo was assessed. The xenograft volume, xenograft weight and apoptosis detection were performed to determine radiosensitivity. The results showed that apigenin or apigenin plus GLUT-1 AS-ODNs improved the radiosensitivity of xenografts. Apigenin or apigenin plus GLUT-1 reduced the expression of GLUT-1, Akt, and PI3K mRNA after X-ray radiation. We found similar results at the protein level. The results suggest that the effects of apigenin on inhibiting xenograft growth and enhancing xenograft radiosensitivity may be associated with suppressing the expression of GLUT-1 via the PI3K/Akt pathway. In addition, apigenin may enhance the effects of GLUT-1 AS-ODNs via the same mechanism.

  6. Coactivation of the PI3K/Akt and ERK signaling pathways in PCB153-induced NF-κB activation and caspase inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Changjiang [MOE Key Lab of Environment and Health, Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030 (China); Key Lab of Birth Defects and Reproductive Health of National Health and Family Planning Commission, Chongqing Population and Family Planning Science and Technology Research Institute, Chongqing 400020 (China); Yang, Jixin [Department of Pediatric Surgery, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030 (China); Fu, Wenjuan; Qi, Suqin; Wang, Chenmin; Quan, Chao [MOE Key Lab of Environment and Health, Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030 (China); Yang, Kedi, E-mail: yangkd@mails.tjmu.edu.cn [MOE Key Lab of Environment and Health, Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030 (China)

    2014-06-15

    Polychlorinated biphenyls (PCBs) are a group of persistent and widely distributed environmental pollutants that have various deleterious effects, e.g., neurotoxicity, endocrine disruption and reproductive abnormalities. In order to verify the hypothesis that the PI3K/Akt and MAPK pathways play important roles in hepatotoxicity induced by PCBs, Sprague–Dawley (SD) rats were dosed with PCB153 intraperitoneally at 0, 4, 16 and 32 mg/kg for five consecutive days; BRL cells (rat liver cell line) were treated with PCB153 (0, 1, 5, and 10 μM) for 24 h. Results indicated that the PI3K/Akt and ERK pathways were activated in vivo and in vitro after exposure to PCB153, and protein levels of phospho-Akt and phospho-ERK were significantly increased. Nuclear factor-κB (NF-κB) activation and caspase-3, -8 and -9 inhibition caused by PCB153 were also observed. Inhibiting the ERK pathway significantly attenuated PCB153-induced NF-κB activation, whereas inhibiting the PI3K/Akt pathway hardly influenced phospho-NF-κB level. However, inhibiting the PI3K/Akt pathway significantly elevated caspase-3, -8 and -9 activities, while the ERK pathway only synergistically regulated caspase-9. Proliferating cell nuclear antigen (PCNA), a reliable indicator of cell proliferation, was also induced. Moreover, PCB153 led to hepatocellular hypertrophy and elevated liver weight. Taken together, PCB153 leads to aberrant proliferation and apoptosis of hepatocytes through NF-κB activation and caspase inhibition, and coactivated PI3K/Akt and ERK pathways play critical roles in PCB153-induced hepatotoxicity. - Highlights: • PCB153 led to hepatotoxicity through NF-κB activation and caspase inhibition. • The PI3K/Akt and ERK pathways were coactivated in vivo and in vitro by PCB153. • The ERK pathway regulated levels of phospho-NF-κB and caspase-9. • The PI3K/Akt pathway regulated levels of caspase-3, -8 and -9.

  7. PI3K/Akt/GSK-3β在去负荷及再负荷大鼠腓肠肌蛋白代谢中的作用%The Effect of PI3K/Akt/GSK-3β Signal Pathway on Gastrocnemius Protein Metabolism in Unloading and Reloading Rats

    Institute of Scientific and Technical Information of China (English)

    张飞鹏; 吴金富; 王晶

    2011-01-01

    目的:观察去负荷及再负荷过程PI3K/Akt/GSK-3β信号途径的变化,并探讨该过程对骨骼肌蛋白分解及合成代谢的影响。研究方法:24只雌性SD大鼠随机分对照组(NC)、去负荷14 d模型组(TS)、去负荷14 d+再负荷自由活动14 d组(NR)、去负荷14 d+再负荷离心运动14 d组(ER)。用免疫印迹半定量分析PI3K、Akt、GSK-3β和P-GSK-3β的表达。研究结果:与NC组相比,TS组腓肠肌总蛋白含量显著下降(P〈0.05);以不同方式再负荷14 d都能使腓肠肌蛋白含量提高,NR与ER组之间没有显著差异;ER组PI3K蛋白表达显著高于NR组(P〈0.05);ER组Akt也高于NR组,但没有显著性差异。ER组的P-GSK-3β和GSK-3β蛋白表达与NR组的相似趋势,其中ER组的P-GSK-3β与NC组相比,有显著性差异(P〈0.05);而GSK3β则显著增加(P〈0.05)。结论:在去负荷条件下,PI3K/Akt/GSK-3β信号对骨骼肌蛋白分解影响较小;再负荷条件下,离心运动能加强PI3K/Akt/GSK-3β信号作用,参与骨骼肌蛋白合成。%objective: To observe PI3K/Akt/GSK-3β signal pathways on skeletal muscle protein metabolism in unloading and reloading,and discuss the relationship between eccentric exercise and PI3K/Akt/GSK-3β signal pathways on the apoptosis and anabolic.Methods: 24 female SD rats were divided into four groups: normal control group(NC),14 days tail-suspension group(TS),14 days tail-suspension 14 days standing naturally group(NR),14 days tail-suspension 14 days eccentric exercise group(ER).Western blotting was used to semi-quantitative analysis PI3K,Ak,GSK-3β and P-GSK-3β protein expression.Results: Compared with NC group,TS group's total protein content dropped significantly(P0.05);In a different way to the reloading in 14 days,the total protein content increased both in NR and ER,but there were no significant differences between NR and ER.PI3K protein expression in ER was more

  8. Derivatives containing both coumarin and benzimidazole potently induce caspase-dependent apoptosis of cancer cells through inhibition of PI3K-AKT-mTOR signaling.

    Science.gov (United States)

    Liu, Haitao; Wang, Yubin; Sharma, Ashok; Mao, Rui; Jiang, Na; Dun, Boying; She, Jin-Xiong

    2015-07-01

    Coumarins are a large family of compounds derived from a wide range of plants, fungi, and bacteria, and coumarin derivatives can have extremely variable structures and consequently diverse biological properties including antitumor activity. Compounds that bear a benzimidazole moiety are known to possess antitumor activity and a variety of other biological activities. High-throughput screening of a compound library identified a coumarin-containing and a benzimidazole-containing compound [#32, 7-(diethylamino)-3-(1-methyl-1H-benzimidazol-2-yl)-2H-chromen-2-one] that has potent anticancer activity. Evaluation of 17 additional analogs further identified three compounds with anticancer activity in 14 different human cancer cell lines. Fluorescence-activated cell sorting and western blotting analyses suggested that these compounds can induce caspase-dependent apoptosis. Real-time reverse transcriptase PCR analyses of 26 cancer-related genes revealed that seven genes (NPPB, ATF3, DDIT4, CDH10, TSPAN14, TXNIP, and AXL) were significantly upregulated and nine genes (PAGE4, LRP8, SNCAIP, IGFBP5, SLCO2A1, CLDN2, ESRRG, D2HGDH, and PDGFRA) were significantly downregulated. The most upregulated gene is natriuretic peptide precursor B (NPPB) or brain natriuretic peptide, which is increased by 7-, 27-, and 197-fold at 12, 24, and 48 h, respectively. The second most upregulated gene is ATF3, which is increased by 23-fold at the 48 h timepoint. PAGE4 and IGFBP5 are the two most downregulated genes, with a 17-fold reduction in both genes. The expression of several genes (DDIT4, PDGFRA, LRP8, IGFBP5) and western blotting data on key signaling proteins indicate that compound #32 significantly inhibits the PI3K-AKT-mTOR pathway, an intracellular signaling pathway critical in cell proliferation and apoptosis.

  9. Catalase expression in MCF-7 breast cancer cells is mainly controlled by PI3K/Akt/mTor signaling pathway.

    Science.gov (United States)

    Glorieux, Christophe; Auquier, Julien; Dejeans, Nicolas; Sid, Brice; Demoulin, Jean-Baptiste; Bertrand, Luc; Verrax, Julien; Calderon, Pedro Buc

    2014-05-15

    Catalase is an antioxidant enzyme that catalyzes mainly the transformation of hydrogen peroxide into water and oxygen. Although catalase is frequently down-regulated in tumors the underlying mechanism remains unclear. Few transcription factors have been reported to directly bind the human catalase promoter. Among them FoxO3a has been proposed as a positive regulator of catalase expression. Therefore, we decided to study the role of the transcription factor FoxO3a and the phosphatidylinositol-3 kinase (PI3K) signaling pathway, which regulates FoxO3a, in the expression of catalase. To this end, we developed an experimental model of mammary breast MCF-7 cancer cells that acquire resistance to oxidative stress, the so-called Resox cells, in which catalase is overexpressed as compared with MCF-7 parental cell line. In Resox cells, Akt expression is decreased but its phosphorylation is enhanced when compared with MCF-7 cells. A similar profile is observed for FoxO3a, with less total protein but more phosphorylated FoxO3a in Resox cells, correlating with its higher Akt activity. The modulation of FoxO3a expression by knockdown and overexpression strategies did not affect catalase expression, neither in MCF-7 nor in Resox cells. Inhibition of PI3K and mTOR by LY295002 and rapamycin, respectively, decreases the phosphorylation of downstream targets (i.e. GSK3β and p70S6K) and leads to an increase of catalase expression only in MCF-7 but not in Resox cells. In conclusion, FoxO3a does not appear to play a critical role in the regulation of catalase expression in both cancer cells. Only MCF-7 cells are sensitive and dependent on PI3K/Akt/mTOR signaling.

  10. Dexmedetomidine attenuates repeated propofol exposure-induced hippocampal apoptosis, PI3K/Akt/Gsk-3β signaling disruption, and juvenile cognitive deficits in neonatal rats.

    Science.gov (United States)

    Wang, Yujie; Wu, Changyi; Han, Bin; Xu, Fei; Mao, Mingfeng; Guo, Xiangyang; Wang, Jun

    2016-07-01

    Propofol is one of the most widely used intravenous anesthetics. However, repeated exposure to propofol may cause neurodegeneration in the developing brain. Dexmedetomidine (Dex), an α2 adrenoceptor agonist, has been previously demonstrated to provide neuroprotection against neuroapoptosis and neurocognitive impairments induced by several anesthetics. Thus, the current study aimed to investigate the effect of Dex on neonatal propofol-induced neuroapoptosis and juvenile spatial learning/memory deficits. Propofol (30 mg/kg) was intraperiotoneally administered to 7‑day‑old Sprague Dawley rats (n=75) three times each day at 90 min intervals for seven consecutive days with or without Dex (75 µg/kg) treatment 20 min prior to propofol injection. Following repeated propofol exposure, reduced Akt and GSK‑3β phosphorylation, increased cleaved caspase‑3 expression levels, an increased Bax/Bcl‑2 ratio, and increased terminal deoxynucleotidyl transferase‑mediated dUTP nick‑end labeling (TUNEL)‑positive cells in the CA1 hippocampal subregion were observed. Morris Water Maze testing at postnatal day 29 also demonstrated spatial learning and memory deficits following propofol treatment compared with the control group. Notably, these changes were significantly attenuated by Dex pretreatment. The results of the current study demonstrated that Dex ameliorates the neurocognitive impairment induced by repeated neonatal propofol challenge in rats, partially via its anti‑apoptotic action and normalization of the disruption to the PI3K/Akt/GSK‑3β signaling pathway. The present study provides preliminary evidence demonstrating the safety of propofol on the neonatal brain and the potential use of dexmedetomidine pretreatment in pediatric patients.

  11. Exposure to Ionizing Radiation Causes Long-Term Increase in Serum Estradiol and Activation of PI3K-Akt Signaling Pathway in Mouse Mammary Gland

    Energy Technology Data Exchange (ETDEWEB)

    Suman, Shubhankar [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States); Johnson, Michael D. [Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC (United States); Fornace, Albert J. [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States); Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC (United States); Datta, Kamal, E-mail: kd257@georgetown.edu [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States)

    2012-10-01

    Purpose: Exposure to ionizing radiation is an established risk factor for breast cancer. Radiation exposure during infancy, childhood, and adolescence confers the highest risk. Although radiation is a proven mammary carcinogen, it remains unclear where it acts in the complex multistage process of breast cancer development. In this study, we investigated the long-term pathophysiologic effects of ionizing radiation at a dose (2 Gy) relevant to fractionated radiotherapy. Methods and Materials: Adolescent (6-8 weeks old; n = 10) female C57BL/6J mice were exposed to 2 Gy total body {gamma}-radiation, the mammary glands were surgically removed, and serum and urine samples were collected 2 and 12 months after exposure. Molecular pathways involving estrogen receptor-{alpha} (ER{alpha}) and phosphatidylinositol-3-OH kinase (PI3K)-Akt signaling were investigated by immunohistochemistry and Western blot. Results: Serum estrogen and urinary levels of the oncogenic estrogen metabolite (16{alpha}OHE1) were significantly increased in irradiated animals. Immunostaining for the cellular proliferative marker Ki-67 and cyclin-D1 showed increased nuclear accumulation in sections of mammary glands from irradiated vs. control mice. Marked increase in p85{alpha}, a regulatory sub-unit of the PI3K was associated with increase in Akt, phospho-Akt, phospho-BAD, phospho-mTOR, and c-Myc in irradiated samples. Persistent increase in nuclear ER{alpha} in mammary tissues 2 and 12 months after radiation exposure was also observed. Conclusions: Taken together, our data not only support epidemiologic observations associating radiation and breast cancer but also, specify molecular events that could be involved in radiation-induced breast cancer.

  12. Protective Effect of DHT on Apoptosis Induced by U18666A via PI3K/Akt Signaling Pathway in C6 Glial Cell Lines.

    Science.gov (United States)

    Yao, Kai; Wu, Junfeng; Zhang, Jianfeng; Bo, Jimei; Hong, Zhen; Zu, Hengbing

    2016-07-01

    Various useful animal models, such as Alzheimer's disease and Niemann-Pick disease, were provided by U18666A. However, the pathogenesis of U18666A-induced diseases, including U18666A-mediated apoptosis, remains incompletely elucidated, and therapeutic strategies are still limited. Dihydrotestosterone (DHT) has been reported to contribute to the prevention and treatment of neurodegenerative disorders. Our study investigated the neuroprotective activity of DHT in U18666A-related diseases. Apoptosis of C6 cells was detected by Hoechst 33258 fluorescent staining and flow cytometry with annexin V-FITC/PI dual staining. Cell viability was assessed using Cell Counting Kit-8. Expression of apoptosis-related proteins, such as Akt, seladin-1, Bcl-2 family proteins, and caspase-3, was determined using Western blot. Our results demonstrated that the apoptotic rate of C6 cells significantly increased after U18666A addition, but was remarkably reduced after DHT treatment. Pretreatment with DHT attenuated U18666A-induced cell viability loss. PI3K inhibitor LY294002 could suppress DHT anti-apoptotic effect. Furthermore, we discovered that U18666A could significantly downregulate seladin-1 expression in a dose-dependent manner, but no significant change was observed in Bcl-xL, Bax, and P-Akt protein expressions. Compared with U18666A-treated group, the expression of P-Akt, seladin-1, and Bcl-xL significantly increased, and the expression of Bax and caspase-3 remarkably reduced after DHT treatment. However, in the presence of LY294002, the effect of DHT was reversed. In conclusion, we found that seladin-1 may take part in U18666A-induced apoptosis. DHT may inhibit U18666A-induced apoptosis by regulating downstream apoptosis-related proteins including seladin-1, caspase-3, Bcl-xL, and Bax through activation of the PI3K/Akt signal pathway.

  13. Amiloride sensitizes human pancreatic cancer cells to erlotinib in vitro through inhibition of the PI3K/AKT signaling pathway

    Science.gov (United States)

    Zheng, Yuan-ting; Yang, Hui-ying; Li, Tao; Zhao, Bei; Shao, Teng-fei; Xiang, Xiao-qiang; Cai, Wei-min

    2015-01-01

    Aim: Blockade of EGFR by EGFR tyrosine kinase inhibitors such as erlotinib is insufficient for effective treatment of human pancreatic cancer due to independent activation of the Akt pathway, while amiloride, a potassium-sparing diuretic, has been found as a potential Akt inhibitor. The aim of this study was to investigate the anticancer effects of combined amiloride with erlotinib against human pancreatic cancer cells in vitro. Methods: Cell proliferation, colony formation, cell cycle and apoptosis were analyzed in 4 human pancreatic cancer cell lines Bxpc-3, PANC-1, Aspc-1 and CFPAC-1 treated with erlotinib or amiloride alone, or in their combination. The synergistic analysis for the effects of combinations of amiloride and erlotinib was performed using Chou-Talalay's combination index isobolographic method. Results: Amiloride (10, 30, and 100 μmol/L) concentration-dependently potentiated erlotinib-induced inhibition of cell proliferation and colony formation in the 4 pancreatic cancer cell lines. Isobolographic analysis confirmed that combinations of amiloride and erlotinib produced synergistic cytotoxic effects. Amiloride significantly potentiated erlotinib-induced G0/G1 cell-cycle arrest and apoptosis in Bxpc-3 and PANC-1 cells. Amiloride inhibited EGF-stimulated phorsphorylation of AKT, and significantly enhanced erlotinib-induced downregulation of phorsphorylation of EGFR, AKT, PI3K P85 and GSK 3β in Bxpc-3 and PANC-1 cells. Conclusion: Amiloride sensitizes human pancreatic cancer cells to erlotinib in vitro through inhibition of the PI3K/AKT signaling pathway. Treatment of pancreatic cancer patients with combination of erlotinib and amiloride merits further investigation. PMID:25864651

  14. Supercritical Fluid Extract of Spent Coffee Grounds Attenuates Melanogenesis through Downregulation of the PKA, PI3K/Akt, and MAPK Signaling Pathways

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    Huey-Chun Huang

    2016-01-01

    Full Text Available The mode of action of spent coffee grounds supercritical fluid CO2 extract (SFE in melanogenesis has never been reported. In the study, the spent coffee grounds were extracted by the supercritical fluid CO2 extraction method; the chemical constituents of the SFE were investigated by gas chromatography-mass spectrometry (GC-MS. The effects of the SFE and its major fatty acid components on melanogenesis were evaluated by mushroom tyrosinase activity assay and determination of intracellular tyrosinase activity and melanin content. The expression level of melanogenesis-related proteins was analyzed by western blotting assay. The results revealed that the SFE of spent coffee grounds (1–10 mg/mL and its major fatty acids such as linoleic acid and oleic acid (6.25–50 μM effectively suppressed melanogenesis in the B16F10 murine melanoma cells. Furthermore, the SFE decreased the expression of melanocortin 1 receptor (MC1R, microphthalmia-associated transcription factor (MITF, tyrosinase, tyrosinase-related protein-1 (TRP-1, and tyrosinase-related protein-2 (TRP-2. The SFE also decreased the protein expression levels of p-JNK, p-p38, p-ERK, and p-CREB. Our results revealed that the SFE of spent coffee grounds attenuated melanogenesis in B16F10 cells by downregulation of protein kinase A (PKA, phosphatidylinositol-3-kinase (PI3K/Akt, and mitogen-activated protein kinases (MAPK signaling pathways, which may be due to linoleic acid and oleic acid.

  15. Liraglutide Exerts Antidiabetic Effect via PTP1B and PI3K/Akt2 Signaling Pathway in Skeletal Muscle of KKAy Mice

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    Wenjun Ji

    2014-01-01

    Full Text Available Background. Liraglutide (a glucagon-like peptide 1 analog was used for the treatment of type 2 diabetes (T2DM which could produce glucose-dependent insulin secretion. Aim. The aim was to investigate whether liraglutide could improve myofibril and mitochondria injury in skeletal muscle and the mechanisms in diabetic KKAy mice. Method. We divided the male KKAy mice into 2 groups: liraglutide group (250 μg/kg/day liraglutide subcutaneous injection and model group; meanwhile, the male C57BL/6J mice were considered as the control. After 6 weeks, the ultrastructure of skeletal muscle was observed by electron microscope. The gene expressions of protein tyrosine phosphatase 1B (PTP1B, phosphatidylinositol 3-kinase (PI3K, and glucose transporter type 4 (GLUT4 were determined by real-time PCR. The protein levels of the above molecules and phospho-Akt2 (p-Akt2 were measured by Western blot. Results. Liraglutide significantly ameliorated the injury of mitochondria by increasing the number (+441% and the area (+113% of mitochondria and mitochondrial area/100 µm2 (+396% in skeletal muscle of KKAy mice. The results of real-time PCR and Western blot showed that liraglutide downregulated PTP1B while it upregulated PI3K and GLUT4 (P<0.01. The protein level of p-Akt2/Akt2 was also increased (P<0.01. Conclusion. These results revealed that liraglutide could improve myofibril and mitochondria injury in skeletal muscle against T2DM via PTP1B and PI3K/Akt2 signaling pathway.

  16. Rutin attenuates H2O2-induced oxidation damage and apoptosis in Leydig cells by activating PI3K/Akt signal pathways.

    Science.gov (United States)

    Sun, Jianhua; Wang, Heng; Liu, Bei; Shi, Wenhao; Shi, Juanzi; Zhang, Zhou; Xing, Junping

    2017-04-01

    Oxidative stress is a primary factor in the pathology of male infertility. The strong antioxidative capacity of rutin has been proven by numerous studies, but a protective role in the context of male reproduction remains to be elucidated. To explore the biological role of rutin in protecting male reproductive function and the potential underlying mechanism, H2O2-induced Leydig cells were used as a cell model of oxidation damage. Our findings showed that rutin at concentrations of 10, 20, and 40μmol/L remarkably increased cell survival rate of H2O2-induced Leydig cells to 70.1%, 86.8%, and 80.3% respectively. Next, rutin with concentrations of 10, 20, and 40μmol/L decreased reactive oxygen species (ROS) and malondialdehyde (MDA) levels but increased the levels of glutathione (GSH) and testosterone in H2O2-induced Leydig cells. The activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were remarkably increased by rutin treatment with concentrations of 20 and 40μmol/L, but glutathione peroxidase (GSH-Px) activity was notably decreased. Moreover, rutin with concentrations of 10, 20, and 40μmol/L increased Bcl-2 protein levels but decreased protein levels of Bax and caspase-3. Furthermore, 20μmol/L rutin significantly abrogated the decrease in levels of phosphoinositide 3-kinase (PI3K) and phosphorylated serine/threonine kinase (p-AKT) induced by H2O2. Pretreatment with LY294002, a PI3K inhibitor, antagonized protective action of 20μmol/L rutin against H2O2-induced cell activities, intracellular oxidant, testosterone, antioxidant enzyme activities, and the apoptosis related protein expression. Taken together, these results suggest that rutin attenuates H2O2-induced oxidation damage and apoptosis in Leydig cells by activating PI3K/Akt signal pathways, providing a promising strategy to decrease oxidative stress associated with male infertility.

  17. MicroRNA-21 Regulates PI3K/Akt/mTOR Signaling by Targeting TGFβI during Skeletal Muscle Development in Pigs.

    Science.gov (United States)

    Bai, Lijing; Liang, Ruyi; Yang, Yalan; Hou, Xinhua; Wang, Zishuai; Zhu, Shiyun; Wang, Chuduan; Tang, Zhonglin; Li, Kui

    2015-01-01

    MicroRNAs (miRNAs), which are short (22-24 base pairs), non-coding RNAs, play critical roles in myogenesis. Using Solexa deep sequencing, we detected the expression levels of 229 and 209 miRNAs in swine skeletal muscle at 90 days post-coitus (E90) and 100 days postnatal (D100), respectively. A total of 138 miRNAs were up-regulated on E90, and 31 were up-regulated on D100. Of these, 9 miRNAs were selected for the validation of the small RNA libraries by quantitative RT-PCR (RT-qPCR). We found that miRNA-21 was down-regulated by 17-fold on D100 (P<0.001). Bioinformatics analysis suggested that the transforming growth factor beta-induced (TGFβI) gene was a potential target of miRNA-21. Both dual luciferase reporter assays and western blotting demonstrated that the TGFβI gene was regulated by miRNA-21. Co-expression analysis revealed that the mRNA expression levels of miRNA-21 and TGFβI were negatively correlated (r = -0.421, P = 0.026) in skeletal muscle during the 28 developmental stages. Our results revealed that more miRNAs are expressed in prenatal than in postnatal skeletal muscle. The miRNA-21 is a novel myogenic miRNA that is involved in skeletal muscle development and regulates PI3K/Akt/mTOR signaling by targeting the TGFβI gene.

  18. MicroRNA-21 Regulates PI3K/Akt/mTOR Signaling by Targeting TGFβI during Skeletal Muscle Development in Pigs.

    Directory of Open Access Journals (Sweden)

    Lijing Bai

    Full Text Available MicroRNAs (miRNAs, which are short (22-24 base pairs, non-coding RNAs, play critical roles in myogenesis. Using Solexa deep sequencing, we detected the expression levels of 229 and 209 miRNAs in swine skeletal muscle at 90 days post-coitus (E90 and 100 days postnatal (D100, respectively. A total of 138 miRNAs were up-regulated on E90, and 31 were up-regulated on D100. Of these, 9 miRNAs were selected for the validation of the small RNA libraries by quantitative RT-PCR (RT-qPCR. We found that miRNA-21 was down-regulated by 17-fold on D100 (P<0.001. Bioinformatics analysis suggested that the transforming growth factor beta-induced (TGFβI gene was a potential target of miRNA-21. Both dual luciferase reporter assays and western blotting demonstrated that the TGFβI gene was regulated by miRNA-21. Co-expression analysis revealed that the mRNA expression levels of miRNA-21 and TGFβI were negatively correlated (r = -0.421, P = 0.026 in skeletal muscle during the 28 developmental stages. Our results revealed that more miRNAs are expressed in prenatal than in postnatal skeletal muscle. The miRNA-21 is a novel myogenic miRNA that is involved in skeletal muscle development and regulates PI3K/Akt/mTOR signaling by targeting the TGFβI gene.

  19. Insulin-like growth factor-1 (IGF-1) promotes myoblast proliferation and skeletal muscle growth of embryonic chickens via the PI3K/Akt signalling pathway.

    Science.gov (United States)

    Yu, Minli; Wang, Huan; Xu, Yali; Yu, Debing; Li, Dongfeng; Liu, Xiuhong; Du, Wenxing

    2015-08-01

    During embryonic development, IGF-1 fulfils crucial roles in skeletal myogenesis. However, the involvement of IGF-1-induced myoblast proliferation in muscle growth is still unclear. In the present study, we have characterised the role of IGF-1 in myoblast proliferation both in vitro and in vivo and have revealed novel details of how exogenous IGF-1 influences myogenic genes in chicken embryos. The results show that IGF-1 significantly induces the proliferation of cultured myoblasts in a dose-dependent manner. Additionally, the IGF-1 treatment significantly promoted myoblasts entering a new cell cycle and increasing the mRNA expression levels of cell cycle-dependent genes. However, these effects were inhibited by the PI3K inhibitor LY294002 and the Akt inhibitor KP372-1. These data indicated that the pro-proliferative effect of IGF-1 was mediated in response to the PI3K/Akt signalling pathway. Moreover, we also showed that exogenous IGF-1 stimulated myoblast proliferation in vivo. IGF-1 administration obviously promoted the incorporation of BrdU and remarkably increased the number of PAX7-positive cells in the skeletal muscle of chicken embryos. Administration of IGF-1 also significantly induced the upregulation of myogenic factors gene, the enhancement of c-Myc and the inhibition of myostatin (Mstn) expression. These findings demonstrate that IGF-1 has strong activity as a promoter of myoblast expansion and muscle fiber formation during early myogenesis. Therefore, this study offers insight into the mechanisms responsible for IGF-1-mediated stimulation of embryonic skeletal muscle development, which could have important implications for the improvement of chicken meat production. © 2015 International Federation for Cell Biology.

  20. Effects of D-Pinitol on Insulin Resistance through the PI3K/Akt Signaling Pathway in Type 2 Diabetes Mellitus Rats.

    Science.gov (United States)

    Gao, Yunfeng; Zhang, Mengna; Wu, Tianchen; Xu, Mengying; Cai, Haonan; Zhang, Zesheng

    2015-07-08

    D-pinitol, a compound isolated from Pinaceae and Leguminosae plants, has been reported to possess insulin-like properties. Although the hypoglycemic activity of D-pinitol was recognized in recent years, the molecular mechanism of D-pinitol in the treatment of diabetes mellitus remains unclear. In this investigation, a model of type 2 diabetes mellitus (T2DM) with insulin resistance was established by feeding a high-fat diet (HFD) and injecting streptozocin (STZ) to Sprague-Dawley (SD) rats, targeting the exploration of more details of the mechanism in the therapy of T2DM. D-pinitol was administrated to the diabetic rats as two doses [30, 60 mg/(kg·body weight·day)]. The level of fasting blood glucose (FBG) was decreased 12.63% in the high-dosage group, and the ability of oral glucose tolerance was improved in D-pinitol-treated groups. The biochemical indices revealed that D-pinitol had a positive effect on hypoglycemic activity. Western boltting suggested that D-pinitol could promote the expression of the phosphatidylinositol-3-kinase (PI3K) p85, PI3Kp110, as well as the downstream target protein kinase B/Akt (at Ser473). Besides, D-pinitol inhibited the expression of glycogen synthesis kinase-3β (GSK-3β) protein and regulated the expression of glycogen synthesis (GS) protein and then accelerated the glycogen synthesis. Above all, D-pinitol played a positive role in regulating insulin-mediated glucose uptake in the liver through translocation and activation of the PI3K/Akt signaling pathway in T2DM rats.

  1. Involvement of PI3K/Akt/FoxO3a and PKA/CREB Signaling Pathways in the Protective Effect of Fluoxetine Against Corticosterone-Induced Cytotoxicity in PC12 Cells.

    Science.gov (United States)

    Zeng, Bingqing; Li, Yiwen; Niu, Bo; Wang, Xinyi; Cheng, Yufang; Zhou, Zhongzhen; You, Tingting; Liu, Yonggang; Wang, Haitao; Xu, Jiangping

    2016-08-01

    The selective serotonin reuptake inhibitor fluoxetine is neuroprotective in several brain injury models. It is commonly used to treat major depressive disorder and related conditions, but its mechanism of action remains incompletely understood. Activation of the phosphatidylinositol-3-kinase/protein kinase B/forkhead box O3a (PI3K/Akt/FoxO3a) and protein kinase A/cAMP-response element binding protein (PKA/CREB) signaling pathways has been strongly implicated in the pathogenesis of depression and might be the downstream target of fluoxetine. Here, we used PC12 cells exposed to corticosterone (CORT) to study the neuroprotective effects of fluoxetine and the involvement of the PI3K/Akt/FoxO3a and PKA/CREB signaling pathways. Our results show that CORT reduced PC12 cells viability by 70 %, and that fluoxetine showed a concentration-dependent neuroprotective effect. Neuroprotective effects of fluoxetine were abolished by inhibition of PI3K, Akt, and PKA using LY294002, KRX-0401, and H89, respectively. Treatment of PC12 cells with fluoxetine resulted in increased phosphorylation of Akt, FoxO3a, and CREB. Fluoxetine also dose-dependently rescued the phosphorylation levels of Akt, FoxO3a, and CREB, following administration of CORT (from 99 to 110, 56 to 170, 80 to 170 %, respectively). In addition, inhibition of PKA and PI3K/Akt resulted in decreased levels of p-CREB, p-Akt, and p-FoxO3a in the presence of fluoxetine. Furthermore, fluoxetine reversed CORT-induced upregulation of p53-upregulated modulator of apoptosis (Puma) and Bcl-2-interacting mediator of cell death (Bim) via the PI3K/Akt/FoxO3a signaling pathway. H89 treatment reversed the effect of fluoxetine on the mRNA level of brain-derived neurotrophic factor, which was decreased in the presence of CORT. Our data indicate that fluoxetine elicited neuroprotection toward CORT-induced cell death that involves dual regulation from PI3K/Akt/FoxO3a and PKA/CREB pathways.

  2. Mefloquine effectively targets gastric cancer cells through phosphatase-dependent inhibition of PI3K/Akt/mTOR signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yanwei [Department of General Surgery, Shiyan Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei Province (China); Chen, Sen [Department of Academic Affairs, Hubei University of Medicine, Shiyan, Hubei Province (China); Xue, Rui [Department of Anesthesiology, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei Province (China); Zhao, Juan [Department of Oncology, Xiangyang Central Hospital, Shiyan, Hubei Province (China); Di, Maojun, E-mail: maoojun_di@163.com [Department of General Surgery, Shiyan Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei Province (China)

    2016-02-05

    Deregulation of PI3K/Akt/mTOR pathway has been recently identified to play a crucial role in the progress of human gastric cancer. In this study, we show that mefloquine, a FDA-approved anti-malarial drug, effectively targets human gastric cancer cells. Mefloquine potently inhibits proliferation and induces apoptosis of a panel of human gastric cancer cell lines, with EC{sub 50} ∼0.5–0.7 μM. In two independent gastric cancer xenograft mouse models, mefloquine significantly inhibits growth of both tumors. The combination of mefloquine with paclitaxel enhances the activity of either drug alone in in vitro and in vivo. In addition, mefloquine potently decreased phosphorylation of PI3K, Akt, mTOR and rS6. Overexpression of constitutively active Akt significantly restored mefloquine-mediated inhibition of mTOR phosphorylation and growth, and induction of apoptosis, suggesting that mefloquine acts on gastric cancer cells via suppressing PI3K/Akt/mTOR pathway. We further show that mefloquine-mediated inhibition of Akt/mTOR singaling is phosphatase-dependent as pretreatment with calyculin A does-dependently reversed mefloquine-mediated inhibition of Akt/mTOR phosphorylation. Since mefloquine is already available for clinic use, these results suggest that it is a useful addition to the treatment armamentarium for gastric cancer. - Highlights: • Mefloquine targets a panel of gastric cancer cell lines in vitro and in vivo. • Combination of mefloquine and paclitaxel is synergistic. • Mefloquine acts on gastric cancer via inhibition of PI3K/Akt/mTOR pathway. • Mefloquine can be repurposed for gastric cancer treatment.

  3. Mefloquine effectively targets gastric cancer cells through phosphatase-dependent inhibition of PI3K/Akt/mTOR signaling pathway.

    Science.gov (United States)

    Liu, Yanwei; Chen, Sen; Xue, Rui; Zhao, Juan; Di, Maojun

    2016-02-05

    Deregulation of PI3K/Akt/mTOR pathway has been recently identified to play a crucial role in the progress of human gastric cancer. In this study, we show that mefloquine, a FDA-approved anti-malarial drug, effectively targets human gastric cancer cells. Mefloquine potently inhibits proliferation and induces apoptosis of a panel of human gastric cancer cell lines, with EC50 ∼ 0.5-0.7 μM. In two independent gastric cancer xenograft mouse models, mefloquine significantly inhibits growth of both tumors. The combination of mefloquine with paclitaxel enhances the activity of either drug alone in in vitro and in vivo. In addition, mefloquine potently decreased phosphorylation of PI3K, Akt, mTOR and rS6. Overexpression of constitutively active Akt significantly restored mefloquine-mediated inhibition of mTOR phosphorylation and growth, and induction of apoptosis, suggesting that mefloquine acts on gastric cancer cells via suppressing PI3K/Akt/mTOR pathway. We further show that mefloquine-mediated inhibition of Akt/mTOR singaling is phosphatase-dependent as pretreatment with calyculin A does-dependently reversed mefloquine-mediated inhibition of Akt/mTOR phosphorylation. Since mefloquine is already available for clinic use, these results suggest that it is a useful addition to the treatment armamentarium for gastric cancer.

  4. Cadmium induces carcinogenesis in BEAS-2B cells through ROS-dependent activation of PI3K/AKT/GSK-3β/β-catenin signaling

    Energy Technology Data Exchange (ETDEWEB)

    Son, Young-Ok; Wang, Lei; Poyil, Pratheeshkumar; Budhraja, Amit; Hitron, J. Andrew; Zhang, Zhuo [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States); Lee, Jeong-Chae [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States); School of Dentistry and Institute of Oral Biosciences (BK21 program), Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin, E-mail: xshi5@email.uky.edu [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States)

    2012-10-15

    Cadmium has been widely used in industry and is known to be carcinogenic to humans. Although it is widely accepted that chronic exposure to cadmium increases the incidence of cancer, the mechanisms underlying cadmium-induced carcinogenesis are unclear. The main aim of this study was to investigate the role of reactive oxygen species (ROS) in cadmium-induced carcinogenesis and the signal transduction pathways involved. Chronic exposure of human bronchial epithelial BEAS-2B cells to cadmium induced cell transformation, as evidenced by anchorage-independent growth in soft agar and clonogenic assays. Chronic cadmium treatment also increased the potential of these cells to invade and migrate. Injection of cadmium-stimulated cells into nude mice resulted in the formation of tumors. In contrast, the cadmium-mediated increases in colony formation, cell invasion and migration were prevented by transfection with catalase, superoxide dismutase-1 (SOD1), or SOD2. In particular, chronic cadmium exposure led to activation of signaling cascades involving PI3K, AKT, GSK-3β, and β-catenin and transfection with each of the above antioxidant enzymes markedly inhibited cadmium-mediated activation of these signaling proteins. Inhibitors specific for AKT or β-catenin almost completely suppressed the cadmium-mediated increase in total and active β-catenin proteins and colony formation. Moreover, there was a marked induction of AKT, GSK-3β, β-catenin, and carcinogenic markers in tumor tissues formed in mice after injection with cadmium-stimulated cells. Collectively, our findings suggest a direct involvement of ROS in cadmium-induced carcinogenesis and implicate a role of AKT/GSK-3β/β-catenin signaling in this process. -- Highlights: ► Chronic exposure to cadmium induces carcinogenic properties in BEAS-2B cells. ► ROS involved in cadmium-induced tumorigenicity of BEAS-2B cells. ► Cadmium activates ROS-dependent AKT/GSK-3β/β-catenin-mediated signaling. ► ROS

  5. Reactive oxygen species via redox signaling to PI3K/AKT pathway contribute to the malignant growth of 4-hydroxy estradiol-transformed mammary epithelial cells.

    Directory of Open Access Journals (Sweden)

    Victor O Okoh

    Full Text Available The purpose of this study was to investigate the effects of 17-β-estradiol (E2-induced reactive oxygen species (ROS on the induction of mammary tumorigenesis. We found that ROS-induced by repeated exposures to 4-hydroxy-estradiol (4-OH-E2, a predominant catechol metabolite of E2, caused transformation of normal human mammary epithelial MCF-10A cells with malignant growth in nude mice. This was evident from inhibition of estrogen-induced breast tumor formation in the xenograft model by both overexpression of catalase as well as by co-treatment with Ebselen. To understand how 4-OH-E2 induces this malignant phenotype through ROS, we investigated the effects of 4-OH-E2 on redox-sensitive signal transduction pathways. During the malignant transformation process we observed that 4-OH-E2 treatment increased AKT phosphorylation through PI3K activation. The PI3K-mediated phosphorylation of AKT in 4-OH-E2-treated cells was inhibited by ROS modifiers as well as by silencing of AKT expression. RNA interference of AKT markedly inhibited 4-OH-E2-induced in vitro tumor formation. The expression of cell cycle genes, cdc2, PRC1 and PCNA and one of transcription factors that control the expression of these genes - nuclear respiratory factor-1 (NRF-1 was significantly up-regulated during the 4-OH-E2-mediated malignant transformation process. The increased expression of these genes was inhibited by ROS modifiers as well as by silencing of AKT expression. These results indicate that 4-OH-E2-induced cell transformation may be mediated, in part, through redox-sensitive AKT signal transduction pathways by up-regulating the expression of cell cycle genes cdc2, PRC1 and PCNA, and the transcription factor - NRF-1. In summary, our study has demonstrated that: (i 4-OH-E2 is one of the main estrogen metabolites that induce mammary tumorigenesis and (ii ROS-mediated signaling leading to the activation of PI3K/AKT pathway plays an important role in the generation of 4-OH-E2

  6. Caulerpa lentillifera extract ameliorates insulin resistance and regulates glucose metabolism in C57BL/KsJ-db/db mice via PI3K/AKT signaling pathway in myocytes.

    Science.gov (United States)

    Sharma, Bhesh Raj; Kim, Hyun Jung; Rhyu, Dong Young

    2015-02-15

    Glucose homeostasis is distorted by defects of the PI3K/AKT and AMPK pathways in insulin-sensitive tissues, allowing the accumulation of glucose in the blood. The purpose of this study was to assess the effects and mechanisms by which ethanol extract of Caulerpa lentillifera (CLE) regulates glucose metabolism in C57BL/KsJ-db/db (db/db) mice. Mice were administered CLE (250 or 500 mg/kg BW) or rosiglitazone (RSG, 10 mg/kg BW) for 6 weeks. Then, oral glucose tolerance test (OGTT) and intraperitoneal insulin tolerance test (IPITT) were performed, and blood glucose was measured in db/db mice. Levels of insulin and insulin resistance factors in plasma, glycogen content in the liver, and IRS, PI3K, AKT, and GLUT4 expressions in skeletal muscles were measured in db/db mice. Glucose uptake and insulin signaling molecules were measured in L6 myocytes, using fluorometry and Western blotting. CLE significantly decreased fasting blood glucose, glucose level in OGTT and IPITT, plasma insulin, homeostatic model assessment-insulin resistant (HOMA-IR), TNF-α, IL-6, FFA, TG and TC levels, and hepatic glycogen content in db/db mice. CLE significantly increased the activation of IRS, AKT, PI3K, and GLUT4, which are the key effector molecules of the PI3K/AKT pathway in L6 myocytes and the skeletal muscles of db/db mice. The enhanced glucose uptake by CLE was abolished by treatment with a PI3K inhibitor (LY294002), but not by an AMPK inhibitor (compound C) in L6 myocytes. CLE regulated glucose uptake and homeostasis via the PI3K/AKT pathway in myocytes and db/db mice, respectively. Our results suggest that CLE could be a potential candidate for the prevention of diabetes.

  7. TOP 1 and 2, polysaccharides from Taraxacum officinale, inhibit NFκB-mediated inflammation and accelerate Nrf2-induced antioxidative potential through the modulation of PI3K-Akt signaling pathway in RAW 264.7 cells.

    Science.gov (United States)

    Park, Chung Mu; Cho, Chung Won; Song, Young Sun

    2014-04-01

    Anti-inflammatory and anti-oxidative activities of polysaccharides from Taraxacum officinale (TOP 1 and 2) were analyzed in RAW 264.7 cells. First, lipopolysaccharide (LPS) was applied to identify anti-inflammatory activity of TOPs, which reduced expression of inducible nitric oxide synthase (iNOS) and tumor necrosis factor (TNF)-α. TOPs treatment inhibited phosphorylation of inflammatory transcription factor, nuclear factor (NF)κB, and its upstream signaling molecule, PI3K/Akt. Second, cytoprotective potential of TOPs against oxidative stress was investigated via heme oxygenase (HO)-1 induction. HO-1, one of phase II enzymes shows antioxidative activity, was potently induced by TOPs treatment, which was in accordance with the nuclear translocation of nuclear factor-erythroid 2 p45-related factor 2 (Nrf2). In addition, TOPs treatment phosphorylated PI3K/Akt with slight activation of c-Jun NH2-terminal kinase (JNK). TOPs-mediated HO-1 induction protected macrophage cells from oxidative stress-induced cell death, which was confirmed by SnPP and CoPP (HO-1 inhibitor and inducer, respectively). Consequently, TOPs potently inhibited NFκB-mediated inflammation and accelerated Nrf2-mediated antioxidative potential through the modulation of PI3K/Akt pathway, which would contribute to their promising strategy for novel anti-inflammatory and anti-oxidative agents.

  8. Puquitinib mesylate (XC-302) induces autophagy via inhibiting the PI3K/AKT/mTOR signaling pathway in nasopharyngeal cancer cells.

    Science.gov (United States)

    Wang, Ke-Feng; Yang, Hang; Jiang, Wen-Qi; Li, Su; Cai, Yu-Chen

    2015-12-01

    provides the evidence that XC-302 can induce autophagy in CNE-2, which promotes the program of cell death and inhibits the PI3K/AKT/mTOR signaling pathway. Furthermore, XC-302 also promoted apoptosis in CNE-2 cells, which could be reduced when autophagy was suppressed, meaning that autophagy may interact with apoptosis to induce cell death.

  9. Arginine deiminase inhibits pancreatic cancer cell invasion by blocking PI3K-AKT signaling pathway%精氨酸脱亚胺酶阻断PI3K-AKT通路抑制胰腺癌细胞侵袭

    Institute of Scientific and Technical Information of China (English)

    刘江波; 雷亮亮; 杨延辉; 黎韡; 马清涌; 刘德纯; 李三强

    2016-01-01

    目的 研究精氨酸脱亚胺酶(arginine deiminase,ADI)对胰腺癌细胞株迁移、侵袭能力的影响及可能的分子机制.方法 选取精氨琥珀酸合成酶表达缺陷和表达阳性的胰腺癌细胞株PANC-1和BxPC-3接受含ADI培养基或普通培养基培养干预.细胞划痕及Transwell试验检测细胞迁移和侵袭能力;实时定量PCR技术及Western blot检测侵袭相关基因mRNA和蛋白的改变.Western blot和Transwell试验检测ADI联合PI3K信号抑制剂LY29400对PAN C-l细胞侵袭行为及分子的影响.结果 ADI可抑制PANC-1细胞的迁移、侵袭(P<0.05),下调PANC-I细胞尿激酶型纤溶酶原激活因子、基质蛋白金属酶(matrix metalloproteinases,MMP)-2、MMP-9,和上调金属蛋白酶类组织抑制剂-2和E-Cadherin的mRNA和/或蛋白表达水平(P<0.05);而对BxPC-3细胞侵袭能力影响不明显.ADI可下调PANC-1细胞PI3K/AKT/核转录因子-κB(nuclear factor-kappa B,NF-κB)信号通路蛋白p-AKT、p-p65的表达水平,而LY294002则协同ADI的这种作用,并协同下调MMP-2水平;Transwell侵袭试验也显示LY294002可协同ADI抑制胰腺癌细胞的侵袭能力(P<0.05).结论 ADI通过阻断PI3K-AKT信号通路调控侵袭相关基因表达抑制胰腺癌细胞侵袭.

  10. Effects of Glut1 gene silencing on proliferation, differentiation and apoptosis of colorectal cancer cells by targeting the TGF-β/PI3K-AKT-mTOR signaling pathway.

