Science.gov

Sample records for gnrh-ii induce cell

  1. Gonadotropin-releasing hormone II (GnRH II) mediates the anorexigenic actions of α-melanocyte-stimulating hormone (α-MSH) and corticotropin-releasing hormone (CRH) in goldfish.

    PubMed

    Kang, Ki Sung; Shimizu, Kanako; Azuma, Morio; Ui, Yuhta; Nakamura, Kouta; Uchiyama, Minoru; Matsuda, Kouhei

    2011-01-01

    Intracerebroventricular (ICV) administration of gonadotropin-releasing hormone II (GnRH II), which plays a crucial role in the regulation of reproduction in vertebrates, markedly reduces food intake in goldfish. However, the neurochemical pathways involved in the anorexigenic action of GnRH II and its interaction with other neuropeptides have not yet been identified. Alpha-melanocyte-stimulating hormone (α-MSH), corticotropin-releasing hormone (CRH) and CRH-related peptides play a major role in feeding control as potent anorexigenic neuropeptides in goldfish. However, our previous study has indicated that the GnRH II-induced anorexigenic action is not blocked by treatment with melanocortin 4 receptor (MC4R) and CRH receptor antagonists. Therefore, in the present study, we further examined whether the anorexigenic effects of α-MSH and CRH in goldfish could be mediated through the GnRH receptor neuronal pathway. ICV injection of the MC4R agonist, melanotan II (80 pmol/g body weight; BW), significantly reduced food intake, and its anorexigenic effect was suppressed by ICV pre-administration of the GnRH type I receptor antagonist, antide (100 pmol/gBW). The CRH-induced (50 pmol/gBW) anorexigenic action was also blocked by treatment with antide. ICV injection of CRH (50 pmol/gBW) induced a significant increase of the GnRH II mRNA level in the hypothalamus, while ICV injection of melanotan II (80 pmol/gBW) had no effect on the level of GnRH II mRNA. These results indicate that, in goldfish, the anorexigenic actions of α-MSH and CRH are mediated through the GnRH type I receptor-signaling pathway, and that the GnRH II system regulates feeding behavior.

  2. An induced junction photovoltaic cell

    NASA Technical Reports Server (NTRS)

    Call, R. L.

    1974-01-01

    Silicon solar cells operating with induced junctions rather than diffused junctions have been fabricated and tested. Induced junctions were created by forming an inversion layer near the surface of the silicon by supplying a sheet of positive charge above the surface. Measurements of the response of the inversion layer cell to light of different wavelengths indicated it to be more sensitive to the shorter wavelengths of the sun's spectrum than conventional cells. The greater sensitivity occurs because of the shallow junction and the strong electric field at the surface.

  3. Differential regulation of two forms of gonadotropin-releasing hormone messenger ribonucleic acid by gonadotropins in human immortalized ovarian surface epithelium and ovarian cancer cells.

    PubMed

    Choi, Jung-Hye; Choi, Kyung-Chul; Auersperg, Nelly; Leung, Peter C K

    2006-06-01

    Although gonadotropin-releasing hormone (GnRH) has been shown to play a role as an autocrine/ paracrine regulator of cell growth in ovarian surface epithelium and ovarian cancer, the factors which regulate the expression of GnRH and its receptor in these cells are not well characterized. In the present study, we employed real-time PCR to determine the potential regulatory effect of gonadotropins on the expression levels of GnRH I (the mammalian GnRH), GnRH II (a second form of GnRH) and their common receptor (GnRHR) in immortalized ovarian surface epithelial (IOSE-80 and IOSE-80PC) cells and ovarian cancer cell lines (A2780, BG-1, CaOV-3, OVCAR-3 and SKOV-3). The cells were treated with increasing concentrations (100 and 1000 ng/ml) of recombinant follicle-stimulating hormone (FSH) or luteinizing hormone (LH) for 24 h. Treatment with FSH or LH reduced GnRH II mRNA levels in both IOSE cell lines and in three out of five ovarian cancer cell lines (A2780, BG-1 and OVCAR-3). A significant decrease in GnRHR mRNA levels was observed in IOSE and ovarian cancer cells, except CaOV-3 cells, following treatment with FSH or LH. In contrast, treatment with either FSH or LH had no effect on GnRH I mRNA levels in these cells, suggesting that gonadotropins regulate the two forms of GnRH and its receptor differentially. In separate experiments, the effect of gonadotropins on the anti-proliferative action of GnRH I and GnRH II agonists in IOSE-80, OVCAR-3 and SKOV-3 cells was investigated. The cells were pretreated with FSH or LH (100 ng/ml) for 24 h after which they were treated with either GnRH I or GnRH II (100 ng/ml) for 2 days, and cell growth was assessed by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide] assay. Pretreatment of the cells with FSH or LH significantly reversed the growth inhibitory effect of GnRH I and GnRH II agonists in these cell types. These results provide the first demonstration of a potential interaction between gonadotropins and the

  4. Parvovirus infection-induced cell death and cell cycle arrest

    PubMed Central

    Chen, Aaron Yun; Qiu, Jianming

    2011-01-01

    The cytopathic effects induced during parvovirus infection have been widely documented. Parvovirus infection-induced cell death is often directly associated with disease outcomes (e.g., anemia resulting from loss of erythroid progenitors during parvovirus B19 infection). Apoptosis is the major form of cell death induced by parvovirus infection. However, nonapoptotic cell death, namely necrosis, has also been reported during infection of the minute virus of mice, parvovirus H-1 and bovine parvovirus. Recent studies have revealed multiple mechanisms underlying the cell death during parvovirus infection. These mechanisms vary in different parvoviruses, although the large nonstructural protein (NS)1 and the small NS proteins (e.g., the 11 kDa of parvovirus B19), as well as replication of the viral genome, are responsible for causing infection-induced cell death. Cell cycle arrest is also common, and contributes to the cytopathic effects induced during parvovirus infection. While viral NS proteins have been indicated to induce cell cycle arrest, increasing evidence suggests that a cellular DNA damage response triggered by an invading single-stranded parvoviral genome is the major inducer of cell cycle arrest in parvovirus-infected cells. Apparently, in response to infection, cell death and cell cycle arrest of parvovirus-infected cells are beneficial to the viral cell lifecycle (e.g., viral DNA replication and virus egress). In this article, we will discuss recent advances in the understanding of the mechanisms underlying parvovirus infection-induced cell death and cell cycle arrest. PMID:21331319

  5. HIV transcription is induced in dying cells

    SciTech Connect

    Woloschak, G.E.; Chang-Liu, Chin-Mei; Schreck, S. |; Panozzo, J.; Libertin, C.R.

    1996-02-01

    Using HeLa cells stably transfected with an HIV-LTR-CAT construct, we demonstrated a peak in CAT induction that occurs in viable (but not necessarily cell-division-competent) cells 24 h following exposure to some cell-killing agents. {gamma} rays were the only cell-killing agent which did not induce HIV transcription; this can be attributed to the fact that {gamma}-ray-induced apoptotic death requires functional p53, which is not present in HeLa cells. For all other agents, HIV-LTR induction was dose-dependent and correlated with the amount of cell killing that occurred in the culture. Doses which caused over 99% cell killing induced HIV-LTR transcription maximally, demonstrating that cells that will go on to die by 14 days are the cells expressing HIV-LTR-CAT.

  6. Local anesthetics induce human renal cell apoptosis.

    PubMed

    Lee, H Thomas; Xu, Hua; Siegel, Cory D; Krichevsky, Igor E

    2003-01-01

    Renal cell apoptosis contributes significantly to the pathogenesis of acute renal failure. Local anesthetics induce apoptosis in neuronal and lymphocytic cell lines. We examined the effects of chronic (48 h) local anesthetic treatment (lidocaine, bupivacaine and tetracaine) on human proximal tubular (HK-2) cells. Apoptosis induction was assessed by detecting poly(ADP)-ribose polymerase fragmentation, caspase activation, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining, DNA laddering and by cellular morphology. Cell death was quantified by measuring neutral red dye uptake and lactate dehydrogenase released into the cell culture medium. All 3 local anesthetics caused concentration-dependent cell death, induced HK-2 cell apoptosis and potentiated TNF-alpha induced apoptosis. Local anesthetics induced HK-2 cell apoptosis by activation of caspases 3, 6, 7, 8 and 9. ZVAD-fmk, a pan-caspase inhibitor, blocked the local anesthetic induced HK-2 cell apoptosis. Local anesthetics also inhibited the activities of anti-apoptotic kinases protein kinase B (Akt) and extracellular signal regulated mitrogen-activated protein kinase. Local anesthetic's pro-apoptotic effects are independent of sodium channel inhibition as tetrodotoxin, a selective voltage-gated sodium channel blocker, failed to mimic local anesthetic-mediated induction or potentiation of HK-2 cell apoptosis. We conclude that local anesthetics induce human renal cell apoptotic signaling by caspase activation and via inhibition of pro-survival signaling pathways.

  7. Listeria monocytogenes induces mast cell extracellular traps.

    PubMed

    Campillo-Navarro, Marcia; Leyva-Paredes, Kahiry; Donis-Maturano, Luis; González-Jiménez, Marco; Paredes-Vivas, Yuriria; Cerbulo-Vázquez, Arturo; Serafín-López, Jeanet; García-Pérez, Blanca; Ullrich, Stephen E; Flores-Romo, Leopoldo; Pérez-Tapia, Sonia M; Estrada-Parra, Sergio; Estrada-García, Iris; Chacón-Salinas, Rommel

    2017-02-01

    Mast cells play an essential role in different immunological phenomena including allergy and infectious diseases. Several bacteria induce mast cell activation leading to degranulation and the production of several cytokines and chemokines. However, mast cells also have different microbicidal activities such as phagocytosis and the release of DNA with embedded granular proteins known as Mast Cell Extracellular Traps (MCETs). Although previous reports indicate that extracellular bacteria are able to induce MCETs little is known if intracellular bacteria can induce these structures. In this work, we evaluated MCETs induction by the intracellular bacteria Listeria monocytogenes. We found that mast cells released DNA after stimulation with L. monocytogenes, and this DNA was complexed to histone and tryptase. Before extracellular DNA release, L. monocytogenes induced modifications to the mast cell nuclear envelope and DNA was detected outside the nucleus. L. monocytogenes stimulated mast cells to produce significant amounts of reactive oxygen species (ROS) and blocking NADPH oxidase diminished DNA release by mast cells. Finally, MCETs showed antimicrobial activity against L. monocytogenes that was partially blocked when β-hexosaminidase activity was inhibited. These results show that L. monocytogenes induces mast cells to produce microbicidal MCETs, suggesting a role for mast cells in containing infection beyond the induction of inflammation.

  8. HIV transcription is induced with cell killing

    SciTech Connect

    Woloschak, G.E.; Schreck, S.; Chang-Liu, Chin-Mei; Panozzo, J.; Libertin, C.R.

    1993-11-01

    In this report, we demonstrate that this induction of HIV-LTR transcription occurs when stably transfected HeLa cells are exposed to agents which mediate cell killing, such as UV radiation, electroporation of sucrose buffer, prolonged heating, and low and high pH. Cells cultured following UV exposure demonstrated a peak in CAT expression that is evident in viable (but not necessarily cell division-competent) cells 24 h after exposure; this inductive response continued until at least 72 h after exposure. HIV-LTR induction was dose-dependent, and the amount of CAT transcription induced was correlated with the amount of cell killing that occurred in the culture.

  9. HIV transcription is induced in dying cells

    SciTech Connect

    Woloschak, G.E.; Chang-Liu, Chin-Mei; Schreck, S. |

    1995-06-01

    Using HeLa cells stably transfected with an HIV-LTR-CAT construct, we demonstrated a peak in CAT induction that occurs in viable (but not necessarily cell-division-competent) cells 24 h following exposure to some cell-killing agents. {gamma} rays were the only cell-killing agent which did not induce HIV transcription; this can be attributed to the fact that {gamma}-ray-induced apoptotic death requires functional p53, which is not present in HeLa cells. For all other agents, HIV-LTR induction was dose-dependent and correlated with the amount of cell killing that occurred in the culture. 14 refs., 4 figs., 1 tab.

  10. Invariant NKT cells increase drug-induced osteosarcoma cell death

    PubMed Central

    Fallarini, S; Paoletti, T; Orsi Battaglini, N; Lombardi, G

    2012-01-01

    BACKGROUND AND PURPOSE In osteosarcoma (OS) patients, only a limited number of drugs are active and the regimens currently in use include a combination of at least two of these drugs: doxorubicin, cisplatin, methotrexate and ifosfamide. Today, 30–40% of patients still die of OS highlighting the urgent need for new treatments. Invariant NKT (iNKT) cells are a lymphocyte lineage with features of both T and NK cells, playing important roles in tumour suppression. Our aim was to test whether the cytoxicity induced by cisplatin, doxorubicin and methotrexate against OS cells can be enhanced by iNKT cell treatment. EXPERIMENTAL APPROACH iNKT cells were purified from human peripheral blood mononuclear cells by cell sorting (Vα24Vβ11+ cells) and used as effector cells against OS cells (U2-OS, HOS, MG-63). Cell death (calcein-AM method), perforin/granzyme B and Fas/FasL expressions were determined by flow cytometry. CD1d expression was analysed at both the gene and protein level. KEY RESULTS iNKT cells were cytotoxic against OS cells through a CD1d-dependent mechanism. This activity was specific for tumour cells, because human CD1d+ mesenchymal stem cells and CD1d- osteoblasts were not affected. iNKT cell treatment enhanced drug-induced OS cell death in a concentration-dependent manner and this effect was reduced in CD1d-silenced OS cells. CONCLUSION AND IMPLICATIONS iNKT cells kill malignant, but not non-malignant, cells. iNKT cell treatment enhances the cytotoxicity of anti-neoplastic drugs against OS cells in a CD1d-dependent manner. The present data encourage further studies on the use of iNKT cells in OS therapy. PMID:22817659

  11. Induced Pluripotent Stem Cells from Nonhuman Primates.

    PubMed

    Mishra, Anuja; Qiu, Zhifang; Farnsworth, Steven L; Hemmi, Jacob J; Li, Miao; Pickering, Alexander V; Hornsby, Peter J

    2016-01-01

    Induced pluripotent stem cells from nonhuman primates (NHPs) have unique roles in cell biology and regenerative medicine. Because of the relatedness of NHPs to humans, NHP iPS cells can serve as a source of differentiated derivatives that can be used to address important questions in the comparative biology of primates. Additionally, when used as a source of cells for regenerative medicine, NHP iPS cells serve an invaluable role in translational experiments in cell therapy. Reprogramming of NHP somatic cells requires the same conditions as previously established for human cells. However, throughout the process, a variety of modifications to the human cell protocols must be made to accommodate significant species differences.

  12. Methadone induced lysis of mammalian cells.

    PubMed

    Will, P C; Noteboom, W D

    1978-08-01

    Methadone induced lysis of human erythrocytes and mouse leukemic cells was studied. The cells lyse without prior swelling that is a necessary step of colloid osmotic lysis. Methadone is accumulated by both cell types, and is widely distributed intracellurly in mouse leukemic cells. The maximum lytic rate is roughly proportional to the amount of methadone uptake and the Q10 for lysis is equal to the Q10 for methadone partitioning between octanol and water. It is concluded that the cells lyse as a result of a non-specific disruption of the plasma membrane.

  13. Sulfur dioxide induced programmed cell death in Vicia guard cells.

    PubMed

    Yi, Huilan; Yin, Jingjing; Liu, Xin; Jing, Xiuqing; Fan, Sanhong; Zhang, Hufang

    2012-04-01

    Sulfur dioxide (SO(2)) induced nuclear condensation and nuclear fragmentation and rapid loss of guard cell viability in detached epidermis of Vicia leaves at concentrations of 1 mM and higher (3 h exposure). Caspase inhibitors Z-Asp-CH(2)-DCB (0.1 mM) and TLCK (0.1 mM) markedly suppressed SO(2)-induced cell death. The typical nuclear morphological changes and the inhibition effects of caspase inhibitors suggest the activation of a programmed cell death (PCD) pathway. SO(2)-induced cell death can be blocked by either antioxidants (0.1 mM AsA or 200 U/mL CAT) or Ca(2+) antagonists (0.1mM EGTA or LaCl(3)). AsA and CAT also blocked SO(2)-induced ROS production and [Ca(2+)](cyt) increase. However, EGTA and LaCl(3) can inhibit SO(2)-induced [Ca(2+)](cyt) increase, but cannot suppress SO(2)-induced ROS production. Our results indicate that high concentrations of SO(2) induce guard cell death via a PCD pathway through ROS mediating [Ca(2+)](cyt) elevation, which causes harmful effects to plants.

  14. Cell Chirality Induces Collective Cell Migration in Epithelial Sheets

    NASA Astrophysics Data System (ADS)

    Sato, Katsuhiko; Hiraiwa, Tetsuya; Shibata, Tatsuo

    2015-10-01

    During early development, epithelial cells form a monolayer sheet and migrate in a uniform direction. Here, we address how this collective migration can occur without breaking the cell-to-cell attachments. Repeated contraction and expansion of the cell-to-cell interfaces enables the cells to rearrange their positions autonomously within the sheet. We show that when the interface tension is strengthened in a direction that is tilted from the body axis, cell rearrangements occur in such a way that unidirectional movement is induced. We use a vertex model to demonstrate that such anisotropic tension can generate the unidirectional motion of cell sheets. Our results suggest that cell chirality facilitates collective cell migration during tissue morphogenesis.

  15. An introduction to induced pluripotent stem cells.

    PubMed

    Hanley, Joanna; Rastegarlari, Ghasem; Nathwani, Amit C

    2010-10-01

    Recent landmark studies show that it is now possible to convert somatic cells, such as skin fibroblasts and B lymphocytes, into pluripotent stem cells that closely resemble embryonic stem cells. These induced pluripotent stem (iPS) cells can be generated without using human embryos or oocytes, thus bypassing some of the ethical issues that have limited the use of human embryonic stems (hES) cells. Additionally, they can be derived from the patient to be treated, thereby overcoming problems of immunological rejection associated with the use of allogeneic hES cell derived progenitors. Whilst these patient-specific iPS cells have great clinical potential, their immediate utility is likely to be in drug screening and for understanding the disease process. This review discusses the promise of iPS cells as well as the challenges to their use in the clinic.

  16. HIV transcription is induced with cell killing

    SciTech Connect

    Woloschak, G.E.; Schreck, S.; Chang-Liu, Chin Mei; Panozzo, J.; Libertin, C.R.

    1994-01-01

    Previous work has shown that HeLa cells stably transfected with an HIV-LTR-CAT construct are induced to express chloramphenicol acetyl transferase (CAT) following exposure to DNA-damaging agents such as ultraviolet radiation, {gamma} rays, neutrons, and others. In this report, the authors demonstrate that this induction of HIV-LTR transcription occurs when stably transfected HeLa cells are exposed to agents which mediate cell killing, such as UV radiation, electroporation of sucrose buffer, prolonged heating, and low and high pH. Cells cultured following UV exposure demonstrated a peak in CAT expression that is evidence in viable (but not necessarily cell division-competent) cells 24 h after exposure; this inductive response continued until at least 72 h after exposure. HIV-LTR induction was dose-dependent, and the amount of CAT transcription induced was correlated with the amount of cell killing that occurred in the culture. Other agents which caused no cell killing (such as heat-shock for up to 2 h, treatment with metronidazole, exposure to sunlight, vitamin C treatment, and others) had no effect on HIV-LTR induction. These results suggest that HIV transcription is induced as a consequence of the turn on of a cellular death or apoptotic pathway.

  17. Schwann cells induce neuronal differentiation of bone marrow stromal cells.

    PubMed

    Zurita, Mercedes; Vaquero, Jesús; Oya, Santiago; Miguel, Miriam

    2005-04-04

    Bone marrow stromal cells are multipotent stem cells that have the potential to differentiate into bone, cartilage, fat and muscle. Recently, bone marrow stromal cells have been shown to have the capacity to differentiate into neurons under specific experimental conditions, using chemical factors. We now describe how bone marrow stromal cells can be induced to differentiate into neuron-like cells when they are co-cultured with Schwann cells. When compared with chemical differentiation, expression of neuronal differentiation markers begins later, but one week after beginning co-culture, most bone marrow stromal cells showed a typical neuronal morphology. Our present findings support the transdifferentiation of bone marrow stromal cells, and the potential utility of these cells for the treatment of degenerative and acquired disorders of the nervous system.

  18. Cisplatin Induces Differentiation of Breast Cancer Cells

    PubMed Central

    Prabhakaran, Praseetha; Hassiotou, Foteini; Blancafort, Pilar; Filgueira, Luis

    2013-01-01

    Breast tumors are heterogeneous including cells with stem cell properties and more differentiated cells. This heterogeneity is reflected into the molecular breast cancer subtypes. Breast cancer stem cells are resistant to chemotherapy, thus recent efforts are focusing on identifying treatments that shift them toward a more differentiated phenotype, making them more susceptible to chemotherapy. We examined whether the drug cisplatin induces differentiation in breast cancer cell lines that represent different breast cancer subtypes. We used three cell lines representing triple-negative breast cancers, BT-549 and MDA-MB-231 (claudin-low), and MDA-MB-468 (basal-like), along with estrogen and progesterone receptor positive MCF-7 cells (luminal). Cisplatin was applied at 2.5, 5, 10, and 20 μM, and cell viability and proliferation were measured using MTS and BrdU assays, respectively. The effect of cisplatin on the cellular hierarchy was examined by flow cytometry, immunofluorescence and qRT-PCR. Cisplatin treatment of 10 and 20 μM reduced cell viability by 36–51% and proliferation capacity by 36–67%. Treatment with cisplatin resulted in 12–67% down-regulation of stem cell markers (CD49f, SSEA4) and 10–130% up-regulation of differentiation markers (CK18, SMA, β-tubulin). At the mRNA level, CD49f was down-regulated whilst β-tubulin was up-regulated in the claudin-low cell lines. SSEA4 protein expression decreased upon cisplatin treatment, but SSEA4 mRNA expression increased indicating a differential regulation of cisplatin at the post-transcriptional level. It is concluded that cisplatin reduces breast cancer cell survival and induces differentiation of stem/progenitor cell subpopulations within breast cancer cell lines. These effects indicate the potential of this drug to target specific chemotherapy-resistant cells within a tumor. PMID:23761858

  19. Induction of Trabecular Meshwork Cells From Induced Pluripotent Stem Cells

    PubMed Central

    Ding, Qiong J.; Zhu, Wei; Cook, Amy C.; Anfinson, Kristin R.; Tucker, Budd A.; Kuehn, Markus H.

    2014-01-01

    Purpose. Loss or dysfunction of trabecular meshwork (TM) cells has been associated with the development of pathologically elevated IOP, and it is conceivable that replacement of damaged TM cells could restore function to the TM. We propose that the use of TM-like cells derived from induced pluripotent stem cells (iPSCs) created from a patient's own dermal fibroblasts offers the best solution to this challenge. Here we demonstrate that mouse iPSCs can be induced to differentiate into TM-like cells suitable for autologous transplantation. Methods. Directed induction of stem cell differentiation was achieved through coculture of mouse iPSCs with human TM cells for up to 21 days. The resultant TM-like cells (iPSC-TM) were characterized morphologically, immunohistochemically, and functionally. Results. The iPSC-TM cells closely resembled cultured human TM cells morphologically and began to express many markers of TM cells while ceasing to express pluripotency markers such as Nanog, Oct4, and Sox2. Functionally, these cells developed the ability to phagocytose particles. Finally, exposure to dexamethasone or phorbol 12-myristate acetate caused a distinct increase in the production and secretion of myocilin and matrix metalloproteinase-3, respectively, behavior characteristic of TM cells. Conclusions. Our data demonstrate that iPSCs can be induced to assume a phenotype that resembles native TM cells in many important aspects. Not only do these cells represent a valuable research tool, but transplantation into glaucomatous eyes with elevated IOP may also restore function to the TM, resulting in re-establishment of IOP. PMID:25298418

  20. Schwann cells induce cancer cell dispersion and invasion.

    PubMed

    Deborde, Sylvie; Omelchenko, Tatiana; Lyubchik, Anna; Zhou, Yi; He, Shizhi; McNamara, William F; Chernichenko, Natalya; Lee, Sei-Young; Barajas, Fernando; Chen, Chun-Hao; Bakst, Richard L; Vakiani, Efsevia; He, Shuangba; Hall, Alan; Wong, Richard J

    2016-04-01

    Nerves enable cancer progression, as cancers have been shown to extend along nerves through the process of perineural invasion, which carries a poor prognosis. Furthermore, the innervation of some cancers promotes growth and metastases. It remains unclear, however, how nerves mechanistically contribute to cancer progression. Here, we demonstrated that Schwann cells promote cancer invasion through direct cancer cell contact. Histological evaluation of murine and human cancer specimens with perineural invasion uncovered a subpopulation of Schwann cells that associates with cancer cells. Coculture of cancer cells with dorsal root ganglion extracts revealed that Schwann cells direct cancer cells to migrate toward nerves and promote invasion in a contact-dependent manner. Upon contact, Schwann cells induced the formation of cancer cell protrusions in their direction and intercalated between the cancer cells, leading to cancer cell dispersion. The formation of these processes was dependent on Schwann cell expression of neural cell adhesion molecule 1 (NCAM1) and ultimately promoted perineural invasion. Moreover, NCAM1-deficient mice showed decreased neural invasion and less paralysis. Such Schwann cell behavior reflects normal Schwann cell programs that are typically activated in nerve repair but are instead exploited by cancer cells to promote perineural invasion and cancer progression.

  1. Schwann cells induce cancer cell dispersion and invasion

    PubMed Central

    Deborde, Sylvie; Lyubchik, Anna; Zhou, Yi; He, Shizhi; McNamara, William F.; Chernichenko, Natalya; Lee, Sei-Young; Barajas, Fernando; Chen, Chun-Hao; Bakst, Richard L.; Vakiani, Efsevia; He, Shuangba; Hall, Alan; Wong, Richard J.

    2016-01-01

    Nerves enable cancer progression, as cancers have been shown to extend along nerves through the process of perineural invasion, which carries a poor prognosis. Furthermore, the innervation of some cancers promotes growth and metastases. It remains unclear, however, how nerves mechanistically contribute to cancer progression. Here, we demonstrated that Schwann cells promote cancer invasion through direct cancer cell contact. Histological evaluation of murine and human cancer specimens with perineural invasion uncovered a subpopulation of Schwann cells that associates with cancer cells. Coculture of cancer cells with dorsal root ganglion extracts revealed that Schwann cells direct cancer cells to migrate toward nerves and promote invasion in a contact-dependent manner. Upon contact, Schwann cells induced the formation of cancer cell protrusions in their direction and intercalated between the cancer cells, leading to cancer cell dispersion. The formation of these processes was dependent on Schwann cell expression of neural cell adhesion molecule 1 (NCAM1) and ultimately promoted perineural invasion. Moreover, NCAM1-deficient mice showed decreased neural invasion and less paralysis. Such Schwann cell behavior reflects normal Schwann cell programs that are typically activated in nerve repair but are instead exploited by cancer cells to promote perineural invasion and cancer progression. PMID:26999607

  2. Induced pluripotent stem cells for regenerative medicine.

    PubMed

    Hirschi, Karen K; Li, Song; Roy, Krishnendu

    2014-07-11

    With the discovery of induced pluripotent stem (iPS) cells, it is now possible to convert differentiated somatic cells into multipotent stem cells that have the capacity to generate all cell types of adult tissues. Thus, there is a wide variety of applications for this technology, including regenerative medicine, in vitro disease modeling, and drug screening/discovery. Although biological and biochemical techniques have been well established for cell reprogramming, bioengineering technologies offer novel tools for the reprogramming, expansion, isolation, and differentiation of iPS cells. In this article, we review these bioengineering approaches for the derivation and manipulation of iPS cells and focus on their relevance to regenerative medicine.

  3. TALEN-Induced Translocations in Human Cells.

    PubMed

    Piganeau, Marion; Renouf, Benjamin; Ghezraoui, Hind; Brunet, Erika

    2016-01-01

    Induction of chromosomal translocations in human cells is of a great interest to study tumorigenesis and genome instability. Here, we explain in detail a method to induce translocations using the transcription activator-like effector nucleases (TALENs). We describe how to detect translocation formation by PCR, calculate translocation frequency by 96-well PCR screen, and analyze breakpoint junctions. When inducing cancer translocations, it is also possible to detect the fusion gene by FISH analysis or western blot.

  4. Optically-Induced Cell Fusion on Cell Pairing Microstructures

    NASA Astrophysics Data System (ADS)

    Yang, Po-Fu; Wang, Chih-Hung; Lee, Gwo-Bin

    2016-02-01

    Cell fusion is a critical operation for numerous biomedical applications including cell reprogramming, hybridoma formation, cancer immunotherapy, and tissue regeneration. However, unstable cell contact and random cell pairings have limited efficiency and yields when utilizing traditional methods. Furthermore, it is challenging to selectively perform cell fusion within a group of cells. This study reports a new approach called optically-induced cell fusion (OICF), which integrates cell-pairing microstructures with an optically-induced, localized electrical field. By projecting light patterns onto a photoconductive film (hydrogen-rich, amorphous silicon) coated on an indium-tin-oxide (ITO) glass while an alternating current electrical field was applied between two such ITO glass slides, “virtual” electrodes could be generated that could selectively fuse pairing cells. At 10 kHz, a 57% cell paring rate and an 87% fusion efficiency were successfully achieved at a driving voltage of 20  Vpp, suggesting that this new technology could be promising for selective cell fusion within a group of cells.

  5. Optically-Induced Cell Fusion on Cell Pairing Microstructures

    PubMed Central

    Yang, Po-Fu; Wang, Chih-Hung; Lee, Gwo-Bin

    2016-01-01

    Cell fusion is a critical operation for numerous biomedical applications including cell reprogramming, hybridoma formation, cancer immunotherapy, and tissue regeneration. However, unstable cell contact and random cell pairings have limited efficiency and yields when utilizing traditional methods. Furthermore, it is challenging to selectively perform cell fusion within a group of cells. This study reports a new approach called optically-induced cell fusion (OICF), which integrates cell-pairing microstructures with an optically-induced, localized electrical field. By projecting light patterns onto a photoconductive film (hydrogen-rich, amorphous silicon) coated on an indium-tin-oxide (ITO) glass while an alternating current electrical field was applied between two such ITO glass slides, “virtual” electrodes could be generated that could selectively fuse pairing cells. At 10 kHz, a 57% cell paring rate and an 87% fusion efficiency were successfully achieved at a driving voltage of 20  Vpp, suggesting that this new technology could be promising for selective cell fusion within a group of cells. PMID:26912054

  6. Induced pluripotent stem cells and neurodegenerative diseases.

    PubMed

    Chen, Chao; Xiao, Shi-Fu

    2011-04-01

    Neurodegenerative diseases, including Parkinson's disease, Alzheimer's disease and Amyotrophic Lateral Sclerosis, are characterized by idiopathic neuron loss in different regions of the central nervous system, which contributes to the relevant dysfunctions in the patients. The application of cell replacement therapy using human embryonic stem (hES) cells, though having attracted much attention, has been hampered by the intrinsic ethical problems. It has been demonstrated that adult somatic cells can be reprogrammed into the embryonic state, called induced pluripotent stem (iPS) cells. It is soon realized that iPS cells may be an alternative source for cell replacement therapy, because it raises no ethical problems and using patient-specific iPS cells for autologous transplantation will not lead to immunological rejection. What's more, certain types of neurons derived from patient-specific iPS cells may display disease-relevant phenotypes. Thus, patient-specific iPS cells can provide a unique opportunity to directly investigate the pathological properties of relevant neural cells in individual patient, and to study the vulnerability of neural cells to pathogenic factors in vitro, which may help reveal the pathogenesis of many neurodegenerative diseases. In this review, the recent development in cellular treatment of neurodegenerative diseases using iPS cells was summarized, and the potential value of iPS cells in the modeling of neurodegenerative disease was discussed.

  7. [Research for cell therapy by induced pluripotent stem cell].

    PubMed

    Sakurai, Hidetoshi; Yamanaka, Shinya

    2011-12-01

    Induced pluripotent stem (iPS) cells, which are generated from somatic cells, are expected to be a hopeful source for cell therapy to treat intractable diseases due to its unlimited proliferation potential, differentiation potentials and the capability of autotransplantation characteristics. In this review, we have summarized the extension of iPS cell researches into cell therapy and the new researches associated with iPS cell technology. However, transplantation of iPS cell-derived tissue is considered to have a risk of tumorigenesis which is one of the major hurdles of using pluripotent stem cell in clinical application. This review is also focused on new strategies for reducing a risk of tumorigenesis.

  8. Failure of cell cleavage induces senescence in tetraploid primary cells.

    PubMed

    Panopoulos, Andreas; Pacios-Bras, Cristina; Choi, Justin; Yenjerla, Mythili; Sussman, Mark A; Fotedar, Rati; Margolis, Robert L

    2014-10-15

    Tetraploidy can arise from various mitotic or cleavage defects in mammalian cells, and inheritance of multiple centrosomes induces aneuploidy when tetraploid cells continue to cycle. Arrest of the tetraploid cell cycle is therefore potentially a critical cellular control. We report here that primary rat embryo fibroblasts (REF52) and human foreskin fibroblasts become senescent in tetraploid G1 after drug- or small interfering RNA (siRNA)-induced failure of cell cleavage. In contrast, T-antigen-transformed REF52 and p53+/+ HCT116 tumor cells rapidly become aneuploid by continuing to cycle after cleavage failure. Tetraploid primary cells quickly become quiescent, as determined by loss of the Ki-67 proliferation marker and of the fluorescent ubiquitination-based cell cycle indicator/late cell cycle marker geminin. Arrest is not due to DNA damage, as the γ-H2AX DNA damage marker remains at control levels after tetraploidy induction. Arrested tetraploid cells finally become senescent, as determined by SA-β-galactosidase activity. Tetraploid arrest is dependent on p16INK4a expression, as siRNA suppression of p16INK4a bypasses tetraploid arrest, permitting primary cells to become aneuploid. We conclude that tetraploid primary cells can become senescent without DNA damage and that induction of senescence is critical to tetraploidy arrest.

  9. Induced DNA repair pathway in mammalian cells

    SciTech Connect

    Overberg, R.

    1985-01-01

    The survival of cultured rat kangaroo cells (PtK-2) and human xeroderma pigmentosum cells incubated with 5 ..mu..M cycloheximide subsequent to ultraviolet irradiation is lower than that of cells incubated without cycloheximide. The drop in survival is considerably larger than that produced by incubation of unirradiated cells with cycloheximide. The phenomenon was also observed when PtK-2 cells were incubated with emetine, another protein synthesis inhibitor, or with 5,6-dichloro-1-..beta..-D-ribofuranosylbenzimidazole, a RNA synthesis inhibitor. PtK cells which received a preliminary UV treatment followed by an incubation period without cycloheximide and then a second irradiation and 24 hour incubation with cycloheximide, survived the effects of the second irradiation better than cells which were incubated in the presence of cycloheximide after the first and second UV irradiation. The application of cycloheximide for 24 hours after UV irradiation of PtK cells resulted in one-half as many 6-thioguanine resistant cells as compared to the number of 6-thioguanine resistant cells found when cycloheximide was not used. These experiments indicate that a UV-inducible cycloheximide-sensitive DNA repair pathway is present in PtK and xeroderma pigmentosum cells, which is error-prone in PtK cells.

  10. Induced pluripotent stem cells in cartilage repair

    PubMed Central

    Lietman, Steven A

    2016-01-01

    Articular cartilage repair techniques are challenging. Human embryonic stem cells and induced pluripotent stem cells (iPSCs) theoretically provide an unlimited number of specialized cells which could be used in articular cartilage repair. However thus far chondrocytes from iPSCs have been created primarily by viral transfection and with the use of cocultured feeder cells. In addition chondrocytes derived from iPSCs have usually been formed in condensed cell bodies (resembling embryoid bodies) that then require dissolution with consequent substantial loss of cell viability and phenotype. All of these current techniques used to derive chondrocytes from iPSCs are problematic but solutions to these problems are on the horizon. These solutions will make iPSCs a viable alternative for articular cartilage repair in the near future. PMID:27004161

  11. Single-Cell-Precision Microplasma-Induced Cancer Cell Apoptosis

    PubMed Central

    Lu, Xinpei; He, Guangyuan; Ostrikov, Kostya

    2014-01-01

    The issue of single-cell control has recently attracted enormous interest. However, in spite of the presently achievable intracellular-level physiological probing through bio-photonics, nano-probe-based, and some other techniques, the issue of inducing selective, single-cell-precision apoptosis, without affecting neighbouring cells remains essentially open. Here we resolve this issue and report on the effective single-cell-precision cancer cell treatment using the reactive chemistry of the localized corona-type plasma discharge around a needle-like electrode with the spot size ∼1 µm. When the electrode is positioned with the micrometer precision against a selected cell, a focused and highly-localized micro-plasma discharge induces apoptosis in the selected individual HepG2 and HeLa cancer cells only, without affecting any surrounding cells, even in small cell clusters. This is confirmed by the real-time monitoring of the morphological and structural changes at the cellular and cell nucleus levels after the plasma exposure. PMID:24971517

  12. Trophoblast lineage cells derived from human induced pluripotent stem cells

    SciTech Connect

    Chen, Ying; Wang, Kai; Chandramouli, Gadisetti V.R.; Knott, Jason G.; Leach, Richard

    2013-07-12

    Highlights: •Epithelial-like phenotype of trophoblast lineage cells derived from human iPS cells. •Trophoblast lineage cells derived from human iPS cells exhibit trophoblast function. •Trophoblasts from iPS cells provides a proof-of-concept in regenerative medicine. -- Abstract: Background: During implantation, the blastocyst trophectoderm attaches to the endometrial epithelium and continues to differentiate into all trophoblast subtypes, which are the major components of a placenta. Aberrant trophoblast proliferation and differentiation are associated with placental diseases. However, due to ethical and practical issues, there is almost no available cell or tissue source to study the molecular mechanism of human trophoblast differentiation, which further becomes a barrier to the study of the pathogenesis of trophoblast-associated diseases of pregnancy. In this study, our goal was to generate a proof-of-concept model for deriving trophoblast lineage cells from induced pluripotency stem (iPS) cells from human fibroblasts. In future studies the generation of trophoblast lineage cells from iPS cells established from patient’s placenta will be extremely useful for studying the pathogenesis of individual trophoblast-associated diseases and for drug testing. Methods and results: Combining iPS cell technology with BMP4 induction, we derived trophoblast lineage cells from human iPS cells. The gene expression profile of these trophoblast lineage cells was distinct from fibroblasts and iPS cells. These cells expressed markers of human trophoblasts. Furthermore, when these cells were differentiated they exhibited invasive capacity and placental hormone secretive capacity, suggesting extravillous trophoblasts and syncytiotrophoblasts. Conclusion: Trophoblast lineage cells can be successfully derived from human iPS cells, which provide a proof-of-concept tool to recapitulate pathogenesis of patient placental trophoblasts in vitro.

  13. Heat induces gene amplification in cancer cells

    SciTech Connect

    Yan, Bin; Ouyang, Ruoyun; Huang, Chenghui; Liu, Franklin; Neill, Daniel; Li, Chuanyuan; Dewhirst, Mark

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer This study discovered that heat exposure (hyperthermia) results in gene amplification in cancer cells. Black-Right-Pointing-Pointer Hyperthermia induces DNA double strand breaks. Black-Right-Pointing-Pointer DNA double strand breaks are considered to be required for the initiation of gene amplification. Black-Right-Pointing-Pointer The underlying mechanism of heat-induced gene amplification is generation of DNA double strand breaks. -- Abstract: Background: Hyperthermia plays an important role in cancer therapy. However, as with radiation, it can cause DNA damage and therefore genetic instability. We studied whether hyperthermia can induce gene amplification in cancer cells and explored potential underlying molecular mechanisms. Materials and methods: (1) Hyperthermia: HCT116 colon cancer cells received water-submerged heating treatment at 42 or 44 Degree-Sign C for 30 min; (2) gene amplification assay using N-(phosphoacetyl)-L-aspartate (PALA) selection of cabamyl-P-synthetase, aspartate transcarbarmylase, dihydro-orotase (cad) gene amplified cells; (3) southern blotting for confirmation of increased cad gene copies in PALA-resistant cells; (4) {gamma}H2AX immunostaining to detect {gamma}H2AX foci as an indication for DNA double strand breaks. Results: (1) Heat exposure at 42 or 44 Degree-Sign C for 30 min induces gene amplification. The frequency of cad gene amplification increased by 2.8 and 6.5 folds respectively; (2) heat exposure at both 42 and 44 Degree-Sign C for 30 min induces DNA double strand breaks in HCT116 cells as shown by {gamma}H2AX immunostaining. Conclusion: This study shows that heat exposure can induce gene amplification in cancer cells, likely through the generation of DNA double strand breaks, which are believed to be required for the initiation of gene amplification. This process may be promoted by heat when cellular proteins that are responsible for checkpoints, DNA replication, DNA repair and

  14. Induced pluripotent stem cells in dentistry

    PubMed Central

    Sunil, Paramel Mohan

    2016-01-01

    Induced pluripotent stem cells (iPSCs), a path-breaking invention, have revolutionized the regenerative medicine field. The biggest advantage of this technology is its patient-specific nature and so it is nonimmunogenic. It involves autologous tissues with limitless source of cells throughout life. The Nobel-winning concept involves the reprograming of terminally differentiated cells by external factors and has a tremendous role in the treatment of genetic disorders, regeneration of tissues, drug discovery, and disease modeling. This short review aims at the probable applications of iPSC technology in dentistry with respect to regeneration of oral and maxillofacial tissues and also its role in oral malignancies. PMID:27829740

  15. Honey induces apoptosis in renal cell carcinoma

    PubMed Central

    Samarghandian, Saeed; Afshari, Jalil Tavakkol; Davoodi, Saiedeh

    2011-01-01

    Background: The fact that antioxidants have several preventative effects against different diseases, such as coronary diseases, inflammatory disorders, neurologic degeneration, aging, and cancer, has led to the search for food rich in antioxidants. Honey has been used as a traditional food and medical source since ancient times. However, recently many scientists have been concentrating on the antioxidant property of honey. By use of human renal cancer cell lines (ACHN), we investigated the antiproliferative activity, apoptosis, and the antitumor activity of honey. Materials and Methods: The cells were cultured in Dulbecco’s modified Eagle’s medium with 10% fetal bovine serum treated with different concentrations of honey for 3 consecutive days. Cell viability was quantitated by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptotic cells were determined using Annexin-V-fluorescein isothiocyanate (FITC) by flow cytometry. Results: Honey decreased the cell viability in the malignant cells in a concentration- and time-dependent manner. The IC 50 values against the ACHN cell lines were determined as 1.7 ± 0.04% and 2.1 ± 0.03% μg/mL after 48 and 72 h, respectively. Honey induced apoptosis of the ACHN cells in a concentration-dependent manner, as determined by flow cytometry histogram of treated cells. Conclusion: It might be concluded that honey may cause cell death in the ACHN cells, in which apoptosis plays an important role. Most of the drugs used in the cancer treatment are apoptotic inducers, hence apoptotic nature of honey is considered vital. Therefore, it prompted us to investigate honey as a potential candidate for renal cancer treatment. PMID:21472079

  16. SWCNTs induced autophagic cell death in human bronchial epithelial cells.

    PubMed

    Park, Eun-Jung; Zahari, Nur Elida M; Lee, Eun-Woo; Song, Jaewhan; Lee, Jae-Hyeok; Cho, Myung-Haing; Kim, Jae-Ho

    2014-04-01

    Carbon nanotubes are being actively introduced in electronics, computer science, aerospace, and other industries. Thus, the urgent need for toxicological studies on CNTs is mounting. In this study, we investigated the alterations in cellular response with morphological changes induced by single-walled carbon nanotubes (SWCNTs) in BEAS-2B cells, a human bronchial epithelial cell line. At 24h after exposure, SWCNTs rapidly decreased ATP production and cell viability as well a slight increase in the number of cells in the subG1 and G1 phases. In addition, SWCNTs increased the expression of superoxide dismutase (SOD)-1, but not SOD-2, and the number of cells generating ROS. The concentration of Cu and Zn ions also increased in a dose-dependent manner in cells exposed to SWCNTs. SWCNTs significantly enhanced the release of nitric oxide, interleukin (IL)-6, and IL-8 and up-regulated the expression of chemokine- and cytokine-related genes. Furthermore, the levels of autophagy-related genes, especially the DRAM1 gene, and the autophagosome formation-related proteins, were clearly up-regulated together with an increase of autophagosome-like vacuoles. Based on these results, we suggest that SWCNTs induce autophagic cell death through mitochondrial dysfunction and cytosolic damage in human bronchial epithelial cells.

  17. Disease-specific induced pluripotent stem cells.

    PubMed

    Park, In-Hyun; Arora, Natasha; Huo, Hongguang; Maherali, Nimet; Ahfeldt, Tim; Shimamura, Akiko; Lensch, M William; Cowan, Chad; Hochedlinger, Konrad; Daley, George Q

    2008-09-05

    Tissue culture of immortal cell strains from diseased patients is an invaluable resource for medical research but is largely limited to tumor cell lines or transformed derivatives of native tissues. Here we describe the generation of induced pluripotent stem (iPS) cells from patients with a variety of genetic diseases with either Mendelian or complex inheritance; these diseases include adenosine deaminase deficiency-related severe combined immunodeficiency (ADA-SCID), Shwachman-Bodian-Diamond syndrome (SBDS), Gaucher disease (GD) type III, Duchenne (DMD) and Becker muscular dystrophy (BMD), Parkinson disease (PD), Huntington disease (HD), juvenile-onset, type 1 diabetes mellitus (JDM), Down syndrome (DS)/trisomy 21, and the carrier state of Lesch-Nyhan syndrome. Such disease-specific stem cells offer an unprecedented opportunity to recapitulate both normal and pathologic human tissue formation in vitro, thereby enabling disease investigation and drug development.

  18. Radiation induced genomic instability in bystander cells

    NASA Astrophysics Data System (ADS)

    Zhou, H.; Gu, S.; Randers-Pehrson, G.; Hei, T.

    There is considerable evidence that exposure to ionizing radiation may induce a heritable genomic instability that leads to a persisting increased frequency of genetic and functional changes in the non-irradiated progeny of a wide variety of irradiated cells Genomic instability is measured as delayed expressions in chromosomal alterations micronucleus formation gene mutations and decreased plating efficiency During the last decade numerous studies have shown that radiation could induce bystander effect in non-irradiated neighboring cells similar endpoints have also been used in genomic instability studies Both genomic instability and the bystander effect are phenomena that result in a paradigm shift in our understanding of radiation biology In the past it seemed reasonable to assume that the production of single- and double-strand DNA breaks are due to direct energy deposition of energy by a charged particle to the nucleus It turns out that biology is not quite that simple Using the Columbia University charged particle microbeam and the highly sensitive human hamster hybrid AL cell mutagenic assay we irradiated 10 of the cells with a lethal dose of 30 alpha particles through the nucleus After overnight incubation the remaining viable bystander cells were replated in dishes for colony formation Clonal isolates were expanded and cultured for 6 consecutive weeks to assess plating efficiency and mutation frequency Preliminary results indicated that there was no significant decrease in plating efficiency among the bystander colonies when compared with

  19. Induced Pluripotent Stem Cells Meet Genome Editing.

    PubMed

    Hockemeyer, Dirk; Jaenisch, Rudolf

    2016-05-05

    It is extremely rare for a single experiment to be so impactful and timely that it shapes and forecasts the experiments of the next decade. Here, we review how two such experiments-the generation of human induced pluripotent stem cells (iPSCs) and the development of CRISPR/Cas9 technology-have fundamentally reshaped our approach to biomedical research, stem cell biology, and human genetics. We will also highlight the previous knowledge that iPSC and CRISPR/Cas9 technologies were built on as this groundwork demonstrated the need for solutions and the benefits that these technologies provided and set the stage for their success.

  20. Induced pluripotent stem cells: the new patient?

    PubMed

    Bellin, Milena; Marchetto, Maria C; Gage, Fred H; Mummery, Christine L

    2012-11-01

    Worldwide increases in life expectancy have been paralleled by a greater prevalence of chronic and age-associated disorders, particularly of the cardiovascular, neural and metabolic systems. This has not been met by commensurate development of new drugs and therapies, which is in part owing to the difficulty in modelling human diseases in laboratory assays or experimental animals. Patient-specific induced pluripotent stem (iPS) cells are an emerging paradigm that may address this. Reprogrammed somatic cells from patients are already applied in disease modelling, drug testing and drug discovery, thus enabling researchers to undertake studies for treating diseases 'in a dish', which was previously inconceivable.

  1. Virus-induced aggregates in infected cells.

    PubMed

    Moshe, Adi; Gorovits, Rena

    2012-10-17

    During infection, many viruses induce cellular remodeling, resulting in the formation of insoluble aggregates/inclusions, usually containing viral structural proteins. Identification of aggregates has become a useful diagnostic tool for certain viral infections. There is wide variety of viral aggregates, which differ by their location, size, content and putative function. The role of aggregation in the context of a specific virus is often poorly understood, especially in the case of plant viruses. The aggregates are utilized by viruses to house a large complex of proteins of both viral and host origin to promote virus replication, translation, intra- and intercellular transportation. Aggregated structures may protect viral functional complexes from the cellular degradation machinery. Alternatively, the activation of host defense mechanisms may involve sequestration of virus components in aggregates, followed by their neutralization as toxic for the host cell. The diversity of virus-induced aggregates in mammalian and plant cells is the subject of this review.

  2. Ischemia-induced endothelial cell dysfunction.

    PubMed

    Keep, R F; Andjelkovic, A V; Stamatovic, S M; Shakui, P; Ennis, S R

    2005-01-01

    Hemorrhagic transformation upon reperfusion therapy has focused attention on ischemia-induced endothelial dysfunction. This study examined whether hyperglycemia may induce hemorrhagic transformation by enhancing endothelial mitochondrial damage during ischemia and whether preconditioning (PC) stimuli may limit ischemia-induced endothelial damage. In vivo, rats received 2.8 M D-glucose or arabinose (1 ml/100 g; i.p.) prior to undergoing two hours of middle cerebral artery occlusion and transcardiac fixation for electron microscopy. In vitro, brain endothelial cells were exposed to a PC impulse (short-term oxygen glucose deprivation; OGD) prior to an injurious event (5 hours OGD). Endothelial injury was assessed by measuring lactate dehydrogenase release. Hyperglycemia during cerebral ischemia resulted in marked changes in endothelial morphology and mitochondrial swelling. Thus, in the ischemic hemisphere, there was no evidence of endothelial mitochondrial swelling in normoglycemic rats (mean profile width 0.22 +/- 0.04 vs. 0.17 +/- 0.01 microm in contralateral hemisphere) but there was marked swelling in hyperglycemic rats (0.44 +/- 0.02 microm). In vitro, cells preconditioned with one hour of OGD one day prior to 5 hours of OGD, showed reduced lactate dehydrogenase release (p < 0.05). In conclusion, hyperglycemia may have specific adverse effects on endothelial cell mitochondria during ischemia. Preventing those effects may help to ameliorate blood-brain barrier disruption on reperfusion. Insights into how to prevent endothelial injury may come from determining the mechanisms involved in endothelial preconditioning.

  3. Human mesenchymal stem cell homing induced by SKOV3 cells

    PubMed Central

    Fan, Dongmei; Xie, Xiaojuan; Qi, Pengwei; Yang, Xianan; Jin, Ximeng

    2017-01-01

    Human mesenchymal stem cell (hMSC) homing is the migration of endogenous and exogenous hMSCS to the target organs and the subsequent colonization under the action chemotaxic factors. This is an important process involved in the repair of damaged tissues. However, we know little about the mechanism of hMSC homing. Stromal cell derived factor-1 (SDF-1) is a cytokine secreted by stromal cells. Its only receptor CXCR4 is widely expressed in blood cells, immune cells and cells in the central nervous system. SDF-1/CXCR4 signaling pathway plays an important role in hMSC homing and tissue repair. Human cbll1 gene encodes E3 ubiquitin-protein ligase Hakai (also known as CBLL1) consisting of RING-finger domain that is involved in ubiquitination, endocytosis and degradation of epithelial cadherin (E-cadherin) as well as in the regulation of cell proliferation. We successfully constructed LV3-CXCR4 siRNA lentiviral vector, LV3-CBLL1 RNAi lentiviral vector and the corresponding cell systems which were used to induce hMSC homing in the presence of SKOV3 cells. Thus the mechanism of hMSC homing was studied. PMID:28337256

  4. UV-Induced cell death in plants.

    PubMed

    Nawkar, Ganesh M; Maibam, Punyakishore; Park, Jung Hoon; Sahi, Vaidurya Pratap; Lee, Sang Yeol; Kang, Chang Ho

    2013-01-14

    Plants are photosynthetic organisms that depend on sunlight for energy. Plants respond to light through different photoreceptors and show photomorphogenic development. Apart from Photosynthetically Active Radiation (PAR; 400-700 nm), plants are exposed to UV light, which is comprised of UV-C (below 280 nm), UV-B (280-320 nm) and UV-A (320-390 nm). The atmospheric ozone layer protects UV-C radiation from reaching earth while the UVR8 protein acts as a receptor for UV-B radiation. Low levels of UV-B exposure initiate signaling through UVR8 and induce secondary metabolite genes involved in protection against UV while higher dosages are very detrimental to plants. It has also been reported that genes involved in MAPK cascade help the plant in providing tolerance against UV radiation. The important targets of UV radiation in plant cells are DNA, lipids and proteins and also vital processes such as photosynthesis. Recent studies showed that, in response to UV radiation, mitochondria and chloroplasts produce a reactive oxygen species (ROS). Arabidopsis metacaspase-8 (AtMC8) is induced in response to oxidative stress caused by ROS, which acts downstream of the radical induced cell death (AtRCD1) gene making plants vulnerable to cell death. The studies on salicylic and jasmonic acid signaling mutants revealed that SA and JA regulate the ROS level and antagonize ROS mediated cell death. Recently, molecular studies have revealed genes involved in response to UV exposure, with respect to programmed cell death (PCD).

  5. ER stress-induced cell death mechanisms

    PubMed Central

    Sano, Renata; Reed, John C.

    2013-01-01

    The endoplasmic-reticulum (ER) stress response constitutes a cellular process that is triggered by a variety of conditions that disturb folding of proteins in the ER. Eukaryotic cells have developed an evolutionarily conserved adaptive mechanism, the unfolded protein response (UPR), which aims to clear unfolded proteins and restore ER homeostasis. In cases where ER stress cannot be reversed, cellular functions deteriorate, often leading to cell death. Accumulating evidence implicates ER stress-induced cellular dysfunction and cell death as major contributors to many diseases, making modulators of ER stress pathways potentially attractive targets for therapeutics discovery. Here, we summarize recent advances in understanding the diversity of molecular mechanisms that govern ER stress signaling in health and disease. PMID:23850759

  6. Derivation of induced pluripotent stem cells from pig somatic cells.

    PubMed

    Ezashi, Toshihiko; Telugu, Bhanu Prakash V L; Alexenko, Andrei P; Sachdev, Shrikesh; Sinha, Sunilima; Roberts, R Michael

    2009-07-07

    For reasons that are unclear the production of embryonic stem cells from ungulates has proved elusive. Here, we describe induced pluripotent stem cells (iPSC) derived from porcine fetal fibroblasts by lentiviral transduction of 4 human (h) genes, hOCT4, hSOX2, hKLF4, and hc-MYC, the combination commonly used to create iPSC in mouse and human. Cells were cultured on irradiated mouse embryonic fibroblasts (MEF) and in medium supplemented with knockout serum replacement and FGF2. Compact colonies of alkaline phosphatase-positive cells emerged after approximately 22 days, providing an overall reprogramming efficiency of approximately 0.1%. The cells expressed porcine OCT4, NANOG, and SOX2 and had high telomerase activity, but also continued to express the 4 human transgenes. Unlike human ESC, the porcine iPSC (piPSC) were positive for SSEA-1, but negative for SSEA-3 and -4. Transcriptional profiling on Affymetrix (porcine) microarrays and real time RT-PCR supported the conclusion that reprogramming to pluripotency was complete. One cell line, ID6, had a normal karyotype, a cell doubling time of approximately 17 h, and has been maintained through >220 doublings. The ID6 line formed embryoid bodies, expressing genes representing all 3 germ layers when cultured under differentiating conditions, and teratomas containing tissues of ectoderm, mesoderm, and endoderm origin in nude mice. We conclude that porcine somatic cells can be reprogrammed to form piPSC. Such cell lines derived from individual animals could provide a means for testing the safety and efficacy of stem cell-derived tissue grafts when returned to the same pigs at a later age.

  7. Reprogramming T cell Lymphocytes to Induced Pluripotent Stem Cells

    NASA Astrophysics Data System (ADS)

    Bared, Kalia

    The discovery of induced pluripotent stem cells (iPSC) provided a novel technology for the study of development and pharmacology and complement embryonic stem cells (ES) for cell therapy applications. Though iPSC are derived from adult tissue they are comparable to ES cells in their behavior; multi-lineage differentiation and self-renewal. This makes iPSC research appealing because they can be studied in great detail and expanded in culture broadly. Fibroblasts were the first cell type reprogrammed to an iPSC using a retrovirus vector, since then alternative cell types including lymphocytes have been used to generate iPSC. Different types of vectors have also been developed to enhance iPSC formation and quality. However, specific T lymphocyte subsets have not been shown to reprogram to a pluripotent state to date. Here, we proposed to derive iPSC from peripheral blood effector and central memory T cells, reasoning that the resultant iPSC will maintain the epigenetic memory of a T lymphocyte, including the T cell receptor (TCR) gene rearrangement. This epigenetic memory will enable the differentiation and expansion of T cell iPSC into professional T cells containing a specific TCR. These could then be used for cell therapy to target specific antigens, as well as to improve culture techniques to expand T cells in vitro. We studied different gene delivery methods to derive iPSC from different types of T lymphocytes. We assessed the viability of viral transduction using flow cytometry to detect green fluorescent marker contained in the viral construct and quantitative real time polymerase chain reaction (qRT-PCR) to detect Oct4, Klf4, Sox2, and c-Myc gene expression. Our results demonstrate that the Sendai virus construct is the most feasible platform to reprogram T lymphocytes. We anticipate that this platform will provide an efficient and safe approach to derive iPSC from different T cell subsets, including memory T cells.

  8. Induction of Germ Cell-like Cells from Porcine Induced Pluripotent Stem Cells

    PubMed Central

    Wang, Hanning; Xiang, Jinzhu; Zhang, Wei; Li, Junhong; Wei, Qingqing; Zhong, Liang; Ouyang, Hongsheng; Han, Jianyong

    2016-01-01

    The ability to generate germ cells from pluripotent stem cells (PSCs) is valuable for human regenerative medicine and animal breeding. Germ cell-like cells (GCLCs) have been differentiated from mouse and human PSCs, but not from porcine PSCs, which are considered an ideal model for stem cell applications. Here, we developed a defined culture system for the induction of primordial germ cell-like cells (PGCLCs) from porcine induced PSCs (piPSCs). The identity of the PGCLCs was characterized by observing cell morphology, detecting germ cell marker gene expression and evaluating epigenetic properties. PGCLCs could further differentiate into spermatogonial stem cell-like cells (SSCLCs) in vitro. Importantly, meiosis occurred during SSCLC induction. Xenotransplantation of GCLCs into seminiferous tubules of infertile immunodeficient mice resulted in immunohistochemically identifiable germ cells in vivo. Overall, our study provides a feasible strategy for directing piPSCs to the germ cell fate and lays a foundation for exploring germ cell development mechanisms. PMID:27264660

  9. How tolerogenic dendritic cells induce regulatory T cells

    PubMed Central

    Maldonado, Roberto A.; von Andrian, Ulrich H.

    2010-01-01

    Since their discovery by Steinman and Cohn in 1973, dendritic cells (DCs) have become increasingly recognized for their crucial role as regulators of innate and adaptive immunity. DCs are exquisitely adept at acquiring, processing and presenting antigens to T cells. They also adjust the context (and hence the outcome) of antigen presentation in response to a plethora of environmental inputs that signal the occurence of pathogens or tissue damage. Such signals generally boost DC maturation, which promotes their migration from peripheral tissues into and within secondary lymphoid organs and their capacity to induce and regulate effector T cell responses. Conversely, more recent observations indicate that DCs are also crucial to ensure immunological peace. Indeed, DCs constantly present innocuous self and non-self antigens in a fashion that promotes tolerance, at least in part, through the control of regulatory T cells (Tregs). Tregs are specialized T cells that exert their immuno-suppressive function through a variety of mechanisms affecting both DCs and effector cells. Here, we review recent advances in our understanding of the relationship between tolerogenic DCs and Tregs. PMID:21056730

  10. Gambogic acid induces apoptosis in diffuse large B-cell lymphoma cells via inducing proteasome inhibition.

    PubMed

    Shi, Xianping; Lan, Xiaoying; Chen, Xin; Zhao, Chong; Li, Xiaofen; Liu, Shouting; Huang, Hongbiao; Liu, Ningning; Zang, Dan; Liao, Yuning; Zhang, Peiquan; Wang, Xuejun; Liu, Jinbao

    2015-04-08

    Resistance to chemotherapy is a great challenge to improving the survival of patients with diffuse large B-cell lymphoma (DLBCL), especially those with activated B-cell-like DLBCL (ABC-DLBCL). Therefore it is urgent to search for novel agents for the treatment of DLBCL. Gambogic acid (GA), a small molecule derived from Chinese herb gamboges, has been approved for Phase II clinical trial for cancer therapy by Chinese FDA. In the present study, we investigated the effect of GA on cell survival and apoptosis in DLBCL cells including both GCB- and ABC-DLBCL cells. We found that GA induced growth inhibition and apoptosis of both GCB- and ABC-DLBCL cells in vitro and in vivo, which is associated with proteasome malfunction. These findings provide significant pre-clinical evidence for potential usage of GA in DLBCL therapy particularly in ABC-DLBCL treatment.

  11. Strategies to generate induced pluripotent stem cells.

    PubMed

    Hayes, Michael; Zavazava, Nicholas

    2013-01-01

    The isolation of embryonic stem cells (ESCs) has furthered our understanding of normal embryonic development and fueled the progression of stem cell derived therapies. However, the generation of ESCs requires the destruction of an embryo, making the use of these cells ethically controversial. In 2006 the Yamanaka group overcame this ethical controversy when they described a protocol whereby somatic cells could be dedifferentiated into a pluripotent state following the transduction of a four transcription factor cocktail. Following this initial study numerous groups have described protocols to generate induced pluripotent stem cells (iPSCs). These protocols have simplified the reprogramming strategy by employing polycistronic reprogramming cassettes and flanking such polycistronic cassettes with loxP or piggyBac recognition sequences. Thus, these strategies allow for excision of the entire transgene cassette, limiting the potential for the integration of exogenous transgenes to have detrimental effect. Others have prevented the potentially deleterious effects of integrative reprogramming strategies by using non-integrating adenoviral vectors, traditional recombinant DNA transfection, transfection of minicircle DNA, or transfection of episomally maintained EBNA1/OriP plasmids. Interestingly, transfection of mRNA or miRNA has also been shown to be capable of reprogramming cells, and multiple groups have developed protocols using cell penetrating peptide tagged reprogramming factors to de-differentiate somatic cells in the absence of exogenous nucleic acid. Despite the numerous different reprogramming strategies that have been developed, the reprogramming process remains extremely inefficient. To overcome this inefficiency multiple groups have successfully used small molecules such as valproic acid, sodium butyrate, PD0325901, and others to generate iPSCs.The fast paced field of cellular reprogramming has recently produced protocols to generate iPSCs using non

  12. Metabolic Stress Induced by Arginine Deprivation Induces Autophagy Cell Death in Prostate Cancer

    DTIC Science & Technology

    2010-08-01

    Arginine deiminase as a novel therapy for prostate cancer induces autophagy and caspase-independent apoptosis. Cancer Research, 69(2):700-708...TITLE: Metabolic stress induced by arginine deprivation induces autophagy cell death in prostate cancer PRINCIPAL INVESTIGATOR: Richard Bold, MD...4. TITLE AND SUBTITLE Metabolic stress induced by arginine deprivation induces autophagy cell 5a. CONTRACT NUMBER death in prostate cancer 5b

  13. [Current progress and application prospects of induced pluripotent stem cells].

    PubMed

    Qin, Tong; Miao, Xiang-Yang

    2010-12-01

    Induced pluripotent stem (iPS) cells can be directly generated from somatic cells by transduction of a few defined transcription factors. This technique avoids immunological rejection and ethical difficulties, which is a great revolution in life sciences. Like embryonic stem (ES) cells, iPS cells have the ability to self-renew through mitotic cell division and thus remain in its undifferentiated state and the ability to differentiate into not only all derivatives of the three primary germ layers: ectoderm, endoderm, and mesoderm, but also many mature cells in vitro. Therefore, iPS cells are important for theoretic study and therapeutic application. Here, we discuss recent advances in generating induced pluripotent stem cells, different reprogramming methods, and clinical applications of iPS cells. Finally, current problems of iPS cells and its prospects in transgenic animals are also discussed. This article is a summary of current research advances in reprogramming cells into induced pluripotent stem cells.

  14. Artesunate induces AIF-dependent apoptosis in A549 cells

    NASA Astrophysics Data System (ADS)

    Zhou, Chen-juan; Chen, Tong-Sheng

    2012-03-01

    Artesunate (ART), a semi-synthetic derivative of the sesquiterpene artemisinin extracted from the Chinese herb Artemisia annua, exerts a broad spectrum of clinical activity against human cancers. It has been shown that ART induces cancer cells death through apoptosis pathway. This study investigated whether ART treatment induced reactive oxygen species (ROS)-dependent cell death in the apoptosis fashion in human lung adenocarconoma A549 cell line and the proapoptotic protein apoptosis inducing factor (AIF) is involved in ART-induced apoptosis. Cells treated with ART exhibited typical apoptotic morphology as chromatin condensation, margination and shrunken nucleus. ART treatment also induced a loss of mitochondrial membrane potential and AIF release from mitochondria. Silencing AIF can remarkable attenuated ART-induced apoptosis. Collectively, ART induces apoptosis by caspase-independent intrinsic pathway in A549 cells.

  15. PDGF upregulates CLEC-2 to induce T regulatory cells.

    PubMed

    Agrawal, Sudhanshu; Ganguly, Sreerupa; Hajian, Pega; Cao, Jia-Ning; Agrawal, Anshu

    2015-10-06

    The effect of platelet derived growth factor (PDGF) on immune cells is not elucidated. Here, we demonstrate PDGF inhibited the maturation of human DCs and induced IL-10 secretion. Culture of PDGF-DCs with T cells induced the polarization of T cells towards FoxP3 expressing T regulatory cells that secreted IL-10. Gene expression studies revealed that PDGF induced the expression of C-type lectin like receptor member 2, (CLEC-2) receptor on DCs. Furthermore, DCs transfected with CLEC-2 induced T regulatory cells in DC-T cell co-culture. CLEC-2 is naturally expressed on platelets. Therefore, to confirm whether CLEC-2 is responsible for inducing the T regulatory cells, T cells were cultured with either CLEC-2 expressing platelets or soluble CLEC-2. Both conditions resulted in the induction of regulatory T cells. The generation of T regulatory cells was probably due to the binding of CLEC-2 with its ligand podoplanin on T cells, since crosslinking of podoplanin on the T cells also resulted in the induction of T regulatory cells. These data demonstrate that PDGF upregulates the expression of CLEC-2 on cells to induce T regulatory cells.

  16. [Dementia study using induced pluripotent stem cells].

    PubMed

    Matsuzono, Kosuke; Abe, Koji; Inoue, Haruhisa

    2016-03-01

    Recent developments in induced pluripotent stem cell (iPSC) technology have facilitated, and have contributed to overcome the difficulty of modeling dementia caused by Alzheimer's disease (AD), dementia with Lewy bodies (DLB), and frontotemporal lobar degeneration (FTLD), etc. The following models using iPSCs were reported: the pathophysiology caused by gene mutations such as presenilin or amyloid β precursor protein in AD, α-synuclein in DLB, and microtubule-associated protein tau, fused in sarcoma, progranulin, or chromosome 9 open reading frame 72 in FTLD, anti-AD drug screening, sortilin-related receptor L 1 haplotype influence in sporadic AD, and amyloid β secretion in Down syndrome. Patient-specific iPSC could be expected to reveal the disease pathology and lead to drug discoveries for dementia patients.

  17. Mechanisms of sulindac-induced apoptosis and cell cycle arrest.

    PubMed

    Jung, Barbara; Barbier, Valerie; Brickner, Howard; Welsh, John; Fotedar, Arun; McClelland, Michael

    2005-02-28

    The mechanism underlying the chemopreventive effects of the non-steroidal anti-inflammatory drug sulindac remains unclear. Its active metabolite, sulindac sulfide, induces cell cycle arrest as well as apoptosis in mammalian cell lines. We now show that in murine thymocytes, sulindac sulfide-induced cell death is p53, bax, Fas, and FasL independent. In contrast, bcl2 transgenic thymocytes are resistant to sulindac sulfide-induced apoptosis. In addition, we demonstrate that sulindac sulfide-induced cell cycle arrest in mouse embryonic fibroblasts (MEFs) is partly mediated by the retinoblastoma tumor suppressor protein (Rb) and the cyclin kinase inhibitor p21waf1/cip1. Furthermore, MEFs deficient in p21 or Rb are more susceptible to sulindac sulfide-induced cell death. These results suggest that sulindac may selectively target premalignant cells with cell cycle checkpoint deficits.

  18. α-Mangostin Induces Apoptosis and Cell Cycle Arrest in Oral Squamous Cell Carcinoma Cell

    PubMed Central

    Kwak, Hyun-Ho; Park, Bong-Soo

    2016-01-01

    Mangosteen has long been used as a traditional medicine and is known to have antibacterial, antioxidant, and anticancer effects. Although the effects of α-mangostin, a natural compound extracted from the pericarp of mangosteen, have been investigated in many studies, there is limited data on the effects of the compound in human oral squamous cell carcinoma (OSCC). In this study, α-mangostin was assessed as a potential anticancer agent against human OSCC cells. α-Mangostin inhibited cell proliferation and induced cell death in OSCC cells in a dose- and time-dependent manner with little to no effect on normal human PDLF cells. α-Mangostin treatment clearly showed apoptotic evidences such as nuclear fragmentation and accumulation of annexin V and PI-positive cells on OSCC cells. α-Mangostin treatment also caused the collapse of mitochondrial membrane potential and the translocation of cytochrome c from the mitochondria into the cytosol. The expressions of the mitochondria-related proteins were activated by α-mangostin. Treatment with α-mangostin also induced G1 phase arrest and downregulated cell cycle-related proteins (CDK/cyclin). Hence, α-mangostin specifically induces cell death and inhibits proliferation in OSCC cells via the intrinsic apoptosis pathway and cell cycle arrest at the G1 phase, suggesting that α-mangostin may be an effective agent for the treatment of OSCC. PMID:27478478

  19. Laser-induced lipolysis on adipose cells

    NASA Astrophysics Data System (ADS)

    Solarte, Efrain; Gutierrez, O.; Neira, Rodrigo; Arroyave, J.; Isaza, Carolina; Ramirez, Hugo; Rebolledo, Aldo F.; Criollo, Willian; Ortiz, C.

    2004-10-01

    Recently, a new liposuction technique, using a low-level laser (LLL) device and Ultrawet solution prior to the procedure, demonstrated the movement of fat from the inside to the outside of the adipocyte (Neira et al., 2002). To determine the mechanisms involved, we have performed Scanning and Transmission Electron Microscopy studies; Light transmittance measurements on adipocyte dilutions; and a study of laser light propagation in adipose tissue. This studies show: 1. Cellular membrane alterations. 2. LLL is capable to reach the deep adipose tissue layer, and 3. The tumescence solution enhances the light propagation by clearing the tissue. MRI studies demonstrated the appearance of fat on laser treated abdominal tissue. Besides, adipocytes were cultivated and irradiated to observe the effects on isolated cells. These last studies show: 1. 635 nm-laser alone is capable of mobilizing cholesterol from the cell membrane; this action is enhanced by the presence of adrenaline and lidocaine. 2. Intracellular fat is released from adipocytes by co joint action of adrenaline, aminophyline and 635 nm-laser. Results are consistent with a laser induced cellular process, which causes fat release from the adipocytes into the intercellular space, besides the modification of the cellular membranes.

  20. HIV transcription is induced with some forms of cell killing

    SciTech Connect

    Woloschak, G.E.; Schreck, S.; Panozzo, J.; Chang-Liu, C.-M.; Libertin, C.R.

    1996-11-01

    Using HeLa cells stably transfected with an HIV-LTR-CAT construct`, we demonstrated a peak in CAT induction that occurs in viable (but not necessarily cell-division-competent) cells 24 h following exposure to some cell-killing agents. {Gamma} rays were the only cell-killing agent which did not induce HIV transcription; this can be attributed to the fact that {gamma}-ray-induced apoptotic death requires function p53, which is missing in HeLa cells. For all other agents, HIV-LTR induction was dose-dependent and correlated with the amount of cell killing that occurred in the culture.

  1. Molecular Mechanisms of Sulfur Mustard Vesicant-Induced Cell Death: Early and Late Cell Responses

    DTIC Science & Technology

    2005-10-01

    Mechanisms of Sulfur Mustard Vesicant-Induced Cell Death : Early and late cell responses 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...It possess mutagenic, carcinogenic, cytotoxic, vesicating effects, and results in cell death . However, the biomedical mechanism of cell death induced... cell death via apoptosis: • In early stage, It induces JNK activity and then triggers apoptosis pathway. • In late stage, sulphur mustard attacks the

  2. Oxidized low-density lipoprotein induces hematopoietic stem cell senescence.

    PubMed

    Zhang, Xian-Ping; Zhang, Gui-Hai; Wang, Yu-Ying; Liu, Jun; Wei, Qiang; Xu, Chun-Yan; Wang, Jian-Wei; Wang, Ya-Ping

    2013-09-01

    We have investigated oxidized low-density lipoprotein (ox-LDL) induced senescence in hematopoietic stem cells (HCs). Mouse Sca-1+ HCs were separated and purified using the magnetic activated cell sorting technique. Ox-LDL induced significant senescence in HCs measured by SA-β-Gal staining, and reduced CFU-Mix colony-forming capacity, arresting cells at G0/G1 phase. In agreement with the cell cycle arrest, ox-LDL markedly reduced the expression of CDK4, cyclin D, and cyclin E. As possible contributing factors for cell senescence, ox-LDL also induced cellular oxidative stress and reduced telomerase activity.

