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Sample records for anti-apoptotic molecule galectin-3

  1. Thyroid cancer imaging in vivo by targeting the anti-apoptotic molecule galectin-3.

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    Armando Bartolazzi

    Full Text Available BACKGROUND: The prevalence of thyroid nodules increases with age, average 4-7% for the U.S.A. adult population, but it is much higher (19-67% when sub-clinical nodules are considered. About 90% of these lesions are benign and a reliable approach to their preoperative characterization is necessary. Unfortunately conventional thyroid scintigraphy does not allow the distinction among benign and malignant thyroid proliferations but it provides only functional information (cold or hot nodules. The expression of the anti-apoptotic molecule galectin-3 is restricted to cancer cells and this feature has potential diagnostic and therapeutic implications. We show here the possibility to obtain thyroid cancer imaging in vivo by targeting galectin-3. METHODS: The galectin-3 based thyroid immuno-scintigraphy uses as radiotracer a specific (99mTc-radiolabeled mAb. A position-sensitive high-resolution mini-gamma camera was used as imaging capture device. Human galectin-3 positive thyroid cancer xenografts (ARO and galectin-3 knockout tumors were used as targets in different experiments in vivo. 38 mice with tumor mass of about 1 gm were injected in the tail vein with 100 microCi of (99mTc-labeled mAb to galectin-3 (30 microg protein/in 100 microl saline solution. Tumor images were acquired at 1 hr, 3 hrs, 6 hrs, 9 hrs and 24 hrs post injection by using the mini-gamma camera. FINDINGS: Results from different consecutive experiments show an optimal visualization of thyroid cancer xenografts between 6 and 9 hours from injection of the radiotracer. Galectin-3 negative tumors were not detected at all. At 6 hrs post-injection galectin-3 expressing tumors were correctly visualized, while the whole-body activity had essentially cleared. CONCLUSIONS: These results demonstrate the possibility to distinguish preoperatively benign from malignant thyroid nodules by using a specific galectin-3 radio-immunotargeting. In vivo imaging of thyroid cancer may allow a better

  2. AT-101, a small molecule inhibitor of anti-apoptotic Bcl-2 family members, activates the SAPK/JNK pathway and enhances radiation-induced apoptosis

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    Rooswinkel Rogier

    2009-10-01

    Full Text Available Abstract Background Gossypol, a naturally occurring polyphenolic compound has been identified as a small molecule inhibitor of anti-apoptotic Bcl-2 family proteins. It induces apoptosis in a wide range of tumor cell lines and enhances chemotherapy- and radiation-induced cytotoxicity both in vitro and in vivo. Bcl-2 and related proteins are important inhibitors of apoptosis and frequently overexpressed in human tumors. Increased levels of these proteins confer radio- and chemoresistance and may be associated with poor prognosis. Consequently, inhibition of the anti-apoptotic functions of Bcl-2 family members represents a promising strategy to overcome resistance to anticancer therapies. Methods We tested the effect of (--gossypol, also denominated as AT-101, radiation and the combination of both on apoptosis induction in human leukemic cells, Jurkat T and U937. Because activation of the SAPK/JNK pathway is important for apoptosis induction by many different stress stimuli, and Bcl-XL is known to inhibit activation of SAPK/JNK, we also investigated the role of this signaling cascade in AT-101-induced apoptosis using a pharmacologic and genetic approach. Results AT-101 induced apoptosis in a time- and dose-dependent fashion, with ED50 values of 1.9 and 2.4 μM in Jurkat T and U937 cells, respectively. Isobolographic analysis revealed a synergistic interaction between AT-101 and radiation, which also appeared to be sequence-dependent. Like radiation, AT-101 activated SAPK/JNK which was blocked by the kinase inhibitor SP600125. In cells overexpressing a dominant-negative mutant of c-Jun, AT-101-induced apoptosis was significantly reduced. Conclusion Our data show that AT-101 strongly enhances radiation-induced apoptosis in human leukemic cells and indicate a requirement for the SAPK/JNK pathway in AT-101-induced apoptosis. This type of apoptosis modulation may overcome treatment resistance and lead to the development of new effective combination

  3. MDM4/HIPK2/p53 cytoplasmic assembly uncovers coordinated repression of molecules with anti-apoptotic activity during early DNA damage response.

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    Mancini, F; Pieroni, L; Monteleone, V; Lucà, R; Fici, L; Luca, E; Urbani, A; Xiong, S; Soddu, S; Masetti, R; Lozano, G; Pontecorvi, A; Moretti, F

    2016-01-14

    The p53 inhibitor, MDM4 (MDMX) is a cytoplasmic protein with p53-activating function under DNA damage conditions. Particularly, MDM4 promotes phosphorylation of p53 at Ser46, a modification that precedes different p53 activities. We investigated the mechanism by which MDM4 promotes this p53 modification and its consequences in untransformed mammary epithelial cells and tissues. In response to severe DNA damage, MDM4 stimulates p53Ser46(P) by binding and stabilizing serine-threonine kinase HIPK2. Under these conditions, the p53-inhibitory complex, MDM4/MDM2, dissociates and this allows MDM4 to promote p53/HIPK2 functional interaction. Comparative proteomic analysis of DNA damage-treated cells versus -untreated cells evidenced a diffuse downregulation of proteins with anti-apoptotic activity, some of which were targets of p53Ser46(P)/HIPK2 repressive activity. Importantly, MDM4 depletion abolishes the downregulation of these proteins indicating the requirement of MDM4 to promote p53-mediated transcriptional repression. Consistently, MDM4-mediated HIPK2/p53 activation precedes HIPK2/p53 nuclear translocation and activity. Noteworthy, repression of these proteins was evident also in mammary glands of mice subjected to γ-irradiation and was significantly enhanced in transgenic mice overexpressing MDM4. This study evidences the flexibility of MDM2/MDM4 heterodimer, which allows the development of a positive activity of cytoplasmic MDM4 towards p53-mediated transcriptional function. Noteworthy, this activity uncovers coordinated repression of molecules with shared anti-apoptotic function which precedes active cell apoptosis and that are frequently overexpressed and/or markers of tumour phenotype in human cancer. PMID:25961923