    Science.gov (United States)

    Wu, Xue-Liang; Wang, Li-Kun; Yang, Dong-Dong; Qu, Ming; Yang, Yong-Jiang; Guo, Fei; Han, Lei; Xue, Jun

    2017-09-08

    This study aims to investigate the effects of glucose transport l (Glut1) gene on proliferation, differentiation and apoptosis of colorectal cancer (CRC) cells by regulating the TGF-β/PI3K-AKT-mTOR signaling pathway. Immunohistochemistry was conducted to detect the positive Glut1 expression. Normal human CRC epithelial cells (CCD-18Co) and CRC cell line HCT116 were grouped into the control, blank, negative control (NC), and shGlut1-1 groups. RT-qPCR and Western blotting were performed to detect the expressions of Glut1, TGF-β1, PI3K, AKT, PTEN, mTOR, Bcl-2 and Bax. Protein expression of phosphorylated-PI3K (p-PI3K), p-S473-AKT, p-S389-S6K1, p-T70-4EBP1, Cleaved caspase-3 and Cleaved-PARP were detected. MTT assay, flow cytometry and colony formation assay were performed in order to detect cell viability, cell cycle and apoptosis, respectively. The positive expression rate of Glut1 in CRC tissues was 75% ± 8%, while in the adjacent normal tissues it was 0%. In comparison to adjacent normal tissues, CRC tissues had increased Glut1, TGF-β1, PI3K, AKT, mTOR and Bcl-2 expressions, and p-PI3K, p-S473-AKT, p-S389-S6K1 and p-T70-4EBP1 expressions; and decreased PTEN, Bax, Cleaved caspase-3 and Cleaved-PARP expressions. On comparison with the blank and NC groups, cells in the shGlut1-1 group showed decreased Glut1, TGF-β1, PI3K, AKT, mTOR and Bcl-2 expressions, and p-PI3K, p-S473-AKT, p-S389-S6K1 and p-T70-4EBP1 expressions; and increased PTEN, Bax, Cleaved caspase-3 and Cleaved-PARP expressions, along with more arrested cells in C0/C1 phase than in S phase and slower cell growth. These results suggested that silencing the Glut1 gene inhibited proliferation and promoted apoptosis of CRC cells by inactivating TGF-β/PI3K-AKT-mTOR signaling pathway. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  11. Effect of lipitor on high glucose-induced HUVEC apoptosis and PI3K/AKT/eNOS signal pathway%立普妥对高糖诱导的HUVEC凋亡及PI3 K/AKT/eNOS信号通路的影响

    Institute of Scientific and Technical Information of China (English)

    刘志辉

    2016-01-01

    目的 探讨立普妥对高糖诱导的人脐静脉内皮细胞(HUVEC)的凋亡及对磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(AKT)/内皮型一氧化氮(eNOS)信号通路的影响.方法 实验分为正常组,模型组(33.3 mol/L葡萄糖),立普妥组(33.3 mol/L葡萄糖+0.1,1,10μmol/L);MTT法检测各组HUVEC活力;倒置显微镜拍照检测各组HUVEC形态;Annexin V-FITC/PI流式双染法检测各组HUVEC凋亡;Gries法检测各组HUVEC上清NO含量;Western blot分析PI3K/AKT激活状况及eNOS的表达情况.结果 与正常组比较,高糖组中HUVEC皱缩,变圆变亮,细胞活力降低,细胞早期凋亡和晚期凋亡率显著提高,NO含量及eNOS、PI3K表达量及AKT磷酸化程度降低,差异均具有显著性(P<0.05);与模型组比较,1,10μmol/L立普妥组中HUVEC形态恢复,细胞活力上升,PI3K表达量提高,差异均具有显著性(P<0.05);0.1,1,10μmol/L立普妥组HUVEC凋亡程度下降,NO含量、eNOS表达量提高,AKT磷酸化水平上升,差异均具有显著性(P<0.05).结论 立普妥可抵抗高糖诱导的HUVEC凋亡,是通过激活PI3 K/AKT/eNOS信号通路实现的.%Objectives To explore effect of lipitor on apoptosis and phosphatidyl inositol-3-kinase ( PI3K)/protein kinase B ( AKT )/endothelial nitric oxide synthase ( eNOS ) signal pathway in high glucose-induced human umbilical vein endothelial cell ( HUVEC) .Methods The cases were randomly divided into normal control group, model control group (33.3 mol/L glucose), lipitor low, medium, high-dose group (0.1,1,10 μmol/L lipitor).The viability of HUVEC was detected by MTT assay.The morphology of HUVEC was photographed by inverted microscope.The apoptosis of HUVEC was examed by Annexin V-FITC/PI flow dual-staining method.The concertration of NO in HUVEC supernatant was exmaed by Gries method.The activation of PI3K/AKT and expression of eNOS was assayed by western blot.Results HUVEC was shrinkage, rounded and brighten, the viability of HUVEC decreased, early and late

  12. Quercetin induces apoptosis and autophagy in primary effusion lymphoma cells by inhibiting PI3K/AKT/mTOR and STAT3 signaling pathways.

    Science.gov (United States)

    Granato, Marisa; Rizzello, Celeste; Gilardini Montani, Maria Saveria; Cuomo, Laura; Vitillo, Marina; Santarelli, Roberta; Gonnella, Roberta; D'Orazi, Gabriella; Faggioni, Alberto; Cirone, Mara

    2017-03-01

    Quercetin, a bioflavonoid contained in several vegetables daily consumed, has been studied for long time for its antiinflammatory and anticancer properties. Quercetin interacts with multiple cancer-related pathways such as PI3K/AKT, Wnt/β-catenin and STAT3. These pathways are hyperactivated in primary effusion lymphoma (PEL), an aggressive B cell lymphoma whose pathogenesis is strictly linked to the oncogenic virus Kaposis' Sarcoma-associated Herpesvirus (KSHV). In this study, we found that quercetin inhibited PI3K/AKT/mTOR and STAT3 pathways in PEL cells, and as a consequence, it down-regulated the expression of the prosurvival cellular proteins such as c-FLIP, cyclin D1 and cMyc. It also reduced the release of IL-6 and IL-10 cytokines, leading to PEL cell death. Moreover, quercetin induced a prosurvival autophagy in these cells and increased the cytotoxic effect of bortezomib, a proteasomal inhibitor, against them. Interestingly, quercetin decreased also the expression of latent and lytic KSHV proteins involved in PEL tumorigenesis and up-regulated the surface expression of HLA-DR and calreticulin, rendering the dying cells more likely detectable by the immune system. The results obtained in this study indicate that quercetin, which does not exert any cytotoxicity against normal B cells, may represent a good candidate for the treatment of this aggressive B cell lymphoma, especially in combination with autophagy inhibitors or with bortezomib. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Quercetin Protects against Okadaic Acid-Induced Injury via MAPK and PI3K/Akt/GSK3β Signaling Pathways in HT22 Hippocampal Neurons

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    Li, Sheng; Zhou, Yue; Shen, Xiu-Yin; He, Feng; Xu, Jie; Wang, Hua-Qiao

    2016-01-01

    Increasing evidence shows that oxidative stress and the hyperphosphorylation of tau protein play essential roles in the progression of Alzheimer’s disease (AD). Quercetin is a major flavonoid that has anti-oxidant, anti-cancer and anti-inflammatory properties. We investigated the neuroprotective effects of quercetin to HT22 cells (a cell line from mouse hippocampal neurons). We found that Okadaic acid (OA) induced the hyperphosphorylation of tau protein at Ser199, Ser396, Thr205, and Thr231 and produced oxidative stress to the HT22 cells. The oxidative stress suppressed the cell viability and decreased the levels of lactate dehydrogenase (LDH), superoxide dismutase (SOD), mitochondria membrane potential (MMP) and Glutathione peroxidase (GSH-Px). It up-regulated malondialdehyde (MDA) production and intracellular reactive oxygen species (ROS). In addition, phosphoinositide 3 kinase/protein kinase B/Glycogen synthase kinase3β (PI3K/Akt/GSK3β) and mitogen activated protein kinase (MAPK) were also involved in this process. We found that pre-treatment with quercetin can inhibited OA-induced the hyperphosphorylation of tau protein and oxidative stress. Moreover, pre-treatment with quercetin not only inhibited OA-induced apoptosis via the reduction of Bax, and up-regulation of cleaved caspase 3, but also via the inhibition of PI3K/Akt/GSK3β, MAPKs and activation of NF-κB p65. Our findings suggest the therapeutic potential of quercetin to treat AD. PMID:27050422

  14. Quercetin Protects against Okadaic Acid-Induced Injury via MAPK and PI3K/Akt/GSK3β Signaling Pathways in HT22 Hippocampal Neurons.

    Directory of Open Access Journals (Sweden)

    Wei Jiang

    Full Text Available Increasing evidence shows that oxidative stress and the hyperphosphorylation of tau protein play essential roles in the progression of Alzheimer's disease (AD. Quercetin is a major flavonoid that has anti-oxidant, anti-cancer and anti-inflammatory properties. We investigated the neuroprotective effects of quercetin to HT22 cells (a cell line from mouse hippocampal neurons. We found that Okadaic acid (OA induced the hyperphosphorylation of tau protein at Ser199, Ser396, Thr205, and Thr231 and produced oxidative stress to the HT22 cells. The oxidative stress suppressed the cell viability and decreased the levels of lactate dehydrogenase (LDH, superoxide dismutase (SOD, mitochondria membrane potential (MMP and Glutathione peroxidase (GSH-Px. It up-regulated malondialdehyde (MDA production and intracellular reactive oxygen species (ROS. In addition, phosphoinositide 3 kinase/protein kinase B/Glycogen synthase kinase3β (PI3K/Akt/GSK3β and mitogen activated protein kinase (MAPK were also involved in this process. We found that pre-treatment with quercetin can inhibited OA-induced the hyperphosphorylation of tau protein and oxidative stress. Moreover, pre-treatment with quercetin not only inhibited OA-induced apoptosis via the reduction of Bax, and up-regulation of cleaved caspase 3, but also via the inhibition of PI3K/Akt/GSK3β, MAPKs and activation of NF-κB p65. Our findings suggest the therapeutic potential of quercetin to treat AD.

  15. Electro-acupuncture at points of Zusanli and Quchi exerts anti-apoptotic effect through the modulation of PI3K/Akt signaling pathway.

    Science.gov (United States)

    Xue, Xiehua; You, Yongmei; Tao, Jing; Ye, Xiaoqian; Huang, Jia; Yang, Shanli; Lin, Zhicheng; Hong, Zhenfeng; Peng, Jun; Chen, Lidian

    2014-01-13

    We evaluated the neuroprotective effect of electro-acupuncture (EA) on cerebral ischemia-reperfusion (IR) injury and deeply investigated the relationship between this neuroprotective effect and PI3K/Akt pathway. Rats underwent focal cerebral IR injured by suture method and received the in vivo therapeutic efficacy of EA at points of Zusanli(ST36) and Quchi(LI11) after the operation. We found that the EA treatment significantly (psignaling resulted in the inhibition of cerebral cell apoptosis in the ischemic penumbra. Simultaneously EA increased the expression of PI3K, p-Akt, p-Bad and Bcl-2 at the protein level and the expression of Bcl-2 at the mRNA level. On the contrary, EA inhibited the Bax and cleaved Caspase-3-positive expression. The selective PI3K inhibitor LY294002 compromised EA-induced neuroprotective effects and reduced the elevation of p-Akt, p-Bad and Bcl-2 levels. Our data suggested that the PI3K/Akt pathway played a critical role in mediating the neuroprotective effects of EA treatment at points of Zusanli and Quchi after the ischemic stroke. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  16. Role for the PI3K/Akt/Nrf2 signaling pathway in the protective effects of carnosic acid against methylglyoxal-induced neurotoxicity in SH-SY5Y neuroblastoma cells.

    Science.gov (United States)

    de Oliveira, Marcos Roberto; Ferreira, Gustavo Costa; Schuck, Patrícia Fernanda; Dal Bosco, Simone Morelo

    2015-12-05

    Glycation, a process that occurs endogenously and generates advanced glycation end products (AGEs), presents an important role in cases of neurodegeneration, as for instance Alzheimer's disease (AD). Methylglyoxal (MG), a dicarbonyl compound, is the most potent inducer of AGEs, whose levels have been found increased in samples obtained from subjects suffering from AD. Moreover, MG induces protein cross-linking and redox impairment in vitro and in vivo. Carnosic acid (CA), a phenolic diterpene isolated from Rosmarinus officinalis, exerts protective effects in neuronal cells by increasing antioxidant defenses and detoxification systems. In the present work, we aimed to investigate whether there is a role for CA against MG-induced neurotoxicity. Data obtained here clearly demonstrate that CA pretreatment (1 μM for 12 h) caused cytoprotective effects and counteracted the damage elicited by MG in SH-SY5Y cells. CA inhibited loss of mitochondrial membrane polarity (MMP) and cytochrome c release from mitochondria, consequently blocking activation of pro-apoptotic caspase enzymes. Furthermore, CA alleviated MG-induced oxidative and nitrosative damage. CA prevented MG-dependent neurotoxicity by activating the PI3K/Akt/Nrf2 signaling pathway and the antioxidant enzymes modulated by Nrf2 transcription factor. Overall, the data presented here show the protective role of CA by its ability to counteract MG negative effects.

  17. Inhibition of melanogenesis by gallic acid: possible involvement of the PI3K/Akt, MEK/ERK and Wnt/β-catenin signaling pathways in B16F10 cells.

    Science.gov (United States)

    Su, Tzu-Rong; Lin, Jen-Jie; Tsai, Chi-Chu; Huang, Tsu-Kei; Yang, Zih-Yan; Wu, Ming-O; Zheng, Yu-Qing; Su, Ching-Chyuan; Wu, Yu-Jen

    2013-10-14

    Gallic acid is one of the major flavonoids found in plants. It acts as an antioxidant, and seems to have anti-inflammatory, anti-viral, and anti-cancer properties. In this study, we investigated the effects of gallic acid on melanogenesis, including the activation of melanogenesis signaling pathways. Gallic acid significantly inhibited both melanin synthesis and tyrosinase activity in a dose- and time-dependent manner, and decreased the expression of melanogenesis-related proteins, such as microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 (TRP1), and dopachrome tautomerase (Dct). In addition, gallic acid also acts by phosphorylating and activating melanogenesis inhibitory proteins such as Akt and mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK). Using inhibitors against PI3K/Akt (LY294002) or MEK/ERK-specific (PD98059), the hypopigmentation effect was suppressed, and the gallic acid-initiated activation of MEK/ERK and PI3K/Akt was also revoked. Gallic acid also increased GSK3β and p-β-catenin expression but down-regulated p-GSK3β. Moreover, GSK3β-specific inhibitor (SB216763) restored gallic acid-induced melanin reduction. These results suggest that activation of the MEK/ERK, PI3K/Akt, and inhibition of Wnt/β-catenin signaling pathways is involved in the melanogenesis signaling cascade, and that activation by gallic acid reduces melanin synthesis via down-regulation of MITF and its downstream signaling pathway. In conclusion, gallic acid may be a potentially agent for the treatment of certain skin conditions.

  18. Inhibition of Melanogenesis by Gallic Acid: Possible Involvement of the PI3K/Akt, MEK/ERK and Wnt/β-Catenin Signaling Pathways in B16F10 Cells

    Directory of Open Access Journals (Sweden)

    Yu-Jen Wu

    2013-10-01

    Full Text Available Gallic acid is one of the major flavonoids found in plants. It acts as an antioxidant, and seems to have anti-inflammatory, anti-viral, and anti-cancer properties. In this study, we investigated the effects of gallic acid on melanogenesis, including the activation of melanogenesis signaling pathways. Gallic acid significantly inhibited both melanin synthesis and tyrosinase activity in a dose- and time-dependent manner, and decreased the expression of melanogenesis-related proteins, such as microphthalmia-associated transcription factor (MITF, tyrosinase, tyrosinase-related protein-1 (TRP1, and dopachrome tautomerase (Dct. In addition, gallic acid also acts by phosphorylating and activating melanogenesis inhibitory proteins such as Akt and mitogen-activated protein kinase (MEK/extracellular signal-regulated kinase (ERK. Using inhibitors against PI3K/Akt (LY294002 or MEK/ERK-specific (PD98059, the hypopigmentation effect was suppressed, and the gallic acid-initiated activation of MEK/ERK and PI3K/Akt was also revoked. Gallic acid also increased GSK3β and p-β-catenin expression but down-regulated p-GSK3β. Moreover, GSK3β-specific inhibitor (SB216763 restored gallic acid-induced melanin reduction. These results suggest that activation of the MEK/ERK, PI3K/Akt, and inhibition of Wnt/β-catenin signaling pathways is involved in the melanogenesis signaling cascade, and that activation by gallic acid reduces melanin synthesis via down-regulation of MITF and its downstream signaling pathway. In conclusion, gallic acid may be a potentially agent for the treatment of certain skin conditions.

  19. Isoorientin induces apoptosis and autophagy simultaneously by reactive oxygen species (ROS)-related p53, PI3K/Akt, JNK, and p38 signaling pathways in HepG2 cancer cells.

    Science.gov (United States)

    Yuan, Li; Wei, Shuping; Wang, Jing; Liu, Xuebo

    2014-06-11

    Cell death is closely related to autophagy under some circumstances; however, the effect of isoorientin (ISO) on autophagy and the interplay between apoptosis and autophagy in human hepatoblastoma cancer (HepG2) cells remains poorly understood. The present study showed that ISO induced autophagy, which was correlated with the formation of autophagic vacuoles and the overexpression of Beclin-1 and LC3-II. The autophagy inhibitor 3-methyladenine (3-MA) markedly inhibited apoptosis, and the apoptosis inhibitor ZVAD-fmk also decreased ISO-induced autophagy. In addition, the PI3K/Akt inhibitor LY294002 enhanced Beclin-1, LC3-II, and poly(ADP-ribose) polymerase (PARP) cleavage levels. Also, the reactive oxygen species (ROS) inhibitor N-acetyl-L-cysteine (NAC), the JNK inhibitor SP600125, and the p38 inhibitor SB203580 efficiently downregulated the levels of these proteins. Moreover, the p53 inhibitor pifithrin-α and the nuclear factor (NF)-κB inhibitor pyrrolidinedithiocarbamic acid (PDTC) clearly suppressed Beclin-1 and LC3-II and increased cytochrome c release, caspase-3 activation, and PARP cleavage. These results demonstrated for the first time that ISO simultaneously induced apoptosis and autophagy by ROS-related p53, PI3K/Akt, JNK, and p38 signaling pathways. Furthermore, ISO-induced apoptosis by activating the Fas receptor-mediated apoptotic pathway and suppressing the p53 and PI3K/Akt-dependent NF-κB signaling pathway, with the subsequent increase in the release of cytochrome c, caspase-3 activation, and PARP cleavage.

  20. c-Src activation promotes nasopharyngeal carcinoma metastasis by inducing the epithelial-mesenchymal transition via PI3K/Akt signaling pathway: a new and promising target for NPC

    Science.gov (United States)

    Lu, Jinping; Xia, Weixiong; Yu, Yahui; Peng, Yongjian; Wang, Li; Wang, Gang; Ye, Yanfang; Yang, Jing; Liang, Hu; Kang, Tiebang; Lv, Xing

    2016-01-01

    Aberrant activation of cellular Src (c-Src), a non-receptor tyrosine kinase, could promote cancer progression through activating its downstream signaling pathways. However, the roles of c-Src and phosphorylated-Src (p-Src) in nasopharyngeal carcinoma (NPC) progression are rarely investigated. Herein, we have identified high c-Src concentrations in the serum of NPC patients with distant metastasis using high-throughput protein microarrays. Levels of c-Src in serum and p-Src in human primary NPC samples were unfavorable independent prognostic factors for cancer-specific survival, disease-free survival, and distant metastasis-free survival. Depletion or inactivation of c-Src in NPC cells using sgRNA with CRISPR/Cas9 system or PP2 decreased cell viability, colony formation, migration and invasion in vitro and metastasis in vivo. In contrast, these malignancies could be up-regulated by overexpressed c-Src in a NPC cell line with low-metastasis potential. Furthermore, p-Src was involved in promoting NPC cell metastasis by inducing the epithelial-mesenchymal transition (EMT) process via activating the PI3K/Akt pathway and cytoskeleton remodeling. The p-Src-induced EMT process could be retarded by PP2, which mediated by down-regulating the PI3K/Akt pathway. In conclusion, elevated levels of c-Src in serum and p-Src in primary NPC tissue correlated with poor outcomes of NPC patients. And aberrant activation of c-Src facilitated NPC cells with malignant potential, especially metastasis ability, which mediated by the PI3K/Akt pathway activation and sequentially induced the EMT process. These findings unveiled a promising approach for targeted therapy of advanced NPC. PMID:27078847

  1. Simvastatin-induced breast cancer cell death and deactivation of PI3K/Akt and MAPK/ERK signalling are reversed by metabolic products of the mevalonate pathway.

    Science.gov (United States)

    Wang, Tingting; Seah, Serena; Loh, Xinyi; Chan, Ching-Wan; Hartman, Mikael; Goh, Boon-Cher; Lee, Soo-Chin

    2016-01-19

    Statins purportedly exert anti-tumoral effects on breast cancer. However, the biologic mechanisms for these actions are not fully elucidated. The aims of this study were 1) to explore the effects of simvastatin on apoptosis, proliferation as well as PI3K/Akt/mTOR and MAPK/ERK pathway in a window-of-opportunity breast cancer trial; 2) to further confirm findings from the clinical trial by functional studies; 3) to explore the regulatory role of mevalonate pathway on the anti-tumoral effects of simvastatin. In clinical samples, simvastatin led to increase in cleaved caspase-3 (p = 0.002) and decreased trend for Ki67 (p = 0.245). Simvastatin markedly suppressed PI3K/Akt/mTOR signalling by activating PTEN (p = 0.005) and by dephosphorylating Akt (p = 0.002) and S6RP (p = 0.033); it also inhibited MAPK/ERK pathway by dephosphorylating c-Raf (p = 0.018) and ERK1/2 (p = 0.002). In ER-positive (MCF-7, T47D) and ER-negative (MDA-MB-231, BT-549) breast cancer cells, simvastatin treatment consistently induced apoptosis and inhibited proliferation by deregulating caspase cascades and cell cycle proteins in a dose dependent manner. Concordantly, simvastatin strongly suppressed PI3K/Akt/mTOR pathway by enhancing PTEN expression and by further sequentially dephosphorylating downstream cascades including Akt, mTOR, p70S6K, S6RP and 4E-BP1. Furthermore, simvastatin significantly inhibited MAPK/ERK pathway by dephosphorylating sequential cascades such as c-Raf, MEK1/2 and ERK1/2. These simvastatin anti-tumoral effects were reversed by metabolic products of the mevalonate pathway, including mevalonate, farnesyl pyrophosphate and geranylgeranyl pyrophosphate. These findings shed light on the biological and potential anti-tumoral effects of simvastatin in breast cancer.

  2. Synthetic and endogenous cannabinoids protect retinal neurons from AMPA excitotoxicity in vivo, via activation of CB1 receptors: Involvement of PI3K/Akt and MEK/ERK signaling pathways.

    Science.gov (United States)

    Kokona, Despina; Thermos, Kyriaki

    2015-07-01

    Cannabinoids have been suggested to protect retinal ganglion cells in different models of toxicity, but their effects on other retinal neurons are poorly known. We investigated the neuroprotective actions of the endocannabinoid N-arachidonoyl ethanolamine (Anandamide/AEA) and the synthetic cannabinoids R1-Methanandamide (MethAEA) and HU-210, in an in vivo retinal model of AMPA excitotoxicity, and the mechanisms involved in the neuroprotection. Sprague-Dawley rats were intravitreally injected with PBS or AMPA in the absence or presence of the cannabinoid agonists. Brain nitric oxide synthase (bNOS) and choline acetyltransferase (ChAT) immunoreactivity (IR), as well as TUNEL staining, assessed the AMPA-induced retinal amacrine cell loss and the dose-dependent neuroprotection afforded by cannabinoids. The CB1 receptor selective antagonist AM251 and the PI3K/Akt inhibitor wortmannin reversed the cannabinoid-induced neuroprotection, suggesting the involvement of CB1 receptors and the PI3K/Akt pathway in cannabinoids' actions. Experiments with the CB2 agonist JWH015 and [(3)H]CP55940 radioligand binding suggested that the CB2 receptor is not involved in the neuroprotection. AEA and HU-210 induced phosphorylation of Akt but only AEA induced phosphorylation of ERK1/2 kinases, as revealed by western blot analysis. To investigate the role of caspase-3 in the AMPA-induced cell death, the caspase-3 inhibitor Z-DEVD-FMK was co-injected with AMPA. Z-DEVD-FMK had no effect on AMPA excitotoxicity. Moreover, no difference was observed in the phosphorylation of SAPK/JNK kinases between PBS- and AMPA-treated retinas. These results suggest that endogenous and synthetic cannabinoids protect retinal amacrine neurons from AMPA excitotoxicity in vivo via a mechanism involving the CB1 receptors, and the PI3K/Akt and/or MEK/ERK1/2 signaling pathways.

  3. Cytoplasmic localization of wild-type survivin is associated with constitutive activation of the PI3K/Akt signaling pathway and represents a favorable prognostic factor in patients with acute myeloid leukemia.

    Science.gov (United States)

    Serrano-López, Juana; Serrano, Josefina; Figueroa, Vianihuini; Torres-Gomez, Antonio; Tabares, Salvador; Casaño, Javier; Fernandez-Escalada, Noemi; Sánchez-Garcia, Joaquín

    2013-12-01

    Survivin is over-expressed in most hematologic malignancies but the prognostic significance of the subcompartmental distribution of wild-type or splicing variants in acute myeloid leukemia has not been addressed yet. Using western blotting, we assessed the expression of wild-type survivin and survivin splice variants 2B and Delta-Ex3 in nuclear and cytoplasmic protein extracts in samples taken from 105 patients at the time of their diagnosis of acute myeloid leukemia. Given that survivin is a downstream effector of the PI3K/Akt signaling pathway, survivin expression was also correlated with pSer473-Akt. Wild-type survivin and the 2B splice variant were positive in 76.3% and 78.0% of samples in the nucleus, cytoplasm or both, whereas the Delta-Ex3 isoform was only positive in the nucleus in 37.7% of samples. Cytoplasmic localization of wild-type survivin was significantly associated with the presence of high levels of pSer473-Akt (P<0.001). Inhibition of the PI3K/Akt pathway with wortmannin and Ly294002 caused a significant reduction in the expression of cytoplasmic wild-type survivin. The presence of cytoplasmic wild-type survivin and pSer473-Akt was associated with a lower fraction of quiescent leukemia stem cells (P=0.02). The presence of cytoplasmic wild-type survivin and pSer473-Akt were favorable independent prognostic factors. Moreover, the activation of the PI3K/Akt pathway with expression of cytoplasmic wild-type survivin identified a subgroup of acute myeloid leukemia patients with an excellent outcome (overall survival rate of 60.0±21.9% and relapse-free survival of 63.0±13.5%). Our findings suggest that cytoplasmic wild-type survivin is a critical downstream effector of the PI3K/Akt pathway leading to more chemosensitive cells and a more favorable outcome in acute myeloid leukemia.

  4. (-)-Epigallocatechin-3-gallate inhibition of Epstein-Barr virus spontaneous lytic infection involves ERK1/2 and PI3-K/Akt signaling in EBV-positive cells.

    Science.gov (United States)

    Liu, Sufang; Li, Hongde; Chen, Lin; Yang, Lifang; Li, Lili; Tao, Yongguan; Li, Wei; Li, Zijian; Liu, Haidan; Tang, Min; Bode, Ann M; Dong, Zigang; Cao, Ya

    2013-03-01

    Epstein-Barr virus (EBV) reactivation into the lytic cycle plays certain roles in the development of EBV-associated diseases, including nasopharyngeal carcinoma and lymphoma. In this study, we investigated the effects of the tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) on EBV spontaneous lytic infection and the mechanism(s) involved in EBV-positive cells. We found that EGCG could effectively inhibit the constitutive lytic infection of EBV at the DNA, gene transcription and protein levels by decreasing the phosphorylation and activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt. By using cellular signaling pathway-specific inhibitors, we also explored the signaling mechanisms underlying the inhibitory effects of EGCG on EBV spontaneous lytic infection in cell models. Results show that specific inhibitors of Mitogen-Activated Protein Kinase Kinase (MEK) (PD98059) and phosphatidylinositol 3-kinase [PI3-K (LY294002)] markedly downregulated gene transcription and expression of BZLF1 and BMRF1 indicating that the MEK/ERK1/2 and PI3-K/Akt pathways are involved in the EBV spontaneous lytic cycle cascade. Therefore, one of the mechanisms by which EGCG inhibits EBV spontaneous lytic infection appears to involve the suppression of the activation of MEK/ERK1/2 and PI3-K/Akt signaling.

  5. Diosgenin and 5-Methoxypsoralen Ameliorate Insulin Resistance through ER-α/PI3K/Akt-Signaling Pathways in HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Ke Fang

    2016-01-01

    Full Text Available To determine the effects and the underlying mechanism of diosgenin (DSG and 5-methoxypsoralen (5-MOP, two main active components in the classical Chinese prescription Hu-Lu-Ba-Wan (HLBW, on insulin resistance, HepG2 cells were incubated in medium containing insulin. Treatments with DSG, 5-MOP, and their combination were performed, respectively. The result showed that the incubation of HepG2 cells with high concentration insulin markedly decreased glucose consumption and glycogen synthesis. However, treatment with DSG, 5-MOP, or their combination significantly reversed the condition and increased the phosphorylated expression of estrogen receptor-α (ERα, sarcoma (Src, Akt/protein kinase B, glycogen synthase kinase-3β (GSK-3β, and the p85 regulatory subunit of phosphatidylinositol 3-kinase p85 (PI3Kp85. At the transcriptional level, expression of the genes mentioned above also increased except for the negative regulation of GSK-3β mRNA. The increased expression of glucose transport-4 (GLUT-4 was meanwhile observed through immunofluorescence. Nevertheless, the synergistic effect of DSG and 5-MOP on improving glycometabolism was not obvious in the present study. These results suggested that DSG and 5-MOP may improve insulin resistance through an ER-mediated PI3K/Akt activation pathway which may be a new strategy for type 2 diabetes mellitus, especially for women in an estrogen-deficient condition.

  6. PI3K/Akt signaling mediated apoptosis blockage and viral gene expression in oral epithelial cells during herpes simplex virus infection.

    Science.gov (United States)

    Hsu, Mei-Ju; Wu, Ching-Yi; Chiang, Hsiao-Han; Lai, Yu-Lin; Hung, Shan-Ling

    2010-10-01

    Phosphatidylinositol 3-kinases (PI3Ks) function in the anti-apoptotic pathway, and are commonly exploited by various viruses to accomplish the viral life cycle. This study examined the role of the PI3K pathway in human oral epithelial cells following herpes simplex virus type 1 (HSV-1) infection. The results showed that HSV-1 induced the phosphorylation of Akt and glycogen synthase kinase 3 (GSK-3). Phosphorylation of Akt, but not GSK-3, induced by HSV-1 was PI3K-dependent. The expression of HSV-1 immediate-early genes may be involved in the initial phosphorylation of Akt and GSK-3. Inhibition of HSV-1-induced PI3K activity increased DNA fragmentation and cleavage of poly ADP-ribose polymerase (PARP), caspase 3 and caspase 7 compared with infected alone. Inhibition of PI3K attenuated the expression of HSV-1-infected cell protein 0 (ICP0), but not thymidine kinase (TK) and viral replication. Collectively, these data suggested that, in oral epithelial cells, the HSV-1-induced PI3K/Akt activation was involved in the regulation of apoptosis blockage and viral gene expression.

  7. PI3K/Akt通路在结肠癌中的研究进展%PI3K/Akt Signaling Path Way and its Advances in Colon Cancer

    Institute of Scientific and Technical Information of China (English)

    曹涤非; 吴琼; 姜洋; 薛佳莹; 黄国庆; 孙尧

    2015-01-01

    结肠癌是我国常发的恶性肿瘤之一,近几年来发病率逐年上升。PI3K/Akt信号传导通路与细胞的增殖和凋亡密切相关,是细胞内调控的重要通路之一。本文对结肠癌中的PI3K/Akt信号传导通路的作用机制进行介绍,有助于加深我们对结肠癌发生、发展的认识,为结肠癌的治疗提供新的研究思路。%Colon cancer is one of the most common malignant tumor in China, and the incidence is increasing in recent years. PI3K/Akt signaling pathway was involved in cell proliferation and apoptosis, which was one of the important pathways for intracellular in colon cancer, and it plays an important role in occurrence and drug treatment.In this review, the mechanism of PI3K/Akt signaling pathway in colon cancer were introduced.

  8. Fungiform papilla pattern: EGF regulates inter-papilla lingual epithelium and decreases papilla number by means of PI3K/Akt, MEK/ERK, and p38 MAPK signaling.

    Science.gov (United States)

    Liu, Hong-Xiang; Henson, Bradley S; Zhou, Yanqiu; D'Silva, Nisha J; Mistretta, Charlotte M

    2008-09-01

    Fungiform papillae are epithelial taste organs that form on the tongue, requiring differentiation of papillae and inter-papilla epithelium. We tested roles of epidermal growth factor (EGF) and the receptor EGFR in papilla development. Developmentally, EGF was localized within and between papillae whereas EGFR was progressively restricted to inter-papilla epithelium. In tongue cultures, EGF decreased papillae and increased cell proliferation in inter-papilla epithelium in a concentration-dependent manner, whereas EGFR inhibitor increased and fused papillae. EGF preincubation could over-ride disruption of Shh signaling that ordinarily would effect a doubling of fungiform papillae. With EGF-induced activation of EGFR, we demonstrated phosphorylation in PI3K/Akt, MEK/ERK, and p38 MAPK pathways; with pathway inhibitors (LY294002, U0126, SB203580) the EGF-mediated decrease in papillae was reversed, and synergistic actions were shown. Thus, EGF/EGFR signaling by means of PI3K/Akt, MEK/ERK, and p38 MAPK contributes to epithelial cell proliferation between papillae; this biases against papilla differentiation and reduces numbers of papillae.

  9. Cell entry of bovine ephemeral fever virus requires activation of Src-JNK-AP1 and PI3K-Akt-NF-κB pathways as well as Cox-2-mediated PGE2 /EP receptor signalling to enhance clathrin-mediated virus endocytosis.

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    Cheng, Ching-Yuan; Huang, Wei-Ru; Chi, Pei-I; Chiu, Hung-Chuan; Liu, Hung-Jen

    2015-07-01

    Although we have previously demonstrated that cell entry of bovine ephemeral fever virus (BEFV) follows a clathrin-mediated and dynamin 2-dependent endocytosis pathway, the cellular mechanism mediating virus entry remains unknown. Here, we report that BEFV triggers simultaneously Src-JNK-AP1 and PI3K-Akt-NF-κB signalling pathways in the stage of virus binding to induce clathrin and dynamin 2 expressions, while vesicular stomatitis virus only activates Src-JNK signalling to enhance its entry. Activation of these pathways by ultraviolet-inactivated BEFV suggests a role for virus binding but not viral internalization and gene expression. By blocking these signalling pathways with specific inhibitors, BEFV-induced expressions of clathrin and dynamin 2 were significantly diminished. By labelling BEFV with 3,3'-dilinoleyloxacarbocyanine perchlorate to track viral entry, we found that virus entry was hindered by both Src and Akt inhibitors, suggesting that these signalling pathways are crucial for efficient virus entry. In addition, BEFV also triggers Cox-2-catalysed prostaglandin E2 (PGE2) synthesis and induces expressions of G-protein-coupled E-prostanoid (EP) receptors 2 and 4, leading to amplify signal cascades of Src-JNK-AP1 and PI3K-Akt-NF-κB, which elevates both clathrin and dynamin 2 expressions. Furthermore, pretreatment of cells with adenylate cyclase (cAMP) inhibitor SQ22536 reduced BEFV-induced Src phosphorylation as well as clathrin and dynamin 2 expressions. Our findings reveal for the first time that BEFV activates the Cox-2-mediated PGE2/EP receptor signalling pathways, further enhancing Src-JNK-AP1 in a cAMP-dependent manner and PI3K-Akt-NF-κB in a cAMP-independent manner. Accordingly, BEFV stimulates PGE2/EP receptor signalling amplifying Src-JNK-AP1 and PI3K-Akt-NF-κB pathways in an autocrine or paracrine fashion to enhance virus entry. © 2015 John Wiley & Sons Ltd.

  10. The Asian-American variant of human papillomavirus type 16 exhibits higher activation of MAPK and PI3K/AKT signaling pathways, transformation, migration and invasion of primary human keratinocytes.

    Science.gov (United States)

    Hochmann, Jimena; Sobrinho, João S; Villa, Luisa L; Sichero, Laura

    2016-05-01

    Asian-American (AA) HPV-16 variants are associated with higher risk of cancer. Abnormal activation of intracellular signaling play a critical role in cancer development and progression. Our aim was to elucidate mechanisms underlying the higher oncogenic potential attributed to AA variant. We evaluated activation of MAPK and PI3K/AKT pathways in primary human keratinocytes (PHKs) transduced with E6/E7 of three HPV-16 variants: E-P, AA, E-350G. Phenotypes examined included migration, anchorage independent growth and invasion. AA PHKs presented the highest levels of active proteins involved in all cascades analyzed: MAPK-ERK, MAPK-p38 and PI3K-AKT. AA PHKs were more efficient in promoting anchorage independent growth, and in stimulating cell migration and invasion. MEK1 inhibition decreased migration. The mesenchymal phenotype marker vimentin was increased in AA PHKs. Our results suggest that MEK1, ERK2, AKT2 hyperactivation influence cellular behavior by means of GSK-3b inactivation and EMT induction prompting AA immortalized PHKs to more efficiently surpass carcinogenesis steps.

  11. Regulative mechanism of PI3K/Akt signal pathway on Skp2 via Cdh1 in non-small cell lung cancer%非小细胞肺癌中PI3K/Akt信号通路通过Cdh1调控Skp2表达的机制研究

    Institute of Scientific and Technical Information of China (English)

    孙秀华; 张洪开; 李玉; 于爱鸣

    2011-01-01

    Objective To investigate the regulative mechanism of phosphatidylinositol 3 kinase (PI3K)/Akt signaling pathway on S-phase kinase-associated protein 2 (Skp2) via Cdc20 homolog 1 ( Cdh1 ) in non-small cell lung cancer (NSCLC). Methods NSCLC cell lines A549, LK2 and H460 were cultured in vitro and treated with LY294002 to block the PI3K/Akt pathway. Western blot method was used to detect the expression of Skp2, Cdh1 and p-Akt proteins. Immunofluorescence (IF) analysis was used to examine the localization of Cdh1 in NSCLC. Results Compared with control cells, the protein expression of Skp2 and p-Akt decreased ( P < 0.01 ). IF result showed a redistribution of Cdh1 to the nucleus. Conclusion The inhibitor of PI3K/Akt signaling pathway LY294002 down-regulated the expression of Skp2, which might correlated with the nuclear localization of Cdh1.%目的 探讨非小细胞肺癌(NSCLC)中Cdc20同源蛋白1(Cdh1)参与磷脂酰肌醇三羟基激酶(PI3K)/Akt信号通路对S期激酶相关蛋白2(Skp2)表达调控的机制.方法 体外培养NSCLC细胞系A549、LK2和H460,LY294002特异性阻断PI3K/Akt信号通路后,Western blot 检测Skp2、Cdh1及p-Akt蛋白表达的变化,免疫荧光(IF)检测Cdh1在NSCLC中的定位变化.结果 LY294002处理后,与对照组相比3种细胞中Skp2蛋白表达和Akt磷酸化水平均降低(P<0.01),Cdh1在3种细胞的核内表达均增多.结论 NSCLC中PI3K/Akt 信号通路抑制剂LY294002使Skp2蛋白表达下调与Cdh1由细胞质向细胞核转位有关.

  12. Amorphous silica nanoparticles trigger vascular endothelial cell injury through apoptosis and autophagy via reactive oxygen species-mediated MAPK/Bcl-2 and PI3K/Akt/mTOR signaling

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    Guo C

    2016-10-01

    Full Text Available Caixia Guo,1,2 Man Yang,2,3 Li Jing,2,3 Ji Wang,2,3 Yang Yu,2,3 Yang Li,2,3 Junchao Duan,2,3 Xianqing Zhou,2,3 Yanbo Li,2,3 Zhiwei Sun2,3 1Department of Occupational and Environmental Health, School of Public Health, 2Beijing Key Laboratory of Environmental Toxicology, 3Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing, People’s Republic of China Abstract: Environmental exposure to silica nanoparticles (SiNPs is inevitable due to their widespread application in industrial, commercial, and biomedical fields. In recent years, most investigators focus on the evaluation of cardiovascular effects of SiNPs in vivo and in vitro. Endothelial injury and dysfunction is now hypothesized to be a dominant mechanism in the development of cardiovascular diseases. This study aimed to explore interaction of SiNPs with endothelial cells, and extensively investigate the exact effects of reactive oxygen species (ROS on the signaling molecules and cytotoxicity involved in SiNPs-induced endothelial injury. Significant induction of cytotoxicity as well as oxidative stress, apoptosis, and autophagy was observed in human umbilical vein endothelial cells following the SiNPs exposure (P<0.05. The oxidative stress was induced by ROS generation, leading to redox imbalance and lipid peroxidation. SiNPs induced mitochondrial dysfunction, characterized by membrane potential collapse, and elevated Bax and declined bcl-2 expression, ultimately leading to apoptosis, and also increased number of autophagosomes and autophagy marker proteins, such as LC3 and p62. Phosphorylated ERK, PI3K, Akt, and mTOR were significantly decreased, but phosphorylated JNK and p38 MAPK were increased in SiNPs-exposed endothelial cells. In contrast, all of these stimulation phenomena were effectively inhibited by N-acetylcysteine. The N-acetylcysteine supplement attenuated SiNPs-induced endothelial toxicity through inhibition of apoptosis

  13. Effects of bone marrow-derived mesenchymal stem cells on the axonal outgrowth through activation of PI3K/AKT signaling in primary cortical neurons followed oxygen-glucose deprivation injury.

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    Yong Liu

    Full Text Available BACKGROUND: Transplantation with bone marrow-derived mesenchymal stem cells (BMSCs improves the survival of neurons and axonal outgrowth after stroke remains undetermined. Here, we investigated whether PI3K/AKT signaling pathway is involved in these therapeutic effects of BMSCs. METHODOLOGY/PRINCIPAL FINDINGS: (1 BMSCs and cortical neurons were derived from Sprague-Dawley rats. The injured neurons were induced by Oxygen-Glucose Deprivation (OGD, and then were respectively co-cultured for 48 hours with BMSCs at different densities (5×10(3, 5×10(5/ml in transwell co-culture system. The average length of axon and expression of GAP-43 were examined to assess the effect of BMSCs on axonal outgrowth after the damage of neurons induced by OGD. (2 The injured neurons were cultured with a conditioned medium (CM of BMSCs cultured for 24 hours in neurobasal medium. During the process, we further identified whether PI3K/AKT signaling pathway is involved through the adjunction of LY294002 (a specific phosphatidylinositide-3-kinase (PI3K inhibitor. Two hours later, the expression of pAKT (phosphorylated AKT and AKT were analyzed by Western blotting. The length of axons, the expression of GAP-43 and the survival of neurons were measured at 48 hours. RESULTS: Both BMSCs and CM from BMSCs inreased the axonal length and GAP-43 expression in OGD-injured cortical neurons. There was no difference between the effects of BMSCs of 5×10(5/ml and of 5×10(3/ml on axonal outgrowth. Expression of pAKT enhanced significantly at 2 hours and the neuron survival increased at 48 hours after the injured neurons cultured with the CM, respectively. These effects of CM were prevented by inhibitor LY294002. CONCLUSIONS/SIGNIFICANCE: BMSCs promote axonal outgrowth and the survival of neurons against the damage from OGD in vitro by the paracrine effects through PI3K/AKT signaling pathway.

  14. Activation of PI3K/AKT and ERK MAPK signal pathways is required for the induction of lytic cycle replication of Kaposi's Sarcoma-associated herpesvirus by herpes simplex virus type 1

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    Lv Zhigang

    2011-10-01

    Full Text Available Abstract Background Kaposi's sarcoma-associated herpesvirus (KSHV is causally linked to several acquired immunodeficiency syndrome-related malignancies, including Kaposi's sarcoma (KS, primary effusion lymphoma (PEL and a subset of multicentric Castleman's disease. Regulation of viral lytic replication is critical to the initiation and progression of KS. Recently, we reported that herpes simplex virus type 1 (HSV-1 was an important cofactor that activated lytic cycle replication of KSHV. Here, we further investigated the possible signal pathways involved in HSV-1-induced reactivation of KSHV. Results By transfecting a series of dominant negative mutants and protein expressing constructs and using pharmacologic inhibitors, we found that either Janus kinase 1 (JAK1/signal transducer and activator of transcription 3 (STAT3 or JAK1/STAT6 signaling failed to regulate HSV-1-induced KSHV replication. However, HSV-1 infection of BCBL-1 cells activated phosphatidylinositol 3-kinase (PI3K/protein kinase B (PKB, also called AKT pathway and inactivated phosphatase and tensin homologue deleted on chromosome ten (PTEN and glycogen synthase kinase-3β (GSK-3β. PTEN/PI3K/AKT/GSK-3β pathway was found to be involved in HSV-1-induced KSHV reactivation. Additionally, extracellular signal-regulated protein kinase (ERK mitogen-activated protein kinase (MAPK pathway also partially contributed to HSV-1-induced KSHV replication. Conclusions HSV-1 infection stimulated PI3K/AKT and ERK MAPK signaling pathways that in turn contributed to KSHV reactivation, which provided further insights into the molecular mechanism controlling KSHV lytic replication, particularly in the context of HSV-1 and KSHV co-infection.

  15. Dequalinium induces cytotoxicity in human leukemia NB4 cells by downregulation of Raf/MEK/ERK and PI3K/Akt signaling pathways and potentiation of specific inhibitors of these pathways.

    Science.gov (United States)

    García-Pérez, Ana I; Galeano, Eva; Nieto, Elena; Estañ, M Cristina; Sancho, Pilar

    2014-07-01

    Delocalized lipophilic cation dequalinium (DQA) selectively accumulates in mitochondria and displays anticancer activity in different malignancies. Our previous studies indicate a DQA-induced cytotoxicity in human acute promyelocytic leukemia NB4 cells by early disturbance in mitochondrial function and oxidative stress. This study shows the ability of DQA to downregulate Raf/MEK/ERK1/2 and PI3K/Akt signaling pathways in NB4 cells which leads to cell death by apoptosis and/or necrosis. Moreover, DQA potentiates the action of specific inhibitors of these pathways. These DQA effects could be mediated by redox regulation of Akt. Our results contribute to a better understanding of the cytotoxic DQA mechanism on leukemia cells and encourage the performance of further studies in combination with other agents such as kinase inhibitors for improving the efficacy of therapies against acute promyelocytic leukemia.

  16. Effect of exogenous TGF-β1 on the cadmium-induced nephrotoxicity by inhibiting apoptosis of proximal tubular cells through PI3K-AKT-mTOR signaling pathway.

    Science.gov (United States)

    Huang, Minyi; Su, Li; Yang, Limin; Zhu, Liangliang; Liu, Zhaowen; Duan, Renyan

    2017-03-22

    Heavy metal polluted soils have been a serious problem for the global ecological balance and people's health. Cadmium (Cd), one of the heavy metals, could induce apoptosis of proximal tubular cells in many experimental models and lead to damage the human kidney. Here, we reported a potent chemokine TGF-β1 which could ameliorate cadmium-induced nephrotoxicity. Interestingly, western blotting and TUNEL staining assays indicated that PI3K-AKT-mTOR signaling pathway was involved in the protective mechanism of TGF-β1 in vitro and in vivo. Moreover, TGF-β1 could alleviate Cd-induced nephrotoxicity by inhibiting apoptosis of proximal tubular cells through detecting the level of caspase 3, 8 and 9. Therefore, up-regulation of exogenous TGF-β1 may be a potential strategy to reverse cadumium-induced nephrotoxicity.