  3. Cannabinoids induce incomplete maturation of cultured human leukemia cells

    SciTech Connect

    Murison, G.; Chubb, C.B.H.; Maeda, S.; Gemmell, M.A.; Huberman, E.

    1987-08-01

    Monocyte maturation markers were induced in cultured human myeloblastic ML-2 leukemia cells after treatment for 1-6 days with 0.03-30 ..mu..M ..delta../sup 9/-tetrahydrocannabinol (THC), the major psychoactive component of marijuana. After a 2-day or longer treatment, 2- to 5-fold increases were found in the percentages of cells exhibiting reactivity with either the murine OKM1 monoclonal antibody of the Leu-M5 monoclonal antibody, staining positively for nonspecific esterase activity, and displaying a promonocyte morphology. The increases in these differentiation markers after treatment with 0.03-1 ..mu..M THC were dose dependent. At this dose range, THC did not cause an inhibition of cell growth. The THC-induced cell maturation was also characterized by specific changes in the patterns of newly synthesized proteins. The THC-induced differentiation did not, however, result in cells with a highly developed mature monocyte phenotype. However, treatment of these incompletely matured cells with either phorbol 12-myristate 13-acetate of 1..cap alpha..,25-dihydroxycholecalciferol, which are inducers of differentiation in myeloid leukemia cells (including ML-2 cells), produced cells with a mature monocyte morphology. The ML-2 cell system described here may be a useful tool for deciphering critical biochemical events that lead to the cannabinoid-induced incomplete cell differentiation of ML-2 cells and other related cell types. Findings obtained from this system may have important implications for studies of cannabinoid effects on normal human bone-marrow progenitor cells.

  4. Glial cell derived neurotrophic factor induces spermatogonial stem cell marker genes in chicken mesenchymal stem cells.

    PubMed

    Boozarpour, Sohrab; Matin, Maryam M; Momeni-Moghaddam, Madjid; Dehghani, Hesam; Mahdavi-Shahri, Naser; Sisakhtnezhad, Sajjad; Heirani-Tabasi, Asieh; Irfan-Maqsood, Muhammad; Bahrami, Ahmad Reza

    2016-06-01

    Mesenchymal stem cells (MSCs) are known with the potential of multi-lineage differentiation. Advances in differentiation technology have also resulted in the conversion of MSCs to other kinds of stem cells. MSCs are considered as a suitable source of cells for biotechnology purposes because they are abundant, easily accessible and well characterized cells. Nowadays small molecules are introduced as novel and efficient factors to differentiate stem cells. In this work, we examined the potential of glial cell derived neurotrophic factor (GDNF) for differentiating chicken MSCs toward spermatogonial stem cells. MSCs were isolated and characterized from chicken and cultured under treatment with all-trans retinoic acid (RA) or glial cell derived neurotrophic factor. Expression analysis of specific genes after 7days of RA treatment, as examined by RT-PCR, proved positive for some germ cell markers such as CVH, STRA8, PLZF and some genes involved in spermatogonial stem cell maintenance like BCL6b and c-KIT. On the other hand, GDNF could additionally induce expression of POU5F1, and NANOG as well as other genes which were induced after RA treatment. These data illustrated that GDNF is relatively more effective in diverting chicken MSCs towards Spermatogonial stem cell -like cells in chickens and suggests GDNF as a new agent to obtain transgenic poultry, nevertheless, exploitability of these cells should be verified by more experiments.

  5. Effect of chaetocin on renal cell carcinoma cells and cytokine-induced killer cells.

    PubMed

    Rombo, Roman; Weiher, Hans; Schmidt-Wolf, Ingo G H

    2016-01-01

    We examined the cytotoxic effects of chaetocin on clear cell renal cell carcinoma (ccRCC) cells and the possibility to combine the effects of chaetocin with the effects of cytokine-induced killer cells (CIK) assayed by MTT assay and FACS analysis. Chaetocin is a thiodioxopiperazine produced by fungi belonging to the chaetomiaceae family. In 2007, it was first reported that chaetocin shows potent and selective ex vivo anti-cancer activity by inducing reactive oxygen species. CIK cells are generated from CD3+/CD56- T lymphocytes with double negative CD4-/CD8- phenotype that are isolated from human blood. The addition of distinct interleukins and antibodies results in the generation of CIK cells that are able to specifically target and destroy renal carcinoma cells. The results of this research state that the anti-ccRCC activity of chaetocin is weak and does not show a high grade of selectivity on clear cell renal cell carcinoma cells. Although the CIK cells show a high grade of selective anti-ccRCC activity, this effect could not be improved by the addition of chaetocin. So chaetocin seems to be no suitable agent for specific targeting ccRCC cells or for the combination therapy with CIK cells in renal cancer.

  6. Effect of chaetocin on renal cell carcinoma cells and cytokine-induced killer cells

    PubMed Central

    Rombo, Roman; Weiher, Hans; Schmidt-Wolf, Ingo G.H.

    2016-01-01

    We examined the cytotoxic effects of chaetocin on clear cell renal cell carcinoma (ccRCC) cells and the possibility to combine the effects of chaetocin with the effects of cytokine-induced killer cells (CIK) assayed by MTT assay and FACS analysis. Chaetocin is a thiodioxopiperazine produced by fungi belonging to the chaetomiaceae family. In 2007, it was first reported that chaetocin shows potent and selective ex vivo anti-cancer activity by inducing reactive oxygen species. CIK cells are generated from CD3+/CD56- T lymphocytes with double negative CD4-/CD8- phenotype that are isolated from human blood. The addition of distinct interleukins and antibodies results in the generation of CIK cells that are able to specifically target and destroy renal carcinoma cells. The results of this research state that the anti-ccRCC activity of chaetocin is weak and does not show a high grade of selectivity on clear cell renal cell carcinoma cells. Although the CIK cells show a high grade of selective anti-ccRCC activity, this effect could not be improved by the addition of chaetocin. So chaetocin seems to be no suitable agent for specific targeting ccRCC cells or for the combination therapy with CIK cells in renal cancer. PMID:27141211

  7. Induced stem cells as a novel multiple sclerosis therapy

    PubMed Central

    Xie, Chong; Liu, Yan-qun; Guan, Yang-tai; Zhang, Guang-Xian

    2016-01-01

    Stem cell replacement is providing hope for many degenerative diseases that lack effective therapeutic methods including multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system. Transplantation of neural stem cells or mesenchymal stem cells is a potential therapy for MS thanks to their capacity for cell repopulation as well as for their immunomodulatory and neurotrophic properties. Induced pluripotent stem cell (iPSC), an emerging cell source in regenerative medicine, is also being tested for the treatment of MS. Remarkable improvement in mobility and robust remyelination have been observed after transplantation of iPSC-derived neural cells into demyelinated models. Direct reprogramming of somatic cells into induced neural cells, such as induced neural stem cells (iNSCs) and induced oligodendrocyte progenitor cells (iOPCs), without passing through the pluripotency stage, is an alternative for transplantation that has been proved effective in the congenital hypomyelination model. iPSC technology is rapidly progressing as efforts are being made to increase the efficiency of iPSC therapy and reduce its potential side effects. In this review, we discuss the recent advances in application of stem cells, with particular focus on induced stem/progenitor cells (iPSCs, iNSC, iOPCs), which are promising in the treatment of MS. PMID:25732737

  8. Sertoli cell condition medium can induce germ like cells from bone marrow derived mesenchymal stem cells

    PubMed Central

    Monfared, Mahdieh Hajian; Minaee, Bagher; Rastegar, Tayebeh; Khrazinejad, Ebrahim; Barbarestani, Mohammad

    2016-01-01

    Objective(s): Although many researchers have confirmed induction of germ cells from bone marrow mesenchymal stem cells (BMMSCs), there are no reports that confirm spontaneous differentiation of germ cells from BMMSCs. In this study, we have evaluated the effect of adult Sertoli cell condition medium (SCCM) as a mutative factor in the induction of germ cells from BMMSCs. Materials and Methods: BMMSCs were collected from the bone marrow of 6-8-week old NMRI mice and their mesenchymal entities were proven using superficial markers (expression of CD44 and CD73 and non-expresion of CD45 and CD11b) by fow cytometry. Their multi-potential entities were proved with differentiation to osteogenic and adipogenic cells for 21 days. Also isolated Sertoli cells were enriched using lectin coated plates and Sertoli cell condition medium (SCCM) was collected. Sertoli cells were identified by immunocytochemistry and Vimentin marker. The cells were then differentiated into germ cells with SCCM for 2 weeks. Finally induced cells were evaluated by RT-PCR and immunocytochemistry. Results: Differentiation of mesenchymal stem cells to osteoblast and adipocyte showed their multi-potential property. Expression of CD44 and CD73 and non-expression of CD45 and CD11b confirmed mesenchyme cells. Immunocytochemistry and RT-PCR results showed expression of germ cells specific marker (Mvh). Conclusion: This study confirmed the effect of SCCM as a motivational factor that can used for differentiation of germ cells from BMMSCs. PMID:27917274

  9. Dendritic cells fused with different pancreatic carcinoma cells induce different T-cell responses

    PubMed Central

    Andoh, Yoshiaki; Makino, Naohiko; Yamakawa, Mitsunori

    2013-01-01

    Background It is unclear whether there are any differences in the induction of cytotoxic T lymphocytes (CTL) and CD4+CD25high regulatory T-cells (Tregs) among dendritic cells (DCs) fused with different pancreatic carcinomas. The aim of this study was to compare the ability to induce cytotoxicity by human DCs fused with different human pancreatic carcinoma cell lines and to elucidate the causes of variable cytotoxicity among cell lines. Methods Monocyte-derived DCs, which were generated from peripheral blood mononuclear cells (PBMCs), were fused with carcinoma cells such as Panc-1, KP-1NL, QGP-1, and KP-3L. The induction of CTL and Tregs, and cytokine profile of PBMCs stimulated by fused DCs were evaluated. Results The cytotoxicity against tumor targets induced by PBMCs cocultured with DCs fused with QGP-1 (DC/QGP-1) was very low, even though PBMCs cocultured with DCs fused with other cell lines induced significant cytotoxicity against the respective tumor target. The factors causing this low cytotoxicity were subsequently investigated. DC/QGP-1 induced a significant expansion of Tregs in cocultured PBMCs compared with DC/KP-3L. The level of interleukin-10 secreted in the supernatants of PBMCs cocultured with DC/QGP-1 was increased significantly compared with that in DC/KP-3L. Downregulation of major histocompatibility complex class I expression and increased secretion of vascular endothelial growth factor were observed with QGP-1, as well as in the other cell lines. Conclusion The present study demonstrated that the cytotoxicity induced by DCs fused with pancreatic cancer cell lines was different between each cell line, and that the reduced cytotoxicity of DC/QGP-1 might be related to the increased secretion of interleukin-10 and the extensive induction of Tregs. PMID:23378772

  10. Induced Pluripotent Stem Cells: Development in the Ophthalmologic Field

    PubMed Central

    2016-01-01

    Human induced pluripotent stem cells (iPSCs) are a type of stem cells that can be derived from human somatic cells by introducing certain transcription factors. Induced pluripotent stem cells can divide indefinitely and are able to differentiate into every cell type, which make them viable for transplantation and individual disease modeling. Recently, various ocular cells, including corneal epithelial-like cells, retinal pigment epithelium (RPE) cells displaying functions similar to native RPE, photoreceptors, and retinal ganglion cells, have all been successfully derived from iPSCs. Transplantation of these cells in animal models showed great promise for reversing blindness, and the first clinical trial on humans started in 2013. Despite these promising results, more research is in demand for preventing inadvertent tumor growth, developing precise functionality of the cells, and promoting integration into the host tissue. PMID:27594887

  11. Entamoeba histolytica induces cell death of HT29 colonic epithelial cells via NOX1-derived ROS.

    PubMed

    Kim, Kyeong Ah; Kim, Ju Young; Lee, Young Ah; Min, Arim; Bahk, Young Yil; Shin, Myeong Heon

    2013-02-01

    Entamoeba histolytica, which causes amoebic colitis and occasionally liver abscess in humans, is able to induce host cell death. However, signaling mechanisms of colon cell death induced by E. histolytica are not fully elucidated. In this study, we investigated the signaling role of NOX in cell death of HT29 colonic epithelial cells induced by E. histolytica. Incubation of HT29 cells with amoebic trophozoites resulted in DNA fragmentation that is a hallmark of apoptotic cell death. In addition, E. histolytica generate intracellular reactive oxygen species (ROS) in a contact-dependent manner. Inhibition of intracellular ROS level with treatment with DPI, an inhibitor of NADPH oxidases (NOXs), decreased Entamoeba-induced ROS generation and cell death in HT29 cells. However, pan-caspase inhibitor did not affect E. histolytica-induced HT29 cell death. In HT29 cells, catalytic subunit NOX1 and regulatory subunit Rac1 for NOX1 activation were highly expressed. We next investigated whether NADPH oxidase 1 (NOX1)-derived ROS is closely associated with HT29 cell death induced by E. histolytica. Suppression of Rac1 by siRNA significantly inhibited Entamoeba-induced cell death. Moreover, knockdown of NOX1 by siRNA, effectively inhibited E. histolytica-triggered DNA fragmentation in HT29 cells. These results suggest that NOX1-derived ROS is required for apoptotic cell death in HT29 colon epithelial cells induced by E. histolytica.

  12. X-ray-induced cell death: Apoptosis and necrosis

    SciTech Connect

    Nakano, Hisako; Shinohara, Kunio

    1994-10-01

    X-ray-induced cell death in MOLT-4N1, a subclone of MOLT-4 cells, and M10 cells was studied with respect to their modes of cell death, apoptosis and necrosis. MOLT-4N1 cells showed radiosensitivity similar to that of M10 cells, a radiosensitive mutant of L5178Y, as determined by the colony formation assay. Analysis of cell size demonstrated that MOLT-4N1 cells increased in size at an early stage after irradiation and then decreased to a size smaller than that of control cells, whereas the size of irradiated M10 cells increased continuously. Apoptosis detected by morphological changes and DNA ladder formation (the cleavage of DNA into oligonucleosomal fragments) occurred in X-irradiated MOLT-4N1 cells but not in M10 cells. Pulsed-field gel electrophoresis showed that the ladder formation involved an intermediate-sized DNA (about 20 kbp). Most of the DNA was detected at the origin in both methods of electrophoresis in the case of M10 cells, though a trace amount of ladder formation was observed. Heat treatment of M10 cells induced apoptosis within 30 min after treatment, in contrast to MOLT-4N1 cells. The results suggest that apoptosis and necrosis are induced by X rays in a manner which is dependent on the cell line irrespective of the capability of the cells to develop apoptosis. DNA fragmentation was the earliest change observed in the development of apoptosis. 27 refs., 8 figs., 1 tab.

  13. Modeling Aggressive Medulloblastoma Using Human-Induced Pluripotent Stem Cells

    DTIC Science & Technology

    2015-07-01

    AWARD NUMBER: W81XWH-14-1-0176 TITLE: Modeling Aggressive Medulloblastoma Using Human-Induced Pluripotent Stem Cells PRINCIPAL INVESTIGATOR...Prescribed by ANSI Std. Z39.18 July 2015 Annual 01-July 2014 -- 30 Jun 2015 Modeling Aggressive Medulloblastoma Using Human-Induced Pluripotent Stem...induced pluripotent stem cells by Atoh1 induction can be efficiently transformed by MYC oncogene to form aggressive brain tumors that recapitulate human

  14. Osteoblasts Protect AML Cells from SDF-1-Induced Apoptosis

    PubMed Central

    Kremer, Kimberly N.; Dudakovic, Amel; McGee-Lawrence, Meghan E.; Philips, Rachael L.; Hess, Allan D.; Smith, B. Douglas; van Wijnen, Andre J.; Karp, Judith E.; Kaufmann, Scott H.; Westendorf, Jennifer J.; Hedin, Karen E.

    2014-01-01

    The bone marrow provides a protective environment for acute myeloid leukemia (AML) cells that often allows leukemic stem cells to survive standard chemotherapeutic regimens. Targeting these leukemic stem cells within the bone marrow is critical for preventing relapse. We recently demonstrated that SDF-1, a chemokine abundant in the bone marrow, induces apoptosis in AML cell lines and in patient samples expressing high levels of its receptor, CXCR4. Here we show that a subset of osteoblast lineage cells within the bone marrow can protect AML cells from undergoing apoptosis in response to the SDF-1 naturally present in that location. In co-culture systems, osteoblasts at various stages of differentiation protected AML cell lines and patient isolates from SDF-1-induced apoptosis. The differentiation of the osteoblast cell lines, MC3T3 and W-20-17, mediated this protection via a cell contact-independent mechanism. In contrast, bone marrow-derived mesenchymal cells, the precursors of osteoblasts, induced apoptosis in AML cells via a CXCR4-dependent mechanism and failed to protect AML cells from exogenously added SDF-1. These results indicate that osteoblasts in the process of differentiation potently inhibit the SDF-1-driven apoptotic pathway of CXCR4-expressing AML cells residing in the bone marrow. Drugs targeting this protective mechanism could potentially provide a new approach to treating AML by enhancing the SDF-1-induced apoptosis of AML cells residing within the bone marrow microenvironment. PMID:24851270

  15. Distinct mechanisms of neonatal tolerance induced by dendritic cells and thymic B cells

    PubMed Central

    1991-01-01

    To assess the role of different types of antigen-presenting cells (APC) in the induction of tolerance, we isolated B cells, macrophages, and dendritic cells from thymus and spleen, and injected these into neonatal BALB/c mice across an Mls-1 antigenic barrier. One week after injection of APC from Mls-1-incompatible mice or from control syngeneic mice, we measured the number of thymic, Mls-1a-reactive, V beta 6+ T cells and the capacity of thymocytes to induce a graft-vs.-host (GVH) reaction in popliteal lymph nodes of Mls-1a mice. Injection of thymic but not spleen B cells deleted thymic, Mls-1a-reactive V beta 6+ T cells and induced tolerance in the GVH assay. The thymic B cells were primarily of the CD5+ type, and fluorescence-activated cell sorter- purified CD5+ thymic B cells were active. Injection of dendritic cells from spleen or thymus also induced tolerance, but the V beta 6 cells were anergized rather than deleted. Macrophages from thymus did not induce tolerance. Dendritic cells and thymic B cells were also effective in inducing tolerance even when injected into Mls-, major histocompatibility complex-incompatible, I-E- mice, but only thymic B cells depleted V beta 6-expressing T cells. Therefore, different types of bone marrow-derived APC have different capacities for inducing tolerance, and the active cell types (dendritic cells and CD5+ thymic B cells) can act by distinct mechanisms. PMID:1900075

  16. Efficient killing of radioresistant breast cancer cells by cytokine-induced killer cells.

    PubMed

    Guo, Qingming; Zhu, Danni; Bu, Xiaocui; Wei, Xiaofang; Li, Changyou; Gao, Daiqing; Wei, Xiaoqiang; Ma, Xuezhen; Zhao, Peng

    2017-03-01

    Recurrence of breast cancer after radiotherapy may be partly explained by the presence of radioresistant cells. Thus, it would be desirable to develop an effective therapy against radioresistant cells. In this study, we demonstrated the intense antitumor activity of cytokine-induced killer cells against MCF-7 and radioresistant MCF-7 cells, as revealed by cytokine-induced killer-mediated cytotoxicity, tumor cell proliferation, and tumor invasion. Radioresistant MCF-7 cells were more susceptible to cytokine-induced killer cell killing. The stronger cytotoxicity of cytokine-induced killer cells against radioresistant MCF-7 cells was dependent on the expression of major histocompatibility complex class I polypeptide-related sequence A/B on radioresistant MCF-7 cells after exposure of cytokine-induced killer cells to sensitized targets. In addition, we demonstrated that cytokine-induced killer cell treatment sensitized breast cancer cells to chemotherapy via the downregulation of TK1, TYMS, and MDR1. These results indicate that cytokine-induced killer cell treatment in combination with radiotherapy and/or chemotherapy may induce synergistic antitumor activities and represent a novel strategy for breast cancer.

  17. Polyphosphate induces matrix metalloproteinase-3-mediated proliferation of odontoblast-like cells derived from induced pluripotent stem cells

    SciTech Connect

    Ozeki, Nobuaki; Hase, Naoko; Yamaguchi, Hideyuki; Hiyama, Taiki; Kawai, Rie; Kondo, Ayami; Nakata, Kazuhiko; Mogi, Makio

    2015-05-01

    Inorganic polyphosphate [Poly(P)] may represent a physiological source of phosphate and has the ability to induce bone differentiation in osteoblasts. We previously reported that cytokine-induced matrix metalloproteinase (MMP)-3 accelerates the proliferation of purified odontoblast-like cells. In this study, MMP-3 small interfering RNA (siRNA) was transfected into odontoblast-like cells derived from induced pluripotent stem cells to investigate whether MMP-3 activity is induced by Poly(P) and/or is associated with cell proliferation and differentiation into odontoblast-like cells. Treatment with Poly(P) led to an increase in both cell proliferation and additional odontoblastic differentiation. Poly(P)-treated cells showed a small but significant increase in dentin sialophosphoprotein (DSPP) and dentin matrix protein-1 (DMP-1) mRNA expression, which are markers of mature odontoblasts. The cells also acquired additional odontoblast-specific properties including adoption of an odontoblastic phenotype typified by high alkaline phosphatase (ALP) activity and a calcification capacity. In addition, Poly(P) induced expression of MMP-3 mRNA and protein, and increased MMP-3 activity. MMP-3 siRNA-mediated disruption of the expression of these effectors potently suppressed the expression of odontoblastic biomarkers ALP, DSPP, and DMP-1, and blocked calcification. Interestingly, upon siRNA-mediated silencing of MMP-3, we noted a potent and significant decrease in cell proliferation. Using specific siRNAs, we revealed that a unique signaling cascade, Poly(P)→MMP-3→DSPP and/or DMP-1, was intimately involved in the proliferation of odontoblast-like cells. - Highlights: • Polyphosphate increases proliferation of iPS cell-derived odontoblast-like cells. • Polyphosphate-induced MMP-3 results in an increase of cell proliferation. • Induced cell proliferation involves MMP-3, DSPP, and/or DMP-1 sequentially. • Induced MMP-3 also results in an increase of odontoblastic

  18. Mechanisms of Virus-Induced Neural Cell Death

    DTIC Science & Technology

    2003-09-01

    We are using experimental infection with reoviruses to study how viruses induce cell death . (apoptosis), and the significance of apoptosis in the...pathogenesis of viral infection. We have developed one of the best-characterized experimental models for investigating and manipulating viral cell death pathways...We have shown that apoptosis is a major mechanism of reovirus-induced cell death in murine models of key human viral infections including

  19. Interferon induces natural killer cell blastogenesis in vivo

    NASA Technical Reports Server (NTRS)

    Biron, C. A.; Sonnenfeld, G.; Welsh, R. M.

    1984-01-01

    Interferon (IFN), types beta and gamma, and IFN inducers polyinosinic-polycytidylic acid and lymphocytic choriomeningitis virus, all stimulated the generation of blast-natural killer (NK) cells in mouse spleens, Blast-NK cells were characterized on the basis of size, 3H-thymidine uptake, and NK cell markers These data indicate that in addition to augmenting NK cell-mediated lysis, IFN may regulate NK cell proliferation in vivo.

  20. Porcine circovirus-2 capsid protein induces cell death in PK15 cells

    SciTech Connect

    Walia, Rupali; Dardari, Rkia Chaiyakul, Mark; Czub, Markus

    2014-11-15

    Studies have shown that Porcine circovirus (PCV)-2 induces apoptosis in PK15 cells. Here we report that cell death is induced in PCV2b-infected PK15 cells that express Capsid (Cap) protein and this effect is enhanced in interferon gamma (IFN-γ)-treated cells. We further show that transient PCV2a and 2b-Cap protein expression induces cell death in PK15 cells at rate similar to PCV2 infection, regardless of Cap protein localization. These data suggest that Cap protein may have the capacity to trigger different signaling pathways involved in cell death. Although further investigation is needed to gain deeper insights into the nature of the pathways involved in Cap-induced cell death, this study provides evidence that PCV2-induced cell death in kidney epithelial PK15 cells can be mapped to the Cap protein and establishes the need for future research regarding the role of Cap-induced cell death in PCV2 pathogenesis. - Highlights: • IFN-γ enhances PCV2 replication that leads to cell death in PK15 cells. • IFN-γ enhances nuclear localization of the PCV2 Capsid protein. • Transient PCV2a and 2b-Capsid protein expression induces cell death. • Cell death is not dictated by specific Capsid protein sub-localization.

  1. Hyperthermia: an effective strategy to induce apoptosis in cancer cells.

    PubMed

    Ahmed, Kanwal; Tabuchi, Yoshiaki; Kondo, Takashi

    2015-11-01

    Heat has been used as a medicinal and healing modality throughout human history. The combination of hyperthermia (HT) with radiation and anticancer agents has been used clinically and has shown positive results to a certain extent. However, the clinical results of HT treatment alone have been only partially satisfactory. Cell death following HT treatment is a function of both temperature and treatment duration. HT induces cancer cell death through apoptosis; the degree of apoptosis and the apoptotic pathway vary in different cancer cell types. HT-induced reactive oxygen species production are responsible for apoptosis in various cell types. However, the underlying mechanism of signal transduction and the genes related to this process still need to be elucidated. In this review, we summarize the molecular mechanism of apoptosis induced by HT, enhancement of heat-induced apoptosis, and the genetic network involved in HT-induced apoptosis.

  2. Induced Pluripotent Stem Cells: Characteristics and Perspectives

    NASA Astrophysics Data System (ADS)

    Cantz, Tobias; Martin, Ulrich

    The induction of pluripotency in somatic cells is widely considered as a major breakthrough in regenerative medicine, because this approach provides the basis for individualized stem cell-based therapies. Moreover, with respect to cell transplantation and tissue engineering, expertise from bioengineering to transplantation medicine is now meeting basic research of stem cell biology.

  3. Arsenic exposure induces the Warburg effect in cultured human cells

    SciTech Connect

    Zhao, Fei; Severson, Paul; Pacheco, Samantha; Futscher, Bernard W.; Klimecki, Walter T.

    2013-08-15

    Understanding how arsenic exacts its diverse, global disease burden is hampered by a limited understanding of the particular biological pathways that are disrupted by arsenic and underlie pathogenesis. A reductionist view would predict that a small number of basic pathways are generally perturbed by arsenic, and manifest as diverse diseases. Following an initial observation that arsenite-exposed cells in culture acidify their media more rapidly than control cells, the report here shows that low level exposure to arsenite (75 ppb) is sufficient to induce aerobic glycolysis (the Warburg effect) as a generalized phenomenon in cultured human primary cells and cell lines. Expanded studies in one such cell line, the non-malignant pulmonary epithelial line, BEAS-2B, established that the arsenite-induced Warburg effect was associated with increased accumulation of intracellular and extracellular lactate, an increased rate of extracellular acidification, and inhibition by the non-metabolized glucose analog, 2-deoxy-D-glucose. Associated with the induction of aerobic glycolysis was a pathway-wide induction of glycolysis gene expression, as well as protein accumulation of an established glycolysis master-regulator, hypoxia-inducible factor 1A. Arsenite-induced alteration of energy production in human cells represents the type of fundamental perturbation that could extend to many tissue targets and diseases. - Highlights: • Chronic arsenite exposure induces aerobic glycolysis, dubbed the “Warburg effect”. • Arsenite-induced Warburg effect is a general phenomenon in cultured human cells. • HIF-1A may mediate arsenite induced Warburg effect.

  4. Ionizing Radiation-Induced Endothelial Cell Senescence and Cardiovascular Diseases

    PubMed Central

    Wang, Yingying; Boerma, Marjan; Zhou, Daohong

    2016-01-01

    Exposure to ionizing radiation induces not only apoptosis but also senescence. While the role of endothelial cell apoptosis in mediating radiation-induced acute tissue injury has been extensively studied, little is known about the role of endothelial cell senescence in the pathogenesis of radiation-induced late effects. Senescent endothelial cells exhibit decreased production of nitric oxide and expression of thrombomodulin, increased expression of adhesion molecules, elevated production of reactive oxygen species and inflammatory cytokines and an inability to proliferate and form capillary-like structures in vitro. These findings suggest that endothelial cell senescence can lead to endothelial dysfunction by dysregulation of vasodilation and hemostasis, induction of oxidative stress and inflammation and inhibition of angiogenesis, which can potentially contribute to radiation-induced late effects such as cardiovascular diseases (CVDs). In this article, we discuss the mechanisms by which radiation induces endothelial cell senescence, the roles of endothelial cell senescence in radiation-induced CVDs and potential strategies to prevent, mitigate and treat radiation-induced CVDs by targeting senescent endothelial cells. PMID:27387862

  5. Mechanisms Involved in Virus-Induced Neural Cell Death

    DTIC Science & Technology

    2001-09-01

    We are using experimental infection with reoviruses as a model to study how viruses induce cell death (apoptosis) and cause dysregulation of the cell...and their ligand (TRAIL). Apoptosis involves both death-receptor (DR) and mitochondrial-associated cell death pathways, and leads to the early

  6. Hexavalent chromium induces chromosome instability in human urothelial cells.

    PubMed

    Wise, Sandra S; Holmes, Amie L; Liou, Louis; Adam, Rosalyn M; Wise, John Pierce

    2016-04-01

    Numerous metals are well-known human bladder carcinogens. Despite the significant occupational and public health concern of metals and bladder cancer, the carcinogenic mechanisms remain largely unknown. Chromium, in particular, is a metal of concern as incidences of bladder cancer have been found elevated in chromate workers, and there is an increasing concern for patients with metal hip implants. However, the impact of hexavalent chromium (Cr(VI)) on bladder cells has not been studied. We compared chromate toxicity in two bladder cell lines; primary human urothelial cells and hTERT-immortalized human urothelial cells. Cr(VI) induced a concentration- and time-dependent increase in chromosome damage in both cell lines, with the hTERT-immortalized cells exhibiting more chromosome damage than the primary cells. Chronic exposure to Cr(VI) also induced a concentration-dependent increase in aneuploid metaphases in both cell lines which was not observed after a 24h exposure. Aneuploidy induction was higher in the hTERT-immortalized cells. When we correct for uptake, Cr(VI) induces a similar amount of chromosome damage and aneuploidy suggesting that the differences in Cr(VI) sensitivity between the two cells lines were due to differences in uptake. The increase in chromosome instability after chronic chromate treatment suggests this may be a mechanism for chromate-induced bladder cancer, specifically, and may be a mechanism for metal-induced bladder cancer, in general.

  7. Ultraviolet Irradiation-Induced Volume Alteration of Corneal Epithelial Cells

    PubMed Central

    Wang, Ling; Lu, Luo

    2016-01-01

    Purpose The purpose of the study is to understand how extracellular stresses, such as ultraviolet (UV) irradiation, affect corneal epithelial cells. Cell volume changes, damage to corneal epithelial integrity, and cellular responses were assessed after exposure to UVC stresses. Methods Primary human and rabbit corneal epithelial cells were exposed to UVC light in culture conditions. Ultraviolet C irradiation–induced changes in cell size and volume were measured by real-time microscopy and self-quenching of the fluorescent dye calcein, respectively. The effects of UVC irradiation on Src and focal adhesion kinase (FAK) phosphorylation and FAK-dependent integrin signaling were detected by ELISA, immunoblotting, and immunostaining. Results Ultraviolet C irradiation induced both size and volume shifts in human and rabbit corneal epithelial cells. Ultraviolet C irradiation-induced decrease of cell volume elicited activation of Src and FAK, characterized by increased phosphorylations of SrcY416, FAKY397, and FAKY925. In addition, immunostaining studies showed UVC irradiation–induced increases in phosphorylation of FAK and formation of integrin β5 clustering. Application of Kv channel blockers, including 4-aminopyridine (4-AP), α-DTX, and depressing substance-1 (BDS-1), effectively suppressed UVC irradiation–induced cell volume changes, and subsequently inhibited UVC irradiation–induced phosphorylation of Src/FAK, and formation of integrin β5 clustering, suggesting UVC irradiation–induced volume changes and Src/FAK activation. Hyperosmotic pressure–induced volume decreases were measured in comparison with effects of UVC irradiation on volume and Src/FAK activation. However, Kv channel blocker, 4-AP, had no effect on hyperosmotic pressure–induced responses. Conclusions The present study demonstrates that UVC irradiation–induced decreases in cell volume lead to Src/FAK activation due to a rapid loss of K ions through membrane Kv channels. PMID:27978555

  8. Inflammation-Induced Cell Proliferation Potentiates DNA Damage-Induced Mutations In Vivo

    PubMed Central

    Kiraly, Orsolya; Gong, Guanyu; Olipitz, Werner; Muthupalani, Sureshkumar; Engelward, Bevin P.

    2015-01-01

    Mutations are a critical driver of cancer initiation. While extensive studies have focused on exposure-induced mutations, few studies have explored the importance of tissue physiology as a modulator of mutation susceptibility in vivo. Of particular interest is inflammation, a known cancer risk factor relevant to chronic inflammatory diseases and pathogen-induced inflammation. Here, we used the fluorescent yellow direct repeat (FYDR) mice that harbor a reporter to detect misalignments during homologous recombination (HR), an important class of mutations. FYDR mice were exposed to cerulein, a potent inducer of pancreatic inflammation. We show that inflammation induces DSBs (γH2AX foci) and that several days later there is an increase in cell proliferation. While isolated bouts of inflammation did not induce HR, overlap between inflammation-induced DNA damage and inflammation-induced cell proliferation induced HR significantly. To study exogenously-induced DNA damage, animals were exposed to methylnitrosourea, a model alkylating agent that creates DNA lesions relevant to both environmental exposures and cancer chemotherapy. We found that exposure to alkylation damage induces HR, and importantly, that inflammation-induced cell proliferation and alkylation induce HR in a synergistic fashion. Taken together, these results show that, during an acute bout of inflammation, there is a kinetic barrier separating DNA damage from cell proliferation that protects against mutations, and that inflammation-induced cell proliferation greatly potentiates exposure-induced mutations. These studies demonstrate a fundamental mechanism by which inflammation can act synergistically with DNA damage to induce mutations that drive cancer and cancer recurrence. PMID:25647331

  9. Crizotinib induces PUMA-dependent apoptosis in colon cancer cells.

    PubMed

    Zheng, Xingnan; He, Kan; Zhang, Lin; Yu, Jian

    2013-05-01

    Oncogenic alterations in MET or anaplastic lymphoma kinase (ALK) have been identified in a variety of human cancers. Crizotinib (PF02341066) is a dual MET and ALK inhibitor and approved for the treatment of a subset of non-small cell lung carcinoma and in clinical development for other malignancies. Crizotinib can induce apoptosis in cancer cells, whereas the underlying mechanisms are not well understood. In this study, we found that crizotinib induces apoptosis in colon cancer cells through the BH3-only protein PUMA. In cells with wild-type p53, crizotinib induces rapid induction of PUMA and Bim accompanied by p53 stabilization and DNA damage response. The induction of PUMA and Bim is mediated largely by p53, and deficiency in PUMA or p53, but not Bim, blocks crizotinib-induced apoptosis. Interestingly, MET knockdown led to selective induction of PUMA, but not Bim or p53. Crizotinib also induced PUMA-dependent apoptosis in p53-deficient colon cancer cells and synergized with gefitinib or sorafenib to induce marked apoptosis via PUMA in colon cancer cells. Furthermore, PUMA deficiency suppressed apoptosis and therapeutic responses to crizotinib in xenograft models. These results establish a critical role of PUMA in mediating apoptotic responses of colon cancer cells to crizotinib and suggest that mechanisms of oncogenic addiction to MET/ALK-mediated survival may be cell type-specific. These findings have important implications for future clinical development of crizotinib.

  10. Type I collagen gel protects murine fibrosarcoma L929 cells from TNFα-induced cell death

    SciTech Connect

    Wang, Hong-Ju; He, Wen-Qi; Chen, Ling; Liu, Wei-Wei; Xu, Qian; Xia, Ming-Yu; Hayashi, Toshihiko; Fujisaki, Hitomi; Hattori, Shunji; Tashiro, Shin-ichi; Onodera, Satoshi; Ikejima, Takashi

    2015-02-20

    Murine fibrosarcoma L929 cells have been used to test efficacy of proinflammatory cytokine TNFα. In the present study, we reported on protective effect of type I collagen gel used as L929 cell culture. L929 cell grew and proliferated well on collagen gel. However, the L929 cells exhibited cobblestone-like morphology which was much different from the spread fusiform shape when cultured on conventional cell dishes as well as the cells tended to aggregate. On conventional cell culture dishes, the cells treated with TNFα became round in shape and eventually died in a necroptotic manner. The cells cultured on collagen gel, however, were completely unaffected. TNFα treatment was reported to induce autophagy in L929 cells on the plastic dish, and therefore we investigated the effect of collagen gel on induction of autophagy. The results indicated that autophagy induced by TNFα treatment was much reduced when the cells were cultured on collagen gel. In conclusion, type I collagen gel protected L929 cell from TNFα-induced cell death. - Highlights: • Collagen gel culture changed the morphology of L929 cells. • L929 cell cultured on collagen gel were resistant to TNFα-induced cell death. • Collagen gel culture inhibited TNFα-induced autophagy in L929 cells.

  11. Ferroptosis is Involved in Acetaminophen Induced Cell Death.

    PubMed

    Lőrincz, Tamás; Jemnitz, Katalin; Kardon, Tamás; Mandl, József; Szarka, András

    2015-09-01

    The recently described form of programmed cell death, ferroptosis can be induced by agents causing GSH depletion or the inhibition of GPX4. Ferroptosis clearly shows distinct morphologic, biochemical and genetic features from apoptosis, necrosis and autophagy. Since NAPQI the highly reactive metabolite of the widely applied analgesic and antipyretic, acetaminophen induces a cell death which can be characterized by GSH depletion, GPX inhibition and caspase independency the involvement of ferroptosis in acetaminophen induced cell death has been investigated. The specific ferroptosis inhibitor ferrostatin-1 failed to elevate the viability of acetaminophen treated HepG2 cells. It should be noticed that these cells do not form NAPQI due to the lack of phase I enzyme expression therefore GSH depletion cannot be observed. However in the case of acetaminophen treated primary mouse hepatocytes the significant elevation of cell viability could be observed upon ferrostatin-1 treatment. Similar to ferrostatin-1 treatment, the addition of the RIP1 kinase inhibitor necrostatin-1 could also elevate the viability of acetaminophen treated primary hepatocytes. Ferrostatin-1 has no influence on the expression of CYP2E1 or on the cellular GSH level which suggest that the protective effect of ferrostatin-1 in APAP induced cell death is not based on the reduced metabolism of APAP to NAPQI or on altered NAPQI conjugation by cellular GSH. Our results suggest that beyond necroptosis and apoptosis a third programmed cell death, ferroptosis is also involved in acetaminophen induced cell death in primary hepatocytes.

  12. Chemically Induced Reprogramming of Somatic Cells to Pluripotent Stem Cells and Neural Cells.

    PubMed

    Biswas, Dhruba; Jiang, Peng

    2016-02-06

    The ability to generate transplantable neural cells in a large quantity in the laboratory is a critical step in the field of developing stem cell regenerative medicine for neural repair. During the last few years, groundbreaking studies have shown that cell fate of adult somatic cells can be reprogrammed through lineage specific expression of transcription factors (TFs)-and defined culture conditions. This key concept has been used to identify a number of potent small molecules that could enhance the efficiency of reprogramming with TFs. Recently, a growing number of studies have shown that small molecules targeting specific epigenetic and signaling pathways can replace all of the reprogramming TFs. Here, we provide a detailed review of the studies reporting the generation of chemically induced pluripotent stem cells (ciPSCs), neural stem cells (ciNSCs), and neurons (ciN). We also discuss the main mechanisms of actions and the pathways that the small molecules regulate during chemical reprogramming.

  13. Chemically Induced Reprogramming of Somatic Cells to Pluripotent Stem Cells and Neural Cells

    PubMed Central

    Biswas, Dhruba; Jiang, Peng

    2016-01-01

    The ability to generate transplantable neural cells in a large quantity in the laboratory is a critical step in the field of developing stem cell regenerative medicine for neural repair. During the last few years, groundbreaking studies have shown that cell fate of adult somatic cells can be reprogrammed through lineage specific expression of transcription factors (TFs)-and defined culture conditions. This key concept has been used to identify a number of potent small molecules that could enhance the efficiency of reprogramming with TFs. Recently, a growing number of studies have shown that small molecules targeting specific epigenetic and signaling pathways can replace all of the reprogramming TFs. Here, we provide a detailed review of the studies reporting the generation of chemically induced pluripotent stem cells (ciPSCs), neural stem cells (ciNSCs), and neurons (ciN). We also discuss the main mechanisms of actions and the pathways that the small molecules regulate during chemical reprogramming. PMID:26861316

  14. Cell therapy using induced pluripotent stem cells or somatic stem cells: this is the question.

    PubMed

    Somoza, Rodrigo A; Rubio, Francisco J

    2012-05-01

    A lot of effort has been developed to bypass the use of embryonic stem cells (ES) in human therapies, because of several concerns and ethical issues. Some unsolved problems of using stem cells for human therapies, excluding the human embryonic origin, are: how to regulate cell plasticity and proliferation, immunological compatibility, potential adverse side-effects when stem cells are systemically administrated, and the in vivo signals to rule out a specific cell fate after transplantation. Currently, it is known that almost all tissues of an adult organism have somatic stem cells (SSC). Whereas ES are primary involved in the genesis of new tissues and organs, SSC are involved in regeneration processes, immuno-regulatory and homeostasis mechanisms. Although the differentiating potential of ES is higher than SSC, several studies suggest that some types of SSC, such as mesenchymal stem cells (MSC), can be induced epigenetically to differentiate into tissue-specific cells of different lineages. This unexpected pluripotency and the variety of sources that they come from, can make MSC-like cells suitable for the treatment of diverse pathologies and injuries. New hopes for cell therapy came from somatic/mature cells and the discovery that could be reprogrammed to a pluripotent stage similar to ES, thus generating induced pluripotent stem cells (iPS). For this, it is necessary to overexpress four main reprogramming factors, Sox2, Oct4, Klf4 and c-Myc. The aim of this review is to analyze the potential and requirements of cellular based tools in human therapy strategies, focusing on the advantage of using MSC over iPS.

  15. Induced pluripotent stem cells in hematology: current and future applications

    PubMed Central

    Focosi, D; Amabile, G; Di Ruscio, A; Quaranta, P; Tenen, D G; Pistello, M

    2014-01-01

    Reprogramming somatic cells into induced pluripotent stem (iPS) cells is nowadays approaching effectiveness and clinical grade. Potential uses of this technology include predictive toxicology, drug screening, pathogenetic studies and transplantation. Here, we review the basis of current iPS cell technology and potential applications in hematology, ranging from disease modeling of congenital and acquired hemopathies to hematopoietic stem and other blood cell transplantation. PMID:24813079

  16. Aspartame-induced apoptosis in PC12 cells.

    PubMed

    Horio, Yukari; Sun, Yongkun; Liu, Chuang; Saito, Takeshi; Kurasaki, Masaaki

    2014-01-01

    Aspartame is an artificial sweetner added to many low-calorie foods. The safety of aspartame remains controversial even though there are many studies on its risks. In this study, to understand the physiological effects of trace amounts of artificial sweetners on cells, the effects of aspartame on apoptosis were investigated using a PC12 cell system. In addition, the mechanism of apoptosis induced by aspartame in PC12 cells and effects on apoptotic factors such as cytochrome c, apoptosis-inducing factor, and caspase family proteins were studied by Western blotting and RT-PCR. Aspartame-induced apoptosis in PC12 cells in a dose-dependent manner. In addition, aspartame exposure increased the expressions of caspases 8 and 9, and cytochrome c. These results indicate that aspartame induces apoptosis mainly via mitochondrial pathway involved in apoptosis due to oxigen toxicity.

  17. Chemically induced bidirectional differentiation of embryonal carcinoma cells in vitro.

    PubMed Central

    Speers, W. C.; Birdwell, C. R.; Dixon, F. J.

    1979-01-01

    N,N-dimethylacetamide, hexamethylene bisacetamide, and Polybrene induced rapid and extensive differentiation in vitro in an otherwise slowly differentiating subline of embryonal carcinoma cells. The type of differentiated cell induced was dependent on the spatial organization of the stem cells during drug treatment. In monalayer culture "epithelial" cells were produced exclusively. However, treatment of aggregated suspension cultures yielded predominantly "fibroblast-like" cells. The undifferentiated embryonal carcinoma cells and the two differentiated cell types were morphologically distinct when examined by light microscopy, scanning electron microscopy, and transmission electron microscopy; and they had differences in cell surface antigens. Both differential cell types produced large amounts of fibronectin, whereas the embryonal carcinoma cells produced only minimal amounts. This system provides a convenient way to induce relatively synchronous differentiation of embryonal carcinoma cells into specific differentiated cell types. Images Figure 5 Figure 6 Figure 1 Figure 2 Figure 3 Figure 4 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 PMID:507191

  18. Endosulfan affects GnRH cells in sexually differentiated juveniles of the perciform Cichlasoma dimerus.

    PubMed

    Piazza, Yanina; Pandolfi, Matías; Da Cuña, Rodrigo; Genovese, Griselda; Lo Nostro, Fabiana

    2015-06-01

    Endosulfan (ES) is an organochlorine pesticide widely used in agriculture despite its high toxicity towards non-target organisms such as fish. It has been demonstrated that ES can cause negative effects on aquatic animals, including disruption of hormonal systems. However, the alterations produced by this pesticide on the reproductive axis of fish prior to sexual maturity, as well as possible modes of action have hardly been studied. This study aimed at assessing the effect of waterborne exposure to the pesticide ES on the reproductive axis during sexual differentiation of juveniles of the South American freshwater cichlid fish Cichlasoma dimerus. No mortality was observed due to ES subchronic exposure (90 days post-fertilization). Exposure to ES did not affect body weight nor morphometric parameters, indicating that larvae nutritional state was not affected. Timing of sexual differentiation, gonadal morphology and sex ratio were likewise not altered by ES. However, ES acted as an endocrine disrupting chemical in this species as the morphometry of gonadotropin-releasing hormones (GnRH) producing cells was altered. Exposure to ES altered nuclear area, cell area and nucleus/cytoplasm ratio of GnRH II neurons, and cell and nuclear area and diameter of GnRH III neurons. Interestingly, in our previous study, exposure before sex differentiation (30 day exposure) caused no alteration to GnRH II and III, and did alter GnRH I and FSH cells. These alterations could lead to changes in circulating hormone levels, especially when fish are exposed for prolonged periods, ultimately impairing reproductive fitness. C. dimerus juveniles can be an interesting biological model to perform toxicological studies with the intent to assess early disruption endpoints in the reproductive axis during development.

  19. Suppression of T cell-induced osteoclast formation

    SciTech Connect

    Karieb, Sahar; Fox, Simon W.

    2013-07-12

    Highlights: •Genistein and coumestrol prevent activated T cell induced osteoclast formation. •Anti-TNF neutralising antibodies prevent the pro-osteoclastic effect of activated T cells. •Phytoestrogens inhibit T cell derived TNF alpha and inflammatory cytokine production. •Phytoestrogens have a broader range of anti-osteoclastic actions than other anti-resorptives. -- Abstract: Inhibition of T cell derived cytokine production could help suppress osteoclast differentiation in inflammatory skeletal disorders. Bisphosphonates are typically prescribed to prevent inflammatory bone loss but are not tolerated by all patients and are associated with an increased risk of osteonecrosis of the jaw. In light of this other anti-resorptives such as phytoestrogens are being considered. However the effect of phytoestrogens on T cell-induced osteoclast formation is unclear. The effect of genistein and coumestrol on activated T cell-induced osteoclastogenesis and cytokine production was therefore examined. Concentrations of genistein and coumestrol (10{sup −7} M) previously shown to directly inhibit osteoclast formation also suppressed the formation of TRAP positive osteoclast induced by con A activated T cells, which was dependent on inhibition of T cell derived TNF-α. While both reduced osteoclast formation their mechanism of action differed. The anti-osteoclastic effect of coumestrol was associated with a dual effect on con A induced T cell proliferation and activation; 10{sup −7} M coumestrol significantly reducing T cell number (0.36) and TNF-α (0.47), IL-1β (0.23) and IL-6 (0.35) expression, whereas genistein (10{sup −7} M) had no effect on T cell number but a more pronounced effect on T cell differentiation reducing expression of TNF-α (0.49), IL-1β (0.52), IL-6 (0.71) and RANKL (0.71). Phytoestrogens therefore prevent the pro-osteoclastic action of T cells suggesting they may have a role in the control of inflammatory bone loss.

  20. MiR-122 Induces Radiosensitization in Non-Small Cell Lung Cancer Cell Line

    PubMed Central

    Ma, Debin; Jia, Hui; Qin, Mengmeng; Dai, Wenjie; Wang, Tao; Liang, Erguang; Dong, Guofu; Wang, Zuojun; Zhang, Zhiyuan; Feng, Fan

    2015-01-01

    MiR-122 is a novel tumor suppresser and its expression induces cell cycle arrest, or apoptosis, and inhibits cell proliferation in multiple cancer cells, including non-small cell lung cancer (NSCLC) cells. Radioresistance of cancer cell leads to the major drawback of radiotherapy for NSCLC and the induction of radiosensitization could be a useful strategy to fix this problem. The present work investigates the function of miR-122 in inducing radiosensitization in A549 cell, a type of NSCLC cells. MiR-122 induces the radiosensitization of A549 cells. MiR-122 also boosts the inhibitory activity of ionizing radiation (IR) on cancer cell anchor-independent growth and invasion. Moreover, miR-122 reduced the expression of its targeted genes related to tumor-survival or cellular stress response. These results indicate that miR-122 would be a novel strategy for NSCLC radiation-therapy. PMID:26389880

  1. Substrate Induced Osteoblast-Like Differentiation of Stromal Stem Cells

    NASA Astrophysics Data System (ADS)

    Belizar, Jacqueline; Glaser, Reena; Hung, Matthew; Simon, Marcia; Jurukovski, Vladimir; Rafailovich, Miriam; Shih, Alice

    2009-03-01

    We have demonstrated that Adipose-derived stem cells (ASCs) can be induced to biomineralize on a polybutadiene (PB) coated Si substrate. The cells began to generate calcium phosphate deposits after a five-day incubation period in the absence of dexamethasone. Control cells plated on tissue culture PS culture dish (TCP) did not biomineralize. In addition, the biomineralizing culture retained proliferative cells In order to determine whether the induction was transient, we transferred the cells exposed to polybutadiene after 14 and 28-day incubation periods to TCP dishes. These cells continued to biominerlize. Genetic testing is underway which will determine whether differentiation is maintained after transfer.

  2. Activation-induced CD154 expression abrogates tolerance induced by apoptotic cells*

    PubMed Central

    Gurung, Prajwal; Kucaba, Tamara A.; Ferguson, Thomas A.; Griffith, Thomas S.

    2009-01-01

    The decision to generate a productive immune response or tolerance often depends on the context in which T cells first see Ag. Using a classical system of tolerance induction, we examined the immunological consequence of Ag encountered in the presence of naïve or activated apoptotic cells. Naïve apoptotic cells induced tolerance when injected i.v.; however, previously activated apoptotic cells induced immunity. Further analysis revealed a key role for CD154, as tolerance resulted after i.v. injection of either naïve or activated apoptotic CD154−/− T cells, while co-injection of an agonistic anti-CD40 mAb with naïve apoptotic T cells induced robust immunity. DC fed activated apoptotic T cells in vitro produced IL-12p40 in a CD154-dependent manner, and the use of IL-12p40−/− mice or mAb-mediated neutralization of IL-12 revealed a link between CD154, IL-12, and the ability of activated apoptotic T cells to induce immunity rather than tolerance. Collectively these results show that CD154 expression on apoptotic T cells can determine the outcome of an immune response to Ag recognized within the context of the apoptotic cells, and suggest the balance between naïve and activated apoptotic T cells may dictate whether a productive immune response is encouraged. PMID:19841180

  3. Inducible expression of endomorphins in murine dendritic cells.

    PubMed

    Yang, Xiaohuai; Xia, Hui; Chen, Yong; Liu, Xiaofen; Zhou, Cheng; Gao, Qin; Li, Zhenghong

    2012-12-15

    Bone marrow precursor cells were extracted from C57BL/6J mice aged 7-8 weeks, and dendritic cells were purified using anti-CD11c (a specific marker for dendritic cells) antibody-coated magnetic beads. Immunofluorescence staining revealed that the expression levels of endomorphin-1 and endomorphin-2 were upregulated in dendritic cells activated by lipopolysaccharide. An enzyme immunoassay showed that lipopolysaccharide and other Toll-like receptor ligands promoted the secretion of endomorphin-1 and endomorphin-2 from activated dendritic cells. [(3)H]-thymidine incorporation demonstrated that endomorphin-1 and endomorphin-2 both inhibited the proliferation of T lymphocyte induced by activated dendritic cells. Furthermore, this immunosuppressive effect was blocked by CTOP, a specific antagonist of µ-opioid receptors. Our experimental findings indicate that activated dendritic cells can induce the expression and secretion of endomorphins, and that endomorphins suppress T lymphocyte proliferation through activation of µ-opioid receptors.

  4. High dose of ascorbic acid induces cell death in mesothelioma cells.

    PubMed

    Takemura, Yukitoshi; Satoh, Motohiko; Satoh, Kiyotoshi; Hamada, Hironobu; Sekido, Yoshitaka; Kubota, Shunichiro

    2010-04-02

    Malignant mesothelioma is an asbestos-related fatal disease with no effective cure. Recently, high dose of ascorbate in cancer treatment has been reexamined. We studied whether high dose of ascorbic acid induced cell death of four human mesothelioma cell lines. High dose of ascorbic acid induced cell death of all mesothelioma cell lines in a dose-dependent manner. We further clarified the cell killing mechanism that ascorbic acid induced reactive oxygen species and impaired mitochondrial membrane potential. In vivo experiment, intravenous administration of ascorbic acid significantly decreased the growth rate of mesothelioma tumor inoculated in mice. These data suggest that ascorbic acid may have benefits for patients with mesothelioma.

  5. Expression of hyaluronidase by tumor cells induces angiogenesis in vivo.

    PubMed Central

    Liu, D; Pearlman, E; Diaconu, E; Guo, K; Mori, H; Haqqi, T; Markowitz, S; Willson, J; Sy, M S

    1996-01-01

    Hyaluronic acid is a proteoglycan present in the extracellular matrix and is important for the maintenance of tissue architecture. Depolymerization of hyaluronic acid may facilitate tumor invasion. In addition, oligosaccharides of hyaluronic acid have been reported to induce angiogenesis. We report here that a hyaluronidase similar to the one on human sperm is expressed by metastatic human melanoma, colon carcinoma, and glioblastoma cell lines and by tumor biopsies from patients with colorectal carcinomas, but not by tissues from normal colon. Moreover, angiogenesis is induced by hyaluronidase+ tumor cells but not hyaluronidase- tumor cells and can be blocked by an inhibitor of hyaluronidase. Tumor cells thus use hyaluronidase as one of the "molecular saboteurs" to depolymerize hyaluronic acid to facilitate invasion. As a consequence, breakdown products of hyaluronic acid can further promote tumor establishment by inducing angiogenesis. Hyaluronidase on tumor cells may provide a target for anti-neoplastic drugs. Images Fig. 1 Fig. 2 Fig. 3 PMID:8755562

  6. Turkish propolis supresses MCF-7 cell death induced by homocysteine.

    PubMed

    Tartik, Musa; Darendelioglu, Ekrem; Aykutoglu, Gurkan; Baydas, Giyasettin

    2016-08-01

    Elevated plasma homocysteine (Hcy) level is a most important risk factor for various vascular diseases including coronary, cerebral and peripheral arterial and venous thrombosis. Propolis is produced by honeybee from various oils, pollens and wax materials. Therefore, it has various biological properties including antioxidant, antitumor and antimicrobial activities. This study investigated the effects of propolis and Hcy on apoptosis in cancer cells. According to our findings, Hcy induced apoptosis in human breast adenocarcinoma (MCF-7) cells by regulating numerous genes and proteins involved in the apoptotic signal transduction pathway. In contrast, treatment with propolis inhibited caspase- 3 and -9 induced by Hcy in MCF-7 cells. It can be concluded that Hcy may augment the activity of anticancer agents that induce excessive reactive oxygen species (ROS) generation and apoptosis in their target cells. In contrast to the previous studies herein we found that propolis in low doses protected cancer cells inhibiting cellular apoptosis mediated by intracellular ROS-dependent mitochondrial pathway.

  7. Expression of Hyaluronidase by Tumor Cells Induces Angiogenesis in vivo

    NASA Astrophysics Data System (ADS)

    Liu, Dacai; Pearlman, Eric; Diaconu, Eugenia; Guo, Kun; Mori, Hiroshi; Haqqi, Tariq; Markowitz, Sanford; Willson, James; Sy, Man-Sun

    1996-07-01

    Hyaluronic acid is a proteoglycan present in the extracellular matrix and is important for the maintenance of tissue architecture. Depolymerization of hyaluronic acid may facilitate tumor invasion. In addition, oligosaccharides of hyaluronic acid have been reported to induce angiogenesis. We report here that a hyaluronidase similar to the one on human sperm is expressed by metastatic human melanoma, colon carcinoma, and glioblastoma cell lines and by tumor biopsies from patients with colorectal carcinomas, but not by tissues from normal colon. Moreover, angiogenesis is induced by hyaluronidase+ tumor cells but not hyaluronidase- tumor cells and can be blocked by an inhibitor of hyaluronidase. Tumor cells thus use hyaluronidase as one of the ``molecular saboteurs'' to depolymerize hyaluronic acid to facilitate invasion. As a consequence, breakdown products of hyaluronic acid can further promote tumor establishment by inducing angiogenesis. Hyaluronidase on tumor cells may provide a target for anti-neoplastic drugs.

  8. Caffeine augments Alprazolam induced cytotoxicity in human cell lines.

    PubMed

    Saha, Biswarup; Mukherjee, Ananda; Samanta, Saheli; Saha, Piyali; Ghosh, Anup Kumar; Santra, Chitta Ranjan; Karmakar, Parimal

    2009-09-01

    Combined effects of alprazolam (Alp), a member of benzodiazepine group of drugs and caffeine on human cell lines, HeLa and THP1 were investigated in this study. Alp mediated cytotoxicity was enhanced while caffeine was present. The cell death was confirmed by observing morphological changes, LDH assay and membrane anisotropic study. Also such combined effects induced elevated level of ROS and depletion of GSH. The mechanism of cell death induced by simultaneous treatment of Alp and caffeine was associated with the calcium-mediated activation of mu-calpain, release of lysosomal protease cathepsin B, activation of PARP and cleavage of caspase 3. Our results indicate that, Alp alone induces apoptosis in human cells but in the presence of caffeine it augments necrosis in a well-regulated pathway. Thus our observations strongly suggest that, alprazolam and caffeine together produce severe cytotoxicity in human cell lines.

  9. Simulating cell apoptosis induced sinus node dysfunction.

    PubMed

    Kharche, Sanjay; Beling, John; Biktasheva, Irina V; Zhang, Henggui; Biktashev, Vadim N

    2013-01-01

    Sinus node dysfunction (SND) is correlated to the pacemaker sinoatrial node (SAN) cell apoptosis. This study explores the effect of such a dysfunctional SAN on electrical propagation into neighboring atrial tissue. The Fenton Karma model was extended to simulate mouse SAN and atrial cell action potentials. The cell models were incorporated into a 2D model consisting of a central SAN region surrounded by atrial tissue. The intercellular gap junctional coupling, as quantified by the diffusion constant, was estimated to give conduction speeds as observed in mouse atrial tissue. The size of mouse SAN pacemaking region was estimated using the 2D model. In multiple simulations, the effects of an increasing proportion of apoptotic pacemaker cells on atrial tissue pacing were simulated and quantified. The SAN size that gave a basal mouse atrial cycle length (ACL) of 295 ms was found to be 0.6 mm in radius. At low pacemaker cell apoptosis proportion, there was a drastic increase of ACL. At modest increase in the number of apoptotic cells, bradycardia was observed. The incidence of sinus arrest was also found to be high. When the number of apoptotic cells were 10% of the total number of pacemaking cells, all pacemaking was arrested. Phenomenological models have been developed to study mouse atrial electrophysiology and confirm experimental findings. The results show the significance of cell apoptosis as a major mechanism of SND.

  10. An inducible caspase 9 safety switch can halt cell therapy-induced autoimmune disease.

    PubMed

    de Witte, Moniek A; Jorritsma, Annelies; Swart, Erwin; Straathof, Karin C; de Punder, Karin; Haanen, John B A G; Rooney, Cliona M; Schumacher, Ton N M

    2008-05-01

    Transfer of either allogeneic or genetically modified T cells as a therapy for malignancies can be accompanied by T cell-mediated tissue destruction. The introduction of an efficient "safety switch" can potentially be used to control the survival of adoptively transferred cell populations and as such reduce the risk of severe graft-vs-host disease. In this study, we have tested the value of an inducible caspase 9-based safety switch to halt an ongoing immune attack in a murine model for cell therapy-induced type I diabetes. The data obtained in this model indicate that self-reactive T cells expressing this conditional safety switch show unimpaired lymphopenia- and vaccine-induced proliferation and effector function in vivo, but can be specifically and rapidly eliminated upon triggering. These data provide strong support for the evaluation of this conditional safety switch in clinical trials of adoptive cell therapy.

  11. NETRIN-4 protects glioblastoma cells FROM temozolomide induced senescence.

    PubMed

    Li, Li; Hu, Yizhou; Ylivinkka, Irene; Li, Huini; Chen, Ping; Keski-Oja, Jorma; Hyytiäinen, Marko

    2013-01-01

    Glioblastoma multiforme is the most common primary tumor of the central nervous system. The drug temozolomide (TMZ) prolongs lifespan in many glioblastoma patients. The sensitivity of glioblastoma cells to TMZ is interfered by many factors, such as the expression of O-6-methylguanine-DNA methyltransferase (MGMT) and activation of AKT signaling. We have recently identified the interaction between netrin-4 (NTN4) and integrin beta-4 (ITGB4), which promotes glioblastoma cell proliferation via activating AKT-mTOR signaling pathway. In the current work we have explored the effect of NTN4/ITGB4 interaction on TMZ induced glioblastoma cell senescence. We report here that the suppression of either ITGB4 or NTN4 in glioblastoma cell lines significantly enhances cellular senescence. The sensitivity of GBM cells to TMZ was primarily determined by the expression of MGMT. To omit the effect of MGMT, we concentrated on the cell lines devoid of expression of MGMT. NTN4 partially inhibited TMZ induced cell senescence and rescued AKT from dephosphorylation in U251MG cells, a cell line bearing decent levels of ITGB4. However, addition of exogenous NTN4 displayed no significant effect on TMZ induced senescence rescue or AKT activation in U87MG cells, which expressed ITGB4 at low levels. Furthermore, overexpression of ITGB4 combined with exogenous NTN4 significantly attenuated U87MG cell senescence induced by TMZ. These data suggest that NTN4 protects glioblastoma cells from TMZ induced senescence, probably via rescuing TMZ triggered ITGB4 dependent AKT dephosphorylation. This suggests that interfering the interaction between NTN4 and ITGB4 or concomitant use of the inhibitors of the AKT pathway may improve the therapeutic efficiency of TMZ.

  12. Chlorpyrifos induces endoplasmic reticulum stress in JEG-3 cells.

    PubMed

    Reyna, Luciana; Flores-Martín, Jésica; Ridano, Magali E; Panzetta-Dutari, Graciela M; Genti-Raimondi, Susana

    2017-04-01

    Chlorpyrifos (CPF) is an organophosphorous pesticide widely used in agricultural, industrial, and household applications. We have previously shown that JEG-3 cells are able to attenuate the oxidative stress induced by CPF through the adaptive activation of the Nrf2/ARE pathway. Considering that there is a relationship between oxidative stress and endoplasmic reticulum stress (ER), herein we investigated whether CPF also induces ER stress in JEG-3 cells. Cells were exposed to 50μM or 100μM CPF during 24h in conditions where cell viability was not altered. Western blot and PCR assays were used to explore the protein and mRNA levels of ER stress biomarkers, respectively. CPF induced an increase of the typical ER stress-related proteins, such as GRP78/BiP and IRE1α, a sensor for the unfolded protein response, as well as in phospho-eIF2α and XBP1 mRNA splicing. Additionally, CPF led to a decrease in p53 protein expression. The downregulation of p53 levels induced by CPF was partially blocked when cells were exposed to CPF in the presence of the proteasome inhibitor MG132. Altogether, these findings point out that CPF induces ER stress in JEG-3 cells; however these cells are able to attenuate it downregulating the levels of the pro-apoptotic protein p53.

  13. PDT-apoptotic tumor cells induce macrophage immune response

    NASA Astrophysics Data System (ADS)

    Zhou, Fei-fan; Xing, Da; Chen, Wei R.

    2008-02-01

    Photodynamic therapy (PDT) functions as a cancer therapy through two major cell death mechanisms: apoptosis and necrosis. Immunological responses induced by PDT has been mainly associated with necrosis while apoptosis associated immune responses have not fully investigated. Heat shock proteins (HSPs) play an important role in regulating immune responses. In present study, we studied whether apoptotic tumor cells could induce immune response and how the HSP70 regulates immune response. The endocytosis of tumor cells by the activated macrophages was observed at single cell level by LSM. The TNF-α release of macrophages induced by co-incubated with PDT-apoptotic tumor cells was detected by ELISA. We found that apoptotic tumor cells treated by PDT could activate the macrophages, and the immune effect decreased evidently when HSP70 was blocked. These findings not only show that apoptosis can induce immunological responses, but also show HSP70 may serves as a danger signal for immune cells and induce immune responses to regulate the efficacy of PDT.

  14. Ceramide metabolism regulates autophagy and apoptotic cell death induced by melatonin in liver cancer cells.

    PubMed

    Ordoñez, Raquel; Fernández, Anna; Prieto-Domínguez, Néstor; Martínez, Laura; García-Ruiz, Carmen; Fernández-Checa, José C; Mauriz, José L; González-Gallego, Javier

    2015-09-01

    Autophagy is a process that maintains homeostasis during stress, although it also contributes to cell death under specific contexts. Ceramides have emerged as important effectors in the regulation of autophagy, mediating the crosstalk with apoptosis. Melatonin induces apoptosis of cancer cells; however, its role in autophagy and ceramide metabolism has yet to be clearly elucidated. This study was aimed to evaluate the effect of melatonin administration on autophagy and ceramide metabolism and its possible link with melatonin-induced apoptotic cell death in hepatocarcinoma (HCC) cells. Melatonin (2 mm) transiently induced autophagy in HepG2 cells through JNK phosphorylation, characterized by increased Beclin-1 expression, p62 degradation, and LC3II and LAMP-2 colocalization, which translated in decreased cell viability. Moreover, ATG5 silencing sensitized HepG2 cells to melatonin-induced apoptosis, suggesting a dual role of autophagy in cell death. Melatonin enhanced ceramide levels through both de novo synthesis and acid sphingomyelinase (ASMase) stimulation. Serine palmitoyltransferase (SPT) inhibition with myriocin prevented melatonin-induced autophagy and ASMase inhibition with imipramine-impaired autophagy flux. However, ASMase inhibition partially protected HepG2 cells against melatonin, while SPT inhibition significantly enhanced cell death. Findings suggest a crosstalk between SPT-mediated ceramide generation and autophagy in protecting against melatonin, while specific ASMase-induced ceramide production participates in melatonin-mediated cell death. Thus, dual blocking of SPT and autophagy emerges as a potential strategy to potentiate the apoptotic effects of melatonin in liver cancer cells.

  15. Matrine induces RIP3-dependent necroptosis in cholangiocarcinoma cells

    PubMed Central

    Xu, Beibei; Xu, Minying; Tian, Yuan; Yu, Qiang; Zhao, Yujie; Chen, Xiong; Mi, Panying; Cao, Hanwei; Zhang, Bing; Song, Gang; Zhan, Yan-yan; Hu, Tianhui

    2017-01-01

    The development of acquired resistance to pro-apoptotic antitumor agents is a major impediment to the cure of cholangiocarcinoma (CCA). Antitumor drugs inducing non-apoptotic cell death are considered as a new approach to overcome such drug resistance. Here, we reported for the first time that matrine-induced necroptosis in CCA cell lines, differing from its classical role to induce apoptosis in many other kinds of cancer cells. CCA cells under matrine treatment exhibited typical necrosis-like but not apoptotic morphologic change. These matrine-induced morphologic change and cell death in CCA cells were greatly attenuated by necroptosis inhibitor necrostatin-1, but not apoptosis inhibitor z-VAD-fmk. Unlike many cancer cells with negative receptor-interacting protein 3 (RIP3) expression, moderate expression of RIP3 in CCA cells was observed and was required for matrine to induce necroptosis, which was switched to apoptosis after knocking down endogenous RIP3. Moreover, matrine could increase RIP3 expression level, which may facilitate the necroptosis process. Translocation of mixed lineage kinase-domain like (MLKL) from cytoplasm to plasma membrane as a downstream event of RIP3, as well as the increased production of reactive oxygen species (ROS) by RIP3/MLKL, was critical for matrine to induce necroptosis. In clinical study, we found RIP3 was lower but still moderately expressed in most CCA tissue samples compared with adjacent normal tissues. Taken together, we identified matrine as a necroptosis inducer in CCA by enhancing RIP3 expression and the following RIP3/MLKL/ROS signaling pathway, which provided new individualized strategies based on RIP3 expression to overcome chemoresistance in CCA therapy. PMID:28179994

  16. Bioactive compounds from crocodile (Crocodylus siamensis) white blood cells induced apoptotic cell death in hela cells.

    PubMed

    Patathananone, Supawadee; Thammasirirak, Sompong; Daduang, Jureerut; Chung, Jing Gung; Temsiripong, Yosapong; Daduang, Sakda

    2016-08-01

    Crocodile (Crocodylus siamensis) white blood cell extracts (WBCex) were examined for anticancer activity in HeLa cell lines using the MTT assay. The percentage viability of HeLa cells significantly deceased after treatment with WBCex in a dose- and time-dependent manner. The IC50 dose was suggested to be approximately 225 μg/mL protein. Apoptotic cell death occurred in a time-dependent manner based on investigation by flow cytometry using annexin V-FITC and PI staining. DAPI nucleic acid staining indicated increased chromatin condensation. Caspase-3, -8 and -9 activities also increased, suggesting the induction of the caspase-dependent apoptotic pathway. Furthermore, the mitochondrial membrane potential (ΔΨm ) of HeLa cells was lost as a result of increasing levels of Bax and reduced levels of Bcl-2, Bcl-XL, Bcl-Xs, and XIAP. The decreased ΔΨm led to the release of cytochrome c and the activation of caspase-9 and -3. Apoptosis-inducing factor translocated into the nuclei, and endonuclease G (Endo G) was released from the mitochondria. These results suggest that anticancer agents in WBCex can induce apoptosis in HeLa cells via both caspase-dependent and -independent pathways. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 986-997, 2016.

  17. Oxidant-induced DNA damage of target cells.

    PubMed Central

    Schraufstätter, I; Hyslop, P A; Jackson, J H; Cochrane, C G

    1988-01-01

    In this study we examined the leukocytic oxidant species that induce oxidant damage of DNA in whole cells. H2O2 added extracellularly in micromolar concentrations (10-100 microM) induced DNA strand breaks in various target cells. The sensitivity of a specific target cell was inversely correlated to its catalase content and the rate of removal of H2O2 by the target cell. Oxidant species produced by xanthine oxidase/purine or phorbol myristate acetate-stimulated monocytes induced DNA breakage of target cells in proportion to the amount of H2O2 generated. These DNA strand breaks were prevented by extracellular catalase, but not by superoxide dismutase. Cytotoxic doses of HOCl, added to target cells, did not induce DNA strand breakage, and myeloperoxidase added extracellularly in the presence of an H2O2-generating system, prevented the formation of DNA strand breaks in proportion to its H2O2 degrading capacity. The studies also indicated that H2O2 formed hydroxyl radical (.OH) intracellularly, which appeared to be the most likely free radical responsible for DNA damage: .OH was detected in cells exposed to H2O2; the DNA base, deoxyguanosine, was hydroxylated in cells exposed to H2O2; and intracellular iron was essential for induction of DNA strand breaks. PMID:2843565

  18. Generation of induced pluripotent stem cells from the pig

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The value of stem cells has become increasingly evident in recent years with the advent of genetic engineering tools that allow site-specific modifications to the genome. The use of stem cells to induce modifications has several potential benefits for the livestock industry including improving anim...

  19. Acanthamoeba induces cell-cycle arrest in host cells.

    PubMed

    Sissons, James; Alsam, Selwa; Jayasekera, Samantha; Kim, Kwang Sik; Stins, Monique; Khan, Naveed Ahmed

    2004-08-01

    Acanthamoeba can cause fatal granulomatous amoebic encephalitis (GAE) and eye keratitis. However, the pathogenesis and pathophysiology of these emerging diseases remain unclear. In this study, the effects of Acanthamoeba on the host cell cycle using human brain microvascular endothelial cells (HBMEC) and human corneal epithelial cells (HCEC) were determined. Two isolates of Acanthamoeba belonging to the T1 genotype (GAE isolate) and T4 genotype (keratitis isolate) were used, which showed severe cytotoxicity on HBMEC and HCEC, respectively. No tissue specificity was observed in their ability to exhibit binding to the host cells. To determine the effects of Acanthamoeba on the host cell cycle, a cell-cycle-specific gene array was used. This screened for 96 genes specific for host cell-cycle regulation. It was observed that Acanthamoeba inhibited expression of genes encoding cyclins F and G1 and cyclin-dependent kinase 6, which are proteins important for cell-cycle progression. Moreover, upregulation was observed of the expression of genes such as GADD45A and p130 Rb, associated with cell-cycle arrest, indicating cell-cycle inhibition. Next, the effect of Acanthamoeba on retinoblastoma protein (pRb) phosphorylation was determined. pRb is a potent inhibitor of G1-to-S cell-cycle progression; however, its function is inhibited upon phosphorylation, allowing progression into S phase. Western blotting revealed that Acanthamoeba abolished pRb phosphorylation leading to cell-cycle arrest at the G1-to-S transition. Taken together, these studies demonstrated for the first time that Acanthamoeba inhibits the host cell cycle at the transcriptional level, as well as by modulating pRb phosphorylation using host cell-signalling mechanisms. A complete understanding of Acanthamoeba-host cell interactions may help in developing novel strategies to treat Acanthamoeba infections.

