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Sample records for display p16ink4a senescence

  1. Aging of mice is associated with p16(Ink4a)- and β-galactosidase-positive macrophage accumulation that can be induced in young mice by senescent cells.

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    Hall, Brandon M; Balan, Vitaly; Gleiberman, Anatoli S; Strom, Evguenia; Krasnov, Peter; Virtuoso, Lauren P; Rydkina, Elena; Vujcic, Slavoljub; Balan, Karina; Gitlin, Ilya; Leonova, Katerina; Polinsky, Alexander; Chernova, Olga B; Gudkov, Andrei V

    2016-07-01

    Senescent cells (SCs) have been considered a source of age-related chronic sterile systemic inflammation and a target for anti-aging therapies. To understand mechanisms controlling the amount of SCs, we analyzed the phenomenon of rapid clearance of human senescent fibroblasts implanted into SCID mice, which can be overcome when SCs were embedded into alginate beads preventing them from immunocyte attack. To identify putative SC killers, we analyzed the content of cell populations in lavage and capsules formed around the SC-containing beads. One of the major cell types attracted by secretory factors of SCs was a subpopulation of macrophages characterized by p16(Ink4a) gene expression and β-galactosidase activity at pH6.0 (β-gal(pH6)), thus resembling SCs. Consistently, mice with p16(Ink4a) promoter-driven luciferase, developed bright luminescence of their peritoneal cavity within two weeks following implantation of SCs embedded in alginate beads. p16(Ink4a)/β-gal(pH6)-expressing cells had surface biomarkers of macrophages F4/80 and were sensitive to liposomal clodronate used for the selective killing of cells capable of phagocytosis. At the same time, clodronate failed to kill bona fide SCs generated in vitro by genotoxic stress. Old mice with elevated proportion of p16(Ink4a)/β-gal(pH6)-positive cells in their tissues demonstrated reduction of both following systemic clodronate treatment, indicating that a significant proportion of cells previously considered to be SCs are actually a subclass of macrophages. These observations point at a significant role of p16(Ink4a)/β-gal(pH6)-positive macrophages in aging, which previously was attributed solely to SCs. They require re-interpretation of the mechanisms underlying rejuvenating effects following eradication of p16(Ink4a)/β-gal(pH6)-positive cells and reconsideration of potential cellular target for anti-aging treatment.

  2. p38 MAPK and JNK antagonistically control senescence and cytoplasmic p16INK4A expression in doxorubicin-treated endothelial progenitor cells.

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    Paolo Spallarossa

    Full Text Available Patients treated with low-dose anthracyclines often show late onset cardiotoxicity. Recent studies suggest that this form of cardiotoxicity is the result of a progenitor cell disease. In this study we demonstrate that Cord Blood Endothelial Progenitor Cells (EPCs exposed to low, sub-apoptotic doses of doxorubicin show a senescence phenotype characterized by increased SA-b-gal activity, decreased TRF2 and chromosomal abnormalities, enlarged cell shape, and disarrangement of F-actin stress fibers accompanied by impaired migratory ability. P16( INK4A localizes in the cytoplasm of doxorubicin-induced senescent EPCs and not in the nucleus as is the case in EPCs rendered senescent by different stimuli. This localization together with the presence of an arrest in G2, and not at the G1 phase boundary, which is what usually occurs in response to the cell cycle regulatory activity of p16(INK4A, suggests that doxorubicin-induced p16( INK4A does not regulate the cell cycle, even though its increase is closely associated with senescence. The effects of doxorubicin are the result of the activation of MAPKs p38 and JNK which act antagonistically. JNK attenuates the senescence, p16( INK4A expression and cytoskeleton remodeling that are induced by activated p38. We also found that conditioned medium from doxorubicin-induced senescent cardiomyocytes does not attract untreated EPCs, unlike conditioned medium from apoptotic cardiomyocytes which has a strong chemoattractant capacity. In conclusion, this study provides a better understanding of the senescence of doxorubicin-treated EPCs, which may be helpful in preventing and treating late onset cardiotoxicity.

  3. Culturing on Wharton's jelly extract delays mesenchymal stem cell senescence through p53 and p16INK4a/pRb pathways.

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    Hao, Haojie; Chen, Guanghui; Liu, Jiejie; Ti, Dongdong; Zhao, Yali; Xu, Shenjun; Fu, Xiaobing; Han, Weidong

    2013-01-01

    Mesenchymal stem cells (MSCs) hold great therapeutic potential. However, MSCs undergo replication senescence during the in vitro expansion process. Wharton's jelly from the human umbilical cord harbors a large number of MSCs. In this study, we hypothesized that Wharton's jelly would be beneficial for in vitro expansion of MSCs. Wharton's jelly extract (WJEs), which is mainly composed of extracellular matrix and cytokines, was prepared as coating substrate. Human MSCs were isolated and cultured on WJE-coated plates. Although the proliferation capacity of cells was not augmented by WJE in early phase culture, adynamic growth in late-phase culture was clearly reduced, suggesting that the replicative senescence of MSCs was efficiently slowed by WJE. This was confirmed by β-galactosidase staining and telomere length measurements of MSCs in late-phase culture. In addition, the decreased differentiation ability of MSCs after long-term culture was largely ameliorated by WJE. Reactive oxygen species (ROS), p53, and p16INK4a/pRb expression increased with passaging. Analysis at the molecular level revealed that WJE-based culture efficiently suppressed the enhancement of intracellular ROS, p53, and p16INK4a/pRb in MSCs. These data demonstrated that WJE provided an ideal microenvironment for MSCs culture expansion in vitro preserved MSC properties by delaying MSCs senescence, and allowed large numbers of MSCs to be obtained for basic research and clinical therapies.

  4. How to measure RNA expression in rare senescent cells expressing any specific protein such as p16Ink4a.

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    Jeyapalan, Jessie C; Sedivy, John M

    2013-02-01

    Here we describe a carefully optimized method for the preparation of high quality RNA by flow sorting of formaldehyde fixed senescent cells immunostained for any intracellular antigen. Replicative cellular senescence is a phenomenon of irreversible growth arrest triggered by the accumulation of a discrete number of cell divisions. The underlying cause of senescence due to replicative exhaustion is telomere shortening. We document here a spontaneous and apparently stochastic process that continuously generates senescent cells in cultures fully immortalized with telomerase. In the course of studying this phenomenon we developed a preparative fluorescence activated flow sorting method based on immunofluorescent staining of intracellular antigens that can also deliver RNA suitable for quantitative analysis of global gene expression. The protocols were developed using normal human diploid fibroblasts (HDF) and up to 5x107 cells could be conveniently processed in a single experiment. The methodology is based on formaldehyde crosslinking of cells, followed by permeabilization, antibody staining, flow sorting, reversal of the crosslinks, and recovery of the RNA. We explored key parameters such as crosslink reversal that affect the fragmentation of RNA. The recovered RNA is of high quality for downstream molecular applications based on short range sequence analysis, such qPCR, hybridization microarrays, and next generation sequencing. The RNA was analyzed by Affymetrix Gene Chip expression profiling and compared to RNA prepared by the direct lysis of cells. The correlation between the data sets was very high, indicating that the procedure does not introduce systematic changes in the mRNA transcriptome. The methods presented in this communication should be of interest to many investigators working in diverse model systems.

  5. SM22α-induced activation of p16INK4a/retinoblastoma pathway promotes cellular senescence caused by a subclinical dose of γ-radiation and doxorubicin in HepG2 cells

    International Nuclear Information System (INIS)

    Kim, Tae Rim; Lee, Hee Min; Lee, So Yong; Kim, Eun Jin; Kim, Kug Chan; Paik, Sang Gi; Cho, Eun Wie; Kim, In Gyu

    2010-01-01

    Research highlights: → SM22α overexpression in HepG2 cells leads cells to a growth arrest state, and the treatment of a subclinical dose of γ-radiation or doxorubicin promotes cellular senescence. → SM22α overexpression elevates p16 INK4a followed by pRB activation, but there are no effects on p53/p21 WAF1/Cip1 pathway. → SM22α-induced MT-1G activates p16 INK4a /pRB pathway, which promotes cellular senescence by damaging agents. -- Abstract: Smooth muscle protein 22-alpha (SM22α) is known as a transformation- and shape change-sensitive actin cross-linking protein found in smooth muscle tissue and fibroblasts; however, its functional role remains uncertain. We reported previously that SM22α overexpression confers resistance against anti-cancer drugs or radiation via induction of metallothionein (MT) isozymes in HepG2 cells. In this study, we demonstrate that SM22α overexpression leads cells to a growth arrest state and promotes cellular senescence caused by treatment with a subclinical dose of γ-radiation (0.05 and 0.1 Gy) or doxorubicin (0.01 and 0.05 μg/ml), compared to control cells. Senescence growth arrest is known to be controlled by p53 phosphorylation/p21 WAF1/Cip1 induction or p16 INK4a /retinoblastoma protein (pRB) activation. SM22α overexpression in HepG2 cells elevated p16 INK4a followed by pRB activation, but did not activate the p53/p21 WAF1/Cip1 pathway. Moreover, MT-1G, which is induced by SM22α overexpression, was involved in the activation of the p16 INK4a /pRB pathway, which led to a growth arrest state and promoted cellular senescence caused by damaging agents. Our findings provide the first demonstration that SM22α modulates cellular senescence caused by damaging agents via regulation of the p16 INK4a /pRB pathway in HepG2 cells and that these effects of SM22α are partially mediated by MT-1G.

  6. Senescence-associated heterochromatin foci are dispensable for cellular senescence, occur in a cell type- and insult-dependent manner, and follow expression of p16 (ink4a)

    Czech Academy of Sciences Publication Activity Database

    Košař, Martin; Bartkova, J.; Hubáčková, Soňa; Hodný, Zdeněk; Lukas, J.; Bartek, Jiří

    2011-01-01

    Roč. 10, č. 3 (2011), s. 457-468 ISSN 1538-4101 R&D Projects: GA ČR GA204/08/1418; GA ČR GA301/08/0353 Institutional research plan: CEZ:AV0Z50520514 Keywords : genotoxic and replicative stress * senescence-associated heterochromatin foci * DNA damage response Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.359, year: 2011

  7. P16INK4a Positive Cells in Human Skin Are Indicative of Local Elastic Fiber Morphology, Facial Wrinkling, and Perceived Age

    DEFF Research Database (Denmark)

    Waaijer, Mariëtte E C; Gunn, David A; Adams, Peter D

    2016-01-01

    Senescent cells are more prevalent in aged human skin compared to young, but evidence that senescent cells are linked to other biomarkers of aging is scarce. We counted cells positive for the tumor suppressor and senescence associated protein p16INK4a in sun-protected upper-inner arm skin biopsies...... wrinkles and a higher perceived age. Participants in the lowest tertile of epidermal p16INK4a counts looked 3 years younger than those in the highest tertile, independently of chronological age and elastic fiber morphology. In conclusion, p16INK4a positive cell numbers in sun-protected human arm skin...

  8. Efficient immortalization of primary human cells by p16INK4a-specific short hairpin RNA or Bmi-1, combined with introduction of hTERT.

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    Haga, Kei; Ohno, Shin-ichi; Yugawa, Takashi; Narisawa-Saito, Mako; Fujita, Masatoshi; Sakamoto, Michiie; Galloway, Denise A; Kiyono, Tohru

    2007-02-01

    Activation of telomerase is sufficient for immortalization of some types of human cells but additional factors may also be essential. It has been proposed that stress imposed by inadequate culture conditions induces senescence due to accumulation of p16(INK4a). Here, we present evidence that many human cell types undergo senescence by activation of the p16(INK4a)/Rb pathway, and that introduction of Bmi-1 can inhibit p16(INK4a) expression and extend the life span of human epithelial cells derived from skin, mammary gland and lung. Introduction of p16(INK4a)-specific short hairpin RNA, as well as Bmi-1, suppressed p16(INK4a) expression in human mammary epithelial cells without promoter methylation, and extended their life span. Subsequent introduction of hTERT, the telomerase catalytic subunit, into cells with low p16(INK4a) levels resulted in efficient immortalization of three cell types without crisis or growth arrest. The majority of the human mammary epithelial cells thus immortalized showed almost normal ploidy as judged by G-banding and spectral karyotyping analysis. Our data suggest that inhibition of p16(INK4a) and introduction of hTERT can immortalize many human cell types with little chromosomal instability.

  9. 5-Aza-2'-deoxycytidine protects against emphysema in mice via suppressing p16Ink4a expression in lung tissue

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    He ZH

    2017-10-01

    Full Text Available Zhi-Hui He,1 Yan Chen,2 Ping Chen,2 Sheng-Dong He,2 Hui-Hui Zeng,2 Ji-Ru Ye,2 Da Liu,2 Jun Cao3 1Intensive Care Unit, 2Department of Respiratory Medicine, Second Xiangya Hospital, Central South University, Changsha, 3Department of Respiratory Medicine, Hunan Provincial People’s Hospital, Changsha, China Background: There is a growing realization that COPD, or at least emphysema, involves several processes presenting in aging and cellular senescence. Endothelial progenitor cells (EPCs contribute to neovascularization and play an important role in the development of COPD. The gene for p16Ink4a is a major dominant senescence one. The aim of the present study was to observe changes in lung function, histomorphology of lung tissue, and expression of p16Ink4a in lung tissue and bone marrow-derived EPCs in emphysematous mice induced by cigarette-smoke extract (CSE, and further to search for a potential candidate agent protecting against emphysema induced by CSE. Materials and methods: An animal emphysema model was induced by intraperitoneal injection of CSE. 5-Aza-2'-deoxycytidine (5-Aza-CdR was administered to the emphysematous mice. Lung function and histomorphology of lung tissue were measured. The p16Ink4a protein and mRNA in EPCs and lung tissues were detected using Western blotting and quantitative reverse-transcription polymerase chain reaction, respectively. Results: CSE induced emphysema with increased p16Ink4a expression in lung tissue and bone marrow-derived EPCs. 5-Aza-CdR partly protected against emphysema, especially in the lung-morphology profile, and partly protest against the overexpression of p16Ink4a in EPCs and lung tissue induced by CSE. Conclusion: 5-Aza-CdR partly protected against emphysema in mice via suppressing p16Ink4a expression in EPCs and lung tissue. Keywords: 5-Aza-2'-deoxycytidine, cigarette smoke, emphysema, endothelial progenitor cells, p16Ink4a

  10. p16(INK4a translation suppressed by miR-24.

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    Ashish Lal

    2008-03-01

    Full Text Available Expression of the tumor suppressor p16(INK4a increases during aging and replicative senescence.Here, we report that the microRNA miR-24 suppresses p16 expression in human diploid fibroblasts and cervical carcinoma cells. Increased p16 expression with replicative senescence was associated with decreased levels of miR-24, a microRNA that was predicted to associate with the p16 mRNA coding and 3'-untranslated regions. Ectopic miR-24 overexpression reduced p16 protein but not p16 mRNA levels. Conversely, introduction of antisense (AS-miR-24 blocked miR-24 expression and markedly enhanced p16 protein levels, p16 translation, and the production of EGFP-p16 reporter bearing the miR-24 target recognition sites.Together, our results suggest that miR-24 represses the initiation and elongation phases of p16 translation.

  11. Chemotherapy and Stem Cell Transplantation Increase p16INK4a Expression, a Biomarker of T-cell Aging

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    William A. Wood

    2016-09-01

    Full Text Available The expression of markers of cellular senescence increases exponentially in multiple tissues with aging. Age-related physiological changes may contribute to adverse outcomes in cancer survivors. To investigate the impact of high dose chemotherapy and stem cell transplantation on senescence markers in vivo, we collected blood and clinical data from a cohort of 63 patients undergoing hematopoietic cell transplantation. The expression of p16INK4a, a well-established senescence marker, was determined in T-cells before and 6 months after transplant. RNA sequencing was performed on paired samples from 8 patients pre- and post-cancer therapy. In patients undergoing allogeneic transplant, higher pre-transplant p16INK4a expression was associated with a greater number of prior cycles of chemotherapy received (p = 0.003, prior autologous transplantation (p = 0.01 and prior exposure to alkylating agents (p = 0.01. Transplantation was associated with a marked increase in p16INK4a expression 6 months following transplantation. Patients receiving autologous transplant experienced a larger increase in p16INK4a expression (3.1-fold increase, p = 0.002 than allogeneic transplant recipients (1.9-fold increase, p = 0.0004. RNA sequencing of T-cells pre- and post- autologous transplant or cytotoxic chemotherapy demonstrated increased expression of transcripts associated with cellular senescence and physiological aging. Cytotoxic chemotherapy, especially alkylating agents, and stem cell transplantation strongly accelerate expression of a biomarker of molecular aging in T-cells.

  12. Epithelial cells derived from human embryonic stem cells display p16INK4A senescence, hypermotility, and differentiation properties shared by many P63+ somatic cell types

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    Dabelsteen, Sally; Hercule, Paula; Barron, Patricia

    2009-01-01

    hESderK cells and keratinocytes a substantially extended lifespan. When exposed to transforming growth factor beta or to an incompletely processed form of Laminin-332, three lifespan-extended or immortalized hESderK lines that we studied became directionally hypermotile, a wound healing and invasion......(+)/K14(+) urothelial and tracheobronchial epithelial cells. Primary and immortalized lines of these cell types had growth requirements and hypermotility responses similar to keratinocytes and bmi1 expression facilitated their immortalization by engineering to express the catalytic subunit of telomerase...

  13. Implications of Genetic and Epigenetic Alterations of CDKN2A (p16INK4a in Cancer

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    Ran Zhao

    2016-06-01

    Full Text Available Aberrant gene silencing is highly associated with altered cell cycle regulation during carcinogenesis. In particular, silencing of the CDKN2A tumor suppressor gene, which encodes the p16INK4a protein, has a causal link with several different types of cancers. The p16INK4a protein plays an executional role in cell cycle and senescence through the regulation of the cyclin-dependent kinase (CDK 4/6 and cyclin D complexes. Several genetic and epigenetic aberrations of CDKN2A lead to enhanced tumorigenesis and metastasis with recurrence of cancer and poor prognosis. In these cases, the restoration of genetic and epigenetic reactivation of CDKN2A is a practical approach for the prevention and therapy of cancer. This review highlights the genetic status of CDKN2A as a prognostic and predictive biomarker in various cancers.

  14. Elevated p16ink4a Expression in Human Labial Salivary Glands as a Potential Correlate of Cognitive Aging in Late Midlife.

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    Christiane Elisabeth Sørensen

    Full Text Available The cell-cycle inhibitor and tumor suppressor cyclin dependent kinase inhibitor, p16ink4a, is one of the two gene products of the ink4a/ARF (cdkn2a locus on chromosome 9q21. Up-regulation of p16ink4a has been linked to cellular senescence, and findings from studies on different mammalian tissues suggest that p16ink4a may be a biomarker of organismal versus chronological age.The aim of this study was to examine the immunolocalization pattern of p16ink4a in human labial salivary gland (LSG tissue, and to analyze whether its expression level in LSGs is a peripheral correlate of cognitive decline in late midlife.The present study was a part of a study of causes and predictors of cognitive decline in middle-aged men in a Danish birth cohort. It is based on data from 181 male participants from the Danish Metropolit birth cohort, born in 1953, who were examined for age-associated alterations in cognition, dental health, and morphological and autonomic innervation characteristics of the LSGs. The participants were allocated to two groups based on the relative change in cognitive performance from young adulthood to late midlife. LSG biopsies were analyzed by qRT-PCR for the expression level of p16ink4a. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded sections of LSGs.p16ink4a immunoreactivity was observed in LSG ductal, myoepithelial, and stromal cells, but not in acinar cells. The mean relative expression of p16ink4a in LSGs was higher in the group of participants with decline in cognitive performance. A logistic regression analysis revealed that the relative p16 expression was predictive of the participant's group assignment. A negative correlation was found between relative p16ink4a expression and the participant's standardized regression residuals from early adulthood to late midlife cognitive performance scores.p16ink4a expression in human LSGs may constitute a potential peripheral correlate of cognitive decline. Human labial

  15. Immunohistochemical study of p16 INK4A and survivin expressions in cervical squamous neoplasm

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    Tan Geok

    2010-01-01

    Full Text Available Introduction:Cervical cancer is the second most common cancer affecting Malaysian women. Despite the implementation of pap smear screening, many women are still diagnosed only in the advanced stage of cervical cancer. This could partly be due to failure of detection of its precursor lesions; hence the need to search for novel biomarkers to assist in the screening and diagnosis of cervical neoplasia. This study aims to determine the expression of p16INK4A and survivin as possible predictive biomarkers in cervical squamous neoplasm. Material and Methods: This is a retrospective study on 201 cases of cervical neoplasm comprising of 129 cervical intraepithelial neoplasia (CIN and 72 squamous cell carcinoma (SCC. All samples were evaluated by two independent observers using p16INK4A and survivin monoclonal antibodies. The p16 INK4A expression was graded as negative, focal and diffuse positivity. The intensity for survivin expression was graded as weak, moderate and intense. Results: It is seen that p16 INK4A expression in CIN 1, CIN 2 and CIN 3 were 25.4%, 42.9% and 95.9% respectively. Majority of SCC (98.6% showed p16 INK4A expression. Survivin expressions in CIN 1, CIN 2, CIN 3 and SCC were 56.7%, 33.4%, 87.5% and 98.6%. There was a linear relationship between increasing grade of CIN and p16 INK4A expressions. Conclusion: Our study showed that p16 INK4A expressions correlate well with the increasing grade of CIN. Although survivin does not correlate well to the increasing grade of CIN, it could be useful in differentiating CIN 3 from SCC.

  16. Expression of p16(INK4A) gene in human pituitary tumours.

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    Machiavelli, Gloria; Cotignola, Javier; Danilowicz, Karina; Carbonara, Carolina; Paes de Lima, Andrea; Basso, Armando; Bruno, Oscar Domingo; Szijan, Irene

    2008-01-01

    Pituitary adenomas comprise 10-15% of primary intracranial tumours but the mechanisms leading to tumour development are yet to be clearly established. The retinoblastoma pathway, which regulates the progression through the cell cycle, is often deregulated in different types of tumours. We studied the cyclin-dependent kinase inhibitor p16(INK4A) gene expression at mRNA level in human pituitary adenomas. Forty-six tumour specimens of different subtypes, 21 clinically non-functioning, 12 growth hormone-secreting, 6 prolactin-secreting, 6 adrenocorticotropin-secreting, and 1 thyrotropin-secreting tumours were studied. All clinically non-functioning and most of the hormone-secreting tumours were macroadenomas (38/46). The RT-PCR assay and electrophoresis of the PCR-products showed that p16(INK4A) mRNA was undetectable in: 62% of non-functioning, 8% of growth hormone-secreting, 17% of prolactin-secreting and 17% of adrenocorticotropin-secreting adenomas. Forty percent of all macroadenomas and 25% of microadenomas had negative p16(INK4A) mRNA, the latter results suggest that the absence of p16(INK4A) product might be an early event in tumours with no expression of this suppressor gene. Within the non-functioning adenomas 63% were "null cell" and 37% were positive for some hormone, both subgroups showed similar percentage of cases with absence of p16(INK4A) mRNA. Our results show that clinically non-functioning macroadenomas have impaired p16(INK4A) expression in a clearly higher proportion than any other pituitary tumour subtype investigated. Other regulatory pathways may be implicated in the development of tumours with positive p16(INK4A) expression.

  17. p16(INK4A) mediates age-related changes in mesenchymal stem cells derived from human dental pulp through the DNA damage and stress response.

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    Feng, Xingmei; Xing, Jing; Feng, Guijuan; Huang, Dan; Lu, Xiaohui; Liu, Suzhe; Tan, Wei; Li, Liren; Gu, Zhifeng

    2014-01-01

    Mesenchymal stem cells derived from human dental pulp (DP-MSCs) are characterized by self-renewal and multi-lineage differentiation, which play important roles in regenerative medicine. Autologous transfers, as non-immunogenic, constitute the safest approach in cellular transplantations. However, their use may be limited by age-related changes. In the study, we compared DP-MSCs isolated from human in five age groups: 5-12 y, 12-20 y, 20-35 y, 35-50 y, and >50 y. We tested the effect of age on proliferation, differentiation, senescence-associated β-galactosidase (SA-β-gal), cell cycle and programmed cell death. DP-MSCs showed characteristics of senescence as a function of age. Meanwhile, the expression of p16(INK4A) and γ-H2A.X significantly increased with age, whereas heat shock protein 60 (HSP60) was decreased in the senescent DP-MSCs. Reactive oxygen species (ROS) staining showed the number of ROS-stained cells and the DCFH fluorescent level were higher in the aged group. Further we examined the senescence of DP-MSCs after modulating p16(INK4A) signaling. The results indicated the dysfunction of DP-MSCs was reversed by p16(INK4A) siRNA. In summary, our study indicated p16(INK4A) pathway may play a critical role in DP-MSCs age-related changes and the DNA damage response (DDR) and stress response may be the main mediators of DP-MSCs senescence induced by excessive activation of p16(INK4A) signaling. Copyright © 2014. Published by Elsevier Ireland Ltd.

  18. Elevated p16ink4a Expression in Human Labial Salivary Glands as a Potential Correlate of Cognitive Aging in Late Midlife

    DEFF Research Database (Denmark)

    Sørensen, Christiane Elisabeth; Tritsaris, Katerina; Reibel, Jesper

    2016-01-01

    BACKGROUND: The cell-cycle inhibitor and tumor suppressor cyclin dependent kinase inhibitor, p16ink4a, is one of the two gene products of the ink4a/ARF (cdkn2a) locus on chromosome 9q21. Up-regulation of p16ink4a has been linked to cellular senescence, and findings from studies on different...... mammalian tissues suggest that p16ink4a may be a biomarker of organismal versus chronological age. OBJECTIVE: The aim of this study was to examine the immunolocalization pattern of p16ink4a in human labial salivary gland (LSG) tissue, and to analyze whether its expression level in LSGs is a peripheral...... correlate of cognitive decline in late midlife. METHODS: The present study was a part of a study of causes and predictors of cognitive decline in middle-aged men in a Danish birth cohort. It is based on data from 181 male participants from the Danish Metropolit birth cohort, born in 1953, who were examined...

  19. Investigation of p16(INK4a) as a prognostic biomarker in oral epithelial dysplasia.

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    Nankivell, Paul; Williams, Hazel; Webster, Keith; Pearson, David; High, Alec; MacLennan, Kenneth; Senguven, Burcu; McConkey, Christopher; Rabbitts, Pamela; Mehanna, Hisham

    2014-04-01

    Human papilloma virus is a risk factor for oropharyngeal cancer. Evidence for a similar aetiological role in the development of oral dysplasia or its transformation to oral cancer is not as clear. Meta-analyses estimate the prevalence of high-risk human papilloma virus (HPV) serotypes to be three times higher in pre-malignant lesions and cancer than in normal oral mucosa. However, this does not imply a causal relationship. Conflicting results are reported from the few studies examining the prognostic significance of HPV positivity in the development of oral cancer. We aimed to examine the ability of p16(INK4a) protein expression, a surrogate marker of HPV infection, to predict malignant progression in a large cohort of oral dysplasia patients. One hundred forty eight oral dysplasia cases underwent immunohistochemical analysis using a monoclonal antibody against p16(INK4a) . Clinical factors were also collated on each case. Slides were double scored independently by two trained observers. Univariate analyses using both logistic and Cox regression models were performed. Thirty nine of 148 cases progressed to cancer. Ten of 148 cases (7%) were p16(INK4a) positive. High grade of dysplasia (P = 0.0002) and lesion morphology (P = 0.03) were found to be prognostic of malignant progression. p16(INK4a) score was not prognostic in this cohort (P = 0.29). This did not change with a time to event analysis (P = 0.24). Few studies have assessed the aetiological role of HPV in cancer development from dysplastic lesions. Our study, using one of the largest cohorts of oral dysplasia, demonstrated a low rate of p16(INK4a) positivity and was unable to confirm a prognostic ability for this biomarker. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. p16(INK4a) promoter methylation and protein expression in breast fibroadenoma and carcinoma.

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    Di Vinci, Angela; Perdelli, Luisa; Banelli, Barbara; Salvi, Sandra; Casciano, Ida; Gelvi, Ilaria; Allemanni, Giorgio; Margallo, Edoardo; Gatteschi, Beatrice; Romani, Massimo

    2005-04-10

    The potential role of p16(INK4a) methylation in breast cancer is controversial whereas there are no data on fibroadenoma. To assess if inactivation of p16(INK4a) by promoter hypermethylation occurs in this hyperproliferative benign breast lesion or, on the contrary, it is strictly related to the carcinogenic process, we have tested the different histological components of 15 cases of fibroadenoma and the intraductal and infiltrating components of 15 cases of carcinoma and their adjacent non-tumoral epithelium. All samples were obtained by laser-assisted microdissection. The relationship between promoter methylation status, immunohistochemical protein expression and ki67 proliferative activity was evaluated for each lesion. Our data demonstrate that hypermethylation of p16(INK4a) promoter is a common event occurring at similar frequency in all the different histological areas of the benign and malignant breast lesions taken into exam. Conversely, protein p16 expression, although heterogeneously distributed within the section, is considerably higher in breast carcinoma as compared to fibroadenoma in both tumoral and non-tumoral epithelia and stroma. The protein localization was almost exclusively nuclear in fibroadenoma and non-tumoral epithelia whereas, in carcinoma, the staining was both nuclear and cytoplasmic or cytoplasmic alone. Furthermore, in a subset of fibroadenoma with higher proliferative activity, p16 protein expression was substantially decreased as compared to those showing lower proliferation. We did not observe this association in carcinomas. Our data demonstrate that the hypermethylation of the p16(INK4a) promoter is not specifically associated with malignancy and that, on the contrary, the overexpression of p16 and its cytoplasmic sequestration is a feature of breast carcinoma. (c) 2004 Wiley-Liss, Inc.

  1. The chromatin remodelling factor BRG1 is a novel binding partner of the tumor suppressor p16INK4a

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    Mann Graham J

    2009-01-01

    Full Text Available Abstract Background CDKN2A/p16INK4a is frequently altered in human cancers and it is the most important melanoma susceptibility gene identified to date. p16INK4a inhibits pRb phosphorylation and induces cell cycle arrest, which is considered its main tumour suppressor function. Nevertheless, additional activities may contribute to the tumour suppressor role of p16INK4a and could help explain its specific association with melanoma predisposition. To identify such functions we conducted a yeast-two-hybrid screen for novel p16INK4a binding partners. Results We now report that p16INK4a interacts with the chromatin remodelling factor BRG1. We investigated the cooperative roles of p16INK4a and BRG1 using a panel of cell lines and a melanoma cell model with inducible p16INK4a expression and BRG1 silencing. We found evidence that BRG1 is not required for p16INK4a-induced cell cycle inhibition and propose that the p16INK4a-BRG1 complex regulates BRG1 chromatin remodelling activity. Importantly, we found frequent loss of BRG1 expression in primary and metastatic melanomas, implicating this novel p16INK4a binding partner as an important tumour suppressor in melanoma. Conclusion This data adds to the increasing evidence implicating the SWI/SNF chromatin remodelling complex in tumour development and the association of p16INK4a with chromatin remodelling highlights potentially new functions that may be important in melanoma predisposition and chemoresistance.

  2. Case report of a p16INK4A-positive branchial cleft cyst.

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    McLean, T; Iseli, C; Amott, D; Taylor, M

    2015-06-01

    To report the occurrence of a concurrent oropharyngeal papilloma and branchial cleft cyst linked by p16(INK4A) and human papillomavirus immunohistochemistry. A 42-year-old woman presented with a 1-month history of a left lateral neck mass. Contrast enhanced computed tomography showed a hypodense lesion 20 mm in diameter anteromedial to the left sternocleidomastoid muscle. Ultrasound-guided fine needle aspiration suggested a branchial cleft cyst. Panendoscopy was performed at the time of neck mass removal, and a papillomatous lesion was removed from the left hypopharynx. Histopathological analysis showed the neck lesion to be a branchial cyst containing lymphoid tissue, and the oral lesion to be a squamous papilloma. Immunohistochemical analysis showed both the branchial cleft cyst and papilloma to be positive for p16(INK4A) expression and human papillomavirus DNA. Histological and immunohistochemical analyses support the cystic transformation of lymph nodes, or the 'Inclusion Theory', as the aetiology of branchial apparatus anomalies, and raise the possibility that human papillomavirus infection may play a much larger role in disease of the head and neck than previously supposed.

  3. Radionuclides in cigarettes may lead to carcinogenesis via p16INK4a inactivation

    International Nuclear Information System (INIS)

    Prueitt, Robyn L.; Goodman, Julie E.; Valberg, Peter A.

    2009-01-01

    It is widely accepted that tobacco smoke is responsible for the vast majority of lung cancers worldwide. There are many known and suspected carcinogens present in cigarette smoke, including α-emitting radioisotopes. Epidemiologic studies have shown that increased lung cancer risk is associated with exposure to ionizing radiation, and it is estimated that the majority of smoking-induced lung cancers may be at least partly attributable to the inhaled and deposited radiation dose from radioisotopes in the cigarette smoke itself. Recent research shows that silencing of the tumor suppressor gene p16 INK4a (p16) by promoter methylation plays a role in smoking-related lung cancer. Inactivation of p16 has also been associated with lung cancer incidence in radiation-exposed workers, suggesting that radionuclides in cigarette smoke may be acting with other compounds to cause smoking-induced lung cancer. We evaluated the mechanism of ionizing radiation as an accepted cause of lung cancer in terms of its dose from tobacco smoke and silencing of p16. Because both radiation and cigarette smoking are associated with inactivation of p16, and p16 inactivation has been shown to play a major role in carcinogenesis, ionizing radiation from cigarette smoke likely plays a role in lung cancer risk. How large a role it plays, relative to chemical carcinogens and other modes of action, remains to be elucidated

  4. p16 (INK4a) has clinicopathological and prognostic impact on oropharynx and larynx squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Silva, S.D. [Departamento de Cirurgia de Cabeça e Pescoço e Otorrinolaringologia, Hospital A.C. Camargo, São Paulo, SP (Brazil); Department of Oncology, Lady Davis Institute for Medical Research and Segal Cancer Centre, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, Quebec (Canada); Department of Otolaryngology-Head and Neck Surgery, Jewish General Hospital, McGill University, Montreal, Quebec (Canada); Nonogaki, S. [Departamento de Anatomia Patológica, Hospital A.C. Camargo, São Paulo, SP (Brazil); Soares, F.A. [Departamento de Anatomia Patológica, Hospital A.C. Camargo, São Paulo, SP (Brazil); Departamento de Estomatologia, Faculdade de Odontologia, Universidade de São Paulo, São Paulo, SP (Brazil); Kowalski, L.P. [Departamento de Cirurgia de Cabeça e Pescoço e Otorrinolaringologia, Hospital A.C. Camargo, São Paulo, SP (Brazil)

    2012-09-07

    CDKN2A encodes proteins such as p16 (INK4a), which negatively regulate the cell-cycle. Molecular genetic studies have revealed that deletions in CDKN2A occur frequently in cancer. Although p16 (INK4a) may be involved in tumor progression, the clinical impact and prognostic implications in head and neck squamous cell carcinoma (HNSCC) are controversial. The objective of this study was to evaluate the frequency of the immunohistochemical expression of p16 (INK4a) in 40 oropharynx and 35 larynx from HNSCC patients treated in a single institution and followed-up at least for 10 years in order to explore potential associations with clinicopathological outcomes and prognostic implications. Forty cases (53.3%) were positive for p16 (INK4a) and this expression was more intense in non-smoking patients (P = 0.050), whose tumors showed negative vascular embolization (P = 0.018), negative lymphatic permeation (P = 0.002), and clear surgical margins (P = 0.050). Importantly, on the basis of negative p16 (INK4a) expression, it was possible to predict a probability of lower survival (P = 0.055) as well as tumors presenting lymph node metastasis (P = 0.050) and capsular rupture (P = 0.0010). Furthermore, increased risk of recurrence was observed in tumors presenting capsular rupture (P = 0.0083). Taken together, the alteration in p16 (INK4a) appears to be a common event in patients with oropharynx and larynx squamous cell carcinoma and the negative expression of this protein correlated with poor prognosis.

  5. p16 (INK4a) has clinicopathological and prognostic impact on oropharynx and larynx squamous cell carcinoma

    International Nuclear Information System (INIS)

    Silva, S.D.; Nonogaki, S.; Soares, F.A.; Kowalski, L.P.

    2012-01-01

    CDKN2A encodes proteins such as p16 (INK4a), which negatively regulate the cell-cycle. Molecular genetic studies have revealed that deletions in CDKN2A occur frequently in cancer. Although p16 (INK4a) may be involved in tumor progression, the clinical impact and prognostic implications in head and neck squamous cell carcinoma (HNSCC) are controversial. The objective of this study was to evaluate the frequency of the immunohistochemical expression of p16 (INK4a) in 40 oropharynx and 35 larynx from HNSCC patients treated in a single institution and followed-up at least for 10 years in order to explore potential associations with clinicopathological outcomes and prognostic implications. Forty cases (53.3%) were positive for p16 (INK4a) and this expression was more intense in non-smoking patients (P = 0.050), whose tumors showed negative vascular embolization (P = 0.018), negative lymphatic permeation (P = 0.002), and clear surgical margins (P = 0.050). Importantly, on the basis of negative p16 (INK4a) expression, it was possible to predict a probability of lower survival (P = 0.055) as well as tumors presenting lymph node metastasis (P = 0.050) and capsular rupture (P = 0.0010). Furthermore, increased risk of recurrence was observed in tumors presenting capsular rupture (P = 0.0083). Taken together, the alteration in p16 (INK4a) appears to be a common event in patients with oropharynx and larynx squamous cell carcinoma and the negative expression of this protein correlated with poor prognosis

  6. Inactivation of p16INK4a, with retention of pRB and p53/p21cip1 function, in human MRC5 fibroblasts that overcome a telomere-independent crisis during immortalization.

    Science.gov (United States)

    Taylor, Lisa M; James, Alexander; Schuller, Christine E; Brce, Jesena; Lock, Richard B; Mackenzie, Karen L

    2004-10-15

    Recent investigations, including our own, have shown that specific strains of fibroblasts expressing telomerase reverse transcriptase (hTERT) have an extended lifespan, but are not immortal. We previously demonstrated that hTERT-transduced MRC5 fetal lung fibroblasts (MRC5hTERTs) bypassed senescence but eventually succumbed to a second mortality barrier (crisis). In the present study, 67 MRC5hTERT clones were established by limiting dilution of a mass culture. Whereas 39/67 clones had an extended lifespan, all 39 extended lifespan clones underwent crisis. 11 of 39 clones escaped crisis and were immortalized. There was no apparent relationship between the fate of clones at crisis and the level of telomerase activity. Telomeres were hyperextended in the majority of the clones analyzed. There was no difference in telomere length of pre-crisis compared with post-crisis and immortal clones, indicating that hyperextended telomeres were conducive for immortalization and confirming that crisis was independent of telomere length. Immortalization of MRC5hTERT cells was associated with repression of the cyclin-dependent kinase inhibitor p16INK4a and up-regulation of pRB. However, the regulation of pRB phosphorylation and the response of the p53/p21cip1/waf1 pathway were normal in immortal cells subject to genotoxic stress. Overexpression of oncogenic ras failed to de-repress p16INK4a in immortal cells. Furthermore, expression of ras enforced senescent-like growth arrest in p16INK4a-positive, but not p16INK4a-negative MRC5hTERT cells. Immortal cells expressing ras formed small, infrequent colonies in soft agarose, but were non-tumorigenic. Overall, these results implicate the inactivation of p16INK4a as a critical event for overcoming telomere-independent crisis, immortalizing MRC5 fibroblasts and overcoming ras-induced premature senescence.

  7. HFE polymorphisms influence the response to chemotherapeutic agents via induction of p16INK4A.

    Science.gov (United States)

    Lee, Sang Y; Liu, Siying; Mitchell, Ryan M; Slagle-Webb, Becky; Hong, Young-Soo; Sheehan, Jonas M; Connor, James R

    2011-11-01

    HFE is a protein that impacts cellular iron uptake. HFE gene variants are identified as risk factors or modifiers for multiple diseases. Using HFE stably transfected human neuroblastoma cells, we found that cells carrying the C282Y HFE variant do not differentiate when exposed to retinoic acid. Therefore, we hypothesized HFE variants would impact response to therapeutic agents. Both the human neuroblastoma and glioma cells that express the C282Y HFE variant are resistant to Temodar, geldanamycin and γ-radiation. A gene array analysis revealed that p16INK4A (p16) expression was increased in association with C282Y expression. Decreasing p16 protein by siRNA resulted in increased vulnerability to all of the therapeutic agents suggesting that p16 is responsible for the resistance. Decreasing HFE expression by siRNA resulted in a 85% decrease in p16 expression in the neuroblastoma cells but not the astrocytoma cells. These data suggest a potential direct relationship between HFE and p16 that may be cell specific or mediated by different pathways in the different cell types. In conclusion, the C282Y HFE variant impacts the vulnerability of cancer cells to current treatment strategies apparently by increasing expression of p16. Although best known as a tumor suppressor, there are multiple reports that p16 is elevated in some forms of cancer. Given the frequency of the HFE gene variants, as high as 10% of the Caucasian population, these data provide compelling evidence that the C282Y HFE variant should be part of a pharmacogenetic strategy for evaluating treatment efficacy in cancer cells. Copyright © 2011 UICC.

  8. Up-regulation of expression and lack of 5' CpG island hypermethylation of p16 INK4a in HPV-positive cervical carcinomas

    International Nuclear Information System (INIS)

    Ivanova, Tatiana A; Golovina, Daria A; Zavalishina, Larisa E; Volgareva, Galina M; Katargin, Alexey N; Andreeva, Yulia Y; Frank, Georgy A; Kisseljov, Fjodor L; Kisseljova, Natalia P

    2007-01-01

    High risk type human papilloma viruses (HR-HPV) induce carcinomas of the uterine cervix by expressing viral oncogenes E6 and E7. Oncogene E7 of HR-HPV disrupts the pRb/E2F interaction, which negatively regulates the S phase entry. Expression of tumor suppressor p16 ink4a drastically increases in majority of HR-HPV associated carcinomas due to removal of pRb repression. The p16 ink4a overexpression is an indicator of an aberrant expression of viral oncogenes and may serve as a marker for early diagnostic of cervical cancer. On the other hand, in 25–57% of cervical carcinomas hypermethylation of the p16 INK4a promoter has been demonstrated using a methylation-specific PCR, MSP. To evaluate a potential usage of the p16 INK4a 5' CpG island hypermethylation as an indicator of tumor cell along with p16 ink4a overexpression, we analyzed the methylation status of p16 INK4a in cervical carcinomas Methylation status of p16 INK4a was analyzed by MSP and by bisulfite-modified DNA sequencing. The expression of p16 ink4a was analyzed by RT-PCR and by immunohistochemical technique. The extensive methylation within p16 INK4a 5' CpG island was not detected either in 13 primary cervical carcinomas or in 5 cancer cell lines by bisulfite-modified DNA sequencing (including those that were positive by MSP in our hands). The number and distribution of rare partially methylated CpG sites did not differ considerably in tumors and adjacent normal tissues. The levels of the p16 INK4a mRNA were increased in carcinomas compared to the normal tissues independently of the number of partially methylated CpGs within 5'CpG island. The transcriptional activation of p16 INK4a was accompanied by p16 ink4a cytoplasmic immunoreactivity in the majority of tumor cells and presence of a varied number of the p16 positive nuclei in different tumors. Hypermethylaion of the p16INK4a 5' CpG island is not a frequent event in HR-HPV-positive cervical carcinomas and cannot be an effective

  9. Screening for human papillomavirus in basaloid squamous carcinoma: utility of p16(INK4a), CISH, and PCR.

    Science.gov (United States)

    Winters, Ryan; Trotman, Winifred; Adamson, Christine S C; Rajendran, Vanitha; Tang, Alice; Elhosseiny, Abdelmonem; Evans, Mark F

    2011-06-01

    This study compares p16( INK4a) immunohistochemistry (IHC), HPV chromogenic in situ hybridization (ISH), and HPV polymerase chain reaction (PCR) genotyping for detection of HPV infection in basaloid squamous carcinoma (BSCC). A retrospective histopathological analysis of 40 BSCC from a single institution was carried out. p16 IHC, HPV DNA extraction and ISH, and HPV PCR genotyping were performed, and there was excellent agreement between all 3 methods of HPV detection. Analysis of variance yielded no significant differences between the results of the 3 tests ( P = .354) and Pearson product-moment correlation coefficients calculated for each pair of tests demonstrated direct correlation (r = .61 for PCR and IHC, r = .61 for PCR and ISH, and r = 1.00 for ISH and IHC). This supports the use of p16(INK4a) IHC as an initial screening tool for HPV infection in BSCC, while definitive evidence of HPV DNA can be sought subsequently with PCR or CISH.

  10. Polymorphisms in promoter sequences of MDM2, p53, and p16INK4a genes in normal Japanese individuals

    Directory of Open Access Journals (Sweden)

    Yasuhito Ohsaka

    2010-01-01

    Full Text Available Research has been conducted to identify sequence polymorphisms of gene promoter regions in patients and control subjects, including normal individuals, and to determine the influence of these polymorphisms on transcriptional regulation in cells that express wild-type or mutant p53. In this study we isolated genomic DNA from whole blood of healthy Japanese individuals and sequenced the promoter regions of the MDM2, p53, and p16INK4a genes. We identified polymorphisms comprising 3 nucleotide substitutions at exon 1 and intron 1 regions of the MDM2 gene and 1 nucleotide insertion at a poly(C nucleotide position in the p53 gene. The Japanese individuals also exhibited p16INK4a polymorphisms at several positions, including position -191. Reporter gene analysis by using luciferase revealed that the polymorphisms of MDM2, p53, and p16INK4a differentially altered luciferase activities in several cell lines, including the Colo320DM, U251, and T98G cell lines expressing mutant p53. Our results indicate that the promoter sequences of these genes differ among normal Japanese individuals and that polymorphisms can alter gene transcription activity.

  11. The Contrasting Role of p16Ink4A Patterns of Expression in Neuroendocrine and Non-Neuroendocrine Lung Tumors: A Comprehensive Analysis with Clinicopathologic and Molecular Correlations.

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    Nicola Fusco

    Full Text Available Lung cancer encompasses a constellation of malignancies with no validated prognostic markers. p16Ink4A expression has been reported in different subtypes of lung cancers; however, its prognostic value is controversial. Here, we sought to investigate the clinical significance of p16Ink4A immunoexpression according to specific staining patterns and its operational implications. A total of 502 tumors, including 277 adenocarcinomas, 84 squamous cell carcinomas, 22 large cell carcinomas, 47 typical carcinoids, 12 atypical carcinoids, 28 large cell neuroendocrine carcinomas, and 32 small cell carcinomas were reviewed and subjected to immunohistochemical analysis for p16Ink4A and Ki67. The spectrum of p16Ink4A expression was annotated for each case as negative, sporadic, focal, or diffuse. Expression at immunohistochemical level showed intra-tumor homogeneity, regardless tumor histotype. Enrichments in cells expressing p16Ink4A were observed from lower- to higher-grade neuroendocrine malignancies, whereas a decrease was seen in poorly and undifferentiated non-neuroendocrine carcinomas. Tumor proliferation indices were higher in neuroendocrine tumors expressing p16Ink4A while non-neuroendocrine malignancies immunoreactive for p16Ink4A showed a decrease in Ki67-positive cells. Quantitative statistical analyses including each histotype and the p16Ink4A status confirmed the independent prognostic role of p16Ink4A expression, being a high-risk indicator in neuroendocrine tumors and a marker of good prognosis in non-neuroendocrine lung malignancies. In this study, we provide circumstantial evidence to suggest that the routinary assessment of p16Ink4A expression using a three-tiered scoring algorithm, even in a small biopsy, may constitute a reliable, reproducible, and cost-effective substrate for a more accurate risk stratification of each individual patient.

  12. Germline CDKN2A/P16INK4A mutations contribute to genetic determinism of sarcoma.

    Science.gov (United States)

    Jouenne, Fanélie; Chauvot de Beauchene, Isaure; Bollaert, Emeline; Avril, Marie-Françoise; Caron, Olivier; Ingster, Olivier; Lecesne, Axel; Benusiglio, Patrick; Terrier, Philippe; Caumette, Vincent; Pissaloux, Daniel; de la Fouchardière, Arnaud; Cabaret, Odile; N'Diaye, Birama; Velghe, Amélie; Bougeard, Gaelle; Mann, Graham J; Koscielny, Serge; Barrett, Jennifer H; Harland, Mark; Newton-Bishop, Julia; Gruis, Nelleke; Van Doorn, Remco; Gauthier-Villars, Marion; Pierron, Gaelle; Stoppa-Lyonnet, Dominique; Coupier, Isabelle; Guimbaud, Rosine; Delnatte, Capucine; Scoazec, Jean-Yves; Eggermont, Alexander M; Feunteun, Jean; Tchertanov, Luba; Demoulin, Jean-Baptiste; Frebourg, Thierry; Bressac-de Paillerets, Brigitte

    2017-09-01

    Sarcomas are rare mesenchymal malignancies whose pathogenesis is poorly understood; both environmental and genetic risk factors could contribute to their aetiology. We performed whole-exome sequencing (WES) in a familial aggregation of three individuals affected with soft-tissue sarcoma (STS) without TP53 mutation (Li-Fraumeni-like, LFL) and found a shared pathogenic mutation in CDKN2A tumour suppressor gene. We searched for individuals with sarcoma among 474 melanoma-prone families with a CDKN2A -/+ genotype and for CDKN2A mutations in 190 TP53 -negative LFL families where the index case was a sarcoma. Including the initial family, eight independent sarcoma cases carried a germline mutation in the CDKN2A /p16 INK4A gene. In five out of seven formalin-fixed paraffin-embedded sarcomas, heterozygosity was lost at germline CDKN2A mutations sites demonstrating complete loss of function. As sarcomas are rare in CDKN2A /p16 INK4A carriers, we searched in constitutional WES of nine carriers for potential modifying rare variants and identified three in platelet-derived growth factor receptor ( PDGFRA ) gene. Molecular modelling showed that two never-described variants could impact the PDGFRA extracellular domain structure. Germline mutations in CDKN2A /P16 INK4A , a gene known to predispose to hereditary melanoma, pancreatic cancer and tobacco-related cancers, account also for a subset of hereditary sarcoma. In addition, we identified PDGFRA as a candidate modifier gene. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  13. Aberrant Expression of ID2 protein and its correlation with EBV-LMP1 and P16(INK4A) in Classical Hodgkin Lymphoma in China

    International Nuclear Information System (INIS)

    Zhao, Po; Lu, Yali; Liu, Lin; Zhong, Mei

    2008-01-01

    The relationships between the expression of ID2, EBV-LMP1 and P16(INK4A) in Chinese classical Hodgkin lymphoma are unknown and need exploring. Samples of classical Hodgkin lymphoma from 60 Chinese patients were analyzed for the expression of ID2, EBV-LMP1 and p16(INK4A) proteins by immunohistochemistry. ID2 protein was expressed in 83.3% of this group of classical Hodgkin lymphoma, staining strongly in both cytoplasm and nucleus of the Hodgkin and Reed-Sternberg (HRS) cells. EBV-LMP1 and P16(INK4A) were overexpressed in 85.0% and 71.7% of Hodgkin lymphoma, respectively. EBV-LMP1 was noted in the cytoplasm, membrane and nucleus of HRS cells; P16(INK4A) was in the nucleus and cytoplasm. Microscopically, ID2, EBV-LMP1 and P16(INK4A) staining distinguished the HRS cells from the complex background of lymphocytes. ID2 was positively correlated with EBV-LMP1(P < 0.01), but P16(INK4A) was inversely related to EBV-LMP1 (P < 0.05). It is suggested that ID2, EBV-LMP1 and P16(INK4A) could play an important role in the evolution of classical Hodgkin lymphoma, and be considered as potential adjunct markers to identify HRS cells in diagnosis

  14. Up-regulation of expression and lack of 5' CpG island hypermethylation of p16 INK4a in HPV-positive cervical carcinomas

    Directory of Open Access Journals (Sweden)

    Frank Georgy A

    2007-03-01

    Full Text Available Abstract Background High risk type human papilloma viruses (HR-HPV induce carcinomas of the uterine cervix by expressing viral oncogenes E6 and E7. Oncogene E7 of HR-HPV disrupts the pRb/E2F interaction, which negatively regulates the S phase entry. Expression of tumor suppressor p16ink4a drastically increases in majority of HR-HPV associated carcinomas due to removal of pRb repression. The p16ink4a overexpression is an indicator of an aberrant expression of viral oncogenes and may serve as a marker for early diagnostic of cervical cancer. On the other hand, in 25–57% of cervical carcinomas hypermethylation of the p16 INK4a promoter has been demonstrated using a methylation-specific PCR, MSP. To evaluate a potential usage of the p16 INK4a 5' CpG island hypermethylation as an indicator of tumor cell along with p16ink4a overexpression, we analyzed the methylation status of p16 INK4a in cervical carcinomas Methods Methylation status of p16 INK4a was analyzed by MSP and by bisulfite-modified DNA sequencing. The expression of p16ink4a was analyzed by RT-PCR and by immunohistochemical technique. Results The extensive methylation within p16 INK4a 5' CpG island was not detected either in 13 primary cervical carcinomas or in 5 cancer cell lines by bisulfite-modified DNA sequencing (including those that were positive by MSP in our hands. The number and distribution of rare partially methylated CpG sites did not differ considerably in tumors and adjacent normal tissues. The levels of the p16 INK4a mRNA were increased in carcinomas compared to the normal tissues independently of the number of partially methylated CpGs within 5'CpG island. The transcriptional activation of p16 INK4a was accompanied by p16ink4a cytoplasmic immunoreactivity in the majority of tumor cells and presence of a varied number of the p16 positive nuclei in different tumors. Conclusion Hypermethylaion of the p16INK4a 5' CpG island is not a frequent event in HR-HPV-positive cervical

  15. EVALUATION OF P16INK4A PROTEIN AS A BIOMARKER FOR CERVICAL INTRAEPITHELIAL NEOPLASIA AND SQUAMOUS CELL CARCINOMA OF THE UTERINE CERVIX

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    Biljana Đorđević

    2011-06-01

    Full Text Available The association of human papilloma virus (HPV infection and cervical intraepithelial neoplasia (CIN is well known. Interaction of HPV proteins with cellular regulatory proteins leads to up regulation of p16INK4A. The aim of this study was to evaluate p16INK4A protein as a biomarker for CIN lesions and squamous cell carcinoma on biopsy specimens of patients who underwent biopsy of the uterine cervix due to abnormal cytological finding.The authors analyzed biopsies from 50 patients with CIN and invasive squamous cell carcinoma of the uterine cervix. Expression of p16INK4A in CIN and invasive squamous cell carcinoma was immunohistochemically analyzed by using monoclonal anti-p16INK4A antibody.A total of 50 patients with CIN and invasive squamous cell carcinoma of the uterine cervix (mean age 40.2±11.5 years, range 20-74 years were analyzed. CIN I lesions were found in 27 (54%, CIN II/CIN III lesions in 9 (18%, and invasive squamous cell carcinoma in 14 (28% patients. Differences in the expression of p16INK4A between CIN I, CIN II/CIN III and squamous cell carcinoma were statistically significant (p<0.0001. Expression of p16INK4A showed low sensitivity (7%, specificity (8%, positive predictive value (8%, and negative predictive value (7% for CIN I. Sensitivity, specificity, positive predictive value, and negative predictive value of p16INK4A were 78%, 61%, 30%, and 93% for CIN II/CIN III, and 100%, 75%, 61%, and 100% for squamous cell carcinoma, respectively.Results of this study suggest that p16INK4A protein may be a sensitive biomarker for CIN II/CIN III lesions and invasive squamous cell carcinoma of the uterine cervix.

  16. Tumor suppressor p16 INK4a: Downregulation of galectin-3, an endogenous competitor of the pro-anoikis effector galectin-1, in a pancreatic carcinoma model.

    Science.gov (United States)

    Sanchez-Ruderisch, Hugo; Fischer, Christian; Detjen, Katharina M; Welzel, Martina; Wimmel, Anja; Manning, Joachim C; André, Sabine; Gabius, Hans-Joachim

    2010-09-01

    The tumor suppressor p16(INK4a) has functions beyond cell-cycle control via cyclin-dependent kinases. A coordinated remodeling of N- and O-glycosylation, and an increase in the presentation of the endogenous lectin galectin-1 sensing these changes on the surface of p16(INK4a)-expressing pancreatic carcinoma cells (Capan-1), lead to potent pro-anoikis signals. We show that the p16(INK4a)-dependent impact on growth-regulatory lectins is not limited to galectin-1, but also concerns galectin-3. By monitoring its expression in relation to p16(INK4a) status, as well as running anoikis assays with galectin-3 and cell transfectants with up- or downregulated lectin expression, a negative correlation between anoikis and the presence of this lectin was established. Nuclear run-off and northern blotting experiments revealed an effect of the presence of p16(INK4a) on steady-state levels of galectin-3-specific mRNA that differed from decreasing the transcriptional rate. On the cell surface, galectin-3 interferes with galectin-1, which initiates signaling toward its pro-anoikis activity via caspase-8 activation. The detected opposite effects of p16(INK4a) at the levels of growth-regulatory galectins-1 and -3 shift the status markedly towards the galectin-1-dependent pro-anoikis activity. A previously undescribed orchestrated fine-tuning of this effector system by a tumor suppressor is discovered.

  17. Dysregulation of the Bmi-1/p16Ink4a pathway provokes an aging-associated decline of submandibular gland function

    Science.gov (United States)

    Yamakoshi, Kimi; Katano, Satoshi; Iida, Mayu; Kimura, Hiromi; Okuma, Atsushi; Ikemoto-Uezumi, Madoka; Ohtani, Naoko; Hara, Eiji; Maruyama, Mitsuo

    2015-01-01

    Bmi-1 prevents stem cell aging, at least partly, by blocking expression of the cyclin-dependent kinase inhibitor p16Ink4a. Therefore, dysregulation of the Bmi-1/p16Ink4a pathway is considered key to the loss of tissue homeostasis and development of associated degenerative diseases during aging. However, because Bmi-1 knockout (KO) mice die within 20 weeks after birth, it is difficult to determine exactly where and when dysregulation of the Bmi-1/p16Ink4a pathway occurs during aging in vivo. Using real-time in vivo imaging of p16Ink4a expression in Bmi-1-KO mice, we uncovered a novel function of the Bmi-1/p16Ink4a pathway in controlling homeostasis of the submandibular glands (SMGs), which secrete saliva into the oral cavity. This pathway is dysregulated during aging in vivo, leading to induction of p16Ink4a expression and subsequent declined SMG function. These findings will advance our understanding of the molecular mechanisms underlying the aging-related decline of SMG function and associated salivary gland hypofunction, which is particularly problematic among the elderly. PMID:25832744

  18. p16INK4a immunostaining in cytological and histological specimens from the uterine cervix: a systematic review and meta-analysis

    Science.gov (United States)

    Tsoumpou, I; Arbyn, M; Kyrgiou, M; Wentzensen, N; Koliopoulos, G; Martin-Hirsch, P; Paraskevaidis, E

    2009-01-01

    Background P16INK4a is a biomarker for transforming HPV infections that could act as an adjunct to current cytological and histological assessment of cervical smears and biopsies, allowing the identification of those women with ambiguous results that require referral to colposcopy and potentially treatment. Material and Methods We conducted a systematic review of all studies that evaluated the use of p16INK4a in cytological or histological specimens from the uterine cervix. We also estimated the mean proportion of samples that were positive for p16INK4a in cytology and histology, stratified by the grade of the lesion. Results Sixty-one studies were included. The proportion of cervical smears overexpressing p16INK4a increased with the severity of cytological abnormality. Among normal smears, only 12% (95% CI: 7–17%) were positive for the biomarker compared to 45% of ASCUS and LSIL (95% CI: 35–54% and 37– 57% respectively) and 89% of HSIL smears (95% CI: 84–95%). Similarly, in histology only 2% of normal biopsies (95% CI: 0.4– 30%) and 38% of CIN1 (95% CI: 23– 53%) showed diffuse staining for p16INK4a compared to 68% of CIN2 (95% CI: 44– 92%) and 82% of CIN3 (95% CI: 72– 92%). Conclusion Although there is good evidence that p16INK4a immunostaining correlates with the severity of cytological/histological abnormalities, the reproducibility is limited due to insufficiently standardized interpretation of the immunostaining. Therefore, a consensus needs to be reached regarding the evaluation of p16INK4a staining and the biomarker needs to be evaluated in various clinical settings addressing specific clinical questions. PMID:19261387

  19. Clinical and prognosis value of the CIMP status combined with MLH1 or p16 INK4a methylation in colorectal cancer.

    Science.gov (United States)

    Saadallah-Kallel, Amana; Abdelmaksoud-Dammak, Rania; Triki, Mouna; Charfi, Slim; Khabir, Abdelmajid; Sallemi-Boudawara, Tahia; Mokdad-Gargouri, Raja

    2017-08-01

    Aberrant DNA methylation of CpG islands occurred frequently in CRC and associated with transcriptional silencing of key genes. In this study, the CIMP combined with MLH1 or p16 INK4a methylation status was determined in CRC patients and correlated with clinicopathological parameters and overall survival. Our data showed that CIMP+ CRCs were identified in 32.9% of cases and that CACNAG1 is the most frequently methylated promoter. When we combined the CIMP with the MLH1 or the p16 INK4a methylation status, we found that CIMP-/MLH1-U (37.8%) and CIMP-/p16 INK4a -U (35.4%) tumors were the most frequent among the four subtypes. Statistical analysis showed that tumor location, lymphovascular invasion, TNM stage, and MSI differed among the group of patients. Kaplan-Meier analyses revealed differences in overall survival according to the CIMP combined with MLH1 or p16 INK4a methylation status. In a multivariate analysis, CIMP/MLH1 and CIMP/p16 INK4a methylation statuses were predictive of prognosis, and the OS was longer for patients with tumors CIMP-/MLH1-M, as well as CIMP-/p16 INK4a -M. Furthermore, DNMT1 is significantly overexpressed in tumors than in normal tissues as well as in CIMP+ than CIMP- tumors. Our results suggest that tumor classification based on the CIMP status combined with MLH1 or p16 INK4a methylation is useful to predict prognosis in CRC patients.

  20. p16(INK4a suppression by glucose restriction contributes to human cellular lifespan extension through SIRT1-mediated epigenetic and genetic mechanisms.

    Directory of Open Access Journals (Sweden)

    Yuanyuan Li

    2011-02-01

    Full Text Available Although caloric restriction (CR has been shown to increase lifespan in various animal models, the mechanisms underlying this phenomenon have not yet been revealed. We developed an in vitro system to mimic CR by reducing glucose concentration in cell growth medium which excludes metabolic factors and allows assessment of the effects of CR at the cellular and molecular level. We monitored cellular proliferation of normal WI-38, IMR-90 and MRC-5 human lung fibroblasts and found that glucose restriction (GR can inhibit cellular senescence and significantly extend cellular lifespan compared with cells receiving normal glucose (NG in the culture medium. Moreover, GR decreased expression of p16(INK4a (p16, a well-known senescence-related gene, in all of the tested cell lines. Over-expressed p16 resulted in early replicative senescence in glucose-restricted cells suggesting a crucial role of p16 regulation in GR-induced cellular lifespan extension. The decreased expression of p16 was partly due to GR-induced chromatin remodeling through effects on histone acetylation and methylation of the p16 promoter. GR resulted in an increased expression of SIRT1, a NAD-dependent histone deacetylase, which has positive correlation with CR-induced longevity. The elevated SIRT1 was accompanied by enhanced activation of the Akt/p70S6K1 signaling pathway in response to GR. Furthermore, knockdown of SIRT1 abolished GR-induced p16 repression as well as Akt/p70S6K1 activation implying that SIRT1 may affect p16 repression through direct deacetylation effects and indirect regulation of Akt/p70S6K1 signaling. Collectively, these results provide new insights into interactions between epigenetic and genetic mechanisms on CR-induced longevity that may contribute to anti-aging approaches and also provide a general molecular model for studying CR in vitro in mammalian systems.

  1. [Sorting role of p16(INK4a)/Ki-67 double immunostaining in the cervical cytology specimens of ASCUS and LSIL cases].

    Science.gov (United States)

    Yu, J; Zhu, H T; Zhao, J J; Su, J Z; Xia, Y D

    2017-05-08

    Objective: To investigate the sorting effect of p16(INK4a)/Ki-67 double immunostaining method in patients with atypical squamous cells of undetermined significance (ASCUS) or low-grade squamous intraepithelial lesion (LSIL) cytology results. Methods: Four-hundred and twenty cases collected during April 2014 to February 2015 of cervical cytology of ASCUS ( n =318) and LSIL ( n =102) were selected, and residual liquid-based cytology specimens were used for p16(INK4a)/Ki-67 double immunostaining. The sensitivity and specificity of the detection of cervical precancerous lesions and cervical cancer were calculated, and the results were compared with high risk HPV. Taking histological follow-up as the gold standard, the test was considered positive when at least one cell exhibited p16(INK4a)/Ki-67 co-staining, without requirement of adjunct morphologic interpretation of positive cells. Results: Further screening CIN2+ in cytology ASCUS and LSIL group , the sensitivity of p16(INK4a)/Ki-67 double immunostaining was slightly lower than high risk HPV (84.2% vs . 94.7%), while the specificity was higher (84.0% vs . 53.9%). For ASCUS patients, the sensitivity of p16(INK4a)/Ki-67 double immunostaining and high risk HPV was 82.6% and 91.3%, and the specificity was 88.8% and 63.7%, respectively. For LSIL patients, the sensitivity of p16(INK4a)/Ki-67 double immunostaining and high risk HPV was 86.7% and 100.0%, and the specificity was 67.8% and 20.7%, respectively. For patients younger and older than 30 years, specificity of p16(INK4a)/Ki-67 double immunostaining was both higher than that of high risk HPV (80.8% vs . 42.3%; 84.6% vs . 56.9%). Conclusions: p16(INK4a)/Ki-67 double immunostaining can effectively identify the high risk population in ASCUS or LSIL, with higher specificity than high risk HPV test. p16(INK4a)/Ki-67 double immunostaining may benefit patients younger than 30 years of age as a preliminary or potential cytology-combining screening tool.

  2. p16INK4A, p53, EGFR expression and KRAS mutation status in squamous cell cancers of the anus: Correlation with outcomes following chemo-radiotherapy

    International Nuclear Information System (INIS)

    Gilbert, Duncan C; Williams, Anthony; Allan, Kimberley; Stokoe, Joanna; Jackson, Tim; Linsdall, Suzanne; Bailey, Charles MH; Summers, Jeff

    2013-01-01

    Background and Purpose: Squamous cell carcinomas of the anal canal are associated with infection with Human Papilloma Viruses (HPVs). Chemo-radiotherapy (CRT) gives 70% 3-year relapse-free survival. Improved predictive markers and therapeutic options are required. Methods: Tumours from 153 patients treated with radical chemo-radiotherapy (50.4 Gy in 28 with concurrent Mitomycin and 5-Fluorouracil between 2004 and 2009) were retrieved and immunohistochemistry performed for p16 INK4A , p53 and EGFR and correlated with outcome. Primary and relapsed samples were analysed for mutations in KRAS. Results: 137/153 (89.5%) stained moderately or strongly for p16 INK4A . p16 INK4A correlated strongly with outcome. 37/137 patients demonstrating moderate/strong p16 INK4A expression relapsed (27.0%), as opposed to 10/16 (62.5%) with absent/weak staining (log rank test p INK4A negative tumours were more frequent in men. p16 INK4A negative patients had significantly worse overall survival (p INK4A is strongly associated with relapse in SCC of the anus and identifies patients with very poor rates of relapse-free and overall survival. Primary and recurrent anal cancer expresses wild type KRAS, unaffected by treatment, supporting trials targeting EGFR in poor risk/recurrent anal cancer

  3. Influence of human papillomavirus and p16INK4a on treatment outcome of patients with anal cancer

    International Nuclear Information System (INIS)

    Koerber, Stefan Alexander; Schoneweg, Clara; Slynko, Alla; Krug, David; Haefner, Matthias F.; Herfarth, Klaus; Debus, Juergen; Sterzing, Florian; Knebel Doeberitz, Magnus von

    2014-01-01

    Background: The purpose of this study was to evaluate HPV-DNA and p16 INK4a (p16) expression as prognostic markers for outcome in patients with anal cancer. Methods: From January 2000 to December 2011 a cohort of 105 anal cancer patients was treated with definitive chemoradiation at our institution. Tumor biopsies from 90 patients were analyzed for HPV-DNA by polymerase chain reaction and for p16 expression by immunohistochemistry. Results: Median follow-up was 48.6 months (range 2.8–169.1 months). HPV-DNA or p16-expression was found in 75 anal cancers each (83.3%), concordance was detectable in 70 tumors (77.8%). Significantly improved overall survival (OS) [77.1% vs. 51.4%, p = 0.005], progression-free survival (PFS) [64.0% vs. 35.0%, p < 0.001] and improved local control [81.0% vs. 55.9%, p = 0.023] was found for concomitant HPV- and p16-positive anal carcinomas (cHPPAC) in univariate analysis. Multivariate analysis showed better OS [p = 0.015] and PFS [p = 0.002] for cHPPAC. Conclusion: The combination of HPV-DNA and p16 can be used as an independent prognostic parameter in anal cancer patients

  4. Association of antibody to E2 protein of human papillomavirus and p16INK4A with progression of HPV-infected cervical lesions.

    Science.gov (United States)

    Chuerduangphui, Jureeporn; Pientong, Chamsai; Swangphon, Piyawut; Luanratanakorn, Sanguanchoke; Sangkomkamhang, Ussanee; Tungsiriwattana, Thumwadee; Kleebkaow, Pilaiwan; Burassakarn, Ati; Ekalaksananan, Tipaya

    2018-05-09

    Human papillomavirus (HPV) E2 and L1 proteins are expressed in cervical cells during the lytic stage of infection. Overexpression of p16 INK4A is a biomarker of HPV-associated cervical neoplasia. This study investigated antibodies to HPV16 E2, HPV16 L1, and p16 INK4A in sera from women with no squamous intraepithelial lesion (No-SIL) of the cervix, low-grade SIL, high-grade SIL, and cervical squamous cell carcinoma (SCC). HPV DNA was detected by polymerase chain reaction. Anti-E2, -L1, and -p16 INK4A antibodies in sera were determined by western blot. Among 116 samples, 69 (60%) were HPV DNA-positive. Percentages seropositive for anti-E2, -L1, and -p16 INK4A antibodies were 39.6, 22.4, and 23.3%, respectively. Anti-E2 antibody was significantly correlated with HPV DNA-positive cases. Eighty-seven women (75%) were regarded as infected with HPV, having at least one positive result from HPV DNA, L1, or E2 antibody. Antibody to p16 INK4A was associated with HPV infection (odds = 5.444, 95% CI 1.203-24.629, P = 0.028) and precancerous cervical lesions (odds = 5.132, 95% CI 1.604-16.415, P = 0.006). Interestingly, the concurrent detection of anti-E2 and -p16 INK4A antibodies was significantly associated with HPV infection (odds = 1.382, 95% CI 1.228-1.555, P = 0.044). These antibodies might be good candidate biomarkers for monitoring HPV-associated cervical lesion development to cancer.

  5. Immunohistochemical characteristic of expression levels of Kі-67, p16INK4a, HPV16 in cervical intraepithelial neoplasia and cervical cancer

    Directory of Open Access Journals (Sweden)

    V. A. Tumanskiy

    2017-08-01

    Full Text Available Squamous cervical cancer (SCC is a common tumor in women, which is preceded by the series of pathological processes, among which the key role is played by cervical intraepithelial neoplasia (CIN. Aim. To study the characteristics of immunohistochemical (IHC expression of Ki-67, p16INK4a, HPV16 in squamous cervical epithelium (SCE with dysplastic changes of varying degree (CIN I–III and also in the tumor cells of SCC. Materials and methods. Pathohistological and IHC studies of uterine cervix biopsies from 53 patients (the age ranged from 18 to 45 years were performed. Results. It was found that SCE with CIN I is characterized by the low Ki-67 expression level (Me = 17.87 % (13.76, 22.44 and the extremely low p16INK4a expression level (Me = 0.00 CUOD (0.00; 29.64. The proportion of HPV16-positive patients with CIN I is 27.27 %. CIN II is characterized by the average proliferation level in SCE (Me = 44.96 % (34.91, 55.41 and the moderate p16INK4a expression level (Me = 75.71 CUOD (51.24, 82, 41. The proportion of HPV16-positive patients with CIN II is 71.43 %. CIN III is characterized by the high proliferation level (Me = 74.62 % (68.50, 84.67 and by the high p16INK4a expression level of in SCE (Me = 117.47 CUOD (95.38, 123, 93; the proportion of HPV16-positive patients with CIN III is 77.78%. In all the patients with SСС, nuclear and cytoplasmic expression of HPV16 was detected in the tumor cells. High expression levels of Ki-67 and p16INK4a were detected in the tumor cells. There are direct correlations between the expression levels of Ki-67, p16INK4a, HPV16 and CIN degree. Conclusions. These data indicate that the expression levels of Ki-67, p16INK4a and HPV16 increase with the increasing of CIN grade. The absence of statistically significant differences between the expression levels of Ki-67, p16INK4a and HPV16 in CIN III and the same levels in the tumor cells of SCC indicates that these markers cannot be used for differential diagnosis

  6. Simulation of Different Truncated p16INK4a Forms and In Silico Study of Interaction with Cdk4

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    Najmeh Fahham

    2009-01-01

    Full Text Available Protein-protein interactions studies can greatly increase the amount of structural and functional information pertaining to biologically active molecules and processes. The information obtained from such studies can lead to design and application of new modification in order to obtain a desired bioactivity. Many application packages and servers performing docking, such as HEX, DOT, AUTODOCK, and ZDOCK are now available for predicting the lowest free energy state of a protein complex. In this study, we have focused on cyclin-dependent kinase 4 (Cdk4, a key molecule in the regulation of cell cycle progression at the G1-S phase restriction point and p16INK4a, a tumor suppressor which inhibits Cdk4 activity. Truncated structures were created to find the more critical regions of p16 for interaction. The tertiary structures were determined by ProSAL, GENO3D Web Server. We evaluated their interactions with Cdk4 using two docking systems, HEX 4.5 and DOT 1. Calculations were performed on a high-speed computer. Minimizations and visualizations were carried out by PdbViewer 3.7. Considering shape and shape/electrostatic total energy, structures containing ANK II, III and IV motifs that lack the N-terminal region of the full length p16 molecule showed the best fi t complexes among the p16 truncated forms. The free energies were compatible with that of p16 full length original form, the full length. It seems that the N-terminal of the molecule is not crucial for the interaction since the truncated structure containing only this region did not show a good total energy.