  17. Suppressing the formation of lipid raft-associated Rac1/PI3K/Akt signaling complexes by curcumin inhibits SDF-1α-induced invasion of human esophageal carcinoma cells.

    Science.gov (United States)

    Lin, Meng-Liang; Lu, Yao-Cheng; Chen, Hung-Yi; Lee, Chuan-Chun; Chung, Jing-Gung; Chen, Shih-Shun

    2014-05-01

    Stromal cell-derived factor-1α (SDF-1α) is a ligand for C-X-C chemokine receptor type 4 (CXCR4), which contributes to the metastasis of cancer cells by promoting cell migration. Here, we show that the SDF-1α/CXCR4 axis can significantly increase invasion of esophageal carcinoma (EC) cells. We accomplished this by examining the effects of CXCR4 knockdown as well as treatment with a CXCR4-neutralizing antibody and the CXCR4-specific inhibitor AMD3100. Curcumin suppressed SDF-1α-induced cell invasion and matrix metalloproteinase-2 (MMP-2) promoter activity, cell surface localization of CXCR4 at lipid rafts, and lipid raft-associated ras-related C3 botulinum toxin substrate 1 (Rac1)/phosphatidylinositol 3-kinase (PI3K) p85α/Akt signaling. Curcumin inhibited SDF-1α-induced cell invasion by suppressing the Rac1-PI3K signaling complex at lipid rafts but did not abrogate lipid raft formation. We further demonstrate that the attenuation of lipid raft-associated Rac1 activity by curcumin was critical for the inhibition of SDF-1α-induced PI3K/Akt/NF-κB activation, cell surface localization of CXCR4 at lipid rafts, MMP-2 promoter activity, and cell invasion. Collectively, our results indicate that curcumin inhibits SDF-1α-induced EC cell invasion by suppressing the formation of the lipid raft-associated Rac1-PI3K-Akt signaling complex, the localization of CXCR4 with lipid rafts at the cell surface, and MMP-2 promoter activity, likely through the inhibition of Rac1 activity.

  18. DHT inhibits the Aβ25-35-induced apoptosis by regulation of seladin-1, survivin, XIAP, bax, and bcl-xl expression through a rapid PI3-K/Akt signaling in C6 glial cell lines.

    Science.gov (United States)

    Bing, Lelin; Wu, Junfeng; Zhang, Jianfeng; Chen, Yinghui; Hong, Zhen; Zu, Hengbing

    2015-01-01

    Previous evidences indicate that androgen is neuroprotective in the brain. However, the underling mechanisms remain to be fully elucidated. Moreover, it is controversial whether dihydrotestosterone (DHT) modulates the expression of apoptosis-related effectors, such as survivin, XIAP, bax, and bcl-xl proteins mediated by the PI3-K/Akt pathway, which contributes to androgen neuroprotection. In this study using a C6 glial cell model, apoptotic cells were detected by flow cytometry. Akt, seladin-1, survivin, XIAP, bcl-xl, and bax protein expression is investigated by Western blot. After amyloid β-protein fragment (Aβ25-35) treatment, apoptotic cells at early (annexin V+, PI-) and late (annexin V+, PI+) stages were significantly increased. Apoptosis at early and late was obviously inhibited in the presence of DHT. The effect of DHT was markedly blocked by PI3-K inhibitor LY294002.To elicit the mechanism of DHT protection, the expression of seladin-1, survivin, XIAP, bax, and bcl-xl protein was determined in C6 cells treated with Aβ25-35, DHT, or LY294002. Aβ25-35 significantly downregulated the expression of seladin-1, survivin, XIAP, bcl-xl protein and upregulated the expression of bax protein. DHT significantly inhibited the expression of bax, seladin-1, survivin, XIAP, and bcl-xl protein induced by Aβ25-35. Further, we found the effect of DHT was significantly inhibited by LY294002. Collectively, in a C6 glial cell model, we firstly found that DHT inhibits Aβ25-35-induced apoptosis by a rapid nongenic PI-3K/Akt activation as well as regulation of seladin-1, survivin, XIAP, bcl-xl, and bax proteins.

  19. Reduced signaling of PI3K-Akt and RAS-MAPK pathways is the key target for weight-loss-induced cancer prevention by dietary calorie restriction and/or physical activity.

    Science.gov (United States)

    Standard, Joseph; Jiang, Yu; Yu, Miao; Su, Xiaoyu; Zhao, Zhihui; Xu, Jianteng; Chen, Jie; King, Brenee; Lu, Lizhi; Tomich, John; Baybutt, Richard; Wang, Weiqun

    2014-12-01

    Weight control through either dietary calorie restriction (DCR) or exercise has been associated with cancer prevention in animal models. However, the underlying mechanisms are not fully defined. Bioinformatics using genomics, proteomics and lipidomics was employed to elucidate the molecular targets of weight control in a mouse skin cancer model. SENCAR mice were randomly assigned into four groups for 10 weeks: ad-libitum-fed sedentary control, ad-libitum-fed exercise (AE), exercise but pair-fed isocaloric amount of control (PE) and 20% DCR. Two hours after topical TPA treatment, skin epidermis was analyzed by Affymetrix for gene expression, DIGE for proteomics and lipidomics for phospholipids. Body weights were significantly reduced in both DCR and PE but not AE mice versus the control. Among 39,000 transcripts, 411, 67 and 110 genes were significantly changed in DCR, PE and AE, respectively. The expression of genes relevant to PI3K-Akt and Ras-MAPK signaling was effectively reduced by DCR and PE but not AE as measured through GenMAPP software. Proteomics analysis identified ~120 proteins, with 27 proteins significantly changed by DCR, including up-regulated apolipoprotein A-1, a key antioxidant protein that decreases Ras-MAPK activity. Of the total 338 phospholipids analyzed by lipidomics, 57 decreased by PE including 5 phophatidylinositol species that serve as PI3K substrates. Although a full impact has not been determined yet, it appears that the reduction of both Ras-MAPK and PI3K-Akt signaling pathways is a cancer preventive target that has been consistently demonstrated by three bioinformatics approaches.

  20. Oxidized ATM promotes abnormal proliferation of breast CAFs through maintaining intracellular redox homeostasis and activating the PI3K-AKT, MEK-ERK, and Wnt-β-catenin signaling pathways.

    Science.gov (United States)

    Tang, Shifu; Hou, Yixuan; Zhang, Hailong; Tu, Gang; Yang, Li; Sun, Yifan; Lang, Lei; Tang, Xi; Du, Yan-E; Zhou, Mingli; Yu, Tenghua; Xu, Liyun; Wen, Siyang; Liu, Chunming; Liu, Manran

    2015-01-01

    Abnormal proliferation is one characteristic of cancer-associated fibroblasts (CAFs), which play a key role in tumorigenesis and tumor progression. Oxidative stress (OS) is the root cause of CAFs abnormal proliferation. ATM (ataxia-telangiectasia mutated protein kinase), an important redox sensor, is involved in DNA damage response and cellular homeostasis. Whether and how oxidized ATM regulating CAFs proliferation remains unclear. In this study, we show that there is a high level of oxidized ATM in breast CAFs in the absence of double-strand breaks (DSBs) and that oxidized ATM plays a critical role in CAFs proliferation. The effect of oxidized ATM on CAFs proliferation is mediated by its regulation of cellular redox balance and the activity of the ERK, PI3K-AKT, and Wnt signaling pathways. Treating cells with antioxidant N-acetyl-cysteine (NAC) partially rescues the proliferation defect of the breast CAFs caused by ATM deficiency. Administrating cells with individual or a combination of specific inhibitors of the ERK, PI3K-AKT, and Wnt signaling pathways mimics the effect of ATM deficiency on breast CAF proliferation. This is mainly ascribed to the β-catenin suppression and down-regulation of c-Myc, thus further leading to the decreased cyclinD1, cyclinE, and E2F1 expression and the enhanced p21(Cip1) level. Our results reveal an important role of oxidized ATM in the regulation of the abnormal proliferation of breast CAFs. Oxidized ATM could serve as a potential target for treating breast cancer.

  1. 3,5,4′-Trimethoxystilbene, a natural methoxylated analog of resveratrol, inhibits breast cancer cell invasiveness by downregulation of PI3K/Akt and Wnt/β-catenin signaling cascades and reversal of epithelial–mesenchymal transition

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Jie-Heng [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan, ROC (China); Hsu, Li-Sung [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan, ROC (China); Clinical Laboratory, Chung Shan Medical University Hospital, Taichung 402, Taiwan, ROC (China); Lin, Chih-Li [Institute of Medicine, Chung Shan Medical University, Taichung 402, Taiwan, ROC (China); Department of Medical Research, Chung Shan Medical University Hospital, Taichung 402, Taiwan, ROC (China); Hong, Hui-Mei [Department of Medical Research, Chung Shan Medical University Hospital, Taichung 402, Taiwan, ROC (China); Department of Biomedical Sciences, Chung Shan Medical University, Taichung 402, Taiwan, ROC (China); Pan, Min-Hsiung [Department of Seafood Science, National Kaohsiung Marine University, Kaohsiung 811, Taiwan, ROC (China); Way, Tzong-Der [Department of Biological Science and Technology, College of Life Sciences, China Medical University, Taichung 40402, Taiwan, ROC (China); Chen, Wei-Jen, E-mail: cwj519@csmu.edu.tw [Department of Medical Research, Chung Shan Medical University Hospital, Taichung 402, Taiwan, ROC (China); Department of Biomedical Sciences, Chung Shan Medical University, Taichung 402, Taiwan, ROC (China)

    2013-11-01

    The molecular basis of epithelial–mesenchymal transition (EMT) functions as a potential therapeutic target for breast cancer because EMT may endow breast tumor-initiating cells with stem-like characteristics and enable the dissemination of breast cancer cells. We have recently verified the antitumor activity of 3,5,4′-trimethoxystilbene (MR-3), a naturally methoxylated derivative of resveratrol, in colorectal cancer xenografts via an induction of apoptosis. The effect of MR-3 on EMT and the invasiveness of human MCF-7 breast adenocarcinoma cell line were also explored. We found that MR-3 significantly increased epithelial marker E-cadherin expression and triggered a cobblestone-like morphology of MCF-7 cells, while reciprocally decreasing the expression of mesenchymal markers, such as snail, slug, and vimentin. In parallel with EMT reversal, MR-3 downregulated the invasion and migration of MCF-7 cells. Exploring the action mechanism of MR-3 on the suppression of EMT and invasion indicates that MR-3 markedly reduced the expression and nuclear translocation of β-catenin, accompanied with the downregulation of β-catenin target genes and the increment of membrane-bound β-catenin. These results suggest the involvement of Wnt/β-catenin signaling in the MR-3-induced EMT reversion of MCF-7 cells. Notably, MR-3 restored glycogen synthase kinase-3β activity by inhibiting the phosphorylation of Akt, the event required for β-catenin destruction via a proteasome-mediated system. Overall, these findings indicate that the anti-invasive activity of MR-3 on MCF-7 cells may result from the suppression of EMT via down-regulating phosphatidylinositol 3-kinase (PI3K)/AKT signaling, and consequently, β-catenin nuclear translocation. These occurrences ultimately lead to the blockage of EMT and the invasion of breast cancer cells. - Highlights: • MR-3 blocked MCF-7 cell invasion by inducing a reversal of EMT. • Wnt/β-catenin signaling is involved in MR-3-induced EMT

  2. High Glucose Promotes Tumor Invasion and Increases Metastasis-Associated Protein Expression in Human Lung Epithelial Cells by Upregulating Heme Oxygenase-1 via Reactive Oxygen Species or the TGF-β1/PI3K/Akt Signaling Pathway

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    Xiaowen Kang

    2015-02-01

    Full Text Available Background: Growing evidence indicates that heme oxygenase-1 (HO-1 is up-regulated in malignancies and subsequently alters tumor aggressiveness and various cancer-related factors, such as high glucose (HG levels. HO-1 expression can be induced when glucose concentrations are above 25 mM; however, the role of HO-1 in lung cancer patients with diabetes remains unknown. Therefore, in this study we investigated the promotion of tumor cell invasion and the expression of metastasis-associated proteins by inducing the up-regulation of HO-1 expression by HG treatment in A549 human lung epithelial cells. Methods: The expression of HO-1and metastasis-associated protein expression was explored by western blot analysis. HO-1 enzymatic activity, reactive oxygen species (ROS production and TGF-β1 production were examined by ELISA. Invasiveness was analyzed using a Transwell chamber. Results: HG treatment of A549 cells induced an increase in HO-1 expression, which was mediated by the HG-induced generation of reactive oxygen species (ROS and transforming growth factor-β1 (TGF-β1 in a concentration- and time-dependent manner. Following the increase in HO-1 expression, the enzymatic activity of HO-1 also increased in HG-treated cells. Pretreatment with N-acetyl-L-cysteine (NAC or with phosphatidylinositol 3-kinase (PI3K/Akt inhibitors attenuated the HG-induced increase in HO-1 expression. HG treatment of A549 cells enhanced the invasion potential of these cells, as shown with a Transwell assay, and increased metastasis-associated protein expression. However, HO-1 siRNA transfection significantly decreased these capabilities. Conclusion: this study is the first to demonstrate that HG treatment of A549 human lung epithelial cells promotes tumor cell invasion and increases metastasis-associated protein expression by up-regulating HO-1 expression via ROS or the TGF-β1/PI3K/Akt signaling pathway.

  3. High expression of G-protein signaling modulator 2 in hepatocellular carcinoma facilitates tumor growth and metastasis by activating the PI3K/AKT signaling pathway.

    Science.gov (United States)

    He, Xiao-Qin; Zhang, Yue-Feng; Yu, Jia-Jun; Gan, Yuan-Yuan; Han, Na-Na; Zhang, Mei-Xia; Ge, Wei; Deng, Jun-Jian; Zheng, Yong-Fa; Xu, Xi-Ming

    2017-03-01

    The aim of this study was to investigate the role of G-protein signaling modulator 2 in the carcinogenesis and progression of hepatocellular carcinoma. We previously showed that G-protein signaling modulator 2 was upregulated in hepatitis B virus-related hepatocellular carcinoma tissues through a hierarchical clustering analysis. With this study, we first assessed the expression pattern of G-protein signaling modulator 2 in hepatocellular carcinoma specimens and adjacent noncancerous tissues; clinical data were analyzed, along survival times, utilizing the Kaplan-Meier method. Moreover, the functions of G-protein signaling modulator 2 were examined using small-interfering RNAs in vitro. The results showed that G-protein signaling modulator 2 was clearly overexpressed in hepatocellular carcinoma tissues and cell lines and that the G-protein signaling modulator 2 expression level was related to tumor size and hepatitis B virus infection. Furthermore, G-protein signaling modulator 2 knockdown studies suggested that G-protein signaling modulator 2 accelerates cell growth, cell cycle, migration, and invasion and inhibits apoptosis, acting as an oncogene in hepatocellular carcinoma. Western blotting indicated that silencing of G-protein signaling modulator 2 in HepG2 and SMMC-7721 cells increased the expression levels of Bax, caspase-3, and E-cadherin, while notably suppressing the cyclin-dependent kinase 4, cyclin-dependent kinase 6, CyclinD1, Snail1, Vimentin, and matrix metallopeptidase 9 expression levels, compared with that in the control groups. In addition, we found that G-protein signaling modulator 2 can affect the expression of key proteins involved in protein kinase B activation. In conclusion, high expression of G-protein signaling modulator 2 was involved in the pathological processes of hepatocellular carcinoma through activation of the phosphatidylinositol 3-kinase/protein kinase B signaling pathway, which may provide an attractive potential diagnostic

  4. Bergapten exerts inhibitory effects on diabetes-related osteoporosis via the regulation of the PI3K/AKT, JNK/MAPK and NF-κB signaling pathways in osteoprotegerin knockout mice

    Science.gov (United States)

    Li, Xue-Ju; Zhu, Zhe; Han, Si-Lin; Zhang, Zi-Long

    2016-01-01

    Diabetes, as a serious metobolic disorder, poses global threat to human health. It is estimated that over 50 million individuals are already affected by diabetes. Currently, diabetes-related osteoporosis has been a research hotspot due to its high incidence rate in older individuals. Osteoprotegerin, as an important protein for the prevention of osteoporosis, has been proven to be key to the suppression of osteoporosis. Hence, the loss of function of osteoprotegerin may promote the development of osteoporosis. Bergapten, as a natural anti-inflammatory and anti-tumor agent isolated from bergamot essential oil, other citrus essential oils, and grapefruit juice, has been proven to have the ability to attenuate a number of metabolic disorders. In view of these findings, in this study, we used a high-fat diet to construct a mouse model of diabetes-related osteoporosis and a mouse model of diabetes-related osteoporosis using osteoprotegerin knockout mice. Enzyme-linked immunosorbent assay (ELISA), qPCR, western blot analysis, immunohistochemical assay, H&E staining, Oil Red O staining, Masson's staining and other biochemical analyses were used to evaluate the related signaling pathways involved in the development of diabetes-related osteoporosis. We also examined the role of osteoprotegerin in the activation of these pathways and in the development of osteoporosis, as well as the protective effects of bergapten against diabetes-related osteoporosis and on the activation of related signaling pathways. Our results revealed that in diabetes-related osteoporosis, the phosphoinositide 3-kinase (PI3K)/AKT, c-Jun N-terminal kinase (JNK)/mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathways were activated and the expression levels of related indicators were increased. At the same time, osteoprotegerin knockout further promoted the activation of these pathways. By contrast, bergapten exerted effects similar to those of osteoprotegerin

  5. Astaxanthin reduces isoflurane-induced neuroapoptosis via the PI3K/Akt pathway.

    Science.gov (United States)

    Wang, Chun-Mei; Cai, Xiao-Lan; Wen, Qing-Ping

    2016-05-01

    Astaxanthin is an oxygen-containing derivative of carotenoids that effectively suppresses reactive oxygen and has nutritional and medicinal value. The mechanisms underlying the effects of astaxanthin on isoflurane‑induced neuroapoptosis remain to be fully understood. The present study was conducted to evaluate the protective effect of astaxanthin to reduce isoflurane‑induced neuroapoptosis and to investigate the underlying mechanisms. The results demonstrated that isoflurane induced brain damage, increased caspase‑3 activity and suppressed the phosphatidylinositol 3‑kinase (PI3K)/protein kinase B (Akt) signaling pathway in an in vivo model. However, treatment with astaxanthin significantly inhibited brain damage, suppressed caspase‑3 activity and upregulated the PI3K/Akt pathway in the isoflurane‑induced rats. Furthermore, isoflurane suppressed cell growth, induced cell apoptosis, enhanced caspase‑3 activity and downregulated the PI3K/Akt pathway in organotypic hippocampal slice culture. Administration of astaxanthin significantly promoted cell growth, reduced cell apoptosis and caspase‑3 activity, and upregulated the PI3K/Akt pathway and isoflurane‑induced neuroapoptosis. The present study demonstrated that downregulation of the PI3K/Akt pathway reduced the effect of astaxanthin to protect against isoflurane‑induced neuroapoptosis in the in vitro model. The results of the current study suggested that the protective effect of astaxanthin reduces the isoflurane-induced neuroapoptosis via activation of the PI3K/Akt signaling pathway.

  6. MiR-126 regulates proliferation and invasion in the bladder cancer BLS cell line by targeting the PIK3R2-mediated PI3K/Akt signaling pathway

    Directory of Open Access Journals (Sweden)

    Xiao J

    2016-08-01

    Full Text Available Jun Xiao,1 Huan-Yi Lin,2 Yuan-Yuan Zhu,3 Yu-Ping Zhu,1 Ling-Wu Chen2 1Department of Urology, Anhui Provincial Hospital, Anhui Medical University, Hefei, 2Department of Urology, First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 3Clinical Laboratory, Anhui Provincial Hospital, Anhui Medical University, Hefei, People’s Republic of China Objective: To assess whether microRNA-126 (miR-126 targets phosphatidylinositol 3-kinase regulatory subunit beta (PIK3R2 and to determine the potential roles of miR-126 in regulating proliferation and invasion via the PIK3R2-mediated phosphatidylinositol 3 kinase (PI3K-protein kinase B (Akt signaling pathway in the human bladder BLS cell line. Materials and methods: A recombinant lentivirus (Lv vector expressing miR-216 (Lv-miR-126 was successfully constructed, and Lv-miR-126 and Lv vector were transfected into the BLS cell line. A direct regulatory relationship between miR-126 and the PIK3R2 gene was demonstrated by luciferase reporter assays. To determine whether PIK3R2 directly participates in the miR-126-induced effects in BLS cells, anti-miR-126 and a PIK3R2 small interfering RNA (siRNA were transfected into the BLS cells. Quantitative real-time polymerase chain reaction was used to measure miR-126 and PIK3R2 expressions. 5-Ethynyl-2'-deoxyuridine and colony formation assays to assess cell proliferation, flow cytometry for cell apoptosis and cell cycle analysis, Transwell assays for cell migration and invasion, and Western blots for PIK3R2, PI3K, phosphorylated PI3K (p-PI3K, Akt, and phosphorylated Akt (p-Akt protein expressions were performed. Results: Lv-miR-126 significantly enhanced the relative expression of miR-126 in the BLS cells after infection (P<0.0001. MiR-126 overexpression inhibited the proliferation, cloning, migration, and invasion of BLS cells, promoted cell apoptosis, and induced S phase arrest (all P<0.05. PIK3R2, p-PI3K, and p-Akt protein expressions were significantly

  7. Targeting the PI3K/Akt pathway in prostate cancer: challenges and opportunities (review).

    Science.gov (United States)

    Toren, Paul; Zoubeidi, Amina

    2014-11-01

    The PI3K/Akt pathway is an actively pursued therapeutic target in oncology. In prostate cancer, the activation of this pathway appears to be characteristic of many aggressive prostate cancers. Further, activation of the PI3K/Akt pathway is more frequently observed as prostate cancer progresses toward a resistant, metastatic disease. Signalling from this pathway activates numerous survival, growth, metabolic and metastatic functions characteristic of aggressive cancer. Biomarkers of this pathway have correlated activation of this pathway to high grade disease and higher risk of disease progression. Therefore there is significant interest in developing effective strategies to target this pathway in prostate cancer. In this review, we discuss the pre-clinical and clinical data relevant to targeting of the PI3K/Akt pathway in prostate cancer. In particular, we review the rationale and relevance of co-targeting approaches against the PI3K/Akt pathway. It is anticipated that through an improved understanding of the biology of the PI3K/Akt pathway in prostate cancer, relevant biomarkers and rationale combination therapies will optimize targeting of this pathway to improve outcomes among patients with aggressive prostate cancer.

  8. Highly active microbial phosphoantigen induces rapid yet sustained MEK/Erk- and PI-3K/Akt-mediated signal transduction in anti-tumor human gammadelta T-cells.

    Directory of Open Access Journals (Sweden)

    Daniel V Correia

    Full Text Available BACKGROUND: The unique responsiveness of Vgamma9Vdelta2 T-cells, the major gammadelta subset of human peripheral blood, to non-peptidic prenyl pyrophosphate antigens constitutes the basis of current gammadelta T-cell-based cancer immunotherapy strategies. However, the molecular mechanisms responsible for phosphoantigen-mediated activation of human gammadelta T-cells remain unclear. In particular, previous reports have described a very slow kinetics of activation of T-cell receptor (TCR-associated signal transduction pathways by isopentenyl pyrophosphate and bromohydrin pyrophosphate, seemingly incompatible with direct binding of these antigens to the Vgamma9Vdelta2 TCR. Here we have studied the most potent natural phosphoantigen yet identified, (E-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP, produced by Eubacteria and Protozoa, and examined its gammadelta T-cell activation and anti-tumor properties. METHODOLOGY/PRINCIPAL FINDINGS: We have performed a comparative study between HMB-PP and the anti-CD3epsilon monoclonal antibody OKT3, used as a reference inducer of bona fide TCR signaling, and followed multiple cellular and molecular gammadelta T-cell activation events. We show that HMB-PP activates MEK/Erk and PI-3K/Akt pathways as rapidly as OKT3, and induces an almost identical transcriptional profile in Vgamma9(+ T-cells. Moreover, MEK/Erk and PI-3K/Akt activities are indispensable for the cellular effects of HMB-PP, including gammadelta T-cell activation, proliferation and anti-tumor cytotoxicity, which are also abolished upon antibody blockade of the Vgamma9(+ TCR Surprisingly, HMB-PP treatment does not induce down-modulation of surface TCR levels, and thereby sustains gammadelta T-cell activation upon re-stimulation. This ultimately translates in potent human gammadelta T-cell anti-tumor function both in vitro and in vivo upon transplantation of human leukemia cells into lymphopenic mice, CONCLUSIONS/SIGNIFICANCE: The development of

  9. Sulfated polysaccharide isolated from the sea cucumber Stichopus japonicas promotes the SDF-1α/CXCR4 axis-induced NSC migration via the PI3K/Akt/FOXO3a, ERK/MAPK, and NF-κB signaling pathways.

    Science.gov (United States)

    Cui, Chao; Wang, Peng; Cui, Ningshan; Song, Shuliang; Liang, Hao; Ji, Aiguo

    2016-03-11

    The present study describes a positive regulatory loop between SJP and the SDF-1α/CXCR4 axis in NSC migration. The treatment of NSCs with SJP and SDF-1α increases the cell migration capacity and promotes cell migration from the neurospheres. These effects are accompanied by the up-regulation of Nestin, N-cadherin, TLR4, TNF-α, Cyclin D1, EGFR, Alpha 6 integrin, MMP-2, MMP-9, and iNOS, including SDF-1α and CXCR4 themselves. However, these effects are blocked by AMD3100, LY294002, U0126, and PDTC. SJP enhances the SDF-1α/CXCR4 axis-induced MMP-2 and MMP-9 secretion and NO release. Results demonstrate that interaction of SJP with the SDF-1α/CXCR4 axis regulates NSC migration via the PI3K/Akt/FOXO3a, ERK-MAPK, and NF-κB signaling pathways.

  10. Thrombopoietin/MPL participates in initiating and maintaining RUNX1-ETO acute myeloid leukemia via PI3K/AKT signaling

    NARCIS (Netherlands)

    J.A. Pulikkan (John); D. Madera (Dmitri); L. Xue (Liting); P. Bradley (Paul); S.F. Landrette (Sean Francis); Y.-H. Kuo (Ya-Huei); S. Abbas (Saman); L.J. Zhu (Lihua Julie); P.J.M. Valk (Peter); L.H. Castilla (Lucio)

    2012-01-01

    textabstractOncogenic mutations in components of cytokine signaling pathways elicit ligand-independent activation of downstream signaling, enhancing proliferation and survival in acute myeloid leukemia (AML). The myeloproliferative leukemia virus oncogene, MPL, a homodimeric receptor activated by

  11. Thrombopoietin/MPL participates in initiating and maintaining RUNX1-ETO acute myeloid leukemia via PI3K/AKT signaling

    NARCIS (Netherlands)

    J.A. Pulikkan (John); D. Madera (Dmitri); L. Xue (Liting); P. Bradley (Paul); S.F. Landrette (Sean Francis); Y.-H. Kuo (Ya-Huei); S. Abbas (Saman); L.J. Zhu (Lihua Julie); P.J.M. Valk (Peter); L.H. Castilla (Lucio)

    2012-01-01

    textabstractOncogenic mutations in components of cytokine signaling pathways elicit ligand-independent activation of downstream signaling, enhancing proliferation and survival in acute myeloid leukemia (AML). The myeloproliferative leukemia virus oncogene, MPL, a homodimeric receptor activated by th

  12. Stichopus japonicus Polysaccharide, Fucoidan, or Heparin Enhanced the SDF-1α/CXCR4 Axis and Promoted NSC Migration via Activation of the PI3K/Akt/FOXO3a Signaling Pathway.

    Science.gov (United States)

    Cui, Chao; Wang, Peng; Cui, Ningshan; Song, Shuliang; Liang, Hao; Ji, Aiguo

    2016-11-01

    Stichopus japonicus Polysaccharide (SJP) is a sulfated polysaccharide from the body wall of the sea cucumber, Stichopus japonicus. Fucoidan is a heparinoid compound that belongs to a family of sulfated polyfucose polysaccharides. Heparin is a glycosaminoglycan. SJP, fucoidan, and heparin profoundly promoted stromal cell-derived factor 1 alpha (SDF-1α)-induced neural stem cell (NSC) migration in a concentration-dependent manner. In addition, the basal migration capacity of cells was significantly promoted after incubation with SJP, fucoidan, or heparin. Interaction of SJP, fucoidan, or heparin with SDF-1α efficiently showed additive effects on the promotion of cell migration from the neurosphere. SJP, fucoidan, or heparin interaction with SDF-1α treatment could increase Nestin expression. SDF-1α modulated by SJP, fucoidan, or heparin activated the CXCR4 receptor and directed cellular migration via the activation of the PI3K/Akt/FOXO3a signaling pathway. Moreover, interaction of SJP, fucoidan, or heparin with SDF-1α effectively promoted NSC migration and induced SDF-1α and CXCR4 expressions. Results suggested that SJP, fucoidan, and heparin might be good candidates for alleviating injury-initiated signals to which NSCs respond.

  13. Angiotensin-(1–7) abrogates angiotensin II-induced proliferation, migration and inflammation in VSMCs through inactivation of ROS-mediated PI3K/Akt and MAPK/ERK signaling pathways

    Science.gov (United States)

    Zhang, Feng; Ren, Xingsheng; Zhao, Mingxia; Zhou, Bing; Han, Ying

    2016-01-01

    The proliferation, migration and inflammation of vascular smooth muscle cells (VSMCs) contribute to the pathogenesis and progression of several cardiovascular diseases such as atherosclerosis and hypertension. Angiotensin (Ang)-(1–7) and Ang II are identified to be involved in regulating cardiovascular activity. The present study is designed to determine the interaction between Ang-(1–7) and Ang II on VSMCs proliferation, migration and inflammation as well as their underlying mechanisms. We found that Ang-(1–7) significantly suppressed the positive effects of Ang II on VSMCs proliferation, migration and inflammation, as well as on induction of the phosphorylation of Akt and ERK1/2 and increase of superoxide anion level and NAD(P)H oxidase activity in VSMCs, whereas Ang-(1–7) alone had no significant effects. This inhibitory effects of Ang-(1–7) were abolished by Mas receptor antagonist A-779. In addition, Ang II type 1 (AT1) receptor antagonist losartan, but not A-779, abolished Ang II induced VSMCs proliferation, migration and inflammation responses. Furthermore, superoxide anion scavenger N-acetyl-L-cysteine (NAC) or NAD(P)H oxidase inhibitor apocynin inhibited Ang II-induced activation of Akt and ERK1/2 signaling. These results indicate that Ang-(1–7) antagonizes the Ang II-induced VSMC proliferation, migration and inflammation through activation of Mas receptor and then suppression of ROS-dependent PI3K/Akt and MAPK/ERK signaling pathways. PMID:27687768

  14. Reactive oxygen species and PI3K/Akt signaling play key roles in the induction of Nrf2-driven heme oxygenase-1 expression in sulforaphane-treated human mesothelioma MSTO-211H cells.

    Science.gov (United States)

    Lee, Yoon-Jin; Jeong, Hyang-Yun; Kim, Yong-Bae; Lee, Yong-Jin; Won, Seong Youn; Shim, Jung-Hyun; Cho, Moon-Kyun; Nam, Hae-Seon; Lee, Sang-Han

    2012-02-01

    The nuclear factor erythroid-derived 2 related factor 2 (Nrf2)/heme oxygenase (HO)-1 induction plays cytoprotective roles against oxidative injury, apoptosis, and anticancer therapy; however, little is known about its regulation in human mesothelioma MSTO-211H cells. In this study, we investigated Nrf2/HO-1 induction in response to sulforaphane and determined the signaling pathways involved in this process. Sulforaphane treatment decreased cell viability and triggered a rapid and transient increase in the intracellular ROS levels. Pretreatment with N-acetylcysteine (NAC) prevented sulforaphane-induced cytotoxicity. Erk1/2 was activated within 1h of sulforaphane addition, whereas Akt phosphorylation was suppressed until the first 8h, and was then maintained at an elevated level until 72h, displaying a biphasic regulatory feature. Nrf2 protein levels in both nuclear and whole cell lysates were increased after sulforaphane treatment and were decreased by pretreatment with NAC, actinomycin D and cycloheximide. Activation of the Nrf2/HO-1 system after sulforaphane treatment was suppressed by pretreatment with NAC or Ly294002, a PI3K inhibitor. Knockdown of Nrf2 with siRNA decreased cell viability and attenuated sulforaphane-induced HO-1 up-regulation. Overall, our results indicate that ROS generation and/or activation of PI3K/Akt signaling regulate cell survival and Nrf2-driven HO-1 expression in sulforaphane-treated MSTO-211H cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. 12b-hydroxy-des-D-garcigerin A enhances glucose metabolism in insulin-resistant HepG2 cells via the IRS-1/PI3-K/Akt cell signaling pathway.

    Science.gov (United States)

    Chen, Yu; Wang, Sha; Tian, Shi-Ting; Hu, Xin; Xu, Jing; Yang, Guang-Zhong; Wang, Chao-Yuan

    2016-11-01

    HepG2 cells were induced with a high concentration of insulin to establish an insulin-resistant cell model (HepG2/IR). The effect of 12b-hydroxy-des-D-garcigerin A (DGA) on the glucose consumption (GC) of HepG2/IR cells was analyzed with the glucose oxidase/peroxidase assay. The results showed that DGA significantly stimulated GC by enhancing the activity of hexokinase (HK) and pyruvate kinase (PK) in HepG2/IR cells. The cell signaling pathway by which DGA enhances the GC of HepG2/IR cells was explored. The results showed that DGA promoted the expression of insulin receptor (InsR) protein, and stimulated the expression of insulin receptor substrate 1 (IRS-1), phosphatidylinositol-3 kinase (p-PI3-K), and phospho-protein kinase B Serine(473) (p-AKT ser(473)). Therefore, we concluded that DGA improved the insulin-resistance of HepG2/IR cells by inducing the IRS-1/PI3-K/Akt cell signaling pathway. Interestingly, DGA had no effect on the phosphorylation of threonine(172) (Thr(172)) in AMP-activated protein kinase (AMPK).

  16. 塞来昔布抑制P13K-Akt信号转导通路及COX-2表达的作用研究%Study on role of celecoxib in inhibiting PI3K-Akt signal transduction pathway and expression of COX-2

    Institute of Scientific and Technical Information of China (English)

    余星平; 黄利鸣; 仝进毅; 黄益玲; 易慕华

    2011-01-01

    Objective: To observe the possible mechanisms of celecoxib in down - regulating COX - 2, inducing apoptosis of cervical cancer HeLa cells and inhibiting PI3K - Akt signal transduction.Methods: MTT method was used to detect the inhibitive effect of celecoxib on proliferation of HeLa cells, flow cytometry was used to detect the effect of celecoxib on proliferative cycle and apoptosis of HeLa cells, and immunohistochemical SP method and RT - PCR were used to detect the effect of celecoxib on PI3K - Akt signal transduction pathway.Results: The inhibitive effect of celecoxib on proliferation of HeLa cells and the inducible effect of celecoxib on apoptosis of HeLa cells showed a dose - and time - dependent manner, after treating HeLa cells with celecoxib of different doses for 24 hours, the proportions of HeLa cells at G1 phase and G2/M phase increased significantly, the proportion of HeLa cells at S phase decreased significantly, the HeLa cells were blocked at G2/M phase; celecoxib inhibited PI3K - Akt signal transduction, showing a dose - and time - dependent manner.Conclusion:Celecoxib can down -regulate the expression of COX -2 in vitro, inhibit the proliferation of HeLa cells and induce the apoptosis of HeLa cells, the mechanism is related to blocking HeLa cells at G2/M phase and inhibiting PI3K - Akt signal transduction pathway.%目的:观察塞来昔布降调节COX-2的表达,诱导宫颈癌HeLa细胞的凋亡作用及阻止PI3K-Akt信号转导的可能机制.方法:采用MTF法检测塞来昔布对HeLa细胞的增殖抑制作用,应用流式细胞术检测塞来昔布对HeLa细胞增殖周期和凋亡的影响,并用免疫组化SP法和RT-PCR法检测寒来昔布对细胞PI3K-Akt信号转导通路的影响.结果:塞来昔布抑制HeLa细胞增殖和诱导HeLa细胞的凋亡作用均呈剂量和时间依赖性,经不同浓度的塞来昔布处理24 h后,HeLa细胞周期的G1期、G2/M期细胞比例明显增多,S期细胞比例明显下降,细胞被阻滞于G2/M

  17. Ganoderma tsugae Induces S Phase Arrest and Apoptosis in Doxorubicin-Resistant Lung Adenocarcinoma H23/0.3 Cells via Modulation of the PI3K/Akt Signaling Pathway

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    Yang-Hao Yu

    2012-01-01

    Full Text Available Ganoderma tsugae (GT is a traditional Chinese medicine that exhibits significant antitumor activities against many types of cancer. This study investigated the molecular mechanism by which GT suppresses the growth of doxorubicin-resistant lung adenocarcinoma H23/0.3 cells. Our results reveal that GT inhibits the viability of H23/0.3 cells in vitro and in vivo and sensitizes the growth suppression effect of doxorubicin on H23/0.3 cells. The data also show that GT induces S phase arrest by interfering with the protein expression of cyclin A, cyclin E, CDK2, and CDC25A. Furthermore, GT induces cellular apoptosis via induction of a mitochondria/caspase pathway. In addition, we also demonstrate that the suppression of cell proliferation by GT is through down-regulation of the PI3K/Akt signaling pathway. In conclusion, this study suggests that GT may be a useful adjuvant therapeutic agent in the treatment of lung cancer.

  18. Tetramethylpyrazine Analogue CXC195 Protects Against Dopaminergic Neuronal Apoptosis via Activation of PI3K/Akt/GSK3β Signaling Pathway in 6-OHDA-Induced Parkinson's Disease Mice.

    Science.gov (United States)

    Chen, Lin; Cheng, Li; Wei, Xinbing; Yuan, Zheng; Wu, Yanmei; Wang, Shuaishuai; Ren, Zhiping; Liu, Xinyong; Liu, Huiqing

    2016-12-22

    Parkinson's disease (PD) is a progressive neurodegenerative disorder and characterized by motor system disorders resulting in loss of dopaminergic (DA) neurons. CXC195, a novel tetramethylpyrazine derivative, has been shown strongest neuroprotective effects due to its anti-apoptotic activity. However, whether CXC195 protects against DA neuronal damage in PD and the mechanisms underlying its beneficial effects are unknown. The purpose of our study was to investigate the potential neuroprotective role of CXC195 and to elucidate its mechanism of action against 6-hydroxydopamine (6-OHDA)-induced mouse model of PD. CXC195 administration improved DA neurodegeneration in PD mice induced by 6-OHDA. Our further findings confirmed treatment of CXC195 at the dose of 10 mg/kg significantly inhibited the apoptosis by decreasing the level of cleaved caspase-3 and Bax, and increasing the level of Bcl-2 in 6-OHDA-lesioned mice. Meanwhile, 6-OHDA also decreased the amount of phosphorylated Akt while increased GSK-3β activity (the amount of phosphorylated GSK-3β at Ser9 was decreased) which was prevented by CXC195. Wortmannin, a specific PI3K inhibitor, dramatically abolished the changes induced by CXC195. Our study firstly demonstrated that CXC195 protected against DA neurodegeneration in 6-OHDA-induced PD model by its anti-apoptotic properties and PI3K/Akt/GSK3β signaling pathway was involved in it.

  19. PI3K/Akt/mTOR信号通路在巨噬细胞自噬及动脉粥样硬化斑块不稳定中的作用%Roles of PI3K/Akt/mTOR signaling pathway in macrophage autophagy and atherosclerotic plaque instability

    Institute of Scientific and Technical Information of China (English)

    王和峰; 翟纯刚; 庞文会; 王晨; 杨敏; 赵凯; 李大庆; 张运; 李继福

    2013-01-01

    目的:探讨磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(Akt)/哺乳动物雷帕霉素靶蛋白(roTOR)信号通路在巨噬细胞自体吞噬以及动脉粥样硬化斑块不稳定中的作用.方法:利用Akt抑制剂康士得(20 lμmol/L)、mTOR抑制剂雷帕霉素(10 nmoL/L)及mTOR-siRNA(30 nmol/L)体外处理小鼠RAW 264.7巨噬细胞株48 h后,透射电镜观察巨噬细胞自噬体的变化,细胞免疫荧光法及Western blotting法检测微管相关蛋白LC3-II表达,实时荧光定量qRT-PCR和Western blotting法检测Akt、mTOR及自噬相关蛋白Beclin 1的表达,ELISA检测巨噬细胞分泌炎症因子水平.体内实验中,24只雄性新西兰兔给予球囊损伤+1%胆固醇喂养8周,然后随机分为对照组、康士得(1.0 mg.kg-1.d-1)组和雷帕霉素(0.5 mg.kg-1.d-1)组,每组8只,干预4周.血管内超声(IVUS)检测斑块的影像学特征,透射电镜观察斑块中巨噬细胞超微结构的改变,免疫荧光法检测微管相关蛋白LC3-II表达,免疫组织化学法检测巨噬细胞Akt和mTOR的蛋白表达.结果:与对照组比较,康士得、雷帕霉素及mTOR-siRNA干预巨噬细胞后,透射电镜下观察到自噬体明显增多,微管相关蛋白LC3-II和自噬相关蛋白Beclin 1的表达水平明显上调,而Akt及mTOR的mRNA及蛋白表达水平明显减少,巨噬细胞分泌的IL-10明显降低,而IFN-γ的分泌显著增加.体内实验:IVUS显示,与对照组比较,康士得组及雷帕霉素组的外弹性膜面积(EEMA)、斑块面积(PA)及斑块负荷(PB)明显减少,透射电镜下观察到巨噬细胞中自噬体增加,组织免疫荧光法示LC3-II明显增加,HE染色显示斑块纤维帽的厚度明显增加,内、中膜厚度显著减低,组织免疫组化染色显示巨噬细胞RAM-11及p-mTOR染色显著减少.结论:选择性抑制PI3 K/Akt/mTOR信号通路能诱导巨噬细胞自噬,减少斑块巨噬细胞的浸润,抑制炎症反应进而稳定动脉粥样硬化易损斑块.%AIM: To investigate

  20. Hydrogen Sulfide Prevents Formation of Reactive Oxygen Species through PI3K/Akt Signaling and Limits Ventilator-Induced Lung Injury

    Directory of Open Access Journals (Sweden)

    Sashko Georgiev Spassov

    2017-01-01

    Full Text Available The development of ventilator-induced lung injury (VILI is still a major problem in mechanically ventilated patients. Low dose inhalation of hydrogen sulfide (H2S during mechanical ventilation has been proven to prevent lung damage by limiting inflammatory responses in rodent models. However, the capacity of H2S to affect oxidative processes in VILI and its underlying molecular signaling pathways remains elusive. In the present study we show that ventilation with moderate tidal volumes of 12 ml/kg for 6 h led to an excessive formation of reactive oxygen species (ROS in mice lungs which was prevented by supplemental inhalation of 80 parts per million of H2S. In addition, phosphorylation of the signaling protein Akt was induced by H2S. In contrast, inhibition of Akt by LY294002 during ventilation reestablished lung damage, neutrophil influx, and proinflammatory cytokine release despite the presence of H2S. Moreover, the ability of H2S to induce the antioxidant glutathione and to prevent ROS production was reversed in the presence of the Akt inhibitor. Here, we provide the first evidence that H2S-mediated Akt activation is a key step in protection against VILI, suggesting that Akt signaling limits not only inflammatory but also detrimental oxidative processes that promote the development of lung injury.

  1. Hydrogen Sulfide Prevents Formation of Reactive Oxygen Species through PI3K/Akt Signaling and Limits Ventilator-Induced Lung Injury

    Science.gov (United States)

    Spassov, Sashko Georgiev; Donus, Rosa; Ihle, Paul Mikael; Engelstaedter, Helen; Hoetzel, Alexander

    2017-01-01

    The development of ventilator-induced lung injury (VILI) is still a major problem in mechanically ventilated patients. Low dose inhalation of hydrogen sulfide (H2S) during mechanical ventilation has been proven to prevent lung damage by limiting inflammatory responses in rodent models. However, the capacity of H2S to affect oxidative processes in VILI and its underlying molecular signaling pathways remains elusive. In the present study we show that ventilation with moderate tidal volumes of 12 ml/kg for 6 h led to an excessive formation of reactive oxygen species (ROS) in mice lungs which was prevented by supplemental inhalation of 80 parts per million of H2S. In addition, phosphorylation of the signaling protein Akt was induced by H2S. In contrast, inhibition of Akt by LY294002 during ventilation reestablished lung damage, neutrophil influx, and proinflammatory cytokine release despite the presence of H2S. Moreover, the ability of H2S to induce the antioxidant glutathione and to prevent ROS production was reversed in the presence of the Akt inhibitor. Here, we provide the first evidence that H2S-mediated Akt activation is a key step in protection against VILI, suggesting that Akt signaling limits not only inflammatory but also detrimental oxidative processes that promote the development of lung injury. PMID:28250891

  2. Chelidonine isolated from ethanolic extract of Chelidonium majus promotes apoptosis in HeLa cells through p38-p53 and PI3K/AKT signalling pathways.

    Science.gov (United States)

    Paul, Avijit; Bishayee, Kausik; Ghosh, Samrat; Mukherjee, Avinaba; Sikdar, Sourav; Chakraborty, Debrup; Boujedaini, Naoual; Khuda-Bukhsh, Anisur Rahman

    2012-09-01

    To evaluate the role of chelidonine isolated from ethanolic extract of Chelidonium majus in inducing apoptosis in HeLa cells and to assess the main signalling pathways involved. Cells were initially treated with different concentrations of chelidonine for 48 h and the median lethal dose (LD50) value was selected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Morphological analysis of nuclear condensation and DNA damage and fragmentation were measured by 4',6-diamidino-2-phenylindole staining and comet assay. Further, reactive oxygen species (ROS) generation, cell cycle arrest and change in mitochondrial membrane potential were also examined and analyzed by flow cytometry. Evaluation of interaction of drug with CT DNA was investigated by circular dichroism (CD) spectral analysis to find any possible drug-CT DNA interaction. The mRNA and protein expressions of major signal proteins like p38, p53, protein kinase B (AKT), phosphatidylinositol 3-kinases (PI3K), Janus kinase 3 (JAK3), signal transducer and activator of transcription 3 (STAT3) and E6 and E7 oncoproteins as well as the pro-apoptotic genes and antiapoptotic genes were also estimated by reverse transcriptase-polymerase chain reaction and Western blotting. Based on LD(50) value (30 μg/mL) of chelidonine, three doses were selected, namely, 22.5 μg/mL (D1), 30.0 μg/mL (D2) and 37.5 μg/mL (D3). Results showed that chelidonine inhibited proliferation and induced apoptosis in HeLa cells through generation of ROS, cell cycle arrest at sub-G1 and G0/G1 stage, change in mitochondrial membrane potential and fragmentation of DNA. Results of CD spectra showed effective interaction between chelidonine and calf thymus DNA. Studies of signalling pathway revealed that chelidonine could efficiently induce apoptosis through up-regulation of expressions of p38, p53 and other pro-apoptotic genes and down-regulation of expressions of AKT, PI3K, JAK3, STAT3, E6, E7 and other antiapoptotic genes

  3. 3-Bromopyruvate induces apoptosis in breast cancer cells by downregulating Mcl-1 through the PI3K/Akt signaling pathway.