  20. Light induced drug delivery into cancer cells.

    PubMed

    Shamay, Yosi; Adar, Lily; Ashkenasy, Gonen; David, Ayelet

    2011-02-01

    Cell-penetrating peptides (CPPs) can be used for intracellular delivery of a broad variety of cargoes, including various nanoparticulate pharmaceutical carriers. However, the cationic nature of all CPP sequences, and thus lack of cell specificity, limits their in vivo use for drug delivery applications. Here, we have devised and tested a strategy for site-specific delivery of dyes and drugs into cancer cells by using polymers bearing a light activated caged CPP (cCPP). The positive charge of Lys residues on the minimum sequence of the CPP penetratin ((52)RRMKWKK(58)) was masked with photo-cleavable groups to minimize non-specific adsorption and cellular uptake. Once illuminated by UV light, these protecting groups were cleaved, the positively charged CPP regained its activity and facilitated rapid intracellular delivery of the polymer-dye or polymer-drug conjugates into cancer cells. We have found that a 10-min light illumination time was sufficient to enhance the penetration of the polymer-CPP conjugates bearing the proapoptotic peptide, (D)(KLAKLAK)(2), into 80% of the target cells, and to promote a 'switch' like cytotoxic activity resulting a shift from 100% to 10% in cell viability after 2 h. This report provides an example for tumor targeting by means of light activation of cell-penetrating peptides for intracellular drug delivery.

  1. Resveratrol-induced autophagocytosis in ovarian cancer cells.

    PubMed

    Opipari, Anthony W; Tan, Lijun; Boitano, Anthony E; Sorenson, Dorothy R; Aurora, Anjili; Liu, J Rebecca

    2004-01-15

    Resveratrol (3,5,4-trihydroxystilbene), a natural phytoalexin present in grapes, nuts, and red wine, has antineoplastic activities. Several molecular mechanisms have been described to underlie its effects on cells in vitro and in vivo. In the present study, the response of ovarian cancer cells to resveratrol is explored. Resveratrol inhibited growth and induced death in a panel of five human ovarian carcinoma cell lines. The response was associated with mitochondrial release of cytochrome c, formation of the apoptosome complex, and caspase activation. Surprisingly, even with these molecular features of apoptosis, analysis of resveratrol-treated cells by light and electron microscopy revealed morphology and ultrastructural changes indicative of autophagocytic, rather than apoptotic, death. This suggests that resveratrol can induce cell death through two distinct pathways. Consistent with resveratrol's ability to kill cells via nonapoptotic processes, cells transfected to express high levels of the antiapoptotic proteins Bcl-x(L) and Bcl-2 are equally sensitive as control cells to resveratrol. Together, these findings show that resveratrol induces cell death in ovarian cancer cells through a mechanism distinct from apoptosis, therefore suggesting that it may provide leverage to treat ovarian cancer that is chemoresistant on the basis of ineffective apoptosis.

  2. Octylphenol induces vitellogenin production and cell death in fish hepatocytes

    SciTech Connect

    Toomey, B.H.; Monteverdi, G.H.; Di Giulio, R.T.

    1999-04-01

    The effects of octylphenol (OP) on vitellogenin production and cell death in hepatocytes from brown bullhead catfish (Americurus nebulosus) were studied. Production of vitellogenin was induced in hepatocytes exposed to 10 to 50 {micro}M OP, whereas a higher concentration of OP (100 {micro}M) induced apoptotic cell death. By 3 h after the addition of 100 {micro}M OP, dying cells showed chromatin condensation and DNA fragmentation as determined by fluorescence microscopy and gel electrophoresis. Later stages of cell death (nuclear membrane breakdown and cell fragmentation into apoptotic bodies) were identified in cells exposed to OP for at least 6 h. Hepatocytes exposed to 100 {micro}M OP also produced less vitellogenin than cells exposed to 50 {micro}M OP. An estrogen receptor antagonist, tamoxifen, greatly decreased vitellogenin production in OP-exposed hepatocytes from male fish but did not decrease cell death in these cells. Thus, although the ability of OP to induce vitellogenin production is likely mediated through interactions with the estrogen receptor, the induction of apoptotic cell death by OP does not appear to be dependent on its estrogenic activity but may be a more general toxic effect.

  3. Methylglyoxal Induces Mitochondrial Dysfunction and Cell Death in Liver

    PubMed Central

    Seo, Kyuhwa; Ki, Sung Hwan

    2014-01-01

    Degradation of glucose is aberrantly increased in hyperglycemia, which causes various harmful effects on the liver. Methylglyoxal is produced during glucose degradation and the levels of methylglyoxal are increased in diabetes patients. In this study we investigated whether methylglyoxal induces mitochondrial impairment and apoptosis in HepG2 cells and induces liver toxicity in vivo. Methylglyoxal caused apoptotic cell death in HepG2 cells. Moreover, methylglyoxal significantly promoted the production of reactive oxygen species (ROS) and depleted glutathione (GSH) content. Pretreatment with antioxidants caused a marked decrease in methylglyoxal-induced apoptosis, indicating that oxidant species are involved in the apoptotic process. Methylglyoxal treatment induced mitochondrial permeability transition, which represents mitochondrial impairment. However, pretreatment with cyclosporin A, an inhibitor of the formation of the permeability transition pore, partially inhibited methylglyoxal-induced cell death. Furthermore, acute treatment of mice with methylglyoxal increased the plasma levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), indicating liver toxicity. Collectively, our results showed that methylglyoxal increases cell death and induces liver toxicity, which results from ROS-mediated mitochondrial dysfunction and oxidative stress. PMID:25343013

  4. Paclitaxel inhibits the hyper-activation of spleen cells by lipopolysaccharide and induces cell death

    PubMed Central

    Kim, Hyun-Ji

    2016-01-01

    Paclitaxel was isolated from the bark of the Pacific yew, Taxus brevifolia, and used as an anticancer agent. Paclitaxel prevents cancer cell division by inhibiting spindle fiber function, inducing cell death. A recent study demonstrated that paclitaxel binds to myeloid differentiation protein-2 of Toll-like receptor 4 and prevents the signal transduction of lipopolysaccharide (LPS). Paclitaxel converts immune cells hypo-responsive to LPS. In this study, we investigated whether paclitaxel can inhibit the phenotype and function of immune cells. To accomplish this, we used spleen cells, a major type of immune cell, LPS, a representative inflammatory agent and a mitogen for B lymphocytes. LPS profoundly increased the activation and cytokine production of spleen cells. However, paclitaxel significantly inhibited LPS-induced hyper-activation of spleen cells. Furthermore, we found that paclitaxel induced cell death of LPS-treated spleen cells. These results suggest that paclitaxel can inhibit the hyper-immune response of LPS in spleen cells via a variety of mechanisms. These findings suggest that paclitaxel can be used as a modulating agent for diseases induced by hyper-activation of B lymphocytes. Taken together, these results demonstrate that paclitaxel inhibits the function of spleen cells activated by LPS, and further induces cell death. PMID:27030196

  5. A minimum number of autoimmune T cells to induce autoimmunity?

    PubMed

    Bosch, Angela J T; Bolinger, Beatrice; Keck, Simone; Stepanek, Ondrej; Ozga, Aleksandra J; Galati-Fournier, Virginie; Stein, Jens V; Palmer, Ed

    2017-03-12

    While autoimmune T cells are present in most individuals, only a minority of the population suffers from an autoimmune disease. To better appreciate the limits of T cell tolerance, we carried out experiments to determine how many autoimmune T cells are required to initiate an experimental autoimmune disease. Variable numbers of autoimmune OT-I T cells were transferred into RIP-OVA mice, which were injected with antigen-loaded DCs in a single footpad; this restricted T cell priming to a few OT-I T cells that are present in the draining popliteal lymph node. Using selective plane illumination microscopy (SPIM) we counted the number of OT-I T cells present in the popliteal lymph node at the time of priming. Analysis of our data suggests that a single autoimmune T cell cannot induce an experimental autoimmune disease, but a "quorum" of 2-5 autoimmune T cells clearly has this capacity.

  6. Rationale and Methodology of Reprogramming for Generation of Induced Pluripotent Stem Cells and Induced Neural Progenitor Cells.

    PubMed

    Tian, Zuojun; Guo, Fuzheng; Biswas, Sangita; Deng, Wenbin

    2016-04-20

    Great progress has been made regarding the capabilities to modify somatic cell fate ever since the technology for generation of induced pluripotent stem cells (iPSCs) was discovered in 2006. Later, induced neural progenitor cells (iNPCs) were generated from mouse and human cells, bypassing some of the concerns and risks of using iPSCs in neuroscience applications. To overcome the limitation of viral vector induced reprogramming, bioactive small molecules (SM) have been explored to enhance the efficiency of reprogramming or even replace transcription factors (TFs), making the reprogrammed cells more amenable to clinical application. The chemical induced reprogramming process is a simple process from a technical perspective, but the choice of SM at each step is vital during the procedure. The mechanisms underlying cell transdifferentiation are still poorly understood, although, several experimental data and insights have indicated the rationale of cell reprogramming. The process begins with the forced expression of specific TFs or activation/inhibition of cell signaling pathways by bioactive chemicals in defined culture condition, which initiates the further reactivation of endogenous gene program and an optimal stoichiometric expression of the endogenous pluri- or multi-potency genes, and finally leads to the birth of reprogrammed cells such as iPSCs and iNPCs. In this review, we first outline the rationale and discuss the methodology of iPSCs and iNPCs in a stepwise manner; and then we also discuss the chemical-based reprogramming of iPSCs and iNPCs.

  7. Rationale and Methodology of Reprogramming for Generation of Induced Pluripotent Stem Cells and Induced Neural Progenitor Cells

    PubMed Central

    Tian, Zuojun; Guo, Fuzheng; Biswas, Sangita; Deng, Wenbin

    2016-01-01

    Great progress has been made regarding the capabilities to modify somatic cell fate ever since the technology for generation of induced pluripotent stem cells (iPSCs) was discovered in 2006. Later, induced neural progenitor cells (iNPCs) were generated from mouse and human cells, bypassing some of the concerns and risks of using iPSCs in neuroscience applications. To overcome the limitation of viral vector induced reprogramming, bioactive small molecules (SM) have been explored to enhance the efficiency of reprogramming or even replace transcription factors (TFs), making the reprogrammed cells more amenable to clinical application. The chemical induced reprogramming process is a simple process from a technical perspective, but the choice of SM at each step is vital during the procedure. The mechanisms underlying cell transdifferentiation are still poorly understood, although, several experimental data and insights have indicated the rationale of cell reprogramming. The process begins with the forced expression of specific TFs or activation/inhibition of cell signaling pathways by bioactive chemicals in defined culture condition, which initiates the further reactivation of endogenous gene program and an optimal stoichiometric expression of the endogenous pluri- or multi-potency genes, and finally leads to the birth of reprogrammed cells such as iPSCs and iNPCs. In this review, we first outline the rationale and discuss the methodology of iPSCs and iNPCs in a stepwise manner; and then we also discuss the chemical-based reprogramming of iPSCs and iNPCs. PMID:27104529

  8. FOXL2-induced follistatin attenuates activin A-stimulated cell proliferation in human granulosa cell tumors

    SciTech Connect

    Cheng, Jung-Chien; Chang, Hsun-Ming; Qiu, Xin; Fang, Lanlan; Leung, Peter C.K.

    2014-01-10

    Highlights: •Activin A stimulates cell proliferation in KGN human granulosa cell tumor-derived cell line. •Cyclin D2 mediates activin A-induced KGN cell proliferation. •FOXL2 induces follistatin expression in KGN cells. •FOXL2-induced follistatin attenuates activin A-stimulated KGN cell proliferation. -- Abstract: Human granulosa cell tumors (GCTs) are rare, and their etiology remains largely unknown. Recently, the FOXL2 402C > G (C134W) mutation was found to be specifically expressed in human adult-type GCTs; however, its function in the development of human GCTs is not fully understood. Activins are members of the transforming growth factor-beta superfamily, which has been shown to stimulate normal granulosa cell proliferation; however, little is known regarding the function of activins in human GCTs. In this study, we examined the effect of activin A on cell proliferation in the human GCT-derived cell line KGN. We show that activin A treatment stimulates KGN cell proliferation. Treatment with the activin type I receptor inhibitor SB431542 blocks activin A-stimulated cell proliferation. In addition, our results show that cyclin D2 is induced by treatment with activin A and is involved in activin A-stimulated cell proliferation. Moreover, the activation of Smad signaling is required for activin A-induced cyclin D2 expression. Finally, we show that the overexpression of the wild-type FOXL2 but not the C134W mutant FOXL2 induced follistatin production. Treatment with exogenous follistatin blocks activin A-stimulated cell proliferation, and the overexpression of wild-type FOXL2 attenuates activin A-stimulated cell proliferation. These results suggest that FOXL2 may act as a tumor suppressor in human adult-type GCTs by inducing follistatin expression, which subsequently inhibits activin-stimulated cell proliferation.

  9. Induced Accelerated Aging in Induced Pluripotent Stem Cell Lines from Patients with Parkinson’s Disease

    DTIC Science & Technology

    2014-07-01

    Induced Pluripotent Stem Cell Lines from Patients with Parkinson’s Disease PRINCIPAL INVESTIGATOR: Dr. Birgitt Schuele CONTRACTING...contained in this report are those of the author( s ) and should not be construed as an official Department of the Army position, policy or decision...Aging in Induced Pluripotent Stem Cell Lines from Patients with Parkinson’s Disease 5b. GRANT NUMBER W81XWH-12-1-0003 5c. PROGRAM ELEMENT NUMBER

  10. Resveratrol induces cell death and inhibits human herpesvirus 8 replication in primary effusion lymphoma cells.

    PubMed

    Tang, Feng-Yi; Chen, Chang-Yu; Shyu, Huey-Wen; Hong, Shin; Chen, Hung-Ming; Chiou, Yee-Hsuan; Lin, Kuan-Hua; Chou, Miao-Chen; Wang, Lin-Yu; Wang, Yi-Fen

    2015-12-05

    Resveratrol (3,4',5-trihydroxy-trans-stilbene) has been reported to inhibit proliferation of various cancer cells. However, the effects of resveratrol on the human herpesvirus 8 (HHV8) harboring primary effusion lymphoma (PEL) cells remains unclear. The anti-proliferation effects and possible mechanisms of resveratrol in the HHV8 harboring PEL cells were examined in this study. Results showed that resveratrol induced caspase-3 activation and the formation of acidic vacuoles in the HHV8 harboring PEL cells, indicating resveratrol treatment could cause apoptosis and autophagy in PEL cells. In addition, resveratrol treatment increased ROS generation but did not lead to HHV8 reactivation. ROS scavenger (N-acetyl cysteine, NAC) could attenuate both the resveratrol induced caspase-3 activity and the formation of acidic vacuoles, but failed to attenuate resveratrol induced PEL cell death. Caspase inhibitor, autophagy inhibitors and necroptosis inhibitor could not block resveratrol induced PEL cell death. Moreover, resveratrol disrupted HHV8 latent infection, inhibited HHV8 lytic gene expression and decreased virus progeny production. Overexpression of HHV8-encoded viral FLICE inhibitory protein (vFLIP) could partially block resveratrol induced cell death in PEL cells. These data suggest that resveratrol-induced cell death in PEL cells may be mediated by disruption of HHV8 replication. Resveratrol may be a potential anti-HHV8 drug and an effective treatment for HHV8-related tumors.

  11. Omi/HtrA2 protease mediates cisplatin-induced cell death in renal cells.

    PubMed

    Cilenti, Lucia; Kyriazis, George A; Soundarapandian, Mangala M; Stratico, Valerie; Yerkes, Adam; Park, Kwon Moo; Sheridan, Alice M; Alnemri, Emad S; Bonventre, Joseph V; Zervos, Antonis S

    2005-02-01

    Omi/HtrA2 is a mitochondrial proapoptotic serine protease that is able to induce both caspase-dependent and caspase-independent cell death. After apoptotic stimuli, Omi is released to the cytoplasm where it binds and cleaves inhibitor of apoptosis proteins. In this report, we investigated the role of Omi in renal cell death following cisplatin treatment. Using primary mouse proximal tubule cells, as well as established renal cell lines, we show that the level of Omi protein is upregulated after treatment with cisplatin. This upregulation is followed by the release of Omi from mitochondria to the cytoplasm and degradation of XIAP. Reducing the endogenous level of Omi protein using RNA interference renders renal cells resistant to cisplatin-induced cell death. Furthermore, we show that the proteolytic activity of Omi is necessary and essential for cisplatin-induced cell death in this system. When renal cells are treated with Omi's specific inhibitor, ucf-101, they become significantly resistant to cisplatin-induced cell death. Ucf-101 was also able to minimize cisplatin-induced nephrotoxic injury in animals. Our results demonstrate that Omi is a major mediator of cisplatin-induced cell death in renal cells and suggest a way to limit renal injury by specifically inhibiting its proteolytic activity.

  12. Glioma-Derived ADAM10 Induces Regulatory B Cells to Suppress CD8+ T Cells

    PubMed Central

    Li, Wen-sheng; Luo, Lun; Huang, Zhen-chao; Guo, Ying

    2014-01-01

    CD8+ T cells play an important role in the anti-tumor activities of the body. The dysfunction of CD8+ T cells in glioma is unclear. This study aims to elucidate the glioma cell-derived ADAM10 (A Disintegrin and metalloproteinase domain-containing protein 10) in the suppression of CD8+ effector T cells by the induction of regulatory B cells. In this study, glioma cells were isolated from surgically removed glioma tissue and stimulated by Phorbol myristate acetage (PMA) in the culture. The levels of ADAM10 in the culture were determined by enzyme-linked immunosorbent assay. Immune cells were assessed by flow cytometry. The results showed that the isolated glioma cells express ADAM10, which was markedly up regulated after stimulated with PMA. The glioma-derived ADAM10 induced activated B cells to differentiate into regulatory B cells, the later suppressed CD8+ T cell proliferation as well as the induced regulatory T cells, which also showed the immune suppressor effect on CD8+ effector T cell proliferation. In conclusion, glioma cells produce ADAM10 to induce Bregs; the latter suppresses CD8+ T cells and induces Tregs. PMID:25127032

  13. Metformin prevents methylglyoxal-induced apoptosis of mouse Schwann cells

    SciTech Connect

    Ota, Kimiko; Nakamura, Jiro; Li, Weiguo; Kozakae, Mika; Watarai, Atsuko; Nakamura, Nobuhisa; Yasuda, Yutaka; Nakashima, Eirtaro; Naruse, Keiko; Watabe, Kazuhiko; Kato, Koichi; Oiso, Yutaka; Hamada, Yoji . E-mail: yhama@med.nagoya-u.ac.jp

    2007-05-25

    Methylglyoxal (MG) is involved in the pathogenesis of diabetic complications via the formation of advanced glycation end products (AGEs) and reactive oxygen species (ROS). To clarify whether the antidiabetic drug metformin prevents Schwann cell damage induced by MG, we cultured mouse Schwann cells in the presence of MG and metformin. Cell apoptosis was evaluated using Hoechst 33342 nuclear staining, caspase-3 activity, and c-Jun-N-terminal kinase (JNK) phosphorylation. Intracellular ROS formation was determined by flow cytometry, and AMP-activated kinase (AMPK) phosphorylation was also examined. MG treatment resulted in blunted cell proliferation, an increase in the number of apoptotic cells, and the activation of caspase-3 and JNK along with enhanced intracellular ROS formation. All of these changes were significantly inhibited by metformin. No significant activation of AMPK by MG or metformin was observed. Taken together, metformin likely prevents MG-induced apoptotic signals in mouse Schwann cells by inhibiting the formation of AGEs and ROS.

  14. Generation of functional podocytes from human induced pluripotent stem cells.

    PubMed

    Ciampi, Osele; Iacone, Roberto; Longaretti, Lorena; Benedetti, Valentina; Graf, Martin; Magnone, Maria Chiara; Patsch, Christoph; Xinaris, Christodoulos; Remuzzi, Giuseppe; Benigni, Ariela; Tomasoni, Susanna

    2016-07-01

    Generating human podocytes in vitro could offer a unique opportunity to study human diseases. Here, we describe a simple and efficient protocol for obtaining functional podocytes in vitro from human induced pluripotent stem cells. Cells were exposed to a three-step protocol, which induced their differentiation into intermediate mesoderm, then into nephron progenitors and, finally, into mature podocytes. After differentiation, cells expressed the main podocyte markers, such as synaptopodin, WT1, α-Actinin-4, P-cadherin and nephrin at the protein and mRNA level, and showed the low proliferation rate typical of mature podocytes. Exposure to Angiotensin II significantly decreased the expression of podocyte genes and cells underwent cytoskeleton rearrangement. Cells were able to internalize albumin and self-assembled into chimeric 3D structures in combination with dissociated embryonic mouse kidney cells. Overall, these findings demonstrate the establishment of a robust protocol that, mimicking developmental stages, makes it possible to derive functional podocytes in vitro.

  15. Lysophosphatidic acid-induced chemotaxis of bone cells.

    SciTech Connect

    Karagiosis, Sue A.; Masiello, Lisa M.; Bollinger, Nikki; Karin, Norm J.

    2006-07-01

    Lysophosphatidic acid (LPA) is a platelet-derived bioactive lipid that is postulated to regulate wound healing. LPA activates G protein-coupled receptors to induce Ca2+ signaling in MC3T3-E1 pre-osteoblasts, and is a potent chemotactic stimulus for these cells. Since bone fracture healing requires the migration of osteoblast progenitors, we postulate that LPA is among the factors that stimulate bone repair. UMR 106-01 cells, which express a more mature osteoblastic phenotype than MC3T3-E1 cells, did not migrate in response to LPA, although they express LPA receptors and exhibit LPA-induced Ca2+ signals. This suggests that LPA differentially induces pre-osteoblast chemotaxis, consistent with our hypothesis that LPA stimulates the motility of osteoblast progenitors during bone healing. LPA-stimulated MC3T3-E1 cells exhibit striking changes in morphology and F-actin architecture, and phosphatidylinositol-3 kinase (PI3K) is required for motility-associated cytoskeletal rearrangements in many cell types. We found a dose-dependent reduction in LPA-induced osteoblast migration when cells also were treated with the PI3K inhibitor, LY294002. Treatment of many cell types with LPA is associated with an autocrine/paracrine transactivation of the EGF receptor (EGFR) via shedding of surface-tethered EGFR ligands, a phenomenon often required for LPA-induced chemotaxis. MC3T3-E1 cells express multiple EGFR ligands (epigen, epiregulin, HB-EGF and amphiregulin) and migrated in response to EGF. However, while EGF-stimulated motility in MC3T3-E1 cells was blocked by an EGFR inhibitor, there was no significant effect on LPA-induced chemotaxis. Activation of MAP kinases is a hallmark of EGFR-mediated signaling, and EGF treatment of MC3T3-E1 cells led to a strong stimulation of ERK1/2 kinase. In contrast, LPA induced only a minor elevation in ERK activity. Thus, it is likely that the increase in ERK activity by LPA is related to cell proliferation associated with lipid treatment. We

  16. Stapled peptide induces cancer cell death.

    PubMed

    Whelan, Jo

    2004-11-01

    Hydrocarbon stapling could enable peptides from the key domains of natural proteins to be used therapeutically. Using the technique on a peptide involved in apoptosis, researchers have succeeded in destroying cancer cells in a mouse model of leukaemia.

  17. Diphenylhydantoin-induced pure red cell aplasia.

    PubMed

    Rusia, Usha; Malhotra, Purnima; Joshi, Panul

    2006-01-01

    Pure red cell aplasia is an uncommon complication of diphenylhydantoin therapy. It has not been reported in Indian literature. Awareness of the entity helps in establishing the cause of anaemia in these patients and alerts the physicians to the need of comprehensive haematological monitoring in these patients. A case of 58-year-old male who developed pure red cell aplasia following three months of diphenylhydantoin therapy is reported here.

  18. UV-induced changes in cell cycle and gene expression within rabbit lens epithelial cells

    SciTech Connect

    Sidjanin, D.; Grdina, D.; Woloschak, G.E.

    1994-11-01

    Damage to lens epithelial cells is a probable initiation process in cataract formation induced by ultraviolet radiation. These experiments investigated the ability of 254 nm radiation on cell cycle progression and gene expression in rabbit lens epithelial cell line N/N1003A. No changes in expression of c-fos, c-jun, alpha- tubulin, or vimentin was observed following UV exposure. Using flow cytometry, an accumulation of cells in G1/S phase of the cell cycle 1 hr following exposure. The observed changes in gene expression, especially the decreased histone transcripts reported here may play a role in UV induced inhibition of cell cycle progression.

  19. Novel synthetic organosulfur compounds induce apoptosis of human leukemic cells.

    PubMed

    Wong, W W; Macdonald, S; Langler, R F; Penn, L Z

    2000-01-01

    It has been well documented that natural organosulfur compounds (OSCs) derived from plants such as garlic, onions and mahogany trees possess antiproliferative properties; however, the essential chemical features of the active OSC compounds remain unclear. To investigate the association between OSC structure and growth inhibitory activity, we synthesized novel relatives of dysoxysulfone, a natural OSC derived from the Fijian medicinal plant, Dysoxylum richii. In this study, we have examined the antiproliferative effects of these novel OSCs on a model human leukemic cell system and show that the compounds segregate into three groups. Group I, consisting of compounds A, B, G and J, did not affect either cell proliferation or the cell cycle profile of the leukemic cell lines. Group II, consisting of compounds F and H, induced the cells to undergo apoptosis from the G2/M phase of the cell cycle. Group III, consisting of compounds C, D, E and I, decreased cell proliferation and induced apoptosis throughout the cell cycle. The apoptotic agonists of Group II and III shared a common disulfide moiety, essential for leukemic cell cytotoxicity. Interestingly, Group II compounds did not affect cell viability of normal human diploid cells, suggesting the regions flanking the disulfide group contributes to the specificity of cell killing. Thus, we provide evidence that structure-activity analysis of natural products can identify novel compounds for the development of new therapeutics that can trigger apoptosis in a tumor-specific manner.

  20. Bisphenol A-induced apoptosis of cultured rat Sertoli cells.

    PubMed

    Iida, Hiroshi; Maehara, Kazue; Doiguchi, Masamichi; Mōri, Takayuki; Yamada, Fumio

    2003-01-01

    Bisphenol A (BPA) was examined for its effects on cultured Sertoli cells established from 18-day-old rat testes. We demonstrated that exposure of cultured Sertoli cells to BPA decreased the cell viability in a dose- and a time-dependent manner and that exposure to BPA brought about morphologic changes of the cells, such as membrane blebs, cell rounding, cytoskeletal collapse, and chromatin condensation or fragmentation, all of which conform to the morphologic criteria for apoptosis. Immunocytochemistry showed that active caspase-3, a major execution caspase, was expressed in round Sertoli cells positively labeled by the TUNEL method. Co-localization of active caspase-3 and aggregated actin fragments was also observed in the round Sertoli cells. Theses results suggest that BPA induces cell death of Sertoli cells by promoting apoptosis. Apoptosis-inducing cell death was observed in cells exposed to 150-200 microM BPA, while BPA at <100 microM had only slight cytotoxic effects on the cells.

  1. Advances and applications of induced pluripotent stem cells.

    PubMed

    Pietronave, Stefano; Prat, Maria

    2012-03-01

    Direct reprogramming of somatic cells into pluripotent cells is an emerging technology for creating patient-specific cells, and potentially opens new scenarios in medical and pharmacological fields. From the discovery of Shinya Yamanaka, who first obtained pluripotent cells from fibroblasts by retrovirus-derived ectopic expression of defined embryonic transcription factors, new methods have been developed to generate safe induced pluripotent stem (iPS) cells without genomic manipulations. This review will focus on the recent advances in iPS technology and their application in pharmacology and medicine.

  2. Elastase induces lung epithelial cell autophagy through placental growth factor

    PubMed Central

    Hou, Hsin-Han; Cheng, Shih-Lung; Chung, Kuei-Pin; Kuo, Mark Yen-Ping; Yeh, Cheng-Chang; Chang, Bei-En; Lu, Hsuan-Hsuan; Wang, Hao-Chien; Yu, Chong-Jen

    2014-01-01

    Chronic obstructive pulmonary disease (COPD) is a devastating disease, which is associated with increasing mortality and morbidity. Therefore, there is a need to clearly define the COPD pathogenic mechanism and to explore effective therapies. Previous studies indicated that cigarette smoke (CS) induces autophagy and apoptosis in lung epithelial (LE) cells. Excessive ELANE/HNE (elastase, neutrophil elastase), a factor involved in protease-antiprotease imbalance and the pathogenesis of COPD, causes LE cell apoptosis and upregulates the expression of several stimulus-responsive genes. However, whether or not elastase induces autophagy in LE cell remains unknown. The level of PGF (placental growth factor) is higher in COPD patients than non-COPD controls. We hypothesize that elastase induces PGF expression and causes autophagy in LE cells. In this study, we demonstrated that porcine pancreatic elastase (PPE) induced PGF expression and secretion in LE cells in vitro and in vivo. The activation of MAPK8/JNK1 (mitogen-activated protein kinase 8) and MAPK14/p38alpha MAPK signaling pathways was involved in the PGF mediated regulation of the TSC (tuberous sclerosis complex) pathway and autophagy in LE cells. Notably, PGF-induced MAPK8 and MAPK14 signaling pathways mediated the inactivation of MTOR (mechanistic target of rapamycin), the upregulation of MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 β) and the increase of autophagosome formation in mice. Furthermore, the PPE-induced autophagy promotes further apoptosis in vitro and in vivo. In summary, elastase-induced autophagy promotes LE cell apoptosis and pulmonary emphysema through the upregulation of PGF. PGF and its downstream MAPK8 and MAPK14 signaling pathways are potential therapeutic targets for the treatment of emphysema and COPD. PMID:24988221

  3. Butyrate-Induced Apoptosis in Prostate Cancer Cell Lines

    DTIC Science & Technology

    2001-09-01

    butyrate-induced apoptosis was independent of cell cycle phase. 14. SUBJECT TERMS 15. NUMBER OF PAGES prostate cancer, histone deacetylase inhibitors, bone...of cells plated) HDI histone deacetylase inhibitor SBHA suberoylbishydroxamate PKC protein kinase C activator SDS-PAGE SDS polyacrylamide gel...cancer cell lines 1. Summary of goals and findings Histone deacetylase inhibitors (HDI) such as butyrate and suberoylbishydroxamate (SBHA) have

  4. Material-induced shunts in multicrystalline silicon solar cells

    SciTech Connect

    Breitenstein, O. Bauer, J.; Rakotoniaina, J. P.

    2007-04-15

    By applying lock-in thermography imaging, light-beam-induced current imaging, electron-beam-induced current imaging at different stages of sample preparation, and infrared light microscopy in transmission mode, the physical nature of the dominant material-induced shunts in multicrystalline solar cells made from p-type silicon material has been investigated. It turns out that these shunts are due to silicon carbide (SiC) filaments, which grow preferentially in grain boundaries and cross the whole cell. These filaments are highly n-type doped, like the emitter layer on the surface of the cells. They are electrically connected both with the emitter and with the back contact, thereby producing internal shunts in the solar cell.

  5. Targeting prohibitins induces apoptosis in acute myeloid leukemia cells

    PubMed Central

    Pomares, Helena; Palmeri, Claudia M; Iglesias-Serret, Daniel; Moncunill-Massaguer, Cristina; Saura-Esteller, José; Núñez-Vázquez, Sonia; Gamundi, Enric; Arnan, Montserrat; Preciado, Sara; Albericio, Fernando; Lavilla, Rodolfo; Pons, Gabriel; González-Barca, Eva M

    2016-01-01

    Fluorizoline is a new synthetic molecule that induces apoptosis by selectively targeting prohibitins (PHBs). In this study, the pro-apoptotic effect of fluorizoline was assessed in two cell lines and 21 primary samples from patients with debut of acute myeloid leukemia (AML). Fluorizoline induced apoptosis in AML cells at concentrations in the low micromolar range. All primary samples were sensitive to fluorizoline irrespectively of patients' clinical or genetic features. In addition, fluorizoline inhibited the clonogenic capacity and induced differentiation of AML cells. Fluorizoline increased the mRNA and protein levels of the pro-apoptotic BCL-2 family member NOXA both in cell lines and primary samples analyzed. These results suggest that targeting PHBs could be a new therapeutic strategy for AML. PMID:27542247

  6. Towards Personalized Regenerative Cell Therapy: Mesenchymal Stem Cells Derived from Human Induced Pluripotent Stem Cells.

    PubMed

    Lin, Lin; Bolund, Lars; Luo, Yonglun

    2016-01-01

    Mesenchymal stem cells (MSCs) are adult stem cells with the capacity of self-renewal and multilineage differentiation, and can be isolated from several adult tissues. However, isolating MSCs from adult tissues for cell therapy is hampered by the invasive procedure, the rarity of the cells and their attenuated proliferation capacity when cultivated and expanded in vitro. Human MSCs derived from induced pluripotent stem cells (iPSC-MSCs) have now evolved as a promising alternative cell source for MSCs and regenerative medicine. Several groups, including ours, have reported successful derivation of functional iPSC-MSCs and applied these cells in MSC-based therapeutic testing. Still, the current experience and understanding of iPSC-MSCs with respect to production methods, safety and efficacy are primitive. In this review, we highlight the methodological progress in iPSC-MSC research, describing the importance of choosing the right sources of iPSCs, iPSC reprogramming methods, iPSC culture systems, embryoid body intermediates, pathway inhibitors, basal medium, serum, growth factors and culture surface coating. We also highlight some progress in the application of iPSC-MSCs in direct cell therapy, tissue engineering and gene therapy.

  7. DA-6034 Induces [Ca(2+)]i Increase in Epithelial Cells.

    PubMed

    Yang, Yu-Mi; Park, Soonhong; Ji, Hyewon; Kim, Tae-Im; Kim, Eung Kweon; Kang, Kyung Koo; Shin, Dong Min

    2014-04-01

    DA-6034, a eupatilin derivative of flavonoid, has shown potent effects on the protection of gastric mucosa and induced the increases in fluid and glycoprotein secretion in human and rat corneal and conjunctival cells, suggesting that it might be considered as a drug for the treatment of dry eye. However, whether DA-6034 induces Ca(2+) signaling and its underlying mechanism in epithelial cells are not known. In the present study, we investigated the mechanism for actions of DA-6034 in Ca(2+) signaling pathways of the epithelial cells (conjunctival and corneal cells) from human donor eyes and mouse salivary gland epithelial cells. DA-6034 activated Ca(2+)-activated Cl(-) channels (CaCCs) and increased intracellular calcium concentrations ([Ca(2+)]i) in primary cultured human conjunctival cells. DA-6034 also increased [Ca(2+)]i in mouse salivary gland cells and human corneal epithelial cells. [Ca(2+)]i increase of DA-6034 was dependent on the Ca(2+) entry from extracellular and Ca(2+) release from internal Ca(2+) stores. Interestingly, these effects of DA-6034 were related to ryanodine receptors (RyRs) but not phospholipase C/inositol 1,4,5-triphosphate (IP3) pathway and lysosomal Ca(2+) stores. These results suggest that DA-6034 induces Ca(2+) signaling via extracellular Ca(2+) entry and RyRs-sensitive Ca(2+) release from internal Ca(2+) stores in epithelial cells.

  8. Mitochondrial control of cell death induced by hyperosmotic stress.

    PubMed

    Criollo, Alfredo; Galluzzi, Lorenzo; Maiuri, M Chiara; Tasdemir, Ezgi; Lavandero, Sergio; Kroemer, Guido

    2007-01-01

    HeLa and HCT116 cells respond differentially to sorbitol, an osmolyte able to induce hypertonic stress. In these models, sorbitol promoted the phenotypic manifestations of early apoptosis followed by complete loss of viability in a time-, dose-, and cell type-specific fashion, by eliciting distinct yet partially overlapping molecular pathways. In HCT116 but not in HeLa cells, sorbitol caused the mitochondrial release of the caspase-independent death effector AIF, whereas in both cell lines cytochrome c was retained in mitochondria. Despite cytochrome c retention, HeLa cells exhibited the progressive activation of caspase-3, presumably due to the prior activation of caspase-8. Accordingly, caspase inhibition prevented sorbitol-induced killing in HeLa, but only partially in HCT116 cells. Both the knock-out of Bax in HCT116 cells and the knock-down of Bax in A549 cells by RNA interference reduced the AIF release and/or the mitochondrial alterations. While the knock-down of Bcl-2/Bcl-X(L) sensitized to sorbitol-induced killing, overexpression of a Bcl-2 variant that specifically localizes to mitochondria (but not of the wild-type nor of a endoplasmic reticulum-targeted form) strongly inhibited sorbitol effects. Thus, hyperosmotic stress kills cells by triggering different molecular pathways, which converge at mitochondria where pro- and anti-apoptotic members of the Bcl-2 family exert their control.

  9. Mitochondrial DNA damage induces apoptosis in senescent cells

    PubMed Central

    Laberge, R-M; Adler, D; DeMaria, M; Mechtouf, N; Teachenor, R; Cardin, G B; Desprez, P-Y; Campisi, J; Rodier, F

    2013-01-01

    Senescence is a cellular response to damage and stress. The senescence response prevents cancer by suppressing the proliferation of cells with a compromised genome and contributes to optimal wound healing in normal tissues. Persistent senescent cells are also thought to drive aging and age-associated pathologies through their secretion of inflammatory factors that modify the tissue microenvironment and alter the function of nearby normal or transformed cells. Understanding how senescent cells alter the microenvironment would be aided by the ability to induce or eliminate senescent cells at will in vivo. Here, we combine the use of the synthetic nucleoside analog ganciclovir (GCV) with herpes simplex virus thymidine kinase (HSVtk) activity to create or eliminate senescent human cells. We show that low concentrations of GCV induce senescence through the accumulation of nuclear DNA damage while higher concentrations of GCV, similar to those used in vivo, kill non-dividing senescent cells via mitochondrial DNA (mtDNA) damage and caspase-dependent apoptosis. Using this system, we effectively eliminated xenografted normal human senescent fibroblasts or induced senescence in human breast cancer cells in vivo. Thus, cellular senescence and mtDNA damage are outcomes of synthetic nucleoside analog treatment, indicating that the GCV–HSVtk combination can be used effectively to promote the targeted formation or eradication of senescent cells. PMID:23868060

  10. Mitochondrial DNA damage induces apoptosis in senescent cells.

    PubMed

    Laberge, R-M; Adler, D; DeMaria, M; Mechtouf, N; Teachenor, R; Cardin, G B; Desprez, P-Y; Campisi, J; Rodier, F

    2013-07-18

    Senescence is a cellular response to damage and stress. The senescence response prevents cancer by suppressing the proliferation of cells with a compromised genome and contributes to optimal wound healing in normal tissues. Persistent senescent cells are also thought to drive aging and age-associated pathologies through their secretion of inflammatory factors that modify the tissue microenvironment and alter the function of nearby normal or transformed cells. Understanding how senescent cells alter the microenvironment would be aided by the ability to induce or eliminate senescent cells at will in vivo. Here, we combine the use of the synthetic nucleoside analog ganciclovir (GCV) with herpes simplex virus thymidine kinase (HSVtk) activity to create or eliminate senescent human cells. We show that low concentrations of GCV induce senescence through the accumulation of nuclear DNA damage while higher concentrations of GCV, similar to those used in vivo, kill non-dividing senescent cells via mitochondrial DNA (mtDNA) damage and caspase-dependent apoptosis. Using this system, we effectively eliminated xenografted normal human senescent fibroblasts or induced senescence in human breast cancer cells in vivo. Thus, cellular senescence and mtDNA damage are outcomes of synthetic nucleoside analog treatment, indicating that the GCV-HSVtk combination can be used effectively to promote the targeted formation or eradication of senescent cells.

  11. Limited hair cell induction from human induced pluripotent stem cells using a simple stepwise method.

    PubMed

    Ohnishi, Hiroe; Skerleva, Desislava; Kitajiri, Shin-ichiro; Sakamoto, Tatsunori; Yamamoto, Norio; Ito, Juichi; Nakagawa, Takayuki

    2015-07-10

    Disease-specific induced pluripotent stem cells (iPS) cells are expected to contribute to exploring useful tools for studying the pathophysiology of inner ear diseases and to drug discovery for treating inner ear diseases. For this purpose, stable induction methods for the differentiation of human iPS cells into inner ear hair cells are required. In the present study, we examined the efficacy of a simple induction method for inducing the differentiation of human iPS cells into hair cells. The induction of inner ear hair cell-like cells was performed using a stepwise method mimicking inner ear development. Human iPS cells were sequentially transformed into the preplacodal ectoderm, otic placode, and hair cell-like cells. As a first step, preplacodal ectoderm induction, human iPS cells were seeded on a Matrigel-coated plate and cultured in a serum free N2/B27 medium for 8 days according to a previous study that demonstrated spontaneous differentiation of human ES cells into the preplacodal ectoderm. As the second step, the cells after preplacodal ectoderm induction were treated with basic fibroblast growth factor (bFGF) for induction of differentiation into otic-placode-like cells for 15 days. As the final step, cultured cells were incubated in a serum free medium containing Matrigel for 48 days. After preplacodal ectoderm induction, over 90% of cultured cells expressed the genes that express in preplacodal ectoderm. By culture with bFGF, otic placode marker-positive cells were obtained, although their number was limited. Further 48-day culture in serum free media resulted in the induction of hair cell-like cells, which expressed a hair cell marker and had stereocilia bundle-like constructions on their apical surface. Our results indicate that hair cell-like cells are induced from human iPS cells using a simple stepwise method with only bFGF, without the use of xenogeneic cells.

  12. Gentian violet induces wtp53 transactivation in cancer cells.

    PubMed

    Garufi, Alessia; D'Orazi, Valerio; Arbiser, Jack L; D'Orazi, Gabriella

    2014-04-01

    Recent studies suggest that gentian violet (GV) may have anticancer activity by inhibiting for instance NADPH oxidases (Nox genes) whose overexpression is linked to tumor progression. Nox1 overexpression has been shown to inhibit transcriptional activity of the oncosuppressor p53, impairing tumor cell response to anticancer drugs. The tumor suppressor p53 is a transcription factor that, upon cellular stress, is activated to induce target genes involved in tumor cell growth inhibition and apoptosis. Thus, its activation is important for efficient tumor eradication. In this study, we examined the effect of GV on wild-type (wt) p53 activity in cancer cells. We found that GV was able to overcome the inhibitory effect of the NADPH oxidase Nox1 on p53 transcriptional activity. For the first time we show that GV was able to directly induce p53/DNA binding and transcriptional activity. In vitro, GV markedly induced cancer cell death and apoptotic marker PARP cleavage in wtp53-carrying cells. GV-induced cell death was partly inhibited in cells deprived of p53, suggesting that the anticancer activity of GV may partly depend on p53 activation. GV is US Food and Drug Administration approved for human use and may, therefore, have therapeutic potential in the management of cancer through p53 activation.

  13. Gentian violet induces wtp53 transactivation in cancer cells

    PubMed Central

    GARUFI, ALESSIA; D’ORAZI, VALERIO; ARBISER, JACK L.; D’ORAZI, GABRIELLA

    2014-01-01

    Recent studies suggest that gentian violet (GV) may have anticancer activity by inhibiting for instance NADPH oxidases (Nox genes) whose overexpression is linked to tumor progression. Nox1 overexpression has been shown to inhibit transcriptional activity of the oncosuppressor p53, impairing tumor cell response to anticancer drugs. The tumor suppressor p53 is a transcription factor that, upon cellular stress, is activated to induce target genes involved in tumor cell growth inhibition and apoptosis. Thus, its activation is important for efficient tumor eradication. In this study, we examined the effect of GV on wild-type (wt) p53 activity in cancer cells. We found that GV was able to overcome the inhibitory effect of the NADPH oxidase Nox1 on p53 transcriptional activity. For the first time we show that GV was able to directly induce p53/DNA binding and transcriptional activity. In vitro, GV markedly induced cancer cell death and apoptotic marker PARP cleavage in wtp53-carrying cells. GV-induced cell death was partly inhibited in cells deprived of p53, suggesting that the anticancer activity of GV may partly depend on p53 activation. GV is US Food and Drug Administration approved for human use and may, therefore, have therapeutic potential in the management of cancer through p53 activation. PMID:24535435

  14. Mitochondrial DNA damage by bleomycin induces AML cell death.

    PubMed

    Yeung, ManTek; Hurren, Rose; Nemr, Carine; Wang, Xiaoming; Hershenfeld, Samantha; Gronda, Marcela; Liyanage, Sanduni; Wu, Yan; Augustine, Jeevan; Lee, Eric A; Spagnuolo, Paul A; Southall, Noel; Chen, Catherine; Zheng, Wei; Jeyaraju, Danny V; Minden, Mark D; Laposa, Rebecca; Schimmer, Aaron D

    2015-06-01

    Mitochondria contain multiple copies of their own 16.6 kb circular genome. To explore the impact of mitochondrial DNA (mtDNA) damage on mitochondrial (mt) function and viability of AML cells, we screened a panel of DNA damaging chemotherapeutic agents to identify drugs that could damage mtDNA. We identified bleomycin as an agent that damaged mtDNA in AML cells at concentrations that induced cell death. Bleomycin also induced mtDNA damage in primary AML samples. Consistent with the observed mtDNA damage, bleomycin reduced mt mass and basal oxygen consumption in AML cells. We also demonstrated that the observed mtDNA damage was functionally important for bleomycin-induced cell death. Finally, bleomycin delayed tumor growth in xenograft mouse models of AML and anti-leukemic concentrations of the drug induced mtDNA damage in AML cells preferentially over normal lung tissue. Taken together, mtDNA-targeted therapy may be an effective strategy to target AML cells and bleomycin could be useful in the treatment of this disease.

  15. Activated microglia cause reversible apoptosis of pheochromocytoma cells, inducing their cell death by phagocytosis

    PubMed Central

    Hornik, Tamara C.; Vilalta, Anna; Brown, Guy C.

    2016-01-01

    ABSTRACT Some apoptotic processes, such as phosphatidylserine exposure, are potentially reversible and do not necessarily lead to cell death. However, phosphatidylserine exposure can induce phagocytosis of a cell, resulting in cell death by phagocytosis: phagoptosis. Phagoptosis of neurons by microglia might contribute to neuropathology, whereas phagoptosis of tumour cells by macrophages might limit cancer. Here, we examined the mechanisms by which BV-2 microglia killed co-cultured pheochromocytoma (PC12) cells that were either undifferentiated or differentiated into neuronal cells. We found that microglia activated by lipopolysaccharide rapidly phagocytosed PC12 cells. Activated microglia caused reversible phosphatidylserine exposure on and reversible caspase activation in PC12 cells, and caspase inhibition prevented phosphatidylserine exposur and decreased subsequent phagocytosis. Nitric oxide was necessary and sufficient to induce the reversible phosphatidylserine exposure and phagocytosis. The PC12 cells were not dead at the time they were phagocytised, and inhibition of their phagocytosis left viable cells. Cell loss was inhibited by blocking phagocytosis mediated by phosphatidylserine, MFG-E8, vitronectin receptors or P2Y6 receptors. Thus, activated microglia can induce reversible apoptosis of target cells, which is insufficient to cause apoptotic cell death, but sufficient to induce their phagocytosis and therefore cell death by phagoptosis. PMID:26567213

  16. Activated microglia cause reversible apoptosis of pheochromocytoma cells, inducing their cell death by phagocytosis.

    PubMed

    Hornik, Tamara C; Vilalta, Anna; Brown, Guy C

    2016-01-01

    Some apoptotic processes, such as phosphatidylserine exposure, are potentially reversible and do not necessarily lead to cell death. However, phosphatidylserine exposure can induce phagocytosis of a cell, resulting in cell death by phagocytosis: phagoptosis. Phagoptosis of neurons by microglia might contribute to neuropathology, whereas phagoptosis of tumour cells by macrophages might limit cancer. Here, we examined the mechanisms by which BV-2 microglia killed co-cultured pheochromocytoma (PC12) cells that were either undifferentiated or differentiated into neuronal cells. We found that microglia activated by lipopolysaccharide rapidly phagocytosed PC12 cells. Activated microglia caused reversible phosphatidylserine exposure on and reversible caspase activation in PC12 cells, and caspase inhibition prevented phosphatidylserine exposur and decreased subsequent phagocytosis. Nitric oxide was necessary and sufficient to induce the reversible phosphatidylserine exposure and phagocytosis. The PC12 cells were not dead at the time they were phagocytised, and inhibition of their phagocytosis left viable cells. Cell loss was inhibited by blocking phagocytosis mediated by phosphatidylserine, MFG-E8, vitronectin receptors or P2Y6 receptors. Thus, activated microglia can induce reversible apoptosis of target cells, which is insufficient to cause apoptotic cell death, but sufficient to induce their phagocytosis and therefore cell death by phagoptosis.

  17. Cell cycle-arrested tumor cells exhibit increased sensitivity towards TRAIL-induced apoptosis

    PubMed Central

    Ehrhardt, H; Wachter, F; Grunert, M; Jeremias, I

    2013-01-01

    Resting tumor cells represent a huge challenge during anticancer therapy due to their increased treatment resistance. TNF-related apoptosis-inducing ligand (TRAIL) is a putative future anticancer drug, currently in phases I and II clinical studies. We recently showed that TRAIL is able to target leukemia stem cell surrogates. Here, we tested the ability of TRAIL to target cell cycle-arrested tumor cells. Cell cycle arrest was induced in tumor cell lines and xenografted tumor cells in G0, G1 or G2 using cytotoxic drugs, phase-specific inhibitors or RNA interference against cyclinB and E. Biochemical or molecular arrest at any point of the cell cycle increased TRAIL-induced apoptosis. Accordingly, when cell cycle arrest was disabled by addition of caffeine, the antitumor activity of TRAIL was reduced. Most important for clinical translation, tumor cells from three children with B precursor or T cell acute lymphoblastic leukemia showed increased TRAIL-induced apoptosis upon knockdown of either cyclinB or cyclinE, arresting the cell cycle in G2 or G1, respectively. Taken together and in contrast to most conventional cytotoxic drugs, TRAIL exerts enhanced antitumor activity against cell cycle-arrested tumor cells. Therefore, TRAIL might represent an interesting drug to treat static-tumor disease, for example, during minimal residual disease. PMID:23744361

  18. Hypoxia Inducible Factor-1α Inactivation Unveils a Link between Tumor Cell Metabolism and Hypoxia-Induced Cell Death

    PubMed Central

    Favaro, Elena; Nardo, Giorgia; Persano, Luca; Masiero, Massimo; Moserle, Lidia; Zamarchi, Rita; Rossi, Elisabetta; Esposito, Giovanni; Plebani, Mario; Sattler, Ulrike; Mann, Thomas; Mueller-Klieser, Wolfgang; Ciminale, Vincenzo; Amadori, Alberto; Indraccolo, Stefano

    2008-01-01

    Hypoxia and the acquisition of a glycolytic phenotype are intrinsic features of the tumor microenvironment. The hypoxia inducible factor-1α (HIF-1α) pathway is activated under hypoxic conditions and orchestrates a complex transcriptional program that enhances cell survival. Although the consequences of HIF-1α inactivation in cancer cells have been widely investigated, only a few studies have addressed the role of HIF-1α in the survival of cancer cells endowed with different glycolytic capacities. In this study, we investigated this aspect in ovarian cancer cells. Hypoxia-induced toxicity was increased in highly glycolytic cells compared with poorly glycolytic cells; it was also associated with a sharp decrease in intracellular ATP levels and was prevented by glucose supplementation. Stable HIF-1α silencing enhanced hypoxia-induced cell death in vitro due to a lack of cell cycle arrest. Tumors bearing attenuated HIF-1α levels had similar growth rates and vascularization as did controls, but tumors showed higher proliferation levels and increased necrosis. Moreover, tumors formed by HIF-1α deficient cells had higher levels of lactate and lower ATP concentrations than controls as shown by metabolic imaging. The findings that such metabolic properties can affect the survival of cancer cells under hypoxic conditions and that these properties contribute to the determination of the consequences of HIF-1α inactivation could have important implications on the understanding of the effects of anti-angiogenic and HIF-1α-targeting drugs in cancer. PMID:18772337

  19. Induced Pluripotent Stem Cells: Emerging Techniques for Nuclear Reprogramming

    PubMed Central

    Han, Ji Woong

    2011-01-01

    Abstract Introduction of four transcription factors, Oct3/4, Sox2, Klf4, and c-Myc, can successfully reprogram somatic cells into embryonic stem (ES)-like cells. These cells, which are referred to as induced pluripotent stem (iPS) cells, closely resemble embryonic stem cells in genomic, cell biologic, and phenotypic characteristics, and the creation of these special cells was a major triumph in cell biology. In contrast to pluripotent stem cells generated by somatic cell nuclear-transfer (SCNT) or ES cells derived from the inner cell mass (ICM) of the blastocyst, direct reprogramming provides a convenient and reliable means of generating pluripotent stem cells. iPS cells have already shown incredible potential for research and for therapeutic applications in regenerative medicine within just a few years of their discovery. In this review, current techniques of generating iPS cells and mechanisms of nuclear reprogramming are reviewed, and the potential for therapeutic applications is discussed. Antioxid. Redox Signal. 15, 1799–1820. PMID:21194386

  20. Peroxide-induced cell death and lipid peroxidation in C6 glioma cells.

    PubMed

    Linden, Arne; Gülden, Michael; Martin, Hans-Jörg; Maser, Edmund; Seibert, Hasso

    2008-08-01

    Peroxides are often used as models to induce oxidative damage in cells in vitro. The aim of the present study was to elucidate the role of lipid peroxidation in peroxide-induced cell death. To this end (i) the ability to induce lipid peroxidation in C6 rat astroglioma cells of hydrogen peroxide (H2O2), cumene hydroperoxide (CHP) and t-butyl hydroperoxide (t-BuOOH) (ii) the relation between peroxide-induced lipid peroxidation and cell death in terms of time and concentration dependency and (iii) the capability of the lipid peroxidation chain breaking alpha-tocopherol to prevent peroxide-induced lipid peroxidation and/or cell death were investigated. Lipid peroxidation was characterised by measuring thiobarbituric acid reactive substances (TBARS) and, by HPLC, malondialdehyde (MDA), 4-hydroxynonenal (4-HNE) and hexanal. Within 2 h CHP, t-BuOOH and H2O2 induced cell death with EC50 values of 59+/-9 microM, 290+/-30 microM and 12+/-1.1 mM, respectively. CHP and t-BuOOH, but not H2O2 induced lipid peroxidation in C6 cells with EC50 values of 15+/-14 microM and 130+/-33 microM, respectively. The TBARS measured almost exclusively consisted of MDA. 4-HNE was mostly not detectable. The concentration of hexanal slightly increased with increasing concentrations of organic peroxides. Regarding time and concentration dependency lipid peroxidation preceded cell death. Pretreatment with alpha-tocopherol (10 microM, 24 h) prevented both, peroxide-induced lipid peroxidation and cell death. The results strongly indicate a major role of lipid peroxidation in the killing of C6 cells by organic peroxides but also that lipid peroxidation is not involved in H2O2 induced cell death.

  1. Inducible human immunodeficiency virus type 1 packaging cell lines.

    PubMed Central

    Yu, H; Rabson, A B; Kaul, M; Ron, Y; Dougherty, J P

    1996-01-01

    Packaging cell lines are important tools for transferring genes into eukaryotic cells. Human immunodeficiency virus type 1 (HIV-1)-based packaging cell lines are difficult to obtain, in part owing to the problem that some HIV-1 proteins are cytotoxic in a variety of cells. To overcome this, we have developed an HIV-1-based packaging cell line which has an inducible expression system. The tetracycline-inducible expression system was utilized to control the expression of the Rev regulatory protein, which in turn controls the expression of the late proteins including Gag, Pol, and Env. Western blotting (immunoblotting) demonstrated that the expression of p24gag and gp120env from the packaging cells peaked on days 6 and 7 postinduction. Reverse transcriptase activity could be detected by day 4 after induction and also peaked on days 6 and 7. Defective vector virus could be propagated, yielding titers as high as 7 x 10(3) CFU/ml, while replication-competent virus was not detectable at any time. Thus, the cell line should enable the transfer of specific genes into CD4+ cells and should be a useful tool for studying the biology of HIV-1. We have also established an inducible HIV-1 Env-expressing cell line which could be used to propagate HIV-1 vectors that require only Env in trans. The env-minus vector virus titer produced from the Env-expressing cells reached 2 x 10(4) CFU/ml. The inducible HIV-1 Env-expressing cell line should be a useful tool for the study of HIV-1 Env as well. PMID:8676479

  2. Light regulation of cadmium-induced cell death in Arabidopsis

    PubMed Central

    Smith, Sarah J; Wang, Yun; Slabas, Antoni R; Chivasa, Stephen

    2014-01-01

    Cadmium is an environmental pollutant with deleterious effects on both prokaryotic and eukaryotic organisms. In plants, the effects of cadmium toxicity are concentration dependent; lower doses destabilize many physiological processes and inhibit cell growth and multiplication, while higher doses evoke a more severe response that triggers activation of cell death. We recently investigated the effects of light on cadmium toxicity in Arabidopsis using a cell suspension culture system. Although not affecting the inhibitory effects on cell multiplication, we found that light is a powerful regulator of Cd-induced cell death. A very specific proteomic response, which was clearly controlled by light, preceded cell death. Here we discuss the implications of these findings and highlight similarities between the regulation of cell death triggered by Cd and fumonisin B1. We consider how both compounds could be useful tools in dissecting plant cell death signaling. PMID:24398567

  3. Mechanisms of radiation-induced neoplastic cell transformation

    SciTech Connect

    Yang, T.C.H.; Tobias, C.A.

    1984-04-01

    Studies with cultured mammalian cells demonstrated clearly that radiation can transform cells directly and can enhance the cell transformation by oncogenic DNA viruses. In general, high-LET heavy-ion radiation can be more effective than X and gamma rays in inducing neoplastic cell transformation. Various experimental results indicate that radiation-induced DNA damage, most likely double-strand breaks, is important for both the initiation of cell transformation and for the enhancement of viral transformation. Some of the transformation and enhancement lesions can be repaired properly in the cell, and the amount of irrepairable lesions produced by a given dose depends on the quality of radiation. An inhibition of repair processes with chemical agents can increase the transformation frequency of cells exposed to radiation and/or oncogenic viruses, suggesting that repair mechanisms may play an important role in the radiation transformation. The progression of radiation-transformed cells appears to be a long and complicated process that can be modulated by some nonmutagenic chemical agents, e.g., DMSO. Normal cells can inhibit the expression of transforming properties of tumorigenic cells through an as yet unknown mechanism. The progression and expression of transformation may involve some epigenetic changes in the irradiated cells. 38 references, 15 figures, 1 table.

  4. Ionizing radiation induces tumor cell lysyl oxidase secretion

    PubMed Central

    2014-01-01

    Background Ionizing radiation (IR) is a mainstay of cancer therapy, but irradiation can at times also lead to stress responses, which counteract IR-induced cytotoxicity. IR also triggers cellular secretion of vascular endothelial growth factor, transforming growth factor β and matrix metalloproteinases, among others, to promote tumor progression. Lysyl oxidase is known to play an important role in hypoxia-dependent cancer cell dissemination and metastasis. Here, we investigated the effects of IR on the expression and secretion of lysyl oxidase (LOX) from tumor cells. Methods LOX-secretion along with enzymatic activity was investigated in multiple tumor cell lines in response to irradiation. Transwell migration assays were performed to evaluate invasive capacity of naïve tumor cells in response to IR-induced LOX. In vivo studies for confirming IR-enhanced LOX were performed employing immunohistochemistry of tumor tissues and ex vivo analysis of murine blood serum derived from locally irradiated A549-derived tumor xenografts. Results LOX was secreted in a dose dependent way from several tumor cell lines in response to irradiation. IR did not increase LOX-transcription but induced LOX-secretion. LOX-secretion could not be prevented by the microtubule stabilizing agent patupilone. In contrast, hypoxia induced LOX-transcription, and interestingly, hypoxia-dependent LOX-secretion could be counteracted by patupilone. Conditioned media from irradiated tumor cells promoted invasiveness of naïve tumor cells, while conditioned media from irradiated, LOX- siRNA-silenced cells did not stimulate their invasive capacity. Locally applied irradiation to tumor xenografts also increased LOX-secretion in vivo and resulted in enhanced LOX-levels in the murine blood serum. Conclusions These results indicate a differential regulation of LOX-expression and secretion in response to IR and hypoxia, and suggest that LOX may contribute towards an IR-induced migratory phenotype in

  5. Optimizing atoh1 induced vestibular hair cell regeneration

    PubMed Central

    Staecker, Hinrich; Schlecker, Christina; Kraft, Shannon; Praetorius, Mark; Hsu, Chi; Brough, Douglas E.

    2016-01-01

    Objectives/Hypothesis Determine the optimal design characteristics of an adenoviral vector to deliver atoh1 and induce regeneration of vestibular hair cells. Study Design Evaluation of a mouse model of intra-labyrinthine gene delivery. Tissue culture of mouse and human macular organs. Methods Macular organs from adult C57Bl/6 mice were treated with binding modified and alternate adenovectors expressing green fluorescent protein (gfp) or luciferase (L). Expression of marker genes was determined over time to determine vector transfection efficiency. The inner ear of adult mice was then injected with modified vectors. Expression of gfp and distribution of vector DNA was followed. Hearing and balance function was evaluated in normal animals to ensure safety of the novel vector designs. An optimized vector was identified and tested for its ability to induce hair cell regeneration in a mouse vestibulopathy model. Finally this vector was tested for its ability to induce hair cell regeneration in human tissue. Results Ad5 serotype based vectors were identified as having a variety of different binding capacities for inner ear tissue. This makes it difficult to limit the dose of vector due to entry into non-targeted cells. Screening of rare adenovector serotypes demonstrated that Ad28 based vectors were ideally suited for delivery to supporting cells and therefore useful for hair cell regeneration studies. Utilization of an Ad28 based vector to deliver atoh1 to a mouse model of vestibular loss resulted significant functional recovery of balance. This vector was also capable of transfecting human macular organs and inducing regeneration of human vestibular hair cells in vitro. Conclusions Improvement in vector design can lead to more specific cell based delivery and reduction of non specific delivery of the trans gene leading to the development of optimized molecular therapeutics to induce hair cell regeneration. Level of Evidence N/A Controlled basic science study. PMID

  6. Xylitol induces cell death in lung cancer A549 cells by autophagy.

    PubMed

    Park, Eunjoo; Park, Mi Hee; Na, Hee Sam; Chung, Jin

    2015-05-01

    Xylitol is a widely used anti-caries agent that has anti-inflammatory effects. We have evaluated the potential of xylitol in cancer treatment. It's effects on cell proliferation and cytotoxicity were measured by MTT assay and LDH assay. Cell morphology and autophagy were examined by immunostaining and immunoblotting. Xylitol inhibited cell proliferation in a dose-dependent manner in these cancer cells: A549, Caki, NCI-H23, HCT-15, HL-60, K562, and SK MEL-2. The IC50 of xylitol in human gingival fibroblast cells was higher than in cancer cells, indicating that it is more specific for cancer cells. Moreover, xylitol induced autophagy in A549 cells that was inhibited by 3-methyladenine, an autophagy inhibitor. These results indicate that xylitol has potential in therapy against lung cancer by inhibiting cell proliferation and inducing autophagy of A549 cells.

  7. Oligogalacturonides induce flowers in tobacco thin cell layers

    SciTech Connect

    Marfa-Riera, V.; Gollin, D.; Mohnen, D.; Darvill, A.; Albersheim, P. )

    1989-04-01

    An optimized tobacco thin-cell-layer (TCL) bioassay was used to study the induction of flowers by plant oligosaccharins. Endopolygalacturonase (EPG)-released fragments of suspension-cultured sycamore cell walls induced flowers on TCLs grown on a medium containing 1.5 {mu}M IBA and 0.9 {mu}M kinetin. The EPG-released fragments were primarily composed of the polysaccharides rhamnogalacturonan I (RG-I), rhamnogalacturonan II (RG-II), and {alpha}-1,4-linked oligogalacturonides. The {alpha}-1,4-linked oligogalacturonides, subsequently purified from the EPG-released sycamore cell wall fragment mixture, induced flowers on TCLs. Purified RG-I and RG-II did not induce flowers. Oligosaccharide fragments, generated by partial acid hydrolysis of citrus pectin, were also capable of inducing flowers on the TCLs. The active components in the pectin fragment mixture were {alpha}-1,4-linked oligogalacturonides. Oligogalacturonides with a degree of polymerization (DP) of 8-16, at concentrations of {approx} 0.1 {mu}M, induced flowers, while oligogalacturonides with a DP 2-7, even at higher concentrations, did not. Oligogalacturonides have previously been shown to induce the synthesis of phytoalexins, protease inhibitors, lignin, and ethylene in other plant systems. Thus, the ability of {alpha}-1,4-linked oligogalacturonides to induce flower formation in the tobacco TCLs represents a new biological activity of these oligosaccharins.

  8. Langerhans Cells Facilitate UVB-induced Epidermal Carcinogenesis

    PubMed Central

    Lewis, Julia M.; Bürgler, Christina D.; Freudzon, Marianna; Golubets, Kseniya; Gibson, Juliet F.; Filler, Renata B.; Girardi, Michael

    2015-01-01

    Ultraviolet B (UVB) light is considered the major environmental inducer of human keratinocyte DNA mutations, including within the tumor-suppressor gene p53, and chronic exposure is associated with cutaneous squamous cell carcinoma (SCC) formation. Langerhans cells (LC) comprise a dendritic network within the suprabasilar epidermis, yet the role of LC in UVB-induced carcinogenesis is largely unknown. Herein, we show that LC-intact epidermis develops UVB-induced tumors more readily than LC-deficient epidermis. While levels of epidermal cyclopyrimidine dimers (CPD) following acute UVB exposure are equivalent in the presence or absence of LC, chronic UVB-induced p53 mutant clonal islands expand more readily in association with LC which remain largely intact and are preferentially found in proximity to the expanding mutant keratinocyte populations. The observed LC facilitation of mutant p53 clonal expansion is completely αβ and γδ T-cell independent, and is associated with increased intraepidermal expression of interleukin (IL)-22 and the presence of group 3 innate lymphoid cells (ILC3). These data demonstrate that LC play a key role in UVB-induced cutaneous carcinogenesis, and suggest that LC locally stimulate keratinocyte proliferation and innate immune cells that provoke tumor outgrowth. PMID:26053049

  9. Unraveling the mechanism of cell death induced by chemical fibrils

    PubMed Central

    Julien, Olivier; Kampmann, Martin; Bassik, Michael C.; Zorn, Julie A.; Venditto, Vincent J.; Shimbo, Kazutaka; Agard, Nicholas J.; Shimada, Kenichi; Rheingold, Arnold L.; Stockwell, Brent R.; Weissman, Jonathan S.

    2014-01-01

    We previously discovered a small-molecule inducer of cell death, named 1541, that non-covalently self-assembles into chemical fibrils (“chemi-fibrils”) and activates procaspase-3 in vitro. We report here that 1541-induced cell death is caused by the fibrillar, rather than the soluble form of the drug. An shRNA screen reveals that knockdown of genes involved in endocytosis, vesicle trafficking, and lysosomal acidification causes partial 1541 resistance. We confirm the role of these pathways using pharmacological inhibitors. Microscopy shows that the fluorescent chemi-fibrils accumulate in punctae inside cells that partially co-localize with lysosomes. Notably, the chemi-fibrils bind and induce liposome leakage in vitro, suggesting they may do the same in cells. The chemi-fibrils induce extensive proteolysis including caspase substrates, yet modulatory profiling reveals that chemi-fibrils form a distinct class from existing inducers of cell death. The chemi-fibrils share similarities to proteinaceous fibrils and may provide insight into their mechanism of cellular toxicity. PMID:25262416

  10. Jasmonic acid signaling modulates ozone-induced hypersensitive cell death.

    PubMed

    Rao, M V; Lee, H; Creelman, R A; Mullet, J E; Davis, K R

    2000-09-01

    Recent studies suggest that cross-talk between salicylic acid (SA)-, jasmonic acid (JA)-, and ethylene-dependent signaling pathways regulates plant responses to both abiotic and biotic stress factors. Earlier studies demonstrated that ozone (O(3)) exposure activates a hypersensitive response (HR)-like cell death pathway in the Arabidopsis ecotype Cvi-0. We now have confirmed the role of SA and JA signaling in influencing O(3)-induced cell death. Expression of salicylate hydroxylase (NahG) in Cvi-0 reduced O(3)-induced cell death. Methyl jasmonate (Me-JA) pretreatment of Cvi-0 decreased O(3)-induced H(2)O(2) content and SA concentrations and completely abolished O(3)-induced cell death. Cvi-0 synthesized as much JA as did Col-0 in response to O(3) exposure but exhibited much less sensitivity to exogenous Me-JA. Analyses of the responses to O(3) of the JA-signaling mutants jar1 and fad3/7/8 also demonstrated an antagonistic relationship between JA- and SA-signaling pathways in controlling the magnitude of O(3)-induced HR-like cell death.

  11. Irradiation strongly reduces tumorigenesis of human induced pluripotent stem cells.

    PubMed

    Inui, Shoki; Minami, Kazumasa; Ito, Emiko; Imaizumi, Hiromasa; Mori, Seiji; Koizumi, Masahiko; Fukushima, Satsuki; Miyagawa, Shigeru; Sawa, Yoshiki; Matsuura, Nariaki

    2017-03-03

    Induced pluripotent stem (iPS) cells have demonstrated they can undergo self-renewal, attain pluripotency, and differentiate into various types of functional cells. In clinical transplantation of iPS cells, however, a major problem is the prevention of tumorigenesis. We speculated that tumor formation could be inhibited by means of irradiation. Since the main purpose of this study was to explore the prevention of tumor formation in human iPS (hiPS) cells, we tested the effects of irradiation on tumor-associated factors such as radiosensitivity, pluripotency and cell death in hiPS cells. The irradiated hiPS cells showed much higher radiosensitivity, because the survival fraction of hiPS cells irradiated with 2 Gy was < 10%, and there was no change of pluripotency. Irradiation with 2 and 4 Gy caused substantial cell death, which was mostly the result of apoptosis. Irradiation with 2 Gy was detrimental enough to cause loss of proliferation capability and trigger substantial cell death in vitro. The hiPS cells irradiated with 2 Gy were injected into NOG mice (NOD/Shi-scid, IL-2 Rγnull) for the analysis of tumor formation. The group of mice into which hiPS cells irradiated with 2 Gy was transplanted showed significant suppression of tumor formation in comparison with that of the group into which non-irradiated hiPS cells were transplanted. It can be presumed that this diminished rate of tumor formation was due to loss of proliferation and cell death caused by irradiation. Our findings suggest that tumor formation following cell therapy or organ transplantation induced by hiPS cells may be prevented by irradiation.

  12. Human papillomavirus 16 E5 induces bi-nucleated cell formation by cell-cell fusion

    SciTech Connect

    Hu Lulin; Plafker, Kendra; Vorozhko, Valeriya; Zuna, Rosemary E.; Hanigan, Marie H.; Gorbsky, Gary J.; Plafker, Scott M.; Angeletti, Peter C.; Ceresa, Brian P.

    2009-02-05

    Human papillomaviruses (HPV) 16 is a DNA virus encoding three oncogenes - E5, E6, and E7. The E6 and E7 proteins have well-established roles as inhibitors of tumor suppression, but the contribution of E5 to malignant transformation is controversial. Using spontaneously immortalized human keratinocytes (HaCaT cells), we demonstrate that expression of HPV16 E5 is necessary and sufficient for the formation of bi-nucleated cells, a common characteristic of precancerous cervical lesions. Expression of E5 from non-carcinogenic HPV6b does not produce bi-nucleate cells. Video microscopy and biochemical analyses reveal that bi-nucleates arise through cell-cell fusion. Although most E5-induced bi-nucleates fail to propagate, co-expression of HPV16 E6/E7 enhances the proliferation of these cells. Expression of HPV16 E6/E7 also increases bi-nucleated cell colony formation. These findings identify a new role for HPV16 E5 and support a model in which complementary roles of the HPV16 oncogenes lead to the induction of carcinogenesis.

  13. Role of hypoxia‑inducible factor‑1α in autophagic cell death in microglial cells induced by hypoxia.

    PubMed

    Wang, Xintao; Ma, Jun; Fu, Qiang; Zhu, Lei; Zhang, Zhiling; Zhang, Fan; Lu, Nan; Chen, Aimin

    2017-03-01

    Microglial cells are phagocytic cells of the central nervous system (CNS) and have been proposed to be a primary component of the innate immune response and maintain efficient CNS homeostasis. Microglial cells are activated during various phases of tissue repair and participate in various pathological conditions in the CNS. Following spinal cord injury (SCI), anoxemia is a key problem that results in tissue destruction. Hypoxia‑inducible factor 1‑α (HIF‑1α) may protect hypoxic cells from apoptosis or necrosis under ischemic and anoxic conditions. However, numerous studies have revealed that hypoxia upregulates HIF‑1α expression leading to the death of microglial cells. The present study investigated the alterations in HIF‑1α expression levels and the mechanism of autophagic cell death mediated by HIF‑1α in microglial cells induced by hypoxia. Hypoxia was demonstrated to induce HIF‑1α expression and autophagic cell death in microglial cells. Enhanced autophagy reduced cell death during the initial stages by restraining the functions of autophagy‑associated genes (microtubule‑associated protein 1A/1B‑light chain 3 phosphatidylethanolamine conjugate and Beclin‑1) and modulating the expression of inflammatory cytokines (tumor necrosis factor‑α and interleukin‑1β). Target value was determined by Cell Counting Kit 8 and cell death by flow cytometry. Transmission electron microscopy, immunohistochemical staining, reverse transcription‑quantitative polymerase chain reaction, western blotting, and ELISA were used for further analysis. However, increased expression of HIF‑1α induced cell death and autophagic cell death in microglial cells. Furthermore, the effects of the HIF‑1α inhibitor 2‑methoxyestradiol and HIF‑1α small interfering RNA on the death and autophagy of microglial cells in vitro were investigated. These investigations revealed the suppression of autophagy, the decrease of cell viability and the increase of

  14. [Cell cycle arrest at M phase induced by vinblastine in MOLT-4 cells].