  7. Protein p 16INK4A expression in cervical intraepithelial neoplasia and invasive squamous cell carcinoma of uterine cervix

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    Gupta Ruchi

    2010-01-01

    Full Text Available The association of human papilloma virus (HPV infection and cervical intraepithelial neoplasia (CIN is well recognized. Interaction of HPV oncogenic proteins with cellular regulatory proteins leads to up regulation of p16 INK4A , a CDK inhibitor, which is a biomarker for HPV infection. We investigated p16 expression in CIN and invasive squamous cell carcinoma (SCC which has not been reported in the Indian population previously. Materials and Methods: Retrospective analysis of 100 cases with 20 cases each of histologically normal cervical epithelium, CIN1, 2, 3 and invasive SCC for p16 expression was performed by immunohistochemistry using commercially available mouse monoclonal antibody to p16 (clone 6H12. Statistical Analysis: For differences in expression among groups, statistical analysis was carried out using ANOVA and post hoc test of Scheffe. Results: p16 immunoreactivity was found to be both nuclear and/or cytoplasmic. The normal cervical epithelium was predominantly negative for p16 (18/20. There was a progressive increase of p16 expression with the grade of CIN. In CIN 1, two cases (20% showed nuclear and nucleocytoplasmic positivity respectively. In contrast, diffuse strong nuclear or nucleocytoplasmic expression was observed in 45 and 55% cases of CIN 2 and CIN 3 respectively. All except one squamous cell carcinoma stained strongly positive for p16. The difference in expression between CIN 2/3 and SCC versus normal cervix was found highly significant (p is equal to 0.008 and p less than 0.001. Conclusions: p16 expression correlates excellently with the grade of CIN and is a sensitive marker of cervical intraepithelial neoplasia.

  8. Stathmin 1 and p16(INK4A) are sensitive adjunct biomarkers for serous tubal intraepithelial carcinoma.

    Science.gov (United States)

    Novak, Marián; Lester, Jenny; Karst, Alison M; Parkash, Vinita; Hirsch, Michelle S; Crum, Christopher P; Karlan, Beth Y; Drapkin, Ronny

    2015-10-01

    To credential Stathmin 1 (STMN1) and p16(INK4A) (p16) as adjunct markers for the diagnosis of serous tubal intraepithelial carcinoma (STIC), and to compare STMN1 and p16 expression in p53-positive and p53-negative STIC and invasive high-grade serous carcinoma (HGSC). Immunohistochemistry (IHC) was used to examine STMN1 and p16 expression in fallopian tube specimens (n=31) containing p53-positive and p53-negative STICs, invasive HGSCs, and morphologically normal FTE (fallopian tube epithelium). STMN1 and p16 expression was scored semiquantitatively by four individuals. The semiquantitative scores were dichotomized, and reported as positive or negative. Pooled siRNA was used to knockdown p53 in a panel of cell lines derived from immortalized FTE and HGSC. STMN1 and p16 were expressed in the majority of p53-positive and p53-negative STICs and concomitant invasive HGSCs, but only scattered positive cells were present in morphologically normal FTE. Both proteins were expressed consistently across multiple STICs from the same patient and in concomitant invasive HGSC. Knockdown of p53 in immortalized FTE cells and in four HGSC-derived cell lines expressing different missense p53 mutations did not affect STMN1 protein levels. This study demonstrates that STMN1 and p16 are sensitive and specific adjunct biomarkers that, when used with p53 and Ki-67, improve the diagnostic accuracy of STIC. The addition of STMN1 and p16 helps to compensate for practical limitations of p53 and Ki-67 that complicate the diagnosis in up to one third of STICs. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Stathmin 1 and p16INK4A are sensitive adjunct biomarkers for serous tubal intraepithelial carcinoma

    Science.gov (United States)

    Novak, Marián; Lester, Jenny; Karst, Alison M.; Parkash, Vinita; Hirsch, Michelle S.; Crum, Christopher P.; Karlan, Beth Y.

    2015-01-01

    Objective To credential Stathmin 1 (STMN1) and p16INK4A (p16) as adjunct markers for the diagnosis of serous tubal intraepithelial carcinoma (STIC), and to compare STMN1 and p16 expression in p53-positive and p53-negative STIC and invasive high-grade serous carcinoma (HGSC). Methods Immunohistochemistry (IHC) was used to examine STMN1 and p16 expression in fallopian tube specimens (n=31) containing p53-positive and p53-negative STICs, invasive HGSCs, and morphologically normal FTE (fallopian tube epithelium). STMN1 and p16 expression was scored semiquantitatively by four individuals. The semiquantitative scores were dichotomized, and reported as positive or negative. Pooled siRNA was used to knockdown p53 in a panel of cell lines derived from immortalized FTE and HGSC. Results STMN1 and p16 were expressed in the majority of p53-positive and p53-negative STICs and concomitant invasive HGSCs, but only scattered positive cells were positive in morphologically normal FTE. Both proteins were expressed consistently across multiple STICs from the same patient and in concomitant invasive HGSC. Knockdown of p53 in immortalized FTE cells and in four HGSC-derived cell lines expressing different missense p53 mutations did not affect STMN1 protein levels. Conclusions This study demonstrates that STMN1 and p16 are sensitive and specific adjunct biomarkers that, when used with p53 and Ki-67, improve the diagnostic accuracy of STIC. The addition of STMN1 and p16 helps to compensate for practical limitations of p53 and Ki-67 that complicate the diagnosis in up to one third of STICs. PMID:26206555

  10. Survey of familial glioma and role of germline p16INK4A/p14ARF and p53 mutation

    DEFF Research Database (Denmark)

    Robertson, Lindsay B; Armstrong, Georgina N; Olver, Bianca D

    2010-01-01

    There is increasing recognition of familial propensity to glioma as a distinct clinical entity beyond a few rare syndromes; however its genetic basis is poorly understood. The role of p16(INK4A)/p14(ARF) and p53 mutations in sporadic glioma provides a strong rationale for investigating germline m...

  11. Deregulated expression of p16INK4a and p53 pathway members in benign and malignant myoepithelial tumours of the salivary glands

    NARCIS (Netherlands)

    Vékony, H.; Röser, K.; Löning, T.; Raaphorst, F.M.; Leemans, C.R.; van der Waal, I.; Bloemena, E.

    2008-01-01

    Aims: Myoepithelial salivary gland tumours are uncommon and follow an unpredictable biological course. The aim was to examine their molecular background to acquire a better understanding of their clinical behaviour. Methods and results: Expression of protein (E2F1, p16INK4a, p53, cyclin D1, Ki67 and

  12. AN UPWARD TREND IN DNA P16INK4A METHYLATION PATTERN AND HIGH RISK HPV INFECTION ACCORDING TO THE SEVERITY OF THE CERVICAL LESION

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    Fernanda Nahoum Carestiato

    2013-09-01

    Full Text Available SUMMARY High-risk human papillomavirus (hr-HPV infection is necessary but not sufficient for cervical cancer development. Recently, P16INK4A gene silencing through hypermethylation has been proposed as an important cofactor in cervical carcinogenesis due to its tumor suppressor function. We aimed to investigate P16INK4A methylation status in normal and neoplastic epithelia and evaluate an association with HPV infection and genotype. This cross-sectional study was performed with 141 cervical samples from patients attending Hospital Moncorvo Filho, Rio de Janeiro. HPV detection and genotyping were performed through PCR and P16INK4A methylation by nested-methylation specific PCR (MSP. HPV frequency was 62.4% (88/141. The most common HPV were HPV16 (37%, HPV18 (16.3% and HPV33/45(15.2%. An upward trend was observed concerning P16INK4A methylation and lesion degree: normal epithelia (10.7%, low grade lesions (22.9%, high grade (57.1% and carcinoma (93.1% (p < 0.0001. A multivariate analysis was performed to evaluate an association between methylation, age, tobacco exposure, HPV infection and genotyping. A correlation was found concerning methylation with HPV infection (p < 0.0001, hr-HPV (p = 0.01, HSIL (p < 0.0007 and malignant lesions (p < 0.0001. Since viral infection and epigenetic alterations are related to cervical carcinoma, we suggest that P16INK4A methylation profile maybe thoroughly investigated as a biomarker to identify patients at risk of cancer.

  13. PD-L1 expression is associated with p16INK4A expression in non-oropharyngeal head and neck squamous cell carcinoma

    Science.gov (United States)

    Chen, San-Chi; Chang, Peter Mu-Hsin; Wang, Hsiao-Jung; Tai, Shyh-Kuan; Chu, Pen-Yuan; Yang, Muh-Hwa

    2018-01-01

    PD-L1 expression is critical in helping tumor cells evade the immune system. However, the level of PD-L1 expression in non-oropharyngeal head and neck squamous cell carcinoma (non-OPHNSCC) and its association with patient prognosis remains unclear. A retrospective clinicopathological analysis was performed on 106 patients with non-OPHNSCC diagnosed between 2007 and 2014. In the current study, tissue arrays from paraffin-embedded non-OPHNSCC samples obtained from patients were constructed, and PD-L1 and p16INK4A expression were determined using immunohistochemistry. Systemic inflammatory factors, including C-reactive protein, serum white blood cell, neutrophil, monocyte and lymphocyte counts were also analyzed. The current study demonstrated that PD-L1 was overexpressed in 32.1% (34/106) and p16INK4A in 20.8% (22/106) of patients. The expression of PD-L1 was associated with p16INK4A expression (P<0.01) but was not associated with levels of systemic inflammatory factors. Tumor stage was determined to be a significant prognostic value (stage I/II vs. III/IV, P=0.03), however, PD-L1, p16INK4A or other clinicopathological factors were not. The current study identified an association between PD-L1 and p16INK4A expression in non-OPHNSCC. This may facilitate the development of anti-PD1/PDL1 therapies to treat patients with head and neck cancer. PMID:29434933

  14. Decreased D2-40 and increased p16INK4A immunoreactivities correlate with higher grade of cervical intraepithelial neoplasia

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    Lu Zhouping

    2011-07-01

    Full Text Available Abstract Background D2-40 has been shown a selective marker for lymphatic endothelium, but also shown in the benign cervical basal cells. However, the application of D2-40 immunoreactivity in the cervical basal cells for identifying the grade of cervical intraepithelial neoplasia (CIN has not been evaluated. Methods In this study, the immunoreactive patterns of D2-40, compared with p16INK4A, which is currently considered as the useful marker for cervical cancers and their precancerous diseases, were examined in total 125 cervical specimens including 32 of CIN1, 37 of CIN2, 35 of CIN3, and 21 of normal cervical tissue. D2-40 and p16INK4A immunoreactivities were scored semiquantitatively according to the intensity and/or extent of the staining. Results Diffuse D2-40 expression with moderate-to-strong intensity was seen in all the normal cervical epithelia (21/21, 100% and similar pattern of D2-40 immunoreactivity with weak-to-strong intensity was observed in CIN1 (31/32, 97.2%. However, negative and/or focal D2-40 expression was found in CIN2 (negative: 20/37, 54.1%; focal: 16/37, 43.2% and CIN3 (negative: 22/35, 62.8%; focal: 12/35, 34.3%. On the other hand, diffuse immunostaining for p16INK4A was shown in 37.5% of CIN1, 64.9% of CIN2, and 80.0% of CIN3. However, the immunoreactive pattern of D2-40 was not associated with the p16INK4A immunoreactivity. Conclusions Immunohistochemical analysis of D2-40 combined with p16INK4A may have a significant implication in clinical practice for better identifying the grade of cervical intraepithelial neoplasia, especially for distinguishing CIN1 from CIN2/3.

  15. p16(INK4a) /Ki-67 dual labelling as a marker for the presence of high-grade cancer cells or disease progression in urinary cytopathology.

    Science.gov (United States)

    Piaton, E; Advenier, A S; Carré, C; Decaussin-Petrucci, M; Mege-Lechevallier, F; Ruffion, A

    2013-10-01

    Overexpression of p16(INK4a) independent of the presence of E6-E7 oncoproteins of high-risk papillomaviruses has been identified in bladder carcinoma in situ lesions with or without concurrent papillary or invasive high-grade (HG) urothelial carcinoma. As p16(INK4a) and Ki-67 co-expression clearly indicates deregulation of the cell cycle, the aim of this study was to investigate the frequency of p16(INK4a) /Ki-67 dual labelling in urinary cytology samples. Immunolabelling was performed in demounted, destained Papanicolaou slides after ThinPrep(®) processing. A total of 84 urinary cytology samples (18 negative, 10 low grade, 19 atypical urothelial cells and 37 high grade) were analysed for p16(INK4a) /Ki-67 co-expression. We assessed underlying urothelial malignancy with cystoscopy, histopathology and follow-up data in every case. Compared with raw histopathological results, p16 (INK4a) /Ki-67 dual labelling was observed in 48 out of 55 (87.3%) HG lesions and in 11 out of 29 (37.9%) negative, papillary urothelial neoplasia of low malignant potential or low-grade carcinomas (P = 0.05). All cases with high-grade/malignant cytology were dual labelled. Sixteen out of 17 (94.1%) carcinoma in situ cases and eight out of 14 (57.1%) cases with atypical urothelial cells matching with HG lesions were dual labelled. Extended follow-up allowed three cases of progression to be diagnosed in dual-labelled cases with negative/low-grade cytology results after a 9- to 11-months delay. The data show that p16(INK4a) /Ki-67 co-expression allows most HG cancer cells to be detected initially and in the follow-up period. Additional studies are needed in order to determine whether dual labelling can be used as a triage tool for atypical urothelial cells in the urine. © 2012 John Wiley & Sons Ltd.

  16. Concurrent disruption of p16INK4a and the ARF-p53 pathway predicts poor prognosis in aggressive non-Hodgkin's lymphoma

    DEFF Research Database (Denmark)

    Grønbaek, K; de Nully Brown, P; Møller, Michael Boe

    2000-01-01

    . By using a panel of PCR-based methods, we have examined the status of the p16INK4a, ARF and p53 genes in 123 cases of non-Hodgkin's lymphoma (NHL) at diagnosis. Alterations of one or more of these genes were detected in seven of 36 (19%) cases with low- to intermediate-grade histology, and in 35 of 87 (40...

  17. Double positivity for HPV-DNA/p16ink4a is the biomarker with strongest diagnostic accuracy and prognostic value for human papillomavirus related oropharyngeal cancer patients.

    Science.gov (United States)

    Mena, Marisa; Taberna, Miren; Tous, Sara; Marquez, Sandra; Clavero, Omar; Quiros, Beatriz; Lloveras, Belen; Alejo, Maria; Leon, Xavier; Quer, Miquel; Bagué, Silvia; Mesia, Ricard; Nogués, Julio; Gomà, Montserrat; Aguila, Anton; Bonfill, Teresa; Blazquez, Carmen; Guix, Marta; Hijano, Rafael; Torres, Montserrat; Holzinger, Dana; Pawlita, Michael; Pavon, Miguel Angel; Bravo, Ignacio G; de Sanjosé, Silvia; Bosch, Francesc Xavier; Alemany, Laia

    2018-03-01

    The etiologic role of human papillomaviruses (HPV) in oropharyngeal cancer (OPC) is well established. Nevertheless, information on survival differences by anatomic sub-site or treatment remains scarce, and it is still unclear the HPV-relatedness definition with best diagnostic accuracy and prognostic value. We conducted a retrospective cohort study of all patients diagnosed with a primary OPC in four Catalonian hospitals from 1990 to 2013. Formalin-fixed, paraffin-embedded cancer tissues were subjected to histopathological evaluation, DNA quality control, HPV-DNA detection, and p16 INK4a /pRb/p53/Cyclin-D1 immunohistochemistry. HPV-DNA positive and a random sample of HPV-DNA negative cases were subjected to HPV-E6*I mRNA detection. Demographic, tobacco/alcohol use, clinical and follow-up data were collected. Multivariate models were used to evaluate factors associated with HPV positivity as defined by four different HPV-relatedness definitions. Proportional-hazards models were used to compare the risk of death and recurrence among HPV-related and non-related OPC. 788 patients yielded a valid HPV-DNA result. The percentage of positive cases was 10.9%, 10.2%, 8.5% and 7.4% for p16 INK4a , HPV-DNA, HPV-DNA/HPV-E6*I mRNA, and HPV-DNA/p16 INK4a , respectively. Being non-smoker or non-drinker was consistently associated across HPV-relatedness definitions with HPV positivity. A suggestion of survival differences between anatomic sub-sites and treatments was observed. Double positivity for HPV-DNA/p16 INK4a showed strongest diagnostic accuracy and prognostic value. Double positivity for HPV-DNA/p16 INK4a , a test that can be easily implemented in the clinical practice, has optimal diagnostic accuracy and prognostic value. Our results have strong clinical implications for patients' classification and handling and also suggest that not all the HPV-related OPC behave similarly. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. High-grade acute organ toxicity and p16INK4A expression as positive prognostic factors in primary radio(chemo)therapy for patients with head and neck squamous cell carcinoma

    International Nuclear Information System (INIS)

    Tehrany, Narges; Rave-Fraenk, Margret; Hess, Clemens F.; Wolff, Hendrik A.; Kitz, Julia; Li, Li; Kueffer, Stefan; Lorenzen, Stephan; Beissbarth, Tim; Burfeind, Peter; Reichardt, Holger M.; Canis, Martin

    2015-01-01

    Superior treatment response and survival for patients with human papilloma virus (HPV)-positive head and neck cancer (HNSCC) are documented in clinical studies. However, the relevance of high-grade acute organ toxicity (HGAOT), which has also been correlated with improved prognosis, has attracted scant attention in HPV-positive HNSCC patients. Hence we tested the hypothesis that both parameters, HPV and HGAOT, are positive prognostic factors in patients with HNSCC treated with definite radiotherapy (RT) or radiochemotherapy (RCT). Pretreatment tumor tissue and clinical records were available from 233 patients receiving definite RT (62 patients) or RCT (171 patients). HPV infection was analysed by means of HPV DNA detection or p16 INK4A expression; HGAOT was defined as the occurrence of acute organ toxicity >grade 2 according to the Common Toxicity Criteria. Both variables were correlated with overall survival (OS) using Cox proportional hazards regression. Positivity for HPV DNA (44 samples, 18.9 %) and p16 INK4A expression (102 samples, 43.8 %) were significantly correlated (p < 0.01), and HGAOT occurred in 77 (33 %) patients. Overall, the 5-year OS was 23 %; stratified for p16 INK4A expression and HGAOT, OS rates were 47 %, 42 %, 20 % and 10 % for patients with p16 INK4A expression and HGAOT, patients with HGAOT only, patients with p16 INK4A expression only, and patients without p16 INK4A expression or HGAOT, respectively. After multivariate testing p16 INK4A expression (p = 0.003) and HGAOT (p < 0.001) were significantly associated with OS. P16 INK4A expression and HGAOT are independent prognostic factors for OS of patients with HNSCC, whereas p16 INK4A expression is particularly important for patients without HGAOT. (orig.) [de

  19. Loss of heterozygosity of CDKN2A (p16INK4a) and RB1 tumor suppressor genes in testicular germ cell tumors

    International Nuclear Information System (INIS)

    Vladusic, Tomislav; Hrascan, Reno; Pecina-Slaus, Nives; Vrhovac, Ivana; Gamulin, Marija; Franekic, Jasna; Kruslin, Bozo

    2010-01-01

    Testicular germ cell tumors (TGCTs) are the most frequent malignances in young adult men. The two main histological forms, seminomas and nonseminomas, differ biologically and clinically. pRB protein and its immediate upstream regulator p16INK4a are involved in the RB pathway which is deregulated in most TGCTs. The objective of this study was to evaluate the occurrence of loss of heterozygosity (LOH) of the CDKN2A (p16INK4a) and RB1 tumor suppressor genes in TGCTs. Forty TGCTs (18 seminomas and 22 nonseminomas) were analyzed by polymerase chain reaction using the restriction fragment length polymorphism or the nucleotide repeat polymorphism method. LOH of the CDKN2A was found in two (6%) out of 34 (85%) informative cases of our total TGCT sample. The observed changes were assigned to two (11%) nonseminomas out of 18 (82%) informative samples. Furthermore, LOH of the RB1 was detected in two (6%) out of 34 (85%) informative cases of our total TGCT sample. Once again, the observed changes were assigned to two (10.5%) nonseminomas out of 19 (86%) informative samples. Both LOHs of the CDKN2A were found in nonseminomas with a yolk sac tumor component, and both LOHs of the RB1 were found in nonseminomas with an embryonal carcinoma component. The higher incidence of observed LOH in nonseminomas may provide a clue to their invasive behavior

  20. Avaliação da expressão imunoistoquímica da proteína p16INK4a no adenocarcinoma de esôfago Protein p16INK4a immunohistochemical expression in adenocarcinoma of the esophagus

    Directory of Open Access Journals (Sweden)

    Mário Henrique Osanai

    2011-12-01

    Full Text Available INTRODUÇÃO: O adenocarcinoma de esôfago apresenta aumento de frequência nas últimas décadas, particularmente em países desenvolvidos. O esôfago de Barrett é reconhecido como a principal lesão precursora e o estudo da sequência metaplasia-displasia-adenocarcinoma mostra a ocorrência de alterações genéticas desde suas fases mais incipientes. As alterações no p16INK4a são relatadas como frequentes no esôfago de Barrett e no carcinoma de esôfago. OBJETIVO: Verificar a prevalência da expressão imunoistoquímica da proteína p16INK4a em exames anatomopatológicos de pacientes com adenocarcinoma de esôfago. MÉTODO: A população do estudo foi constituída de 37 pacientes com adenocarcinoma de esôfago. A expressão da proteína p16 foi detectada por meio de análise imunoistoquímica, com anticorpo primário p16INK4aAb-7, clone 16P07, NeoMarkers e avaliada de acordo com o Sistema de Escore de Imunorreatividade (Immunoreactive scoring system - IRS modificado. RESULTADOS: No grupo houve predominância de pacientes do sexo masculino (86,5% e a maioria dos casos correspondia a estádios avançados (III e IV = 67,5%. Em 12 casos (32,4% foi identificada expressão imunoistoquímica da proteína p16INK4a. Não foi observada relação significativa entre a perda da expressão da proteína p16INK4a e o grau de diferenciação histológica (p=0,81 nem com o estadiamento da doença (p=0,485. CONCLUSÃO: Ocorre perda da expressão imunoistoquímica da proteína p16INK4a, corroborando as informações de que a inativação do gene p16 é um evento frequente e que pode exercer papel importante na carcinogênese do adenocarcinoma de esôfago.BACKGROUND: The esophageal adenocarcinoma shows an increasing frequence in the last decades, specially in the developed countries. The Barrett´s esophagus is accepted as the major premalignant lesion and the metaplasia-dysplasia-adenocarcinoma sequence presents a lot of genetic changes since its early

  1. Sexual behaviour, HPV status and p16INK4a expression in oropharyngeal and oral cavity squamous cell carcinomas: a case-case comparison study.

    Science.gov (United States)

    Emmett, Sarah; Boros, Samuel; Whiteman, David C; Porceddu, Sandro V; Panizza, Benedict J; Antonsson, Annika

    2018-06-01

    A significant proportion of mucosal squamous cell carcinomas of the head and neck (HNSCC; particularly of the oropharynx) are directly attributable to the human papillomavirus (HPV). The increase in the incidence of HPV-related tumours has been postulated to be due to changing sexual practices in the community. We analysed 136 formalin-fixed paraffin-embedded squamous cell carcinomas from the oral cavity (n=40) and oropharynx (n=96) recruited from the Princess Alexandra Hospital (Brisbane, Australia). Samples were analysed for the presence of HPV DNA using a combination of mucosal HPV general primer GP+ PCR and sequencing; p 16INK4a expression was assessed by immunohistochemistry. Each patient completed a questionnaire detailing their lifestyle factors, such as tobacco smoking and alcohol consumption, marital status, and sexual behaviour and history. The HPV DNA prevalence was 5 % in the oral cavity cancers and 72 % in the oropharyngeal cancers (P<0.0001). HPV-16 was the most commonly detected HPV type (found in 91 % of all HPV-positive tumours). There was a strong correlation between HPV DNA positivity and positive p16 INK4a staining in oropharyngeal tumours (P<0.0001). Having an HPV-related tumour was associated with being married or having been married previously (P=0.046), an increasing number of passionate kissing partners (P=0.046), ever having given oral sex (P=0.0007) and an increasing number of oral sex partners (P=0.0015). This study found a higher prevalence of HPV in oropharyngeal compared to oral cavity tumours, with a strong association being identified between oral sex behaviours and HPV-positive tumours. Further research is needed to establish that vaccines will reduce the transmission and carriage of oropharyngeal HPV infections.

  2. p16(INK4A) inhibits the pro-metastatic potentials of osteosarcoma cells through targeting the ERK pathway and TGF-β1.

    Science.gov (United States)

    Silva, Gabriela; Aboussekhra, Abdelilah

    2016-05-01

    Extracellular signal-regulated kinase (ERK) is a downstream component of the evolutionarily conserved mitogen-activated protein kinase-signaling pathway, which controls the expression of a plethora of genes implicated in various physiological processes. This pathway is often hyper-activated by mutations or abnormal extracellular signaling in different types of human cancer, including the most common primary malignant bone tumor osteosarcomas. p16(INK4A) is an important tumor suppressor gene frequently lost in osteosarcomas, and is associated with the progression of these malignancies. We have shown, here, that the ERK1/2 protein kinase is also activated by p16(INK4A) down-regulation in osteosarcoma cells and normal human as well as mouse cells. This inhibitory effect is associated with the suppression of the upstream kinase MEK1/2, and is mediated via the repression of miR-21-5p and the consequent up-regulation of the MEK/ERK antagonist SPRY2 in osteosarcoma cells. Furthermore, we have shown that p16(INK4) inhibits the migration/invasion abilities of these cells through miR-21-5p-dependent inhibition of ERK1/2. In addition, we present clear evidence that p16(INK4) represses the paracrine pro-migratory effect of osteosarcoma cells on stromal fibroblasts through the inhibition of the TGF-β1 expression/secretion. This effect is also ERK1/2-dependent, indicating that in addition to their cell-autonomous actions, p16(INK4) and ERK1/2 have also non-cell-autonomous cancer-related functions. Together, these results indicate that the tumor suppressor p16(INK4) protein represses the carcinogenic process of osteosarcoma cells not only as a cell cycle regulator, but also as a negative regulator of pro-carcinogenic/-metastatic pathways. This indicates that targeting the ERK pathway is of utmost therapeutic value. © 2015 Wiley Periodicals, Inc.

  3. Immunostaining for p16(INK4a) used as a conjunctive tool improves interobserver agreement of the histologic diagnosis of cervical intraepithelial neoplasia

    DEFF Research Database (Denmark)

    Horn, L.C.; Reichert, A.; Oster, A.

    2008-01-01

    The quality of cervical histopathology is critical to cervical cancer prevention, cancer treatment, and research programs. On the basis of the histology results further patient management is determined. However, the diagnostic interpretation of histologic hematoxylin-eosin (H&E)-stained slides is...... immunohistochemistry as an adjunct to conventional H&E-stained specimens thus contributes to a more reproducible diagnosis of cervical intraepithelial neoplasia, and may be a valuable aid for the interpretation of cervical histology Udgivelsesdato: 2008/4......The quality of cervical histopathology is critical to cervical cancer prevention, cancer treatment, and research programs. On the basis of the histology results further patient management is determined. However, the diagnostic interpretation of histologic hematoxylin-eosin (H&E)-stained slides......) immunohistochemistry may increase the performance of pathologists in diagnosing squamous lesions in cervical punch and cone biopsies. When using a consecutive p 16(INK4a)-stained slide in conjunction to the H&E-stained slide, interobserver agreement between 6 pathologists improved significantly for both cervical punch...

  4. Usefulness of p16ink4a, ProEX C, and Ki-67 for the diagnosis of glandular dysplasia and adenocarcinoma of the cervix uteri.

    Science.gov (United States)

    Negri, Giovanni; Bellisano, Giulia; Carico, Elisabetta; Faa, Gavino; Kasal, Armin; Antoniazzi, Sonia; Egarter-Vigl, Eduard; Piccin, Andrea; Dalla Palma, Paolo; Vittadello, Fabio

    2011-07-01

    Although the diagnostic criteria of in-situ and invasive adenocarcinomas of the cervix uteri are well established, the differentiation from benign mimics may be difficult and the morphologic features of the precursors of endocervical adenocarcinoma are still debated. In this study, we evaluated the usefulness of p16ink4a (p16), ProEX C, and Ki-67 for the diagnosis of endocervical adenocarcinoma and its precursors. Immunohistochemistry with p16, ProEX C, and Ki-67 was performed in 82 glandular lesions including 15 invasive adenocarcinomas, 29 adenocarcinomas in situ (AIS), 22 non-neoplastic samples, and 16 cases of glandular dysplasia (GD), which showed significant nuclear abnormalities but did not meet the diagnostic criteria for AIS. The immunohistochemical expression pattern was scored according to the percentage of the stained cells (0, 1+, 2+, and 3+ when 0% to 5%, 6% to 25%, 26% to 50%, and more than 50% of the cells were stained, respectively) and was evaluated for each antibody. p16 was at least focally expressed (1+ or more) in 14 of 15 invasive adenocarcinomas, in all AIS and in 7 negative samples. ProEX C and Ki-67 both scored 1+ or more in all adenocarcinomas and AIS and in 8 and 6 negative samples, respectively. Of the GD 15, 14, and 15 expressed p16, ProEX C, and Ki-67, respectively. The score differences between neoplastic and non-neoplastic samples were highly significant for each marker (Pcervix uteri and may also improve the diagnostic accuracy of endocervical GD. In particularly problematic cases, the combination of p16 and a proliferation marker can provide additional help for the interpretation of these lesions.

  5. The PPARα/p16INK4a Pathway inhibits Vascular Smooth Muscle Cell Proliferation by repressing Cell Cycle-dependent Telomerase Activation

    Science.gov (United States)

    Gizard, Florence; Nomiyama, Takashi; Zhao, Yue; Findeisen, Hannes M.; Heywood, Elizabeth B.; Jones, Karrie L.; Staels, Bart; Bruemmer, Dennis

    2009-01-01

    Peroxisome Proliferator-Activated Receptor (PPAR) α, the molecular target for fibrates used to treat dyslipidemia, exerts pleiotropic effects on vascular cells. In vascular smooth muscle cells (VSMCs), we have previously demonstrated that PPARα activation suppresses G1→S cell cycle progression by targeting the cyclin-dependent kinase inhibitor p16INK4a (p16). In the present study, we demonstrate that this inhibition of VSMC proliferation by PPARα is mediated through a p16-dependent suppression of telomerase activity, which has been implicated in key cellular functions including proliferation. PPARα activation inhibited mitogen-induced telomerase activity by repressing the catalytic subunit telomerase reverse transcriptase (TERT) through negative cross-talk with an E2F-1-dependent trans-activation of the TERT promoter. This trans-repression involved the recruitment of the retinoblastoma (RB) family proteins p107 and p130 to the TERT promoter resulting in impaired E2F-1 binding, an effect which was dependent on p16. The inhibition of cell proliferation by PPARα activation was lost in VSMC following TERT overexpression or knock-down, pointing to a key role of telomerase as a target for the antiproliferative effects of PPARα. Finally, we demonstrate that PPARα agonists suppress telomerase activation during the proliferative response following vascular injury indicating that these findings are applicable in vivo. In concert, these results demonstrate that the anti-proliferative effects of PPARα in VSMCs depend on the suppression of telomerase activity by targeting the p16/RB/E2F transcriptional cascade. PMID:18818403

  6. Are adjunctive markers useful in routine cervical cancer screening? Application of p16(INK4a) and HPV-PCR on ThinPrep samples with histological follow-up

    DEFF Research Database (Denmark)

    Schledermann, D; Andersen, B T; Bisgaard, K

    2008-01-01

    The objectives of the study were to evaluate 1) the diagnostic sensitivity and specificity of p16(INK4a) as a marker for high-grade cervical lesions, 2) the results of a real-time polymerase chain reaction detecting high-risk human papillomavirus, and 3) the interobserver variability of the p16(INK...

  7. A pilot study to compare the detection of HPV-16 biomarkers in salivary oral rinses with tumour p16INK4a expression in head and neck squamous cell carcinoma patients

    International Nuclear Information System (INIS)

    Chai, Ryan C.; Lim, Yenkai; Frazer, Ian H.; Wan, Yunxia; Perry, Christopher; Jones, Lee; Lambie, Duncan; Punyadeera, Chamindie

    2016-01-01

    Human papilloma virus-16 (HPV-16) infection is a major risk factor for a subset of head and neck squamous cell carcinoma (HNSCC), in particular oropharyngeal squamous cell carcinoma (OPSCC). Current techniques for assessing the HPV-16 status in HNSCC include the detection of HPV-16 DNA and p16 INK4a expression in tumor tissues. When tumors originate from hidden anatomical sites, this method can be challenging. A non-invasive and cost-effective alternative to biopsy is therefore desirable for HPV-16 detection especially within a community setting to screen at-risk individuals. The present study compared detection of HPV-16 DNA and RNA in salivary oral rinses with tumor p16 INK4a status, in 82 HNSCC patients using end-point and quantitative polymerase chain reaction (PCR). Of 42 patients with p16 INK4a -positive tumours, 39 (sensitivity = 92.9 %, PPV = 100 % and NPV = 93 %) had oral rinse samples with detectable HPV-16 DNA, using end-point and quantitative PCR. No HPV-16 DNA was detected in oral rinse samples from 40 patients with p16 INK4a negative tumours, yielding a test specificity of 100 %. For patients with p16 INK4a positive tumours, HPV-16 mRNA was detected using end-point reverse transcription PCR (RT-PCR) in 24/40 (sensitivity = 60 %, PPV = 100 % and NPV = 71 %), and using quantitative RT-PCR in 22/40 (sensitivity = 55 %, PPV = 100 % and NPV = 69 %). No HPV-16 mRNA was detected in oral rinse samples from the p16 INK4a -negative patients, yielding a specificity of 100 %. We demonstrate that the detection of HPV-16 DNA in salivary oral rinse is indicative of HPV status in HNSCC patients and can potentially be used as a diagnostic tool in addition to the current methods. The online version of this article (doi:10.1186/s12885-016-2217-1) contains supplementary material, which is available to authorized users

  8. Detection of HPV and the role of p16INK4A overexpression as a surrogate marker for the presence of functional HPV oncoprotein E7 in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Lardon Filip

    2010-03-01

    Full Text Available Abstract Background Based on the well-recognized etiological role of human papillomavirus (HPV in cervical, anogenital and oropharyngeal carcinogenesis, a potential role of HPV in colorectal carcinogenesis has been suggested. For that reason, the aim of the present study was to investigate the presence of HPV DNA in colorectal carcinomas (CRC and to study overexpression of p16INK4A as a marker for the presence of an active HPV oncoprotein E7. These findings were correlated with clinical and pathological prognostic factors of CRC. Methods The presence of HPV was assessed using a multiplex PCR system of 10 non-biotinylated primers. The amplified fragments of HPV positive samples were further analyzed by a highly sensitive, broad spectrum SPF10 PCR and subsequently genotyped using reverse hybridization in a line probe assay. P16INK4A protein expression was investigated in a subset of 90 (30 HPV positive and 60 HPV negative CRC samples by immunohistochemistry. Results HPV DNA was found in 14.2% of the CRC samples with HPV16 as the most prevalent type. No significant differences in clinical and pathological variables were found between HPV positive and negative CRCs, except for age. HPV positive patients were significantly younger (p = 0.05. There was no significant correlation between the presence of HPV and overexpression of p16INK4A (p = 0.325. Conclusions In conclusion, the presence of oncogenic HPV DNA in a small cohort of CRC samples may suggest that HPV may be involved in the carcinogenesis of some CRC. However, contrary to what has been observed in head and neck squamous cell cancer and cancer of the uterine cervix, p16INK4A does not seem to be a surrogate marker for an active HPV infection in CRC. Therefore, further functional analyses are necessary to elucidate the role of HPV in CRC.

  9. Disruptive cell cycle regulation involving epigenetic downregulation of Cdkn2a (p16Ink4a) in early-stage liver tumor-promotion facilitating liver cell regeneration in rats

    International Nuclear Information System (INIS)

    Tsuchiya, Takuma; Wang, Liyun; Yafune, Atsunori; Kimura, Masayuki; Ohishi, Takumi; Suzuki, Kazuhiko; Mitsumori, Kunitoshi; Shibutani, Makoto

    2012-01-01

    Cell cycle aberration was immunohistochemically examined in relation to preneoplastic liver cell foci expressing glutathione S-transferase placental form (GST-P) at early stages of tumor-promotion in rats with thioacetamide (TAA), a hepatocarcinogen facilitating liver cell regeneration. Immunoexpression of p16 Ink4a following exposure to other hepatocarcinogens/promoters and its DNA methylation status were also analyzed during early and late tumor-promotion stages. GST-P + liver cell foci increased cell proliferation and decreased apoptosis when compared with surrounding liver cells. In concordance with GST-P + foci, checkpoint proteins at G 1 /S (p21 Cip1 , p27 Kip1 and p16 Ink4a ) and G 2 /M (phospho-checkpoint kinase 1, Cdc25c and phospho-Wee1) were either up- or downregulated. Cellular distribution within GST-P + foci was either increased or decreased with proteins related to G 2 -M phase or DNA damage (topoisomerase IIα, phospho-histone H2AX, phospho-histone H3 and Cdc2). In particular, p16 Ink4a typically downregulated in GST-P + foci and regenerative nodules at early tumor-promotion stage with hepatocarcinogens facilitating liver cell regeneration and in neoplastic lesions at late tumor-promotion stage with hepatocarcinogens/promoters irrespective of regenerating potential. Hypermethylation at exon 2 of Cdkn2a was detected at both early- and late-stages. Thus, diverse disruptive expression of G 1 /S and G 2 /M proteins, which allows for clonal selection of GST-P + foci, results in the acquisition of multiple aberrant phenotypes to disrupt checkpoint function. Moreover, increased DNA-damage responses within GST-P + foci may be the signature of genetic alterations. Intraexonic hypermethylation may be responsible for p16 Ink4a -downregulation, which facilitates cell cycle progression in early preneoplastic lesions produced by repeated cell regeneration and late-stage neoplastic lesions irrespective of the carcinogenic mechanism.

  10. Inmunohistoquímica de la proteína p16INK4a en biopsias y extendidos cervicovaginales y su relación con HPV por PCR Immunohistochemistry of p16INK4a in biopsies and cervicovaginal smears, and its correlation with HPV detected by PCR

    Directory of Open Access Journals (Sweden)

    Alejandro García

    2008-12-01

    Full Text Available Estudios recientes sugieren que la sobreexpresión de p16, determinada por inmunohistoquímica, sería un marcador específico de células escamosas displásicas y neoplásicas con alta asociación con HPV de alto riesgo. Nuestro objetivo fue correlacionar los hallazgos cito/histológicos con la expresión de p16 y el subtipo de HPV por PCR. Seleccionamos 95 biopsias de cuello uterino y 4 legrados endocervicales de 99 individuos, y 30 extendidos cervicovaginales de otros 30 individuos, que se dividieron según el diagnóstico morfológico. Inmunomarcamos cortes del material incluido en parafina y los extendidos con el kit CINtecT p16INK4a (DAKO. Evaluamos HPV por PCR utilizando 25/99 biopsias con lesión intraepitelial escamosa de bajo grado. Observamos marcación positiva para p16 en 1/35 biopsias (2.9% y 1/11 extendidos (9% en los grupos sin HPV ni displasia; 16/25 biopsias (64% y 6/10 extendidos (60% en aquellos con lesión de bajo grado y 38/39 biopsias (97.4% y 8/9 extendidos (89% en los grupos con lesión de alto grado y carcinoma escamoso. Todas las muestras con HPV-6/11 fueron negativas o positivas focales para p16, en tanto que aquellas con HPV-18 u otros subtipos fueron mayoritariamente positivas de tipo difuso. Concluimos que la expresión de p16 presenta alta correlación con el diagnóstico cito/histológico y alta asociación entre la marcación difusa y la presencia de HPV de alto riesgo, aportando mayor objetividad en casos dudosos y ayudando a seleccionar grupos de individuos con riesgo de progresión de enfermedad, con un costo aceptable para estudiar grandes grupos.Recent studies suggest that p16 overexpression determined by immunohistochemistry would be a specific marker for neoplastic and dysplastic squamous cells associated with high-risk HPV. The purpose of this study was to assess the correlation between cyto-histological findings, p16 expression and HPV subtype. A total of 99 biopsies were selected, 4 endocervical

  11. Involvement of Bmi-1 gene in the development of gastrointestinal stromal tumor by regulating p16Ink4A/p14ARF gene expressions: An in vivo and in vitro study.

    Science.gov (United States)

    Wang, Jiang-Li; Wu, Jiang-Hong; Hong, Cai; Wang, Ya-Nong; Zhou, Ye; Long, Zi-Wen; Zhou, Ying; Qin, Hai-Shu

    2017-12-01

    This study was conducted in order to explore the role that Bmi-1 plays during the development of a gastrointestinal stromal tumor (GIST) by regulation of the p16 Ink4A and p14 ARF expressions. Eighty-six patients diagnosed with GIST were selected to take part in this experiment. The Bmi-1 protein expressions in GIST and adjacent normal tissues were detected using immunohistochemistry and further analyzed by using photodensitometry. To monitor and track the progression of the GIST, a 3-year follow-up was conducted for all affected patients. After cell transfection, the GIST cells were assigned into the control group (without transfection), the negative control (NC) group (transfected with Bmi-1-Scramble plasmid), and the Bmi-1 shRNA group (transfected with the pcDNA3.1-Bmi-1 shRNA plasmid). Protein and mRNA expressions collected from Bmi-1, p16 lnk4A , P14 ARF , cyclin D1, and CDK4 were measured using both the RT-qPCR and western blotting methods Cell senescence was assessed and obtained by using the β-Galactosidase (β-Gal) activity assay. The use of a Soft agar colony formation assay and CCK-8 assay were performed in order to detect the cell growth and subsequent proliferation. Cell invasion and migration were analyzed using the Transwell assay and scratch test. Bmi-1 in the GIST tissues was found to be significantly higher and the p16 lnk4A and P14 ARF expressions were lower than those in the adjacent normal tissues. Bmi-1 was negatively correlated with p16 lnk4A and P14 ARF expressions according to the correlation analysis. Bmi-1 expression was associated with the TNM stage, postoperative recurrence, metastasis, tumor size, and the 5-year survival rate. Area under ROC curve was calculated at 0.884, and sensitivity, specificity, and accuracy of Bmi-1 predicting the GIST were 67.44%, 97.67%, and 65.12%, respectively. Patients exhibiting a high Bmi-1 expression in the GIST tissues had lower survival rates than those with low Bmi-1 expression. In comparison with

  12. Immunoexpression of P16INK4a, Rb and TP53 proteins in bronchiolar columnar cell dysplasia (BCCD in lungs resected due to primary non-small cell lung cancer.

    Directory of Open Access Journals (Sweden)

    Lech Chyczewski

    2008-02-01

    Full Text Available Lung cancer is the leading cause of death worldwide. High mortality comes out mainly of the fact that majority of the cases are diagnosed in advanced stadium. An expanded diagnostics of precancerous conditions would certainly contribute to lowering the mortality rate. Many of the molecular changes accompanying the multistep cancer development could be observed using the immunohistochemistry method. In this paper we describe the morphology and cell cycle proteins immunoexpression of the novel probable preinvasive lesion - bronchiolar columnar cell dysplasia (BCCD. Thirty cases of BCCD selected out of 193 patients population, treated for primary non-small cell lung cancer were investigated. Loss of P16INK4a protein was observed in 70% of all cases and was statistically significant in patients with adenocarcinoma. Two cases show abnormal cytoplasmic localization of this protein. TP53 protein accumulates in 26.7% of all BCCD. Rb protein was active in 48.3% of the BCCD cases. In two cases we observed differentiation of the cells composing BCCD into multilayer epithelium of the squamous type, which occurs with formation of desmosomes. We suppose that BCCD may be preneoplastic lesion leading to adenocarcinoma as well as to peripheral squamous cell lung cancer.

  13. Epigenetic changes in the CDKN2A locus are associated with differential expression of P16INK4A and P14ARF in HPV-positive oropharyngeal squamous cell carcinoma

    International Nuclear Information System (INIS)

    Schlecht, Nicolas F; Ben-Dayan, Miriam; Anayannis, Nicole; Lleras, Roberto A; Thomas, Carlos; Wang, Yanhua; Smith, Richard V; Burk, Robert D; Harris, Thomas M; Childs, Geoffrey; Ow, Thomas J; Prystowsky, Michael B; Belbin, Thomas J

    2015-01-01

    Human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) is recognized as a distinct disease entity associated with improved survival. DNA hypermethylation profiles differ significantly by HPV status suggesting that a specific subset of methylated CpG loci could give mechanistic insight into HPV-driven OPSCC. We analyzed genome-wide DNA methylation of primary tumor samples and adjacent normal mucosa from 46 OPSCC patients undergoing treatment at Montefiore Medical Center, Bronx, NY using the Illumina HumanMethylation27 beadchip. For each matched tissue set, we measured differentially methylated CpG loci using a change in methylation level (M value). From these analyses, we identified a 22 CpG loci panel for HPV+ OPSCC that included four CDKN2A loci downstream of the p16(INK4A) and p14(ARF) transcription start sites. This panel was significantly associated with overall HPV detection (P < 0.05; ROC area under the curve = 0.96, 95% CI: 0.91–1.0) similar to the subset of four CDKN2A-specific CpG loci (0.90, 95% CI: 0.82–0.99) with equivalence to the full 22 CpG panel. DNA hypermethylation correlated with a significant increase in alternative open reading frame (ARF) expression in HPV+ OPSCC primary tumors, but not to the other transcript variant encoded by the CDKN2A locus. Overall, this study provides evidence of epigenetic changes to the downstream region of the CDKN2A locus in HPV+ oropharyngeal cancer that are associated with changes in expression of the coded protein products

  14. Anti-proliferative and pro-apoptotic activity of whole extract and isolated indicaxanthin from Opuntia ficus-indica associated with re-activation of the onco-suppressor p16INK4a gene in human colorectal carcinoma (Caco-2) cells

    International Nuclear Information System (INIS)

    Naselli, Flores; Tesoriere, Luisa; Caradonna, Fabio; Bellavia, Daniele; Attanzio, Alessandro; Gentile, Carla; Livrea, Maria A.

    2014-01-01

    Highlights: • Cactus pear fruit extract and indicaxanthin cause apoptosis of colon cancer cells. • Indicaxanthin does not cause ROS formation, but affects epigenoma in Caco-2 cells. • Indicaxanthin reverses methylation of oncosuppressor p16 INK4a gene in Caco-2 cells. • Indicaxanthin reactivates retinoblastoma in Caco-2 cells. • Bioavailable indicaxanthin may have chemopreventive activity in colon cancer. - Abstract: Phytochemicals may exert chemo-preventive effects on cells of the gastro-intestinal tract by modulating epigenome-regulated gene expression. The effect of the aqueous extract from the edible fruit of Opuntia ficus-indica (OFI extract), and of its betalain pigment indicaxanthin (Ind), on proliferation of human colon cancer Caco-2 cells has been investigated. Whole extract and Ind caused a dose-dependent apoptosis of proliferating cells at nutritionally relevant amounts, with IC 50 400 ± 25 mg fresh pulp equivalents/mL, and 115 ± 15 μM (n = 9), respectively, without toxicity for post-confluent differentiated cells. Ind accounted for ∼80% of the effect of the whole extract. Ind did not cause oxidative stress in proliferating Caco-2 cells. Epigenomic activity of Ind was evident as de-methylation of the tumor suppressor p16 INK4a gene promoter, reactivation of the silenced mRNA expression and accumulation of p16 INK4a , a major controller of cell cycle. As a consequence, decrease of hyper-phosphorylated, in favor of the hypo-phosphorylated retinoblastoma was observed, with unaltered level of the cycline-dependent kinase CDK4. Cell cycle showed arrest in the G2/M-phase. Dietary cactus pear fruit and Ind may have chemo-preventive potential in intestinal cells

  15. Anti-proliferative and pro-apoptotic activity of whole extract and isolated indicaxanthin from Opuntia ficus-indica associated with re-activation of the onco-suppressor p16(INK4a) gene in human colorectal carcinoma (Caco-2) cells.

    Science.gov (United States)

    Naselli, Flores; Tesoriere, Luisa; Caradonna, Fabio; Bellavia, Daniele; Attanzio, Alessandro; Gentile, Carla; Livrea, Maria A

    2014-07-18

    Phytochemicals may exert chemo-preventive effects on cells of the gastro-intestinal tract by modulating epigenome-regulated gene expression. The effect of the aqueous extract from the edible fruit of Opuntia ficus-indica (OFI extract), and of its betalain pigment indicaxanthin (Ind), on proliferation of human colon cancer Caco-2 cells has been investigated. Whole extract and Ind caused a dose-dependent apoptosis of proliferating cells at nutritionally relevant amounts, with IC50 400±25 mg fresh pulp equivalents/mL, and 115±15 μM (n=9), respectively, without toxicity for post-confluent differentiated cells. Ind accounted for ∼80% of the effect of the whole extract. Ind did not cause oxidative stress in proliferating Caco-2 cells. Epigenomic activity of Ind was evident as de-methylation of the tumor suppressor p16(INK4a) gene promoter, reactivation of the silenced mRNA expression and accumulation of p16(INK4a), a major controller of cell cycle. As a consequence, decrease of hyper-phosphorylated, in favor of the hypo-phosphorylated retinoblastoma was observed, with unaltered level of the cycline-dependent kinase CDK4. Cell cycle showed arrest in the G2/M-phase. Dietary cactus pear fruit and Ind may have chemo-preventive potential in intestinal cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Estudo de p27, p21, p16 em epitélio escamoso normal, papiloma escamoso e carcinoma de células escamosas da cavidade oral Comparative analysis of the immunohistochemistry expression of p27, p21WAF/Cip1, and p16INK4a in oral normal epithelium, squamous papilloma and squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Ana Beatriz Piazza Queiroz

    2009-12-01

    Full Text Available INTRODUÇÃO E OBJETIVO: O tipo de câncer oral mais frequente é o carcinoma de células escamosas, que corresponde a 95% dos casos(9. O papiloma escamoso oral é uma neoplasia benigna normalmente associada à infecção pelo papilomavírus humano (HPV(21. A análise da literatura mostra alterações nos genes reguladores do ciclo celular p27, p21WAF/Cip1 e p16INK4a, porém sem uma definição de seus papéis na carcinogênese oral. O objetivo foi caracterizar imuno-histoquimicamente p27, p21WAF/Cip1 e p16NK4a em epitélio escamoso normal, papilomas escamosos e carcinomas de células escamosas da cavidade oral. MÉTODOS: Imuno-histoquímica para p27, p21WAF/Cip1 e p16NK4a em 32 casos de epitélio escamoso normal, 30 casos de papiloma escamoso e 34 de carcinoma de células escamosas da cavidade oral. RESULTADOS: p27: 97,06% dos casos de carcinoma de células escamosas apresentaram imunopositividade focal. O grupo papiloma escamoso apresentou 33,33% e o grupo controle, 18,75%. p21WAF/Cip1: 100% de imunopositividade focal tanto no grupo controle como no grupo carcinoma de células escamosas, e 90% no grupo papiloma escamoso. p16INK4a: 100% de imunopositividade focal para os grupos controle e papiloma escamoso, e 94% para o grupo carcinoma de células escamosas. CONCLUSÃO: Imuno-histoquimicamente demonstrou-se diferença significativa para p27 quando feita comparação dos grupos controle e papiloma escamoso com o grupo carcinoma de células escamosas. O p21WAF/Cip1 não demonstrou poder de diferenciar os grupos analisados. O p16INK4a apresentou imunopositividade difusa em uma minoria dos casos do grupo carcinoma de células escamosas. O grupo papiloma escamoso se comportou de maneira similar ao grupo controle em relação aos três marcadores.INTRODUCTION: The most frequent type of oral cancer is the squamous cell carcinoma, which corresponds to 95% of the cases(9.The oral squamous papilloma is a benign neoplasia, commonly associated with

  17. The H3K27me3 demethylase JMJD3 contributes to the activation of the INK4A-ARF locus in response to oncogene- and stress-induced senescence

    DEFF Research Database (Denmark)

    Agger, Karl; Cloos, Paul A C; Rudkjaer, Lise

    2009-01-01

    The tumor suppressor proteins p16INK4A and p14ARF, encoded by the INK4A-ARF locus, are key regulators of cellular senescence. The locus is epigenetically silenced by the repressive H3K27me3 mark in normally growing cells, but becomes activated in response to oncogenic stress. Here, we show that e...... in mouse embryonic fibroblasts results in suppression of p16Ink4a and p19Arf expression and in their immortalization....

  18. Do senescence markers correlate in vitro and in situ within individual human donors?

    DEFF Research Database (Denmark)

    Waaijer, Mariëtte E C; Gunn, David A; van Heemst, Diana

    2018-01-01

    Little is known on how well senescence markers in vitro and in situ correlate within individual donors. We studied correlations between the same and different in vitro markers. Furthermore, we tested correlations between in vitro markers with in situ p16INK4a positivity.From 100 donors (20-91 yea...

  19. Mechanisms of Diabetes-Induced Endothelial Cell Senescence: Role of Arginase 1

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    Esraa Shosha

    2018-04-01

    Full Text Available We have recently found that diabetes-induced premature senescence of retinal endothelial cells is accompanied by NOX2-NADPH oxidase-induced increases in the ureohydrolase enzyme arginase 1 (A1. Here, we used genetic strategies to determine the specific involvement of A1 in diabetes-induced endothelial cell senescence. We used A1 knockout mice and wild type mice that were rendered diabetic with streptozotocin and retinal endothelial cells (ECs exposed to high glucose or transduced with adenovirus to overexpress A1 for these experiments. ABH [2(S-Amino-6-boronohexanoic acid] was used to inhibit arginase activity. We used Western blotting, immunolabeling, quantitative PCR, and senescence associated β-galactosidase (SA β-Gal activity to evaluate senescence. Analyses of retinal tissue extracts from diabetic mice showed significant increases in mRNA expression of the senescence-related proteins p16INK4a, p21, and p53 when compared with non-diabetic mice. SA β-Gal activity and p16INK4a immunoreactivity were also increased in retinal vessels from diabetic mice. A1 gene deletion or pharmacological inhibition protected against the induction of premature senescence. A1 overexpression or high glucose treatment increased SA β-Gal activity in cultured ECs. These results demonstrate that A1 is critically involved in diabetes-induced senescence of retinal ECs. Inhibition of arginase activity may therefore be an effective therapeutic strategy to alleviate diabetic retinopathy by preventing premature senescence.

  20. Autocrine IL-6 mediates pituitary tumor senescence

    Science.gov (United States)

    Fuertes, Mariana; Ajler, Pablo; Carrizo, Guillermo; Cervio, Andrés; Sevlever, Gustavo; Stalla, Günter K.; Arzt, Eduardo

    2017-01-01

    Cellular senescence is a stable proliferative arrest state. Pituitary adenomas are frequent and mostly benign, but the mechanism for this remains unknown. IL-6 is involved in pituitary tumor progression and is produced by the tumoral cells. In a cell autonomous fashion, IL-6 participates in oncogene-induced senescence in transduced human melanocytes. Here we prove that autocrine IL-6 participates in pituitary tumor senescence. Endogenous IL-6 inhibition in somatotroph MtT/S shRNA stable clones results in decreased SA-β-gal activity and p16INK4a but increased pRb, proliferation and invasion. Nude mice injected with IL-6 silenced clones develop tumors contrary to MtT/S wild type that do not, demonstrating that clones that escape senescence are capable of becoming tumorigenic. When endogenous IL-6 is silenced, cell cultures derived from positive SA-β-gal human tumor samples decrease the expression of the senescence marker. Our results establish that IL-6 contributes to maintain senescence by its autocrine action, providing a natural model of IL-6 mediated benign adenoma senescence. PMID:27902467

  1. Bmi1 is down-regulated in the aging brain and displays antioxidant and protective activities in neurons.

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    Mohamed Abdouh

    Full Text Available Aging increases the risk to develop several neurodegenerative diseases, although the underlying mechanisms are poorly understood. Inactivation of the Polycomb group gene Bmi1 in mice results in growth retardation, cerebellar degeneration, and development of a premature aging-like phenotype. This progeroid phenotype is characterized by formation of lens cataracts, apoptosis of cortical neurons, and increase of reactive oxygen species (ROS concentrations, owing to p53-mediated repression of antioxidant response (AOR genes. Herein we report that Bmi1 expression progressively declines in the neurons of aging mouse and human brains. In old brains, p53 accumulates at the promoter of AOR genes, correlating with a repressed chromatin state, down-regulation of AOR genes, and increased oxidative damages to lipids and DNA. Comparative gene expression analysis further revealed that aging brains display an up-regulation of the senescence-associated genes IL-6, p19(Arf and p16(Ink4a, along with the pro-apoptotic gene Noxa, as seen in Bmi1-null mice. Increasing Bmi1 expression in cortical neurons conferred robust protection against DNA damage-induced cell death or mitochondrial poisoning, and resulted in suppression of ROS through activation of AOR genes. These observations unveil that Bmi1 genetic deficiency recapitulates aspects of physiological brain aging and that Bmi1 over-expression is a potential therapeutic modality against neurodegeneration.

  2. The SETD8/PR-Set7 Methyltransferase Functions as a Barrier to Prevent Senescence-Associated Metabolic Remodeling

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    Hiroshi Tanaka

    2017-02-01

    Full Text Available Summary: Cellular senescence is an irreversible growth arrest that contributes to development, tumor suppression, and age-related conditions. Senescent cells show active metabolism compared with proliferating cells, but the underlying mechanisms remain unclear. Here we show that the SETD8/PR-Set7 methyltransferase, which catalyzes mono-methylation of histone H4 at lysine 20 (H4K20me1, suppresses nucleolar and mitochondrial activities to prevent cellular senescence. SETD8 protein was selectively downregulated in both oncogene-induced and replicative senescence. Inhibition of SETD8 alone was sufficient to trigger senescence. Under these states, the expression of genes encoding ribosomal proteins (RPs and ribosomal RNAs as well as the cyclin-dependent kinase (CDK inhibitor p16INK4A was increased, with a corresponding reduction of H4K20me1 at each locus. As a result, the loss of SETD8 concurrently stimulated nucleolar function and retinoblastoma protein-mediated mitochondrial metabolism. In conclusion, our data demonstrate that SETD8 acts as a barrier to prevent cellular senescence through chromatin-mediated regulation of senescence-associated metabolic remodeling. : Tanaka et al. show that SETD8/PR-Set7 methyltransferase represses senescence-associated genes including ribosomal proteins, ribosomal RNAs, and p16INK4A by catalyzing mono-methylation of histone H4 at lysine 20. Depletion of SETD8 derepresses these genes, resulting in nucleolar and mitochondrial coactivation characteristic of senescence-associated metabolic remodeling. Keywords: SETD8/PR-Set7, H4K20 methylation, senescence-associated metabolic remodeling, nucleolus, mitochondria

  3. Identification of target genes of the p16INK4A-pRB-E2F pathway

    DEFF Research Database (Denmark)

    Vernell, Richard; Helin, Kristian; Müller, Heiko

    2003-01-01

    as physiological targets of the pRB pathway, and the further characterization of these genes should provide insights into how this pathway controls proliferation. We show that Gibbs sampling detects enrichment of several sequence motifs, including E2F consensus binding sites, in the upstream regions of these genes...

  4. "Primary Squamous Cell Carcinoma of the Vagina: HPV Detection, p16INK4A Overexpression and Clinicopathological Correlations"

    OpenAIRE

    Fuste , Victoria; Del Pino , Marta; Perez , Assumpta; Garcia , Angel; Torne , Aureli; Pahisa , Jaume; Ordi , Jaume

    2010-01-01

    Abstract Aim: To determine the role of HPV in the pathogenesis of primary squamous cell carcinoma of the vagina (SCCVa), and to evaluate its clinico-pathological significance. Methods: All cases of SCCVa diagnosed over a 15 year period from two hospitals in Barcelona, Spain (n=32) were retrieved. Patients with a history of carcinoma of the cervix diagnosed less than 5 years before were excluded. HPV was detected and typed by PCR using the SPF10 primers. Immunohistochemistry for...

  5. Curcumin Triggers p16-Dependent Senescence in Active Breast Cancer-Associated Fibroblasts and Suppresses Their Paracrine Procarcinogenic Effects

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    Siti-Fauziah Hendrayani

    2013-06-01

    Full Text Available Activated cancer-associated fibroblasts (CAFs or myofibroblasts not only facilitate tumor growth and spread but also affect tumor response to therapeutic agents. Therefore, it became clear that efficient therapeutic regimens should also take into account the presence of these supportive cells and inhibit their paracrine effects. To this end, we tested the effect of low concentrations of curcumin, a pharmacologically safe natural product, on patient-derived primary breast CAF cells. We have shown that curcumin treatment upregulates p16INK4A and other tumor suppressor proteins while inactivates the JAK2/STAT3 pathway. This reduced the level of alpha-smooth muscle actin (α-SMA and the migration/invasion abilities of these cells. Furthermore, curcumin suppressed the expression/secretion of stromal cell-derived factor-1 (SDF-1, interleukin-6 (IL-6, matrix metalloproteinase-2 (MMP-2, MMP-9, and transforming growth factor-β, which impeded their paracrine procarcinogenic potential. Intriguingly, these effects were sustained even after curcumin withdrawal and cell splitting. Therefore, using different markers of senescence [senescence-associated β-galactosidase (SA-β-gal activity, Ki-67 and Lamin B1 levels, and bromodeoxyuridine incorporation], we have shown that curcumin markedly suppresses Lamin B1 and triggers DNA damage-independent senescence in proliferating but not quiescent breast stromal fibroblasts. Importantly, this curcumin-related senescence was p16INK4A-dependent and occurred with no associated inflammatory secretory phenotype. These results indicate the possible inactivation of cancer-associated myofibroblasts and present the first indication that curcumin can trigger DNA damage-independent and safe senescence in stromal fibroblasts.

  6. The Polycomb group proteins bind throughout the INK4A-ARF locus and are disassociated in senescent cells

    DEFF Research Database (Denmark)

    Bracken, Adrian P; Kleine-Kohlbrecher, Daniela; Dietrich, Nikolaj

    2007-01-01

    The p16INK4A and p14ARF proteins, encoded by the INK4A-ARF locus, are key regulators of cellular senescence, yet the mechanisms triggering their up-regulation are not well understood. Here, we show that the ability of the oncogene BMI1 to repress the INK4A-ARF locus requires its direct association...... and is dependent on the continued presence of the EZH2-containing Polycomb-Repressive Complex 2 (PRC2) complex. Significantly, EZH2 is down-regulated in stressed and senescing populations of cells, coinciding with decreased levels of associated H3K27me3, displacement of BMI1, and activation of transcription...

  7. Exercise Prevents Diet-Induced Cellular Senescence in Adipose Tissue.

    Science.gov (United States)

    Schafer, Marissa J; White, Thomas A; Evans, Glenda; Tonne, Jason M; Verzosa, Grace C; Stout, Michael B; Mazula, Daniel L; Palmer, Allyson K; Baker, Darren J; Jensen, Michael D; Torbenson, Michael S; Miller, Jordan D; Ikeda, Yasuhiro; Tchkonia, Tamara; van Deursen, Jan M; Kirkland, James L; LeBrasseur, Nathan K

    2016-06-01

    Considerable evidence implicates cellular senescence in the biology of aging and chronic disease. Diet and exercise are determinants of healthy aging; however, the extent to which they affect the behavior and accretion of senescent cells within distinct tissues is not clear. Here we tested the hypothesis that exercise prevents premature senescent cell accumulation and systemic metabolic dysfunction induced by a fast-food diet (FFD). Using transgenic mice that express EGFP in response to activation of the senescence-associated p16(INK4a) promoter, we demonstrate that FFD consumption causes deleterious changes in body weight and composition as well as in measures of physical, cardiac, and metabolic health. The harmful effects of the FFD were associated with dramatic increases in several markers of senescence, including p16, EGFP, senescence-associated β-galactosidase, and the senescence-associated secretory phenotype (SASP) specifically in visceral adipose tissue. We show that exercise prevents the accumulation of senescent cells and the expression of the SASP while nullifying the damaging effects of the FFD on parameters of health. We also demonstrate that exercise initiated after long-term FFD feeding reduces senescent phenotype markers in visceral adipose tissue while attenuating physical impairments, suggesting that exercise may provide restorative benefit by mitigating accrued senescent burden. These findings highlight a novel mechanism by which exercise mediates its beneficial effects and reinforces the effect of modifiable lifestyle choices on health span. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  8. The role of hypoxia inducible factor-1 alpha in bypassing oncogene-induced senescence.

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    Mehtap Kilic Eren

    Full Text Available Oncogene induced senescence (OIS is a sustained anti-proliferative response acutely induced in primary cells via activation of mitogenic oncogenes such as Ras/BRAF. This mechanism acts as an initial barrier preventing normal cells transformation into malignant cell. Besides oncogenic activation and DNA damage response (DDR, senescence is modulated by a plethora of other factors, and one of the most important one is oxygen tension of the tissue. The aim of this study was to determine the impact of hypoxia on RasV12-induced senescence in human diploid fibroblasts (HDFs. We showed here that hypoxia prevents execution of oncogene induced senescence (OIS, through a strong down-regulation of senescence hallmarks, such as SA- β-galactosidase, H3K9me3, HP1γ, p53, p21CIP1 and p16INK4a in association with induction of hypoxia inducible factor-1α (HIF-1α. In addition, hypoxia also decreased marks of H-RasV12-induced DDR in both cell lines through down-regulation of ATM/ATR, Chk1 and Chk2 phosphorylation as well as decreased γ-H2AX positivity. Utilizing shRNA system targeting HIF-1α we show that HIF-1α is directly involved in down regulation of p53 and its target p21CIP1 but not p16INK4a. In line with this finding we found that knock down of HIF-1α leads to a strong induction of apoptotic response, but not restoration of senescence in Ras expressing HDFs in hypoxia. This indicates that HIF-1α is an important player in early steps of tumorigenesis, leading to suppression of senescence through its negative regulation of p53 and p21CIP1. In our work we describe a mechanism through which hypoxia and specifically HIF-1α preclude cells from maintaining senescence-driven anti proliferative response. These findings indicate the possible mechanism through which hypoxic environment helps premalignant cells to evade impingement of cellular failsafe pathways.

  9. T cells in multiple myeloma display features of exhaustion and senescence at the tumor site

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    Claudia Zelle-Rieser

    2016-11-01

    Full Text Available Abstract Background Multiple myeloma is an incurable plasma cell malignancy that is mostly restricted to the bone marrow. Cancer-induced dysfunction of cytotoxic T cells at the tumor site may be responsible for immune evasion and therapeutical failure of immunotherapies. Therefore, enhanced knowledge about the actual status of T cells in myeloma bone marrow is urgently needed. Here, we assessed the expression of inhibitory molecules PD-1, CTLA-4, 2B4, CD160, senescence marker CD57, and CD28 on T cells of naive and treated myeloma patients in the bone marrow and peripheral blood and collected data on T cell subset distribution in both compartments. In addition, T cell function concerning proliferation and expression of T-bet, IL-2, IFNγ, and CD107a was investigated after in vitro stimulation by CD3/CD28. Finally, data was compared to healthy, age-matched donor T cells from both compartments. Methods Multicolor flow cytometry was utilized for the analyses of surface molecules, intracellular staining of cytokines was also performed by flow cytometry, and proliferation was assessed by 3H-thymidine incorporation. Statistical analyses were performed utilizing unpaired T test and Mann-Whitney U test. Results We observed enhanced T cell exhaustion and senescence especially at the tumor site. CD8+ T cells expressed several molecules associated with T cell exhaustion (PD-1, CTLA-4, 2B4, CD160 and T cell senescence (CD57, lack of CD28. This phenotype was associated with lower proliferative capacity and impaired function. Despite a high expression of the transcription factor T-bet, CD8+ T cells from the tumor site failed to produce IFNγ after CD3/CD28 in vitro restimulation and displayed a reduced ability to degranulate in response to T cell stimuli. Notably, the percentage of senescent CD57+CD28− CD8+ T cells was significantly lower in treated myeloma patients when compared to untreated patients. Conclusions T cells from the bone marrow of myeloma

  10. Resveratrol Induced Premature Senescence Is Associated with DNA Damage Mediated SIRT1 and SIRT2 Down-Regulation.

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    Mehtap Kilic Eren

    Full Text Available The natural polyphenolic compound resveratrol (3,4,5-trihydroxy-trans-stilbene has broad spectrum health beneficial activities including antioxidant, anti-inflammatory, anti-aging, anti-cancer, cardioprotective, and neuroprotective effects. Remarkably, resveratrol also induces apoptosis and cellular senescence in primary and cancer cells. Resveratrol's anti-aging effects both in vitro and in vivo attributed to activation of a (NAD-dependent histone deacetylase family member sirtuin-1 (SIRT1 protein. In mammals seven members (SIRT1-7 of sirtuin family have been identified. Among those, SIRT1 is the most extensively studied with perceptive effects on mammalian physiology and suppression of the diseases of aging. Yet no data has specified the role of sirtuins, under conditions where resveratrol treatment induces senescence. Current study was undertaken to investigate the effects of resveratrol in human primary dermal fibroblasts (BJ and to clarify the role of sirtuin family members in particular SIRT1 and SIRT2 that are known to be involved in cellular stress responses and cell cycle, respectively. Here, we show that resveratrol decreases proliferation of BJ cells in a time and dose dependent manner. In addition the increase in senescence associated β-galactosidase (SA-β-gal activity and methylated H3K9-me indicate the induction of premature senescence. A significant increase in phosphorylation of γ-H2AX, a surrogate of DNA double strand breaks, as well as in levels of p53, p21CIP1 and p16INK4A is also detected. Interestingly, at concentrations where resveratrol induced premature senescence we show a significant decrease in SIRT1 and SIRT2 levels by Western Blot and quantitative RT-PCR analysis. Conversely inhibition of SIRT1 and SIRT2 via siRNA or sirtinol treatment also induced senescence in BJ fibroblasts associated with increased SA-β-gal activity, γ-H2AX phosphorylation and p53, p21CIP1 and p16INK4A levels. Interestingly DNA damaging

  11. Dysregulated ΔNp63α inhibits expression of Ink4a/arf, blocks senescence, and promotes malignant conversion of keratinocytes.

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    Linan Ha

    Full Text Available p63 is critical for squamous epithelial development, and elevated levels of the ΔNp63α isoform are seen in squamous cell cancers of various organ sites. However, significant controversy exists regarding the role of p63 isoforms as oncoproteins or tumor suppressors. Here, lentiviruses were developed to drive long-term overexpression of ΔNp63α in primary keratinocytes. Elevated levels of ΔNp63α in vitro promote long-term survival and block both replicative and oncogene-induced senescence in primary keratinocytes, as evidenced by the expression of SA-β-gal and the presence of nuclear foci of heterochromatin protein 1γ. The contribution of ΔNp63α to cancer development was assessed using an in vivo grafting model of experimental skin tumorigenesis that allows distinction between benign and malignant tumors. Grafted lenti-ΔNp63α keratinocytes do not form tumors, whereas lenti-GFP/v-ras(Ha keratinocytes develop well-differentiated papillomas. Lenti-ΔNp63α/v-ras(Ha keratinocytes form undifferentiated carcinomas. The average volume of lenti-ΔNp63α/v-ras(Ha tumors was significantly higher than those in the lenti-GFP/v-ras(Ha group, consistent with increased BrdU incorporation detected by immunohistochemistry. The block in oncogene-induced senescence corresponds to sustained levels of E2F1 and phosphorylated AKT, and is associated with loss of induction of p16(ink4a/p19(arf. The relevance of p16(ink4a/p19(arf loss was demonstrated in grafting studies of p19(arf-null keratinocytes, which develop malignant carcinomas in the presence of v-ras(Ha similar to those arising in wildtype keratinocytes that express lenti-ΔNp63α and v-ras(Ha. Our findings establish that ΔNp63α has oncogenic activity and its overexpression in human squamous cell carcinomas contributes to the malignant phenotype, and implicate its ability to regulate p16(ink4a/p19(arf in the process.