    Science.gov (United States)

    Liu, Zhe; Zhang, Yuan-Yuan; Zhang, Qian-Wen; Zhao, Su-Rong; Wu, Cheng-Zhu; Cheng, Xiu; Jiang, Chen-Chen; Jiang, Zhi-Wen; Liu, Hao

    2014-04-01

    The hexokinase inhibitor 3-bromopyruvate (3-BrPA) can inhibit glycolysis in tumor cells to reduce ATP production, resulting in apoptosis. However, as 3-BrPA is an alkylating agent, its cytotoxic action may be induced by other molecular mechanisms. The results presented here reveal that 3-BrPA-induced apoptosis is caspase independent. Further, 3-BrPA induces the generation of reactive oxygen species in MDA-MB-231 cells, leading to mitochondria-mediated apoptosis. These results suggest that caspase-independent apoptosis may be induced by the generation of reactive oxygen species. In this study, we also demonstrated that 3-BrPA induces apoptosis through the downregulation of myeloid cell leukemia-1 (Mcl-1) in MDA-MB-231 breast cancer cells. The results of Mcl-1 knockdown indicate that Mcl-1 plays an important role in 3-BrPA-induced apoptosis. Further, the upregulation of Mcl-1 expression in 3-BrPA-treated MDA-MB-231 cells significantly increases cell viability. In addition, 3-BrPA treatment resulted in the downregulation of p-Akt, suggesting that 3-BrPA may downregulate Mcl-1 through the phosphoinositide-3-kinase/Akt pathway. These findings indicate that 3-BrPA induces apoptosis in breast cancer cells by downregulating Mcl-1 through the phosphoinositide-3-kinase/Akt signaling pathway.

  4. Asperosaponin VI promotes bone marrow stromal cell osteogenic differentiation through the PI3K/AKT signaling pathway in an osteoporosis model

    Science.gov (United States)

    Ke, Ke; Li, Qi; Yang, Xiaofeng; Xie, Zhijian; Wang, Yu; Shi, Jue; Chi, Linfeng; Xu, Weijian; Hu, Lingling; Shi, Huali

    2016-01-01

    Asperosaponin VI (ASA VI), a natural compound isolated from the well-known traditional Chinese herb Radix Dipsaci, has an important role in promoting osteoblast formation. However, its effects on osteoblasts in the context of osteoporosis is unknown. This study aimed to investigate the effects and mechanism of ASA VI action on the proliferation and osteogenic differentiation of bone marrow stromal cells isolated from the ovariectomized rats (OVX rBMSCs). The toxicity of ASA VI and its effects on the proliferation of OVX rBMSCs were measured using a CCK-8 assay. Various osteogenic differentiation markers were also analyzed, such as ALP activity, calcified nodule formation, and the expression of osteogenic genes, i.e., ALP, OCN, COL 1 and RUNX2. The results indicated that ASA VI promoted the proliferation of OVX rBMSCs and enhanced ALP activity and calcified nodule formation. In addition, while ASA VI enhanced the expression of ALP, OCN, Col 1 and RUNX2, treatment with LY294002 reduced all of these osteogenic effects and reduced the p-AKT levels induced by ASA VI. These results suggest that ASA VI promotes the osteogenic differentiation of OVX rBMSCs by acting on the phosphatidylinositol—3 kinase/AKT signaling pathway. PMID:27756897

  5. Both mitogen-activated protein kinase (MAPK)/extracellular-signal-regulated kinases (ERK) 1/2 and phosphatidylinositide-3-OH kinase (PI3K)/Akt pathways regulate activation of E-twenty-six (ETS)-like transcription factor 1 (Elk-1) in U138 glioblastoma cells.

    Science.gov (United States)

    Mut, Melike; Lule, Sevda; Demir, Ozlem; Kurnaz, Isil Aksan; Vural, Imran

    2012-02-01

    Epidermal growth factor (EGF) and its receptor (EGFR) have been shown to play a significant role in the pathogenesis of glioblastoma. In our study, the EGFR was stimulated with EGF in human U138 glioblastoma cells. We show that the activated mitogen-activated protein kinase (MAPK)/extracellular-signal-regulated kinases (ERK) 1/2 pathway phosphorylated the E twenty-six (ETS)-like transcription factor 1 (Elk-1) mainly at serine 383 residue. Mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor, UO126 and ERK inhibitor II, FR180204 blocked the Elk-1 phosphorylation and activation. The phosphatidylinositide-3-OH kinase (PI3K)/Akt pathway was also involved in the Elk-1 activation. Activation of the Elk-1 led to an increased survival and a proliferative response with the EGF stimulation in the U138 glioblastoma cells. Knocking-down the Elk-1 using an RNA interference technique caused a decrease in survival of the unstimulated U138 glioblastoma cells and also decreased the proliferative response to the EGF stimulation. The Elk-1 transcription factor was important for the survival and proliferation of U138 glioblastoma cells upon the stimulation of EGFR with EGF. The MAPK/ERK1/2 and PI3K/Akt pathways regulated this response via activation of the Elk-1 transcription factor. The Elk-1 may be one of the convergence points for pathways located downstream of EGFR in glioblastoma cells. Utilization of the Elk-1 as a therapeutic target may lead to a novel strategy in treatment of glioblastoma.

  6. Fine-Tuning of PI3K/AKT Signalling by the Tumour Suppressor PTEN Is Required for Maintenance of Flight Muscle Function and Mitochondrial Integrity in Ageing Adult Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Lawrence B Mensah

    Full Text Available Insulin/insulin-like growth factor signalling (IIS, acting primarily through the PI3-kinase (PI3K/AKT kinase signalling cassette, plays key evolutionarily conserved regulatory roles in nutrient homeostasis, growth, ageing and longevity. The dysfunction of this pathway has been linked to several age-related human diseases including cancer, Type 2 diabetes and neurodegenerative disorders. However, it remains unclear whether minor defects in IIS can independently induce the age-dependent functional decline in cells that accompany some of these diseases or whether IIS alters the sensitivity to other aberrant signalling. We identified a novel hypomorphic allele of PI3K's direct antagonist, Phosphatase and tensin homologue on chromosome 10 (Pten, in the fruit fly, Drosophila melanogaster. Adults carrying combinations of this allele, Pten5, combined with strong loss-of-function Pten mutations exhibit subtle or no increase in mass, but are highly susceptible to a wide range of stresses. They also exhibit dramatic upregulation of the oxidative stress response gene, GstD1, and a progressive loss of motor function that ultimately leads to defects in climbing and flight ability. The latter phenotype is associated with mitochondrial disruption in indirect flight muscles, although overall muscle structure appears to be maintained. We show that the phenotype is partially rescued by muscle-specific expression of the Bcl-2 homologue Buffy, which in flies, maintains mitochondrial integrity, modulates energy homeostasis and suppresses cell death. The flightless phenotype is also suppressed by mutations in downstream IIS signalling components, including those in the mechanistic Target of Rapamycin Complex 1 (mTORC1 pathway, suggesting that elevated IIS is responsible for functional decline in flight muscle. Our data demonstrate that IIS levels must be precisely regulated by Pten in adults to maintain the function of the highly metabolically active indirect flight

  7. Pseudomonas aeruginosa pyocyanin activates NRF2-ARE-mediated transcriptional response via the ROS-EGFR-PI3K-AKT/MEK-ERK MAP kinase signaling in pulmonary epithelial cells.

    Science.gov (United States)

    Xu, Ying; Duan, Chaohui; Kuang, Zhizhou; Hao, Yonghua; Jeffries, Jayme L; Lau, Gee W

    2013-01-01

    The redox-active pyocyanin (PCN) secreted by the respiratory pathogen Pseudomonas aeruginosa generates reactive oxygen species (ROS) and causes oxidative stress to pulmonary epithelial cells. Nuclear factor (erythroid-derived 2)-like 2 (NRF2) confers protection against ROS-mediated cell death by inducing the expression of detoxifying enzymes and proteins via its binding to the cis-acting antioxidant response element (ARE). However, a clear relationship between NRF2 and PCN-mediated oxidative stress has not been established experimentally. In this study, we investigated the induction of NRF2-ARE response by PCN in the pulmonary epithelial cells. We analyzed the effect of PCN on NRF2 expression and nuclear translocation in cultured human airway epithelial cells, and in a mouse model of chronic PCN exposure. NRF2-dependent transcription of antioxidative enzymes was also assessed. Furthermore, we used inhibitors to examine the involvement of EGFR and its downstream signaling components that mediate NRF2-ARE-activation in response to PCN. PCN enhances the nuclear NRF2 accumulation and activates the transcription of ARE-mediated antioxidant genes. Furthermore, PCN activates NRF2 by inducing the EGFR-phosphoinositide-3-kinase (PI3K) signaling pathway and its main downstream effectors, AKT and MEK1/2-ERK1/2 MAP kinases. Inhibition of the EGFR-PI3K signaling markedly attenuates PCN-stimulated NRF2 accumulation in the nucleus. We demonstrate for the first time that PCN-mediated oxidative stress activates the EGFR-PI3K-AKT/MEK1/2-ERK1/2 MAP kinase signaling pathway, leading to nuclear NRF2 translocation and ARE responsiveness in pulmonary epithelial cells.

  8. 4-1BB signaling activates the t cell factor 1 effector/β-catenin pathway with delayed kinetics via ERK signaling and delayed PI3K/AKT activation to promote the proliferation of CD8+ T Cells.

    Directory of Open Access Journals (Sweden)

    Do Y Lee

    Full Text Available 4-1BB (CD137, an inducible costimulatory molecule, strongly enhances the proliferation and effector function of CD8(+ T cells. Since the serine/threonine kinase, glycogen synthase kinase-3 (GSK-3, is involved in a variety of signaling pathways of cellular proliferation, migration, immune responses, and apoptosis, we examined whether 4-1BB signaling activates GSK-3/β-catenin signaling and downstream transcription factors to enhance the proliferation of CD8(+ T cells. 4-1BB signaling induces rapid activation of ERK and IκB degradation, and shows delayed activation of AKT at 24 h post 4-1BB stimulation on anti-CD3 activated T cells. ERK and AKT signals were required for sustained β-catenin levels by inactivating GSK-3, which was also observed with delayed kinetics after 4-1BB stimulation. As a transcriptional partner of β-catenin, 4-1BB signaling decreased levels of FOXO1 and increased levels of stimulatory TCF1 in CD8(+ T cells at 2-3 days but not at early time points after 4-1BB engagement. The enhanced proliferation of CD8(+ T cells due to 4-1BB signaling was completely abolished by treatment with the TCF1/β-catenin inhibitor quercetin. These results show that 4-1BB signaling enhances the proliferation of activated CD8(+ T cells by activating the TCF1/β-catenin axis via the PI3K/AKT/ERK pathway. As effects of 4-1BB on AKT, FOXO1, β-catenin and GSK-3β showed delayed kinetics it is likely that an intervening molecule induced by 4-1BB and ERK signaling in activated T cells is responsible for these effects. These effects were observed on CD8(+ but not on CD4(+ T cells. Moreover, 4-1BB appeared to be unique among several TNFRs tested in inducing increase in stimulatory over inhibitory TCF-1.

  9. Tetramethylpyrazine Ameliorated Hypoxia-Induced Myocardial Cell Apoptosis via HIF-1α/JNK/p38 and IGFBP3/BNIP3 Inhibition to Upregulate PI3K/Akt Survival Signaling

    Directory of Open Access Journals (Sweden)

    Kuan-Ho Lin

    2015-05-01

    Full Text Available Background: Hemorrhagic shock (HS is the major cause of death from trauma. Hemorrhagic shock may lead to cellular hypoxia and organ damage. Our previous findings showed that HS induced a cardiac apoptosis pathway and synergistically caused myocardial cell damage in diabetic rats under trauma-induced HS. Tetramethylpyrazine (TMP is a major biologically active ingredient purified from the rhizome of Ligusticum wallichii (called Chuang Xiong in Chinese. Chuan Xiong rescued cells from synergistic cardiomyoblast cell injury under high-glucose (HG conditions plus hypoxia. TMP is one of the most important active ingredients that elevated the survival rate in ischemic brain injury and prevented inducible NO synthase expression to have anti-inflammatory effects against cell damage in different cell types. Method: Here, we further investigate whether TMP can protect against hypoxic (Results: Our results showed that hypoxia mediated through HIF-1α/JNK/p38 activation significantly elevated the levels of the hypoxia-related proteins HIF-1α, BNIP3 and IGFBP3, further enhanced the pro-apoptotic protein Bak and upregulated downstream Caspase 9 and 3, resulting in cell death. All of these phenomena were fully recovered under TMP treatment. We observed that TMP exerted this effect by activating the IGF1 receptor survival pathway, dependent primarily on PI3K/Akt. When PI3K (class I was blocked by specific siRNA, the hypoxia-induced activated caspase 3 and cell apoptosis could not be reversed by TMP treatment. Conclusion: Our results strongly suggest that TMP could be used to restore hypoxia-induced myocardial cell apoptosis and cardiac hypoxic damage.

  10. Avian Reovirus Protein p17 Functions as a Nucleoporin Tpr Suppressor Leading to Activation of p53, p21 and PTEN and Inactivation of PI3K/AKT/mTOR and ERK Signaling Pathways.

    Directory of Open Access Journals (Sweden)

    Wei-Ru Huang

    Full Text Available Avian reovirus (ARV protein p17 has been shown to regulate cell cycle and autophagy by activation of p53/PTEN pathway; nevertheless, it is still unclear how p53 and PTEN are activated by p17. Here, we report for the first time that p17 functions as a nucleoporin Tpr suppressor that leads to p53 nuclear accumulation and consequently activates p53, p21, and PTEN. The nuclear localization signal (119IAAKRGRQLD128 of p17 has been identified for Tpr binding. This study has shown that Tpr suppression occurs by p17 interacting with Tpr and by reducing the transcription level of Tpr, which together inhibit Tpr function. In addition to upregulation of PTEN by activation of p53 pathway, this study also suggests that ARV protein p17 acts as a positive regulator of PTEN. ARV p17 stabilizes PTEN by stimulating phosphorylation of cytoplasmic PTEN and by elevating Rak-PTEN association to prevent it from E3 ligase NEDD4-1 targeting. To activate PTEN, p17 is able to promote β-arrestin-mediated PTEN translocation from the cytoplasm to the plasma membrane via a Rock-1-dependent manner. The accumulation of p53 in the nucleus induces the PTEN- and p21-mediated downregulation of cyclin D1 and CDK4. Furthermore, Tpr and CDK4 knockdown increased virus production in contrast to depletion of p53, PTEN, and LC3 reducing virus yield. Taken together, our data suggest that p17-mediated Tpr suppression positively regulates p53, PTEN, and p21 and negatively regulates PI3K/AKT/mTOR and ERK signaling pathways, both of which are beneficial for virus replication.

  11. Avian Reovirus Protein p17 Functions as a Nucleoporin Tpr Suppressor Leading to Activation of p53, p21 and PTEN and Inactivation of PI3K/AKT/mTOR and ERK Signaling Pathways.

    Science.gov (United States)

    Huang, Wei-Ru; Chiu, Hung-Chuan; Liao, Tsai-Ling; Chuang, Kuo-Pin; Shih, Wing-Ling; Liu, Hung-Jen

    2015-01-01

    Avian reovirus (ARV) protein p17 has been shown to regulate cell cycle and autophagy by activation of p53/PTEN pathway; nevertheless, it is still unclear how p53 and PTEN are activated by p17. Here, we report for the first time that p17 functions as a nucleoporin Tpr suppressor that leads to p53 nuclear accumulation and consequently activates p53, p21, and PTEN. The nuclear localization signal (119IAAKRGRQLD128) of p17 has been identified for Tpr binding. This study has shown that Tpr suppression occurs by p17 interacting with Tpr and by reducing the transcription level of Tpr, which together inhibit Tpr function. In addition to upregulation of PTEN by activation of p53 pathway, this study also suggests that ARV protein p17 acts as a positive regulator of PTEN. ARV p17 stabilizes PTEN by stimulating phosphorylation of cytoplasmic PTEN and by elevating Rak-PTEN association to prevent it from E3 ligase NEDD4-1 targeting. To activate PTEN, p17 is able to promote β-arrestin-mediated PTEN translocation from the cytoplasm to the plasma membrane via a Rock-1-dependent manner. The accumulation of p53 in the nucleus induces the PTEN- and p21-mediated downregulation of cyclin D1 and CDK4. Furthermore, Tpr and CDK4 knockdown increased virus production in contrast to depletion of p53, PTEN, and LC3 reducing virus yield. Taken together, our data suggest that p17-mediated Tpr suppression positively regulates p53, PTEN, and p21 and negatively regulates PI3K/AKT/mTOR and ERK signaling pathways, both of which are beneficial for virus replication.

  12. Infection of Female BWF1 Lupus Mice with Malaria Parasite Attenuates B Cell Autoreactivity by Modulating the CXCL12/CXCR4 Axis and Its Downstream Signals PI3K/AKT, NFκB and ERK.

    Science.gov (United States)

    Badr, Gamal; Sayed, Ayat; Abdel-Maksoud, Mostafa A; Mohamed, Amany O; El-Amir, Azza; Abdel-Ghaffar, Fathy A; Al-Quraishy, Saleh; Mahmoud, Mohamed H

    2015-01-01

    Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by abnormal autoreactivity in B cells. Lymphocytes and their soluble mediators contribute to the disease pathogenesis. We recently demonstrated that infecting lupus mice with malaria confers protection against lupus nephritis by attenuating oxidative stress in both liver and kidney tissues. In the current study, we further investigated B cell autoreactivity in female BWF1 lupus mice after infection with either live or gamma-irradiated malaria, using ELISA, flow cytometry and Western blot analysis. The lupus mice exhibited a significant elevation in plasma levels of IL-4, IL-6, IL-7, IL-12, IL-17, IFN-α, IFN-γ, TGF-β, BAFF and APRIL and a marked elevation of IgG2a, IgG3 and ant-dsDNA autoantibodies compared with normal healthy mice. Infecting lupus mice with live but not gamma-irradiated malaria parasite partially and significantly restored the levels of the soluble mediators that contribute to the progression of lupus. Furthermore, the B cells of lupus mice exhibited an increased proliferative capacity; aberrant overexpression of the chemokine receptor CXCR4; and a marked elevation in responsiveness to their cognate ligand (CXCL12) via aberrant activation of the PI3K/AKT, NFκB and ERK signaling pathways. Interestingly, infecting lupus mice with live but not gamma-irradiated malaria parasite restored a normal proliferative capacity, surface expression of CXCR4 and B cell response to CXCL-12. Taken together, our data present interesting findings that clarify, for the first time, the molecular mechanisms of how infection of lupus mice with malaria parasite controls B cell autoreactivity and thus confers protection against lupus severity.

  13. Molecular targets for cancer therapy in the PI3K/AKT/mTOR pathway.

    Science.gov (United States)

    Polivka, Jiri; Janku, Filip

    2014-05-01

    Aberrations in various cellular signaling pathways are instrumental in regulating cellular metabolism, tumor development, growth, proliferation, metastasis and cytoskeletal reorganization. The fundamental cellular signaling cascade involved in these processes, the phosphatidylinositol 3-kinase/protein kinase-B/mammalian target of rapamycin (PI3K/AKT/mTOR), closely related to the mitogen-activated protein kinase (MAPK) pathway, is a crucial and intensively explored intracellular signaling pathway in tumorigenesis. Various activating mutations in oncogenes together with the inactivation of tumor suppressor genes are found in diverse malignancies across almost all members of the pathway. Substantial progress in uncovering PI3K/AKT/mTOR alterations and their roles in tumorigenesis has enabled the development of novel targeted molecules with potential for developing efficacious anticancer treatment. Two approved anticancer drugs, everolimus and temsirolimus, exemplify targeted inhibition of PI3K/AKT/mTOR in the clinic and many others are in preclinical development as well as being tested in early clinical trials for many different types of cancer. This review focuses on targeted PI3K/AKT/mTOR signaling from the perspective of novel molecular targets for cancer therapy found in key pathway members and their corresponding experimental therapeutic agents. Various aberrant prognostic and predictive biomarkers are also discussed and examples are given. Novel approaches to PI3K/AKT/mTOR pathway inhibition together with a better understanding of prognostic and predictive markers have the potential to significantly improve the future care of cancer patients in the current era of personalized cancer medicine.

  14. Honokiol induces autophagy of neuroblastoma cells through activating the PI3K/Akt/mTOR and endoplasmic reticular stress/ERK1/2 signaling pathways and suppressing cell migration.

    Science.gov (United States)

    Yeh, Poh-Shiow; Wang, Weu; Chang, Ya-An; Lin, Chien-Ju; Wang, Jhi-Joung; Chen, Ruei-Ming

    2016-01-01

    autophagy of neuroblastoma cells and consequent apoptosis through activating the PI3K/Akt/mTOR and ERS/ROS/ERK1/2 signaling pathways and suppressing cell migration. Thus, honokiol has potential for treating neuroblastomas.

  15. Rutaecarpine ameliorates hyperlipidemia and hyperglycemia in fat-fed, streptozotocin-treated rats via regulating the IRS-1/PI3K/Akt and AMPK/ACC2 signaling pathways.

    Science.gov (United States)

    Nie, Xu-qiang; Chen, Huai-hong; Zhang, Jian-yong; Zhang, Yu-jing; Yang, Jian-wen; Pan, Hui-jun; Song, Wen-xia; Murad, Ferid; He, Yu-qi; Bian, Ka

    2016-04-01

    and ACC2, and increased glucose uptake. Rutaecarpine ameliorates hyperlipidemia and hyperglycemia in fat-fed, streptozotocin-treated rats via regulating IRS-1/PI3K/Akt signaling pathway in liver and AMPK/ACC2 signaling pathway in skeletal muscles.

  16. The Effects of IGF-1 on TNF-α-Treated DRG Neurons by Modulating ATF3 and GAP-43 Expression via PI3K/Akt/S6K Signaling Pathway.

    Science.gov (United States)

    Zhang, Lei; Yue, Yaping; Ouyang, Meishuo; Liu, Huaxiang; Li, Zhenzhong

    2017-02-16

    imply that IGF-1 counteracts the toxic effect of higher concentration of TNF-α, while potentiates the growth-promoting effect of lower concentration of TNF-α, with the node for TNF-α and IGF-1 interaction being the PI3K/Akt/S6K signaling pathway. This study is helpful for interpretation of the association of IGF-1 with TNF-α and the neurobiological effects elicited by interaction of IGF-1 and TNF-α in neurological disorders.

  17. Control of fibroblast fibronectin expression and alternative splicing via the PI3K/Akt/mTOR pathway

    Energy Technology Data Exchange (ETDEWEB)

    White, Eric S., E-mail: docew@umich.edu [Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI (United States); Sagana, Rommel L.; Booth, Adam J.; Yan, Mei; Cornett, Ashley M.; Bloomheart, Christopher A.; Tsui, Jessica L.; Wilke, Carol A.; Moore, Bethany B. [Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI (United States); Ritzenthaler, Jeffrey D.; Roman, Jesse [Department of Medicine, University of Louisville School of Medicine, Louisville, KY (United States); Muro, Andres F. [International Centre for Genetic Engineering and Biotechnology, Trieste (Italy)

    2010-10-01

    Fibronectin (FN), a ubiquitous glycoprotein that plays critical roles in physiologic and pathologic conditions, undergoes alternative splicing which distinguishes plasma FN (pFN) from cellular FN (cFN). Although both pFN and cFN can be incorporated into the extracellular matrix, a distinguishing feature of cFN is the inclusion of an alternatively spliced exon termed EDA (for extra type III domain A). The molecular steps involved in EDA splicing are well-characterized, but pathways influencing EDA splicing are less clear. We have previously found an obligate role for inhibition of the tumor suppressor phosphatase and tensin homologue on chromosome 10 (PTEN), the primary regulator of the PI3K/Akt pathway, in fibroblast activation. Here we show TGF-{beta}, a potent inducer of both EDA splicing and fibroblast activation, inhibits PTEN expression and activity in mesenchymal cells, corresponding with enhanced PI3K/Akt signaling. In pten{sup -/-} fibroblasts, which resemble activated fibroblasts, inhibition of Akt attenuated FN production and decreased EDA alternative splicing. Moreover, inhibition of mammalian target of rapamycin (mTOR) in pten{sup -/-} cells also blocked FN production and EDA splicing. This effect was due to inhibition of Akt-mediated phosphorylation of the primary EDA splicing regulatory protein SF2/ASF. Importantly, FN silencing in pten{sup -/-} cells resulted in attenuated proliferation and migration. Thus, our results demonstrate that the PI3K/Akt/mTOR axis is instrumental in FN transcription and alternative splicing, which regulates cell behavior.

  18. MAPK/ERK和PI3K/Akt信号通道的基因变异与甲状腺癌的发生发展及诊治%Genetic Alterations in MAPK and PI3K/Akt Signaling Pathways and the Generation, Progression, Diagnosis and Therapy of Thyroid Cancer

    Institute of Scientific and Technical Information of China (English)

    刘斌

    2012-01-01

    通过将细胞外信号转导至细胞核内,丝裂原活化蛋白激酶(MAPK)和磷脂酰肌醇-3羟基激酶/蛋白激酶B(PI3K/Akt)信号通道在细胞的生长、增殖及凋亡等活动中发挥着重要的调节作用.甲状腺癌细胞MAPK/ERK和PI3K/Akt信号通道蛋白的编码基因多异常表达.基因变异致MAPK/ERK和PI3K/Akt信号通道的过度活化及相互作用,与甲状腺癌的发生及进展密切相关.本文主要就MAPK和PI3K/Akt信号通道的基因变异在甲状腺癌发生、进展及诊断中的作用作一综述.此外,本文还将探讨同步抑制MAPK和PI3K/Akt信号通道,恢复细胞的摄碘能力,介导放射性核素靶向治疗甲状腺癌的治疗潜力.%The mitogen-activated protein kinase/extracellular signal-regulated kinase ( MAPK/ERK ) and phoshoinositide-3-kinase/protein kinase B (PI3K/Akt) signaling pathways play a major role in regulating cell growth, proliferation and apoptosis, via transmission of cell signals to cell nucleus. The genes, coding the MAPK/ ERK and PI3K/Akt signaling cascade proteins, are significantly mutated in thyroid cancer. Genetic alternations contribute to aberrant activations and interaction of MAPK/ERK and PI3K/Akt signaling pathways in consequence of malignant follicular cell transformation and progression. This review focuses mainly on the role of genetic alterations in coding MAPK/ERK and PI3K/Akt signaling pathway proteins in generation, progression and diagnosis of thyroid cancer. Moreover, it additionally points out a therapeutic potential in restoring iodine avidity of thyroid cancer cells for radionuclide targeted treatment, by synergistically inhibiting activity of signaling pathways.

  19. Presence of both alterations in FGFR/FGF and PI3K/AKT/mTOR confer improved outcomes for patients with metastatic breast cancer treated with PI3K/AKT/mTOR inhibitors.

    Science.gov (United States)

    Wheler, Jennifer J; Atkins, Johnique T; Janku, Filip; Moulder, Stacy L; Stephens, Philip J; Yelensky, Roman; Valero, Vicente; Miller, Vincent; Kurzrock, Razelle; Meric-Bernstam, Funda

    2016-01-01

    There is limited data on co-expression of FGFR/FGR amplifications and PI3K/ AKT/mTOR alterations in breast cancer. Tumors from patients with metastatic breast cancer referred to our Phase I Program were analyzed by next generation sequencing (NGS). Genomic libraries were selected for all exons of 236 (or 182) cancer-related genes sequenced to average depth of >500× in a CLIA laboratory (Foundation Medicine, Cambridge, MA, USA) and analyzed for all classes of genomic alterations. We report genomic profiles of 112 patients with metastatic breast cancer, median age 55 years (range, 27-78). Twenty-four patients (21%) had at least one amplified FGFR or FGF. Fifteen of the 24 patients (63%) also had an alteration in the PI3K/ AKT/mTOR pathway. There was no association between alterations in FGFR/FGF and PI3K/AKT/mTOR (P=0.49). Patients with simultaneous amplification in FGFR/FGF signaling and the PI3K/AKT/mTOR pathway had a higher rate of SD≥6 months/PR/ CR when treated with therapies targeting the PI3K/AKT/mTOR pathway than patients with only alterations in the PI3K/AKT/mTOR pathway (73% vs. 34%; P=0.0376) and remained on treatment longer (6.8 vs. 3.7 months; P=0.053). Higher response rates were seen in patients with simultaneous amplification in FGFR/FGF signaling and alterations in the PI3K/AKT/mTOR pathway who were treated with inhibitors of that pathway.

  20. L-securinine induces apoptosis in the human promyelocytic leukemia cell line HL-60 and influences the expression of genes involved in the PI3K/AKT/mTOR signaling pathway.

    Science.gov (United States)

    Han, Shuwen; Zhang, Gang; Li, Maidong; Chen, Dongyun; Wang, Ying; Ye, Wencai; Ji, Zhaoning

    2014-05-01

    The Securinega alkaloids are a class of natural products isolated from plants of the Euphorbiaceae family. L-securinine induces apoptosis in the human promyelocytic leukemia cell line HL-60 indicating its potential as an efficient natural antitumor drug with low toxicity. The aim of the present study was to investigate the apoptotic effects of L-securinine on HL-60 cells and to explore its potential underlying molecular mechanism(s) as an antitumor agent. HL-60 cells were cultured with L-securinine. The proliferation and changes in cell morphology were evaluated by cell counting Kit-8 (CCK-8) assay and electron microscopy, respectively. Induction of apoptosis and cell cycle progression were investigated by flow cytometry. The PI3K/AKT/mTOR pathway gene expression was measured by quantitative PCR (qPCR). L-securinine decreased the viability of HL-60 cells in a dose- and time-dependent manner, with IC50 values at 24, 48 and 72 h post-treatment of 47.88, 23.85 and 18.87 µmol/l, respectively. Numerous apoptotic bodies were observed in the HL-60 cells treated with 25 µmol/l L-securinine for 48 h. L-securinine at 12.5, 25 and 50 µmol/l increased the rate of apoptosis in HL-60 cells, and G1/S phase progression was retarded. Furthermore, L-securinine induced downregulation of PI3K, AKT and mTOR gene expression and upregulation of PTEN gene expression in a dose-dependent manner. In conclusion, L-securinine induces apoptosis and inhibition of cell cycle progression in HL-60 cells by modulation of the PI3K/AKT/mTOR pathway gene expression. These observations indicate the potential of L-securinine as an antitumor agent.

  1. Roles of PI3K/Akt and c-Jun signaling pathways in human papillomavirus type 16 oncoprotein-induced HIF-1α, VEGF, and IL-8 expression and in vitro angiogenesis in non-small cell lung cancer cells.

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    Erying Zhang

    Full Text Available Human papillomavirus (HPV-16 infection may be related to non-smoking associated lung cancer. Our previous studies have found that HPV-16 oncoproteins promoted angiogenesis via enhancing hypoxia-inducible factor-1α (HIF-1α, vascular endothelial growth factor (VEGF, and interleukin-8 (IL-8 expression in non-small cell lung cancer (NSCLC cells. In this study, we further investigated the roles of PI3K/Akt and c-Jun signaling pathways in it.Human NSCLC cell lines, A549 and NCI-H460, were stably transfected with pEGFP-16 E6 or E7 plasmids. Western blotting was performed to analyze the expression of HIF-1α, p-Akt, p-P70S6K, p-P85S6K, p-mTOR, p-JNK, and p-c-Jun proteins. VEGF and IL-8 protein secretion and mRNA levels were determined by ELISA and Real-time PCR, respectively. The in vitro angiogenesis was observed by human umbilical vein endothelial cells (HUVECs tube formation assay. Co-immunoprecipitation was performed to analyze the interaction between c-Jun and HIF-1α.HPV-16 E6 and E7 oncoproteins promoted the activation of Akt, P70S6K, P85S6K, mTOR, JNK, and c-Jun. LY294002, a PI3K inhibitor, inhibited HPV-16 oncoprotein-induced activation of Akt, P70S6K, and P85S6K, expression of HIF-1α, VEGF, and IL-8, and in vitro angiogenesis. c-Jun knockdown by specific siRNA abolished HPV-16 oncoprotein-induced HIF-1α, VEGF, and IL-8 expression and in vitro angiogenesis. Additionally, HPV-16 oncoproteins promoted HIF-1α protein stability via blocking proteasome degradation pathway, but c-Jun knockdown abrogated this effect. Furthermore, HPV-16 oncoproteins increased the quantity of c-Jun binding to HIF-1α.PI3K/Akt signaling pathway and c-Jun are involved in HPV-16 oncoprotein-induced HIF-1α, VEGF, and IL-8 expression and in vitro angiogenesis. Moreover, HPV-16 oncoproteins promoted HIF-1α protein stability possibly through enhancing the interaction between c-Jun and HIF-1α, thus making a contribution to angiogenesis in NSCLC cells.

  2. Effects of the PI-3K/AKT signal transduction pathway on the chronic myeloproliferative diseases with JAK2 gene mutation%CMPN基因突变及其机制与生物学意义的探讨

    Institute of Scientific and Technical Information of China (English)

    牛志云; 郭晓玲; 张敬宇; 杨琳; 罗建民

    2013-01-01

    transcriptional PCR (FQ-PCR),the protein expression levels of PI3K,AKT and p-AKT were detected by western blotting.RESULTS:The percentage of this gene mutation was 75.0%,46.7% and 26.7% in PV,ET and IMF groups respectively.Compared with healthy volunteers group,the expression levels of G-CSFR mRNA were increased 263.16%,276.32% and 247.37%; the expression levels of EPOR mRNA were increased 213.95%,220.93%and 218.61%; the expression levels of TPOR mRNA were increased by 172.55%,176.47% and 182.35% in PV,ET and IMF groups respectively.The expression levels of PI3K and p-AKT protein in PV,ET and IMF groups were increased markedly.The expression levels of PI3K protein were increased by 115.79%,92.11% and 100.00%.The expression levels of p-AKT protein were increased by 226.09%,243.48% and 200.00% (P<0.05).The expression levels of AKT protein had on significant difference (P>0.05).CONCLUSIONS:Many of CMPN patients have JAK2/V617F gene mutation.This mutation may participate in the mechanisms of CMPN by affecting the signal transduction of many cytokines and the pathway of PI-3K/AKT,which can inhibit the apoptosis and promote the proliferation of cells.

  3. Combination of Endothelial-Monocyte-Activating Polypeptide-II with Temozolomide Suppress Malignant Biological Behaviors of Human Glioblastoma Stem Cells via miR-590-3p/MACC1 Inhibiting PI3K/AKT/mTOR Signal Pathway

    Science.gov (United States)

    Zhou, Wei; Liu, Libo; Xue, Yixue; Zheng, Jian; Liu, Xiaobai; Ma, Jun; Li, Zhen; Liu, Yunhui

    2017-01-01

    This study aims to investigate the effect of Endothelial-Monocyte-Activating Polypeptide-II (EMAP-II) combined with temozolomide (TMZ) upon glioblastoma stem cells (GSCs) and its possible molecular mechanisms. In this study, combination of EMAP-II with TMZ inhibited cell viability, migration and invasion in GSCs, and autophagy inhibitor 3-methyl adenine (3-MA) and chloroquine (CQ) partly reverse the anti-proliferative effect of the combination treatment. Autophagic vacuoles were formed in GSCs after the combination therapy, accompanied with the up-regulation of LC3-II and Beclin-1 as well as the down-regulation of p62/SQSTM1. Further, miR-590-3p was up-regulated and Metastasis-associated in colon cancer 1 (MACC1) was down-regulated by the combination treatment in GSCs; MiR-590-3p overexpression and MACC1 knockdown up-regulated LC3-II and Beclin-1 as well as down-regulated p62/SQSTM1 in GSCs; MACC1 was identified as a direct target of miR-590-3p, mediating the effects of miR-590-3p in the combination treatment. Furthermore, the combination treatment and MACC1 knockdown decreased p-PI3K, p-Akt, p-mTOR, p-S6 and p-4EBP in GSCs; PI3K/Akt agonist insulin-like growth factor-1(IGF-1) partly blocked the effect of the combination treatment. Moreover, in vivo xenograft models, the mice given stable overexpressed miR-590-3p cells and treated with EMAP-II and TMZ had the smallest tumor sizes, besides, miR-590-3p + EMAP-II + TMZ up-regulated the expression level of miR-590-3p, LC3-II and Beclin-1 as well as down-regulated p62/SQSTM1. In conclusion, these results elucidated anovel molecular mechanism of EMAP-II in combination with TMZ suppressed malignant biological behaviors of GSCs via miR-590-3p/MACC1 inhibiting PI3K/AKT/mTOR signaling pathway, and might provide potential therapeutic approaches for human GSCs.

  4. Molecular and Functional Characterization of Three Different Postzygotic Mutations in PIK3CA-Related Overgrowth Spectrum (PROS Patients: Effects on PI3K/AKT/mTOR Signaling and Sensitivity to PIK3 Inhibitors.

    Directory of Open Access Journals (Sweden)

    Daria C Loconte

    Full Text Available PIK3CA-related overgrowth spectrum (PROS include a group of disorders that affect only the terminal portion of a limb, such as type I macrodactyly, and conditions like fibroadipose overgrowth (FAO, megalencephaly-capillary malformation (MCAP syndrome, congenital lipomatous asymmetric overgrowth of the trunk, lymphatic, capillary, venous, and combined-type vascular malformations, epidermal nevi, skeletal and spinal anomalies (CLOVES syndrome and Hemihyperplasia Multiple Lipomatosis (HHML. Heterozygous postzygotic PIK3CA mutations are frequently identified in these syndromes, while timing and tissue specificity of the mutational event are likely responsible for the extreme phenotypic variability observed.We carried out a combination of Sanger sequencing and targeted deep sequencing of genes involved in the PI3K/AKT/mTOR pathway in three patients (1 MCAP and 2 FAO to identify causative mutations, and performed immunoblot analyses to assay the phosphorylation status of AKT and P70S6K in affected dermal fibroblasts. In addition, we evaluated their ability to grow in the absence of serum and their response to the PI3K inhibitors wortmannin and LY294002 in vitro.Our data indicate that patients' cells showed constitutive activation of the PI3K/Akt pathway. Of note, PI3K pharmacological blockade resulted in a significant reduction of the proliferation rate in culture, suggesting that inhibition of PI3K might prove beneficial in future therapies for PROS patients.

  5. Metastatic function of BMP-2 in gastric cancer cells: The role of PI3K/AKT, MAPK, the NF-{kappa}B pathway, and MMP-9 expression

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Myoung Hee [Graduate School of Medicine, Korea University College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Oh, Sang Cheul [Division of Oncology/Hematology, Department of Internal Medicine, Korea University College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Lee, Hyun Joo [Department of Pathology, Korea University College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Kang, Han Na; Kim, Jung Lim [Graduate School of Medicine, Korea University College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Kim, Jun Suk [Division of Oncology/Hematology, Department of Internal Medicine, Korea University College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of); Yoo, Young A., E-mail: ydanbi@korea.ac.kr [Brain Korea 21 Program for Biomedical Science, Korea University College of Medicine, Korea University, Seoul 136-705 (Korea, Republic of)

    2011-07-15

    Bone morphogenetic proteins (BMPs) have been implicated in tumorigenesis and metastatic progression in various types of cancer cells, but the role and cellular mechanism in the invasive phenotype of gastric cancer cells is not known. Herein, we determined the roles of phosphoinositide 3-kinase (PI3K)/AKT, extracellular signal-regulated protein kinase (ERK), nuclear factor (NF)-{kappa}B, and matrix metalloproteinase (MMP) expression in BMP-2-mediated metastatic function in gastric cancer. We found that stimulation of BMP-2 in gastric cancer cells enhanced the phosphorylation of AKT and ERK. Accompanying activation of AKT and ERK kinase, BMP-2 also enhanced phosphorylation/degradation of I{kappa}B{alpha} and the nuclear translocation/activation of NF-{kappa}B. Interestingly, blockade of PI3K/AKT and ERK signaling using LY294002 and PD98059, respectively, significantly inhibited BMP-2-induced motility and invasiveness in association with the activation of NF-{kappa}B. Furthermore, BMP-2-induced MMP-9 expression and enzymatic activity was also significantly blocked by treatment with PI3K/AKT, ERK, or NF-{kappa}B inhibitors. Immunohistochemistry staining of 178 gastric tumor biopsies indicated that expression of BMP-2 and MMP-9 had a significant positive correlation with lymph node metastasis and a poor prognosis. These results indicate that the BMP-2 signaling pathway enhances tumor metastasis in gastric cancer by sequential activation of the PI3K/AKT or MAPK pathway followed by the induction of NF-{kappa}B and MMP-9 activity, indicating that BMP-2 has the potential to be a therapeutic molecular target to decrease metastasis.

  6. Alisertib induces cell cycle arrest and autophagy and suppresses epithelial-to-mesenchymal transition involving PI3K/Akt/mTOR and sirtuin 1-mediated signaling pathways in human pancreatic cancer cells

    Directory of Open Access Journals (Sweden)

    Wang F

    2015-01-01

    PC-3 cells in G2/M phase via regulating the expression of cyclin-dependent kinases 1 and 2, cyclin B1, cyclin D1, p21 Waf1/Cip1, p27 Kip1, and p53. ALS concentration-dependently induced autophagy in PANC-1 and BxPC-3 cells, which may be attributed to the inhibition of phosphatidylinositol 3-kinase (PI3K/protein kinase B (Akt/mammalian target of rapamycin (mTOR, p38 mitogen-activated protein kinase (p38 MAPK, and extracellular signal-regulated kinases 1 and 2 (Erk1/2 but activation of 5'-AMP-dependent kinase signaling pathways. ALS significantly inhibited EMT in PANC-1 and BxPC-3 cells with an increase in the expression of E-cadherin and a decrease in N-cadherin. In addition, ALS suppressed the expression of sirtuin 1 (Sirt1 and pre-B cell colony-enhancing factor/visfatin in both cell lines with a rise in the level of acetylated p53. These findings show that ALS induces cell cycle arrest and promotes autophagic cell death but inhibits EMT in pancreatic cancer cells with the involvement of PI3K/Akt/mTOR, p38 MAPK, Erk1/2, and Sirt1-mediated signaling pathways. Taken together, ALS may represent a promising anticancer drug for pancreatic cancer treatment. More studies are warranted to investigate other molecular targets and mechanisms and verify the efficacy and safety of ALS in the treatment of pancreatic cancer.Keywords: alisertib, pancreatic cancer, cell cycle, autophagy, EMT, Sirt1

  7. PI3K/Akt/GSK-3β信号通路在二氮嗪后处理减轻大鼠心肌缺血再灌注损伤中的作用:离体实验%Role of PI3K/Akt/GSK-3β signaling pathway in mitigation of ischemia-reperfusion injury by diazoxide postconditioning in isolated rat hearts

    Institute of Scientific and Technical Information of China (English)

    王英; 谢平; 张琳; 刘兴奎; 喻田

    2014-01-01

    目的 评价磷酸肌醇3激酶/蛋白激酶B/糖原合成酶激酶3β(PI3K/Akt/GSK-3β)信号通路在二氮嗪后处理减轻大鼠心肌缺血再灌注损伤中的作用.方法 取清洁级SD成年大鼠,制备离体灌注心脏30个,采用随机数字表法分为5组(n=6):正常对照组(C组)、缺血再灌注组(I/R组)、二氮嗪后处理组(DZ组)、PI3K抑制剂LY294002组(LY组)和二氮嗪后处理+LY294002组(DZ+ LY组).C组采用K-H液平衡灌注70 min;I/R组灌注4℃ST-Thomas停跳液10 ml/kg,继之停止灌注泵造成全心缺血,40 min后再次灌注K-H液30 min;DZ组于再灌注开始即刻经主动脉逆行灌注50 μmol/L二氮嗪5 min; LY组于再灌注开始即刻经主动逆行脉灌注15μmol/L LY294002 5 min;DZ+ LY组于再灌注开始即刻经主动脉逆行灌注15 μmol/L LY294002 5 min,随后逆行灌注50 μmol/L二氮嗪5 min.于平衡灌注20 min时(T1)和再灌注30 min时(T2)记录HR、冠状动脉流量(CF)、左心室发展压(LVDP)、左室舒张末压(LVEDP)和压力瞬时最大变化率(±dp/dtmax).采用Western blot法测定心肌组织总Akt(t-Akt)和总GSK-3β(t-GSK-3β)表达水平及其磷酸化水平.结果 与C组比较,其余4组T2时HR、LVDP和±dp/dtmax降低,LVEDP升高,I/R组、LY组和DZ+ LY组CF降低,DZ组心肌组织Akt和GSK-3β磷酸化水平升高(P<0.01);与I/R组比较,DZ组T2时HR、CF、LVDP和±dp/dtmax升高,LVEDP降低,心肌组织Akt和GSK-3β磷酸化水平升高(P<0.01),LY组和DZ+ LY组心肌组织Akt和GSK-3β磷酸化水平差异无统计学意义(P>0.05);与DZ组比较,LY组和DZ+ LY组HR、CF、LVDP和±dp/dtmax降低,LVEDP升高,心肌组织Akt和GSK-3β磷酸化水平降低(P<0.01).结论 PI3K/Akt/GSK-3β信号通路参与了二氮嗪后处理减轻大鼠心肌缺血再灌注损伤.%Objective To evaluate the role of phosphoinositide 3 kinase/protein kinase B/glycogen synthase kinase 3β (PI3K/Akt/GSK-3β) signaling pathway in mitigation of ischemia-reperfusion (I/R) injury by

  8. COMP-angiopoietin 1 increases proliferation, differentiation, and migration of stem-like cells through Tie-2-mediated activation of p38 MAPK and PI3K/Akt signal transduction pathways

    Energy Technology Data Exchange (ETDEWEB)

    Kook, Sung-Ho [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of); Lim, Shin-Saeng [School of Dentistry and Dental Research Institute, Seoul National University, Seoul (Korea, Republic of); Cho, Eui-Sic; Lee, Young-Hoon; Han, Seong-Kyu; Lee, Kyung-Yeol [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of); Kwon, Jungkee [College of Veterinary Medicine, Chonbuk National University, Jeonju (Korea, Republic of); Hwang, Jae-Won; Bae, Cheol-Hyeon [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of); Seo, Young-Kwon [Research Institute of Biotechnology, Dongguk University, Seoul (Korea, Republic of); Lee, Jeong-Chae, E-mail: leejc88@jbnu.ac.kr [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of)

    2014-12-12

    Highlights: • COMP-Ang1 induces Tie-2 activation in BMMSCs, but not in primary osteoblasts. • Tie-2 knockdown inhibits COMP-Ang1-stimulated proliferation and osteoblastogenesis. • Tie-2 knockdown prevents COMP-Ang1-induced activation of PI3K/Akt and p38 MAPK. • COMP-Ang1 induces migration of cells via activation of PI3K/Akt and CXCR4 pathways. • COMP-Ang1 stimulates in vivo migration of PDLSCs into a calvarial defect site of rats. - Abstract: Recombinant COMP-Ang1, a chimera of angiopoietin-1 (Ang1) and a short coiled-coil domain of cartilage oligomeric matrix protein (COMP), is under consideration as a therapeutic agent capable of inducing the homing of cells with increased angiogenesis. However, the potentials of COMP-Ang1 to stimulate migration of mesenchymal stem cells (MSCs) and the associated mechanisms are not completely understood. We examined the potential of COMP-Ang1 on bone marrow (BM)-MSCs, human periodontal ligament stem cells (PDLSCs), and calvarial osteoblasts. COMP-Ang1 augmented Tie-2 induction at protein and mRNA levels and increased proliferation and expression of runt-related transcription factor 2 (Runx2), osterix, and CXCR4 in BMMSCs, but not in osteoblasts. The COMP-Ang1-mediated increases were inhibited by Tie-2 knockdown and by treating inhibitors of phosphoinositide 3-kinase (PI3K), LY294002, or p38 mitogen-activated protein kinase (MAPK), SB203580. Phosphorylation of p38 MAPK and Akt was prevented by siRNA-mediated silencing of Tie-2. COMP-Ang1 also induced in vitro migration of BMMSCs and PDLSCs. The induced migration was suppressed by Tie-2 knockdown and by CXCR4-specific peptide antagonist or LY294002, but not by SB203580. Furthermore, COMP-Ang1 stimulated the migration of PDLSCs into calvarial defect site of rats. Collectively, our results demonstrate that COMP-Ang1-stimulated proliferation, differentiation, and migration of progenitor cells may involve the Tie-2-mediated activation of p38 MAPK and PI3K/Akt pathways.