    PubMed

    Zhong, Yi-Sheng; Pan, Chang-Chuan; Jin, Chang-Nan; Li, Jian-Jun; Xiong, Gong-Peng; Zhang, Jian-Xi; Gong, Jian-Ping

    2009-04-01

    This study was purposed to investigate the biological effect of vinblastine (VLS), usually known as inductor of mitotic arrest, on MOLT-4 of ALL cells and to evaluate its significance. The cell arrest in M phase and/or cell apoptosis were induced by treatment of MOLT-4 cells with 0.05 microg/ml VLS for 0 - 12 hours; the DNA histogram was detected by flow cytometry; the morphological changes of cells were observed by confocal microscopy; the cell cycle distribution, cell apoptosis and morphological changes of cells before and after arrest were analyzed by using arrest increasing rate (AIR), arrest efficiency (AE), apoptosis rate (AR) and morphologic parameters respectively. The results indicated that the cell arrest did not accompanied by significant increase of apoptosis rate; the DNA histogram of cell arrest showed dynamic change of cell cycle in time-dependent manner; the arrest efficiency could be quantified. The cell arrest at M phase was accompanied by cell stack in S phase, the cell proliferation rate dropped after cell arrest occurred. The cells arrested at M phase possessed of characteristic morphologic features in cell mitosis. It is concluded that the vinblastine can solely induce arrest of MOLT-4 cells at M phase. This study provides experimental basis for further investigating the relation of cell cycle arrest to apoptosis, mechanism of checkpoint and development of new anticancer drugs.

  15. Sodium azide induces necrotic cell death in rat squamous cell carcinoma SCC131.

    PubMed

    Sato, Eiju; Suzuki, Toshimitsu; Hoshi, Nobuo; Sugino, Takashi; Hasegawa, Hiroshi

    2008-12-01

    Sodium azide (NaN(3)) is widely used in industry and agriculture, and also in laboratories as a potent preservative. NaN(3) induces cell death when applied to cultured cells. However, whether the mode of cell death is apoptosis or necrosis remains a subject of debate. There have been no previous reports on NaN(3)-induced cell death in squamous cell carcinoma (SCC), and so we studied the mode of cell death induced by NaN(3) using the rat SCC cell line, SCC131. In this experiment, SCC131 cells died 48-72 h after NaN(3) treatment with concentrations greater than 5 mM. The NaN(3) treatment reduced the mitochondrial membrane potential and ATP content. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and DNA ladder detection assay indicated that no DNA fragmentation occurred. In addition, phosphatidyl serine did not appear on the cell surface, according to the findings of dye-uptake bioassay and flow cytometric analysis of Annexin V labeling. Electron microscopic analysis revealed that the NaN(3)-treated cells showed mitochondrial swelling and rupture of the cell membrane. In conclusion, NaN(3) induces necrotic cell death in SCC131. This experimental model may be used in the study of necrotic cell death.

  16. Shape anisotropy induces rotations in optically trapped red blood cells

    NASA Astrophysics Data System (ADS)

    Bambardekar, Kapil; Dharmadhikari, Jayashree A.; Dharmadhikari, Aditya K.; Yamada, Toshihoro; Kato, Tsuyoshi; Kono, Hirohiko; Fujimura, Yuichi; Sharma, Shobhona; Mathur, Deepak

    2010-07-01

    A combined experimental and theoretical study is carried out to probe the rotational behavior of red blood cells (RBCs) in a single beam optical trap. We induce shape changes in RBCs by altering the properties of the suspension medium in which live cells float. We find that certain shape anisotropies result in the rotation of optically trapped cells. Indeed, even normal (healthy) RBCs can be made to rotate using linearly polarized trapping light by altering the osmotic stress the cells are subjected to. Hyperosmotic stress is found to induce shape anisotropies. We also probe the effect of the medium's viscosity on cell rotation. The observed rotations are modeled using a Langevin-type equation of motion that takes into account frictional forces that are generated as RBCs rotate in the medium. We observe good correlation between our measured data and calculated results.

  17. Cuprous oxide nanoparticles selectively induce apoptosis of tumor cells

    PubMed Central

    Wang, Ye; Zi, Xiao-Yuan; Su, Juan; Zhang, Hong-Xia; Zhang, Xin-Rong; Zhu, Hai-Ying; Li, Jian-Xiu; Yin, Meng; Yang, Feng; Hu, Yi-Ping

    2012-01-01

    In the rapid development of nanoscience and nanotechnology, many researchers have discovered that metal oxide nanoparticles have very useful pharmacological effects. Cuprous oxide nanoparticles (CONPs) can selectively induce apoptosis and suppress the proliferation of tumor cells, showing great potential as a clinical cancer therapy. Treatment with CONPs caused a G1/G0 cell cycle arrest in tumor cells. Furthermore, CONPs enclosed in vesicles entered, or were taken up by mitochondria, which damaged their membranes, thereby inducing apoptosis. CONPs can also produce reactive oxygen species (ROS) and initiate lipid peroxidation of the liposomal membrane, thereby regulating many signaling pathways and influencing the vital movements of cells. Our results demonstrate that CONPs have selective cytotoxicity towards tumor cells, and indicate that CONPs might be a potential nanomedicine for cancer therapy. PMID:22679374

  18. Quantification of Depletion-Induced Adhesion of Red Blood Cells

    NASA Astrophysics Data System (ADS)

    Steffen, P.; Verdier, C.; Wagner, C.

    2013-01-01

    Red blood cells (RBCs) are known to form aggregates in the form of rouleaux due to the presence of plasma proteins under physiological conditions. The formation of rouleaux can also be induced in vitro by the addition of macromolecules to the RBC suspension. Current data on the adhesion strength between red blood cells in their natural discocyte shapes mostly originate from indirect measurements such as flow chamber experiments, but data is lacking at the single cell level. Here, we present measurements on the dextran-induced aggregation of red blood cells using atomic force microscopy-based single cell force spectroscopy. The effects of dextran concentration and molecular weight on the interaction energy of adhering RBCs were determined. The results on adhesion energy are in excellent agreement with a model based on the depletion effect and previous experimental studies. Furthermore, our method allowed to determine the adhesion force, a quantity that is needed in theoretical investigations on blood flow.

  19. Reversine Induced Multinucleated Cells, Cell Apoptosis and Autophagy in Human Non-Small Cell Lung Cancer Cells

    PubMed Central

    Lin, Ching-Yen; Chen, Yih-Yuan; Chen, Ping-Tzu; Tseng, Ya-Shih

    2016-01-01

    Reversine, an A3 adenosine receptor antagonist, has been shown to induce differentiated myogenic-lineage committed cells to become multipotent mesenchymal progenitor cells. We and others have reported that reversine has an effect on human tumor suppression. This study revealed anti-tumor effects of reversine on proliferation, apoptosis and autophagy induction in human non-small cell lung cancer cells. Treatment of these cells with reversine suppressed cell growth in a time- and dosage-dependent manner. Moreover, polyploidy occurred after reversine treatment. In addition, caspase-dependent apoptosis and activation of autophagy by reversine in a dosage-dependent manner were also observed. We demonstrated in this study that reversine contributes to growth inhibition, apoptosis and autophagy induction in human lung cancer cells. Therefore, reversine used as a potential therapeutic agent for human lung cancer is worthy of further investigation. PMID:27385117

  20. Imipramine protects mouse hippocampus against tunicamycin-induced cell death.

    PubMed

    Ono, Yoko; Shimazawa, Masamitsu; Ishisaka, Mitsue; Oyagi, Atsushi; Tsuruma, Kazuhiro; Hara, Hideaki

    2012-12-05

    Endoplasmic reticulum (ER) stress is implicated in various diseases. Recently, some reports have suggested that the sigma-1 receptor may play a role in ER stress, and many antidepressants have a high affinity for the sigma-1 receptor. In the present study, we focused on imipramine, a widely used antidepressant, and investigated whether it might protect against the neuronal cell death induced by tunicamycin, an ER stress inducer. In mouse cultured hippocampal HT22 cells, imipramine inhibited cell death and caspase-3 activation induced by tunicamycin, although it did not alter the elevated expressions of 78 kDa glucose-regulated protein (GRP78) and C/EBP-homologous protein (CHOP). Interestingly, in such cells application of imipramine normalized the expression of the sigma-1 receptor, which was decreased by treatment with tunicamycin alone. Additionally, NE-100, a selective sigma-1 receptor antagonist, abolished the protective effect of imipramine against such tunicamycin-induced cell death. Imipramine inhibited the reduction of mitochondrial membrane potential induced by tunicamycin, and NE-100 blocked this modulating effect of imipramine. Furthermore, in anesthetized mice intracerebroventricular administration of tunicamycin decreased the number of neuronal cells in the hippocampus, particularly in the CA1 and dentate gyrus (DG) areas, and 7 days' imipramine treatment (10mg/kg/day; i.p.) significantly suppressed these reductions in CA1 and DG. These findings suggest that imipramine protects against ER stress-induced hippocampal neuronal cell death both in vitro and in vivo. Such protection may be partly due to the sigma-1 receptor.

  1. Autophagonizer, a novel synthetic small molecule, induces autophagic cell death

    SciTech Connect

    Choi, In-Kwon; Cho, Yoon Sun; Jung, Hye Jin; Kwon, Ho Jeong

    2010-03-19

    Autophagy is an apoptosis-independent mechanism of cell death that protects the cell from environmental imbalances and infection by pathogens. We identified a novel small molecule, 2-(3-Benzyl-4-oxo-3,4,5,6,7,8-hexahydro-benzo[4,5]thieno[2,3-d] pyrimidin-2-ylsulfanylmethyl)-oxazole-4-carboxylic acid (2-pyrrolidin-1-yl-ethyl)-amide (referred as autophagonizer), using high-content cell-based screening and the autophagosome marker EGFP-LC3. Autophagonizer inhibited growth and induced cell death in the human tumor cell lines MCF7, HeLa, HCT116, A549, AGS, and HT1080 via a caspase-independent pathway. Conversion of cytosolic LC3-I to autophagosome-associated LC3-II was greatly enhanced by autophagonizer treatment. Transmission electron microscopy and acridine orange staining revealed increased autophagy in the cytoplasm of autophagonizer-treated cells. In conclusion, autophagonizer is a novel autophagy inducer with unique structure, which induces autophagic cell death in the human tumor cell lines.

  2. Effect of Induced Pluripotent Stem Cell Technology in Blood Banking

    PubMed Central

    Focosi, Daniele

    2016-01-01

    Summary Population aging has imposed cost-effective alternatives to blood donations. Artificial blood is still at the preliminary stages of development, and the need for viable cells seems unsurmountable. Because large numbers of viable cells must be promptly available for clinical use, stem cell technologies, expansion, and banking represent ideal tools to ensure a regular supply. Provided key donors can be identified, induced pluripotent stem cell (iPSC) technology could pave the way to a new era in transfusion medicine, just as it is already doing in many other fields of medicine. The present review summarizes the current state of research on iPSC technology in the field of blood banking, highlighting hurdles, and promises. Significance The aging population in Western countries is causing a progressive reduction of blood donors and a constant increase of blood recipients. Because blood is the main therapeutic option to treat acute hemorrhage, cost-effective alternatives to blood donations are being actively investigated. The enormous replication capability of induced pluripotent stem cells and their promising results in many other fields of medicine could be an apt solution to produce the large numbers of viable cells required in transfusion and usher in a new era in transfusion medicine. The present report describes the potentiality, technological hurdles, and promises of induced pluripotent stem cells to generate red blood cells by redifferentiation. PMID:26819256

  3. Linalool Induces Cell Cycle Arrest and Apoptosis in Leukemia Cells and Cervical Cancer Cells through CDKIs

    PubMed Central

    Chang, Mei-Yin; Shieh, Den-En; Chen, Chung-Chi; Yeh, Ching-Sheng; Dong, Huei-Ping

    2015-01-01

    Plantaginaceae, a popular traditional Chinese medicine, has long been used for treating various diseases from common cold to cancer. Linalool is one of the biologically active compounds that can be isolated from Plantaginaceae. Most of the commonly used cytotoxic anticancer drugs have been shown to induce apoptosis in susceptible tumor cells. However, the signaling pathway for apoptosis remains undefined. In this study, the cytotoxic effect of linalool on human cancer cell lines was investigated. Water-soluble tetrazolium salts (WST-1) based colorimetric cellular cytotoxicity assay, was used to test the cytotoxic ability of linalool against U937 and HeLa cells, and flow cytometry (FCM) and genechip analysis were used to investigate the possible mechanism of apoptosis. These results demonstrated that linalool exhibited a good cytotoxic effect on U937 and HeLa cells, with the IC50 value of 2.59 and 11.02 μM, respectively, compared with 5-FU with values of 4.86 and 12.31 μM, respectively. After treating U937 cells with linalool for 6 h, we found an increased sub-G1 peak and a dose-dependent phenomenon, whereby these cells were arrested at the G0/G1 phase. Furthermore, by using genechip analysis, we observed that linalool can promote p53, p21, p27, p16, and p18 gene expression. Therefore, this study verified that linalool can arrest the cell cycle of U937 cells at the G0/G1 phase and can arrest the cell cycle of HeLa cells at the G2/M phase. Its mechanism facilitates the expression of the cyclin-dependent kinases inhibitors (CDKIs) p53, p21, p27, p16, and p18, as well as the non-expression of cyclin-dependent kinases (CDKs) activity. PMID:26703569

  4. Current progress and prospects of induced pluripotent stem cells.

    PubMed

    Chen, LingYi; Liu, Lin

    2009-07-01

    Induced pluripotent stem (iPS) cells are derived from somatic cells by ectopic expression of few transcription factors. Like embryonic stem (ES) cells, iPS cells are able to self-renew indefinitely and to differentiate into all types of cells in the body. iPS cells hold great promise for regenerative medicine, because iPS cells circumvent not only immunological rejection but also ethical issues. Since the first report on the derivation of iPS cells in 2006, many laboratories all over the world started research on iPS cells and have made significant progress. This paper reviews recent progress in iPS cell research, including the methods to generate iPS cells, the molecular mechanism of reprogramming in the formation of iPS cells, and the potential applications of iPS cells in cell replacement therapy. Current problems that need to be addressed and the prospects for iPS research are also discussed.

  5. Retinoic acid from retinal pigment epithelium induces T regulatory cells.

    PubMed

    Kawazoe, Yuko; Sugita, Sunao; Keino, Hiroshi; Yamada, Yukiko; Imai, Ayano; Horie, Shintaro; Mochizuki, Manabu

    2012-01-01

    Primary cultured retinal pigment epithelial (RPE) cells can convert T cells into T regulatory cells (Tregs) through inhibitory factor(s) including transforming growth factor β (TGFβ) in vitro. Retinoic acid (RA) enhances induction of CD4(+) Tregs in the presence of TGFβ. We investigated whether RA produced by RPE cells can promote generation of Tregs. We found that in vitro, RA-treated T cells expressed high levels of Foxp3 in the presence of recombinant TGFβ. In GeneChip analysis, cultured RPE cells constitutively expressed RA-associated molecules such as RA-binding proteins, enzymes, and receptors. RPE from normal mice, but not vitamin A-deficient mice, contained significant levels of TGFβ. RPE-induced Tregs from vitamin A-deficient mice failed to suppress activation of target T cells. Only a few Foxp3(+) T cells were found in intraocular cells from vitamin A-deficient experimental autoimmune uveitis (EAU) mice, whereas expression was higher in cells from normal EAU mice. RA receptor antagonist-pretreated or RA-binding protein-siRNA-transfected RPE cells failed to convert CD4(+) T cells into Tregs. Our data support the hypothesis that RPE cells produce RA, thereby enabling bystander T cells to be converted into Tregs through TGFβ promotion, which can then participate in the establishment of immune tolerance in the eye.

  6. Cell-Cell Fusion Induced by Measles Virus Amplifies the Type I Interferon Response▿ †

    PubMed Central

    Herschke, F.; Plumet, S.; Duhen, T.; Azocar, O.; Druelle, J.; Laine, D.; Wild, T. F.; Rabourdin-Combe, C.; Gerlier, D.; Valentin, H.

    2007-01-01

    Measles virus (MeV) infection is characterized by the formation of multinuclear giant cells (MGC). We report that beta interferon (IFN-β) production is amplified in vitro by the formation of virus-induced MGC derived from human epithelial cells or mature conventional dendritic cells. Both fusion and IFN-β response amplification were inhibited in a dose-dependent way by a fusion-inhibitory peptide after MeV infection of epithelial cells. This effect was observed at both low and high multiplicities of infection. While in the absence of virus replication, the cell-cell fusion mediated by MeV H/F glycoproteins did not activate any IFN-α/β production, an amplified IFN-β response was observed when H/F-induced MGC were infected with a nonfusogenic recombinant chimerical virus. Time lapse microscopy studies revealed that MeV-infected MGC from epithelial cells have a highly dynamic behavior and an unexpected long life span. Following cell-cell fusion, both of the RIG-I and IFN-β gene deficiencies were trans complemented to induce IFN-β production. Production of IFN-β and IFN-α was also observed in MeV-infected immature dendritic cells (iDC) and mature dendritic cells (mDC). In contrast to iDC, MeV infection of mDC induced MGC, which produced enhanced amounts of IFN-α/β. The amplification of IFN-β production was associated with a sustained nuclear localization of IFN regulatory factor 3 (IRF-3) in MeV-induced MGC derived from both epithelial cells and mDC, while the IRF-7 up-regulation was poorly sensitive to the fusion process. Therefore, MeV-induced cell-cell fusion amplifies IFN-α/β production in infected cells, and this indicates that MGC contribute to the antiviral immune response. PMID:17898060

  7. C/EBPα poises B cells for rapid reprogramming into induced pluripotent stem cells.

    PubMed

    Di Stefano, Bruno; Sardina, Jose Luis; van Oevelen, Chris; Collombet, Samuel; Kallin, Eric M; Vicent, Guillermo P; Lu, Jun; Thieffry, Denis; Beato, Miguel; Graf, Thomas

    2014-02-13

    CCAAT/enhancer binding protein-α (C/EBPα) induces transdifferentiation of B cells into macrophages at high efficiencies and enhances reprogramming into induced pluripotent stem (iPS) cells when co-expressed with the transcription factors Oct4 (Pou5f1), Sox2, Klf4 and Myc (hereafter called OSKM). However, how C/EBPα accomplishes these effects is unclear. Here we find that in mouse primary B cells transient C/EBPα expression followed by OSKM activation induces a 100-fold increase in iPS cell reprogramming efficiency, involving 95% of the population. During this conversion, pluripotency and epithelial-mesenchymal transition genes become markedly upregulated, and 60% of the cells express Oct4 within 2 days. C/EBPα acts as a 'path-breaker' as it transiently makes the chromatin of pluripotency genes more accessible to DNase I. C/EBPα also induces the expression of the dioxygenase Tet2 and promotes its translocation to the nucleus where it binds to regulatory regions of pluripotency genes that become demethylated after OSKM induction. In line with these findings, overexpression of Tet2 enhances OSKM-induced B-cell reprogramming. Because the enzyme is also required for efficient C/EBPα-induced immune cell conversion, our data indicate that Tet2 provides a mechanistic link between iPS cell reprogramming and B-cell transdifferentiation. The rapid iPS reprogramming approach described here should help to fully elucidate the process and has potential clinical applications.

  8. Long-term maintenance of human induced pluripotent stem cells by automated cell culture system

    PubMed Central

    Konagaya, Shuhei; Ando, Takeshi; Yamauchi, Toshiaki; Suemori, Hirofumi; Iwata, Hiroo

    2015-01-01

    Pluripotent stem cells, such as embryonic stem cells and induced pluripotent stem (iPS) cells, are regarded as new sources for cell replacement therapy. These cells can unlimitedly expand under undifferentiated conditions and be differentiated into multiple cell types. Automated culture systems enable the large-scale production of cells. In addition to reducing the time and effort of researchers, an automated culture system improves the reproducibility of cell cultures. In the present study, we newly designed a fully automated cell culture system for human iPS maintenance. Using an automated culture system, hiPS cells maintained their undifferentiated state for 60 days. Automatically prepared hiPS cells had a potency of differentiation into three germ layer cells including dopaminergic neurons and pancreatic cells. PMID:26573336

  9. Cysteine aggravates palmitate-induced cell death in hepatocytes

    PubMed Central

    Dou, Xiaobing; Wang, Zhigang; Yao, Tong; Song, Zhenyuan

    2011-01-01

    Aims Lipotoxicity, defined as cell death induced by excessive fatty acids, especially saturated fatty acids, is critically involved in the development of non-alcoholic steatohepatitis (NASH). Recent studies report that plasma cysteine concentrations is elevated in the subjects with either alcoholic steatohepatitis (ASH) or NASH than normal subjects. The present study was conducted to determine if elevation of cysteine could be a deleterious factor in palmitate-induced hepatocyte cell death. Main methods HepG2 and Hep3B cells were treated with palmitate with/without the inclusion of cysteine in the media for 24 hours. The effects of cysteine inclusion on palmitate induced cell death were determined by lactate dehydrogenase (LDH) release and MTT assay. Oxidative stress was evaluated by intracellular glutathione (GSH) level, malondialdehyde (MDA) formation, and DCFH-DA assay. Western blotting was performed to detect the changes of endoplasmic reticulum(ER) stress markers: C/EBP homologous transcription factor (CHOP), GRP-78, and phosphorylated c-jun N-terminal kinase (p-JNK). Key findings Elevated intracellular cysteine aggravates hepatocytes to palmitate-induced cell death. Enhancement of ER stress, specifically increased activation of JNK pathway, contributed to this cell death process. Significance Increase of plasma cysteine levels, as observed in both ASH and NASH patients, may play a pathological role in the development of the liver diseases. Manipulation of dietary amino acids supplementation could be a therapeutic choice. PMID:22008477

  10. Modeling human neurological disorders with induced pluripotent stem cells.

    PubMed

    Imaizumi, Yoichi; Okano, Hideyuki

    2014-05-01

    Human induced pluripotent stem (iPS) cells obtained by reprogramming technology are a source of great hope, not only in terms of applications in regenerative medicine, such as cell transplantation therapy, but also for modeling human diseases and new drug development. In particular, the production of iPS cells from the somatic cells of patients with intractable diseases and their subsequent differentiation into cells at affected sites (e.g., neurons, cardiomyocytes, hepatocytes, and myocytes) has permitted the in vitro construction of disease models that contain patient-specific genetic information. For example, disease-specific iPS cells have been established from patients with neuropsychiatric disorders, including schizophrenia and autism, as well as from those with neurodegenerative diseases, including Parkinson's disease and Alzheimer's disease. A multi-omics analysis of neural cells originating from patient-derived iPS cells may thus enable investigators to elucidate the pathogenic mechanisms of neurological diseases that have heretofore been unknown. In addition, large-scale screening of chemical libraries with disease-specific iPS cells is currently underway and is expected to lead to new drug discovery. Accordingly, this review outlines the progress made via the use of patient-derived iPS cells toward the modeling of neurological disorders, the testing of existing drugs, and the discovery of new drugs. The production of human induced pluripotent stem (iPS) cells from the patients' somatic cells and their subsequent differentiation into specific cells have permitted the in vitro construction of disease models that contain patient-specific genetic information. Furthermore, innovations of gene-editing technologies on iPS cells are enabling new approaches for illuminating the pathogenic mechanisms of human diseases. In this review article, we outlined the current status of neurological diseases-specific iPS cell research and described recently obtained

  11. Progesterone prevents radiation-induced apoptosis in breast cancer cells.

    PubMed

    Vares, Guillaume; Ory, Katherine; Lectard, Bruno; Levalois, Céline; Altmeyer-Morel, Sandrine; Chevillard, Sylvie; Lebeau, Jérôme

    2004-06-03

    Sex steroid hormones play an essential role in the control of homeostasis in the mammary gland. Although the involvement of progesterone in cellular proliferation and differentiation is well established, its exact role in the control of cell death still remains unclear. As dysregulation of the apoptotic process plays an important role in the pathogenesis of breast cancer, we investigated the regulation of apoptosis by progesterone in various breast cancer cell lines. Our results show that progesterone treatment protects against radiation-induced apoptosis. This prevention appears to be mediated by the progesterone receptor and is unrelated to p53 status. There is also no correlation with the intrinsic hormonal effect on cell proliferation, as the presence of cells in a particular phase of the cell cycle. Surprisingly, progesterone partly allows bypassing of the irradiation-induced growth arrest in G(2)/M in PgR+ cells, leading to an increase in cell proliferation after irradiation. One consequence of this effect is a higher rate of chromosome damage in these proliferating progesterone-treated cells compared to what is observed in untreated irradiated cells. We propose that progesterone, by inhibiting apoptosis and promoting the proliferation of cells with DNA damage, potentially facilitates the emergence of genetic mutations that may play a role in malignant transformation.

  12. Chestnut extract induces apoptosis in AGS human gastric cancer cells.

    PubMed

    Lee, Hyun Sook; Kim, Eun Ji; Kim, Sun Hyo

    2011-06-01

    In Korea, chestnut production is increasing each year, but consumption is far below production. We investigated the effect of chestnut extracts on antioxidant activity and anticancer effects. Ethanol extracts of raw chestnut (RCE) or chestnut powder (CPE) had dose-dependent superoxide scavenging activity. Viable numbers of MDA-MD-231 human breast cancer cells, DU145 human prostate cancer cells, and AGS human gastric cancer cells decreased by 18, 31, and 69%, respectively, following treatment with 200 µg/mL CPE for 24 hr. CPE at various concentrations (0-200 µg/mL) markedly decreased AGS cell viability and increased apoptotic cell death dose and time dependently. CPE increased the levels of cleaved caspase-8, -7, -3, and poly (ADP-ribose) polymerase in a dose-dependent manner but not cleaved caspase-9. CPE exerted no effects on Bcl-2 and Bax levels. The level of X-linked inhibitor of apoptosis protein decreased within a narrow range following CPE treatment. The levels of Trail, DR4, and Fas-L increased dose-dependently in CPE-treated AGS cells. These results show that CPE decreases growth and induces apoptosis in AGS gastric cancer cells and that activation of the death receptor pathway contributes to CPE-induced apoptosis in AGS cells. In conclusion, CPE had more of an effect on gastric cancer cells than breast or prostate cancer cells, suggesting that chestnuts would have a positive effect against gastric cancer.

  13. Enhancing cytokine-induced killer cell therapy of multiple myeloma.

    PubMed

    Liu, Chunsheng; Suksanpaisan, Lukkana; Chen, Yun-Wen; Russell, Stephen J; Peng, Kah-Whye

    2013-06-01

    Cytokine-induced killer (CIK) cells are in clinical testing against various tumor types, including multiple myeloma. In this study, we show that CIK cells have activity against subcutaneous and disseminated models of human myeloma (KAS-6/1), which can be enhanced by infecting the CIK cells with an oncolytic measles virus (MV) or by pretreating the myeloma cells with ionizing radiation (XRT). KAS-6/1 cells were killed by coculture with CIK or MV-infected CIK (CIK/MV) cells, and the addition of an anti-NKG2D antibody inhibited cytolysis by 50%. However, human bone marrow stromal cells can reduce CIK and CIK/MV mediated killing of myeloma cells (RPMI 8226, JJN-3 and MM1). In vivo, CIK and CIK/MV prolonged the survival of mice with systemic myeloma, although CIK/MV showed enhanced antitumor activity compared with CIK. Irradiation of the KAS-6/1 cells induced mRNA and protein expression of NKG2D ligands, MICA, and MICB in a dose-dependent manner and enhanced delivery of CIK/MV to the irradiated tumors. In both subcutaneous and disseminated myeloma models, XRT at 2 Gy resulted in superior prolongation of the survival of mice given CIK/MV therapy compared with CIK/MV with no XRT. This study demonstrates the potential of CIK against myeloma and that the combination of virotherapy with radiation could be used to further enhance therapeutic outcome using CIK cells.

  14. Prazosin induces p53-mediated autophagic cell death in H9C2 cells.

    PubMed

    Yang, Yi-Fan; Wu, Chau-Chung; Chen, Wen-Pin; Chen, Yuh-Lien; Su, Ming-Jai

    2011-08-01

    Prazosin, a quinazoline-based α(1)-adrenoceptor antagonist, is known to induce cell death, and this effect is independent of its α-blockade activity. However, the detailed molecular mechanisms involved are still not fully understood. In this study, we found that prazosin, but not doxazosin, could induce patterns of autophagy in H9C2 cells, including intracellular vacuole formation, microtubule-associated protein 1 light chain 3 (LC3) conversion, and acidic vesicular organelle (AVO) augmentation. Western blot analysis of phosphorylated proteins showed that exposure to prazosin increased the levels of phospho-p53 and phospho-adenosine monophosphate-activated protein kinase (AMPK) but dramatically decreased the levels of phospho-mammalian target of rapamycin (mTOR), phospho-protein kinase B (Akt), and phospho-ribosomal protein S6 kinase (p70S6K). Furthermore, although pretreatments with the pharmacological autophagy inhibitor 3-methyladenine and the p53 inhibitor pifithrin-α suppressed prazosin-induced AVO formation, they did not reverse prazosin-induced decline in cell viability but enhanced prazosin-induced caspase-3 activation. From these results we suggest that prazosin induces autophagic cell death via a p53-mediated mechanism. When the autophagy pathway was inhibited, prazosin still induced programmed cell death, at least in part through apoptotic caspase-3 cascade enhancement. Thus, our results indicate a potential new target in prazosin-induced cell death.

  15. Photo-Induced Effect on Bacterial Cells

    NASA Astrophysics Data System (ADS)

    El Batanouny, M. H.; Amin, Rehab M.; Naga, M. I.; Ibrahim, M. K.

    2010-04-01

    Bacterial resistance against antibiotics is an increasing problem in medicine. This stimulates study of other bactericidal regimens, one of which is photodynamic therapy (PDT), which involves the killing of bacterial species by low power laser light (LLL) in the presence of photosensitizing agent. It has already been shown that, various gram- negative and gram-positive bacteria can be killed by photodynamic therapy in vitro, using exogenous sensitizers. The mechanisms of laser action on bacteria are not adequately understood. Here, PDT on H. pylori, as an example of gram negative bacteria was studied. The ultra structure changes of the organism after PDT were examined under electron microscope. Neither Irradiation with laser without sensitizer nor sensitizing without laser has any lethal effect on bacterial cells. However, the successful lethal photosensitization was achieved by applying certain laser dose with the corresponding concentration of the photosensitizer. On the other hand, PDT has no significant effect on the genomic DNA of the cells.

  16. Derivation of Induced Trophoblast Cell Lines in Cattle by Doxycycline-Inducible piggyBac Vectors

    PubMed Central

    Hayashi, Masafumi; Tsukiyama, Tomoyuki; Kimura, Koji; Matsuyama, Shuichi; Minami, Naojiro; Yamada, Masayasu; Imai, Hiroshi

    2016-01-01

    Trophectoderm lineage specification is one of the earliest differentiation events in mammalian development. The trophoblast lineage, which is derived from the trophectoderm, mediates implantation and placental formation. However, the processes involved in trophoblastic differentiation and placental formation in cattle remain unclear due to interspecies differences when compared with other model systems and the small repertoire of available trophoblast cell lines. Here, we describe the generation of trophoblast cell lines (biTBCs) from bovine amnion-derived cells (bADCs) using an induced pluripotent stem cell technique. bADCs were introduced with piggyBac vectors containing doxycycline (Dox)-inducible transcription factors (Oct3⁄4(POU5F1), Sox2, Klf4, and c-Myc). Colonies that appeared showed a flattened epithelial-like morphology similar to cobblestones, had a more definite cell boundary between cells, and frequently formed balloon-like spheroids similar to trophoblastic vesicles (TVs). biTBCs were propagated for over 60 passages and expressed trophoblast-related (CDX2, ELF5, ERRβ, and IFN-τ) and pluripotency-related genes (endogenous OCT3/4, SOX2, KLF4, and c-MYC). Furthermore, when biTBCs were induced to differentiate by removing Dox from culture, they formed binucleate cells and began to express pregnancy-related genes (PL, PRP1, and PAG1). This is the first report demonstrating that the induction of pluripotency in bovine amniotic cells allows the generation of trophoblastic cell lines that possess trophoblast stem cell-like characteristics and have the potential to differentiate into the extra-embryonic cell lineage. These cell lines can be a new cell source as a model for studying trophoblast cell lineages and implantation processes in cattle. PMID:27907214

  17. Fluorescence lifetime imaging of induced pluripotent stem cells

    NASA Astrophysics Data System (ADS)

    Uchugonova, Aisada; Batista, Ana; König, Karsten

    2014-02-01

    The multiphoton FLIM tomograph MPTflex with its flexible scan head, articulated arm, and the tunable femtosecond laser source was employed to study cell monolayers and 3D cell clusters. FLIM was performed with 250 ps temporal resolution and submicron special resolution using time-correlated single photon counting. The autofluorescence based on NAD(P)H and flavins/flavoproteins has been measured in mouse embryonic fibroblasts, induced pluripotent stem cells (iPS cells) originated from mouse embryonic fibroblasts and non-proliferative mouse embryonic fibroblasts.

  18. Gingerol sensitizes TRAIL-induced apoptotic cell death of glioblastoma cells

    SciTech Connect

    Lee, Dae-Hee; Kim, Dong-Wook; Jung, Chang-Hwa; Lee, Yong J.; Park, Daeho

    2014-09-15

    Glioblastoma multiforme (GBM) is the most lethal and aggressive astrocytoma of primary brain tumors in adults. Although there are many clinical trials to induce the cell death of glioblastoma cells, most glioblastoma cells have been reported to be resistant to TRAIL-induced apoptosis. Here, we showed that gingerol as a major component of ginger can induce TRAIL-mediated apoptosis of glioblastoma. Gingerol increased death receptor (DR) 5 levels in a p53-dependent manner. Furthermore, gingerol decreased the expression level of anti-apoptotic proteins (survivin, c-FLIP, Bcl-2, and XIAP) and increased pro-apoptotic protein, Bax and truncate Bid, by generating reactive oxygen species (ROS). We also found that the sensitizing effects of gingerol in TRAIL-induced cell death were blocked by scavenging ROS or overexpressing anti-apoptotic protein (Bcl-2). Therefore, we showed the functions of gingerol as a sensitizing agent to induce cell death of TRAIL-resistant glioblastoma cells. This study gives rise to the possibility of applying gingerol as an anti-tumor agent that can be used for the purpose of combination treatment with TRAIL in TRAIL-resistant glioblastoma tumor therapy. - Highlights: • Most GBM cells have been reported to be resistant to TRAIL-induced apoptosis. • Gingerol enhances the expression level of anti-apoptotic proteins by ROS. • Gingerol enhances TRAIL-induced apoptosis through actions on the ROS–Bcl2 pathway.

  19. Role of cells in freezing-induced cell-fluid-matrix interactions within engineered tissues.

    PubMed

    Seawright, Angela; Ozcelikkale, Altug; Dutton, Craig; Han, Bumsoo

    2013-09-01

    During cryopreservation, ice forms in the extracellular space resulting in freezing-induced deformation of the tissue, which can be detrimental to the extracellular matrix (ECM) microstructure. Meanwhile, cells dehydrate through an osmotically driven process as the intracellular water is transported to the extracellular space, increasing the volume of fluid for freezing. Therefore, this study examines the effects of cellular presence on tissue deformation and investigates the significance of intracellular water transport and cell-ECM interactions in freezing-induced cell-fluid-matrix interactions. Freezing-induced deformation characteristics were examined through cell image deformetry (CID) measurements of collagenous engineered tissues embedded with different concentrations of MCF7 breast cancer cells versus microspheres as their osmotically inactive counterparts. Additionally, the development of a biophysical model relates the freezing-induced expansion of the tissue due to the cellular water transport and the extracellular freezing thermodynamics for further verification. The magnitude of the freezing-induced dilatation was found to be not affected by the cellular water transport for the cell concentrations considered; however, the deformation patterns for different cell concentrations were different suggesting that cell-matrix interactions may have an effect. It was, therefore, determined that intracellular water transport during freezing was insignificant at the current experimental cell concentrations; however, it may be significant at concentrations similar to native tissue. Finally, the cell-matrix interactions provided mechanical support on the ECM to minimize the expansion regions in the tissues during freezing.

  20. Induced pluripotent stem cells in the study of neurological diseases

    PubMed Central

    2011-01-01

    Five years after their initial derivation from mouse somatic cells, induced pluripotent stem (iPS) cells are an important tool for the study of neurological diseases. By offering an unlimited source of patient-specific disease-relevant neuronal and glial cells, iPS cell-based disease models hold enormous promise for identification of disease mechanisms, discovery of molecular targets and development of phenotypic screens for drug discovery. The present review focuses on the recent advancements in modeling neurological disorders, including the demonstration of disease-specific phenotypes in iPS cell-derived neurons generated from patients with spinal muscular atrophy, familial dysautonomia, Rett syndrome, schizophrenia and Parkinson disease. The ability of this approach to detect treatment effects from known therapeutic compounds has also been demonstrated, providing proof of principle for the use of iPS cell-derived cells in drug discovery. PMID:21936964

  1. Multiple sclerosis: getting personal with induced pluripotent stem cells

    PubMed Central

    Di Ruscio, A; Patti, F; Welner, R S; Tenen, D G; Amabile, G

    2015-01-01

    Human induced pluripotent stem (iPS) cells can be derived from lineage-restricted cells and represent an important tool to develop novel patient-specific cell therapies and research models for inherited and acquired diseases. Recently, patient-derived iPS cells, containing donor genetic background, have offered a breakthrough approach to study human genetics of neurodegenerative diseases. By offering an unlimited source of patient-specific disease-relevant cells, iPS cells hold great promise for understanding disease mechanisms, identifying molecular targets and developing phenotypic screens for drug discovery. This review will discuss the potential impact of using iPS cell-derived models in multiple sclerosis (MS) research and highlight some of the current challenges and prospective for generating novel therapeutic treatments for MS patients. PMID:26158512

  2. Human induced pluripotent stem cells: A disruptive innovation.

    PubMed

    De Vos, J; Bouckenheimer, J; Sansac, C; Lemaître, J-M; Assou, S

    2016-01-01

    This year (2016) will mark the 10th anniversary of the discovery of induced pluripotent stem cells (iPSCs). The finding that the transient expression of four transcription factors can radically remodel the epigenome, transcriptome and metabolome of differentiated cells and reprogram them into pluripotent stem cells has been a major and groundbreaking technological innovation. In this review, we discuss the major applications of this technology that we have grouped in nine categories: a model to study cell fate control; a model to study pluripotency; a model to study human development; a model to study human tissue and organ physiology; a model to study genetic diseases in a dish; a tool for cell rejuvenation; a source of cells for drug screening; a source of cells for regenerative medicine; a tool for the production of human organs in animals.

  3. Simvastatin suppresses breast cancer cell proliferation induced by senescent cells

    PubMed Central

    Liu, Su; Uppal, Harpreet; Demaria, Marco; Desprez, Pierre-Yves; Campisi, Judith; Kapahi, Pankaj

    2015-01-01

    Cellular senescence suppresses cancer by preventing the proliferation of damaged cells, but senescent cells can also promote cancer though the pro-inflammatory senescence-associated secretory phenotype (SASP). Simvastatin, an HMG-coA reductase inhibitor, is known to attenuate inflammation and prevent certain cancers. Here, we show that simvastatin decreases the SASP of senescent human fibroblasts by inhibiting protein prenylation, without affecting the senescent growth arrest. The Rho family GTPases Rac1 and Cdc42 were activated in senescent cells, and simvastatin reduced both activities. Further, geranylgeranyl transferase, Rac1 or Cdc42 depletion reduced IL-6 secretion by senescent cells. We also show that simvastatin mitigates the effects of senescent conditioned media on breast cancer cell proliferation and endocrine resistance. Our findings identify a novel activity of simvastatin and mechanism of SASP regulation. They also suggest that senescent cells, which accumulate after radio/chemo therapy, promote endocrine resistance in breast cancer and that simvastatin might suppress this resistance. PMID:26658759

  4. Apoptosis induced by propolis in human hepatocellular carcinoma cell line.

    PubMed

    Choi, Y H; Lee, W Y; Nam, S Y; Choi, K C; Park, Y E

    1999-07-01

    Propolis has been reported to exhibit a wide spectrum of activities including antibiotic, antiviral, anti-inflammatory, immunostimulatory and tumor carcinostatic properties. We showed propolis induced apoptosis in a human hepatoma cell line (SNU449) by FITC-Annexin V/PI staining. We also compared the apoptosis inducing effect between Korean and Commercial (Sigma # p-1010) propolis. There was no difference on apoptosis between them.

  5. Astaxanthin Inhibits Proliferation and Induces Apoptosis and Cell Cycle Arrest of Mice H22 Hepatoma Cells

    PubMed Central

    Shao, Yiye; Ni, Yanbo; Yang, Jing; Lin, Xutao; Li, Jun; Zhang, Lixia

    2016-01-01

    Background It is widely recognized that astaxanthin (ASX), a member of the carotenoid family, has strong biological activities including antioxidant, anti-inflammation, and immune-modulation activities. Previous studies have confirmed that ASX can effectively inhibit hepatoma cells in vitro. Material/Methods MTT was used to assay proliferation of mice H22 cells, and flow cytometry was used to determine apoptosis and cell cycle arrest of H22 cells in vitro and in vivo. Moreover, anti-tumor activity of ASX was observed in mice. Results ASX inhibited the proliferation of H22 cells, promoted cell necrosis, and induced cell cycle arrest in G2 phase in vitro and in vivo. Conclusions This study indicated that ASX can inhibit proliferation and induce apoptosis and cell cycle arrest in mice H22 hepatoma cells in vitro and in vivo. PMID:27333866

  6. Bovine herpesvirus type 1 induces cell death by a cell-type-dependent fashion.

    PubMed

    Geiser, Vicki; Rose, Suzanne; Jones, Clinton

    2008-06-01

    Bovine herpesvirus 1 (BHV-1), a member of the alpha-herpesvirinae sub-family, causes significant losses to the cattle industry. BHV-1 establishes latency in trigeminal ganglionic sensory neurons, but periodically reactivates from latency. Previous studies suggested that infection with BHV-1-induced novel morphological changes in rabbit skin (RS) cells versus bovine kidney cells (MDBK). Consequently, we hypothesized that viral infection led to a novel form of cell death in RS cells compared to MDBK cells. To test this hypothesis, we examined the levels of apoptosis in these cell types following infection with BHV-1. Infection of RS, but not MDBK, cells leads to high levels of apoptosis compared to mock-infected cells. Previous studies indicated that a BHV-1 recombinant virus that does not express the bICP0 protein grows poorly in permissive cells and induces a persistent-like infection. This suggested that bICP0 played an important role in regulating cell death following infection. To test this hypothesis, we compared the levels of apoptosis in cells infected with the bICP0 null mutant versus viral strains that expressed bICP0. The bICP0 null mutant induces low levels of apoptosis in RS or MDBK cells. When MDBK cells are treated with UV light prior to infection, bICP0 expressing viral strains, but not the bICP0 null mutant, inhibited UV-induced apoptosis. Infection of MDBK cells with the bICP0 null mutant, leads to an accumulation of autophagosomes that are not detected following infection with bICP0 expressing viruses. These studies suggest that the bICP0 null mutant induces autophagy in MDBK cells, and bICP0 protein expression mediates cell-type specific cytotoxicity.

  7. The role of hypoxia-inducible factor-1α in radiation-induced autophagic cell death in breast cancer cells.

    PubMed

    Zhong, Rui; Xu, Huiying; Chen, Ge; Zhao, Gang; Gao, Yan; Liu, Xiaodong; Ma, Shumei; Dong, Lihua

    2015-09-01

    Hypoxia-inducible factor-1α (HIF-1α) is a major effector in cell survival response to hypoxia, while the roles of HIF-1α in radiation-induced autophagy are still unclear in breast cancer cells. Human breast cancer carcinoma MCF-7 cells were stably transfected with pSUPER-shRNA against human HIF-1α or a scrambled sequence with no homology to mammalian genes, named as pSUPER-HIF-1α and pSUPER-SC, respectively. Cell Counting Kit-8 (CCK-8) assay and colony formation assay were used to detect cell viability, Western blot was used to detect protein expression, monodansylcadaverine (MDC) staining was used to analyze autophagy, and Hoechts/PI staining was used to assess apoptosis. Ionizing radiation (IR) and cobalt chloride (CoCl2) could induce HIF-1α expression and increase the microtubule-associated protein 1 light chain 3 (MAPLC3)-II/MAPLC3-I ratio, especially in radiation + CoCl2 group. After the silencing of HIF-1α, the radiosensitivity of MCF-7 cells increased and the autophagy level decreased in response to DNA damage induced by ionizing radiation, but there was no influence on IR-induced apoptosis. HIF-1α silencing also increased the expression of phospho-Akt, mTOR, and P70S6K and activated the mTOR signals significantly. Hypoxia can induce autophagy and also improve the IR-induced autophagy via the suppression of Akt/mTOR/P70S6K pathway, which consequently lead to radioresistance.

  8. Cell Therapy for Chemically Induced Ovarian Failure in Mice

    PubMed Central

    Terraciano, Paula; Durli, Isabel; Baggio, Melchiani; Kuhl, Cristiana Palma; Laurino, Claudia; Passos, Eduardo; Paz, Ana Helena; Cirne-Lima, Elizabeth

    2014-01-01

    Cell therapy has been linked to an unexplained return of ovarian function and fertility in some cancer survivors. Studies modeling this in mice have shown that cells transplantation generates donor-derived oocytes in chemotherapy-treated recipients. This study was conducted to further clarify the impact of cell transplantation from different sources on female reproductive function after chemotherapy using a preclinical mouse model. Methods. Female mice were administered 7.5 mg/kg cisplatin followed by cell transplantation (one week later) using GFP+ female cell donors. For cell tracking, adipose derived stem cell GFP+ (ADSC), female germline stem cell GFP+/MVH+ (FGSC), or ovary cell suspension GFP+ mice were transplanted into cisplatin-treated wild-type recipients. After 7 or 14 days animals were killed and histological analysis, IHQ for GFP cells, and ELISA for estradiol were performed. Results. Histological examinations showed that ADSC, ovary cell suspension, and FGSC transplant increase the number of follicles with apparent normal structure in the cells recipient group euthanized on day 7. Cell tracking showed GFP+ samples 7 days after transplant. Conclusion. These data suggest that intraovarian injection of ADSCs and FGSC into mice with chemotherapy-induced ovarian failure diminished the damage caused by cisplatin. PMID:25548574

  9. IL-33 induces both regulatory B cells and regulatory T cells in dextran sulfate sodium-induced colitis.

    PubMed

    Zhu, Junfeng; Xu, Ying; Zhu, Chunyu; Zhao, Jian; Meng, Xinrui; Chen, Siyao; Wang, Tianqi; Li, Xue; Zhang, Li; Lu, Changlong; Liu, Hongsheng; Sun, Xun

    2017-05-01

    Interleukin (IL)-33 is a member of the IL-1 family. Serum levels of IL-33 are increased in inflammatory bowel diseases (IBD), suggesting that IL-33 is involved in the pathogenesis of IBD, although its role is not clear. In this study, we investigated the role of IL-33 in the regulation of T-helper (Th) cell and B cell responses in mesenteric lymph nodes (MLN) in mice with dextran sulfate sodium (DSS)-induced colitis. Here, we showed that IL-33-treated mice were susceptible to DSS-induced colitis as compared with PBS-treated mice. The production of spontaneous inflammatory cytokines production by macrophages or dendritic cells (DC) in MLN significantly increased, and the responses of Th2, regulatory T cells (Treg) and regulatory B cells (Breg) were markedly upregulated, while Th1 responses were significantly downregulated in MLN of IL-33-treated mice with DSS-induced colitis. Our results demonstrate that IL-33 contributes to the pathogenesis of DSS-induced colitis in mice by promoting Th2 responses, but suppressing Th1 responses, in MLN. Moreover, IL-33 treatment increased Breg and Treg responses in MLN in mice with DSS-induced colitis. Therefore, modulation of IL-33/ST2 signaling is implicated as a novel biological therapy for inflammatory diseases associated with Th1 responses.

  10. Autophagy Protects Against Aminochrome-Induced Cell Death in Substantia Nigra-Derived Cell Line

    PubMed Central

    Paris, Irmgard; Muñoz, Patricia; Huenchuguala, Sandro; Couve, Eduardo; Sanders, Laurie H.; Greenamyre, John Timothy; Caviedes, Pablo; Segura-Aguilar, Juan

    2011-01-01

    Aminochrome, the precursor of neuromelanin, has been proposed to be involved in the neurodegeneration neuromelanin-containing dopaminergic neurons in Parkinson’s disease. We aimed to study the mechanism of aminochrome-dependent cell death in a cell line derived from rat substantia nigra. We found that aminochrome (50μM), in the presence of NAD(P)H-quinone oxidoreductase, EC 1.6.99.2 (DT)-diaphorase inhibitor dicoumarol (DIC) (100μM), induces significant cell death (62 ± 3%; p < 0.01), increase in caspase-3 activation (p < 0.001), release of cytochrome C, disruption of mitochondrial membrane potential (p < 0.01), damage of mitochondrial DNA, damage of mitochondria determined with transmission electron microscopy, a dramatic morphological change characterized as cell shrinkage, and significant increase in number of autophagic vacuoles. To determine the role of autophagy on aminochrome-induced cell death, we incubated the cells in the presence of vinblastine and rapamycin. Interestingly, 10μM vinblastine induces a 5.9-fold (p < 0.001) and twofold (p < 0.01) significant increase in cell death when the cells were incubated with 30μM aminochrome in the absence and presence of DIC, respectively, whereas 10μM rapamycin preincubated 24 h before addition of 50μM aminochrome in the absence and the presence of 100μM DIC induces a significant decrease (p < 0.001) in cell death. In conclusion, autophagy seems to be an important protective mechanism against two different aminochrome-induced cell deaths that initially showed apoptotic features. The cell death induced by aminochrome when DT-diaphorase is inhibited requires activation of mitochondrial pathway, whereas the cell death induced by aminochrome alone requires inhibition of autophagy-dependent degrading of damaged organelles and recycling through lysosomes. PMID:21427056

  11. Polar/apolar compounds induce leukemia cell differentiation by modulating cell-surface potential.

    PubMed Central

    Arcangeli, A; Carlà, M; Del Bene, M R; Becchetti, A; Wanke, E; Olivotto, M

    1993-01-01

    The mechanism of action of polar/apolar inducers of cell differentiation, such as dimethyl sulfoxide and hexamethylene-bisacetamide, is still obscure. In this paper evidence is provided that their effects on murine erythroleukemia cells are modulated by various extracellular cations as a precise function of the cation effects on membrane surface potential. The interfacial effects of the inducers were directly measured on the charged electrode, showing that both dimethyl sulfoxide and hexamethylene-bisacetamide, at the effective concentrations for cell differentiation and within the physiological range of charge density, adsorb at the charged surface and produce a potential shift. A linear correlation was found between this shift and the inducer effects on cell differentiation. Besides offering a different interpretation of the mechanism of action of the inducers, these findings indicate that surface potential has a signaling function. They may also be relevant to cancer treatments based on tumor-cell commitment to terminal differentiation. Images Fig. 1 PMID:8516337

  12. Fucoidan inhibits angiogenesis induced by multiple myeloma cells.

    PubMed

    Liu, Fen; Luo, Guoping; Xiao, Qing; Chen, Liping; Luo, Xiaohua; Lv, Jinglong; Chen, Lixue

    2016-10-01

    Multiple myeloma (MM) remains an incurable hematological neoplasms. Our previous studies showed that Fucoidan possessed anti-myeloma effect by inducing apoptosis and inhibiting invasion of myeloma cells. In this study, we evaluated the effect of Fucoidan on angiogenesis induced by human myeloma cells and elucidated its possible mechanisms. Multiple myeloma cells were treated with Fucoidan at different concentrations, then the conditioned medium (CM) was collected. The levels of VEGF in the CM were tested by ELISA. The results showed that Fucoidan significantly decreased VEGF secretion by RPMI-8226 and U266 cells. The tube formation assay and migration test on human umbilical vein endothelial cells (HUVECs) were used to examine the effect of Fucoidan on angiogenesis induced by human myeloma cells. The results showed that Fucoidan decreased HUVECs formed tube structures and inhibited HUVECs migration, and suppressed the angiogenic ability of multiple myeloma RPMI-8226 and U266 cells in a dose-dependent manner. The study also showed that Fucoidan downregulated the expression of several kinds of proteins, which may be correlated with the reduction of angiogenesis induced by myeloma cells. Moreover, results were compared from normoxic and hypoxic conditions, they showed that Fucoidan had anti-angiogenic activity. Furthermore, in a multiple myeloma xenograft mouse model, it indicated that Fucoidan negatively affected tumor growth and angiogenesis in vivo. In conclusion, our results demonstrate that Fucoidan was able to interfere with angiogenesis of multiple myeloma cells both in vitro and in vivo and may have a substantial potential in the treatment of MM.

  13. The antiangiogenic agent Neovastat (AE-941) induces endothelial cell apoptosis.

    PubMed

    Boivin, Dominique; Gendron, Sébastien; Beaulieu, Edith; Gingras, Denis; Béliveau, Richard

    2002-08-01

    Neovastat (AE-941), a naturally occurring multifunctional antiangiogenic agent, has been shown to inhibit key components of the angiogenic process, including matrix metalloproteinases and vascular endothelial growth factor-mediated signaling events. In this study, we report the presence of a proapoptotic activity within this compound. Neovastat treatment of bovine aortic endothelial cells caused cell death with characteristics of apoptosis, including chromatin condensation and DNA fragmentation. Neovastat markedly induced caspase-3, caspase-8, and caspase-9 activities, at similar levels to those measured in cells treated with tumor necrosis factor-alpha. Activation of caspases by Neovastat appears to be essential for its proapoptotic effects because all apoptotic features were blocked by zVAD-fmk, a broad-spectrum caspase inhibitor. The activation of caspases was correlated with the cleavage of the nuclear substrate poly(ADP-ribose) polymerase, and by a concomitant release of cytochrome c from mitochondria to the cytoplasm. Neovastat-induced apoptosis appears to be specific to endothelial cells because treatment of other cell types such as U-87, COS-7, NIH-3T3, and SW1353 did not result in increased caspase-3 activity. These results demonstrate that Neovastat contains a proapoptotic factor that specifically induces the activation of caspases in endothelial cells and the resulting apoptosis of these cells.

  14. Signaling events in pathogen-induced macrophage foam cell formation.

    PubMed

    Shaik-Dasthagirisaheb, Yazdani B; Mekasha, Samrawit; He, Xianbao; Gibson, Frank C; Ingalls, Robin R

    2016-08-01

    Macrophage foam cell formation is a key event in atherosclerosis. Several triggers induce low-density lipoprotein (LDL) uptake by macrophages to create foam cells, including infections with Porphyromonas gingivalis and Chlamydia pneumoniae, two pathogens that have been linked to atherosclerosis. While gene regulation during foam cell formation has been examined, comparative investigations to identify shared and specific pathogen-elicited molecular events relevant to foam cell formation are not well documented. We infected mouse bone marrow-derived macrophages with P. gingivalis or C. pneumoniae in the presence of LDL to induce foam cell formation, and examined gene expression using an atherosclerosis pathway targeted plate array. We found over 30 genes were significantly induced in response to both pathogens, including PPAR family members that are broadly important in atherosclerosis and matrix remodeling genes that may play a role in plaque development and stability. Six genes mainly involved in lipid transport were significantly downregulated. The response overall was remarkably similar and few genes were regulated in a pathogen-specific manner. Despite very divergent lifestyles, P. gingivalis and C. pneumoniae activate similar gene expression profiles during foam cell formation that may ultimately serve as targets for modulating infection-elicited foam cell burden, and progression of atherosclerosis.

  15. Apoptotic pathway induced by noscapine in human myelogenous leukemic cells.

    PubMed

    Heidari, Nastaran; Goliaei, Bahram; Moghaddam, Parvaneh Rahimi; Rahbar-Roshandel, Nahid; Mahmoudian, Massoud

    2007-11-01

    It has been shown that noscapine, an opium-derived phthalideisoquinoline alkaloid that is currently being used as an oral antitussive drug, induces apoptosis in myeloid leukemia cells. The molecular mechanism responsible for the anticancer effects of noscapine is poorly understood. In the current study, the apoptotic effects of noscapine on two myeloid cell lines, apoptosis-proficient HL60 cells and apoptosis-resistant K562 cells, were analyzed. An increase in the activity of caspase-2, -3, -6, -8 and -9, poly(ADP ribose) polymerase cleavage, detection of phosphatidylserine on the outer layer of the cell membrane, nucleation of chromatin, and DNA fragmentation suggested the induction of apoptosis. Noscapine increased the Bax/Bcl-2 ratio with a significant decrease of Bcl-2 expression accompanied with Bcl-2 phosphorylation. Using an inhibitory approach, the activation of the caspase cascade involved in the noscapine-induced apoptosis was analyzed. We observed no inhibitory effect of the caspase-8 inhibitor on caspase-9 activity. In view of these results and taking into consideration that K562 cells are Fas-null, we suggested that caspase-8 is activated in a Fas-independent manner downstream of caspase-9. In conclusion, noscapine can induce apoptosis in both apoptosis-proficient and apoptosis-resistant leukemic cells, and it can be a novel candidate in the treatment of hematological malignancies.

  16. Statins and Voriconazole Induce Programmed Cell Death in Acanthamoeba castellanii

    PubMed Central

    López-Arencibia, Atteneri; Sifaoui, Ines; Reyes-Batlle, María; Valladares, Basilio; Martínez-Carretero, Enrique; Piñero, José E.; Maciver, Sutherland K.; Lorenzo-Morales, Jacob

    2015-01-01

    Members of the genus Acanthamoeba are facultative pathogens of humans, causing a sight-threatening keratitis and a life-threatening encephalitis. In order to treat those infections properly, it is necessary to target the treatment not only to the trophozoite but also to the cyst. Furthermore, it may be advantageous to avoid parasite killing by necrosis, which may induce local inflammation. We must also avoid toxicity of host tissue. Many drugs which target eukaryotes are known to induce programmed cell death (PCD), but this process is poorly characterized in Acanthamoeba. Here, we study the processes of programmed cell death in Acanthamoeba, induced by several drugs, such as statins and voriconazole. We tested atorvastatin, fluvastatin, simvastatin, and voriconazole at the 50% inhibitory concentrations (IC50s) and IC90s that we have previously established. In order to evaluate this phenomenon, we investigated the DNA fragmentation, one of the main characteristics of PCD, with quantitative and qualitative techniques. Also, the changes related to phosphatidylserine exposure on the external cell membrane and cell permeability were studied. Finally, because caspases are key to PCD pathways, caspase activity was evaluated in Acanthamoeba. All the drugs assayed in this study induced PCD in Acanthamoeba. To the best of our knowledge, this is the first study where PCD induced by drugs is described quantitatively and qualitatively in Acanthamoeba. PMID:25733513

  17. Inducible immortality in hTERT-human mesenchymal stem cells.

    PubMed

    Piper, Samantha L; Wang, Miqi; Yamamoto, Akira; Malek, Farbod; Luu, Andrew; Kuo, Alfred C; Kim, Hubert T

    2012-12-01

    Human mesenchymal stem cells (hMSCs) are attractive candidates for tissue engineering and cell-based therapy because of their multipotentiality and availability in adult donors. However, in vitro expansion and differentiation of these cells is limited by replicative senescence. The proliferative capacity of hMSCs can be enhanced by ectopic expression of telomerase, allowing for long-term culture. However, hMSCs with constitutive telomerase expression demonstrate unregulated growth and even tumor formation. To address this problem, we used an inducible Tet-On gene expression system to create hMSCs in which ectopic telomerase expression can be induced selectively by the addition of doxycycline (i-hTERT hMSCs). i-hTERT hMSCs have inducible hTERT expression and telomerase activity, and are able to proliferate significantly longer than wild type hMSCs when hTERT expression is induced. They stop proliferating when hTERT expression is turned off and can be rescued when expression is re-induced. They retain multipotentiality in vitro even at an advanced age. We also used a selective inhibitor of telomere elongation to show that the mechanism driving immortalization of hMSCs by hTERT is dependent upon maintenance of telomere length. Thanks to their extended lifespan, preserved multipotentiality and controlled growth, i-hTERT hMSCs may prove to be a useful tool for the development and testing of novel stem cell therapies.

  18. Noscapine induces apoptosis in human glioma cells by an apoptosis-inducing factor-dependent pathway.

    PubMed

    Newcomb, Elizabeth W; Lukyanov, Yevgeniy; Smirnova, Iva; Schnee, Tona; Zagzag, David

    2008-07-01

    Previously, we identified noscapine as a small molecule inhibitor of the hypoxia-inducible factor-1 pathway in hypoxic human glioma cells and human umbilical vein endothelial cells. Noscapine is a nontoxic ingredient in cough medicine currently used in clinical trials for patients with non-Hodgkin's lymphoma or chronic lymphocytic leukemia to assess antitumor efficacy. Here, we have evaluated the sensitivity of four human glioma cell lines to noscapine-induced apoptosis. Noscapine was a potent inhibitor of proliferation and inducer of apoptosis. Induction of apoptosis was associated with activation of the c-jun N-terminal kinase signaling pathway concomitant with inactivation of the extracellular signal regulated kinase signaling pathway and phosphorylation of the antiapoptotic protein Bcl-2. Noscapine-induced apoptosis was associated with the release of mitochondrial proteins apoptosis-inducing factor (AIF) and/or cytochrome c. In some glioma cell lines, only AIF release occurred without cytochrome c release or poly (ADP-ribose) polymerase cleavage. Knock-down of AIF decreased noscapine-induced apoptosis. Our results suggest the potential importance of noscapine as a novel agent for use in patients with glioblastoma owing to its low toxicity profile and its potent anticancer activity.

  19. The physics of photon induced degradation of perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Joshi, Pranav H.; Zhang, Liang; Hossain, Istiaque M.; Abbas, Hisham A.; Kottokkaran, Ranjith; Nehra, Satyapal P.; Dhaka, Mahendra; Noack, Max; Dalal, Vikram L.

    2016-11-01

    Lead-trihalide perovskite solar cells are an important photovoltaic technology. We investigate the effect of light induced degradation on perovskite solar cells. During exposure, the open-circuit voltage (Voc) of the device increases, whereas the short-circuit current (Isc) shows a decrease. The degradation can be completely recovered using thermal annealing in dark. We develop a model based on light induced generation of ions and migration of these ions inside the material to explain the changes in Isc, Voc, capacitance and dark current upon light exposure and post-exposure recovery. There was no change in defect density in the material upon exposure.

  20. Chromomycin A2 induces autophagy in melanoma cells.

    PubMed

    Guimarães, Larissa Alves; Jimenez, Paula Christine; Sousa, Thiciana da Silva; Freitas, Hozana Patrícia S; Rocha, Danilo Damasceno; Wilke, Diego Veras; Martín, Jesús; Reyes, Fernando; Deusdênia Loiola Pessoa, Otília; Costa-Lotufo, Letícia Veras

    2014-12-04

    The present study highlights the biological effects of chromomycin A2 toward metastatic melanoma cells in culture. Besides chromomycin A2, chromomycin A3 and demethylchromomycin A2 were also identified from the extract derived from Streptomyces sp., recovered from Paracuru Beach, located in the northeast region of Brazil. The cytotoxic activity of chromomycin A2 was evaluated across a panel of human tumor cell lines, which found IC50 values in the nM-range for exposures of 48 and 72 h. MALME-3M, a metastatic melanoma cell line, showed the highest sensitivity to chromomycin A2 after 48h incubation, and was chosen as a model to investigate this potent cytotoxic effect. Treatment with chromomycin A2 at 30 nM reduced cell proliferation, but had no significant effect upon cell viability. Additionally, chromomycin A2 induced accumulation of cells in G0/G1 phase of the cell cycle, with consequent reduction of S and G2/M and unbalanced expression of cyclins. Chromomycin A2 treated cells depicted several cellular fragments resembling autophagosomes and increased expression of proteins LC3-A and LC3-B. Moreover, exposure to chromomycin A2 also induced the appearance of acidic vacuolar organelles in treated cells. These features combined are suggestive of the induction of autophagy promoted by chromomycin A2, a feature not previously described for chromomycins.

  1. Chromomycin A2 Induces Autophagy in Melanoma Cells

    PubMed Central

    Guimarães, Larissa Alves; Jimenez, Paula Christine; Sousa, Thiciana da Silva; Freitas, Hozana Patrícia S.; Rocha, Danilo Damasceno; Wilke, Diego Veras; Martín, Jesús; Reyes, Fernando; Pessoa, Otília Deusdênia Loiola; Costa-Lotufo, Letícia Veras

    2014-01-01

    The present study highlights the biological effects of chromomycin A2 toward metastatic melanoma cells in culture. Besides chromomycin A2, chromomycin A3 and demethylchromomycin A2 were also identified from the extract derived from Streptomyces sp., recovered from Paracuru Beach, located in the northeast region of Brazil. The cytotoxic activity of chromomycin A2 was evaluated across a panel of human tumor cell lines, which found IC50 values in the nM-range for exposures of 48 and 72 h. MALME-3M, a metastatic melanoma cell line, showed the highest sensitivity to chromomycin A2 after 48h incubation, and was chosen as a model to investigate this potent cytotoxic effect. Treatment with chromomycin A2 at 30 nM reduced cell proliferation, but had no significant effect upon cell viability. Additionally, chromomycin A2 induced accumulation of cells in G0/G1 phase of the cell cycle, with consequent reduction of S and G2/M and unbalanced expression of cyclins. Chromomycin A2 treated cells depicted several cellular fragments resembling autophagosomes and increased expression of proteins LC3-A and LC3-B. Moreover, exposure to chromomycin A2 also induced the appearance of acidic vacuolar organelles in treated cells. These features combined are suggestive of the induction of autophagy promoted by chromomycin A2, a feature not previously described for chromomycins. PMID:25486109

  2. Mechanical Stress Promotes Cisplatin-Induced Hepatocellular Carcinoma Cell Death

    PubMed Central

    Riad, Sandra; Bougherara, Habiba

    2015-01-01

    Cisplatin (CisPt) is a commonly used platinum-based chemotherapeutic agent. Its efficacy is limited due to drug resistance and multiple side effects, thereby warranting a new approach to improving the pharmacological effect of CisPt. A newly developed mathematical hypothesis suggested that mechanical loading, when coupled with a chemotherapeutic drug such as CisPt and immune cells, would boost tumor cell death. The current study investigated the aforementioned mathematical hypothesis by exposing human hepatocellular liver carcinoma (HepG2) cells to CisPt, peripheral blood mononuclear cells, and mechanical stress individually and in combination. HepG2 cells were also treated with a mixture of CisPt and carnosine with and without mechanical stress to examine one possible mechanism employed by mechanical stress to enhance CisPt effects. Carnosine is a dipeptide that reportedly sequesters platinum-based drugs away from their pharmacological target-site. Mechanical stress was achieved using an orbital shaker that produced 300 rpm with a horizontal circular motion. Our results demonstrated that mechanical stress promoted CisPt-induced death of HepG2 cells (~35% more cell death). Moreover, results showed that CisPt-induced death was compromised when CisPt was left to mix with carnosine 24 hours preceding treatment. Mechanical stress, however, ameliorated cell death (20% more cell death). PMID:25685789

  3. Expression of inducible nitric oxide in human lung epithelial cells.

    PubMed

    Robbins, R A; Barnes, P J; Springall, D R; Warren, J B; Kwon, O J; Buttery, L D; Wilson, A J; Geller, D A; Polak, J M

    1994-08-30

    Nitric oxide (NO) is increased in the exhaled air of subjects with several airway disorders. To determine if cytokines could stimulate epithelial cells accounting for the increased NO, the capacity of the proinflammatory cytokines (cytomix: tumor necrosis factor-alpha, interleukin-1 beta, and interferon-gamma) to increase inducible nitric oxide synthase (iNOS) was investigated in A549 and primary cultures of human bronchial epithelial cells. Cytomix induced a time-dependent increase in nitrite levels in culture supernatant fluids (p < 0.05). Increased numbers of cells stained for iNOS and increased iNOS mRNA was detected in the cytokine-stimulated cells compared to control (p < 0.05). Dexamethasone diminished the cytokine-induced increase in nitrite, iNOS by immunocytochemistry, and iNOS mRNA. These data demonstrate that cytokines, such as those released by mononuclear cells, can induce lung epithelial iNOS expression and NO release, and that this is attenuated by dexamethasone.

  4. Ethylene insensitivity modulates ozone-induced cell death in birch.

    PubMed

    Vahala, Jorma; Ruonala, Raili; Keinänen, Markku; Tuominen, Hannele; Kangasjärvi, Jaakko

    2003-05-01

    We have used genotypic variation in birch (Betula pendula Roth) to investigate the roles of ozone (O(3))-induced ethylene (ET), jasmonic acid, and salicylic acid in the regulation of tissue tolerance to O(3). Of these hormones, ET evolution correlated best with O(3)-induced cell death. Disruption of ET perception by transformation of birch with the dominant negative mutant allele etr1-1 of the Arabidopsis ET receptor gene ETR1 or blocking of ET perception with 1-methylcyclopropene reduced but did not completely prevent the O(3)-induced cell death, when inhibition of ET biosynthesis with aminooxyacetic acid completely abolished O(3) lesion formation. This suggests the presence of an ET-signaling-independent but ET biosynthesis-dependent component in the ET-mediated stimulation of cell death in O(3)-exposed birch. Functional ET signaling was required for the O(3) induction of the gene encoding beta-cyanoalanine synthase, which catalyzes detoxification of the cyanide formed during ET biosynthesis. The results suggest that functional ET signaling is required to protect birch from the O(3)-induced cell death and that a decrease in ET sensitivity together with a simultaneous, high ET biosynthesis can potentially cause cell death through a deficient detoxification of cyanide.

  5. Inhibition of inducible heat shock protein-70 (hsp72) enhances bortezomib-induced cell death in human bladder cancer cells.

    PubMed

    Qi, Wei; White, Matthew C; Choi, Woonyoung; Guo, Charles; Dinney, Colin; McConkey, David J; Siefker-Radtke, Arlene

    2013-01-01

    The proteasome inhibitor bortezomib (Velcade) is a promising new agent for bladder cancer therapy, but inducible cytoprotective mechanisms may limit its potential efficacy. We used whole genome mRNA expression profiling to study the effects of bortezomib on stress-induced gene expression in a panel of human bladder cancer cell lines. Bortezomib induced strong upregulation of the inducible HSP70 isoforms HSPA1A and HSPA1B isoforms of Hsp72 in 253J B-V and SW780 (HSPA1A(high)) cells, but only induced the HSPA1B isoform in UM-UC10 and UM-UC13 (HSPA1A(low)) cells. Bortezomib stimulated the binding of heat shock factor-1 (HSF1) to the HSPA1A promoter in 253JB-V but not in UM-UC13 cells. Methylation-specific PCR revealed that the HSPA1A promoter was methylated in the HSPA1A(low) cell lines (UM-UC10 and UM-UC13), and exposure to the chromatin demethylating agent 5-aza-2'-deoxycytidine restored HSPA1A expression. Overexpression of Hsp72 promoted bortezomib resistance in the UM-UC10 and UM-UC13 cells, whereas transient knockdown of HSPA1B further sensitized these cells to bortezomib, and exposure to the chemical HSF1 inhibitor KNK-437 promoted bortezomib sensitivity in the 253J B-V cells. Finally, shRNA-mediated stable knockdown of Hsp72 in 253J B-V promoted sensitivity to bortezomib in vitro and in tumor xenografts in vivo. Together, our results provide proof-of-concept for using Hsp72 inhibitors to promote bortezomib sensitivity in bladder cancers and suggest that selective targeting of HSPA1B could produce synthetic lethality in tumors that display HSPA1A promoter methylation.

  6. Roles for Cell-Cell Adhesion and Contact in Obesity-Induced Hepatic Myeloid Cell Accumulation and Glucose Intolerance.

    PubMed

    Miyachi, Yasutaka; Tsuchiya, Kyoichiro; Komiya, Chikara; Shiba, Kumiko; Shimazu, Noriko; Yamaguchi, Shinobu; Deushi, Michiyo; Osaka, Mizuko; Inoue, Kouji; Sato, Yuta; Matsumoto, Sayaka; Kikuta, Junichi; Wake, Kenjiro; Yoshida, Masayuki; Ishii, Masaru; Ogawa, Yoshihiro

    2017-03-14

    Obesity promotes infiltration of inflammatory cells into various tissues, leading to parenchymal and stromal cell interaction and development of cellular and organ dysfunction. Liver sinusoidal endothelial cells (LSECs) are the first cells that contact portal blood cells and substances in the liver, but their functions in the development of obesity-associated glucose metabolism remain unclear. Here, we find that LSECs are involved in obesity-associated accumulation of myeloid cells via VLA-4-dependent cell-cell adhesion. VLA-4 blockade in mice fed a high-fat diet attenuated myeloid cell accumulation in the liver to improve hepatic inflammation and systemic glucose intolerance. Ex vivo studies further show that cell-cell contact between intrahepatic leukocytes and parenchymal hepatocytes induces gluconeogenesis via a Notch-dependent pathway. These findings suggest that cell-cell interaction between parenchymal and stromal cells regulates hepatic glucose metabolism and offers potential strategies for treatment or prevention of obesity-associated glucose intolerance.

  7. Sphingosine kinase-1 mediates androgen-induced osteoblast cell growth

    SciTech Connect

    Martin, Claire; Lafosse, Jean-Michel; Malavaud, Bernard; Cuvillier, Olivier

    2010-01-01

    Herein we report that the lipid kinase sphingosine kinase-1 (SphK1) is instrumental in mediating androgen-induced cell proliferation in osteoblasts. Dihydrotestosterone (DHT) triggered cell growth in steroid-deprived MC3T3 cells, which was associated with a rapid stimulation of SphK1 and activation of both Akt and ERK signaling pathways. This mechanism relied on functional androgen receptor/PI3K/Akt nongenotropic signaling as pharmacological antagonists could block SphK1 stimulation by DHT and its consequences. Finally, SphK1 inhibition not only abrogated DHT-induced ERK activation but also blocked cell proliferation, while ERK inhibition had no impact, suggesting that SphK1 was critical for DHT signaling yet independently of the ERK.