  12. The nuclear receptor NR2E1/TLX controls senescence

    Science.gov (United States)

    Krusche, Benjamin; Pemberton, Helen; Alonso, Marta M.; Chandler, Hollie; Brookes, Sharon; Parrinello, Simona; Peters, Gordon; Gil, Jesús

    2014-01-01

    The nuclear receptor NR2E1 (also known as TLX or tailless) controls the self-renewal of neural stem cells (NSCs) and has been implied as an oncogene which initiates brain tumours including glioblastomas. Despite NR2E1 regulating targets like p21CIP1 or PTEN we still lack a full explanation for its role in NSC self-renewal and tumorigenesis. We know that Polycomb repressive complexes (PRC) also control stem cell self-renewal and tumorigenesis, but so far, no formal connection has been established between NR2E1 and PRCs. In a screen for transcription factors regulating the expression of the Polycomb protein CBX7, we identified NR2E1 as one of its more prominent regulators. NR2E1 binds at the CBX7 promoter, inducing its expression. Notably CBX7 represses NR2E1 as part of a regulatory loop. Ectopic NR2E1 expression inhibits cellular senescence, extending cellular lifespan in fibroblasts via CBX7-mediated regulation of p16INK4a and direct repression of p21CIP1. In addition NR2E1 expression also counteracts oncogene-induced senescence (OIS). The importance of NR2E1 to restrain senescence is highlighted through the process of knocking down its expression, which causes premature senescence in human fibroblasts and epithelial cells. We also confirmed that NR2E1 regulates CBX7 and restrains senescence in NSCs. Finally, we observed that the expression of NR2E1 directly correlates with that of CBX7 in human glioblastoma multiforme. Overall we identified control of senescence and regulation of Polycomb action as two possible mechanisms that can join those so far invoked to explain the role of NR2E1 in control of NSC self-renewal and cancer. PMID:25328137

  13. The nuclear receptor NR2E1/TLX controls senescence.

    Science.gov (United States)

    O'Loghlen, Ana; Martin, Nadine; Krusche, Benjamin; Pemberton, Helen; Alonso, Marta M; Chandler, Hollie; Brookes, Sharon; Parrinello, Simona; Peters, Gordon; Gil, Jesús

    2015-07-30

    The nuclear receptor NR2E1 (also known as TLX or tailless) controls the self-renewal of neural stem cells (NSCs) and has been implied as an oncogene which initiates brain tumors including glioblastomas. Despite NR2E1 regulating targets like p21(CIP1) or PTEN we still lack a full explanation for its role in NSC self-renewal and tumorigenesis. We know that polycomb repressive complexes also control stem cell self-renewal and tumorigenesis, but so far, no formal connection has been established between NR2E1 and PRCs. In a screen for transcription factors regulating the expression of the polycomb protein CBX7, we identified NR2E1 as one of its more prominent regulators. NR2E1 binds at the CBX7 promoter, inducing its expression. Notably CBX7 represses NR2E1 as part of a regulatory loop. Ectopic NR2E1 expression inhibits cellular senescence, extending cellular lifespan in fibroblasts via CBX7-mediated regulation of p16(INK4a) and direct repression of p21(CIP1). In addition NR2E1 expression also counteracts oncogene-induced senescence. The importance of NR2E1 to restrain senescence is highlighted through the process of knocking down its expression, which causes premature senescence in human fibroblasts and epithelial cells. We also confirmed that NR2E1 regulates CBX7 and restrains senescence in NSCs. Finally, we observed that the expression of NR2E1 directly correlates with that of CBX7 in human glioblastoma multiforme. Overall we identified control of senescence and regulation of polycomb action as two possible mechanisms that can join those so far invoked to explain the role of NR2E1 in control of NSC self-renewal and cancer.

  14. Multiple effects of TRAIL in human carcinoma cells: Induction of apoptosis, senescence, proliferation, and cytokine production

    International Nuclear Information System (INIS)

    Levina, Vera; Marrangoni, Adele M.; DeMarco, Richard; Gorelik, Elieser; Lokshin, Anna E.

    2008-01-01

    TRAIL is a death ligand that induces apoptosis in malignant but not normal cells. Recently the ability of TRAIL to induce proliferation in apoptosis-resistant normal and malignant cells was reported. In this study, we analyzed TRAIL effects in apoptosis sensitive MCF7, OVCAR3 and H460 human tumor cell lines. TRAIL at low concentrations preferentially induced cell proliferation. At 100 ng/ml, apoptotic death was readily observed, however surviving cells acquired higher proliferative capacity. TRAIL-stimulated production of several cytokines, IL-8, RANTES, MCP-1 and bFGF, and activation of caspases 1 and 8 was essential for this effect. Antibodies to IL-8, RANTES, and bFGF blocked TRAIL-induced cell proliferation and further stimulated apoptosis. For the first time, we report that high TRAIL concentrations induced cell senescence as determined by the altered morphology and expression of several senescence markers: SA-β-gal, p21 Waf1/Cip1 , p16 INK4a , and HMGA. Caspase 9 inhibition protected TRAIL-treated cells from senescence, whereas inhibition of caspases 1 and 8 increased the yield of SLP cells. In conclusion, in cultured human carcinoma cells, TRAIL therapy results in three functional outcomes, apoptosis, proliferation and senescence. TRAIL-induced proapoptotic and prosurvival responses correlate with the strength of signaling. TRAIL-induced cytokine production is responsible for its proliferative and prosurvival effects

  15. HIV and drug abuse mediate astrocyte senescence in a β-catenin-dependent manner leading to neuronal toxicity.

    Science.gov (United States)

    Yu, Chunjiang; Narasipura, Srinivas D; Richards, Maureen H; Hu, Xiu-Ti; Yamamoto, Bryan; Al-Harthi, Lena

    2017-10-01

    Emerging evidence suggests that cell senescence plays an important role in aging-associated diseases including neurodegenerative diseases. HIV leads to a spectrum of neurologic diseases collectively termed HIV-associated neurocognitive disorders (HAND). Drug abuse, particularly methamphetamine (meth), is a frequently abused psychostimulant among HIV+ individuals and its abuse exacerbates HAND. The mechanism by which HIV and meth lead to brain cell dysregulation is not entirely clear. In this study, we evaluated the impact of HIV and meth on astrocyte senescence using in vitro and several animal models. Astrocytes constitute up to 50% of brain cells and play a pivotal role in marinating brain homeostasis. We show here that HIV and meth induce significant senescence of primary human fetal astrocytes, as evaluated by induction of senescence markers (β-galactosidase and p16 INK 4A ), senescence-associated morphologic changes, and cell cycle arrest. HIV- and meth-mediated astrocyte senescence was also demonstrated in three small animal models (humanized mouse model of HIV/NSG-huPBMCs, HIV-transgenic rats, and in a meth administration rat model). Senescent astrocytes in turn mediated neuronal toxicity. Further, we show that β-catenin, a pro-survival/proliferation transcriptional co-activator, is downregulated by HIV and meth in human astrocytes and this downregulation promotes astrocyte senescence while induction of β-catenin blocks HIV- and meth-mediated astrocyte senescence. These studies, for the first time, demonstrate that HIV and meth induce astrocyte senescence and implicate the β-catenin pathway as potential therapeutic target to overcome astrocyte senescence. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  16. Deregulated expression of E2F family members induces S-phase entry and overcomes p16INK4A-mediated growth suppression

    DEFF Research Database (Denmark)

    Lukas, J; Petersen, B O; Holm, K

    1996-01-01

    The E2F family of transcription factors regulate genes, whose products are essential for progression through the mammalian cell cycle. The transcriptional activity of the E2Fs is inhibited through the specific binding of the retinoblastoma protein, pRB, and the pRB homologs p107 and p130 to their......The E2F family of transcription factors regulate genes, whose products are essential for progression through the mammalian cell cycle. The transcriptional activity of the E2Fs is inhibited through the specific binding of the retinoblastoma protein, pRB, and the pRB homologs p107 and p130...

  17. TMEM45A, SERPINB5 and p16INK4A transcript levels are predictive for development of high-grade cervical lesions

    DEFF Research Database (Denmark)

    Manawapat-Klopfer, Anna; Thomsen, Louise T; Martus, Peter

    2016-01-01

    Women persistently infected with human papillomavirus (HPV) type 16 are at high risk for development of cervical intraepithelial neoplasia grade 3 or cervical cancer (CIN3+). We aimed to identify biomarkers for progression to CIN3+ in women with persistent HPV16 infection. In this prospective study......, 11,088 women aged 20-29 years were enrolled during 1991-1993, and re-invited for a second visit two years later. Cervical cytology samples obtained at both visits were tested for HPV DNA by Hybrid Capture 2 (HC2), and HC2-positive samples were genotyped by INNO-LiPA. The cohort was followed for up...... to 19 years via a national pathology register. To identify markers for progression to CIN3+, we performed microarray analysis on RNA extracted from cervical swabs of 30 women with persistent HPV16-infection and 11 HPV-negative women. Six genes were selected and validated by quantitative PCR. Three genes...

  18. The negative predictive value of p16INK4a to assess the outcome of cervical intraepithelial neoplasia 1 in the uterine cervix

    DEFF Research Database (Denmark)

    Hariri, Jalil; Øster, Anne

    2007-01-01

    The immunohistochemical expression of p16 in formalin-fixed and paraffin-embedded histological sections was evaluated in a retrospective study comprising a low-grade group of 100 cases of cervical intraepithelial neoplasia (CIN) 1, a high-grade group of 50 cases of CIN 2 to 3, and a benign group...

  19. Alteration of keratinocyte differentiation and senescence by the tumor promoter dioxin

    International Nuclear Information System (INIS)

    Ray, Soma S.; Swanson, Hollie I.

    2003-01-01

    Exposure to the environmental contaminant dioxin, elicits a variety of responses, which includes tumor promotion, embryotoxicity/teratogenesis, and carcinogenesis in both animals and humans. Many of the effects of dioxin are mediated by the aryl hydrocarbon receptor (AHR), a ligand-activated bHLH (basic helix-loop-helix)/PAS transcription factor. We initiated this study to determine whether dioxin's tumor-promoting activities may lie in its ability to alter proliferation, differentiation, and/or senescence using normal human epidermal keratinocytes (HEKs). Here, we report that dioxin appears to accelerate differentiation as measured by flow cytometry and by increased expression of the differentiation markers involucrin and filaggrin. In addition, dioxin appears to increase proliferation as indicated by an increase in NADH/NADPH production and changes in cell cycle. Finally, dioxin decreases SA (senescence associated) β-galactosidase staining, an indicator of senescence, in the differentiating keratinocytes. These changes were accompanied by decreases in the expression levels of key cell cycle regulatory proteins p53, p16 INK4a , and p14 ARF . Our findings support the idea that dioxin may exert its tumor-promoting actions, in part, by downregulating the expression levels of key tumor suppressor proteins, which may impair the cell's ability to maintain its appropriate cellular status

  20. Partial sleep deprivation activates the DNA damage response (DDR) and the senescence-associated secretory phenotype (SASP) in aged adult humans.

    Science.gov (United States)

    Carroll, Judith E; Cole, Steven W; Seeman, Teresa E; Breen, Elizabeth C; Witarama, Tuff; Arevalo, Jesusa M G; Ma, Jeffrey; Irwin, Michael R

    2016-01-01

    Age-related disease risk has been linked to short sleep duration and sleep disturbances; however, the specific molecular pathways linking sleep loss with diseases of aging are poorly defined. Key cellular events seen with aging, which are thought to contribute to disease, may be particularly sensitive to sleep loss. We tested whether one night of partial sleep deprivation (PSD) would increase leukocyte gene expression indicative of DNA damage responses (DDR), the senescence-associated secretory phenotype (SASP), and senescence indicator p16(INK4a) in older adult humans, who are at increased risk for cellular senescence. Community-dwelling older adults aged 61-86years (n=29; 48% male) underwent an experimental partial sleep deprivation (PSD) protocol over 4 nights, including adaptation, an uninterrupted night of sleep, partial sleep deprivation (sleep restricted 3-7AM), and a subsequent full night of sleep. Blood samples were obtained each morning to assess peripheral blood mononuclear cell (PBMC) gene expression using Illumina HT-12 arrays. Analyses of microarray results revealed that SASP (psleep deprivation activates PBMC gene expression patterns consistent with biological aging in this older adult sample. PSD enhanced the SASP and increased the accumulation of damage that initiates cell cycle arrest and promotes cellular senescence. These findings causally link sleep deprivation to the molecular processes associated with biological aging. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Tissue depletion of taurine accelerates skeletal muscle senescence and leads to early death in mice.

    Directory of Open Access Journals (Sweden)

    Takashi Ito

    Full Text Available Taurine (2-aminoethanesulfonic acid is found in milimolar concentrations in mammalian tissues. One of its main functions is osmoregulation; however, it also exhibits cytoprotective activity by diminishing injury caused by stress and disease. Taurine depletion is associated with several defects, many of which are found in the aging animal, suggesting that taurine might exert anti-aging actions. Therefore, in the present study, we examined the hypothesis that taurine depletion accelerates aging by reducing longevity and accelerating aging-associated tissue damage. Tissue taurine depletion in taurine transporter knockout (TauTKO mouse was found to shorten lifespan and accelerate skeletal muscle histological and functional defects, including an increase in central nuclei containing myotubes, a reduction in mitochondrial complex 1 activity and an induction in an aging biomarker, Cyclin-dependent kinase 4 inhibitor A (p16INK4a. Tissue taurine depletion also enhances unfolded protein response (UPR, which may be associated with an improvement in protein folding by taurine. Our data reveal that tissue taurine depletion affects longevity and cellular senescence; an effect possibly linked to a disturbance in protein folding.

  2. Long Term Exposure to Polyphenols of Artichoke (Cynara scolymus L.) Exerts Induction of Senescence Driven Growth Arrest in the MDA-MB231 Human Breast Cancer Cell Line.

    Science.gov (United States)

    Mileo, Anna Maria; Di Venere, Donato; Abbruzzese, Claudia; Miccadei, Stefania

    2015-01-01

    Polyphenolic extracts from the edible part of artichoke (Cynara scolymus L.) have been shown to be potential chemopreventive and anticancer dietary compounds. High doses of polyphenolic extracts (AEs) induce apoptosis and decrease the invasive potential of the human breast cancer cell line, MDA-MB231. However, the molecular mechanism underlying AEs antiproliferative effects is not completely understood. We demonstrate that chronic and low doses of AEs treatment at sublethal concentrations suppress human breast cancer cell growth via a caspases-independent mechanism. Furthermore, AEs exposure induces a significant increase of senescence-associated β-galactosidase (SA-β-gal) staining and upregulation of tumour suppressor genes, p16(INK4a) and p21(Cip1/Waf1) in MDA-MB231 cells. AEs treatment leads to epigenetic alterations in cancer cells, modulating DNA hypomethylation and lysine acetylation levels in total proteins. Cell growth arrest correlates with increased reactive oxygen species (ROS) production in AEs treated breast cancer cells. Inhibition of ROS generation by N-acetylcysteine (NAC) attenuates the antiproliferative effect. These findings demonstrate that chronic AEs treatment inhibits breast cancer cell growth via the induction of premature senescence through epigenetic and ROS-mediated mechanisms. Our results suggest that artichoke polyphenols could be a promising dietary tool either in cancer chemoprevention or/and in cancer treatment as a nonconventional, adjuvant therapy.

  3. Angelica Sinensis Polysaccharide Prevents Hematopoietic Stem Cells Senescence in D-Galactose-Induced Aging Mouse Model

    Directory of Open Access Journals (Sweden)

    Xinyi Mu

    2017-01-01

    Full Text Available Age-related regression in hematopoietic stem/progenitor cells (HSC/HPCs limits replenishment of the blood and immune system and hence contributes to hematopoietic diseases and declined immunity. In this study, we employed D-gal-induced aging mouse model and observed the antiaging effects of Angelica Sinensis Polysaccharide (ASP, a major active ingredient in dong quai (Chinese Angelica Sinensis, on the Sca-1+ HSC/HPCs in vivo. ASP treatment prevents HSC/HPCs senescence with decreased AGEs levels in the serum, reduced SA-β-Gal positive cells, and promoted CFU-Mix formation in the D-gal administrated mouse. We further found that multiple mechanisms were involved: (1 ASP treatment prevented oxidative damage as total antioxidant capacity was increased and levels of reactive oxygen species (ROS, 8-OHdG, and 4-HNE were declined, (2 ASP reduced the expression of γ-H2A.X which is a DNA double strand breaks (DSBs marker and decreased the subsequent ectopic expressions of effectors in p16Ink4a-RB and p19Arf-p21Cip1/Waf senescent pathways, and (3 ASP inhibited the excessive activation of Wnt/β-catenin signaling in aged HSC/HPCs, as the expressions of β-catenin, phospho-GSK-3β, and TCF-4 were decreased, and the cyto-nuclear translocation of β-catenin was inhibited. Moreover, compared with the positive control of Vitamin E, ASP exhibited a better antiaging effect and a weaker antioxidation ability, suggesting a novel protective role of ASP in the hematopoietic system.

  4. Senescence-Derived Extracellular Molecules as Modulators of Oral Cancer Development: A Mini-Review.

    Science.gov (United States)

    Parkinson, Eric Kenneth; James, Emma L; Prime, Stephen S

    2016-01-01

    Oral cancers are predominantly oral squamous cell carcinomas (OSCCs) derived from keratinocytes, and there is now very detailed knowledge of the genetics and molecular biology of the epithelial tumourigenic component of these cancers, including the identification of cancer stem or tumour-initiating cells. Several key genetic alterations have been identified including the near ubiquitous loss of the CDKN2A/p16INK4A and p53 pathways and telomerase activation, together with frequent inactivation of the NOTCH1 canonical pathway either by somatic genetic alterations or by the presence of human papilloma virus. There is also evidence that OSCCs arise from a 'field' of altered cells and that malignant conversion takes place pre-dominantly at the microscopic level. However, in the last decade, it has been realised that tumour development and progression are influenced by the cells of the microenvironment with cross-talk between the epithelial (tumour) and mesenchymal components. OSCCs, especially those that have bypassed cellular senescence, produce an array of proteins and metabolites that induce cellular senescence in the normal surrounding cells; indeed, senescence is a common property of cancer-associated fibroblasts (CAFs). Cellular senescence is defined as an irreversible cell cycle arrest and is associated with the release of molecules known as the senescence-associated secretory phenotype that can selectively promote the growth of pre-neoplastic keratinocytes (osteopontin) and cancer invasion (transforming growth factor β, matrix metalloproteinases, interleukin 6 and lactate). In addition, both old and new work has shown that keratinocytes harbouring NOTCH loss-of-function mutations that lead to defective keratinocyte differentiation and loss of squamous epithelial barrier function may act as a tumour-promoting stimulus for initiated cells harbouring RAS pathway mutations by activating a wound response in the tumour mesenchyme. Thus, not all keratinocytes in the

  5. Insertional mutagenesis in mice deficient for p15Ink4b, p16Ink4a, p21Cip1, and p27Kip1 reveals cancer gene interactions and correlations with tumor phenotypes

    DEFF Research Database (Denmark)

    Kool, Jaap; Uren, Anthony G; Martins, Carla P

    2010-01-01

    -throughput murine leukemia virus insertional mutagenesis screens in mice that are deficient for one or two CDK inhibitors. We retrieved 9,117 retroviral insertions from 476 lymphomas to define hundreds of loci that are mutated more frequently than expected by chance. Many of these loci are skewed toward a specific...... revealed a significant overlap between the datasets. Together, our findings highlight the importance of genetic context within large-scale mutation detection studies, and they show a novel use for insertional mutagenesis data in prioritizing disease-associated genes that emerge from genome-wide association...

  6. Evaluation of p16INK4a/Ki-67 dual stain in comparison with an mRNA human papillomavirus test on liquid-based cytology samples with low-grade squamous intraepithelial lesion

    DEFF Research Database (Denmark)

    Waldstrom, M.; Christensen, R. K.; Ornskov, D.

    2013-01-01

    with significantly lower values than the CINtec PLUS test. For patients with CIN2+, the APTIMA HPV Assay had a specificity of 36.1% versus 51.3% for the CINtec PLUS test, and for women with CIN3+, the specificity was 33.8% versus 48.2%, respectively. The difference was even more pronounced when analyzing women aged...... sensitivity that was similar to that of the APTIMA HPV Assay in the detection of underlying high-grade disease but with enhanced specificity, especially among women aged

  7. Immunostaining of p16INK4a/Ki-67 and L1 Capsid Protein on Liquid-based Cytology Specimens Obtained from ASC-H and LSIL-H Cases

    OpenAIRE

    Byun, Seung Won; Lee, Ahwon; Kim, Suyeon; Choi, Yeong Jin; Lee, Youn Soo; Park, Jong Sup

    2013-01-01

    Background: Atypical squamous cell cannot exclude high-grade squamous intraepithelial lesion (ASC-H) and low-grade intraepithelial lesion cannot exclude high-grade squamous intraepithelial lesion (LSIL-H) are ambiguous diagnostic entities for the prediction of high-grade cervical lesion. Objective and reproducible tests for predicting high-grade cervical lesions are needed to reduce unnecessary colposcopic referrals or follow-ups. Objective: We aimed to identify an adequate set of adjunctive ...

  8. Kallistatin reduces vascular senescence and aging by regulating microRNA-34a-SIRT1 pathway.

    Science.gov (United States)

    Guo, Youming; Li, Pengfei; Gao, Lin; Zhang, Jingmei; Yang, Zhirong; Bledsoe, Grant; Chang, Eugene; Chao, Lee; Chao, Julie

    2017-08-01

    Kallistatin, an endogenous protein, protects against vascular injury by inhibiting oxidative stress and inflammation in hypertensive rats and enhancing the mobility and function of endothelial progenitor cells (EPCs). We aimed to determine the role and mechanism of kallistatin in vascular senescence and aging using cultured EPCs, streptozotocin (STZ)-induced diabetic mice, and Caenorhabditis elegans (C. elegans). Human kallistatin significantly decreased TNF-α-induced cellular senescence in EPCs, as indicated by reduced senescence-associated β-galactosidase activity and plasminogen activator inhibitor-1 expression, and elevated telomerase activity. Kallistatin blocked TNF-α-induced superoxide levels, NADPH oxidase activity, and microRNA-21 (miR-21) and p16 INK 4a synthesis. Kallistatin prevented TNF-α-mediated inhibition of SIRT1, eNOS, and catalase, and directly stimulated the expression of these antioxidant enzymes. Moreover, kallistatin inhibited miR-34a synthesis, whereas miR-34a overexpression abolished kallistatin-induced antioxidant gene expression and antisenescence activity. Kallistatin via its active site inhibited miR-34a, and stimulated SIRT1 and eNOS synthesis in EPCs, which was abolished by genistein, indicating an event mediated by tyrosine kinase. Moreover, kallistatin administration attenuated STZ-induced aortic senescence, oxidative stress, and miR-34a and miR-21 synthesis, and increased SIRT1, eNOS, and catalase levels in diabetic mice. Furthermore, kallistatin treatment reduced superoxide formation and prolonged wild-type C. elegans lifespan under oxidative or heat stress, although kallistatin's protective effect was abolished in miR-34 or sir-2.1 (SIRT1 homolog) mutant C. elegans. Kallistatin inhibited miR-34, but stimulated sir-2.1 and sod-3 synthesis in C. elegans. These in vitro and in vivo studies provide significant insights into the role and mechanism of kallistatin in vascular senescence and aging by regulating miR-34a-SIRT1

  9. Use of NAP gene to manipulate leaf senescence in plants

    Science.gov (United States)

    Gan, Susheng; Guo, Yongfeng

    2013-04-16

    The present invention discloses transgenic plants having an altered level of NAP protein compared to that of a non-transgenic plant, where the transgenic plants display an altered leaf senescence phenotype relative to a non-transgenic plant, as well as mutant plants comprising an inactivated NAP gene, where mutant plants display a delayed leaf senescence phenotype compared to that of a non-mutant plant. The present invention also discloses methods for delaying leaf senescence in a plant, as well as methods of making a mutant plant having a decreased level of NAP protein compared to that of a non-mutant plant, where the mutant plant displays a delayed leaf senescence phenotype relative to a non-mutant plant. Methods for causing precocious leaf senescence or promoting leaf senescence in a plant are also disclosed. Also disclosed are methods of identifying a candidate plant suitable for breeding that displays a delayed leaf senescence and/or enhanced yield phenotype.

  10. Senescence is not inevitable

    DEFF Research Database (Denmark)

    Jones, Owen; Vaupel, James W.

    2017-01-01

    trajectories exists. These empirical observations support theoretical work indicating that a wide range of mortality and fertility trajectories is indeed possible, including senescence, negligible senescence and even negative senescence (improvement). Although many mysteries remain in the field...

  11. Up-regulation of leucocytes genes implicated in telomere dysfunction and cellular senescence correlates with depression and anxiety severity scores.

    Directory of Open Access Journals (Sweden)

    Jean-Raymond Teyssier

    Full Text Available BACKGROUND: Major depressive disorder (MDD is frequently associated with chronic medical illness responsible of increased disability and mortality. Inflammation and oxidative stress are considered to be the major mediators of the allostatic load, and has been shown to correlate with telomere erosion in the leucocytes of MDD patients, leading to the model of accelerated aging. However, the significance of telomere length as an exclusive biomarker of aging has been questioned on both methodological and biological grounds. Furthermore, telomeres significantly shorten only in patients with long lasting MDD. Sensitive and dynamic functional biomarkers of aging would be clinically useful to evaluate the somatic impact of MDD. METHODOLOGY: To address this issue we have measured in the blood leucocytes of MDD patients (N=17 and controls (N=16 the expression of two genes identified as robust biomarkers of human aging and telomere dysfunction: p16(INK4a and STMN1. We have also quantified the transcripts of genes involved in the repair of oxidative DNA damage at telomeres (OGG1, telomere regulation and elongation (TERT, and in the response to biopsychological stress (FOS and DUSP1. RESULTS: The OGG1, p16(INK4a, and STMN1 gene were significantly up-regulated (25 to 100% in the leucocytes of MDD patients. Expression of p16(INK4a and STMN1 was directly correlated with anxiety scores in the depression group, and that of p16(INK4a, STMN and TERT with the depression and anxiety scores in the combined sample (MDD plus controls. Furthermore, we identified a unique correlative pattern of gene expression in the leucocytes of MDD subjects. CONCLUSIONS: Expression of p16(INK4 and STMN1 is a promising biomarker for future epidemiological assessment of the somatic impact of depressive and anxious symptoms, at both clinical and subclinical level in both depressive patients and general population.

  12. Delayed Senescence

    Science.gov (United States)

    2004-01-01

    Researcher Dr. Yi Li developed a technique to manipulate certain characteristics of plant growth such as anit-senescence. For example, the tobacco leaf was clipped from a transgenic plant (right), and a wildtype plant (left). During ground-based laboratory studies, both leaves were left in a darkened area for 4 months. When retrieved, the wildtype plant leaf was dried-out and the transgenic leaf remained fresh and green. A variation of this technology that involves manipulating plant hormones has been conducted in space-based studies on tomato plants through BioServe Space Technologies. The transport and distribution of auxin, an important plant hormone has shown to be influenced by microgravity, which could lead to improving the quality of fruits and vegetables grown on Earth.

  13. Spontaneously immortalised bovine mammary epithelial cells exhibit a distinct gene expression pattern from the breast cancer cells

    Directory of Open Access Journals (Sweden)

    Li Qianqian

    2010-10-01

    Full Text Available Abstract Background Spontaneous immortalisation of cultured mammary epithelial cells (MECs is an extremely rare event, and the molecular mechanism behind spontaneous immortalisation of MECs is unclear. Here, we report the establishment of a spontaneously immortalised bovine mammary epithelial cell line (BME65Cs and the changes in gene expression associated with BME65Cs cells. Results BME65Cs cells maintain the general characteristics of normal mammary epithelial cells in morphology, karyotype and immunohistochemistry, and are accompanied by the activation of endogenous bTERT (bovine Telomerase Reverse Transcriptase and stabilisation of the telomere. Currently, BME65Cs cells have been passed for more than 220 generations, and these cells exhibit non-malignant transformation. The expression of multiple genes was investigated in BME65Cs cells, senescent BMECs (bovine MECs cells, early passage BMECs cells and MCF-7 cells (a human breast cancer cell line. In comparison with early passage BMECs cells, the expression of senescence-relevant apoptosis-related gene were significantly changed in BME65Cs cells. P16INK4a was downregulated, p53 was low expressed and Bax/Bcl-2 ratio was reversed. Moreover, a slight upregulation of the oncogene c-Myc, along with an undetectable level of breast tumor-related gene Bag-1 and TRPS-1, was observed in BME65Cs cells while these genes are all highly expressed in MCF-7. In addition, DNMT1 is upregulated in BME65Cs. These results suggest that the inhibition of both senescence and mitochondrial apoptosis signalling pathways contribute to the immortality of BME65Cs cells. The expression of p53 and p16INK4a in BME65Cs was altered in the pattern of down-regulation but not "loss", suggesting that this spontaneous immortalization is possibly initiated by other mechanism rather than gene mutation of p53 or p16INK4a. Conclusions Spontaneously immortalised BME65Cs cells maintain many characteristics of normal BMEC cells and

  14. NONO couples the circadian clock to the cell cycle.

    Science.gov (United States)

    Kowalska, Elzbieta; Ripperger, Juergen A; Hoegger, Dominik C; Bruegger, Pascal; Buch, Thorsten; Birchler, Thomas; Mueller, Anke; Albrecht, Urs; Contaldo, Claudio; Brown, Steven A

    2013-01-29

    Mammalian circadian clocks restrict cell proliferation to defined time windows, but the mechanism and consequences of this interrelationship are not fully understood. Previously we identified the multifunctional nuclear protein NONO as a partner of circadian PERIOD (PER) proteins. Here we show that it also conveys circadian gating to the cell cycle, a connection surprisingly important for wound healing in mice. Specifically, although fibroblasts from NONO-deficient mice showed approximately normal circadian cycles, they displayed elevated cell doubling and lower cellular senescence. At a molecular level, NONO bound to the p16-Ink4A cell cycle checkpoint gene and potentiated its circadian activation in a PER protein-dependent fashion. Loss of either NONO or PER abolished this activation and circadian expression of p16-Ink4A and eliminated circadian cell cycle gating. In vivo, lack of NONO resulted in defective wound repair. Because wound healing defects were also seen in multiple circadian clock-deficient mouse lines, our results therefore suggest that coupling of the cell cycle to the circadian clock via NONO may be useful to segregate in temporal fashion cell proliferation from tissue organization.

  15. Senescence in the aging process [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Richard GA Faragher

    2017-07-01

    Full Text Available The accumulation of ‘senescent’ cells has long been proposed to act as an ageing mechanism. These cells display a radically altered transcriptome and degenerative phenotype compared with their growing counterparts. Tremendous progress has been made in recent years both in understanding the molecular mechanisms controlling entry into the senescent state and in the direct demonstration that senescent cells act as causal agents of mammalian ageing. The challenges now are to gain a better understanding of how the senescent cell phenotype varies between different individuals and tissues, discover how senescence predisposes to organismal frailty, and develop mechanisms by which the deleterious effects of senescent cells can be ameliorated.

  16. Senescence Meets Dedifferentiation

    Science.gov (United States)

    Givaty Rapp, Yemima; Ransbotyn, Vanessa; Grafi, Gideon

    2015-01-01

    Senescence represents the final stage of leaf development but is often induced prematurely following exposure to biotic and abiotic stresses. Leaf senescence is manifested by color change from green to yellow (due to chlorophyll degradation) or to red (due to de novo synthesis of anthocyanins coupled with chlorophyll degradation) and frequently culminates in programmed death of leaves. However, the breakdown of chlorophyll and macromolecules such as proteins and RNAs that occurs during leaf senescence does not necessarily represent a one-way road to death but rather a reversible process whereby senescing leaves can, under certain conditions, re-green and regain their photosynthetic capacity. This phenomenon essentially distinguishes senescence from programmed cell death, leading researchers to hypothesize that changes occurring during senescence might represent a process of trans-differentiation, that is the conversion of one cell type to another. In this review, we highlight attributes common to senescence and dedifferentiation including chromatin structure and activation of transposable elements and provide further support to the notion that senescence is not merely a deterioration process leading to death but rather a unique developmental state resembling dedifferentiation. PMID:27135333

  17. PML, SUMOylation and senescence

    Directory of Open Access Journals (Sweden)

    Hugues eDe Thé

    2013-07-01

    Full Text Available Since its discovery, 25 years ago, PML has been an enigma. Implicated in the oncogenic PML/RARA fusion, forming elusive intranuclear domains, triggering cell death or senescence, controlled by and perhaps controlling SUMOylation... there are multiple PML-related issues. Here we review the reciprocal interactions between PML, senescence and SUMOylation, notably in the context of cellular transformation.

  18. Evolution of plant senescence

    Directory of Open Access Journals (Sweden)

    Young Mike

    2009-07-01

    Full Text Available Abstract Background Senescence is integral to the flowering plant life-cycle. Senescence-like processes occur also in non-angiosperm land plants, algae and photosynthetic prokaryotes. Increasing numbers of genes have been assigned functions in the regulation and execution of angiosperm senescence. At the same time there has been a large expansion in the number and taxonomic spread of plant sequences in the genome databases. The present paper uses these resources to make a study of the evolutionary origins of angiosperm senescence based on a survey of the distribution, across plant and microbial taxa, and expression of senescence-related genes. Results Phylogeny analyses were carried out on protein sequences corresponding to genes with demonstrated functions in angiosperm senescence. They include proteins involved in chlorophyll catabolism and its control, homeoprotein transcription factors, metabolite transporters, enzymes and regulators of carotenoid metabolism and of anthocyanin biosynthesis. Evolutionary timelines for the origins and functions of particular genes were inferred from the taxonomic distribution of sequences homologous to those of angiosperm senescence-related proteins. Turnover of the light energy transduction apparatus is the most ancient element in the senescence syndrome. By contrast, the association of phenylpropanoid metabolism with senescence, and integration of senescence with development and adaptation mediated by transcription factors, are relatively recent innovations of land plants. An extended range of senescence-related genes of Arabidopsis was profiled for coexpression patterns and developmental relationships and revealed a clear carotenoid metabolism grouping, coordinated expression of genes for anthocyanin and flavonoid enzymes and regulators and a cluster pattern of genes for chlorophyll catabolism consistent with functional and evolutionary features of the pathway. Conclusion The expression and phylogenetic

  19. Evasion of Cell Senescence Leads to Medulloblastoma Progression

    Directory of Open Access Journals (Sweden)

    Lukas Tamayo-Orrego

    2016-03-01

    Full Text Available How brain tumors progress from precancerous lesions to advanced cancers is not well understood. Using Ptch1+/− mice to study medulloblastoma progression, we found that Ptch1 loss of heterozygosity (LOH is an early event that is associated with high levels of cell senescence in preneoplasia. In contrast, advanced tumors have evaded senescence. Remarkably, we discovered that the majority of advanced medulloblastomas display either spontaneous, somatic p53 mutations or Cdkn2a locus inactivation. Consistent with senescence evasion, these p53 mutations are always subsequent to Ptch1 LOH. Introduction of a p53 mutation prevents senescence, accelerates tumor formation, and increases medulloblastoma incidence. Altogether, our results show that evasion of senescence associated with Ptch1 LOH allows progression to advanced tumors.

  20. The Immortal Senescence.

    Science.gov (United States)

    Bianchi-Smiraglia, Anna; Lipchick, Brittany C; Nikiforov, Mikhail A

    2017-01-01

    Activation of oncogenic signaling paradoxically results in the permanent withdrawal from cell cycle and induction of senescence (oncogene-induced senescence (OIS)). OIS is a fail-safe mechanism used by the cells to prevent uncontrolled tumor growth, and, as such, it is considered as the first barrier against cancer. In order to progress, tumor cells thus need to first overcome the senescent phenotype. Despite the increasing attention gained by OIS in the past 20 years, this field is still rather young due to continuous emergence of novel pathways and processes involved in OIS. Among the many factors contributing to incomplete understanding of OIS are the lack of unequivocal markers for senescence and the complexity of the phenotypes revealed by senescent cells in vivo and in vitro. OIS has been shown to play major roles at both the cellular and organismal levels in biological processes ranging from embryonic development to barrier to cancer progression. Here we will briefly outline major advances in methodologies that are being utilized for induction, identification, and characterization of molecular processes in cells undergoing oncogene-induced senescence. The full description of such methodologies is provided in the corresponding chapters of the book.

  1. Possible involvement of loss of imprinting in immortalization of human fibroblasts.

    Science.gov (United States)

    Okamura, Kotaro; Ohno, Maki; Tsutsui, Takeki

    2011-04-01

    Disruption of the normal pattern of parental origin-specific gene expression is referred to as loss of imprinting (LOI), which is common in various cancers. To investigate a possible role of LOI in the early stage of human cell transformation, we studied LOI in 18 human fibroblast cell lines immortalized spontaneously, by viral oncogenes, by chemical or physical carcinogens, or by infection with a retrovirus vector encoding the human telomerase catalytic subunit, hTERT cDNA. LOI was observed in all the 18 immortal cell lines. The gene most commonly exhibiting LOI was NDN which displayed LOI in 15 of the 18 cell lines (83%). The other genes exhibiting LOI at high frequencies were PEG3 (50%), MAGE-L2 (61%) and ZNF 127 (50%). Expression of NDN that was lost in the immortal cell lines was restored by treatment with 5-aza-2'-deoxycytidine. The ratio of histone H3 lysine 9 methylation to histone H3 lysine 4 methylation of the chromatin containing the NDN promoter in the immortal WI-38VA13 cells was greater than that in the parental cells, suggesting chromatin structure-mediated regulation of NDN expression. We previously demonstrated that inactivation of the p16INK4a/pRb pathway is necessary for immortalization of human cells. Human fibroblasts in the pre-crisis phase and cells with an extended lifespan that eventually senesce, both of which have the normal p16INK4a/pRb pathway, did not show LOI at any imprinted gene examined. Although it is not clear if LOI plays a causal role in immortalization of human cells or is merely coincidental, these findings indicate a possible involvement of LOI in immortalization of human cells or a common mechanism involved in both processes.

  2. Cytokine loops driving senescence

    Czech Academy of Sciences Publication Activity Database

    Bartek, Jiří; Hodný, Zdeněk; Lukáš, Jan

    2008-01-01

    Roč. 10, č. 8 (2008), s. 887-889 ISSN 1465-7392 Institutional research plan: CEZ:AV0Z50520514 Keywords : cellular senescence * cytokines * autocrine feedback loop Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 17.774, year: 2008

  3. Identification of 30 protein species involved in replicative senescence and stress-induced premature senescence

    DEFF Research Database (Denmark)

    Dierick, Jean François; Kalume, Dário E; Wenders, Frédéric

    2002-01-01

    Exposure of human proliferative cells to subcytotoxic stress triggers stress-induced premature senescence (SIPS) which is characterized by many biomarkers of replicative senescence. Proteomic comparison of replicative senescence and stress-induced premature senescence indicates that, at the level...

  4. Cellular Senescence: A Translational Perspective

    Directory of Open Access Journals (Sweden)

    James L. Kirkland

    2017-07-01

    Full Text Available Cellular senescence entails essentially irreversible replicative arrest, apoptosis resistance, and frequently acquisition of a pro-inflammatory, tissue-destructive senescence-associated secretory phenotype (SASP. Senescent cells accumulate in various tissues with aging and at sites of pathogenesis in many chronic diseases and conditions. The SASP can contribute to senescence-related inflammation, metabolic dysregulation, stem cell dysfunction, aging phenotypes, chronic diseases, geriatric syndromes, and loss of resilience. Delaying senescent cell accumulation or reducing senescent cell burden is associated with delay, prevention, or alleviation of multiple senescence-associated conditions. We used a hypothesis-driven approach to discover pro-survival Senescent Cell Anti-apoptotic Pathways (SCAPs and, based on these SCAPs, the first senolytic agents, drugs that cause senescent cells to become susceptible to their own pro-apoptotic microenvironment. Several senolytic agents, which appear to alleviate multiple senescence-related phenotypes in pre-clinical models, are beginning the process of being translated into clinical interventions that could be transformative.

  5. [Immunological theory of senescence].

    Science.gov (United States)

    Drela, Nadzieja

    2014-01-01

    Senescence can result from decreased potential of the immune system to respond to foreign and self antigens. The most common effect is the inhibition to destroy dying and cancer cells and the decrease of the immune response to pathogens. Aging is closely related to inflammatory phenotype, which facilitate the development of age-related diseases. The mammal immune system is highly organized and adapted to react to a wide range of antigens. According to the immunological theory, the causative agents of senescence are multilevel changes of development and functions of immune cells. Some of changes can be beneficial for the maintenance of homeostasis and lifespan in continuously changing endogenous environment and immune history of the organism.

  6. Cellular senescence and organismal aging.

    Science.gov (United States)

    Jeyapalan, Jessie C; Sedivy, John M

    2008-01-01

    Cellular senescence, first observed and defined using in vitro cell culture studies, is an irreversible cell cycle arrest which can be triggered by a variety of factors. Emerging evidence suggests that cellular senescence acts as an in vivo tumor suppression mechanism by limiting aberrant proliferation. It has also been postulated that cellular senescence can occur independently of cancer and contribute to the physiological processes of normal organismal aging. Recent data have demonstrated the in vivo accumulation of senescent cells with advancing age. Some characteristics of senescent cells, such as the ability to modify their extracellular environment, could play a role in aging and age-related pathology. In this review, we examine current evidence that links cellular senescence and organismal aging.

  7. Accumulation of senescent cells in mitotic tissue of aging primates.

    Science.gov (United States)

    Jeyapalan, Jessie C; Ferreira, Mark; Sedivy, John M; Herbig, Utz

    2007-01-01

    Cellular senescence, a stress induced growth arrest of somatic cells, was first documented in cell cultures over 40 years ago, however its physiological significance has only recently been demonstrated. Using novel biomarkers of cellular senescence we examined whether senescent cells accumulate in tissues from baboons of ages encompassing the entire lifespan of this species. We show that dermal fibroblasts, displaying markers of senescence such as telomere damage, active checkpoint kinase ATM, high levels of heterochromatin proteins and elevated levels of p16, accumulate in skin biopsies from baboons with advancing age. The number of dermal fibroblasts containing damaged telomeres reaches a value of over 15% of total fibroblasts, whereas 80% of cells contain high levels of the heterochromatin protein HIRA. In skeletal muscle, a postmitotic tissue, only a small percentage of myonuclei containing damaged telomeres were detected regardless of animal age. The presence of senescent cells in mitotic tissues might therefore be a contributing factor to aging and age related pathology and provides further evidence that cellular senescence is a physiological event.

  8. Biomarkers of replicative senescence revisited

    DEFF Research Database (Denmark)

    Nehlin, Jan

    2016-01-01

    Biomarkers of replicative senescence can be defined as those ultrastructural and physiological variations as well as molecules whose changes in expression, activity or function correlate with aging, as a result of the gradual exhaustion of replicative potential and a state of permanent cell cycle...... arrest. The biomarkers that characterize the path to an irreversible state of cell cycle arrest due to proliferative exhaustion may also be shared by other forms of senescence-inducing mechanisms. Validation of senescence markers is crucial in circumstances where quiescence or temporary growth arrest may...... be triggered or is thought to be induced. Pre-senescence biomarkers are also important to consider as their presence indicate that induction of aging processes is taking place. The bona fide pathway leading to replicative senescence that has been extensively characterized is a consequence of gradual reduction...

  9. Plant senescence and crop productivity

    DEFF Research Database (Denmark)

    Gregersen, Per L.; Culetic, Andrea; Boschian, Luca

    2013-01-01

    Senescence is a developmental process which in annual crop plants overlaps with the reproductive phase. Senescence might reduce crop yield when it is induced prematurely under adverse environmental conditions. This review covers the role of senescence for the productivity of crop plants....... With the aim to enhance productivity, a number of functional stay-green cultivars have been selected by conventional breeding, in particular of sorghum and maize. In many cases, a positive correlation between leaf area duration and yield has been observed, although in a number of other cases, stay...... plants, the expression of the IPT gene under control of senescence-associated promoters has been the most successful. The promoters employed for senescence-regulated expression contain cis-elements for binding of WRKY transcription factors and factors controlled by abscisic acid. In most crops...

  10. Translational researches on leaf senescence for enhancing plant productivity and quality.

    Science.gov (United States)

    Guo, Yongfeng; Gan, Su-Sheng

    2014-07-01

    Leaf senescence is a very important trait that limits yield and biomass accumulation of agronomic crops and reduces post-harvest performance and the nutritional value of horticultural crops. Significant advance in physiological and molecular understanding of leaf senescence has made it possible to devise ways of manipulating leaf senescence for agricultural improvement. There are three major strategies in this regard: (i) plant hormone biology-based leaf senescence manipulation technology, the senescence-specific gene promoter-directed IPT system in particular; (ii) leaf senescence-specific transcription factor biology-based technology; and (iii) translation initiation factor biology-based technology. Among the first strategy, the P SAG12 -IPT autoregulatory senescence inhibition system has been widely explored and successfully used in a variety of plant species for manipulating senescence. The vast majority of the related research articles (more than 2000) showed that crops harbouring the autoregulatory system displayed a significant delay in leaf senescence without any abnormalities in growth and development, a marked increase in grain yield and biomass, dramatic improvement in horticultural performance, and/or enhanced tolerance to drought stress. This technology is approaching commercialization. The transcription factor biology-based and translation initiation factor biology-based technologies have also been shown to be very promising and have great potentials for manipulating leaf senescence in crops. Finally, it is speculated that technologies based on the molecular understanding of nutrient recycling during leaf senescence are highly desirable and are expected to be developed in future translational leaf senescence research. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  11. Regulation of hTERT Expression and Function in Newly Immortalized p53(+) Human Mammary Epithelial Cell Lines

    Science.gov (United States)

    2008-06-01

    senescence: Putting the brakes on tumor develop- ment. Cancer Res 2006; 66:2881-4. 17. Jones CJ, Kipling D, Morris M, Hepburn P, Skinner J, Bounacer A...A, Bonner-Weir S, Sharpless NE. P16ink4a induces an age-dependent decline in islet regenerative potential. Nature 2006; 443:453-7. 67...195L HMEC (Group A) fall into two categories : genes previously iden- tified as cancer-associated (including several antigens pro- posed as cancer

  12. Androgen receptor drives cellular senescence.

    Directory of Open Access Journals (Sweden)

    Yelena Mirochnik

    Full Text Available The accepted androgen receptor (AR role is to promote proliferation and survival of prostate epithelium and thus prostate cancer progression. While growth-inhibitory, tumor-suppressive AR effects have also been documented, the underlying mechanisms are poorly understood. Here, we for the first time link AR anti-cancer action with cell senescence in vitro and in vivo. First, AR-driven senescence was p53-independent. Instead, AR induced p21, which subsequently reduced ΔN isoform of p63. Second, AR activation increased reactive oxygen species (ROS and thereby suppressed Rb phosphorylation. Both pathways were critical for senescence as was proven by p21 and Rb knock-down and by quenching ROS with N-Acetyl cysteine and p63 silencing also mimicked AR-induced senescence. The two pathways engaged in a cross-talk, likely via PML tumor suppressor, whose localization to senescence-associated chromatin foci was increased by AR activation. All these pathways contributed to growth arrest, which resolved in senescence due to concomitant lack of p53 and high mTOR activity. This is the first demonstration of senescence response caused by a nuclear hormone receptor.

  13. Genome-wide transcriptional reorganization associated with senescence-to-immortality switch during human hepatocellular carcinogenesis.

    Directory of Open Access Journals (Sweden)

    Gokhan Yildiz

    Full Text Available Senescence is a permanent proliferation arrest in response to cell stress such as DNA damage. It contributes strongly to tissue aging and serves as a major barrier against tumor development. Most tumor cells are believed to bypass the senescence barrier (become "immortal" by inactivating growth control genes such as TP53 and CDKN2A. They also reactivate telomerase reverse transcriptase. Senescence-to-immortality transition is accompanied by major phenotypic and biochemical changes mediated by genome-wide transcriptional modifications. This appears to happen during hepatocellular carcinoma (HCC development in patients with liver cirrhosis, however, the accompanying transcriptional changes are virtually unknown. We investigated genome-wide transcriptional changes related to the senescence-to-immortality switch during hepatocellular carcinogenesis. Initially, we performed transcriptome analysis of senescent and immortal clones of Huh7 HCC cell line, and identified genes with significant differential expression to establish a senescence-related gene list. Through the analysis of senescence-related gene expression in different liver tissues we showed that cirrhosis and HCC display expression patterns compatible with senescent and immortal phenotypes, respectively; dysplasia being a transitional state. Gene set enrichment analysis revealed that cirrhosis/senescence-associated genes were preferentially expressed in non-tumor tissues, less malignant tumors, and differentiated or senescent cells. In contrast, HCC/immortality genes were up-regulated in tumor tissues, or more malignant tumors and progenitor cells. In HCC tumors and immortal cells genes involved in DNA repair, cell cycle, telomere extension and branched chain amino acid metabolism were up-regulated, whereas genes involved in cell signaling, as well as in drug, lipid, retinoid and glycolytic metabolism were down-regulated. Based on these distinctive gene expression features we developed a 15

  14. Premeiotic germ cell defect in seminiferous tubules of Atm-null testis

    International Nuclear Information System (INIS)

    Takubo, Keiyo; Hirao, Atsushi; Ohmura, Masako; Azuma, Masaki; Arai, Fumio; Nagamatsu, Go; Suda, Toshio

    2006-01-01

    Lifelong spermatogenesis is maintained by coordinated sequential processes including self-renewal of stem cells, proliferation of spermatogonial cells, meiotic division, and spermiogenesis. It has been shown that ataxia telangiectasia-mutated (ATM) is required for meiotic division of the seminiferous tubules. Here, we show that, in addition to its role in meiosis, ATM has a pivotal role in premeiotic germ cell maintenance. ATM is activated in premeiotic spermatogonial cells and the Atm-null testis shows progressive degeneration. In Atm-null testicular cells, differing from bone marrow cells of Atm-null mice, reactive oxygen species-mediated p16 Ink4a activation does not occur in Atm-null premeiotic germ cells, which suggests the involvement of different signaling pathways from bone marrow defects. Although Atm-null bone marrow undergoes p16 Ink4a -mediated cellular senescence program, Atm-null premeiotic germ cells exhibited cell cycle arrest and apoptotic elimination of premeiotic germ cells, which is different from p16 Ink4a -mediated senescence

  15. Predatory senescence in ageing wolves.

    Science.gov (United States)

    MacNulty, Daniel R; Smith, Douglas W; Vucetich, John A; Mech, L David; Stahler, Daniel R; Packer, Craig

    2009-12-01

    It is well established that ageing handicaps the ability of prey to escape predators, yet surprisingly little is known about how ageing affects the ability of predators to catch prey. Research into long-lived predators has assumed that adults have uniform impacts on prey regardless of age. Here we use longitudinal data from repeated observations of individually-known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park to demonstrate that adult predatory performance declines with age and that an increasing ratio of senescent individuals in the wolf population depresses the rate of prey offtake. Because this ratio fluctuates independently of population size, predatory senescence may cause wolf populations of equal size but different age structure to have different impacts on prey populations. These findings suggest that predatory senescence is an important, though overlooked, factor affecting predator-prey dynamics.

  16. Predatory senescence in aging wolves

    Science.gov (United States)

    MacNulty, Daniel R.; Smith, Douglas W.; Vucetich, John A.; Mech, L. David; Stahler, Daniel R.; Packer, Craig

    2009-01-01

    It is well established that ageing handicaps the ability of prey to escape predators, yet surprisingly little is known about how ageing affects the ability of predators to catch prey. Research into long-lived predators has assumed that adults have uniform impacts on prey regardless of age. Here we use longitudinal data from repeated observations of individually-known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park to demonstrate that adult predatory performance declines with age and that an increasing ratio of senescent individuals in the wolf population depresses the rate of prey offtake. Because this ratio fluctuates independently of population size, predatory senescence may cause wolf populations of equal size but different age structure to have different impacts on prey populations. These findings suggest that predatory senescence is an important, though overlooked, factor affecting predator-prey dynamics.

  17. Predatory senescence in ageing wolves

    Science.gov (United States)

    MacNulty, D.R.; Smith, D.W.; Vucetich, J.A.; Mech, L.D.; Stahler, D.R.; Packer, C.

    2009-01-01

    It is well established that ageing handicaps the ability of prey to escape predators, yet surprisingly little is known about how ageing affects the ability of predators to catch prey. Research into long-lived predators has assumed that adults have uniform impacts on prey regardless of age. Here we use longitudinal data from repeated observations of individually-known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park to demonstrate that adult predatory performance declines with age and that an increasing ratio of senescent individuals in the wolf population depresses the rate of prey offtake. Because this ratio fluctuates independently of population size, predatory senescence may cause wolf populations of equal size but different age structure to have different impacts on prey populations. These findings suggest that predatory senescence is an important, though overlooked, factor affecting predator-prey dynamics. ?? 2009 Blackwell Publishing Ltd/CNRS.

  18. Genome-wide evaluation of histone methylation changes associated with leaf senescence in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Judy A Brusslan

    Full Text Available Leaf senescence is the orderly dismantling of older tissue that allows recycling of nutrients to developing portions of the plant and is accompanied by major changes in gene expression. Histone modifications correlate to levels of gene expression, and this study utilizes ChIP-seq to classify activating H3K4me3 and silencing H3K27me3 marks on a genome-wide scale for soil-grown mature and naturally senescent Arabidopsis leaves. ChIPnorm was used to normalize data sets and identify genomic regions with significant differences in the two histone methylation patterns, and the differences were correlated to changes in gene expression. Genes that showed an increase in the H3K4me3 mark in older leaves were senescence up-regulated, while genes that showed a decrease in the H3K4me3 mark in the older leaves were senescence down-regulated. For the H3K27me3 modification, genes that lost the H3K27me3 mark in older tissue were senescence up-regulated. Only a small number of genes gained the H3K27me3 mark, and these were senescence down-regulated. Approximately 50% of senescence up-regulated genes lacked the H3K4me3 mark in both mature and senescent leaf tissue. Two of these genes, SAG12 and At1g73220, display strong senescence up-regulation without the activating H3K4me3 histone modification. This study provides an initial epigenetic framework for the developmental transition into senescence.

  19. Selective insulin resistance in hepatocyte senescence

    International Nuclear Information System (INIS)

    Aravinthan, Aloysious; Challis, Benjamin; Shannon, Nicholas; Hoare, Matthew; Heaney, Judith; Alexander, Graeme J.M.

    2015-01-01

    Insulin resistance has been described in association with chronic liver disease for decades. Hepatocyte senescence has been demonstrated in chronic liver disease and as many as 80% of hepatocytes show a senescent phenotype in advanced liver disease. The aim of this study was to understand the role of hepatocyte senescence in the development of insulin resistance. Senescence was induced in HepG2 cells via oxidative stress. The insulin metabolic pathway was studied in control and senescent cells following insulin stimulation. GLUT2 and GLUT4 expressions were studied in HepG2 cells and human liver tissue. Further, GLUT2 and GLUT4 expressions were studied in three independent chronic liver disease cohorts. Signalling impairment distal to Akt in phosphorylation of AS160 and FoxO1 was evident in senescent HepG2 cells. Persistent nuclear localisation of FoxO1 was demonstrated in senescent cells despite insulin stimulation. Increased GLUT4 and decreased GLUT2 expressions were evident in senescent cells, human cirrhotic liver tissue and publically available liver disease datasets. Changes in GLUT expressions were associated with a poor clinical prognosis. In conclusion, selective insulin resistance is evident in senescent HepG2 cells and changes in GLUT expressions can be used as surrogate markers of hepatocyte senescence. - Highlights: • Senescent hepatocytes demonstrate selective insulin resistance. • GLUT changes act as markers of hepatocyte senescence and have prognostic value. • Study offers insight into long noticed intimacy of cirrhosis and insulin resistance

  20. Selective insulin resistance in hepatocyte senescence

    Energy Technology Data Exchange (ETDEWEB)

    Aravinthan, Aloysious [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Challis, Benjamin [Institute of Metabolic Sciences, University of Cambridge, Cambridge (United Kingdom); Shannon, Nicholas [Cancer Research UK Cambridge Institute, Cambridge (United Kingdom); Hoare, Matthew [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Cancer Research UK Cambridge Institute, Cambridge (United Kingdom); Heaney, Judith [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Foundation for Liver Research, Institute of Hepatology, London (United Kingdom); Alexander, Graeme J.M., E-mail: gja1000@doctors.org.uk [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom)

    2015-02-01

    Insulin resistance has been described in association with chronic liver disease for decades. Hepatocyte senescence has been demonstrated in chronic liver disease and as many as 80% of hepatocytes show a senescent phenotype in advanced liver disease. The aim of this study was to understand the role of hepatocyte senescence in the development of insulin resistance. Senescence was induced in HepG2 cells via oxidative stress. The insulin metabolic pathway was studied in control and senescent cells following insulin stimulation. GLUT2 and GLUT4 expressions were studied in HepG2 cells and human liver tissue. Further, GLUT2 and GLUT4 expressions were studied in three independent chronic liver disease cohorts. Signalling impairment distal to Akt in phosphorylation of AS160 and FoxO1 was evident in senescent HepG2 cells. Persistent nuclear localisation of FoxO1 was demonstrated in senescent cells despite insulin stimulation. Increased GLUT4 and decreased GLUT2 expressions were evident in senescent cells, human cirrhotic liver tissue and publically available liver disease datasets. Changes in GLUT expressions were associated with a poor clinical prognosis. In conclusion, selective insulin resistance is evident in senescent HepG2 cells and changes in GLUT expressions can be used as surrogate markers of hepatocyte senescence. - Highlights: • Senescent hepatocytes demonstrate selective insulin resistance. • GLUT changes act as markers of hepatocyte senescence and have prognostic value. • Study offers insight into long noticed intimacy of cirrhosis and insulin resistance.

  1. Transgenic plants with altered senescence characteristics

    Science.gov (United States)

    Amasino, Richard M.; Gan, Susheng; Noh, Yoo-Sun

    2002-03-19

    The identification of senescence-specific promoters from plants is described. Using information from the first senescence-specific promoter, SAG12 from Arabidopsis, other homologous promoters from another plant have been identified. Such promoters may be used to delay senescence in commercially important plants.

  2. From the Hayflick mosaic to the mosaics of ageing. Role of stress-induced premature senescence in human ageing.

    Science.gov (United States)

    Toussaint, Olivier; Remacle, Jose; Dierick, Jean-François; Pascal, Thierry; Frippiat, Christophe; Zdanov, Stéphanie; Magalhaes, Joao Pedro; Royer, Véronique; Chainiaux, Florence

    2002-11-01

    The Hayflick limit-senescence of proliferative cell types-is a fundamental feature of proliferative cells in vitro. Various human proliferative cell types exposed in vitro to many types of subcytotoxic stresses undergo stress-induced premature senescence (SIPS) (also called stress-induced premature senescence-like phenotype, according to the definition of senescence). The known mechanisms of appearance the main features of SIPS are reviewed: senescent-like morphology, growth arrest, senescence-related changes in gene expression, telomere shortening. Long before telomere-shortening induces senescence, other factors such as culture conditions or lack of 'feeder cells' can trigger either SIPS or prolonged reversible G(0) phase of the cell cycle. In vivo, 'proliferative' cell types of aged individuals are likely to compose a mosaic made of cells irreversibly growth arrested or not. The higher level of stress to which these cells have been exposed throughout their life span, the higher proportion of the cells of this mosaic will be in SIPS rather than in telomere-shortening dependent senescence. All cell types undergoing SIPS in vivo, most notably the ones in stressful conditions, are likely to participate in the tissular changes observed along ageing. For instance, human diploid fibroblasts (HDFs) exposed in vivo and in vitro to pro-inflammatory cytokines display biomarkers of senescence and might participate in the degradation of the extracellular matrix observed in ageing.

  3. Escherichia coli producing colibactin triggers premature and transmissible senescence in mammalian cells.

    Directory of Open Access Journals (Sweden)

    Thomas Secher

    Full Text Available Cellular senescence is an irreversible state of proliferation arrest evoked by a myriad of stresses including oncogene activation, telomere shortening/dysfunction and genotoxic insults. It has been associated with tumor activation, immune suppression and aging, owing to the secretion of proinflammatory mediators. The bacterial genotoxin colibactin, encoded by the pks genomic island is frequently harboured by Escherichia coli strains of the B2 phylogenetic group. Mammalian cells exposed to live pks+ bacteria exhibit DNA-double strand breaks (DSB and undergo cell-cycle arrest and death. Here we show that cells that survive the acute bacterial infection with pks+ E. coli display hallmarks of cellular senescence: chronic DSB, prolonged cell-cycle arrest, enhanced senescence-associated β-galactosidase (SA-β-Gal activity, expansion of promyelocytic leukemia nuclear foci and senescence-associated heterochromatin foci. This was accompanied by reactive oxygen species production and pro-inflammatory cytokines, chemokines and proteases secretion. These mediators were able to trigger DSB and enhanced SA-β-Gal activity in bystander recipient cells treated with conditioned medium from senescent cells. Furthermore, these senescent cells promoted the growth of human tumor cells. In conclusion, the present data demonstrated that the E. coli genotoxin colibactin induces cellular senescence and subsequently propel bystander genotoxic and oncogenic effects.

  4. Overexpression of the novel senescence marker β-galactosidase (GLB1 in prostate cancer predicts reduced PSA recurrence.

    Directory of Open Access Journals (Sweden)

    Jennifer Wagner

    Full Text Available Senescence is a terminal growth arrest that functions as a tumor suppressor in aging and precancerous cells and is a response to selected anticancer compounds. Lysosomal-β-galactosidase (GLB1 hydrolyzes β-galactose from glycoconjugates and is the origin of senescence-associated β-gal activity (SA-β-gal. Using a new GLB1 antibody, senescence biology was investigated in prostate cancer (PCa tissues.In vitro characterization of GLB1 was determined in primary prostate epithelial cell cultures passaged to replicative senescence and in therapy-induced senescence in PCa lines using chemotherapeutic agents. FFPE tissue microarrays were subjected to immunofluorescent staining for GLB1, Ki67 and HP1γ and automated quantitative imaging initially using AQUA in exploratory samples and Vectra in a validation series.GLB1 expression accumulates in replicative and induced senescence and correlates with senescent morphology and P16 (CDKN2 expression. In tissue arrays, quantitative imaging detects increased GLB1 expression in high-grade prostatic intraepithelial neoplasia (HGPIN, known to contain senescent cells, and cancer compared to benign prostate tissues (p<0.01 and senescent cells contain low Ki67 and elevated HP1γ. Within primary tumors, elevated GLB1 associates with lower T stage (p=0.01, localized versus metastatic disease (p=0.0003 and improved PSA-free survival (p=0.03. Increased GLB1 stratifies better PSA-free survival in intermediate grade PCa (0.01. Tissues that elaborate higher GLB1 display increased uniformity of expression.Increased GLB1 is a valuable marker in formalin-fixed paraffin-embedded (FFPE tissues for the senescence-like phenotype and associates with improved cancer outcomes. This protein addresses a lack of senescence markers and should be applicable to study the biologic role of senescence in other cancers.

  5. NAC transcription factors in senescence

    DEFF Research Database (Denmark)

    Podzimska-Sroka, Dagmara; O'Shea, Charlotte; Gregersen, Per L.

    2015-01-01

    involving the hormone abscisic acid, Arabidopsis NAP promotes chlorophyll degradation, a hallmark of senescence. Furthermore, studies of the functional rice ortholog, OsNAP, suggest that NAC genes can be targeted to obtain specific changes in lifespan control and nutrient remobilization in crop plants...

  6. Identification of novel senescence-associated genes in ionizing radiation-induced senescent carcinoma cells

    International Nuclear Information System (INIS)

    Lee, Jae Seon; Kim, Bong Cho; Han, Na Kyung; Hong, Mi Na; Park, Su Min; Yoo, Hee Jung; Chu, In Sun; Lee, Sun Hee

    2009-01-01

    Cellular senescence is considered as a defense mechanism to prevent tumorigenesis. Ionizing radiation (IR) induces stress-induced premature senescence as well as apoptosis in various cancer cells. Senescent cells undergo functional and morphological changes including large and flattened cell shape, senescence-associated β-galactosidase (SA-βGal) activity, and altered gene expressions. Even with the recent findings of several gene expression profiles and supporting functional data, it is obscure that mechanism of IR-induced premature senescence in cancer cells. We performed microarray analysis to identify the common regulated genes in ionizing radiation-induced prematurely senescent human carcinoma cell lines

  7. The oxidative hypothesis of senescence

    Directory of Open Access Journals (Sweden)

    Gilca M

    2007-01-01

    Full Text Available The oxidative hypothesis of senescence, since its origin in 1956, has garnered significant evidence and growing support among scientists for the notion that free radicals play an important role in ageing, either as "damaging" molecules or as signaling molecules. Age-increasing oxidative injuries induced by free radicals, higher susceptibility to oxidative stress in short-lived organisms, genetic manipulations that alter both oxidative resistance and longevity and the anti-ageing effect of caloric restriction and intermittent fasting are a few examples of accepted scientific facts that support the oxidative theory of senescence. Though not completely understood due to the complex "network" of redox regulatory systems, the implication of oxidative stress in the ageing process is now well documented. Moreover, it is compatible with other current ageing theories (e.g., those implicating the mitochondrial damage/mitochondrial-lysosomal axis, stress-induced premature senescence, biological "garbage" accumulation, etc. This review is intended to summarize and critically discuss the redox mechanisms involved during the ageing process: sources of oxidant agents in ageing (mitochondrial -electron transport chain, nitric oxide synthase reaction- and non-mitochondrial- Fenton reaction, microsomal cytochrome P450 enzymes, peroxisomal β -oxidation and respiratory burst of phagocytic cells, antioxidant changes in ageing (enzymatic- superoxide dismutase, glutathione-reductase, glutathion peroxidase, catalase- and non-enzymatic glutathione, ascorbate, urate, bilirubine, melatonin, tocopherols, carotenoids, ubiquinol, alteration of oxidative damage repairing mechanisms and the role of free radicals as signaling molecules in ageing.

  8. A comparison of oncogene-induced senescence and replicative senescence: implications for tumor suppression and aging.

    Science.gov (United States)

    Nelson, David M; McBryan, Tony; Jeyapalan, Jessie C; Sedivy, John M; Adams, Peter D

    2014-06-01

    Cellular senescence is a stable proliferation arrest associated with an altered secretory pathway, the senescence-associated secretory phenotype. However, cellular senescence is initiated by diverse molecular triggers, such as activated oncogenes and shortened telomeres, and is associated with varied and complex physiological endpoints, such as tumor suppression and tissue aging. The extent to which distinct triggers activate divergent modes of senescence that might be associated with different physiological endpoints is largely unknown. To begin to address this, we performed gene expression profiling to compare the senescence programs associated with two different modes of senescence, oncogene-induced senescence (OIS) and replicative senescence (RS [in part caused by shortened telomeres]). While both OIS and RS are associated with many common changes in gene expression compared to control proliferating cells, they also exhibit substantial differences. These results are discussed in light of potential physiological consequences, tumor suppression and aging.

  9. PPARgamma Deficiency Counteracts Thymic Senescence

    Directory of Open Access Journals (Sweden)

    David Ernszt

    2017-11-01

    Full Text Available Thymic senescence contributes to increased incidence of infection, cancer and autoimmunity at senior ages. This process manifests as adipose involution. As with other adipose tissues, thymic adipose involution is also controlled by PPARgamma. This is supported by observations reporting that systemic PPARgamma activation accelerates thymic adipose involution. Therefore, we hypothesized that decreased PPARgamma activity could prevent thymic adipose involution, although it may trigger metabolic adverse effects. We have confirmed that both human and murine thymic sections show marked staining for PPARgamma at senior ages. We have also tested the thymic lobes of PPARgamma haplo-insufficient and null mice. Supporting our working hypothesis both adult PPARgamma haplo-insufficient and null mice show delayed thymic senescence by thymus histology, thymocyte mouse T-cell recombination excision circle qPCR and peripheral blood naive T-cell ratio by flow-cytometry. Delayed senescence showed dose–response with respect to PPARgamma deficiency. Functional immune parameters were also evaluated at senior ages in PPARgamma haplo-insufficient mice (null mice do not reach senior ages due to metabolic adverse affects. As expected, sustained and elevated T-cell production conferred oral tolerance and enhanced vaccination efficiency in senior PPARgamma haplo-insufficient, but not in senior wild-type littermates according to ELISA IgG measurements. Of note, humans also show increased oral intolerance issues and decreased protection by vaccines at senior ages. Moreover, PPARgamma haplo-insufficiency also exists in human known as a rare disease (FPLD3 causing metabolic adverse effects, similar to the mouse. When compared to age- and metabolic disorder-matched other patient samples (FPLD2 not affecting PPARgamma activity, FPLD3 patients showed increased human Trec (hTrec values by qPCR (within healthy human range suggesting delayed thymic senescence, in accordance with

  10. Forging a signature of in vivo senescence.

    Science.gov (United States)

    Sharpless, Norman E; Sherr, Charles J

    2015-07-01

    'Cellular senescence', a term originally defining the characteristics of cultured cells that exceed their replicative limit, has been broadened to describe durable states of proliferative arrest induced by disparate stress factors. Proposed relationships between cellular senescence, tumour suppression, loss of tissue regenerative capacity and ageing suffer from lack of uniform definition and consistently applied criteria. Here, we highlight caveats in interpreting the importance of suboptimal senescence-associated biomarkers, expressed either alone or in combination. We advocate that more-specific descriptors be substituted for the now broadly applied umbrella term 'senescence' in defining the suite of diverse physiological responses to cellular stress.

  11. Senescence induction; a possible cancer therapy

    Directory of Open Access Journals (Sweden)

    Kondoh Hiroshi

    2009-01-01

    Full Text Available Abstract Cellular immortalization is a crucial step during the development of human cancer. Primary mammalian cells reach replicative exhaustion after several passages in vitro, a process called replicative senescence. During such a state of permanent growth arrest, senescent cells are refractory to physiological proliferation stimuli: they have altered cell morphology and gene expression patterns, although they remain viable with preserved metabolic activity. Interestingly, senescent cells have also been detected in vivo in human tumors, particularly in benign lesions. Senescence is a mechanism that limits cellular lifespan and constitutes a barrier against cellular immortalization. During immortalization, cells acquire genetic alterations that override senescence. Tumor suppressor genes and oncogenes are closely involved in senescence, as their knockdown and ectopic expression confer immortality and senescence induction, respectively. By using high throughput genetic screening to search for genes involved in senescence, several candidate oncogenes and putative tumor suppressor genes have been recently isolated, including subtypes of micro-RNAs. These findings offer new perspectives in the modulation of senescence and open new approaches for cancer therapy.

  12. Cellular Senescence Promotes Adverse Effects of Chemotherapy and Cancer Relapse

    NARCIS (Netherlands)

    Demaria, Marco; O'Leary, Monique N.; Chang, Jianhui; Shao, Lijian; Liu, Su; Alimirah, Fatouma; Koenig, Kristin; Le, Catherine; Mitin, Natalia; Deal, Allison M.; Alston, Shani; Academia, Emmeline C.; Kilmarx, Sumner; Valdovinos, Alexis; Wang, Boshi; de Bruin, Alain; Kennedy, Brian K.; Melov, Simon; Zhou, Daohong; Sharpless, Norman E.; Muss, Hyman; Campisi, Judith

    Cellular senescence suppresses cancer by irreversibly arresting cell proliferation. Senescent cells acquire a proinfl ammatory senescence-associated secretory phenotype. Many genotoxic chemotherapies target proliferating cells nonspecifi cally, often with adverse reactions. In accord with prior

  13. Increased storage and secretion of phosphatidylcholines by senescent human peritoneal mesothelial cells.

    Science.gov (United States)

    Bartosova, Maria; Rudolf, Andras; Pichl, Sebastian; Schmidt, Kathrin; Okun, Jürgen G; Straub, Beate K; Rutkowski, Rafael; Witowski, Janusz; Schmitt, Claus P

    2016-08-01

    Human peritoneal mesothelial cells (HPMC) secrete phosphatidylcholines (PC) which form a lipid bilayer lining the peritoneum. They prevent frictions and adhesions and act as a barrier to the transport of water-soluble solutes while permitting water flux. PC may play an essential role in peritoneal integrity and function, the role of PD induced HPMC senescence on PC homeostasis, however, is unknown. HPMC cell lines were isolated from four non-uremic patients. Expression of the three PC synthesis genes (rt-PCR), and cellular storage and secretion of PC (ESI-mass-spectrometry) were analyzed in young and senescent HPMC (>Hayflick-limit). Senescent cells displayed significantly altered morphology; flow cytometry demonstrated extensive staining for senescence-associated beta galactosidase. Nine different PC were detected in HPMC with palmitoyl-myristoyl phosphatidylcholine (PMPC) being most abundant. In senescent HPMC mRNA expression of the three key PC synthesis genes was 1.5-, 2.4- and 6-fold increased as compared to young HPMC, with the latter, phosphatidylcholine cytidylyltransferase, being rate limiting. Intracellular storage of the nine PC was 75-450 % higher in senescent vs. young HPMC, PC secretion rates were 100-300 % higher. Intracellular PC concentrations were not correlated with the PC secretion rates. Electron microscopy demonstrated lamellar bodies, the primary storage site of PC, in senescent but not in young cells. Senescent HPMC store and secrete substantially more PC than young cells. Our findings indicate a novel protective mechanism, which should counteract peritoneal damage induced by chronic exposure to PD fluids.