  9. Inhibition of PI3K/Akt pathway impairs G2/M transition of cell cycle in late developing progenitors of the avian embryo retina.

    Directory of Open Access Journals (Sweden)

    Isis Moraes Ornelas

    Full Text Available PI3K/Akt is an important pathway implicated in the proliferation and survival of cells in the CNS. Here we investigated the participation of the PI3K/Akt signal pathway in cell cycle of developing retinal progenitors. Immunofluorescence assays performed in cultures of chick embryo retinal cells and intact tissues revealed the presence of phosphorylated Akt and 4E-BP1 in cells with typical mitotic profiles. Blockade of PI3K activity with the chemical inhibitor LY 294002 (LY in retinal explants blocked the progression of proliferating cells through G2/M transition, indicated by an expressive increase in the number of cells labeled for phosphorylated histone H3 in the ventricular margin of the retina. No significant level of cell death could be detected at this region. Retinal explants treated with LY for 24 h also showed a significant decrease in the expression of phospho-Akt, phospho-GSK-3 and the hyperphosphorylated form of 4E-BP1. Although no change in the expression of cyclin B1 was detected, a significant decrease in CDK1 expression was noticed after 24 h of LY treatment both in retinal explants and monolayer cultures. Our results suggest that PI3K/Akt is an active pathway during proliferation of retinal progenitors and its activity appears to be required for proper CDK1 expression levels and mitosis progression of these cells.

  10. Inhibition of PI3K/Akt pathway impairs G2/M transition of cell cycle in late developing progenitors of the avian embryo retina.

    Science.gov (United States)

    Ornelas, Isis Moraes; Silva, Thayane Martins; Fragel-Madeira, Lucianne; Ventura, Ana Lucia Marques

    2013-01-01

    PI3K/Akt is an important pathway implicated in the proliferation and survival of cells in the CNS. Here we investigated the participation of the PI3K/Akt signal pathway in cell cycle of developing retinal progenitors. Immunofluorescence assays performed in cultures of chick embryo retinal cells and intact tissues revealed the presence of phosphorylated Akt and 4E-BP1 in cells with typical mitotic profiles. Blockade of PI3K activity with the chemical inhibitor LY 294002 (LY) in retinal explants blocked the progression of proliferating cells through G2/M transition, indicated by an expressive increase in the number of cells labeled for phosphorylated histone H3 in the ventricular margin of the retina. No significant level of cell death could be detected at this region. Retinal explants treated with LY for 24 h also showed a significant decrease in the expression of phospho-Akt, phospho-GSK-3 and the hyperphosphorylated form of 4E-BP1. Although no change in the expression of cyclin B1 was detected, a significant decrease in CDK1 expression was noticed after 24 h of LY treatment both in retinal explants and monolayer cultures. Our results suggest that PI3K/Akt is an active pathway during proliferation of retinal progenitors and its activity appears to be required for proper CDK1 expression levels and mitosis progression of these cells.

  11. EMP-1 promotes tumorigenesis of NSCLC through PI3K/AKT pathway.

    Science.gov (United States)

    Lai, Senyan; Wang, Guihua; Cao, Xiaonian; Li, Zhaoming; Hu, Junbo; Wang, Jing

    2012-12-01

    This study examined the role of EMP-1 in tumorigenesis of non-small cell lung carcinoma (NSCLC) and the possible mechanism. Specimens were collected from 28 patients with benign lung diseases and 28 with NSCLC, and immunohistochemically detected to evaluate the correlation of EMP-1 expression to the clinical features of NSCLC. Recombinant adenovirus was constructed to over-express EMP-1 and then infect PC9 cells. Cell proliferation was measured by Ki67 staining. Western blotting was performed to examine the effect of EMP-1 on the PI3K/AKT signaling. Moreover, tumor xenografts were established by subcutaneous injection of PC9 cell suspension (about 5×10(7)/mL in 100 μL of PBS) into the right hind limbs of athymic nude mice. The results showed EMP-1 was significantly up-regulated in NSCLC patients as compared with those with benign lung diseases. Over-expression of EMP-1 promoted proliferation of PC9 cells, which coincided with the activation of the PI3K/AKT pathway. EMP-1 promoted the growth of xenografts of PC9 cells in athymic nude mice. It was concluded that EMP-1 expression may contribute to the development and progress of NSCLC by activating PI3K/AKT pathway.

  12. PI3K/Akt contributes to increased expression of Toll-like receptor 4 in macrophages exposed to hypoxic stress

    Energy Technology Data Exchange (ETDEWEB)

    Kim, So Young; Jeong, Eunshil; Joung, Sun Myung [School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Lee, Joo Young, E-mail: joolee@catholic.ac.kr [School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); College of Pharmacy, The Catholic University of Korea, Bucheon 420-743 (Korea, Republic of)

    2012-03-16

    Highlights: Black-Right-Pointing-Pointer Hypoxic stress-induced TLR4 expression is mediated by PI3K/Akt in macrophages. Black-Right-Pointing-Pointer PI3K/Akt regulated HIF-1 activation leading to TLR4 expression. Black-Right-Pointing-Pointer p38 mitogen-activated protein kinase was not involved in TLR4 expression by hypoxic stress. Black-Right-Pointing-Pointer Sulforaphane suppressed hypoxia-mediated TLR4 expression by inhibiting PI3K/Akt. -- Abstract: Toll-like receptors (TLRs) play critical roles in triggering immune and inflammatory responses by detecting invading microbial pathogens and endogenous danger signals. Increased expression of TLR4 is implicated in aggravated inflammatory symptoms in ischemic tissue injury and chronic diseases. Results from our previous study showed that TLR4 expression was upregulated by hypoxic stress mediated by hypoxia-inducible factor-1 (HIF-1) at a transcriptional level in macrophages. In this study, we further investigated the upstream signaling pathway that contributed to the increase of TLR4 expression by hypoxic stress. Either treatment with pharmacological inhibitors of PI3K and Akt or knockdown of Akt expression by siRNA blocked the increase of TLR4 mRNA and protein levels in macrophages exposed to hypoxia and CoCl{sub 2}. Phosphorylation of Akt by hypoxic stress preceded nuclear accumulation of HIF-1{alpha}. A PI3K inhibitor (LY294002) attenuated CoCl{sub 2}-induced nuclear accumulation and transcriptional activation of HIF-1{alpha}. In addition, HIF-1{alpha}-mediated upregulation of TLR4 expression was blocked by LY294002. Furthermore, sulforaphane suppressed hypoxia- and CoCl{sub 2}-induced upregulation of TLR4 mRNA and protein by inhibiting PI3K/Akt activation and the subsequent nuclear accumulation and transcriptional activation of HIF-1{alpha}. However, p38 was not involved in HIF-1{alpha} activation and TLR4 expression induced by hypoxic stress in macrophages. Collectively, our results demonstrate that PI3K/Akt

  13. Upregulation of heme oxygenase-1 via PI3K/Akt and Nrf-2 signaling pathways mediates the anti-inflammatory activity of Schisandrin in Porphyromonas gingivalis LPS-stimulated macrophages.

    Science.gov (United States)

    Park, Sun Young; Park, Da Jung; Kim, Young Hun; Kim, Younghee; Kim, Sun Gun; Shon, Kwang Jae; Choi, Young-Whan; Lee, Sang-Joon

    2011-09-30

    The lipopolysaccharide (LPS) of Porphyromonas gingivalis is thought to induce periodontitis. In this study, we isolated Schisandrin from the dried fruits of Schisandra chinensis and examined the anti-inflammatory effect of Schisandrin in macrophages stimulated with LPS from P. gingivalis. First, Schisandrin inhibited LPS-induced pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6. And Schisandrin suppressed the nuclear translocation and activity of NF-κB and phosphorylation of IκBα in LPS-stimulated RAW 264.7 cells. Next, the presence of a selective inhibitor of HO-1 (SnPP) and a siRNA specific for HO-1 inhibited Schisandrin-mediated anti-inflammatory activity. Furthermore, Schisandrin induced HO-1 expression of RAW 264.7 cells through Nrf-2, PI3K/Akt, and ERK activation. Therefore, these results suggest that the anti-inflammatory effects of Schisandrin on P. gingivalis LPS-stimulated RAW 264.7 cells may be due to a reduction of NF-κB activity and induction of the expression of HO-1, leading to TNF-α, IL-1β, and IL-6 down-regulation.

  14. Neurotrophic Effect of Asiatic acid, a Triterpene of Centella asiatica Against Chronic 1-Methyl 4-Phenyl 1, 2, 3, 6-Tetrahydropyridine Hydrochloride/Probenecid Mouse Model of Parkinson's disease: The Role of MAPK, PI3K-Akt-GSK3β and mTOR Signalling Pathways.

    Science.gov (United States)

    Nataraj, Jagatheesan; Manivasagam, Thamilarasan; Justin Thenmozhi, Arokiasamy; Essa, Musthafa Mohamed

    2017-02-08

    Regulation of various signalling (Ras-MAPK, PI3K and AKT) pathways by augmented activity of neurotrophic factors (NTFs) could prevent or halt the progress of dopaminergic loss in Parkinson's disease (PD). Various in vitro and in vivo experimental studies indicated anti-parkinsonic potential of asiatic acid (AA), a pentacyclic triterpene obtained from Centella asiatica. So the present study is designed to determine the neurotrophic effect of AA against 1-methyl 4-phenyl 1, 2, 3, 6-tetrahydropyridine hydrochloride/probenecid (MPTP/p) neurotoxicity in mice model of PD. AA treatment for 5 weeks significantly attenuated MPTP/p induced motor abnormalities, dopamine depletion and diminished expressions NTFs and tyrosine kinase receptors (TrKB). We further, revealed that AA treatment significantly inhibited the MPTP/p-induced phosphorylation of MAPK/P38 related proteins such as JNK and ERK. Moreover, AA treatment increased the phosphorylation of PI3K, Akt, GSK-3β and mTOR, suggesting that AA activated PI3K/Akt/mTOR signalling pathway, which might be the cause of neuroprotection offered by AA. The present findings provided more elaborate in vivo evidences to support the neuroprotective effect of AA on dopaminergic neurons of chronic Parkinson's disease mouse model and the potential of AA to be developed as a possible new therapeutic target to treat PD.

  15. Targeted deletion of murine CEACAM 1 activates PI3K-Akt signaling and contributes to the expression of (Pro)renin receptor via CREB family and NF-κB transcription factors.

    Science.gov (United States)

    Huang, Jiqian; Ledford, Kelly J; Pitkin, William B; Russo, Lucia; Najjar, Sonia M; Siragy, Helmy M

    2013-08-01

    The carcinoembryonic antigen-related cell adhesion molecule 1 regulates insulin sensitivity by promoting hepatic insulin clearance. Mice bearing a null mutation of Ceacam1 gene (Cc1(-/-)) develop impaired insulin clearance followed by hyperinsulinemia and insulin resistance, in addition to visceral obesity and increased plasma fatty acids. Because insulin resistance is associated with increased blood pressure, we investigated whether they develop higher blood pressure with activated renal renin-angiotensin system and whether this is mediated, in part, by the upregulation of renal (pro)renin receptor (PRR) expression. Compared with age-matched wild-type littermates, Cc1(-/-) mice exhibited increased blood pressure with increased activation of renal renin-angiotensin systems and renal PRR expression. Cytoplasmic and nuclear immunostaining of phospho-PI3K p85α and phospho-Akt was enhanced in the kidney of Cc1(-/-) mice. In murine renal inner medullary collecting duct epithelial cells with lentiviral-mediated small hairpin RNA knockdown of carcinoembryonic antigen-related cell adhesion molecule 1, PRR expression was upregulated and phosphorylation of PI3K (Tyr508), Akt (Ser473), NF-κB p65 (Ser276), cAMP response element-binding protein/activated transcription factor (ATF)-1 (Ser133), and ATF-2 (Thr71) was enhanced. Inhibiting PI3K with LY294002 or Akt with Akt inhibitor VIII attenuated PRR expression. In conclusion, global null deletion of Ceacam1 caused an increase in blood pressure with increased renin-angiotensin system activation together with upregulation of PRR via PI3K-Akt activation of cAMP response element-binding protein 1, ATF-1, ATF-2, and NF-κB p65 transcription factors.

  16. VEGFA upregulates FLJ10540 and modulates migration and invasion of lung cancer via PI3K/AKT pathway.

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    Chang-Han Chen

    Full Text Available BACKGROUND: Lung adenocarcinoma is the leading cause of cancer-related deaths among both men and women in the world. Despite recent advances in diagnosis and treatment, the mortality rates with an overall 5-year survival of only 15%. This high mortality is probably attributable to early metastasis. Although several well-known markers correlated with poor/metastasis prognosis in lung adenocarcinoma patients by immunohistochemistry was reported, the molecular mechanisms of lung adenocarcinoma development are still not clear. To explore novel molecular markers and their signaling pathways will be crucial for aiding in treatment of lung adenocarcinoma patients. METHODOLOGY/PRINCIPAL FINDINGS: To identify novel lung adenocarcinoma-associated /metastasis genes and to clarify the underlying molecular mechanisms of these targets in lung cancer progression, we created a bioinformatics scheme consisting of integrating three gene expression profile datasets, including pairwise lung adenocarcinoma, secondary metastatic tumors vs. benign tumors, and a series of invasive cell lines. Among the novel targets identified, FLJ10540 was overexpressed in lung cancer tissues and is associated with cell migration and invasion. Furthermore, we employed two co-expression strategies to identify in which pathway FLJ10540 was involved. Lung adenocarcinoma array profiles and tissue microarray IHC staining data showed that FLJ10540 and VEGF-A, as well as FLJ10540 and phospho-AKT exhibit positive correlations, respectively. Stimulation of lung cancer cells with VEGF-A results in an increase in FLJ10540 protein expression and enhances complex formation with PI3K. Treatment with VEGFR2 and PI3K inhibitors affects cell migration and invasion by activating the PI3K/AKT pathway. Moreover, knockdown of FLJ10540 destabilizes formation of the P110-alpha/P85-alpha-(PI3K complex, further supporting the participation of FLJ10540 in the VEGF-A/PI3K/AKT pathway. CONCLUSIONS

  17. Mutation of genes of the PI3K/AKT pathway in breast cancer supports their potential importance as biomarker for breast cancer aggressiveness.

    Science.gov (United States)

    Tserga, Aggeliki; Chatziandreou, Ilenia; Michalopoulos, Nicolaos V; Patsouris, Efstratios; Saetta, Angelica A

    2016-07-01

    Deregulation of phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway is closely associated with cancer development and cancer progression. PIK3CA, AKT1, and PTEN are the fundamental molecules of the PI3K/AKT pathway with increased mutation rates in cancer cases leading to aberrant regulation of the pathway. Even though molecular alterations of the PI3K/AKT pathway have been studied in breast cancer, correlations between specific molecular alterations and clinicopathological features remain contradictory. In this study, we examined mutations of the PI3K/AKT pathway in 75 breast carcinomas using high-resolution melting analysis and pyrosequencing, in parallel with analysis of relative expression of PIK3CA and AKT2 genes. Mutations of PIK3CA were found in our cohort in 21 cases (28 %), 10 (13 %) in exon 9 and 11(15 %) in exon 20. Mutation frequency of AKT1 and PTEN genes was 4 and 3 %, respectively. Overall, alterations in the PI3K/AKT signaling cascade were detected in 35 % of the cases. Furthermore, comparison of 50 breast carcinomas with adjacent normal tissues showed elevated PIK3CA messenger RNA (mRNA) levels in 18 % of tumor cases and elevated AKT2 mRNA levels in 14 %. Our findings, along with those of previous studies, underline the importance of the PI3K/AKT pathway components as potential biomarkers for breast carcinogenesis.

  18. PIK3R1 targeting by miR-21 suppresses tumor cell migration and invasion by reducing PI3K/AKT signaling and reversing EMT, and predicts clinical outcome of breast cancer.

    Science.gov (United States)

    Yan, Li-Xu; Liu, Yan-Hui; Xiang, Jian-Wen; Wu, Qi-Nian; Xu, Lei-Bo; Luo, Xin-Lan; Zhu, Xiao-Lan; Liu, Chao; Xu, Fang-Ping; Luo, Dong-Lan; Mei, Ping; Xu, Jie; Zhang, Ke-Ping; Chen, Jie

    2016-02-01

    We have previously shown that dysregulation of miR-21 functioned as an oncomiR in breast cancer. The aim of the present study was to elucidate the mechanisms by which miR-21 regulate breast tumor migration and invasion. We applied pathway analysis on genome microarray data and target-predicting algorithms for miR-21 target screening, and used luciferase reporting assay to confirm the direct target. Thereafter, we investigated the function of the target gene phosphoinositide-3-kinase, regulatory subunit 1 (α) (PIK3R1), and detected PIK3R1 coding protein (p85α) by immunohistochemistry and miR-21 by RT-qPCR on 320 archival paraffin-embedded tissues of breast cancer to evaluate the correlation of their expression with prognosis. First, we found that PIK3R1 suppressed growth, invasiveness, and metastatic properties of breast cancer cells. Next, we identified the PIK3R1 as a direct target of miR-21 and showed that it was negatively regulated by miR-21. Furthermore, we demonstrated that p85α overexpression phenocopied the suppression effects of antimiR-21 on breast cancer cell growth, migration and invasion, indicating its tumor suppressor role in breast cancer. On the contrary, PIK3R1 knockdown abrogated antimiR‑21-induced effect on breast cancer cells. Notably, antimiR-21 induction increased p85α, accompanied by decreased p-AKT level. Besides, antimiR-21/PIK3R1-induced suppression of invasiveness in breast cancer cells was mediated by reversing epithelial-mesenchymal transition (EMT). p85α downregulation was found in 25 (7.8%) of the 320 breast cancer patients, and was associated with inferior 5-year disease-free survival (DFS) and overall survival (OS). Taken together, we provide novel evidence that miR-21 knockdown suppresses cell growth, migration and invasion partly by inhibiting PI3K/AKT activation via direct targeting PIK3R1 and reversing EMT in breast cancer. p85α downregulation defined a specific subgroup of breast cancer with shorter 5-year DFS and OS

  19. Momordin Ic induces HepG2 cell apoptosis through MAPK and PI3K/Akt-mediated mitochondrial pathways.

    Science.gov (United States)

    Wang, Jing; Yuan, Li; Xiao, Haifang; Xiao, Chunxia; Wang, Yutang; Liu, Xuebo

    2013-06-01

    Momordin Ic is a natural triterpenoid saponin enriched in various Chinese and Japanese natural medicines such as the fruit of Kochia scoparia (L.) Schrad. So far, there is little scientific evidence for momordin Ic with regard to the anti-tumor activities. The aim of this work was to elucidate the anti-tumor effect of momordin Ic and the signal transduction pathways involved. We found that momordin Ic induced apoptosis in human hepatocellular carcinoma HepG2 cells, which were supported by DNA fragmentation, caspase-3 activation and PARP cleavage. Meanwhile, momordin Ic triggered reactive oxygen species (ROS) production together with collapse of mitochondrial membrane potential, cytochrome c release, down-regulation of Bcl-2 and up-regulation of Bax expression. The activation of p38 and JNK, inactivation of Erk1/2 and Akt were also demonstrated. Although ROS production rather than NO was stimulated, the expression of iNOS and HO-1 were altered after momordin Ic treatment for 4 h. Furthermore, the cytochrome c release, caspase-3 activation, Bax/Bcl-2 expression and PARP cleavage were promoted with LY294002 and U0126 intervention but were blocked by SB203580, SP600125, PI3K activator, NAC and 1,400 W pretreatment, demonstrating the mitochondrial disruption. Furthermore, momordin Ic combination with NAC influenced MAPK, PI3K/Akt and HO-1, iNOS pathways, MAPK and PI3K/Akt pathways also regulated the expression of HO-1 and iNOS. These results indicated that momordin Ic induced apoptosis through oxidative stress-regulated mitochondrial dysfunction involving the MAPK and PI3K-mediated iNOS and HO-1 pathways. Thus, momordin Ic might represent a potential source of anticancer candidate.

  20. Metabolic Reprogramming by the PI3K-Akt-mTOR Pathway in Cancer.

    Science.gov (United States)

    Lien, Evan C; Lyssiotis, Costas A; Cantley, Lewis C

    In the past decade, there has been a resurgence of interest in elucidating how metabolism is altered in cancer cells and how such dependencies can be targeted for therapeutic gain. At the core of this research is the concept that metabolic pathways are reprogrammed in cancer cells to divert nutrients toward anabolic processes to facilitate enhanced growth and proliferation. Importantly, physiological cellular signaling mechanisms normally tightly regulate the ability of cells to gain access to and utilize nutrients, posing a fundamental barrier to transformation. This barrier is often overcome by aberrations in cellular signaling that drive tumor pathogenesis by enabling cancer cells to make critical cellular decisions in a cell-autonomous manner. One of the most frequently altered pathways in human cancer is the PI3K-Akt-mTOR signaling pathway. Here, we describe mechanisms by which this signaling network is responsible for controlling cellular metabolism. Through both the post-translational regulation and the induction of transcriptional programs, the PI3K-Akt-mTOR pathway coordinates the uptake and utilization of multiple nutrients, including glucose, glutamine, nucleotides, and lipids, in a manner best suited for supporting the enhanced growth and proliferation of cancer cells. These regulatory mechanisms illustrate how metabolic changes in cancer are closely intertwined with oncogenic signaling pathways that drive tumor initiation and progression.

  1. Porcine circovirus type 2 activates PI3K/Akt and p38 MAPK pathways to promote interleukin-10 production in macrophages via Cap interaction of gC1qR.

    Science.gov (United States)

    Du, Qian; Huang, Yong; Wang, Tongtong; Zhang, Xiujuan; Chen, Yu; Cui, Beibei; Li, Delong; Zhao, Xiaomin; Zhang, Wenlong; Chang, Lingling; Tong, Dewen

    2016-04-05

    Porcine circovirus type 2 (PCV2) infection caused PCV2-associated diseases (PCVAD) is one of the major emerging immunosuppression diseases in pig industry. In this study, we investigated how PCV2 inoculation increases interleukin (IL)-10 expression in porcine alveolar macrophages (PAMs). PCV2 inoculation significantly upregulated IL-10 expression compared with PCV1. Upon initial PCV2 inoculation, PI3K/Akt cooperated with NF-κB pathways to promote IL-10 transcription via p50, CREB and Ap1 transcription factors, whereas inhibition of PI3K/Akt activation blocked Ap1 and CREB binding to the il10 promoter, and decreased the binding level of NF-κB1 p50 with il10 promoter, leading to great reduction in early IL-10 transcription. In the later phase of inoculation, PCV2 further activated p38 MAPK and ERK pathways to enhance IL-10 production by promoting Sp1 binding to the il10 promoter. For PCV2-induced IL-10 production in macrophages, PCV2 capsid protein Cap, but not the replicase Rep or ORF3, was the critical component. Cap activated PI3K/Akt, p38 MAPK, and ERK signaling pathways to enhance IL-10 expression. In the whole process, gC1qR mediated PCV2-induced PI3K/Akt and p38 MAPK activation to enhance IL-10 induction by interaction with Cap. Depletion of gC1qR blocked PI3K/Akt and p38 MAPK activation, resulting in significant decrease in IL-10 production in PCV2-inoculated cells. Thus, gC1qR might be a critical functional receptor for PCV2-induced IL-10 production. Taken together, these data demonstrated that Cap protein binding with host gC1qR induction of PI3K/Akt and p38 MAPK signalings activation is a critical process in enhancing PCV2-induced IL-10 production in porcine alveolar macrophages.

  2. PI3K/AKT and ERK regulate retinoic acid-induced neuroblastoma cellular differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, Jingbo [Department of Pediatric Surgery, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Paul, Pritha; Lee, Sora [Department of Pediatric Surgery, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Qiao, Lan; Josifi, Erlena; Tiao, Joshua R. [Department of Pediatric Surgery, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Chung, Dai H., E-mail: dai.chung@vanderbilt.edu [Department of Pediatric Surgery, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN 37232 (United States)

    2012-08-03

    Highlights: Black-Right-Pointing-Pointer Retinoic acid (RA) induces neuroblastoma cells differentiation, which is accompanied by G0/G1 cell cycle arrest. Black-Right-Pointing-Pointer RA resulted in neuroblastoma cell survival and inhibition of DNA fragmentation; this is regulated by PI3K pathway. Black-Right-Pointing-Pointer RA activates PI3K and ERK1/2 pathway; PI3K pathway mediates RA-induced neuroblastoma cell differentiation. Black-Right-Pointing-Pointer Upregulation of p21 is necessary for RA-induced neuroblastoma cell differentiation. -- Abstract: Neuroblastoma, the most common extra-cranial solid tumor in infants and children, is characterized by a high rate of spontaneous remissions in infancy. Retinoic acid (RA) has been known to induce neuroblastoma differentiation; however, the molecular mechanisms and signaling pathways that are responsible for RA-mediated neuroblastoma cell differentiation remain unclear. Here, we sought to determine the cell signaling processes involved in RA-induced cellular differentiation. Upon RA administration, human neuroblastoma cell lines, SK-N-SH and BE(2)-C, demonstrated neurite extensions, which is an indicator of neuronal cell differentiation. Moreover, cell cycle arrest occurred in G1/G0 phase. The protein levels of cyclin-dependent kinase inhibitors, p21 and p27{sup Kip}, which inhibit cell proliferation by blocking cell cycle progression at G1/S phase, increased after RA treatment. Interestingly, RA promoted cell survival during the differentiation process, hence suggesting a potential mechanism for neuroblastoma resistance to RA therapy. Importantly, we found that the PI3K/AKT pathway is required for RA-induced neuroblastoma cell differentiation. Our results elucidated the molecular mechanism of RA-induced neuroblastoma cellular differentiation, which may be important for developing novel therapeutic strategy against poorly differentiated neuroblastoma.

  3. PI3K-AKT-mTOR inhibition in cancer immunotherapy, redux.

    Science.gov (United States)

    O'Donnell, Jake S; Massi, Daniela; Teng, Michele W L; Mandala, Mario

    2017-05-02

    Cancer therapies will increasingly be utilized in combination to treat advanced malignancies so as to increase their long-term efficacy in a greater proportion of patients. In particular, much attention has focused on developing targeted therapies that inhibit the PI3K-AKT-mTOR signaling network which is dysregulated in many cancer types. In addition, there is now a growing appreciation that targeting of these pathways can impact not only on cancer cells, but also host immunity. The clinical success of cancer immunotherapies targeting T-cell immune checkpoint receptors PD-1/PD-L1 has demonstrated the importance of immunoevasion as a hallmark of cancer. In this review, we discuss how PI3K-AKT-mTOR inhibitors target cancer cell biology, attenuate immune cell effector function and modulate the tumor microenvironment. We next discuss how the immunomodulatory potential of these inhibitors can be exploited through rational combinations with immunotherapies and targeted therapies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. FGF-2 Transcriptionally Down-Regulates the Expression of BNIP3L via PI3K/Akt/FoxO3a Signaling and Inhibits Necrosis and Mitochondrial Dysfunction Induced by High Concentrations of Hydrogen Peroxide in H9c2 Cells

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    Qian Chen

    2016-12-01

    Full Text Available Background/Aims: Cardiovascular disease is a growing major global public health problem. Necrosis is one of the main forms of cardiomyocyte death in heart disease. Oxidative stress is regarded as one of the key regulators of cardiac necrosis, which eventually leads to cardiovascular disease. Many pharmacological and in vitro studies have suggested that FGF-2 can act directly on cardiomyocytes to maintain the integrity and function of the myocardium and prevent damage during oxidative stress. However, the mechanisms by which FGF-2 rescues the myocardium from oxidative stress damage in cardiovascular disease remain unclear. The present study explored the protective effects of FGF-2 in the H2O2-induced necrosis of H9C2 cardiomyocytes as well as the possible signaling pathways involved. Methods: Necrosis of H9c2 cardiomyocytes was induced by H2O2 and assessed using a Cell Counting Kit-8 (CCK8 assay and flow cytometry analysis. The cells were pretreated with the PI3K/Akt inhibitor Wortmannin to investigate the possible involvement of the PI3K/Akt pathway in the protection by FGF-2. The levels of Akt, p-Akt, FoxO3a, p-FoxO3a, and BNIP3L were detected by Western blot. Chromatin immuno-precipitation (ChIP analysis was used to test whether FoxO3a binds directly to the BNIP3L promoter region. A luciferase assay was used to study the effects of FoxO3a on BNIP3L gene promoter activity. Mitochondrial ΔΨM was quantified using tetramethylrhodamine methyl ester perchlorate (TMRM. The mitochondrial oxygen consumption rate (OCR was assessed with a Seahorse XF24 Analyzer. Results: Treatment with H2O2 decreased the phosphorylation of Akt and FoxO3a, and it induced the nuclear localization of FoxO3a and the necrosis of H9c2 cells. These effects of H2O2 were abrogated by pretreatment with FGF-2. Furthermore, the protective effects of FGF-2 were abolished by the PI3K/Akt inhibitor Wortmannin. ChIP analyses indicated that FoxO3a binds directly to the BNIP3L promoter

  5. 组织因子/因子Ⅶ激活PI3K/Akt信号途径调控阿霉素诱导人胶质母细胞瘤细胞凋亡的研究%Tissue factor/FⅦ regulates doxorubicin-induced apoptosis in glioblastoma via activating PI3K/Akt signaling

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective: To investigate the role of tissue factor (TF) in chemotherapeutic reagent - induced apoptosis on human glioblastoma and explore its mechanism. Methods: The expression of TF was examined by Western blotting. The cytotoxicity of doxorubicin was determined by WST assay. The activation of Caspase-3 and PARP induced by adoxorubicin were tested by Western blotting. Results: Human glioblastoma ceil line U373MG expressed high level of TF while LN-229was with low-TF level. The chemotherapeutic reagent doxorubicin revealed stronger cytotoxic effect on high-TF U373MGcells than low-TF LN-229 cells. Enforced strong expression of TF was achieved by transfection of TF-pcDNA3 combinant on LN-229 cells in a dose-dependent manner. Enforced TF expression in transfected LN-229 cells not only impaired the doxorubicin-induced cleavage of Caspase-3 and PARP, but also inhibited the cytotoxic effect of doxorubicin. Furthermore,activation of Akt was strong in high-TF U373MG cells but weak in low-TF LN-229 cells. Incubation of factor Ⅶ (FⅦ) with enforced TF-expressing LN-229 cells increased the phosphorylation of Akt in a time-dependent manner. Conclusion: These results suggest that over-expression of TF on glioblastoma could inhibit doxorubicin-induced apoptosis. Interaction of FⅦand TF activates the downstream PI3K/Akt pathway. Tumor-derived over-expression of TF might play a role in chemotherapy resistance in glioblastoma, at lest in part, by activating PI3K/Akt-mediated survival and anti-apoptotic mechanism through theinteraction of TF/FⅦ signaling.

  6. Integrin αIIb-mediated PI3K/Akt activation in platelets.

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    Haixia Niu

    Full Text Available Integrin αIIbβ3 mediated bidirectional signaling plays a critical role in thrombosis and haemostasis. Signaling mediated by the β3 subunit has been extensively studied, but αIIb mediated signaling has not been characterized. Previously, we reported that platelet granule secretion and TxA2 production induced by αIIb mediated outside-in signaling is negatively regulated by the β3 cytoplasmic domain residues R(724KEFAKFEEER(734. In this study, we identified part of the signaling pathway utilized by αIIb mediated outside-in signaling. Platelets from humans and gene deficient mice, and genetically modified CHO cells as well as a variety of kinase inhibitors were used for this work. We found that aggregation of TxA2 production and granule secretion by β3Δ724 human platelets initiated by αIIb mediated outside-in signaling was inhibited by the Src family kinase inhibitor PP2 and the PI3K inhibitor wortmannin, respectively, but not by the MAPK inhibitor U0126. Also, PP2 and wortmannin, and the palmitoylated β3 peptide R(724KEFAKFEEER(734, each inhibited the phosphorylation of Akt residue Ser473 and prevented TxA2 production and storage granule secretion. Similarly, Akt phosphorylation in mouse platelets stimulated by the PAR4 agonist peptide AYPGKF was αIIbβ3-dependent, and blocked by PP2, wortmannin and the palmitoylated peptide p-RKEFAKFEEER. Akt was also phosphorylated in response to mAb D3 plus Fg treatment of CHO cells in suspension expressing αIIbβ3-Δ724 or αIIbβ3E(724AERKFERKFE(734, but not in cells expressing wild type αIIbβ3. In summary, SFK(s and PI3K/Akt signaling is utilized by αIIb-mediated outside-in signaling to activate platelets even in the absence of all but 8 membrane proximal residues of the β3 cytoplasmic domain. Our results provide new insight into the signaling pathway used by αIIb-mediated outside-in signaling in platelets.

  7. The rLrp of Mycobacterium tuberculosis inhibits proinflammatory cytokine production and downregulates APC function in mouse macrophages via a TLR2-mediated PI3K/Akt pathway activation-dependent mechanism.

    Science.gov (United States)

    Liu, Yuan; Li, Jia-Yun; Chen, Su-Ting; Huang, Hai-Rong; Cai, Hong

    2016-11-01

    We demonstrate that Mycobacterium tuberculosis recombinant leucine-responsive regulatory protein (rLrp) inhibits lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNF-α), interleukin-6, and interleukin-12 production and blocks the nuclear translocation of subunits of the nuclear-receptor transcription factor NF-κB (Nuclear factor-kappa B). Moreover, rLrp attenuated LPS-induced DNA binding and NF-κB transcriptional activity, which was accompanied by the degradation of inhibitory IκBα and a consequent decrease in the nuclear translocation of the NF-κB p65 subunit. RLrp interfered with the LPS-induced clustering of TNF receptor-associated factor 6 and with interleukin-1 receptor-associated kinase 1 binding to TAK1. Furthermore, rLrp did not attenuate proinflammatory cytokines or the expression of CD86 and major histocompatibility complex class-II induced by interferon-gamma in the macrophages of Toll-like receptor 2 deletion (TLR2(-/-)) mice and in protein kinase b (Akt)-depleted mouse cells, indicating that the inhibitory effects of rLrp were dependent on TLR2-mediated activation of the phosphatidylinositol 3-OH kinase (PI3K)/Akt pathway. RLrp could also activate the PI3K/Akt pathway by stimulating the rapid phosphorylation of PI3K, Akt, and glycogen synthase kinase 3 beta in macrophages. In addition, 19 amino acid residues in the N-terminus of rLrp were determined to be important and required for the inhibitory effects mediated by TLR2. The inhibitory function of these 19 amino acids of rLrp raises the possibility that mimetic inhibitory peptides could be used to restrict innate immune responses in situations in which prolonged TLR signaling has deleterious effects. Our study offers new insight into the inhibitory mechanisms by which the TLR2-mediated PI3K/Akt pathway ensures the transient expression of potent inflammatory mediators.

  8. PI3K / Akt Signaling Pathway on Expression of BACE1 mRNA in Hippocampus Neurons%胰岛素信号通路PI3K/Akt对海马神经元β-淀粉样前体蛋白裂解酶1mRNA水平的影响

    Institute of Scientific and Technical Information of China (English)

    王国祥; 李洁颖; 晏勇

    2011-01-01

    Objective To investigate the effect of beta-site amyloid precursor protein cleaving enzyme-1 (BACE1) mRNA on phosphatidylinosi-tol-3 kinase / serine threohine kinase( PI3K / Akt) signaling pathway in the hippocampus neurons of rat brain. Methods Insulin and the specific inhibitor of PI3 K Wortmannin were used to activate and inhibit the signaling pathway , 20SD rats randomly divided into four group: blank control group, sham-operated group, insulin group and Wortmannin group. RT-PCR were used to analyse the proteins related to the insulin signaling Akt and BACE1 mRNA. Results The expression of signaling pathway downstream molecules Akt mRNA were up-regulated(p =0. 047, p = 0. 002) ,the expression of BACE1 mRNA significantly down-regulated(p =0. 004 ,p =0. 01 )in insulin group. The expression of BACE1 mRNA was opposite after treatment with inhibitor of PDK( p =0. 039 ,p =0. 018) ,Akt mRNA were also inhibited(p =0. 002,p =0. 039). Conclusion PI3K / Akt signaling pathway might effect the expression of BACE1, which demonstrates that impaired signaling pathway shoud make the amyloid precursor protein easy to be processed by BACE1, thus to involve the pathology of Alzheimer's disease.%目的 通过胰岛素和磷脂酰肌醇-3激酶(PI3K)抑制剂渥曼青霉素(wortmannin)对PI3K/丝氨酸苏氨酸蛋白激酶(PI3K/Akt)信号通路的激活和抑制作用,观察PI3K/Akt信号通路对海马神经元β-淀粉样前体蛋白裂解酶1(BACE1)mRNA水平表达的影响.方法 20只SD大鼠随机分为空白对照组、假手术组、胰岛素组和渥曼青霉素组,海马立体定向注射胰岛素和PI3K抑制剂渥曼青霉素.逆转录-聚合酶链反应(RT-PCR)检测PI3K/Akt信号传导下游蛋白Akt以及BACE1 mRNA水平.结果 注射胰岛素的海马PI3K信号通路下游信号分子:Akt mRNA表达上调(分别较空白和阴性对照组p=0.047,p =0.002),而BACE1 mRNA表达下调(分别较空白和阴性对照组p=0.004,p=0.01).渥曼青霉素组的PI3K

  9. Novel PI3K/Akt inhibitors screened by the cytoprotective function of human immunodeficiency virus type 1 Tat.

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    Yuri Kim

    Full Text Available The PI3K/Akt pathway regulates various stress-related cellular responses such as cell survival, cell proliferation, metabolism and protein synthesis. Many cancer cell types display the activation of this pathway, and compounds inhibiting this cell survival pathway have been extensively evaluated as anti-cancer agents. In addition to cancers, several human viruses, such as HTLV, HPV, HCV and HIV-1, also modulate this pathway, presumably in order to extend the life span of the infected target cells for productive viral replication. The expression of HIV-1 Tat protein exhibited the cytoprotective effect in macrophages and a human microglial cell line by inhibiting the negative regulator of this pathway, PTEN. This cytoprotective effect of HIV-1 appears to contribute to the long-term survival and persistent HIV-1 production in human macrophage reservoirs. In this study we exploited the PI3K/Akt dependent cytoprotective effect of Tat-expressing CHME5 cells. We screened a collection of compounds known to modulate inflammation, and identified three novel compounds: Lancemaside A, Compound K and Arctigenin that abolished the cytoprotective phenotype of Tat-expressing CHME5 cells. All three compounds antagonized the kinase activity of Akt. Further detailed signaling studies revealed that each of these three compounds targeted different steps of the PI3K/Akt pathway. Arctigenin regulates the upstream PI3K enzyme from converting PIP2 to PIP3. Lancemaside A1 inhibited the movement of Akt to the plasma membrane, a critical step for Akt activation. Compound K inhibited Akt phosphorylation. This study supports that Tat-expressing CHME5 cells are an effective model system for screening novel PI3K/Akt inhibitors.

  10. Novel PI3K/Akt Inhibitors Screened by the Cytoprotective Function of Human Immunodeficiency Virus Type 1 Tat

    Science.gov (United States)

    Kim, Dong-Hyun; Kim, Baek

    2011-01-01

    The PI3K/Akt pathway regulates various stress-related cellular responses such as cell survival, cell proliferation, metabolism and protein synthesis. Many cancer cell types display the activation of this pathway, and compounds inhibiting this cell survival pathway have been extensively evaluated as anti-cancer agents. In addition to cancers, several human viruses, such as HTLV, HPV, HCV and HIV-1, also modulate this pathway, presumably in order to extend the life span of the infected target cells for productive viral replication. The expression of HIV-1 Tat protein exhibited the cytoprotective effect in macrophages and a human microglial cell line by inhibiting the negative regulator of this pathway, PTEN. This cytoprotective effect of HIV-1 appears to contribute to the long-term survival and persistent HIV-1 production in human macrophage reservoirs. In this study we exploited the PI3K/Akt dependent cytoprotective effect of Tat-expressing CHME5 cells. We screened a collection of compounds known to modulate inflammation, and identified three novel compounds: Lancemaside A, Compound K and Arctigenin that abolished the cytoprotective phenotype of Tat-expressing CHME5 cells. All three compounds antagonized the kinase activity of Akt. Further detailed signaling studies revealed that each of these three compounds targeted different steps of the PI3K/Akt pathway. Arctigenin regulates the upstream PI3K enzyme from converting PIP2 to PIP3. Lancemaside A1 inhibited the movement of Akt to the plasma membrane, a critical step for Akt activation. Compound K inhibited Akt phosphorylation. This study supports that Tat-expressing CHME5 cells are an effective model system for screening novel PI3K/Akt inhibitors. PMID:21765914

  11. The role of the PI3K/Akt/mTOR pathway in glial scar formation following spinal cord injury.

    Science.gov (United States)

    Chen, Chun-Hong; Sung, Chun-Sung; Huang, Shi-Ying; Feng, Chien-Wei; Hung, Han-Chun; Yang, San-Nan; Chen, Nan-Fu; Tai, Ming-Hong; Wen, Zhi-Hong; Chen, Wu-Fu

    2016-04-01

    Several studies suggest that glial scars pose as physical and chemical barriers that limit neurite regeneration after spinal cord injury (SCI). Evidences suggest that the activation of the PI3K/Akt/mTOR signaling pathway is involved in glial scar formation. Therefore, inhibition of the PI3K/Akt/mTOR pathway may beneficially attenuate glial scar formation after SCI. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) negatively regulates the PI3K/Akt/mTOR pathway. Therefore, we hypothesized that the overexpression of PTEN in the spinal cord will have beneficial effects after SCI. In the present study, we intrathecally injected a recombinant adenovirus carrying the pten gene (Ad-PTEN) to cause overexpression of PTEN in rats with contusion injured spinal cords. The results suggest overexpression of PTEN in spinal cord attenuated glial scar formation and led to improved locomotor function after SCI. Overexpression of PTEN following SCI attenuated gliosis, affected chondroitin sulfate proteoglycan expression, and improved axon regeneration into the lesion site. Furthermore, we suggest that the activation of the PI3K/Akt/mTOR pathway in astrocytes at 3 days after SCI may be involved in glial scar formation. Because delayed treatment with Ad-PTEN enhanced motor function recovery more significantly than immediate treatment with Ad-PTEN after SCI, the results suggest that the best strategy to attenuate glial scar formation could be to introduce 3 days after SCI. This study's findings thus have positive implications for patients who are unable to receive immediate medical attention after SCI.