  8. Functional inactivation of Rb sensitizes cancer cells to TSC2 inactivation induced cell death.

    PubMed

    Danos, Arpad M; Liao, Yang; Li, Xuan; Du, Wei

    2013-01-01

    We showed previously that inactivation of TSC2 induces death in cancer cells lacking the Retinoblastoma (Rb) tumor suppressor under stress conditions, suggesting that inactivation of TSC2 can potentially be used as an approach to specifically kill cancers that have lost WT Rb. As Rb is often inactivated in cancers by overexpression of cyclin D1, loss of p16(ink4a) cdk inhibitor, or expression of viral oncoproteins, it will be interesting to determine if such functional inactivation of Rb would similarly sensitize cancer cells to TSC2 inactivation induced cell death. In addition, many cancers lack functional Pten, resulting in increased PI3K/Akt signaling that has been shown to modulate E2F-induced cell death. Therefore it will be interesting to test whether loss of Pten will affect TSC2 inactivation induced killing of Rb mutant cancer cells. Here, we show that overexpression of Cyclin D1 or the viral oncogene E1a sensitizes cancer cells to TSC2 knockdown induced cell death and growth inhibition. On the other hand, knockdown of p16(ink4a) sensitizes cancer cells to TSC2 knockdown induced cell death in a manner that is likely dependant on serum induction of Cyclin D1 to inactivate the Rb function. Additionally, we demonstrate that loss of Pten does not interfere with TSC2 knockdown induced cell death in Rb mutant cancer cells. Together, these results suggest that TSC2 is potentially a useful target for a large spectrum of cancer types with an inactivated Rb pathway.

  9. Recent Advances in Therapeutic Applications of Induced Pluripotent Stem Cells.

    PubMed

    Rami, Farzaneh; Beni, Shamsi Naderi; Kahnamooi, Mahboobeh Mojaver; Rahimmanesh, Ilnaz; Salehi, Ahmad Reza; Salehi, Rasoul

    2017-04-01

    Induced pluripotent stem (iPS) cells are generated by reprogramming of differentiated somatic cells. These cells are identical to human embryonic stem cells (hESCs) in gene expression pattern and the ability to differentiate. iPS cells can be used in in vitro modeling of diseases, testing drugs, assessing gene therapy methods, and cell therapy. Yet, the most important and promising application of iPS cells is in regenerative medicine. Regenerative medicine is a novel area in medicine aiming at the treatment of impaired or lost tissues by replacing them with functional and healthy ones. Currently, organ transplantation, which is considered the only treatment and cure for a number of diseases, is limited by shortage of organ donors and availability of the right match. Therefore, utilization of an alternative source of cells and tissues is critical in transplantation therapy. In this study, we review recent advances in therapeutic application of iPS cells in diseases where organ transplantation remains the only solution and will discuss the potential and usage of iPS cells in different areas of regenerative medicine. The primary theory of using iPS cells in regenerative medicine has brought lots of promises due to its potential for solving the immunological, social, and ethical problems of using ESCs. Nevertheless, several issues and problems have to be resolved before applying iPS cells in therapeutic applications.

  10. The tricyclic antidepressant imipramine induces autophagic cell death in U-87MG glioma cells.

    PubMed

    Jeon, Seung-Hyun; Kim, Se Hyun; Kim, Yeni; Kim, Yong Sik; Lim, Yoongho; Lee, Young Han; Shin, Soon Young

    2011-09-23

    In this study, we investigated the antitumor effects of the tricyclic antidepressant 3-(10,11-dihydro-5H-dibenzo[b,f]azepin-5-yl)-N,N-dimethylpropan-1-amine (imipramine) on glioma cells. We found that exposure of U-87MG cells to imipramine resulted in the inhibition of PI3K/Akt/mTOR signaling, reduction of clonogenicity, and induction of cell death. Imipramine stimulated the formation of acidic vesicular organelles, the conversion of LC3-I to LC3-II, and the redistribution of LC3 to autophagosomes, suggesting that it stimulates the progression of autophagy. It did not, however, induce apoptosis. We further showed that knockdown of Beclin-1 using siRNA abrogated imipramine-induced cell death. These results suggest that imipramine exerts antitumor effects on PTEN-null U-87MG human glioma cells by inhibiting PI3K/Akt/mTOR signaling and by inducing autophagic cell death.

  11. Ultraviolet-induced cell death is independent of DNA replication in rat kangaroo cells.

    PubMed

    Miyaji, E N; Menck, C F

    1995-05-01

    Rat kangaroo (Potorous tridactylus) cells have an efficient repair system for photoreactivation of lethal lesions induced by 254 nm UV. However, this ability is lost with increasing time after UV, being completely ineffective after 24 h. Critical events leading to UV-induced cell death must occur within this period of time. DNA synthesis was inhibited by the DNA polymerase inhibitor aphidicolin and the loss of the capability to photorepair lethal lesions was maintained as for replicating cells. Similar data were obtained in synchronized cells UV irradiated immediately before S phase. Under the same conditions, the ability to remove cyclobutane pyrimidine dimers by photoreactivation in these cells remained unchanged 24 h after irradiation. These data indicate that the critical events responsible for UV-induced cell death occur in the absence of DNA replication.

  12. A green-light inducible lytic system for cyanobacterial cells

    PubMed Central

    2014-01-01

    Background Cyanobacteria are an attractive candidate for the production of biofuel because of their ability to capture carbon dioxide by photosynthesis and grow on non-arable land. However, because huge quantities of water are required for cultivation, strict water management is one of the greatest issues in algae- and cyanobacteria-based biofuel production. In this study, we aim to construct a lytic cyanobacterium that can be regulated by a physical signal (green-light illumination) for future use in the recovery of biofuel related compounds. Results We introduced T4 bacteriophage-derived lysis genes encoding holin and endolysin under the control of the green-light regulated cpcG2 promoter in Synechocystis sp. PCC 6803. When cells harboring the lysis genes were illuminated with both red and green light, we observed a considerable decrease in growth rate, a significant increase in cellular phycocyanin released in the medium, and a considerable fraction of dead cells. These effects were not observed when these cells were illuminated with only red light, or when cells not containing the lysis genes were grown under either red light or red and green light. These results indicate that our constructed green-light inducible lytic system was clearly induced by green-light illumination, resulting in lytic cells that released intracellular phycocyanin into the culture supernatant. This property suggests a future possibility to construct photosynthetic genetically modified organisms that are unable to survive under sunlight exposure. Expression of the self-lysis system with green-light illumination was also found to greatly increase the fragility of the cell membrane, as determined by subjecting the induced cells to detergent, osmotic-shock, and freeze-thaw treatments. Conclusions A green-light inducible lytic system was constructed in Synechocystis sp. PCC 6803. The engineered lytic cyanobacterial cells should be beneficial for the recovery of biofuels and related compounds

  13. Salidroside induces cell-cycle arrest and apoptosis in human breast cancer cells

    SciTech Connect

    Hu, Xiaolan; Zhang, Xianqi; Qiu, Shuifeng; Yu, Daihua; Lin, Shuxin

    2010-07-16

    Research highlights: {yields} Salidroside inhibits the growth of human breast cancer cells. {yields} Salidroside induces cell-cycle arrest of human breast cancer cells. {yields} Salidroside induces apoptosis of human breast cancer cell lines. -- Abstract: Recently, salidroside (p-hydroxyphenethyl-{beta}-D-glucoside) has been identified as one of the most potent compounds isolated from plants of the Rhodiola genus used widely in traditional Chinese medicine, but pharmacokinetic data on the compound are unavailable. We were the first to report the cytotoxic effects of salidroside on cancer cell lines derived from different tissues, and we found that human breast cancer MDA-MB-231 cells (estrogen receptor negative) were sensitive to the inhibitory action of low-concentration salidroside. To further investigate the cytotoxic effects of salidroside on breast cancer cells and reveal possible ER-related differences in response to salidroside, we used MDA-MB-231 cells and MCF-7 cells (estrogen receptor-positive) as models to study possible molecular mechanisms; we evaluated the effects of salidroside on cell growth characteristics, such as proliferation, cell cycle duration, and apoptosis, and on the expression of apoptosis-related molecules. Our results demonstrated for the first time that salidroside induces cell-cycle arrest and apoptosis in human breast cancer cells and may be a promising candidate for breast cancer treatment.

  14. Phenylpropenoic Acid Glucoside from Rooibos Protects Pancreatic Beta Cells against Cell Death Induced by Acute Injury

    PubMed Central

    Himpe, Eddy; Cunha, Daniel A.; Song, Imane; Bugliani, Marco; Marchetti, Piero; Cnop, Miriam; Bouwens, Luc

    2016-01-01

    Objective Previous studies demonstrated that a phenylpropenoic acid glucoside (PPAG) from rooibos (Aspalathus linearis) extract had anti-hyperglycemic activity and significant protective effects on the pancreatic beta cell mass in a chronic diet-induced diabetes model. The present study evaluated the cytoprotective effect of the phytochemical on beta cells exposed to acute cell stress. Methods Synthetically prepared PPAG was administered orally in mice treated with a single dose of streptozotocin to acutely induce beta cell death and hyperglycemia. Its effect was assessed on beta cell mass, proliferation and apoptotic cell death. Its cytoprotective effect was also studied in vitro on INS-1E beta cells and on human pancreatic islet cells. Results Treatment with the phytochemical PPAG protected beta cells during the first days after the insult against apoptotic cell death, as evidenced by TUNEL staining, and prevented loss of expression of anti-apoptotic protein BCL2 in vivo. In vitro, PPAG protected INS-1E beta cells from streptozotocin-induced apoptosis and necrosis in a BCL2-dependent and independent way, respectively, depending on glucose concentration. PPAG also protected human pancreatic islet cells against the cytotoxic action of the fatty acid palmitate. Conclusions These findings show the potential use of PPAG as phytomedicine which protects the beta cell mass exposed to acute diabetogenic stress. PMID:27299564

  15. [Establishment of hemophilia A patient-specific inducible pluripotent stem cells with urine cells].

    PubMed

    Hu, Zhiqing; Hu, Xuyun; Pang, Jialun; Wang, Xiaolin; Lin Peng, Siyuan; Li, Zhuo; Wu, Yong; Wu, Lingqian; Liang, Desheng

    2015-10-01

    OBJECTIVE To generate hemophilia A (HA) patient-specific inducible pluripotent stem cells (iPSCs) and induce endothelial differentiation. METHODS Tubular epithelial cells were isolated and cultured from the urine of HA patients. The iPSCs were generated by forced expression of Yamanaka factors (Oct4, Sox2, c-Myc and Klf4) using retroviruses and characterized by cell morphology, pluripotent marker staining and in vivo differentiation through teratoma formation. Induced endothelial differentiation of the iPSCs was achieved with the OP9 cell co-culture method. RESULTS Patient-specific iPSCs were generated from urine cells of the HA patients, which could be identified by cell morphology, pluripotent stem cell surface marker staining and in vivo differentiation of three germ layers. The teratoma experiment has confirmed that such cells could differentiate into endothelial cells expressing the endothelial-specific markers CD144, CD31 and vWF. CONCLUSION HA patient-specific iPSCs could be generated from urine cells and can differentiate into endothelial cells. This has provided a new HA disease modeling approach and may serve as an applicable autologous cell source for gene correction and cell therapy studies for HA.

  16. CD4+ regulatory T cell responses induced by T cell vaccination in patients with multiple sclerosis

    PubMed Central

    Hong, Jian; Zang, Ying C. Q.; Nie, Hong; Zhang, Jingwu Z.

    2006-01-01

    Immunization with irradiated autologous T cells (T cell vaccination) is shown to induce regulatory T cell responses that are poorly understood. In this study, CD4+ regulatory T cell lines were generated from patients with multiple sclerosis that received immunization with irradiated autologous myelin basic protein-reactive T cells. The resulting CD4+ regulatory T cell lines had marked inhibition on autologous myelin basic protein-reactive T cells and displayed two distinctive patterns distinguishable by the expression of transcription factor Foxp3 and cytokine profile. The majority of the T cell lines had high Foxp3 expression and secreted both IFN-γ and IL-10 as compared with the other pattern characteristic of low Foxp3 expression and predominant production of IL-10 but not IFN-γ. CD4+ regulatory T cell lines of both patterns expressed CD25 and reacted with activated autologous T cells but not resting T cells, irrespective of antigen specificity of the target T cells. It was evident that they recognized preferentially a synthetic peptide corresponding to residues 61–73 of the IL-2 receptor α chain. T cell vaccination correlated with increased Foxp3 expression and T cell reactivity to peptide 61–73. The findings have important implications in the understanding of the role of CD4+ regulatory T cell response induced by T cell vaccination. PMID:16547138

  17. Monomethylarsonous acid induces transformation of human bladder cells

    SciTech Connect

    Bredfeldt, Tiffany G.; Jagadish, Bhumasamudram; Eblin, Kylee E.; Mash, Eugene A.; Gandolfi, A. Jay . E-mail: gandolfi@pharmacy.arizona.edu

    2006-10-01

    Arsenic is a human bladder carcinogen. Arsenic is methylated to both monomethyl and dimethyl metabolites which have been detected in human urine. The trivalent methylated arsenicals are more toxic than inorganic arsenic. It is unknown if these trivalent methylated metabolites can directly cause malignant transformation in human cells. The goal of this study is determine if monomethylarsonous acid (MMA{sup III}) can induce malignant transformation in a human bladder urothelial cell line. To address this goal, a non-tumorigenic human urothelial cell line (UROtsa) was continuously exposed to 0.05 {mu}M MMA{sup III} for 52 weeks. Hyperproliferation was the first phenotypic change observed in exposed UROtsa (URO-MSC). After 12 weeks of exposure, doubling time had decreased from 42 h in unexposed control cells to 27 h in URO-MSC. Hyperproliferation continued to be a quality possessed by the URO-MSC cells after both 24 and 52 weeks of exposure to MMA{sup III}, which had a 40-50% reduction in doubling time. Throughout the 52-week exposure, URO-MSC cells retained an epithelial morphology with subtle morphological differences from control cells. 24 weeks of MMA{sup III} exposure was required to induce anchorage-independent growth as detected by colony formation in soft agar, a characteristic not found in UROtsa cells. To further substantiate that malignant transformation had occurred, URO-MSC cells were tested after 24 and 52 weeks of exposure to MMA{sup III} for the ability to form tumors in SCID mice. Enhanced tumorigenicity in SCID mouse xenografts was observed after 52 weeks of treatment with MMA{sup III}. These observations are the first demonstration of MMA{sup III}-induced malignant transformation in a human bladder urothelial cell line and provide important evidence that MMA{sup III} may be carcinogenic in human tissues.

  18. Involvement of ROS in Curcumin-induced Autophagic Cell Death.

    PubMed

    Lee, Youn Ju; Kim, Nam-Yi; Suh, Young-Ah; Lee, Chuhee

    2011-02-01

    Many anticancer agents as well as ionizing radiation have been shown to induce autophagy which is originally described as a protein recycling process and recently reported to play a crucial role in various disorders. In HCT116 human colon cancer cells, we found that curcumin, a polyphenolic phytochemical extracted from the plant Curcuma longa, markedly induced the conversion of microtubule-associated protein 1 light chain 3 (LC3)-I to LC3-II and degradation of sequestome-1 (SQSTM1) which is a marker of autophagosome degradation. Moreover, we found that curcumin caused GFP-LC3 formation puncta, a marker of autophagosome, and decrease of GFP-LC3 and SQSTM1 protein level in GFP-LC3 expressing HCT116 cells. It was further confirmed that treatment of cells with hydrogen peroxide induced increase of LC3 conversion and decrease of GFP-LC3 and SQSTM1 levels, but these changes by curcumin were almost completely blocked in the presence of antioxidant, N-acetylcystein (NAC), indicating that curcumin leads to reactive oxygen species (ROS) production, which results in autophagosome development and autolysosomal degradation. In parallel with NAC, SQSTM1 degradation was also diminished by bafilomycin A, a potent inhibitor of autophagosome-lysosome fusion, and cell viability assay was further confirmed that cucurmin-induced cell death was partially blocked by bafilomycin A as well as NAC. We also observed that NAC abolished curcumin-induced activation of extracelluar signal-regulated kinases (ERK) 1/2 and p38 mitogen-activated protein kinases (MAPK), but not Jun N-terminal kinase (JNK). However, the activation of ERK1/2 and p38 MAPK seemed to have no effect on the curcumin-induced autophagy, since both the conversion of LC3 protein and SQSTM1 degradation by curcumin was not changed in the presence of NAC. Taken together, our data suggest that curcumin induced ROS production, which resulted in autophagic activation and concomitant cell death in HCT116 human colon cancer cell

  19. Involvement of ROS in Curcumin-induced Autophagic Cell Death

    PubMed Central

    Lee, Youn Ju; Kim, Nam-Yi; Suh, Young-Ah

    2011-01-01

    Many anticancer agents as well as ionizing radiation have been shown to induce autophagy which is originally described as a protein recycling process and recently reported to play a crucial role in various disorders. In HCT116 human colon cancer cells, we found that curcumin, a polyphenolic phytochemical extracted from the plant Curcuma longa, markedly induced the conversion of microtubule-associated protein 1 light chain 3 (LC3)-I to LC3-II and degradation of sequestome-1 (SQSTM1) which is a marker of autophagosome degradation. Moreover, we found that curcumin caused GFP-LC3 formation puncta, a marker of autophagosome, and decrease of GFP-LC3 and SQSTM1 protein level in GFP-LC3 expressing HCT116 cells. It was further confirmed that treatment of cells with hydrogen peroxide induced increase of LC3 conversion and decrease of GFP-LC3 and SQSTM1 levels, but these changes by curcumin were almost completely blocked in the presence of antioxidant, N-acetylcystein (NAC), indicating that curcumin leads to reactive oxygen species (ROS) production, which results in autophagosome development and autolysosomal degradation. In parallel with NAC, SQSTM1 degradation was also diminished by bafilomycin A, a potent inhibitor of autophagosome-lysosome fusion, and cell viability assay was further confirmed that cucurmin-induced cell death was partially blocked by bafilomycin A as well as NAC. We also observed that NAC abolished curcumin-induced activation of extracelluar signal-regulated kinases (ERK) 1/2 and p38 mitogen-activated protein kinases (MAPK), but not Jun N-terminal kinase (JNK). However, the activation of ERK1/2 and p38 MAPK seemed to have no effect on the curcumin-induced autophagy, since both the conversion of LC3 protein and SQSTM1 degradation by curcumin was not changed in the presence of NAC. Taken together, our data suggest that curcumin induced ROS production, which resulted in autophagic activation and concomitant cell death in HCT116 human colon cancer cell

  20. Differentiation state affects morphine induced cell regulation in neuroblastoma cultured cells.

    PubMed

    Fiore, Giovina; Ghelardini, Carla; Bruni, Giancarlo; Guarna, Massimo; Bianchi, Enrica

    2013-10-25

    Neuroblastoma (NB) is the most common extracranial solid cancer in childhood and the most common cancer in infancy. Our purpose was to investigate in vitro how cancer cell survival occurs in presence of morphine in undifferentiated and differentiated SHSY-5Y human neuroblastoma cultured cell line. Exposure of differentiated cells to morphine dose-dependently induced apoptosis in these cells through c-Jun N-terminal kinase (JNK)/caspase pathway. Otherwise, morphine induced activation for mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway, caused positive regulation of cell survival in undifferentiated cells. Therefore, cell differentiation state bimodally affects the cellular regulation activity triggered by morphine in isolated cultured neuroblastoma cells raising concerns about the application of morphine to this type of cancer patients.

  1. Vincristine sulfate-induced cell transformation, mitotic inhibition and aneuploidy in cultured Syrian hamster embryo cells

    SciTech Connect

    Tsutsui, T.; Suzuki, N.; Maizumi, H.; Barrett, J.C.

    1986-01-01

    Vincristine, a naturally occurring Vinca alkaloid and widely used anti-neoplastic agent, was examined for its ability to induce cell transformation, inhibition of growth and mitosis, and genetic effects in Syrian hamster embryo cells in culture. Treatment of the cells with doses of less than or equal to 1 ng/ml vincristine sulfate (VCR) had no effect on cell growth, while exposure to greater than or equal to 3 ng/ml reduced the growth rate and treatment with 30 ng/ml resulted in no detectable increase in cell number. At this latter dose the mitotic index of the cells increased significantly suggesting that VCR delayed completion of mitosis. Exposure of the cells to VCR at doses of 1-10 ng/ml for 48 h resulted in morphological transformation of the cells in a doserelated fashion. The vincristine-treated transformed colonies were morphologically indistinguishable from colonies transformed by benzo(a)pyrene or other chemical carcinogens. Morphological transformation was induced by VCR at non-toxic and slightly toxic doses as measured by a reduction in colony-forming ability of the treated cells. Over the dose range which resulted in cell transformation, VCR failed to induce either detectable gene mutations at two genetic loci, unscheduled DNA synthesis, or chromosome aberrations in the Syrian hamster embryo cells. However, a significant dose-dependent increase in aneuploid cells with a near-diploid chromosome number was induced by VCR. Both chromosome losses and gains were induced which is consistent with a non-disjunctional mechanism. These results further support our hypothesis that aneuploidy is one possible mechanism for induction of this early step in the neoplastic transformation of Syrian hamster embryo cells. Furthermore, these findings indicate that VCR may have some carcinogenic potential if exposure to rapidly dividing cells occurs.

  2. Late steps of parvoviral infection induce changes in cell morphology.

    PubMed

    Pakkanen, Kirsi; Nykky, Jonna; Vuento, Matti

    2008-11-01

    Previously, virus-induced non-filopodial extensions have not been encountered in connection with viral infections. Here, we report emergence of long extensions protruding from Norden laboratory feline kidney (NLFK) and A72 (canine fibroma) cells infected with canine parvovirus for 72 h. These extensions significantly differ in length and number from those appearing in control cells. The most striking feature in the extensions is the length, reaching up to 130 microm, almost twice the average length of a healthy NLFK cell. In A72 cells, the extensions were even longer, up to 200 microm. The results presented here also suggest that the events leading to the growth of these extensions start earlier in infection and abnormal extension growth is detectable already at 24-h post-infection (p.i.). These extensions may have a vital role in the cell-to-cell transmission of the virus.

  3. Induced pluripotent stem cells: a new revolution for clinical neurology?

    PubMed

    Mattis, Virginia B; Svendsen, Clive N

    2011-04-01

    Why specific neuronal populations are uniquely susceptible in neurodegenerative diseases remains a mystery. Brain tissue samples from patients are rarely available for testing, and animal models frequently do not recapitulate all features of a specific disorder; therefore, pathophysiological investigations are difficult. An exciting new avenue for neurological research and drug development is the discovery that patients' somatic cells can be reprogrammed to a pluripotent state; these cells are known as induced pluripotent stem cells. Once pluripotency is reinstated, cell colonies can be expanded and differentiated into specific neural populations. The availability of these cells enables the monitoring in vitro of temporal features of disease initiation and progression, and testing of new drug treatments on the patient's own cells. Hence, this swiftly growing area of research has the potential to contribute greatly to our understanding of the pathophysiology of neurodegenerative and neurodevelopmental diseases.

  4. Antithymocyte Globulin Induces a Tolerogenic Phenotype in Human Dendritic Cells

    PubMed Central

    Roider, Tobias; Katzfuß, Michael; Matos, Carina; Singer, Katrin; Renner, Kathrin; Oefner, Peter J.; Dettmer-Wilde, Katja; Herr, Wolfgang; Holler, Ernst; Kreutz, Marina; Peter, Katrin

    2016-01-01

    Antithymocyte globulin (ATG) is used in the prevention of graft-versus-host disease during allogeneic hematopoietic stem cell transplantation. It is generally accepted that ATG mediates its immunosuppressive effect primarily via depletion of T cells. Here, we analyzed the impact of ATG-Fresenius (now Grafalon®) on human monocyte-derived dendritic cells (DC). ATG induced a semi-mature phenotype in DC with significantly reduced expression of CD14, increased expression of HLA-DR, and intermediate expression of CD54, CD80, CD83, and CD86. ATG-DC showed an increase in IL-10 secretion but no IL-12 production. In line with this tolerogenic phenotype, ATG caused a significant induction of indoleamine 2,3-dioxygenase expression and a concomitant increase in levels of tryptophan metabolites in the supernatants of DC. Further, ATG-DC did not induce the proliferation of allogeneic T cells in a mixed lymphocyte reaction but actively suppressed the T cell proliferation induced by mature DC. These data suggest that besides its well-known effect on T cells, ATG modulates the phenotype of DC in a tolerogenic way, which might constitute an essential part of its immunosuppressive action in vivo. PMID:27973435

  5. Interferon-inducible GTPases in cell autonomous and innate immunity.

    PubMed

    Meunier, Etienne; Broz, Petr

    2016-02-01

    Detection and clearance of invading pathogens requires a coordinated response of the adaptive and innate immune system. Host cell, however, also features different mechanisms that restrict pathogen replication in a cell-intrinsic manner, collectively referred to as cell-autonomous immunity. In immune cells, the ability to unleash those mechanisms strongly depends on the activation state of the cell, which is controlled by cytokines or the detection of pathogen-associated molecular patterns by pattern-recognition receptors. The interferon (IFN) class of cytokines is one of the strongest inducers of antimicrobial effector mechanisms and acts against viral, bacterial and parasitic intracellular pathogens. This has been linked to the upregulation of several hundreds of IFN-stimulated genes, among them the so-called IFN-inducible GTPases. Two subfamilies of IFN-inducible GTPases, the immunity-related GTPases (IRGs) and the guanylate-binding proteins (GBPs), have gained attention due to their exceptional ability to specifically target intracellular vacuolar pathogens and restrict their replication by destroying their vacuolar compartment. Their repertoire has recently been expanded to the regulation of inflammasome complexes, which are cytosolic multi-protein complexes that control an inflammatory cell death called pyroptosis and the release of cytokines like interleukin-1β and interleukin-18. Here we discuss recent advances in understanding the function, the targeting and regulation of IRG and GBP proteins during microbial infections.

  6. Lipopolysaccharide induces autotaxin expression in human monocytic THP-1 cells

    SciTech Connect

    Li Song; Zhang Junjie

    2009-01-09

    Autotaxin (ATX) is a secreted enzyme with lysophospholipase D (lysoPLD) activity, which converts lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA), a bioactive phospholipid involved in numerous biological activities, including cell proliferation, differentiation, and migration. In the present study, we found that bacterial lipopolysaccharide (LPS), a well-known initiator of the inflammatory response, induced ATX expression in monocytic THP-1 cells. The activation of PKR, JNK, and p38 MAPK was required for the ATX induction. The LPS-induced ATX in THP-1 cells was characterized as the {beta} isoform. In the presence of LPC, ATX could promote the migrations of THP-1 and Jurkat cells, which was inhibited by pertussis toxin (PTX), an inhibitor of Gi-mediated LPA receptor signaling. In summary, LPS induces ATX expression in THP-1 cells via a PKR, JNK and p38 MAPK-mediated mechanism, and the ATX induction is likely to enhance immune cell migration in proinflammatory response by regulating LPA levels in the microenvironment.

  7. Idelalisib induces PUMA-dependent apoptosis in colon cancer cells

    PubMed Central

    Yang, Shida; Zhu, Zhiyong; Zhang, Xiaobing; Zhang, Ning; Yao, Zhicheng

    2017-01-01

    Idelalisib, a PI3K inhibitor, specifically targeting p110δ, has been approved for the treatment of chronic lymphocytic leukemia/small lymphocytic lymphoma and follicular lymphoma. However, the mechanisms of action of idelalisib in colon cancer cells are not well understood. We investigated how idelalisib suppresses colon cancer cells growth and potentiates effects of other chemotherapeutic drugs. In this study, we found that idelalisib treatment induces PUMA in colon cancer cells irrespective of p53 status through the p65 pathway following AKT inhibition and glycogen synthase kinase 3β (GSK3β) activation. PUMA is necessary for idelalisib-induced apoptosis in colon cancer cells. Idelalisib also synergized with 5-FU or regorafenib to induce marked apoptosis via PUMA in colon cancer cells. Furthermore, PUMA deficiency suppressed apoptosis and antitumor effect of idelalisib in xenograft model. These results demonstrate a critical role of PUMA in mediating the anticancer effects of idelalisib in colon cancer cells and suggest that PUMA induction can be used as an indicator of idelalisib sensitivity, and also have important implications for it clinical applications. PMID:28008149

  8. Idelalisib induces PUMA-dependent apoptosis in colon cancer cells.

    PubMed

    Yang, Shida; Zhu, Zhiyong; Zhang, Xiaobing; Zhang, Ning; Yao, Zhicheng

    2017-01-24

    Idelalisib, a PI3K inhibitor, specifically targeting p110δ, has been approved for the treatment of chronic lymphocytic leukemia/small lymphocytic lymphoma and follicular lymphoma. However, the mechanisms of action of idelalisib in colon cancer cells are not well understood. We investigated how idelalisib suppresses colon cancer cells growth and potentiates effects of other chemotherapeutic drugs. In this study, we found that idelalisib treatment induces PUMA in colon cancer cells irrespective of p53 status through the p65 pathway following AKT inhibition and glycogen synthase kinase 3β (GSK3β) activation. PUMA is necessary for idelalisib-induced apoptosis in colon cancer cells. Idelalisib also synergized with 5-FU or regorafenib to induce marked apoptosis via PUMA in colon cancer cells. Furthermore, PUMA deficiency suppressed apoptosis and antitumor effect of idelalisib in xenograft model. These results demonstrate a critical role of PUMA in mediating the anticancer effects of idelalisib in colon cancer cells and suggest that PUMA induction can be used as an indicator of idelalisib sensitivity, and also have important implications for it clinical applications.

  9. Viral infection induces cytokine release by beta islet cells.

    PubMed Central

    Cavallo, M G; Baroni, M G; Toto, A; Gearing, A J; Forsey, T; Andreani, D; Thorpe, R; Pozzilli, P

    1992-01-01

    Viral infection has been suggested to play a triggering role in the pancreatic beta cell destruction which occurs in insulin-dependent diabetes (IDDM). However, the underlying mechanism of this phenomenon is unknown. In this study a human insulinoma cell line has been infected with measles, mumps and rubella viruses since a temporal association is reported between the clinical onset of IDDM and diseases caused by these viruses. The infection with measles and mumps viruses induced the release of interleukin-1 (IL-1) and interleukin-6 (IL-6) by the cell line as assessed by a bioassay and up-regulated the expression of human leucocyte antigen (HLA) class I and class II antigens as evaluated by cytofluorimetric analysis. Stimulation with rubella virus induced the release of IL-6 only and had no effect on HLA antigen expression. These data show for the first time that IL-1 and IL-6 secretion by an insulinoma cell line may occur after viral infection and suggest that cytokine release and increased expression of HLA molecules by beta cells may act to induce the immune response towards beta cells in IDDM. PMID:1592439

  10. Stress-induced cleavage of Myc promotes cancer cell survival

    PubMed Central

    Conacci-Sorrell, Maralice; Ngouenet, Celine; Anderson, Sarah; Brabletz, Thomas; Eisenman, Robert N.

    2014-01-01

    Evasion of apoptosis is critical in Myc-induced tumor progression. Here we report that cancer cells evade death under stress by activating calpain-mediated proteolysis of Myc. This generates Myc-nick, a cytoplasmic, transcriptionally inactive cleavage product of Myc. We found conversion of Myc into Myc-nick in cell lines and tissues derived from multiple cancers. In colon cancer, the production of Myc-nick is enhanced under stress conditions such as hypoxia and nutrient deprivation. Under these conditions, ectopic expression of Myc-nick promotes anchorage-independent growth and cell survival at least in part by promoting autophagy. Myc-nick also delays colon cancer cell death after treatment with chemotherapeutic drugs such as etoposide, cisplatin, and imatinib. Furthermore, colon cancer cells expressing a cleavage-resistant form of Myc undergo extensive apoptosis but are rescued by overexpression of Myc-nick. We also found that ectopic expression of Myc-nick results in the induction of the actin-bundling protein fascin, formation of filopodia, and increased cell motility—all mediators of tumor metastasis. Myc-nick-induced survival, autophagy, and motility require Myc box II (MBII), a region of Myc-nick that recruits acetyltransferases that in turn modify cytoplasmic proteins, including α-tubulin and ATG3. Our results suggest that Myc-nick-induced survival and motility contribute to colon cancer progression and metastasis. PMID:24696454

  11. Fractalkine-induced smooth muscle cell proliferation in pulmonary hypertension.

    PubMed

    Perros, F; Dorfmüller, P; Souza, R; Durand-Gasselin, I; Godot, V; Capel, F; Adnot, S; Eddahibi, S; Mazmanian, M; Fadel, E; Hervé, P; Simonneau, G; Emilie, D; Humbert, M

    2007-05-01

    Pulmonary hypertension is characterised by a progressive increase in pulmonary arterial resistance due to endothelial and smooth muscle cell proliferation resulting in chronic obstruction of small pulmonary arteries. There is evidence that inflammatory mechanisms may contribute to the pathogenesis of human and experimental pulmonary hypertension. The aim of the study was to address the role of fractalkine (CX3CL1) in the inflammatory responses and pulmonary vascular remodelling of a monocrotaline-induced pulmonary hypertension model. The expression of CX3CL1 and its receptor CX3CR1 was studied in monocrotaline-induced pulmonary hypertension by means of immunohistochemistry and quantitative reverse-transcription PCR on laser-captured microdissected pulmonary arteries. It was demonstrated that CX3CL1 was expressed by inflammatory cells surrounding pulmonary arterial lesions and that smooth muscle cells from these vessels had increased CX3CR1 expression. It was then shown that cultured rat pulmonary artery smooth muscle cells expressed CX3CR1 and that CX3CL1 induced proliferation but not migration of these cells. In conclusion, the current authors proposed that fractalkine may act as a growth factor for pulmonary artery smooth muscle cells. Chemokines may thus play a role in pulmonary artery remodelling.

  12. Cytoprotective effects of fisetin against hypoxia-induced cell death in PC12 cells.

    PubMed

    Chen, Pei-Yi; Ho, Yi-Ru; Wu, Ming-Jiuan; Huang, Shun-Ping; Chen, Po-Kong; Tai, Mi-Hsueh; Ho, Chi-Tang; Yen, Jui-Hung

    2015-01-01

    Fisetin (3,7,3',4'-tetrahydroxyflavone), a flavonol compound of flavonoids, exhibits a broad spectrum of biological activities including anti-oxidant, anti-inflammatory, anti-cancer and neuroprotective effects. The aim of this study is to investigate the cytoprotective effect of fisetin and the underlying molecular mechanism against hypoxia-induced cell death in PC12 cells. The results of this study showed that fisetin significantly restored the cell viability of PC12 cells under both cobalt chloride (CoCl₂)- and low oxygen-induced hypoxic conditions. Treatment with fisetin successfully reduced the CoCl₂-mediated reactive oxygen species (ROS) production, which was accompanied by an increase in the cell viability of PC12 cells. Furthermore, we found that treatment of PC12 cells with fisetin markedly upregulated hypoxia-inducible factor 1α (HIF-1α), its nuclear accumulation and the hypoxia-response element (HRE)-driven transcriptional activation. The fisetin-mediated cytoprotection during CoCl₂ exposure was significantly attenuated through the administration of HIF-1α siRNA. Moreover, we demonstrated that MAPK/ERK kinase 1/2 (MEK1/2), p38 MAPK and phosphatidylinositol 3-kinase (PI3 K) inhibitors significantly blocked the increase in cell survival that was induced by fisetin treatment under hypoxic conditions. Consistently, increased phosphorylation of ERK, p38 and Akt proteins was observed in PC12 cells treated with fisetin. However, the fisetin-induced HRE-driven transcription was not affected by inhibition of these kinase signaling pathways. Current results reveal for the first time that fisetin promotes cell survival and protects against hypoxia-induced cell death through ROS scavenging and the activation of HIF1α-, MAPK/ERK-, p38 MAPK- and PI3 K/Akt-dependent signaling pathways in PC12 cells.

  13. Generation of colonies of induced trophoblast cells during standard reprogramming of porcine fibroblasts to induced pluripotent stem cells.

    PubMed

    Ezashi, Toshihiko; Matsuyama, Haruyo; Telugu, Bhanu Prakash V L; Roberts, R Michael

    2011-10-01

    During reprogramming of porcine mesenchymal cells with a four-factor (POU5F1/SOX2/KLF4/MYC) mixture of vectors, a fraction of the colonies had an atypical phenotype and arose earlier than the recognizable porcine induced pluripotent stem (iPS) cell colonies. Within days after each passage, patches of cells with an epithelial phenotype formed raised domes, particularly under 20% O(2) conditions. Relative to gene expression of the iPS cells, there was up-regulation of genes for transcription factors associated with trophoblast (TR) lineage emergence, e.g., GATA2, PPARG, MSX2, DLX3, HAND1, GCM1, CDX2, ID2, ELF5, TCFAP2C, and TEAD4 and for genes required for synthesis of products more typical of differentiated TR, such as steroids (HSD17B1, CYP11A1, and STAR), pregnancy-associated glycoproteins (PAG6), and select cytokines (IFND, IFNG, and IL1B). Although POU5F1 was down-regulated relative to that in iPS cells, it was not silenced in the induced TR (iTR) cells over continued passage. Like iPS cells, iTR cells did not senesce on extended passage and displayed high telomerase activity. Upon xenografting into immunodeficient mice, iTR cells formed nonhemorrhagic teratomas composed largely of layers of epithelium expressing TR markers. When cultured under conditions that promoted embryoid body formation, iTR cells formed floating spheres consisting of a single epithelial sheet whose cells were tethered laterally by desmosome-like structures. In conclusion, reprogramming of porcine fibroblasts to iPS cells generates, as a by-product, colonies composed of self-renewing populations of TR cells, possibly containing TR stem cells.

  14. Cell transplantation therapies for spinal cord injury focusing on induced pluripotent stem cells.

    PubMed

    Nakamura, Masaya; Okano, Hideyuki

    2013-01-01

    Stimulated by the 2012 Nobel Prize in Physiology or Medicine awarded for Shinya Yamanaka and Sir John Gurdon, there is an increasing interest in the induced pluripotent stem (iPS) cells and reprograming technologies in medical science. While iPS cells are expected to open a new era providing enormous opportunities in biomedical sciences in terms of cell therapies and regenerative medicine, safety-related concerns for iPS cell-based cell therapy should be resolved prior to the clinical application of iPS cells. In this review, the pre-clinical investigations of cell therapy for spinal cord injury (SCI) using neural stem/progenitor cells derived from iPS cells, and their safety issues in vivo, are outlined. We also wish to discuss the strategy for the first human trails of iPS cell-based cell therapy for SCI patients.

  15. [Mechanisms of gamma-inducible death of Jurkat cells line].

    PubMed

    Gamkrelidze, M M; Bezhitashvili, N D; Pavliashvili, A T; Mchedlishvili, T V; Sanikidze, T V

    2008-06-01

    Mechanisms of radio-inducible death of Jurkat cells were investigated. Human lymphoblastoid T-cell line Jurkat is widely established model for studying apoptosis mechanisms. The cell was radiated by "Teragam" (Czech Republic) by dose 2 g during 1 minute. After radiation cells were incubated at standard conditions during 24 hours. After gamma radiation in cell population amount of cells in gaplois (apoptotic G 0) stage was increased 8,2 folds, in diplois (G 0/G1) stage - by 17%, in synthetic (S) stage decreased by 35% and tetraploid (G2/M) stage by 73% in comparison to control group. It was revealed intensive production of free radicals of oxygen and nitric oxide and decreasing activity of antioxidant enzymes (superoxidismutasa, catalasa and glutathione peroxidase). Revealed dependence between intensification of apoptosis and radiation-induced arrest of cell cycle G2/M phase may be determined by excess amount of free oxygen and nitrogen radicals generated in Jurkat cells as a result of nondirect effects of low doses of gamma radiation.

  16. Mercury induces inflammatory mediator release from human mast cells

    PubMed Central

    2010-01-01

    Background Mercury is known to be neurotoxic, but its effects on the immune system are less well known. Mast cells are involved in allergic reactions, but also in innate and acquired immunity, as well as in inflammation. Many patients with Autism Spectrum Disorders (ASD) have "allergic" symptoms; moreover, the prevalence of ASD in patients with mastocytosis, characterized by numerous hyperactive mast cells in most tissues, is 10-fold higher than the general population suggesting mast cell involvement. We, therefore, investigated the effect of mercuric chloride (HgCl2) on human mast cell activation. Methods Human leukemic cultured LAD2 mast cells and normal human umbilical cord blood-derived cultured mast cells (hCBMCs) were stimulated by HgCl2 (0.1-10 μM) for either 10 min for beta-hexosaminidase release or 24 hr for measuring vascular endothelial growth factor (VEGF) and IL-6 release by ELISA. Results HgCl2 induced a 2-fold increase in β-hexosaminidase release, and also significant VEGF release at 0.1 and 1 μM (311 ± 32 pg/106 cells and 443 ± 143 pg/106 cells, respectively) from LAD2 mast cells compared to control cells (227 ± 17 pg/106 cells, n = 5, p < 0.05). Addition of HgCl2 (0.1 μM) to the proinflammatory neuropeptide substance P (SP, 0.1 μM) had synergestic action in inducing VEGF from LAD2 mast cells. HgCl2 also stimulated significant VEGF release (360 ± 100 pg/106 cells at 1 μM, n = 5, p < 0.05) from hCBMCs compared to control cells (182 ± 57 pg/106 cells), and IL-6 release (466 ± 57 pg/106 cells at 0.1 μM) compared to untreated cells (13 ± 25 pg/106 cells, n = 5, p < 0.05). Addition of HgCl2 (0.1 μM) to SP (5 μM) further increased IL-6 release. Conclusions HgCl2 stimulates VEGF and IL-6 release from human mast cells. This phenomenon could disrupt the blood-brain-barrier and permit brain inflammation. As a result, the findings of the present study provide a biological mechanism for how low levels of mercury may contribute to ASD

  17. Metabolic Stress Induced by Arginine Deprivation Induces Autophagy Cell Death in Prostate Cancer

    DTIC Science & Technology

    2011-08-01

    arginine deiminase W81XWH-08-1-0385 1 AUG 2010 - 31 JUL 2011Annual01-08-2011 University of California, Davis Davis, CA 95618 Metabolic Stress Induced...J Coates, T Bowles, J Sutcliffe, R Jung, R Gandour-Edwards, R Bold, HJ Kung. Arginine deiminase : a novel therapy for prostate cancer and a tool to...R Jung, R Gandour-Edwards, R Bold, HJ Kung. Arginine deiminase induces autophagic cell death in human prostate cancer. EMBO Conference: Autophagy

  18. Induced Pluripotent Stem Cells: Challenges and Opportunities for Cancer Immunotherapy

    PubMed Central

    Sachamitr, Patty; Hackett, Simon; Fairchild, Paul Jonathan

    2014-01-01

    Despite recent advances in cancer treatment over the past 30 years, therapeutic options remain limited and do not always offer a cure for malignancy. Given that tumor-associated antigens (TAA) are, by definition, self-proteins, the need to productively engage autoreactive T cells remains at the heart of strategies for cancer immunotherapy. These have traditionally focused on the administration of autologous monocyte-derived dendritic cells (moDC) pulsed with TAA, or the ex vivo expansion and adoptive transfer of tumor-infiltrating lymphocytes (TIL) as a source of TAA-specific cytotoxic T cells (CTL). Although such approaches have shown some efficacy, success has been limited by the poor capacity of moDC to cross present exogenous TAA to the CD8+ T-cell repertoire and the potential for exhaustion of CTL expanded ex vivo. Recent advances in induced pluripotency offer opportunities to generate patient-specific stem cell lines with the potential to differentiate in vitro into cell types whose properties may help address these issues. Here, we review recent success in the differentiation of NK cells from human induced pluripotent stem (iPS) cells as well as minor subsets of dendritic cells (DCs) with therapeutic potential, including CD141+XCR1+ DC, capable of cross presenting TAA to naïve CD8+ T cells. Furthermore, we review recent progress in the use of TIL as the starting material for the derivation of iPSC lines, thereby capturing their antigen specificity in a self-renewing stem cell line, from which potentially unlimited numbers of naïve TAA-specific T cells may be differentiated, free of the risks of exhaustion. PMID:24860566

  19. URI prevents potassium dichromate-induced oxidative stress and cell death in gastric cancer cells

    PubMed Central

    Luo, Dongwei; Xu, Zhonghai; Hu, Xiaoxia; Zhang, Fei; Bian, Huiqin; Li, Na; Wang, Qian; Lu, Yaojuan; Zheng, Qiping; Gu, Junxia

    2016-01-01

    Chromium VI can provoke oxidative stress, DNA damage, cytotoxicity, mutagenesis and carcinogenesis. Aberrantly high level of reactive oxygen species (ROS) has been associated with oxidative stress and subsequent DNA damage. Notably, multiple previous studies have shown the increased level of ROS in chromium (VI) induced oxidative stress, but its effect on cell death and the underlying mechanism remain to be determined. In this study, we aimed to investigate the role of URI, an unconventional prefoldin RBP5 interactor, in potassium dichromate induced oxidative stress and cell death through in vitro loss-of-function studies. We have shown that knockdown of URI in human gastric cancer SGC-7901 cells by URI siRNA enhanced potassium dichromate-induced production of ROS. The level of rH2AX, a marker of DNA damage, was significantly increased, along with a reduced cell viability in URI siRNA treated cells that were also exposed to potassium dichromate. Comet assay showed that URI knockdown increased the tail moment in potassium dichromate-treated SGC-7901 cells. Accordingly, the cell rates of apoptosis and necrosis were also increased in URI knockdown cells treated with potassium dichromate at different concentrations. Together, these results suggest that URI is preventive for the oxidative stress and cell death induced by potassium dichromate, which potentially leads to cancer cell survival and therapeutic resistance. PMID:28078011

  20. Tumourigenicity and Immunogenicity of Induced Neural Stem Cell Grafts Versus Induced Pluripotent Stem Cell Grafts in Syngeneic Mouse Brain

    PubMed Central

    Gao, Mou; Yao, Hui; Dong, Qin; Zhang, Hongtian; Yang, Zhijun; Yang, Yang; Zhu, Jianwei; Xu, Minhui; Xu, Ruxiang

    2016-01-01

    Along with the development of stem cell-based therapies for central nervous system (CNS) disease, the safety of stem cell grafts in the CNS, such as induced pluripotent stem cells (iPSCs) and induced neural stem cells (iNSCs), should be of primary concern. To provide scientific basis for evaluating the safety of these stem cells, we determined their tumourigenicity and immunogenicity in syngeneic mouse brain. Both iPSCs and embryonic stem cells (ESCs) were able to form tumours in the mouse brain, leading to tissue destruction along with immune cell infiltration. In contrast, no evidence of tumour formation, brain injury or immune rejection was observed with iNSCs, neural stem cells (NSCs) or mesenchymal stem cells (MSCs). With the help of gene ontology (GO) enrichment analysis, we detected significantly elevated levels of chemokines in the brain tissue and serum of mice that developed tumours after ESC or iPSC transplantation. Moreover, we also investigated the interactions between chemokines and NF-κB signalling and found that NF-κB activation was positively correlated with the constantly rising levels of chemokines, and vice versa. In short, iNSC grafts, which lacked any resulting tumourigenicity or immunogenicity, are safer than iPSC grafts. PMID:27417157

  1. PTPN2 attenuates T-cell lymphopenia-induced proliferation

    NASA Astrophysics Data System (ADS)

    Wiede, Florian; La Gruta, Nicole L.; Tiganis, Tony

    2014-01-01

    When the peripheral T-cell pool is depleted, T cells undergo homoeostatic expansion. This expansion is reliant on the recognition of self-antigens and/or cytokines, in particular interleukin-7. The T cell-intrinsic mechanisms that prevent excessive homoeostatic T-cell responses and consequent overt autoreactivity remain poorly defined. Here we show that protein tyrosine phosphatase N2 (PTPN2) is elevated in naive T cells leaving the thymus to restrict homoeostatic T-cell proliferation and prevent excess responses to self-antigens in the periphery. PTPN2-deficient CD8+ T cells undergo rapid lymphopenia-induced proliferation (LIP) when transferred into lymphopenic hosts and acquire the characteristics of antigen-experienced effector T cells. The enhanced LIP is attributed to elevated T-cell receptor-dependent, but not interleukin-7-dependent responses, results in a skewed T-cell receptor repertoire and the development of autoimmunity. Our results identify a major mechanism by which homoeostatic T-cell responses are tuned to prevent the development of autoimmune and inflammatory disorders.

  2. Glutathione-Induced Calcium Shifts in Chick Retinal Glial Cells

    PubMed Central

    Freitas, Hercules R.; Ferraz, Gabriel; Ferreira, Gustavo C.; Ribeiro-Resende, Victor T.; Chiarini, Luciana B.; do Nascimento, José Luiz M.; Matos Oliveira, Karen Renata H.; Pereira, Tiago de Lima; Ferreira, Leonardo G. B.; Kubrusly, Regina C.; Faria, Robson X.

    2016-01-01

    Neuroglia interactions are essential for the nervous system and in the retina Müller cells interact with most of the neurons in a symbiotic manner. Glutathione (GSH) is a low-molecular weight compound that undertakes major antioxidant roles in neurons and glia, however, whether this compound could act as a signaling molecule in neurons and/or glia is currently unknown. Here we used embryonic avian retina to obtain mixed retinal cells or purified Müller glia cells in culture to evaluate calcium shifts induced by GSH. A dose response curve (0.1–10mM) showed that 5–10mM GSH, induced calcium shifts exclusively in glial cells (later labeled and identified as 2M6 positive cells), while neurons responded to 50mM KCl (labeled as βIII tubulin positive cells). BBG 100nM, a P2X7 blocker, inhibited the effects of GSH on Müller glia. However, addition of DNQX 70μM and MK-801 20μM, non-NMDA and NMDA blockers, had no effect on GSH calcium induced shift. Oxidized glutathione (GSSG) at 5mM failed to induce calcium mobilization in glia cells, indicating that the antioxidant and/or structural features of GSH are essential to promote elevations in cytoplasmic calcium levels. Indeed, a short GSH pulse (60s) protects Müller glia from oxidative damage after 30 min of incubation with 0.1% H2O2. Finally, GSH induced GABA release from chick embryonic retina, mixed neuron-glia or from Müller cell cultures, which were inhibited by BBG or in the absence of sodium. GSH also induced propidium iodide uptake in Müller cells in culture in a P2X7 receptor dependent manner. Our data suggest that GSH, in addition to antioxidant effects, could act signaling calcium shifts at the millimolar range particularly in Müller glia, and could regulate the release of GABA, with additional protective effects on retinal neuron-glial circuit. PMID:27078878

  3. Defining the chromatin signature of inducible genes in T cells

    PubMed Central

    2009-01-01

    Background Specific chromatin characteristics, especially the modification status of the core histone proteins, are associated with active and inactive genes. There is growing evidence that genes that respond to environmental or developmental signals may possess distinct chromatin marks. Using a T cell model and both genome-wide and gene-focused approaches, we examined the chromatin characteristics of genes that respond to T cell activation. Results To facilitate comparison of genes with similar basal expression levels, we used expression-profiling data to bin genes according to their basal expression levels. We found that inducible genes in the lower basal expression bins, especially rapidly induced primary response genes, were more likely than their non-responsive counterparts to display the histone modifications of active genes, have RNA polymerase II (Pol II) at their promoters and show evidence of ongoing basal elongation. There was little or no evidence for the presence of active chromatin marks in the absence of promoter Pol II on these inducible genes. In addition, we identified a subgroup of genes with active promoter chromatin marks and promoter Pol II but no evidence of elongation. Following T cell activation, we find little evidence for a major shift in the active chromatin signature around inducible gene promoters but many genes recruit more Pol II and show increased evidence of elongation. Conclusions These results suggest that the majority of inducible genes are primed for activation by having an active chromatin signature and promoter Pol II with or without ongoing elongation. PMID:19807913

  4. Sulfated lentinan induced mitochondrial dysfunction leads to programmed cell death of tobacco BY-2 cells.

    PubMed

    Wang, Jie; Wang, Yaofeng; Shen, Lili; Qian, Yumei; Yang, Jinguang; Wang, Fenglong

    2017-04-01

    Sulphated lentinan (sLTN) is known to act as a resistance inducer by causing programmed cell death (PCD) in tobacco suspension cells. However, the underlying mechanism of this effect is largely unknown. Using tobacco BY-2 cell model, morphological and biochemical studies revealed that mitochondrial reactive oxygen species (ROS) production and mitochondrial dysfunction contribute to sLNT induced PCD. Cell viability, and HO/PI fluorescence imaging and TUNEL assays confirmed a typical cell death process caused by sLNT. Acetylsalicylic acid (an ROS scavenger), diphenylene iodonium (an inhibitor of NADPH oxidases) and protonophore carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (a protonophore and an uncoupler of mitochondrial oxidative phosphorylation) inhibited sLNT-induced H2O2 generation and cell death, suggesting that ROS generation linked, at least partly, to a mitochondrial dysfunction and caspase-like activation. This conclusion was further confirmed by double-stained cells with the mitochondria-specific marker MitoTracker RedCMXRos and the ROS probe H2DCFDA. Moreover, the sLNT-induced PCD of BY-2 cells required cellular metabolism as up-regulation of the AOX family gene transcripts and induction of the SA biosynthesis, the TCA cycle, and miETC related genes were observed. It is concluded that mitochondria play an essential role in the signaling pathway of sLNT-induced ROS generation, which possibly provided new insight into the sLNT-mediated antiviral response, including PCD.

  5. The fungicide mancozeb induces toxic effects on mammalian granulosa cells

    SciTech Connect

    Paro, Rita; Tiboni, Gian Mario; Buccione, Roberto; Rossi, Gianna; Cellini, Valerio; Canipari, Rita; Cecconi, Sandra

    2012-04-15

    The ethylene-bis-dithiocarbamate mancozeb is a widely used fungicide with low reported toxicity in mammals. In mice, mancozeb induces embryo apoptosis, affects oocyte meiotic spindle morphology and impairs fertilization rate even when used at very low concentrations. We evaluated the toxic effects of mancozeb on the mouse and human ovarian somatic granulosa cells. We examined parameters such as cell morphology, induction of apoptosis, and p53 expression levels. Mouse granulosa cells exposed to mancozeb underwent a time- and dose-dependent modification of their morphology, and acquired the ability to migrate but not to proliferate. The expression level of p53, in terms of mRNA and protein content, decreased significantly in comparison with unexposed cells, but no change in apoptosis was recorded. Toxic effects could be attributed, at least in part, to the presence of ethylenthiourea (ETU), the main mancozeb catabolite, which was found in culture medium. Human granulosa cells also showed dose-dependent morphological changes and reduced p53 expression levels after exposure to mancozeb. Altogether, these results indicate that mancozeb affects the somatic cells of the mammalian ovarian follicles by inducing a premalignant-like status, and that such damage occurs to the same extent in both mouse and human GC. These results further substantiate the concept that mancozeb should be regarded as a reproductive toxicant. Highlights: ► The fungicide mancozeb affects oocyte spindle morphology and fertilization rate. ► We investigated the toxic effects of mancozeb on mouse and human granulosa cells. ► Granulosa cells modify their morphology and expression level of p53. ► Mancozeb induces a premalignant-like status in exposed cells.

  6. NITROTYROSINE ATTENUATES RSV-INDUCED INFLAMMATION IN AIRWAY EPITHELIAL CELLS

    EPA Science Inventory

    Nitrotyrosine attenuates RSV-induced inflammation in airway epithelial cells. Joleen Soukup, Zuowei Li, Susanne Becker and Yuh-Chin Huang. NHEERL, ORD, USEPA, RTP, North Carolina, CEMALB, University of North Carolina, Chapel Hill, North Carolina

    Nitrotyrosine (NO2Tyr) is a...

  7. NAP reduces murine microvascular endothelial cells proliferation induced by hyperglycemia.

    PubMed

    D'Amico, Agata Grazia; Scuderi, Soraya; Maugeri, Grazia; Cavallaro, Sebastiano; Drago, Filippo; D'Agata, Velia

    2014-11-01

    Hyperglycemia has been identified as a risk factor responsible for micro- and macrovascular complications in diabetes. NAP (Davunetide) is a peptide whose neuroprotective actions are widely demonstrated, although its biological role on endothelial dysfunctions induced by hyperglycemia remains uninvestigated. In the present study we hypothesized that NAP could play a protective role on hyperglycemia-induced endothelial cell proliferation. To this end we investigated the effects of NAP on an in vitro model of murine microvascular endothelial cells grown in high glucose for 7 days. The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay and cyclin D1 protein expression analysis revealed that NAP treatment significantly reduces viability and proliferation of the cells. Hyperglycemia induced the activation of mitogen-activated protein kinase/extracellular signal-regulated protein kinase and/or phosphatidylinositol-3 kinase/Akt pathways in a time-dependent manner. NAP treatment reduced the phosphorylation levels of ERK and AKT in cells grown in high glucose. These evidences suggest that NAP might be effective in the regulation of endothelial dysfunction induced by hyperglycemia.

  8. Calcium accentuates injury induced by ethanol in human gastric cells.

    PubMed

    Kokoska, E R; Smith, G S; Deshpande, Y; Wolff, A B; Rieckenberg, C; Miller, T A

    1999-01-01

    The mechanism(s) whereby ethanol induces cellular injury remains poorly understood. Furthermore, the role of calcium in gastric mucosal injury under in vitro conditions is poorly defined. The major objectives of this study were to (1) define the temporal relationship between intracellular calcium accumulation induced by ethanol and cellular injury, (2) characterize the mechanism(s) whereby ethanol increases cellular calcium content, and (3) determine whether calcium removal would attenuate ethanol-induced cellular injury. Human gastric cells (AGS) were used for all experiments. Sustained intracellular calcium accumulation induced by ethanol, but not transient changes, preceded and directly correlated with cellular injury. Cells exposed to damaging concentrations of ethanol demonstrated an initial calcium surge that appeared to be a consequence of inositol 1,4,5-triphosphate (IP3) generation and subsequent internal store release followed by a sustained plateau resulting from extracellular calcium influx through store-operated calcium channels. Finally, both morphologic (cellular injury) and functional (clearance of bovine serum albumin) changes induced by ethanol were significantly attenuated when extracellular Ca(+&plus) influx was prevented, and further decreased when intracellular Ca(++) stores were depleted. These data indicate that calcium plays a significant role in cellular injury induced by ethanol.

  9. Interferon-inducible effector mechanisms in cell-autonomous immunity.

    PubMed

    MacMicking, John D

    2012-04-25

    Interferons (IFNs) induce the expression of hundreds of genes as part of an elaborate antimicrobial programme designed to combat infection in all nucleated cells - a process termed cell-autonomous immunity. As described in this Review, recent genomic and subgenomic analyses have begun to assign functional properties to novel IFN-inducible effector proteins that restrict bacteria, protozoa and viruses in different subcellular compartments and at different stages of the pathogen life cycle. Several newly described host defence factors also participate in canonical oxidative and autophagic pathways by spatially coordinating their activities to enhance microbial killing. Together, these IFN-induced effector networks help to confer vertebrate host resistance to a vast and complex microbial world.

  10. SPARC expression induces cell cycle arrest via STAT3 signaling pathway in medulloblastoma cells

    SciTech Connect

    Chetty, Chandramu; Dontula, Ranadheer; Gujrati, Meena; Lakka, Sajani S.

    2012-01-13

    Highlights: Black-Right-Pointing-Pointer Ectopic expression of SPARC impaired cell proliferation in medulloblastoma cells. Black-Right-Pointing-Pointer SPARC expression induces STAT3 mediated cell cycle arrest in medulloblastoma cells. Black-Right-Pointing-Pointer SPARC expression significantly inhibited pre-established tumor growth in nude-mice. -- Abstract: Dynamic cell interaction with ECM components has profound influence in cancer progression. SPARC is a component of the ECM, impairs the proliferation of different cell types and modulates tumor cell aggressive features. We previously reported that SPARC expression significantly impairs medulloblastoma tumor growth in vivo. In this study, we demonstrate that expression of SPARC inhibits medulloblastoma cell proliferation. MTT assay indicated a dose-dependent reduction in tumor cell proliferation in adenoviral mediated expression of SPARC full length cDNA (Ad-DsRed-SP) in D425 and UW228 cells. Flow cytometric analysis showed that Ad-DsRed-SP-infected cells accumulate in the G2/M phase of cell cycle. Further, immunoblot and immunoprecipitation analyses revealed that SPARC induced G2/M cell cycle arrest was mediated through inhibition of the Cyclin-B-regulated signaling pathway involving p21 and Cdc2 expression. Additionally, expression of SPARC decreased STAT3 phosphorylation at Tyr-705; constitutively active STAT3 expression reversed SPARC induced G2/M arrest. Ad-DsRed-SP significantly inhibited the pre-established orthotopic tumor growth and tumor volume in nude-mice. Immunohistochemical analysis of tumor sections from mice treated with Ad-DsRed-SP showed decreased immunoreactivity for pSTAT3 and increased immunoreactivity for p21 compared to tumor section from mice treated with mock and Ad-DsRed. Taken together our studies further reveal that STAT3 plays a key role in SPARC induced G2/M arrest in medulloblastoma cells. These new findings provide a molecular basis for the mechanistic understanding of the

  11. Present and future challenges of induced pluripotent stem cells

    PubMed Central

    Ohnuki, Mari; Takahashi, Kazutoshi

    2015-01-01

    Growing old is our destiny. However, the mature differentiated cells making up our body can be rejuvenated to an embryo-like fate called pluripotency which is an ability to differentiate into all cell types by enforced expression of defined transcription factors. The discovery of this induced pluripotent stem cell (iPSC) technology has opened up unprecedented opportunities in regenerative medicine, disease modelling and drug discovery. In this review, we introduce the applications and future perspectives of human iPSCs and we also show how iPSC technology has evolved along the way. PMID:26416678

  12. Induced pluripotent stem cells in research and therapy.

    PubMed

    Teoh, Hoon-Koon; Cheong, Soon-Keng

    2012-06-01

    Induced pluripotent stem cells (iPSC) are derived from human somatic cells through ectopic expression of transcription factors. This landmark discovery has been considered as a major development towards patient-specific iPSC for various biomedical applications. Unlimited self renewal capacity, pluripotency and ease of accessibility to donor tissues contribute to the versatility of iPSC. The therapeutic potential of iPSC in regenerative medicine, cell-based therapy, disease modelling and drug discovery is indeed very promising. Continuous progress in iPSC technology provides clearer understanding of disease pathogenesis and ultimately new optimism in developing treatment or cure for human diseases.

  13. Mast Cell Hyperplasia and Eosinophilia Induced by Ascaris Body Fluid

    PubMed Central

    Archer, G. T.; Binet, J.-L.

    1971-01-01

    Daily i.p. injections of dilute Ascaris body fluid into rats induced peritoneal eosinophilia and the formation of pin-point follicles in the omentum. The follicles comprised plasma cells, macrophages and fibroblasts together with large numbers of eosinophils and mast cells. Electron microscopy of eosinophils in the follicles revealed loss of cytoplasmic granules and numerous vesicular and tubular structures in the cytoplasm. The mast cells showed clear areas round the granules, suggesting dissolution of granule components. ImagesFigs. 4-6Figs. 7-8Figs. 13-14Figs. 9-10Figs. 1-3Figs. 11-12 PMID:5135540

  14. Contact Lens-induced Limbal Stem Cell Deficiency.

    PubMed

    Rossen, Jennifer; Amram, Alec; Milani, Behrad; Park, Dongwook; Harthan, Jennifer; Joslin, Charlotte; McMahon, Timothy; Djalilian, Ali

    2016-10-01

    Limbal stem cell deficiency (LSCD) is a pathologic condition caused by the dysfunction and/or destruction of stem cell precursors of the corneal epithelium, typified clinically by corneal conjunctivalization. The purpose of this review is to critically discuss a less well-known cause of limbal stem cell disease: contact lens (CL) wear. A literature search was conducted to include original articles containing patients with CL-induced LSCD. This review describes epidemiology, diagnostic strategies, pathogenesis, differential diagnosis, and treatment modalities for this condition.

  15. Crowding induces live cell extrusion to maintain homeostatic cell numbers in epithelia.

    PubMed

    Eisenhoffer, George T; Loftus, Patrick D; Yoshigi, Masaaki; Otsuna, Hideo; Chien, Chi-Bin; Morcos, Paul A; Rosenblatt, Jody

    2012-04-15

    For an epithelium to provide a protective barrier, it must maintain homeostatic cell numbers by matching the number of dividing cells with the number of dying cells. Although compensatory cell division can be triggered by dying cells, it is unknown how cell death might relieve overcrowding due to proliferation. When we trigger apoptosis in epithelia, dying cells are extruded to preserve a functional barrier. Extrusion occurs by cells destined to die signalling to surrounding epithelial cells to contract an actomyosin ring that squeezes the dying cell out. However, it is not clear what drives cell death during normal homeostasis. Here we show in human, canine and zebrafish cells that overcrowding due to proliferation and migration induces extrusion of live cells to control epithelial cell numbers. Extrusion of live cells occurs at sites where the highest crowding occurs in vivo and can be induced by experimentally overcrowding monolayers in vitro. Like apoptotic cell extrusion, live cell extrusion resulting from overcrowding also requires sphingosine 1-phosphate signalling and Rho-kinase-dependent myosin contraction, but is distinguished by signalling through stretch-activated channels. Moreover, disruption of a stretch-activated channel, Piezo1, in zebrafish prevents extrusion and leads to the formation of epithelial cell masses. Our findings reveal that during homeostatic turnover, growth and division of epithelial cells on a confined substratum cause overcrowding that leads to their extrusion and consequent death owing to the loss of survival factors. These results suggest that live cell extrusion could be a tumour-suppressive mechanism that prevents the accumulation of excess epithelial cells.

  16. Induced pluripotent stem (iPS) cells from human fetal stem cells.

    PubMed

    Guillot, Pascale V

    2016-02-01

    Pluripotency defines the ability of stem cells to differentiate into all the lineages of the three germ layers and self-renew indefinitely. Somatic cells can regain the developmental potential of embryonic stem cells following ectopic expression of a set of transcription factors or, in certain circumstances, via modulation of culture conditions and supplementation with small molecule, that is, induced pluripotent stem (iPS) cells. Here, we discuss the use of fetal tissues for reprogramming, focusing in particular on stem cells derived from human amniotic fluid, and the development of chemical reprogramming. We next address the advantages and disadvantages of deriving pluripotent cells from fetal tissues and the potential clinical applications.

  17. NIF (neurite-inducing factor): a novel peptide inducing neurite formation in PC12 cells.

    PubMed

    Wagner, J A

    1986-01-01

    Neurite-inducing factor (NIF) is a novel protein that has been partially purified from mouse submaxillary glands. NIF induces neurite formation in PC12 pheochromocytoma cells, and the NIF-induced neurites are indistinguishable from NGF-induced neurites in both their morphology and the time course of their formation. Neurite-inducing activity can be recovered at a position corresponding to a molecular weight of 20,000 Da after fractionation of partially purified preparations via SDS-PAGE. Partially purified preparations of NIF are about half as potent as pure beta NGF, and since the neurite-inducing activity does not correspond to any of the major proteins in this fraction, specific activity of purified NIF will probably be significantly greater than the 60 ng/ml found for our partially purified material. NIF is distinct from beta NGF by four criteria: (1) antibodies to beta NGF can block the activity of beta NGF, but not the activity of NIF; (2) beta NGF can induce ornithine decarboxylase (ODC) in PC12 cells at concentrations significantly below those required to induce neurites, while NIF induces ODC only at concentrations greatly in excess of those required to induce neurite formation; (3) by the criterion of SDS-PAGE, there is insufficient beta NGF in our partially purified preparations of NIF to explain the biological activity of this fraction; and (4) the biological activity of NIF has a molecular weight (20,000 Da) that is distinct from beta NGF (13,000 Da). We conclude that NIF is probably a novel peptide that is very active in promoting morphological differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Osteopontin Facilitates Ultraviolet B-induced Squamous Cell Carcinoma Development

    PubMed Central

    Chang, Pi-Ling; Hsieh, Yu-Hua; Wang, Chao-Cheng; Juliana, M. Margaret; Tsuruta, Yuko; Timares, Laura; Elmets, Craig; Ho, Kang-Jey

    2014-01-01

    Background Osteopontin (OPN) is a matricellular glycoprotein that is markedly expressed in cutaneous squamous cell carcinomas (cSCCs) and in actinic keratoses implicating its role in photocarcinogenesis. Objective To determine whether OPN facilitates the development of cSCC and its function. Methods cSCCs development was compared between wild-type (WT) and OPN-null mice subjected to UVB irradiation for 43 weeks. UVB-induced OPN expression was determined by Western blot, immunoprecipitation, ELISA, and semi-quantitative RT-PCR. Epidermal layer and TUNEL analyses assessed if OPN mediates UVB-induced epidermal hyperplasia or suppresses UVB-induced apoptosis of basal keratinocytes, respectively. In vitro experiments determined whether OPN enhances cell survival of UVB-induced apoptosis and its potential mechanisms. Immunohistochemical analyses of epidermis assessed the expression of CD44 and focal adhesion kinase (FAK), molecules that mediate OPN survival function. Results Compared to female WT mice, OPN-null mice did not develop cSCCs. UVB irradiation stimulated OPN protein expression in the dorsal skin by 11 h and remains high at 24 to 48h.OPN did not mediate UVB-induced epidermal hyperplasia; instead, it protected basal keratinocytes from undergoing apoptosis upon UVB exposure. Likewise, the addition of OPN suppressed UVB-induced OPN-null cSCC cell apoptosis, the activation of caspase-9 activity, and increased phosphorylation of FAK at Y397. Furthermore, the expression of CD44 and FAK in WT mice epidermis was greater than that of OPN-null mice prior to and during early acute UVB exposure. Conclusion These data support the hypothesis that chronic UVB-induced OPN expression protects the survival of initiated basal keratinocytes and, consequently, facilitates cSCC develop. PMID:24888687

  19. NKT Cells in the Induced Sputum of Severe Asthmatics

    PubMed Central

    Hamzaoui, Agnes; Cheik Rouhou, Sana; Graïri, Hedia; Abid, Hanadi; Ammar, Jamel; Chelbi, Hanene; Hamzaoui, Kamel

    2006-01-01

    To determine whether there was a specific inflammatory process in severe asthmatics, the phenotypic characteristics of induced sputum immune cells were analysed among patients with severe asthma. Twenty-two induced sputa (10 severe asthmatics) were studied. Flow cytometric analysis was performed using immune cells of the sputum and monoclonal antibodies to CD3, CD4, CD8, CD56, CD25, and TCRγδ. The number of NKT (CD3+CD56+) cells was significantly higher in the sputum of severe asthmatics compared with mild asthmatic and healthy control groups (P < .05). CD8+CD56+ cells were the predominant subtype of the increased NKT cells in severe asthmatics. CD3+CD56+Vα24+, TCRγδ+ CD56+, and CD4+CD25+ T cells were significantly increased in severe asthmatic patients. These results suggest that the immunopathogenesis of severe asthmatics vary between severe and mild asthmatics, and that CD8+CD56+ NKT cells may play an important role in the immunopathogenesis of severe asthma. PMID:16883065

  20. Heme oxygenase-1 accelerates erastin-induced ferroptotic cell death.

    PubMed

    Kwon, Min-Young; Park, Eunhee; Lee, Seon-Jin; Chung, Su Wol

    2015-09-15

    The oncogenic RAS-selective lethal small molecule Erastin triggers a unique iron-dependent form of nonapoptotic cell death termed ferroptosis. Ferroptosis is dependent upon the production of intracellular iron-dependent reactive oxygen species (ROS), but not other metals. However, key regulators remain unknown. The heme oxygenase (HO) is a major intracellular source of iron. In this study, the role of heme oxygenase in Erastin-triggered ferroptotic cancer cell death has been investigated. Zinc protoporphyrin IX (ZnPP), a HO-1 inhibitor, prevented Erastin-triggered ferroptotic cancer cell death. Furthermore, Erastin induced the protein and mRNA levels of HO-1 in HT-1080 fibrosarcoma cells. HO-1+/+ and HO-1-/- fibroblast, HO-1 overexpression, and chycloheximide-treated experiments revealed that the expression of HO-1 has a decisive effects in Erastin-triggered cell death. Hemin and CO-releasing molecules (CORM) promote Erastin-induced ferroptotic cell death, not by biliverdin and bilirubin. In addition, hemin and CORM accelerate the HO-1 expression in the presence of Erastin and increase membranous lipid peroxidation. Thus, HO-1 is an essential enzyme for iron-dependent lipid peroxidation during ferroptotic cell death.

  1. Phorbol esters induce multidrug resistance in human breast cancer cells

    SciTech Connect

    Fine, R.L.; Patel, J.; Chabner, B.A.

    1988-01-01

    Mechanisms responsible for broad-based resistance to antitumor drugs derived from natural products (multidrug resistance) are incompletely understood. Agents known to reverse the multidrug-resistant phenotype (verapamil and trifluoperazine) can also inhibit the activity of protein kinase C. When the authors assayed human breast cancer cell lines for protein kinase C activity, they found that enzyme activity was 7-fold higher in the multidrug-resistance cancer cells compared with the control, sensitive parent cells. Exposure of drug-sensitive cells to the phorbol ester phorbol 12,13-dibutyate (P(BtO)/sub 2/) led to an increase in protein kinase C activity and induced a drug-resistance phenotype, whereas exposure of drug-resistant cells to P(BtO)/sub 2/ further increased drug resistance. In sensitive cells, this increased resistance was accomplished by a 3.5-fold increased phosphorylation of a 20-kDa particulate protein and a 35-40% decreased intracellular accumulation of doxorubicin and vincristine. P(BtO)/sub 2/ induced resistance to agents involved in the multidrug-resistant phenotype (doxorubicin and vincristine) but did not affect sensitivity to an unrelated alkylating agent (melphalan). The increased resistance was partially or fully reversible by the calcium channel blocker verapamil and by the calmodulin-antagonist trifluoperazine. These data suggest that stimulation of protein kinase C playus a role in the drug-transport changes in multidrug-resistant cells. This may occur through modulation of an efflux pump by protein phosphorylation.