  14. YUCCA6 over-expression demonstrates auxin function in delaying leaf senescence in Arabidopsis thaliana

    KAUST Repository

    Kim, Jeong Im

    2011-04-21

    The Arabidopsis thaliana YUCCA family of flavin monooxygenase proteins catalyses a rate-limiting step in de novo auxin biosynthesis. A YUCCA6 activation mutant, yuc6-1D, has been shown to contain an elevated free IAA level and to display typical high-auxin phenotypes. It is reported here that Arabidopsis plants over-expressing YUCCA6, such as the yuc6-1D activation mutant and 35S:YUC6 transgenic plants, displayed dramatic longevity. In addition, plants over-expressing YUCCA6 exhibited classical, delayed dark-induced and hormone-induced senescence in assays using detached rosette leaves. However, plants over-expressing an allele of YUCCA6, that carries mutations in the NADPH cofactor binding site, exhibited neither delayed leaf senescence phenotypes nor phenotypes typical of auxin overproduction. When the level of free IAA was reduced in yuc6-1D by conjugation to lysine, yuc6-1D leaves senesced at a rate similar to the wild-type leaves. Dark-induced senescence in detached leaves was accompanied by a decrease in their free IAA content, by the reduced expression of auxin biosynthesis enzymes such as YUCCA1 and YUCCA6 that increase cellular free IAA levels, and by the increased expression of auxin-conjugating enzymes encoded by the GH3 genes that reduce the cellular free auxin levels. Reduced transcript abundances of SAG12, NAC1, and NAC6 during senescence in yuc6-1D compared with the wild type suggested that auxin delays senescence by directly or indirectly regulating the expression of senescence-associated genes. 2011 The Author(s).

  15. The senescent microenvironment promotes the emergence of heterogeneous cancer stem-like cells.

    Science.gov (United States)

    Castro-Vega, Luis Jaime; Jouravleva, Karina; Ortiz-Montero, Paola; Liu, Win-Yan; Galeano, Jorge Luis; Romero, Martha; Popova, Tatiana; Bacchetti, Silvia; Vernot, Jean Paul; Londoño-Vallejo, Arturo

    2015-10-01

    There is a well-established association between aging and the onset of metastasis. Although the mechanisms through which age impinges upon the malignant phenotype remain uncharacterized, the role of a senescent microenvironment has been emphasized. We reported previously that human epithelial cells that undergo telomere-driven chromosome instability (T-CIN) display global microRNA (miR) deregulation and develop migration and invasion capacities. Here, we show that post-crisis cells are not able to form tumors unless a senescent microenvironment is provided. The characterization of cell lines established from such tumors revealed that these cells have acquired cell autonomous tumorigenicity, giving rise to heterogeneous tumors. Further experiments demonstrate that explanted cells, while displaying differences in cell differentiation markers, are all endowed of enhanced stem cell properties including self-renewal and multilineage differentiation capacity. Treatments of T-CIN+ cells with senescence-conditioned media induce sphere formation exclusively in cells with senescence-associated tumorigenicity, a capacity that depends on miR-145 repression. These results indicate that the senescent microenvironment, while promoting further transdifferentiations in cells with genome instability, is able to propel the progression of premalignant cells towards a malignant, cell stem-like state. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Physiology and molecular biology of petal senescence

    NARCIS (Netherlands)

    Doorn, van W.G.; Woltering, E.J.

    2008-01-01

    Petal senescence is reviewed, with the main emphasis on gene expression in relation to physiological functions. Autophagy seems to be the major mechanism for large-scale degradation of macromolecules, but it is still unclear if it contributes to cell death. Depending on the species, petal senescence

  17. Targeting senescence cells in pancreatic cancer | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Targeting senescence cells in pancreatic cancer. Cellular senescence is a programmed response to oncogenic (tumour-causing) stress that aims to halt the expansion of cells with malignant potential. It does this by stopping the proliferation of pre-cancerous lesions and recruitment of the immune system for their elimination.

  18. Oncogenic senescence: a multi-functional perspective

    NARCIS (Netherlands)

    Baker, D.J.; Alimirah, F.; Deursen, J.M.A. van; Campisi, J.; Hildesheim, J.

    2017-01-01

    Cellular senescence is defined as an irreversible growth arrest with the acquisition of a distinctive secretome. The growth arrest is a potent anticancer mechanism whereas the secretome facilitates wound healing, tissue repair, and development. The senescence response has also become increasingly

  19. Possible Roles of Strigolactones during Leaf Senescence

    Directory of Open Access Journals (Sweden)

    Yusuke Yamada

    2015-09-01

    Full Text Available Leaf senescence is a complicated developmental process that involves degenerative changes and nutrient recycling. The progress of leaf senescence is controlled by various environmental cues and plant hormones, including ethylene, jasmonic acid, salicylic acid, abscisic acid, cytokinins, and strigolactones. The production of strigolactones is induced in response to nitrogen and phosphorous deficiency. Strigolactones also accelerate leaf senescence and regulate shoot branching and root architecture. Leaf senescence is actively promoted in a nutrient-poor soil environment, and nutrients are transported from old leaves to young tissues and seeds. Strigolactones might act as important signals in response to nutrient levels in the rhizosphere. In this review, we discuss the possible roles of strigolactones during leaf senescence.

  20. Octopus senescence: the beginning of the end.

    Science.gov (United States)

    Anderson, Roland C; Wood, James B; Byrne, Ruth A

    2002-01-01

    Senescence is a normal stage of an octopus's life cycle that often occurs before death. Some of the following symptoms typify it: lack of feeding, retraction of skin around the eyes, uncoordinated movement, increased undirected activity, and white unhealing lesions on the body. There is inter- and intraspecific variability. Senescence is not a disease or a result of disease, although diseases can also be a symptom of it. Both males and females go through a senescent stage before dying-the males after mating, the females while brooding eggs and after the eggs hatch. There are many aspects of octopus senescence that have not yet been studied. This study discusses the ecological implications of senescence.

  1. Piper betle L. Modulates Senescence-Associated Genes Expression in Replicative Senescent Human Diploid Fibroblasts

    Directory of Open Access Journals (Sweden)

    Lina Wati Durani

    2017-01-01

    Full Text Available Piper betle (PB is a traditional medicine that is widely used to treat different diseases around Asian region. The leaf extracts contain various bioactive compounds, which were reported to have antidiabetic, antibacterial, anti-inflammatory, antioxidant, and anticancer effects. In this study, the effect of PB aqueous extracts on replicative senescent human diploid fibroblasts (HDFs was investigated by determining the expressions of senescence-associated genes using quantitative PCR. Our results showed that PB extracts at 0.4 mg/ml can improve cell proliferation of young (143%, presenescent (127.3%, and senescent (157.3% HDFs. Increased expressions of PRDX6, TP53, CDKN2A, PAK2, and MAPK14 were observed in senescent HDFs compared to young and/or presenescent HDFs. Treatment with PB extracts modulates the transcriptional profile changes in senescent HDFs. By contrast, expressions of SOD1 increased, whereas GPX1, PRDX6, TP53, CDKN2A, PAK2, and MAPK14 were decreased in PB-treated senescent HDFs compared to untreated senescent HDFs. In conclusion, this study indicates the modulation of PB extracts on senescence-associated genes expression of replicative senescent HDFs. Further studies warrant determining the mechanism of PB in modulating replicative senescence of HDFs through these signaling pathways.

  2. Piper betle L. Modulates Senescence-Associated Genes Expression in Replicative Senescent Human Diploid Fibroblasts.

    Science.gov (United States)

    Durani, Lina Wati; Khor, Shy Cian; Tan, Jen Kit; Chua, Kien Hui; Mohd Yusof, Yasmin Anum; Makpol, Suzana

    2017-01-01

    Piper betle (PB) is a traditional medicine that is widely used to treat different diseases around Asian region. The leaf extracts contain various bioactive compounds, which were reported to have antidiabetic, antibacterial, anti-inflammatory, antioxidant, and anticancer effects. In this study, the effect of PB aqueous extracts on replicative senescent human diploid fibroblasts (HDFs) was investigated by determining the expressions of senescence-associated genes using quantitative PCR. Our results showed that PB extracts at 0.4 mg/ml can improve cell proliferation of young (143%), presenescent (127.3%), and senescent (157.3%) HDFs. Increased expressions of PRDX6 , TP53 , CDKN2A , PAK2 , and MAPK14 were observed in senescent HDFs compared to young and/or presenescent HDFs. Treatment with PB extracts modulates the transcriptional profile changes in senescent HDFs. By contrast, expressions of SOD1 increased, whereas GPX1 , PRDX6 , TP53 , CDKN2A , PAK2 , and MAPK14 were decreased in PB-treated senescent HDFs compared to untreated senescent HDFs. In conclusion, this study indicates the modulation of PB extracts on senescence-associated genes expression of replicative senescent HDFs. Further studies warrant determining the mechanism of PB in modulating replicative senescence of HDFs through these signaling pathways.

  3. Modulation of the Senescence-Associated Inflammatory Phenotype in Human Fibroblasts by Olive Phenols

    Directory of Open Access Journals (Sweden)

    Beatrice Menicacci

    2017-10-01

    Full Text Available Senescent cells display an increase in the secretion of growth factors, inflammatory cytokines and proteolytic enzymes, termed the “senescence-associated-secretory-phenotype” (SASP, playing a major role in many age-related diseases. The phenolic compounds present in extra-virgin olive oil are inhibitors of oxidative damage and have been reported to play a protective role in inflammation-related diseases. Particularly, hydroxytyrosol and oleuropein are the most abundant and more extensively studied. Pre-senescent human lung (MRC5 and neonatal human dermal (NHDF fibroblasts were used as cellular model to evaluate the effect of chronic (4–6 weeks treatment with 1 μM hydroxytyrosol (HT or 10 μM oleuropein aglycone (OLE on senescence/inflammation markers. Both phenols were effective in reducing β-galactosidase-positive cell number and p16 protein expression. In addition, senescence/inflammation markers such as IL-6 and metalloprotease secretion, and Ciclooxigenase type 2 (COX-2 and α-smooth-actin levels were reduced by phenol treatments. In NHDF, COX-2 expression, Nuclear Factor κ-light-chain-enhancer of activated B cells (NFκB protein level and nuclear localization were augmented with culture senescence and decreased by OLE and HT treatment. Furthermore, the inflammatory effect of Tumor Necrosis Factor α (TNFα exposure was almost completely abolished in OLE- and HT-pre-treated NHDF. Thus, the modulation of the senescence-associated inflammatory phenotype might be an important mechanism underlying the beneficial effects of olive oil phenols.

  4. Suppressor of Overexpression of CO 1 Negatively Regulates Dark-Induced Leaf Degreening and Senescence by Directly Repressing Pheophytinase and Other Senescence-Associated Genes in Arabidopsis.

    Science.gov (United States)

    Chen, Junyi; Zhu, Xiaoyu; Ren, Jun; Qiu, Kai; Li, Zhongpeng; Xie, Zuokun; Gao, Jiong; Zhou, Xin; Kuai, Benke

    2017-03-01

    Although the biochemical pathway of chlorophyll (Chl) degradation has been largely elucidated, how Chl is rapidly yet coordinately degraded during leaf senescence remains elusive. Pheophytinase (PPH) is the enzyme for catalyzing the removal of the phytol group from pheophytin a , and PPH expression is significantly induced during leaf senescence. To elucidate the transcriptional regulation of PPH , we used a yeast ( Saccharomyces cerevisiae ) one-hybrid system to screen for its trans-regulators. SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1), a key flowering pathway integrator, was initially identified as one of the putative trans-regulators of PPH After dark treatment, leaves of an SOC1 knockdown mutant ( soc1-6 ) showed an accelerated yellowing phenotype, whereas those of SOC1 -overexpressing lines exhibited a partial stay-green phenotype. SOC1 and PPH expression showed a negative correlation during leaf senescence. Substantially, SOC1 protein could bind specifically to the CArG box of the PPH promoter in vitro and in vivo, and overexpression of SOC1 significantly inhibited the transcriptional activity of the PPH promoter in Arabidopsis ( Arabidopsis thaliana ) protoplasts. Importantly, soc1-6 pph-1 (a PPH knockout mutant) double mutant displayed a stay-green phenotype similar to that of pph-1 during dark treatment. These results demonstrated that SOC1 inhibits Chl degradation via negatively regulating PPH expression. In addition, measurement of the Chl content and the maximum photochemical efficiency of photosystem II of soc1-6 and SOC1-OE leaves after dark treatment suggested that SOC1 also negatively regulates the general senescence process. Seven SENESCENCE-ASSOCIATED GENES ( SAGs ) were thereafter identified as its potential target genes, and NONYELLOWING1 and SAG113 were experimentally confirmed. Together, we reveal that SOC1 represses dark-induced leaf Chl degradation and senescence in general in Arabidopsis. © 2017 American Society of Plant Biologists. All

  5. The matricellular protein TSP1 promotes human and mouse endothelial cell senescence through CD47 and Nox1.

    Science.gov (United States)

    Meijles, Daniel N; Sahoo, Sanghamitra; Al Ghouleh, Imad; Amaral, Jefferson H; Bienes-Martinez, Raquel; Knupp, Heather E; Attaran, Shireen; Sembrat, John C; Nouraie, Seyed M; Rojas, Mauricio M; Novelli, Enrico M; Gladwin, Mark T; Isenberg, Jeffrey S; Cifuentes-Pagano, Eugenia; Pagano, Patrick J

    2017-10-17

    Senescent cells withdraw from the cell cycle and do not proliferate. The prevalence of senescent compared to normally functioning parenchymal cells increases with age, impairing tissue and organ homeostasis. A contentious principle governing this process has been the redox theory of aging. We linked matricellular protein thrombospondin 1 (TSP1) and its receptor CD47 to the activation of NADPH oxidase 1 (Nox1), but not of the other closely related Nox isoforms, and associated oxidative stress, and to senescence in human cells and aged tissue. In human endothelial cells, TSP1 promoted senescence and attenuated cell cycle progression and proliferation. At the molecular level, TSP1 increased Nox1-dependent generation of reactive oxygen species (ROS), leading to the increased abundance of the transcription factor p53. p53 mediated a DNA damage response that led to senescence through Rb and p21 cip , both of which inhibit cell cycle progression. Nox1 inhibition blocked the ability of TSP1 to increase p53 nuclear localization and p21 cip abundance and its ability to promote senescence. Mice lacking TSP1 showed decreases in ROS production, p21 cip expression, p53 activity, and aging-induced senescence. Conversely, lung tissue from aging humans displayed increases in the abundance of vascular TSP1, Nox1, p53, and p21 cip Finally, genetic ablation or pharmacological blockade of Nox1 in human endothelial cells attenuated TSP1-mediated ROS generation, restored cell cycle progression, and protected against senescence. Together, our results provide insights into the functional interplay between TSP1 and Nox1 in the regulation of endothelial senescence and suggest potential targets for controlling the aging process at the molecular level. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  6. Knockdown of IL-8 Provoked Premature Senescence of Placenta-Derived Mesenchymal Stem Cells.

    Science.gov (United States)

    Li, Juan-Juan; Ma, Feng-Xia; Wang, You-Wei; Chen, Fang; Lu, Shi-Hong; Chi, Ying; Du, Wen-Jing; Song, Bao-Quan; Hu, Liang-Ding; Chen, Hu; Han, Zhong-Chao

    2017-06-15

    Mesenchymal stem cells (MSCs) have shown promise for use in cell therapy, and due to their tumor tropism can serve as vehicles for delivering therapeutic agents to tumor sites. Because interleukin-8 (IL-8) is known to mediate the protumor effect of MSCs, elimination of IL-8 secretion by MSCs may enhance their safety for use in cancer gene therapy. However, little is known concerning the effect of endogenously secreted IL-8 on MSCs. We performed studies using placenta-derived MSCs (PMSCs) to determine whether knockdown of IL-8 would influence their biological activity. We first verified that IL-8 and its membrane receptor CXCR2, but not CXCR1, were highly expressed in PMSCs. We then employed lentivirus-mediated small hairpin RNA interference to generate stable IL-8-silenced PMSCs, which displayed a variety of characteristic senescent phenotypes. We observed that at day 9 post-transfection, IL-8-silenced PMSCs had become larger and displayed a more flattened appearance when compared with their controls. Moreover, their proliferation, colony forming unit-fibroblast formation, adipogenic and osteogenic differentiation, and immunosuppressive potentials were significantly impaired. Enhanced senescence-associated β-galactosidase (SA-β-gal) activity and specific global gene expression profiles confirmed that IL-8 silencing evoked the senescence process in PMSCs. Increased levels of p-Akt and decreased levels of FOXO3a protein expression suggested that reactive oxygen species played a role in the initiation and maintenance of senescence in IL-8-silenced PMSCs. Notably, the majority of CXCR2 ligands were downregulated in presenescent IL-8-silenced PMSCs but upregulated in senescent cells, indicating an antagonistic pleiotropy of the IL-8/CXCR2 signaling pathway in PMSCs. This effect may promote the proliferation of young cells and accelerate senescence of old cells.

  7. The different fates of mitochondria and chloroplasts during dark-induced senescence in Arabidopsis leaves.

    Science.gov (United States)

    Keech, Olivier; Pesquet, Edouard; Ahad, Abdul; Askne, Anna; Nordvall, Dag; Vodnala, Sharvani Munender; Tuominen, Hannele; Hurry, Vaughan; Dizengremel, Pierre; Gardeström, Per

    2007-12-01

    Senescence is an active process allowing the reallocation of valuable nutrients from the senescing organ towards storage and/or growing tissues. Using Arabidopsis thaliana leaves from both whole darkened plants (DPs) and individually darkened leaves (IDLs), we investigated the fate of mitochondria and chloroplasts during dark-induced leaf senescence. Combining in vivo visualization of fates of the two organelles by three-dimensional reconstructions of abaxial parts of leaves with functional measurements of photosynthesis and respiration, we showed that the two experimental systems displayed major differences during 6 d of dark treatment. In whole DPs, organelles were largely retained in both epidermal and mesophyll cells. However, while the photosynthetic capacity was maintained, the capacity of mitochondrial respiration decreased. In contrast, IDLs showed a rapid decline in photosynthetic capacity while maintaining a high capacity for mitochondrial respiration throughout the treatment. In addition, we noticed an unequal degradation of organelles in the different cell types of the senescing leaf. From these data, we suggest that metabolism in leaves of the whole DPs enters a 'stand-by mode' to preserve the photosynthetic machinery for as long as possible. However, in IDLs, mitochondria actively provide energy and carbon skeletons for the degradation of cell constituents, facilitating the retrieval of nutrients. Finally, the heterogeneity of the degradation processes involved during senescence is discussed with regard to the fate of mitochondria and chloroplasts in the different cell types.

  8. Quantitative identification of senescent cells in aging and disease.

    Science.gov (United States)

    Biran, Anat; Zada, Lior; Abou Karam, Paula; Vadai, Ezra; Roitman, Lior; Ovadya, Yossi; Porat, Ziv; Krizhanovsky, Valery

    2017-08-01

    Senescent cells are present in premalignant lesions and sites of tissue damage and accumulate in tissues with age. In vivo identification, quantification and characterization of senescent cells are challenging tasks that limit our understanding of the role of senescent cells in diseases and aging. Here, we present a new way to precisely quantify and identify senescent cells in tissues on a single-cell basis. The method combines a senescence-associated beta-galactosidase assay with staining of molecular markers for cellular senescence and of cellular identity. By utilizing technology that combines flow cytometry with high-content image analysis, we were able to quantify senescent cells in tumors, fibrotic tissues, and tissues of aged mice. Our approach also yielded the finding that senescent cells in tissues of aged mice are larger than nonsenescent cells. Thus, this method provides a basis for quantitative assessment of senescent cells and it offers proof of principle for combination of different markers of senescence. It paves the way for screening of senescent cells for identification of new senescence biomarkers, genes that bypass senescence or senolytic compounds that eliminate senescent cells, thus enabling a deeper understanding of the senescent state in vivo. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  9. Transcriptional analyses of natural leaf senescence in maize.

    Directory of Open Access Journals (Sweden)

    Wei Yang Zhang

    Full Text Available Leaf senescence is an important biological process that contributes to grain yield in crops. To study the molecular mechanisms underlying natural leaf senescence, we harvested three different developmental ear leaves of maize, mature leaves (ML, early senescent leaves (ESL, and later senescent leaves (LSL, and analyzed transcriptional changes using RNA-sequencing. Three sets of data, ESL vs. ML, LSL vs. ML, and LSL vs. ESL, were compared, respectively. In total, 4,552 genes were identified as differentially expressed. Functional classification placed these genes into 18 categories including protein metabolism, transporters, and signal transduction. At the early stage of leaf senescence, genes involved in aromatic amino acids (AAAs biosynthetic process and transport, cellular polysaccharide biosynthetic process, and the cell wall macromolecule catabolic process, were up-regulated. Whereas, genes involved in amino acid metabolism, transport, apoptosis, and response to stimulus were up-regulated at the late stage of leaf senescence. Further analyses reveals that the transport-related genes at the early stage of leaf senescence potentially take part in enzyme and amino acid transport and the genes upregulated at the late stage are involved in sugar transport, indicating nutrient recycling mainly takes place at the late stage of leaf senescence. Comparison between the data of natural leaf senescence in this study and previously reported data for Arabidopsis implies that the mechanisms of leaf senescence in maize are basically similar to those in Arabidopsis. A comparison of natural and induced leaf senescence in maize was performed. Athough many basic biological processes involved in senescence occur in both types of leaf senescence, 78.07% of differentially expressed genes in natural leaf senescence were not identifiable in induced leaf senescence, suggesting that differences in gene regulatory network may exist between these two leaf senescence

  10. Senescence from glioma stem cell differentiation promotes tumor growth

    International Nuclear Information System (INIS)

    Ouchi, Rie; Okabe, Sachiko; Migita, Toshiro; Nakano, Ichiro; Seimiya, Hiroyuki

    2016-01-01

    Glioblastoma (GBM) is a lethal brain tumor composed of heterogeneous cellular populations including glioma stem cells (GSCs) and differentiated non-stem glioma cells (NSGCs). While GSCs are involved in tumor initiation and propagation, NSGCs' role remains elusive. Here, we demonstrate that NSGCs undergo senescence and secrete pro-angiogenic proteins, boosting the GSC-derived tumor formation in vivo. We used a GSC model that maintains stemness in neurospheres, but loses the stemness and differentiates into NSGCs upon serum stimulation. These NSGCs downregulated telomerase, shortened telomeres, and eventually became senescent. The senescent NSGCs released pro-angiogenic proteins, including vascular endothelial growth factors and senescence-associated interleukins, such as IL-6 and IL-8. Conditioned medium from senescent NSGCs promoted proliferation of brain microvascular endothelial cells, and mixed implantation of GSCs and senescent NSGCs into mice enhanced the tumorigenic potential of GSCs. The senescent NSGCs seem to be clinically relevant, because both clinical samples and xenografts of GBM contained tumor cells that expressed the senescence markers. Our data suggest that senescent NSGCs promote malignant progression of GBM in part via paracrine effects of the secreted proteins. - Highlights: • Non-stem glioma cells (NSGCs) lose telomerase and eventually become senescent. • Senescent NSGCs secrete pro-angiogenic proteins, such as VEGFs, IL-6, and IL-8. • Senescent NSGCs enhance the growth of brain microvascular endothelial cells. • Senescent NSGCs enhance the tumorigenic potential of glioma stem cells in vivo.

  11. Senescence from glioma stem cell differentiation promotes tumor growth

    Energy Technology Data Exchange (ETDEWEB)

    Ouchi, Rie [Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Laboratory of Molecular Target Therapy of Cancer, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Okabe, Sachiko; Migita, Toshiro [Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Nakano, Ichiro [Department of Neurosurgery, Comprehensive Cancer Center, University of Alabama at Birmingham, 1824 6th Avenue South, Birmingham, AL 35233 (United States); Seimiya, Hiroyuki, E-mail: hseimiya@jfcr.or.jp [Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Laboratory of Molecular Target Therapy of Cancer, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan)

    2016-02-05

    Glioblastoma (GBM) is a lethal brain tumor composed of heterogeneous cellular populations including glioma stem cells (GSCs) and differentiated non-stem glioma cells (NSGCs). While GSCs are involved in tumor initiation and propagation, NSGCs' role remains elusive. Here, we demonstrate that NSGCs undergo senescence and secrete pro-angiogenic proteins, boosting the GSC-derived tumor formation in vivo. We used a GSC model that maintains stemness in neurospheres, but loses the stemness and differentiates into NSGCs upon serum stimulation. These NSGCs downregulated telomerase, shortened telomeres, and eventually became senescent. The senescent NSGCs released pro-angiogenic proteins, including vascular endothelial growth factors and senescence-associated interleukins, such as IL-6 and IL-8. Conditioned medium from senescent NSGCs promoted proliferation of brain microvascular endothelial cells, and mixed implantation of GSCs and senescent NSGCs into mice enhanced the tumorigenic potential of GSCs. The senescent NSGCs seem to be clinically relevant, because both clinical samples and xenografts of GBM contained tumor cells that expressed the senescence markers. Our data suggest that senescent NSGCs promote malignant progression of GBM in part via paracrine effects of the secreted proteins. - Highlights: • Non-stem glioma cells (NSGCs) lose telomerase and eventually become senescent. • Senescent NSGCs secrete pro-angiogenic proteins, such as VEGFs, IL-6, and IL-8. • Senescent NSGCs enhance the growth of brain microvascular endothelial cells. • Senescent NSGCs enhance the tumorigenic potential of glioma stem cells in vivo.

  12. CIRCADIAN CLOCK-ASSOCIATED 1 Inhibits Leaf Senescence in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Yi Song

    2018-03-01

    Full Text Available Leaf senescence is an integral part of plant development, and the timing and progressing rate of senescence could substantially affect the yield and quality of crops. It has been known that a circadian rhythm synchronized with external environmental cues is critical for the optimal coordination of various physiological and metabolic processes. However, the reciprocal interactions between the circadian clock and leaf senescence in plants remain unknown. Here, through measuring the physiological and molecular senescence related markers of several circadian components mutants, we found that CIRCADIAN CLOCK-ASSOCIATED 1 inhibits leaf senescence. Further molecular and genetic studies revealed that CCA1 directly activates GLK2 and suppresses ORE1 expression to counteract leaf senescence. As plants age, the expression and periodic amplitude of CCA1 declines and thus weakens the inhibition of senescence. Our findings reveal an age-dependent circadian clock component of the process of leaf senescence.

  13. In vitro senescence of immune cells.

    Science.gov (United States)

    Effros, Rita B; Dagarag, Mirabelle; Valenzuela, Hector F

    2003-01-01

    Immune cells are eminently suitable model systems in which to address the possible role of replicative senescence during in vivo aging. Since there are more than 10(8) unique antigen specificities present within the total T lymphocyte population of each individual, the immune response to any single antigen requires massive clonal expansion of the small proportion of T cells whose receptors recognize that antigen. The Hayflick Limit may, therefore, constitute a barrier to effective immune function, at least for those T cells that encounter their specific antigen more than once over the life course. Application of the fibroblast replicative senescence model to the so-called cytotoxic or CD8 T cell, the class of T cells that controls viral infection and cancer, has revealed certain features in common with other cell types as well as several characteristics that are unique to T cells. One senescence-associated change that is T cell-specific is the complete loss of expression of the activation signaling surface molecule, CD28, an alteration that enabled the documentation of high proportions of senescent T cells in vivo. The T cell model has also provided the unique opportunity to analyze telomere dynamics in a cell type that has the ability to upregulate telomerase yet nevertheless undergoes senescence. The intimate involvement of the immune system in the control of pathogens and cancer as well as in modulation of bone homeostasis suggests that more extensive analysis of the full range of characteristics of senescent T cells may help elucidate a broad spectrum of age-associated physiological changes.

  14. Drying without senescence in resurrection plants

    Science.gov (United States)

    Griffiths, Cara A.; Gaff, Donald F.; Neale, Alan D.

    2014-01-01

    Research into extreme drought tolerance in resurrection plants using species such as Craterostigma plantagineum, C. wilmsii, Xerophyta humilis, Tortula ruralis, and Sporobolus stapfianus has provided some insight into the desiccation tolerance mechanisms utilized by these plants to allow them to persist under extremely adverse environmental conditions. Some of the mechanisms used to ensure cellular preservation during severe dehydration appear to be peculiar to resurrection plants. Apart from the ability to preserve vital cellular components during drying and rehydration, such mechanisms include the ability to down-regulate growth-related metabolism rapidly in response to changes in water availability, and the ability to inhibit dehydration-induced senescence programs enabling reconstitution of photosynthetic capacity quickly following a rainfall event. Extensive research on the molecular mechanism of leaf senescence in non-resurrection plants has revealed a multi-layered regulatory network operates to control programed cell death pathways. However, very little is known about the molecular mechanisms that resurrection plants employ to avoid undergoing drought-related senescence during the desiccation process. To survive desiccation, dehydration in the perennial resurrection grass S. stapfianus must proceed slowly over a period of 7 days or more. Leaves detached from the plant before 60% relative water content (RWC) is attained are desiccation-sensitive indicating that desiccation tolerance is conferred in vegetative tissue of S. stapfianus when the leaf RWC has declined to 60%. Whilst some older leaves remaining attached to the plant during dehydration will senesce, suggesting dehydration-induced senescence may be influenced by leaf age or the rate of dehydration in individual leaves, the majority of leaves do not senesce. Rather these leaves dehydrate to air-dryness and revive fully following rehydration. Hence it seems likely that there are genes expressed in

  15. Emerging roles of lncRNAs in senescence

    DEFF Research Database (Denmark)

    Montes Resano, Marta; Lund, Anders H

    2016-01-01

    Cellular senescence is a complex stress response that leads to an irreversible state of cell growth arrest. Senescence may be induced by different stimuli such as telomere shortening, DNA damage or oncogenic insult among others. Senescent cells are metabolically highly active producing a wealth...

  16. Senescence rates in patients with end-stage renal disease

    DEFF Research Database (Denmark)

    Koopman, J J E; Rozing, M P; Kramer, Ada

    2011-01-01

    function of the Gompertz equation as a superior descriptor of senescence rate. Here, we tested both measures of the rate of senescence in a population of patients with end-stage renal disease. It is clinical dogma that patients on dialysis experience accelerated senescence, whereas those with a functional...

  17. A stochastic step model of replicative senescence explains ROS production rate in ageing cell populations.

    Directory of Open Access Journals (Sweden)

    Conor Lawless

    Full Text Available Increases in cellular Reactive Oxygen Species (ROS concentration with age have been observed repeatedly in mammalian tissues. Concomitant increases in the proportion of replicatively senescent cells in ageing mammalian tissues have also been observed. Populations of mitotic human fibroblasts cultured in vitro, undergoing transition from proliferation competence to replicative senescence are useful models of ageing human tissues. Similar exponential increases in ROS with age have been observed in this model system. Tracking individual cells in dividing populations is difficult, and so the vast majority of observations have been cross-sectional, at the population level, rather than longitudinal observations of individual cells.One possible explanation for these observations is an exponential increase in ROS in individual fibroblasts with time (e.g. resulting from a vicious cycle between cellular ROS and damage. However, we demonstrate an alternative, simple hypothesis, equally consistent with these observations which does not depend on any gradual increase in ROS concentration: the Stochastic Step Model of Replicative Senescence (SSMRS. We also demonstrate that, consistent with the SSMRS, neither proliferation-competent human fibroblasts of any age, nor populations of hTERT overexpressing human fibroblasts passaged beyond the Hayflick limit, display high ROS concentrations. We conclude that longitudinal studies of single cells and their lineages are now required for testing hypotheses about roles and mechanisms of ROS increase during replicative senescence.

  18. A stochastic step model of replicative senescence explains ROS production rate in ageing cell populations.

    Science.gov (United States)

    Lawless, Conor; Jurk, Diana; Gillespie, Colin S; Shanley, Daryl; Saretzki, Gabriele; von Zglinicki, Thomas; Passos, João F

    2012-01-01

    Increases in cellular Reactive Oxygen Species (ROS) concentration with age have been observed repeatedly in mammalian tissues. Concomitant increases in the proportion of replicatively senescent cells in ageing mammalian tissues have also been observed. Populations of mitotic human fibroblasts cultured in vitro, undergoing transition from proliferation competence to replicative senescence are useful models of ageing human tissues. Similar exponential increases in ROS with age have been observed in this model system. Tracking individual cells in dividing populations is difficult, and so the vast majority of observations have been cross-sectional, at the population level, rather than longitudinal observations of individual cells.One possible explanation for these observations is an exponential increase in ROS in individual fibroblasts with time (e.g. resulting from a vicious cycle between cellular ROS and damage). However, we demonstrate an alternative, simple hypothesis, equally consistent with these observations which does not depend on any gradual increase in ROS concentration: the Stochastic Step Model of Replicative Senescence (SSMRS). We also demonstrate that, consistent with the SSMRS, neither proliferation-competent human fibroblasts of any age, nor populations of hTERT overexpressing human fibroblasts passaged beyond the Hayflick limit, display high ROS concentrations. We conclude that longitudinal studies of single cells and their lineages are now required for testing hypotheses about roles and mechanisms of ROS increase during replicative senescence.

  19. Senescence and the pro-tumorigenic stroma.

    Science.gov (United States)

    Alspach, Elise; Fu, Yujie; Stewart, Sheila A

    2013-01-01

    Hayflick and Moorhead first described senescence in the late 1960's as a permanent growth arrest that primary cells underwent after a defined number of cellular divisions in culture. This observation gave rise to the hypothesis that cells contained an internal counting mechanism that limited cellular division and that this limit was an important barrier to cellular transformation. What began as an in vitro observation has led to an immense body of work that reaches into all fields of biology and is of particular interest in the areas of aging, tissue regeneration, and tumorigenesis. The initially simplistic view that senescence limits cellular division and contributes to aging while stymying tumorigenesis has now evolved into an important and complex biological process that has numerous caveats and often opposing effects on tumorigenesis. In this review, we limit our discussion to the complex role senescence plays in tumorigenesis. Throughout the review we attempt to draw many parallels to other systems including the role senescent cells play in the tumor microenvironment and their significant molecular and phenotypic similarities to cancer associated fibroblasts (CAFs).

  20. biomedical challenges of human senescence: a review

    African Journals Online (AJOL)

    2002-12-12

    Dec 12, 2002 ... generation per mitochondrion. Understanding the role of cellular ageing in vivo is another major challenge for integrative study. The in vitro model of cell replicative senescence pioneered by. Sith and Pereira has elucidated the mechanisms limiting cell proliferation(30). Until recently the link between in.

  1. Sirtuins, Cell Senescence, and Vascular Aging.

    Science.gov (United States)

    Kida, Yujiro; Goligorsky, Michael S

    2016-05-01

    The sirtuins (SIRTs) constitute a class of proteins with nicotinamide adenine dinucleotide-dependent deacetylase or adenosine diphosphate-ribosyltransferase activity. Seven SIRT family members have been identified in mammals, from SIRT1, the best studied for its role in vascular aging, to SIRT7. SIRT1 and SIRT2 are localized in the nucleus and cytoplasm. SIRT3, SIRT4, and SIRT5 are mitochondrial, and SIRT6 and SIRT7 are nuclear. Extensive studies have clearly revealed that SIRT proteins regulate diverse cell functions and responses to stressors. Vascular aging involves the aging process (senescence) of endothelial and vascular smooth muscle cells. Two types of cell senescence have been identified: (1) replicative senescence with telomere attrition; and (2) stress-induced premature senescence without telomere involvement. Both types of senescence induce vascular cell growth arrest and loss of vascular homeostasis, and contribute to the initiation and progression of cardiovascular diseases. Previous mechanistic studies have revealed in detail that SIRT1, SIRT3, and SIRT6 show protective functions against vascular aging, and definite vascular function of other SIRTs is under investigation. Thus, direct SIRT modulation and nicotinamide adenine dinucleotide stimulation of SIRT are promising candidates for cardiovascular disease therapy. A small number of pilot studies have been conducted to assess SIRT modulation in humans. These clinical studies have not yet provided convincing evidence that SIRT proteins alleviate morbidity and mortality in patients with cardiovascular diseases. The outcomes of multiple ongoing clinical trials are awaited to define the efficacy of SIRT modulators and SIRT activators in cardiovascular diseases, along with the potential adverse effects of chronic SIRT modulation. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  2. Molecular bases of cellular senescence: Hayflick phenomenon 50 years later

    Directory of Open Access Journals (Sweden)

    Patrycja Sosińska

    2016-03-01

    Full Text Available Normal human somatic cells have strictly limited proliferative capacity and reach a state of senescence when it becomes exhausted. It is believed that senescence is a response to extensive and irreparable DNA injury, localized in telomeric and/or non-telomeric regions of the genome. Main cause of this damage is oxidative stress, increasing due to deteriorated function of mitochondria. Senescent cells accumulate in tissues during aging, which is causatively linked with the development of various pathologies in elderly individuals, including cancer. This paper, prepared exactly 50 years after Leonard Hayflick’s discovery of the relationship between cellular senescence and organismal aging is aimed at presenting the current knowledge about molecular determinants of senescence, with particular emphasis paid to the role of oxidative stress, effectors of senescence at the level of cell cycle, markers of this phenomenon, and the effect of senescent cells on the development of certain age-related diseases.

  3. Functional displays

    International Nuclear Information System (INIS)

    Angelis De, F.; Haentjens, J.

    1995-01-01

    The Functional Displays are directly derived from the Man-Machine Design key document: Function-Based Task Analysis. The presentation defines and describes the goals-means structure of the plant function along with applicable control volumes and parameters of interest. The purpose of the subject is to show, through an example of a preliminary design, what the main parts of a function are. (3 figs.)

  4. Display hardware

    International Nuclear Information System (INIS)

    Myers, D.R.

    1983-01-01

    To appreciate the limitations and possibilities of computer graphics it is necessary to have some acquaintance with the available technology. The aim of this chapter is to mention briefly the different display types and their 'ball-park' price ranges. It must be stressed that prices change rapidly, and so those quoted here are only intended to give an idea of the cost at the time of writing.

  5. Inducers of Senescence, Toxic Compounds, and Senolytics: The Multiple Faces of Nrf2-Activating Phytochemicals in Cancer Adjuvant Therapy

    Directory of Open Access Journals (Sweden)

    Marco Malavolta

    2018-01-01

    Full Text Available The reactivation of senescence in cancer and the subsequent clearance of senescent cells are suggested as therapeutic intervention in the eradication of cancer. Several natural compounds that activate Nrf2 (nuclear factor erythroid-derived 2-related factor 2 pathway, which is involved in complex cytoprotective responses, have been paradoxically shown to induce cell death or senescence in cancer. Promoting the cytoprotective Nrf2 pathway may be desirable for chemoprevention, but it might be detrimental in later stages and advanced cancers. However, senolytic activity shown by some Nrf2-activating compounds could be used to target senescent cancer cells (particularly in aged immune-depressed organisms that escape immunosurveillance. We herein describe in vitro and in vivo effects of fifteen Nrf2-interacting natural compounds (tocotrienols, curcumin, epigallocatechin gallate, quercetin, genistein, resveratrol, silybin, phenethyl isothiocyanate, sulforaphane, triptolide, allicin, berberine, piperlongumine, fisetin, and phloretin on cellular senescence and discuss their use in adjuvant cancer therapy. In light of available literature, it can be concluded that the meaning and the potential of adjuvant therapy with natural compounds in humans remain unclear, also taking into account the existence of few clinical trials mostly characterized by uncertain results. Further studies are needed to investigate the therapeutic potential of those compounds that display senolytic activity.

  6. The effect of 648 nm diode laser irradiation on second messengers in senescent human keratinocytes

    Science.gov (United States)

    Hawkins Evans, D.; Abrahamse, H.

    2009-02-01

    Background/purpose: Stress induced premature senescence (SIPS) is defined as the long-term effect of subcytotoxic stress on proliferative cell types. Cells in SIPS display differences at the level of protein expression which affect energy metabolism, defense systems, redox potential, cell morphology and transduction pathways. This study aimed to determine the effect of laser irradiation on second messengers in senescent cells and to establish if that effect can be directly linked to changes in cellular function such as cell viability or proliferation. Materials and Methods: Human keratinocyte cell cultures were modified to induce premature senescence using repeated sub-lethal stresses of 200 uM H2O2 or 5% OH every day for four days with two days recovery. SIPS was confirmed by senescence-associated β-galactosidase staining. Control conditions included normal, repeated stress of 500 uM H2O2 to induce apoptosis and 200 uM PBN as an anti-oxidant or free radical scavenger. Cells were irradiated with 1.5 J/cm2 on day 1 and 4 using a 648 nm diode laser (3.3 mW/cm2) and cellular responses were measured 1 h post irradiation. The affect on second messengers was assessed by measuring cAMP, cGMP, nitric oxide and intracellular calcium (Ca2+) while functional changes were assessed using cell morphology, ATP cell viability, LDH membrane integrity and WST-1 cell proliferation. Results: Results indicate an increase in NO and a decrease in cGMP and Ca2+ in 200 uM H2O2 irradiated cells while PBN irradiated cells showed a decrease in cAMP and an increase in ATP viability and cell proliferation. Conclusion: Laser irradiation influences cell signaling which ultimately changes the biological function of senescent cells. If laser therapy can stimulate the biological function of senescent cells it may be beneficial to conditions such as immune senescence, skin ageing, muscle atrophy, premature ageing of arteries in patients with advanced heart disease, neurodegenerative disorders and

  7. Molecular genetic approaches to the study of cellular senescence.

    Science.gov (United States)

    Goletz, T J; Smith, J R; Pereira-Smith, O M

    1994-01-01

    Cellular senescence is an inability of cells to synthesize DNA and divide, which results in a terminal loss of proliferation despite the maintenance of basic metabolic processes. Senescence has been proposed as a model for the study of aging at the cellular level, and the basis for this model system and its features have been summarized. Although strong experimental evidence exists to support the hypothesis that cellular senescence is a dominant active process, the mechanisms responsible for this phenomenon remain a mystery. Investigators have taken several approaches to gain a better understanding of senescence. Several groups have documented the differences between young and senescent cells, and others have identified changes that occur during the course of a cell's in vitro life span. Using molecular and biochemical approaches, important changes in gene expression and function of cell-cycle-associated products have been identified. The active production of an inhibitor of DNA synthesis has been demonstrated. This may represent the final step in a cascade of events governing senescence. The study of immortal cells which have escaped senescence has also provided useful information, particularly with regard to the genes governing the senescence program. These studies have identified four complementation groups for indefinite division, which suggests that there are at least four genes or gene pathways in the senescence program. Through the use of microcell-mediated chromosome transfer, chromosomes encoding senescence genes have been identified; efforts to clone these genes are ongoing.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Growth Hormone Receptor Antagonist Transgenic Mice Have Increased Subcutaneous Adipose Tissue Mass, Altered Glucose Homeostasis and No Change in White Adipose Tissue Cellular Senescence.

    Science.gov (United States)

    Comisford, Ross; Lubbers, Ellen R; Householder, Lara A; Suer, Ozan; Tchkonia, Tamara; Kirkland, James L; List, Edward O; Kopchick, John J; Berryman, Darlene E

    2016-01-01

    Growth hormone (GH)-resistant/deficient mice experience improved glucose homeostasis and substantially increased lifespan. Recent evidence suggests that long-lived GH-resistant/deficient mice are protected from white adipose tissue (WAT) dysfunction, including WAT cellular senescence, impaired adipogenesis and loss of subcutaneous WAT in old age. This preservation of WAT function has been suggested to be a potential mechanism for the extended lifespan of these mice. The objective of this study was to examine WAT senescence, WAT distribution and glucose homeostasis in dwarf GH receptor antagonist (GHA) transgenic mice, a unique mouse strain having decreased GH action but normal longevity. 18-month-old female GHA mice and wild-type (WT) littermate controls were used. Prior to dissection, body composition, fasting blood glucose as well as glucose and insulin tolerance tests were performed. WAT distribution was determined by weighing four distinct WAT depots at the time of dissection. Cellular senescence in four WAT depots was assessed using senescence-associated β-galactosidase staining to quantify the senescent cell burden, and real-time qPCR to quantify gene expression of senescence markers p16 and IL-6. GHA mice had a 22% reduction in total body weight, a 33% reduction in lean mass and a 10% increase in body fat percentage compared to WT controls. GHA mice had normal fasting blood glucose and improved insulin sensitivity; however, they exhibited impaired glucose tolerance. Moreover, GHA mice displayed enhanced lipid storage in the inguinal subcutaneous WAT depot (p < 0.05) and a 1.7-fold increase in extra-/intraperitoneal WAT ratio compared to controls (p < 0.05). Measurements of WAT cellular senescence showed no difference between GHA mice and WT controls. Similar to other mice with decreased GH action, female GHA mice display reduced age-related lipid redistribution and improved insulin sensitivity, but no change in cellular senescence. The similar abundance of

  9. Growth hormone receptor antagonist (GHA) transgenic mice have increased subcutaneous adipose tissue mass, altered glucose homeostasis, and no change in white adipose tissue cellular senescence

    Science.gov (United States)

    Comisford, Ross; Lubbers, Ellen R.; Householder, Lara; Suer, Ozan; Tchkonia, Tamara; Kirkland, James L.; List, Edward O.; Kopchick, John J.; Berryman, Darlene E.

    2015-01-01

    Background Growth hormone (GH) resistant/deficient mice experience improved glucose homeostasis and substantially increased lifespan. Recent evidence suggests long-lived GH resistant/deficient mice are protected from white adipose tissue (WAT) dysfunction, including WAT cellular senescence, impaired adipogenesis and loss of subcutaneous WAT in old age. This preservation of WAT function has been suggested to be a potential mechanism for the extended lifespan of these mice. OBJECTIVE The objective of this study was to examine white adipose tissue (WAT) senescence, WAT distribution, and glucose homeostasis in dwarf growth hormone receptor antagonist (GHA) transgenic mice, a unique mouse strain having decreased GH action but normal longevity. METHODS 18mo old female GHA mice and wild type (WT) littermate controls were used. Prior to dissection, body composition, fasting blood glucose, and glucose and insulin tolerance tests were performed. WAT distribution was determined by weighing four distinct WAT depots at the time of dissection. Cellular senescence in four WAT depots was assessed using senescence-associated β-galactosidase (SA-β-gal) staining to quantify the senescent cell burden and real time qPCR to quantify gene expression of senescence markers p16 and IL-6. RESULTS GHA mice had a 22% reduction in total body weight, 33% reduction in lean mass, and a 10% increase in body fat percentage compared to WT controls. GHA mice had normal fasting blood glucose and improved insulin sensitivity; however, they exhibited impaired glucose tolerance. Moreover, GHA mice displayed enhanced lipid storage in the inguinal subcutaneous WAT depot (p<.05) and a 1.7 fold increase in extra-/intraperitoneal WAT ratio compared to controls (p<.05). Measurements of WAT cellular senescence showed no difference between GHA mice and WT controls. CONCLUSIONS Similar to other mice with decreased GH action, female GHA mice display reduced age-related lipid redistribution and improved insulin

  10. Markers of T Cell Senescence in Humans

    Directory of Open Access Journals (Sweden)

    Weili Xu

    2017-08-01

    Full Text Available Many countries are facing the aging of their population, and many more will face a similar obstacle in the near future, which could be a burden to many healthcare systems. Increased susceptibility to infections, cardiovascular and neurodegenerative disease, cancer as well as reduced efficacy of vaccination are important matters for researchers in the field of aging. As older adults show higher prevalence for a variety of diseases, this also implies higher risk of complications, including nosocomial infections, slower recovery and sequels that may reduce the autonomy and overall quality of life of older adults. The age-related effects on the immune system termed as “immunosenescence” can be exemplified by the reported hypo-responsiveness to influenza vaccination of the elderly. T cells, which belong to the adaptive arm of the immune system, have been extensively studied and the knowledge gathered enables a better understanding of how the immune system may be affected after acute/chronic infections and how this matters in the long run. In this review, we will focus on T cells and discuss the surface and molecular markers that are associated with T cell senescence. We will also look at the implications that senescent T cells could have on human health and diseases. Finally, we will discuss the benefits of having these markers for investigators and the future work that is needed to advance the field of T cell senescence markers.

  11. Functional loss of GABA transaminase (GABA-T expressed early leaf senescence under various stress conditions in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Syed Uzma Jalil

    2017-06-01

    Full Text Available GABA-transaminase (GABA-T involved in carbon and nitrogen metabolism during the plant development process via GABA shunt and GABA-T mutant, which is defective in GABA catabolism, is ideal model to examine the role of GABA-T in plant development and leaf senescence of plant. We have characterized GABA transaminase knock out mutant pop2-1 that is transition and pop2-3 which is T-DNA insertion mutant of Arabidopsis thaliana during various stress conditions.The GABA-T knockout mutant plants displayed precocious leaf senescence, which was accompanied by the assays of physiological parameters of leaf senescence during various stress conditions. Furthermore, our physiological evidence indicates that pop2-1 and pop2-3 mutations rapidly decreased the efficiency of leaf photosynthesis, chlorophyll content, GABA content, GABA-T, and glutamate decarboxylase (GAD activity and on the other hand increases membrane ion leakage, malondialdehyde (MDA level in stress induced leaves. However, cell viability assay by trypan blue and insitu Hydrogen peroxidation assay by 3,3-diaminobenzidine (DAB in stress induced leaves also display that pop2-1 and pop2-3 mutant leaves show oversensitivity in response to different stress conditions as compared to wild type. These results strongly indicate that the loss-of-function of GABA transaminase gene induces early leaf senescence in Arabidopsis thaliana during various stress conditions.

  12. Downregulation of Melanoma Cell Adhesion Molecule (MCAM/CD146) Accelerates Cellular Senescence in Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells.

    Science.gov (United States)

    Jin, Hye Jin; Kwon, Ji Hye; Kim, Miyeon; Bae, Yun Kyung; Choi, Soo Jin; Oh, Wonil; Yang, Yoon Sun; Jeon, Hong Bae

    2016-04-01

    Therapeutic applications of mesenchymal stem cells (MSCs) for treating various diseases have increased in recent years. To ensure that treatment is effective, an adequate MSC dosage should be determined before these cells are used for therapeutic purposes. To obtain a sufficient number of cells for therapeutic applications, MSCs must be expanded in long-term cell culture, which inevitably triggers cellular senescence. In this study, we investigated the surface markers of human umbilical cord blood-derived MSCs (hUCB-MSCs) associated with cellular senescence using fluorescence-activated cell sorting analysis and 242 cell surface-marker antibodies. Among these surface proteins, we selected the melanoma cell adhesion molecule (MCAM/CD146) for further study with the aim of validating observed expression differences and investigating the associated implications in hUCB-MSCs during cellular senescence. We observed that CD146 expression markedly decreased in hUCB-MSCs following prolonged in vitro expansion. Using preparative sorting, we found that hUCB-MSCs with high CD146 expression displayed high growth rates, multilineage differentiation, expression of stemness markers, and telomerase activity, as well as significantly lower expression of the senescence markers p16, p21, p53, and senescence-associated β-galactosidase, compared with that observed in hUCB-MSCs with low-level CD146 expression. In contrast, CD146 downregulation with small interfering RNAs enhanced the senescence phenotype. In addition, CD146 suppression in hUCB-MSCs caused downregulation of other cellular senescence regulators, including Bmi-1, Id1, and Twist1. Collectively, our results suggest that CD146 regulates cellular senescence; thus, it could be used as a therapeutic marker to identify senescent hUCB-MSCs. One of the fundamental requirements for mesenchymal stem cell (MSC)-based therapies is the expansion of MSCs during long-term culture because a sufficient number of functional cells is required

  13. Leaf senescence and nutrient remobilisation in barley and wheat

    DEFF Research Database (Denmark)

    Gregersen, P L; Holm, P B; Krupinska, K

    2008-01-01

    Extensive studies have been undertaken on senescence processes in barley and wheat and their importance for the nitrogen use efficiency of these crop plants. During the senescence processes, proteins are degraded and nutrients are re-mobilised from senescing leaves to other organs, especially...... of chloroplasts is summarised. Rubisco is thought to be released from chloroplasts into vesicles containing stroma material (RCB = Rubisco-containing bodies). These vesicles may then take different routes for their degradation. Transcriptome analyses on barley and wheat senescence have identified genes involved...... in degradative, metabolic and regulatory processes that could be used in future strategies aimed at modifying the senescence process. The breeding of crops for characters related to senescence processes, e.g. higher yields and better nutrient use efficiency, is complex. Such breeding has to cope with the dilemma...

  14. Cellular Senescence in Postmitotic Cells: Beyond Growth Arrest.

    Science.gov (United States)

    Sapieha, Przemyslaw; Mallette, Frédérick A

    2018-04-25

    In mitotic cells, cellular senescence is a permanent state of G1 arrest, that may have evolved in parallel to apoptosis, to limit proliferation of damaged cells and oncogenesis. Recent studies have suggested that postmitotic cells are also capable of entering a state of senescence, although the repercussions of postmitotic cellular senescence (PoMiCS) on tissue health and function are currently ill-defined. In tissues made largely of post-mitotic cells, it is evolutionary advantageous to preserve cellular integrity and cellular senescence of post-mitotic cells may prevent stressor-induced tissue degeneration and promote tissue repair. Paradoxically, PoMiCS may also contribute to disease progression through the generation of inflammatory mediators, termed the senescence-associated secretory phenotype. Here, we discuss the potential roles of PoMiCS and propose to enlarge the current definition of cellular senescence to postmitotic terminally differentiated cells. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. The WRKY transcription factor family and senescence in switchgrass.

    Science.gov (United States)

    Rinerson, Charles I; Scully, Erin D; Palmer, Nathan A; Donze-Reiner, Teresa; Rabara, Roel C; Tripathi, Prateek; Shen, Qingxi J; Sattler, Scott E; Rohila, Jai S; Sarath, Gautam; Rushton, Paul J

    2015-11-09

    Early aerial senescence in switchgrass (Panicum virgatum) can significantly limit biomass yields. WRKY transcription factors that can regulate senescence could be used to reprogram senescence and enhance biomass yields. All potential WRKY genes present in the version 1.0 of the switchgrass genome were identified and curated using manual and bioinformatic methods. Expression profiles of WRKY genes in switchgrass flag leaf RNA-Seq datasets were analyzed using clustering and network analyses tools to identify both WRKY and WRKY-associated gene co-expression networks during leaf development and senescence onset. We identified 240 switchgrass WRKY genes including members of the RW5 and RW6 families of resistance proteins. Weighted gene co-expression network analysis of the flag leaf transcriptomes across development readily separated clusters of co-expressed genes into thirteen modules. A visualization highlighted separation of modules associated with the early and senescence-onset phases of flag leaf growth. The senescence-associated module contained 3000 genes including 23 WRKYs. Putative promoter regions of senescence-associated WRKY genes contained several cis-element-like sequences suggestive of responsiveness to both senescence and stress signaling pathways. A phylogenetic comparison of senescence-associated WRKY genes from switchgrass flag leaf with senescence-associated WRKY genes from other plants revealed notable hotspots in Group I, IIb, and IIe of the phylogenetic tree. We have identified and named 240 WRKY genes in the switchgrass genome. Twenty three of these genes show elevated mRNA levels during the onset of flag leaf senescence. Eleven of the WRKY genes were found in hotspots of related senescence-associated genes from multiple species and thus represent promising targets for future switchgrass genetic improvement. Overall, individual WRKY gene expression profiles could be readily linked to developmental stages of flag leaves.

  16. The evolution of senescence in the tree of life

    DEFF Research Database (Denmark)

    Salguero-Gómez, Roberto

    The existing theories on the evolution of senescence assume that senescence is inevitable in all organisms. However, recent studies have shown that this is not necessarily true. A better understanding of senescence and its underlying mechanisms could have far-reaching consequences for conservation...... and eco-evolutionary research. This book is the first to offer interdisciplinary perspectives on the evolution of senescence in many species, setting the stage for further developments. It brings together new insights from a wide range of scientific fields and cutting-edge research done on a multitude...

  17. Senescent intervertebral disc cells exhibit perturbed matrix homeostasis phenotype.

    Science.gov (United States)

    Ngo, Kevin; Patil, Prashanti; McGowan, Sara J; Niedernhofer, Laura J; Robbins, Paul D; Kang, James; Sowa, Gwendolyn; Vo, Nam

    2017-09-01

    Aging greatly increases the risk for intervertebral disc degeneration (IDD) as a result of proteoglycan loss due to reduced synthesis and enhanced degradation of the disc matrix proteoglycan (PG). How disc matrix PG homeostasis becomes perturbed with age is not known. The goal of this study is to determine whether cellular senescence is a source of this perturbation. We demonstrated that disc cellular senescence is dramatically increased in the DNA repair-deficient Ercc1 -/Δ mouse model of human progeria. In these accelerated aging mice, increased disc cellular senescence is closely associated with the rapid loss of disc PG. We also directly examine PG homeostasis in oxidative damage-induced senescent human cells using an in vitro cell culture model system. Senescence of human disc cells treated with hydrogen peroxide was confirmed by growth arrest, senescence-associated β-galactosidase activity, γH2AX foci, and acquisition of senescence-associated secretory phenotype. Senescent human disc cells also exhibited perturbed matrix PG homeostasis as evidenced by their decreased capacity to synthesize new matrix PG and enhanced degradation of aggrecan, a major matrix PG. of the disc. Our in vivo and in vitro findings altogether suggest that disc cellular senescence is an important driver of PG matrix homeostatic perturbation and PG loss. Published by Elsevier B.V.

  18. Early nodule senescence is activated in symbiotic mutants of pea (Pisum sativum L.) forming ineffective nodules blocked at different nodule developmental stages.

    Science.gov (United States)

    Serova, Tatiana A; Tsyganova, Anna V; Tsyganov, Viktor E

    2018-04-03

    Plant symbiotic mutants are useful tool to uncover the molecular-genetic mechanisms of nodule senescence. The pea (Pisum sativum L.) mutants SGEFix - -1 (sym40), SGEFix - -3 (sym26), and SGEFix - -7 (sym27) display an early nodule senescence phenotype, whereas the mutant SGEFix - -2 (sym33) does not show premature degradation of symbiotic structures, but its nodules show an enhanced immune response. The nodules of these mutants were compared with each other and with those of the wild-type SGE line using seven marker genes that are known to be activated during nodule senescence. In wild-type SGE nodules, transcript levels of all of the senescence-associated genes were highest at 6 weeks after inoculation (WAI). The senescence-associated genes showed higher transcript abundance in mutant nodules than in wild-type nodules at 2 WAI and attained maximum levels in the mutant nodules at 4 WAI. Immunolocalization analyses showed that the ethylene precursor 1-aminocyclopropane-1-carboxylate accumulated earlier in the mutant nodules than in wild-type nodules. Together, these results showed that nodule senescence was activated in ineffective nodules blocked at different developmental stages in pea lines that harbor mutations in four symbiotic genes.

  19. Senescence-Associated Molecular and Epigenetic Alterations in Mesenchymal Stem Cell Cultures from Amniotic Fluid of Normal and Fetus-Affected Pregnancy

    Directory of Open Access Journals (Sweden)

    Jūratė Savickienė

    2016-01-01

    Full Text Available Human amniotic-fluid-derived mesenchymal stem cells (AF-MSCs are interesting for their multilineage differentiation potential and wide range of therapeutic applications due to the ease of culture expansion. However, MSCs undergo replicative senescence. So far, the molecular mechanisms that underlie fetal diseases and cell senescence are still poorly understood. Here, we analyzed senescence-associated morphologic, molecular, and epigenetic characteristics during propagation of MSCs derived from AF of normal and fetus-affected pregnancy. AF-MSCs cultures from both cell sources displayed quite similar morphology and expression of specific cell surface (CD44, CD90, and CD105 and stemness (Oct4, Nanog, Sox2, and Rex1 markers but had interindividual variability in proliferation capability and time to reach senescence. Within passages 4 and 8, senescent cultures exhibited typical morphological features, senescence-associated β-galactosidase activity, increased levels of p16, and decreased levels of miR-17 and miR-21 but showed differential expression of p21, p53, and ATM dependently on the onset of cell senescence. These differences correlated with changes in the level of chromatin modifiers (DNMT1 and HDAC1 and polycomb group proteins (EZH2, SUZ12, and BMI1 paralleling with changes in the expression of repressive histone marks (H3K9me3 and H3K27me3 and stemness markers (Oct4, Nanog, Sox2, and Rex1. Therefore epigenetic factors are important for AF-MSCs senescence process that may be related with individuality of donor or a fetus malignancy status.

  20. Strigolactone Regulates Leaf Senescence in Concert with Ethylene in Arabidopsis.

    Science.gov (United States)

    Ueda, Hiroaki; Kusaba, Makoto

    2015-09-01

    Leaf senescence is not a passive degenerative process; it represents a process of nutrient relocation, in which materials are salvaged for growth at a later stage or to produce the next generation. Leaf senescence is regulated by various factors, such as darkness, stress, aging, and phytohormones. Strigolactone is a recently identified phytohormone, and it has multiple functions in plant development, including repression of branching. Although strigolactone is implicated in the regulation of leaf senescence, little is known about its molecular mechanism of action. In this study, strigolactone biosynthesis mutant strains of Arabidopsis (Arabidopsis thaliana) showed a delayed senescence phenotype during dark incubation. The strigolactone biosynthesis genes MORE AXIALLY GROWTH3 (MAX3) and MAX4 were drastically induced during dark incubation and treatment with the senescence-promoting phytohormone ethylene, suggesting that strigolactone is synthesized in the leaf during leaf senescence. This hypothesis was confirmed by a grafting experiment using max4 as the stock and Columbia-0 as the scion, in which the leaves from the Columbia-0 scion senesced earlier than max4 stock leaves. Dark incubation induced the synthesis of ethylene independent of strigolactone. Strigolactone biosynthesis mutants showed a delayed senescence phenotype during ethylene treatment in the light. Furthermore, leaf senescence was strongly accelerated by the application of strigolactone in the presence of ethylene and not by strigolactone alone. These observations suggest that strigolactone promotes leaf senescence by enhancing the action of ethylene. Thus, dark-induced senescence is regulated by a two-step mechanism: induction of ethylene synthesis and consequent induction of strigolactone synthesis in the leaf. © 2015 American Society of Plant Biologists. All Rights Reserved.

  1. Identification and characterization of PaMTH1, a putative O-methyltransferase accumulating during senescence of Podospora anserina cultures

    DEFF Research Database (Denmark)

    Averbeck, N B; Jensen, Ole Nørregaard; Mann, M

    2000-01-01

    A differential protein display screen resulted in the identification of a 27-kDa protein which strongly accumulates during the senescence of Podospora anserina cultures grown under standard conditions. After partial determination of the amino-acid sequence by mass-spectrometry analysis of trypsin...

  2. Polyamines, peroxidase and proteins involved in the senescence ...

    African Journals Online (AJOL)

    Senescence is the natural aging process at the cellular level or range of phenomena associated with this process. The objective of this review was to show the involvement of substances that may be related to senescence in plants, such as polyamines, peroxidase and proteins. These substances were related with the ...

  3. CLCA2 as a p53-Inducible Senescence Mediator

    Directory of Open Access Journals (Sweden)

    Chizu Tanikawa

    2012-02-01

    Full Text Available p53 is a tumor suppressor gene that is frequently mutated in multiple cancer tissues. Activated p53 protein regulates its downstream genes and subsequently inhibits malignant transformation by inducing cell cycle arrest, apoptosis, DNA repair, and senescence. However, genes involved in the p53-mediated senescence pathway are not yet fully elucidated. Through the screening of two genome-wide expression profile data sets, one for cells in which exogenous p53 was introduced and the other for senescent fibroblasts, we have identified chloride channel accessory 2 (CLCA2 as a p53-inducible senescence-associated gene. CLCA2 was remarkably induced by replicative senescence as well as oxidative stress in a p53-dependent manner. We also found that ectopically expressed CLCA2 induced cellular senescence, and the down-regulation of CLCA2 by small interfering RNA caused inhibition of oxidative stress-induced senescence. Interestingly, the reduced expression of CLCA2 was frequently observed in various kinds of cancers including prostate cancer, whereas its expression was not affected in precancerous prostatic intraepithelial neoplasia. Thus, our findings suggest a crucial role of p53/CLCA2-mediated senescence induction as a barrier for malignant transformation.

  4. Cellular and molecular aspects of quinoa leaf senescence.

    Science.gov (United States)

    López-Fernández, María Paula; Burrieza, Hernán Pablo; Rizzo, Axel Joel; Martínez-Tosar, Leandro Julián; Maldonado, Sara

    2015-09-01

    During leaf senescence, degradation of chloroplasts precede to changes in nuclei and other cytoplasmic organelles, RuBisCO stability is progressively lost, grana lose their structure, plastidial DNA becomes distorted and degraded, the number of plastoglobuli increases and abundant senescence-associated vesicles containing electronically dense particles emerge from chloroplasts pouring their content into the central vacuole. This study examines quinoa leaf tissues during development and senescence using a range of well-established markers of programmed cell death (PCD), including: morphological changes in nuclei and chloroplasts, degradation of RuBisCO, changes in chlorophyll content, DNA degradation, variations in ploidy levels, and changes in nuclease profiles. TUNEL reaction and DNA electrophoresis demonstrated that DNA fragmentation in nuclei occurs at early senescence, which correlates with induction of specific nucleases. During senescence, metabolic activity is high and nuclei endoreduplicate, peaking at 4C. At this time, TEM images showed some healthy nuclei with condensed chromatin and nucleoli. We have found that DNA fragmentation, induction of senescence-associated nucleases and endoreduplication take place during leaf senescence. This provides a starting point for further research aiming to identify key genes involved in the senescence of quinoa leaves. Published by Elsevier Ireland Ltd.

  5. Delay of Iris flower senescence by protease inhibitors

    NARCIS (Netherlands)

    Pak, C.; Doorn, van W.G.

    2005-01-01

    asterisk inside a circle sign Visible senescence of the flag tepals in Iris x hollandica (cv. Blue Magic) was preceded by a large increase in endoprotease activity. Just before visible senescence about half of total endoprotease activity was apparently due to cysteine proteases, somewhat less than

  6. Exercise Prevents Diet-Induced Cellular Senescence in Adipose Tissue

    NARCIS (Netherlands)

    Schafer, M.J.; White, T.A.; Evans, G.; Tonne, J.M.; Verzosa, G.C.; Stout, M.B.; Mazula, D.L.; Palmer, A.K.; Baker, D.J.; Jensen, M.D.; Torbenson, M.S.; Miller, J.D.; Ikeda, Y.; Tchkonia, T.; Deursen, J.M.A. van; Kirkland, J.L.; LeBrasseur, N.K.

    2016-01-01

    Considerable evidence implicates cellular senescence in the biology of aging and chronic disease. Diet and exercise are determinants of healthy aging; however, the extent to which they affect the behavior and accretion of senescent cells within distinct tissues is not clear. Here we tested the

  7. Life History Trade-Offs Modulate the Speed of Senescence

    DEFF Research Database (Denmark)

    Salguero-Gómez, Roberto; Jones, Owen

    2017-01-01

    that the speed of senescence varies dramatically across the Tree of Life and that it has a moderate phylogenetic signal when considering both plants and animals but that this signal is stronger in animals than in plants, indicating that the strength of selection on the trait may differ between kingdoms. We next...... examined the speed of senescence at two taxonomic levels: comparing kingdoms, with plants more likely to postpone senescence than animals, and, when the data allowed for it, comparing taxonomic classes, where we found that pine trees are particularly slow to senesce, followed by reptiles and sponges. Most...... puzzling and worthy of investigation in itself. We used two open-data repositories of high-quality demographic information for animals and plants to present a novel overview of the degree of variation in life-history strategies and their component life-history traits, including the speed of senescence...

  8. Senescence gives insights into the morphogenetic evolution of anamniotes

    Directory of Open Access Journals (Sweden)

    Éric Villiard

    2017-06-01

    Full Text Available Senescence represents a mechanism to avoid undesired cell proliferation that plays a role in tumor suppression, wound healing and embryonic development. In order to gain insight on the evolution of senescence, we looked at its presence in developing axolotls (urodele amphibians and in zebrafish (teleost fish, which are both anamniotes. Our data indicate that cellular senescence is present in various developing structures in axolotls (pronephros, olfactory epithelium of nerve fascicles, lateral organs, gums and in zebrafish (epithelium of the yolk sac and in the lower part of the gut. Senescence was particularly associated with transient structures (pronephros in axolotls and yolk sac in zebrafish suggesting that it may play a role in the elimination of these tissues. Our data supports the notion that cellular senescence evolved early in vertebrate evolution to influence embryonic development.

  9. Arabidopsis CPR5 is a senescence-regulatory gene with pleiotropic functions as predicted by the evolutionary theory of senescence

    NARCIS (Netherlands)

    Jing, Hai-Chun; Anderson, Lisa; Sturre, Marcel J. G.; Hille, Jacques; Dijkwel, Paul P.

    2007-01-01

    Arabidopsis CPR5 is a senescence-regulatory gene with pleiotropic functions as predicted by the evolutionary theory of senescence Hai-Chun Jing1,2, Lisa Anderson3, Marcel J.G. Sturre1, Jacques Hille1 and Paul P. Dijkwel1,* 1Molecular Biology of Plants, Groningen Biomolecular Sciences and

  10. Satellite cell senescence underlies myopathy in a mouse model of limb-girdle muscular dystrophy 2H

    Science.gov (United States)

    Kudryashova, Elena; Kramerova, Irina; Spencer, Melissa J.

    2012-01-01

    Mutations in the E3 ubiquitin ligase tripartite motif-containing 32 (TRIM32) are responsible for the disease limb-girdle muscular dystrophy 2H (LGMD2H). Previously, we generated Trim32 knockout mice (Trim32–/– mice) and showed that they display a myopathic phenotype accompanied by neurogenic features. Here, we used these mice to investigate the muscle-specific defects arising from the absence of TRIM32, which underlie the myopathic phenotype. Using 2 models of induced atrophy, we showed that TRIM32 is dispensable for muscle atrophy. Conversely, TRIM32 was necessary for muscle regrowth after atrophy. Furthermore, TRIM32-deficient primary myoblasts underwent premature senescence and impaired myogenesis due to accumulation of PIAS4, an E3 SUMO ligase and TRIM32 substrate that was previously shown to be associated with senescence. Premature senescence of myoblasts was also observed in vivo in an atrophy/regrowth model. Trim32–/– muscles had substantially fewer activated satellite cells, increased PIAS4 levels, and growth failure compared with wild-type muscles. Moreover, Trim32–/– muscles exhibited features of premature sarcopenia, such as selective type II fast fiber atrophy. These results imply that premature senescence of muscle satellite cells is an underlying pathogenic feature of LGMD2H and reveal what we believe to be a new mechanism of muscular dystrophy associated with reductions in available satellite cells and premature sarcopenia. PMID:22505452

  11. Use of Human Tissue to Assess the Oncogenic Activity of Melanoma-Associated Mutations

    OpenAIRE

    Chudnovsky, Yakov; Adams, Amy E.; Robbins, Paul B.; Lin, Qun; Khavari, Paul A.

    2005-01-01

    Multiple genetic alterations occur in melanoma, a lethal skin malignancy of increasing incidence1,2. These include mutations that activate Ras and two of its effector cascades, Raf and phosphoinositide 3-kinase (PI3K). Ras and Raf induction can occur via active N-Ras and B-Raf mutants as well as by gene amplification3–5. Activation of PI3K pathway components occurs by PTEN loss and by AKT amplification6–8. Melanomas also commonly display impairment of p16INK4A-CDK4-Rb and ARF-HDM2-p53 tumor s...

  12. Senescent mouse cells fail to overtly regulate the HIRA histone chaperone and do not form robust Senescence Associated Heterochromatin Foci

    Directory of Open Access Journals (Sweden)

    Enders Greg H

    2010-06-01

    Full Text Available Abstract Background Cellular senescence is a permanent growth arrest that occurs in response to cellular stressors, such as telomere shortening or activation of oncogenes. Although the process of senescence growth arrest is somewhat conserved between mouse and human cells, there are some critical differences in the molecular pathways of senescence between these two species. Recent studies in human fibroblasts have defined a cell signaling pathway that is initiated by repression of a specific Wnt ligand, Wnt2. This, in turn, activates a histone chaperone HIRA, and culminates in formation of specialized punctate domains of facultative heterochromatin, called Senescence-Associated Heterochromatin Foci (SAHF, that are enriched in the histone variant, macroH2A. SAHF are thought to repress expression of proliferation-promoting genes, thereby contributing to senescence-associated proliferation arrest. We asked whether this Wnt2-HIRA-SAHF pathway is conserved in mouse fibroblasts. Results We show that mouse embryo fibroblasts (MEFs and mouse skin fibroblasts, do not form robust punctate SAHF in response to an activated Ras oncogene or shortened telomeres. However, senescent MEFs do exhibit elevated levels of macroH2A staining throughout the nucleus as a whole. Consistent with their failure to fully activate the SAHF assembly pathway, the Wnt2-HIRA signaling axis is not overtly regulated between proliferating and senescent mouse cells. Conclusions In addition to the previously defined differences between mouse and human cells in the mechanisms and phenotypes associated with senescence, we conclude that senescent mouse and human fibroblasts also differ at the level of chromatin and the signaling pathways used to regulate chromatin. These differences between human and mouse senescence may contribute to the increased propensity of mouse fibroblasts (and perhaps other mouse cell types to become immortalized and transformed, compared to human cells.

  13. Different transcriptional profiling between senescent and non-senescent human coronary artery endothelial cells (HCAECs) by Omeprazole and Lansoprazole treatment.