  12. Effects of Salvianlic Acid A on Inhibition of Human Lung Cancer Cells by Regulating PTEN_PI3K/AKT Signaling Pathway%丹酚酸A调控PTEN_PI3K/AKT信号通路对人肺癌细胞增殖的影响

    Institute of Scientific and Technical Information of China (English)

    毕蕾; 陈卫平; 陈建平; 颜晓静

    2012-01-01

    目的 通过研究丹酚酸A(Salvianolic acid A,SalA)对人肺癌A549细胞PTEN_PI3K/AKT信号通路的影响,探讨SalA抑制肺癌细胞增殖的作用机制.方法 以人肺癌A549细胞为靶细胞,运用高内涵细胞成像分析系统,检测SalA对A549细胞增殖的影响;MTT法观察SalA对A549细胞增殖影响的量效关系;通过Western Blotting实验,检测SalA用于人肺癌A549细胞,对PTEN蛋白、磷酸化AKT(P-AKT)蛋白、非磷酸化AKT(T-AKT)蛋白的影响.结果 SalA对A549细胞增殖有抑制作用,并呈现剂量依赖性,而SalA可以促进PTEN蛋白及T-AKT蛋白的表达,抑制P-AKT蛋白的表达.结论 SalA具有抑制肺癌A549细胞增殖的作用,人肺癌A549细胞中存在有活性的PTEN_PI3K/AKT信号通路,SalA可能通过抑制PTEN_PI3K/AKT信号通路中P-AKT蛋白的表达,促进PTEN蛋白及T-AKT蛋白的表达,来抑制肺癌细胞增殖,促进癌细胞凋亡.%OBJECTIVE To study the effect of Salvianolic acid A(SalA) on PTEN_PI3K/AKT signaling pathway of human lung cancer cell line A549,to explore the mechanism of Sal A in vitro inhibition of lung cancer cell. METHODS Human lung cancer cell line A549 were used as target cells, and High Content Imaging Analysis System was used for detecting the effect of Sal A on inhibits growth of A549 cells. MTT method was used to observe the effects of different concentrations of Sal A on A549 cells. Protein levels of PTENXP-AKT and T-AKT were measured by Western-blotting methods. RESULTS The growth of A549 cells was inhibited by Sal A, and show a certain degree of dose dependent. Results from Western Blotting showed that Sal A up-regulated PTEN protein level and T-AKT protein level, as well as down-regulated P-AKT protein level. CONCLUSION SalA can inhibit A549 cells. We could fund active PTEN_PI3K/AKT signaling pathway from Human lung cancer A549 cells. These results indicate that Sal A.negatively mediates lung cancer cell line A549 growth or apoptosis most likely through

  13. Changes in Expression of PI3K/Akt/mTOR Signaling Pathway-related Cytokines in Mice with H22 Liver Cancer during Interventions of Exercise and Spider Macrothele Raven Venom%PI3K/Akt/mTOR信号通路相关细胞因子在小鼠H22肝癌增殖及运动与药物干预中的差异表达

    Institute of Scientific and Technical Information of China (English)

    陈薇薇; 陈嘉勤; 朱敬生; 张国华; 罗赤苗; 陈锐; 魏荣林; 陈伟

    2013-01-01

    目的:观察有氧运动联合雷氏大疣蛛毒素对小鼠皮下移植H22肝肿瘤中PI3K/Akt/mTOR信号通路及相关细胞因子差异表达的影响及其分子机制.方法:40只雄性KM小鼠随机均分为模型组(M组)、有氧运动组(E组)、负重有氧运动组(OE组)和有氧运动联合雷氏大疣蛛毒素组(E+MR组).采用小鼠颈部皮下移植成瘤模型,各干预组于建模成功后第3天进行雷氏大疣蛛毒素和运动干预.尾静脉注射0.3 ml雷氏大疣蛛毒素(药剂浓度为2μg/g体重)连续20天;运动干预采用有氧游泳训练,每周6次,共5周.4组动物每4天测量1次肿瘤体积,并绘制肿瘤生长曲线.实验结束后小鼠禁食过夜,随后分离出肿瘤组织.采用HE染色对其进行显微结构形态学观察;免疫组化法检测肿瘤组织PI3K、Akt、mTOR、PTEN、IGF-1因子蛋白表达;实时荧光定量(Reahime-PCR)技术检测肿瘤组织PI3K、Akt、mTOR、PTEN、IGF-1 mRNA表达.结果:①肿瘤体积测量结果显示:模型组肿瘤体积生长速度最快,有氧运动组肿瘤体积生长速度次之,负重有氧运动组肿瘤生长速度较有氧运动组生长速度慢,有氧运动联合雷氏大疣蛛毒素组生长速度最慢;②HE染色结果显示:模型对照组肿瘤细胞排列紧密、规整,有氧运动组细胞排列疏松欠规则,负重有氧运动组细胞出现坏死区,有氧运动联合雷氏大疣蛛毒素干预组细胞可见较大坏死区域.③免疫组织化学染色结果显示:三个干预组小鼠肿瘤组织PTEN阳性表达均高于模型非干预组,而PI3K、Akt、mTOR、IGF-1阳性表达较模型组低(P<0.01).④Real-time PCR检测结果显示:三个干预组小鼠肿瘤中PTEN mRNA表达明显高于模型非干预组(P<0.01),其中有氧运动联合雷氏大疣蛛毒素组PTEN mRNA表达水平最高.结论:有氧运动联合雷氏大疣蛛毒素与有氧运动、负重有氧运动,能提高PTEN的含量,降低促肝癌细胞增殖的有关

  14. Effect of blocking PI3K/AKT pathway by wortmannin on hypoxia-inducible factor 1α and glycolysis in esophageal carcinoma%Wortmannin阻断PI3K/AKT途径对食管癌缺氧诱导因子-1α及糖酵解的影响

    Institute of Scientific and Technical Information of China (English)

    何桂钧; 朱宏; 唐娜娜; 丁宗励; 郝波; 施瑞华

    2012-01-01

    目的 探讨人食管癌细胞TE1、TE13中应用wortmannin阻断PI3K/AKT通路对缺氧诱导因子(HIF)-1α的抑制效果及对糖酵解相关基因表达的影响,分析PI3K/AKT-HIF-1α途径对食管癌细胞糖酵解通路之间的关系.方法 wortmannin(2μmol/L)预处理食管癌细胞TE1、TE13后常氧和缺氧培养,分为①常氧组(N);②缺氧组(H);③常氧处理组(N+W);④缺氧处理组(H+W).采用Western印迹检测细胞中HIF-1α蛋白及己糖激酶(HK)-Ⅱ、葡萄糖载体蛋白(GLUT)-1、乳酸脱氢酶(LDH )-A等糖酵解相关基因蛋白的表达;实时定量PCR检测HIF-1α及HK-Ⅱ、GLUT-1、LDH-A等糖酵解相关基因mRNA的表达;分光光度法测定胞液中LDH、HK-Ⅱ活性和培养上清液中乳酸浓度.结果 常氧状态下,在TE1细胞中存在HIF-1α蛋白的表达,wortmannin(2 μmol/L)能抑制HIF-1α蛋白表达,12 h后抑制效应最明显,故选取12 h为后续实验的缺氧时间.TE1、TE13细胞经wortmannin预处理后HIF-1α、HK-Ⅱ、GLUT-1、LDHA蛋白表达较未加药细胞明显减弱(P<0.05);HIF-1α、HK-ⅡmRNA表达较未加药细胞明显减弱(P<0.05).常氧和缺氧条件下加用wortmannin的TE1,TE13组食管癌细胞胞液LDH、HK-Ⅱ活性均较未加药细胞组明显减弱(P<0.05),未加药细胞缺氧后酶活性增强(P<0.05).常氧和缺氧条件下加用wortmannin组较未加药组细胞上清液乳酸浓度明显减低(P<0.05),加wortmannin组细胞缺氧后表达增强(P<0.05).结论 常氧及缺氧条件下,wortmannin能通过抑制食管癌细胞HIF-1α和糖酵解相关基因的表达导致乳酸水平降低,表明PI3K/AKT- HIF-1α途径与食管癌细胞糖酵解通路密切相关.%Objective To investigate the inhibitory effect of blocking PI3K/AKT pathway by wortmannin on hypoxia-inducible factor 1α (HIF-1α) and the effect on the expression of glycolysis associated genes in human esophageal carcinoma cell lines TE1 and TE13,and to analyze the relation

  15. Effect of orthodontic force on the expression of PI3K, Akt, and P70S6 K in the human periodontal ligament during orthodontic loading.

    Science.gov (United States)

    Xu, Yunhe; Shen, Jiayuan; Muhammed, Fenik Kaml; Zheng, Bowen; Zhang, Yuejiao; Liu, Yi

    2017-08-28

    The mammalian target of rapamycin (mTOR) is an atypical serine/threonine protein kinases involved in the regulation of cell growth, proliferation, and differentiation through the PI3K/Akt/mTOR/P70S6 K signalling pathway. P70S6 K as a downstream molecule of mTOR is activated by phosphorylation and subsequently promotes the synthesis of ribosomal and translational proteins. In this study, we investigated the role of PI3K, Akt, and P70S6 K in human periodontal tissue remodelling during orthodontic loading. The prepared tissue specimens taken from 4 extracted premolars were processed for immunolabelling. The changes in the expression of PI3K, Akt, and P70S6 K in the periodontal tissues were detected by real-time quantitative-polymerase chain reaction and Western blot analysis. The results from real-time quantitative-polymerase chain reaction and Western blot both showed that the expression of PI3K, Akt, and P70S6 K in the experimental group began to increase at 3 days and increased significantly at 10 days, then decreased approaching the control group level at 28 days. Our findings showed that the expression of PI3K, Akt, and P70S6 K in human periodontal ligament demonstrated a variability during the orthodontic loading, which suggested that the PI3K/Akt/mTOR/P70S6 K signal pathway was involved in orthodontic tooth movement and played a role in the process of periodontium remodelling. Copyright © 2017 John Wiley & Sons, Ltd.

  16. Lovastatin protects mesenchymal stem cells against hypoxia and serum deprivation-induced apoptosis through activation of PI3K/Akt and ERK1/2 signaling pathways%洛伐他汀经PI3K/Akt和ERK1/2信号通路抑制大鼠骨髓间充质干细胞凋亡

    Institute of Scientific and Technical Information of China (English)

    徐瑞霞; 陈曦; 胡盛寿; 陈静海; 刘学文; 刘学彬; 石林惠; 丛祥凤

    2008-01-01

    Objective To investigated the effect of lovastatin on hypoxia and serum deprivation (Hypoxia/SD) induced rat MSCs apoptosis in vitro and associated signaling pathway changes. Methods MSCs were isolated from Sprague-Dawley rats. The anti-apoptotic effects of lovastatin were detected using Hoechst33342 and annexin V-FITC/PI binding assay by Flow cytometric analysis. The phosphorylation of Akt and ERK1/2, the cytochrome C and the cleaved caspase-3 were detected by Western blot. Results Lovastatin (0. 01 - 1 μmol/L)significantly reduced Hypoxia/SD-induced MSCs apoptosis and increased Akt phosphorylation, reduced caspase-3 activation and cytochrome c release from mitochondria to cytosol in a time dependent manner. These effects could be significantly blocked by both PI3K inhibitor, LY294002 and ERK1/2 inhibitor, U0126. Conclusions Our results showed that lovastatin protects MSCs from Hypoxia/ SD-induced apoptosis via activating PI3K/Akt and ERK1/2 signaling pathways suggesting a potential role of statins as an adjunct therapeutic agent during transplanting MSCs into damaged heart after myocardial infarction.%目的 体外以缺氧无血清条件模拟心肌梗死后的心脏缺血微环境,研究洛伐他汀能否抑制缺氧无血清引起的骨髓间充质干细胞(MSC)凋亡并探讨其机制.方法 以Hocchst33342染色荧光显微镜观察法及Annexin V/PI流式细胞术检测洛伐他汀的抗凋亡作用,并进一步采用Westernblot方法 检测洛伐他汀对线粒体凋亡途径的抑制作用以及对磷脂酰肌醇3激酶(PI3K)/丝氨酸苏氨酸激酶(Akt)途径和丝裂原活化的蛋白激酶(MAPK)的激酶(MEK)/细胞内信号调节蛋白激酶(ERK1/2)途径的激活作用.结果 0.01~1 μmol/L浓度范围的洛伐他汀能够有效地抑制缺氧无血清引起的MSC凋亡.洛伐他汀抑制线粒体凋亡途径,洛伐他汀抑制细胞色素C释放,降低天冬氨酸特异性半胱氨酸蛋白酶-3(caspase-3)活化,从而保护线粒体功能.洛

  17. Effect of PI3K-Akt signaling pathways on human Hct-8/FU drug-resistant cell P-GP expression and drug resistance%PI3K-Akt信号通路对人大肠癌hct-8/FU耐药细胞P-GP表达和耐药性的影响

    Institute of Scientific and Technical Information of China (English)

    张劲远; 张银旭; 张俊华

    2013-01-01

    目的:研究磷脂酰肌醇3-激酶/蛋白激酶B(PI3K-Akt)信号通路对人大肠癌hct-8/FU耐药细胞P-糖蛋白(P-GP)表达和耐药性的影响,探讨其逆转hct-8/FU多药耐药性的作用.方法:MTT法检测人大肠癌hct-8细胞、hct-8/FU耐药细胞、PI3K-Akt通路抑制剂LY294002处理的hct-8/FU耐药细胞对5-FU的半数生长抑制率和耐药指数;蛋白质印迹法检测hct-8、hct-8/FU细胞、LY294002处理的hct-8/FU耐药细胞PI3K、Akt、P-Akt、P-GP的表达变化.结果:大肠癌hct-8细胞对5-FU的半数生长抑制率为(43.2±1.4)mg·L-1,hct-8/FU耐药细胞为(516.00±20.03)mg·L-1,耐药指数为11.9;LY294002处理hct-8/FU耐药细胞后半数生长抑制率为(58.2±4.3)mg·L-1,耐药指数为1.37,较用药前对5-FU的敏感性提高,逆转指数为8.8(P<0.01);hct-8/FU耐药细胞PI3K、Akt、P-Akt、P-GP表达较hct-8细胞明显增加(均P<0.01),LY294002作用后其PI3K、Akt、P-Akt、P-GP表达较用药前明显下降(P<0.01).结论:PI3K-AKT信号通路可能通过促进人大肠癌hct-8 P-GP的表达,增加其对5-FU的耐药性,降低肿瘤细胞对药物的敏感性.%Objective: To study the effect of the PI3K-Akt signaling pathways on P- glycoprotein ( P-GP ) expression and drug resistance of human colorectal carcinoma cells HCT- 8/FU drug- resistant cells in vitro. Methods: MTT method was used to detect the IC50 of 5-FU and resistance index among human colorectal carcinoma cells HCT-8 cells, HCT-8/FU resistant cells and HCT-8/FU drug-resistant cell treated with PDK-Akt channel inhibitors LY294002. Meanwhile, Western blot method was adopted to detect PI3K, Akt, P- Akt and P- GP expressions of the cell lines mentioned above. Results: The The IC50 of 5-FU was ( 43. 2 ± 1. 4 )mg·L-1 and (516.00 ± 20.03 ) mg·L-1 in the colorectal carcinoma cells HCT-8 and HCT-8/FU drug-resistant cells, respectively,with a resistance index being 11. 9 for the latter cells;while after HCT-8/FU drug-resistant cells were treated

  18. Flavonoids Isolated from Flowers of Lonicera japonica Thunb. Inhibit Inflammatory Responses in BV2 Microglial Cells by Suppressing TNF-α and IL-β Through PI3K/Akt/NF-kb Signaling Pathways.

    Science.gov (United States)

    Han, Min Ho; Lee, Won Sup; Nagappan, Arulkumar; Hong, Su Hyun; Jung, Ji Hyun; Park, Cheol; Kim, Hye Jung; Kim, Gi-Young; Kim, GonSup; Jung, Jin-Myung; Ryu, Chung Ho; Shin, Sung Chul; Hong, Soon Chan; Choi, Yung Hyun

    2016-11-01

    Decoctions of the dried flowers of Lonicera japonica Thunb. (Indongcho) have been utilized in folk remedies against various inflammatory diseases, and it is reported neuroprotective effects. The cytokines release from microglia is closely linked to various chronic neurodegenerative diseases like Alzheimer's disease and Parkinson's disease. It is still unknown whether the neuroprotective effects are associated with the antiinflammatory effects. Here, we determined whether polyphenols extracted from lyophilized Lonicera japonica Thunb. (PELJ) would inhibit inflammatory cytokines and mediators. We stimulated microglia with lipopolysaccharide (LPS) to produce inflammatory cytokines, and then assessed the effects of PELJ on these cytokines. PELJ significantly inhibited LPS-induced interleukin-1β and tumor necrosis factor-α expressions and LPS-induced nitric oxide (NO) and prostaglandin E2 expressions by down-regulating inducible enzyme NO synthase and cyclooxygenase-2 at the protein and mRNA levels. All the suppression of these mediators did not cause any significant cytotoxicity. PELJ also inhibited the nuclear translocation of nuclear factor-kappa B and phosphorylated Akt. These findings suggest that PELJ may offer substantial therapeutic potential for treating inflammatory and neurodegenerative diseases by inhibiting pro-inflammatory cytokines through inhibiting phosphoinositol 3-kinase /Akt/nuclear factor-kappa B signaling pathway. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  19. Icariin Prevents Amyloid Beta-Induced Apoptosis via the PI3K/Akt Pathway in PC-12 Cells

    Directory of Open Access Journals (Sweden)

    Dongdong Zhang

    2015-01-01

    Full Text Available Icariin is a prenylated flavonol glycoside derived from the Chinese herb Epimedium sagittatum that exerts a variety of pharmacological activities and shows promise in the treatment and prevention of Alzheimer’s disease. In this study, we investigated the neuroprotective effects of icariin against amyloid beta protein fragment 25–35 (Aβ25–35 induced neurotoxicity in cultured rat pheochromocytoma PC12 cells and explored potential underlying mechanisms. Our results showed that icariin dose-dependently increased cell viability and decreased Aβ25–35-induced apoptosis, as assessed by MTT assay and Annexin V/propidium iodide staining, respectively. Results of western blot analysis revealed that the selective phosphatidylinositol 3-kinase (PI3K inhibitor LY294002 suppressed icariin-induced Akt phosphorylation, suggesting that the protective effects of icariin are associated with activation of the PI3K/Akt signaling pathway. LY294002 also blocked the icariin-induced downregulation of proapoptotic factors Bax and caspase-3 and upregulation of antiapoptotic factor Bcl-2 in Aβ25–35-treated PC12 cells. These findings provide further evidence for the clinical efficacy of icariin in the treatment of Alzheimer’s disease.

  20. Involvement of ERK1/2, p38 MAPK, and PI3K/Akt signaling pathways in the regulation of cell cycle progression by PTHrP in colon adenocarcinoma cells.

    Science.gov (United States)

    Calvo, Natalia; Martín, María Julia; de Boland, Ana Russo; Gentili, Claudia

    2014-08-01

    Parathyroid hormone-related peptide (PTHrP) is distributed in most fetal and adult tissues, and its expression correlates with the severity of colon carcinoma. Recently we obtained evidence that in Caco-2 cells, a cell line from human colorectal adenocarcinoma, exogenous PTHrP increases the number of live cells, via ERK1/2, p38 MAPK, and PI3-kinase and induces the expression of cyclin D1, a cell cycle regulatory protein. In this study, we further investigated the role of PTHrP in the regulation of the cell cycle progression in these intestinal cells. Flow cytometry analysis revealed that PTHrP treatment diminishes the number of cells in the G0/G1 phase and increases the number in both S and G2/M phases. The hormone increases the expression of CDK6 and diminishes the amount of negative cell cycle regulators p27Kip1, p15INK4B, and p53. However, PTHrP does not modify the expression of cyclin D3, CDK4, and p16INK4A. In addition, inhibitors of ERK1/2 (PD98059), p38 MAPK (SB203580), and PI3Kinase (LY294002) reversed PTHrP response in Caco-2 cells. Taken together, our results suggest that PTHrP positively modulates cell cycle progression and changes the expression of proteins involved in cell cycle regulation via ERK1/2, p38 MAPK, and PI3K signaling pathways in Caco-2 cells.

  1. Effects of circulation hyperthermic perfusion chemotherapy on tumor marker content and PI3K/Akt/mTOR pathway function of gastric cancer peritoneal effusion patients

    Institute of Scientific and Technical Information of China (English)

    Li Ding

    2015-01-01

    Objective: To study the effects of circulation hyperthermic perfusion chemotherapy on tumor marker content and PI3K/Akt/mTOR pathway function of gastric cancer peritoneal effusion patients. Methods: 80 cases of gastric cancer peritoneal effusion patients in our hospital from May 2013 to August 2014 were enrolled and randomly divided into two groups. Observation group received circulation hyperthermic perfusion chemotherapy; control group received conventional perfusion chemotherapy. Then blood tumor markers, LAG3 and HSP content, PI3K-AKT-mTOR signal molecules were assayed. Results:(1) tumor markers: DDK1, EXOSC2 contents and PGR ratio of observation group were lower than those of control group; PGI and PGII contents were higher than those of control group; (2) LAG3 and HSP contents: HSP27 and HSP90 contents of observation group were lower than those of control group; sLAG-3 content was higher than that of control group; (3) signal molecules: mRNA contents of PI3K, Akt and mTOR molecules of observation group were lower than those of control group. Conclusion: Circulation hyperthermic perfusion chemotherapy is helpful to kill tumor cells, reduce tumor marker releasing into blood, regulate LAG3 and HSP expression and inhibit PI3K/Akt/mTOR pathway function; it’s an ideal method for treating peritoneal effusion.

  2. Tetrandrine inhibits migration and invasion of rheumatoid arthritis fibroblast-like synoviocytes through down-regulating the expressions of Rac1, Cdc42, and RhoA GTPases and activation of the PI3K/Akt and JNK signaling pathways.

    Science.gov (United States)

    Lv, Qi; Zhu, Xian-Yang; Xia, Yu-Feng; Dai, Yue; Wei, Zhi-Feng

    2015-11-01

    Tetrandrine (Tet), the main active constituent of Stephania tetrandra root, has been demonstrated to alleviate adjuvant-induced arthritis in rats. The present study was designed to investigate the effects of Tet on the migration and invasion of rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) and explore the underlying mechanisms. By using cultures of primary FLS isolated from synoviums of RA patients and cell line MH7A, Tet (0.3, 1 μmol·L(-1)) was proven to significantly impede migration and invasion of RA-FLS, but not cell proliferation. Tet also greatly reduced the activation and expressions of matrix degrading enzymes MMP-2/9, the expression of F-actin and the activation of FAK, which controlled the morphologic changes in migration process of FLS. To identify the key signaling pathways by which Tet exerts anti-migration effect, the specific inhibitors of multiple signaling pathways LY294002, Triciribine, SP600125, U0126, SB203580, and PDTC (against PI3K, Akt, JNK, ERK, p38 MAPK and NF-κB-p65, respectively) were used. Among them, LY294002, Triciribine, and SP600125 were shown to obviously inhibit the migration of MH7A cells. Consistently, Tet was able to down-regulate the activation of Akt and JNK as demonstrated by Western blotting assay. Moreover, Tet could reduce the expressions of migration-related proteins Rho GTPases Rac1, Cdc42, and RhoA in MH7A cells. In conclusion, Tet can impede the migration and invasion of RA-FLS, which provides a plausible explanation for its protective effect on RA. The underlying mechanisms involve the reduction of the expressions of Rac1, Cdc42, and RhoA, inhibition of the activation of Akt and JNK, and subsequent down-regulation of activation and/or expressions of MMP-2/9, F-actin, and FAK.

  3. Tumor-associated macrophages promoting invasion and migration of pancreatic cancer via PI3K/Akt signaling pathway%肿瘤相关巨噬细胞通过PI3K/Akt途径促进胰腺癌浸润迁移的研究

    Institute of Scientific and Technical Information of China (English)

    叶会霖; 叶良涛; 周雨; 周泉波; 林青; 李志花; 刘宜敏; 陈汝福

    2015-01-01

    Objective To explore the influence of PI3K/Akt signaling pathway on invasive and mi-gratory ability of pancreatic cancer cell line PANC-1, and further investigate the molecule mechanism of tu-mor-associated macrophages'promotion in the occurrence and development of pancreatic cancer. Methods Mononuclear cells were isolated from peripheral blood of healthy adults by density gradient centrifugation, and treated with IL-4 to obtain M2 in vitro. Expression of PI3K and Akt was evaluated by quantitative Real-time polymerase chain reaction and Western blotting. The ability of cellular invasion and migration was as-sessed by transwell chamber assay and wound healing assay. Results To simulate pancreatic cancer mi-croenvironment, we co-cultured pancreatic cancer PANC-1 cells and Ua or M2. The mRNA and protein lev-els of PI3K and Akt were remarkably increased analyzing by qRT-PCR and western blotting. In addition, transwell chamber assays and wound healing assays revealed that alternatively activated macrophages signif-icantly promoted the invasion and migration of PANC-1 cells in 20 h. Conclusion Tumor-associated macrophages may promote invasion and migration of pancreatic cancer cells via PI3K/Akt signaling pathway.%目的研究PI3K/Akt信号通路对胰腺癌细胞PANC-1浸润迁移能力的影响,进一步探讨肿瘤相关巨噬细胞促进胰腺癌发生发展的分子机制。方法通过密度梯度离心法从健康成人外周血中分离单个核细胞,用IL-4体外诱导选择性激活的巨噬细胞(M2)。采用实时荧光定量PCR和Western blotting法检测胰腺癌PANC-1细胞PI3K、Akt mRNA 和蛋白表达水平的变化,利用Transwell侵袭实验与划痕实验观察细胞浸润迁移能力的变化。结果体外模拟胰腺癌微环境,将胰腺癌PANC-1细胞与不同激活状态的巨噬细胞共培养,证明M2可显著上调胰腺癌PANC-1细胞PI3K、Akt的mRNA和蛋白水平,共培养20 h后可明显促进胰腺癌PANC-1细胞的浸润

  4. 磷脂酰肌醇-3-激酶/蛋白激酶B信号转导通路与针刺保护癫痫继发海马神经元损伤的关系%PI 3 K/Akt Signaling Pathway Contributed to the Protective Effect of Acupuncture Intervention on Epileptic Seizure-induced Injury of Hippocampal Pyramidal Cells in Epilepsy Rats

    Institute of Scientific and Technical Information of China (English)

    杨帆; 昂文平; 沈德凯; 刘向国; 杨永清; 马允

    2013-01-01

    Objective To observe the protective effect of acupuncture stimulation on pyramidal cells in hippocampal CA 1 and CA 3 regions and to analyze the involvement of phosphatidy linositol-3-kinase (PI 3 K) /protein kinase B(PKB or Akt) signaling pathway in the acupuncture effect in epilepsy rats. Methods A total of 120 SD rats were randomly divided into normal control group, model group, LY 294002 (a specific antagonist for PI 3 K/Akt signaling) group, acupuncture + LY 294002 group and acupuncture group (n = 24 in each group, 12 for H. E. staining, and 12 for electron microscope observation). Epilepsy model was established by intraperitoneal injection of pentylenetetrazol (PTZ, 5 μL). Manual acupuncture stimulation was applied to "Baihui" (GV20) and "Dazhui" (GV 14) once daily for 5 days. Dimethyl Sulfoxide (DMSO, 5 μL, a control solvent) was given to rats of the normal, model and acupuncture groups, and LY 294002 (5 μL, dissolved in DMSO) given to rats of the LY 294002 and acupuncture+LY 294002 groups by lateral ventricular injection. Four hours and 24 h after modeling, the hippocampus tissues were sampled for observing pathological changes of CA 1 and CA 3 regions after H. E. staining under light microscope and for checking ultrastructural changes of the pyramidal cells under transmission electron microscope. Results In comparison with the normal control group, the numbers of pyramidal cells of hippocampal CA3 region in the model group were decreased significantly 4 h and 24 h after epileptic seizure (P0. 05). Findings of the light microscope and electron microscope showed that the injury severity of pyramidal cells of hippocampal CA 1 and CA 3 regions was moderate 4 h after epileptic seizure and even worse 24 h after seizure in the model group, LY 294002 group and acupuncture + LY 294002 group, but relatively lighter in the acupuncture group. These results suggested an elimination of the acupuncture effect after blocking the PI 3 K/Akt signaling pathway by lateral

  5. Protective Effects of PI3K/Akt1 Signaling Pathway Involved in Hydrogen Sulfide in a Rat Mod-el of Liver Cirrhosis Ischemia-reperfusion Injury%硫化氢对肝纤维化大鼠肝脏缺血再灌注损伤的保护作用

    Institute of Scientific and Technical Information of China (English)

    黄红珏; 魏来; 邹毅; 孔高茵

    2015-01-01

    [Objective] To explore the relationship between the protective effects of hydrogen sulfide on hepatic fibrosis in a rat model of liver ischemia‐reperfusion injury and PI3K/Akt1 pathway .[Methods]A total of 32 Sprague‐Dawley (SD) rats were randomly divided into 4 groups of sham ,hepatic ischemia‐reperfusion in‐jury (HIRI ) , sodium hydrosulfide preconditioning (NaHS ) and NaHS pretreatment + PI3K inhibitor (LY294002) ( n = 8 each) .After reperfusion ,the levels of aspartate transaminase (AST ) ,alanine amin‐otransferase (ALT) ,superoxide dismutase (SOD) and malondialdehyde (MDA) were detected and autophagy vacuoles observed by transmission electron microscope .And the protein levels of Beclin1 ,LC3B and AKt in left hepatic lobe tissue by Western blot .[Results]Compared with sham contrast ,the levels of AST ,ALT and MDA were significantly elevated in three other groups ( P<0 .05) .Injury was less in NaHS group than HIRI group ( P <0 .05) and LY294002 group was more severe than NaHS group ( P<0 .05) .And similar results were obtained in autophagy .[Conclusion] One of the protection mechanisms of exogenous hydrogen sulfide working for hepatic fibrosis may be inhibiting autophagy via PI3K/Akt signaling pathway in rats of liver ische‐mia‐reperfusion injury .%【目的】探讨硫化氢(H2 S)对肝纤维化大鼠肝脏缺血再灌注损伤(HIRI)的保护作用。【方法】32只SD大鼠通过胆总管结扎法建立大鼠肝纤维化模型,随机分为4组:①假手术组(Sham组),② HIRI组,③硫化氢钠(NaHS)预处理组(NaHS组),④NaHS预处理+ PI3K抑制剂组(LY294002组)。检测各组谷草转氨酶(Aspartate transaminase ,AST)、谷丙转氨酶(Alanine aminotransferase ,ALT)、超氧化物歧化酶(Super‐oxide Dismutase ,SOD)、丙二醛(Malondialdehyde ,MDA)水平;取左肝外叶组织,透射电镜观察肝细胞细胞中自噬泡情况;Western Blot技术检测各

  6. Prostate cancer ETS rearrangements switch a cell migration gene expression program from RAS/ERK to PI3K/AKT regulation.

    Science.gov (United States)

    Selvaraj, Nagarathinam; Budka, Justin A; Ferris, Mary W; Jerde, Travis J; Hollenhorst, Peter C

    2014-03-19

    The RAS/ERK and PI3K/AKT pathways induce oncogenic gene expression programs and are commonly activated together in cancer cells. Often, RAS/ERK signaling is activated by mutation of the RAS or RAF oncogenes, and PI3K/AKT is activated by loss of the tumor suppressor PTEN. In prostate cancer, PTEN deletions are common, but, unlike other carcinomas, RAS and RAF mutations are rare. We have previously shown that over-expression of "oncogenic" ETS transcription factors, which occurs in about one-half of prostate tumors due to chromosome rearrangement, can bypass the need for RAS/ERK signaling in the activation of a cell migration gene expression program. In this study we test the role of RAS/ERK and PI3K/AKT signaling in the function of oncogenic ETS proteins. We find that oncogenic ETS expression negatively correlates with RAS and RAF mutations in prostate tumors. Furthermore, the oncogenic ETS transcription factors only increased cell migration in the absence of RAS/ERK activation. In contrast to RAS/ERK, it has been reported that oncogenic ETS expression positively correlates with PI3K/AKT activation. We identified a mechanistic explanation for this finding by showing that oncogenic ETS proteins required AKT signaling to activate a cell migration gene expression program through ETS/AP-1 binding sequences. Levels of pAKT correlated with the ability of oncogenic ETS proteins to increase cell migration, but this process did not require mTORC1. Our findings indicate that oncogenic ETS rearrangements cause a cell migration gene expression program to switch from RAS/ERK control to PI3K/AKT control and provide a possible explanation for the high frequency of PTEN, but not RAS/RAF mutations in prostate cancer.

  7. Ochratoxin A activates opposing c-MET/PI3K/Akt and MAPK/ERK 1-2 pathways in human proximal tubule HK-2 cells.

    Science.gov (United States)

    Özcan, Zeynep; Gül, Gizem; Yaman, Ibrahim

    2015-08-01

    Ochratoxin A (OTA) is a mycotoxin produced as a secondary metabolite by filamentous fungi, such as Aspergillus and Penicillium. Because OTA is a common contaminant of food and feeds, humans and animals are frequently exposed to OTA in daily life. It has been classified as a carcinogen in rodents and a possible carcinogen in humans. OTA has been shown to deregulate a variety of different signal transduction pathways in a cell type- and dosage-depending manner resulting in contrasting physiological effects, such as survival or cell death. While the ERK1-2 and JNK/SAPK MAPK pathways are major targets, knowledge about their role in OTA-mediated cell survival and death is fragmented. Similarly, the contribution of the PI3K/Akt pathway to the carcinogenic effect of OTA in proximal tubule cells has not been elucidated in detail. In this study, we demonstrated that OTA induced sustained activation of the PI3K/Akt and MEK/ERK1-2 signaling pathways in a dose- and time-dependent manner in HK-2 cells. Chemical inhibition of ERK1-2 activation or overexpression of dominant-negative and kinase-dead MEK1 leads to increased cell viability and decreased apoptosis in OTA-treated cells. Blockage of PI3K/Akt with Wortmannin aggravated the negative effect of OTA on cell viability and increased the levels of apoptosis. Moreover, we identified the c-MET proto-oncogene as an upstream receptor tyrosine kinase responsible for OTA-induced activation of PI3K/Akt signaling in HK-2 cells. Our data suggest that OTA may potentiate carcinogenesis by sustained activation of c-MET/PI3K/Akt signaling through suppression of apoptosis induced by MEK/ERK1-2 activation in damaged renal proximal tubule epithelial cells.

  8. ErbB3 ablation impairs phosphatidylinositol 3-kinase (PI3K)/AKT-dependent mammary tumorigenesis

    Science.gov (United States)

    Cook, Rebecca S.; Garrett, Joan T.; Sánchez, Violeta; Stanford, Jamie C.; Young, Christian; Chakravarty, Anindita; Rinehart, Cammie; Zhang, Yixian; Wu, Yaming; Greenberger, Lee; Horak, Ivan D.; Arteaga, Carlos L.

    2011-01-01

    Summary The ErbB receptor family member ErbB3 has been implicated in breast cancer growth but it has yet to be determined whether its disruption is therapeutically valuable. In a mouse model of mammary carcinoma driven by the polyomavirus middle T (PyVmT) oncogene, the ErbB2 tyrosine kinase inhibitor lapatinib reduced the activation of ErbB3 and Akt along with tumor cell growth. In this phosphatidylinositol-3 kinase (PI3K)-dependent tumor model, ErbB2 is part of a complex containing PyVmT, p85 (PI3K), ErbB3, and Src, that is disrupted by treatment with lapatinib. Thus, full engagement of PI3K/Akt by ErbB2 in this oncogene-induced mouse tumor model may involve its ability to dimerize with and phosphorylate ErbB3, which itself directly binds PI3K. Here we report that ErbB3 is critical for PI3K/AKT-driven tumor formation triggered by the PyVmT oncogene. Tissue-specific, Cre-mediated deletion of ErbB3 reduced Akt phosphorylation, primary tumor growth and pulmonary metastasis. Further EZN-3920, a chemically stabilized antisense oligonucleotide that targets the ErbB3 mRNA in vivo, produced similar effects while causing no mouse toxicity. Our findings offer further preclinical evidence that ErbB3 ablation may be therapeutically effective in tumors where ErbB3 engages PI3K/Akt signaling. PMID:21482676

  9. Effects of PI3K/Akt signaling pathway on acetaldehyde-stimulated proliferation of hepatic stellate cells HSC-T6%PI3K/Akt 信号传导通路在乙醛刺激下大鼠肝星状细胞株 HSC-T6增殖中的作用

    Institute of Scientific and Technical Information of China (English)

    张迪; 程敏; 康馨丹; 陈卫刚; 郑勇

    2016-01-01

    目的:探讨磷脂酰肌醇3激酶/蛋白激酶 B(PI3K/Akt)信号传导通路在乙醛刺激的大鼠肝星状细胞株HSC-T6增殖中的作用。方法将大鼠 HSC-T6随机分为6组:空白对照组(A 组):采用10%胎牛血清的 DMEM培养液培养;乙醛组(B 组):在 A 组基础上加乙醛,使终浓度为200μmol/L;实验组在 B 组基础上加入不同浓度(25、50、75、100μmol/L)的 PI3K/Akt 通路抑制剂 LY294002,分别称为 C、D、E、F 组。用 CCK-8法检测大鼠 HSC-T6增殖活力(用 A 值表示)。再随机将 HSC-T6分为3组:空白对照组(10%胎牛血清的 DMEM培养液培养)、乙醛组(在空白对照组基础上加乙醛,使终浓度为200μmol/L)、乙醛+LY294002组(在乙醛组的基础上加入50μmol/L LY294002),用 Western blotting 法检测大鼠 HSC-T6中 PI3K、p-Akt 蛋白的表达情况。结果 A、B、C、D、E、F 组 A 值分别为0.5450±0.0244、0.9523±0.0455、0.9273±0.0419、0.8658±0.0289、0.8143±0.0247、0.7593±0.2200。与 A 组比较,其他各组 A 值均升高;与 B、C 组比较,D、E、F 组降低(P 均<0.01)。与空白对照组比较,乙醛组、乙醛+LY294002组 PI3K、p-AKT 蛋白相对表达量高(P 均<0.01),与乙醛组比较,乙醛+LY294002组降低(P <0.05)。结论 PI3K/Akt 信号传导通路部分参与调控乙醛刺激的大鼠 HSC-T6增殖。%Objective To investigate the effects of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway spe-cific inhibitor LY294002 on the proliferation of rat hepatic stellate cells (HSC-T6)stimulated by acetaldehyde.Methods The rat HSC-T6 cells were randomly divided into six groups:the blank control group (group A):we used DMEMculture solution with 10% fetal bovine serum (FBS)to culture,the acetaldehyde group (group B):we added acetaldehyde on the basis of the blank control group and made the final

  10. PI3K/Akt is involved in brown adipogenesis mediated by growth differentiation factor-5 in association with activation of the Smad pathway

    Energy Technology Data Exchange (ETDEWEB)

    Hinoi, Eiichi; Iezaki, Takashi; Fujita, Hiroyuki; Watanabe, Takumi; Odaka, Yoshiaki; Ozaki, Kakeru; Yoneda, Yukio, E-mail: yyoneda@p.kanazawa-u.ac.jp

    2014-07-18

    Highlights: • Akt is preferentially phosphorylated in BAT and sWAT of aP2-GDF5 mice. • PI3K/Akt signaling is involved in GDF5-induced brown adipogenesis. • PI3K/Akt signaling regulates GDF5-induced Smad5 phosphorylation. - Abstract: We have previously demonstrated promotion by growth differentiation factor-5 (GDF5) of brown adipogenesis for systemic energy expenditure through a mechanism relevant to activating the bone morphological protein (BMP) receptor/mothers against decapentaplegic homolog (Smad)/peroxisome proliferator-activated receptor gamma co-activator 1α (PGC-1α) pathway. Here, we show the involvement of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in brown adipogenesis mediated by GDF5. Overexpression of GDF5 in cells expressing adipocyte protein-2 markedly accelerated the phosphorylation of Smad1/5/8 and Akt in white and brown adipose tissues. In brown adipose tissue from heterozygous GDF5{sup Rgsc451} mutant mice expressing a dominant-negative (DN) GDF5 under obesogenic conditions, the basal phosphorylation of Smad1/5/8 and Akt was significantly attenuated. Exposure to GDF5 not only promoted the phosphorylation of both Smad1/5/8 and Akt in cultured brown pre-adipocytes, but also up-regulated Pgc1a and uncoupling protein-1 expression in a manner sensitive to the PI3K/Akt inhibitor Ly294002 as well as retroviral infection with DN-Akt. GDF5 drastically promoted BMP-responsive luciferase reporter activity in a Ly294002-sensitive fashion. Both Ly294002 and DN-Akt markedly inhibited phosphorylation of Smad5 in the nuclei of brown pre-adipocytes. These results suggest that PI3K/Akt signals play a role in the GDF5-mediated brown adipogenesis through a mechanism related to activation of the Smad pathway.

  11. Niacin activates the PI3K/Akt cascade via PKC- and EGFR-transactivation-dependent pathways through hydroxyl-carboxylic acid receptor 2.

    Directory of Open Access Journals (Sweden)

    Huawang Sun

    Full Text Available Niacin has been demonstrated to activate a PI3K/Akt signaling cascade to prevent brain damage after stroke and UV-induced skin damage; however, the underlying molecular mechanisms for HCA2-induced Akt activation remain to be elucidated. Using CHO-K1 cells stably expressing HCA2 and A431 cells, a human epidermoid cell line with high levels of endogenous expression of functional HCA2 receptors, we first demonstrated that niacin induced a robust Akt phosphorylation at both Thr308 and Ser473 in a time-dependent fashion, with a maximal activation at 5 min and a subsequent reduction to baseline by 30 min through HCA2, and that the activation was significantly blocked by pertussis toxin. The HCA2-mediated activation of Akt was also significantly inhibited by the PKC inhibitors GF109203x and Go6983 in both cell lines, by the PDGFR-selective inhibitor tyrphostin A9 in CHO-HCA2 cells and by the MMP inhibitor GM6001 and EGFR-specific inhibitor AG1478 in A431 cells. These results suggest that the PKC pathway and PDGFR/EGFR transactivation pathway play important roles in HCA2-mediated Akt activation. Further investigation indicated that PI3K and the Gβγ subunit were likely to play an essential role in HCA2-induced Akt activation. Moreover, Immunobloting analyses using an antibody that recognizes p70S6K1 phosphorylated at Thr389 showed that niacin evoked p70S6K1 activation via the PI3K/Akt pathway. The results of our study provide new insight into the signaling pathways involved in HCA2 activation.

  12. Role of PI3-K/Akt pathway and its effect on glial cell line-derived neurotrophic factor in midbrain dopamine cells

    Institute of Scientific and Technical Information of China (English)

    Hong-jun WANG; Jun-ping CAO; Jing-kao YU; Dian-shuai GAO

    2007-01-01

    Aim: To explore the intracellular mechanisms underlying the survival/differentia-don effect of the glial cell line-derived neurotrophic factor (GDNF) on dopamine(DA) cells. Methods: Midbrain slice culture and primary cell culture were established, and the cultures were divided into 3 groups: control group, GDNF group, and the phosphatidylinositol 3-kinase/Akt (PI3-K/Akt) pathway-inhibited group. Then the expression of tyrosine hydroxylase (TH) was detected by immunostaining as well as Western blotting. Results: GDNF treatment induced an increase in the number of TH-immunoreactive (ir) cells and the neurite number of TH-ir cells, as well as in the level of TH expression in cultures (Number of TH-ir cells in the slice culture: control group, 8.76±0.75; GDNF group, 18.63±0.95.Number of TH-ir cells and neurite number of TH-ir cells in cell culture: controlgroup, 3.65±0.88 and 2.49±0.42; GDNF group, 6.01±0.43 and 4.89±0.46). Meanwhile, the stimulation of cultured cells with GDNF increased the phosphorylation of Akt, which is a downstream effector of PI3-K/Akt. The effects of GDNF were specifically blocked by the inhibitor of the PI3-K/Akt pathway, wortmannin (Number of TH-ir cells in slice culture: PI3-K/Akt pathway-inhibited group, 6.98±0.58. Num-ber of TH-ir cells and neurite number of TH-ir cells in cell culture: PI3-K/Aktpathway-inhibited group, 3.79±0.62 and 2.50±0.25, respectively). Conclusion: The PI3-K/Akt pathway mediates the survival/differentiation effect of GDNF on DA cells.8±0.58.

  13. The role of sodium hydrosulfide in attenuating the aging process via PI3K/AKT and CaMKKβ/AMPK pathways

    Directory of Open Access Journals (Sweden)

    Xubo Chen

    2017-08-01

    Full Text Available Age-related dysfunction of the central auditory system, known as central presbycusis, is characterized by defects in speech perception and sound localization. It is important to determine the pathogenesis of central presbycusis in order to explore a feasible and effective intervention method. Recent work has provided fascinating insight into the beneficial function of H2S on oxidative stress and stress-related disease. In this study, we investigated the pathogenesis of central presbycusis and tried to explore the mechanism of H2S action on different aspects of aging by utilizing a mimetic aging rat and senescent cellular model. Our results indicate that NaHS decreased oxidative stress and apoptosis levels in an aging model via CaMKKβ and PI3K/AKT signaling pathways. Moreover, we found that NaHS restored the decreased activity of antioxidants such as GSH, SOD and CAT in the aging model in vivo and in vitro by regulating CaMKKβ and PI3K/AKT. Mitochondria function was preserved by NaHS, as indicated by the following: DNA POLG and OGG-1, the base excision repair enzymes in mitochondrial, were upregulated; OXPHOS activity was downregulated; mitochondrial membrane potential was restored; ATP production was increased; and mtDNA damage, indicated by the common deletion (CD, declined. These effects were also achieved by activating CaMKKβ/AMPK and PI3K/AKT signaling pathways. Lastly, protein homeostasis, indicated by HSP90 alpha, was strengthened by NaHS via CaMKKβ and PI3K/AKT. Our findings demonstrate that the ability to resist oxidative stress and mitochondria function are both decreased as aging developed; however, NaHS, a novel free radical scavenger and mitochondrial protective agent, precludes the process of oxidative damage by activating CaMKKβ and PI3K/AKT. This study might provide a therapeutic target for aging and age-related disease.

  14. Cytoglobin inhibits migration through PI3K/AKT/mTOR pathway in fibroblast cells.

    Science.gov (United States)

    Demirci, Selami; Doğan, Ayşegül; Apdik, Hüseyin; Tuysuz, Emre Can; Gulluoglu, Sukru; Bayrak, Omer Faruk; Şahin, Fikrettin

    2017-06-15

    Cell proliferation and migration are crucial in many physiological processes including development, cancer, tissue repair, and wound healing. Cell migration is regulated by several signaling molecules. Identification of genes related to cell migration is required to understand molecular mechanism of non-healing chronic wounds which is a major concern in clinics. In the current study, the role of cytoglobin (CYGB) gene in fıbroblast cell migration and proliferation was described. L929 mouse fibroblast cells were transduced with lentiviral particles for CYGB and GFP, and analyzed for cell proliferation and migration ability. Fibroblast cells overexpressing CYGB displayed decreased cell proliferation, colony formation capacity, and cell migration. Phosphorylation levels of mTOR and two downstream effectors S6 and 4E-BP1 which take part in PI3K/AKT/mTOR signaling declined in CYGB-overexpressing cells. Microarray analysis indicated that CYGB overexpression leads to downregulation of cell proliferation, migration, and tumor growth associated genes in L929 cell line. This study demonstrated the role of CYGB in fibroblast cell motility and proliferation. CYGB could be a promising candidate for further studies as a potential target for diseases related to cell migration such as cancer and chronic wound treatment.

  15. Quercetin postconditioning attenuates myocardial ischemia/reperfusion injury in rats through the PI3K/Akt pathway

    Directory of Open Access Journals (Sweden)

    Y. Wang

    2013-09-01

    Full Text Available Quercetin (Que, a plant-derived flavonoid, has multiple benefical actions on the cardiovascular system. The current study investigated whether Que postconditioning has any protective effects on myocardial ischemia/reperfusion (I/R injury in vivo and its potential cardioprotective mechanisms. Male Sprague-Dawley rats were randomly allocated to 5 groups (20 animals/group: sham, I/R, Que postconditioning, Que+LY294002 [a phosphatidylinositol 3-kinase (PI3K/Akt signaling pathway inhibitor], and LY294002+I/R. I/R was produced by 30-min coronary occlusion followed by 2-h reperfusion. At the end of reperfusion, myocardial infarct size and biochemical changes were compared. Apoptosis was evaluated by both TUNEL staining and measurement of activated caspase-3 immunoreactivity. The phosphorylation of Akt and protein expression of Bcl-2 and Bax were determined by Western blotting. Que postconditioning significantly reduced infarct size and serum levels of creatine kinase and lactate dehydrogenase compared with the I/R group (all P<0.05. Apoptotic cardiomyocytes and caspase-3 immunoreactivity were also suppressed in the Que postconditioning group compared with the I/R group (both P<0.05. Akt phosphorylation and Bcl-2 expression increased after Que postconditioning, but Bax expression decreased. These effects were inhibited by LY294002. The data indicate that Que postconditioning can induce cardioprotection by activating the PI3K/Akt signaling pathway and modulating the expression of Bcl-2 and Bax proteins.

  16. Quercetin postconditioning attenuates myocardial ischemia/reperfusion injury in rats through the PI3K/Akt pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Zhang, Z.Z.; Wu, Y.; Ke, J.J.; He, X.H.; Wang, Y.L. [Department of Anesthesiology, Zhongnan Hospital, Wuhan University, Wuhan (China)

    2013-09-24

    Quercetin (Que), a plant-derived flavonoid, has multiple benefical actions on the cardiovascular system. The current study investigated whether Que postconditioning has any protective effects on myocardial ischemia/reperfusion (I/R) injury in vivo and its potential cardioprotective mechanisms. Male Sprague-Dawley rats were randomly allocated to 5 groups (20 animals/group): sham, I/R, Que postconditioning, Que+LY294002 [a phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway inhibitor], and LY294002+I/R. I/R was produced by 30-min coronary occlusion followed by 2-h reperfusion. At the end of reperfusion, myocardial infarct size and biochemical changes were compared. Apoptosis was evaluated by both TUNEL staining and measurement of activated caspase-3 immunoreactivity. The phosphorylation of Akt and protein expression of Bcl-2 and Bax were determined by Western blotting. Que postconditioning significantly reduced infarct size and serum levels of creatine kinase and lactate dehydrogenase compared with the I/R group (all P<0.05). Apoptotic cardiomyocytes and caspase-3 immunoreactivity were also suppressed in the Que postconditioning group compared with the I/R group (both P<0.05). Akt phosphorylation and Bcl-2 expression increased after Que postconditioning, but Bax expression decreased. These effects were inhibited by LY294002. The data indicate that Que postconditioning can induce cardioprotection by activating the PI3K/Akt signaling pathway and modulating the expression of Bcl-2 and Bax proteins.