  2. Lipopolysaccharide induces a fibrotic-like phenotype in endothelial cells.

    PubMed

    Echeverría, César; Montorfano, Ignacio; Sarmiento, Daniela; Becerra, Alvaro; Nuñez-Villena, Felipe; Figueroa, Xavier F; Cabello-Verrugio, Claudio; Elorza, Alvaro A; Riedel, Claudia; Simon, Felipe

    2013-06-01

    Endothelial dysfunction is crucial in endotoxaemia-derived sepsis syndrome pathogenesis. It is well accepted that lipopolysaccharide (LPS) induces endothelial dysfunction through immune system activation. However, LPS can also directly generate actions in endothelial cells (ECs) in the absence of participation by immune cells. Although interactions between LPS and ECs evoke endothelial death, a significant portion of ECs are resistant to LPS challenge. However, the mechanism that confers endothelial resistance to LPS is not known. LPS-resistant ECs exhibit a fibroblast-like morphology, suggesting that these ECs enter a fibrotic programme in response to LPS. Thus, our aim was to investigate whether LPS is able to induce endothelial fibrosis in the absence of immune cells and explore the underlying mechanism. Using primary cultures of ECs and culturing intact blood vessels, we demonstrated that LPS is a crucial factor to induce endothelial fibrosis. We demonstrated that LPS was able and sufficient to promote endothelial fibrosis, in the absence of immune cells through an activin receptor-like kinase 5 (ALK5) activity-dependent mechanism. LPS-challenged ECs showed an up-regulation of both fibroblast-specific protein expression and extracellular matrix proteins secretion, as well as a down-regulation of endothelial markers. These results demonstrate that LPS is a crucial factor in inducing endothelial fibrosis in the absence of immune cells through an ALK5-dependent mechanism. It is noteworthy that LPS-induced endothelial fibrosis perpetuates endothelial dysfunction as a maladaptive process rather than a survival mechanism for protection against LPS. These findings are useful in improving current treatment against endotoxaemia-derived sepsis syndrome and other inflammatory diseases.

  3. Therapeutic Potential of Lung Epithelial Progenitor Cells Derived from Embryonic and Induced Pluripotent Stem Cells

    PubMed Central

    Wetsel, Rick A.; Wang, Dachun; Calame, Daniel G.

    2015-01-01

    Embryonic stem (ES) cells derived from preimplantation blastocysts and induced pluripotent stem (iPS) cells generated from somatic cell sources are pluripotent and capable of indefinite expansion in vitro. They provide a possible unlimited source of cells that could be differentiated into lung progenitor cells for potential clinical use in pulmonary regenerative medicine. Because of inherent difficulties in deriving endodermal cells from undifferentiated cell cultures, applications using lung epithelial cells derived from ES and iPS cells have lagged behind similar efforts devoted to other tissues, such as the heart and spinal cord. However, during the past several years, significant advances in culture, differentiation, and purification protocols, as well as in bioengineering methodologies, have fueled enthusiasm for the development of stem cell–based lung therapeutics. This article provides an overview of recent research achievements and discusses future technical challenges that must be met before the promise of stem cell applications for lung disease can be realized. PMID:21226612

  4. Generation of parthenogenetic induced pluripotent stem cells from parthenogenetic neural stem cells.

    PubMed

    Do, Jeong Tae; Joo, Jin Young; Han, Dong Wook; Araúzo-Bravo, Marcos J; Kim, Min Jung; Greber, Boris; Zaehres, Holm; Sobek-Klocke, Ingeborg; Chung, Hyung Min; Schöler, Hans R

    2009-12-01

    Somatic cells can achieve a pluripotent cell state in a process called pluripotential reprogramming. Multipotent stem cells can differentiate into cells of only one lineage, but pluripotent stem cells can give rise to cells of all three germ layers of an organism. In this study, we generated induced pluripotent stem (iPS) cells from bimaternal (uniparental) parthenogenetic neural stem cells (pNSCs) by transduction with either four (4F: Oct4, Klf4, Sox2, and c-Myc) or two (2F: Oct4 and Klf4) transcription factors. The resultant maternal iPS cells, which were reprogrammed directly from pNSCs, were capable of generating germ line-competent chimeras. Interestingly, analysis of global gene expression and imprinting status revealed that parthenogenetic iPS cells clustered closer to parthenogenetic ESCs than to female ESCs, with patterns that were clearly distinct from those of pNSCs.

  5. Ayanin diacetate-induced cell death is amplified by TRAIL in human leukemia cells

    SciTech Connect

    Marrero, Maria Teresa; Estevez, Sara; Negrin, Gledy; Quintana, Jose; Leon, Francisco; Estevez, Francisco

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer Ayanin diacetate as apoptotic inducer in leukemia cells. Black-Right-Pointing-Pointer Cell death was prevented by caspase inhibitors and by the overexpression of Bcl-x{sub L}. Black-Right-Pointing-Pointer The intrinsic and the extrinsic pathways are involved in the mechanism of action. Black-Right-Pointing-Pointer Death receptors are up-regulated and TRAIL enhances apoptotic cell death. -- Abstract: Here we demonstrate that the semi-synthetic flavonoid ayanin diacetate induces cell death selectively in leukemia cells without affecting the proliferation of normal lymphocytes. Incubation of human leukemia cells with ayanin diacetate induced G{sub 2}-M phase cell cycle arrest and apoptosis which was prevented by the non-specific caspase inhibitor z-VAD-fmk and reduced by the overexpression of Bcl-x{sub L}. Ayanin diacetate-induced cell death was found to be associated with: (i) loss of inner mitochondrial membrane potential, (ii) the release of cytochrome c, (iii) the activation of multiple caspases, (iv) cleavage of poly(ADP-ribose) polymerase and (v) the up-regulation of death receptors for TRAIL, DR4 and DR5. Moreover, the combined treatment with ayanin diacetate and TRAIL amplified cell death, compared to single treatments. These results provide a basis for further exploring the potential applications of this combination for the treatment of cancer.

  6. Pterostilbene induces accumulation of autophagic vacuoles followed by cell death in HL60 human leukemia cells.

    PubMed

    Siedlecka-Kroplewska, K; Jozwik, A; Boguslawski, W; Wozniak, M; Zauszkiewicz-Pawlak, A; Spodnik, J H; Rychlowski, M; Kmiec, Z

    2013-10-01

    Pterostilbene, a naturally occurring structural analog of resveratrol, has been reported to exert antiproliferative and proapoptotic effects in various cancer types. Recently, it has been demonstrated to induce both autophagy and apoptosis in human bladder and breast cancer cell lines. The aim of this study was to evaluate the effects of pterostilbene on HL60 human leukemia cells. Cell morphology was examined using confocal and electron microscopy. Cell viability was determined by MTT, neutral red uptake and trypan blue exclusion assays. LC3 processing was studied based on Western blotting and immunofluorescence analyses. Flow cytometry was used to study cell cycle distribution, phosphatidylserine externalization, caspase activation, disruption of mitochondrial membrane potential and intracellular production of reactive oxygen species. DNA degradation was examined by gel electrophoresis. We found that treatment of HL60 cells with pterostilbene at the IC90 concentration resulted in the G0/G1 cell cycle arrest. Pterostilbene induced conversion of cytosolic LC3-I to membrane-bound LC3-II and accumulation of large LC3-positive vacuolar structures. Pterostilbene also led to phosphatidylserine externalization, internucleosomal DNA fragmentation, caspase activation and disruption of mitochondrial membrane potential. Moreover, it did not induce oxidative stress. Our results suggest that pterostilbene induces accumulation of autophagic vacuoles followed by cell death in HL60 cells.

  7. Cadmium induces direct morphological changes in mesangial cell culture.

    PubMed

    L'Azou, Béatrice; Dubus, Isabelle; Ohayon-Courtès, Céline; Labouyrie, Jean; Perez, Laurent; Pouvreau, Carole; Juvet, Ludivine; Cambar, Jean

    2002-10-15

    The cadmium produced by industrial and agricultural practice represents a major environmental pollutant which may induce severe damage, especially in the kidney where cadmium accumulates. While cadmium is known to severely impair renal tubular functions, glomerular structures are also potential targets. The present study investigated the effects of cadmium on glomerular mesangial cell cultures after short- and long-term exposures, requiring for each endpoint specific culture conditions. After 30 min exposure to 1 microM CdCl(2), used as non-lethal concentration, 0.14 ng/microg proteins of cadmium was internalized by the cells as evaluated by atomic emision spectrometry and induced a significant, cell surface reduction (8.9+/-1.9%). These morphological changes could be correlated to smooth muscle alpha-actin disorganization, without quantitative change in its protein expression level as evaluated by Western-blot and Northern-blot analysis (SMAmRNA/28sRNA, 1.78 CdCl(2) vs. 1.42 control). For longer exposure times, in complex medium, cadmium uptake was efficient (0.36 ng/microg proteins) and induced changes in the actin cytoskeleton with no loss of cell membrane integrity. This study suggests that cultured mesangial cells provide an alternative model to study the effect of cadmium, and underlines the importance of using well-defined conditions to study further intracellular mechanisms.

  8. Pyrintegrin Induces Soft Tissue Formation by Transplanted or Endogenous Cells

    PubMed Central

    Shah, Bhranti S.; Chen, Mo; Suzuki, Takahiro; Embree, Mildred; Kong, Kimi; Lee, Chang H.; He, Ling; Xiang, Lusai; Ahn, Jeffrey A.; Ding, Sheng; Mao, Jeremy J.

    2017-01-01

    Focal adipose deficiency, such as lipoatrophy, lumpectomy or facial trauma, is a formidable challenge in reconstructive medicine, and yet scarcely investigated in experimental studies. Here, we report that Pyrintegrin (Ptn), a 2,4-disubstituted pyrimidine known to promote embryonic stem cells survival, is robustly adipogenic and induces postnatal adipose tissue formation in vivo of transplanted adipose stem/progenitor cells (ASCs) and recruited endogenous cells. In vitro, Ptn stimulated human adipose tissue derived ASCs to differentiate into lipid-laden adipocytes by upregulating peroxisome proliferator-activated receptor (PPARγ) and CCAAT/enhancer-binding protein-α (C/EBPα), with differentiated cells increasingly secreting adiponectin, leptin, glycerol and total triglycerides. Ptn-primed human ASCs seeded in 3D-bioprinted biomaterial scaffolds yielded newly formed adipose tissue that expressed human PPARγ, when transplanted into the dorsum of athymic mice. Remarkably, Ptn-adsorbed 3D scaffolds implanted in the inguinal fat pad had enhanced adipose tissue formation, suggesting Ptn’s ability to induce in situ adipogenesis of endogenous cells. Ptn promoted adipogenesis by upregulating PPARγ and C/EBPα not only in adipogenesis induction medium, but also in chemically defined medium specifically for osteogenesis, and concurrently attenuated Runx2 and Osx via BMP-mediated SMAD1/5 phosphorylation. These findings suggest Ptn’s novel role as an adipogenesis inducer with a therapeutic potential in soft tissue reconstruction and augmentation. PMID:28128224

  9. Environmental stress induces trinucleotide repeat mutagenesis in human cells

    PubMed Central

    Chatterjee, Nimrat; Lin, Yunfu; Santillan, Beatriz A.; Yotnda, Patricia; Wilson, John H.

    2015-01-01

    The dynamic mutability of microsatellite repeats is implicated in the modification of gene function and disease phenotype. Studies of the enhanced instability of long trinucleotide repeats (TNRs)—the cause of multiple human diseases—have revealed a remarkable complexity of mutagenic mechanisms. Here, we show that cold, heat, hypoxic, and oxidative stresses induce mutagenesis of a long CAG repeat tract in human cells. We show that stress-response factors mediate the stress-induced mutagenesis (SIM) of CAG repeats. We show further that SIM of CAG repeats does not involve mismatch repair, nucleotide excision repair, or transcription, processes that are known to promote TNR mutagenesis in other pathways of instability. Instead, we find that these stresses stimulate DNA rereplication, increasing the proportion of cells with >4 C-value (C) DNA content. Knockdown of the replication origin-licensing factor CDT1 eliminates both stress-induced rereplication and CAG repeat mutagenesis. In addition, direct induction of rereplication in the absence of stress also increases the proportion of cells with >4C DNA content and promotes repeat mutagenesis. Thus, environmental stress triggers a unique pathway for TNR mutagenesis that likely is mediated by DNA rereplication. This pathway may impact normal cells as they encounter stresses in their environment or during development or abnormal cells as they evolve metastatic potential. PMID:25775519

  10. Clostridium perfringens Delta-Toxin Induces Rapid Cell Necrosis

    PubMed Central

    Seike, Soshi; Miyamoto, Kazuaki; Kobayashi, Keiko; Takehara, Masaya; Nagahama, Masahiro

    2016-01-01

    Clostridium perfringens delta-toxin is a β-pore-forming toxin and a putative pathogenic agent of C. perfringens types B and C. However, the mechanism of cytotoxicity of delta-toxin remains unclear. Here, we investigated the mechanisms of cell death induced by delta-toxin in five cell lines (A549, A431, MDCK, Vero, and Caco-2). All cell lines were susceptible to delta-toxin. The toxin caused rapid ATP depletion and swelling of the cells. Delta-toxin bound and formed oligomers predominantly in plasma membrane lipid rafts. Destruction of the lipid rafts with methyl β-cyclodextrin inhibited delta-toxin-induced cytotoxicity and ATP depletion. Delta-toxin caused the release of carboxyfluorescein from sphingomyelin-cholesterol liposomes and formed oligomers; toxin binding to the liposomes declined with decreasing cholesterol content in the liposomes. Flow cytometric assays with annexin V and propidium iodide revealed that delta-toxin treatment induced an elevation in the population of annexin V-negative and propidium iodide-positive cells. Delta-toxin did not cause the fragmentation of DNA or caspase-3 activation. Furthermore, delta-toxin caused damage to mitochondrial membrane permeability and cytochrome c release. In the present study, we demonstrate that delta-toxin produces cytotoxic activity through necrosis. PMID:26807591

  11. Mortalin sensitizes human cancer cells to MKT-077-induced senescence.

    PubMed

    Deocaris, Custer C; Widodo, Nashi; Shrestha, Bhupal G; Kaur, Kamaljit; Ohtaka, Manami; Yamasaki, Kazuhiko; Kaul, Sunil C; Wadhwa, Renu

    2007-07-18

    Mortalin is a chaperone protein that functions in many cellular processes such as mitochondrial biogenesis, intracellular trafficking, cell proliferation and signaling. Its upregulation in many human cancers makes it a candidate target for therapeutic intervention by small molecule drugs. In continuation to our earlier studies showing mortalin as a cellular target of MKT-077, a mitochondrion-seeking delocalized cationic dye that causes selective death of cancer cells, in this work, we report that MKT-077 binds to the nucleotide-binding domain of mortalin, causes tertiary structural changes in the protein, inactivates its chaperone function, and induces senescence in human tumor cell lines. Interestingly, in tumor cells with elevated level of mortalin expression, fairly low drug doses were sufficient to induce senescence. Guided by molecular screening for mortalin in tumor cells, our results led to the idea that working at low doses of the drug could be an alternative senescence-inducing cancer therapeutic strategy that could, in theory, avoid renal toxicities responsible for the abortion of MKT-077 clinical trials. Our work may likely translate to a re-appraisal of the therapeutic benefits of low doses of several classes of anti-tumor drugs, even of those that had been discontinued due to adverse effects.

  12. Rapid flow-induced responses in endothelial cells

    NASA Technical Reports Server (NTRS)

    Stamatas, G. N.; McIntire, L. V.

    2001-01-01

    Endothelial cells alter their morphology, growth rate, and metabolism in response to fluid shear stress. To study rapid flow-induced responses in the 3D endothelial cell morphology and calcium distribution, coupled fluorescence microscopy with optical sectioning, digital imaging, and numerical deconvolution techniques have been utilized. Results demonstrate that within the first minutes of flow application nuclear calcium is increasing. In the same time frame whole cell height and nuclear height are reduced by about 1 microm. Whole cell height changes may facilitate reduction of shear stress gradients on the luminal surface, whereas nuclear structural changes may be important for modulating endothelial growth rate and metabolism. To study the role of the cytoskeleton in these responses, endothelial cells have been treated with specific disrupters (acrylamide, cytochalasin D, and colchicine) of each of the cytoskeleton elements (intermediate filaments, microfilaments, and microtubules, respectively). None of these compounds had any effect on the shear-induced calcium response. Cytochalasin D and acrylamide did not affect the shear-induced nuclear morphology changes. Colchicine, however, completely abrogated the response, indicating that microtubules may be implicated in force transmission from the plasma membrane to the nucleus. A pedagogical model based on tensegrity theory principles is presented that is consistent with the results on the 3D endothelial morphology.

  13. Two endogenous proteins that induce cell wall extension in plants

    NASA Technical Reports Server (NTRS)

    McQueen-Mason, S.; Durachko, D. M.; Cosgrove, D. J.

    1992-01-01

    Plant cell enlargement is regulated by wall relaxation and yielding, which is thought to be catalyzed by elusive "wall-loosening" enzymes. By employing a reconstitution approach, we found that a crude protein extract from the cell walls of growing cucumber seedlings possessed the ability to induce the extension of isolated cell walls. This activity was restricted to the growing region of the stem and could induce the extension of isolated cell walls from various dicot stems and the leaves of amaryllidaceous monocots, but was less effective on grass coleoptile walls. Endogenous and reconstituted wall extension activities showed similar sensitivities to pH, metal ions, thiol reducing agents, proteases, and boiling in methanol or water. Sequential HPLC fractionation of the active wall extract revealed two proteins with molecular masses of 29 and 30 kD associated with the activity. Each protein, by itself, could induce wall extension without detectable hydrolytic breakdown of the wall. These proteins appear to mediate "acid growth" responses of isolated walls and may catalyze plant cell wall extension by a novel biochemical mechanism.

  14. Chlorambucil effectively induces deletion mutations in mouse germ cells

    SciTech Connect

    Russell, L.B.; Hunsicker, P.R.; Cacheiro, N.L.A.; Bangham, J.W.; Russell, W.L.; Shelby, M.D. )

    1989-05-01

    The chemotherapeutic agent chlorambucil was found to be more effective than x-rays or any chemical investigated to data in inducing high yields of mouse germ-line mutations that appear to be deletions or other structural changes. Induction of mutations involving seven specific loci was studied after exposures of various male germ-cell stages to chlorambucil at 10-25 mg/kg. A total of 60,750 offspring was scored. Mutation rates in spermatogonial stem cells were not significantly increased over control values; this negative result is not attributable to selective elimination of mutant cells. Mutations were, however, clearly induced in treated post-stem-cell stages, among which marked variations in mutational response were found. Maximum yield occurred after exposure of early spermatids, with {approx} 1% of all offspring carrying a specific-locus mutation in the 10 mg/kg group. The stage-response pattern for chlorambucil differs from that of all other chemicals investigated to date in the specific-locus test. Thus far, all but one of the tested mutations induced by chlorambucil in post-stem-cell stages have been proved deletions or other structural changes by genetic, cytogenetic, and/or molecular criteria. Deletion mutations have recently been useful for molecular mapping and for structure-function correlations of genomic regions. For generating presumed large-lesion germline mutations at highest frequencies, chlorambucil may be the mutagen of choice.

  15. DNA damage in cells exhibiting radiation-induced genomic instability

    DOE PAGES

    Keszenman, Deborah J.; Kolodiuk, Lucia; Baulch, Janet E.

    2015-02-22

    Cells exhibiting radiation induced genomic instability exhibit varied spectra of genetic and chromosomal aberrations. Even so, oxidative stress remains a common theme in the initiation and/or perpetuation of this phenomenon. Isolated oxidatively modified bases, abasic sites, DNA single strand breaks and clustered DNA damage are induced in normal mammalian cultured cells and tissues due to endogenous reactive oxygen species generated during normal cellular metabolism in an aerobic environment. While sparse DNA damage may be easily repaired, clustered DNA damage may lead to persistent cytotoxic or mutagenic events that can lead to genomic instability. In this study, we tested the hypothesismore » that DNA damage signatures characterised by altered levels of endogenous, potentially mutagenic, types of DNA damage and chromosomal breakage are related to radiation-induced genomic instability and persistent oxidative stress phenotypes observed in the chromosomally unstable progeny of irradiated cells. The measurement of oxypurine, oxypyrimidine and abasic site endogenous DNA damage showed differences in non-double-strand breaks (DSB) clusters among the three of the four unstable clones evaluated as compared to genomically stable clones and the parental cell line. These three unstable clones also had increased levels of DSB clusters. The results of this study demonstrate that each unstable cell line has a unique spectrum of persistent damage and lead us to speculate that alterations in DNA damage signaling and repair may be related to the perpetuation of genomic instability.« less

  16. DNA damage in cells exhibiting radiation-induced genomic instability

    SciTech Connect

    Keszenman, Deborah J.; Kolodiuk, Lucia; Baulch, Janet E.

    2015-02-22

    Cells exhibiting radiation induced genomic instability exhibit varied spectra of genetic and chromosomal aberrations. Even so, oxidative stress remains a common theme in the initiation and/or perpetuation of this phenomenon. Isolated oxidatively modified bases, abasic sites, DNA single strand breaks and clustered DNA damage are induced in normal mammalian cultured cells and tissues due to endogenous reactive oxygen species generated during normal cellular metabolism in an aerobic environment. While sparse DNA damage may be easily repaired, clustered DNA damage may lead to persistent cytotoxic or mutagenic events that can lead to genomic instability. In this study, we tested the hypothesis that DNA damage signatures characterised by altered levels of endogenous, potentially mutagenic, types of DNA damage and chromosomal breakage are related to radiation-induced genomic instability and persistent oxidative stress phenotypes observed in the chromosomally unstable progeny of irradiated cells. The measurement of oxypurine, oxypyrimidine and abasic site endogenous DNA damage showed differences in non-double-strand breaks (DSB) clusters among the three of the four unstable clones evaluated as compared to genomically stable clones and the parental cell line. These three unstable clones also had increased levels of DSB clusters. The results of this study demonstrate that each unstable cell line has a unique spectrum of persistent damage and lead us to speculate that alterations in DNA damage signaling and repair may be related to the perpetuation of genomic instability.

  17. Cholesterol induces proliferation of chicken primordial germ cells.

    PubMed

    Chen, Dongyang; Chen, Meijuan; Lu, Zhenping; Yang, Mengmeng; Xie, Long; Zhang, Wenxin; Xu, Huiyan; Lu, Kehuan; Lu, Yangqing

    2016-08-01

    Primordial germ cells (PGCs) are the precursors of sperm and eggs and may serve as suitable cells for use in research in developmental biology and transgenic animals. However, the long-term propagation of PGCs in vitro has so far been plagued by the loss of their germ cell characteristics. This is largely because of the scarcity of knowledge concerning cell division and proliferation in these cells and the poor optimization of the culture medium. The sonic hedgehog (SHH) signaling pathway is involved in proliferation of many types of cells, but little is known about its role in chicken PGCs. The results of the current study indicate that the proliferation of chicken PGCs increases significantly when cholesterol, a molecule that facilitates the trafficking of HH ligands, is supplemented in the culture medium. This effect was attenuated when an SHH antagonist, cyclopamine was added, suggesting the involvement of SHH signaling in this process. The characterization of PGCs treated with cholesterol has shown that these cells express germ-cell-related markers and retain their capability to colonize the embryonic gonad after re-introduction to vasculature of stage-15 HH embryos, indicating that proliferation of PGCs induced by cholesterol does not alter the germ cell characteristics of these cells.

  18. Heat stress induces ferroptosis-like cell death in plants.

    PubMed

    Distéfano, Ayelén Mariana; Martin, María Victoria; Córdoba, Juan Pablo; Bellido, Andrés Martín; D'Ippólito, Sebastián; Colman, Silvana Lorena; Soto, Débora; Roldán, Juan Alfredo; Bartoli, Carlos Guillermo; Zabaleta, Eduardo Julián; Fiol, Diego Fernando; Stockwell, Brent R; Dixon, Scott J; Pagnussat, Gabriela Carolina

    2017-02-01

    In plants, regulated cell death (RCD) plays critical roles during development and is essential for plant-specific responses to abiotic and biotic stresses. Ferroptosis is an iron-dependent, oxidative, nonapoptotic form of cell death recently described in animal cells. In animal cells, this process can be triggered by depletion of glutathione (GSH) and accumulation of lipid reactive oxygen species (ROS). We investigated whether a similar process could be relevant to cell death in plants. Remarkably, heat shock (HS)-induced RCD, but not reproductive or vascular development, was found to involve a ferroptosis-like cell death process. In root cells, HS triggered an iron-dependent cell death pathway that was characterized by depletion of GSH and ascorbic acid and accumulation of cytosolic and lipid ROS. These results suggest a physiological role for this lethal pathway in response to heat stress in Arabidopsis thaliana The similarity of ferroptosis in animal cells and ferroptosis-like death in plants suggests that oxidative, iron-dependent cell death programs may be evolutionarily ancient.

  19. Dragon (RGMb) induces oxaliplatin resistance in colon cancer cells.

    PubMed

    Shi, Ying; Huang, Xiao-Xiao; Chen, Guo-Bin; Wang, Ying; Zhi, Qiang; Liu, Yuan-Sheng; Wu, Xiao-Ling; Wang, Li-Fen; Yang, Bing; Xiao, Chuan-Xing; Xing, Hui-Qin; Ren, Jian-Lin; Xia, Yin; Guleng, Bayasi

    2016-07-26

    Colorectal cancer (CRC) is one of the most commonly diagnosed cancers and a major cause of cancer mortality. Chemotherapy resistance remains a major challenge for treating advanced CRC. Therefore, the identification of targets that induce drug resistance is a priority for the development of novel agents to overcome resistance. Dragon (also known as RGMb) is a member of the repulsive guidance molecule (RGM) family. We previously showed that Dragon expression increases with CRC progression in human patients. In the present study, we found that Dragon inhibited apoptosis and increased viability of CMT93 and HCT116 cells in the presence of oxaliplatin. Dragon induced resistance of xenograft tumor to oxaliplatinin treatment in mice. Mechanistically, Dragon inhibited oxaliplatin-induced JNK and p38 MAPK activation, and caspase-3 and PARP cleavages. Our results indicate that Dragon may be a novel target that induces drug resistance in CRC.

  20. T Cell Receptor-induced Activation and Apoptosis In Cycling Human T Cells Occur throughout the Cell Cycle

    PubMed Central

    Karas, Michael; Zaks, Tal Z.; JL, Liu; LeRoith, Derek

    1999-01-01

    Previous studies have found conflicting associations between susceptibility to activation-induced cell death and the cell cycle in T cells. However, most of the studies used potentially toxic pharmacological agents for cell cycle synchronization. A panel of human melanoma tumor-reactive T cell lines, a CD8+ HER-2/neu-reactive T cell clone, and the leukemic T cell line Jurkat were separated by centrifugal elutriation. Fractions enriched for the G0–G1, S, and G2–M phases of the cell cycle were assayed for T cell receptor-mediated activation as measured by intracellular Ca2+ flux, cytolytic recognition of tumor targets, and induction of Fas ligand mRNA. Susceptibility to apoptosis induced by recombinant Fas ligand and activation-induced cell death were also studied. None of the parameters studied was specific to a certain phase of the cell cycle, leading us to conclude that in nontransformed human T cells, both activation and apoptosis through T cell receptor activation can occur in all phases of the cell cycle. PMID:10588669

  1. Pfaffosidic Fraction from Hebanthe paniculata Induces Cell Cycle Arrest and Caspase-3-Induced Apoptosis in HepG2 Cells

    PubMed Central

    da Silva, Tereza Cristina; Cogliati, Bruno; Latorre, Andréia Oliveira; Akisue, Gokithi; Nagamine, Márcia Kazumi; Haraguchi, Mitsue; Hansen, Daiane; Sanches, Daniel Soares; Dagli, Maria Lúcia Zaidan

    2015-01-01

    Hebanthe paniculata roots (formerly Pfaffia paniculata and popularly known as Brazilian ginseng) show antineoplastic, chemopreventive, and antiproliferative properties. Functional properties of these roots and their extracts are usually attributed to the pfaffosidic fraction, which is composed mainly by pfaffosides A–F. However, the therapeutic potential of this fraction in cancer cells is not yet entirely understood. This study aimed to analyze the antitumoral effects of the purified pfaffosidic fraction or saponinic fraction on the human hepatocellular carcinoma HepG2 cell line. Cellular viability, proliferation, and apoptosis were evaluated, respectively, by MTT assay, BrdU incorporation, activated caspase-3 immunocytochemistry, and DNA fragmentation assay. Cell cycle was analyzed by flow cytometry and the cell cycle-related proteins were analyzed by quantitative PCR and Western blot. The cells exposed to pfaffosidic fraction had reduced viability and cellular growth, induced G2/M at 48 h or S at 72 h arrest, and increased sub-G1 cell population via cyclin E downregulation, p27KIP1 overexpression, and caspase-3-induced apoptosis, without affecting the DNA integrity. Antitumoral effects of pfaffosidic fraction from H. paniculata in HepG2 cells originated by multimechanisms of action might be associated with cell cycle arrest in the S phase, by CDK2 and cyclin E downregulation and p27KIP1 overexpression, besides induction of apoptosis through caspase-3 activation. PMID:26075002

  2. Sensitization of acute lymphoblastic leukemia cells for LCL161-induced cell death by targeting redox homeostasis.

    PubMed

    Haß, Christina; Belz, Katharina; Schoeneberger, Hannah; Fulda, Simone

    2016-04-01

    Disturbed redox homeostasis with both elevated reactive oxygen species (ROS) levels and antioxidant defense mechanisms has been reported in acute lymphoblastic leukemia (ALL). We therefore hypothesized that inhibition of pathways responsible for ROS detoxification renders ALL cells more susceptible for cell death. Here, we report that pharmacological inhibitors of key pathways for the elimination of ROS, i.e. Erastin, buthionine sulfoximine (BSO) and Auranofin, sensitize ALL cells for cell death upon treatment with the Smac mimetic LCL161 that antagonizes Inhibitor of Apoptosis (IAP) proteins. Erastin, BSO or Auranofin significantly increase LCL161-induced cell death and also act in concert with LCL161 to profoundly suppress long-term clonogenic survival in several ALL cell lines. Erastin or BSO cooperates with LCL161 to stimulate ROS production and lipid peroxidation prior to cell death. ROS production and lipid peroxidation are required for this cotreatment-induced cell death, since ROS scavengers or pharmacological inhibition of lipid peroxidation provides significant protection against cell death. These results emphasize that inhibition of antioxidant defense mechanisms can serve as a potent approach to prime ALL cells for LCL161-induced cell death.

  3. Neuroprotection by GH against excitotoxic-induced cell death in retinal ganglion cells.

    PubMed

    Martínez-Moreno, Carlos G; Ávila-Mendoza, José; Wu, Yilun; Arellanes-Licea, Elvira Del Carmen; Louie, Marcela; Luna, Maricela; Arámburo, Carlos; Harvey, Steve

    2016-08-01

    Retinal growth hormone (GH) has been shown to promote cell survival in retinal ganglion cells (RGCs) during developmental waves of apoptosis during chicken embryonic development. The possibility that it might also against excitotoxicity-induced cell death was therefore examined in the present study, which utilized quail-derived QNR/D cells as an in vitro RGC model. QNR/D cell death was induced by glutamate in the presence of BSO (buthionine sulfoxamide) (an enhancer of oxidative stress), but this was significantly reduced (P<0.01) in the presence of exogenous recombinant chicken GH (rcGH). Similarly, QNR/D cells that had been prior transfected with a GH plasmid to overexpress secreted and non-secreted GH. This treatment reduced the number of TUNEL-labeled cells and blocked their release of lactate dehydrogenase (LDH). In a further experiment with dissected neuroretinal explants from ED (embryonic day) 10 embryos, rcGH treatment of the explants also reduced (P<0.01) the number of glutamate-BSO-induced apoptotic cells and blocked the explant release of LDH. This neuroprotective action was likely mediated by increased STAT5 phosphorylation and increased bcl-2 production, as induced by exogenous rcGH treatment and the media from GH-overexpressing QNR/D cells. As rcGH treatment and GH-overexpression cells also increased the content of IGF-1 and IGF-1 mRNA this neuroprotective action of GH is likely to be mediated, at least partially, through an IGF-1 mechanism. This possibility is supported by the fact that the siRNA knockdown of GH or IGF-1 significantly reduced QNR/D cell viability, as did the immunoneutralization of IGF-1. GH is therefore neuroprotective against excitotoxicity-induced RGC cell death by anti-apoptotic actions involving IGF-1 stimulation.

  4. Cell entry of Lassa virus induces tyrosine phosphorylation of dystroglycan.

    PubMed

    Moraz, Marie-Laurence; Pythoud, Christelle; Turk, Rolf; Rothenberger, Sylvia; Pasquato, Antonella; Campbell, Kevin P; Kunz, Stefan

    2013-05-01

    The extracellular matrix (ECM) receptor dystroglycan (DG) serves as a cellular receptor for the highly pathogenic arenavirus Lassa virus (LASV) that causes a haemorrhagic fever with high mortality in human. In the host cell, DG provides a molecular link between the ECM and the actin cytoskeleton via the adapter proteins utrophin or dystrophin. Here we investigated post-translational modifications of DG in the context of LASV cell entry. Using the tyrosine kinase inhibitor genistein, we found that tyrosine kinases are required for efficient internalization of virus particles, but not virus-receptor binding. Engagement of cellular DG by LASV envelope glycoprotein (LASV GP) in human epithelial cells induced tyrosine phosphorylation of the cytoplasmic domain of DG. LASV GP binding to DG further resulted in dissociation of the adapter protein utrophin from virus-bound DG. This virus-induced dissociation of utrophin was affected by genistein treatment, suggesting a role of receptor tyrosine phosphorylation in the process.

  5. Cytotoxicity induced by nanobacteria and nanohydroxyapatites in human choriocarcinoma cells

    NASA Astrophysics Data System (ADS)

    Zhang, Mingjun; Yang, Jinmei; Shu, Jing; Fu, Changhong; Liu, Shengnan; Xu, Ge; Zhang, Dechun

    2014-11-01

    We explored the cytotoxic effects of nanobacteria (NB) and nanohydroxyapatites (nHAPs) against human choriocarcinoma cells (JAR) and the mechanisms of action underlying their cytotoxicity. JAR cells were co-cultured with NB and nHAPs for 48 h, and ultrastructural changes were more readily induced by NB than nHAPs. Autophagy in the plasma of JAR cells were observed in the NB group. The rate of apoptosis induced by NB was higher than that for nHAPs. The expression of Bax and FasR proteins in the NB group was stronger than that for the nHAP group. NB probably resulted in autophagic formation. Apoptosis was possibly activated via FasL binding to the FasR signaling pathway.

  6. Depletion induced clustering of red blood cells in microchannels

    NASA Astrophysics Data System (ADS)

    Wagner, Christian; Brust, Mathias; Podgorski, Thomas; Coupier, Gwennou

    2012-11-01

    The flow properties of blood are determined by the physical properties of its main constituents, the red blood cells (RBC's). At low shear rates RBC's form aggregates, so called rouleaux. Higher shear rates can break them up and the viscosity of blood shows a shear thinning behavior. The physical origin of the rouleaux formation is not yet fully resolved and there are two competing models available. One predicts that the adhesion is induced by bridging of the plasma (macromolecular) proteins in-between two RBC's. The other is based on the depletion effect and thus predicts the absence of macromolecules in-between the cells of a rouleaux. Recent single cell force measurements by use of an AFM support strongly the depletion model. By varying the concentration of Dextran at different molecular weights we can control the adhesions strength. Measurements at low hematocrit in a microfluidic channel show that the number of size of clusters is determined by the depletion induced adhesion strength.

  7. Pulse mode of laser photodynamic treatment induced cell apoptosis.

    PubMed

    Klimenko, Vladimir V; Knyazev, Nickolay A; Moiseenko, Fedor V; Rusanov, Anatoliy A; Bogdanov, Alexey A; Dubina, Michael V

    2016-03-01

    One of the factors limiting photodynamic therapy (PDT) is hypoxia in tumor cells during photodynamic action. PDT with pulse mode irradiation and appropriate irradiation parameters could be more effective in the singlet oxygen generation and tissue re-oxygenation than continuous wave (CW) mode. We theoretically demonstrate differences between the cumulative singlet oxygen concentration in PDT using pulse mode and CW mode of laser irradiation. In vitro experimental results show that photodynamic treatment with pulse mode irradiation has similar cytotoxicity to CW mode and induces mainly cell apoptosis, whereas CW mode induces necrotic cell death. We assume that the cumulative singlet oxygen concentration and the temporal distribution of singlet oxygen are important in photodynamic cytotoxicity and apoptosis initiation. We expect our research may improve irradiation protocols and photodynamic therapy efficiency.

  8. Cell entry of Lassa virus induces tyrosine phosphorylation of dystroglycan

    PubMed Central

    Moraz, Marie-Laurence; Pythoud, Christelle; Turk, Rolf; Rothenberger, Sylvia; Pasquato, Antonella; Campbell, Kevin P.; Kunz, Stefan

    2013-01-01

    The extracellular matrix (ECM) receptor dystroglycan (DG) serves as a cellular receptor for the highly pathogenic arenavirus Lassa virus (LASV) that causes a hemorrhagic fever with high mortality in man. In the host cell, DG provides a molecular link between the ECM and the actin cytoskeleton via the adapter proteins utrophin or dystrophin. Here we investigated post-translational modifications of DG in the context of LASV cell entry. Using the tyrosine kinase inhibitor genistein, we found that tyrosine kinases are required for efficient internalization of virus particles, but not virus-receptor binding. Engagement of cellular DG by LASV envelope glycoprotein (LASV GP) in human epithelial cells induced tyrosine phosphorylation of the cytoplasmic domain of DG. LASV GP binding to DG further resulted in dissociation of the adapter protein utrophin from virus-bound DG. This virus-induced dissociation of utrophin was affected by genistein treatment, suggesting a role of receptor tyrosine phosphorylation in the process. PMID:23279385

  9. DNA damage response induced by HZE particles in human cells

    NASA Astrophysics Data System (ADS)

    Chen, David; Aroumougame, Asaithamby

    Convincing evidences indicate that high-linear energy transfer (LET) ionizing radiation (IR) induced complex DNA lesions are more difficult to repair than isolated DNA lesions induced by low-LET IR; this has been associated with the increased RBE for cell killing, chromosomal aberrations, mutagenesis, and carcinogenesis in high energy charged-particle irradiated human cells. We have employed an in situ method to directly monitor induction and repair of clustered DNA lesions at the single-cell level. We showed, consistent with biophysical modeling, that the kinetics of loss of clustered DNA lesions was substantially compromised in human fibroblasts. The unique spatial distribution of different types of DNA lesions within the clustered damages determined the cellular ability to repair these damages. Importantly, examination of metaphase cells derived from HZE particle irradiated cells revealed that the extent of chromosome aberrations directly correlated with the levels of unrepaired clustered DNA lesions. In addition, we used a novel organotypic human lung three-dimensional (3D) model to investigate the biological significance of unrepaired DNA lesions in differentiated lung epithelial cells. We found that complex DNA lesions induced by HZE particles were even more difficult to be repaired in organotypic 3D culture, resulting enhanced cell killing and chromosome aberrations. Our data suggest that DNA repair capability in differentiated cells renders them vulnerable to DSBs, promoting genome instability that may lead to carcinogenesis. As the organotypic 3D model mimics human lung, it opens up new experimental approaches to explore the effect of radiation in vivo and will have important implications for evaluating radiation risk in human tissues.

  10. Equine Airway Mast Cells are Sensitive to Cell Death Induced by Lysosomotropic Agents.

    PubMed

    Wernersson, S; Riihimäki, M; Pejler, G; Waern, I

    2017-01-01

    Mast cells are known for their detrimental effects in various inflammatory conditions. Regimens that induce selective mast cell apoptosis may therefore be of therapeutic significance. Earlier studies have demonstrated that murine- and human-cultured mast cells are highly sensitive to apoptosis induced by the lysosomotropic agent LeuLeuOMe (LLME). However, the efficacy of lysosomotropic agents for inducing apoptosis of in vivo-derived airway mast cells and the impact on mast cells in other species have not been assessed. Here we addressed whether lysosomotropic agents can induce cell death of equine in vivo-derived mast cells. Bronchoalveolar lavage (BAL) fluids from horses were incubated with LLME at 15-100 μm for up to 48 h. The overall cell viability was unaffected by 15 μm LLME up to 48 h, whereas a relatively modest drop in total cell counts (~30%) was seen at the highest LLME dose used. In contrast to the relatively low effect on total cell counts, LLME efficiently and dose dependently reduced the number of mast cells in BAL fluids, with an almost complete depletion (96%) of mast cells after 24 h of incubation with 100 μm LLME. A significant but less dramatic reduction (up to ~45%) of lymphocytes was also seen, whereas macrophages and neutrophils were essentially resistant. The appearance of apoptotic bodies suggested a mechanism involving apoptosis rather than necrosis. These findings suggest that equine airway mast cells are highly sensitive to lysosomotropic agents. Possibly, lysosomotropic agents could be of therapeutic value to treat disorders involving harmful accumulation of mast cells in the airways.

  11. Apoptotic and autophagic cell death induced by glucolaxogenin in cervical cancer cells.

    PubMed

    Sánchez-Sánchez, L; Escobar, M L; Sandoval-Ramírez, J; López-Muñoz, H; Fernández-Herrera, M A; Hernández-Vázquez, J M V; Hilario-Martínez, C; Zenteno, E

    2015-12-01

    The antiproliferative and cytotoxic activity of glucolaxogenin and its ability to induce apoptosis and autophagy in cervical cancer cells are reported. We ascertained that glucolaxogenin exerts an inhibitory effect on the proliferation of HeLa, CaSki and ViBo cells in a dose-dependent manner. Analysis of DNA distribution in the cell-cycle phase of tumor cells treated with glucolaxogenin suggests that the anti-proliferative activity of this steroid is not always dependent on the cell cycle. Cytotoxic activity was evaluated by detection of the lactate dehydrogenase enzyme in supernatants from tumor cell cultures treated with the steroid. Glucolaxogenin exhibited null cytotoxic activity. With respect to the apoptotic activity, the generation of apoptotic bodies, the presence of active caspase-3 and annexin-V, as well as the DNA fragmentation observed in all tumor lines after treatment with glucolaxogenin suggests that this compound does indeed induce cell death by apoptosis. Also, a significantly increased presence of the LC3-II, LC3 and Lamp-1 proteins was evidenced with the ultrastructural existence of autophagic vacuoles in cells treated with this steroidal glycoside, indicating that glucolaxogenin also induces autophagic cell death. It is important to note that this compound showed no cytotoxic effect and did not affect the proliferative capacity of mononuclear cells obtained from normal human peripheral blood activated by phytohaemagglutinin. Thus, glucolaxogenin is a compound with anti-proliferative properties that induces programmed cell death in cancer cell lines, though it is selective with respect to normal lymphocytic cells. These findings indicate that this glycoside could have a selective action on tumor cells and, therefore, be worthy of consideration as a therapeutic candidate with anti-tumor potential.

  12. Electromagnetically induced transparency in paraffin-coated vapor cells

    SciTech Connect

    Klein, M.; Hohensee, M.; Walsworth, R. L.; Phillips, D. F.

    2011-01-15

    Antirelaxation coatings in atomic vapor cells allow ground-state coherent spin states to survive many collisions with the cell walls. This reduction in the ground-state decoherence rate gives rise to ultranarrow-bandwidth features in electromagnetically induced transparency (EIT) spectra, which can form the basis of, for example, long-time scale slow and stored light, sensitive magnetometers, and precise frequency standards. Here we study, both experimentally and theoretically, how Zeeman EIT contrast and width in paraffin-coated rubidium vapor cells are determined by cell and laser-beam geometry, laser intensity, and atomic density. Using a picture of Ramsey pulse sequences, where atoms alternately spend ''bright'' and ''dark'' time intervals inside and outside the laser beam, we explain the behavior of EIT features in coated cells, highlighting their unique characteristics and potential applications.

  13. Electromagnetically induced transparency in paraffin-coated vapor cells

    NASA Astrophysics Data System (ADS)

    Klein, M.; Hohensee, M.; Phillips, D. F.; Walsworth, R. L.

    2011-01-01

    Antirelaxation coatings in atomic vapor cells allow ground-state coherent spin states to survive many collisions with the cell walls. This reduction in the ground-state decoherence rate gives rise to ultranarrow-bandwidth features in electromagnetically induced transparency (EIT) spectra, which can form the basis of, for example, long-time scale slow and stored light, sensitive magnetometers, and precise frequency standards. Here we study, both experimentally and theoretically, how Zeeman EIT contrast and width in paraffin-coated rubidium vapor cells are determined by cell and laser-beam geometry, laser intensity, and atomic density. Using a picture of Ramsey pulse sequences, where atoms alternately spend “bright” and “dark” time intervals inside and outside the laser beam, we explain the behavior of EIT features in coated cells, highlighting their unique characteristics and potential applications.

  14. Transcriptional control of embryonic and induced pluripotent stem cells.

    PubMed

    Guenther, Matthew G

    2011-06-01

    Embryonic stem cells (ESCs) have the potential to generate virtually any cell type or tissue type in the body. This remarkable plasticity has yielded great interest in using these cells to understand early development and in treating human disease. In an effort to understand the basis of ESC pluripotency, genetic and genomic studies have revealed transcriptional regulatory circuitry that maintains the pluripotent cell state and poises the genome for downstream activation. Critical components of this circuitry include ESC transcription factors, chromatin regulators, histone modifications, signaling molecules and regulatory RNAs. This article will focus on our current understanding of these components and how they influence ESC and induced pluripotent stem cell states. Emerging themes include regulation of the pluripotent genome by a core set of transcription factors, transcriptional poising of developmental genes by chromatin regulatory complexes and the establishment of multiple layers of repression at key genomic loci.

  15. Icaritin induces apoptotic and autophagic cell death in human glioblastoma cells

    PubMed Central

    Li, Zhaopei; Meng, Xiangwen; Jin, Lin

    2016-01-01

    Background: GBM represents the most aggressive type of glioma which is featured by extremely aggressive invasion and destructive malignancy with a high proliferation rate. The aim of this study was to investigate the in vitro anti-tumor effect of icaritin in human GBM cell line U87. Methods: The effect of icaritin on In vitro cell viability was determined by MTT assay and colony formation assay. The inducing effect of icaritin on cell cycle arrest, mitochondrial membrane potential loss, apoptosis, autophagy and intracellular ROS generation was assessed by flow cytometry. The apoptotic cell death was also confirmed by TUNEL assay. The expression levels of target or marker molecules were examined by western blot. The activity of caspase-3, -8 and -9 was detected with ELISA kit. Results: Our results showed that icaritin significantly induced both caspase-dependent apoptosis and autophagy in human GBM cell line U87. Additionally, our findings revealed that icaritin exerted anti-tumor effect by modulating Stat3 through generating ROS and subsequent activation of AMPK and inhibition of mTOR. Further investigation also showed that icaritin-induced autophagy served as a pro-death function and possibly contributed to icaritin-induced apoptosis. Conclusion: Icaritin potently inhibit the cell growth of human GBM cell line U87 through inducing both caspase-dependent apoptosis and autophagy. Base on our findings, icaritin can be considered as a promising candidate therapeutic agent for treatment of GBM, though further studies are needed. PMID:27904667

  16. Trichodermin induces cell apoptosis through mitochondrial dysfunction and endoplasmic reticulum stress in human chondrosarcoma cells

    SciTech Connect

    Su, Chen-Ming; Wang, Shih-Wei; Lee, Tzong-Huei; Tzeng, Wen-Pei; Hsiao, Che-Jen; Liu, Shih-Chia; Tang, Chih-Hsin

    2013-10-15

    Chondrosarcoma is the second most common primary bone tumor, and it responds poorly to both chemotherapy and radiation treatment. Nalanthamala psidii was described originally as Myxosporium in 1926. This is the first study to investigate the anti-tumor activity of trichodermin (trichothec-9-en-4-ol, 12,13-epoxy-, acetate), an endophytic fungal metabolite from N. psidii against human chondrosarcoma cells. We demonstrated that trichodermin induced cell apoptosis in human chondrosarcoma cell lines (JJ012 and SW1353 cells) instead of primary chondrocytes. In addition, trichodermin triggered endoplasmic reticulum (ER) stress protein levels of IRE1, p-PERK, GRP78, and GRP94, which were characterized by changes in cytosolic calcium levels. Furthermore, trichodermin induced the upregulation of Bax and Bid, the downregulation of Bcl-2, and the dysfunction of mitochondria, which released cytochrome c and activated caspase-3 in human chondrosarcoma. In addition, animal experiments illustrated reduced tumor volume, which led to an increased number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells and an increased level of cleaved PARP protein following trichodermin treatment. Together, this study demonstrates that trichodermin is a novel anti-tumor agent against human chondrosarcoma cells both in vitro and in vivo via mitochondrial dysfunction and ER stress. - Highlights: • Trichodermin induces chondrosarcoma apoptosis. • ER stress is involved in trichodermin-induced cell death. • Trichodermin induces chondrosarcoma death in vivo.

  17. Hispidulin induces mitochondrial apoptosis in acute myeloid leukemia cells by targeting extracellular matrix metalloproteinase inducer

    PubMed Central

    Gao, Hui; Liu, Yongji; Li, Kan; Wu, Tianhui; Peng, Jianjun; Jing, Fanbo

    2016-01-01

    Acute myeloid leukemia (AML) represents a heterogeneous group of hematological neoplasms with marked heterogeneity in response to both standard therapy and survival. Hispidulin, a flavonoid compound that is anactive ingredient in the traditional Chinese medicinal herb Salvia plebeia R. Br, has recently been reported to have anantitumor effect against solid tumors in vitro and in vivo. The aim of the present study was to investigate the effects of hispidulin on the human leukemia cell line in vitro and the underlying mechanisms of its actions on these cells. Our results showed that hispidulin inhibits AML cell proliferation in a dose- and time-dependent manner, and induces cell apoptosis throughan intrinsic mitochondrial pathway. Our results also revealed that hispidulin treatment significantly inhibits extracellular matrix metalloproteinase inducer (EMMPRIN) expression in both tested AML cell lines in a dose-dependent manner, and that the overexpression of EMMPRIN protein markedly attenuates hispidulin-induced cell apoptosis. Furthermore, our results strongly indicated that the modulating effect of hispidulin on EMMPRIN is correlated with its inhibitory effect on both the Akt and STAT3 signaling pathways. PMID:27158398

  18. Lipopolysaccharide-induced multinuclear cells: Increased internalization of polystyrene beads and possible signals for cell fusion

    SciTech Connect

    Nakanishi-Matsui, Mayumi Yano, Shio; Futai, Masamitsu

    2013-11-01

    Highlights: •LPS induces multinuclear cells from murine macrophage-derived RAW264.7 cells. •Large beads are internalized by cells actively fusing to become multinuclear. •The multinuclear cell formation is inhibited by anti-inflammatory cytokine, IL10. •Signal transduction for cell fusion is different from that for inflammation. -- Abstract: A murine macrophage-derived line, RAW264.7, becomes multinuclear on stimulation with lipopolysaccharide (LPS), an outer membrane component of Gram-negative bacteria. These multinuclear cells internalized more polystyrene beads than mononuclear cells or osteoclasts (Nakanishi-Matsui, M., Yano, S., Matsumoto, N., and Futai, M., 2012). In this study, we analyzed the time courses of cell fusion in the presence of large beads. They were internalized into cells actively fusing to become multinuclear. However, the multinuclear cells once formed showed only low phagocytosis activity. These results suggest that formation of the multinuclear cells and bead internalization took place simultaneously. The formation of multinuclear cells was blocked by inhibitors for phosphoinositide 3-kinase, phospholipase C, calcineurin, and c-Jun N-terminal kinase. In addition, interleukin 6 and 10 also exhibited inhibitory effects. These signaling molecules and cytokines may play a crucial role in the LPS-induced multinuclear cell formation.

  19. 188Rhenium-induced cell death and apoptosis in a panel of tumor cell lines

    NASA Astrophysics Data System (ADS)

    Antoccia, Antonio; Banzato, Alessandra; Bello, Michele; Bollini, Dante; De Notaristefani, Francesco; Giron, Cecilia; Mazzi, Ulderico; Alafort, Laura Melendez; Moschini, Giuliano; Nadali, Anna; Navarria, Francesco; Perrotta, Andrea; Rosato, Antonio; Tanzarella, Caterina; Uzunov, Nikolay

    2007-02-01

    Assessment of "in vitro" tumor growth inhibition and radiobiological effects, such as apoptosis, have been evaluated in human neoplastic cells of different histotypes (H460 lung cancer cells, U87 glioblastoma, LnCaP prostate tumor cells) treated using solutions of 188Rhenium-perrhenate. The MTT assay, which measures mitochondrial metabolism in the entire cell culture is a recognized test for cytotoxicity and was used in cells exposed 48-72 h to specific activities ranged from 37 to 148 GBq/l. Whereas H460 and LnCaP were particularly sensitive to treatment, U87 glioblastoma cells behaved as radioresistant ones. However, evaluation of 188Re-induced apoptosis indicated that this kind of cell death contributed only marginally to the reduction in cell viability of H460 and LNCaP lines, suggesting the existence of protective mechanisms against apoptosis. In this respect, the membrane receptor, CD44, whose expression is dysregulated in most malignant cell types has proven to alter the response of cancer cells to apoptotic stimuli, including ionizing radiation. Cell samples decorated with a FITC-labelled CD44 antibody indicated, that in H460 and U87 cells the CD44(+) correlated well with an apoptosis-resistant response. Conversely, LnCap cells proven as CD44(-) did not display however sensitivity to radio-induced apoptosis.

  20. Fascin, an Actin-bundling Protein, Induces Membrane Protrusions and Increases Cell Motility of Epithelial Cells

    PubMed Central

    Yamashiro, Shigeko; Yamakita, Yoshihiko; Ono, Shoichiro; Matsumura, Fumio

    1998-01-01

    Fascin is an actin-bundling protein that is found in membrane ruffles, microspikes, and stress fibers. The expression of fascin is greatly increased in many transformed cells, as well as in specialized normal cells including neuronal cells and antigen-presenting dendritic cells. A morphological characteristic common to these cells expressing high levels of fascin is the development of many membrane protrusions in which fascin is predominantly present. To examine whether fascin contributes to the alterations in microfilament organization at the cell periphery, we have expressed fascin in LLC-PK1 epithelial cells to levels as high as those found in transformed cells and in specialized normal cells. Expression of fascin results in large changes in morphology, the actin cytoskeleton, and cell motility: fascin-transfected cells form an increased number of longer and thicker microvilli on apical surfaces, extend lamellipodia-like structures at basolateral surfaces, and show disorganization of cell–cell contacts. Cell migration activity is increased by 8–17 times when assayed by modified Boyden chamber. Microinjection of a fascin protein into LLC-PK1 cells causes similar morphological alterations including the induction of lamellipodia at basolateral surfaces and formation of an increased number of microvilli on apical surfaces. Furthermore, microinjection of fascin into REF-52 cells, normal fibroblasts, induces the formation of many lamellipodia at all regions of cell periphery. These results together suggest that fascin is directly responsible for membrane protrusions through reorganization of the microfilament cytoskeleton at the cell periphery. PMID:9571235

  1. A High Concentration of Genistein Induces Cell Death in Human Uterine Leiomyoma Cells by Autophagy

    PubMed Central

    Castro, Lysandra; Gao, Xioahua; Moore, Alicia B; Yu, Linda; Di, Xudong; Kissling, Grace E; Dixon, Darlene

    2016-01-01

    Genistein, an estrogenic, soy-derived isoflavone, may play a protective role against hormone-related cancers. We have reported that a high concentration of genistein inhibits cell proliferation and induces apoptosis in human uterine smooth muscle cells, but not in leiomyoma (fibroid) cells. To better understand the differential cell death responses of normal and tumor cells to a high concentration of genistein, we treated uterine smooth muscle cells and uterine leiomyoma cells with 50 μg/ml of genistein for 72 h and 168 h, and assessed for mediators of apoptosis, cytotoxicity and autophagy. We found that leiomyoma cells had increased protection from apoptosis by expressing an increased ratio of Bcl-2: bak at 72 h and 168 h; however, in smooth muscle cells, the Bcl-2: bak ratio was decreased at 72 h, but significantly rebounded by 168 h. The apoptosis extrinsic factors, Fas ligand and Fas receptor, were highly expressed in uterine smooth muscle cells following genistein treatment at both time points as evidenced by confocal microscopy. This was not seen in the uterine leiomyoma cells; however, cytotoxicity as indicated by elevated lactate dehydrogenase levels was significantly enhanced at 168 h. Increased immunoexpression of an autophagy/autophagosome marker was also observed in the leiomyoma cells, although minimally present in smooth muscle cells at 72 h. Ultrastructurally, there was evidence of autophagic vacuoles in the leiomyoma cells; whereas, the normal smooth muscle cells showed nuclear fragmentation indicative of apoptosis. In summary, our data show differential cell death pathways induced by genistein in tumor and normal uterine smooth muscle cells, and suggest novel cell death pathways that can be targeted for preventive and intervention strategies for inhibiting fibroid tumor cell growth in vivo. PMID:27512718

  2. Induced pluripotent stem cells and neurological disease models.

    PubMed

    Cai, Sa; Chan, Ying-Shing; Shum, Daisy Kwok-Yan

    2014-02-25

    The availability of human stem cells heralds a new era for in vitro cell-based modeling of neurodevelopmental and neurodegenerative diseases. Adding to the excitement is the discovery that somatic cells of patients can be reprogrammed to a pluripotent state from which neural lineage cells that carry the disease genotype can be derived. These in vitro cell-based models of neurological diseases hold promise for monitoring of disease initiation and progression, and for testing of new drug treatments on the patient-derived cells. In this review, we focus on the prospective applications of different stem cell types for disease modeling and drug screening. We also highlight how the availability of patient-specific induced pluripotent stem cells (iPS cells) offers a unique opportunity for studying and modeling human neurodevelopmental and neurodegenerative diseases in vitro and for testing small molecules or other potential therapies for these disorders. Finally, the limitations of this technology from the standpoint of reprogramming efficiency and therapeutic safety are discussed.

  3. Cell Adhesion Molecules in Chemically-Induced Renal Injury

    PubMed Central

    Prozialeck, Walter C.; Edwards, Joshua R.

    2007-01-01

    Cell adhesion molecules are integral cell-membrane proteins that maintain cell-cell and cell-substrate adhesion, and in some cases, act as regulators of intracellular signaling cascades. In the kidney, cell adhesion molecules such as the cadherins, the catenins, ZO-1, occludin and the claudins are essential for maintaining the epithelial polarity and barrier integrity that are necessary for the normal absorption/excretion of fluid and solutes. A growing volume of evidence indicates that these cell adhesion molecules are important early targets for a variety of nephrotoxic substances including metals, drugs, and venom components. In addition, it is now widely appreciated that molecules such as ICAM-1, the integrins and selectins play important roles in the recruitment of leukocytes and inflammatory responses that are associated with nephrotoxic injury. This review summarizes the results of recent in vitro and in vivo studies indicating that these cell adhesion molecules may be primary molecular targets in many types of chemically-induced renal injury. Some of the specific agents that are discussed include Cd, Hg, Bi, cisplatin, aminoglycoside antibiotics, S-(1,2-dichlorovinyl-L-cysteine) (DCVC) and various venom toxins. This review also includes a discussion of the various mechanisms by which these substances can affect cell adhesion molecules in the kidney. PMID:17316817

  4. ETOPOSIDE INDUCES CHROMOSOMAL ABNORMALITIES IN SPERMATOCYTES AND SPERMATOGONIAL STEM CELLS

    SciTech Connect

    Marchetti, F; Pearson, F S; Bishop, J B; Wyrobek, A J

    2005-07-15

    Etoposide (ET) is a chemotherapeutic agent widely used in the treatment of leukemia, lymphomas and many solid tumors, such as testicular and ovarian cancers, that affect patients in their reproductive years. The purpose of the study was to use sperm FISH analyses to characterize the long-term effects of ET on male germ cells. We used a mouse model to characterize the induction of chromosomal aberrations (partial duplications and deletions) and whole chromosomal aneuploidies in sperm of mice treated with a clinical dose of ET. Semen samples were collected at 25 and 49 days after dosing to investigate the effects of ET on meiotic pachytene cells and spermatogonial stem-cells, respectively. ET treatment resulted in major increases in the frequencies of sperm carrying chromosomal aberrations in both meiotic pachytene (27- to 578-fold) and spermatogonial stem-cells (8- to 16-fold), but aneuploid sperm were induced only after treatment of meiotic cells (27-fold) with no persistent effects in stem cells. These results demonstrate that male meiotic germ cells are considerably more sensitive to ET than spermatogonial stem-cell and that increased frequencies of sperm with structural aberrations persist after spermatogonial stem-cell treatment. These findings predict that patients who undergo chemotherapy with ET may have transient elevations in the frequencies of aneuploid sperm, but more importantly, may have persistent elevations in the frequencies of sperm with chromosomal aberrations, placing them at higher risk for abnormal reproductive outcomes long after the end of their chemotherapy.

  5. Valproic acid induces apoptosis and cell cycle arrest in poorly differentiated thyroid cancer cells.

    PubMed

    Catalano, Maria G; Fortunati, Nicoletta; Pugliese, Mariateresa; Costantino, Lucia; Poli, Roberta; Bosco, Ornella; Boccuzzi, Giuseppe

    2005-03-01

    Poorly differentiated thyroid carcinoma is an aggressive human cancer that is resistant to conventional therapy. Histone deacetylase inhibitors are a promising class of drugs, acting as antiproliferative agents by promoting differentiation, as well as inducing apoptosis and cell cycle arrest. Valproic acid (VPA), a class I selective histone deacetylase inhibitor widely used as an anticonvulsant, promotes differentiation in poorly differentiated thyroid cancer cells by inducing Na(+)/I(-) symporter and increasing iodine uptake. Here, we show that it is also highly effective at suppressing growth in poorly differentiated thyroid cancer cell lines (N-PA and BHT-101). Apoptosis induction and cell cycle arrest are the underlying mechanisms of VPA's effect on cell growth. It induces apoptosis by activating the intrinsic pathway; caspases 3 and 9 are activated but not caspase 8. Cell cycle is selectively arrested in G(1) and is associated with the increased expression of p21 and the reduced expression of cyclin A. Both apoptosis and cell cycle arrest are induced by treatment with 1 mm VPA, a dose that promotes cell redifferentiation and that is slightly above the serum concentration reached in patients treated for epilepsy. These multifaceted properties make VPA of clinical interest as a new approach to treating poorly differentiated thyroid cancer.

  6. OXIDATIVE STRESS INDUCES CELL DEATH IN CD-1 MOUSE CRANIAL NEURAL CREST CELLS IN VITRO

    EPA Science Inventory

    OXIDATIVE STRESS INDUCES CELL DEATH IN CD-1 MOUSE CRANIAL NEURAL CREST CELLS IN VITRO. J.B. Smith, K.K. Sulik, E.S. Hunter III. University of North Carolina at Chapel Hill, Chapel Hill, NC 27599.
    The induction of craniofacial defects by ethanol exposure is mediated in part by...

  7. Protection of Bovine Mammary Epithelial Cells from Hydrogen Peroxide-Induced Oxidative Cell Damage by Resveratrol.

    PubMed

    Jin, Xiaolu; Wang, Kai; Liu, Hongyun; Hu, Fuliang; Zhao, Fengqi; Liu, Jianxin

    2016-01-01

    The mammary epithelial cells (MECs) of high-producing dairy cows are likely to be subject to oxidative stress (OS) due to the intensive cell metabolism. The objectives of this study were to investigate the cytoprotective effects of resveratrol against hydrogen peroxide- (H2O2-) induced OS in cultured bovine MECs (MAC-T). Pretreatment of MAC-T cells with resveratrol could rescue the decrease in cell viability and resulted in lower intracellular reactive oxygen species (ROS) accumulation after H2O2 exposure. Resveratrol helped MAC-T cells to prevent H2O2-induced endoplasmic reticulum stress and mitochondria-related cell apoptosis. Moreover, resveratrol induced mRNA expression of multiple antioxidant defense genes in MAC-T cells under normal/oxidative conditions. Nuclear factor erythroid 2-related factor 2 (Nrf2) was required for the cytoprotective effects on MAC-T cells by resveratrol, as knockdown of Nrf2 significantly abolished resveratrol-induced cytoprotective effects against OS. In addition, by using selective inhibitors, we further confirmed that the induction of Nrf2 by resveratrol was mediated through the prolonged activation of PI3K/Akt and ERK/MAPK pathways but negatively regulated by p38/MAPK pathway. Overall, resveratrol has beneficial effects on bovine MECs redox balance and may be potentially used as a therapeutic medicine against oxidative insult in lactating animals.

  8. Human prion protein-induced autophagy flux governs neuron cell damage in primary neuron cells.

    PubMed

    Moon, Ji-Hong; Lee, Ju-Hee; Nazim, Uddin Md; Lee, You-Jin; Seol, Jae-Won; Eo, Seong-Kug; Lee, John-Hwa; Park, Sang-Youel

    2016-05-24

    An unusual molecular structure of the prion protein, PrPsc is found only in mammals with transmissible prion diseases. Prion protein stands for either the infectious pathogen itself or a main component of it. Recent studies suggest that autophagy is one of the major functions that keep cells alive and has a protective effect against the neurodegeneration. In this study, we investigated that the effect of human prion protein on autophagy-lysosomal system of primary neuronal cells. The treatment of human prion protein induced primary neuron cell death and decreased both LC3-II and p62 protein amount indicating autophagy flux activation. Electron microscope pictures confirmed the autophagic flux activation in neuron cells treated with prion protein. Inhibition of autophagy flux using pharmacological and genetic tools prevented neuron cell death induced by human prion protein. Autophagy flux induced by prion protein is more activated in prpc expressing cells than in prpc silencing cells. These data demonstrated that prion protein-induced autophagy flux is involved in neuron cell death in prion disease and suggest that autophagy flux might play a critical role in neurodegenerative diseases including prion disease.

  9. Protection of Bovine Mammary Epithelial Cells from Hydrogen Peroxide-Induced Oxidative Cell Damage by Resveratrol

    PubMed Central

    Jin, Xiaolu; Wang, Kai; Liu, Hongyun; Hu, Fuliang; Zhao, Fengqi; Liu, Jianxin

    2016-01-01

    The mammary epithelial cells (MECs) of high-producing dairy cows are likely to be subject to oxidative stress (OS) due to the intensive cell metabolism. The objectives of this study were to investigate the cytoprotective effects of resveratrol against hydrogen peroxide- (H2O2-) induced OS in cultured bovine MECs (MAC-T). Pretreatment of MAC-T cells with resveratrol could rescue the decrease in cell viability and resulted in lower intracellular reactive oxygen species (ROS) accumulation after H2O2 exposure. Resveratrol helped MAC-T cells to prevent H2O2-induced endoplasmic reticulum stress and mitochondria-related cell apoptosis. Moreover, resveratrol induced mRNA expression of multiple antioxidant defense genes in MAC-T cells under normal/oxidative conditions. Nuclear factor erythroid 2-related factor 2 (Nrf2) was required for the cytoprotective effects on MAC-T cells by resveratrol, as knockdown of Nrf2 significantly abolished resveratrol-induced cytoprotective effects against OS. In addition, by using selective inhibitors, we further confirmed that the induction of Nrf2 by resveratrol was mediated through the prolonged activation of PI3K/Akt and ERK/MAPK pathways but negatively regulated by p38/MAPK pathway. Overall, resveratrol has beneficial effects on bovine MECs redox balance and may be potentially used as a therapeutic medicine against oxidative insult in lactating animals. PMID:26962394

  10. Axin expression reduces staurosporine-induced mitochondria-mediated cell death in HeLa cells.

    PubMed

    Shin, Jee-Hye; Kim, Hyun-wook; Rhyu, Im Joo; Song, Ki-Joon; Kee, Sun-Ho

    2012-10-01

    Cytoplasmic axin expression frequently produces punctuate structures in cells, but the nature of axin puncta has not been fully elucidated. In an effort to analyze cytoplasmic axin puncta, we established HeLa cells expressing axin in a doxycycline-inducible manner (HeLa-Axin). We observed that axin accumulated in an aggregate-like pattern in perinuclear areas and appeared to be associated with mitochondria, Golgi apparatus, and endoplasmic reticulum (ER), but not lysosomes. Further biochemical analysis suggested that some part of the cytoplasmic axin pool was associated with mitochondria. In addition, mitochondrial proteins [i.e., cytochrome oxidase IV (CoxIV) and cytochrome c] were slightly higher in HeLa-Axin cells than in HeLa-EV cells, suggesting altered mitochondrial degradation. HeLa-Axin cells were then treated with staurosporine (STS) to determine if the mitochondria-induced apoptosis pathway was altered. Compared to STS-treated control cells (HeLa-EV), HeLa-Axin cells had less STS-induced cytotoxicity and reduced caspase-3 activation and PARP cleavage. Given that mitochondria outer membrane potential was unchanged, HeLa-Axin cells might be relatively resistant to STS-mediated mitochondrial damage. Mitochondria associated with axin aggregates were resistant to detergent-mediated permeabilization. These results suggest that axin forms aggregate-like structures in association with mitochondria, which render mitochondria resistant to STS-induced membrane damage and cytotoxicity.

  11. Photodynamic therapy-induced programmed cell death in carcinoma cell lines

    NASA Astrophysics Data System (ADS)

    He, Xiao-Yan; Sikes, Robert A.; Thomsen, Sharon L.; Chung, L.; Jacques, Steven L.

    1993-06-01

    The mode of cell death following photodynamic therapy (PDT) was investigated from the perspective of programmed cell death (apoptosis). Human prostate carcinoma cells (PC3), human non-small cell lung carcinoma (H322a), and rat mammary carcinoma (MTF7) were treated by PDT following sensitization with dihematoporphyrin ether (DHE). The response of these carcinoma cell lines to PDT was variable. An examination of extracted cellular DNA by gel electrophoresis showed the characteristic DNA ladder pattern indicative of internucleosomal cleavage of DNA during apoptosis. MTF7 and PC3 responded to PDT by inducing apoptosis while H322a had no apoptotic response. The magnitude of the response and the PDT dosage required to induce the effect were different in PC3 and MTF7. MTF7 cells responded with rapid apoptosis at the dose of light and drug that yielded 50% cell death (LD50). In contrast, PC3 showed only marginal apoptosis at the LD50 but had a marked response at the LD85. Furthermore, the onset of apoptosis followed slower kinetics in PC3 (2 hr - 4 hr) than in MTF7 (< 1 hr). H322a cells were killed by PDT but failed to exhibit any apoptotic response. This study indicates that apoptosis may occur during PDT induced cell death, but this pathway is not universal for all cancer cell lines.

  12. The fungicide mancozeb induces toxic effects on mammalian granulosa cells.

    PubMed

    Paro, Rita; Tiboni, Gian Mario; Buccione, Roberto; Rossi, Gianna; Cellini, Valerio; Canipari, Rita; Cecconi, Sandra

    2012-04-15

    The ethylene-bis-dithiocarbamate mancozeb is a widely used fungicide with low reported toxicity in mammals. In mice, mancozeb induces embryo apoptosis, affects oocyte meiotic spindle morphology and impairs fertilization rate even when used at very low concentrations. We evaluated the toxic effects of mancozeb on the mouse and human ovarian somatic granulosa cells. We examined parameters such as cell morphology, induction of apoptosis, and p53 expression levels. Mouse granulosa cells exposed to mancozeb underwent a time- and dose-dependent modification of their morphology, and acquired the ability to migrate but not to proliferate. The expression level of p53, in terms of mRNA and protein content, decreased significantly in comparison with unexposed cells, but no change in apoptosis was recorded. Toxic effects could be attributed, at least in part, to the presence of ethylenthiourea (ETU), the main mancozeb catabolite, which was found in culture medium. Human granulosa cells also showed dose-dependent morphological changes and reduced p53 expression levels after exposure to mancozeb. Altogether, these results indicate that mancozeb affects the somatic cells of the mammalian ovarian follicles by inducing a premalignant-like status, and that such damage occurs to the same extent in both mouse and human GC. These results further substantiate the concept that mancozeb should be regarded as a reproductive toxicant.

  13. Tumor-induced immune dysfunctions caused by myeloid suppressor cells.

    PubMed

    Bronte, V; Serafini, P; Apolloni, E; Zanovello, P

    2001-01-01

    In the late 1970s, several findings suggested that accessory cells distinct from lymphocytes might suppress immune reactivity in tumor-bearing hosts. Studies in animal models and patients later confirmed that cells driven to act as dominant immune suppressors by growing cancers could subvert the immune system. These cells have also been termed natural suppressors, a functional definition connoting their ability to hamper various T- and B-lymphocyte responses without prior activation and independently from antigen and MHC restriction. These properties were attributed to distinct cell populations. The phenotypic discrepancies, together with the lack of antigen specificity, have generated serious restraints to research on tumor-induced suppression. Recent evidence indicates that suppressor cells are closely related to immature myeloid precursors and can be found in several situations that can exert adverse effects on the immunotherapy of cancer. The present review is an attempt to address the nature and properties of immature myeloid suppressors and their relationship to dendritic cells and macrophages, with the aim of clarifying the complex network of tumor-induced, negative regulators of the immune system.