    Science.gov (United States)

    Costarelli, Laura; Giacconi, Robertina; Malavolta, Marco; Basso, Andrea; Piacenza, Francesco; Provinciali, Mauro; Maggio, Marcello G; Corsonello, Andrea; Lattanzio, Fabrizia

    2017-04-01

    Recent evidence suggests that high dose and/or long term use of proton pump inhibitors (PPIs) may increase the risk of adverse cardiovascular events in older patients, but mechanisms underlying these detrimental effects are not known. Taking into account that the senescent endothelial cells have been implicated in the genesis or promotion of age-related cardiovascular disease, we hypothesized an active role of PPIs in senescent cells. The aim of this study is to investigate the changes in gene expression occurring in senescent and non-senescent human coronary artery endothelial cells (HCAECs) following Omeprazole (OPZ) or Lansoprazole (LPZ) treatment. Here, we show that atherogenic response is among the most regulated processes in PPI-treated HCAECs. PPIs induced down-regulation of anti-atherogenic chemokines (CXCL11, CXCL12 and CX3CL1) in senescent but not in non-senescent cells, while the same chemokines were up-regulated in untreated senescent cells. These findings support the hypothesis that up-regulated anti-atherogenic chemokines may represent a defensive mechanism against atherosclerosis during cellular senescence, and suggest that PPIs could activate pro-atherogenic pathways by changing the secretory phenotype of senescent HCAECs. Moreover, the genes coding for fatty acid binding protein 4 (FABP4) and piezo-type mechanosensitive ion channel component 2 (PIEZO2) were modulated by PPIs treatment with respect to untreated cells. In conclusions, our results show that long-term and high dose use of PPI could change the secretory phenotype of senescent cells, suggesting one of the potential mechanisms by which use of PPI can increase adverse outcomes in older subjects.

  14. Senescent phenotypes of skin fibroblasts from patients with Tangier disease

    International Nuclear Information System (INIS)

    Matsuura, Fumihiko; Hirano, Ken-ichi; Ikegami, Chiaki; Sandoval, Jose C.; Oku, Hiroyuki; Yuasa-Kawase, Miyako; Tsubakio-Yamamoto, Kazumi; Koseki, Masahiro; Masuda, Daisaku; Tsujii, Ken-ichi; Ishigami, Masato; Nishida, Makoto; Shimomura, Iichiro; Hori, Masatsugu; Yamashita, Shizuya

    2007-01-01

    Tangier disease (TD) is characterized by a deficiency of high density lipoprotein (HDL) in plasma and patients with TD have an increased risk for coronary artery disease (CAD). Recently, we reported that fibroblasts from TD exhibited large and flattened morphology, which is often observed in senescent cells. On the other hand, data have accumulated to show the relationship between cellular senescence and development of atherosclerotic CAD. The aim of the present study was to investigate whether TD fibroblasts exhibited cellular senescence. The proliferation of TD fibroblasts was gradually decreased at population doubling level (PDL) ∼10 compared with control cells. TD cells practically ceased proliferation at PDL ∼30. DNA synthesis was markedly decreased in TD fibroblasts. TD cells exhibited a higher positive rate for senescence-associated β-galactosidase (SA-β-gal), which is one of the biomarkers of cellular senescence in vitro. These data showed that TD cells reached cellular senescence at an earlier PDL compared with controls. Although, there was no difference in the telomere length of fibroblasts between TD and controls at the earlier passage (PDL 6), the telomere length of TD cells was shorter than that of controls at the late passage (PDL 25). Taken together, the current study demonstrates that the late-passaged TD fibroblasts showed senescent phenotype in vitro, which might be related to the increased cardiovascular manifestations in TD patients

  15. Contrasting patterns of cytokinins between years in senescing aspen leaves

    Czech Academy of Sciences Publication Activity Database

    Edlund, E.; Novák, Ondřej; Karady, M.; Ljung, K.; Jansson, S.

    2017-01-01

    Roč. 40, č. 5 (2017), s. 622-634 ISSN 0140-7791 R&D Projects: GA ČR GA14-34792S; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : leaf senescence * arabidopsis-thaliana * autumn senescence * gene-expression * populus-trichocarpa * mass-spectrometry * tobacco plants * translocation * biosynthesis * identification * autumn senescence * gene expression * metabolism * Populus tremula * profiling Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Plant sciences, botany Impact factor: 6.173, year: 2016

  16. The commitment of human cells to senescence.

    Science.gov (United States)

    Holliday, Robin

    2014-01-01

    Fifty years ago, it was demonstrated by Leonard Hayflick that human diploid fibroblasts grown in culture have a finite lifespan. Since that time, innumerable experiments have been published to discover the mechanism(s) that are responsible for this 'Hayflick limit' to continuous growth. Much new information has been gained, but there are certain features of this experimental system which have not been fully understood. One is the fact that different populations of the foetal lung strains WI-38 and MRC-5 have a range in division potential of at least a millionfold. The commitment theory of cellular aging, published more than 30 years ago, is able to explain this, but it has been consistently ignored. The theory predicts that bottlenecks, which are transient reductions in population size, can significantly reduce lifespan, or increase variability of lifespans. Computer simulations specify the effects of bottlenecks on longevity, and these were confirmed in two series of experiments. Commitment to senescence may be the loss of telomerase, which leads to the erosion of telomeres and the inability to grow indefinitely. Many experiments have been done with skin fibroblasts from human donors of different age, and it was originally thought that in vitro lifespan was inversely correlated with donor age. In these experiments, a single skin biopsy produces a population of cells that are grown to senescence. However, there is no reason to believe that skin fibroblasts are less variable in their in vitro lifespan than foetal lung strains, in which case the data points with skin cells are so variable that they may completely obscure any inverse correlation between culture lifespans and donor age.

  17. Rescuing loading induced bone formation at senescence.

    Directory of Open Access Journals (Sweden)

    Sundar Srinivasan

    2010-09-01

    Full Text Available The increasing incidence of osteoporosis worldwide requires anabolic treatments that are safe, effective, and, critically, inexpensive given the prevailing overburdened health care systems. While vigorous skeletal loading is anabolic and holds promise, deficits in mechanotransduction accrued with age markedly diminish the efficacy of readily complied, exercise-based strategies to combat osteoporosis in the elderly. Our approach to explore and counteract these age-related deficits was guided by cellular signaling patterns across hierarchical scales and by the insight that cell responses initiated during transient, rare events hold potential to exert high-fidelity control over temporally and spatially distant tissue adaptation. Here, we present an agent-based model of real-time Ca(2+/NFAT signaling amongst bone cells that fully described periosteal bone formation induced by a wide variety of loading stimuli in young and aged animals. The model predicted age-related pathway alterations underlying the diminished bone formation at senescence, and hence identified critical deficits that were promising targets for therapy. Based upon model predictions, we implemented an in vivo intervention and show for the first time that supplementing mechanical stimuli with low-dose Cyclosporin A can completely rescue loading induced bone formation in the senescent skeleton. These pre-clinical data provide the rationale to consider this approved pharmaceutical alongside mild physical exercise as an inexpensive, yet potent therapy to augment bone mass in the elderly. Our analyses suggested that real-time cellular signaling strongly influences downstream bone adaptation to mechanical stimuli, and quantification of these otherwise inaccessible, transient events in silico yielded a novel intervention with clinical potential.

  18. Identification and expression analysis of ERF transcription factor genes in petunia during flower senescence and in response to hormone treatments.

    Science.gov (United States)

    Liu, Juanxu; Li, Jingyu; Wang, Huinan; Fu, Zhaodi; Liu, Juan; Yu, Yixun

    2011-01-01

    Ethylene-responsive element-binding factor (ERF) genes constitute one of the largest transcription factor gene families in plants. In Arabidopsis and rice, only a few ERF genes have been characterized so far. Flower senescence is associated with increased ethylene production in many flowers. However, the characterization of ERF genes in flower senescence has not been reported. In this study, 13 ERF cDNAs were cloned from petunia. Based on the sequence characterization, these PhERFs could be classified into four of the 12 known ERF families. Their predicted amino acid sequences exhibited similarities to ERFs from other plant species. Expression analyses of PhERF mRNAs were performed in corollas and gynoecia of petunia flower. The 13 PhERF genes displayed differential expression patterns and levels during natural flower senescence. Exogenous ethylene accelerates the transcription of the various PhERF genes, and silver thiosulphate (STS) decreased the transcription of several PhERF genes in corollas and gynoecia. PhERF genes of group VII showed a strong association with the rise in ethylene production in both petals and gynoecia, and might be associated particularly with flower senescence in petunia. The effect of sugar, methyl jasmonate, and the plant hormones abscisic acid, salicylic acid, and 6-benzyladenine in regulating the different PhERF transcripts was investigated. Functional nuclear localization signal analyses of two PhERF proteins (PhERF2 and PhERF3) were carried out using fluorescence microscopy. These results supported a role for petunia PhERF genes in transcriptional regulation of petunia flower senescence processes.

  19. Molecular characterization of radon-induced rat lung tumors

    International Nuclear Information System (INIS)

    Guillet Bastide, K.

    2008-11-01

    The radon gas is a well known lung carcinogenic factor in human at high doses but the cancer risk at low doses is not established. Indeed, epidemiological studies at low doses are difficult to conduct because of the human exposure to other lung carcinogenic factors. These data underlined the necessity to conduct experiments on lung tumors developed on animal model. The aim of this work was to characterize rat lung tumors by working on a series of radon-induced tumors that included adenocarcinomas (A.C.), squamous cell carcinomas (S.C.C.) and adeno-squamous carcinomas (A.S.C.), that are mixed tumors with both A.C. and S.C.C. cellular components. A C.G.H. analysis of the three types of tumors allowed us to define chromosomal recurrent unbalances and to target candidate genes potentially implicated in lung carcinogenesis, as p16Ink4a, p19Arf, Rb1, K-Ras or c-Myc. A more precise analysis of the p16Ink4a/Cdk4/Rb1 and p19Arf/Mdm2/Tp53 pathways was performed and indicated that the Rb1 pathway was frequently inactivated through an absence of p16 Ink4a protein expression, indicating that it has a major role in rat lung carcinogenesis. Finally, a comparative transcriptomic analysis of the three types of tumors allowed us to show for the first time that the complex tumors A.S.C. have a transcriptomic profile in accordance with their mixed nature but that they also display their own expression profiles specificities. This work allowed us to find molecular characteristics common to murine and human lung tumors, indicating that the model of lung tumors in rat is pertinent to search for radiation-induced lung tumors specificities and to help for a better molecular identification of this type of tumors in human. (author)

  20. Hypersensitivity to contact inhibition provides a clue to cancer resistance of naked mole-rat.

    Science.gov (United States)

    Seluanov, Andrei; Hine, Christopher; Azpurua, Jorge; Feigenson, Marina; Bozzella, Michael; Mao, Zhiyong; Catania, Kenneth C; Gorbunova, Vera

    2009-11-17

    The naked mole-rat is the longest living rodent with a maximum lifespan exceeding 28 years. In addition to its longevity, naked mole-rats have an extraordinary resistance to cancer as tumors have never been observed in these rodents. Furthermore, we show that a combination of activated Ras and SV40 LT fails to induce robust anchorage-independent growth in naked mole-rat cells, while it readily transforms mouse fibroblasts. The mechanisms responsible for the cancer resistance of naked mole-rats were unknown. Here we show that naked mole-rat fibroblasts display hypersensitivity to contact inhibition, a phenomenon we termed "early contact inhibition." Contact inhibition is a key anticancer mechanism that arrests cell division when cells reach a high density. In cell culture, naked mole-rat fibroblasts arrest at a much lower density than those from a mouse. We demonstrate that early contact inhibition requires the activity of p53 and pRb tumor suppressor pathways. Inactivation of both p53 and pRb attenuates early contact inhibition. Contact inhibition in human and mouse is triggered by the induction of p27(Kip1). In contrast, early contact inhibition in naked mole-rat is associated with the induction of p16(Ink4a). Furthermore, we show that the roles of p16(Ink4a) and p27(Kip1) in the control of contact inhibition became temporally separated in this species: the early contact inhibition is controlled by p16(Ink4a), and regular contact inhibition is controlled by p27(Kip1). We propose that the additional layer of protection conferred by two-tiered contact inhibition contributes to the remarkable tumor resistance of the naked mole-rat.

  1. Transcriptional profile of genes involved in ascorbate glutathione cycle in senescing leaves for an early senescence leaf (esl) rice mutant.

    Science.gov (United States)

    Li, Zhaowei; Su, Da; Lei, Bingting; Wang, Fubiao; Geng, Wei; Pan, Gang; Cheng, Fangmin

    2015-03-15

    To clarify the complex relationship between ascorbate-glutathione (AsA-GSH) cycle and H2O2-induced leaf senescence, the genotype-dependent difference in some senescence-related physiological parameters and the transcript levels and the temporal patterns of genes involved in the AsA-GSH cycle during leaf senescence were investigated using two rice genotypes, namely, the early senescence leaf (esl) mutant and its wild type. Meanwhile, the triggering effect of exogenous H2O2 on the expression of OsAPX genes was examined using detached leaves. The results showed that the esl mutant had higher H2O2 level than its wild type at the initial stage of leaf senescence. At transcriptional level, the association of expression of various genes involved in the AsA-GSH cycle with leaf senescence was isoform dependent. For OsAPXs, the transcripts of two cytosolic OsAPX genes (OsAPX1 and OsAPX2), thylakoid-bound OsAPX8, chloroplastic OsAPX7 and peroxisomal OsAPX4 exhibited remarkable genotype-dependent variation in their expression levels and temporal patterns during leaf senescence, there were significantly increasing transcripts of OsAXP1 and OsAPX7, severely repressed transcripts of OsAPX4 and OsAPX8 for the esl rice at the initial leaf senescence. In contrast, the repressing transcript of OsAPX8 was highly sensitive to the increasing H2O2 level in the senescing rice leaves, while higher H2O2 concentration resulted in the enhancing transcripts of two cytosolic OsAPX genes, OsAPX7 transcript was greatly variable with different H2O2 concentrations and incubating duration, suggesting that the different OsAPXs isoforms played a complementary role in perceiving and scavenging H2O2 accumulation at various H2O2 concentrations during leaf senescence. Higher H2O2 level, increased AsA level, higher activities of APX and glutathione reductase (GR), and relatively stable GSH content during the entire sampling period in the leaves of esl mutant implied that a close interrelationship existed

  2. Telomeres and replicative senescence: Is it only length that counts?

    Science.gov (United States)

    von Zglinicki, T

    2001-07-26

    Telomeres are well established as a major 'replicometer', counting the population doublings in primary human cell cultures and ultimately triggering replicative senescence. However, neither is the pace of this biological clock inert, nor is there a fixed threshold telomere length acting as the universal trigger of replicative senescence. The available data suggest that opening of the telomeric loop and unscheduled exposure of the single-stranded G-rich telomeric overhang might act like a semaphore to signal senescent cell cycle arrest. Short telomere length, telomeric single-strand breaks, low levels of loop-stabilizing proteins, or other factors may trigger this opening of the loop. Thus, both telomere shortening and the ultimate signalling into senescence are able to integrate different environmental and genetic factors, especially oxidative stress-mediated damage, which might otherwise become a thread to genomic stability.

  3. Interaction Mortality: Senescence May Have Evolved because It Increases Lifespan

    DEFF Research Database (Denmark)

    Wensink, M. J.; Wrycza, T. F.; Baudisch, A.

    2014-01-01

    Given an extrinsic challenge, an organism may die or not depending on how the threat interacts with the organism's physiological state. To date, such interaction mortality has been only a minor factor in theoretical modeling of senescence. We describe a model of interaction mortality that does...... not involve specific functions, making only modest assumptions. Our model distinguishes explicitly between the physiological state of an organism and potential extrinsic, age-independent threats. The resulting mortality may change with age, depending on whether the organism's state changes with age. We find...... that depending on the physiological constraints, any outcome, be it 'no senescence' or 'high rate of senescence', can be found in any environment; that the highest optimal rate of senescence emerges for an intermediate physiological constraint, i.e. intermediate strength of trade-off; and that the optimal rate...

  4. Assessing senescence patterns in populations of large mammals

    Directory of Open Access Journals (Sweden)

    Gaillard, J.-M.

    2004-06-01

    Full Text Available Theoretical models such as those of Gompertz and Weibull are commonly used to study senescence in survival for humans and laboratory or captive animals. For wild populations of vertebrates, senescence in survival has more commonly been assessed by fitting simple linear or quadratic relationships between survival and age. By using appropriate constraints on survival parameters in Capture-Mark-Recapture (CMR models, we propose a first analysis of the suitability of the Gompertz and the two-parameter Weibull models for describing aging-related mortality in free-ranging populations of ungulates. We first show how to handle the Gompertz and the two-parameter Weibull models in the context of CMR analyses. Then we perform a comparative analysis of senescence patterns in both sexes of two ungulate species highly contrasted according to the intensity of sexual selection. Our analyses provide support to the Gompertz model for describing senescence patterns in ungulates. Evolutionary implications of our results are discussed

  5. Role of P53 in Mammary Epithelial Cell Senescence

    National Research Council Canada - National Science Library

    Dimri, Goberdhan P

    2006-01-01

    .... We also chose several other targets of p53 that are induced by DNA damage. The RT PCR analysis aws carried out using mRNA prepared from young growing early passage and senescent late passage HMECs...

  6. Senescent vs. non-senescent cells in the human annulus in vivo: Cell harvest with laser capture microdissection and gene expression studies with microarray analysis

    Directory of Open Access Journals (Sweden)

    Ingram Jane A

    2010-01-01

    Full Text Available Abstract Background Senescent cells are well-recognized in the aging/degenerating human disc. Senescent cells are viable, cannot divide, remain metabolically active and accumulate within the disc over time. Molecular analysis of senescent cells in tissue offers a special challenge since there are no cell surface markers for senescence which would let one use fluorescence-activated cell sorting as a method for separating out senescent cells. Methods We employed a novel laser capture microdissection (LCM design to selectively harvest senescent and non-senescent annulus cells in paraffin-embedded tissue, and compared their gene expression with microarray analysis. LCM was used to separately harvest senescent and non-senescent cells from 11 human annulus specimens. Results Microarray analysis revealed significant differences in expression levels in senescent cells vs non-senescent cells: 292 genes were upregulated, and 321 downregulated. Genes with established relationships to senescence were found to be significantly upregulated in senescent cells vs. non-senescent cells: p38 (MPAK14, RB-Associated KRAB zinc finger, Discoidin, CUB and LCCL domain, growth arrest and DNA-damage inducible beta, p28ING5, sphingosine-1-phosphate receptor 2 and somatostatin receptor 3; cyclin-dependent kinase 8 showed significant downregulation in senescent cells. Nitric oxidase synthase 1, and heat shock 70 kDa protein 6, both of which were significantly down-regulated in senescent cells, also showed significant changes. Additional genes related to cytokines, cell proliferation, and other processes were also identified. Conclusions Our LCM-microarray analyses identified a set of genes associated with senescence which were significantly upregulated in senescent vs non-senescent cells in the human annulus. These genes include p38 MAP kinase, discoidin, inhibitor of growth family member 5, and growth arrest and DNA-damage-inducible beta. Other genes, including genes

  7. Calculating the Rate of Senescence From Mortality Data

    DEFF Research Database (Denmark)

    Koopman, Jacob J E; Rozing, Maarten P; Kramer, Anneke

    2016-01-01

    , they do not fit mortality rates at young and old ages. Therefore, we developed a method to calculate senescence rates from the acceleration of mortality directly without modeling the mortality rates. We applied the different methods to age group-specific mortality data from the European Renal Association......, the rate of senescence can be calculated directly from non-modeled mortality rates, overcoming the disadvantages of an indirect estimation based on modeled mortality rates....

  8. Gene pathways that delay Caenorhabditis elegans reproductive senescence.

    Directory of Open Access Journals (Sweden)

    Meng C Wang

    2014-12-01

    Full Text Available Reproductive senescence is a hallmark of aging. The molecular mechanisms regulating reproductive senescence and its association with the aging of somatic cells remain poorly understood. From a full genome RNA interference (RNAi screen, we identified 32 Caenorhabditis elegans gene inactivations that delay reproductive senescence and extend reproductive lifespan. We found that many of these gene inactivations interact with insulin/IGF-1 and/or TGF-β endocrine signaling pathways to regulate reproductive senescence, except nhx-2 and sgk-1 that modulate sodium reabsorption. Of these 32 gene inactivations, we also found that 19 increase reproductive lifespan through their effects on oocyte activities, 8 of them coordinate oocyte and sperm functions to extend reproductive lifespan, and 5 of them can induce sperm humoral response to promote reproductive longevity. Furthermore, we examined the effects of these reproductive aging regulators on somatic aging. We found that 5 of these gene inactivations prolong organismal lifespan, and 20 of them increase healthy life expectancy of an organism without altering total life span. These studies provide a systemic view on the genetic regulation of reproductive senescence and its intersection with organism longevity. The majority of these newly identified genes are conserved, and may provide new insights into age-associated reproductive senescence during human aging.

  9. Density dependence triggers runaway selection of reduced senescence.

    Directory of Open Access Journals (Sweden)

    Robert M Seymour

    2007-12-01

    Full Text Available In the presence of exogenous mortality risks, future reproduction by an individual is worth less than present reproduction to its fitness. Senescent aging thus results inevitably from transferring net fertility into younger ages. Some long-lived organisms appear to defy theory, however, presenting negligible senescence (e.g., hydra and extended lifespans (e.g., Bristlecone Pine. Here, we investigate the possibility that the onset of vitality loss can be delayed indefinitely, even accepting the abundant evidence that reproduction is intrinsically costly to survival. For an environment with constant hazard, we establish that natural selection itself contributes to increasing density-dependent recruitment losses. We then develop a generalized model of accelerating vitality loss for analyzing fitness optima as a tradeoff between compression and spread in the age profile of net fertility. Across a realistic spectrum of senescent age profiles, density regulation of recruitment can trigger runaway selection for ever-reducing senescence. This novel prediction applies without requirement for special life-history characteristics such as indeterminate somatic growth or increasing fecundity with age. The evolution of nonsenescence from senescence is robust to the presence of exogenous adult mortality, which tends instead to increase the age-independent component of vitality loss. We simulate examples of runaway selection leading to negligible senescence and even intrinsic immortality.

  10. Experimental warming delays autumn senescence in a boreal spruce bog: Initial results from the SPRUCE experiment

    Science.gov (United States)

    Richardson, Andrew; Furze, Morgan; Aubrecht, Donald; Milliman, Thomas; Nettles, Robert; Krassovski, Misha; Hanson, Paul

    2016-04-01

    Phenology is considered one of the most robust indicators of the biological impacts of global change. In temperate and boreal regions, long-term data show that rising temperatures are advancing spring onset (e.g. budburst and flowering) and delaying autumn senescence (e.g. leaf coloration and leaf fall) in a wide range of ecosystems. While warm and cold temperatures, day length and insolation, precipitation and water availability, and other factors, have all been shown to influence plant phenology, the future response of phenology to rising temperatures and elevated CO2 still remains highly uncertain because of the challenges associated with conducting realistic manipulative experiments to simulate future environmental conditions. At the SPRUCE (Spruce and Peatland Responses Under Climatic and Environmental Change) experiment in the north-central United States, experimental temperature (0 to +9° C above ambient) and CO2 (ambient and elevated) treatments are being applied to mature, and intact, Picea mariana-Sphagnum spp. bog communities in their native habitat through the use of ten large (approximately 12 m wide, 10 m high) open-topped enclosures. We are tracking vegetation green-up and senescence in these chambers, at both the individual and whole-community level, using repeat digital photography. Within each chamber, digital camera images are recorded every 30 minutes and uploaded to the PhenoCam (http://phenocam.sr.unh.edu) project web page, where they are displayed in near-real-time. Image processing is conducted nightly to extract quantitative measures of canopy color, which we characterize using Gcc, the green chromatic coordinate. Data from a camera mounted outside the chambers (since November 2014) indicate strong seasonal variation in Gcc for both evergreen shrubs and trees. Shrub Gcc rises steeply in May and June, and declines steeply in September and October. By comparison, tree Gcc rises gradually from March through June, and declines gradually from

  11. Stress-Induced Premature Senescence or Stress-Induced Senescence-Like Phenotype: One In Vivo Reality, Two Possible Definitions?

    OpenAIRE

    Toussaint, Olivier; Dumont, Patrick; Remacle, Jose; Dierick, Jean-Francois; Pascal, Thierry; Frippiat, Christophe; Magalhaes, Joao Pedro; Zdanov, Stephanie; Chainiaux, Florence

    2002-01-01

    No consensus exists so far on the definition of cellular senescence. The narrowest definition of senescence is irreversible growth arrest triggered by telomere shortening counting cell generations (definition 1). Other authors gave an enlarged functional definition encompassing any kind of irreversible arrest of proliferative cell types induced by damaging agents or cell cycle deregulations after overexpression of proto-oncogenes (definition 2). As stress increases, the proportion of cells in...

  12. Overexpression of CHMP7 from rapeseed and Arabidopsis causes dwarfism and premature senescence in Arabidopsis.

    Science.gov (United States)

    Yang, Hongli; Liu, Jing; Lin, Jiulu; Deng, Linbin; Fan, Shihang; Guo, Yan; Sun, Fengming; Hua, Wei

    2016-10-01

    Endosomal sorting complexes required for transport (ESCRT) are well known in mammalians and yeast and plays an essential role in the formation of multi-vesicular bodies. Accumulating evidence has shown that ESCRT proteins contribute to proper plant development. CHMP7 (charged multi-vesicular body protein 7) is an ESCRT-III-related protein and functions in the endosomal sorting pathway in humans. However, its function in plants has not been explored in detail. In this study, we isolate the putative homolog of CHMP7 from rapeseed, BnCHMP7, which contains eight exons and encodes a protein consisting of 423 amino acid residues. Compared with the wild-type, overexpression of BnCHMP7 in Arabidopsis disturbs plant growth and decreases seed yield. Moreover, the transgenic plants also display early leaf senescence and hypersensitivity to dark treatment due to defects in autophagic degradation. Further study showed that BnCHMP7 is highly expressed in leaves and that YFP-BnCHMP7 is predominantly localized in endosome. Compared with human CHMP7, we found that BnCHMP7 not only interacts with ESCRT-III subunits SNF7.2 (CHMP4B), but also with VPS2.2 and CHMP1B. As expected, microarray analysis revealed that the expression of ESCRT transport genes is significantly affected. Additionally, the expression of some genes that are involved in senescence, protein synthesis and protein degradation is also altered in BnCHMP7-overexpressing plants. Taken together, BnCHMP7 encodes an endosome-localized protein, which causes dwarfism and leaf senescence as an ESCRT-III-related component. Copyright © 2016 Elsevier GmbH. All rights reserved.

  13. Autophagy and senescence, stress responses induced by the DNA-damaging mycotoxin alternariol

    International Nuclear Information System (INIS)

    Solhaug, A.; Torgersen, M.L.; Holme, J.A.; Lagadic-Gossmann, D.; Eriksen, G.S.

    2014-01-01

    Highlights: • AOH induces autophagy, lamellar bodies and senescence in RAW264.7 macrophages. • DNA damage is suggested as a triggering signal. • The Sestrin2-AMPK-mTOR-S6K pathway is proposed to link DNA damage to autophagy. - Abstract: The mycotoxin alternariol (AOH), a frequent contaminant in fruit and grain, is known to induce cellular stress responses such as reactive oxygen production, DNA damage and cell cycle arrest. Cellular stress is often connected to autophagy, and we employed the RAW264.7 macrophage model to test the hypothesis that AOH induces autophagy. Indeed, AOH treatment led to a massive increase in acidic vacuoles often observed upon autophagy induction. Moreover, expression of the autophagy marker LC3 was markedly increased and there was a strong accumulation of LC3-positive puncta. Increased autophagic activity was verified biochemically by measuring the degradation rate of long-lived proteins. Furthermore, AOH induced expression of Sestrin2 and phosphorylation of AMPK as well as reduced phosphorylation of mTOR and S6 kinase, common mediators of signaling pathways involved in autophagy. Transmission electron microscopy analyzes of AOH treated cells not only clearly displayed structures associated with autophagy such as autophagosomes and autolysosomes, but also the appearance of lamellar bodies. Prolonged AOH treatment resulted in changed cell morphology from round into more star-shaped as well as increased β-galactosidase activity. This suggests that the cells eventually entered senescence. In conclusion, our data identify here AOH as an inducer of both autophagy and senescence. These effects are suggested to be to be linked to AOH-induced DSB (via a reported effect on topoisomerase activity), resulting in an activation of p53 and the Sestrin2-AMPK-mTOR-S6K signaling pathway

  14. PTTG1 attenuates drug-induced cellular senescence.

    Directory of Open Access Journals (Sweden)

    Yunguang Tong

    Full Text Available As PTTG1 (pituitary tumor transforming gene abundance correlates with adverse outcomes in cancer treatment, we determined mechanisms underlying this observation by assessing the role of PTTG1 in regulating cell response to anti-neoplastic drugs. HCT116 cells devoid of PTTG1 (PTTG1(-/- exhibited enhanced drug sensitivity as assessed by measuring BrdU incorporation in vitro. Apoptosis, mitosis catastrophe or DNA damage were not detected, but features of senescence were observed using low doses of doxorubicin and TSA. The number of drug-induced PTTG1(-/- senescent cells increased ∼4 fold as compared to WT PTTG1-replete cells (p<0.001. p21, an important regulator of cell senescence, was induced ∼3 fold in HCT116 PTTG1(-/- cells upon doxorubicin or Trichostatin A treatment. Binding of Sp1, p53 and p300 to the p21 promoter was enhanced in PTTG1(-/- cells after treatment, suggesting transcriptional regulation of p21. p21 knock down abrogated the observed senescent effects of these drugs, indicating that PTTG1 likely suppresses p21 to regulate drug-induced senescence. PTTG1 also regulated SW620 colon cancer cells response to doxorubicin and TSA mediated by p21. Subcutaneously xenografted PTTG1(-/- HCT116 cells developed smaller tumors and exhibited enhanced responses to doxorubicin. PTTG1(-/- tumor tissue derived from excised tumors exhibited increased doxorubicin-induced senescence. As senescence is a determinant of cell responses to anti-neoplastic treatments, these findings suggest PTTG1 as a tumor cell marker to predict anti-neoplastic treatment outcomes.

  15. The forms and fitness cost of senescence : Age-specific recapture, survival, reproduction, and reproductive value in a wild bird population

    NARCIS (Netherlands)

    Bouwhuis, Sandra; Choquet, Remi; Sheldon, Ben C.; Verhulst, Simon

    Longitudinal studies of senescence accumulate rapidly from natural populations. However, it is largely unknown whether different fitness components senesce in parallel, how reproductive and survival senescence contribute to declines in reproductive value, and how large the fitness cost of senescence

  16. Invisible Display in Aluminum

    DEFF Research Database (Denmark)

    Prichystal, Jan Phuklin; Hansen, Hans Nørgaard; Bladt, Henrik Henriksen

    2005-01-01

    Bang & Olufsen a/s has been working with ideas for invisible integration of displays in metal surfaces. Invisible integration of information displays traditionally has been possible by placing displays behind transparent or semitransparent materials such as plastic or glass. The wish for an integ......Bang & Olufsen a/s has been working with ideas for invisible integration of displays in metal surfaces. Invisible integration of information displays traditionally has been possible by placing displays behind transparent or semitransparent materials such as plastic or glass. The wish...... for an integrated display in a metal surface is often ruled by design and functionality of a product. The integration of displays in metal surfaces requires metal removal in order to clear the area of the display to some extent. The idea behind an invisible display in Aluminum concerns the processing of a metal...

  17. Inactivation of AKT Induces Cellular Senescence in Uterine Leiomyoma

    Science.gov (United States)

    Xu, Xiaofei; Lu, Zhenxiao; Qiang, Wenan; Vidimar, Vania; Kong, Beihua

    2014-01-01

    Uterine leiomyomas (fibroids) are a major public health problem. Current medical treatments with GnRH analogs do not provide long-term benefit. Thus, permanent shrinkage or inhibition of fibroid growth via medical means remains a challenge. The AKT pathway is a major growth and survival pathway for fibroids. We propose that AKT inhibition results in a transient regulation of specific mechanisms that ultimately drive cells into cellular senescence or cell death. In this study, we investigated specific mechanisms of AKT inhibition that resulted in senescence. We observed that administration of MK-2206, an allosteric AKT inhibitor, increased levels of reactive oxygen species, up-regulated the microRNA miR-182 and several senescence-associated genes (including p16, p53, p21, and β-galactosidase), and drove leiomyoma cells into stress-induced premature senescence (SIPS). Moreover, induction of SIPS was mediated by HMGA2, which colocalized to senescence-associated heterochromatin foci. This study provides a conceivable molecular mechanism of SIPS by AKT inhibition in fibroids. PMID:24476133

  18. Oxidative Stress Induces Senescence in Cultured RPE Cells.

    Science.gov (United States)

    Aryan, Nona; Betts-Obregon, Brandi S; Perry, George; Tsin, Andrew T

    2016-01-01

    The aim of this research is to determine whether oxidative stress induces cellular senescence in human retinal pigment epithelial cells. Cultured ARPE19 cells were subjected to different concentrations of hydrogen peroxide to induce oxidative stress. Cells were seeded into 24-well plates with hydrogen peroxide added to cell medium and incubated at 37°C + 5% CO2 for a 90-minute period [at 0, 300, 400 and 800 micromolar (MCM) hydrogen peroxide]. The number of viable ARPE19 cells were recorded using the Trypan Blue Dye Exclusion Method and cell senescence was measured by positive staining for senescence-associated beta-galactosidase (SA-beta-Gal) protein. Without hydrogen peroxide treatment, the number of viable ARPE19 cells increased significantly from 50,000 cells/well to 197,000 within 72 hours. Treatment with hydrogen peroxide reduced this level of cell proliferation significantly (to 52,167 cells at 400 MCM; to 49,263 cells at 800 MCM). Meanwhile, cells with a high level of positive senescence-indicator SA-Beta-Gal-positive staining was induced by hydrogen peroxide treatment (from a baseline level of 12% to 80% at 400 MCM and at 800 MCM). Our data suggests that oxidative stress from hydrogen peroxide treatment inhibited ARPE19 cell proliferation and induced cellular senescence.

  19. Regulation of replicative senescence by NADP+ -dependent isocitrate dehydrogenase.

    Science.gov (United States)

    Kil, In Sup; Huh, Tae Lin; Lee, Young Sup; Lee, You Mie; Park, Jeen-Woo

    2006-01-01

    The free radical hypothesis of aging postulates that senescence is due to an accumulation of cellular oxidative damage, caused largely by reactive oxygen species that are produced as by-products of normal metabolic processes. Recently, we demonstrated that the control of cytosolic and mitochondrial redox balance and the cellular defense against oxidative damage is one of the primary functions of cytosolic (IDPc) and mitochondrial NADP+ -dependent isocitrate dehydrogenase (IDPm) by supplying NADPH for antioxidant systems. In this paper, we demonstrate that modulation of IDPc or IDPm activity in IMR-90 cells regulates cellular redox status and replicative senescence. When we examined the regulatory role of IDPc and IDPm against the aging process with IMR-90 cells transfected with cDNA for IDPc or IDPm in sense and antisense orientations, a clear inverse relationship was observed between the amount of IDPc or IDPm expressed in target cells and their susceptibility to senescence, which was reflected by changes in replicative potential, cell cycle, senescence-associated beta-galactosidase activity, expression of p21 and p53, and morphology of cells. Furthermore, lipid peroxidation, oxidative DNA damage, and intracellular peroxide generation were higher and cellular redox status shifted to a prooxidant condition in the cell lines expressing the lower level of IDPc or IDPm. The results suggest that IDPc and IDPm play an important regulatory role in cellular defense against oxidative stress and in the senescence of IMR-90 cells.

  20. Plant senescence and proteolysis: two processes with one destiny.

    Science.gov (United States)

    Diaz-Mendoza, Mercedes; Velasco-Arroyo, Blanca; Santamaria, M Estrella; González-Melendi, Pablo; Martinez, Manuel; Diaz, Isabel

    2016-01-01

    Senescence-associated proteolysis in plants is a complex and controlled process, essential for mobilization of nutrients from old or stressed tissues, mainly leaves, to growing or sink organs. Protein breakdown in senescing leaves involves many plastidial and nuclear proteases, regulators, different subcellular locations and dynamic protein traffic to ensure the complete transformation of proteins of high molecular weight into transportable and useful hydrolysed products. Protease activities are strictly regulated by specific inhibitors and through the activation of zymogens to develop their proteolytic activity at the right place and at the proper time. All these events associated with senescence have deep effects on the relocation of nutrients and as a consequence, on grain quality and crop yield. Thus, it can be considered that nutrient recycling is the common destiny of two processes, plant senescence and, proteolysis. This review article covers the most recent findings about leaf senescence features mediated by abiotic and biotic stresses as well as the participants and steps required in this physiological process, paying special attention to C1A cysteine proteases, their specific inhibitors, known as cystatins, and their potential targets, particularly the chloroplastic proteins as source for nitrogen recycling.

  1. Upregulation of a tonoplast-localized cytochrome P450 during petal senescence in Petunia inflata

    Directory of Open Access Journals (Sweden)

    Ishida Hiroyuki

    2006-04-01

    Full Text Available Abstract Background Gene expression in Petunia inflata petals undergoes major changes following compatible pollination. Severe flower wilting occurs reproducibly within 36 hours, providing an excellent model for investigation of petal senescence and programmed cell death. Expression of a number of genes and various enzyme activities involved in the degradation and remobilization of macromolecules have been found to be upregulated during the early stages of petal senescence. Results By performing differential display of cDNAs during Petunia inflata petal senescence, a highly upregulated gene encoding a cytochrome P450 was identified. Analysis of the complete cDNA sequence revealed that the predicted protein is a member of the CYP74C family (CYP74C9 and is highly similar to a tomato CYP74C allene oxide synthase (AOS that is known to be active on 9-hydroperoxides. Cloning of the petunia genomic DNA revealed an intronless gene with a promoter region that carries signals found in stress-responsive genes and potential binding sites for Myb transcription factors. Transcripts were present at detectable levels in root and stem, but were 40 times more abundant in flowers 36 hours after pollination. Ethylene and jasmonate treatment resulted in transitory increases in expression in detached flowers. A protein fusion of the CYP74C coding region to a C-terminal GFP was found to be located in the tonoplast. Conclusion Though oxylipins, particularly jasmonates, are known to be involved in stress responses, the role of other products of CYP74 enzymes is less well understood. The identification of a CYP74C family member as a highly upregulated gene during petal senescence suggests that additional products of fatty acid metabolism may play important roles during programmed cell death. In contrast to the chloroplast localization of AOS proteins in the CYP74A subfamily, GFP fusion data indicates that the petunia CYP74C9 enzyme is in the tonoplast. This result

  2. Stromal-epithelial interactions in aging and cancer: Senescent fibroblasts alter epithelial cell differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Parrinello, Simona; Coppe, Jean-Philippe; Krtolica, Ana; Campisi, Judith

    2004-07-14

    Cellular senescence suppresses cancer by arresting cells at risk for malignant tumorigenesis. However, senescent cells also secrete molecules that can stimulate premalignant cells to proliferate and form tumors, suggesting the senescence response is antagonistically pleiotropic. We show that premalignant mammary epithelial cells exposed to senescent human fibroblasts in mice irreversibly lose differentiated properties, become invasive and undergo full malignant transformation. Moreover, using cultured mouse or human fibroblasts and non-malignant breast epithelial cells, we show that senescent fibroblasts disrupt epithelial alveolar morphogenesis, functional differentiation, and branching morphogenesis. Further, we identify MMP-3 as the major factor responsible for the effects of senescent fibroblasts on branching morphogenesis. Our findings support the idea that senescent cells contribute to age-related pathology, including cancer, and describe a new property of senescent fibroblasts--the ability to alter epithelial differentiation--that might also explain the loss of tissue function and organization that is a hallmark of aging.

  3. Long-term Neuroglial Cocultures as a Brain Aging Model: Hallmarks of Senescence, MicroRNA Expression Profiles, and Comparison With In Vivo Models.

    Science.gov (United States)

    Bigagli, Elisabetta; Luceri, Cristina; Scartabelli, Tania; Dolara, Piero; Casamenti, Fiorella; Pellegrini-Giampietro, Domenico E; Giovannelli, Lisa

    2016-01-01

    Our purpose was to evaluate long-term neuroglial cocultures as a model for investigating senescence in the nervous system and to assess its similarities with in vivo models. To this aim, we maintained the cultures from 15 days in vitro (mature cultures) up to 27 days in vitro (senescent cultures), measuring senescence-associated, neuronal, dendritic, and astrocytic markers. Whole microRNA expression profiles were compared with those measured in the cortex of 18- and 24-month-old C57Bl/6J aged mice and of transgenic TgCRND8 mice, a model of amyloid-β deposition. Neuroglial cocultures displayed features of cellular senescence (increased senescence-associated-β-galactosidase activity, oxidative stress, γ-H2AX expression, IL-6 production, astrogliosis) that were concentration dependently counteracted by the antiaging compound resveratrol (1-5 µM). Among the 1,080 microRNAs analyzed, 335 were downregulated or absent in 27 compared with 15 days in vitro and resveratrol reversed this effect. A substantial overlapping was found between age-associated changes in microRNA expression profiles in vitro and in TgCRND8 mice but not in physiologically aged mice, indicating that this culture model displays more similarities with pathological than physiological brain aging. Our results demonstrate that neuroglial cocultures aged in vitro can be useful for investigating the cellular and molecular mechanisms of brain aging and for preliminary testing of protective compounds. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. European display scene

    Science.gov (United States)

    Bartlett, Christopher T.

    2000-08-01

    The manufacture of Flat Panel Displays (FPDs) is dominated by Far Eastern sources, particularly in Active Matrix Liquid Crystal Displays (AMLCD) and Plasma. The United States has a very powerful capability in micro-displays. It is not well known that Europe has a very active research capability which has lead to many innovations in display technology. In addition there is a capability in display manufacturing of organic technologies as well as the licensed build of Japanese or Korean designs. Finally, Europe has a display systems capability in military products which is world class.

  5. Handbook of display technology

    CERN Document Server

    Castellano, Joseph A

    1992-01-01

    This book presents a comprehensive review of technical and commercial aspects of display technology. It provides design engineers with the information needed to select proper technology for new products. The book focuses on flat, thin displays such as light-emitting diodes, plasma display panels, and liquid crystal displays, but it also includes material on cathode ray tubes. Displays include a large number of products from televisions, auto dashboards, radios, and household appliances, to gasoline pumps, heart monitors, microwave ovens, and more.For more information on display tech

  6. The Pace and Shape of Senescence in Angiosperms

    DEFF Research Database (Denmark)

    Baudisch, Annette; Salguero-Gómez, Roberto; Jones, Owen

    2013-01-01

    1. Demographic senescence, the decay in fertility and increase in the risk of mortality with age, is one of the most striking phenomena in ecology and evolution. Comparative studies of senescence patterns of plants are scarce, and consequently, little is known about senescence and its determinants...... (‘senescence’), decreases (‘negative senescence’) or remains constant over age (‘negligible senescence’). 3. We extract mortality trajectories from ComPADRe III, a data base that contains demographic information for several hundred plant species. We apply age-from-stage matrix decomposition methods to obtain...... age-specific trajectories from 290 angiosperm species of various growth forms distributed globally. From these trajectories, we survey pace and shape values and investigate how growth form and ecoregion influence these two aspects of mortality using a Bayesian regression analysis that accounts...

  7. The emerging role of alternative splicing in senescence and aging.

    Science.gov (United States)

    Deschênes, Mathieu; Chabot, Benoit

    2017-10-01

    Deregulation of precursor mRNA splicing is associated with many illnesses and has been linked to age-related chronic diseases. Here we review recent progress documenting how defects in the machinery that performs intron removal and controls splice site selection contribute to cellular senescence and organismal aging. We discuss the functional association linking p53, IGF-1, SIRT1, and ING-1 splice variants with senescence and aging, and review a selection of splicing defects occurring in accelerated aging (progeria), vascular aging, and Alzheimer's disease. Overall, it is becoming increasingly clear that changes in the activity of splicing factors and in the production of key splice variants can impact cellular senescence and the aging phenotype. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  8. Activation of a PGC-1-related Coactivator (PRC)-dependent Inflammatory Stress Program Linked to Apoptosis and Premature Senescence*

    Science.gov (United States)

    Gleyzer, Natalie; Scarpulla, Richard C.

    2013-01-01

    PGC-1-related coactivator (PRC), a growth-regulated member of the PGC-1 coactivator family, contributes to the expression of the mitochondrial respiratory apparatus. PRC also orchestrates a robust response to metabolic stress by promoting the expression of multiple genes specifying inflammation, proliferation, and metabolic reprogramming. Here, we demonstrate that this PRC-dependent stress program is activated during apoptosis and senescence, two major protective mechanisms against cellular dysfunction. Both PRC and its targets (IL1α, SPRR2D, and SPRR2F) were rapidly induced by menadione, an agent that promotes apoptosis through the generation of intracellular oxidants. Menadione-induced apoptosis and the PRC stress program were blocked by the antioxidant N-acetylcysteine. The PRC stress response was also activated by the topoisomerase I inhibitor 7-ethyl-10-hydroxycamptothecin (SN-38), an inducer of premature senescence in tumor cells. Cells treated with SN-38 displayed morphological characteristics of senescence and express senescence-associated β-galactosidase activity. In contrast to menadione, the SN-38 induction of the PRC program occurred over an extended time course and was antioxidant-insensitive. The potential adaptive function of the PRC stress response was investigated by treating cells with meclizine, a drug that promotes glycolytic energy metabolism and has been linked to cardio- and neuroprotection against ischemia-reperfusion injury. Meclizine increased lactate production and was a potent inducer of the PRC stress program, suggesting that PRC may contribute to the protective effects of meclizine. Finally, c-MYC and PRC were coordinately induced under all conditions tested, implicating c-MYC in the biological response to metabolic stress. The results suggest a general role for PRC in the adaptive response to cellular dysfunction. PMID:23364789

  9. Senescent T-Cells Promote Bone Loss in Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Johannes Fessler

    2018-02-01

    Full Text Available ObjectiveT-cells are critical players in the pathogenesis of osteoporosis in patients with rheumatoid arthritis (RA. Premature senescence of lymphocytes including the accumulation of senescent CD4+ T-cells is a hallmark feature of RA. Whether T-cell senescence is associated with bone loss in RA patients is elusive so far.MethodsThis includes a prospective study of consecutive patients with RA (n = 107, patients with primary osteopenia/-porosis (n = 75, and healthy individuals (n = 38. Bone mineral density (BMD was determined by dual-energy X-ray absorptiometry scan. Flow cytometry, magnetic-associated cell sorting, and cell culture experiments were performed to analyze the pro-osteoclastic phenotype and the function of senescent CD4+CD28− T-cells.ResultsPatients with osteopenia/-porosis yielded a higher prevalence of senescent CD4+CD28− T-cells than individuals with normal BMD, in the RA, as well as in the non-RA cohort. Receptor activator of nuclear factor kappa-B ligand (RANKL was expressed at higher levels on CD4+CD28− T-cells as compared to CD28+ T-cells. Stimulation with interleukin-15 led to an up-regulation of RANKL expression, particularly on CD28− T-cells. CD4+CD28− T-cells induced osteoclastogenesis more efficiently than CD28+ T-cells.ConclusionOur data indicate that senescent T-cells promote osteoclastogenesis more efficiently than conventional CD28+ T-cells, which might contribute to the pathogenesis of systemic bone loss in RA and primary osteoporosis.

  10. A Compressive Superresolution Display

    KAUST Repository

    Heide, Felix; Gregson, James; Wetzstein, Gordon; Raskar, Ramesh; Heidrich, Wolfgang

    2014-01-01

    In this paper, we introduce a new compressive display architecture for superresolution image presentation that exploits co-design of the optical device configuration and compressive computation. Our display allows for superresolution, HDR, or glasses-free 3D presentation.

  11. A Compressive Superresolution Display

    KAUST Repository

    Heide, Felix

    2014-06-22

    In this paper, we introduce a new compressive display architecture for superresolution image presentation that exploits co-design of the optical device configuration and compressive computation. Our display allows for superresolution, HDR, or glasses-free 3D presentation.

  12. Analysis of individual cells identifies cell-to-cell variability following induction of cellular senescence.

    Science.gov (United States)

    Wiley, Christopher D; Flynn, James M; Morrissey, Christapher; Lebofsky, Ronald; Shuga, Joe; Dong, Xiao; Unger, Marc A; Vijg, Jan; Melov, Simon; Campisi, Judith

    2017-10-01

    Senescent cells play important roles in both physiological and pathological processes, including cancer and aging. In all cases, however, senescent cells comprise only a small fraction of tissues. Senescent phenotypes have been studied largely in relatively homogeneous populations of cultured cells. In vivo, senescent cells are generally identified by a small number of markers, but whether and how these markers vary among individual cells is unknown. We therefore utilized a combination of single-cell isolation and a nanofluidic PCR platform to determine the contributions of individual cells to the overall gene expression profile of senescent human fibroblast populations. Individual senescent cells were surprisingly heterogeneous in their gene expression signatures. This cell-to-cell variability resulted in a loss of correlation among the expression of several senescence-associated genes. Many genes encoding senescence-associated secretory phenotype (SASP) factors, a major contributor to the effects of senescent cells in vivo, showed marked variability with a subset of highly induced genes accounting for the increases observed at the population level. Inflammatory genes in clustered genomic loci showed a greater correlation with senescence compared to nonclustered loci, suggesting that these genes are coregulated by genomic location. Together, these data offer new insights into how genes are regulated in senescent cells and suggest that single markers are inadequate to identify senescent cells in vivo. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  13. An Essential Role for Senescent Cells in Optimal Wound Healing through Secretion of PDGF-AA

    NARCIS (Netherlands)

    Demaria, Marco; Ohtani, Naoko; Youssef Hassan, Sameh|info:eu-repo/dai/nl/374027080; Rodier, Francis; Toussaint, Wendy; Mitchell, James R; Laberge, Remi-Martin; Vijg, Jan; Van Steeg, Harry; Dollé, Martijn E T; Hoeijmakers, Jan H J; de Bruin, Alain|info:eu-repo/dai/nl/304837261; Hara, Eiji; Campisi, Judith

    2014-01-01

    Cellular senescence suppresses cancer by halting the growth of premalignant cells, yet the accumulation of senescent cells is thought to drive age-related pathology through a senescence-associated secretory phenotype (SASP), the function of which is unclear. To understand the physiological role(s)

  14. An essential role for senescent cells in optimal wound healing through secretion of PDGF-AA

    NARCIS (Netherlands)

    Demaria, Marco; Ohtani, Naoko; Youssef, Sameh A; Rodier, Francis; Toussaint, Wendy; Mitchell, James R; Laberge, Remi-Martin; Vijg, Jan; Van Steeg, Harry; Dollé, Martijn E T; Hoeijmakers, Jan H J; de Bruin, Alain; Hara, Eiji; Campisi, Judith

    2014-01-01

    Cellular senescence suppresses cancer by halting the growth of premalignant cells, yet the accumulation of senescent cells is thought to drive age-related pathology through a senescence-associated secretory phenotype (SASP), the function of which is unclear. To understand the physiological role(s)

  15. An essential role for senescent cells in optimal wound healing through secretion of PDGF-AA

    NARCIS (Netherlands)

    M. Demaria (Marco); N. Ohtani (Naoko); S. Youssef (SamehA.); F. Rodier (Francis); W. Toussaint (Wendy); J. Mitchell (JamesR.); R.-M. Laberge (Remi-Martin); J. Vijg (Jan); H. VanSteeg (Harry); M. Dollé (MartijnE.T.); J. Hoeijmakers (JanH.J.); A. deBruin (Alain); E. Hara (Eiji); J. Campisi (Judith)

    2014-01-01

    textabstractCellular senescence suppresses cancer by halting the growth of premalignant cells, yet the accumulation of senescent cells is thought to drive age-related pathology through a senescence-associated secretory phenotype (SASP), the function of which is unclear. To understand the

  16. Insulin-like growth factor binding protein-6 delays replicative senescence of human fibroblasts

    DEFF Research Database (Denmark)

    Micutkova, Lucia; Diener, Thomas; Li, Chen

    2011-01-01

    Cellular senescence can be induced by a variety of mechanisms, and recent data suggest a key role for cytokine networks to maintain the senescent state. Here, we have used a proteomic LC-MS/MS approach to identify new extracellular regulators of senescence in human fibroblasts. We identified 26 e...

  17. Targeting Senescent Cells : Possible Implications for Delaying Skin Aging: A Mini-Review

    NARCIS (Netherlands)

    Velarde, Michael C.; Demaria, Marco

    2016-01-01

    Senescent cells are induced by a wide variety of stimuli. They accumulate in several tissues during aging, including the skin. Senescent cells secrete proinflammatory cytokines, chemokines, growth factors, and proteases, a phenomenon called senescence-associated secretory phenotype (SASP), which are

  18. Liquid crystal display

    International Nuclear Information System (INIS)

    Takami, K.

    1981-01-01

    An improved liquid crystal display device is described which can display letters, numerals and other necessary patterns in the night time using a minimized amount of radioactive material. To achieve this a self-luminous light source is placed in a limited region corresponding to a specific display area. (U.K.)

  19. Establishment of ultra long-lived cell lines by transfection of TERT into normal human fibroblast TIG-1 and their characterization.

    Science.gov (United States)

    Kamada, Mizuna; Kumazaki, Tsutomu; Matsuo, Taira; Mitsui, Youji; Takahashi, Tomoko

    2012-06-01

    To establish useful human normal cell lines, TERT (telomerase reverse transcriptase) cDNA was transfected into normal female lung fibroblast, TIG-1. After long-term-sub-cultivation of 74 individual clones selected for resistance to G418, we obtained 55 cultures with normal range of life span [75 PDL (population doubling level)], 16 cultures with extended life span (75-140 PDL). In addition, 3 immortal cell strains and unexpectedly, one ultra long-lived cell line (ULT-1) with life span of 166 PDL were established. IMT-1, one of the immortal cell strains was confirmed to maintain long telomere length, high telomerase activity and an extremely low level of p16INK4A. They also showed moderate p53 and p21CIP1 expression, keeping vigorous growth rate even at 450 PDL. High level of fibronectin and collagen 1α expression confirmed IMT-1 as normal fibroblasts, although one X chromosome had been lost. ULT-1, however, kept a near normal karyotypes and had shortening of telomere length, high expression of p16INK4A, moderate levels of senescence associated-β-galactosidase positive cells and decreased growth rate only after 150 PDs (population doublings), and finally reached senescence at 166 PDL with morphology of normal senescent fibroblasts. As resources of standard normal human cell, abundant vials of early and middle passages of ULT-1 have been stocked. The use of the cell line is discussed, focusing on isograft of artificial skin and screening of anti-aging or safe chemical agents.

  20. Liquid Crystal Airborne Display

    Science.gov (United States)

    1977-08-01

    Cum.nings, J. P., et al., Properties and Limitations oe Liquid Crystals for Aircraft Displays, Honeywell Corporate Researc ."I Center, Final Report HR-72...basic module could be used to build displays for both the commercial and military! 157- marhecs, and so would establi sh a broad and sizable market ... market for the display becomes a reality; therein lies, f TABLE 16 THE COURSE OF FUTURE DISPLAY DEVELOPMENT Today 1976-77 1980 1985 Display Size 2" 1 3.2

  1. Displays in scintigraphy

    International Nuclear Information System (INIS)

    Todd-Pokropek, A.E.; Pizer, S.M.

    1977-01-01

    Displays have several functions: to transmit images, to permit interaction, to quantitate features and to provide records. The main characteristics of displays used for image transmission are their resolution, dynamic range, signal-to-noise ratio and uniformity. Considerations of visual acuity suggest that the display element size should be much less than the data element size, and in current practice at least 256X256 for a gamma camera image. The dynamic range for image transmission should be such that at least 64 levels of grey (or equivalent) are displayed. Scanner displays are also considered, and in particular, the requirements of a whole-body camera are examined. A number of display systems and devices are presented including a 'new' heated object colour display system. Interaction with displays is considered, including background subtraction, contrast enhancement, position indication and region-of-interest generation. Such systems lead to methods of quantitation, which imply knowledge of the expected distributions. Methods for intercomparing displays are considered. Polaroid displays, which have for so long dominated the field, are in the process of being replaced by stored image displays, now that large cheap memories exist which give an equivalent image quality. The impact of this in nuclear medicine is yet to be seen, but a major effect will be to enable true quantitation. (author)

  2. Cell Cycle Inhibitors and Outcome after Radiotherapy in Bladder Cancer Patients

    International Nuclear Information System (INIS)

    Roetterud, Ranveig; Pettersen, Erik O.; Berner, Aasmund; Holm, Ruth; Olsen, Dag Rune; Fossaa, Sophie D.

    2002-01-01

    The aim of this study was to correlate the expression of cell cycle inhibitors with outcome of patients with muscle-invasive bladder cancer treated with preoperative radiotherapy (46 Gy/4-5 weeks or 20 Gy/1 week) and cystectomy. Patients with pT3b (n=42) or pT0 (n=17) were included in the study. Expression of p16INK4a and p27KIP1 was assessed immunohistochemically in pre-radiotherapy biopsies and cystectomy specimens. Previously reported results of p21CIP1 expression were also included. No difference in pretreatment protein expression was found between patients with pT0 and pT3b. Expression of p21CIP1 and p27KIP1 was lower in cystectomy specimens than in pretreatment biopsies. None of the proteins showed significant impact on survival when analysed separately. However, patients with tumours showing > 50% expression of p16INK4a, p21CIP1, or p27KIP1 displayed poorer cancer-specific survival rates compared with the remaining patients (p=0.025). This effect was more pronounced in patients receiving 46 Gy than in those receiving 20 Gy. In conclusion, low expression of cell cycle inhibitors is related to favourable survival after precystectomy radiotherapy

  3. effect of farmyard manure on senescence, nitrogen and protein

    African Journals Online (AJOL)

    DR. AMINU

    treatment (manurex2) at the ratio of 5:1 soil to manure and the control (no manure added). Plastic pots of ... seasons, senescence started earlier rainy season than in dry season. On the other hand ... These changes, visible to the naked eye are.

  4. Alkaline protease from senesced leaves of invasive weed | Gaur ...

    African Journals Online (AJOL)

    step procedure involving ammonium sulfate precipitation and Sephadex G-250 gel permeation chromatography. The Sephadex-G-250 fraction of senesced leaves of Lantana camara showed 28.31 fold with a yield of 6.19%. The enzyme was ...

  5. Role of polyamines and ethylene as modulators of plant senescence

    Indian Academy of Sciences (India)

    Unknown

    Plant Biotechnology Division, Institute of Himalayan Bioresource Technology, Palampur 176 061, India ... Under optimal conditions of growth, senescence, a terminal phase of development, sets in after a certain physio- logical age. It is a dynamic ..... Escribano M I and Merodio C 1994 The relevance of polyamine levels in ...

  6. Testosterone supplementation restores vasopressin innervation in the senescent rat brain

    NARCIS (Netherlands)

    Goudsmit, E.; Fliers, E.; Swaab, D. F.

    1988-01-01

    The vasopressin (AVP) innervation in the male rat brain is decreased in senescence. This decrease is particularly pronounced in brain regions where AVP fiber density is dependent on plasma levels of sex steroids. Since plasma testosterone levels decrease progressively with age in the rat, the

  7. Functional age as an indicator of reservoir senescence

    Science.gov (United States)

    Miranda, Leandro E.; Krogman, R. M.

    2015-01-01

    It has been conjectured that reservoirs differ in the rate at which they manifest senescence, but no attempt has been made to find an indicator of senescence that performs better than chronological age. We assembled an indicator of functional age by creating a multimetric scale consisting of 10 metrics descriptive of reservoir environments that were expected to change directionally with reservoir senescence. In a sample of 1,022 U.S. reservoirs, chronological age was not correlated with functional age. Functional age was directly related to percentage of cultivated land in the catchment and inversely related to reservoir depth. Moreover, aspects of reservoir fishing quality and fish population characteristics were related to functional age. A multimetric scale to indicate reservoir functional age presents the possibility for management intervention from multiple angles. If a reservoir is functionally aging at an accelerated rate, action may be taken to remedy the conditions contributing most to functional age. Intervention to reduce scores of selected metrics in the scale can potentially reduce the rate of senescence and increase the life expectancy of the reservoir. This leads to the intriguing implication that steps can be taken to reduce functional age and actually make the reservoir grow younger.

  8. Transcriptome profiling reveals regulatory mechanisms underlying Corolla Senescence in Petunia

    Science.gov (United States)

    Genetic regulatory mechanisms that govern petal natural senescence in petunia is complicated and unclear. To identify key genes and pathways that regulate the process, we initiated a transcriptome analysis in petunia petals at four developmental time points, including petal opening without anthesis ...

  9. F4/80+ Macrophages Contribute to Clearance of Senescent Cells in the Mouse Postpartum Uterus.

    Science.gov (United States)

    Egashira, Mahiro; Hirota, Yasushi; Shimizu-Hirota, Ryoko; Saito-Fujita, Tomoko; Haraguchi, Hirofumi; Matsumoto, Leona; Matsuo, Mitsunori; Hiraoka, Takehiro; Tanaka, Tomoki; Akaeda, Shun; Takehisa, Chiaki; Saito-Kanatani, Mayuko; Maeda, Kei-Ichiro; Fujii, Tomoyuki; Osuga, Yutaka

    2017-07-01

    Cellular senescence, defined as an irreversible cell cycle arrest, exacerbates the tissue microenvironment. Our previous study demonstrated that mouse uterine senescent cells were physiologically increased according to gestational days and that their abnormal accumulation was linked to the onset of preterm delivery. We hypothesized that there is a mechanism for removal of senescent cells after parturition to maintain uterine function. In the current study, we noted abundant uterine senescent cells and their gradual disappearance in wild-type postpartum mice. F4/80+ macrophages were present specifically around the area rich in senescent cells. Depletion of macrophages in the postpartum mice using anti-F4/80 antibody enlarged the area of senescent cells in the uterus. We also found excessive uterine senescent cells and decreased second pregnancy success rate in a preterm birth model using uterine p53-deleted mice. Furthermore, a decrease in F4/80+ cells and an increase in CD11b+ cells with a senescence-associated inflammatory microenvironment were observed in the p53-deleted uterus, suggesting that uterine p53 deficiency affects distribution of the macrophage subpopulation, interferes with senescence clearance, and promotes senescence-induced inflammation. These findings indicate that the macrophage is a key player in the clearance of uterine senescent cells to maintain postpartum uterine function. Copyright © 2017 Endocrine Society.

  10. Selective elimination of senescent cells by mitochondrial targeting is regulated by ANT2

    DEFF Research Database (Denmark)

    Hubackova, Sona; Davidova, Eliska; Rohlenova, Katerina

    2018-01-01

    and development of age-related diseases. We found that the anticancer agent mitochondria-targeted tamoxifen (MitoTam), unlike conventional anticancer agents, kills cancer cells without inducing senescence in vitro and in vivo. Surprisingly, it also selectively eliminates both malignant and non-cancerous senescent...... cells. In naturally aged mice treated with MitoTam for 4 weeks, we observed a significant decrease of senescence markers in all tested organs compared to non-treated animals. Mechanistically, we found that the susceptibility of senescent cells to MitoTam is linked to a very low expression level...... of adenine nucleotide translocase-2 (ANT2), inherent to the senescent phenotype. Restoration of ANT2 in senescent cells resulted in resistance to MitoTam, while its downregulation in non-senescent cells promoted their MitoTam-triggered elimination. Our study documents a novel, translationally intriguing role...

  11. HJURP regulates cellular senescence in human fibroblasts and endothelial cells via a p53-dependent pathway.

    Science.gov (United States)

    Heo, Jong-Ik; Cho, Jung Hee; Kim, Jae-Ryong

    2013-08-01

    Holliday junction recognition protein (HJURP), a centromere protein-A (CENP-A) histone chaperone, mediates centromere-specific assembly of CENP-A nucleosome, contributing to high-fidelity chromosome segregation during cell division. However, the role of HJURP in cellular senescence of human primary cells remains unclear. We found that the expression levels of HJURP decreased in human dermal fibroblasts and umbilical vein endothelial cells in replicative or premature senescence. Ectopic expression of HJURP in senescent cells partially overcame cell senescence. Conversely, downregulation of HJURP in young cells led to premature senescence. p53 knockdown, but not p16 knockdown, abolished senescence phenotypes caused by HJURP reduction. These data suggest that HJURP plays an important role in the regulation of cellular senescence through a p53-dependent pathway and might contribute to tissue or organismal aging and protection of cellular transformation.

  12. Mitochondrial pAL2-1 plasmid homologs are senescence factors in Podospora anserina independent of intrinsic senescence

    NARCIS (Netherlands)

    Diepeningen, van A.D.; Debets, A.J.M.; Slakhorst-Wandel, S.M.; Hoekstra, R.F.

    2008-01-01

    Since the first description of a linear mitochondrial plasmid in Podospora anserina, pAL2-1, and homologous plasmids have gone from being considered beneficial longevity plasmids, via neutral genetic elements, toward mutator plasmids causing senescence. The plasmid has an invertron structure, with

  13. Mitochondrial pAL2-1 plasmid homologs are senescence factors in Podospora anserina independent of intrinsic senescence

    NARCIS (Netherlands)

    van Diepeningen, Anne D; Debets, Alfons J M; Slakhorst, S Marijke; Hoekstra, Rolf F

    Since the first description of a linear mitochondrial plasmid in Podospora anserina, pAL2-1, and homologous plasmids have gone from being considered beneficial longevity plasmids, via neutral genetic elements, toward mutator plasmids causing senescence. The plasmid has an invertron structure, with

  14. OLED displays and lighting

    CERN Document Server

    Koden, Mitsuhiro

    2017-01-01

    Organic light-emitting diodes (OLEDs) have emerged as the leading technology for the new display and lighting market. OLEDs are solid-state devices composed of thin films of organic molecules that create light with the application of electricity. OLEDs can provide brighter, crisper displays on electronic devices and use less power than conventional light-emitting diodes (LEDs) or liquid crystal displays (LCDs) used today. This book covers both the fundamentals and practical applications of flat and flexible OLEDs.

  15. Scalable Resolution Display Walls

    KAUST Repository

    Leigh, Jason; Johnson, Andrew; Renambot, Luc; Peterka, Tom; Jeong, Byungil; Sandin, Daniel J.; Talandis, Jonas; Jagodic, Ratko; Nam, Sungwon; Hur, Hyejung; Sun, Yiwen

    2013-01-01

    This article will describe the progress since 2000 on research and development in 2-D and 3-D scalable resolution display walls that are built from tiling individual lower resolution flat panel displays. The article will describe approaches and trends in display hardware construction, middleware architecture, and user-interaction design. The article will also highlight examples of use cases and the benefits the technology has brought to their respective disciplines. © 1963-2012 IEEE.

  16. JAVA Stereo Display Toolkit

    Science.gov (United States)

    Edmonds, Karina

    2008-01-01

    This toolkit provides a common interface for displaying graphical user interface (GUI) components in stereo using either specialized stereo display hardware (e.g., liquid crystal shutter or polarized glasses) or anaglyph display (red/blue glasses) on standard workstation displays. An application using this toolkit will work without modification in either environment, allowing stereo software to reach a wider audience without sacrificing high-quality display on dedicated hardware. The toolkit is written in Java for use with the Swing GUI Toolkit and has cross-platform compatibility. It hooks into the graphics system, allowing any standard Swing component to be displayed in stereo. It uses the OpenGL graphics library to control the stereo hardware and to perform the rendering. It also supports anaglyph and special stereo hardware using the same API (application-program interface), and has the ability to simulate color stereo in anaglyph mode by combining the red band of the left image with the green/blue bands of the right image. This is a low-level toolkit that accomplishes simply the display of components (including the JadeDisplay image display component). It does not include higher-level functions such as disparity adjustment, 3D cursor, or overlays all of which can be built using this toolkit.

  17. Displays and simulators

    Science.gov (United States)

    Mohon, N.

    A 'simulator' is defined as a machine which imitates the behavior of a real system in a very precise manner. The major components of a simulator and their interaction are outlined in brief form, taking into account the major components of an aircraft flight simulator. Particular attention is given to the visual display portion of the simulator, the basic components of the display, their interactions, and their characteristics. Real image displays are considered along with virtual image displays, and image generators. Attention is given to an advanced simulator for pilot training, a holographic pancake window, a scan laser image generator, the construction of an infrared target simulator, and the Apollo Command Module Simulator.

  18. Assessment of health status by molecular measures in adults ranging from middle-aged to old

    DEFF Research Database (Denmark)

    Waaijer, M. E. C.; Westendorp, R. G. J.; Goldeck, D.

    2017-01-01

    In addition to measures already used in clinical practice, molecular measures have been proposed to assess health status, but these have not yet been introduced into clinical practice. We aimed to test the association of functional capacity measures used in current practice and molecular measures...... with age and health status. The cohort consisted of 178 middle-aged to old participants of the Leiden Longevity Study (range 42-82years). We tested associations between functional capacity measures (physical tests: grip strength, 4-meter walk, chair stand test; cognitive tests: Stroop test, digit symbol...... substitution test and 15-picture learning test) with age and with cardiovascular or metabolic disease as a measure of the health status. These associations with age and health status were also tested for molecular measures (C reactive protein (CRP), numbers of senescent p16INK4a positive cells in the epidermis...

  19. Chlorophyll loss associated with heat-induced senescence in bentgrass.

    Science.gov (United States)

    Jespersen, David; Zhang, Jing; Huang, Bingru

    2016-08-01

    Heat stress-induced leaf senescence is characterized by the loss of chlorophyll from leaf tissues. The objectives of this study were to examine genetic variations in the level of heat-induced leaf senescence in hybrids of colonial (Agrostis capillaris)×creeping bentgrass (Agrostis stolonifera) contrasting in heat tolerance, and determine whether loss of leaf chlorophyll during heat-induced leaf senescence was due to suppressed chlorophyll synthesis and/or accelerated chlorophyll degradation in the cool-season perennial grass species. Plants of two hybrid backcross genotypes ('ColxCB169' and 'ColxCB190') were exposed to heat stress (38/33°C, day/night) for 28 d in growth chambers. The analysis of turf quality, membrane stability, photochemical efficiency, and chlorophyll content demonstrated significant variations in the level of leaf senescence induced by heat stress between the two genotypes, with ColXCB169 exhibiting a lesser degree of decline in chlorophyll content, photochemical efficiency and membrane stability than ColXCB190. The assays of enzymatic activity or gene expression of several major chlorophyll-synthesizing (porphobilinogen deaminase, Mg-chelatase, protochlorophyllide-reductase) and chlorophyll-degrading enzymes (chlorophyllase, pheophytinase, and chlorophyll-degrading peroxidase) indicated heat-induced decline in leaf chlorophyll content was mainly due to accelerated chlorophyll degradation, as manifested by increased gene expression levels of chlorophyllase and pheophytinase, and the activity of pheophytinase (PPH), while chlorophyll-synthesizing genes and enzymatic activities were not differentially altered by heat stress in the two genotypes. The analysis of heat-induced leaf senescence of pph mutants of Arabidopsis further confirmed that PPH could be one enzymes that plays key roles in regulating heat-accelerated chlorophyll degradation. Further research on enzymes responsible in part for the loss of chlorophyll during heat

  20. Displays enabling mobile multimedia

    Science.gov (United States)

    Kimmel, Jyrki

    2007-02-01

    With the rapid advances in telecommunications networks, mobile multimedia delivery to handsets is now a reality. While a truly immersive multimedia experience is still far ahead in the mobile world, significant advances have been made in the constituent audio-visual technologies to make this become possible. One of the critical components in multimedia delivery is the mobile handset display. While such alternatives as headset-style near-to-eye displays, autostereoscopic displays, mini-projectors, and roll-out flexible displays can deliver either a larger virtual screen size than the pocketable dimensions of the mobile device can offer, or an added degree of immersion by adding the illusion of the third dimension in the viewing experience, there are still challenges in the full deployment of such displays in real-life mobile communication terminals. Meanwhile, direct-view display technologies have developed steadily, and can provide a development platform for an even better viewing experience for multimedia in the near future. The paper presents an overview of the mobile display technology space with an emphasis on the advances and potential in developing direct-view displays further to meet the goal of enabling multimedia in the mobile domain.

  1. Visual merchandising window display

    Directory of Open Access Journals (Sweden)

    Opris (Cas. Stanila M.

    2013-12-01

    Full Text Available Window display plays a major part in the selling strategies; it does not only include the simple display of goods, nowadays it is a form of art, also having the purpose of sustaining the brand image. This article wants to reveal the tools that are essential in creating a fabulous window display. Being a window designer is not an easy job, you have to always think ahead trends, to have a sense of colour, to know how to use light to attract customers in the store after only one glance at the window. The big store window displays are theatre scenes: with expensive backgrounds, special effects and high fashion mannequins. The final role of the displays is to convince customers to enter the store and trigger the purchasing act which is the final goal of the retail activity.

  2. The impact of cellular senescence in skin ageing: A notion of mosaic and therapeutic strategies.

    Science.gov (United States)

    Toutfaire, Marie; Bauwens, Emilie; Debacq-Chainiaux, Florence

    2017-10-15

    Cellular senescence is now recognized as one of the nine hallmarks of ageing. Recent data show the involvement of senescent cells in tissue ageing and some age-related diseases. Skin represents an ideal model for the study of ageing. Indeed, skin ageing varies between individuals depending on their chronological age but also on their exposure to various exogenous factors (mainly ultraviolet rays). If senescence traits can be detected with ageing in the skin, the senescent phenotype varies among the various skin cell types. Moreover, the origin of cellular senescence in the skin is still unknown, and multiple origins are possible. This reflects the mosaic of skin ageing. Senescent cells can interfere with their microenvironment, either via the direct secretion of factors (the senescence-associated secretory phenotype) or via other methods of communication, such as extracellular vesicles. Knowledge regarding the impact of cellular senescence on skin ageing could be integrated into dermatology research, especially to limit the appearance of senescent cells after photo(chemo)therapy or in age-related skin diseases. Therapeutic approaches include the clearance of senescent cells via the use of senolytics or via the cooperation with the immune system. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Oxygen concentration modulates cellular senescence and autophagy in human trophoblast cells.