  17. Upregulation of the PI3K/Akt pathway in the tumorigenesis of canine thyroid carcinoma

    NARCIS (Netherlands)

    Campos, M; Kool, M M J; Daminet, S; Ducatelle, R; Rutteman, G; Kooistra, H S; Galac, S; Mol, J A

    2014-01-01

    BACKGROUND: Information on the genetic events leading to thyroid cancer in dogs is lacking. HYPOTHESIS/OBJECTIVES: Upregulation of the PI3K/Akt pathway has an important role in the tumorigenesis of thyroid carcinoma in dogs. ANIMALS: Fifty-nine dogs with thyroid carcinoma and 10 healthy controls. ME

  18. IL-10 Protects Neurites in Oxygen-Glucose-Deprived Cortical Neurons through the PI3K/Akt Pathway.

    Directory of Open Access Journals (Sweden)

    Longzai Lin

    Full Text Available IL-10, as a cytokine, has an anti-inflammatory cascade following various injuries, but it remains blurred whether IL-10 protects neurites of cortical neurons after oxygen-glucose deprivation injury. Here, we reported that IL-10, in a concentration-dependent manner, reduced neuronal apoptosis and increased neuronal survival in oxygen-glucose-deprived primary cortical neurons, producing an optimal protective effect at 20ng/ml. After staining NF-H and GAP-43, we found that IL-10 significantly protected neurites in terms of axon length and dendrite number by confocal microscopy. Furthermore, it induced the phosphorylation of AKT, suppressed the activation of caspase-3, and up-regulated the protein expression of GAP-43. In contrast, LY294002, a specific inhibitor of PI3K/AKT, reduced the level of AKT phosphorylation and GAP-43 expression, increased active caspase-3 expression and thus significantly weakened IL-10-mediated protective effect in the OGD-induced injury model. IL-10NA, the IL-10 neutralizing antibody, reduced the level of p-PI3K phosphorylation and increased the expression of active caspase-3. These findings suggest that IL-10 provides neuroprotective effects by protecting neurites through PI3K/AKT signaling pathway in oxygen-glucose-deprived primary cortical neurons.

  19. Matrine Suppresses Proliferation and Invasion of SGC7901 Cells through Inactivation of PI3K/Akt/uPA Pathway.

    Science.gov (United States)

    Peng, Xiaochun; Zhou, Dawei; Wang, Xianwang; Hu, Zhifan; Yan, Yan; Huang, Jiangrong

    2016-09-01

    This study was to examine the inhibitory effect of matrine on the proliferation and metastasis of gastric cancer cells, and to explore the possible mechanisms involved in these processes. MTT was used to evaluate the proliferation ability of SGC7901 cells. A two and three-dimensional cell migration assay were performed to determine the effect of matrine on the migration of SGC7901 cells. Then, the changes of the uPA protein and other possible signal molecules were detected by western blot. We found that the proliferation ability of SGC 7901 cells was suppressed by matrine (pmatrine when compared to the control in a two-dimensional cell migration assay. In addition, SGC7901cells treated with matrine (50μg/ml) migrated less than the control cells in a three-dimensional cell migration assay. At the meantime, the decreased uPA protein expression in SGC7901 cells treated with matrine was observed, and the PI3K/Akt pathway was inhibited. These results suggested that matrine can inhibit the proliferation and metastasis of gastric cancer cells through the PI3K/Akt/uPA pathway, indicating that matrine might be a potential molecular target for treatment of gastric carcinoma.

  20. Pro-apoptotic and pro-autophagic effects of the Aurora kinase A inhibitor alisertib (MLN8237 on human osteosarcoma U-2 OS and MG-63 cells through the activation of mitochondria-mediated pathway and inhibition of p38 MAPK/PI3K/Akt/mTOR signaling pathway

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    Niu NK

    2015-03-01

    mesenchymal transition (EMT and the underlying mechanisms in two human OS cell lines U-2 OS and MG-63. The results showed that ALS had potent growth inhibitory, pro-apoptotic, pro-autophagic, and EMT inhibitory effects on U-2 OS and MG-63 cells. ALS remarkably induced G2/M arrest and down-regulated the expression levels of cyclin-dependent kinases 1 and 2 and cyclin B1 in both U-2 OS and MG-63 cells. ALS markedly induced mitochondria-mediated apoptosis with a significant increase in the expression of key pro-apoptotic proteins and a decrease in main anti-apoptotic proteins. Furthermore, ALS promoted autophagic cell death via the inhibition of phosphatidylinositol 3-kinase (PI3K/protein kinase B (Akt/mammalian target of rapamycin (mTOR and p38 mitogen-activated protein kinase (p38 MAPK signaling pathways, and activation of 5'-AMP-dependent kinase (AMPK signaling pathway. Inducers or inhibitors of apoptosis or autophagy simultaneously altered ALS-induced apoptotic and autophagic death in both U-2 OS and MG-63 cells, suggesting a crosstalk between these two primary modes of programmed cell death. Moreover, ALS suppressed EMT-like phenotypes with a marked increase in the expression of E-cadherin but a decrease in N-cadherin in U-2 OS and MG-63 cells. ALS treatment also induced reactive oxygen species (ROS generation but inhibited the expression levels of sirtuin 1 and nuclear factor-erythroid-2-related factor 2 (Nrf2 in both cell lines. Taken together, these findings show that ALS promotes apoptosis and autophagy but inhibits EMT via PI3K/Akt/mTOR, p38 MAPK, and AMPK signaling pathways with involvement of ROS- and sirtuin 1-associated pathways in U-2 OS and MG-63 cells. ALS is a promising anticancer agent in OS treatment and further studies are needed to confirm its efficacy and safety in OS chemotherapy. Keywords: ALS, autophagy, apoptosis, osteosarcoma, PI3K/Akt/mTOR pathway, EMT

  1. Insulin induces drug resistance in melanoma through activation of the PI3K/Akt pathway

    Directory of Open Access Journals (Sweden)

    Chi M

    2014-02-01

    Full Text Available Mengna Chi,1 Yan Ye,1 Xu Dong Zhang,1 Jiezhong Chen2,3 1School of Medicine and Public Health, The University of Newcastle, Newcastle, NSW, Australia; 2School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia; 3Faculty of Science, Medicine and Health, The University of Wollongong, Wollongong, NSW, Australia Introduction: There is currently no curative treatment for melanoma once the disease spreads beyond the original site. Although activation of the PI3K/Akt pathway resulting from genetic mutations and epigenetic deregulation of its major regulators is known to cause resistance of melanoma to therapeutic agents, including the conventional chemotherapeutic drug dacarbazine and the Food and Drug Administration-approved mutant BRAF inhibitors vemurafenib and dabrafenib, the role of extracellular stimuli of the pathway, such as insulin, in drug resistance of melanoma remains less understood. Objective: To investigate the effect of insulin on the response of melanoma cells to dacarbazine, and in particular, the effect of insulin on the response of melanoma cells carrying the BRAFV600E mutation to mutant BRAF inhibitors. An additional aim was to define the role of the PI3K/Akt pathway in the insulin-triggered drug resistance. Methods: The effect of insulin on cytotoxicity induced by dacarbazine or the mutant BRAF inhibitor PLX4720 was tested by pre-incubation of melanoma cells with insulin. Cytotoxicity was determined by the MTS assay. The role of the PI3K/Akt pathway in the insulin-triggered drug resistance was examined using the PI3K inhibitor LY294002 and the PI3K and mammalian target of rapamycin dual inhibitor BEZ-235. Activation of the PI3K/Akt pathway was monitored by Western blot analysis of phosphorylated levels of Akt. Results: Recombinant insulin attenuated dacarbazine-induced cytotoxicity in both wild-type BRAF and BRAFV600E melanoma cells, whereas it also reduced killing of BRAFV600E melanoma cells by PLX4720

  2. SDF-1对糖尿病外周血EPCs功能的影响及其与PI3K/AKT信号通路的关系%Effects of Stromal Cell-Derived-Factor-1 on Endothelial Progenitor Cells of Peripheral Blood and Their Relationship with PI3K/AKT Signal Transduction Pathway in Patients with Diabetes

    Institute of Scientific and Technical Information of China (English)

    黎金凤; 林安华; 邓颖; 霍亚南; 刘精东; 吴明斌; 王晨秀

    2014-01-01

    Objective To observe the effects of stromal cell-derived-factor-1(SDF-1) on the function of endotheli⁃al progenitor cells(EPCs)of peripheral blood in patients with diabetes, and to discuss the effects of PI3K/AKT signaling path⁃way on the role of SDF-1 in EPCs. Methods The peripheral blood samples (30 mL) were collected in 10 diabetes patients (DM group) and 10 healthy controls (HC group). (1) The 100μg/L SDF-1 was added in intervention group. EGM-2MV was added in non-intervention group. The Boyden chamber and in vitro angiogenesis kit were used to analyze the migration and in vitro angiogenesis of EPCs. (2) Cultured EPCs were divided into blank control group, 1μg/L SDF-1 group, 10μg/L SDF-1 group, 100μg/L SDF-1 group, pure AMD3100 group and 100μg/L SDF-1+AMD3100 group. AKT protein expression lev⁃els of endothelial progenitor cells were detected by Western blot assay in each group. Results (1) Without intervention with SDF-1, EPCs’migration and angiogenesis ability were lower in DM group than those in HC group. After intervention with SDF-1, the migration and angiogenesis ability were enhanced in two groups, but the increased level was higher in DM group than that of HC group. (2) Under the same concentration, AKT protein expression level was significantly lower in DM group than that in HC group (P<0.01). AKT protein expression levels were increased with the increased levels of SDF-1 in DM group and HC group (P<0.05). AKT protein expression was significantly lower in 100μg/L SDF-1+AMD3100 group than that of 100μg/L SDF-1 group (P<0.05). Conclusion SDF-1 can increase the chemotactic migration and angiogenesis ability of EPCs in peripheral blood, especially for patients with diabetes. The effects of SDF-1 on EPCs were related to the PI3K/AKT signaling pathway.%目的:观察基质细胞衍生因子-1(SDF-1)对糖尿病外周血内皮祖细胞(EPCs)功能的影响,探讨SDF-1对EPCs的影响是否与PI3K/AKT信号通路有关。方法采集

  3. GPR30下调对子宫内膜癌细胞及裸鼠移植瘤组织 PI3K/Akt信号通路的影响%Influence of down-regulation of GPR30 on PI3 K/Akt signaling pathway in endometrial carcinoma cells and tumor tissue of nude mice

    Institute of Scientific and Technical Information of China (English)

    雷冬梅; 郭瑞霞; 刘泇希; 葛新; 乔玉环

    2015-01-01

    目的:探讨G蛋白偶联受体(GPR 30)下调对子宫内膜癌细胞及裸鼠移植瘤组织PI3K/Akt信号通路的影响。方法:采用免疫细胞化学SP法观察子宫内膜癌细胞系HEC-1A和Ishikawa细胞中GPR30、Akt和磷酸化Akt (p-Akt)蛋白的定位。以pGFP-V-RS(对照)和pGFP-V-RS-GPR30(干扰)分别转染两种细胞,用蛋白印迹法检测两种细胞中GPR30、Akt及p-Akt蛋白的表达水平。构建裸鼠移植瘤模型(分别接种上述4种转染细胞,共4组),用免疫组化SP法检测4组裸鼠移植瘤组织中p-Akt蛋白的表达。结果:①HEC-1A和Ishikawa细胞中,GPR30、Akt和p-Akt蛋白阳性表达均呈棕黄色,定位于细胞质。②稳定转染pGFP-VR-S -GPR30的两种细胞株中GPR30和p -Akt的表达均下调( P<0.05)。③与接种转染pGFP-V-RS细胞的2组裸鼠相比,接种转染pGFP-V-RS-GPR30细胞的2组裸鼠移植瘤组织中p-Akt表达降低。结论:在子宫内膜癌细胞及裸鼠移植瘤组织中, GPR30下调可能抑制了PI3K/Akt通路的活化。%Aim:To investigate the influence of down-regulation of G protein-coupled estrogen receptor 30 ( GPR30 ) on activation of PI3K/Akt signaling pathway in endometrial carcinoma cells and tumor tissue of nude mice .Methods:The location of GPR30, Akt and p-Akt protein in HEC-1A and Ishikawa cells was detected by immunocytochemical SP method . The expression of GPR30 in HEC-1A and Ishikawa cells was down-regulated by transfection with pGFP-V-RS-GPR30, a GPR30 antisense expression vector , and the cells transfected with pGFP-V-RS were the control; the levels of GPR30,Akt and p-Akt were detected by Western blot .The nude mice were allocated into 4 groups and inoculated the above transfected cells, and immunohistochemistry was performed to observe the changes of the expression level of p -Akt in the xenograft tis-sue.Results:Immunocytochemical SP method showed that GPR 30, Akt and p-Akt was stained as brown and

  4. Swimming Training Inhibits Type 2 Diabetes-Induced Myocardial Apoptosis Activating the PI3K-Akt Signaling Pathway%游泳训练通过激活PI3K-Akt信号通路抑制2型糖尿病引起的心肌细胞凋亡

    Institute of Scientific and Technical Information of China (English)

    江红轲

    2012-01-01

    ) phosphorylation levels was noteworthy higher than that of other two groups(P <0. 05). Meanwhile, the results also showed that insulin receptor subtype 1 (IR1) expression was down-regulated(P <0.05)and PI3K-Akt signal cascades were inactivated. Correspondingly, swimming exercise could decline the ratio of Bax/Bcl-2, considerably improve the survival pathway and further activate GSK-3β protein phosphorylation { P < 0. 05 ). In addition, swimming exercise also could augment insulin receptor IR1 (P < 0.05) contents. Although the level of IR2 was enhanced, there is no divergence for statistics. Conclusion; Swim training can effectively inhibit type 2 diabetes-induced myocardial apoptosis in Wistar rats. This anti-apoptotic effect may be through, at least in part, increasing the contents of IR1 receptor, and thereby activate PI3K-Akt signal cascade and further decline the phosphorylation expression of its key downstream of protein-GSK-3β, suggesting that swimming training may be an appropriate modality for combating with myocardial cell damage caused by T2DM.

  5. Upregulated WDR26 serves as a scaffold to coordinate PI3K/ AKT pathway-driven breast cancer cell growth, migration, and invasion.

    Science.gov (United States)

    Ye, Yuanchao; Tang, Xiaoyun; Sun, Zhizeng; Chen, Songhai

    2016-04-01

    The phosphatidylinositol 3-kinase (PI3K)/AKT pathway transmits signals downstream of receptor tyrosine kinases and G protein-coupled receptors (GPCRs), and is one of the most dysregulated pathways in breast cancer. PI3Ks and AKTs consist of multiple isoforms that play distinct and even opposite roles in breast cancer cell growth and metastasis. However, it remains unknown how the activities of various PI3K and AKT isoforms are coordinated during breast cancer progression. Previously, we showed WDR26 is a novel WD40 protein that binds Gβγ and promotes Gβγ signaling. Here, we demonstrate that WDR26 is overexpressed in highly malignant breast tumor cell lines and human breast cancer samples, and that WDR26 overexpression correlates with shortened survival of breast cancer patients. In highly malignant cell lines (MDA-MB231, DU4475 and BT549), downregulation of WDR26 expression selectively alleviated GPCR- but not EGF receptor-stimulated PI3K/AKT signaling and tumor cell growth, migration and invasion. In contrast, in a less malignant cell line (MCF7), WDR26 overexpression had the opposite effect. Additional studies indicate that downstream of GPCR stimulation, WDR26 serves as a scaffold that fosters assembly of a specific signaling complex consisting of Gβγ, PI3Kβ and AKT2. In an orthotopic xenograft mouse model of breast cancer, disrupting formation of this complex, by overexpressing WDR26 mutants in MDA-MB231 cells, abrogated PI3K/AKT activation and tumor cell growth and metastasis. Together, our results identify a novel mechanism regulating GPCR-dependent activation of the PI3K/AKT signaling axis in breast tumor cells, and pinpoint WDR26 as a potential therapeutic target for breast cancer.

  6. Novel agents and associated toxicities of inhibitors of the pi3k/Akt/mtor pathway for the treatment of breast cancer

    OpenAIRE

    Chia, S.; Gandhi, S.; Joy, A.A.; Edwards, S.; Gorr, M.; Hopkins, S; Kondejewski, J.; Ayoub, J.P.; Califaretti, N.; Rayson, D.; Dent, S.F.

    2015-01-01

    The pi3k/Akt/mtor (phosphatidylinositol 3 kinase/ Akt/mammalian target of rapamycin) signalling pathway is an established driver of oncogenic activity in human malignancies. Therapeutic targeting of this pathway holds significant promise as a treatment strategy. Everolimus, an mtor inhibitor, is the first of this class of agents approved for the treatment of hormone receptor–positive, human epidermal growth factor receptor 2–negative advanced breast cancer. Everolimus has been associated with...

  7. PI3K/Akt inhibition and down-regulation of BCRP re-sensitize MCF7 breast cancer cell line to mitoxantrone chemotherapy

    Directory of Open Access Journals (Sweden)

    Tahereh Komeili-Movahhed

    2015-05-01

    Full Text Available Objective(s:Multidrug resistance (MDR of cancer cells is a major obstacle to successful chemotherapy. Overexpression of breast cancer resistance protein (BCRP is one of the major causes of MDR. In addition, it has been shown that PI3K/Akt signaling pathway involves in drug resistance. Therefore, we evaluated the effects of novel approaches including siRNA directed against BCRP and targeted therapy against PI3K/Akt signaling pathway using LY294002 (LY to re-sensitize breast cancer MCF7 cell line to mitoxantrone (MTX chemotherapy. Materials and Methods: Anticancer effects of MTX, siRNA, and LY alone and in combination were evaluated in MCF7 cells using MTT cytotoxicity assay and flow cytometry analysis of cell cycle distribution and apoptosis induction. Results: MTT and apoptosis assays showed that both MTX and LY inhibited cell proliferation and induced apoptosis in MCF7 cells. Results indicated that inhibition of BCRP by siRNA or PI3K/Akt signaling pathway by LY significantly increased sensitivity of MCF7 cells to antiproliferation and apoptosis induction of MTX. Furthermore, MTX showed G2/M arrest, whereas LY induced G0/G1 arrest in cell cycle distribution of MCF7 cells. Combination of siRNA or LY with MTX chemotherapy significantly increased accumulation of MCF7 cells in the G2/M phase of cell cycle. Conclusion: Combination of MTX chemotherapy with BCRP siRNA and PI3K/Akt inhibition can overcome MDR in breast cancer cells. This study furthermore suggests that novel therapeutic approaches are needed to enhance anticancer effects of available drugs in breast cancer

  8. PI3K/Akt inhibition and down-regulation of BCRP re-sensitize MCF7 breast cancer cell line to mitoxantrone chemotherapy

    Science.gov (United States)

    Komeili-Movahhed, Tahereh; Fouladdel, Shamileh; Barzegar, Elmira; Atashpour, Shekoufeh; Hossein Ghahremani, Mohammad; Nasser Ostad, Seyed; Madjd, Zahra; Azizi, Ebrahim

    2015-01-01

    Objective(s): Multidrug resistance (MDR) of cancer cells is a major obstacle to successful chemotherapy. Overexpression of breast cancer resistance protein (BCRP) is one of the major causes of MDR. In addition, it has been shown that PI3K/Akt signaling pathway involves in drug resistance. Therefore, we evaluated the effects of novel approaches including siRNA directed against BCRP and targeted therapy against PI3K/Akt signaling pathway using LY294002 (LY) to re-sensitize breast cancer MCF7 cell line to mitoxantrone (MTX) chemotherapy. Materials and Methods: Anticancer effects of MTX, siRNA, and LY alone and in combination were evaluated in MCF7 cells using MTT cytotoxicity assay and flow cytometry analysis of cell cycle distribution and apoptosis induction. Results: MTT and apoptosis assays showed that both MTX and LY inhibited cell proliferation and induced apoptosis in MCF7 cells. Results indicated that inhibition of BCRP by siRNA or PI3K/Akt signaling pathway by LY significantly increased sensitivity of MCF7 cells to antiproliferation and apoptosis induction of MTX. Furthermore, MTX showed G2/M arrest, whereas LY induced G0/G1 arrest in cell cycle distribution of MCF7 cells. Combination of siRNA or LY with MTX chemotherapy significantly increased accumulation of MCF7 cells in the G2/M phase of cell cycle. Conclusion: Combination of MTX chemotherapy with BCRP siRNA and PI3K/Akt inhibition can overcome MDR in breast cancer cells. This study furthermore suggests that novel therapeutic approaches are needed to enhance anticancer effects of available drugs in breast cancer. PMID:26124933

  9. The PI3K/Akt pathway contributes to arenavirus budding.

    Science.gov (United States)

    Urata, Shuzo; Ngo, Nhi; de la Torre, Juan Carlos

    2012-04-01

    Several arenaviruses, chiefly Lassa virus (LASV), cause hemorrhagic fever (HF) disease in humans and pose a significant public health concern in regions where they are endemic. On the other hand, evidence indicates that the globally distributed prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) is a neglected human pathogen. The phosphatidylinositol 3-kinase (PI3K)/Akt pathway participates in many cellular processes, including cell survival and differentiation, and also has been shown to play important roles in different steps of the life cycles of a variety of viruses. Here we report that the inhibition of the PI3K/Akt pathway inhibited budding and to a lesser extent RNA synthesis, but not cell entry, of LCMV. Accordingly, BEZ-235, a PI3K inhibitor currently in cancer clinical trials, inhibited LCMV multiplication in cultured cells. These findings, together with those previously reported for Junin virus (JUNV), indicate that targeting the PI3K/Akt pathway could represent a novel antiviral strategy to combat human-pathogenic arenaviruses.

  10. RLIP76-dependent suppression of PI3K/AKT/Bcl-2 pathway by miR-101 induces apoptosis in prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jing; Song, Qi; Cai, Yi; Wang, Peng; Wang, Min; Zhang, Dong, E-mail: zhangd1117@yahoo.com

    2015-08-07

    MicroRNA-101 (miR-101) participates in carcinogenesis and tumor progression in various cancers. However, its biological functions in prostate cancer are still unclear. Here, we demonstrate that miR-101 represents a critical role in regulating cell apoptosis in prostate cancer cells. We first demonstrated that miR-101 treatment promoted apoptosis in DU145 and PC3 cells by using flow cytometric analysis and transmission electron microscopy (TEM). To verify the mechanisms, we identified a novel miR-101 target, Ral binding protein 1 (RLIP76). We found miR-101 transfection significantly suppresses RLIP76 expression, which can transactivate phosphorylation of PI3K-Akt signaling, and resulted in an amplification of Bcl2-induced apoptosis. Furthermore, we demonstrated that RLIP76 overexpression could reverse the anti-tumor effects of miR-101 in DU145 and PC3 cells by using flow cytometry assay and MTT assay. Taken together, our results revealed that the effect of miR-101 on prostate cancer cell apoptosis was due to RLIP76 regulation of the PI3K/Akt/Bcl-2 signaling pathway. - Highlights: • miR-101 inhibited prostate cancer cell proliferation and enhanced apoptosis. • miR-101 directly targeted and regulated RLIP76 expression. • miR-101 suppressed PI3K/Akt/Bcl-2 signaling pathway by targeting RLIP76.

  11. Carvedilol protects bone marrow stem cells against hydrogen peroxide-induced cell death via PI3K-AKT pathway.

    Science.gov (United States)

    Chen, Meihui; Chen, Shudong; Lin, Dingkun

    2016-03-01

    Carvedilol, a nonselective β-adrenergic receptor blocker, has been reported to exert potent anti-oxidative activities. In the present study, we aimed to investigate the effects of carvedilol against hydrogen peroxide (H2O2)-induced bone marrow-derived mesenchymal stem cells (BMSCs) death, which imitate the microenvironment surrounding transplanted cells in the injured spinal cord in vitro. Carvedilol significantly reduced H2O2-induced reactive oxygen species production, apoptosis and subsequent cell death. LY294002, the PI3K inhibitor, blocked the protective effects and up-regulation of Akt phosphorylation of carvedilol. Together, our results showed that carvedilol protects H2O2-induced BMSCs cell death partly through PI3K-Akt pathway, suggesting carvedilol could be used in combination with BMSCs for the treatment of spinal cord injury by improving the cell survival and oxidative stress microenvironments.

  12. Blood -brain barrier disruption was less under isoflurane than pentobarbital anesthesia via a PI3K/Akt pathway in early cerebral ischemia.

    Science.gov (United States)

    Chi, Oak Z; Mellender, Scott J; Kiss, Geza K; Liu, Xia; Weiss, Harvey R

    2017-02-24

    One of the important factors altering the degree of blood-brain barrier (BBB) disruption in cerebral ischemia is the anesthetic used. The phosphoinositide 3-kinase (PI3K)/Akt signaling pathway has been reported to be involved in modulating BBB permeability and in isoflurane induced neuroprotection. This study was performed to compare the degree of BBB disruption in focal cerebral ischemia under isoflurane vs pentobarbital anesthesia and to determine whether inhibition of PI3K/Akt would affect the disruption in the early stage of focal cerebral ischemia. Permanent middle cerebral artery (MCA) occlusion was performed in rats under 1.4% isoflurane or pentobarbital (50mg/kg i.p.) anesthesia with controlled ventilation. In half of each group LY294002, which is a PI3K/Akt inhibitor, was applied on the ischemic cortex immediately after MCA occlusion. After one hour of MCA occlusion, the transfer coefficient (Ki) of (14)C-α-aminoisobutyric acid ((14)C-AIB) was determined to quantify the degree of BBB disruption. MCA occlusion increased the Ki both in the isoflurane and pentobarbital anesthetized rats. However, the value of Ki was lower under isoflurane (11.5±6.0μL/g/min) than under pentobarbital (18.3±7.1μL/g/min) anesthesia. The Ki of the contralateral cortex of the pentobarbital group was higher (+74%) than that of the isoflurane group. Application of LY294002 on the ischemic cortex increased the Ki (+99%) only in the isoflurane group. The degree of BBB disruption by MCA occlusion was significantly lower under isoflurane than pentobarbital anesthesia in the early stage of cerebral ischemia. Our data demonstrated the importance of choice of anesthetics and suggest that PI3K/Akt signaling pathway plays a significant role in altering BBB disruption in cerebral ischemia during isoflurane but not during pentobarbital anesthesia.

  13. Involvement of PI3K/AKT and MAPK Pathways for TNF-α Production in SiHa Cervical Mucosal Epithelial Cells Infected with Trichomonas vaginalis.

    Science.gov (United States)

    Yang, Jung-Bo; Quan, Juan-Hua; Kim, Ye-Eun; Rhee, Yun-Ee; Kang, Byung-Hyun; Choi, In-Wook; Cha, Guang-Ho; Yuk, Jae-Min; Lee, Young-Ha

    2015-08-01

    Trichomonas vaginalis; induces proinflammation in cervicovaginal mucosal epithelium. To investigate the signaling pathways in TNF-α production in cervical mucosal epithelium after T. vaginalis infection, the phosphorylation of PI3K/AKT and MAPK pathways were evaluated in T. vaginalis-infected SiHa cells in the presence and absence of specific inhibitors. T. vaginalis increased TNF-α production in SiHa cells, in a parasite burden-dependent and incubation time-dependent manner. In T. vaginalis-infected SiHa cells, AKT, ERK1/2, p38 MAPK, and JNK were phosphorylated from 1 hr after infection; however, the phosphorylation patterns were different from each other. After pretreatment with inhibitors of the PI3K/AKT and MAPK pathways, TNF-α production was significantly decreased compared to the control; however, TNF-α reduction patterns were different depending on the type of PI3K/MAPK inhibitors. TNF-α production was reduced in a dose-dependent manner by treatment with wortmannin and PD98059, whereas it was increased by SP600125. These data suggested that PI3K/AKT and MAPK signaling pathways are important in regulation of TNF-α production in cervical mucosal epithelial SiHa cells. However, activation patterns of each pathway were different from the types of PI3K/MAPK pathways.

  14. Cbl-b and PI3K/Akt pathway are differently involved in oxygen-glucose deprivation preconditioning in PC12 cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; YU Huan; ZOU Wei; WANG Yan-fu; LIANG Xiao-feng; ZHANG Bo; KONG Jing-jing

    2013-01-01

    Background Transient sublethal ischemia is known as ischemic preconditioning,which enables cells and tissues to survive subsequent prolonged lethal ischemic injury.Ischemic preconditioning exerts neuroprotection through phosphatidylinositol 3-kinase (PI3K)/Akt pathway.Cbl-b belongs to the Casitas B-lineage lymphoma (Cbl) family,and it can regulate the cell signal transduction.The roles of ubiquitin ligase Cbl-b and PI3K/Akt pathway and the relationship between them in oxygen-glucose deprivation preconditioning (OGDPC) in PC12 cells were investigated in the present study.Methods Oxygen and glucose deprivation (OGD) model in PC12 cells was used in the present study.The 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay,nuclear staining with Hoechst 33258,and Western blotting were applied to explore the roles of Cbl-b and PI3K/Akt pathway and the relationship between them in OGDPC in PC12 cells.Results Cell viability was significantly changed by OGD and OGDPC.OGD significantly decreased cell viability compared with the control group (P <0.05),and preconditioning could rescue this damage was demonstrated by the increase of cell viability (P <0.05).The expression of Cbl-b was significantly increased after OGD treatment.However,the activation of Akt and GSK3β was greatly inhibited.Preconditioning could inhibit the increase of Cbl-b caused by OGD and increase the activation of Akt and GSK3β.LY294002,a specific inhibitor of PI3K,could effectively inhibit the increase of Akt and GSK3β after preconditioning treatment.It partly inhibited the decrease of Cbl-b expression after preconditioning treatment.Conclusion Ubiquitin ligase Cbl-b and PI3K/Akt pathway are differently involved in OGDPC in PC12 cells.

  15. Targeting the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway: an emerging treatment strategy for squamous cell lung carcinoma.

    Science.gov (United States)

    Beck, Joseph Thaddeus; Ismail, Amen; Tolomeo, Christina

    2014-09-01

    Squamous cell lung carcinoma accounts for approximately 30% of all non-small cell lung cancers (NSCLCs). Despite progress in the understanding of the biology of cancer, cytotoxic chemotherapy remains the standard of care for patients with squamous cell lung carcinoma, but the prognosis is generally poor. The phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway is one of the most commonly activated signaling pathways in cancer, leading to cell proliferation, survival, and differentiation. It has therefore become a major focus of clinical research. Various alterations in the PI3K/AKT/mTOR pathway have been identified in squamous cell lung carcinoma and a number of agents targeting these alterations are in clinical development for use as single agents and in combination with other targeted and conventional treatments. These include pan-PI3K inhibitors, isoform-specific PI3K inhibitors, AKT inhibitors, mTOR inhibitors, and dual PI3K/mTOR inhibitors. These agents have demonstrated antitumor activity in preclinical models of NSCLC and preliminary clinical evidence is also available for some agents. This review will discuss the role of the PI3K/AKT/mTOR pathway in cancer and how the discovery of genetic alterations in this pathway in patients with squamous cell lung carcinoma can inform the development of targeted therapies for this disease. An overview of ongoing clinical trials investigating PI3K/AKT/mTOR pathway inhibitors in squamous cell lung carcinoma will also be included.

  16. PI3K/Akt pathway involving into apoptosis and invasion in human colon cancer cells LoVo.

    Science.gov (United States)

    Jiang, Qun Guang; Li, Tai Yuan; Liu, Dong Ning; Zhang, Hai Tao

    2014-05-01

    In this study we determined the effects of Curcumin on human colon cancer cells line LoVo. We found that Curcumin significantly inhibited the proliferation, migration and invasion, and clone formation of LoVo cells in a dose-dependent manner. Curcumin also dose-dependently reduced the phosphorylation of proteins Akt and increased expression levels of the genes caspase-3, cytochrome-c, Bax mRNA in LoVo cells. In addition, Curcumin dose-dependently decreased gene Bcl-2 mRNA expression. Similar results were observed in LoVo cells treated with LY294002. These in vitro studies suggest that Curcumin may play its anti-cancer actions partly via suppressing PI3K/Akt signal pathway in LoVo cells.

  17. Neuroprotective effects of salidroside through PI3K/Akt pathway activation in Alzheimer’s disease models

    Science.gov (United States)

    Zhang, Bei; Wang, Ying; Li, Hui; Xiong, Ran; Zhao, Zongbo; Chu, Xingkun; Li, Qiongqiong; Sun, Suya; Chen, Shengdi

    2016-01-01

    Alzheimer’s disease (AD) is a devastating neurodegenerative disorder characterized by deposits of aggregated amyloid-β (Aβ) peptide and neurofibrillary tangles in the brain parenchyma. Despite considerable research to elucidate the pathological mechanisms and identify therapeutic strategies for AD, effective treatments are still lacking. In the present study, we found that salidroside (Sal), a phenylpropanoid glycoside isolated from Rhodiola rosea L., can protect against Aβ-induced neurotoxicity in four transgenic Drosophila AD models. Both longevity and locomotor activity were improved in Sal-fed Drosophila. Sal also decreased Aβ levels and Aβ deposition in brain and ameliorated toxicity in Aβ-treated primary neuronal culture. The neuroprotective effect of Sal was associated with upregulated phosphatidylinositide 3-kinase (PI3K)/Akt signaling. Our findings identify a compound that may possess potential therapeutic benefits for AD and other forms of neurodegeneration. PMID:27103787

  18. Anti-inflammatory effect of honokiol is mediated by PI3K/Akt pathway suppression1

    Institute of Scientific and Technical Information of China (English)

    Byung Hun KIM; Jae Youl CHO

    2008-01-01

    Aim: In this study, we investigated the regulatory effects of honokiol on various inflammatory events mediated by monocytes/macrophages (U937/RAW264.7 cells)and lymphocytes (splenic lymphocytes and CTLL-2 cells) and their putative ac-tion mechanism. Methods: In order to investigate the regulatory effects, various cell lines and primary cells (U937, RAW264.7, CTLL-2 cells, and splenic lymphocytes) were employed and various inflammatory events, such as the pro-duction of inflammatory mediators, cell adhesion, cell proliferation, and the early signaling cascade, were chosen. Results: Honokiol strongly inhibited various inflammatory responses, such as: (ⅰ) the upregulation of nitric oxide (NO), pros-taglandin.E2 and TNF-α production and costimulatory molecule CD80 induced by lipopolysaccharide (LPS); (ⅱ) the functional activation of β1-integrin (CD29) as-sessed by U937 cell-cell and cell-fibronectin adhesions; (ⅲ) the enhancement of lymphocytes and CD8+CTLL-2 cell proliferation stimulated by LPS, phytohemaglutinin A (PHA), and concanavalin A or interleukin (IL)-2; and (ⅳ) the transcriptional upregulation of inducible NO synthase, TNF-α, cyclooxygenase-2, IL-12, and monocyte chemoattractant protein (MCP)-1. These anti-inflammatory effects of honokiol seem to be mediated by interrupting the early activated intra-cellular signaling molecule phosphoinositide 3-kinase (PI3K)/Akt, but not Src, the extracellular signal-regulated kinase, and p38, according to pharmacological, biochemical, and functional analyses. Conclusion: These results suggest that honokiol may act as a potent anti-inflammatory agent with multipotential activities due to an inhibitory effect on the PI3K/Akt pathway.

  19. Protection of chlorophyllin against oxidative damage by inducing HO-1 and NQO1 expression mediated by PI3K/Akt and Nrf2.

    Science.gov (United States)

    Zhang, Yanlin; Guan, Li; Wang, Xifu; Wen, Tao; Xing, Junjie; Zhao, Jinyuan

    2008-04-01

    Green vegetables are thought to have a chemoprotective effect on the basis of epidemiologic evidence. This study investigated whether chlorophyllin (CHL) could induce antioxidant enzymes and confer protection against oxidative damage. The results showed that CHL could induce HO-1 and NQO1 expression in human umbilical vein endothelial cell (HUVEC) in a time- and dose-dependent manner and protect them against hydrogen peroxide caused oxidative damage. The induction of HO-1 and NQO1 by CHL was accompanied with the accumulation of transcription factor Nrf2 in nucleus and the activation of PI3K/Akt signalling pathway. Additionally, the specific inhibitor of PI3K/Akt could obviously decrease not only the induced expression of HO-1 and NQO1 but also the antioxidant effect of CHL. In conclusion, this study proved that CHL exerts antioxidant effect by inducing HO-1 and NQO1 expression mediated by PI3K/Akt and Nrf2. One thinks CHL may have promise to be prophylactic pharmaceuticals without adverse effects.

  20. Antitumor Activity of Tenacissoside H on Esophageal Cancer through Arresting Cell Cycle and Regulating PI3K/Akt-NF-κB Transduction Cascade.

    Science.gov (United States)

    Jia, Yong-Sen; Hu, Xue-Qin; Gabriella, Hegyi; Qin, Li-Juan; Meggyeshazi, Nora

    2015-01-01

    Objective. The purpose of the study was to elucidate the molecular mechanism of tenacissoside H (TDH) inhibiting esophageal carcinoma infiltration and proliferation. Methods. In vitro, EC9706 cells were treated with TDH. Cells proliferation and cell cycle were assayed. PI3K and NF-κB mRNAs expression were determined by real time PCR. In vivo, model of nude mice with tumor was established. Mice were treated with TDH. Inhibition ratio of tumor volume was calculated. PCNA expression was examined. Protein expression in PI3K/Akt-NF-κB signaling pathway was determined. Results. In vitro, TDH significantly inhibited cells proliferation in a time-and-dose-dependent manner. TDH arrested the cell cycle in S phase and significantly inhibited PI3K and NF-κB mRNA expression, compared with blank controlled group (P TDH strongly inhibits tumor growth and volume. PCNA expression was significantly decreased after treatment of TDH. TDH downregulated proteins expression in PI3K/Akt-NF-κB transduction cascade (P TDH inhibited esophageal carcinoma infiltration and proliferation both in vitro and in vivo. The anticancer activity has relation to arresting the cell cycle at the S phase, inhibited the PCNA expression of transplanted tumors in nude mice, and regulated the protein expression in the PI3K/Akt-NF-κB transduction cascade.

  1. Naringin inhibits TNF-α induced oxidative stress and inflammatory response in HUVECs via Nox4/NF-κ B and PI3K/Akt pathways.

    Science.gov (United States)

    Li, Wenshuang; Wang, Changyuan; Peng, Jinyong; Liang, Jing; Jin, Yue; Liu, Qi; Meng, Qiang; Liu, Kexin; Sun, Huijun

    2014-01-01

    In the development of atherosclerosis, naringin has exhibited potential protective effects. However, the specific mechanisms are not clearly understood. The aim of this trial was to determine the anti-oxidative and anti-inflammatory effects of naringin and uncover the mechanisms in Tumor Necrosis Factor-alpha (TNF-α) induced Human Umbilical Vein Endothelial Cells (HUVECs). Reactive Oxygen Species (ROS) were measured by flow cytometry assay. The levels of NADPH oxidase 4 (Nox4), p22(phox), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) over-expressions were measured by qRT-PCR and Western blotting analyses. Activation of Phosphatidylinositol 3-kinase/Akt (PI3K/Akt) and Nuclear Factor-κB (NF-κB) was evaluated by Western blotting. Naringin inhibited ROS production as well as over-expression levels of Nox4, p22(phox) induced by TNF-α. Naringin inhibited TNF-α induced mRNA and protein over-expressions of ICAM-1 and VCAM-1. Naringin also suppressed activation of NF-κB and PI3K/Akt signaling pathways. These results indicated the preventive effects of naringin on HUVECs injury caused by oxidative stress and inflammation response and the effects might be obtained via inhibition of Nox4 and NF-κB pathways as well as activation of PI3K/Akt pathway. Naringin may be useful in preventing endothelial dysfunction, therefore to ameliorate the development of atherosclerosis.

  2. Microcystin-LR promotes epithelial-mesenchymal transition in colorectal cancer cells through PI3-K/AKT and SMAD2.

    Science.gov (United States)

    Ren, Yan; Yang, Mengli; Chen, Meng; Zhu, Qiangqiang; Zhou, Lihua; Qin, Wei; Wang, Ting

    2017-01-04

    Increasing evidences suggest that microcystins, a kind of toxic metabolites, produced by cyanobacteria in contaminated water may contribute to the aggravation of the human colorectal carcinoma. Our previous study showed that microcystin-LR (MC-LR) exposure caused significant invasion and migration of colorectal cancer cells. However, the roles of MC-LR in regulating epithelial-mesenchymal transition (EMT) in colorectal cancer cells remain unknown. In our study, we observed that MC-LR treatment decreased epithelial marker E-cadherin expression and up-regulated the levels of mesenchymal markers Vimentin and Snail in colorectal cancer cells. Moreover, MC-LR stimulated protein expression of SMAD2 and phospho-SMAD2 by PI3-K/AKT activation. The activated PI3-K/AKT and SMAD2 signaling largely accounted for MC-LR-induced EMT, which could be reversed by SMAD2 RNA interference or PI3-K/AKT chemical inhibitor in colorectal cancer cells. Our results show that MC-LR could induce SMAD2 expression to promote colorectal cancer cells EMT, which not only provides a mechanistic insight on MC-LR promotes EMT in colorectal cancer cells, but also support to the development of therapies aimed at SMAD2 in colorectal cancer induced by MC-LR. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Antitumor Activity of Tenacissoside H on Esophageal Cancer through Arresting Cell Cycle and Regulating PI3K/Akt-NF-κB Transduction Cascade

    Directory of Open Access Journals (Sweden)

    Yong-sen Jia

    2015-01-01

    Full Text Available Objective. The purpose of the study was to elucidate the molecular mechanism of tenacissoside H (TDH inhibiting esophageal carcinoma infiltration and proliferation. Methods. In vitro, EC9706 cells were treated with TDH. Cells proliferation and cell cycle were assayed. PI3K and NF-κB mRNAs expression were determined by real time PCR. In vivo, model of nude mice with tumor was established. Mice were treated with TDH. Inhibition ratio of tumor volume was calculated. PCNA expression was examined. Protein expression in PI3K/Akt-NF-κB signaling pathway was determined. Results. In vitro, TDH significantly inhibited cells proliferation in a time-and-dose-dependent manner. TDH arrested the cell cycle in S phase and significantly inhibited PI3K and NF-κB mRNA expression, compared with blank controlled group (P<0.05. In vivo, TDH strongly inhibits tumor growth and volume. PCNA expression was significantly decreased after treatment of TDH. TDH downregulated proteins expression in PI3K/Akt-NF-κB transduction cascade (P<0.05. Conclusion. TDH inhibited esophageal carcinoma infiltration and proliferation both in vitro and in vivo. The anticancer activity has relation to arresting the cell cycle at the S phase, inhibited the PCNA expression of transplanted tumors in nude mice, and regulated the protein expression in the PI3K/Akt-NF-κB transduction cascade.

  4. The PI3K/Akt pathway is involved in early infection of some exogenous avian leukosis viruses.

    Science.gov (United States)

    Feng, Shao-zhen; Cao, Wei-sheng; Liao, Ming

    2011-07-01

    Avian leukosis virus (ALV) is an enveloped and oncogenic retrovirus. Avian leukosis caused by the members of ALV subgroups A, B and J has become one of the major problems challenging the poultry industry in China. However, the cellular factors such as signal transduction pathways involved in ALV infection are not well defined. In this study, our data demonstrated that ALV-J strain NX0101 infection in primary chicken embryo fibroblasts or DF-1 cells was correlated with the activity and phosphorylation of Akt. Akt activation was initiated at a very early stage of infection independently of NX0101 replication. The specific phosphatidylinositol 3-kinase (PI3K) inhibitors LY294002 or wortmannin could suppress Akt phosphorylation, indicating that NX0101-induced Akt phosphorylation is PI3K-dependent. ALV-A strain GD08 or ALV-B strain CD08 infection also demonstrated a similar profile of PI3K/Akt activation. Treatment of DF-1 cells with the drug 5-(N, N-hexamethylene) amiloride that inhibits the activity of chicken Na(+)/H(+) exchanger type 1 significantly reduced Akt activation induced by NX0101, but not by GD08 and CD08. Akt activation triggered by GD08 or CD08 was abolished by clathrin-mediated endocytosis inhibitor chlorpromazine. Receptor-mediated endocytosis inhibitor dansylcadaverine had a negligible effect on all ALV-induced Akt phosphorylation. Moreover, viral replication of ALV was suppressed by LY294002 in a dose-dependent manner, which was due to the inhibition of virus infection by LY294002. These data suggest that the activation of the PI3K/Akt signalling pathway by exogenous ALV infection plays an important role in viral entry, yet the precise mechanism remains under further investigation.

  5. PKD1 mediates negative feedback of PI3K/Akt activation in response to G protein-coupled receptors.

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    Yang Ni

    Full Text Available We examined whether protein kinase D1 (PKD1 mediates negative feeback of PI3K/Akt signaling in intestinal epithelial cells stimulated with G protein-coupled receptor (GPCR agonists. Exposure of intestinal epithelial IEC-18 cells to increasing concentrations of the PKD family inhibitor kb NB 142-70, at concentrations that inhibited PKD1 activation, strikingly potentiated Akt phosphorylation at Thr(308 and Ser(473 in response to the mitogenic GPCR agonist angiotensin II (ANG II. Enhancement of Akt activation by kb NB 142-70 was also evident in cells with other GPCR agonists, including vasopressin and lysophosphatidic acid. Cell treatment with the structurally unrelated PKD family inhibitor CRT0066101 increased Akt phosphorylation as potently as kb NB 142-70 [corrected]. Knockdown of PKD1 with two different siRNAs strikingly enhanced Akt phosphorylation in response to ANG II stimulation in IEC-18 cells. To determine whether treatment with kb NB 142-70 enhances accumulation of phosphatidylinositol (3,4,5-trisphosphate (PIP3 in the plasma membrane, we monitored the redistribution of Akt-pleckstrin homology domain-green fluorescent protein (Akt-PH-GFP in single IEC-18 cells. Exposure to kb NB 142-70 strikingly increased membrane accumulation of Akt-PH-GFP in response to ANG II. The translocation of the PIP3 sensor to the plasma membrane and the phosphorylation of Akt was completed prevented by prior exposure to the class I p110α specific inhibitor A66. ANG II markedly increased the phosphorylation of p85α detected by a PKD motif-specific antibody and enhanced the association of p85α with PTEN. Transgenic mice overexpressing PKD1 showed a reduced phosphorylation of Akt at Ser(473 in intestinal epithelial cells compared to wild type littermates. Collectively these results indicate that PKD1 activation mediates feedback inhibition of PI3K/Akt signaling in intestinal epithelial cells in vitro and in vivo.