  14. Deletion of the Mitochondrial Flavoprotein Apoptosis Inducing Factor (AIF) Induces β-Cell Apoptosis and Impairs β-Cell Mass

    PubMed Central

    Schulthess, Fabienne T.; Katz, Sophie; Ardestani, Amin; Kawahira, Hiroshi; Georgia, Senta; Bosco, Domenico; Bhushan, Anil; Maedler, Kathrin

    2009-01-01

    Background Apoptosis is a hallmark of β-cell death in both type 1 and type 2 diabetes mellitus. Understanding how apoptosis contributes to β-cell turnover may lead to strategies to prevent progression of diabetes. A key mediator of apoptosis, mitochondrial function, and cell survival is apoptosis inducing factor (AIF). In the present study, we investigated the role of AIF on β-cell mass and survival using the Harlequin (Hq) mutant mice, which are hypomorphic for AIF. Methodology/Principal Findings Immunohistochemical evaluation of pancreata from Hq mutant mice displayed much smaller islets compared to wild-type mice (WT). Analysis of β-cell mass in these mice revealed a greater than 4-fold reduction in β-cell mass together with an 8-fold increase in β-cell apoptosis. Analysis of cell cycle dynamics, using BrdU pulse as a marker for cells in S-phase, did not detect significant differences in the frequency of β-cells in S-phase. In contrast, double staining for phosphorylated Histone H3 and insulin showed a 3-fold increase in β-cells in the G2 phase in Hq mutant mice, but no differences in M-phase compared to WT mice. This suggests that the β-cells from Hq mutant mice are arrested in the G2 phase and are unlikely to complete the cell cycle. β-cells from Hq mutant mice display increased sensitivity to hydrogen peroxide-induced apoptosis, which was confirmed in human islets in which AIF was depleted by siRNA. AIF deficiency had no effect on glucose stimulated insulin secretion, but the impaired effect of hydrogen peroxide on β-cell function was potentiated. Conclusions/Significance Our results indicate that AIF is essential for maintaining β-cell mass and for oxidative stress response. A decrease in the oxidative phosphorylation capacity may counteract the development of diabetes, despite its deleterious effects on β-cell survival. PMID:19197367

  15. Fibrogenic Lung Injury Induces Non-Cell-Autonomous Fibroblast Invasion.

    PubMed

    Ahluwalia, Neil; Grasberger, Paula E; Mugo, Brian M; Feghali-Bostwick, Carol; Pardo, Annie; Selman, Moisés; Lagares, David; Tager, Andrew M

    2016-06-01

    Pathologic accumulation of fibroblasts in pulmonary fibrosis appears to depend on their invasion through basement membranes and extracellular matrices. Fibroblasts from the fibrotic lungs of patients with idiopathic pulmonary fibrosis (IPF) have been demonstrated to acquire a phenotype characterized by increased cell-autonomous invasion. Here, we investigated whether fibroblast invasion is further stimulated by soluble mediators induced by lung injury. We found that bronchoalveolar lavage fluids from bleomycin-challenged mice or patients with IPF contain mediators that dramatically increase the matrix invasion of primary lung fibroblasts. Further characterization of this non-cell-autonomous fibroblast invasion suggested that the mediators driving this process are produced locally after lung injury and are preferentially produced by fibrogenic (e.g., bleomycin-induced) rather than nonfibrogenic (e.g., LPS-induced) lung injury. Comparison of invasion and migration induced by a series of fibroblast-active mediators indicated that these two forms of fibroblast movement are directed by distinct sets of stimuli. Finally, knockdown of multiple different membrane receptors, including platelet-derived growth factor receptor-β, lysophosphatidic acid 1, epidermal growth factor receptor, and fibroblast growth factor receptor 2, mitigated the non-cell-autonomous fibroblast invasion induced by bronchoalveolar lavage from bleomycin-injured mice, suggesting that multiple different mediators drive fibroblast invasion in pulmonary fibrosis. The magnitude of this mediator-driven fibroblast invasion suggests that its inhibition could be a novel therapeutic strategy for pulmonary fibrosis. Further elaboration of the molecular mechanisms that drive non-cell-autonomous fibroblast invasion consequently may provide a rich set of novel drug targets for the treatment of IPF and other fibrotic lung diseases.

  16. Isoliquiritigenin inhibits cell proliferation and induces apoptosis in human hepatoma cells.

    PubMed

    Hsu, Ya-Ling; Kuo, Po-Lin; Lin, Liang-Tzung; Lin, Chun-Ching

    2005-02-01

    Isoliquiritigenin (4,2',4'-trihydroxychalcone, ISL) is a natural pigment with a simple chalcone structure. In this study, we report the ISL-induced inhibition on the growth of human hepatoma cells (Hep G2) for the first time. The cell growth inhibition achieved by ISL treatment resulted in programmed cell death in a caspase activation-dependent manner, with an IC50 of 10.51 microg/mL. Outcomes of ISL treatment included the up-regulation of IkappaBalpha expression in the cytoplasm, and the decrease of NF-kappaB level as well as its activity in the nucleus. In addition, ISL also suppressed the expression of Bcl-XL and c-IAP1/2 protein, the downstream target molecule of NF-kappaB. These results demonstrated that ISL treatment inhibited the NF-kappaB cell survival-signaling pathway and induced apoptotic cell death in Hep G2 cells.

  17. Mesenchymal Stem Cells Induce Directional Migration of Invasive Breast Cancer Cells through TGF-β

    PubMed Central

    McAndrews, Kathleen M.; McGrail, Daniel J.; Ravikumar, Nithin; Dawson, Michelle R.

    2015-01-01

    Mesenchymal stem cells (MSCs) are recruited to the tumor microenvironment and influence tumor progression; however, how MSCs induce the invasion of cancer cells is not completely understood. Here, we used a 3D coculture model to determine how MSCs affect the migration of invasive breast cancer cells. Coculture with MSCs increases the elongation, directional migration, and traction generation of breast cancer cells. MSC-induced directional migration directly correlates with traction generation and is mediated by transforming growth factor β (TGF-β) and the migratory proteins rho-associated kinase, focal adhesion kinase, and matrix metalloproteinases. Treatment with MSC conditioned media or recombinant TGF-β1 elicits a similar migration response to coculture. Taken together, this work suggests TGF-β is secreted by MSCs, leading to force-dependent directional migration of invasive breast cancer cells. These pathways may be potential targets for blocking cancer cell invasion and subsequent metastasis. PMID:26585689

  18. Oxidative stress induces mitochondrial fragmentation in frataxin-deficient cells

    SciTech Connect

    Lefevre, Sophie; Sliwa, Dominika; Rustin, Pierre; Camadro, Jean-Michel; Santos, Renata

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer Yeast frataxin-deficiency leads to increased proportion of fragmented mitochondria. Black-Right-Pointing-Pointer Oxidative stress induces complete mitochondrial fragmentation in {Delta}yfh1 cells. Black-Right-Pointing-Pointer Oxidative stress increases mitochondrial fragmentation in patient fibroblasts. Black-Right-Pointing-Pointer Inhibition of mitochondrial fission in {Delta}yfh1 induces oxidative stress resistance. -- Abstract: Friedreich ataxia (FA) is the most common recessive neurodegenerative disease. It is caused by deficiency in mitochondrial frataxin, which participates in iron-sulfur cluster assembly. Yeast cells lacking frataxin ({Delta}yfh1 mutant) showed an increased proportion of fragmented mitochondria compared to wild-type. In addition, oxidative stress induced complete fragmentation of mitochondria in {Delta}yfh1 cells. Genetically controlled inhibition of mitochondrial fission in these cells led to increased resistance to oxidative stress. Here we present evidence that in yeast frataxin-deficiency interferes with mitochondrial dynamics, which might therefore be relevant for the pathophysiology of FA.

  19. Salidroside inhibits endogenous hydrogen peroxide induced cytotoxicity of endothelial cells.

    PubMed

    Zhao, Xingyu; Jin, Lianhai; Shen, Nan; Xu, Bin; Zhang, Wei; Zhu, Hongli; Luo, Zhengli

    2013-01-01

    Salidroside, a phenylpropanoid glycoside isolated from Rhodiola rosea L., shows potent antioxidant property. Herein, we investigated the protective effects of salidroside against hydrogen peroxide (H2O2)-induced oxidative damage in human endothelial cells (EVC-304). EVC-304 cells were incubated in the presence or absence of low steady states of H2O2 (3-4 µM) generated by glucose oxidase (GOX) with or without salidroside. 3(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) assays were performed, together with Hoechst 33258 staining and flow cytometric analysis using Annexin-V and propidium iodide (PI) label. The results indicated that salidroside pretreatment attenuated endogenous H2O2 induced apoptotic cell death in EVC-304 cells in a dose-dependent pattern. Furthermore, Western blot data revealed that salidroside inhibited activation of caspase-3, 9 and cleavage of poly(ADP-ribose) polymerase (PARP) induced by endogenous H2O2. It also decreased the expression of Bax and rescued the balance of pro- and anti-apoptotic proteins. All these results demonstrated that salidroside may present a potential therapy for oxidative stress in cardiovascular and cerebrovascular diseases.

  20. How Heme Oxygenase-1 Prevents Heme-Induced Cell Death.

    PubMed

    Lanceta, Lilibeth; Mattingly, Jacob M; Li, Chi; Eaton, John W

    2015-01-01

    Earlier observations indicate that free heme is selectively toxic to cells lacking heme oxygenase-1 (HO-1) but how this enzyme prevents heme toxicity remains unexplained. Here, using A549 (human lung cancer) and immortalized human bronchial epithelial cells incubated with exogenous heme, we find knock-down of HO-1 using siRNA does promote the accumulation of cell-associated heme and heme-induced cell death. However, it appears that the toxic effects of heme are exerted by "loose" (probably intralysosomal) iron because cytotoxic effects of heme are lessened by pre-incubation of HO-1 deficient cells with desferrioxamine (which localizes preferentially in the lysosomal compartment). Desferrioxamine also decreases lysosomal rupture promoted by intracellularly generated hydrogen peroxide. Supporting the importance of endogenous oxidant production, both chemical and siRNA inhibition of catalase activity predisposes HO-1 deficient cells to heme-mediated killing. Importantly, it appears that HO-1 deficiency somehow blocks the induction of ferritin; control cells exposed to heme show ~10-fold increases in ferritin heavy chain expression whereas in heme-exposed HO-1 deficient cells ferritin expression is unchanged. Finally, overexpression of ferritin H chain in HO-1 deficient cells completely prevents heme-induced cytotoxicity. Although two other products of HO-1 activity--CO and bilirubin--have been invoked to explain HO-1-mediated cytoprotection, we conclude that, at least in this experimental system, HO-1 activity triggers the induction of ferritin and the latter is actually responsible for the cytoprotective effects of HO-1 activity.

  1. Transcriptomics and Functional Genomics of ROS-Induced Cell Death Regulation by RADICAL-INDUCED CELL DEATH1

    PubMed Central

    Salojärvi, Jarkko; Cui, Fuqiang; Sipari, Nina; Leppälä, Johanna; Lamminmäki, Airi; Tomai, Gloria; Narayanasamy, Shaman; Reddy, Ramesha A.; Keinänen, Markku; Overmyer, Kirk; Kangasjärvi, Jaakko

    2014-01-01

    Plant responses to changes in environmental conditions are mediated by a network of signaling events leading to downstream responses, including changes in gene expression and activation of cell death programs. Arabidopsis thaliana RADICAL-INDUCED CELL DEATH1 (RCD1) has been proposed to regulate plant stress responses by protein-protein interactions with transcription factors. Furthermore, the rcd1 mutant has defective control of cell death in response to apoplastic reactive oxygen species (ROS). Combining transcriptomic and functional genomics approaches we first used microarray analysis in a time series to study changes in gene expression after apoplastic ROS treatment in rcd1. To identify a core set of cell death regulated genes, RCD1-regulated genes were clustered together with other array experiments from plants undergoing cell death or treated with various pathogens, plant hormones or other chemicals. Subsequently, selected rcd1 double mutants were constructed to further define the genetic requirements for the execution of apoplastic ROS induced cell death. Through the genetic analysis we identified WRKY70 and SGT1b as cell death regulators functioning downstream of RCD1 and show that quantitative rather than qualitative differences in gene expression related to cell death appeared to better explain the outcome. Allocation of plant energy to defenses diverts resources from growth. Recently, a plant response termed stress-induced morphogenic response (SIMR) was proposed to regulate the balance between defense and growth. Using a rcd1 double mutant collection we show that SIMR is mostly independent of the classical plant defense signaling pathways and that the redox balance is involved in development of SIMR. PMID:24550736

  2. Induced melanin reduces mutations and cell killing in mouse melanoma.

    PubMed

    Li, W; Hill, H Z

    1997-03-01

    When melanin absorbs light energy, it can produce potentially damaging active oxygen species. There is little doubt that constitutive pigment in dark-skinned individuals is photoprotective against skin cancer, but induced pigment-as in tanning-may not be. The first step in cancer induction is mutation in DNA. The most suitable systems for evaluating the role of melanin are those in which pigment can be varied and mutations can be measured. Several cell lines from Cloudman S91 mouse melanoma can be induced to form large quantities of melanin pigment after treatment with a number of different agents enabling comparison of mutant yields in the same cells differing principally in pigment concentration. In these studies, melanin was induced with synthetic alpha-melanocyte-stimulating hormone and with isobutyl methyl xanthine in the cell line S91/mel. The former inducer produced about 50% more pigment than the latter. Survival and mutation induction at the Na+/K(+)-ATPase locus were studied using ethyl methane sulfonate (EMS), a standard mutagen and five UV lamps emitting near monochromatic and polychromatic UV light in the three wave-length ranges of UV. There was greater protection against killing and mutation induction in the more heavily pigmented cells after exposure to EMS and after irradiation with monochromatic UVC and UVB. There was significant protection against killing by polychromatic UVB + UVA (FS20), but the small degree of protection against mutation was not significant. No significant change in killing and mutation using the same protocol was seen in S91/amel, a related cell line that does not respond to these inducers. No mutants were produced by either monochromatic or polychromatic UVA at doses that killed 50% of the cells. Our results show that induced pigment-shown earlier to be eumelanin (K. A. Cieszka et al., Exp. Dermatol. 4, 192-198, 1995)-is photo- and chemoprotective, but it is less effective in protection against mutagenesis by polychromatic

  3. Tangeretin induces cell cycle arrest and apoptosis through upregulation of PTEN expression in glioma cells.

    PubMed

    Ma, Li-Li; Wang, Da-Wei; Yu, Xu-Dong; Zhou, Yan-Ling

    2016-07-01

    Tangeretin (TANG), present in peel of citrus fruits, has been shown to various medicinal properties such as chemopreventive and neuroprotective. However, the chemopreventive effect of TANG on glioblastoma cells has not been examined. The present study was designed to explore the anticancer potential of TANG in glioblastoma cells and to investigate the related mechanism. Human glioblastoma U-87MG and LN-18 cells were treated with 45μM concentration of TANG and cell growth was measured by MTT assay. The cell cycle distribution and cell death were measured by flow cytometry. The expression of cell cycle and apoptosis related genes were analyzed by quantitative RT-PCR and western blot. The cells treated with TANG were significantly increased cell growth suppression and cell death effects than vehicle treated cells. Further, TANG treatment increases G2/M arrest and apoptosis by modulating PTEN and cell-cycle regulated genes such as cyclin-D and cdc-2 mRNA and protein expressions. Moreover, the ability of TANG to decrease cell growth and to induce cell death was compromised when PTEN was knockdown by siRNA. Taken together, the chemopreventive effect of TANG is associated with regulation of cell-cycle and apoptosis in glioblastoma, thereby attenuating glioblastoma cell growth. Hence, the present findings suggest that TANG may be a therapeutic agent for glioblastoma treatment.

  4. Apigenin induces autophagic cell death in human papillary thyroid carcinoma BCPAP cells.

    PubMed

    Zhang, Li; Cheng, Xian; Gao, Yanyan; Zheng, Jie; Xu, Qiang; Sun, Yang; Guan, Haixia; Yu, Huixin; Sun, Zhen

    2015-11-01

    Apigenin, abundantly present in fruits and vegetables, is recognized as a flavonoid with anti-inflammatory, antioxidant and anticancer properties. In this study, we first investigated the anti-neoplastic effects of apigenin on papillary thyroid carcinoma (PTC) cell line BCPAP cells. Our results show that apigenin inhibited the viability of BCPAP cells in a dose-dependent manner. A large body of evidence demonstrates that autophagy contributes to cell death in certain contexts. In the present study, autophagy was induced by apigenin treatment in BCPAP cells, as evidenced by Beclin-1 accumulation, conversion of LC3 protein, p62 degradation as well as the significantly increased formation of acidic vesicular organelles (AVOs) compared to the control group. 3-MA, an autophagy inhibitor, rescued the cells from apigenin-induced cell death. Notably, apigenin enhanced production of reactive oxygen species (ROS), and subsequent induction of significant DNA damage as monitored by the TUNEL assay. In addition, apigenin treatment caused a significant accumulation of cells in the G2/M phase via down-regulation of Cdc25C expression. Our findings reveal that apigenin inhibits papillary thyroid cancer cell viability by the stimulation of reactive oxygen species (ROS) production, induction of DNA damage, leading to G2/M cell cycle arrest followed by autophagic cell death. Thus, our results provide new insights into the molecular mechanisms underlying apigenin-mediated autophagic cell death and suggest apigenin as a potential chemotherapeutic agent which is able to fight against papillary thyroid cancer.

  5. Induction of Skin-Derived Precursor Cells from Human Induced Pluripotent Stem Cells

    PubMed Central

    Sugiyama-Nakagiri, Yoriko; Fujimura, Tsutomu; Moriwaki, Shigeru

    2016-01-01

    The generation of full thickness human skin from dissociated cells is an attractive approach not only for treating skin diseases, but also for treating many systemic disorders. However, it is currently not possible to obtain an unlimited number of skin dermal cells. The goal of this study was to develop a procedure to produce skin dermal stem cells from induced pluripotent stem cells (iPSCs). Skin-derived precursor cells (SKPs) were isolated as adult dermal precursors that could differentiate into both neural and mesodermal progenies and could reconstitute the dermis. Thus, we attempted to generate SKPs from iPSCs that could reconstitute the skin dermis. Human iPSCs were initially cultured with recombinant noggin and SB431542, an inhibitor of activin/nodal and TGFβ signaling, to induce neural crest progenitor cells. Those cells were then treated with SKP medium that included CHIR99021, a WNT signal activator. The induction efficacy from neural crest progenitor cells to SKPs was more than 97%. No other modifiers tested were able to induce those cells. Those human iPSC-derived SKPs (hiPSC-SKPs) showed a similar gene expression signature to SKPs isolated from human skin dermis. Human iPSC-SKPs differentiated into neural and mesodermal progenies, including adipocytes, skeletogenic cell types and Schwann cells. Moreover, they could be induced to follicular type keratinization when co-cultured with human epidermal keratinocytes. We here provide a new efficient protocol to create human skin dermal stem cells from hiPSCs that could contribute to the treatment of various skin disorders. PMID:27992514

  6. Adipose-derived stromal cells inhibit prostate cancer cell proliferation inducing apoptosis

    SciTech Connect

    Takahara, Kiyoshi; Ii, Masaaki; Inamoto, Teruo; Komura, Kazumasa; Ibuki, Naokazu; Minami, Koichiro; Uehara, Hirofumi; Hirano, Hajime; Nomi, Hayahito; Kiyama, Satoshi; Asahi, Michio; Azuma, Haruhito

    2014-04-18

    Highlights: • AdSC transplantation exhibits inhibitory effect on tumor progressions of PCa cells. • AdSC-induced PCa cell apoptosis may occur via the TGF-β signaling pathway. • High expression of the TGF-β1 gene in AdSCs. - Abstract: Mesenchymal stem cells (MSCs) have generated a great deal of interest in the field of regenerative medicine. Adipose-derived stromal cells (AdSCs) are known to exhibit extensive proliferation potential and can undergo multilineage differentiation, sharing similar characteristics to bone marrow-derived MSCs. However, as the effect of AdSCs on tumor growth has not been studied sufficiently, we assessed the degree to which AdSCs affect the proliferation of prostate cancer (PCa) cell. Human AdSCs exerted an inhibitory effect on the proliferation of androgen-responsive (LNCaP) and androgen-nonresponsive (PC3) human PCa cells, while normal human dermal fibroblasts (NHDFs) did not, and in fact promoted PCa cell proliferation to a degree. Moreover, AdSCs induced apoptosis of LNCaP cells and PC3 cells, activating the caspase3/7 signaling pathway. cDNA microarray analysis suggested that AdSC-induced apoptosis in both LNCaP and PC3 cells was related to the TGF-β signaling pathway. Consistent with our in vitro observations, local transplantation of AdSCs delayed the growth of tumors derived from both LNCaP- and PC3-xenografts in immunodeficient mice. This is the first preclinical study to have directly demonstrated that AdSC-induced PCa cell apoptosis may occur via the TGF-β signaling pathway, irrespective of androgen-responsiveness. Since autologous AdSCs can be easily isolated from adipose tissue without any ethical concerns, we suggest that therapy with these cells could be a novel approach for patients with PCa.

  7. The advantages of hair follicle pluripotent stem cells over embryonic stem cells and induced pluripotent stem cells for regenerative medicine.

    PubMed

    Amoh, Yasuyuki; Katsuoka, Kensei; Hoffman, Robert M

    2010-12-01

    Multipotent adult stem cells have many potential therapeutic applications. Our recent findings suggest that hair follicles are a promising source of easily accessible multipotent stem cells. Stem cells in the hair follicle area express the neural stem cell marker nestin, suggesting that hair-follicle stem cells and neural stem cells have common features. Nestin-expressing hair follicle stem cells can form neurons and other cell types, and thus adult hair follicle stem cells could have important therapeutic applications, particularly for neurologic diseases. Transplanted hair follicle stem cells promote the functional recovery of injured peripheral nerve and spinal cord. Recent findings suggest that direct transplantation of hair-follicle stem cells without culture can promote nerve repair, which makes them potentially clinically practical. Human hair follicle stem cells as well as mouse hair follicle stem cells promote nerve repair and can be applied to test the hypothesis that human hair follicle stem cells can provide a readily available source of neurologically therapeutic stem cells. The use of hair follicle stem cells for nerve regeneration overcomes critical problems of embryonic stem cells or induced pluripotent stem cells in that the hair follicle stem cells are multipotent, readily accessible, non-oncogenic, and are not associated with ethical issues.

  8. Induced pluripotent stem cells with a pathological mitochondrial DNA deletion

    PubMed Central

    Cherry, Anne B. C.; Gagne, Katelyn E.; McLoughlin, Erin M.; Baccei, Anna; Gorman, Bryan; Hartung, Odelya; Miller, Justine D.; Zhang, Jin; Zon, Rebecca L.; Ince, Tan A.; Neufeld, Ellis J.; Lerou, Paul H.; Fleming, Mark D.; Daley, George Q.; Agarwal, Suneet

    2013-01-01

    In congenital mitochondrial DNA (mtDNA) disorders, a mixture of normal and mutated mtDNA (termed heteroplasmy) exists at varying levels in different tissues, which determines the severity and phenotypic expression of disease. Pearson marrow pancreas syndrome (PS) is a congenital bone marrow failure disorder caused by heteroplasmic deletions in mtDNA. The cause of the hematopoietic failure in PS is unknown, and adequate cellular and animal models are lacking. Induced pluripotent stem (iPS) cells are particularly amenable for studying mtDNA disorders, as cytoplasmic genetic material is retained during direct reprogramming. Here we derive and characterize iPS cells from a patient with PS. Taking advantage of the tendency for heteroplasmy to change with cell passage, we isolated isogenic PS-iPS cells without detectable levels of deleted mtDNA. We found that PS-iPS cells carrying a high burden of deleted mtDNA displayed differences in growth, mitochondrial function, and hematopoietic phenotype when differentiated in vitro, compared to isogenic iPS cells without deleted mtDNA. Our results demonstrate that reprogramming somatic cells from patients with mtDNA disorders can yield pluripotent stem cells with varying burdens of heteroplasmy that might be useful in the study and treatment of mitochondrial diseases. PMID:23400930

  9. 6K2-induced vesicles can move cell to cell during turnip mosaic virus infection

    PubMed Central

    Grangeon, Romain; Jiang, Jun; Wan, Juan; Agbeci, Maxime; Zheng, Huanquan; Laliberté, Jean-François

    2013-01-01

    To successfully infect plants, viruses replicate in an initially infected cell and then move to neighboring cells through plasmodesmata (PDs). However, the nature of the viral entity that crosses over the cell barrier into non-infected ones is not clear. The membrane-associated 6K2 protein of turnip mosaic virus (TuMV) induces the formation of vesicles involved in the replication and intracellular movement of viral RNA. This study shows that 6K2-induced vesicles trafficked toward the plasma membrane and were associated with plasmodesmata (PD). We demonstrated also that 6K2 moved cell-to-cell into adjoining cells when plants were infected with TuMV. 6K2 was then fused to photo-activable GFP (6K2:PAGFP) to visualize how 6K2 moved intercellularly during TuMV infection. After activation, 6K2:PAGFP-tagged vesicles moved to the cell periphery and across the cell wall into adjacent cells. These vesicles were shown to contain the viral RNA-dependent RNA polymerase and viral RNA. Symplasmic movement of TuMV may thus be achieved in the form of a membrane-associated viral RNA complex induced by 6K2. PMID:24409170

  10. Characterization of nicardipine hydrochloride-induced cell injury in human vascular endothelial cells.

    PubMed

    Ochi, Masanori; Kawai, Yoshiko; Tanaka, Yoshiyuki; Toyoda, Hiromu

    2015-02-01

    Nicardipine hydrochloride (NIC), a dihydropyridine calcium-channel blocking agent, has been widely used for the treatment of hypertension. Especially, nicardipine hydrochloride injection is used as first-line therapy for emergency treatment of abnormally high blood pressure. Although NIC has an attractive pharmacological profile, one of the dose-limiting factors of NIC is severe peripheral vascular injury after intravenous injection. The goal of this study was to better understand and thereby reduce NIC-mediated vascular injury. Here, we investigated the mechanism of NIC-induced vascular injury using human dermal microvascular endothelial cells (HMVECs). NIC decreased cell viability and increased percent of dead cells in a dose-dependent manner (10-30 μg/mL). Although cell membrane injury was not significant over 9 hr exposure, significant changes of cell morphology and increases in vacuoles in HMVECs were observed within 30 min of NIC exposure (30 μg/mL). Autophagosome labeling with monodansylcadaverine revealed increased autophagosomes in the NIC-treated cells, whereas caspase 3/7 activity was not increased in the NIC-treated cells (30 μg/mL). Additionally, NIC-induced reduction of cell viability was inhibited by 3-methyladenine, an inhibitor of autophagosome formation. These findings suggest that NIC causes severe peripheral venous irritation via induction of autophagic cell death and that inhibition of autophagy could contribute to the reduction of NIC-induced vascular injury.

  11. Blockade of the ERK pathway markedly sensitizes tumor cells to HDAC inhibitor-induced cell death

    SciTech Connect

    Ozaki, Kei-ichi; Minoda, Ai; Kishikawa, Futaba; Kohno, Michiaki . E-mail: kohnom@net.nagasaki-u.ac.jp

    2006-01-27

    Constitutive activation of the extracellular signal-regulated kinase (ERK) pathway is associated with the neoplastic phenotype of a large number of human tumor cells. Although specific blockade of the ERK pathway by treating such tumor cells with potent mitogen-activated protein kinase/ERK kinase (MEK) inhibitors completely suppresses their proliferation, it by itself shows only a modest effect on the induction of apoptotic cell death. However, these MEK inhibitors markedly enhance the efficacy of histone deacetylase (HDAC) inhibitors to induce apoptotic cell death: such an enhanced cell death is observed only in tumor cells in which the ERK pathway is constitutively activated. Co-administration of MEK inhibitor markedly sensitizes tumor cells to HDAC inhibitor-induced generation of reactive oxygen species, which appears to mediate the enhanced cell death induced by the combination of these agents. These results suggest that the combination of MEK inhibitors and HDAC inhibitors provides an efficient chemotherapeutic strategy for the treatment of tumor cells in which the ERK pathway is constitutively activated.

  12. 2'-Nitroflavone induces cell cycle arrest and apoptosis in HeLa human cervical carcinoma cells.

    PubMed

    Cárdenas, Mariano G; Blank, Viviana C; Marder, Mariel; Roguin, Leonor P

    2008-09-08

    The mechanism of antitumor action of a synthetic nitroflavone derivative, 2'-nitroflavone, was evaluated in vitro in HeLa human cervix adenocarcinoma cells. We showed that the nitroflavone derivative slowed down the cell cycle at the S phase and increase the population of cells at the G2/M phase after 24h of incubation. The treatment with 2'-nitroflavone also induced an apoptotic response, characterized by an increase of the sub-G1 fraction of cells, by cells with chromatin condensation and membrane blebbing, by a typical ladder of DNA fragmentation and by detection of apoptotic cells stained with Annexin V. The observed apoptosis was regulated by caspase-8 and -9, both contributing to the activation of the effector caspase-3. In addition, inhibitors of caspase-8 or -9 partially protected HeLa cells from 2'-nitroflavone-induced cell death. We also found that 2'-nitroflavone did not affect the total amount of Bax and Bcl-2 proteins, although a translocation of Bax from cytosol to mitochondria was evident after 6h of exposure. Furthermore, 2'-nitroflavone decreased the expression of the anti-apoptotic Bcl-XL protein, induced the release of cytochrome C to cytosol and increased the levels of Fas and Fas-L. Our results indicated that both death receptor and mitochondria-dependent pathways are involved in the apoptotic cell death triggered by 2'-nitroflavone and suggest that this derivative could be a potentially useful agent for the treatment of certain malignancies.

  13. Type of cell death induced by seven metals in cultured mouse osteoblastic cells.

    PubMed

    Contreras, René García; Vilchis, José Rogelio Scougall; Sakagami, Hiroshi; Nakamura, Yuko; Nakamura, Yukio; Hibino, Yasushi; Nakajima, Hiroshi; Shimada, Jun

    2010-01-01

    The use of dental metal alloys in the daily clinic makes it necessary to evaluate the cytotoxicity of eluted metal components against oral cells. However, the cytotoxic mechanism and the type of cell death induced by dental metals in osteoblasts have not been well characterized. This study investigated the cytotoxicity of seven metals against the mouse osteoblastic cell line MC3T3-E1. alpha-MEM was used as a culture medium, since this medium provided much superior proliferation of MC3T3-E1 cells over DMEM. Ag (NH(3))(2)F was the most cytotoxic, followed by CuCl>CuCl(2) >CoCl(2), NiCl(2)>FeCl(3) and FeCl(2) (least toxic). None of the metals showed any apparent growth stimulating effect (so-called 'hormesis') at lower concentrations. A time course study demonstrated that two hours of contact between oral cells and Ag (NH(3))(2)F, CuCl, CoCl(2) or NiCl(2) induced irreversible cell death. Contact with these metals induced a smear pattern of DNA fragmentation without activation of caspase-3. Preincubation of MC3T3-E1 cells with either a caspase inhibitor (Z-VAD-FMK) or autophagy inhibitors (3-methyladenine, bafilomycin) failed to rescue them from metal cytotoxicity. These data suggest the induction of necrotic cell death rather than apoptosis and autophagy by metals in this osteoblastic cell line.

  14. Novel self-micellizing anticancer lipid nanoparticles induce cell death of colorectal cancer cells.

    PubMed

    Sundaramoorthy, Pasupathi; Baskaran, Rengarajan; Mishra, Siddhartha Kumar; Jeong, Keun-Yeong; Oh, Seung Hyun; Kyu Yoo, Bong; Kim, Hwan Mook

    2015-11-01

    In the present study, we developed a novel drug-like self-micellizing anticancer lipid (SMAL), and investigated its anticancer activity and effects on cell death pathways in human colorectal cancer (CRC) cell lines. Three self-assembled nanoparticles were prepared, namely, SMAL102 (lauramide derivative), SMAL104 (palmitamide derivative), and SMAL108 (stearamide derivative) by a thin-film hydration technique, and were characterized for physicochemical and biological parameters. SMAL102 were nanosized (160.23 ± 8.11 nm) with uniform spherical shape, while SMAL104 and SMAL108 did not form spherical shape but formed large size nanoparticles and irregular in shape. Importantly, SMAL102 showed a cytotoxic effect towards CRC cell lines (HCT116 and HT-29), and less toxicity to a normal colon fibroblast cell line (CCD-18Co). Conversely, SMAL104 and SMAL108 did not have an anti-proliferative effect on CRC cell lines. SMAL102 nanoparticles were actively taken up by CRC cell lines, localized in the cell membrane, and exhibited remarkable cytotoxicity in a concentration-dependent manner. The normal colon cell line showed significantly less cellular uptake and non-cytotoxicity as compared with the CRC cell lines. SMAL102 nanoparticles induced caspase-3, caspase-9, and PARP cleavage in HT-29 cells, indicating the induction of apoptosis; whereas LC3B was activated in HCT116 cells, indicating autophagy-induced cell death. Collectively, these results demonstrate that SMAL102 induced cell death via activation of apoptosis and autophagy in CRC cell lines. The present study could be a pioneer for further preclinical and clinical development of such compounds.

  15. Differentiation of human foreskin fibroblast-derived induced pluripotent stem cells into hepatocyte-like cells.

    PubMed

    Wang, Jianjun; Zhao, Ping; Wan, Zhihong; Jin, Xueyuan; Cheng, Yongqian; Yan, Tao; Qing, Song; Ding, Ning; Xin, Shaojie

    2016-10-01

    The aim of this study was to investigate the differentiation potential of induced pluripotent stem cells (iPSCs) derived from human foreskin fibroblasts (HFFs) into hepatocyte-like cells (HLCs). The iPSCs were firstly induced by transduction of OCT4, SOX2, KLF4, and c-MYC into HFFs using retrovirus. Afterwards, expressions of pluripotency factors were identified by semiquantitative reverse transcription-polymerase chain reaction and immunofluorescence staining, and karyotype, embryoid, and teratoma were observed by microscope. Then, iPSCs were gradually differentiated into endoderm cells, hepatic progenitor cells, and mature HLCs by special culture medium. During this process, differentiation efficiency into each kind of cells was evaluated by detecting SOX17, HNF4a, and ALB using flow cytometry, respectively. Besides, enzyme-linked immunosorbent assay was conducted to detect the secretion of ALB in iPSC-induced HLCs and quantitative reverse transcription-polymerase chain reaction was performed to detect the expression levels of hepatocyte-specific genes. The iPSCs were successfully induced by HFFs, which exhibited typical embryonic stem cells morphology, positive alkaline phosphatase staining, normal diploid karyotype, and positive expression of various pluripotency factors. Meanwhile, spherical embryoid and teratoma with 3 germ layers were formed by iPSCs. The iPSCs were consecutively induced into endoderm cells, hepatic progenitor cells and mature HLCs, and the differentiation efficiency was 55.7 ± 2.9%, 45.7 ± 4.8%, and 35.0 ± 3.9%, respectively. Besides, the secretion of ALB and expression of various hepatocyte-specific genes was highly detected in iPSC-induced HLCs. The iPSCs were successfully derived from HFFs and then differentiated into HLCs, which proved a new source for hepatocyte transplantation.

  16. IFN-inducible GTPases in host cell defense.

    PubMed

    Kim, Bae-Hoon; Shenoy, Avinash R; Kumar, Pradeep; Bradfield, Clinton J; MacMicking, John D

    2012-10-18

    From plants to humans, the ability to control infection at the level of an individual cell-a process termed cell-autonomous immunity-equates firmly with survival of the species. Recent work has begun to unravel this programmed cell-intrinsic response and the central roles played by IFN-inducible GTPases in defending the mammalian cell's interior against a diverse group of invading pathogens. These immune GTPases regulate vesicular traffic and protein complex assembly to stimulate oxidative, autophagic, membranolytic, and inflammasome-related antimicrobial activities within the cytosol, as well as on pathogen-containing vacuoles. Moreover, human genome-wide association studies and disease-related transcriptional profiling have linked mutations in the Immunity-Related GTPase M (IRGM) locus and altered expression of guanylate binding proteins (GBPs) with tuberculosis susceptibility and Crohn's colitis.

  17. Electrolyte-induced inversion layer Schottky junction solar cells.

    PubMed

    Wadhwa, Pooja; Seol, Gyungseon; Petterson, Maureen K; Guo, Jing; Rinzler, Andrew G

    2011-06-08

    A new type of crystalline silicon solar cell is described. Superficially similar to a photoelectrochemical cell a liquid electrolyte creates a depletion (inversion) layer in an n-type silicon wafer, however no regenerative redox couple is present to ferry charge between the silicon and a counter electrode. Instead holes trapped in the electrolyte-induced inversion layer diffuse along the layer until they come to widely spaced grid lines, where they are extracted. The grid lines consist of a single-walled carbon nanotube film etched to cover only a fraction of the n-Si surface. Modeling and simulation shows the inversion layer to be a natural consequence of the device electrostatics. With electronic gating, recently demonstrated to boost the efficiency in related devices, the cell achieves a power conversion efficiency of 12%, exceeding the efficiency of dye sensitized solar cells.

  18. Sulforaphane induces differential modulation of mitochondrial biogenesis and dynamics in normal cells and tumor cells.

    PubMed

    Negrette-Guzmán, Mario; Huerta-Yepez, Sara; Vega, Mario I; León-Contreras, Juan Carlos; Hernández-Pando, Rogelio; Medina-Campos, Omar Noel; Rodríguez, Esteban; Tapia, Edilia; Pedraza-Chaverri, José

    2017-02-01

    Antioxidant-based chemotherapy has been intensely debated. Herein, we show that sulforaphane (SFN) induced mitochondrial biogenesis followed by mitochondrial fusion in a kidney cell line commonly used in nephroprotective models. At the same concentration and exposure time, SFN induced cell death in prostate cancer cells accompanied by mitochondrial biogenesis and fragmentation. Stabilization of the nuclear factor E2-related factor-2 (Nrf2) could be associated with these effects in the tumor cell line. An increase in the peroxisome proliferator-activated receptor-γ co-activator-1α (PGC1α) level and a decrease in the hypoxia-inducible factor-1α (HIF1α) level would suggest a possible metabolic shift. The knockdown in the nuclear respiratory factor-1 (NRF1) attenuated the SFN-induced effect on prostate cancer cells demonstrating that mitochondrial biogenesis plays an important role in cell death for this kind of tumor cells. This evidence supports SFN as a potential antineoplastic agent that could inhibit tumor development and could protect normal tissues by modulating common processes.

  19. Enhancement of ultrasonically induced cell damage by phthalocyanines in vitro.

    PubMed

    Milowska, Katarzyna; Gabryelak, Teresa

    2008-12-01

    In this work, erythrocytes from carp were used as a nucleated cell model to test the hypothesis that the phthalocyanines (zinc--ZnPc and chloroaluminium -AlClPc) enhance ultrasonically induced damage in vitro. In order to confirm and complete our earlier investigation, the influence of ultrasound (US) and phthalocyanines (Pcs) on unresearched cellular components, was studied. Red blood cells were exposed to 1 MHz continuous ultrasound wave (0.61 and/or 2.44 W/cm(2)) in the presence or absence of phthalocyanines (3 microM). To identify target cell damage, we studied hemolysis, membrane fluidity and morphology of erythrocytes. To demonstrate the changes in the fluidity of plasma membrane we used the spectrofluorimetric methods using two fluorescence probes: 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5,-hexatriene (TMA-DPH) and 1,6-diphenyl-1,3,5-hexatriene (DPH). The effect of US and Pcs on nucleated erythrocytes morphology was estimated on the basis of microscopic observation. The enhancement of ultrasonically induced membrane damage by both phthalocyanines was observed in case of hemolysis, and membrane surface fluidity, in comparison to ultrasound. The authors also observed changes in the morphology of erythrocytes. The obtained results support the hypothesis that the Pcs enhance ultrasonically induced cell damage in vitro. Furthermore, the influence of ultrasound on phthalocyanines (Pcs) in medium and in cells was tested. The authors observed changes in the phthalocyanines absorption spectra in the medium and the increase in the intensity of phthalocyanines fluorescence in the cells. These data can suggest changes in the structure of phthalocyanines after ultrasound action.

  20. Acetaminophen Induces Human Neuroblastoma Cell Death through NFKB Activation

    PubMed Central

    Posadas, Inmaculada; Santos, Pablo; Ceña, Valentín

    2012-01-01

    Neuroblastoma resistance to apoptosis may contribute to the aggressive behavior of this tumor. Therefore, it would be relevant to activate endogenous cellular death mechanisms as a way to improve neuroblastoma therapy. We used the neuroblastoma SH-SY5Y cell line as a model to study the mechanisms involved in acetaminophen (AAP)-mediated toxicity by measuring CYP2E1 enzymatic activity, NFkB p65 subunit activation and translocation to the nucleus, Bax accumulation into the mitochondria, cytochrome c release and caspase activation. AAP activates the intrinsic death pathway in the SH-SY5Y human neuroblastoma cell line. AAP metabolism is partially responsible for this activation, because blockade of the cytochrome CYP2E1 significantly reduced but did not totally prevent, AAP-induced SH-SY5Y cell death. AAP also induced NFkB p65 activation by phosphorylation and its translocation to the nucleus, where NFkB p65 increased IL-1β production. This increase contributed to neuroblastoma cell death through a mechanism involving Bax accumulation into the mitochondria, cytochrome c release and caspase3 activation. Blockade of NFkB translocation to the nucleus by the peptide SN50 prevented AAP-mediated cell death and IL-1β production. Moreover, overexpression of the antiapoptotic protein Bcl-xL did not decrease AAP-mediated IL-1β production, but prevented both AAP and IL-1β-mediated cell death. We also confirmed the AAP toxic actions on SK-N-MC neuroepithelioma and U87MG glioblastoma cell lines. The results presented here suggest that AAP activates the intrinsic death pathway in neuroblastoma cells through a mechanism involving NFkB and IL-1β. PMID:23166834

  1. Induced pluripotent stem cells: from Nobel Prizes to clinical applications.

    PubMed

    Rashid, S Tamir; Alexander, Graeme J M

    2013-03-01

    Advances in basic hepatology have been constrained for many years by the inability to culture primary hepatocytes in vitro, until just over five years ago when the scientific playing field was changed beyond recognition with the demonstration that human skin fibroblasts could be reprogrammed to resemble embryonic cells. The reprogrammed cells, known as induced pluripotent stem cells (iPSCs), were then shown to have the capacity to re-differentiate into almost any human cell type, including hepatocytes. The unlimited number and isogenic nature of the cells that can be generated from tiny fragments of tissue have massive implications for the study of human liver diseases in vitro. Of more immediate clinical importance were recent data demonstrating precision gene therapy on patient specific iPSCs, which opens up the real and exciting possibility of autologous hepatocyte transplantation as a substitute for allogeneic whole liver transplantation, which has been an effective approach to end-stage liver disease, but one that has now been outstripped by demand. In this review, we describe the historical development, current technology and potential clinical applications of induced pluripotency, concluding with a perspective on possible future directions in this dynamic field.

  2. [Progress and potential applications of induced pluripotent stem cell technology].

    PubMed

    Wu, Cui-Ling; Zhang, Yu-Ming

    2014-08-01

    Differentiated somatic cells can be reprogrammed to a pluripotent state through ectopic expression of specific transcription factors. These reprogrammed cells, which were designated as induced pluripotent stem (iPS) cells, are detected to exhibit unlimited self-renewal capacity and pluripotency. This breakthrough in stem cell research provides a powerful and novel tool for the studies on pathogenesis of diseases, reprogramming mechanism and development of new therapies. For this reason, the iPSC technology has currently become one of the hot topics in stem cells research. Recently, major progress in this field has been achieved: initially, researchers succeeded in inducing the reprogramming of mouse fibroblasts by retroviral transduction of four specific transcription factors; in succession, the accelerated development of iPSC technology by employing non-integrating viral vectors, non-viral vectors or removing the introduced foreign genes via gene knock-out has ensured the yields of much safer iPSC; meanwhile, some researches discovered the proofs that a number of micro molecular compounds were potent in accelerating the cellular reprogramming. For a prospect, iPSC are highly promising for regenerative medicine, disease modeling and drug screening. In this review, the recent progress in the generation of iPSC, prospects of their possible clinical applications and problems in the iPSC research are summarized and discussed.

  3. Fenofibrate Induces Ketone Body Production in Melanoma and Glioblastoma Cells

    PubMed Central

    Grabacka, Maja M.; Wilk, Anna; Antonczyk, Anna; Banks, Paula; Walczyk-Tytko, Emilia; Dean, Matthew; Pierzchalska, Malgorzata; Reiss, Krzysztof

    2016-01-01

    Ketone bodies [beta-hydroxybutyrate (bHB) and acetoacetate] are mainly produced in the liver during prolonged fasting or starvation. bHB is a very efficient energy substrate for sustaining ATP production in peripheral tissues; importantly, its consumption is preferred over glucose. However, the majority of malignant cells, particularly cancer cells of neuroectodermal origin such as glioblastoma, are not able to use ketone bodies as a source of energy. Here, we report a novel observation that fenofibrate, a synthetic peroxisome proliferator-activated receptor alpha (PPARa) agonist, induces bHB production in melanoma and glioblastoma cells, as well as in neurospheres composed of non-transformed cells. Unexpectedly, this effect is not dependent on PPARa activity or its expression level. The fenofibrate-induced ketogenesis is accompanied by growth arrest and downregulation of transketolase, but the NADP/NADPH and GSH/GSSG ratios remain unaffected. Our results reveal a new, intriguing aspect of cancer cell biology and highlight the benefits of fenofibrate as a supplement to both canonical and dietary (ketogenic) therapeutic approaches against glioblastoma. PMID:26869992

  4. Cyanide-induced death of cells in plant leaves.

    PubMed

    Vasil'ev, L A; Vorobyov, A A; Dzyubinskaya, E V; Nesov, A V; Shestak, A A; Samuilov, V D

    2007-05-01

    Destruction of guard cell nuclei in epidermis isolated from leaves of pea, maize, sunflower, and haricot bean, as well as destruction of cell nuclei in leaves of the aquatic plants waterweed and eelgrass were induced by cyanide. Destruction of nuclei was strengthened by illumination, prevented by the antioxidant alpha-tocopherol and an electron acceptor N,N,N ,N -tetramethyl-p-phenylenediamine, and removed by quinacrine. Photosynthetic O2 evolution by the leaf slices of a C3 plant (pea), or a C4 plant (maize) was inhibited by CN- inactivating ribulose-1,5-bisphosphate carboxylase, and was renewed by subsequent addition of the electron acceptor p-benzoquinone.

  5. Facilitated Anion Transport Induces Hyperpolarization of the Cell Membrane That Triggers Differentiation and Cell Death in Cancer Stem Cells.

    PubMed

    Soto-Cerrato, Vanessa; Manuel-Manresa, Pilar; Hernando, Elsa; Calabuig-Fariñas, Silvia; Martínez-Romero, Alicia; Fernández-Dueñas, Víctor; Sahlholm, Kristoffer; Knöpfel, Thomas; García-Valverde, María; Rodilla, Ananda M; Jantus-Lewintre, Eloisa; Farràs, Rosa; Ciruela, Francisco; Pérez-Tomás, Ricardo; Quesada, Roberto

    2015-12-23

    Facilitated anion transport potentially represents a powerful tool to modulate various cellular functions. However, research into the biological effects of small molecule anionophores is still at an early stage. Here we have used two potent anionophore molecules inspired in the structure of marine metabolites tambjamines to gain insight into the effect induced by these compounds at the cellular level. We show how active anionophores, capable of facilitating the transmembrane transport of chloride and bicarbonate in model phospholipid liposomes, induce acidification of the cytosol and hyperpolarization of plasma cell membranes. We demonstrate how this combined effect can be used against cancer stem cells (CSCs). Hyperpolarization of cell membrane induces cell differentiation and loss of stemness of CSCs leading to effective elimination of this cancer cell subpopulation.

  6. Xanthohumol induces apoptosis and S phase cell cycle arrest in A549 non-small cell lung cancer cells

    PubMed Central

    Yong, Wai Kuan; Ho, Yen Fong; Malek, Sri Nurestri Abd

    2015-01-01

    Background: Xanthohumol, a major prenylated chalcone found in female hop plant, Humulus lupulus, was reported to have various chemopreventive and anti-cancer properties. However, its apoptotic effect on human alveolar adenocarcinoma cell line (A549) of non-small cell lung cancer (NSCLC) was unknown. Objective: This study aimed to investigate the effects of xanthohumol on apoptosis in A549 human NSCLC cells. Materials and Methods: A549 cell proliferation was determined by sulforhodamine B assay. Morphological changes of the cells were studied via phase contrast and fluorescent microscopy. Induction of apoptosis was assessed by Annexin-V fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) staining, DNA fragmentation (TUNEL) assay mitochondrial membrane potential assay, cell cycle analysis, and caspase activity studies. Results: Xanthohumol was found to decrease cell proliferation in A549 cells but had relatively low cytotoxicity on normal human lung fibroblast cell line (MRC-5). Typical cellular and nuclear apoptotic features were also observed in A549 cells treated with xanthohumol. Onset of apoptosis in A549 cells was further confirmed by externalization of phosphatidylserine, changes in mitochondrial membrane potential, and DNA fragmentation in the cells after treatment. Xanthohumol induced accumulation of cells in sub G1 and S phase based on cell cycle analysis and also increased the activities of caspase-3, -8, and -9. Conclusion: This work suggests that xanthohumol as an apoptosis inducer, may be a potent therapeutic compound for NSCLC. PMID:26664015

  7. Physical modalities inducing immunogenic tumor cell death for cancer immunotherapy

    PubMed Central

    Adkins, Irena; Fucikova, Jitka; Garg, Abhishek D; Agostinis, Patrizia; Špíšek, Radek

    2015-01-01

    The concept of immunogenic cancer cell death (ICD), as originally observed during the treatment with several chemotherapeutics or ionizing irradiation, has revolutionized the view on the development of new anticancer therapies. ICD is defined by endoplasmic reticulum (ER) stress response, reactive oxygen species (ROS) generation, emission of danger-associated molecular patterns and induction of antitumor immunity. Here we describe known and emerging cancer cell death-inducing physical modalities, such as ionizing irradiation, ultraviolet C light, Photodynamic Therapy (PDT) with Hypericin, high hydrostatic pressure (HHP) and hyperthermia (HT), which have been shown to elicit effective antitumor immunity. We discuss the evidence of ICD induced by these modalities in cancer patients together with their applicability in immunotherapeutic protocols and anticancer vaccine development. PMID:25964865

  8. Artocarpus communis Induces Autophagic Instead of Apoptotic Cell Death in Human Hepatocellular Carcinoma Cells.

    PubMed

    Tzeng, Cheng-Wei; Tzeng, Wen-Sheng; Lin, Liang-Tzung; Lee, Chiang-Wen; Yen, Ming-Hong; Yen, Feng-Lin; Lin, Chun-Ching

    2015-01-01

    For centuries, natural plant extracts have played an important role in traditional medicine for curing and preventing diseases. Studies have revealed that Artocarpus communis possess various bioactivities, such as anti-inflammation, anti-oxidant, and anticancer activities. A. communis offers economic value as a source of edible fruit, yields timber, and is widely used in folk medicines. However, little is known about its molecular mechanisms of anticancer activity. Here, we demonstrate the antiproliferative activity of A. communis methanol extract (AM) and its dichloromethane fraction (AD) in two human hepatocellular carcinoma (HCC) cell lines, HepG2 and PLC/PRF/5. Colony assay showed the long-term inhibitory effect of both extracts on cell growth. DNA laddering and immunoblotting analyses revealed that both extracts did not induce apoptosis in the hepatoma cell lines. AM and AD-treated cells demonstrated different cell cycle distribution compared to UV-treated cells, which presented apoptotic cell death with high sub-G1 ratio. Instead, acridine orange staining revealed that AM and AD triggered autophagosome accumulation. Immunoblotting showed a significant expression of autophagy-related proteins, which indicated the autophagic cell death (ACD) of hepatoma cell lines. This study therefore demonstrates that A. communis AM and its dichloromethane fraction can induce ACD in HCC cells and elucidates the potential of A. communis extracts for development as anti tumor therapeutic agents that utilize autophagy as mechanism in mediating cancer cell death.

  9. Nicotinamide induces differentiation of embryonic stem cells into insulin-secreting cells

    SciTech Connect

    Vaca, Pilar; Berna, Genoveva; Araujo, Raquel; Carneiro, Everardo M.; Bedoya, Francisco J.; Soria, Bernat; Martin, Franz

    2008-03-10

    The poly(ADP-ribose) polymerase (PARP) inhibitor, nicotinamide, induces differentiation and maturation of fetal pancreatic cells. In addition, we have previously reported evidence that nicotinamide increases the insulin content of cells differentiated from embryonic stem (ES) cells, but the possibility of nicotinamide acting as a differentiating agent on its own has never been completely explored. Islet cell differentiation was studied by: (i) X-gal staining after neomycin selection; (ii) BrdU studies; (iii) single and double immunohistochemistry for insulin, C-peptide and Glut-2; (iv) insulin and C-peptide content and secretion assays; and (v) transplantation of differentiated cells, under the kidney capsule, into streptozotocin (STZ)-diabetic mice. Here we show that undifferentiated mouse ES cells treated with nicotinamide: (i) showed an 80% decrease in cell proliferation; (ii) co-expressed insulin, C-peptide and Glut-2; (iii) had values of insulin and C-peptide corresponding to 10% of normal mouse islets; (iv) released insulin and C-peptide in response to stimulatory glucose concentrations; and (v) after transplantation into diabetic mice, normalized blood glucose levels over 7 weeks. Our data indicate that nicotinamide decreases ES cell proliferation and induces differentiation into insulin-secreting cells. Both aspects are very important when thinking about cell therapy for the treatment of diabetes based on ES cells.

  10. Rho1-Wnd signaling regulates loss-of-cell polarity-induced cell invasion in Drosophila.

    PubMed

    Ma, X; Chen, Y; Zhang, S; Xu, W; Shao, Y; Yang, Y; Li, W; Li, M; Xue, L

    2016-02-18

    Both cell polarity and c-Jun N-terminal kinase (JNK) activity are essential to the maintenance of tissue homeostasis, and disruption of either is commonly seen in cancer progression. Despite the established connection between loss-of-cell polarity and JNK activation, much less is known about the molecular mechanism by which aberrant cell polarity induces JNK-mediated cell migration and tumor invasion. Here we show results from a genetic screen using an in vivo invasion model via knocking down cell polarity gene in Drosophila wing discs, and identify Rho1-Wnd signaling as an important molecular link that mediates loss-of-cell polarity-triggered JNK activation and cell invasion. We show that Wallenda (Wnd), a protein kinase of the mitogen-activated protein kinase kinase kinase family, by forming a complex with the GTPase Rho1, is both necessary and sufficient for Rho1-induced JNK-dependent cell invasion, MMP1 activation and epithelial-mesenchymal transition. Furthermore, Wnd promotes cell proliferation and tissue growth through wingless production when apoptosis is inhibited by p35. Finally, Wnd shows oncogenic cooperation with Ras(V12) to trigger tumor growth in eye discs and causes invasion into the ventral nerve cord. Together, our data not only provides a novel mechanistic insight on how cell polarity loss contributes to cell invasion, but also highlights the value of the Drosophila model system to explore human cancer biology.

  11. Generation of induced pluripotent stem cells from human kidney mesangial cells.

    PubMed

    Song, Bi; Niclis, Jonathan C; Alikhan, Maliha A; Sakkal, Samy; Sylvain, Aude; Kerr, Peter G; Laslett, Andrew L; Bernard, Claude A; Ricardo, Sharon D

    2011-07-01

    Glomerular injury and podocyte loss leads to secondary tubulointerstitial damage and the development of fibrosis. The possibility of genetically reprogramming adult cells, termed induced pluripotent stem cells (iPS), may pave the way for patient-specific stem-cell-based therapies. Here, we reprogrammed normal human mesangial cells to pluripotency by retroviral transduction using defined factors (OCT4, SOX2, KLF4 and c-Myc). The kidney iPS (kiPS) cells resembled human embryonic stem-cell-like colonies in morphology and gene expression: They were alkaline phosphatase-positive; expressed OCT3/4, TRA-1 to 60 and TRA-1 to 81 proteins; and showed downregulation of mesangial cell markers. Quantitative (qPCR) showed that kiPS cells expressed genes analogous to embryonic stem cells and exhibited silencing of the retroviral transgenes by the fourth passage of differentiation. Furthermore, kiPS cells formed embryoid bodies and expressed markers of all three germ layers. The injection of undifferentiated kiPS colonies into immunodeficient mice formed teratomas, thereby demonstrating pluripotency. These results suggest that reprogrammed kidney induced pluripotent stem cells may aid the study of genetic kidney diseases and lead to the development of novel therapies.

  12. Analogs of farnesylcysteine induce apoptosis in HL-60 cells.

    PubMed

    Pérez-Sala, D; Gilbert, B A; Rando, R R; Cañada, F J

    1998-04-24

    S-Farnesyl-thioacetic acid (FTA), a competitive inhibitor of isoprenylated protein methyltransferase, potently suppressed the growth of HL-60 cells and induced apoptosis, as evidenced by the development of increased annexin-V binding, decreased binding of DNA dyes and internucleosomal DNA degradation. FTA did not impair the membrane association of ras proteins, conversely, it brought about a decrease in the proportion of ras present in the cytosolic fraction. Farnesylated molecules which are weak inhibitors of the methyltransferase also induced DNA laddering and reduced the proportion of cytosolic ras. These findings suggest that neither inhibition of isoprenylated protein methylation nor impairment of ras membrane association are essential for apoptosis induced by farnesylcysteine analogs.

  13. Signalling mechanisms mediating Zn2+-induced TRPM2 channel activation and cell death in microglial cells

    PubMed Central

    Mortadza, Sharifah Syed; Sim, Joan A.; Stacey, Martin; Jiang, Lin-Hua

    2017-01-01

    Excessive Zn2+ causes brain damage via promoting ROS generation. Here we investigated the role of ROS-sensitive TRPM2 channel in H2O2/Zn2+-induced Ca2+ signalling and cell death in microglial cells. H2O2/Zn2+ induced concentration-dependent increases in cytosolic Ca2+ concentration ([Ca2+]c), which was inhibited by PJ34, a PARP inhibitor, and abolished by TRPM2 knockout (TRPM2-KO). Pathological concentrations of H2O2/Zn2+ induced substantial cell death that was inhibited by PJ34 and DPQ, PARP inhibitors, 2-APB, a TRPM2 channel inhibitor, and prevented by TRPM2-KO. Further analysis indicate that Zn2+ induced ROS production, PARP-1 stimulation, increase in the [Ca2+]c and cell death, all of which were suppressed by chelerythrine, a protein kinase C inhibitor, DPI, a NADPH-dependent oxidase (NOX) inhibitor, GKT137831, a NOX1/4 inhibitor, and Phox-I2, a NOX2 inhibitor. Furthermore, Zn2+-induced PARP-1 stimulation, increase in the [Ca2+]c and cell death were inhibited by PF431396, a Ca2+-sensitive PYK2 inhibitor, and U0126, a MEK/ERK inhibitor. Taken together, our study shows PKC/NOX-mediated ROS generation and PARP-1 activation as an important mechanism in Zn2+-induced TRPM2 channel activation and, TRPM2-mediated increase in the [Ca2+]c to trigger the PYK2/MEK/ERK signalling pathway as a positive feedback mechanism that amplifies the TRPM2 channel activation. Activation of these TRPM2-depenent signalling mechanisms ultimately drives Zn2+-induced Ca2+ overloading and cell death. PMID:28322340

  14. Pixantrone induces cell death through mitotic perturbations and subsequent aberrant cell divisions

    PubMed Central

    Beeharry, Neil; Di Rora, Andrea Ghelli Luserna; Smith, Mitchell R; Yen, Timothy J

    2015-01-01

    Pixantrone is a novel aza-anthracenedione active against aggressive lymphoma and is being evaluated for use against various hematologic and solid tumors. The drug is an analog of mitoxantrone, but displays less cardiotoxicity than mitoxantrone or the more commonly used doxorubicin. Although pixantrone is purported to inhibit topoisomerase II activity and intercalate with DNA, exact mechanisms of how it induces cell death remain obscure. Here we evaluated the effect of pixantrone on a panel of solid tumor cell lines to understand its mechanism of cell killing. Initial experiments with pixantrone showed an apparent discrepancy between its anti-proliferative effects in MTS assays (short-term) compared with clonogenic assays (long-term). Using live cell videomicroscopy to track the fates of cells, we found that cells treated with pixantrone underwent multiple rounds of aberrant cell division before eventually dying after approximately 5 d post-treatment. Cells underwent abnormal mitosis in which chromosome segregation was impaired, generating chromatin bridges between cells or within cells containing micronuclei. While pixantrone-treated cells did not display γH2AX foci, a marker of DNA damage, in the main nuclei, such foci were often detected in the micronuclei. Using DNA content analysis, we found that pixantrone concentrations that induced cell death in a clonogenic assay did not impede cell cycle progression, further supporting the lack of canonical DNA damage signaling. These findings suggest pixantrone induces a latent type of DNA damage that impairs the fidelity of mitosis, without triggering DNA damage response or mitotic checkpoint activation, but is lethal after successive rounds of aberrant division. PMID:26177126

  15. Potent Paracrine Effects of human induced Pluripotent Stem Cell-derived Mesenchymal Stem Cells Attenuate Doxorubicin-induced Cardiomyopathy

    PubMed Central

    Zhang, Yuelin; Liang, Xiaoting; Liao, Songyan; Wang, Weixin; Wang, Junwen; Li, Xiang; Ding, Yue; Liang, Yingmin; Gao, Fei; Yang, Mo; Fu, Qingling; Xu, Aimin; Chai, Yuet-Hung; He, Jia; Tse, Hung-Fat; Lian, Qizhou

    2015-01-01

    Transplantation of bone marrow mesenchymal stem cells (BM-MSCs) can protect cardiomyocytes against anthracycline-induced cardiomyopathy (AIC) through paracrine effects. Nonetheless the paracrine effects of human induced pluripotent stem cell-derived MSCs (iPSC-MSCs) on AIC are poorly understood. In vitro studies reveal that doxorubicin (Dox)-induced reactive oxidative stress (ROS) generation and cell apoptosis in neonatal rat cardiomyocytes (NRCMs) are significantly reduced when treated with conditioned medium harvested from BM-MSCs (BM-MSCs-CdM) or iPSC-MSCs (iPSC-MSCs-CdM). Compared with BM-MSCs-CdM, NRCMs treated with iPSC-MSCs-CdM exhibit significantly less ROS and cell apoptosis in a dose-dependent manner. Transplantation of BM-MSCs-CdM or iPSC-MSCs-CdM into mice with AIC remarkably attenuated left ventricular (LV) dysfunction and dilatation. Compared with BM-MSCs-CdM, iPSC-MSCs-CdM treatment showed better alleviation of heart failure, less cardiomyocyte apoptosis and fibrosis. Analysis of common and distinct cytokines revealed that macrophage migration inhibitory factor (MIF) and growth differentiation factor-15 (GDF-15) were uniquely overpresented in iPSC-MSC-CdM. Immunodepletion of MIF and GDF-15 in iPSC-MSCs-CdM dramatically decreased cardioprotection. Injection of GDF-15/MIF cytokines could partially reverse Dox-induced heart dysfunction. We suggest that the potent paracrine effects of iPSC-MSCs provide novel “cell-free” therapeutic cardioprotection against AIC, and that MIF and GDF-15 in iPSC-MSCs-CdM are critical for these enhanced cardioprotective effects. PMID:26057572

  16. Statins induce differentiation and cell death in neurons and astroglia.

    PubMed

    März, Pia; Otten, Uwe; Miserez, André R

    2007-01-01

    Statins are potent inhibitors of the hydroxy-methyl-glutaryl-coenzyme A reductase, the rate limiting enzyme for cholesterol biosynthesis. Experimental and clinical studies with statins suggest that they have beneficial effects on neurodegenerative disorders. Thus, it was of interest to characterize the direct effects of statins on CNS neurons and glial cells. We have treated defined cultures of neurons and astrocytes of newborn rats with two lipophilic statins, atorvastatin and simvastatin, and analyzed their effects on morphology and survival. Treatment of astrocytes with statins induced a time- and dose-dependent stellation, followed by apoptosis. Similarly, statins elicited programmed cell death of cerebellar granule neurons but with a higher sensitivity. Analysis of different signaling cascades revealed that statins fail to influence classical pathways such as Akt or MAP kinases, known to be activated in CNS cells. In addition, astrocyte stellation triggered by statins resembled dibutryl-cyclic AMP (db-cAMP) induced morphological differentiation. However, in contrast to db-cAMP, statins induced upregulation of low-density lipoprotein receptors, without affecting GFAP expression, indicating separate underlying mechanisms. Analysis of the cholesterol biosynthetic pathway revealed that lack of mevalonate and of its downstream metabolites, mainly geranylgeranyl-pyrophosphate (GGPP), is responsible for the statin-induced apoptosis of neurons and astrocytes. Moreover, astrocytic stellation triggered by statins was inhibited by mevalonate and GGPP. Interestingly, neuronal cell death was significantly reduced in astrocyte/neuron co-cultures treated with statins. We postulate that under these conditions signals provided by astrocytes, e.g., isoprenoids play a key role in neuronal survival.

  17. Generation of Induced Pluripotent Stem Cells from Mammalian Endangered Species.

    PubMed

    Ben-Nun, Inbar Friedrich; Montague, Susanne C; Houck, Marlys L; Ryder, Oliver; Loring, Jeanne F

    2015-01-01

    For some highly endangered species there are too few reproductively capable animals to maintain adequate genetic diversity, and extraordinary measures are necessary to prevent their extinction. Cellular reprogramming is a means to capture the genomes of individual animals as induced pluripotent stem cells (iPSCs), which may eventually facilitate reintroduction of genetic material into breeding populations. Here, we describe a method for generating iPSCs from fibroblasts of mammalian endangered species.

  18. Monocyte cell surface glycosaminoglycans positively modulate IL-4-induced differentiation toward dendritic cells.

    PubMed

    den Dekker, Els; Grefte, Sander; Huijs, Tonnie; ten Dam, Gerdy B; Versteeg, Elly M M; van den Berk, Lieke C J; Bladergroen, Bellinda A; van Kuppevelt, Toin H; Figdor, Carl G; Torensma, Ruurd

    2008-03-15

    IL-4 induces the differentiation of monocytes toward dendritic cells (DCs). The activity of many cytokines is modulated by glycosaminoglycans (GAGs). In this study, we explored the effect of GAGs on the IL-4-induced differentiation of monocytes toward DCs. IL-4 dose-dependently up-regulated the expression of DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN), CD80, CD206, and CD1a. Monocytes stained positive with Abs against heparan sulfate (HS) and chondroitin sulfate (CS) B (CSB; dermatan sulfate), but not with Abs that recognize CSA, CSC, and CSE. Inhibition of sulfation of monocyte/DC cell surface GAGs by sodium chlorate reduced the reactivity of sulfate-recognizing single-chain Abs. This correlated with hampered IL-4-induced DC differentiation as evidenced by lower expression of DC-SIGN and CD1a and a decreased DC-induced PBL proliferation, suggesting that sulfated monocyte cell surface GAGs support IL-4 activity. Furthermore, removal of cell surface chondroitin sulfates by chondroitinase ABC strongly impaired IL-4-induced STAT6 phosphorylation, whereas removal of HS by heparinase III had only a weak inhibitory effect. IL-4 bound to heparin and CSB, but not to HS, CSA, CSC, CSD, and CSE. Binding of IL-4 required iduronic acid, an N-sulfate group (heparin) and specific O sulfates (CSB and heparin). Together, these data demonstrate that monocyte cell surface chondroitin sulfates play an important role in the IL-4-driven differentiation of monocytes into DCs.

  19. Resveratrol-induced apoptosis in human T-cell acute lymphoblastic leukaemia MOLT-4 cells.

    PubMed

    Cecchinato, Valentina; Chiaramonte, Raffaella; Nizzardo, Monica; Cristofaro, Brunella; Basile, Andrea; Sherbet, Gajanan V; Comi, Paola

    2007-12-03

    Resveratrol (RES) is a natural occurring phytoalexin that has been shown to have chemopreventive activity. Resveratrol acts both by suppressing cell proliferation and inducing apoptosis in a variety of cancer cell lines. In this study, we show that RES induces apoptosis in MOLT-4 acute lymphoblastic leukaemia cells by modulating three different pathways that regulate cells survival and cell death. We show for the first time that RES inhibits the survival signalling pathways Notch and their down stream effector and modulates the operation of interacting signalling systems. It induces an increase in the levels of the pro-apoptotic proteins p53, its effector p21waf and Bax. We also show that RES inhibits the PI3K/Akt pathway and activates Gsk-3beta. The data presented here demonstrate unequivocally that RES induces apoptosis by inhibiting the Notch pathway and markedly influencing the operation of the interacting apoptosis pathways mediated by p53 and PI3K/Akt. These data support findings from other laboratories that have suggested the use of RES as a chemopreventive agent. Here, we have identified potential signalling pathways influenced by RES and this could lead to the identification of the targets of RES-induced apoptosis and growth control.

  20. Autophagy contributes to gefitinib-induced glioma cell growth inhibition

    SciTech Connect

    Chang, Cheng-Yi; Kuan, Yu-Hsiang; Ou, Yen-Chuan; Li, Jian-Ri; Wu, Chih-Cheng; Pan, Pin-Ho; Chen, Wen-Ying; Huang, Hsuan-Yi; Chen, Chun-Jung

    2014-09-10

    Epidermal growth factor receptor tyrosine kinase inhibitors, including gefitinib, have been evaluated in patients with malignant gliomas. However, the molecular mechanisms involved in gefitinib-mediated anticancer effects against glioma are incompletely understood. In the present study, the cytostatic potential of gefitinib was demonstrated by the inhibition of glioma cell growth, long-term clonogenic survival, and xenograft tumor growth. The cytostatic consequences were accompanied by autophagy, as evidenced by monodansylcadaverine staining of acidic vesicle formation, conversion of microtubule-associated protein-1 light chain 3-II (LC3-II), degradation of p62, punctate pattern of GFP-LC3, and conversion of GFP-LC3 to cleaved-GFP. Autophagy inhibitor 3-methyladenosine and chloroquine and genetic silencing of LC3 or Beclin 1 attenuated gefitinib-induced growth inhibition. Gefitinib-induced autophagy was not accompanied by the disruption of the Akt/mammalian target of rapamycin signaling. Instead, the activation of liver kinase-B1/AMP-activated protein kinase (AMPK) signaling correlated well with the induction of autophagy and growth inhibition caused by gefitinib. Silencing of AMPK suppressed gefitinib-induced autophagy and growth inhibition. The crucial role of AMPK activation in inducing glioma autophagy and growth inhibition was further supported by the actions of AMP mimetic AICAR. Gefitinib was shown to be capable of reducing the proliferation of glioma cells, presumably by autophagic mechanisms involving AMPK activation. - Highlights: • Gefitinib causes cytotoxic and cytostatic effect on glioma. • Gefitinib induces autophagy. • Gefitinib causes cytostatic effect through autophagy. • Gefitinib induces autophagy involving AMPK.

  1. Extracellular delivery induced by ultrasound and microbubbles in cells

    NASA Astrophysics Data System (ADS)

    Hussein, Farah; Antonescu, Costin; Karshafian, Raffi

    2017-03-01

    Ultrasound and microbubble treatment (USMB) can enhance the intracellular uptake of molecules, which otherwise would be excluded from the cell, through USMB-mediated transient membrane disruption and through enhanced endocytosis. However, the effect of USMB on the outward movement of molecules from cells is not well understood. This study investigates the effects of USMB on the release of molecules from various cellular compartments including cytoplasm, lysosomes, and recycling endosomes. In vitro ARPE-19 (RPE henceforth) cells were loaded with Alexa fluor-labeled transferrin as a marker for recycling endosomes, LAMP-1 antibody was used to detect the fusion of lysosomes with the plasma membrane, GFP-transfected RPE cells were used to examine the release of GFP from the cytoplasm, and 7-AAD was used to assess cell viability. Subsequently, cells were exposed to USMB (106 cells/mL, 300 kPa peak negative pressure, 1 min treatment duration, and 20 µL/mL Definity microbubbles). Following USMB, the release of the fluorescent markers was examined at 1.5, 11.5, and 21.5 minutes from the start of USMB. The mean fluorescent intensity (MFI) of untreated and USMB treated samples were measured using flow cytometry. USMB increased the extracellular delivery of GFP molecules from the cytoplasm; the MFI in USMB treated GFP-transfected RPE cells decreased by 17% in viable cells and this MFI decreased by 70% in non-viable cells. This could be due to diffusion of GFP through the membrane disruptions induced by USMB. Additionally, the MFI of viable cells stained with LAMP-1 antibody increased by 50% and this increase was 15 folds in the non-viable cells indicating lysosome exocytosis as a mechanism for membrane repair. Furthermore, the MFI of cells loaded with fluorescent transferrin decreased by 22% after USMB treatment in viable cells, indicating a significant increase in transferrin recycling to the cell membrane. However, the increased recycling was not statistically significant

  2. Autophagy is involved in aldosterone-induced mesangial cell proliferation

    PubMed Central

    Yang, Min; Wang, Bin; Miao, Liying; Xu, Xianlin; He, Xiaozhou

    2016-01-01

    The aim of the present study was to investigate whether autophagy is involved in aldosterone (Aldo)-induced mesangial cell (MC) proliferation. MCs were incubated with 10−7 M Aldo for 24 h. Proliferation of MCs, and the underlying mechanisms, were subsequently analyzed using [3H]thymidine assay, cell counting assay, western blotting and RNA interference (RNAi). Aldo was revealed to induce autophagy, as indicated by the increased conversion from microtubule-associated protein 1A/1B-light chain 3 (LC3)-I to LC3-II, the increased expression levels of autophagy-related gene 7 (Atg7) and the increased degradation of p62, which was accompanied by MC proliferation. Notably, pharmacological inhibition of autophagy or RNAi-mediated knockdown of Atg7 attenuated Aldo-induced MC proliferation, suggesting that autophagy was at least partially responsible for this effect. The results of the present study provided evidence that autophagy is critical for regulating Aldo-induced MC proliferation. PMID:27748808

  3. Excess glucose induces hypoxia-inducible factor-1α in pancreatic cancer cells and stimulates glucose metabolism and cell migration

    PubMed Central

    Liu, Zhiwen; Jia, Xiaohui; Duan, Yijie; Xiao, Huijie; Sundqvist, Karl-Gösta; Permert, Johan; Wang, Feng

    2013-01-01

    Pancreatic cancer patients frequently show hyperglycemia, but it is uncertain whether hyperglycemia stimulates pancreatic cancer cells. We have investigated whether excess glucose induces hypoxia-inducible factor-1α (HIF-1α) and stimulates glucose metabolism and cell migration in pancreatic cancer cells. We studied wild-type (wt) MiaPaCa2 pancreatic cancer cells and a MiaPaCa2 subline (namely si-MiaPaCa2) that had HIF-1α-specific small interfering RNA. Wt-MiaPaCa2 cells are known to be HIF-1α-positive in hypoxia and HIF-1α-negative in normoxia, whereas si-MiaPaCa2 cells are devoid of HIF-1α in both normoxia and hypoxia. We incubated these cells with different amounts of glucose and determined HIF-1α mRNA and protein by real-time polymerase chain reaction and western blotting. We determined glucose consumption, lactate production and intracellular hexokinase-II and ATP to assess glucose metabolisms and determined pyruvate dehydrogenase kinase-1, reactive oxygen species and fumarate to assess mitochondrial activities. Further, we studied cell migration using a Boyden chamber. Excess glucose (16.7−22.2mM) increased HIF-1α in hypoxic wt-MiaPaCa2 cells. HIF-1α expression increased ATP contents and inhibited mitochondrial activities. Extracellular glucose and hypoxia stimulated glucose metabolisms independent of HIF-1α. Excess glucose stimulated the migration of wt- and si-MiaPaCa2 cells in both normoxia and hypoxia. Thus, glucose stimulated cell migration independent of HIF-1α. Nevertheless, hypoxic wt-MiaPaCa2 cells showed greater migrating ability than their si-MiaPaCa2 counterparts. We conclude that (1) excess glucose increases HIF-1α and ATP in hypoxic wt-MiaPaCa2 cells, (2) extracellular glucose and hypoxia regulate glucose metabolisms independent of HIF-1α and (3) glucose stimulates cell migration by mechanisms that are both dependent on HIF-1α and independent of it. PMID:23377827

  4. Cell wall dynamics modulate acetic acid-induced apoptotic cell death of Saccharomyces cerevisiae

    PubMed Central

    Rego, António; Duarte, Ana M.; Azevedo, Flávio; Sousa, Maria J.; Côrte-Real, Manuela; Chaves, Susana R.