    Science.gov (United States)

    Seno, Kotomi; Tanikawa, Nao; Takahashi, Hironori; Ohkuchi, Akihide; Suzuki, Hirotada; Matsubara, Shigeki; Iwata, Hisataka; Kuwayama, Takehito; Shirasuna, Koumei

    2018-02-15

    We investigated the effect of oxygen concentrations on cellular senescence and autophagy and examined the role of autophagy in human trophoblast cells. Human first-trimester trophoblast cells (Sw.71) were incubated under 21%, 5%, or 1% O 2 concentrations for 24 hours. We examined the extent of senescence caused using senescence-associated β-galactosidase (SA-β-Gal) and senescence-associated secretory phenotype (SASP) as markers. Moreover, we examined the role of autophagy in causing cellular senescence using an autophagy inhibitor (3-methyladenine, 3MA). Physiological normoxia (5% O 2 ) decreased SA-β-Gal-positive cells and SASP including interleukin-6 (IL-6) and IL-8 compared with cultured cells in 21% O 2 . Pathophysiological hypoxia (1% O 2 ) caused cytotoxicity, including extracellular release of ATP and lactate dehydrogenase, and decreased senescence phenotypes. 3MA-treated trophoblast cells significantly suppressed senescence markers (SA-β-Gal-positive cells and SASP secretion) in O 2 -independent manner. We conclude that O 2 concentration modulates cellular senescence phenotypes regulating autophagy in the human trophoblast cells. Moreover, inhibiting autophagy suppresses cellular senescence, suggesting that autophagy contributes to oxygen stress-induced cellular senescence. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Astragaloside IV Prevents Cardiac Remodeling in the Apolipoprotein E-Deficient Mice by Regulating Cardiac Homeostasis and Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Xiong-Zhi Li

    2017-12-01

    Full Text Available Background: Hypercholesterolemia is a risk factor for the development of cardiac hypertrophy. Astragaloside IV (AST-IV possesses cardiovascular protective properties. We hypothesize that AST-IV prevents cardiac remodeling with hypercholesterolemia via modulating tissue homeostasis and alleviating oxidative stress. Methods: The ApoE-/- mice were treated with AST-IV at 1 or 10 mg/kg for 8 weeks. The blood lipids tests, echocardiography, and TUNEL were performed. The mRNA expression profile was detected by real-time PCR. The myocytes size and number, and the expressions of proliferation (ki67, senescence (p16INK4a, oxidant (NADPH oxidase 4, NOX4 and antioxidant (superoxide dismutase, SOD were observed by immunofluorescence staining. Results: Neither 1 mg/kg nor 10 mg/kg AST-IV treatment could decrease blood lipids in ApoE-/- mice. However, the decreased left ventricular ejection fraction (LVEF and fractional shortening (FS in ApoE–/– mice were significantly improved after AST-IV treatment. The cardiac collagen volume fraction declined nearly in half after AST-IV treatment. The enlarged myocyte size was suppressed, and myocyte number was recovered, and the alterations of genes expressions linked to cell cycle, proliferation, senescence, p53-apoptosis pathway and oxidant-antioxidants in the hearts of ApoE-/- mice were reversed after AST-IV treatment. The decreased ki67 and increased p16INK4a in the hearts of ApoE-/- mice were recovered after AST-IV treatment. The percentages of apoptotic myocytes and NOX4-positive cells in AST-IV treated mice were decreased, which were consistent with the gene expressions. Conclusion: AST-IV treatment could prevent cardiac remodeling and recover the impaired ventricular function induced by hypercholesterolemia. The beneficial effect of AST-IV might partly be through regulating cardiac homeostasis and anti-oxidative stress.

  5. In vivo inhibition of cysteine proteases provides evidence for the involvement of 'senescence-associated vacuoles' in chloroplast protein degradation during dark-induced senescence of tobacco leaves.

    Science.gov (United States)

    Carrión, Cristian A; Costa, María Lorenza; Martínez, Dana E; Mohr, Christina; Humbeck, Klaus; Guiamet, Juan J

    2013-11-01

    Breakdown of leaf proteins, particularly chloroplast proteins, is a massive process in senescing leaves. In spite of its importance in internal N recycling, the mechanism(s) and the enzymes involved are largely unknown. Senescence-associated vacuoles (SAVs) are small, acidic vacuoles with high cysteine peptidase activity. Chloroplast-targeted proteins re-localize to SAVs during senescence, suggesting that SAVs might be involved in chloroplast protein degradation. SAVs were undetectable in mature, non-senescent tobacco leaves. Their abundance, visualized either with the acidotropic marker Lysotracker Red or by green fluorescent protein (GFP) fluorescence in a line expressing the senescence-associated cysteine protease SAG12 fused to GFP, increased during senescence induction in darkness, and peaked after 2-4 d, when chloroplast dismantling was most intense. Increased abundance of SAVs correlated with higher levels of SAG12 mRNA. Activity labelling with a biotinylated derivative of the cysteine protease inhibitor E-64 was used to detect active cysteine proteases. The two apparently most abundant cysteine proteases of senescing leaves, of 40kDa and 33kDa were detected in isolated SAVs. Rubisco degradation in isolated SAVs was completely blocked by E-64. Treatment of leaf disks with E-64 in vivo substantially reduced degradation of Rubisco and leaf proteins. Overall, these results indicate that SAVs contain most of the cysteine protease activity of senescing cells, and that SAV cysteine proteases are at least partly responsible for the degradation of stromal proteins of the chloroplast.

  6. Members of the barley NAC transcription factor gene family show differential co-regulation with senescence-associated genes during senescence of flag leaves

    DEFF Research Database (Denmark)

    Christiansen, Michael W; Gregersen, Per L.

    2014-01-01

    -expressed with members of the NAC gene family. In conclusion, a list of up to 15 NAC genes from barley that are strong candidates for being regulatory factors of importance for senescence and biotic stress-related traits affecting the productivity of cereal crop plants has been generated. Furthermore, a list of 71...... in the NAC transcription factor family during senescence of barley flag leaves was studied. Several members of the NAC transcription factor gene family were up-regulated during senescence in a microarray experiment, together with a large range of senescence-associated genes, reflecting the coordinated...... activation of degradation processes in senescing barley leaf tissues. This picture was confirmed in a detailed quantitative reverse transcription–PCR (qRT–PCR) experiment, which also showed distinct gene expression patterns for different members of the NAC gene family, suggesting a group of ~15 out of the 47...

  7. The role of SUMOylation in ageing and senescent decline.

    Science.gov (United States)

    Princz, Andrea; Tavernarakis, Nektarios

    2017-03-01

    Posttranslational protein modifications are playing crucial roles in essential cellular mechanisms. SUMOylation is a reversible posttranslational modification of specific target proteins by the attachment of a small ubiquitin-like protein. Although the mechanism of conjugation of SUMO to proteins is analogous to ubiquitination, it requires its own, specific set of enzymes. The consequences of SUMOylation are widely variable, depending on the physiological state of the cell and the attached SUMO isoform. Accumulating recent findings have revealed a prominent role of SUMOylation in molecular pathways that govern senescence and ageing. Here, we review the link between SUMO attachment events and cellular processes that influence senescence and ageing, including promyelocytic leukaemia (PML) nuclear body and telomere function, autophagy, reactive oxygen species (ROS) homeostasis and growth factor signalling. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Stress-induced premature senescence of endothelial cells.

    Science.gov (United States)

    Chen, Jun; Patschan, Susann; Goligorsky, Michael S

    2008-01-01

    Stress-induced premature senescence (SIPS) is characterized by cell cycle arrest and curtailed Hayflick limit. Studies support a central role for Rb protein in controlling this process via signaling from the p53 and p16 pathways. Cellular senescence is considered an essential contributor to the aging process and has been shown to be an important tumor suppression mechanism. In addition, emerging evidence suggests that SIPS may be involved in the pathogenesis of chronic human diseases. Here, focusing on endothelial cells, we discuss recent advances in our understanding of SIPS and the pathways that trigger it, evaluate their correlation with the apoptotic response and examine their links to the development of chronic diseases, with the emphasis on vasculopathy. Emerging novel therapeutic interventions based on recent experimental findings are also reviewed.

  9. Microlaser-based displays

    Science.gov (United States)

    Bergstedt, Robert; Fink, Charles G.; Flint, Graham W.; Hargis, David E.; Peppler, Philipp W.

    1997-07-01

    Laser Power Corporation has developed a new type of projection display, based upon microlaser technology and a novel scan architecture, which provides the foundation for bright, extremely high resolution images. A review of projection technologies is presented along with the limitations of each and the difficulties they experience in trying to generate high resolution imagery. The design of the microlaser based projector is discussed along with the advantage of this technology. High power red, green, and blue microlasers have been designed and developed specifically for use in projection displays. These sources, in combination with high resolution, high contrast modulator, produce a 24 bit color gamut, capable of supporting the full range of real world colors. The new scan architecture, which reduces the modulation rate and scan speeds required, is described. This scan architecture, along with the inherent brightness of the laser provides the fundamentals necessary to produce a 5120 by 4096 resolution display. The brightness and color uniformity of the display is excellent, allowing for tiling of the displays with far fewer artifacts than those in a traditionally tiled display. Applications for the display include simulators, command and control centers, and electronic cinema.

  10. Immune senescence: relative contributions of age and cytomegalovirus infection.

    Directory of Open Access Journals (Sweden)

    Andrea Mekker

    Full Text Available Immune senescence, defined as the age-associated dysregulation and dysfunction of the immune system, is characterised by impaired protective immunity and decreased efficacy of vaccines. Recent clinical, epidemiological and immunological studies suggest that Cytomegalovirus (CMV infection may be associated with accelerated immune senescence, possibly by restricting the naïve T cell repertoire. However, direct evidence whether and how CMV-infection is implicated in immune senescence is still lacking. In this study, we have investigated whether latent mouse CMV (MCMV infection with or without thymectomy (Tx alters antiviral immunity of young and aged mice. After infection with lymphocytic choriomeningitis virus (LCMV or Vaccinia virus, specific antiviral T cell responses were significantly reduced in old, old MCMV-infected and/or Tx mice compared to young mice. Importantly, control of LCMV replication was more profoundly impaired in aged MCMV-infected mice compared to age-matched MCMV-naïve or young mice. In addition, latent MCMV infection was associated with slightly reduced vaccination efficacy in old Tx mice. In contrast to the prevailing hypothesis of a CMV-mediated restriction of the naïve T cell repertoire, we found similar naïve T cell numbers in MCMV-infected and non-infected mice, whereas ageing and Tx clearly reduced the naïve T cell pool. Instead, MCMV-infection expanded the total CD8(+ T cell pool by a massive accumulation of effector memory T cells. Based on these results, we propose a new model of increased competition between CMV-specific memory T cells and any 'de novo' immune response in aged individuals. In summary, our results directly demonstrate in a mouse model that latent CMV-infection impairs immunity in old age and propagates immune senescence.

  11. A continuum mathematical model of endothelial layer maintenance and senescence

    Directory of Open Access Journals (Sweden)

    Friedman Avner

    2007-08-01

    Full Text Available Abstract Background The monolayer of endothelial cells (ECs lining the inner wall of blood vessels deteriorates as a person ages due to a complex interplay of a variety of causes including cell death arising from shear stress of blood flow and cellular oxidative stress, cellular senescence, and decreased rate of replacement of dead ECs by progenitor stem cells. Results A continuum mathematical model is developed to describe the dynamics of large EC populations of the endothelium using a system of differential equations for the number densities of cells of different generations starting from endothelial progenitors to senescent cells, as well as the densities of dead cells and the holes created upon clearing dead cells. Aging of cells is manifested in three ways, namely, losing the ability to divide when the Hayflick limit of 50 generations is reached, decreasing replication rate parameters and increasing death rate parameters as cells divide; due to the dependence of these rate parameters on cell generation, the model predicts a narrow distribution of cell densities peaking at a particular cell generation. As the chronological age of a person advances, the peak of the distribution – corresponding to the age of the endothelium – moves towards senescence correspondingly. However, computer simulations also demonstrate that sustained and enhanced stem cell homing can halt the aging process of the endothelium by maintaining a stationary cell density distribution that peaks well before the Hayflick limit. The healing rates of damaged endothelia for young, middle-aged, and old persons are compared and are found to be particularly sensitive to the stem cell homing parameter. Conclusion The proposed model describes the aging of the endothelium as being driven by cellular senescence, with a rate that does not necessarily correspond to the chronological aging of a person. It is shown that the age of the endothelium depends sensitively on the homing

  12. A continuum mathematical model of endothelial layer maintenance and senescence.

    Science.gov (United States)

    Wang, Ying; Aguda, Baltazar D; Friedman, Avner

    2007-08-10

    The monolayer of endothelial cells (ECs) lining the inner wall of blood vessels deteriorates as a person ages due to a complex interplay of a variety of causes including cell death arising from shear stress of blood flow and cellular oxidative stress, cellular senescence, and decreased rate of replacement of dead ECs by progenitor stem cells. A continuum mathematical model is developed to describe the dynamics of large EC populations of the endothelium using a system of differential equations for the number densities of cells of different generations starting from endothelial progenitors to senescent cells, as well as the densities of dead cells and the holes created upon clearing dead cells. Aging of cells is manifested in three ways, namely, losing the ability to divide when the Hayflick limit of 50 generations is reached, decreasing replication rate parameters and increasing death rate parameters as cells divide; due to the dependence of these rate parameters on cell generation, the model predicts a narrow distribution of cell densities peaking at a particular cell generation. As the chronological age of a person advances, the peak of the distribution - corresponding to the age of the endothelium - moves towards senescence correspondingly. However, computer simulations also demonstrate that sustained and enhanced stem cell homing can halt the aging process of the endothelium by maintaining a stationary cell density distribution that peaks well before the Hayflick limit. The healing rates of damaged endothelia for young, middle-aged, and old persons are compared and are found to be particularly sensitive to the stem cell homing parameter. The proposed model describes the aging of the endothelium as being driven by cellular senescence, with a rate that does not necessarily correspond to the chronological aging of a person. It is shown that the age of the endothelium depends sensitively on the homing rates of EC progenitor cells.

  13. Cytokines shape chemotherapy-induced and 'bystander' senescence

    Czech Academy of Sciences Publication Activity Database

    Hodný, Zdeněk; Hubáčková, Soňa; Bartek, Jiří

    2010-01-01

    Roč. 2, č. 2 (2010), s. 375-376 ISSN 1945-4589 R&D Projects: GA ČR GA204/08/1418; GA ČR GA301/08/0353 Institutional research plan: CEZ:AV0Z50520514 Keywords : bystander cellular senescence * cytokines * PML Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.964, year: 2010

  14. Cytoplasmic chromatin triggers inflammation in senescence and cancer.

    Science.gov (United States)

    Dou, Zhixun; Ghosh, Kanad; Vizioli, Maria Grazia; Zhu, Jiajun; Sen, Payel; Wangensteen, Kirk J; Simithy, Johayra; Lan, Yemin; Lin, Yanping; Zhou, Zhuo; Capell, Brian C; Xu, Caiyue; Xu, Mingang; Kieckhaefer, Julia E; Jiang, Tianying; Shoshkes-Carmel, Michal; Tanim, K M Ahasan Al; Barber, Glen N; Seykora, John T; Millar, Sarah E; Kaestner, Klaus H; Garcia, Benjamin A; Adams, Peter D; Berger, Shelley L

    2017-10-19

    Chromatin is traditionally viewed as a nuclear entity that regulates gene expression and silencing. However, we recently discovered the presence of cytoplasmic chromatin fragments that pinch off from intact nuclei of primary cells during senescence, a form of terminal cell-cycle arrest associated with pro-inflammatory responses. The functional significance of chromatin in the cytoplasm is unclear. Here we show that cytoplasmic chromatin activates the innate immunity cytosolic DNA-sensing cGAS-STING (cyclic GMP-AMP synthase linked to stimulator of interferon genes) pathway, leading both to short-term inflammation to restrain activated oncogenes and to chronic inflammation that associates with tissue destruction and cancer. The cytoplasmic chromatin-cGAS-STING pathway promotes the senescence-associated secretory phenotype in primary human cells and in mice. Mice deficient in STING show impaired immuno-surveillance of oncogenic RAS and reduced tissue inflammation upon ionizing radiation. Furthermore, this pathway is activated in cancer cells, and correlates with pro-inflammatory gene expression in human cancers. Overall, our findings indicate that genomic DNA serves as a reservoir to initiate a pro-inflammatory pathway in the cytoplasm in senescence and cancer. Targeting the cytoplasmic chromatin-mediated pathway may hold promise in treating inflammation-related disorders.

  15. Ageing induced vascular smooth muscle cell senescence in atherosclerosis.

    Science.gov (United States)

    Uryga, Anna K; Bennett, Martin R

    2016-04-15

    Atherosclerosis is a disease of ageing in that its incidence and prevalence increase with age. However, atherosclerosis is also associated with biological ageing, manifest by a number of typical hallmarks of ageing in the atherosclerotic plaque. Thus, accelerated biological ageing may be superimposed on the effects of chronological ageing in atherosclerosis. Tissue ageing is seen in all cells that comprise the plaque, but particularly in vascular smooth muscle cells (VSMCs). Hallmarks of ageing include evidence of cell senescence, DNA damage (including telomere attrition), mitochondrial dysfunction, a pro-inflammatory secretory phenotype, defects in proteostasis, epigenetic changes, deregulated nutrient sensing, and exhaustion of progenitor cells. In this model, initial damage to DNA (genomic, telomeric, mitochondrial and epigenetic changes) results in a number of cellular responses (cellular senescence, deregulated nutrient sensing and defects in proteostasis). Ultimately, ongoing damage and attempts at repair by continued proliferation overwhelm reparative capacity, causing loss of specialised cell functions, cell death and inflammation. This review summarises the evidence for accelerated biological ageing in atherosclerosis, the functional consequences of cell ageing on cells comprising the plaque, and the causal role that VSMC senescence plays in atherogenesis. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  16. Oxidative stress induces senescence in human mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Brandl, Anita [Department of Anesthesiology, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 11, 93042 Regensburg (Germany); Meyer, Matthias; Bechmann, Volker [Department of Trauma Surgery, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 11, 93042 Regensburg (Germany); Nerlich, Michael [Department of Anesthesiology, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 11, 93042 Regensburg (Germany); Angele, Peter, E-mail: Peter.Angele@klinik.uni-regensburg.de [Department of Trauma Surgery, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 11, 93042 Regensburg (Germany)

    2011-07-01

    Mesenchymal stem cells (MSCs) contribute to tissue repair in vivo and form an attractive cell source for tissue engineering. Their regenerative potential is impaired by cellular senescence. The effects of oxidative stress on MSCs are still unknown. Our studies were to investigate into the proliferation potential, cytological features and the telomere linked stress response system of MSCs, subject to acute or prolonged oxidant challenge with hydrogen peroxide. Telomere length was measured using the telomere restriction fragment assay, gene expression was determined by rtPCR. Sub-lethal doses of oxidative stress reduced proliferation rates and induced senescent-morphological features and senescence-associated {beta}-galactosidase positivity. Prolonged low dose treatment with hydrogen peroxide had no effects on cell proliferation or morphology. Sub-lethal and prolonged low doses of oxidative stress considerably accelerated telomere attrition. Following acute oxidant insult p21 was up-regulated prior to returning to initial levels. TRF1 was significantly reduced, TRF2 showed a slight up-regulation. SIRT1 and XRCC5 were up-regulated after oxidant insult and expression levels increased in aging cells. Compared to fibroblasts and chondrocytes, MSCs showed an increased tolerance to oxidative stress regarding proliferation, telomere biology and gene expression with an impaired stress tolerance in aged cells.

  17. The thorny path linking cellular senescence to organismalaging

    Energy Technology Data Exchange (ETDEWEB)

    Patil, Christopher K.; Mian, Saira; Campisi, Judith

    2005-08-09

    Half a century is fast approaching since Hayflick and colleagues formally described the limited ability of normal human cells to proliferate in culture (Hayflick and Moorhead, 1961). This finding--that normal somatic cells, in contrast to cancer cells, cannot divide indefinitely--challenged the prevailing idea that cells from mortal multicellular organisms were intrinsically ''immortal'' (Carrell, 1912). It also spawned two hypotheses, essential elements of which persist today. The first held that the restricted proliferation of normal cells, now termed cellular senescence, suppresses cancer (Hayflick, 1965; Sager, 1991; Campisi, 2001). The second hypothesis, as explained in the article by Lorenzini et al., suggested that the limited proliferation of cells in culture recapitulated aspects of organismal aging (Hayflick, 1965; Martin, 1993). How well have these hypotheses weathered the ensuing decades? Before answering this question, we first consider current insights into the causes and consequences of cellular senescence. Like Lorenzini et al., we limit our discussion to mammals. We also focus on fibroblasts, the cell type studied by Lorenzini et al., but consider other types as well. We suggest that replicative capacity in culture is not a straightforward assessment, and that it correlates poorly with both longevity and body mass. We speculate this is due to the malleable and variable nature of replicative capacity, which renders it an indirect metric of qualitative and quantitative differences among cells to undergo senescence, a response that directly alters cellular phenotype and might indirectly alter tissue structure and function.

  18. ENERGY STAR Certified Displays

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 7.0 ENERGY STAR Program Requirements for Displays that are effective as of July 1, 2016....

  19. Improvements in data display

    International Nuclear Information System (INIS)

    Ellis, G.W.

    1979-01-01

    An analog signal processor is described in this patent for connecting a source of analog signals to a cathode ray tube display in order to extend the dynamic range of the display. This has important applications in the field of computerised X-ray tomography since significant medical information, such as tumours in soft tissue, is often represented by minimal level changes in image density. Cathode ray tube displays are limited to approximately 15 intensity levels. Thus if both strong and weak absorption of the X-rays occurs, the dynamic range of the transmitted signals will be too large to permit small variations to be examined directly on a cathode ray display. Present tomographic image reconstruction methods are capable of quantising X-ray absorption density measurements into 256 or more distinct levels and a description is given of the electronics which enables the upper and lower range of intensity levels to be independently set and continuously varied. (UK)

  20. Gamma camera display system

    International Nuclear Information System (INIS)

    Stout, K.J.

    1976-01-01

    A gamma camera having an array of photomultipliers coupled via pulse shaping circuitry and a resistor weighting circuit to a display for forming an image of a radioactive subject is described. A linearizing circuit is coupled to the weighting circuit, the linearizing circuit including a nonlinear feedback circuit with diode coupling to the weighting circuit for linearizing the correspondence between points of the display and points of the subject. 4 Claims, 5 Drawing Figures

  1. Flexible displays, rigid designs?

    DEFF Research Database (Denmark)

    Hornbæk, Kasper

    2015-01-01

    Rapid technological progress has enabled a wide range of flexible displays for computing devices, but the user experience--which we're only beginning to understand--will be the key driver for successful designs.......Rapid technological progress has enabled a wide range of flexible displays for computing devices, but the user experience--which we're only beginning to understand--will be the key driver for successful designs....

  2. MicroRNA-33 promotes the replicative senescence of mouse embryonic fibroblasts by suppressing CDK6

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Shun; Huang, Haijiao; Li, Nanhong; Zhang, Bing; Jia, Yubin; Yang, Yukun; Yuan, Yuan; Xiong, Xing-dong; Wang, Dengchuan; Zheng, Hui-ling [Institute of Aging Research, Guangdong Medical University, Dongguan (China); Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Dongguan (China); Institute of Biochemistry & Molecular Biology, Guangdong Medical University, Zhanjiang (China); Liu, Xinguang, E-mail: xgliu64@126.com [Institute of Aging Research, Guangdong Medical University, Dongguan (China); Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Dongguan (China); Institute of Biochemistry & Molecular Biology, Guangdong Medical University, Zhanjiang (China)

    2016-05-13

    MicroRNAs are a large class of tiny noncoding RNAs, which have emerged as critical regulators of gene expression, and thus are involved in multiple cellular processes, including cellular senescence. MicroRNA-33 has previously been established to exert crucial effect on cell proliferation, lipid metabolism and cholesterol metabolism. Nonetheless, the association between microRNA-33 and cellular senescence and its underlying molecular mechanism are far to be elucidated. The present study has attempted to probe into the effect of microRNA-33 on MEFs senescence. Our data unveiled that microRNA-33 was dramatically down-regulated in senescent MEFs compared to the young MEFs, and ectopic expression of microRNA-33 promoted MEFs senescence, while knock-down of microRNA-33 exhibited a protective effect against senescence phenotype. Moreover, we verified CDK6 as a direct target of microRNA-33 in mouse. Silencing of CDK6 induced the premature senescence phenotype of MEFs similarly as microRNA-33, while enforced expression of CDK6 significantly reverse the senescence-induction effect of microRNA-33. Taken together, our results suggested that microRNA-33 enhanced the replicative senescence of MEFs potentially by suppressing CDK6 expression. -- Highlights: •MicroRNA-33 was dramatically down-regulated in senescent MEF cells. •Altered expression of microRNA-33 exerted a critical role in MEFs senescence. •MicroRNA-33 promoted the replicative senescence of MEFs via targeting of CDK6.

  3. Senescence in the wild: Insights from a long-term study on Seychelles warblers.

    Science.gov (United States)

    Hammers, Martijn; Kingma, Sjouke A; Bebbington, Kat; van de Crommenacker, Janske; Spurgin, Lewis G; Richardson, David S; Burke, Terry; Dugdale, Hannah L; Komdeur, Jan

    2015-11-01

    Senescence--the progressive age-dependent decline in performance--occurs in most organisms. There is considerable variation in the onset and rate of senescence between and within species. Yet the causes of this variation are still poorly understood, despite being central to understanding the evolution of senescence. Long-term longitudinal studies on wild animals are extremely well-suited to studying the impact of environmental and individual characteristics (and the interaction between the two) on senescence, and can help us to understand the mechanisms that shape the evolution of senescence. In this review, we summarize and discuss the insights gained from our comprehensive long-term individual-based study of the Seychelles warbler (Acrocephalus sechellensis). This species provides an excellent model system in which to investigate the evolution of senescence in the wild. We found that Seychelles warblers show senescent declines in survival and reproduction, and discuss how individual characteristics (body condition, body size) and environmental effects (low- versus high-quality environments) may affect the onset and rate of senescence. Further, we highlight the evidence for trade-offs between early-life investment and senescence. We describe how key cellular and physiological processes (oxidative stress and telomere shortening) underpinning senescence are affected by individual and environmental characteristics in the Seychelles warbler (e.g. food availability, reproductive investment, disease) and we discuss how such physiological variation may mediate the relationship between environmental characteristics and senescence. Based on our work using Seychelles warblers as a model system, we show how insights from long-term studies of wild animals may help unravel the causes of the remarkable variation in senescence observed in natural systems, and highlight areas for promising future research.

  4. MicroRNA-33 promotes the replicative senescence of mouse embryonic fibroblasts by suppressing CDK6

    International Nuclear Information System (INIS)

    Xu, Shun; Huang, Haijiao; Li, Nanhong; Zhang, Bing; Jia, Yubin; Yang, Yukun; Yuan, Yuan; Xiong, Xing-dong; Wang, Dengchuan; Zheng, Hui-ling; Liu, Xinguang

    2016-01-01

    MicroRNAs are a large class of tiny noncoding RNAs, which have emerged as critical regulators of gene expression, and thus are involved in multiple cellular processes, including cellular senescence. MicroRNA-33 has previously been established to exert crucial effect on cell proliferation, lipid metabolism and cholesterol metabolism. Nonetheless, the association between microRNA-33 and cellular senescence and its underlying molecular mechanism are far to be elucidated. The present study has attempted to probe into the effect of microRNA-33 on MEFs senescence. Our data unveiled that microRNA-33 was dramatically down-regulated in senescent MEFs compared to the young MEFs, and ectopic expression of microRNA-33 promoted MEFs senescence, while knock-down of microRNA-33 exhibited a protective effect against senescence phenotype. Moreover, we verified CDK6 as a direct target of microRNA-33 in mouse. Silencing of CDK6 induced the premature senescence phenotype of MEFs similarly as microRNA-33, while enforced expression of CDK6 significantly reverse the senescence-induction effect of microRNA-33. Taken together, our results suggested that microRNA-33 enhanced the replicative senescence of MEFs potentially by suppressing CDK6 expression. -- Highlights: •MicroRNA-33 was dramatically down-regulated in senescent MEF cells. •Altered expression of microRNA-33 exerted a critical role in MEFs senescence. •MicroRNA-33 promoted the replicative senescence of MEFs via targeting of CDK6.

  5. Premature aging/senescence in cancer cells facing therapy: good or bad?

    Science.gov (United States)

    Gonzalez, Llilians Calvo; Ghadaouia, Sabrina; Martinez, Aurélie; Rodier, Francis

    2016-02-01

    Normal and cancer cells facing their demise following exposure to radio-chemotherapy can actively participate in choosing their subsequent fate. These programmed cell fate decisions include true cell death (apoptosis-necroptosis) and therapy-induced cellular senescence (TIS), a permanent "proliferative arrest" commonly portrayed as premature cellular aging. Despite a permanent loss of proliferative potential, senescent cells remain viable and are highly bioactive at the microenvironment level, resulting in a prolonged impact on tissue architecture and functions. Cellular senescence is primarily documented as a tumor suppression mechanism that prevents cellular transformation. In the context of normal tissues, cellular senescence also plays important roles in tissue repair, but contributes to age-associated tissue dysfunction when senescent cells accumulate. Theoretically, in multi-step cancer progression models, cancer cells have already bypassed cellular senescence during their immortalization step (see hallmarks of cancer). It is then perhaps surprising to find that cancer cells often retain the ability to undergo TIS, or premature aging. This occurs because cellular senescence results from multiple signalling pathways, some retained in cancer cells, aiming to prevent cell cycle progression in damaged cells. Since senescent cancer cells persist after therapy and secrete an array of cytokines and growth factors that can modulate the tumor microenvironment, these cells may have beneficial and detrimental effects regarding immune modulation and survival of remaining proliferation-competent cancer cells. Similarly, while normal cells undergoing senescence are believed to remain indefinitely growth arrested, whether this is true for senescent cancer cells remains unclear, raising the possibility that these cells may represent a reservoir for cancer recurrence after treatment. This review discusses our current knowledge on cancer cell senescence and highlight questions

  6. Redox regulation of peroxiredoxin and proteinases by ascorbate and thiols during pea root nodule senescence.

    Science.gov (United States)

    Groten, Karin; Dutilleul, Christelle; van Heerden, Philippus D R; Vanacker, Hélène; Bernard, Stéphanie; Finkemeier, Iris; Dietz, Karl-Josef; Foyer, Christine H

    2006-02-20

    Redox factors contributing to nodule senescence were studied in pea. The abundance of the nodule cytosolic peroxiredoxin but not the mitochondrial peroxiredoxin protein was modulated by ascorbate. In contrast to redox-active antioxidants such as ascorbate and cytosolic peroxiredoxin that decreased during nodule development, maximal extractable nodule proteinase activity increased progressively as the nodules aged. Cathepsin-like activities were constant throughout development but serine and cysteine proteinase activities increased during senescence. Senescence-induced cysteine proteinase activity was inhibited by cysteine, dithiotreitol, or E-64. Senescence-dependent decreases in redox-active factors, particularly ascorbate and peroxiredoxin favour decreased redox-mediated inactivation of cysteine proteinases.

  7. The emerging role of senescent cells in tissue homeostasis and pathophysiology

    Directory of Open Access Journals (Sweden)

    Kaoru Tominaga

    2015-05-01

    Full Text Available Cellular senescence is a state of permanent growth arrest and is thought to play a pivotal role in tumor suppression. Cellular senescence may play an important role in tumor suppression, wound healing, and protection against tissue fibrosis in physiological conditions in vivo. However, accumulating evidence that senescent cells may have harmful effects in vivo and may contribute to tissue remodeling, organismal aging, and many age-related diseases also exists. Cellular senescence can be induced by various intrinsic and extrinsic factors. Both p53/p21 and p16/RB pathways are important for irreversible growth arrest in senescent cells. Senescent cells secret numerous biologically active factors. This specific secretion phenotype by senescent cells may largely contribute to physiological and pathological consequences in organisms. Here I review the molecular basis of cell cycle arrest and the specific secretion phenotype in cellular senescence. I also summarize the current knowledge of the role of cellular senescence in vivo in physiological and pathological settings.

  8. Actuarial senescence in a long-lived orchid challenges our current understanding of ageing.

    Science.gov (United States)

    Dahlgren, Johan Petter; Colchero, Fernando; Jones, Owen R; Øien, Dag-Inge; Moen, Asbjørn; Sletvold, Nina

    2016-11-16

    The dominant evolutionary theory of actuarial senescence-an increase in death rate with advancing age-is based on the concept of a germ cell line that is separated from the somatic cells early in life. However, such a separation is not clear in all organisms. This has been suggested to explain the paucity of evidence for actuarial senescence in plants. We used a 32 year study of Dactylorhiza lapponica that replaces its organs each growing season, to test whether individuals of this tuberous orchid senesce. We performed a Bayesian survival trajectory analysis accounting for reproductive investment, for individuals under two types of land use, in two climatic regions. The mortality trajectory was best approximated by a Weibull model, showing clear actuarial senescence. Rates of senescence in this model declined with advancing age, but were slightly higher in mown plots and in the more benign climatic region. At older ages, senescence was evident only when accounting for a positive effect of reproductive investment on mortality. Our results demonstrate actuarial senescence as well as a survival-reproduction trade-off in plants, and indicate that environmental context may influence senescence rates. This knowledge is crucial for understanding the evolution of demographic senescence and for models of plant population dynamics. © 2016 The Author(s).

  9. Identification and characterization of secretory proteins during ionizing radiation-induced premature senescence

    International Nuclear Information System (INIS)

    Han, Na Kyung; Hong, Mi Na; Jung, Seung Hee; Kang, Kyoung Ah; Lee, Jae Seon; Chi, Seong Gil

    2011-01-01

    Cellular senescence was first described by Hayflick and Moorhead in 1961 who observed that cultures of normal human fibroblasts had a limited replicative potential and eventually became irreversibly arrest. The majority of senescent cells assume a characteristic flattened and enlarged morphological change, senescence associated β alactosidase positivity. Recently a large number of molecular phenotypes such as changes in gene expression, protein processing and chromatin organization have been also described. In contrast to apoptosis, senescence does not destroy the cells but leaves them metabolically and synthetically active and therefore able to affect their microenvironment. In particular, senescent fibroblasts and some cancer cells were found to secrete proteins with known or putative tumor-promoting functions such as growth factors or proteolytic enzymes. However, the knowledge about secreted proteins from senescent tumor cells and their functions to surrounding cells is still lacking. In this study, changes of senescence associated secretory protein expression profile were observed in MCF7 human breast cancer cells exposed to gamma-ray radiation using two dimensional electrophoresis. Also, we identified up-regulated secretory proteins during ionizing radiation-induced cellular senescence. Here, we show that senescent human breast cancer MCF7 cells promote the proliferation, invasion and migration of neighboring cells

  10. Aberrant localization of lamin B receptor (LBR) in cellular senescence in human cells

    Energy Technology Data Exchange (ETDEWEB)

    Arai, Rumi; En, Atsuki; Ukekawa, Ryo [Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027 (Japan); Miki, Kensuke [Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027 (Japan); Ichiban Life Corporation, 1-1-7 Horai-cho, Naka-ku, Yokohama 231-0048 (Japan); Fujii, Michihiko, E-mail: mifuji@yokohama-cu.ac.jp [Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027 (Japan); Ayusawa, Dai [Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027 (Japan); Ichiban Life Corporation, 1-1-7 Horai-cho, Naka-ku, Yokohama 231-0048 (Japan)

    2016-05-13

    5-Bromodeoxyuridine (BrdU), a thymidine analogue, induces cellular senescence in mammalian cells. BrdU induces cellular senescence probably through the regulation of chromatin because BrdU destabilizes or disrupts nucleosome positioning and decondenses heterochromatin. Since heterochromatin is tethered to the nuclear periphery through the interaction with the nuclear envelope proteins, we examined the localization of the several nuclear envelope proteins such as lamins, lamin-interacting proteins, nuclear pore complex proteins, and nuclear transport proteins in senescent cells. We have shown here that lamin B receptor (LBR) showed a change in localization in both BrdU-induced and replicative senescent cells.

  11. Physiological and biochemical aspects of flower development and senescence in Nicotiana plumbaginifolia Viv.

    Directory of Open Access Journals (Sweden)

    Nisar Shaziya

    2017-06-01

    Full Text Available Healthy buds of Nicotiana plumbaginifolia growing in the Kashmir University Botanic Garden were selected for the present study. Flower development and senescence was divided into seven stages, viz., tight bud stage (I, mature bud stage (II, pencil stage (III, partially open stage (IV, open stage (V, partially senescent stage (VI and senescent stage (VII. Various physiological and biochemical changes were recorded at each stage of flower development and senescence. Floral diameter, fresh mass, dry mass and water content showed an increase up to flower opening (stage V and thereafter a significant decrease was recorded as the flower development progressed towards senescence through stages VI and VII. An increase in α-amino acids, total phenols and sugars was registered towards anthesis (stage V and a decrease in these parameters was recorded with senescence. Protease activity showed a significant increase towards senescence with a concomitant decrease in soluble proteins. Based on the quantitative analysis of various biochemical parameters, the flower opening in N. plumbaginifolia seems to be accompanied by an increase in the water content, soluble proteins, α‑amino acids and phenols. A decrease in these parameters, besides an increase in protease activity induces senescence in the beautiful flowers of N. plumbaginifolia. Understanding flower senescence may help in improving the postharvest performance of this beautiful ornamental flower to make it a potential material for the floriculture industry.

  12. Identification and characterization of secretory proteins during ionizing radiation-induced premature senescence

    Energy Technology Data Exchange (ETDEWEB)

    Han, Na Kyung; Hong, Mi Na; Jung, Seung Hee; Kang, Kyoung Ah; Lee, Jae Seon [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Chi, Seong Gil [Korea University, Seoul (Korea, Republic of)

    2011-05-15

    Cellular senescence was first described by Hayflick and Moorhead in 1961 who observed that cultures of normal human fibroblasts had a limited replicative potential and eventually became irreversibly arrest. The majority of senescent cells assume a characteristic flattened and enlarged morphological change, senescence associated {beta} alactosidase positivity. Recently a large number of molecular phenotypes such as changes in gene expression, protein processing and chromatin organization have been also described. In contrast to apoptosis, senescence does not destroy the cells but leaves them metabolically and synthetically active and therefore able to affect their microenvironment. In particular, senescent fibroblasts and some cancer cells were found to secrete proteins with known or putative tumor-promoting functions such as growth factors or proteolytic enzymes. However, the knowledge about secreted proteins from senescent tumor cells and their functions to surrounding cells is still lacking. In this study, changes of senescence associated secretory protein expression profile were observed in MCF7 human breast cancer cells exposed to gamma-ray radiation using two dimensional electrophoresis. Also, we identified up-regulated secretory proteins during ionizing radiation-induced cellular senescence. Here, we show that senescent human breast cancer MCF7 cells promote the proliferation, invasion and migration of neighboring cells

  13. The Role of the S40 Gene Family in Leaf Senescence

    Directory of Open Access Journals (Sweden)

    Muhammad Jehanzeb

    2017-10-01

    Full Text Available Senescence affect different traits of plants, such as the ripening of fruit, number, quality and timing of seed maturation. While senescence is induced by age, growth hormones and different environmental stresses, a highly organized genetic mechanism related to substantial changes in gene expression regulates the process. Only a few genes associated to senescence have been identified in crop plants despite the vital significance of senescence for crop yield. The S40 gene family has been shown to play a role in leaf senescence. The barley HvS40 gene is one of the senescence marker genes which shows expression during age-dependent as well as dark-induced senescence. Like barley HvS40, the Arabidopsis AtS40-3 gene is also induced during natural senescence as well as in response to treatment with abscisic acid, salicylic acid, darkness and pathogen attack. It is speculated that rice OsS40 has a similar function in the leaf senescence of rice.

  14. The Dual Role of Cellular Senescence in Developing Tumors and Their Response to Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Markus Schosserer

    2017-11-01

    Full Text Available Cellular senescence describes an irreversible growth arrest characterized by distinct morphology, gene expression pattern, and secretory phenotype. The final or intermediate stages of senescence can be reached by different genetic mechanisms and in answer to different external and internal stresses. It has been maintained in the literature but never proven by clearcut experiments that the induction of senescence serves the evolutionary purpose of protecting the individual from development and growth of cancers. This hypothesis was recently scrutinized by new experiments and found to be partly true, but part of the gene activities now known to happen in senescence are also needed for cancer growth, leading to the view that senescence is a double-edged sword in cancer development. In current cancer therapy, cellular senescence is, on the one hand, intended to occur in tumor cells, as thereby the therapeutic outcome is improved, but might, on the other hand, also be induced unintentionally in non-tumor cells, causing inflammation, secondary tumors, and cancer relapse. Importantly, organismic aging leads to accumulation of senescent cells in tissues and organs of aged individuals. Senescent cells can occur transiently, e.g., during embryogenesis or during wound healing, with beneficial effects on tissue homeostasis and regeneration or accumulate chronically in tissues, which detrimentally affects the microenvironment by de- or transdifferentiation of senescent cells and their neighboring stromal cells, loss of tissue specific functionality, and induction of the senescence-associated secretory phenotype, an increased secretory profile consisting of pro-inflammatory and tissue remodeling factors. These factors shape their surroundings toward a pro-carcinogenic microenvironment, which fuels the development of aging-associated cancers together with the accumulation of mutations over time. We are presenting an overview of well-documented stress

  15. Information rich display design

    International Nuclear Information System (INIS)

    Welch, Robin; Braseth, Alf Ove; Veland, Oeystein

    2004-01-01

    This paper presents the concept Information Rich Displays. The purpose of Information Rich Displays (IRDs) is to condensate prevailing information in process displays in such a way that each display format (picture) contains more relevant information for the user. Compared to traditional process control displays, this new concept allows the operator to attain key information at a glance and at the same time allows for improved monitoring of larger portions of the process. This again allows for reduced navigation between both process and trend displays and ease the cognitive demand on the operator. This concept has been created while working on designing display prototypes for the offshore petroleum production facilities of tomorrow. Offshore installations basically consist of wells, separation trains (where oil, gas and water are separated from each other), an oil tax measurement system (where oil quality is measured and the pressure increased to allow for export), gas compression (compression of gas for export) and utility systems (water treatment, chemical systems etc.). This means that an offshore control room operator has to deal with a complex process that comprises several functionally different systems. The need for a new approach to offshore display format design is in particular based on shortcomings in today's designs related to the keyhole effect, where the display format only reveals a fraction of the whole process. Furthermore, the upcoming introduction of larger off- and on-shore operation centres will increase the size and complexity of the operators' work domain. In the light of the increased demands on the operator, the proposed IRDs aim to counter the negative effects this may have on the workload. In this work we have attempted to classify the wide range of different roles an operator can have in different situations. The information content and amount being presented to the operator in a display should be viewed in context of the roles the

  16. Dichroic Liquid Crystal Displays

    Science.gov (United States)

    Bahadur, Birendra

    The following sections are included: * INTRODUCTION * DICHROIC DYES * Chemical Structure * Chemical and Photochemical Stability * THEORETICAL MODELLING * DEFECTS CAUSED BY PROLONGED LIGHT IRRADIATION * CHEMICAL STRUCTURE AND PHOTOSTABILITY * OTHER PARAMETERS AFFECTING PHOTOSTABILITY * CELL PREPARATION * DICHROIC PARAMETERS AND THEIR MEASUREMENTS * Order Parameter and Dichroic Ratio Of Dyes * Absorbance, Order Parameter and Dichroic Ratio Measurements * IMPACT OF DYE STRUCTURE AND LIQUID CRYSTAL HOST ON PHYSICAL PROPERTIES OF A DICHROIC MIXTURE * Order Parameter and Dichroic Ratio * EFFECT OF LENGTH OF DICHROIC DYES ON THE ORDER PARAMETER * EFFECT OF THE BREADTH OF DYE ON THE ORDER PARAMETER * EFFECT OF THE HOST ON THE ORDER PARAMETER * TEMPERATURE VARIATION OF THE ORDER PARAMETER OF DYES IN A LIQUID CRYSTAL HOST * IMPACT OF DYE CONCENTRATION ON THE ORDER PARAMETER * Temperature Range * Viscosity * Dielectric Constant and Anisotropy * Refractive Indices and Birefringence * solubility43,153-156 * Absorption Wavelength and Auxochromic Groups * Molecular Engineering of Dichroic Dyes * OPTICAL, ELECTRO-OPTICAL AND LIFE PARAMETERS * Colour And CIE Colour space120,160-166 * CIE 1931 COLOUR SPACE * CIE 1976 CHROMATICITY DIAGRAM * CIE UNIFORM COLOUR SPACES & COLOUR DIFFERENCE FORMULAE120,160-166 * Electro-Optical Parameters120 * LUMINANCE * CONTRAST AND CONTRAST RATIO * SWITCHING SPEED * Life Parameters and Failure Modes * DICHROIC MIXTURE FORMULATION * Monochrome Mixture * Black Mixture * ACHROMATIC BLACK MIXTURE FOR HEILMEIER DISPLAYS * Effect of Illuminant on Display Colour * Colour of the Field-On State * Effect of Dye Linewidth * Optimum Centroid Wavelengths * Effect of Dye Concentration * Mixture Formulation Using More Than Three Dyes * ACHROMATIC MIXTURE FOR WHITE-TAYLOR TYPE DISPLAYS * HEILMEIER DISPLAYS * Theoretical Modelling * Threshold Characteristic * Effects of Dye Concentration on Electro-optical Parameters * Effect of Cholesteric Doping * Effect of Alignment

  17. On Integrity of Flexible Displays

    Science.gov (United States)

    Bouten, Piet C. P.

    Nowadays two display types are dominant in the display market: the bulky cathode ray tube (CRT) and liquid crystal displays (LCD). Both types use glass as substrate material. The LCD display is the dominant player for mobile applications, in for instance mobile phones and portable computers. In the development of displays and their applications a clear interest exists to replace the rigid rectangular display cells by free-shaped, curved or even roll-up cells. These types of applications require flexible displays.

  18. Age-Associated Loss of OPA1 in Muscle Impacts Muscle Mass, Metabolic Homeostasis, Systemic Inflammation, and Epithelial Senescence.

    Science.gov (United States)

    Tezze, Caterina; Romanello, Vanina; Desbats, Maria Andrea; Fadini, Gian Paolo; Albiero, Mattia; Favaro, Giulia; Ciciliot, Stefano; Soriano, Maria Eugenia; Morbidoni, Valeria; Cerqua, Cristina; Loefler, Stefan; Kern, Helmut; Franceschi, Claudio; Salvioli, Stefano; Conte, Maria; Blaauw, Bert; Zampieri, Sandra; Salviati, Leonardo; Scorrano, Luca; Sandri, Marco

    2017-06-06

    Mitochondrial dysfunction occurs during aging, but its impact on tissue senescence is unknown. Here, we find that sedentary but not active humans display an age-related decline in the mitochondrial protein, optic atrophy 1 (OPA1), that is associated with muscle loss. In adult mice, acute, muscle-specific deletion of Opa1 induces a precocious senescence phenotype and premature death. Conditional and inducible Opa1 deletion alters mitochondrial morphology and function but not DNA content. Mechanistically, the ablation of Opa1 leads to ER stress, which signals via the unfolded protein response (UPR) and FoxOs, inducing a catabolic program of muscle loss and systemic aging. Pharmacological inhibition of ER stress or muscle-specific deletion of FGF21 compensates for the loss of Opa1, restoring a normal metabolic state and preventing muscle atrophy and premature death. Thus, mitochondrial dysfunction in the muscle can trigger a cascade of signaling initiated at the ER that systemically affects general metabolism and aging. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  19. Paediatric dose display

    International Nuclear Information System (INIS)

    Griffin, D.W.; Derges, S.; Hesslewood, S.

    1984-01-01

    A compact, inexpensive unit, based on an 8085 microprocessor, has been designed for calculating doses of intravenous radioactive injections for children. It has been used successfully for over a year. The dose is calculated from the body surface area and the result displayed in MBq. The operator can obtain the required dose on a twelve character alphanumeric display by entering the age of the patient and the adult dose using a hexadecimal keyboard. Circuit description, memory map and input/output, and firmware are dealt with. (U.K.)

  20. MicroRNA Regulation of Ionizing Radiation-Induced Premature Senescence

    International Nuclear Information System (INIS)

    Wang Yong; Scheiber, Melissa N.; Neumann, Carola; Calin, George A.; Zhou Daohong

    2011-01-01

    Purpose: MicroRNAs (miRNAs) have emerged as critical regulators of many cellular pathways. Ionizing radiation (IR) exposure causes DNA damage and induces premature senescence. However, the role of miRNAs in IR-induced senescence has not been well defined. Thus, the purpose of this study was to identify and characterize senescence-associated miRNAs (SA-miRNAs) and to investigate the role of SA-miRNAs in IR-induced senescence. Methods and Materials: In human lung (WI-38) fibroblasts, premature senescence was induced either by IR or busulfan (BU) treatment, and replicative senescence was accomplished by serial passaging. MiRNA microarray were used to identify SA-miRNAs, and real-time reverse transcription (RT)-PCR validated the expression profiles of SA-miRNAs in various senescent cells. The role of SA-miRNAs in IR-induced senescence was characterized by knockdown of miRNA expression, using anti-miRNA oligonucleotides or by miRNA overexpression through the transfection of pre-miRNA mimics. Results: We identified eight SA-miRNAs, four of which were up-regulated (miR-152, -410, -431, and -493) and four which were down-regulated (miR-155, -20a, -25, and -15a), that are differentially expressed in both prematurely senescent (induced by IR or BU) and replicatively senescent WI-38 cells. Validation of the expression of these SA-miRNAs indicated that down-regulation of miR-155, -20a, -25, and -15a is a characteristic miRNA expression signature of cellular senescence. Functional analyses revealed that knockdown of miR-155 or miR-20a, but not miR-25 or miR-15a, markedly enhanced IR-induced senescence, whereas ectopic overexpression of miR-155 or miR-20a significantly inhibited senescence induction. Furthermore, our studies indicate that miR-155 modulates IR-induced senescence by acting downstream of the p53 and p38 mitogen-activated protein kinase (MAPK) pathways and in part via regulating tumor protein 53-induced nuclear protein 1 (TP53INP1) expression. Conclusion: Our

  1. Resveratrol reduces senescence-associated secretory phenotype by SIRT1/NF-κB pathway in gut of the annual fish Nothobranchius guentheri.

    Science.gov (United States)

    Liu, Shan; Zheng, Zhaodi; Ji, Shuhua; Liu, Tingting; Hou, Yanhan; Li, Shasha; Li, Guorong

    2018-06-13

    Senescent cells display a senescence-associated secretory phenotype (SASP), which contributes to aging. Resveratrol, an activator of SIRT1, has anti-aging, anti-inflammatory, anti-oxidant, anti-free radical and other pharmacological effects. The genus of the annual fish Nothobranchius has become an emerging animal model for studying aging. However, the underlying mechanism for resveratrol to delay aging by SASP regulation has not been elucidated in vertebrates. In this study, the annual fish N. guentheri were fed with resveratrol for long-term treatment. The results showed that resveratrol reversed intensive senescence-associated β-galactosidase activity with aging process, down-regulated levels of SASP-associated proinflammatory cytokines IL-8 and TNFα, and up-regulated expression of anti-inflammatory cytokine IL-10 in gut of the fish. Resveratrol increased SIRT1 expression, and inhibited NF-κB by decreasing RelA/p65, Ac-RelA/p65 and p-IκBα levels and by increasing the interaction between SIRT1 and RelA/p65. Moreover, resveratrol reversed the decline of intestinal epithelial cells (IECs) and intestinal stem cells (ISCs) caused by aging in gut of the fish. Together, our results implied that resveratrol inhibited SASP through SIRT1/NF-κB signaling pathway and delayed aging of the annual fish N. guentheri. Copyright © 2018. Published by Elsevier Ltd.

  2. Sun Ginseng Protects Endothelial Progenitor Cells From Senescence Associated Apoptosis

    Science.gov (United States)

    Im, Wooseok; Chung, Jin-Young; Bhan, Jaejun; Lim, Jiyeon; Lee, Soon-Tae; Chu, Kon; Kim, Manho

    2012-01-01

    Endothelial progenitor cells (EPC) are a population of cells that circulate in the blood stream. They play a role in angiogenesis and, therefore, can be prognostic markers of vascular repair. Ginsenoside Rg3 prevents endothelial cell apoptosis through the inhibition of the mitochondrial caspase pathway. It also affects estrogen activity, which reduces EPC senescence. Sun ginseng (SG), which is heat-processed ginseng, has a high content of ginsenosides. The purpose of this study was to investigate the protective effects of SG on senescence-associated apoptosis in EPCs. In order to isolate EPCs, mononuclear cells of human blood buffy coats were cultured and characterized by their uptake of acetylated low-density lipoprotein (acLDL) and their binding of Ulex europaeus agglutinin I (ulex-lectin). Flow cytometry with annexin-V staining was performed in order to assess early and late apoptosis. Senescence was determined by β-galactosidase (β-gal) staining. Staining with 4′-6-Diamidino-2-phenylindole verified that most adherent cells (93±2.7%) were acLDL-positive and ulex-lectin-positive. The percentage of β-gal-positive EPCs was decreased from 93.8±2.0% to 62.5±3.6% by SG treatment. A fluorescence-activated cell sorter (FACS) analysis showed that 4.9% of EPCs were late apoptotic in controls. Sun ginseng decreased the apoptotic cell population by 39% in the late stage of apoptosis from control baseline levels. In conclusion, these results show antisenescent and antiapoptotic effects of SG in human-derived EPCs, indicating that SG can enhance EPC-mediated repair mechanisms. PMID:23717107

  3. Refreshing Refreshable Braille Displays.

    Science.gov (United States)

    Russomanno, Alexander; O'Modhrain, Sile; Gillespie, R Brent; Rodger, Matthew W M

    2015-01-01

    The increased access to books afforded to blind people via e-publishing has given them long-sought independence for both recreational and educational reading. In most cases, blind readers access materials using speech output. For some content such as highly technical texts, music, and graphics, speech is not an appropriate access modality as it does not promote deep understanding. Therefore blind braille readers often prefer electronic braille displays. But, these are prohibitively expensive. The search is on, therefore, for a low-cost refreshable display that would go beyond current technologies and deliver graphical content as well as text. And many solutions have been proposed, some of which reduce costs by restricting the number of characters that can be displayed, even down to a single braille cell. In this paper, we demonstrate that restricting tactile cues during braille reading leads to poorer performance in a letter recognition task. In particular, we show that lack of sliding contact between the fingertip and the braille reading surface results in more errors and that the number of errors increases as a function of presentation speed. These findings suggest that single cell displays which do not incorporate sliding contact are likely to be less effective for braille reading.

  4. Small - Display Cartography

    DEFF Research Database (Denmark)

    Nissen, Flemming; Hvas, Anders; Münster-Swendsen, Jørgen

    Service Communication and finally, Part IV: Concluding remarks and topics for further research on small-display cartography. Part II includes a separate Appendix D consisting of a cartographic design specification. Part III includes a separate Appendix C consisting of a schema specification, a separate...

  5. Nuclear image display controller

    International Nuclear Information System (INIS)

    Roth, D.A.

    1985-01-01

    In a nuclear imaging system the digitized x and y coordinates of gamma ray photon emission events address memory locations corresponding to the coordinates. The respective locations are incremented each time they are addressed so at the end of a selected time or event count period the locations contain digital values or raw data corresponding to the intensity of pixels comprising an image frame. The raw data for a frame is coupled to one input of an arithmetic logic unit (ALU) whose output is coupled to a display controller memory. The output of the controller memory is coupled to another ALU input with a feedback bus and is also coupled to a further signal processing circuit which includes means for converting processed data to analog video signals for television display. The ALU is selectively controlled to let raw image data pass through to the display controllor memory or alternately to add (or subtract) raw data for the last image frame developed to the raw data for preceding frames held in the display controller to thereby produce the visual effect on the television screen of an isotope flowing through anatomy

  6. Plant state display device

    International Nuclear Information System (INIS)

    Kadota, Kazuo; Ito, Toshiichiro.

    1994-01-01

    The device of the present invention conducts information processing suitable for a man to solve a problem in a plant such as a nuclear power plant incorporating a great amount of information, where safety is required and provides information to an operator. Namely, theories and rules with respect to the flow and balanced state of materials and energy upon plant start-up, and a vapor cycle of operation fluids are symbolized and displayed on the display screen of the device. Then, the display of the plant information suitable to the information processing for a man to dissolve problems is provided. Accordingly, a mechanism for analyzing a purpose of the plant is made more definite, thereby enabling to prevent an erroneous judgement of an operator and occurrence of plant troubles. In addition, a simular effect can also be expected when the theories and rules with respect to the flow and the balanced state of materials and energy and thermohydrodynamic behavior of the operation fluids in a state of after-heat removing operation during shutdown of the plant are symbolized and displayed. (I.S.)

  7. Amyloid β Protein Aggravates Neuronal Senescence and Cognitive Deficits in 5XFAD Mouse Model of Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Zhen Wei

    2016-01-01

    Conclusions: oAβ-accelerated neuronal senescence may be associated with the cognitive impairment in 5XFAD mice. Senescence-associated marker p16 can serve as an indicator to estimate the cognitive prognosis for AD population.

  8. Cytokine expression and signaling in drug-induced cellular senescence

    Czech Academy of Sciences Publication Activity Database

    Nováková, Zora; Hubáčková, Soňa; Košař, Martin; Janderová-Rossmeislová, Lenka; Dobrovolná, Jana; Vašicová, Pavla; Vančurová, Markéta; Hořejší, Zuzana; Hozák, Pavel; Bartek, Jiří; Hodný, Zdeněk

    2010-01-01

    Roč. 29, č. 2 (2010), s. 273-284 ISSN 0950-9232 R&D Projects: GA AV ČR IAA500390501; GA ČR GA204/08/1418; GA MŠk LC545 Grant - others:EC(XE) TRIREME Institutional research plan: CEZ:AV0Z50520514; CEZ:AV0Z50200510 Keywords : cellular senescence * cytokines * JAK/STAT signaling pathway Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.414, year: 2010

  9. Long noncoding RNA PANDA and scaffold-attachment-factor SAFA control senescence entry and exit.

    Science.gov (United States)

    Puvvula, Pavan Kumar; Desetty, Rohini Devi; Pineau, Pascal; Marchio, Agnés; Moon, Anne; Dejean, Anne; Bischof, Oliver

    2014-11-19

    Cellular senescence is a stable cell cycle arrest that limits the proliferation of pre-cancerous cells. Here we demonstrate that scaffold-attachment-factor A (SAFA) and the long noncoding RNA PANDA differentially interact with polycomb repressive complexes (PRC1 and PRC2) and the transcription factor NF-YA to either promote or suppress senescence. In proliferating cells, SAFA and PANDA recruit PRC complexes to repress the transcription of senescence-promoting genes. Conversely, the loss of SAFA-PANDA-PRC interactions allows expression of the senescence programme. Accordingly, we find that depleting either SAFA or PANDA in proliferating cells induces senescence. However, in senescent cells where PANDA sequesters transcription factor NF-YA and limits the expression of NF-YA-E2F-coregulated proliferation-promoting genes, PANDA depletion leads to an exit from senescence. Together, our results demonstrate that PANDA confines cells to their existing proliferative state and that modulating its level of expression can cause entry or exit from senescence.

  10. Effects of PSAG12-IPT gene expression on development and senescence in transgenic Lettuce

    NARCIS (Netherlands)

    McCabe, M.S.; Garratt, L.C.; Schepers, F.; Jordi, W.J.R.M.; Stoopen, G.M.; Davelaar, E.; Rhijn, van J.H.A.; Power, J.B.; Davey, M.R.

    2001-01-01

    An ipt gene under control of the senescence-specific SAG12 promoter from Arabidopsis (PSAG12-IPT) significantly delayed developmental and postharvest leaf senescence in mature heads of transgenic lettuce (Lactuca sativa L. cv Evola) homozygous for the transgene. Apart from retardation of leaf

  11. Basal metabolic rate and the rate of senescence in the great tit

    NARCIS (Netherlands)

    Bouwhuis, Sandra; Sheldon, Ben C.; Verhulst, Simon; Koteja, Pawel

    1. Between-individual variation in rates of senescence has recently been found to relate to natal and early-life conditions in several natural populations. Mechanistic theories of senescence have predicted between-individual variation in basal metabolic rate (BMR) to also underlie such variation in

  12. The Splicing Factor SRSF1 as a Marker for Endothelial Senescence

    Science.gov (United States)

    Blanco, Francisco Javier; Bernabéu, Carmelo

    2012-01-01

    Aging is the major risk factor per se for the development of cardiovascular diseases. The senescence of the endothelial cells (ECs) that line the lumen of blood vessels is the cellular basis for these age-dependent vascular pathologies, including atherosclerosis and hypertension. During their lifespan, ECs may reach a stage of senescence by two different pathways; a replicative one derived from their preprogrammed finite number of cell divisions; and one induced by stress stimuli. Also, certain physiological stimuli, such as transforming growth factor-β, are able to modulate cellular senescence. Currently, the cellular aging process is being widely studied to identify novel molecular markers whose changes correlate with senescence. This review focuses on the regulation of alternative splicing mediated by the serine–arginine splicing factor 1 (SRSF1, or ASF/SF2) during endothelial senescence, a process that is associated with a differential subcellular localization of SRSF1, which typically exhibits a scattered distribution throughout the cytoplasm. Based on its senescence-dependent involvement in alternative splicing, we postulate that SRSF1 is a key marker of EC senescence, regulating the expression of alternative isoforms of target genes such as endoglin (ENG), vascular endothelial growth factor A (VEGFA), tissue factor (T3), or lamin A (LMNA) that integrate in a common molecular senescence program. PMID:22470345

  13. Finding Shangri-La: Limiting the Impact of Senescence on Aging.

    Science.gov (United States)

    Trabucco, Sally E; Zhang, Hong

    2016-03-03

    Senescence plays an important role in the age-associated decline of tissue functions. Recent studies now show that targeting senescent cells can enhance the functions of stem/progenitor cells in aged mice and extend lifespan. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. A decrease in cyclin B1 levels leads to polyploidization in DNA damage-induced senescence.

    Science.gov (United States)

    Kikuchi, Ikue; Nakayama, Yuji; Morinaga, Takao; Fukumoto, Yasunori; Yamaguchi, Naoto

    2010-05-04

    Adriamycin, an anthracycline antibiotic, has been used for the treatment of various types of tumours. Adriamycin induces at least two distinct types of growth repression, such as senescence and apoptosis, in a concentration-dependent manner. Cellular senescence is a condition in which cells are unable to proliferate further, and senescent cells frequently show polyploidy. Although abrogation of cell division is thought to correlate with polyploidization, the mechanisms underlying induction of polyploidization in senescent cells are largely unclear. We wished, therefore, to explore the role of cyclin B1 level in polyploidization of Adriamycin-induced senescent cells. A subcytotoxic concentration of Adriamycin induced polyploid cells having the features of senescence, such as flattened and enlarged cell shape and activated beta-galactosidase activity. In DNA damage-induced senescent cells, the levels of cyclin B1 were transiently increased and subsequently decreased. The decrease in cyclin B1 levels occurred in G2 cells during polyploidization upon treatment with a subcytotoxic concentration of Adriamycin. In contrast, neither polyploidy nor a decrease in cyclin B1 levels was induced by treatment with a cytotoxic concentration of Adriamycin. These results suggest that a decrease in cyclin B1 levels is induced by DNA damage, resulting in polyploidization in DNA damage-induced senescence.

  15. Actuarial senescence in a long-lived orchid challenges our current understanding of ageing

    Science.gov (United States)

    Colchero, Fernando; Jones, Owen R.; Øien, Dag-Inge; Moen, Asbjørn; Sletvold, Nina

    2016-01-01

    The dominant evolutionary theory of actuarial senescence—an increase in death rate with advancing age—is based on the concept of a germ cell line that is separated from the somatic cells early in life. However, such a separation is not clear in all organisms. This has been suggested to explain the paucity of evidence for actuarial senescence in plants. We used a 32 year study of Dactylorhiza lapponica that replaces its organs each growing season, to test whether individuals of this tuberous orchid senesce. We performed a Bayesian survival trajectory analysis accounting for reproductive investment, for individuals under two types of land use, in two climatic regions. The mortality trajectory was best approximated by a Weibull model, showing clear actuarial senescence. Rates of senescence in this model declined with advancing age, but were slightly higher in mown plots and in the more benign climatic region. At older ages, senescence was evident only when accounting for a positive effect of reproductive investment on mortality. Our results demonstrate actuarial senescence as well as a survival–reproduction trade-off in plants, and indicate that environmental context may influence senescence rates. This knowledge is crucial for understanding the evolution of demographic senescence and for models of plant population dynamics. PMID:27852801

  16. Early Autumn Senescence in Red Maple (Acer rubrum L.) Is Associated with High Leaf Anthocyanin Content.

    Science.gov (United States)

    Anderson, Rachel; Ryser, Peter

    2015-08-05

    Several theories exist about the role of anthocyanins in senescing leaves. To elucidate factors contributing to variation in autumn leaf anthocyanin contents among individual trees, we analysed anthocyanins and other leaf traits in 27 individuals of red maple (Acer rubrum L.) over two growing seasons in the context of timing of leaf senescence. Red maple usually turns bright red in the autumn, but there is considerable variation among the trees. Leaf autumn anthocyanin contents were consistent between the two years of investigation. Autumn anthocyanin content strongly correlated with degree of chlorophyll degradation mid to late September, early senescing leaves having the highest concentrations of anthocyanins. It also correlated positively with leaf summer chlorophyll content and dry matter content, and negatively with specific leaf area. Time of leaf senescence and anthocyanin contents correlated with soil pH and with canopy openness. We conclude that the importance of anthocyanins in protection of leaf processes during senescence depends on the time of senescence. Rather than prolonging the growing season by enabling a delayed senescence, autumn anthocyanins in red maple in Ontario are important when senescence happens early, possibly due to the higher irradiance and greater danger of oxidative damage early in the season.

  17. Proteome oxidative carbonylation during oxidative stress-induced premature senescence of WI-38 human fibroblasts

    DEFF Research Database (Denmark)

    Le Boulch, Marine; Ahmed, Emad K; Rogowska-Wrzesinska, Adelina

    2018-01-01

    Accumulation of oxidatively damaged proteins is a hallmark of cellular and organismal ageing, and is also a phenotypic feature shared by both replicative senescence and stress-induced premature senescence of human fibroblasts. Moreover, proteins that are building up as oxidized (i.e. the "Oxi-pro...

  18. Identification of Secreted Proteins from Ionizing Radiation-Induced Senescent MCF7 Cells Using Comparative Proteomics

    International Nuclear Information System (INIS)

    Han, Na Kyung; Kim, Han Na; Hong, Mi Na; Park, Su Min; Lee, Jae Seon; Chi, Seong Gil

    2010-01-01

    Cellular senescence was first described by Hayflick and Moorhead in 1961 who observed that cultures of normal human fibroblasts had a limited replicative potential and eventually became irreversibly arrest. The majority of senescent cells assume a characteristic flattened and enlarged morphological change, senescence associated β-galactosidase positivity and over the years a large number of molecular phenotypes have been described, such as changes in gene expression, protein processing and chromatin organization. In contrast to apoptosis, senescence does not destroy the cells but leaves them metabolically and synthetically active and therefore able to affect their microenvironment. In particular, senescent fibroblasts and some cancer cells were found to secrete proteins with known or putative tumor-promoting functions such as growth factors or proteolytic enzymes. However, the knowledge about secreted proteins from senescent tumor cells and their functions to surrounding cells is still lacking. In this study, changes of senescence-associated secretory protein expression profile were observed in MCF7 human breast cancer cells exposed to gamma-ray radiation using two dimensional electrophoresis. Also, we identified up-regulated secretory proteins during ionizing radiation-induced cellular senescence

  19. Replicative senescence of T cells: does the Hayflick Limit lead to immune exhaustion?

    Science.gov (United States)

    Effros, R B; Pawelec, G

    1997-09-01

    Extensive in vitro research on fibroblasts has defined numerous genetic and phenotypic changes associated with replicative senescence. Identification of T-cell replicative senescence as a feature of human immunodeficiency virus (HIV) disease and ageing suggests this phenomenon merits more careful consideration by immunologists, especially with regard to chronic infection, memory and adoptive immunotherapy.

  20. The cell cycle regulator protein P16 and the cellular senescence of dental follicle cells.

    Science.gov (United States)

    Morsczeck, Christian; Hullmann, Markus; Reck, Anja; Reichert, Torsten E

    2018-02-01

    Cellular senescence is a restricting factor for regenerative therapies with somatic stem cells. We showed previously that the onset of cellular senescence inhibits the osteogenic differentiation in stem cells of the dental follicle (DFCs), although the mechanism remains elusive. Two different pathways are involved in the induction of the cellular senescence, which are driven either by the cell cycle protein P21 or by the cell cycle protein P16. In this study, we investigated the expression of cell cycle proteins in DFCs after the induction of cellular senescence. The induction of cellular senescence was proved by an increased expression of β-galactosidase and an increased population doubling time after a prolonged cell culture. Cellular senescence regulated the expression of cell cycle proteins. The expression of cell cycle protein P16 was up-regulated, which correlates with the induction of cellular senescence markers in DFCs. However, the expression of cyclin-dependent kinases (CDK)2 and 4 and the expression of the cell cycle protein P21 were successively decreased in DFCs. In conclusion, our data suggest that a P16-dependent pathway drives the induction of cellular senescence in DFCs.

  1. NAC Transcription Factors in Senescence: From Molecular Structure to Function in Crops

    Directory of Open Access Journals (Sweden)

    Dagmara Podzimska-Sroka

    2015-07-01

    Full Text Available Within the last decade, NAC transcription factors have been shown to play essential roles in senescence, which is the focus of this review. Transcriptome analyses associate approximately one third of Arabidopsis NAC genes and many crop NAC genes with senescence, thereby implicating NAC genes as important regulators of the senescence process. The consensus DNA binding site of the NAC domain is used to predict NAC target genes, and protein interaction sites can be predicted for the intrinsically disordered transcription regulatory domains of NAC proteins. The molecular characteristics of these domains determine the interactions in gene regulatory networks. Emerging local NAC-centered gene regulatory networks reveal complex molecular mechanisms of stress- and hormone-regulated senescence and basic physiological steps of the senescence process. For example, through molecular interactions involving the hormone abscisic acid, Arabidopsis NAP promotes chlorophyll degradation, a hallmark of senescence. Furthermore, studies of the functional rice ortholog, OsNAP, suggest that NAC genes can be targeted to obtain specific changes in lifespan control and nutrient remobilization in crop plants. This is also exemplified by the wheat NAM1 genes which promote senescence and increase grain zinc, iron, and protein content. Thus, NAC genes are promising targets for fine-tuning senescence for increased yield and quality.

  2. Identification of Secreted Proteins from Ionizing Radiation-Induced Senescent MCF7 Cells Using Comparative Proteomics

    Energy Technology Data Exchange (ETDEWEB)

    Han, Na Kyung; Kim, Han Na; Hong, Mi Na; Park, Su Min; Lee, Jae Seon [Korea Institue of Radiological and Medical Sciences, Seoul (Korea, Republic of); Chi, Seong Gil [Korea University, Seoul (Korea, Republic of)

    2010-05-15

    Cellular senescence was first described by Hayflick and Moorhead in 1961 who observed that cultures of normal human fibroblasts had a limited replicative potential and eventually became irreversibly arrest. The majority of senescent cells assume a characteristic flattened and enlarged morphological change, senescence associated beta-galactosidase positivity and over the years a large number of molecular phenotypes have been described, such as changes in gene expression, protein processing and chromatin organization. In contrast to apoptosis, senescence does not destroy the cells but leaves them metabolically and synthetically active and therefore able to affect their microenvironment. In particular, senescent fibroblasts and some cancer cells were found to secrete proteins with known or putative tumor-promoting functions such as growth factors or proteolytic enzymes. However, the knowledge about secreted proteins from senescent tumor cells and their functions to surrounding cells is still lacking. In this study, changes of senescence-associated secretory protein expression profile were observed in MCF7 human breast cancer cells exposed to gamma-ray radiation using two dimensional electrophoresis. Also, we identified up-regulated secretory proteins during ionizing radiation-induced cellular senescence

  3. JNK inhibition sensitizes tumor cells to radiation-induced premature senescence via Bcl-2/ROS/DDR signaling pathway

    International Nuclear Information System (INIS)

    Lee, Jae Seon; Lee, Je Jung

    2009-01-01

    Premature senescence is considered as a cellular defense mechanism to prevent tumorigenesis. Although recent evidences demonstrate that c-Jun N-terminal kinase (JNK) is involved in the senescence process, the target and exact mechanism of JNK signaling in the regulation of cell proliferation has yet to be defined. In this study, we investigated the role of JNK in premature senescence and demonstrated JNK inhibition sensitized tumor cells to radiation-induced premature senescence

  4. Actuarial senescence in a long-lived orchid challenges our current understanding of ageing

    DEFF Research Database (Denmark)

    Dahlgren, Johan; Colchero, Fernando; Jones, Owen

    2016-01-01

    The dominant evolutionary theory of actuarial senescence – an increase in death rate with advancing age – is based on the concept of a germ cell line that is separated from the somatic cells early in life. However, such a separation is not clear in all organisms. This has been suggested to explain...... the paucity of evidence for actuarial senescence in plants. We used a 32-year study of Dactylorhiza lapponica that replaces its organs each growing season, to test whether individuals of this tuberous orchid senesce. We performed a Bayesian survival trajectory analysis accounting for reproductive investment......, for individuals under two types of land-use, in two climatic regions. The mortality trajectory was best-approximated by a Weibull model, showing clear actuarial senescence. Rates of senescence in this model declined with advancing age, but were slightly higher in mown plots and in the more benign climatic region...