  6. COX-2 Induces Breast Cancer Stem Cells via EP4/PI3K/AKT/NOTCH/WNT Axis.

    Science.gov (United States)

    Majumder, Mousumi; Xin, Xiping; Liu, Ling; Tutunea-Fatan, Elena; Rodriguez-Torres, Mauricio; Vincent, Krista; Postovit, Lynne-Marie; Hess, David; Lala, Peeyush K

    2016-09-01

    Cancer stem-like cells (SLC) resist conventional therapies, necessitating searches for SLC-specific targets. We established that cyclo-oxygenase(COX)-2 expression promotes human breast cancer progression by activation of the prostaglandin(PG)E-2 receptor EP4. Present study revealed that COX-2 induces SLCs by EP4-mediated NOTCH/WNT signaling. Ectopic COX-2 over-expression in MCF-7 and SKBR-3 cell lines resulted in: increased migration/invasion/proliferation, epithelial-mesenchymal transition (EMT), elevated SLCs (spheroid formation), increased ALDH activity and colocalization of COX-2 and SLC markers (ALDH1A, CD44, β-Catenin, NANOG, OCT3/4, SOX-2) in spheroids. These changes were reversed with COX-2-inhibitor or EP4-antagonist (EP4A), indicating dependence on COX-2/EP4 activities. COX-2 over-expression or EP4-agonist treatments of COX-2-low cells caused up-regulation of NOTCH/WNT genes, blocked with PI3K/AKT inhibitors. NOTCH/WNT inhibitors also blocked COX-2/EP4 induced SLC induction. Microarray analysis showed up-regulation of numerous SLC-regulatory and EMT-associated genes. MCF-7-COX-2 cells showed increased mammary tumorigenicity and spontaneous multiorgan metastases in NOD/SCID/IL-2Rγ-null mice for successive generations with limiting cell inocula. These tumors showed up-regulation of VEGF-A/C/D, Vimentin and phospho-AKT, down-regulation of E-Cadherin and enrichment of SLC marker positive and spheroid forming cells. MCF-7-COX-2 cells also showed increased lung colonization in NOD/SCID/GUSB-null mice, an effect reversed with EP4-knockdown or EP4A treatment of the MCF-7-COX-2 cells. COX-2/EP4/ALDH1A mRNA expression in human breast cancer tissues were highly correlated with one other, more marked in progressive stage of disease. In situ immunostaining of human breast tumor tissues revealed co-localization of SLC markers with COX-2, supporting COX-2 inducing SLCs. High COX-2/EP4 mRNA expression was linked with reduced survival. Thus, EP4 represents a novel SLC

  7. Spatholobus suberectus Column Extract Inhibits Estrogen Receptor Positive Breast Cancer via Suppressing ER MAPK PI3K/AKT Pathway

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    Jia-Qi Sun

    2016-01-01

    Full Text Available Although Chinese herbal compounds have long been alternatively applied for cancer treatment in China, their treatment effects have not been sufficiently investigated. The Chinese herb Spatholobus suberectus is commonly prescribed to cancer patients. HPLC analysis has shown that the main components of Spatholobus suberectus are flavonoids that can be classified as phytoestrogens, having a structure similar to estrogen. This study was designed to investigate the effects of Spatholobus suberectus column extract (SSCE on the estrogen receptor-positive (ER+ breast cancer cell line MCF-7 and its possible molecular mechanism. In our study, MTT assay was performed to evaluate cell viability. The results show that SSCE (80, 160, and 320 μg/ml significantly decreased the viability of MCF-7 cells. SSCE also triggered apoptosis, arrested the cell cycle at the G0/G1 phase, and inhibited cell migration. A dual-luciferase reporter system showed that SSCE suppressed intranuclear p-ER activity; Western blot analysis confirmed the repressed expression of phosphorylated-ER alpha (p-ERα, ERK1/2, p-ERK1/2, AKT, p-AKT, p-mTOR, PI3K, and p-PI3K, indicating that SSCE suppressed the MAPK PI3K/AKT signaling pathway. Collectively, our results suggest that SSCE causes apoptosis, an arrest in the G0/G1 phase, and a decrease in migration in ER+ MCF-7 cells via hypoactivity of the ER and suppression of the MAPK PI3K/AKT pathway.

  8. Placental growth factor enhances angiogenesis in human intestinal microvascular endothelial cells via PI3K/Akt pathway: Potential implications of inflammation bowel disease

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yi, E-mail: mondayzy@126.com; Tu, Chuantao, E-mail: tu.chuantao@zs-hospital.sh.cn; Zhao, Yuan, E-mail: zhao.yuan@zs-hospital.sh.cn; Liu, Hongchun, E-mail: liuhch@aliyun.com; Zhang, Shuncai, E-mail: zhang.shuncai@zs-hospital.sh.cn

    2016-02-19

    Background: Angiogenesis plays a major role in the pathogenesis of inflammatory bowel disease (IBD). Placental growth factor (PlGF) is a specific regulator of pathological angiogenesis and is upregulated in the sera of IBD patients. Therefore, the role of PlGF in IBD angiogenesis was investigated here using HIMECs. Methods: The expression of PlGF and its receptors in human intestinal microvascular endothelial cells (HIMECs) and inflamed mucosa of IBD patients were examined using quantitative PCR and western blot analysis and the role of PlGF in IBD HIMECs was further explored using small interfering RNA (siRNA). The induction of pro-inflammatory cytokine by PlGF in HIMECs was confirmed by ELISA. The capacity of PlGF to induce angiogenesis in HIMECs was tested through proliferation, cell-migration, matrigel tubule-formation assays and its underlying signaling pathway were explored by western blot analysis of ERK1/2 and PI3K/Akt phosphorylation. Results: mRNA and protein expression of PlGF and its receptor NRP-1 were significantly increased in IBD HIMECs. Inflamed mucosa of IBD patients also displayed higher expression of PIGF. The production of IL-6 and TNF-α in culture supernatant of HIMECs treated with exogenous recombinant human PlGF-1 (rhPlGF-1) were increased. Furthermore, rhPlGF-1 significantly induced HIMECs migration and tube formation in a dose-dependent manner and knockdown of endogenous PlGF in IBD HIMECs using siRNA substantially reduced these angiogenesis activities. PlGF induced PI3K/Akt phosphorylation in HIMECs and pretreatment of PlGF-stimulated HIMECs with PI3K inhibitor (LY294002) significantly inhibited the PlGF-induced cell migration and tube formation. Conclusion: Our results demonstrated the pro-inflammatory and angiogenic effects of PlGF on HIMECs in IBD through activation of PI3K/Akt signaling pathway. PlGF/PI3K/Akt signaling may serve as a potential therapeutic target for IBD. - Highlights: • Expression of PlGF and its receptor NRP-1

  9. Regulation of ENaC-mediated alveolar fluid clearance by insulin via PI3K/Akt pathway in LPS-induced acute lung injury

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    Deng Wang

    2012-03-01

    Full Text Available Abstract Background Stimulation of epithelial sodium channel (ENaC increases Na+ transport, a driving force of alveolar fluid clearance (AFC to keep alveolar spaces free of edema fluid that is beneficial for acute lung injury (ALI. It is well recognized that regulation of ENaC by insulin via PI3K pathway, but the mechanism of this signaling pathway to regulate AFC and ENaC in ALI remains unclear. The aim of this study was to investigate the effect of insulin on AFC in ALI and clarify the pathway in which insulin regulates the expression of ENaC in vitro and in vivo. Methods A model of ALI (LPS at a dose of 5.0 mg/kg with non-hyperglycemia was established in Sprague-Dawley rats receiving continuous exogenous insulin by micro-osmotic pumps and wortmannin. The lungs were isolated for measurement of bronchoalveolar lavage fluid(BALF, total lung water content(TLW, and AFC after ALI for 8 hours. Alveolar epithelial type II cells were pre-incubated with LY294002, Akt inhibitor and SGK1 inhibitor 30 minutes before insulin treatment for 2 hours. The expressions of α-,β-, and γ-ENaC were detected by immunocytochemistry, reverse transcriptase polymerase chain reaction (RT-PCR and western blotting. Results In vivo, insulin decreased TLW, enchanced AFC, increased the expressions of α-,β-, and γ-ENaC and the level of phosphorylated Akt, attenuated lung injury and improved the survival rate in LPS-induced ALI, the effects of which were blocked by wortmannin. Amiloride, a sodium channel inhibitor, significantly reduced insulin-induced increase in AFC. In vitro, insulin increased the expressions of α-,β-, and γ-ENaC as well as the level of phosphorylated Akt but LY294002 and Akt inhibitor significantly prevented insulin-induced increase in the expression of ENaC and the level of phosphorylated Akt respectively. Immunoprecipitation studies showed that levels of Nedd4-2 binding to ENaC were decreased by insulin via PI3K/Akt pathway. Conclusions Our study

  10. L-arginine stimulates fibroblast proliferation through the GPRC6A-ERK1/2 and PI3K/Akt pathway.

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    Takashi Fujiwara

    Full Text Available L-arginine is considered a conditionally essential amino acid and has been shown to enhance wound healing. However, the molecular mechanisms through which arginine stimulates cutaneous wound repair remain unknown. Here, we evaluated the effects of arginine supplementation on fibroblast proliferation, which is a key process required for new tissue formation. We also sought to elucidate the signaling pathways involved in mediating the effects of arginine on fibroblasts by evaluation of extracellular signal-related kinase (ERK 1/2 activation, which is important for cell growth, survival, and differentiation. Our data demonstrated that addition of 6 mM arginine significantly enhanced fibroblast proliferation, while arginine deprivation increased apoptosis, as observed by enhanced DNA fragmentation. In vitro kinase assays demonstrated that arginine supplementation activated ERK1/2, Akt, PKA and its downstream target, cAMP response element binding protein (CREB. Moreover, knockdown of GPRC6A using siRNA blocked fibroblast proliferation and decreased phosphorylation of ERK1/2, Akt and CREB. The present experiments demonstrated a critical role for the GPRC6A-ERK1/2 and PI3K/Akt signaling pathway in arginine-mediated fibroblast survival. Our findings provide novel mechanistic insights into the positive effects of arginine on wound healing.

  11. PI3K/AKT/mTOR: role in breast cancer progression, drug resistance, and treatment.

    Science.gov (United States)

    Guerrero-Zotano, Angel; Mayer, Ingrid A; Arteaga, Carlos L

    2016-12-01

    Anti-cancer cancer-targeted therapies are designed to exploit a particular vulnerability in the tumor, which in most cases results from its dependence on an oncogene and/or loss of a tumor suppressor. Mutations in the phosphoinositide 3-kinase (PI3K)/AKT/mTOR pathway are freqcuently found in breast cancers and associated with cellular transformation, tumorigenesis, cancer progression, and drug resistance. Several drugs targeting PI3K/ATK/mTOR are currently in clinical trials, mainly in combination with endocrine therapy and anti-HER2 therapy. These drugs are the focus of this review.

  12. IGF-1 promotes Brn-4 expression and neuronal differentiation of neural stem cells via the PI3K/Akt pathway.

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    Xinhua Zhang

    Full Text Available Our previous studies indicated that transcription factor Brn-4 is upregulated in the surgically denervated hippocampus in vivo, promoting neuronal differentiation of hippocampal neural stem cells (NSCs in vitro. The molecules mediating Brn-4 upregulation in the denervated hippocampus remain unknown. In this study we examined the levels of insulin-like growth factor-1 (IGF-1 in hippocampus following denervation. Surgical denervation led to a significant increase in IGF-1 expression in vivo. We also report that IGF-1 treatment on NSCs in vitro led to a marked acceleration of Brn-4 expression and cell differentiation down neuronal pathways. The promotion effects were blocked by PI3K-specific inhibitor (LY294002, but not MAPK inhibitor (PD98059; levels of phospho-Akt were increased by IGF-1 treatment. In addition, inhibition of IGF-1 receptor (AG1024 and mTOR (rapamycin both attenuated the increased expression of Brn-4 induced by IGF-1. Together, the results demonstrated that upregulation of IGF-1 induced by hippocampal denervation injury leads to activation of the PI3K/Akt signaling pathway, which in turn gives rise to upregulation of the Brn-4 and subsequent stem cell differentiation down neuronal pathways.

  13. PI3K/Akt/mTOR inhibitors in breast cancer

    Institute of Scientific and Technical Information of China (English)

    Joycelyn JX Lee; Kiley Loh; Yoon-Sim Yap

    2015-01-01

    Activation of the phosphoinositide 3 kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is common in breast cancer. hTere is preclinical data to support inhibition of the pathway, and phase I to III trials involving inhibitors of the pathway have been or are being conducted in solid tumors and breast cancer. Everolimus, an mTOR inhibitor, is currently approved for the treatment of hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. In this review, we summarise the efficacy and toxicity findings from the randomised clinical trials, with simpliifed guidelines on the management of potential adverse effects. Education of healthcare professionals and patients is critical for safety and compliance. While there is some clinical evidence of activity of mTOR inhibition in HR-positive and HER2-positive breast cancers, the benefits may be more pronounced in selected subsets rather than in the overall population. Further development of predictive biomarkers will be useful in the selection of patients who will beneift from inhibition of the PI3K/Akt/mTOR (PAM) pathway.

  14. Danusertib, a potent pan-Aurora kinase and ABL kinase inhibitor, induces cell cycle arrest and programmed cell death and inhibits epithelial to mesenchymal transition involving the PI3K/Akt/mTOR-mediated signaling pathway in human gastric cancer AGS and NCI-N78 cells

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    Yuan CX

    2015-03-01

    autophagy-inducing effects on AGS and NCI-N78 cells. Danusertib arrested AGS and NCI-N78 cells in G2/M phase, with downregulation of expression of cyclin B1 and cyclin-dependent kinase 1 and upregulation of expression of p21 Waf1/Cip1, p27 Kip1, and p53. Danusertib induced mitochondria-mediated apoptosis, with an increase in expression of proapoptotic protein and a decrease in antiapoptotic proteins in both cell lines. Danusertib induced release of cytochrome c from the mitochondria to the cytosol and triggered activation of caspase 9 and caspase 3 in AGS and NCI-N78 cells. Further, danusertib induced autophagy, with an increase in expression of beclin 1 and conversion of microtubule-associated protein 1A/1B-light chain 3 (LC3-I to LC3-II in both cell lines. Inhibition of phosphatidylinositol 3-kinase (PI3K/protein kinase B (Akt/mammalian target of rapamycin (mTOR and p38 mitogen-activated protein kinase pathways as well as activation of 5' AMP-activated protein kinase contributed to the proautophagic effect of danusertib in AGS and NCI-N78 cells. SB202191 and wortmannin enhanced the autophagy-inducing effect of danusertib in AGS and NCI-N78 cells. In addition, danusertib inhibited epithelial to mesenchymal transition with an increase in expression of E-cadherin and a decrease in expression of N-cadherin in both cell lines. Taken together, danusertib has potent inducing effects on cell cycle arrest, apoptosis, and autophagy, but has an inhibitory effect on epithelial to mesenchymal transition, with involvement of signaling pathways mediated by PI3K/Akt/mTOR, p38 mitogen-activated protein kinase, and 5' AMP-activated protein kinase in AGS and NCI-N78 cells. Keywords: danusertib, gastric cancer, Aurora kinase, apoptosis, autophagy, epithelial to mesenchymal transition

  15. Target regulation of PI3K/Akt/mTOR pathway by cannabidiol in treatment of experimental multiple sclerosis.

    Science.gov (United States)

    Giacoppo, Sabrina; Pollastro, Federica; Grassi, Gianpaolo; Bramanti, Placido; Mazzon, Emanuela

    2017-01-01

    This study was aimed to investigate whether treatment with purified cannabidiol (CBD) may counteract the development of experimental multiple sclerosis (MS), by targeting the PI3K/Akt/mTOR pathway. Although the PI3K/Akt/mTOR pathway was found to be activated by cannabinoids in several immune and non-immune cells, currently, there is no data about the effects of CBD in the PI3K/Akt/mTOR activity in MS. Experimental Autoimmune Encephalomyelitis (EAE), the most common model of MS, was induced in C57BL/6 mice by immunization with myelin oligodendroglial glycoprotein peptide (MOG)35-55. After EAE onset, which occurs approximately 14days after disease induction, mice were daily intraperitoneally treated with CBD (10mg/kg mouse) and observed for clinical signs of EAE. At 28days from EAE-induction, mice were euthanized and spinal cord tissues were sampled to perform immunohistochemical evaluations and western blot analysis. Our results showed a clear downregulation of the PI3K/Akt/mTOR pathway following EAE induction. CBD treatment was able to restore it, increasing significantly the phosphorylation of PI3K, Akt and mTOR. Also, an increased level of BNDF in CBD-treated mice seems to be involved in the activation of PI3K/Akt/mTOR pathway. In addition, our data demonstrated that therapeutic efficacy of CBD treatment is due to reduction of pro-inflammatory cytokines, like IFN-γ and IL-17 together with an up-regulation of PPARγ. Finally, CBD was found to promote neuronal survival by inhibiting JNK and p38 MAP kinases. These results provide an interesting discovery about the regulation of the PI3K/Akt/mTOR pathway by cannabidiol administration, that could be a new potential therapeutic target for MS management.

  16. Interleukin-10-induced gene expression and suppressive function are selectively modulated by the PI3K-Akt-GSK3 pathway

    Science.gov (United States)

    Antoniv, Taras T; Ivashkiv, Lionel B

    2011-01-01

    Interleukin-10 (IL-10) is an immunosuppressive cytokine that inhibits inflammatory gene expression. Phosphatidylinositol 3-kinase (PI3K) -mediated signalling regulates inflammatory responses and can induce IL-10 production, but a role for PI3K signalling in cellular responses to IL-10 is not known. In this study we investigated the involvement of the PI3K-Akt-GSK3 signalling pathway in IL-10-induced gene expression and IL-10-mediated suppression of Toll-like receptor-induced gene expression in primary human macrophages. A combination of loss and gain of function approaches using kinase inhibitors, expression of constitutively active Akt, and RNA interference in primary human macrophages showed that expression of a subset of IL-10-inducible genes was dependent on PI3K-Akt signalling. The effects of PI3K-Akt signalling on IL-10 responses were mediated at least in part by glycogen synthase kinase 3 (GSK3). In accordance with a functional role for PI3K pathways in contributing to the suppressive actions of IL-10, PI3K signalling augmented IL-10-mediated inhibition of lipopolysaccharide-induced IL-1, IL-8 and cyclo-oxygenase-2 expression. The PI3K signalling selectively modulated IL-10 responses, as it was not required for inhibition of tumour necrosis factor expression or for induction of certain IL-10-inducible genes such as SOCS3. These findings identify a new mechanism by which PI3K-mediated signalling can suppress inflammation by regulating IL-10-mediated gene induction and anti-inflammatory function. PMID:21255011

  17. Saposin C promotes survival and prevents apoptosis via PI3K/Akt-dependent pathway in prostate cancer cells

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    Lee Tae-Jin

    2004-11-01

    Full Text Available Abstract Background In addition to androgens, growth factors are also implicated in the development and neoplastic growth of the prostate gland. Prosaposin is a potent neurotrophic molecule. Homozygous inactivation of prosaposin in mice has led to the development of a number of abnormalities in the male reproductive system, including atrophy of the prostate gland and inactivation of mitogen-activated protein kinase (MAPK and Akt in prostate epithelial cells. We have recently reported that prosaposin is expressed at a higher level by androgen-independent (AI prostate cancer cells as compared to androgen-sensitive prostate cancer cells or normal prostate epithelial and stromal cells. In addition, we have demonstrated that a synthetic peptide (prosaptide TX14A, derived from the trophic sequence of the saposin C domain of prosaposin, stimulated cell proliferation, migration and invasion and activated the MAPK signaling pathway in prostate cancer cells. The biological significances of saposin C and prosaposin in prostate cancer are not known. Results Here, we report that saposin C, in a cell type-specific and dose-dependent manner, acts as a survival factor, activates the Akt-signaling pathway, down-modulates caspase-3, -7, and -9 expression and/or activity, and decreases the cleaved nuclear substrate of caspase-3 in prostate cancer cells under serum-starvation stress. In addition, prosaptide TX14A, saposin C, or prosaposin decreased the growth-inhibitory effect, caspase-3/7 activity, and apoptotic cell death induced by etoposide. We also discovered that saposin C activates the p42/44 MAP kinase pathway in a pertussis toxin-sensitive and phosphatidylinositol 3-kinase (PI3K /Akt-dependent manner in prostate cancer cells. Our data also show that the anti-apoptotic activity of saposin C is at least partially mediated via PI3K/Akt signaling pathway. Conclusion We postulate that as a mitogenic, survival, and anti-apoptotic factor for prostate cancer cells

  18. Ganoderma atrum polysaccharide improves aortic relaxation in diabetic rats via PI3K/Akt pathway.

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    Zhu, Ke-Xue; Nie, Shao-Ping; Li, Chuan; Gong, Deming; Xie, Ming-Yong

    2014-03-15

    A newly identified polysaccharide (PSG-1) has been purified from Ganoderma atrum. The study was to investigate the protective effect of PSG-1 on diabetes-induced endothelial dysfunction in rat aorta. Rats were fed a high fat diet for 8 weeks and then injected with a low dose of streptozotocin to induce type 2 diabetes. The diabetic rats were orally treated with PSG-1 for 4 weeks. It was found that administration of PSG-1 significantly reduced levels of fasting blood glucose, improved endothelium-dependent aortic relaxation, increased levels of phosphoinositide 3-kinase (PI3K), phospho-Akt (p-Akt), endothelial nitric oxide synthase (eNOS) and nitric oxide in the aorta from diabetic rats, compared to un-treated diabetics. These results suggested that the protective effects of PSG-1 against endothelial dysfunction may be related to activation of the PI3K/Akt/eNOS pathway.

  19. Salvianolic acid A reverses paclitaxel resistance in human breast cancer MCF-7 cells via targeting the expression of transgelin 2 and attenuating PI3 K/Akt pathway.

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    Cai, Jiangxia; Chen, Siying; Zhang, Weipeng; Zheng, Xiaowei; Hu, Sasa; Pang, Chengsen; Lu, Jun; Xing, Jianfeng; Dong, Yalin

    2014-10-15

    Chemotherapy resistance represents a major problem for the treatment of patients with breast cancer and greatly restricts the use of first-line chemotherapeutics paclitaxel. The purpose of this study was to investigate the role of transgelin 2 in human breast cancer paclitaxel resistance cell line (MCF-7/PTX) and the reversal mechanism of salvianolic acid A (SAA), a phenolic active compound extracted from Salvia miltiorrhiza. Western blotting and real-time quantitative polymerase chain reaction (qRT-PCR) indicated that transgelin 2 may mediate paclitaxel resistance by activating the phosphatidylinositol 3-kinase (PI3 K)/Akt signaling pathway to suppress MCF-7/PTX cells apoptosis. The reversal ability of SAA was confirmed by MTT assay and flow cytometry, with a superior 9.1-fold reversal index and enhancement of the apoptotic cytotoxicity induced by paclitaxel. In addition, SAA effectively prevented transgelin 2 and adenosine-triphosphate binding cassette transporter (ABC transporter) including P-glycoprotein (P-gp), multidrug resistance associated protein 1 (MRP1), and breast cancer resistance protein (BCRP) up-regulation and exhibited inhibitory effect on PI3 K/Akt signaling pathway in MCF-7/PTX cells. Taken together, SAA can reverse paclitaxel resistance through suppressing transgelin 2 expression by mechanisms involving attenuation of PI3 K/Akt pathway activation and ABC transporter up-regulation. These results not only provide insight into the potential application of SAA in reversing paclitaxel resistance, thus facilitating the sensitivity of breast cancer chemotherapy, but also highlight a potential role of transgelin 2 in the development of paclitaxel resistance in breast cancer.

  20. Obesity enhances nongenomic estrogen receptor crosstalk with the PI3K/Akt and MAPK pathways to promote in vitro measures of breast cancer progression.

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    Bowers, Laura W; Cavazos, David A; Maximo, Ilane X F; Brenner, Andrew J; Hursting, Stephen D; deGraffenried, Linda A

    2013-01-01

    Epidemiological and clinical studies indicate that obesity is associated with a worse postmenopausal breast cancer prognosis and an increased risk of endocrine therapy resistance. However, the mechanisms mediating these effects remain poorly understood. Here we investigate the molecular pathways by which obesity-associated circulating factors in the blood enhance estrogen receptor alpha (ERα) positive breast cancer cell viability and growth. Blood serum was collected from postmenopausal breast cancer patients and pooled by body mass index (BMI) category (Control: 18.5 to 24.9 kg/m²; Obese: ≥30.0 kg/m²). The effects of patient sera on MCF-7 and T47D breast cancer cell viability and growth were examined by MTT and colony formation assays, respectively. Insulin-like growth factor receptor 1(IGF-1R), Akt, and ERK1/2 activation and genomic ERα activity were assessed to determine their possible contribution to obese patient sera-induced cell viability and growth. To further define the relative contribution of these signaling pathways, cells grown in patient sera were treated with various combinations of ERα, PI3K/Akt and MAPK targeted therapies. Comparisons between cells exposed to different experimental conditions were made using one-way analysis of variance (ANOVA) and Student's t test. Cells grown in media supplemented with obese patient sera displayed greater cell viability and growth as well as IGF-1R, Akt and ERK1/2 activation relative to control sera. Despite the lack of a significant difference in genomic ERα activity following growth in obese versus control patient sera, we observed a dramatic reduction in cell viability and growth after concurrent inhibition of the ERα and PI3K/Akt signaling pathways. Further, we demonstrated that ERα inhibition was sufficient to attenuate obese serum-induced Akt and ERK1/2 activation. Together, these data suggest that obesity promotes greater ERα positive breast cancer cell viability and growth through enhanced

  1. Epicatechin induces NF-kappaB, activator protein-1 (AP-1) and nuclear transcription factor erythroid 2p45-related factor-2 (Nrf2) via phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) and extracellular regulated kinase (ERK) signalling in HepG2 cells.

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    Granado-Serrano, Ana Belén; Martín, María Angeles; Haegeman, Guy; Goya, Luis; Bravo, Laura; Ramos, Sonia

    2010-01-01

    The dietary flavonoid epicatechin has been reported to exhibit a wide range of biological activities. The objective of the present study was to investigate the time-dependent regulation by epicatechin on the activity of the main transcription factors (NF-kappaB, activator protein-1 (AP-1) and nuclear transcription factor erythroid 2p45-related factor (Nrf2)) related to antioxidant defence and survival and proliferation pathways in HepG2 cells. Treatment of cells with 10 microm-epicatechin induced the NF-kappaB pathway in a time-dependent manner characterised by increased levels of IkappaB kinase (IKK) and phosphorylated inhibitor of kappaB subunit-alpha (p-IkappaBalpha) and proteolytic degradation of IkappaB, which was consistent with an up-regulation of the NF-kappaB-binding activity. Time-dependent activation of the AP-1 pathway, in concert with enhanced c-Jun nuclear levels and induction of Nrf2 translocation and phosphorylation were also demonstrated. Additionally, epicatechin-induced NF-kappaB and Nrf2 were connected to reactive oxygen species intracellular levels and to the activation of cell survival and proliferation pathways, being phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) and extracellular regulated kinase (ERK) associated to Nrf2 modulation and ERK to NF-kappaB induction. These data suggest that the epicatechin-induced survival effect occurs by the induction of redox-sensitive transcription factors through a tight regulation of survival and proliferation pathways.

  2. Cucurbitacin E inhibits TNF-α-induced inflammatory cytokine production in human synoviocyte MH7A cells via suppression of PI3K/Akt/NF-κB pathways.

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    Jia, Qingyun; Cheng, Wenxiang; Yue, Ye; Hu, Yipping; Zhang, Jian; Pan, Xiaohua; Xu, Zhanwang; Zhang, Peng

    2015-12-01

    Increasing studies indicated that Cucurbitacin E (CuE), a compound isolated from Cucurbitaceae, has been shown anti-inflammatory effect. However, the effect of CuE on rheumatoid arthritis (RA) inflammatory response and its potential molecular mechanism are still unknown. In this study, we demonstrated that CuE significantly suppressed TNF-α-induced inflammatory cytokines production interleukin-1β (IL-1β), interleukin-6 (IL-6), and interleukin-8 (IL-8) mRNA and protein expression in human synoviocyte MH7A cells. Furthermore, we found that CuE also inhibited TNF-α-induced phosphorylation of NF-κBp65, IKKα/β, and IκBα in a dose-and time-dependent manner as well as NF-κBp65 nuclear translocation. Finally, we showed that CuE blocked the upstream targets of NF-κB pathway RIP1/PI3K/Akt. Interestingly, PI3K inhibitor LY294002 completely blocked the TNF-α-induced activation of p85, Akt and the whole cascade of the NF-κB signaling components and suppressed inflammatory cytokines production in mRNA and protein levels similarly as CuE. Our studies provided the first evidence that CuE inhibited TNF-α-induced inflammatory cytokine production in human synoviocyte MH7A cells via modulation of PI3K/Akt/NF-κB pathway. These findings indicated that CuE is a potential candidate for RA therapy.

  3. Inhibition of protein kinase C delta attenuates allergic airway inflammation through suppression of PI3K/Akt/mTOR/HIF-1 alpha/VEGF pathway.

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    Yun Ho Choi

    Full Text Available Vascular endothelial growth factor (VEGF is supposed to contribute to the pathogenesis of allergic airway disease. VEGF expression is regulated by a variety of stimuli such as nitric oxide, growth factors, and hypoxia-inducible factor-1 alpha (HIF-1α. Recently, inhibition of the mammalian target of rapamycin (mTOR has been shown to alleviate cardinal asthmatic features, including airway hyperresponsiveness, eosinophilic inflammation, and increased vascular permeability in asthma models. Based on these observations, we have investigated whether mTOR is associated with HIF-1α-mediated VEGF expression in allergic asthma. In studies with the mTOR inhibitor rapamycin, we have elucidated the stimulatory role of a mTOR-HIF-1α-VEGF axis in allergic response. Next, the mechanisms by which mTOR is activated to modulate this response have been evaluated. mTOR is known to be regulated by phosphoinositide 3-kinase (PI3K/Akt or protein kinase C-delta (PKC δ in various cell types. Consistent with these, our results have revealed that suppression of PKC δ by rottlerin leads to the inhibition of PI3K/Akt activity and the subsequent blockade of a mTOR-HIF-1α-VEGF module, thereby attenuating typical asthmatic attack in a murine model. Thus, the present data indicate that PKC δ is necessary for the modulation of the PI3K/Akt/mTOR signaling cascade, resulting in a tight regulation of HIF-1α activity and VEGF expression. In conclusion, PKC δ may represent a valuable target for innovative therapeutic treatment of allergic airway disease.

  4. Dietary flavonoid fisetin: A novel dual inhibitor of PI3K/Akt and mTOR for prostate cancer management

    Science.gov (United States)

    Adhami, Vaqar Mustafa; Syed, Deeba; Khan, Naghma; Mukhtar, Hasan

    2013-01-01

    Epidemiologic and case control population based studies over the past few decades have identified diet as an important determinant of cancer risk. This evidence has kindled an interest into research on bioactive food components and has till date resulted in the identification of many compounds with cancer preventive and therapeutic potential. Among such compounds has been fisetin (3,7,3’,4’-tetrahydroxyflavone), a flavonol and a member of the flavonoid polyphenols that also include quercetin, myricetin and kaempferol. Fisetin is commonly found in many fruits and vegetables such as apples, persimmons, grapes, kiwis, strawberries, onions and cucumbers. We evaluated the effects of fisetin against melanoma and cancers of the prostate, pancreas and the lungs. Using prostate and lung adenocarcinoma cells, we observed that fisetin acts as a dual inhibitor of the PI3K/Akt and the mTOR pathways. This is a significant finding considering the fact that mTOR is phosphorylated and its activation is more frequent in tumors with overexpression of PI3K/Akt. Dual inhibitors of PI3K/Akt and mTOR signaling have been suggested as valuable agents for treating such cancers. Here, we summarize our findings on the dietary flavonoid fisetin and its effects on cancer with particular focus on prostate cancer. Our observations and findings from other laboratories suggest that fisetin could be a useful chemotherapeutic agent that could be used either alone or as an adjuvant with conventional chemotherapeutic drugs for the management of prostate and other cancers. PMID:22842629

  5. Effects of orexin A on glucose metabolism in human hepatocellular carcinoma in vitro via PI3K/Akt/mTOR-dependent and -independent mechanism.

    Science.gov (United States)

    Liu, Yuanyuan; Zhao, Yuyan; Guo, Lei

    2016-01-15

    Orexins are hypothalamic neuropeptides that regulate food intake, energy homeostasis, reward system and sleep/wakefulness states. The purpose of this study was to investigate the effects of orexin A on glucose metabolism in human hepatocellular carcinoma cell line, Hep3B, and determine the possible mechanisms. Hep3B cells were incubated with different concentrations of orexin A (10(-9)-10(-7) M) in vitro in the presence or absence of the orexin receptor 1 (OX1R) inhibitor (SB334867), Akt inhibitor (PF-04691502) and mammalian target of rapamycin (mTOR) inhibitor (temsirolimus). Subsequently, OX1R protein expression, glucose transporter 1 (GLUT1) expression, glucose uptake, the mRNA expression of lactate dehydrogenase (LDHA), pyruvate dehydrogenase kinase 1 (PDK1) and pyruvate dehydrogenase B (PDHB), lactate generation and mitochondrial pyruvate dehydrogenase (PDH) enzyme activity were measured. The activity of phosphoinositide 3-kinase (PI3K)/Akt/mTOR signaling was also determined. OX1R was expressed in hepatoma tissues and Hep3B cells. Stimulation of the Hep3B cells with orexin A resulted in a dose-dependent increase of GLUT1 expression and glucose uptake, which was associated with the activation of PI3K/Akt/mTOR pathway. Further, orexin A increased PDHB expression and PDH enzyme activity, decreased LDHA, PDK1 mRNA levels and lactate generation independent of PI3K/Akt/mTOR pathway. Our results demonstrated that orexin A directed the cellular metabolism towards mitochondrial glucose oxidation rather than glycolysis. These findings provide functional evidence of the metabolic actions of orexin A in hepatocellular carcinoma cells.

  6. Methylglyoxal induces platelet hyperaggregation and reduces thrombus stability by activating PKC and inhibiting PI3K/Akt pathway.

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    Karin Hadas

    Full Text Available Diabetes is characterized by a dysregulation of glucose homeostasis and platelets from patients with diabetes are known to be hyper-reactive and contribute to the accelerated development of vascular diseases. Since many of the deleterious effects of glucose have been attributed to its metabolite methylgyloxal (MG rather than to hyperglycemia itself, the aim of the present study was to characterize the effects of MG on platelet function. Washed human platelets were pre-incubated for 15 min with MG and platelet aggregation, adhesion on matrix-coated slides and signaling (Western blot were assessed ex vivo. In vivo, the effect of MG on thrombus formation was determined using the FeCl3-induced carotid artery injury model. MG potentiated thrombin-induced platelet aggregation and dense granule release, but inhibited platelet spreading on fibronectin and collagen. In vivo, MG accelerated thrombus formation but decreased thrombus stability. At the molecular level, MG increased intracellular Ca(2+ and activated classical PKCs at the same time as inhibiting PI3K/Akt and the β3-integrin outside-in signaling. In conclusion, these findings indicate that the enhanced MG concentration measured in diabetic patients can directly contribute to the platelet dysfunction associated with diabetes characterized by hyperaggregability and reduced thrombus stability.

  7. Methylglyoxal induces platelet hyperaggregation and reduces thrombus stability by activating PKC and inhibiting PI3K/Akt pathway.

    Science.gov (United States)

    Hadas, Karin; Randriamboavonjy, Voahanginirina; Elgheznawy, Amro; Mann, Alexander; Fleming, Ingrid

    2013-01-01

    Diabetes is characterized by a dysregulation of glucose homeostasis and platelets from patients with diabetes are known to be hyper-reactive and contribute to the accelerated development of vascular diseases. Since many of the deleterious effects of glucose have been attributed to its metabolite methylgyloxal (MG) rather than to hyperglycemia itself, the aim of the present study was to characterize the effects of MG on platelet function. Washed human platelets were pre-incubated for 15 min with MG and platelet aggregation, adhesion on matrix-coated slides and signaling (Western blot) were assessed ex vivo. In vivo, the effect of MG on thrombus formation was determined using the FeCl3-induced carotid artery injury model. MG potentiated thrombin-induced platelet aggregation and dense granule release, but inhibited platelet spreading on fibronectin and collagen. In vivo, MG accelerated thrombus formation but decreased thrombus stability. At the molecular level, MG increased intracellular Ca(2+) and activated classical PKCs at the same time as inhibiting PI3K/Akt and the β3-integrin outside-in signaling. In conclusion, these findings indicate that the enhanced MG concentration measured in diabetic patients can directly contribute to the platelet dysfunction associated with diabetes characterized by hyperaggregability and reduced thrombus stability.

  8. Luteolin enhances cholinergic activities in PC12 cells through ERK1/2 and PI3K/Akt pathways.

    Science.gov (United States)

    El Omri, Abdelfatteh; Han, Junkyu; Kawada, Kiyokazu; Ben Abdrabbah, Manef; Isoda, Hiroko

    2012-02-09

    Luteolin, a 3', 4', 5, 7-tetrahydroxyflavone, is an active compound in Rosmarinus officinalis (Lamiacea), and has been reported to exert several benefits in neuronal cells. However cholinergic-induced activities of luteolin still remain unknown. Neuronal differentiation encompasses an elaborate developmental program which plays a key role in the development of the nervous system. The advent of several cell lines, like PC12 cells, able to differentiate in culture proved to be the turning point for gaining and understanding of molecular neuroscience. In this work, we investigated the ability of luteolin to induce PC12 cell differentiation and its effect on cholinergic activities. Our findings showed that luteolin treatment significantly induced neurite outgrowth extension, enhanced acetylcholinesterase (AChE) activity, known as neuronal differentiation marker, and increased the level of total choline and acetylcholine in PC12 cells. In addition, luteolin persistently, activated extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt; while the addition of pharmacological MEK/ERK1/2 inhibitor (U0126) and PI3k/Akt inhibitor (LY294002) attenuated luteolin-induced AChE activity and neurite outgrowth in PC12 cells. The above findings suggest that luteolin induces neurite outgrowth and enhanced cholinergic activities, at least in part, through the activation of ERK1/2 and Akt signaling.

  9. De novo somatic mutations in components of the PI3K-AKT3-mTOR pathway cause hemimegalencephaly.

    Science.gov (United States)

    Lee, Jeong Ho; Huynh, My; Silhavy, Jennifer L; Kim, Sangwoo; Dixon-Salazar, Tracy; Heiberg, Andrew; Scott, Eric; Bafna, Vineet; Hill, Kiley J; Collazo, Adrienne; Funari, Vincent; Russ, Carsten; Gabriel, Stacey B; Mathern, Gary W; Gleeson, Joseph G

    2012-06-24

    De novo somatic mutations in focal areas are well documented in diseases such as neoplasia but are rarely reported in malformation of the developing brain. Hemimegalencephaly (HME) is characterized by overgrowth of either one of the two cerebral hemispheres. The molecular etiology of HME remains a mystery. The intractable epilepsy that is associated with HME can be relieved by the surgical treatment hemispherectomy, allowing sampling of diseased tissue. Exome sequencing and mass spectrometry analysis in paired brain-blood samples from individuals with HME (n = 20 cases) identified de novo somatic mutations in 30% of affected individuals in the PIK3CA, AKT3 and MTOR genes. A recurrent PIK3CA c.1633G>A mutation was found in four separate cases. Identified mutations were present in 8-40% of sequenced alleles in various brain regions and were associated with increased neuronal S6 protein phosphorylation in the brains of affected individuals, indicating aberrant activation of mammalian target of rapamycin (mTOR) signaling. Thus HME is probably a genetically mosaic disease caused by gain of function in phosphatidylinositol 3-kinase (PI3K)-AKT3-mTOR signaling.

  10. Neuroprotective effects of salidroside through PI3K/Akt pathway activation in Alzheimer’s disease models

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    Zhang B

    2016-04-01

    Full Text Available Bei Zhang,1,2 Ying Wang,1 Hui Li,1 Ran Xiong,1 Zongbo Zhao,1 Xingkun Chu,2 Qiongqiong Li,1 Suya Sun,1 Shengdi Chen1,2 1Department of Neurology, Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China; 2Laboratory of Neurodegenerative Diseases, The Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China Abstract: Alzheimer’s disease (AD is a devastating neurodegenerative disorder characterized by deposits of aggregated amyloid-β (Aβ peptide and neurofibrillary tangles in the brain parenchyma. Despite considerable research to elucidate the pathological mechanisms and identify therapeutic strategies for AD, effective treatments are still lacking. In the present study, we found that salidroside (Sal, a phenylpropanoid glycoside isolated from Rhodiola rosea L., can protect against Aβ-induced neurotoxicity in four transgenic Drosophila AD models. Both longevity and locomotor activity were improved in Sal-fed Drosophila. Sal also decreased Aβ levels and Aβ deposition in brain and ameliorated toxicity in Aβ-treated primary neuronal culture. The neuroprotective effect of Sal was associated with upregulated phosphatidylinositide 3-kinase (PI3K/Akt signaling. Our findings identify a compound that may possess potential therapeutic benefits for AD and other forms of neurodegeneration. Keywords: Alzheimer’s disease, amyloid-β, salidroside, Drosophila, neuroprotective effect

  11. Asiaticoside attenuates diabetes-induced cognition deficits by regulating PI3K/Akt/NF-κB pathway.

    Science.gov (United States)

    Yin, Zhujun; Yu, Haiyang; Chen, She; Ma, Chunhua; Ma, Xiao; Xu, Lixing; Ma, Zhanqiang; Qu, Rong; Ma, Shiping

    2015-10-01

    Diabetes-associated cognitive dysfunction, referred as "diabetic encephalopathy", has been confirmed in a great deal of literature. Current evidence support that oxidative stress, inflammation, energy metabolism imbalance, and aberrant insulin signaling are associated with cognition deficits induced by diabetes. The present study explore the effect of asiaticoside on the cognition behaviors, synapses, and oxidative stress in diabetic rats. Asiaticoside could markedly ameliorate the performance in the Morris Water Maze (decreased latency time and path length, and increased time spent in the target quadrant), which was correlated with its capabilities of suppressing oxidative stress, restoring Na(+)-K(+)-ATPase activity and protecting hippocampal synapses. In vitro, asiaticoside could up-regulate synaptic proteins expression via modulating Phosphoinositide 3-kinase (PI3K)/Protein Kinase B(AKT)/Nuclear Factor -kappa B (NF-κB)-mediated inflammatory pathway in SH-SY5Y cells incubated with high glucose chronically. In conclusion, asiaticoside had beneficial effects on the prevention and treatment of diabetes-associated cognitive deficits, which was involved in oxidative stress, PI3K/Akt/NF-κB pathway and synaptic function in the development of cognitive decline induced by diabetes.

  12. Esculetin induces apoptosis of SMMC-7721 cells through IGF-1/PI3K/Akt-mediated mitochondrial pathways.

    Science.gov (United States)

    Li, Juan; Li, Shuang; Wang, Xiuli; Wang, Hongxin

    2017-07-01

    Esculetin (6,7-dihydroxycoumarin) is a coumarin derivative extracted from natural plants and has been reported to have anticancer activity. However, the mechanism by which esculetin prevents human hepatic cancer cell growth is still largely unknown. In this study, we investigated the effect of esculetin on human hepatocellular carcinoma (HCC) SMMC-7721 cells and explored the cell signal mechanism. Our data indicated that esculetin induced apoptosis in SMMC-7721 cells, which were supported by DAPI staining and Annexin V/PI staining. Meanwhile, esculetin increased the activities of caspase-3 and caspase-9, promoted bax expression, decreased bcl-2 expression, and triggered collapse of mitochondrial membrane potential, and increased cytochrome c release from mitochondria. In addition, the inactivation of IGF-1, PI3K, and Akt was observed after esculetin administration. Furthermore, pretreatment with IGF-1 before esculetin administration abrogated the pro-apoptotic effects of esculetin, while PI3K inhibitor increased the pro-apoptotic effects of esculetin. These results indicated that esculetin induced the apoptosis of SMMC-7721 cells through IGF-1/PI3K/Akt-regulated mitochondrial dysfunction.

  13. Age-dependent accumulation of soluble amyloid beta (Abeta) oligomers reverses the neuroprotective effect of soluble amyloid precursor protein-alpha (sAPP(alpha)) by modulating phosphatidylinositol 3-kinase (PI3K)/Akt-GSK-3beta pathway in Alzheimer mouse model.

    Science.gov (United States)

    Jimenez, Sebastian; Torres, Manuel; Vizuete, Marisa; Sanchez-Varo, Raquel; Sanchez-Mejias, Elisabeth; Trujillo-Estrada, Laura; Carmona-Cuenca, Irene; Caballero, Cristina; Ruano, Diego; Gutierrez, Antonia; Vitorica, Javier

    2011-05-27

    Neurotrophins, activating the PI3K/Akt signaling pathway, control neuronal survival and plasticity. Alterations in NGF, BDNF, IGF-1, or insulin signaling are implicated in the pathogenesis of Alzheimer disease. We have previously characterized a bigenic PS1×APP transgenic mouse displaying early hippocampal Aβ deposition (3 to 4 months) but late (17 to 18 months) neurodegeneration of pyramidal cells, paralleled to the accumulation of soluble Aβ oligomers. We hypothesized that PI3K/Akt/GSK-3β signaling pathway could be involved in this apparent age-dependent neuroprotective/neurodegenerative status. In fact, our data demonstrated that, as compared with age-matched nontransgenic controls, the Ser-9 phosphorylation of GSK-3β was increased in the 6-month PS1×APP hippocampus, whereas in aged PS1×APP animals (18 months), GSK-3β phosphorylation levels displayed a marked decrease. Using N2a and primary neuronal cell cultures, we demonstrated that soluble amyloid precursor protein-α (sAPPα), the predominant APP-derived fragment in young PS1×APP mice, acting through IGF-1 and/or insulin receptors, activated the PI3K/Akt pathway, phosphorylated the GSK-3β activity, and in consequence, exerted a neuroprotective action. On the contrary, several oligomeric Aβ forms, present in the soluble fractions of aged PS1×APP mice, inhibited the induced phosphorylation of Akt/GSK-3β and decreased the neuronal survival. Furthermore, synthetic Aβ oligomers blocked the effect mediated by different neurotrophins (NGF, BDNF, insulin, and IGF-1) and sAPPα, displaying high selectivity for NGF. In conclusion, the age-dependent appearance of APP-derived soluble factors modulated the PI3K/Akt/GSK-3β signaling pathway through the major neurotrophin receptors. sAPPα stimulated and Aβ oligomers blocked the prosurvival signaling. Our data might provide insights into the selective vulnerability of specific neuronal groups in Alzheimer disease.

  14. The promotion of angiogenesis induced by three-dimensional porous beta-tricalcium phosphate scaffold with different interconnection sizes via activation of PI3K/Akt pathways

    Science.gov (United States)

    Xiao, Xin; Wang, Wei; Liu, Dong; Zhang, Haoqiang; Gao, Peng; Geng, Lei; Yuan, Yulin; Lu, Jianxi; Wang, Zhen

    2015-03-01

    The porous architectural characteristics of biomaterials play an important role in scaffold revascularization. However, no consensus exists regarding optimal interconnection sizes for vascularization and its scaffold bioperformance with different interconnection sizes. Therefore, a series of disk-type beta-tricalcium phosphates with the same pore sizes and variable interconnections were produced to evaluate how the interconnection size influenced biomaterial vascularization in vitro and in vivo. We incubated human umbilical vein endothelial cells on scaffolds with interconnections of various sizes. Results showed that scaffolds with a 150 μm interconnection size ameliorated endothelial cell function evidenced by promoting cell adhesion and migration, increasing cell proliferation and enhancing expression of platelet-endothelial cell adhesion molecules and vascular endothelial growth factor. In vivo study was performed on rabbit implanted with scaffolds into the bone defect on femoral condyles. Implantation with scaffolds with 150 μm interconnection size significantly improved neovascularization as shown by micro-CT as compared to scaffolds with 100 and 120 μm interconnection sizes. Moreover, the aforementioned positive effects were abolished by blocking PI3K/Akt/eNOS pathway with LY-294002. Our study explicitly demonstrates that the scaffold with 150 μm interconnection size improves neovascularization