    2014-01-01

    Acetic acid triggers apoptotic cell death in Saccharomyces cerevisiae, similar to mammalian apoptosis. To uncover novel regulators of this process, we analyzed whether impairing MAPK signaling affected acetic acid-induced apoptosis and found the mating-pheromone response and, especially, the cell wall integrity pathways were the major mediators, especially the latter, which we characterized further. Screening downstream effectors of this pathway, namely targets of the transcription factor Rlm1p, highlighted decreased cell wall remodeling as particularly important for acetic acid resistance. Modulation of cell surface dynamics therefore emerges as a powerful strategy to increase acetic acid resistance, with potential application in industrial fermentations using yeast, and in biomedicine to exploit the higher sensitivity of colorectal carcinoma cells to apoptosis induced by acetate produced by intestinal propionibacteria. PMID:28357256

  5. Dendritic Cells in the Periphery Control Antigen-Specific Natural and Induced Regulatory T Cells

    PubMed Central

    Yamazaki, Sayuri; Morita, Akimichi

    2013-01-01

    Dendritic cells (DCs) are specialized antigen-presenting cells that regulate both immunity and tolerance. DCs in the periphery play a key role in expanding naturally occurring Foxp3+ CD25+ CD4+ regulatory T cells (Natural T-regs) and inducing Foxp3 expression (Induced T-regs) in Foxp3− CD4+ T cells. DCs are phenotypically and functionally heterogeneous, and further classified into several subsets depending on distinct marker expression and their location. Recent findings indicate the presence of specialized DC subsets that act to expand Natural T-regs or induce Foxp3+ T-regs from Foxp3− CD4+ T cells. For example, two major subsets of DCs in lymphoid organs act differentially in inducing Foxp3+ T-regs from Foxp3− cells or expanding Natural T-regs with model-antigen delivery by anti-DC subset monoclonal antibodies in vivo. Furthermore, DCs expressing CD103 in the intestine induce Foxp3+ T-regs from Foxp3− CD4+ T cells with endogenous TGF-β and retinoic acid. In addition, antigen-presenting DCs have a capacity to generate Foxp3+ T-regs in the oral cavity where many antigens and commensals exist, similar to intestine and skin. In skin and skin-draining lymph nodes, at least six DC subsets have been identified, suggesting a complex DC-T-reg network. Here, we will review the specific activity of DCs in expanding Natural T-regs and inducing Foxp3+ T-regs from Foxp3− precursors, and further discuss the critical function of DCs in maintaining tolerance at various locations including skin and oral cavity. PMID:23801989

  6. NLRP1 inflammasome activation induces pyroptosis of hematopoietic progenitor cells

    PubMed Central

    Masters, Seth L.; Gerlic, Motti; Metcalf, Donald; Preston, Simon; Pellegrini, Marc; O’Donnell, Joanne A.; McArthur, Kate; Baldwin, Tracey M.; Chevrier, Stephane; Nowell, Cameron J.; Cengia, Louise H.; Henley, Katya J.; Collinge, Janelle E.; Kastner, Daniel L.; Feigenbaum, Lionel; Hilton, Douglas J.; Alexander, Warren S.; Kile, Benjamin T.; Croker, Ben A.

    2014-01-01

    Cytopenias are key prognostic indicators of life-threatening infection, contributing to immunosuppression and mortality. Here we define a role for Caspase-1-dependent death, known as pyroptosis, in infection-induced cytopenias by studying inflammasome activation in hematopoietic progenitor cells. The NLRP1a inflammasome is expressed in hematopoietic progenitor cells and its activation triggers their pyroptotic death. Active NLRP1a induced a lethal systemic inflammatory disease that was driven by Caspase-1 and IL-1β but was independent of apoptosis-associated speck-like protein containing a CARD (ASC) and ameliorated by IL-18. Surprisingly, in the absence of IL-1β-driven inflammation, active NLRP1a triggered pyroptosis of hematopoietic progenitor cells resulting in leukopenia in the steady state. During periods of hematopoietic stress induced by chemotherapy or lymphocytic choriomeningitis virus (LCMV) infection, active NLRP1a caused prolonged cytopenia, bone marrow hypoplasia and immunosuppression. Conversely, NLRP1-deficient mice showed enhanced recovery from chemotherapy and LCMV infection, demonstrating that NLRP1 acts as a cellular sentinel to alert Caspase-1 to hematopoietic and infectious stress. PMID:23219391

  7. Kinetin induces cell death in root cortex cells of Vicia faba ssp. minor seedlings.

    PubMed

    Kunikowska, Anita; Byczkowska, Anna; Kaźmierczak, Andrzej

    2013-08-01

    The double fluorescence staining with acridine orange and ethidium bromide (AO/EB) revealed that treatment of Vicia faba ssp. minor seedlings with kinetin-induced programmed cell death (PCD) in root cortex cells. Kinetin-induced cell death reflected by the morphological changes of nuclei including their invagination, volume increase, chromatin condensation and degradation as well as formation of micronuclei showed by AO/EB and 4,6-diamidino-2-phenylindol staining was accompanied by changes including increase in conductivity of cell electrolytes secreted to culture media, decrease in the number of the G1- and G2-phase cells and appearance of fraction of hypoploid cells as the effect of DNA degradation without ladder formation. Decrease in the number of mitochondria and in the activity of cellular dehydrogenases, production of reactive oxygen species (ROS), appearance of small and then large lytic vacuoles and increase in the amount of cytosolic calcium ions were also observed. The PCD was also manifested by increased width and weight of apical fragments of roots as well as decreased length of cortex cells which led to shortening of the whole roots. The kinetin-induced PCD process was almost completely inhibited by adenine, an inhibitor of phosphoribosyl transferase, and mannitol, an inhibitor of ROS production. These cell-death hallmarks and pathway of this process suggested that the induction of kinetin-specific vacuolar type of death, expressed itself with similar intensity on both morphological and metabolic levels, was a transient protecting whole roots and whole seedlings against elimination.

  8. Femtosecond laser-induced fusion of nonadherent cells and two-cell porcine embryos

    NASA Astrophysics Data System (ADS)

    Kuetemeyer, Kai; Lucas-Hahn, Andrea; Petersen, Bjoern; Niemann, Heiner; Heisterkamp, Alexander

    2011-08-01

    Cell fusion is a fundamental biological process that can be artificially induced by different methods. Although femtosecond (fs) lasers have been successfully employed for cell fusion over the past few years, the underlying mechanisms are still unknown. In our experimental study, we investigated the correlation between fs laser-induced cell fusion and membrane perforation, and the influence of laser parameters on the fusion efficiency of nonadherent HL-60 cells. We found that shorter exposure times resulted in higher fusion efficiencies with a maximum of 21% at 10 ms and 100 mJ/cm2 (190 mW). Successful cell fusion was indicated by the formation of a long-lasting vapor bubble in the irradiated area with an average diameter much larger than in cell perforation experiments. With this knowledge, we demonstrated, for the first time, the fusion of very large parthenogenetic two-cell porcine embryos with high efficiencies of 55% at 20 ms and 360 mJ/cm2 (670 mW). Long-term viability of fused embryos was proven by successful development up to the blastocyst stage in 70% of cases with no significant difference to controls. In contrast to previous studies, our results indicate that fs laser-induced cell fusion occurs when the membrane pore size exceeds a critical value, preventing immediate membrane resealing.

  9. Para-toluenesulfonamide induces tongue squamous cell carcinoma cell death through disturbing lysosomal stability.

    PubMed

    Liu, Zhe; Liang, Chenyuan; Zhang, Zhuoyuan; Pan, Jian; Xia, Hui; Zhong, Nanshan; Li, Longjiang

    2015-11-01

    Para-toluenesulfonamide (PTS) has been implicated with anticancer effects against a variety of tumors. In the present study, we investigated the inhibitory effects of PTS on tongue squamous cell carcinoma (Tca-8113) and explored the lysosomal and mitochondrial changes after PTS treatment in vitro. High-performance liquid chromatography showed that PTS selectively accumulated in Tca-8113 cells with a relatively low concentration in normal fibroblasts. Next, the effects of PTS on cell viability, invasion, and cell death were determined. PTS significantly inhibited Tca-8113 cells' viability and invasive ability with increased cancer cell death. Flow cytometric analysis and the lactate dehydrogenase release assay showed that PTS induced cancer cell death by activating apoptosis and necrosis simultaneously. Morphological changes, such as cellular shrinkage, nuclear condensation as well as formation of apoptotic body and secondary lysosomes, were observed, indicating that PTS might induce cell death through disturbing lysosomal stability. Lysosomal integrity assay and western blot showed that PTS increased lysosomal membrane permeabilization associated with activation of lysosomal cathepsin B. Finally, PTS was shown to inhibit ATP biosynthesis and induce the release of mitochondrial cytochrome c. Therefore, our findings provide a novel insight into the use of PTS in cancer therapy.

  10. Antibiotic drug tigecycline inhibited cell proliferation and induced autophagy in gastric cancer cells

    SciTech Connect

    Tang, Chunling; Yang, Liqun; Jiang, Xiaolan; Xu, Chuan; Wang, Mei; Wang, Qinrui; Zhou, Zhansong; Xiang, Zhonghuai; Cui, Hongjuan

    2014-03-28

    Highlights: • Tigecycline inhibited cell growth and proliferation in human gastric cancer cells. • Tigecycline induced autophagy not apoptosis in human gastric cancer cells. • AMPK/mTOR/p70S6K pathway was activated after tigecycline treatment. • Tigecycline inhibited tumor growth in xenograft model of human gastric cancer cells. - Abstract: Tigecycline acts as a glycylcycline class bacteriostatic agent, and actively resists a series of bacteria, specifically drug fast bacteria. However, accumulating evidence showed that tetracycline and their derivatives such as doxycycline and minocycline have anti-cancer properties, which are out of their broader antimicrobial activity. We found that tigecycline dramatically inhibited gastric cancer cell proliferation and provided an evidence that tigecycline induced autophagy but not apoptosis in human gastric cancer cells. Further experiments demonstrated that AMPK pathway was activated accompanied with the suppression of its downstream targets including mTOR and p70S6K, and ultimately induced cell autophagy and inhibited cell growth. So our data suggested that tigecycline might act as a candidate agent for pre-clinical evaluation in treatment of patients suffering from gastric cancer.

  11. Induced pluripotent stem cells for modeling neurological disorders.

    PubMed

    Russo, Fabiele B; Cugola, Fernanda R; Fernandes, Isabella R; Pignatari, Graciela C; Beltrão-Braga, Patricia C B

    2015-12-24

    Several diseases have been successfully modeled since the development of induced pluripotent stem cell (iPSC) technology in 2006. Since then, methods for increased reprogramming efficiency and cell culture maintenance have been optimized and many protocols for differentiating stem cell lines have been successfully developed, allowing the generation of several cellular subtypes in vitro. Gene editing technologies have also greatly advanced lately, enhancing disease-specific phenotypes by creating isogenic cell lines, allowing mutations to be corrected in affected samples or inserted in control lines. Neurological disorders have benefited the most from iPSC-disease modeling for its capability for generating disease-relevant cell types in vitro from the central nervous system, such as neurons and glial cells, otherwise only available from post-mortem samples. Patient-specific iPSC-derived neural cells can recapitulate the phenotypes of these diseases and therefore, considerably enrich our understanding of pathogenesis, disease mechanism and facilitate the development of drug screening platforms for novel therapeutic targets. Here, we review the accomplishments and the current progress in human neurological disorders by using iPSC modeling for Alzheimer's disease, Parkinson's disease, Huntington's disease, spinal muscular atrophy, amyotrophic lateral sclerosis, duchenne muscular dystrophy, schizophrenia and autism spectrum disorders, which include Timothy syndrome, Fragile X syndrome, Angelman syndrome, Prader-Willi syndrome, Phelan-McDermid, Rett syndrome as well as Nonsyndromic Autism.

  12. Shear induced diffusion in a red blood cell suspension

    NASA Astrophysics Data System (ADS)

    Podgorski, Thomas; Grandchamp, Xavier; Srivastav, Aparna; Coupier, Gwennou

    2012-11-01

    In the microcirculation, blood exhibits an inhomogeneous structure which results in the well know Fahraeus-Lindqvist effect : the apparent viscosity decreases when the diameter of the capillary decreases due to the formation of a marginal cell depletion layer (known as plasma skimming). This structure is a consequence of several phenomena, which include i) the migration of cells aways from walls due to lift forces and gradients of shear and ii) shear induced diffusion due to collisions and interactions among cells. We investigated these phenomena through experiments in simple shear and microchannel flows, with dilute suspensions of vesicles and blood cells. Pairwise interactions between suspended objects result in non-linear and flow-dependent diffusion, whose properties have been measured in different experiments for vesicles and blood cells. The injection of a sheet of concentrated blood cell suspension in a microchannel with a rectangular cross-section allows, through the measurement of its widening along the channel, to measure the diffusivity of blood cells, both in the local plane of shear and in the vorticity direction.

  13. Mechanisms underlying the formation of induced pluripotent stem cells.

    PubMed

    González, Federico; Huangfu, Danwei

    2016-01-01

    Human pluripotent stem cells (hPSCs) offer unique opportunities for studying human biology, modeling diseases, and therapeutic applications. The simplest approach so far to generate human PSC lines is through reprogramming of somatic cells from an individual by defined factors, referred to simply as reprogramming. Reprogramming circumvents the ethical controversies associated with human embryonic stem cells (hESCs) and nuclear transfer hESCs (nt-hESCs), and the resulting induced pluripotent stem cells (hiPSCs) retain the same basic genetic makeup as the somatic cell used for reprogramming. Since the first report of iPSCs by Takahashi and Yamanaka (Cell 2006, 126:663-676), the molecular mechanisms of reprogramming have been extensively investigated. A better mechanistic understanding of reprogramming is fundamental not only to iPSC biology and improving the quality of iPSCs for therapeutic use, but also to our understanding of the molecular basis of cell identity, pluripotency, and plasticity. Here, we summarize the genetic, epigenetic, and cellular events during reprogramming, and the roles of various factors identified thus far in the reprogramming process. WIREs Dev Biol 2016, 5:39-65. doi: 10.1002/wdev.206 For further resources related to this article, please visit the WIREs website.

  14. Induced pluripotent stem cells for modeling neurological disorders

    PubMed Central

    Russo, Fabiele B; Cugola, Fernanda R; Fernandes, Isabella R; Pignatari, Graciela C; Beltrão-Braga, Patricia C B

    2015-01-01

    Several diseases have been successfully modeled since the development of induced pluripotent stem cell (iPSC) technology in 2006. Since then, methods for increased reprogramming efficiency and cell culture maintenance have been optimized and many protocols for differentiating stem cell lines have been successfully developed, allowing the generation of several cellular subtypes in vitro. Gene editing technologies have also greatly advanced lately, enhancing disease-specific phenotypes by creating isogenic cell lines, allowing mutations to be corrected in affected samples or inserted in control lines. Neurological disorders have benefited the most from iPSC-disease modeling for its capability for generating disease-relevant cell types in vitro from the central nervous system, such as neurons and glial cells, otherwise only available from post-mortem samples. Patient-specific iPSC-derived neural cells can recapitulate the phenotypes of these diseases and therefore, considerably enrich our understanding of pathogenesis, disease mechanism and facilitate the development of drug screening platforms for novel therapeutic targets. Here, we review the accomplishments and the current progress in human neurological disorders by using iPSC modeling for Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, spinal muscular atrophy, amyotrophic lateral sclerosis, duchenne muscular dystrophy, schizophrenia and autism spectrum disorders, which include Timothy syndrome, Fragile X syndrome, Angelman syndrome, Prader-Willi syndrome, Phelan-McDermid, Rett syndrome as well as Nonsyndromic Autism. PMID:26722648

  15. DJ-1 mediates paraquat-induced dopaminergic neuronal cell death.

    PubMed

    Kwon, Hyun Joo; Heo, Jun Young; Shim, Jung Hee; Park, Ji Hoon; Seo, Kang Sik; Ryu, Min Jeong; Han, Jeong Su; Shong, Minho; Son, Jin H; Kweon, Gi Ryang

    2011-04-25

    There are two causes of Parkinson's disease (PD): environmental insults and genetic mutations of PD-associated genes. Environmental insults and genetic mutations lead to mitochondrial dysfunction, and a combination of mitochondrial dysfunction and increased oxidative stress in dopaminergic neurons is thought to contribute to the pathogenesis of PD. Among the PD-associated genes, DJ-1 acts as a redox sensor for oxidative stress and has been also proposed to maintain mitochondrial complex I activity. To understand molecular functions of DJ-1 in the cell, we have generated DJ-1 null cells from the DJ-1(-/-) mouse embryos. Using these null cells, we investigated the susceptibility to an environmental toxin, paraquat, which is known to inhibit mitochondrial complex I. Interestingly, we found that DJ-1 null cells showed a resistance to paraquat-induced apoptosis, including reduced poly (ADP-ribose) polymerase and procaspase-3. Also DJ-1 null cells generated less superoxide than SN4741 cells by paraquat treatment. Consistent with the reduced paraquat sensitivity, DJ-1 null cells showed reduced complex I activity, which was partially rescued by ectopic DJ-I expression. In summary, our results suggest that DJ-1 is critical to maintain mitochondrial complex I and complex I could be a key target in interaction of paraquat toxicity and DJ-1 for giving rise to PD.

  16. Tubular cell apoptosis and cidofovir-induced acute renal failure.

    PubMed

    Ortiz, Alberto; Justo, Pilar; Sanz, Ana; Melero, Rosa; Caramelo, Carlos; Guerrero, Manuel Fernández; Strutz, Frank; Müller, Gerhard; Barat, Antonio; Egido, Jesus

    2005-01-01

    Cidofovir is an antiviral drug with activity against a wide array of DNA viruses including poxvirus. The therapeutic use of cidofovir is marred by a dose-limiting side effect, nephrotoxicity, leading to proximal tubular cell injury and acute renal failure. Treatment with cidofovir requires the routine use of prophylactic measures. A correct knowledge of the cellular and molecular mechanisms of cidofovir toxicity may lead to the development of alternative prophylactic strategies. We recently cared for a patient with irreversible acute renal failure due to cidofovir. Renal biopsy showed tubular cell apoptosis. Cidofovir induced apoptosis in primary cultures of human proximal tubular cells in a temporal (peak apoptosis at 7 days) and concentration (10-40 microg/ml) pattern consistent with that of clinical toxicity. Apoptosis was identified by the presence of hypodiploid cells, by the exposure of annexin V binding sites and by morphological features and was associated with the appearance of active caspase-3 fragments. Cell death was specific as it was also present in a human proximal tubular epithelial cell line (HK-2), but not in a human kidney fibroblast cell line, and was prevented by probenecid. An inhibitor of caspase-3 (DEVD) prevented cidofovir apoptosis. The survival factors present in serum, insulin-like growth factor-1 and hepatocyte growth factor, were also protective. The present data suggest that apoptosis induction is a mechanism contributing to cidofovir nephrotoxicity. The prophylactic administration of factors with survival activity for tubular epithelium should be further explored in cidofovir renal injury.

  17. Induced pluripotent stem cells and their implication for regenerative medicine.

    PubMed

    Csobonyeiova, Maria; Polak, Stefan; Koller, Jan; Danisovic, Lubos

    2015-06-01

    In 2006 Yamanaka's group showed that stem cells with properties similar to embryonic stem cells could be generated from mouse fibroblasts by introducing four genes. These cells were termed induced pluripotent stem cells (iPSCs). Because iPSCs avoid many of ethical concerns associated with the use of embryonic material, they have great potential in cell-based regenerative medicine. They are suitable also for other various purposes, including disease modelling, personalized cell therapy, drug or toxicity screening and basic research. Moreover, in the future, there might become possible to generate organs for human transplantation. Despite these progresses, several studies have raised the concern for genetic and epigenetic abnormalities of iPSCs that could contribute to immunogenicity of some cells differentiated from iPSCs. Recent methodological improvements are increasing the ease and efficacy of reprogramming, and reducing the genomic modification. However, to minimize or eliminate genetic alternations in the derived iPSC line creation, factor-free human iPSCs are necessary. In this review we discuss recent possibilities of using iPSCs for clinical applications and new advances in field of their reprogramming methods. The main goal of present article was to review the current knowledge about iPSCs and to discuss their potential for regenerative medicine.

  18. Human-induced pluripotent stem cells: potential for neurodegenerative diseases.

    PubMed

    Ross, Christopher A; Akimov, Sergey S

    2014-09-15

    The cell biology of human neurodegenerative diseases has been difficult to study till recently. The development of human induced pluripotent stem cell (iPSC) models has greatly enhanced our ability to model disease in human cells. Methods have recently been improved, including increasing reprogramming efficiency, introducing non-viral and non-integrating methods of cell reprogramming, and using novel gene editing techniques for generating genetically corrected lines from patient-derived iPSCs, or for generating mutations in control cell lines. In this review, we highlight accomplishments made using iPSC models to study neurodegenerative disorders such as Huntington's disease, Parkinson's disease, Amyotrophic Lateral Sclerosis, Fronto-Temporal Dementia, Alzheimer's disease, Spinomuscular Atrophy and other polyglutamine diseases. We review disease-related phenotypes shown in patient-derived iPSCs differentiated to relevant neural subtypes, often with stressors or cell "aging", to enhance disease-specific phenotypes. We also discuss prospects for the future of using of iPSC models of neurodegenerative disorders, including screening and testing of therapeutic compounds, and possibly of cell transplantation in regenerative medicine. The new iPSC models have the potential to greatly enhance our understanding of pathogenesis and to facilitate the development of novel therapeutics.

  19. PDT-induced apoptosis in arterial smooth muscles cells

    NASA Astrophysics Data System (ADS)

    Nyamekye, Isaac; Renick, R.; Gilbert, C.; McEwan, Jean R.; Evan, G.; Bishop, Christopher C. R.; Bown, Stephen G.

    1995-03-01

    PDT kills smooth muscle cells (SMC) in vivo and thus prevents intimal hyperplasia after angioplasty. It causes little inflammation and structural integrity of the artery is not compromised. We have studied the process of the SMC death in vitro. Cultured rat SMC (cell line sv40 ATCC) were sensitized with aluminum disulphonated phthalocyanine (AlS2Pc), and then irradiated with 675 nm laser light (2.5 J/cm2). Controls were studied using only sensitizer or laser for treatment. The cells were incubated and the dying process observed with a time lapse video and microscope system. PDT caused a characteristic pattern of death. Cells lost contact with neighbors, shrank, and showed hyperactivity and membrane ruffling. The cells imploded into active and condensed membrane bound vesicles which were terminally reduced to residual bodies. These are the morphological changes of apoptosis. The control cells which were given AlS2Pc alone or laser alone showed no death. PDT induced cultured arterial SMC death by apoptosis rather than necrosis. An apoptotic mechanism of cell death in vivo would explain the relative lack of inflammation and local tissue destruction in the face of massive death.

  20. Potential of laryngeal muscle regeneration using induced pluripotent stem cell-derived skeletal muscle cells.

    PubMed

    Dirja, Bayu Tirta; Yoshie, Susumu; Ikeda, Masakazu; Imaizumi, Mitsuyoshi; Nakamura, Ryosuke; Otsuki, Koshi; Nomoto, Yukio; Wada, Ikuo; Hazama, Akihiro; Omori, Koichi

    2016-01-01

    Conclusion Induced pluripotent stem (iPS) cells may be a new potential cell source for laryngeal muscle regeneration in the treatment of vocal fold atrophy after recurrent laryngeal nerve paralysis. Objectives Unilateral vocal fold paralysis can lead to degeneration, atrophy, and loss of force of the thyroarytenoid muscle. At present, there are some treatments such as thyroplasty, arytenoid adduction, and vocal fold injection. However, such treatments cannot restore reduced mass of the thyroarytenoid muscle. iPS cells have been recognized as supplying a potential resource for cell transplantation. The aim of this study was to assess the effectiveness of the use of iPS cells for the regeneration of laryngeal muscle through the evaluation of both in vitro and in vivo experiments. Methods Skeletal muscle cells were generated from tdTomato-labeled iPS cells using embryoid body formation. Differentiation into skeletal muscle cells was analyzed by gene expression and immunocytochemistry. The tdTomato-labeled iPS cell-derived skeletal muscle cells were transplanted into the left atrophied thyroarytenoid muscle. To evaluate the engraftment of these cells after transplantation, immunohistochemistry was performed. Results The tdTomato-labeled iPS cells were successfully differentiated into skeletal muscle cells through an in vitro experiment. These cells survived in the atrophied thyroarytenoid muscle after transplantation.

  1. Butyl benzyl phthalate suppresses the ATP-induced cell proliferation in human osteosarcoma HOS cells

    SciTech Connect

    Liu, P.-S.; Chen, C.-Y.

    2010-05-01

    Butyl benzyl phthalate (BBP), an endocrine disruptor present in the environment, exerts its genomic effects via intracellular steroid receptors and elicits non-genomic effects by interfering with membrane ion-channel receptors. We previously found that BBP blocks the calcium signaling coupled with P2X receptors in PC12 cells (Liu and Chen, 2006). Osteoblast P2X receptors were recently reported to play a role in cell proliferation and bone remodeling. In this present study, the effects of BBP on ATP-induced responses were investigated in human osteosarcoma HOS cells. These receptors mRNA had been detected, named P2X4, P2X7, P2Y2, P2Y4, P2Y5, P2Y9, and P2Y11, in human osteosarcoma HOS cells by RT-PCR. The enhancement of cell proliferation and the decrease of cytoviability had both been shown to be coupled to stimulation via different concentrations of ATP. BBP suppressed the ATP-induced calcium influx (mainly coupled with P2X) and cell proliferation but not the ATP-induced intracellular calcium release (mainly coupled with P2Y) and cytotoxicity in human osteosarcoma HOS cells. Suramin, a common P2 receptor's antagonist, blocked the ATP-induced calcium signaling, cell proliferation, and cytotoxicity. We suggest that P2X is mainly responsible for cell proliferation, and P2Y might be partially responsible for the observed cytotoxicity. BBP suppressed the calcium signaling coupled with P2X, suppressing cell proliferation. Since the importance of P2X receptors during bone metastasis has recently become apparent, the possible toxic risk of environmental BBP during bone remodeling is a public problem of concern.

  2. Middle infrared radiation induces G2/M cell cycle arrest in A549 lung cancer cells.

    PubMed

    Chang, Hsin-Yi; Shih, Meng-Her; Huang, Hsuan-Cheng; Tsai, Shang-Ru; Juan, Hsueh-Fen; Lee, Si-Chen

    2013-01-01

    There were studies investigating the effects of broadband infrared radiation (IR) on cancer cell, while the influences of middle-infrared radiation (MIR) are still unknown. In this study, a MIR emitter with emission wavelength band in the 3-5 µm region was developed to irradiate A549 lung adenocarcinoma cells. It was found that MIR exposure inhibited cell proliferation and induced morphological changes by altering the cellular distribution of cytoskeletal components. Using quantitative PCR, we found that MIR promoted the expression levels of ATM (ataxia telangiectasia mutated), ATR (ataxia-telangiectasia and Rad3-related and Rad3-related), TP53 (tumor protein p53), p21 (CDKN1A, cyclin-dependent kinase inhibitor 1A) and GADD45 (growth arrest and DNA-damage inducible), but decreased the expression levels of cyclin B coding genes, CCNB1 and CCNB2, as well as CDK1 (Cyclin-dependent kinase 1). The reduction of protein expression levels of CDC25C, cyclin B1 and the phosphorylation of CDK1 at Thr-161 altogether suggest G(2)/M arrest occurred in A549 cells by MIR. DNA repair foci formation of DNA double-strand breaks (DSB) marker γ-H2AX and sensor 53BP1 was induced by MIR treatment, it implies the MIR induced G(2)/M cell cycle arrest resulted from DSB. This study illustrates a potential role for the use of MIR in lung cancer therapy by initiating DSB and blocking cell cycle progression.

  3. Rosiglitazone inhibits cell proliferation by inducing G1 cell cycle arrest and apoptosis in ADPKD cyst-lining epithelia cells.

    PubMed

    Liu, Yawei; Dai, Bing; Fu, Lili; Jia, Jieshuang; Mei, Changlin

    2010-06-01

    Abnormal proliferation is an important pathological feature of autosomal dominant polycystic kidney disease (ADPKD). Many drugs inhibiting cell proliferation have been proved to be effective in slowing the disease progression in ADPKD. Recent evidence has suggested that peroxisome proliferator-activated receptor gamma (PPARgamma) ligands have anti-neoplasm effects through inhibiting cell growth and inducing cell apoptosis in various cancer cells. In the present study, we examined the expression of PPARgamma in human ADPKD kidney tissues and cyst-lining epithelial cell line, and found that the expression of PPARgamma was greater in ADPKD kidney tissues and cyst-lining epithelial cell line than in normal kidney tissues and human kidney cortex (HKC) cell line. Rosiglitazone inhibited significantly proliferation of cyst-lining epithelial cells in a concentration- and time-dependent manner. These effects were diminished by GW9662, a specific PPARgamma antagonist. Cell cycle analysis showed a G0/G1 arrest in human ADPKD cyst-lining epithelial cells with rosiglitazone treatment. Analysis of cell cycle regulatory proteins revealed that rosiglitazone decreased the protein levels of proliferating cell nuclear antigen, pRb, cyclin D1, cyclin D2 and Cdk4 but increased the levels of p21 and p27 in a dose-dependent manner. Rosiglitazone also induced apoptosis in cyst-lining epithelial cells, which was correlated with increased bax expression and decreased bcl-2 expression. These results suggest PPARgamma agonist might serve as a promising drug for the treatment of ADPKD.

  4. Acute Hypoglycemia Induces Retinal Cell Death in Mouse

    PubMed Central

    Emery, Martine; Schorderet, Daniel F.; Roduit, Raphaël

    2011-01-01

    Background Glucose is the most important metabolic substrate of the retina and maintenance of normoglycemia is an essential challenge for diabetic patients. Glycemic excursions could lead to cardiovascular disease, nephropathy, neuropathy and retinopathy. A vast body of literature exists on hyperglycemia namely in the field of diabetic retinopathy, but very little is known about the deleterious effect of hypoglycemia. Therefore, we decided to study the role of acute hypoglycemia in mouse retina. Methodology/Principal Findings To test effects of hypoglycemia, we performed a 5-hour hyperinsulinemic/hypoglycemic clamp; to exclude an effect of insulin, we made a hyperinsulinemic/euglycemic clamp as control. We then isolated retinas from each group at different time-points after the clamp to analyze cells apoptosis and genes regulation. In parallel, we used 661W photoreceptor cells to confirm in vivo results. We showed herein that hypoglycemia induced retinal cell death in mouse via caspase 3 activation. We then tested the mRNA expression of glutathione transferase omega 1 (Gsto1) and glutathione peroxidase 3 (Gpx3), two genes involved in glutathione (GSH) homeostasis. The expression of both genes was up-regulated by low glucose, leading to a decrease of reduced glutathione (GSH). In vitro experiments confirmed the low-glucose induction of 661W cell death via superoxide production and activation of caspase 3, which was concomitant with a decrease of GSH content. Moreover, decrease of GSH content by inhibition with buthionine sulphoximine (BSO) at high glucose induced apoptosis, while complementation with extracellular glutathione ethyl ester (GSHee) at low glucose restored GSH level and reduced apoptosis. Conclusions/Significance We showed, for the first time, that acute insulin-induced hypoglycemia leads to caspase 3-dependant retinal cell death with a predominant role of GSH content. PMID:21738719

  5. Calcium fingerprints induced by calmodulin interactors in eukaryotic cells.

    PubMed

    Dagher, Rania; Brière, Christian; Fève, Marie; Zeniou, Maria; Pigault, Claire; Mazars, Christian; Chneiweiss, Hervé; Ranjeva, Raoul; Kilhoffer, Marie-Claude; Haiech, Jacques

    2009-06-01

    Calcium (Ca2+) is a ubiquitous second messenger which promotes cell responses through transient changes in intracellular concentrations. The prominent role of Ca2+ in cell physiology is mediated by a whole set of proteins constituting a Ca2+-signalling toolkit involved in Ca2+-signal generation, deciphering and arrest. The different Ca2+-signalosomes deliver Ca2+-signals with spatial and temporal dynamics to control the function of specific cell types. Among the intracellular proteins involved in Ca2+-signal deciphering, calmodulin (CaM) plays a pivotal role in controlling Ca2+-homeostasis and downstream Ca2+-based signalling events. Due to its ubiquitous expression in eukaryotic cells and the variety of proteins it interacts with, CaM is central in Ca2+-signalling networks. For these reasons, it is expected that disrupting or modifying CaM interactions with its target proteins will affect Ca2+-homeostasis and cellular responses. The resulting calcium response will vary depending on which interactions between CaM and target proteins are altered by the molecules and on the specific Ca2+-toolkit expressed in a given cell, even in the resting state. In the present paper, the effect of six classical CaM interactors (W5, W7, W12, W13, bifonazole and calmidazolium) was studied on Ca2+-signalling in tumor initiating cells isolated from human glioblastoma (TG1) and tobacco cells (BY-2) using the fluorescent Ca2+-sensitive Indo-1 dye and aequorin, respectively. Various Ca2+-fingerprints were obtained depending both on the CaM interactor used and the cell type investigated. These data demonstrate that interaction between the antagonists and CaM results in a differential inhibition of CaM-dependent proteins involved in Ca2+-signal regulation. In addition, the distinct Ca2+-fingerprints in tobacco and human tumor initiating glioblastoma cells induced by a given CaM interactor highlight the specificity of the Ca2+-signalosome in eukaryotic cells.

  6. Blockade of maitotoxin-induced oncotic cell death reveals zeiosis

    PubMed Central

    Estacion, Mark; Schilling, William P

    2002-01-01

    Background Maitotoxin (MTX) initiates cell death by sequentially activating 1) Ca2+ influx via non-selective cation channels, 2) uptake of vital dyes via formation of large pores, and 3) release of lactate dehydrogenase, an indication of cell lysis. MTX also causes formation of membrane blebs, which dramatically dilate during the cytolysis phase. To determine the role of phospholipase C (PLC) in the cell death cascade, U73122, a specific inhibitor of PLC, and U73343, an inactive analog, were examined on MTX-induced responses in bovine aortic endothelial cells. Results Addition of either U73122 or U73343, prior to MTX, produced a concentration-dependent inhibition of the cell death cascade (IC50 ≈ 1.9 and 0.66 μM, respectively) suggesting that the effect of these agents was independent of PLC. Addition of U73343 shortly after MTX, prevented or attenuated the effects of the toxin, but addition at later times had little or no effect. Time-lapse videomicroscopy showed that U73343 dramatically altered the blebbing profile of MTX-treated cells. Specifically, U73343 blocked bleb dilation and converted the initial blebbing event into "zeiosis", a type of membrane blebbing commonly associated with apoptosis. Cells challenged with MTX and rescued by subsequent addition of U73343, showed enhanced caspase-3 activity 48 hr after the initial insult, consistent with activation of the apoptotic program. Conclusions Within minutes of MTX addition, endothelial cells die by oncosis. Rescue by addition of U73343 shortly after MTX showed that a small percentage of cells are destined to die by oncosis, but that a larger percentage survive; cells that survive the initial insult exhibit zeiosis and may ultimately die by apoptotic mechanisms. PMID:11825342

  7. A23187-induced translocation of 5-lipoxygenase in osteosarcoma cells

    PubMed Central

    1992-01-01

    In a previous study, osteosarcoma cells expressing both 5-lipoxygenase (5-LO) and 5 lipoxygenase-activating protein (FLAP) synthesized leukotrienes upon A23187 stimulation (Dixon, R. A. F., R. E. Diehl, E. Opas, E. Rands, P. J. Vickers, J. F. Evans, J. W. Gillard, and D. K. Miller. 1990. Nature (Lond.). 343:282-284). Osteosarcoma cells expressing 5-LO but not expressing FLAP were unable to synthesize leukotrienes. Thus, it was determined that FLAP was required for the cellular synthesis of leukotrienes. To examine the role of FLAP in A23187-induced translocation of 5-LO to a membrane fraction, we have studied the A23187-stimulated translocation of 5-LO in osteosarcoma cells expressing both 5-LO and FLAP, and in osteosarcoma cells expressing 5-LO only. We demonstrate that in cells expressing both 5-LO and FLAP, 5-LO translocates to membranes in response to A23187 stimulation. This 5-LO translocation is inhibited when cells are stimulated in the presence of MK-886. In osteosarcoma cells expressing 5-LO but not expressing FLAP, 5-LO is able to associate with membranes following A23187 stimulation. In contrast to the cells containing both 5-LO and FLAP, MK-886 is unable to prevent 5-LO membrane association in cells transfected with 5-LO alone. Therefore, we have demonstrated that in this cell system, 5-LO membrane association and activation can be separated into at least two distinct steps: (1) calcium-dependent movement of 5-LO to membranes without product formation, which can occur in the absence of FLAP (membrane association), and (2) activation of 5-LO with product formation, which is FLAP dependent and inhibited by MK-886 (enzyme activation). PMID:1469057

  8. Saikosaponin-d, a novel SERCA inhibitor, induces autophagic cell death in apoptosis-defective cells.

    PubMed

    Wong, V K W; Li, T; Law, B Y K; Ma, E D L; Yip, N C; Michelangeli, F; Law, C K M; Zhang, M M; Lam, K Y C; Chan, P L; Liu, L

    2013-07-11

    Autophagy is an important cellular process that controls cells in a normal homeostatic state by recycling nutrients to maintain cellular energy levels for cell survival via the turnover of proteins and damaged organelles. However, persistent activation of autophagy can lead to excessive depletion of cellular organelles and essential proteins, leading to caspase-independent autophagic cell death. As such, inducing cell death through this autophagic mechanism could be an alternative approach to the treatment of cancers. Recently, we have identified a novel autophagic inducer, saikosaponin-d (Ssd), from a medicinal plant that induces autophagy in various types of cancer cells through the formation of autophagosomes as measured by GFP-LC3 puncta formation. By computational virtual docking analysis, biochemical assays and advanced live-cell imaging techniques, Ssd was shown to increase cytosolic calcium level via direct inhibition of sarcoplasmic/endoplasmic reticulum Ca(2+) ATPase pump, leading to autophagy induction through the activation of the Ca(2+)/calmodulin-dependent kinase kinase-AMP-activated protein kinase-mammalian target of rapamycin pathway. In addition, Ssd treatment causes the disruption of calcium homeostasis, which induces endoplasmic reticulum stress as well as the unfolded protein responses pathway. Ssd also proved to be a potent cytotoxic agent in apoptosis-defective or apoptosis-resistant mouse embryonic fibroblast cells, which either lack caspases 3, 7 or 8 or had the Bax-Bak double knockout. These results provide a detailed understanding of the mechanism of action of Ssd, as a novel autophagic inducer, which has the potential of being developed into an anti-cancer agent for targeting apoptosis-resistant cancer cells.

  9. Hypermutator Salmonella Heidelberg induces an early cell death in epithelial cells.

    PubMed

    Le Gall-David, Sandrine; Zenbaa, Neila; Bouchard, Damien; Lavault, Marie-Thérèse; Bonnaure-Mallet, Martine; Jolivet-Gougeon, Anne; Bousarghin, Latifa

    2015-10-22

    We have previously described that a strain of Salmonella Heidelberg with a hypermutator phenotype, B182, adhered strongly to HeLa cells. In this work, we showed that this hypermutator Salmonella strain invaded HeLa epithelial cells and induced cytoskeleton alteration. Those changes lead to HeLa cell death which was characteristic of apoptosis. For the first time, we showed that this hypermutator strain induced apoptosis associated with the activation of caspases 2, 9 and 3. Complementation of B182 strain showed a decrease in cells death induction. In the presence of other Salmonella Heidelberg with a normomutator phenotype, such as WT and SL486, cell death and caspase 3 were undetectable. These results suggested that early apoptosis and caspase 3 activation were specific to B182. Besides, B182 induced LDH release and caspase 3 activation in CaCo-2 and HCT116 cells. Heat-treated B182 and diffusible products failed to induce this phenotype. Epithelial cells treatment with cytochalasin D caused the inhibition of B182 internalisation and caspase 3 activation. These results showed that this cell death required active S. Heidelberg B182 protein synthesis and bacterial internalisation. However sipB and sopB, usually involved in apoptosis induced by Salmonella were not overexpressed in B182, contrary to fimA and fliC. Comparative genome analysis showed numerous mutations as in rpoS which would be more investigated. The role of the hypermutator phenotype might be suspected to be implicated in these specific features. This result expands our knowledge about strong mutators frequently found in bacterial organisms isolated from clinical specimens.

  10. Naphthazarin enhances ionizing radiation-induced cell cycle arrest and apoptosis in human breast cancer cells.

    PubMed

    Kim, Min Young; Park, Seong-Joon; Shim, Jae Woong; Yang, Kwangmo; Kang, Ho Sung; Heo, Kyu

    2015-04-01

    Naphthazarin (Naph, DHNQ, 5,8-dihydroxy-l,4-naphthoquinone) is one of the naturally available 1,4-naphthoquinone derivatives that are well-known for their anti-inflammatory, antioxidant, antibacterial and antitumor cytotoxic effects in cancer cells. Herein, we investigated whether Naph has effects on cell cycle arrest and apoptosis in MCF-7 human breast cancer cells exposed to ionizing radiation (IR). Naph reduced the MCF-7 cell viability in a dose-dependent manner. We also found that Naph and/or IR increased the p53-dependent p21 (CIP/WAF1) promoter activity. Noteworthy, our ChIP assay results showed that Naph and IR combined treatment activated the p21 promoter via inhibition of binding of multi-domain proteins, DNMT1, UHRF1 and HDAC1. Apoptosis and cell cycle analyses demonstrated that Naph and IR combined treatment induced cell cycle arrest and apoptosis in MCF-7 cells. Herein, we showed that Naph treatment enhances IR-induced cell cycle arrest and death in MCF-7 human breast cancer cells through the p53-dependent p21 activation mechanism. These results suggest that Naph might sensitize breast cancer cells to radiotherapy by enhancing the p53-p21 mechanism activity.

  11. Calprotectin induces cell death in human prostate cancer cell (LNCaP) through survivin protein alteration.

    PubMed

    Sattari, Mina; Pazhang, Yaghub; Imani, Mehdi

    2014-11-01

    Calprotectin (CP), an abundant heterodimeric cytosolic protein of neutrophils, conveys a variety of functions such as tumor cell growth arrest and antimicrobial activity. We investigated CP activity and its possible apoptosis-inducing mechanism of action against an antiandrogen therapy-resistance prostate cancer cell line LNCaP. Cell viability and Annexin V FITC assays were performed in order to investigate its cell death activity and apoptosis, respectively. In order to address cell death inducing mechanism(s), immunocytochemistry and immunobloting analysis, reactive oxygen species (ROS) and nitric oxide (NO) measurements were performed. The effective concentration of CP against LNCaP promoting LNCaP cell death was 200 µg/mL. ROS and NO levels of cells remarkably were enhanced following treatment with 50 and 100 µg/mL of CP, respectively. Protein expression of anti-apoptotic protein survivin was significantly decreased after administration of tumor cells with CP. Our data indicate that CP regulates the LNCaP cells viability via survivin-mediated pathway and ROS and NO enhancement. Thus, inhibition of survivin expression, enhancement of ROS and NO level by CP or other similar pharmaceutical agents might be effective in lowering the malignant proliferation of human prostate cancer cells.

  12. Memantine Induces NMDAR1-Mediated Autophagic Cell Death in Malignant Glioma Cells

    PubMed Central

    Yoon, Wan-Soo; Yeom, Mi-Young; Kang, Eun-Sun; Chung, Yong-An; Chung, Dong-Sup; Jeun, Sin-Soo

    2017-01-01

    Objective Autophagy is one of the key responses of cells to programmed cell death. Memantine, an approved anti-dementia drug, has an antiproliferative effect on cancer cells but the mechanism is poorly understood. The aim of the present study was to test the possibility of induction of autophagic cell death by memantine in glioma cell lines. Methods Glioma cell lines (T-98 G and U-251 MG) were used for this study. Results The antiproliferative effect of memantine was shown on T-98 G cells, which expressed N-methyl-D-aspartate 1 receptor (NMDAR1). Memantine increased the autophagic-related proteins as the conversion ratio of light chain protein 3-II (LC3-II)-/LC3-I and the expression of beclin-1. Memantine also increased formation of autophagic vacuoles observed under a transmission electron microscope. Transfection of small interfering RNA (siRNA) to knock down NMDAR1 in the glioma cells induced resistance to memantine and decreased the LC3-II/LC3-I ratio in T-98 G cells. Conclusion Our study demonstrates that in glioma cells, memantine inhibits proliferation and induces autophagy mediated by NMDAR1. PMID:28264232

  13. Mitomycin C-induced cell death in mouse lens epithelial cells.

    PubMed

    Park, Hyun-Kyung; Lee, Kwang-Won; Choi, Jun-Sub; Joo, Choun-Ki

    2002-01-01

    The mode of action of mitomycin C (MMC)-induced cell death in lens epithelia was investigated using cell culture system. The cytotoxicity of MMC on alpha-TN4 mouse lens epithelial cells (LECs) was measured by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT)-based assay. To determine the type of cell death induced by MMC, we stained LECs with acridine orange and ethidium bromide, and performed TUNEL assay and electron microscopic examination. The activation of MMC was also investigated with N-acetly-L-cystein (NAC), a free radical scavenger, and dicumarol, an inhibitor of DT-diaphorase, to analyze one- and two-electron reduction pathways involved in the activation of MMC. MTT assay showed that 400 microg/ml of MMC decreased the cell viability of the control cells to 45%, and the cytotoxicity of MMC on alpha-TN4 cells was increased in a dose-dependent manner. Based on the results obtained from acridine orange and ethidium bromide staining, the TUNEL assay, and transmission electron microscopic examination, we confirmed that MMC-induced cell death, at 400 microg/ml of MMC, occurs with necrosis as well as apoptotis. The treatment of cells with 2 mM NAC for 1 h or 20 microM dicumarol for 30 min, prior to 5 min of MMC (400 microg/ml) treatment, restored the growth suppression to 76 and 80% of the control level, respectively. In addition, the cotreatment of cells with NAC and dicumarol restored cell viability to 90% of the control level. The cellular death in MMC-treated LECs showed the involvement of oxidative stress in this apoptosis accounting for 22% of the observed cell death at 400 microg/ml of MMC.

  14. Limiting replication stress during somatic cell reprogramming reduces genomic instability in induced pluripotent stem cells

    PubMed Central

    Ruiz, Sergio; Lopez-Contreras, Andres J.; Gabut, Mathieu; Marion, Rosa M.; Gutierrez-Martinez, Paula; Bua, Sabela; Ramirez, Oscar; Olalde, Iñigo; Rodrigo-Perez, Sara; Li, Han; Marques-Bonet, Tomas; Serrano, Manuel; Blasco, Maria A.; Batada, Nizar N.; Fernandez-Capetillo, Oscar

    2015-01-01

    The generation of induced pluripotent stem cells (iPSC) from adult somatic cells is one of the most remarkable discoveries in recent decades. However, several works have reported evidence of genomic instability in iPSC, raising concerns on their biomedical use. The reasons behind the genomic instability observed in iPSC remain mostly unknown. Here we show that, similar to the phenomenon of oncogene-induced replication stress, the expression of reprogramming factors induces replication stress. Increasing the levels of the checkpoint kinase 1 (CHK1) reduces reprogramming-induced replication stress and increases the efficiency of iPSC generation. Similarly, nucleoside supplementation during reprogramming reduces the load of DNA damage and genomic rearrangements on iPSC. Our data reveal that lowering replication stress during reprogramming, genetically or chemically, provides a simple strategy to reduce genomic instability on mouse and human iPSC. PMID:26292731

  15. Big Animal Cloning Using Transgenic Induced Pluripotent Stem Cells: A Case Study of Goat Transgenic Induced Pluripotent Stem Cells.

    PubMed

    Song, Hui; Li, Hui; Huang, Mingrui; Xu, Dan; Wang, Ziyu; Wang, Feng

    2016-02-01

    Using of embryonic stem cells (ESCs) could improve production traits and disease resistance by improving the efficiency of somatic cell nuclear transfer (SCNT) technology. However, robust ESCs have not been established from domestic ungulates. In the present study, we generated goat induced pluripotent stem cells (giPSCs) and transgenic cloned dairy goat induced pluripotent stem cells (tgiPSCs) from dairy goat fibroblasts (gFs) and transgenic cloned dairy goat fibroblasts (tgFs), respectively, using lentiviruses that contained hOCT4, hSOX2, hMYC, and hKLF4 without chemical compounds. The giPSCs and tgiPSCs expressed endogenous pluripotent markers, including OCT4, SOX2, MYC, KLF4, and NANOG. Moreover, they were able to maintain a normal karyotype and differentiate into derivatives from all three germ layers in vitro and in vivo. Using SCNT, tgFs and tgiPSCs were used as donor cells to produce embryos, which were named tgF-Embryos and tgiPSC-Embryos. The fusion rates and cleavage rates had no significant differences between tgF-Embryos and tgiPSC-Embryos. However, the expression of IGF-2, which is an important gene associated with embryonic development, was significantly lower in tgiPSC-Embryos than in tgF-Embryos and was not significantly different from vivo-Embryos.

  16. Induced Pluripotent Stem Cell-Derived Natural Killer Cells for Treatment of Ovarian Cancer.

    PubMed

    Hermanson, David L; Bendzick, Laura; Pribyl, Lee; McCullar, Valarie; Vogel, Rachel Isaksson; Miller, Jeff S; Geller, Melissa A; Kaufman, Dan S

    2016-01-01

    Natural killer (NK) cells can provide effective immunotherapy for ovarian cancer. Here, we evaluated the ability of NK cells isolated from peripheral blood (PB) and NK cells derived from induced pluripotent stem cell (iPSC) to mediate killing of ovarian cancer cells in a mouse xenograft model. A mouse xenograft model was used to evaluate the intraperitoneal delivery of three different NK cell populations: iPSC-derived NK cells, PB-NK cells that had been activated and expanded in long-term culture, and overnight activated PB-NK cells that were isolated through CD3/CD19 depletion of PB B and T cells. Bioluminescent imaging was used to monitor tumor burden of luciferase expressing tumor lines. Tumors were allowed to establish prior to administering NK cells via intraperitoneal injection. These studies demonstrate a single dose of any of the three NK cell populations significantly reduced tumor burden. When mice were given three doses of either iPSC-NK cells or expanded PB-NK cells, the median survival improved from 73 days in mice untreated to 98 and 97 days for treated mice, respectively. From these studies, we conclude iPSC-derived NK cells mediate antiovarian cancer killing at least as well as PB-NK cells, making these cells a viable resource for immunotherapy for ovarian cancer. Due to their ability to be easily differentiated into NK cells and their long-term expansion potential, iPSCs can be used to produce large numbers of well-defined NK cells that can be banked and used to treat a large number of patients including treatment with multiple doses if necessary.

  17. Oct4 and klf4 reprogram dermal papilla cells into induced pluripotent stem cells.

    PubMed

    Tsai, Su-Yi; Clavel, Carlos; Kim, Soo; Ang, Yen-Sin; Grisanti, Laura; Lee, Dung-Fang; Kelley, Kevin; Rendl, Michael

    2010-02-01

    Direct reprogramming of somatic cells into induced pluripotent stem (iPS) cells by only four transcription factors (Oct4, Sox2, Klf4, and c-Myc) has great potential for tissue-specific regenerative therapies, eliminating the ethical issues surrounding the use of embryonic stem cells and the rejection problems of using non-autologous cells. The reprogramming efficiency generally is very low, however, and the problems surrounding the introduction of viral genetic material are only partially investigated. Recent efforts to reduce the number of virally expressed transcription factors succeeded at reprogramming neural stem cells into iPS cells by overexpressing Oct4 alone. However, the relative inaccessibility and difficulty of obtaining neural cells in humans remains to be resolved. Here we report that dermal papilla (DP) cells, which are specialized skin fibroblasts thought to instruct hair follicle stem cells, endogenously express high levels of Sox2 and c-Myc, and that these cells can be reprogrammed into iPS cells with only Oct4 and Klf4. Moreover, we show that DP cells are reprogrammed more efficiently than skin and embryonic fibroblasts. iPS cells derived from DP cells expressed pluripotency genes and differentiated into cells from all germ layers in vitro and widely contributed to chimeric mice in vivo, including the germline. Our work establishes DP cells as an easily accessible source to generate iPS cells with efficiency and with less genetic material. This opens up the possibility of streamlined generation of skin-derived, patient-specific pluripotent stem cells and of ultimately replacing the remaining two factors with small molecules for safe generation of transplantable cells.

  18. Establishment of Human Neural Progenitor Cells from Human Induced Pluripotent Stem Cells with Diverse Tissue Origins

    PubMed Central

    Fukusumi, Hayato; Shofuda, Tomoko; Bamba, Yohei; Yamamoto, Atsuyo; Kanematsu, Daisuke; Handa, Yukako; Okita, Keisuke; Nakamura, Masaya; Yamanaka, Shinya; Okano, Hideyuki; Kanemura, Yonehiro

    2016-01-01

    Human neural progenitor cells (hNPCs) have previously been generated from limited numbers of human induced pluripotent stem cell (hiPSC) clones. Here, 21 hiPSC clones derived from human dermal fibroblasts, cord blood cells, and peripheral blood mononuclear cells were differentiated using two neural induction methods, an embryoid body (EB) formation-based method and an EB formation method using dual SMAD inhibitors (dSMADi). Our results showed that expandable hNPCs could be generated from hiPSC clones with diverse somatic tissue origins. The established hNPCs exhibited a mid/hindbrain-type neural identity and uniform expression of neural progenitor genes. PMID:27212953

  19. Current methods for inducing pluripotency in somatic cells.

    PubMed

    Tavernier, Geertrui; Mlody, Barbara; Demeester, Jo; Adjaye, James; De Smedt, Stefaan C

    2013-05-28

    The groundbreaking discovery of reprogramming fibroblasts towards pluripotency merely by introducing four transcription factors (OCT4, SOX2, KLF4 and c-MYC) by means of retroviral transduction has created a promising revolution in the field of regenerative medicine. These so-called induced pluripotent stem cells (iPSCs) can provide a cell source for disease-modelling, drug-screening platforms, and transplantation strategies to treat incurable degenerative diseases, while circumventing the ethical issues and immune rejections associated with the use of non-autologous embryonic stem cells. The risk of insertional mutagenesis, caused both by the viral and transgene nature of the technique has proven to be the major limitation for iPSCs to be used in a clinical setting. In view of this, a variety of alternative techniques have been developed to induce pluripotency in somatic cells. This review provides an overview on current reprogramming protocols, discusses their pros and cons and future challenges to provide safe and transgene-free iPSCs.

  20. T cell responses induced by allergen-specific immunotherapy

    PubMed Central

    Maggi, E

    2010-01-01

    Allergen-specific immunotherapy is recognized as a highly effective practice in the treatment of patients with severe allergic rhinitis and/or asthma and is recommended by World Health Organization as an integrated part of allergy management strategy. Several studies have shown that allergen-specific immunotherapy, based on the administration of increasing doses of allergen, achieves a hyposensitization and reduces both early and late responses occurring during the natural exposure to the allergen itself. This is the unique antigen-specific immunomodulatory treatment in current use for human diseases. Successful immunotherapy is associated with reductions in symptoms and medication scores and improved quality of life. After interruption it usually confers long-term remission of symptoms and prevents the onset of new sensitizations in children up to a number of years. Subcutaneous immunotherapy usually suppresses the allergen-induced late response in target organs, likely due to the reduction of the infiltration of T cells, eosinophils, basophils, mast cells and neutrophils. In addition to the reduction of cells of allergic inflammation, immunotherapy also decreases inflammatory mediators at the site of allergen exposure. This review provides an update on the immunological T cell responses induced by conventional subcutaneous and sublingual immunotherapy, and gives a unifying view to reconciling the old dualism between immunoredirecting and immunoregulating mechanisms. PMID:20408857

  1. Aloe-emodin-induced apoptosis in human gastric carcinoma cells.

    PubMed

    Chen, Sheng-Hsuan; Lin, Kai-Yuan; Chang, Chun-Chao; Fang, Chia-Lang; Lin, Chih-Ping

    2007-11-01

    The purpose of this study was to investigate the anticancer effect of aloe-emodin, an anthraquinone compound present in the leaves of Aloe vera, on two distinct human gastric carcinoma cell lines, AGS and NCI-N87. We demonstrate that aloe-emodin induced cell death in a dose- and time-dependent manner. Noteworthy is that the AGS cells were generally more sensitive than the NCI-N87 cells. Aloe-emodin caused the release of apoptosis-inducing factor and cytochrome c from mitochondria, followed by the activation of caspase-3, leading to nuclear shrinkage and apoptosis. In addition, exposure to aloe-emodin suppressed the casein kinase II activity in a time-dependent manner and was accompanied by a reduced phosphorylation of Bid, a downstream substrate of casein kinase II and a pro-apoptotic molecule. These preclinical studies suggest that aloe-emodin represents a suitable and novel chemotherapeutic drug candidate for the treatment of human gastric carcinoma.

  2. Bortezomib induces autophagic death in proliferating human endothelial cells

    SciTech Connect

    Belloni, Daniela; Veschini, Lorenzo; Foglieni, Chiara; Dell'Antonio, Giacomo; Caligaris-Cappio, Federico; Ferrarini, Marina; Ferrero, Elisabetta

    2010-04-01

    The proteasome inhibitor Bortezomib has been approved for the treatment of relapsed/refractory multiple myeloma (MM), thanks to its ability to induce MM cell apoptosis. Moreover, Bortezomib has antiangiogenic properties. We report that endothelial cells (EC) exposed to Bortezomib undergo death to an extent that depends strictly on their activation state. Indeed, while quiescent EC are resistant to Bortezomib, the drug results maximally toxic in EC switched toward angiogenesis with FGF, and exerts a moderate effect on subconfluent HUVEC. Moreover, EC activation state deeply influences the death pathway elicited by Bortezomib: after treatment, angiogenesis-triggered EC display typical features of apoptosis. Conversely, death of subconfluent EC is preceded by ROS generation and signs typical of autophagy, including intense cytoplasmic vacuolization with evidence of autophagosomes at electron microscopy, and conversion of the cytosolic MAP LC3 I form toward the autophagosome-associated LC3 II form. Treatment with the specific autophagy inhibitor 3-MA prevents both LC3 I/LC3 II conversion and HUVEC cell death. Finally, early removal of Bortezomib is accompanied by the recovery of cell shape and viability. These findings strongly suggest that Bortezomib induces either apoptosis or autophagy in EC; interfering with the autophagic response may potentiate the antiangiogenic effect of the drug.

  3. Different types of cell death induced by enterotoxins.

    PubMed

    Lin, Chiou-Feng; Chen, Chia-Ling; Huang, Wei-Ching; Cheng, Yi-Lin; Hsieh, Chia-Yuan; Wang, Chi-Yun; Hong, Ming-Yuan

    2010-08-01

    The infection of bacterial organisms generally causes cell death to facilitate microbial invasion and immune escape, both of which are involved in the pathogenesis of infectious diseases. In addition to the intercellular infectious processes, pathogen-produced/secreted enterotoxins (mostly exotoxins) are the major weapons that kill host cells and cause diseases by inducing different types of cell death, particularly apoptosis and necrosis. Blocking these enterotoxins with synthetic drugs and vaccines is important for treating patients with infectious diseases. Studies of enterotoxin-induced apoptotic and necrotic mechanisms have helped us to create efficient strategies to use against these well-characterized cytopathic toxins. In this article, we review the induction of the different types of cell death from various bacterial enterotoxins, such as staphylococcal enterotoxin B, staphylococcal alpha-toxin, Panton-Valentine leukocidin, alpha-hemolysin of Escherichia coli, Shiga toxins, cytotoxic necrotizing factor 1, heat-labile enterotoxins, and the cholera toxin, Vibrio cholerae. In addition, necrosis caused by pore-forming toxins, apoptotic signaling through cross-talk pathways involving mitochondrial damage, endoplasmic reticulum stress, and lysosomal injury is discussed.

  4. Minocycline fails to protect cerebellar granular cell cultures against malonate-induced cell death.

    PubMed

    Fernandez-Gomez, F J; Gomez-Lazaro, M; Pastor, D; Calvo, S; Aguirre, N; Galindo, M F; Jordán, J

    2005-11-01

    Experimental and clinical studies support the view that the semisynthetic tetracycline minocycline exhibits neuroprotective roles in several models of neurodegenerative diseases, including ischemia, Huntington, Parkinson diseases, and amyotrophic lateral sclerosis. However, recent evidence indicates that minocycline does not always present beneficial actions. For instance, in an in vivo model of Huntington's disease, it fails to afford protection after malonate intrastriatal injection. Moreover, it reverses the neuroprotective effect of creatine in nigrostriatal dopaminergic neurons. This apparent contradiction prompted us to analyze the effect of this antibiotic on malonate-induced cell death. We show that, in rat cerebellar granular cells, the succinate dehydrogenase inhibitor malonate induces cell death in a concentration-dependent manner. By using DFCA, monochlorobimane and 10-N-nonyl-Acridin Orange to measure, respectively, H2O2-derived oxidant species and reduced forms of GSH and cardiolipin, we observed that malonate induced reactive oxygen species (ROS) production to an extent that surpasses the antioxidant defense capacity of the cells, resulting in GSH depletion and cardiolipin oxidation. The pre-treatment for 4 h with minocycline (10-100 microM) did not present cytoprotective actions. Moreover, minocycline failed to block ROS production and to abrogate malonate-induced oxidation of GSH and cardiolipin. Additional experiments revealed that minocycline was also unsuccessful to prevent the mitochondrial swelling induced by malonate. Furthermore, malonate did not induce the expression of the iNOS, caspase-3, -8, and -9 genes which have been shown to be up-regulated in several models where minocycline resulted cytoprotective. In addition, malonate-induced down-regulation of the antiapoptotic gene Bcl-2 was not prevented by minocycline, controversially the mechanism previously proposed to explain minocycline protective action. These results suggest that the

  5. From cloned frogs to patient matched stem cells: induced pluripotency or somatic cell nuclear transfer?

    PubMed

    Yamada, Mitsutoshi; Byrne, James; Egli, Dieter

    2015-10-01

    Nuclear transfer has seen a remarkable comeback in the past few years. Three groups have independently reported the derivation of stem cell lines by somatic cell nuclear transfer, from either adult, neonatal or fetal cells. Though the ability of human oocytes to reprogram somatic cells to stem cells had long been anticipated, success did not arrive on a straightforward path. Little was known about human oocyte biology, and nuclear transfer protocols developed in animals required key changes to become effective with human eggs. By overcoming these challenges, human nuclear transfer research has contributed to a greater understanding of oocyte biology, provided a point of reference for the comparison of induced pluripotent stem cells, and delivered a method for the generation of personalized stem cells with therapeutic potential.

  6. Generation of induced pluripotent stem cell-derived mice by reprogramming of a mature NKT cell.

    PubMed

    Ren, Yue; Dashtsoodol, Nyambayar; Watarai, Hiroshi; Koseki, Haruhiko; Quan, Chengshi; Taniguchi, Masaru

    2014-10-01

    NKT cells are characterized by their expression of an NKT-cell-specific invariant antigen-receptor α chain encoded by Vα14Jα18 gene segments. These NKT cells bridge the innate and acquired immune systems to mediate effective and augmented responses; however, the limited number of NKT cells in vivo hampers their analysis. Here, two lines of induced pluripotent stem cell-derived mice (NKT-iPSC-derived mice) were generated by reprogramming of mature NKT cells, where one harbors both rearranged Vα14Jα18 and Vβ7 genes and the other carries rearranged Vα14Jα18 on both alleles but germline Vβ loci. The analysis of NKT-iPSC-derived mice showed a significant increase in NKT cell numbers with relatively normal frequencies of functional subsets, but significantly enhanced in some cases, and acquired functional NKT cell maturation in peripheral lymphoid organs. NKT-iPSC-derived mice also showed normal development of other immune cells except for the absence of γδT cells and disturbed development of conventional CD4 αβT cells. These results suggest that the NKT-iPSC-derived mice are a better model for NKT cell development and function study rather than transgenic mouse models reported previously and also that the presence of a pre-rearranged Vα14Jα18 in the natural chromosomal context favors the developmental fate of NKT cells.

  7. L1 CELL ADHESION MOLECULE IS NEUROPROTECTIVE OF ALCOHOL INDUCED CELL DEATH

    PubMed Central

    Gubitosi-Klug, Rose; Larimer, Corena G.; Bearer, Cynthia F.

    2009-01-01

    L1 cell adhesion molecule (L1), a protein critical for appropriate development of the central nervous system, is a target for ethanol teratogenicity. Ethanol inhibits both L1 mediated cell adhesion as well as L1 mediated neurite outgrowth. L1 has been shown to increase cell survival in cerebellar granule cells while ethanol has been shown to increase cell death. We sought to determine if L1 protected cells from ethanol induced cell death. Cerebellar granule cells from postnatal day 6 rat pups were cultured on either poly L-lysine with or without an L1 substratum. Alcohol was added at 2 hours post plating and cell survival was measured at various times. L1 substratum significantly increased cell survival at 72 and 120 hours. Ethanol significantly reduced cell survival at 48 hours, with no effect at 72 or 120 hours, both in the presence and absence of L1. At 48 hours, L1 significantly increased cell survival in the presence of ethanol. We conclude that ethanol interferes with processes other than L1-L1 interactions in causing cell death, and that ethanol effects would be more severe in the absence of L1. PMID:17267039

  8. [Establishment of induced pluripotent stem cells from adipose tissue-derived stem cells for dendritic cell-based cancer vaccines].

    PubMed

    Matsushita, Norimasa; Kobayashi, Hajime; Aruga, Atsushi; Yamamoto, Masakazu

    2014-04-01

    Recently, studies on regenerative stem cell therapy are being encouraged, and efforts to generate dendritic cells, which play important roles in cancer immunotherapy, from stem cells are being made in the field of tumor immunology. Therapeutic acquisition of stem cells has important clinical applications. Studies on induced pluripotent stem(iPS)cells generated from somatic cells with pluripotent genes have advanced in recent years. Stem cells are reported to be found in adipose tissue (adipose-derived stem cells, ADSC). Our goal is to develop a new cancer vaccine by using dendritic cells generated from ADSC. In a preliminary study, we examined whether iPS cells can be generated from ADSC to serve as a source of dendritic cells.We introduced a plasmid with pluripotent genes(OCT3/4, KLF4, SOX2, L-MYC, LIN28, p53-shRNA)into an ADSC strain derived from adipose tissue by electroporation and subsequently cultured the cells for further examination. A colony sugges- tive of iPS cells from ADSC was observed. OCT3/4, KLF4, SOX2, L-MYC, and LIN28 mRNAs were expressed in the cultured cells, as confirmed by reverse transcriptase-polymerase chain reaction(RT-PCR). On the basis of these results, we confirmed that iPS cells were generated from ADSC. The method of inducing dendritic cells from iPS cells has already been reported, and the results of this study suggest that ADSC is a potential source of dendritic cells.

  9. Docosahexaenoic Acid Induces Apoptosis in Primary Chronic Lymphocytic Leukemia Cells

    PubMed Central

    Gyan, Emmanuel; Tournilhac, Olivier; Halty, Christelle; Veyrat-Masson, Richard; Akil, Saïda; Berger, Marc; Hérault, Olivier; Callanan, Mary; Bay, Jacques-Olivier

    2015-01-01

    Chronic lymphocytic leukemia is an indolent disorder with an increased infectious risk remaining one of the main causes of death. Development of therapies with higher safety profile is thus a challenging issue. Docosahexaenoic acid (DHA, 22:6) is an omega-3 fatty acid, a natural compound of normal cells, and has been shown to display antitumor potency in cancer. We evaluated the potential in vitro effect of DHA in primary CLL cells. DHA induces high level of in vitro apoptosis compared to oleic acid in a dose-dependent and time-dependent manner. Estimation of IC50 was only of 4.813 µM, which appears lower than those reported in solid cancers. DHA is highly active on CLL cells in vitro. This observation provides a rationale for further studies aiming to understand its mechanisms of action and its potent in vivo activity. PMID:26734128

  10. Light-induced performance increase of silicon heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Kobayashi, Eiji; De Wolf, Stefaan; Levrat, Jacques; Christmann, Gabriel; Descoeudres, Antoine; Nicolay, Sylvain; Despeisse, Matthieu; Watabe, Yoshimi; Ballif, Christophe

    2016-10-01

    Silicon heterojunction solar cells consist of crystalline silicon (c-Si) wafers coated with doped/intrinsic hydrogenated amorphous silicon (a-Si:H) bilayers for passivating-contact formation. Here, we unambiguously demonstrate that carrier injection either due to light soaking or (dark) forward-voltage bias increases the open circuit voltage and fill factor of finished cells, leading to a conversion efficiency gain of up to 0.3% absolute. This phenomenon contrasts markedly with the light-induced degradation known for thin-film a-Si:H solar cells. We associate our performance gain with an increase in surface passivation, which we find is specific to doped a-Si:H/c-Si structures. Our experiments suggest that this improvement originates from a reduced density of recombination-active interface states. To understand the time dependence of the observed phenomena, a kinetic model is presented.

  11. Perfluorooctane sulfonate induces apoptosis in N9 microglial cell line.

    PubMed

    Zhang, Ling; Li, Yuan-yuan; Zeng, Huai-cai; Li, Miao; Wan, Yan-Jian; Schluesener, Hermann J; Zhang, Zhi-yuan; Xu, Shun-qing

    2011-03-01

    Perfluorooctane sulfonate (PFOS) is an environmental persistent acid found at low levels in human, wildlife, and environmental media samples. To study the apoptosis effects of PFOS on microglia, murine N9 cell line was used as a model in current research. The results showed that PFOS could reduce the cell viability significantly, and the cellular apoptosis induced by PFOS was closely accompanied with dissipation of mitochondria membrane potential, upregulation messenger RNAs (mRNAs) of p53, Bax, caspase 9, and caspase 3, and decreased expression of Bcl-2 mRNA. These results suggested that PFOS could disturb homeostasis of N9 cells, impact mitochondria, and affect gene expression of apoptotic regulators, all of which resulted in a start-up of apoptosis.

  12. Peptide-Induced Antiviral Protection by Cytotoxic T Cells

    NASA Astrophysics Data System (ADS)

    Schulz, Manfred; Zinkernagel, Rolf M.; Hengartner, Hans

    1991-02-01

    A specific antiviral cytotoxic immune response in vivo could be induced by the subcutaneous injection of the T-cell epitope of the lymphocytic choriomeningitis virus (LCMV) nucleoprotein as an unmodified free synthetic peptide (Arg-Pro-Gln-Ala-Ser-Gly-Val-Tyr-Met-Gly-Asn-Leu-Thr-Ala-Gln) emulsified in incomplete Freund's adjuvant. This immunization rendered mice into a LCMV-specific protective state as shown by the inhibition of LCMV replication in spleens of such mice. The protection level of these mice correlated with the ability to respond to the peptide challenge by CD8^+ virus-specific cytotoxic T cells. This is a direct demonstration that peptide vaccines can be antivirally protective in vivo, thus encouraging further search for appropriate mixtures of stable peptides that may be used as T-cell vaccines.

  13. Enterotoxigenic Escherichia coli infection induces intestinal epithelial cell autophagy.

    PubMed

    Tang, Yulong; Li, Fengna; Tan, Bie; Liu, Gang; Kong, Xiangfeng; Hardwidge, Philip R; Yin, Yulong

    2014-06-25

    The morbidity and mortality in piglets caused by enterotoxigenic Escherichia coli (ETEC) results in large economic losses to the swine industry, but the precise pathogenesis of ETEC-associated diseases remains unknown. Intestinal epithelial cell autophagy serves as a host defense against pathogens. We found that ETEC induced autophagy, as measured by both the increased punctae distribution of GFP-LC3 and the enhanced conversion of LC3-I to LC3-II. Inhibiting autophagy resulted in decreased survival of IPEC-1 cells infected with ETEC. ETEC triggered autophagy in IPEC-1 cells through a pathway involving the mammalian target of rapamycin (mTOR), the extracellular signal-regulated kinases 1/2 (ERK1/2), and the AMP-activated protein kinase (AMPK).

  14. IL22/IL-22R pathway induces cell survival in human glioblastoma cells.

    PubMed

    Akil, Hussein; Abbaci, Amazigh; Lalloué, Fabrice; Bessette, Barbara; Costes, Léa M M; Domballe, Linda; Charreau, Sandrine; Guillo