  5. Blocking negative effects of senescence in human skin fibroblasts with a plant extract.

    Science.gov (United States)

    Lämmermann, Ingo; Terlecki-Zaniewicz, Lucia; Weinmüllner, Regina; Schosserer, Markus; Dellago, Hanna; de Matos Branco, André Dargen; Autheried, Dominik; Sevcnikar, Benjamin; Kleissl, Lisa; Berlin, Irina; Morizot, Frédérique; Lejeune, Francois; Fuzzati, Nicola; Forestier, Sandra; Toribio, Alix; Tromeur, Anaïs; Weinberg, Lionel; Higareda Almaraz, Juan Carlos; Scheideler, Marcel; Rietveld, Marion; El Ghalbzouri, Abdoel; Tschachler, Erwin; Gruber, Florian; Grillari, Johannes

    2018-01-01

    There is increasing evidence that senescent cells are a driving force behind many age-related pathologies and that their selective elimination increases the life- and healthspan of mice. Senescent cells negatively affect their surrounding tissue by losing their cell specific functionality and by secreting a pro-tumorigenic and pro-inflammatory mixture of growth hormones, chemokines, cytokines and proteases, termed the senescence-associated secretory phenotype (SASP). Here we identified an extract from the plant Solidago virgaurea subsp. alpestris , which exhibited weak senolytic activity, delayed the acquisition of a senescent phenotype and induced a papillary phenotype with improved functionality in human dermal fibroblasts. When administered to stress-induced premature senescent fibroblasts, this extract changed their global mRNA expression profile and particularly reduced the expression of various SASP components, thereby ameliorating the negative influence on nearby cells. Thus, the investigated plant extract represents a promising possibility to block age-related loss of tissue functionality.

  6. Fatty acid and sterol contents during tulip leaf senescence induced by methyl jasmonate

    Directory of Open Access Journals (Sweden)

    Marian Saniewski

    2013-12-01

    Full Text Available It has been shown previously that methyl jasmonate (JA-Me applied in lanolin paste on the bottom surface of intact tulip leaves causes a rapid and intense its senescence. The aim of this work was to study the effect of JA-Me on free and bound fatty acid and sterol contents during tulip leaf senescence. The main free and bound fatty acids of tulip leaf, in decreasing order of their abundance, were linolenic, linoleic, palmitic, oleic, stearic and myristic acids. Only the content of free linolenic acid decreased after treatment with JA-Me during visible stage of senescence. ß-Sitosterol (highest concentration, campesterol, stigmasterol and cholesterol were identified in tulip leaf. Methyl jasmonate evidently increased the level of ß-sitosterol, campesterol and stigmasterol during induced senescence. It is suggested that the increase in sterol concentrations under the influence of methyl jasmonate induced changes in membrane fluidity and permeability, which may be responsible for senescence.

  7. Process of endogenous homeostatic characteristics decline in two suproopganismal biosystems from the standpoint of parametabolistic theory of senescence.

    Science.gov (United States)

    Makrushin, A V; Aladin, N V

    2016-01-01

    Endogenous decline in homeostatic characteristics of supraorganismal level systems is similar to individual senescence. Similarity is in the fact that this decline as individual senescence is called by negative consequences from specialization of elements the system consists. In systems of supraorganismal level these effects are analogues of parametabolic reactions of senescence individuals.

  8. Comparison between various biomarkers of senescence in bone marrow-derived stromal cells in vitro and ex-vivo

    DEFF Research Database (Denmark)

    Nehlin, Jan; Kassem, Moustapha; Frary, Charles

    Senescent stem cells are classified as non-quiescent, irreversibly growth-arrested, non-terminally differentiated, apoptosis resistant multipotent stem cells that maintain an altered gene expression from their juvenescent precursors. Established markers of senescence such as senescent-associated ...

  9. Position display device

    International Nuclear Information System (INIS)

    Nishizawa, Yukio.

    1974-01-01

    Object: To provide a device capable of easily and quickly reading mutual mounting relations of control bodies such as control rods mounted on a nuclear reactor and positions to which the control bodies are driven. Structure: A scanning circuit is provided to scan positions of controllably mounted control bodies such as control rods. Values detected by scanning the positions are converted into character signals according to the values and converted into preranked color signals. The character signals and color signals are stored in a memory circuit by synchronous signals in synchronism with the scanning in the scanning circuit. Outputs of the memory circuit are displayed by a display unit such as a color Braun tube in accordance with the synchronous signals to provide color representations according to positions to which control bodies are driven in the same positional relation as the mounting of the control bodies. (Kamimura, M.)

  10. Multichannel waveform display system

    International Nuclear Information System (INIS)

    Kolvankar, V.G.

    1989-01-01

    For any multichannel data acquisition system, a multichannel paper chart recorder undoubtedly forms an essential part of the system. When deployed on-line, it instantaneously provides, for visual inspection, hard copies of the signal waveforms on common time base at any desired sensitivity and time resolution. Within the country, only a small range of these strip chart recorder s is available, and under stringent specifications imported recorders are often procured. The cost of such recorders may range from 1 to 5 lakhs of rupees in foreign exchange. A system to provide on the oscilloscope a steady display of multichannel waveforms, refreshed from the digital data stored in the memory is developed. The merits and demerits of the display system are compared with that built around a conventional paper chart recorder. Various illustrations of multichannel seismic event data acquired at Gauribidanur seismic array station are also presented. (author). 2 figs

  11. NMDA receptor function during senescence: implication on cognitive performance

    Directory of Open Access Journals (Sweden)

    Ashok eKumar

    2015-12-01

    Full Text Available N-methyl-D-aspartate (NMDA receptors, a family of L-glutamate receptors, play an important role in learning and memory, and are critical for spatial memory. These receptors are tetrameric ion channels composed of a family of related subunits. One of the hallmarks of the aging human population is a decline in cognitive function; studies in the past couple of years have demonstrated deterioration in NMDA receptor subunit expression and function with advancing age. However, a direct relationship between impaired memory function and a decline in NMDA receptors is still ambiguous. Recent studies indicate a link between an age-associated NMDA receptor hypofunction and memory impairment and provide evidence that age-associated enhanced oxidative stress might be contributing to the alterations associated with senescence. However, clear evidence is still deficient in demonstrating the underlying mechanisms and a relationship between age-associated impaired cognitive faculties and NMDA receptor hypofunction. The current review intends to present an overview of the research findings regarding changes in expression of various NMDA receptor subunits and deficits in NMDA receptor function during senescence and its implication in age-associated impaired hippocampal-dependent memory function.

  12. Placental telomere shortening in stillbirth: a sign of premature senescence?

    Science.gov (United States)

    Ferrari, Francesca; Facchinetti, Fabio; Saade, George; Menon, Ramkumar

    2016-01-01

    The objective of this study is to investigate placental telomere shortening in unexplained stillbirths (SBs) as an indication of premature senescence. Placentas were collected from 42 unexplained SB (>22 weeks), 43 term and 15 preterm live births, at the Policlinico Hospital of Modena (Italy). DNA extracted from placentae was studied for telomere length by real time PCR. Standard curves were generated for telomere lengths from single copy gene amplifications using a reference DNA. The telomere length for each sample was derived based on the ratio of telomere length between the sample and single copy gene standard (T/S ratio). The mean ratio of placental telomere in term live births was 5.181 ± 3.841. A twofold decrease in telomere length was seen in SBs (over all 2.455 ± 1.239; p PTBs) (6.382 ± 5.525; p < 0.01), whereas SBs telomere length were similar to those of preterm premature rupture of membranes (pPROM) (3.296 ± 3.599; p = ns). Substantial reduction in telomere length in SBs is indicative of placental senescence. These data provide mechanistic insights that premature aging may lead to placental dysfunction as an initiator of fetal demise in unexplained SBs.

  13. Senescence as biologic endpoint following pharmacological targeting of receptor tyrosine kinases in cancer.

    Science.gov (United States)

    Francica, Paola; Aebersold, Daniel M; Medová, Michaela

    2017-02-15

    Cellular senescence was first described in 1961 in a seminal study by Hayflick and Moorhead as a limit to the replicative lifespan of somatic cells after serial cultivation. Since then, major advances in our understanding of senescence have been achieved suggesting that this mechanism is activated also by oncogenic stimuli, oxidative stress and DNA damage, giving rise to the concept of premature senescence. Regardless of the initial trigger, numerous experimental observations have been provided to support the notion that both replicative and premature senescence play pivotal roles in early stages of tumorigenesis and in response of tumor cells to anticancer treatments. Moreover, various studies have suggested that the induction of senescence by both chemo- and radiotherapy in a variety of cancer types correlates with treatment outcome. As it is widely accepted that cellular senescence may function as a fundamental barrier of tumor progression, the significance of senescence for clinical interventions that make use of novel molecular targeting-based modalities needs to be well defined. Interestingly, despite numerous studies evaluating efficacies of receptor tyrosine kinases (RTKs) targeting strategies in both preclinical and clinical settings, the relevance of RTKs inhibition-associated senescence in tumors remains less characterized. Here we review the available literature that describes premature senescence as a major mechanism following targeting of RTKs in preclinical as well as in clinical settings. Additionally, we discuss the possible role of diverse RTKs in regulating the induction of senescence following cellular stress and possible implications of this crosstalk in identification of biomarkers of inhibitor-mediated chemo- and radiosensitization approaches. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Refrigerated display cabinets; Butikskyla

    Energy Technology Data Exchange (ETDEWEB)

    Fahlen, Per

    2000-07-01

    This report summarizes experience from SP research and assignments regarding refrigerated transport and storage of food, mainly in the retail sector. It presents the fundamentals of heat and mass transfer in display cabinets with special focus on indirect systems and secondary refrigerants. Moreover, the report includes a brief account of basic food hygiene and the related regulations. The material has been compiled for educational purposes in the Masters program at Chalmers Technical University.

  15. Helicopter Display Improvement Study

    Science.gov (United States)

    1975-05-01

    PRESSURE INDICATOR 43 TURN A N D SLIP INDICATOR 21 ENGINE AND SDG OIL IN TEMPERATURE INDICATOR 44 COURSE INDICATOR 22 RADIO MAGNETIC COMPASS INDICATOR... compass seemed to present a problem to several H-l series pilots In that It was poorly located and should be moved. Possible locations Included...the UH-lNs standby compass . Both H/L and L/L pilots agreed that internal, white light was the best system currently in use. INDIVIDUAL DISPLAYS

  16. Dyes for displays

    Science.gov (United States)

    Claussen, U.

    1984-01-01

    The improvement of contrast and visibility of LCD by two different means was undertaken. The two methods are: (1) development of fluorescent dyes to increase the visibility of fluorescent activated displays (FLAD); and (2) development of dichroic dyes to increase the contrast of displays. This work was done in close cooperation with the electronic industry, where the newly synthesized dyes were tested. The targets for the chemical synthesis were selected with the help of computer model calculations. A marketable range of dyes was developed. Since the interest of the electronic industries concerning FLAD was low, the investigations were stopped. Dichroic dyes, especially black mixtures with good light fastness, order parameter, and solubility in nematic phases were developed. The application of these dyes is restricted to indoor use because of an increase of viscosity below -10 C. Applications on a technical scale, e.g., for the automotive industry, will be possible if the displays work at temperatures down to -40 C. This problem requires a complex optimization of the dye/nematic phase system.

  17. Handbook of Visual Display Technology

    CERN Document Server

    Cranton, Wayne; Fihn, Mark

    2012-01-01

    The Handbook of Visual Display Technology is a unique work offering a comprehensive description of the science, technology, economic and human interface factors associated with the displays industry. An invaluable compilation of information, the Handbook will serve as a single reference source with expert contributions from over 150 international display professionals and academic researchers. All classes of display device are covered including LCDs, reflective displays, flexible solutions and emissive devices such as OLEDs and plasma displays, with discussion of established principles, emergent technologies, and particular areas of application. The wide-ranging content also encompasses the fundamental science of light and vision, image manipulation, core materials and processing techniques, display driving and metrology.

  18. Book Display as Adult Service

    Directory of Open Access Journals (Sweden)

    Matthew S. Moore

    1997-03-01

    Full Text Available 無Book display as an adult service is defined as choosing and positioning adult books from the collection to increase their circulation. The author contrasts bookstore arrangement for sales versus library arrangement for access. The paper considers the library-as-a-whole as a display, examines the right size for an in-library display, and discusses mass displays, end-caps, on-shelf displays, and the Tiffany approach. The author proposes that an effective display depends on an imaginative, unifying theme, and that book displays are part of the joy of libraries.

  19. NCAP projection displays

    Science.gov (United States)

    Havens, John R.; Ishioka, J.; Jones, Philip J.; Lau, Aldrich; Tomita, Akira; Asano, A.; Konuma, Nobuhiro; Sato, Kazuhiko; Takemoto, Iwao

    1997-05-01

    Projectors based on polymer-eNCAPsulated liquid crystals can provide bright displays suitable for use in conference rooms with normal lighting. Contrast is generated by light scattering among the droplets, rather than by light absorption with crossed polarizers. We have demonstrated a full-color, compact projector showing 1200 ANSI lumens with 200 watts of lamp power - a light efficiency of 6 lumens/watt. This projector is based on low-voltage NCAP material, highly reflective CMOS die, and matched illumination and projection optics. We will review each of these areas and discuss the integrated system performance.

  20. Integrin Beta 3 Regulates Cellular Senescence by Activating the TGF-β Pathway

    Directory of Open Access Journals (Sweden)

    Valentina Rapisarda

    2017-03-01

    Full Text Available Cellular senescence is an important in vivo mechanism that prevents the propagation of damaged cells. However, the precise mechanisms regulating senescence are not well characterized. Here, we find that ITGB3 (integrin beta 3 or β3 is regulated by the Polycomb protein CBX7. β3 expression accelerates the onset of senescence in human primary fibroblasts by activating the transforming growth factor β (TGF-β pathway in a cell-autonomous and non-cell-autonomous manner. β3 levels are dynamically increased during oncogene-induced senescence (OIS through CBX7 Polycomb regulation, and downregulation of β3 levels overrides OIS and therapy-induced senescence (TIS, independently of its ligand-binding activity. Moreover, cilengitide, an αvβ3 antagonist, has the ability to block the senescence-associated secretory phenotype (SASP without affecting proliferation. Finally, we show an increase in β3 levels in a subset of tissues during aging. Altogether, our data show that integrin β3 subunit is a marker and regulator of senescence.

  1. Oxidative Stress Induces Endothelial Cell Senescence via Downregulation of Sirt6

    Directory of Open Access Journals (Sweden)

    Rong Liu

    2014-01-01

    Full Text Available Accumulating evidence has shown that diabetes accelerates aging and endothelial cell senescence is involved in the pathogenesis of diabetic vascular complications, including diabetic retinopathy. Oxidative stress is recognized as a key factor in the induction of endothelial senescence and diabetic retinopathy. However, specific mechanisms involved in oxidative stress-induced endothelial senescence have not been elucidated. We hypothesized that Sirt6, which is a nuclear, chromatin-bound protein critically involved in many pathophysiologic processes such as aging and inflammation, may have a role in oxidative stress-induced vascular cell senescence. Measurement of Sirt6 expression in human endothelial cells revealed that H2O2 treatment significantly reduced Sirt6 protein. The loss of Sirt6 was associated with an induction of a senescence phenotype in endothelial cells, including decreased cell growth, proliferation and angiogenic ability, and increased expression of senescence-associated β-galactosidase activity. Additionally, H2O2 treatment reduced eNOS expression, enhanced p21 expression, and dephosphorylated (activated retinoblastoma (Rb protein. All of these alternations were attenuated by overexpression of Sirt6, while partial knockdown of Sirt6 expression by siRNA mimicked the effect of H2O2. In conclusion, these results suggest that Sirt6 is a critical regulator of endothelial senescence and oxidative stress-induced downregulation of Sirt6 is likely involved in the pathogenesis of diabetic retinopathy.

  2. Cell Electrical Impedance as a Novel Approach for Studies on Senescence Not Based on Biomarkers

    Directory of Open Access Journals (Sweden)

    Jung-Joon Cha

    2016-01-01

    Full Text Available Senescence of cardiac myocytes is frequently associated with heart diseases. To analyze senescence in cardiac myocytes, a number of biomarkers have been isolated. However, due to the complex nature of senescence, multiple markers are required for a single assay to accurately depict complex physiological changes associated with senescence. In single cells, changes in both cytoplasm and cell membrane during senescence can affect the changes in electrical impedance. Based on this phenomenon, we developed MEDoS, a novel microelectrochemical impedance spectroscopy for diagnosis of senescence, which allows us to precisely measure quantitative changes in electrical properties of aging cells. Using cardiac myocytes isolated from 3-, 6-, and 18-month-old isogenic zebrafish, we examined the efficacy of MEDoS and showed that MEDoS can identify discernible changes in electrical impedance. Taken together, our data demonstrated that electrical impedance in cells at different ages is distinct with quantitative values; these results were comparable with previously reported ones. Therefore, we propose that MEDoS be used as a new biomarker-independent methodology to obtain quantitative data on the biological senescence status of individual cells.

  3. SIRT1 suppresses the senescence-associated secretory phenotype through epigenetic gene regulation.

    Directory of Open Access Journals (Sweden)

    Tomohisa Hayakawa

    Full Text Available Senescent cells develop a pro-inflammatory response termed the senescence-associated secretory phenotype (SASP. As many SASP components affect surrounding cells and alter their microenvironment, SASP may be a key phenomenon in linking cellular senesence with individual aging and age-related diseases. We herein demonstrated that the expression of Sirtuin1 (SIRT1 was decreased and the expression of SASP components was reciprocally increased during cellular senescence. The mRNAs and proteins of SASP components, such as IL-6 and IL-8, quickly accumulated in SIRT1-depleted cells, and the levels of these factors were also higher than those in control cells, indicating that SIRT1 negatively regulated the expression of SASP factors at the transcriptional level. SIRT1 bound to the promoter regions of IL-8 and IL-6, but dissociated from them during cellular senescence. The acetylation of Histone H3 (K9 and H4 (K16 of the IL-8 and IL-6 promoter regions gradually increased during cellular senescence. In SIRT1-depleted cells, the acetylation levels of these regions were already higher than those in control cells in the pre-senescent stage. Moreover, these acetylation levels in SIRT1-depleted cells were significantly higher than those in control cells during cellular senescence. These results suggest that SIRT1 repressed the expression of SASP factors through the deacetylation of histones in their promoter regions.

  4. Extracellular cystatin SN and cathepsin B prevent cellular senescence by inhibiting abnormal glycogen accumulation.

    Science.gov (United States)

    Oh, Sang-Seok; Park, Soojong; Lee, Ki-Won; Madhi, Hamadi; Park, Sae Gwang; Lee, Hee Gu; Cho, Yong-Yeon; Yoo, Jiyun; Dong Kim, Kwang

    2017-04-06

    Cystatin SN (CST1), a known inhibitor of cathepsin B (CatB), has important roles in tumor development. Paradoxically, CatB is a member of the cysteine cathepsin family that acts in cellular processes, such as tumor development and invasion. However, the relationship between CST1 and CatB, and their roles in tumor development are poorly understood. In this study, we observed that the knockdown of CST1 induced the activity of senescence-associated β-galactosidase, a marker of cellular senescence, and expression of senescence-associated secretory phenotype genes, including interleukin-6 and chemokine (C-C motif) ligand 20, in MDA-MB-231 and SW480 cancer cells. Furthermore, CST1 knockdown decreased extracellular CatB activity, and direct CatB inhibition, using specific inhibitors or shCatB, induced cellular senescence. Reconstitution of CST1 restored CatB activity and inhibited cellular senescence in CST1 knockdown cells. CST1 knockdown or CatB inhibition increased glycogen synthase (GS) kinase 3β phosphorylation at serine 9, resulting in the activation of GS and the induction of glycogen accumulation associated with cellular senescence. Importantly, CST1 knockdown suppressed cancer cell proliferation, soft agar colony growth and tumor growth in a xenograft model. These results indicate that CST1-mediated extracellular CatB activity enhances tumor development by preventing cellular senescence. Our findings suggest that antagonists of CST1 or inhibitors of CatB are potential anticancer agents.

  5. Girassol ornamental: caracterização, pós-colheita e escala de senescência Ornamental sunflower: characterization, postharvest and senescence scale

    Directory of Open Access Journals (Sweden)

    Gilberto Luiz Curti

    2012-06-01

    Full Text Available O girassol ornamental amplia o mercado de comercialização de plantas ornamentais no Brasil. Desta forma, este trabalho teve como objetivo apresentar uma caracterização do manejo pós-colheita e propor uma escala de senescência da cultura do girassol ornamental quanto à senescência, durabilidade das flores e referências de valores de comercialização. A produção de flores é uma atividade de alto risco pela fragilidade do produto, qualidades estéticas e as condições de produção, bem como a menor durabilidade pós-colheita do produto. Esse estudo propõe uma escala de senescência para cultivares de girassol ornamental quanto à senescência dos capítulos para atribuir diferentes remunerações e possibilidades de comercialização da cultura.The ornamental sunflower widen the market of ornamental plants in Brazil. Thus, this study aimed to present a characterization of post-harvest management and to propose a range of senescence stage of sunflower as an ornamental in relation to senescence, flower longevity and benchmark values of trade. The production of flowers is a high risk activity for the fragility of the product, aesthetic qualities and conditions of production as well as lower post-harvest durability of the product. This study proposes a range of senescence stages for ornamental sunflower cultivars as the aging of different chapters to assign salaries and marketability of the crop.

  6. Painting Reproductions on Display

    Directory of Open Access Journals (Sweden)

    Joanna Iranowska

    2017-09-01

    Full Text Available Paintings in museums might occasionally be replaced by a photoprint mimicking the original. This article is an investigation of what constitutes a good reproduction of an artwork (oil painting that is meant to be displayed. The article discusses what the usefulness of reproductions depends on, applying the Valuation Studies approach, which means the primary concern is with the practice of valuing itself. In other words, the study focuses on how museum experts evaluate reproduc-tions of oil paintings. The article analyses three cases of displaying digitally prin-ted copies of Edvard Munch's oil paintings between 2013 and 2015 in the Munch Museum and in the National Gallery in Oslo. The study is based on a series of semi-structured interviews with the experts, working at and for the museums, that were involved in producing and exhibiting of the photoprints: curators, con-servators, museum educators, and external manufacturers. The interviews were grouped into five clusters, which I have chosen to call registers of valuing following Frank Heuts and Annemarie Mol (2013. The described valuation practices have to do with delivering experiences to the public, obtaining mimetic resemblance, solving ethical aspects, exhibitions' budget, and last but not least, with the time perspective.

  7. Unsolicited displays of insights

    DEFF Research Database (Denmark)

    Brouwer, Catherine E.

    2015-01-01

    This study is based on videorecorded interactional data from a specific type of institutional setting which consists of a variety of 'language stimulation activities' for bilingual children in Danish preschools. Bilingual children, with a variety of linguistic backgrounds, take part in these acti......This study is based on videorecorded interactional data from a specific type of institutional setting which consists of a variety of 'language stimulation activities' for bilingual children in Danish preschools. Bilingual children, with a variety of linguistic backgrounds, take part...... in these activities in small groups together with a specialized preschool teacher. One pervasive feature of this kind of data is the ongoing orientation to, and guidance from the adult towards the children on what the main business of their interaction is - what they relevantly are doing. In this light, the paper......: Unsolicited displays may lead to side sequences, they may lead to a shift in the main business of the talk, or they may be explicitly or implicitly ignored. The paper discusses whether and how these unsolicited displays of understanding then can be thought of as leading to opportunities for (language...

  8. Ionizing Radiation Induces Cellular Senescence of Articular Chondrocytes via Negative Regulation of SIRT1 by p38 Kinase

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Eun Hee; Hwang, Sang Gu [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2009-05-15

    Senescent cells exhibit irreversible growth arrest, large flat morphology, and up-regulated senescence-associated {beta}-galactosidase activity at pH 6.0. Several conditions, including oncogenic stress, oxidative stress, and DNA damage are associated with cellular senescence. Massive acute DNA double-strand breaks occurring as a result of mechanical and chemical stress can be repaired, but some DNA damage persists, eventually triggering premature senescence. Since ionizing radiation directly induces DBS, it is possible that cellular senescence is activated under these conditions. The biological events in chondrocytes following irradiation are poorly understood, and limited information is available on the molecular signal transduction mechanisms of cellular senescence at present. In this study, we identify SIRT1 as a target molecule of p38 kinase and demonstrate that the interactions between p38 kinase and SIRT1 protein play an important role in the regulation of cellular senescence in response to IR.

  9. IGF-I enhances cellular senescence via the reactive oxygen species-p53 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Handayaningsih, Anastasia-Evi; Takahashi, Michiko; Fukuoka, Hidenori; Iguchi, Genzo; Nishizawa, Hitoshi; Yamamoto, Masaaki; Suda, Kentaro [Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe (Japan); Takahashi, Yutaka, E-mail: takahash@med.kobe-u.ac.jp [Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe (Japan)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Cellular senescence plays an important role in tumorigenesis and aging process. Black-Right-Pointing-Pointer We demonstrated IGF-I enhanced cellular senescence in primary confluent cells. Black-Right-Pointing-Pointer IGF-I enhanced cellular senescence in the ROS and p53-dependent manner. Black-Right-Pointing-Pointer These results may explain the underlying mechanisms of IGF-I involvement in tumorigenesis and in regulation of aging. -- Abstract: Cellular senescence is characterized by growth arrest, enlarged and flattened cell morphology, the expression of senescence-associated {beta}-galactosidase (SA-{beta}-gal), and by activation of tumor suppressor networks. Insulin-like growth factor-I (IGF-I) plays a critical role in cellular growth, proliferation, tumorigenesis, and regulation of aging. In the present study, we show that IGF-I enhances cellular senescence in mouse, rat, and human primary cells in the confluent state. IGF-I induced expression of a DNA damage marker, {gamma}H2AX, the increased levels of p53 and p21 proteins, and activated SA-{beta}-gal. In the confluent state, an altered downstream signaling of IGF-I receptor was observed. Treatment with a reactive oxygen species (ROS) scavenger, N-acetylcystein (NAC) significantly suppressed induction of these markers, indicating that ROS are involved in the induction of cellular senescence by IGF-I. In p53-null mouse embryonic fibroblasts, the IGF-I-induced augmentation of SA-{beta}-gal and p21 was inhibited, demonstrating that p53 is required for cellular senescence induced by IGF-I. Thus, these data reveal a novel pathway whereby IGF-I enhances cellular senescence in the ROS and p53-dependent manner and may explain the underlying mechanisms of IGF-I involvement in tumorigenesis and in regulation of aging.

  10. Stress-induced premature senescence (SIPS)--influence of SIPS on radiotherapy.

    Science.gov (United States)

    Suzuki, Masatoshi; Boothman, David A

    2008-03-01

    Replicative senescence is a fundamental feature in normal human diploid cells and results from dysfunctional telomeres at the Hayflick cell division limit. Ionizing radiation (IR) prematurely induces the same phenotypes as replicative senescence prior to the Hayflick limit. This process is known as stress-induced premature senescence (SIPS). Since the cell cycle is irreversibly arrested in SIPS-induced cells, even if they are stimulated by various growth factors, it is thought that SIPS is a form of cell death, irreversibly eliminating replicating cells. IR-induced-focus formation of DNA repair proteins, a marker of DNA damage, is detected in SIPS as well as replicative senescent cells. Furthermore, both processes persistently induce cell cycle checkpoint mechanisms, indicating DNA damage created by ionizing radiation induces SIPS in normal cells, possibly by the same mechanisms as those occurring in replicative senescence. Interestingly, IR induces SIPS not only in normal cells, but also in tumor cells. Due to the expression of telomerase in tumor cells, telomere-dependent replicative senescence does not occur. However, SIPS is induced under certain conditions after IR exposure. Thus, cell death triggered by IR can be attributed to apoptosis or SIPS in tumor cells. However, metabolic function remains intact in SIPS-induced cancer cells, and recent studies show that senescence eliminate cells undergoing SIPS secrete various kinds of factors outside the cell, changing the microenvironment. Evidence using co-culture systems containing normal senescent stromal cells and epithelial tumor cells show that factors secreted from senescent stroma cells promote the growth of tumor epithelial cells both in vitro and in vivo. Thus, regulation of factors secreted from SIPS-induced stromal cells, as well as tumor cells, may affect radiotherapy.

  11. Stress-induced premature senescence (SIPS). Influence of SIPS on radiotherapy

    International Nuclear Information System (INIS)

    Suzuki, Masatoshi; Boothman, D.A.

    2008-01-01

    Replicative senescence is a fundamental feature in normal human diploid cells and results from dysfunctional telomeres at the Hayflick cell division limit. Ionizing radiation (IR) prematurely induces the same phenotypes as replicative senescence prior to the Hayflick limit. This process is known as stress-induced premature senescence (SIPS). Since the cell cycle is irreversibly arrested in SIPS-induced cells, even if they are stimulated by various growth factors, it is thought that SIPS is a form of cell death, irreversibly eliminating replicating cells. IR-induced-focus formation of DNA repair proteins, a marker of DNA damage, is detected in SIPS as well as replicative senescent cells. Furthermore, both processes persistently induce cell cycle checkpoint mechanisms, indicating DNA damage created by ionizing radiation induces SIPS in normal cells, possibly by the same mechanisms as those occurring in replicative senescence. Interestingly, IR induces SIPS not only in normal cells, but also in tumor cells. Due to the expression of telomerase in tumor cells, telomere-dependent replicative senescence does not occur. However, SIPS is induced under certain conditions after IR exposure. Thus, cell death triggered by IR can be attributed to apoptosis or SIPS in tumor cells. However, metabolic function remains intact in SIPS-induced cancer cells, and recent studies show that senescence eliminate cells undergoing SIPS secrete various kinds of factors outside the cell, changing the microenvironment. Evidence using co-culture systems containing normal senescent stromal cells and epithelial tumor cells show that factors secreted from senescent stroma cells promote the growth of tumor epithelial cells both in vitro and in vivo. Thus, regulation of factors secreted from SIPS-induced stromal cells, as well as tumor cells, may affect radiotherapy. (author)

  12. IGF-I enhances cellular senescence via the reactive oxygen species–p53 pathway

    International Nuclear Information System (INIS)

    Handayaningsih, Anastasia-Evi; Takahashi, Michiko; Fukuoka, Hidenori; Iguchi, Genzo; Nishizawa, Hitoshi; Yamamoto, Masaaki; Suda, Kentaro; Takahashi, Yutaka

    2012-01-01

    Highlights: ► Cellular senescence plays an important role in tumorigenesis and aging process. ► We demonstrated IGF-I enhanced cellular senescence in primary confluent cells. ► IGF-I enhanced cellular senescence in the ROS and p53-dependent manner. ► These results may explain the underlying mechanisms of IGF-I involvement in tumorigenesis and in regulation of aging. -- Abstract: Cellular senescence is characterized by growth arrest, enlarged and flattened cell morphology, the expression of senescence-associated β-galactosidase (SA-β-gal), and by activation of tumor suppressor networks. Insulin-like growth factor-I (IGF-I) plays a critical role in cellular growth, proliferation, tumorigenesis, and regulation of aging. In the present study, we show that IGF-I enhances cellular senescence in mouse, rat, and human primary cells in the confluent state. IGF-I induced expression of a DNA damage marker, γH2AX, the increased levels of p53 and p21 proteins, and activated SA-β-gal. In the confluent state, an altered downstream signaling of IGF-I receptor was observed. Treatment with a reactive oxygen species (ROS) scavenger, N-acetylcystein (NAC) significantly suppressed induction of these markers, indicating that ROS are involved in the induction of cellular senescence by IGF-I. In p53-null mouse embryonic fibroblasts, the IGF-I-induced augmentation of SA-β-gal and p21 was inhibited, demonstrating that p53 is required for cellular senescence induced by IGF-I. Thus, these data reveal a novel pathway whereby IGF-I enhances cellular senescence in the ROS and p53-dependent manner and may explain the underlying mechanisms of IGF-I involvement in tumorigenesis and in regulation of aging.

  13. Deacetylation of H4-K16Ac and heterochromatin assembly in senescence

    Directory of Open Access Journals (Sweden)

    Contrepois Kévin

    2012-08-01

    Full Text Available Abstract Background Cellular senescence is a stress response of mammalian cells leading to a durable arrest of cell proliferation that has been implicated in tumor suppression, wound healing, and aging. The proliferative arrest is mediated by transcriptional repression of genes essential for cell division by the retinoblastoma protein family. This repression is accompanied by varying degrees of heterochromatin assembly, but little is known regarding the molecular mechanisms involved. Results We found that both deacetylation of H4-K16Ac and expression of HMGA1/2 can contribute to DNA compaction during senescence. SIRT2, an NAD-dependent class III histone deacetylase, contributes to H4-K16Ac deacetylation and DNA compaction in human fibroblast cell lines that assemble striking senescence-associated heterochromatin foci (SAHFs. Decreased H4-K16Ac was observed in both replicative and oncogene-induced senescence of these cells. In contrast, this mechanism was inoperative in a fibroblast cell line that did not assemble extensive heterochromatin during senescence. Treatment of senescent cells with trichostatin A, a class I/II histone deacetylase inhibitor, also induced rapid and reversible decondensation of SAHFs. Inhibition of DNA compaction did not significantly affect the stability of the senescent state. Conclusions Variable DNA compaction observed during senescence is explained in part by cell-type specific regulation of H4 deacetylation and HMGA1/2 expression. Deacetylation of H4-K16Ac during senescence may explain reported decreases in this mark during mammalian aging and in cancer cells.

  14. Latest development of display technologies

    International Nuclear Information System (INIS)

    Gao Hong-Yue; Yao Qiu-Xiang; Liu Pan; Zheng Zhi-Qiang; Liu Ji-Cheng; Zheng Hua-Dong; Zeng Chao; Yu Ying-Jie; Sun Tao; Zeng Zhen-Xiang

    2016-01-01

    In this review we will focus on recent progress in the field of two-dimensional (2D) and three-dimensional (3D) display technologies. We present the current display materials and their applications, including organic light-emitting diodes (OLEDs), flexible OLEDs quantum dot light emitting diodes (QLEDs), active-matrix organic light emitting diodes (AMOLEDs), electronic paper (E-paper), curved displays, stereoscopic 3D displays, volumetric 3D displays, light field 3D displays, and holographic 3D displays. Conventional 2D display devices, such as liquid crystal devices (LCDs) often result in ambiguity in high-dimensional data images because of lacking true depth information. This review thus provides a detailed description of 3D display technologies. (topical review)

  15. Aging and senescence of skin cells in culture

    DEFF Research Database (Denmark)

    Rattan, Suresh

    2015-01-01

    Studying age-related changes in the physiology, biochemistry, and molecular biology of isolated skin cell populations in culture has greatly expanded the understanding of the fundamental aspects of skin aging. The three main cell types that have been studied extensively with respect to cellular...... aging in vitro are dermal fibroblasts, epidermal keratinocytes, and melanocytes. Serial subcultivation of normal diploid skin cells can be performed only a limited number of times, and the emerging senescent phenotype can be categorized into structural, physiological, biochemical, and molecular...... phenotypes, which can be used as biomarkers of cellular aging in vitro. The rate and phenotype of aging are different in different cell types. There are both common features and specific features of aging of skin fibroblasts, keratinocytes, melanocytes, and other cell types. A progressive accumulation...

  16. Retardation of senescence by UV-A light in barley (Hordeum vulgare L.) leaf segments

    International Nuclear Information System (INIS)

    Cuello, J.; Sanchez, M.D.; Sabater, B.

    1994-01-01

    The effects of low intensity (0.9–2.2 W m −2 ) UV-A radiation on barley leaf senescence were investigated. UV-A inhibited chlorophyll loss and caused increases in membrane permeability and chloroplast endopeptidases associated with senescence. The treatment of leaf segments with UV-A changed the type of proteins synthesized by chloroplasts, stimulating the synthesis of some specific polypeptides. It is concluded that the senescence of detached leaves provides an appropriate system for investigating effects of low UV-A intensities which are probably mediated by synthesis of specific proteins. (author)

  17. Senescence-associated microRNAs target cell cycle regulatory genes in normal human lung fibroblasts.

    Science.gov (United States)

    Markopoulos, Georgios S; Roupakia, Eugenia; Tokamani, Maria; Vartholomatos, George; Tzavaras, Theodore; Hatziapostolou, Maria; Fackelmayer, Frank O; Sandaltzopoulos, Raphael; Polytarchou, Christos; Kolettas, Evangelos

    2017-10-01

    Senescence recapitulates the ageing process at the cell level. A senescent cell stops dividing and exits the cell cycle. MicroRNAs (miRNAs) acting as master regulators of transcription, have been implicated in senescence. In the current study we investigated and compared the expression of miRNAs in young versus senescent human fibroblasts (HDFs), and analysed the role of mRNAs expressed in replicative senescent HFL-1 HDFs. Cell cycle analysis confirmed that HDFs accumulated in G 1 /S cell cycle phase. Nanostring analysis of isolated miRNAs from young and senescent HFL-1 showed that a distinct set of 15 miRNAs were significantly up-regulated in senescent cells including hsa-let-7d-5p, hsa-let-7e-5p, hsa-miR-23a-3p, hsa-miR-34a-5p, hsa-miR-122-5p, hsa-miR-125a-3p, hsa-miR-125a-5p, hsa-miR-125b-5p, hsa-miR-181a-5p, hsa-miR-221-3p, hsa-miR-222-3p, hsa-miR-503-5p, hsa-miR-574-3p, hsa-miR-574-5p and hsa-miR-4454. Importantly, pathway analysis of miRNA target genes down-regulated during replicative senescence in a public RNA-seq data set revealed a significant high number of genes regulating cell cycle progression, both G 1 /S and G 2 /M cell cycle phase transitions and telomere maintenance. The reduced expression of selected miRNA targets, upon replicative and oxidative-stress induced senescence, such as the cell cycle effectors E2F1, CcnE, Cdc6, CcnB1 and Cdc25C was verified at the protein and/or RNA levels. Induction of G1/S cell cycle phase arrest and down-regulation of cell cycle effectors correlated with the up-regulation of miR-221 upon both replicative and oxidative stress-induced senescence. Transient expression of miR-221/222 in HDFs promoted the accumulation of HDFs in G1/S cell cycle phase. We propose that miRNAs up-regulated during replicative senescence may act in concert to induce cell cycle phase arrest and telomere erosion, establishing a senescent phenotype. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Effect of L1-ORF2 on senescence of GES-1 cells and its molecular mechanisms

    Directory of Open Access Journals (Sweden)

    Ying-nan LI

    2016-06-01

    Full Text Available Objective  To investigate the effect of long interspersed nuclear elements 1 open reading frame 2(L1-ORF2 gene on the senescence of GES-1 cells and its mechanism of molecular regulation. Methods  Cell culture of high glucose was used to construct stable model of senescent GES-1 cells. L1-ORF2 siRNA vector was constructed and then transfected into normal GES1 and senescent ones with liposome transfection reagents for transient expression. Forty eight hours after transfection, cell growth curves were drawn to show the speed of cell proliferation, flow cytometry was used to analyze the cell cycle, β-galactosidase staining to detect cell aging and Western blotting to detect the expressions of L1-ORF2, P53 and P21proteins. Results  Senescent GES-1 cell model and L1-ORF2 siRNA vector were constructed. Compared with negative control group, the L1-ORF2 expression decreased in normal and senescent GES-1 cells transfected with L1-ORF2 siRNA vector. There was a faster proliferation of senescent GES1 cells (P<0.05 and lower ratio of β-galactosidase (56% vs 69%, P<0.05 and G0/G1 phase (34.2% vs 39.3%, P<0.05 in senescent GES-1 cells transfected with L1-ORE2 siRNA vector than those transfected with negative control vector, while there was no obvious difference between normal GES-1 cells transfected with L1-ORF2 siRNA vector and negative control vector (P>0.05. P53 protein was expressed only in senescent GES-1 cell, while P21 protein was expressed in both normal and senescent GES-1 cells, and the latter had a higher expression level (P<0.05. The GES-1 cells transfected with L1-ORF2 siRNA vector showed lower expressions of P53 and P21 proteins than those transfected with negative control vector (P<0.05. Conclusions  L1-ORF2-siRNA vector could down-regulate the expression of L1-ORF2 protein in normal and senescent GES-1 cells and promote the proliferation of senescent GES-1 cells. P21 and P53 proteins participate in the process of L1-ORF2 regulating

  19. 3D display system using monocular multiview displays

    Science.gov (United States)

    Sakamoto, Kunio; Saruta, Kazuki; Takeda, Kazutoki

    2002-05-01

    A 3D head mounted display (HMD) system is useful for constructing a virtual space. The authors have researched the virtual-reality systems connected with computer networks for real-time remote control and developed a low-priced real-time 3D display for building these systems. We developed a 3D HMD system using monocular multi-view displays. The 3D displaying technique of this monocular multi-view display is based on the concept of the super multi-view proposed by Kajiki at TAO (Telecommunications Advancement Organization of Japan) in 1996. Our 3D HMD has two monocular multi-view displays (used as a visual display unit) in order to display a picture to the left eye and the right eye. The left and right images are a pair of stereoscopic images for the left and right eyes, then stereoscopic 3D images are observed.

  20. Demographic analysis reveals gradual senescence in the flatworm Macrostomum lignano

    Directory of Open Access Journals (Sweden)

    Braeckman Bart P

    2009-07-01

    Full Text Available Abstract Free-living flatworms ("Turbellaria" are appropriate model organisms to gain better insight into the role of stem cells in ageing and rejuvenation. Ageing research in flatworms is, however, still scarce. This is partly due to culture difficulties and the lack of a complete set of demographic data, including parameters such as median lifespan and age-specific mortality rate. In this paper, we report on the first flatworm survival analysis. We used the species Macrostomum lignano, which is an emerging model for studying the reciprocal influence between stem cells, ageing and rejuvenation. This species has a median lifespan of 205 ± 13 days (average ± standard deviation [SD] and a 90th percentile lifespan of 373 ± 32 days. The maximum lifespan, however, is more than 745 days, and the average survival curve is characterised by a long tail because a small number of individuals lives twice as long as 90% of the population. Similar to earlier observations in a wide range of animals, in M. lignano the age-specific mortality rate increases exponentially, but levels off at the oldest ages. To compare the senescence of M. lignano with that of other ageing models, we determined the mortality rate doubling time, which is 0.20 ± 0.02 years. As a result, we can conclude that M. lignano shows gradual senescence at a rate similar to the vertebrate ageing models Rattus norvegicus and Mus musculus. We argue that M. lignano is a suitable model for ageing and rejuvenation research, and especially for the role of stem cells in these processes, due to its accessible stem cell system and regeneration capacity, and the possibility of combining stem cell studies with demographic analyses.

  1. Regulation of neutrophil senescence by microRNAs.

    Directory of Open Access Journals (Sweden)

    Jon R Ward

    2011-01-01

    Full Text Available Neutrophils are rapidly recruited to sites of tissue injury or infection, where they protect against invading pathogens. Neutrophil functions are limited by a process of neutrophil senescence, which renders the cells unable to respond to chemoattractants, carry out respiratory burst, or degranulate. In parallel, aged neutrophils also undergo spontaneous apoptosis, which can be delayed by factors such as GMCSF. This is then followed by their subsequent removal by phagocytic cells such as macrophages, thereby preventing unwanted inflammation and tissue damage. Neutrophils translate mRNA to make new proteins that are important in maintaining functional longevity. We therefore hypothesised that neutrophil functions and lifespan might be regulated by microRNAs expressed within human neutrophils. Total RNA from highly purified neutrophils was prepared and subjected to microarray analysis using the Agilent human miRNA microarray V3. We found human neutrophils expressed a selected repertoire of 148 microRNAs and that 6 of these were significantly upregulated after a period of 4 hours in culture, at a time when the contribution of apoptosis is negligible. A list of predicted targets for these 6 microRNAs was generated from http://mirecords.biolead.org and compared to mRNA species downregulated over time, revealing 83 genes targeted by at least 2 out of the 6 regulated microRNAs. Pathway analysis of genes containing binding sites for these microRNAs identified the following pathways: chemokine and cytokine signalling, Ras pathway, and regulation of the actin cytoskeleton. Our data suggest that microRNAs may play a role in the regulation of neutrophil senescence and further suggest that manipulation of microRNAs might represent an area of future therapeutic interest for the treatment of inflammatory disease.

  2. Liver damage and senescence increases in patients developing hepatocellular carcinoma.

    Science.gov (United States)

    Rey, Silvia; Quintavalle, Cristina; Burmeister, Katharina; Calabrese, Diego; Schlageter, Manuel; Quagliata, Luca; Cathomas, Gieri; Diebold, Joachim; Molinolo, Alfredo; Heim, Markus H; Terracciano, Luigi M; Matter, Matthias S

    2017-08-01

    Most patients with a hepatocellular carcinoma (HCC) have an underlying chronic liver inflammation, which causes a continuous damage leading to liver cirrhosis and eventually HCC. However, only a minority of cirrhotic patients develop HCC. To assess a possible differential impact of liver inflammation in patients developing HCC versus patients remaining tumor-free, we designed a longitudinal study and analysed liver tissue of the same patients (n = 33) at two points in time: once when no HCC was present and once several years later when an HCC was present. As a control group, we followed cirrhotic patients (n = 37) remaining tumor-free over a similar time frame. We analysed cell damage and senescence of hepatocytes by measuring γ-H2AX positivity, p16 INK4 and p21 WAF/Cip1 expression, nuclear size, and telomere length. γ-H2AX positivity, p16 INK4 and p21 WAF/Cip1 expression, in the first liver biopsy was similar in patients developing HCC later on and cirrhotic patients remaining tumor free. In contrast, γ-H2AX positivity, p16 INK4 and p21 WAF/Cip1 expression, was significantly higher in the second non-tumoral liver biopsy of HCC patients than in the control patients. Consequently, the individual increase in γ-H2AX positivity, p16 INK4 and p21 WAF/Cip1 expression, from the first biopsy to the second biopsy was significantly higher in patients developing HCC than in patients remaining tumor free. In addition, changes in nuclear size and telomere length revealed a more pronounced cell aging in patients developing HCC than in patients remaining tumor free. Hepatocytes from patients developing HCC go through more pronounced cell damage and senescence in contrast to cirrhotic patients remaining tumor free. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  3. Polymer Dispersed Liquid Crystal Displays

    Science.gov (United States)

    Doane, J. William

    The following sections are included: * INTRODUCTION AND HISTORICAL DEVELOPMENT * PDLC MATERIALS PREPARATION * Polymerization induced phase separation (PIPS) * Thermally induced phase separation (TIPS) * Solvent induced phase separation (SIPS) * Encapsulation (NCAP) * RESPONSE VOLTAGE * Dielectric and resistive effects * Radial configuration * Bipolar configuration * Other director configurations * RESPONSE TIME * DISPLAY CONTRAST * Light scattering and index matching * Incorporation of dyes * Contrast measurements * PDLC DISPLAY DEVICES AND INNOVATIONS * Reflective direct view displays * Large-scale, flexible displays * Switchable windows * Projection displays * High definition spatial light modulator * Haze-free PDLC shutters: wide angle view displays * ENVIRONMENTAL STABILITY * ACKNOWLEDGEMENTS * REFERENCES

  4. Crosstalk evaluation in stereoscopic displays

    NARCIS (Netherlands)

    Wang, L.; Teunissen, C.; Tu, Yan; Chen, Li; Zhang, P.; Zhang, T.; Heynderickx, I.E.J.

    2011-01-01

    Substantial progress in liquid-crystal display and polarization film technology has enabled several types of stereoscopic displays. Despite all progress, some image distortions still exist in these 3-D displays, of which interocular crosstalk - light leakage of the image for one eye to the other eye

  5. Implication of p53-dependent cellular senescence related gene, TARSH in tumor suppression

    International Nuclear Information System (INIS)

    Wakoh, Takeshi; Uekawa, Natsuko; Terauchi, Kunihiko; Sugimoto, Masataka; Ishigami, Akihito; Shimada, Jun-ichi; Maruyama, Mitsuo

    2009-01-01

    A novel target of NESH-SH3 (TARSH) was identified as a cellular senescence related gene in mouse embryonic fibroblasts (MEFs) replicative senescence, the expression of which has been suppressed in primary clinical lung cancer specimens. However, the molecular mechanism underlying the regulation of TARSH involved in pulmonary tumorigenesis remains unclear. Here we demonstrate that the reduction of TARSH gene expression by short hairpin RNA (shRNA) system robustly inhibited the MEFs proliferation with increase in senescence-associated β-galactosidase (SA-β-gal) activity. Using p53 -/- MEFs, we further suggest that this growth arrest by loss of TARSH is evoked by p53-dependent p21 Cip1 accumulation. Moreover, we also reveal that TARSH reduction induces multicentrosome in MEFs, which is linked in chromosome instability and tumor development. These results suggest that TARSH plays an important role in proliferation of replicative senescence and may serve as a trigger of tumor development.

  6. Nitric oxide prevents alveolar senescence and emphysema in a mouse model.

    Directory of Open Access Journals (Sweden)

    Amanda E Boe

    Full Text Available Nω-nitro-L-arginine methyl ester (L-NAME treatment induces arteriosclerosis and vascular senescence. Here, we report that the systemic inhibition of nitric oxide (NO production by L-NAME causes pulmonary emphysema. L-NAME-treated lungs exhibited both the structural (alveolar tissue destruction and functional (increased compliance and reduced elastance characteristics of emphysema development. Furthermore, we found that L-NAME-induced emphysema could be attenuated through both genetic deficiency and pharmacological inhibition of plasminogen activator inhibitor-1 (PAI-1. Because PAI-1 is an important contributor to the development of senescence both in vitro and in vivo, we investigated whether L-NAME-induced senescence led to the observed emphysematous changes. We found that L-NAME treatment was associated with molecular and cellular evidence of premature senescence in mice, and that PAI-1 inhibition attenuated these increases. These findings indicate that NO serves to protect and defend lung tissue from physiological aging.

  7. Lovastatin-induced RhoA modulation and its effect on senescence in prostate cancer cells

    International Nuclear Information System (INIS)

    Lee, Jeeyun; Lee, Inkyoung; Park, Chaehwa; Kang, Won Ki

    2006-01-01

    Lovastatin inhibits a 3-hydroxy 3-methylglutaryl coenzyme A reductase and prevents the synthesis of cholesterol precursors, such as farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP), responsible for important cell signaling in cell proliferation and migration. Recently, the anti-cancer effect of lovastatin has been suggested in various tumor types. In this study, we showed that a low dose lovastatin induced senescence and G1 cell cycle arrest in human prostate cancer cells. Addition of GGPP or mevalonate, but not FPP, prevented the lovastatin-induced G1 phase cell cycle arrest and cell senescence. We found that constitutively active RhoA (caRhoA) reversed lovastatin-induced senescence in caRhoA-transfected PC-3 cells. Thus, we postulate that modulation of RhoA may be critical in lovastatin-induced senescence in PC-3 cells

  8. Cytokine-induced 'bystander' senescence in DDR and immuno-surveillance

    Czech Academy of Sciences Publication Activity Database

    Hodný, Zdeněk; Hubáčková, Soňa; Bartek, Jiří

    2013-01-01

    Roč. 4, č. 10 (2013), s. 1552-1553 ISSN 1949-2553 Institutional support: RVO:68378050 Keywords : cell senescence * cytokines * immuno-surveillance Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.627, year: 2013

  9. Suppression of the vacuolar invertase gene delays senescent sweetening in chipping potatoes

    Science.gov (United States)

    Background: Potato chip processors require potato tubers that meet quality specifications for fried chip color, and color depends largely upon tuber sugar contents. At later times in storage, potatoes accumulate sucrose, glucose and fructose. This developmental process, senescent sweetening, manifes...

  10. [The contribution of plant physiology to understanding the nature of senescence and oncogenesis].

    Science.gov (United States)

    Makrushin, A V

    2008-01-01

    It is suggested to consider a destructive effect on parenchymal tissue of propagative connective-tissue cells in senescence and tumor cells in oncogenesis as a particular case of the apical dominance, the process described for plants.

  11. Repeated summer drought and re-watering during the first growing year of oak (Quercus petraea delay autumn senescence and bud burst in the following spring

    Directory of Open Access Journals (Sweden)

    Kristine Vander Mijnsbrugge

    2016-03-01

    Full Text Available Climate change predicts harsher summer droughts for mid-latitudes in Europe. To enhance our understanding of the putative impacts on forest regeneration, we studied the response of oak seedlings (Quercus petraea to water deficit. Potted seedlings originating from three locally sourced provenances were subjected to two successive drought periods during the first growing season each followed by a plentiful re-watering. Here we describe survival and phenological responses after the second drought treatment, applying general linear mixed modelling. From the 441 drought treated seedlings 189 subsisted with higher chances of survival among smaller plants and among single plants per pot compared to doubles. Remarkably, survival was independent of the provenance, although relatively more plants had died off in two provenances compared to the third one with mean plant height being higher in one provenance and standard deviation of plant height being higher in the other. Timing of leaf senescence was clearly delayed after the severe drought treatment followed by re-watering, with two seedlings per pot showing a lesser retardation compared to single plants. This delay can be interpreted as a compensation time in which plants recover before entering the subsequent developmental process of leaf senescence, although it renders seedlings more vulnerable to early autumn frosts because of the delayed hardening of the shoots. Onset of bud flush in the subsequent spring still showed a significant but small delay in the drought treated group, independent of the number of seedlings per pot, and can be considered as an after effect of the delayed senescence. In both phenological models significant differences among the three provenances were detected independent from the treatment. The only provenance that is believed to be local of origin, displayed the earliest leaf senescence and the latest flushing, suggesting an adaptation to the local maritime climate. This

  12. Delayed animal aging through the recovery of stem cell senescence by platelet rich plasma.

    Science.gov (United States)

    Liu, Hen-Yu; Huang, Chiung-Fang; Lin, Tzu-Chieh; Tsai, Ching-Yu; Tina Chen, Szu-Yu; Liu, Alice; Chen, Wei-Hong; Wei, Hong-Jian; Wang, Ming-Fu; Williams, David F; Deng, Win-Ping

    2014-12-01

    Aging is related to loss of functional stem cell accompanying loss of tissue and organ regeneration potentials. Previously, we demonstrated that the life span of ovariectomy-senescence accelerated mice (OVX-SAMP8) was significantly prolonged and similar to that of the congenic senescence-resistant strain of mice after platelet rich plasma (PRP)/embryonic fibroblast transplantation. The aim of this study is to investigate the potential of PRP for recovering cellular potential from senescence and then delaying animal aging. We first examined whether stem cells would be senescent in aged mice compared to young mice. Primary adipose derived stem cells (ADSCs) and bone marrow derived stem cells (BMSCs) were harvested from young and aged mice, and found that cell senescence was strongly correlated to animal aging. Subsequently, we demonstrated that PRP could recover cell potential from senescence, such as promote cell growth (cell proliferation and colony formation), increase osteogenesis, decrease adipogenesis, restore cell senescence related markers and resist the oxidative stress in stem cells from aged mice. The results also showed that PRP treatment in aged mice could delay mice aging as indicated by survival, body weight and aging phenotypes (behavior and gross morphology) in term of recovering the cellular potential of their stem cells compared to the results on aged control mice. In conclusion these findings showed that PRP has potential to delay aging through the recovery of stem cell senescence and could be used as an alternative medicine for tissue regeneration and future rejuvenation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Oncogene-induced senescence is part of the tumorigenesis barrier imposed by DNA damage checkpoints

    DEFF Research Database (Denmark)

    Bartkova, Jirina; Rezaei, Nousin; Liontos, Michalis

    2006-01-01

    Recent studies have indicated the existence of tumorigenesis barriers that slow or inhibit the progression of preneoplastic lesions to neoplasia. One such barrier involves DNA replication stress, which leads to activation of the DNA damage checkpoint and thereby to apoptosis or cell cycle arrest...... and senescence markers cosegregate closely. Thus, senescence in human preneoplastic lesions is a manifestation of oncogene-induced DNA replication stress and, together with apoptosis, provides a barrier to malignant progression....

  14. LHCb Event display

    CERN Document Server

    Trisovic, Ana

    2014-01-01

    The LHCb Event Display was made for educational purposes at the European Organization for Nuclear Research, CERN in Geneva, Switzerland. The project was implemented as a stand-alone application using C++ and ROOT, a framework developed by CERN for data analysis. This paper outlines the development and architecture of the application in detail, as well as the motivation for the development and the goals of the exercise. The application focuses on the visualization of events recorded by the LHCb detector, where an event represents a set of charged particle tracks in one proton-proton collision. Every particle track is coloured by its type and can be selected to see its essential information such as mass and momentum. The application allows students to save this information and calculate the invariant mass for any pair of particles. Furthermore, the students can use additional calculating tools in the application and build up a histogram of these invariant masses. The goal for the students is to find a $D^0$ par...

  15. Colorimetry for CRT displays.

    Science.gov (United States)

    Golz, Jürgen; MacLeod, Donald I A

    2003-05-01

    We analyze the sources of error in specifying color in CRT displays. These include errors inherent in the use of the color matching functions of the CIE 1931 standard observer when only colorimetric, not radiometric, calibrations are available. We provide transformation coefficients that prove to correct the deficiencies of this observer very well. We consider four different candidate sets of cone sensitivities. Some of these differ substantially; variation among candidate cone sensitivities exceeds the variation among phosphors. Finally, the effects of the recognized forms of observer variation on the visual responses (cone excitations or cone contrasts) generated by CRT stimuli are investigated and quantitatively specified. Cone pigment polymorphism gives rise to variation of a few per cent in relative excitation by the different phosphors--a variation larger than the errors ensuing from the adoption of the CIE standard observer, though smaller than the differences between some candidate cone sensitivities. Macular pigmentation has a larger influence, affecting mainly responses to the blue phosphor. The estimated combined effect of all sources of observer variation is comparable in magnitude with the largest differences between competing cone sensitivity estimates but is not enough to disrupt very seriously the relation between the L and M cone weights and the isoluminance settings of individual observers. It is also comparable with typical instrumental colorimetric errors, but we discuss these only briefly.

  16. Web Extensible Display Manager

    Energy Technology Data Exchange (ETDEWEB)

    Slominski, Ryan [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Larrieu, Theodore L. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2018-02-01

    Jefferson Lab's Web Extensible Display Manager (WEDM) allows staff to access EDM control system screens from a web browser in remote offices and from mobile devices. Native browser technologies are leveraged to avoid installing and managing software on remote clients such as browser plugins, tunnel applications, or an EDM environment. Since standard network ports are used firewall exceptions are minimized. To avoid security concerns from remote users modifying a control system, WEDM exposes read-only access and basic web authentication can be used to further restrict access. Updates of monitored EPICS channels are delivered via a Web Socket using a web gateway. The software translates EDM description files (denoted with the edl suffix) to HTML with Scalable Vector Graphics (SVG) following the EDM's edl file vector drawing rules to create faithful screen renderings. The WEDM server parses edl files and creates the HTML equivalent in real-time allowing existing screens to work without modification. Alternatively, the familiar drag and drop EDM screen creation tool can be used to create optimized screens sized specifically for smart phones and then rendered by WEDM.

  17. Display systems for NPP control

    International Nuclear Information System (INIS)

    Rozov, S.S.

    1988-01-01

    Main trends in development of display systems used as the means for image displaying in NPP control systems are considered. It is shown that colour display devices appear to be the most universal means for concentrated data presentation. Along with digital means the display systems provide for high-speed response, sufficient for operative control of executive mechanisms. A conclusion is drawn that further development of display systems will move towards creation of large colour fields (on reflection base or with multicolour gas-discharge elements)

  18. A crucial role for CDC42 in senescence-associated inflammation and atherosclerosis.

    Directory of Open Access Journals (Sweden)

    Takashi K Ito

    Full Text Available Risk factors for atherosclerosis accelerate the senescence of vascular endothelial cells and promote atherogenesis by inducing vascular inflammation. A hallmark of endothelial senescence is the persistent up-regulation of pro-inflammatory genes. We identified CDC42 signaling as a mediator of chronic inflammation associated with endothelial senescence. Inhibition of CDC42 or NF-κB signaling attenuated the sustained up-regulation of pro-inflammatory genes in senescent human endothelial cells. Endothelium-specific activation of the p53/p21 pathway, a key mediator of senescence, also resulted in up-regulation of pro-inflammatory molecules in mice, which was reversed by Cdc42 deletion in endothelial cells. Likewise, endothelial-specific deletion of Cdc42 significantly attenuated chronic inflammation and plaque formation in atherosclerotic mice. While inhibition of NF-κB suppressed the pro-inflammatory responses in acute inflammation, the influence of Cdc42 deletion was less marked. Knockdown of cdc-42 significantly down-regulated pro-inflammatory gene expression and restored the shortened lifespan to normal in mutant worms with enhanced inflammation. These findings indicate that the CDC42 pathway is critically involved in senescence-associated inflammation and could be a therapeutic target for chronic inflammation in patients with age-related diseases without compromising host defenses.

  19. NOX2-Induced Activation of Arginase and Diabetes-Induced Retinal Endothelial Cell Senescence

    Directory of Open Access Journals (Sweden)

    Modesto Rojas

    2017-06-01

    Full Text Available Increases in reactive oxygen species (ROS and decreases in nitric oxide (NO have been linked to vascular dysfunction during diabetic retinopathy (DR. Diabetes can reduce NO by increasing ROS and by increasing activity of arginase, which competes with nitric oxide synthase (NOS for their commons substrate l-arginine. Increased ROS and decreased NO can cause premature endothelial cell (EC senescence leading to defective vascular repair. We have previously demonstrated the involvement of NADPH oxidase 2 (NOX2-derived ROS, decreased NO and overactive arginase in DR. Here, we investigated their impact on diabetes-induced EC senescence. Studies using diabetic mice and retinal ECs treated with high glucose or H2O2 showed that increases in ROS formation, elevated arginase expression and activity, and decreased NO formation led to premature EC senescence. NOX2 blockade or arginase inhibition prevented these effects. EC senescence was also increased by inhibition of NOS activity and this was prevented by treatment with a NO donor. These results indicate that diabetes/high glucose-induced activation of arginase and decreases in NO bioavailability accelerate EC senescence. NOX2-generated ROS contribute importantly to this process. Blockade of NOX2 or arginase represents a strategy to prevent diabetes-induced premature EC senescence by preserving NO bioavailability.

  20. Targeted Apoptosis of Senescent Cells Restores Tissue Homeostasis in Response to Chemotoxicity and Aging.

    Science.gov (United States)

    Baar, Marjolein P; Brandt, Renata M C; Putavet, Diana A; Klein, Julian D D; Derks, Kasper W J; Bourgeois, Benjamin R M; Stryeck, Sarah; Rijksen, Yvonne; van Willigenburg, Hester; Feijtel, Danny A; van der Pluijm, Ingrid; Essers, Jeroen; van Cappellen, Wiggert A; van IJcken, Wilfred F; Houtsmuller, Adriaan B; Pothof, Joris; de Bruin, Ron W F; Madl, Tobias; Hoeijmakers, Jan H J; Campisi, Judith; de Keizer, Peter L J

    2017-03-23

    The accumulation of irreparable cellular damage restricts healthspan after acute stress or natural aging. Senescent cells are thought to impair tissue function, and their genetic clearance can delay features of aging. Identifying how senescent cells avoid apoptosis allows for the prospective design of anti-senescence compounds to address whether homeostasis can also be restored. Here, we identify FOXO4 as a pivot in senescent cell viability. We designed a FOXO4 peptide that perturbs the FOXO4 interaction with p53. In senescent cells, this selectively causes p53 nuclear exclusion and cell-intrinsic apoptosis. Under conditions where it was well tolerated in vivo, this FOXO4 peptide neutralized doxorubicin-induced chemotoxicity. Moreover, it restored fitness, fur density, and renal function in both fast aging Xpd TTD/TTD and naturally aged mice. Thus, therapeutic targeting of senescent cells is feasible under conditions where loss of health has already occurred, and in doing so tissue homeostasis can effectively be restored. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Changes in protein patterns and in vivo protein synthesis during senescence of hibiscus petals

    International Nuclear Information System (INIS)

    Woodson, W.R.; Handa, A.K.

    1986-01-01

    Changes in proteins associated with senescence of the flowers of Hibiscus rosa-sinensis was studied using SDS-PAGE. Total extractable protein from petals decreased with senescence. Changes were noted in patterns of proteins from aging petals. Flower opening and senescence was associated with appearance and disappearance of several polypeptides. One new polypeptide with an apparent mw of 41 kd was first seen the day of flower opening and increased to over 9% of the total protein content of senescent petal tissue. Protein synthesis during aging was investigated by following uptake and incorporation of 3 H-leucine into TCA-insoluble fraction of petal discs. Protein synthesis, as evidenced by the percent of label incorporated into the TCA-insoluble fraction, was greatest (32%) the day before flower opening. Senescent petal tissue incorporated 4% of label taken up into protein. Proteins were separated by SDS-PAGE and labelled polypeptides identified by fluorography. In presenescent petal tissue, radioactivity was distributed among several major polypeptides. In senescent tissue, much of the radioactivity was concentrated in the 41 kd polypeptide

  2. Environmental stress, ageing and glial cell senescence: a novel mechanistic link to Parkinson's disease?

    Science.gov (United States)

    Chinta, S J; Lieu, C A; Demaria, M; Laberge, R-M; Campisi, J; Andersen, J K

    2013-05-01

    Exposure to environmental toxins is associated with a variety of age-related diseases including cancer and neurodegeneration. For example, in Parkinson's disease (PD), chronic environmental exposure to certain toxins has been linked to the age-related development of neuropathology. Neuronal damage is believed to involve the induction of neuroinflammatory events as a consequence of glial cell activation. Cellular senescence is a potent anti-cancer mechanism that occurs in a number of proliferative cell types and causes the arrest of proliferation of cells at risk of malignant transformation following exposure to potentially oncogenic stimuli. With age, senescent cells accumulate and express a senescence-associated secretory phenotype (SASP; that is the robust secretion of many inflammatory cytokines, growth factors and proteases). Whereas cell senescence in peripheral tissues has been causally linked to a number of age-related pathologies, little is known about the induction of cellular senescence and the SASP in the brain. On the basis of recently reported findings, we propose that environmental stressors associated with PD may act in part by eliciting senescence and the SASP within non neuronal glial cells in the ageing brain, thus contributing to the characteristic decline in neuronal integrity that occurs in this disorder. © 2013 The Association for the Publication of the Journal of Internal Medicine.

  3. Environmental stress, ageing and glial cell senescence: a novel mechanistic link to Parkinson’s disease?

    Science.gov (United States)

    Chinta, Shankar J; Lieu, Christopher A; DeMaria, Marco; Laberge, Remi-Martin; Campisi, Judith; Andersen, Julie K

    2013-01-01

    Exposure to environmental toxins is associated with a variety of age-related diseases including cancer and neurodegeneration. For example, in Parkinson’s disease (PD), chronic environmental exposure to certain toxins has been linked to the age-related development of neuropathology. Neuronal damage is believed to involve the induction of neuroinflammatory events as a consequence of glial cell activation. Cellular senescence is a potent anti-cancer mechanism that occurs in a number of proliferative cell types and causes the arrest of proliferation of cells at risk of malignant transformation following exposure to potentially oncogenic stimuli. With age, senescent cells accumulate and express a senescence-associated secretory phenotype (SASP; i.e. the robust secretion of many inflammatory cytokines, growth factors and proteases). Whereas cell senescence in peripheral tissues has been causally linked to a number of age-related pathologies, little is known about the induction of cellular senescence and the SASP in the brain. Based on recently reported findings, we propose that environmental stressors associated with PD may act in part by eliciting senescence and the SASP within non-neuronal glial cells in the ageing brain, thus contributing to the characteristic decline in neuronal integrity that occurs in this disorder. PMID:23600398

  4. Arctigenin induced gallbladder cancer senescence through modulating epidermal growth factor receptor pathway.

    Science.gov (United States)

    Zhang, Mingdi; Cai, Shizhong; Zuo, Bin; Gong, Wei; Tang, Zhaohui; Zhou, Di; Weng, Mingzhe; Qin, Yiyu; Wang, Shouhua; Liu, Jun; Ma, Fei; Quan, Zhiwei

    2017-05-01

    Gallbladder cancer has poor prognosis and limited therapeutic options. Arctigenin, a representative dibenzylbutyrolactone lignan, occurs in a variety of plants. However, the molecular mechanisms involved in the antitumor effect of arctigenin on gallbladder cancer have not been fully elucidated. The expression levels of epidermal growth factor receptor were examined in 100 matched pairs of gallbladder cancer tissues. A positive correlation between high epidermal growth factor receptor expression levels and poor prognosis was observed in gallbladder cancer tissues. Pharmacological inhibition or inhibition via RNA interference of epidermal growth factor receptor induced cellular senescence in gallbladder cancer cells. The antitumor effect of arctigenin on gallbladder cancer cells was primarily achieved by inducing cellular senescence. In gallbladder cancer cells treated with arctigenin, the expression level of epidermal growth factor receptor significantly decreased. The analysis of the activity of the kinases downstream of epidermal growth factor receptor revealed that the RAF-MEK-ERK signaling pathway was significantly inhibited. Furthermore, the cellular senescence induced by arctigenin could be reverted by pcDNA-epidermal growth factor receptor. Arctigenin also potently inhibited the growth of tumor xenografts, which was accompanied by the downregulation of epidermal growth factor receptor and induction of senescence. This study demonstrates arctigenin could induce cellular senescence in gallbladder cancer through the modulation of epidermal growth factor receptor pathway. These data identify epidermal growth factor receptor as a key regulator in arctigenin-induced gallbladder cancer senescence.

  5. Proteomic and Biochemical Changes during Senescence of Phalaenopsis 'Red Dragon' Petals.

    Science.gov (United States)

    Chen, Cong; Zeng, Lanting; Ye, Qingsheng

    2018-04-28

    Phalaenopsis flowers are some of the most popular ornamental flowers in the world. For most ornamental plants, petal longevity determines postharvest quality and garden performance. Therefore, it is important to have insight into the senescence mechanism of Phalaenopsis . In the present study, a proteomic approach combined with ultrastructural observation and activity analysis of antioxidant enzymes was used to profile the molecular and biochemical changes during pollination-induced petal senescence in Phalaenopsis “Red Dragon”. Petals appeared to be visibly wilting at 24 h after pollination, accompanied by the mass degradation of macromolecules and organelles during senescence. In addition, 48 protein spots with significant differences in abundance were found by two-dimensional electrophoresis (2-DE) and subjected to matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/TOF-MS). There were 42 protein spots successfully identified and homologous to known functional protein species involved in key biological processes, including antioxidant pathways, stress response, protein metabolism, cell wall component metabolism, energy metabolism, cell structure, and signal transduction. The activity of all reactive oxygen species (ROS)-scavenging enzymes was increased, keeping the content of ROS at a low level at the early stage of senescence. These results suggest that two processes, a counteraction against increased levels of ROS and the degradation of cellular constituents for maintaining nutrient recycling, are activated during pollination-induced petal senescence in Phalaenopsis . The information provides a basis for understanding the mechanism regulating petal senescence and prolonging the florescence of Phalaenopsis .

  6. ROS, Cell Senescence, and Novel Molecular Mechanisms in Aging and Age-Related Diseases

    Directory of Open Access Journals (Sweden)

    Pierpaola Davalli

    2016-01-01

    Full Text Available The aging process worsens the human body functions at multiple levels, thus causing its gradual decrease to resist stress, damage, and disease. Besides changes in gene expression and metabolic control, the aging rate has been associated with the production of high levels of Reactive Oxygen Species (ROS and/or Reactive Nitrosative Species (RNS. Specific increases of ROS level have been demonstrated as potentially critical for induction and maintenance of cell senescence process. Causal connection between ROS, aging, age-related pathologies, and cell senescence is studied intensely. Senescent cells have been proposed as a target for interventions to delay the aging and its related diseases or to improve the diseases treatment. Therapeutic interventions towards senescent cells might allow restoring the health and curing the diseases that share basal processes, rather than curing each disease in separate and symptomatic way. Here, we review observations on ROS ability of inducing cell senescence through novel mechanisms that underpin aging processes. Particular emphasis is addressed to the novel mechanisms of ROS involvement in epigenetic regulation of cell senescence and aging, with the aim to individuate specific pathways, which might promote healthy lifespan and improve aging.

  7. Inhibition of phosphatidylcholine-specific phospholipase C prevents bone marrow stromal cell senescence in vitro.

    Science.gov (United States)

    Sun, Chunhui; Wang, Nan; Huang, Jie; Xin, Jie; Peng, Fen; Ren, Yinshi; Zhang, Shangli; Miao, Junying

    2009-10-01

    Bone marrow stromal cells (BMSCs) can proliferate in vitro and can be transplanted for treating many kinds of diseases. However, BMSCs become senescent with long-term culture, which inhibits their application. To understand the mechanism underlying the senescence, we investigated the activity of phosphatidylcholine-specific phospholipase C (PC-PLC) and levels of integrin beta4, caveolin-1 and ROS with BMSC senescence. The activity of PC-PLC and levels of integrin beta4, caveolin-1 and ROS increased greatly during cell senescence. Selective inhibition of increased PC-PLC activity with D609 significantly decreased the number of senescence-associated beta galactosidase positive cells in BMSCs. Furthermore, D609 restored proliferation of BMSCs and their differentiation into adipocytes. Moreover, D609 suppressed the elevated levels of integrin beta4, caveolin-1 and ROS. The data suggest that PC-PLC is involved in senescence of BMSCs, and its function is associated with integrin beta4, caveolin-1 and ROS. (c) 2009 Wiley-Liss, Inc.

  8. Photosynthetic Characteristics of Flag Leaves in Rice White Stripe Mutant 6001 During Senescence Process

    Directory of Open Access Journals (Sweden)

    Xiao-hui ZHEN

    2014-11-01

    Full Text Available Physiological, biochemical and electron microscopy analyses were used to investigate the photosynthetic performance of flag leaves in rice white stripe mutant 6001 during the senescence process. Results showed that the chlorophyll content at the heading and milk-ripe stages in rice mutant 6001 were about 34.78% and 3.00% less than those in wild type 6028, respectively. However, the chlorophyll content at the fully-ripe stage in rice mutant 6001 was higher than that in wild type 6028. At the heading stage, the net photosynthetic rate (Pn in rice mutant 6001 was lower than that in wild type 6028. Rice mutant 6001 also exhibited a significantly slower decrease rate of Pn than wild type 6028 during the senescence progress, especially at the later stage. Furthermore, Ca2+-ATPase, Mg2+-ATPase and photophosphorylation activities exhibited the similar trends as the Pn. During the senescence process, the 68 kDa polypeptide concentrations in the thylakoid membrane proteins exhibited a significant change, which was one of the critical factors that contributed to the observed change in photosynthesis. We also observed that the chloroplasts of rice mutant 6001 exhibited higher integrity than those of wild type 6028, and the chloroplast membrane of rice mutant 6001 disintegrated more slow during the senescence process. In general, rice mutant 6001 had a relatively slower senescence rate than wild type 6028, and exhibited anti-senescence properties.

  9. Non-Cell Autonomous Effects of the Senescence-Associated Secretory Phenotype in Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Tareq Saleh

    2018-05-01

    Full Text Available In addition to promoting various forms of cell death, most conventional anti-tumor therapies also promote senescence. There is now extensive evidence that therapy-induced senescence (TIS might be transient, raising the concern that TIS could represent an undesirable outcome of therapy by providing a mechanism for tumor dormancy and eventual disease recurrence. The senescence-associated secretory phenotype (SASP is a hallmark of TIS and may contribute to aberrant effects of cancer therapy. Here, we propose that the SASP may also serve as a major driver of escape from senescence and the re-emergence of proliferating tumor cells, wherein factors secreted from the senescent cells contribute to the restoration of tumor growth in a non-cell autonomous fashion. Accordingly, anti-SASP therapies might serve to mitigate the deleterious outcomes of TIS. In addition to providing an overview of the putative actions of the SASP, we discuss recent efforts to identify and eliminate senescent tumor cells.

  10. Twist1 suppresses senescence programs and thereby accelerates and maintains mutant Kras-induced lung tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Phuoc T Tran

    Full Text Available KRAS mutant lung cancers are generally refractory to chemotherapy as well targeted agents. To date, the identification of drugs to therapeutically inhibit K-RAS have been unsuccessful, suggesting that other approaches are required. We demonstrate in both a novel transgenic mutant Kras lung cancer mouse model and in human lung tumors that the inhibition of Twist1 restores a senescence program inducing the loss of a neoplastic phenotype. The Twist1 gene encodes for a transcription factor that is essential during embryogenesis. Twist1 has been suggested to play an important role during tumor progression. However, there is no in vivo evidence that Twist1 plays a role in autochthonous tumorigenesis. Through two novel transgenic mouse models, we show that Twist1 cooperates with Kras(G12D to markedly accelerate lung tumorigenesis by abrogating cellular senescence programs and promoting the progression from benign adenomas to adenocarcinomas. Moreover, the suppression of Twist1 to physiological levels is sufficient to cause Kras mutant lung tumors to undergo senescence and lose their neoplastic features. Finally, we analyzed more than 500 human tumors to demonstrate that TWIST1 is frequently overexpressed in primary human lung tumors. The suppression of TWIST1 in human lung cancer cells also induced cellular senescence. Hence, TWIST1 is a critical regulator of cellular senescence programs, and the suppression of TWIST1 in human tumors may be an effective example of pro-senescence therapy.

  11. Ring-like distribution of constitutive heterochromatin in bovine senescent cells.

    Science.gov (United States)

    Pichugin, Andrey; Beaujean, Nathalie; Vignon, Xavier; Vassetzky, Yegor

    2011-01-01

    Cells that reach "Hayflick limit" of proliferation, known as senescent cells, possess a particular type of nuclear architecture. Human senescent cells are characterized by the presence of highly condensed senescent associated heterochromatin foci (SAHF) that can be detected both by immunostaining for histone H3 three-methylated at lysine 9 (H3K9me3) and by DAPI counterstaining. We have studied nuclear architecture in bovine senescent cells using a combination of immunofluorescence and 3D fluorescent in-situ hybridization (FISH). Analysis of heterochromatin distribution in bovine senescent cells using fluorescent in situ hybridization for pericentric chromosomal regions, immunostaining of H3K9me3, centromeric proteins CENP A/B and DNA methylation showed a lower level of heterochromatin condensation as compared to young cells. No SAHF foci were observed. Instead, we observed fibrous ring-like or ribbon-like heterochromatin patterns that were undetectable with DAPI counterstaining. These heterochromatin fibers were associated with nucleoli. Constitutive heterochromatin in bovine senescent cells is organized in ring-like structures.

  12. Ring-like distribution of constitutive heterochromatin in bovine senescent cells.

    Directory of Open Access Journals (Sweden)

    Andrey Pichugin

    Full Text Available BACKGROUND: Cells that reach "Hayflick limit" of proliferation, known as senescent cells, possess a particular type of nuclear architecture. Human senescent cells are characterized by the presence of highly condensed senescent associated heterochromatin foci (SAHF that can be detected both by immunostaining for histone H3 three-methylated at lysine 9 (H3K9me3 and by DAPI counterstaining. METHODS: We have studied nuclear architecture in bovine senescent cells using a combination of immunofluorescence and 3D fluorescent in-situ hybridization (FISH. RESULTS: Analysis of heterochromatin distribution in bovine senescent cells using fluorescent in situ hybridization for pericentric chromosomal regions, immunostaining of H3K9me3, centromeric proteins CENP A/B and DNA methylation showed a lower level of heterochromatin condensation as compared to young cells. No SAHF foci were observed. Instead, we observed fibrous ring-like or ribbon-like heterochromatin patterns that were undetectable with DAPI counterstaining. These heterochromatin fibers were associated with nucleoli. CONCLUSIONS: Constitutive heterochromatin in bovine senescent cells is organized in ring-like structures.

  13. Perception of Arabidopsis AtPep peptides, but not bacterial elicitors, accelerates starvation-induced senescence

    Directory of Open Access Journals (Sweden)

    Kay eGully

    2015-01-01

    Full Text Available Members of the AtPep group of Arabidopsis endogenous peptides have frequently been reported to induce pattern-triggered immunity and to increase resistance to diverse pathogens by amplifying the innate immune response. Here, we made the surprising observation that dark-induced leaf senescence was accelerated by the presence of Peps. Adult leaves as well as leaf discs of Col-0 wild type plants showed a Pep-triggered early onset of chlorophyll breakdown and leaf yellowing whereas pepr1 pepr2 double mutant plants were insensitive. In addition, this response was dependent on ethylene signaling and inhibited by the addition of cytokinins. Notably, addition of the bacterial elicitors flg22 or elf18, both potent inducers of pattern-triggered immunity, did not provoke an early onset of leaf senescence.Continuous darkness leads to energy deprivation and starvation and therewith promotes leaf senescence. We found that continuous darkness also strongly induced PROPEP3 transcription. Moreover, Pep-perception led to a rapid induction of PAO, APG7 and APG8a, genes indispensable for chlorophyll degradation as well as autophagy, respectively, and all three hallmarks of starvation and senescence. Notably, addition of sucrose as a source of energy inhibited the Pep-triggered early onset of senescence. In conclusion, we report that Pep-perception accelerates dark/starvation-induced senescence via an early induction of chlorophyll degradation and autophagy. This represents a novel and unique characteristic of PEPR signaling, unrelated to pattern-triggered immunity.

  14. Limited role of murine ATM in oncogene-induced senescence and p53-dependent tumor suppression.

    Directory of Open Access Journals (Sweden)

    Alejo Efeyan

    Full Text Available Recent studies in human fibroblasts have provided a new general paradigm of tumor suppression according to which oncogenic signaling produces DNA damage and this, in turn, results in ATM/p53-dependent cellular senescence. Here, we have tested this model in a variety of murine experimental systems. Overexpression of oncogenic Ras in murine fibroblasts efficiently induced senescence but this occurred in the absence of detectable DNA damage signaling, thus suggesting a fundamental difference between human and murine cells. Moreover, lung adenomas initiated by endogenous levels of oncogenic K-Ras presented abundant senescent cells, but undetectable DNA damage signaling. Accordingly, K-Ras-driven adenomas were also senescent in Atm-null mice, and the tumorigenic progression of these lesions was only modestly accelerated by Atm-deficiency. Finally, we have examined chemically-induced fibrosarcomas, which possess a persistently activated DNA damage response and are highly sensitive to the activity of p53. We found that the absence of Atm favored genomic instability in the resulting tumors, but did not affect the persistent DNA damage response and did not impair p53-dependent tumor suppression. All together, we conclude that oncogene-induced senescence in mice may occur in the absence of a detectable DNA damage response. Regarding murine Atm, our data suggest that it plays a minor role in oncogene-induced senescence or in p53-dependent tumor suppression, being its tumor suppressive activity probably limited to the maintenance of genomic stability.

  15. Enhanced molecular aging in late-life depression: the Senescent Associated Secretory Phenotype

    Science.gov (United States)

    Diniz, Breno Satler; Reynolds, Charles F.; Sibille, Etienne; Lin, Chien-Wei; Tseng, George; Lotrich, Francis; Aizenstein, Howard J.; Butters, Meryl A.

    2016-01-01

    Objective This study aims to investigate whether a systemic molecular pattern associated with aging (senescent-associated secretory phenotype – SASP) is elevated in adults with late-life depression (LLD), compared to never-depressed elderly comparison participants. Design Cross-sectional study. Participants We included 111 older adults (80 with LLD and 31 comparison participants) in this study. Measurement A panel of 22 SASP-related proteins was extracted from a previous multiplex protein panel performed in these participants. We conducted a principal component analysis to create the SASP index based on individual weights of each of protein. Results Participants with LLD showed a significantly increased SASP index compared to comparison participants, after controlling for age, depressive symptoms, medical comorbidity (CIRS-G) scores, gender, and cognitive performance (F(1,98)=7.3, p=0.008). Correlation analyses revealed that the SASP index was positively correlated with age (r=0.2, p = 0.03) and CIRS score (r=0.27, p=0.005), and negatively correlated with information processing speed (r=−0.34, p=0.001), executive function (r=−0.27, p=0.004) and global cognitive performance (r=−0.28, p=0.007). Conclusions To the best of our knowledge, this is the first study to show that a set of proteins (i.e., SASP index) primarily associated with cellular aging, is abnormally regulated and elevated in LLD. These results suggest that individuals with LLD display enhanced aging-related molecular patterns that are associated with higher medical comorbidity and worse cognitive function. Finally, we provide a set of proteins that can serve as potential therapeutic targets and biomarkers to monitor the effects of therapeutic or preventative interventions in LLD. PMID:27856124

  16. Intrinsic radiation resistance in human chondrosarcoma cells

    International Nuclear Information System (INIS)

    Moussavi-Harami, Farid; Mollano, Anthony; Martin, James A.; Ayoob, Andrew; Domann, Frederick E.; Gitelis, Steven; Buckwalter, Joseph A.

    2006-01-01

    Human chondrosarcomas rarely respond to radiation treatment, limiting the options for eradication of these tumors. The basis of radiation resistance in chondrosarcomas remains obscure. In normal cells radiation induces DNA damage that leads to growth arrest or death. However, cells that lack cell cycle control mechanisms needed for these responses show intrinsic radiation resistance. In previous work, we identified immortalized human chondrosarcoma cell lines that lacked p16 ink4a , one of the major tumor suppressor proteins that regulate the cell cycle. We hypothesized that the absence of p16 ink4a contributes to the intrinsic radiation resistance of chondrosarcomas and that restoring p16 ink4a expression would increase their radiation sensitivity. To test this we determined the effects of ectopic p16 ink4a expression on chondrosarcoma cell resistance to low-dose γ-irradiation (1-5 Gy). p16 ink4a expression significantly increased radiation sensitivity in clonogenic assays. Apoptosis did not increase significantly with radiation and was unaffected by p16 ink4a transduction of chondrosarcoma cells, indicating that mitotic catastrophe, rather than programmed cell death, was the predominant radiation effect. These results support the hypothesis that p16 ink4a plays a role in the radiation resistance of chondrosarcoma cell lines and suggests that restoring p16 expression will improve the radiation sensitivity of human chondrosarcomas

  17. Augmenting digital displays with computation

    Science.gov (United States)

    Liu, Jing

    As we inevitably step deeper and deeper into a world connected via the Internet, more and more information will be exchanged digitally. Displays are the interface between digital information and each individual. Naturally, one fundamental goal of displays is to reproduce information as realistically as possible since humans still care a lot about what happens in the real world. Human eyes are the receiving end of such information exchange; therefore it is impossible to study displays without studying the human visual system. In fact, the design of displays is rather closely coupled with what human eyes are capable of perceiving. For example, we are less interested in building displays that emit light in the invisible spectrum. This dissertation explores how we can augment displays with computation, which takes both display hardware and the human visual system into consideration. Four novel projects on display technologies are included in this dissertation: First, we propose a software-based approach to driving multiview autostereoscopic displays. Our display algorithm can dynamically assign views to hardware display zones based on multiple observers' current head positions, substantially reducing crosstalk and stereo inversion. Second, we present a dense projector array that creates a seamless 3D viewing experience for multiple viewers. We smoothly interpolate the set of viewer heights and distances on a per-vertex basis across the arrays field of view, reducing image distortion, crosstalk, and artifacts from tracking errors. Third, we propose a method for high dynamic range display calibration that takes into account the variation of the chrominance error over luminance. We propose a data structure for enabling efficient representation and querying of the calibration function, which also allows user-guided balancing between memory consumption and the amount of computation. Fourth, we present user studies that demonstrate that the ˜ 60 Hz critical flicker fusion

  18. Display Parameters and Requirements

    Science.gov (United States)

    Bahadur, Birendra

    The following sections are included: * INTRODUCTION * HUMAN FACTORS * Anthropometry * Sensory * Cognitive * Discussions * THE HUMAN VISUAL SYSTEM - CAPABILITIES AND LIMITATIONS * Cornea * Pupil and Iris * Lens * Vitreous Humor * Retina * RODS - NIGHT VISION * CONES - DAY VISION * RODS AND CONES - TWILIGHT VISION * VISUAL PIGMENTS * MACULA * BLOOD * CHOROID COAT * Visual Signal Processing * Pathways to the Brain * Spatial Vision * Temporal Vision * Colour Vision * Colour Blindness * DICHROMATISM * Protanopia * Deuteranopia * Tritanopia * ANOMALOUS TRICHROMATISM * Protanomaly * Deuteranomaly * Tritanomaly * CONE MONOCHROMATISM * ROD MONOCHROMATISM * Using Colour Effectively * COLOUR MIXTURES AND THE CHROMATICITY DIAGRAM * Colour Matching Functions and Chromaticity Co-ordinates * CIE 1931 Colour Space * CIE PRIMARIES * CIE COLOUR MATCHING FUNCTIONS AND CHROMATICITY CO-ORDINATES * METHODS FOR DETERMINING TRISTIMULUS VALUES AND COLOUR CO-ORDINATES * Spectral Power Distribution Method * Filter Method * CIE 1931 CHROMATICITY DIAGRAM * ADDITIVE COLOUR MIXTURE * CIE 1976 Chromaticity Diagram * CIE Uniform Colour Spaces and Colour Difference Formulae * CIELUV OR L*u*v* * CIELAB OR L*a*b* * CIE COLOUR DIFFERENCE FORMULAE * Colour Temperature and CIE Standard Illuminants and source * RADIOMETRIC AND PHOTOMETRIC QUANTITIES * Photopic (Vλ and Scotopic (Vλ') Luminous Efficiency Function * Photometric and Radiometric Flux * Luminous and Radiant Intensities * Incidence: Illuminance and Irradiance * Exitance or Emittance (M) * Luminance and Radiance * ERGONOMIC REQUIREMENTS OF DISPLAYS * ELECTRO-OPTICAL PARAMETERS AND REQUIREMENTS * Contrast and Contrast Ratio * Luminance and Brightness * Colour Contrast and Chromaticity * Glare * Other Aspects of Legibility * SHAPE AND SIZE OF CHARACTERS * DEFECTS AND BLEMISHES * FLICKER AND DISTORTION * ANGLE OF VIEW * Switching Speed * Threshold and Threshold Characteristic * Measurement Techniques For Electro-optical Parameters * RADIOMETRIC

  19. The overexpression of p16 is not a surrogate marker for high-risk human papilloma virus genotypes and predicts clinical outcomes for vulvar cancer.

    Science.gov (United States)

    Sznurkowski, Jacek J; Żawrocki, Anton; Biernat, Wojciech

    2016-07-13

    We aimed to evaluate the correlation between p16(ink4a)-overexpression and high risk (hr)HPV-DNA in vulvar squamous cell carcinoma (vSCC) tumors as well as the impact of both biomarkers on the prognosis of vSCC patients. PCR-detection of (hr)HPV-DNA and immunohistochemical staining for p16(ink4a) were conducted in 85 vSCC tumors. Survival analyses included the Kaplan-Meier method, log-rank test and Cox proportional hazards model. p16(ink4a)-overexpression and (hr)HPV-DNA were detected in 35 and 37 of the 85 tumors, respectively. Among the 35 p16(ink4a)-positive tumors, 10 lacked (hr)HPV-DNA (29 %). Among the 50 p16(ink4a)-negative tumors, (hr)HPV-DNA was detected in 12 cases (24 %). The median follow-up was 89.20 months (range 1.7-189.5 months). P16(ink4a)-overexpression, but not (hr)HPV-DNA positivity of the primary tumor, was correlated with prolonged overall survival (OS) (p = 0.009). P16(ink4a)-overexpression predicted a better response to radiotherapy (p overexpression (p = 0.022), and adjuvant RTX (p overexpression (HR 1-2.11, 95 % CI 1.13-3.95, p = 0.001) are independent prognostic factors. The discovered overlap suggests the use of p16(ink4a) in combination with HPV-DNA detection as an ancillary test for future research and clinical studies in vSCC. The prognostic and predictive value of p16(ink4a)-overexpression should be tested in larger cohort studies.

  20. Rplp1 bypasses replicative senescence and contributes to transformation

    Energy Technology Data Exchange (ETDEWEB)

    Artero-Castro, A. [Pathology Department, Fundacio Institut de Recerca Hospital Vall d' Hebron, Passeig Vall d' Hebron 119-129, 08035 Barcelona (Spain); Kondoh, H. [Department of Geriatric Medicine, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Fernandez-Marcos, P.J.; Serrano, M. [Spanish National Cancer Research Center (CNIO), 3 Melchor Fernandez Almagro St, Madrid 28029 (Spain); Ramon y Cajal, S. [Pathology Department, Fundacio Institut de Recerca Hospital Vall d' Hebron, Passeig Vall d' Hebron 119-129, 08035 Barcelona (Spain); LLeonart, M.E., E-mail: melleona@ir.vhebron.net [Pathology Department, Fundacio Institut de Recerca Hospital Vall d' Hebron, Passeig Vall d' Hebron 119-129, 08035 Barcelona (Spain)

    2009-05-01

    To determine whether genes expressed by embryonic stem cells have a proliferative effect in primary cells, primary mouse embryonic fibroblasts were infected with an ES cell cDNA library. This led to identification of the ribosomal protein, Rplp1, a member of the P group of ribosomal proteins, whose putative role for bypassing replicative senescence in MEFs was investigated. Our results show that Rplp1 produces a two-fold increase in the expression of an E2F1 promoter and upregulation of cyclin E in MEFs. Therefore, this study is the first to show that overexpression of a single ribosomal protein, Rplp1, is a cause and not a consequence of cell proliferation. In addition, co-expression of Rplp1 with mutant ras{sup Val12} contributed to transformation in NIH3T3 cells, as was evidenced by colony production in soft-agar assays. Moreover, the Rplp1 protein was upregulated in MEFs and NIH3T3 cells upon expression of a p53 dominant negative mutant gene designated p53R175H. Hence, mutation of p53 may facilitate immortalization in vitro by upregulating Rplp1. Lastly, Rplp1 mRNA was found to be upregulated in 16 of 26 human colon cancer biopsy specimens, a finding that may be of relevance to cancer research.

  1. Rplp1 bypasses replicative senescence and contributes to transformation

    International Nuclear Information System (INIS)

    Artero-Castro, A.; Kondoh, H.; Fernandez-Marcos, P.J.; Serrano, M.; Ramon y Cajal, S.; LLeonart, M.E.

    2009-01-01

    To determine whether genes expressed by embryonic stem cells have a proliferative effect in primary cells, primary mouse embryonic fibroblasts were infected with an ES cell cDNA library. This led to identification of the ribosomal protein, Rplp1, a member of the P group of ribosomal proteins, whose putative role for bypassing replicative senescence in MEFs was investigated. Our results show that Rplp1 produces a two-fold increase in the expression of an E2F1 promoter and upregulation of cyclin E in MEFs. Therefore, this study is the first to show that overexpression of a single ribosomal protein, Rplp1, is a cause and not a consequence of cell proliferation. In addition, co-expression of Rplp1 with mutant ras Val12 contributed to transformation in NIH3T3 cells, as was evidenced by colony production in soft-agar assays. Moreover, the Rplp1 protein was upregulated in MEFs and NIH3T3 cells upon expression of a p53 dominant negative mutant gene designated p53R175H. Hence, mutation of p53 may facilitate immortalization in vitro by upregulating Rplp1. Lastly, Rplp1 mRNA was found to be upregulated in 16 of 26 human colon cancer biopsy specimens, a finding that may be of relevance to cancer research.

  2. Whole plant senescence of sunflower following seedhead removal

    International Nuclear Information System (INIS)

    Ho, InSun; Below, F.E.

    1989-01-01

    This study was undertaken to further clarify the relationship between seed development and monocarpic senescence of sunflower (Helianthus annuus L.). Field-grown plants with and without seedheads were evaluated for rate and duration of accumulation of dry weight, reduced N, and P by whole shoots, and for partitioning of these constituents within the individual plant parts. Concurrent with seedhead removal, [ 15 N]nitrate was applied to the plants in a selected are of the experimental plot. Whole plants (above ground portions) were harvested seven times during the seed-filling period and analyzed from dry weight, reduced N, and P. Although seedhead removal depressed the rates of dry weight, reduced N, and P accumulation by whole shoots, it extended the duration of accumulation of these constituents, relative to headed control plants. As a result, the final whole shoot dry weight and N and P contents at seed maturity were similar for deheaded and headed plants. Seedhead removal also affected the partitioning of dry matter, reduced N, and P but the relative proportions varied as a function of constituent and growth stage. Analysis of 15 N present in whole shoots at physiological maturity showed that similar amounts of nitrate were absorbed during the postflowering period by headed and deheaded plants. These data indicate that the absence of seeds does not affect the total accumulation of dry matter, reduced N, or P, by sunflower plants, but does alter the rates of accumulation and partitioning of these constituents

  3. Zmpste24-/- mouse model for senescent wound healing research.

    Science.gov (United States)

    Butala, Parag; Szpalski, Caroline; Soares, Marc; Davidson, Edward H; Knobel, Denis; Warren, Stephen M

    2012-12-01

    The graying of our population has motivated the authors to better understand age-related impairments in wound healing. To increase research throughput, the authors hypothesized that the Hutchinson-Gilford progeria syndrome Zmpste24-deficient (Zmpste24(-/-)) mouse could serve as a model of senescent wound healing. Using a stented excisional wound closure model, the authors tested this hypothesis on 8-week-old male Zmpste24(-/-) mice (n = 25) and age-matched male C57BL/6J wild-type mice (n = 25). Wounds were measured photogrammetrically and harvested for immunohistochemistry, enzyme-linked immunosorbent assay, and quantitative real-time polymerase chain reaction, and circulating vasculogenic progenitor cells were measured by flow cytometry. Zmpste24(-/-) mice had a significant delay in wound closure compared with wild-type mice during the proliferative/vasculogenic phase. Zmpste24(-/-) wounds had decreased proliferation, increased 8-hydroxy-2'-deoxyguanosine levels, increased proapoptotic signaling (i.e., p53, PUMA, BAX), decreased antiapoptotic signaling (i.e., Bcl-2), and increased DNA fragmentation. These changes correlated with decreased local vasculogenic growth factor expression, decreased mobilization of bone marrow-derived vasculogenic progenitor cells, and decreased new blood vessel formation. Age-related impairments in wound closure are multifactorial. The authors' data suggest that the Hutchinson-Gilford progeria syndrome Zmpste24(-/-) progeroid syndrome shares mechanistic overlap with normal aging and therefore might provide a uniquely informative model with which to study age-associated impairments in wound closure.

  4. WRKY54 and WRKY70 co-operate as negative regulators of leaf senescence in Arabidopsis thaliana

    OpenAIRE

    Besseau, Sébastien; Li, Jing; Palva, E. Tapio

    2012-01-01

    The plant-specific WRKY transcription factor (TF) family with 74 members in Arabidopsis thaliana appears to be involved in the regulation of various physiological processes including plant defence and senescence. WRKY53 and WRKY70 were previously implicated as positive and negative regulators of senescence, respectively. Here the putative function of other WRKY group III proteins in Arabidopsis leaf senescence has been explored and the results suggest the involvement of two additional WRKY TF...

  5. Lipid profiling demonstrates that suppressing Arabidopsis phospholipase Dδ retards ABA-promoted leaf senescence by attenuating lipid degradation.

    Directory of Open Access Journals (Sweden)

    Yanxia Jia

    Full Text Available Senescence is the last phase of the plant life cycle and has an important role in plant development. Degradation of membrane lipids is an essential process during leaf senescence. Several studies have reported fundamental changes in membrane lipids and phospholipase D (PLD activity as leaves senesce. Suppression of phospholipase Dα1 (PLDα1 retards abscisic acid (ABA-promoted senescence. However, given the absence of studies that have profiled changes in the compositions of membrane lipid molecules during leaf senescence, there is no direct evidence that PLD affects lipid composition during the process. Here, we show that application of n-butanol, an inhibitor of PLD, and N-Acylethanolamine (NAE 12∶0, a specific inhibitor of PLDα1, retarded ABA-promoted senescence to different extents. Furthermore, phospholipase Dδ (PLDδ was induced in leaves treated with ABA, and suppression of PLDδ retarded ABA-promoted senescence in Arabidopsis. Lipid profiling revealed that detachment-induced senescence had different effects on plastidic and extraplastidic lipids. The accelerated degradation of plastidic lipids during ABA-induced senescence in wild-type plants was attenuated in PLDδ-knockout (PLDδ-KO plants. Dramatic increases in phosphatidic acid (PA and decreases in phosphatidylcholine (PC during ABA-induced senescence were also suppressed in PLDδ-KO plants. Our results suggest that PLDδ-mediated hydrolysis of PC to PA plays a positive role in ABA-promoted senescence. The attenuation of PA formation resulting from suppression of PLDδ blocks the degradation of membrane lipids, which retards ABA-promoted senescence.

  6. Herança da senescência retardada em milho Inheritance of the delayed senescence in maize

    Directory of Open Access Journals (Sweden)

    Emiliano Fernandes Nassau Costa

    2008-02-01

    Full Text Available O objetivo deste trabalho foi estudar a herança da senescência retardada em milho. Foram realizados cruzamentos dialélicos parciais entre 50 linhagens e cinco testadores. Os 250 cruzamentos resultantes, além de seis híbridos comerciais utilizados como testemunhas, foram avaliados em oito ambientes, no delineamento látice simples 16x16, com duas repetições por ambiente. Os cruzamentos dialélicos foram analisados utilizando o método 4 do modelo 1 de Griffing, adaptado para múltiplos ambientes. A contribuição da capacidade geral de combinação (CGC para a expressão do caráter "stay-green" (69,06% foi maior que a da capacidade específica de combinação (CEC (30,94%, evidenciando que os efeitos aditivos são mais importantes que os efeitos não aditivos na expressão deste caráter. Tanto a CGC como a CEC interagiram significativamente com o ambiente, indicando que a seleção para este caráter deve ser realizada com base nas médias de experimentos em diversos ambientes.The objective of this research was to study the inheritance of delayed senescence in maize. Partial diallel crosses among 50 inbred lines and five testers were made. The 250 crosses, along with six commercial hybrids used as checks, were evaluated at eight environments in lattices 16x16 with two replications per environment. The diallel crosses were analyzed following the method 4 model 1 of Griffing, extended to multiple environments. The contribution of the general combining ability (CGA for the expression of the stay-green trait (69.06% was greater than the specific combining ability (SCA (30.94%, showing that additive effects are more important than non-additive effects for the expression of this trait. Both GCA and SCA interacted significantly with the environments, indicating that the selection for this trait should be based on the means across environments.

  7. Laser illuminated flat panel display

    Energy Technology Data Exchange (ETDEWEB)

    Veligdan, J.T.

    1995-12-31

    A 10 inch laser illuminated flat panel Planar Optic Display (POD) screen has been constructed and tested. This POD screen technology is an entirely new concept in display technology. Although the initial display is flat and made of glass, this technology lends itself to applications where a plastic display might be wrapped around the viewer. The display screen is comprised of hundreds of planar optical waveguides where each glass waveguide represents a vertical line of resolution. A black cladding layer, having a lower index of refraction, is placed between each waveguide layer. Since the cladding makes the screen surface black, the contrast is high. The prototype display is 9 inches wide by 5 inches high and approximately I inch thick. A 3 milliwatt HeNe laser is used as the illumination source and a vector scanning technique is employed.

  8. Flat panel planar optic display

    Energy Technology Data Exchange (ETDEWEB)

    Veligdan, J.T. [Brookhaven National Lab., Upton, NY (United States). Dept. of Advanced Technology

    1994-11-01

    A prototype 10 inch flat panel Planar Optic Display, (POD), screen has been constructed and tested. This display screen is comprised of hundreds of planar optic class sheets bonded together with a cladding layer between each sheet where each glass sheet represents a vertical line of resolution. The display is 9 inches wide by 5 inches high and approximately 1 inch thick. A 3 milliwatt HeNe laser is used as the illumination source and a vector scanning technique is employed.

  9. Curcumin elevates sirtuin level but does not postpone in vitro senescence of human cells building the vasculature

    Science.gov (United States)

    Grabowska, Wioleta; Suszek, Małgorzata; Wnuk, Maciej; Lewinska, Anna; Wasiak, Emilia; Sikora, Ewa; Bielak-Zmijewska, Anna

    2016-01-01

    It is believed that curcumin, a component of the turmeric that belongs to hormetins, possesses anti-aging propensity. This property of curcumin can be partially explained by its influence on the level of sirtuins. Previously, we have shown that relatively high (2.5-10 μM) doses of curcumin induce senescence of cancer cells and cells building the vasculature. In the present study we examined whether curcumin at low doses (0.1 and 1 μM) is able to delay cell senescence and upregulate the level of sirtuins in human cells building the vasculature, namely vascular smooth muscle (VSMC) and endothelial (EC) cells. To this end we used cells senescing in a replicative and premature manner. We showed that low doses of curcumin in case of VSMC neither postponed the replicative senescence nor protected from premature senescence induced by doxorubicin. Moreover, curcumin slightly accelerated replicative senescence of EC. Despite some fluctuations, a clear increasing tendency in the level of sirtuins was observed in curcumin-treated young, senescing or already senescent cells. Sirtuin activation could be caused by the activation of AMPK resulting from superoxide elevation and ATP reduction. Our results show that curcumin at low doses can increase the level of sirtuins without delaying senescence of VSMC. PMID:27034011

  10. Glycogen Synthase Kinase 3 Inactivation Induces Cell Senescence through Sterol Regulatory Element Binding Protein 1-Mediated Lipogenesis in Chang Cells.

    Science.gov (United States)

    Kim, You-Mie; Song, Insun; Seo, Yong-Hak; Yoon, Gyesoon

    2013-12-01

    Enhanced lipogenesis plays a critical role in cell senescence via induction of expression of the mature form of sterol regulatory element binding protein 1 (SREBP1), which contributes to an increase in organellar mass, one of the indicators of senescence. We investigated the molecular mechanisms by which signaling molecules control SREBP1-mediated lipogenesis and senescence. We developed cellular models for stress-induced senescence, by exposing Chang cells, which are immortalized human liver cells, to subcytotoxic concentrations (200 µM) of deferoxamine (DFO) and H2O2. In this model of stress-induced cell senescence using DFO and H2O2, the phosphorylation profile of glycogen synthase kinase 3α (GSK3α) and β corresponded closely to the expression profile of the mature form of SREBP-1 protein. Inhibition of GSK3 with a subcytotoxic concentration of the selective GSK3 inhibitor SB415286 significantly increased mature SREBP1 expression, as well as lipogenesis and organellar mass. In addition, GSK3 inhibition was sufficient to induce senescence in Chang cells. Suppression of GSK3 expression with siRNAs specific to GSK3α and β also increased mature SREBP1 expression and induced senescence. Finally, blocking lipogenesis with fatty acid synthase inhibitors (cerulenin and C75) and siRNA-mediated silencing of SREBP1 and ATP citrate lyase (ACL) significantly attenuated GSK3 inhibition-induced senescence. GSK3 inactivation is an important upstream event that induces SREBP1-mediated lipogenesis and consequent cell senescence.

  11. Display technologies for augmented reality

    Science.gov (United States)

    Lee, Byoungho; Lee, Seungjae; Jang, Changwon; Hong, Jong-Young; Li, Gang

    2018-02-01

    With the virtue of rapid progress in optics, sensors, and computer science, we are witnessing that commercial products or prototypes for augmented reality (AR) are penetrating into the consumer markets. AR is spotlighted as expected to provide much more immersive and realistic experience than ordinary displays. However, there are several barriers to be overcome for successful commercialization of AR. Here, we explore challenging and important topics for AR such as image combiners, enhancement of display performance, and focus cue reproduction. Image combiners are essential to integrate virtual images with real-world. Display performance (e.g. field of view and resolution) is important for more immersive experience and focus cue reproduction may mitigate visual fatigue caused by vergence-accommodation conflict. We also demonstrate emerging technologies to overcome these issues: index-matched anisotropic crystal lens (IMACL), retinal projection displays, and 3D display with focus cues. For image combiners, a novel optical element called IMACL provides relatively wide field of view. Retinal projection displays may enhance field of view and resolution of AR displays. Focus cues could be reconstructed via multi-layer displays and holographic displays. Experimental results of our prototypes are explained.

  12. Accelerated cellular senescence phenotype of GAPDH-depleted human lung carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Phadke, Manali; Krynetskaia, Natalia [Temple University School of Pharmacy, Philadelphia, PA 19140 (United States); Mishra, Anurag [Jayne Haines Center for Pharmacogenomics, Temple University School of Pharmacy, Philadelphia, PA 19140 (United States); Krynetskiy, Evgeny, E-mail: ekrynets@temple.edu [Temple University School of Pharmacy, Philadelphia, PA 19140 (United States); Jayne Haines Center for Pharmacogenomics, Temple University School of Pharmacy, Philadelphia, PA 19140 (United States)

    2011-07-29

    Highlights: {yields} We examined the effect of glyceraldehyde 3-phosphate (GAPDH) depletion on proliferation of human carcinoma A549 cells. {yields} GAPDH depletion induces accelerated senescence in tumor cells via AMPK network, in the absence of DNA damage. {yields} Metabolic and genetic rescue experiments indicate that GAPDH has regulatory functions linking energy metabolism and cell cycle. {yields} Induction of senescence in LKB1-deficient lung cancer cells via GAPDH depletion suggests a novel strategy to control tumor cell proliferation. -- Abstract: Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is a pivotal glycolytic enzyme, and a signaling molecule which acts at the interface between stress factors and the cellular apoptotic machinery. Earlier, we found that knockdown of GAPDH in human carcinoma cell lines resulted in cell proliferation arrest and chemoresistance to S phase-specific cytotoxic agents. To elucidate the mechanism by which GAPDH depletion arrests cell proliferation, we examined the effect of GAPDH knockdown on human carcinoma cells A549. Our results show that GAPDH-depleted cells establish senescence phenotype, as revealed by proliferation arrest, changes in morphology, SA-{beta}-galactosidase staining, and more than 2-fold up-regulation of senescence-associated genes DEC1 and GLB1. Accelerated senescence following GAPDH depletion results from compromised glycolysis and energy crisis leading to the sustained AMPK activation via phosphorylation of {alpha} subunit at Thr172. Our findings demonstrate that GAPDH depletion switches human tumor cells to senescent phenotype via AMPK network, in the absence of DNA damage. Rescue experiments using metabolic and genetic models confirmed that GAPDH has important regulatory functions linking the energy metabolism and the cell cycle networks. Induction of senescence in LKB1-deficient non-small cell lung cancer cells via GAPDH depletion suggests a novel strategy to control tumor cell proliferation.

  13. Cytokinin delays dark-induced senescence in rice by maintaining the chlorophyll cycle and photosynthetic complexes.

    Science.gov (United States)

    Talla, Sai Krishna; Panigrahy, Madhusmita; Kappara, Saivishnupriya; Nirosha, P; Neelamraju, Sarla; Ramanan, Rajeshwari

    2016-03-01

    The phytohormone cytokinin (CK) is known to delay senescence in plants. We studied the effect of a CK analog, 6-benzyl adenine (BA), on rice leaves to understand the possible mechanism by which CK delays senescence in a drought- and heat-tolerant rice cultivar Nagina22 (N22) using dark-induced senescence (DIS) as a surrogate for natural senescence of leaves. Leaves of N22-H-dgl162, a stay-green mutant of N22, and BA-treated N22 showed retention of chlorophyll (Chl) pigments, maintenance of the Chl a/b ratio, and delay in reduction of both photochemical efficiency and rate of oxygen evolution during DIS. HPLC analysis showed accumulation of 7-hydroxymethyl chlorophyll (HmChl) during DIS, and the kinetics of its accumulation correlated with progression of senescence. Transcriptome analysis revealed that several plastid-localized genes, specifically those associated with photosystem II (PSII), showed higher transcript levels in BA-treated N22 and the stay-green mutant leaves compared with naturally senescing N22 leaves. Real-time PCR analyses showed that genes coding for enzymes associated with Chl a/b interconversion and proteins associated with light-harvesting complexes maintained higher transcript levels up to 72h of DIS following BA treatment. The pigment-protein complexes analyzed by green gel remained intact in both N22-H-dgl162 and BA-treated N22 leaves even after 96h of DIS. Thus, CK delays senescence by accumulation of HmChl and up-regulating genes in the Chl cycle, thereby maintaining the Chl a/b ratio. Also, CK treatment retains higher transcript levels of PSII-related genes, resulting in the stability of photosynthetic pigment complexes and functional stay-greenness in rice. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  14. Possible role of ginsenoside Rb1 in skin wound healing via regulating senescent skin dermal fibroblast.

    Science.gov (United States)

    Hou, Jingang; Kim, Sunchang

    2018-05-05

    Cellular senescence suppresses cancer by inducing irreversible cell growth arrest. Nevertheless, senescent cells is proposed as causal link with aging and aging-related pathologies. The physiological beneficial functions of senescent cells are still of paucity. Here we show that senescent human dermal fibroblast accelerates keratinocytes scratch wound healing and stimulates differentiation of fibroblast. Using oxidative stress (100 μM H 2 O 2 exposure for 1 h) induction, we successfully triggered fibroblast senescence and developed senescence associated secretory phenotype (SASP). The induction of SASP was regulated by p38MAPK/MSK2/NF-κB pathway. Interestingly, inhibition of p38MAPK activation only partially suppressed SASP. However, SASP was significantly inhibited by SB747651A, a specific MSK inhibitor. Additionally, we demonstrate that SASP stimulates migration of keratinocytes and myofibroblast transition of fibroblast, through fold-increased secretion of growth factors, platelet-derived growth factor AA (PDGF-AA) and AB (PDGF-AB), transforming growth factor beta 1 (TGF-β1) and beta 2 (TGF-β2), vascular endothelial growth factor A (VEGF-A) and D (VEGF-D), vascular endothelial growth factor receptor 2 (VEGFR2) and 3 (VEGFR3). Importantly, we also confirmed ginsenoside Rb1 promoted SASP-mediated healing process via p38MAPK/MSK2/NF-κB pathway. The results pointed to senescent fibroblast as a potential mechanism of wound healing control in human skin. Further, it provided a candidate targeted for wound therapy. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Involvement of NADPH oxidase isoforms in the production of O2- manipulated by ABA in the senescing leaves of early-senescence-leaf (esl) mutant rice (Oryza sativa).

    Science.gov (United States)

    Li, Zhaowei; Wang, Fubiao; Zhao, Qian; Liu, Jianchao; Cheng, Fangmin

    2018-01-01

    In this study, the differences in reactive oxygen species (ROS) generation and abscisic acid (ABA) accumulation in senescing leaves were investigated by early-senescence-leaf (esl) mutant and its wild type, to clarify the relationship among ABA levels, ROS generation, and NADPH oxidase (Nox) in senescing leaves of rice (Oryza sativa). The temporal expression levels of OsNox isoforms in senescing leaves and their expression patterns in response to ABA treatment were determined through quantitative real-time reverse transcription PCR (qRT-PCR). Results showed that the flag leaf of the esl mutant generated more O2- concentrations and accumulated higher ABA levels than the wild-type cultivar did in the grain-filling stage. Exogenous ABA treatment induced O2- generation; however, it was depressed by diphenyleneiodonium chloride (DPI) pretreatment in the detached leaf segments. This finding suggested the involvement of NADPH oxidase in ABA-induced O2- generation. The esl mutant exhibited significantly higher expression of OsNox2, OsNox5, OsNox6, and OsNox7 in the initial of grain-filling stage, followed by sharply decrease. The transcriptional levels of OsNox1, OsNox3, and OsFR07 in the flag leaf of the esl mutant were significantly lower than those in the wild-type cultivar. The expression levels of OsNox2, OsNox5, OsNox6, and OsNox7 were significantly enhanced by exogenous ABA treatments. The enhanced expression levels of OsNox2 and OsNox6 were dependent on the duration of ABA treatment. The inducible expression levels of OsNox5 and OsNox7 were dependent on ABA concentrations. By contrast, exogenous ABA treatment severely repressed the transcripts of OsNox1, OsNox3, and OsFR07 in the detached leaf segments. Therefore, OsNox2, OsNox5, OsNox6, and OsNox7 were probably involved in the ABA-induced O2- generation in the initial stage of leaf senescence. Subsequently, other oxidases activated in deteriorating cells were associated with ROS generation and accumulation in the

  16. The DNA glycosylases OGG1 and NEIL3 influence differentiation potential, proliferation, and senescence-associated signs in neural stem cells

    International Nuclear Information System (INIS)

    Reis, Amilcar; Hermanson, Ola

    2012-01-01

    Highlights: ► DNA glycosylases OGG1 and NEIL3 are required for neural stem cell state. ► No effect on cell viability by OGG1 or NEIL3 knockdown in neural stem cells. ► OGG1 or NEIL3 RNA knockdown result in decreased proliferation and differentiation. ► Increased HP1γ immunoreactivity after NEIL3 knockdown suggests premature senescence. -- Abstract: Embryonic neural stem cells (NSCs) exhibit self-renewal and multipotency as intrinsic characteristics that are key parameters for proper brain development. When cells are challenged by oxidative stress agents the resulting DNA lesions are repaired by DNA glycosylases through the base excision repair (BER) pathway as a means to maintain the fidelity of the genome, and thus, proper cellular characteristics. The functional roles for DNA glycosylases in NSCs have however remained largely unexplored. Here we demonstrate that RNA knockdown of the DNA glycosylases OGG1 and NEIL3 decreased NSC differentiation ability and resulted in decreased expression of both neuronal and astrocytic genes after mitogen withdrawal, as well as the stem cell marker Musashi-1. Furthermore, while cell survival remained unaffected, NEIL3 deficient cells displayed decreased cell proliferation rates along with an increase in HP1γ immunoreactivity, a sign of premature senescence. Our results suggest that DNA glycosylases play multiple roles in governing essential neural stem cell characteristics.

  17. The DNA glycosylases OGG1 and NEIL3 influence differentiation potential, proliferation, and senescence-associated signs in neural stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Amilcar [Linnaeus Center in Developmental Biology for Regenerative Medicine (DBRM), Department of Neuroscience, Karolinska Institutet, SE 17177 Stockholm (Sweden); Hermanson, Ola, E-mail: ola.hermanson@ki.se [Linnaeus Center in Developmental Biology for Regenerative Medicine (DBRM), Department of Neuroscience, Karolinska Institutet, SE 17177 Stockholm (Sweden)

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer DNA glycosylases OGG1 and NEIL3 are required for neural stem cell state. Black-Right-Pointing-Pointer No effect on cell viability by OGG1 or NEIL3 knockdown in neural stem cells. Black-Right-Pointing-Pointer OGG1 or NEIL3 RNA knockdown result in decreased proliferation and differentiation. Black-Right-Pointing-Pointer Increased HP1{gamma} immunoreactivity after NEIL3 knockdown suggests premature senescence. -- Abstract: Embryonic neural stem cells (NSCs) exhibit self-renewal and multipotency as intrinsic characteristics that are key parameters for proper brain development. When cells are challenged by oxidative stress agents the resulting DNA lesions are repaired by DNA glycosylases through the base excision repair (BER) pathway as a means to maintain the fidelity of the genome, and thus, proper cellular characteristics. The functional roles for DNA glycosylases in NSCs have however remained largely unexplored. Here we demonstrate that RNA knockdown of the DNA glycosylases OGG1 and NEIL3 decreased NSC differentiation ability and resulted in decreased expression of both neuronal and astrocytic genes after mitogen withdrawal, as well as the stem cell marker Musashi-1. Furthermore, while cell survival remained unaffected, NEIL3 deficient cells displayed decreased cell proliferation rates along with an increase in HP1{gamma} immunoreactivity, a sign of premature senescence. Our results suggest that DNA glycosylases play multiple roles in governing essential neural stem cell characteristics.

  18. You Be the Judge: Display.

    Science.gov (United States)

    Koeninger, Jimmy G.

    The instructional package was developed to provide the distributive education teacher-coordinator with visual materials that can be used to supplement existing textbook offerings in the area of display (visual merchandising). Designed for use with 35mm slides of retail store displays, the package allows the student to view the slides of displays…

  19. Displays: Entering a New Dimension

    Science.gov (United States)

    Starkman, Neal

    2007-01-01

    As display technologies prepare to welcome 3-D, the 21st-century classroom will soon bear little resemblance to anything students and teachers have ever seen. In this article, the author presents the latest innovations in the world of digital display technology. These include: (1) Touchlight, an interactive touch screen program that takes a normal…

  20. Software for graphic display systems

    International Nuclear Information System (INIS)

    Karlov, A.A.

    1978-01-01

    In this paper some aspects of graphic display systems are discussed. The design of a display subroutine library is described, with an example, and graphic dialogue software is considered primarily from the point of view of the programmer who uses a high-level language. (Auth.)

  1. Flexible Bistable Cholesteric Reflective Displays

    Science.gov (United States)

    Yang, Deng-Ke

    2006-03-01

    Cholesteric liquid crystals (ChLCs) exhibit two stable states at zero field condition-the reflecting planar state and the nonreflecting focal conic state. ChLCs are an excellent candidate for inexpensive and rugged electronic books and papers. This paper will review the display cell structure,materials and drive schemes for flexible bistable cholesteric (Ch) reflective displays.

  2. Molecular Mechanisms Underlying Hepatocellular Carcinoma

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    Christian Trepo

    2009-11-01

    Full Text Available Hepatocarcinogenesis is a complex process that remains still partly understood. That might be explained by the multiplicity of etiologic factors, the genetic/epigenetic heterogeneity of tumors bulks and the ignorance of the liver cell types that give rise to tumorigenic cells that have stem cell-like properties. The DNA stress induced by hepatocyte turnover, inflammation and maybe early oncogenic pathway activation and sometimes viral factors, leads to DNA damage response which activates the key tumor suppressive checkpoints p53/p21Cip1 and p16INK4a/pRb responsible of cell cycle arrest and cellular senescence as reflected by the cirrhosis stage. Still obscure mechanisms, but maybe involving the Wnt signaling and Twist proteins, would allow pre-senescent hepatocytes to bypass senescence, acquire immortality by telomerase reactivation and get the last genetic/epigenetic hits necessary for cancerous transformation. Among some of the oncogenic pathways that might play key driving roles in hepatocarcinogenesis, c-myc and the Wnt/β-catenin signaling seem of particular interest. Finally, antiproliferative and apoptosis deficiencies involving TGF-β, Akt/PTEN, IGF2 pathways for instance are prerequisite for cancerous transformation. Of evidence, not only the transformed liver cell per se but the facilitating microenvironment is of fundamental importance for tumor bulk growth and metastasis.

  3. Induction of senescence and identification of differentially expressed genes in tomato in response to monoterpene.

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    Sumit Ghosh

    Full Text Available Monoterpenes, which are among the major components of plant essential oils, are known for their ecological roles as well for pharmaceutical properties. Geraniol, an acyclic monoterpene induces cell cycle arrest and apoptosis/senescence in various cancer cells and plants; however, the genes involved in the process and the underlying molecular mechanisms are not well understood. In this study, we demonstrate that treatment of tomato plants with geraniol results in induction of senescence due to a substantial alteration in transcriptome. We have identified several geraniol-responsive protein encoding genes in tomato using suppression subtractive hybridization (SSH approach. These genes comprise of various components of signal transduction, cellular metabolism, reactive oxygen species (ROS, ethylene signalling, apoptosis and DNA damage response. Upregulation of NADPH oxidase and antioxidant genes, and increase in ROS level after geraniol treatment point towards the involvement of ROS in geraniol-mediated senescence. The delayed onset of seedling death and induced expression of geraniol-responsive genes in geraniol-treated ethylene receptor mutant (Nr suggest that geraniol-mediated senescence involves both ethylene dependent and independent pathways. Moreover, expression analysis during tomato ripening revealed that geraniol-responsive genes are also associated with the natural organ senescence process.

  4. Induction of Senescence and Identification of Differentially Expressed Genes in Tomato in Response to Monoterpene

    Science.gov (United States)

    Kumar, Vinay; Kumar, Anil; Irfan, Mohammad; Chakraborty, Niranjan; Chakraborty, Subhra; Datta, Asis

    2013-01-01

    Monoterpenes, which are among the major components of plant essential oils, are known for their ecological roles as well for pharmaceutical properties. Geraniol, an acyclic monoterpene induces cell cycle arrest and apoptosis/senescence in various cancer cells and plants; however, the genes involved in the process and the underlying molecular mechanisms are not well understood. In this study, we demonstrate that treatment of tomato plants with geraniol results in induction of senescence due to a substantial alteration in transcriptome. We have identified several geraniol-responsive protein encoding genes in tomato using suppression subtractive hybridization (SSH) approach. These genes comprise of various components of signal transduction, cellular metabolism, reactive oxygen species (ROS), ethylene signalling, apoptosis and DNA damage response. Upregulation of NADPH oxidase and antioxidant genes, and increase in ROS level after geraniol treatment point towards the involvement of ROS in geraniol-mediated senescence. The delayed onset of seedling death and induced expression of geraniol-responsive genes in geraniol-treated ethylene receptor mutant (Nr) suggest that geraniol-mediated senescence involves both ethylene dependent and independent pathways. Moreover, expression analysis during tomato ripening revealed that geraniol-responsive genes are also associated with the natural organ senescence process. PMID:24098759

  5. Identification of senescence-associated genes in human bone marrow mesenchymal stem cells

    International Nuclear Information System (INIS)

    Ryu, Eunsook; Hong, Su; Kang, Jaeku; Woo, Junghoon; Park, Jungjun; Lee, Jongho; Seo, Jeong-Sun

    2008-01-01

    Human bone marrow mesenchymal stem cells (hBMMSCs) are multipotent stem cells that can differentiate into several specialized cell types, including bone, cartilage, and fat cells. The proliferative capacity of hBMMSCs paves the way for the development of regenerative medicine and tissue engineering. However, long-term in vitro culture of hBMMSCs leads to a reduced life span of the cells due to senescence, which leads eventually to growth arrest. To investigate the molecular mechanism behind the cellular senescence of hBMMSCs, microarray analysis was used to compare the expression profiles of early passage hBMMSCs, late passage hBMMSCs and hBMMSCs ectopically expressing human telomerase reverse transcriptase (hTERT). Using an intersection analysis of 3892 differentially expressed genes (DEGs) out of 27,171 total genes analyzed, we identified 338 senescence-related DEGs. GO term categorization and pathway network analysis revealed that the identified genes are strongly related to known senescence pathways and mechanisms. The genes identified using this approach will facilitate future studies of the mechanisms underlying the cellular senescence of hBMMSCs

  6. The Antioxidant Machinery of Young and Senescent Human Umbilical Vein Endothelial Cells and Their Microvesicles

    Directory of Open Access Journals (Sweden)

    Guillermo Bodega

    2017-01-01

    Full Text Available We examine the antioxidant role of young and senescent human umbilical vein endothelial cells (HUVECs and their microvesicles (MVs. Proteomic and Western blot studies have shown young HUVECs to have a complete and well-developed antioxidant system. Their MVs also contain antioxidant molecules, though of a smaller and more specific range, specialized in the degradation of hydrogen peroxide and the superoxide anion via the thioredoxin-peroxiredoxin system. Senescence was shown to be associated with a large increase in the size of the antioxidant machinery in both HUVECs and their MVs. These responses might help HUVECs and their MVs deal with the more oxidising conditions found in older cells. Functional analysis confirmed the antioxidant machinery of the MVs to be active and to increase in size with senescence. No glutathione or nonpeptide antioxidant (ascorbic acid and vitamin E activity was detected in the MVs. Endothelial cells and MVs seem to adapt to higher ROS concentrations in senescence by increasing their antioxidant machinery, although this is not enough to recover completely from the senescence-induced ROS increase. Moreover, MVs could be involved in the regulation of the blood plasma redox status by functioning as ROS scavengers.

  7. Persistent Amplification of DNA Damage Signal Involved in Replicative Senescence of Normal Human Diploid Fibroblasts

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    Masatoshi Suzuki

    2012-01-01

    Full Text Available Foci of phosphorylated histone H2AX and ATM are the surrogate markers of DNA double strand breaks. We previously reported that the residual foci increased their size after irradiation, which amplifies DNA damage signals. Here, we addressed whether amplification of DNA damage signal is involved in replicative senescence of normal human diploid fibroblasts. Large phosphorylated H2AX foci (>1.5 μm diameter were specifically detected in presenescent cells. The frequency of cells with large foci was well correlated with that of cells positive for senescence-associated β-galactosidase staining. Hypoxic cell culture condition extended replicative life span of normal human fibroblast, and we found that the formation of large foci delayed in those cells. Our immuno-FISH analysis revealed that large foci partially localized at telomeres in senescent cells. Importantly, large foci of phosphorylated H2AX were always colocalized with phosphorylated ATM foci. Furthermore, Ser15-phosphorylated p53 showed colocalization with the large foci. Since the treatment of senescent cells with phosphoinositide 3-kinase inhibitor, wortmannin, suppressed p53 phosphorylation, it is suggested that amplification of DNA damage signaling sustains persistent activation of ATM-p53 pathway, which is essential for replicative senescence.

  8. Interplay between Selenium Levels and Replicative Senescence in WI-38 Human Fibroblasts: A Proteomic Approach.

    Science.gov (United States)

    Hammad, Ghania; Legrain, Yona; Touat-Hamici, Zahia; Duhieu, Stéphane; Cornu, David; Bulteau, Anne-Laure; Chavatte, Laurent

    2018-01-20

    Selenoproteins are essential components of antioxidant defense, redox homeostasis, and cell signaling in mammals, where selenium is found in the form of a rare amino acid, selenocysteine. Selenium, which is often limited both in food intake and cell culture media, is a strong regulator of selenoprotein expression and selenoenzyme activity. Aging is a slow, complex, and multifactorial process, resulting in a gradual and irreversible decline of various functions of the body. Several cellular aspects of organismal aging are recapitulated in the replicative senescence of cultured human diploid fibroblasts, such as embryonic lung fibroblast WI-38 cells. We previously reported that the long-term growth of young WI-38 cells with high (supplemented), moderate (control), or low (depleted) concentrations of selenium in the culture medium impacts their replicative lifespan, due to rapid changes in replicative senescence-associated markers and signaling pathways. In order to gain insight into the molecular link between selenium levels and replicative senescence, in the present work, we have applied a quantitative proteomic approach based on 2-Dimensional Differential in-Gel Electrophoresis (2D-DIGE) to the study of young and presenescent cells grown in selenium-supplemented, control, or depleted media. Applying a restrictive cut-off (spot intensity ±50% and a p value iii) spots varying in response to selenium concentration in presenescent cells. Interestingly, a 72% overlap between the impact of senescence and selenium was observed in our proteomic results, demonstrating a strong interplay between selenium, selenoproteins, and replicative senescence.

  9. Senescence-Induced Alterations of Laminin Chain Expression Modulate Tumorigenicity of Prostate Cancer Cells1

    Science.gov (United States)

    Sprenger, Cynthia C T; Drivdahl, Rolf H; Woodke, Lillie B; Eyman, Daniel; Reed, May J; Carter, William G; Plymate, Stephen R

    2008-01-01

    Prostate cancer is an age-associated epithelial cancer, and as such, it contributes significantly to the mortality of the elderly. Senescence is one possible mechanism by which the body defends itself against various epithelial cancers. Senescent cells alter the microenvironment, in part, through changes to the extracellular matrix. Laminins (LMs) are extracellular proteins important to both the structure and function of the microenvironment. Overexpression of the senescence-associated gene mac25 in human prostate cancer cells resulted in increased mRNA levels of the LM α4 and β2 chains compared to empty vector control cells. The purpose of this study was to examine the effects of these senescence-induced LM chains on tumorigenicity of prostate cancer cells. We created stable M12 human prostate cancer lines overexpressing either the LM α4 or β2 chain or both chains. Increased expression of either the LM α4 or β2 chain resulted in increased in vitro migration and in vivo tumorigenicity of those cells, whereas high expression of both chains led to decreased in vitro proliferation and in vivo tumorigenicity compared to M12 control cells. This study demonstrates that senescent prostate epithelial cells can alter the microenvironment and that these changes modulate progression of prostate cancer. PMID:19048114

  10. Senescence-Induced Alterations of Laminin Chain Expression Modulate Tumorigenicity of Prostate Cancer Cells

    Directory of Open Access Journals (Sweden)

    Cynthia C.T. Sprenger

    2008-12-01

    Full Text Available Prostate cancer is an age-associated epithelial cancer, and as such, it contributes significantly to the mortality of the elderly. Senescence is one possible mechanism by which the body defends itself against various epithelial cancers. Senescent cells alter the microenvironment, in part, through changes to the extracellular matrix. Laminins (LMs are extracellular proteins important to both the structure and function of the microenvironment. Overexpression of the senescence-associated gene mac25 in human prostate cancer cells resulted in increased mRNA levels of the LM α4 and β2 chains compared to empty vector control cells. The purpose of this study was to examine the effects of these senescence-induced LM chains on tumorigenicity of prostate cancer cells. We created stable M12 human prostate cancer lines overexpressing either the LM α4 or β2 chain or both chains. Increased expression of either the LM α4 or β2 chain resulted in increased in vitro migration and in vivo tumorigenicity of those cells, whereas high expression of both chains led to decreased in vitro proliferation and in vivo tumorigenicity compared to M12 control cells. This study demonstrates that senescent prostate epithelial cells can alter the microenvironment and that these changes modulate progression of prostate cancer.

  11. Modulation of Cell Cycle Profile by Chlorella vulgaris Prevents Replicative Senescence of Human Diploid Fibroblasts

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    Tayyebeh Saberbaghi

    2013-01-01

    Full Text Available In this study, the effects of Chlorella vulgaris (CV on replicative senescence of human diploid fibroblasts (HDFs were investigated. Hot water extract of CV was used to treat HDFs at passages 6, 15, and 30 which represent young, presenescence, and senescence ages, respectively. The level of DNA damage was determined by comet assay while apoptosis and cell cycle profile were determined using FACSCalibur flow cytometer. Our results showed direct correlation between increased levels of damaged DNA and apoptosis with senescence in untreated HDFs (P<0.05. Cell cycle profile showed increased population of untreated senescent cells that enter G0/G1 phase while the cell population in S phase decreased significantly (P<0.05. Treatment with CV however caused a significant reduction in the level of damaged DNA and apoptosis in all age groups of HDFs (P<0.05. Cell cycle analysis showed that treatment with CV increased significantly the percentage of senescent HDFs in S phase and G2/M phases but decreased the population of cells in G0/G1 phase (P<0.05. In conclusion, hot water extract of Chlorella vulgaris effectively decreased the biomarkers of ageing, indicating its potential as an antiageing compound.

  12. The Japanese diet from 1975 delays senescence and prolongs life span in SAMP8 mice.

    Science.gov (United States)

    Yamamoto, Kazushi; E, Shuang; Hatakeyama, Yu; Sakamoto, Yu; Honma, Taro; Jibu, Yuri; Kawakami, Yuki; Tsuduki, Tsuyoshi

    2016-01-01

    Life expectancy in Japan is high, suggesting that the Japanese diet, Nihon shoku (Japanese food), has significant health benefits. However, these benefits have been called into question over the past 50 y, during which time the Japanese diet has become increasingly Westernized. The aim of the present study was to focus on senescence delay and to examine the effects of Japanese diets from different years to identify which Japanese diet is most effective in enhancing life expectancy and delaying senescence. Weekly menus from the years 1960, 1975, 1990, and 2005 were reproduced based on the National Health and Nutrition Survey in Japan and prepared as powdered foods. The senescence-accelerated mouse prone 8 (SAMP8) mice were fed standard laboratory chow supplemented with a 30% mix of Japanese meals from various years ad libitum throughout their lifetime. Additionally, the control group was given standard laboratory chow only, to examine the development of mice reared under standard conditions. In the group that ingested the traditional 1975 Japanese diet, life span was prolonged, senescence was delayed, and learning and memory capacities were maintained compared with the group fed the 2005 Japanese diet. The life span of the group that ingested the 1990 Japanese diet showed a tendency to be longer than SAMP8 mice fed the 2005 diet. The results of the present study suggested that the traditional Japanese diet is more effective in enhancing life expectancy and delaying senescence than the current Japanese diet. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Haplo-insufficiency of both BubR1 and SGO1 accelerates cellular senescence

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    Sung-Hyun Park

    2016-02-01

    Full Text Available Abstract Background Spindle assembly checkpoint components BubR1 and Sgo1 play a key role in the maintenance of chromosomal instability during cell division. These proteins function to block the anaphase entry until all condensed chromosomes have been attached by the microtubules emanating from both spindle poles. Haplo-insufficiency of either BubR1 or SGO1 results in enhanced chromosomal instability and tumor development in the intestine. Recent studies show that spindle checkpoint proteins also have a role in slowing down the ageing process. Therefore, we want to study whether haplo-insufficiency of both BubR1 and SGO1 accelerates cellular senescence in mice. Methods We took advantage of the availability of BubR1 and SGO1 knockout mice and generated primary murine embryonic fibroblasts (MEFs with mutations in either BubR1, SGO1, or both and analyzed cellular senescence of the MEFs of various genetic backgrounds. Results We observed that BubR1 +/− SGO +/− MEFs had an accelerated cellular senescence characterized by morphological changes and expressed senescence-associated β-galactosidase. In addition, compared with wild-type MEFs or MEFs with a single gene deficiency, BubR1 +/− SGO1 +/− MEFs expressed enhanced levels of p21 but not p16. Conclusions Taken together, our observations suggest that combined deficiency of BubR1 and Sgo1 accelerates cellular senescence.

  14. Mitochondrial dysfunction accounts for the stochastic heterogeneity in telomere-dependent senescence.

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    João F Passos

    2007-05-01

    Full Text Available Aging is an inherently stochastic process, and its hallmark is heterogeneity between organisms, cell types, and clonal populations, even in identical environments. The replicative lifespan of primary human cells is telomere dependent; however, its heterogeneity is not understood. We show that mitochondrial superoxide production increases with replicative age in human fibroblasts despite an adaptive UCP-2-dependent mitochondrial uncoupling. This mitochondrial dysfunction is accompanied by compromised [Ca(2+]i homeostasis and other indicators of a retrograde response in senescent cells. Replicative senescence of human fibroblasts is delayed by mild mitochondrial uncoupling. Uncoupling reduces mitochondrial superoxide generation, slows down telomere shortening, and delays formation of telomeric gamma-H2A.X foci. This indicates mitochondrial production of reactive oxygen species (ROS as one of the causes of replicative senescence. By sorting early senescent (SES cells from young proliferating fibroblast cultures, we show that SES cells have higher ROS levels, dysfunctional mitochondria, shorter telomeres, and telomeric gamma-H2A.X foci. We propose that mitochondrial ROS is a major determinant of telomere-dependent senescence at the single-cell level that is responsible for cell-to-cell variation in replicative lifespan.

  15. Elevated COX2 expression and PGE2 production by downregulation of RXRα in senescent macrophages

    International Nuclear Information System (INIS)

    Chen, Huimin; Ma, Feng; Hu, Xiaona; Jin, Ting; Xiong, Chuhui; Teng, Xiaochun

    2013-01-01

    Highlights: •Downregulation of RXRα in senescent macrophage. •RXRα suppresses NF-κB activity and COX2 expression. •Increased PGE2 production due to downregulation of RXRα. -- Abstract: Increased systemic level of inflammatory cytokines leads to numerous age-related diseases. In senescent macrophages, elevated prostaglandin E2 (PGE2) production contributes to the suppression of T cell function with aging, which increases the susceptibility to infections. However, the regulation of these inflammatory cytokines and PGE2 with aging still remains unclear. We have verified that cyclooxygenase (COX)-2 expression and PGE2 production are higher in LPS-stimulated macrophages from old mice than that from young mice. Downregulation of RXRα, a nuclear receptor that can suppress NF-κB activity, mediates the elevation of COX2 expression and PGE2 production in senescent macrophages. We also have found less induction of ABCA1 and ABCG1 by RXRα agonist in senescent macrophages, which partially accounts for high risk of atherosclerosis in aged population. Systemic treatment with RXRα antagonist HX531 in young mice increases COX2, TNF-α, and IL-6 expression in splenocytes. Our study not only has outlined a mechanism of elevated NF-κB activity and PGE2 production in senescent macrophages, but also provides RXRα as a potential therapeutic target for treating the age-related diseases

  16. Innate immunity and cellular senescence: The good and the bad in the developmental and aged brain.

    Science.gov (United States)

    Santoro, Antonietta; Spinelli, Chiara Carmela; Martucciello, Stefania; Nori, Stefania Lucia; Capunzo, Mario; Puca, Annibale Alessandro; Ciaglia, Elena

    2018-03-01

    Ongoing studies evidence cellular senescence in undifferentiated and specialized cells from tissues of all ages. Although it is believed that senescence plays a wider role in several stress responses in the mature age, its participation in certain physiological and pathological processes throughout life is coming to light. The "senescence machinery" has been observed in all brain cell populations, including components of innate immunity (e.g., microglia and astrocytes). As the beneficial versus detrimental implications of senescence is an open question, we aimed to analyze the contribution of immune responses in regulatory mechanisms governing its distinct functions in healthy (development, organogenesis, danger patrolling events) and diseased brain (glioma, neuroinflammation, neurodeneration), and the putative connection between cellular and molecular events governing the 2 states. Particularly this review offers new insights into the complex roles of senescence both as a chronological event as age advances, and as a molecular mechanism of brain homeostasis through the important contribution of innate immune responses and their crosstalk with neighboring cells in brain parenchyma. We also highlight the impact of the recently described glymphatic system and brain lymphatic vasculature in the interplay between peripheral and central immune surveillance and its potential implication during aging. This will open new ways to understand brain development, its deterioration during aging, and the occurrence of several oncological and neurodegenerative diseases. ©2018 Society for Leukocyte Biology.

  17. Happily (never after: Aging in the context of oxidative stress, proteostasis loss and cellular senescence

    Directory of Open Access Journals (Sweden)

    Annika Höhn

    2017-04-01

    Full Text Available Aging is a complex phenomenon and its impact is becoming more relevant due to the rising life expectancy and because aging itself is the basis for the development of age-related diseases such as cancer, neurodegenerative diseases and type 2 diabetes. Recent years of scientific research have brought up different theories that attempt to explain the aging process. So far, there is no single theory that fully explains all facets of aging. The damage accumulation theory is one of the most accepted theories due to the large body of evidence found over the years. Damage accumulation is thought to be driven, among others, by oxidative stress. This condition results in an excess attack of oxidants on biomolecules, which lead to damage accumulation over time and contribute to the functional involution of cells, tissues and organisms. If oxidative stress persists, cellular senescence is a likely outcome and an important hallmark of aging. Therefore, it becomes crucial to understand how senescent cells function and how they contribute to the aging process. This review will cover cellular senescence features related to the protein pool such as morphological and molecular hallmarks, how oxidative stress promotes protein modifications, how senescent cells cope with them by proteostasis mechanisms, including antioxidant enzymes and proteolytic systems. We will also highlight the nutritional status of senescent cells and aged organisms (including human clinical studies by exploring trace elements and micronutrients and on their importance to develop strategies that might increase both, life and health span and postpone aging onset.

  18. The Lcn2-engineered HEK-293 cells show senescence under stressful condition

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    Bahareh Bahmani

    2015-05-01

    Full Text Available Objective(s: Lipocalin2 (Lcn2 gene is highly expressed in response to various types of cellular stresses. The precise role of Lcn2 has not been fully understood yet. However, it plays a key role in controlling vital cellular processes such as proliferation, apoptosis and metabolism. Recently it was shown that Lcn2 decreases senescence and increases proliferation of mesenchymal stem cells (MSC with finite life span under either normal or oxidative stress conditions. However, Lcn2 effects on immortal cell line with infinite proliferation are not defined completely.  Materials and Material and Methods: HEK-293 cells were transfected with recombinant pcDNA3.1 containing Lcn2 fragment (pcDNA3.1-Lcn2. Expression of lipocalin2 in transfected cells was evaluated by RT-PCR, real time RT-PCR, and ELISA. Different cell groups were treated with H2O2 and WST-1 assay was performed to determine their proliferation rate. Senescence was studied by β-galactosidase and gimsa staining methods as well as evaluation of the expression of senescence-related genes by real time RT-PCR. Results: Lcn2 increased cell proliferation under normal culture condition, while the proliferation slightly decreased under oxidative stress.  This decrease was further found to be attributed to senescence. Conclusion: Our findings indicated that under harmful conditions, Lcn2 gene is responsible for the regulation of cell survival through senescence.

  19. Identification of volatile compound markers during the ripening and senescence of lulo (Solanum quitoense Lam.).

    Science.gov (United States)

    Corpas Iguarán, Eduardo; Taborda Ocampo, Gonzalo; Tapasco Alzate, Omar

    2018-01-01

    Lulo ( Solanum quitoense Lam.) is an exotic fruit cultivated in Colombia. During ripening and senescence, this climactic fruit undergoes biochemical processes that produce the volatiles responsible for its aroma. This study aimed to evaluate the changes in the volatile content during the ripening and senescence of lulo. Analysis of the volatile composition of lulo harvested in each of its five ripening stages and during its senescence time when stored at 18 ± 2 °C was performed using HS-SPME with GC-MS. Throughout ripening, the most notable change was the transformation of alcohols such as (Z)-3-hexen-1-ol and 1-penten-3-ol to afford esters such as (Z)-3-hexenyl acetate and ketones such as 1-penten-3-one. Some acids reacted with alcohols to produce acetate and hexanoate esters, concentrations which increased more than sixfold between stage one and five. Moreover, all the major compounds were C 6 straight chain compounds related to the lipoxygenase pathway. During senescence, majority of compounds were methyl esters, which increased in concentration consistently until day eight. Remarkably, the content of methyl butanoate increased from 0.9% of the total amount of volatiles on day two up to 76.4% on day eight. Some of these volatiles are probably contributors to the "off flavor" during senescence.

  20. Critical transition in tissue homeostasis accompanies murine lung senescence.

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    Carla L Calvi

    Full Text Available BACKGROUND: Respiratory dysfunction is a major contributor to morbidity and mortality in aged populations. The susceptibility to pulmonary insults is attributed to "low pulmonary reserve", ostensibly reflecting a combination of age-related musculoskeletal, immunologic and intrinsic pulmonary dysfunction. METHODS/PRINCIPAL FINDINGS: Using a murine model of the aging lung, senescent DBA/2 mice, we correlated a longitudinal survey of airspace size and injury measures with a transcriptome from the aging lung at 2, 4, 8, 12, 16 and 20 months of age. Morphometric analysis demonstrated a nonlinear pattern of airspace caliber enlargement with a critical transition occurring between 8 and 12 months of age marked by an initial increase in oxidative stress, cell death and elastase activation which is soon followed by inflammatory cell infiltration, immune complex deposition and the onset of airspace enlargement. The temporally correlative transcriptome showed exuberant induction of immunoglobulin genes coincident with airspace enlargement. Immunohistochemistry, ELISA analysis and flow cytometry demonstrated increased immunoglobulin deposition in the lung associated with a contemporaneous increase in activated B-cells expressing high levels of TLR4 (toll receptor 4 and CD86 and macrophages during midlife. These midlife changes culminate in progressive airspace enlargement during late life stages. CONCLUSION/SIGNIFICANCE: Our findings establish that a tissue-specific aging program is evident during a presenescent interval which involves early oxidative stress, cell death and elastase activation, followed by B lymphocyte a