  4. AT-101, a small molecule inhibitor of anti-apoptotic Bcl-2 family members, activates the SAPK/JNK pathway and enhances radiation-induced apoptosis

    International Nuclear Information System (INIS)

    Gossypol, a naturally occurring polyphenolic compound has been identified as a small molecule inhibitor of anti-apoptotic Bcl-2 family proteins. It induces apoptosis in a wide range of tumor cell lines and enhances chemotherapy- and radiation-induced cytotoxicity both in vitro and in vivo. Bcl-2 and related proteins are important inhibitors of apoptosis and frequently overexpressed in human tumors. Increased levels of these proteins confer radio- and chemoresistance and may be associated with poor prognosis. Consequently, inhibition of the anti-apoptotic functions of Bcl-2 family members represents a promising strategy to overcome resistance to anticancer therapies. We tested the effect of (-)-gossypol, also denominated as AT-101, radiation and the combination of both on apoptosis induction in human leukemic cells, Jurkat T and U937. Because activation of the SAPK/JNK pathway is important for apoptosis induction by many different stress stimuli, and Bcl-XL is known to inhibit activation of SAPK/JNK, we also investigated the role of this signaling cascade in AT-101-induced apoptosis using a pharmacologic and genetic approach. AT-101 induced apoptosis in a time- and dose-dependent fashion, with ED50 values of 1.9 and 2.4 μM in Jurkat T and U937 cells, respectively. Isobolographic analysis revealed a synergistic interaction between AT-101 and radiation, which also appeared to be sequence-dependent. Like radiation, AT-101 activated SAPK/JNK which was blocked by the kinase inhibitor SP600125. In cells overexpressing a dominant-negative mutant of c-Jun, AT-101-induced apoptosis was significantly reduced. Our data show that AT-101 strongly enhances radiation-induced apoptosis in human leukemic cells and indicate a requirement for the SAPK/JNK pathway in AT-101-induced apoptosis. This type of apoptosis modulation may overcome treatment resistance and lead to the development of new effective combination therapies

  5. Extracellular galectin-3 in tumor progression and metastasis

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    MauroSergioPavao

    2014-06-01

    Full Text Available Galectin-3, the only chimera galectin found in vertebrates, is one of the best-studied galectins. It is expressed in several cell types and is involved in a broad range of physiological and pathological processes, such as cell adhesion, cell activation and chemoattraction, cell cycle, apoptosis and cell growth and differentiation. However, this molecule raises special interest due to its role in regulating cancer cell activities. Galectin-3 has high affinity for beta-1,6-N-acetylglucosamine branched glycans, which are formed by the action of the beta-1,6-N-acetylglucosaminyltransferase V (Mgat5. Mgat5-related changes in protein/lipid glycosylation on cell surface lead to alterations in the clustering of membrane proteins through lattice formation, resulting in functional advantages for tumor cells. Galectin-3 presence enhances migration and/or invasion of many tumors. Galectin-3-dependent clustering of integrins promotes ligand-induced integrin activation, leading to cell motility. Galectin-3 binding to mucin-1 increases transendothelial invasion, decreasing metastasis-free survival in an experimental metastasis model. Galectin-3 also affects endothelial cell behavior by regulating capillary tube formation. This lectin is found in the tumor stroma, suggesting a role for microenvironmental galectin-3 in tumor progression. Galectin-3 also seems to be involved in the recruitment of tumor-associated macrophages, possibly contributing to angiogenesis and tumor growth. This lectin can be a relevant factor in turning bone marrow in a sanctuary for leukemia cells, favoring resistance to therapy. Finally, galectin-3 seems to play a relevant role in orchestrating distinct cell events in tumor microenvironment and for this reason, it can be considered a target in tumor therapies. In conclusion, this review aims to describe the processes of tumor progression and metastasis involving extracellular galectin-3 and its expression and regulation.

  6. Galectin-3 Determines Tumor Cell Adaptive Strategies in Stressed Tumor Microenvironments

    Science.gov (United States)

    Cardoso, Ana Carolina Ferreira; Andrade, Luciana Nogueira de Sousa; Bustos, Silvina Odete; Chammas, Roger

    2016-01-01

    Galectin-3 is a member of the β-galactoside-binding lectin family, whose expression is often dysregulated in cancers. While galectin-3 is usually an intracellular protein found in the nucleus and in the cytoplasm, under certain conditions, galectin-3 can be secreted by an yet unknown mechanism. Under stressing conditions (e.g., hypoxia and nutrient deprivation) galectin-3 is upregulated, through the activity of transcription factors, such as HIF-1α and NF-κB. Here, we review evidence that indicates a positive role for galectin-3 in MAPK family signal transduction, leading to cell proliferation and cell survival. Galectin-3 serves as a scaffold protein, which favors the spatial organization of signaling proteins as K-RAS. Upon secretion, extracellular galectin-3 interacts with a variety of cell surface glycoproteins, such as growth factor receptors, integrins, cadherins, and members of the Notch family, among other glycoproteins, besides different extracellular matrix molecules. Through its ability to oligomerize, galectin-3 forms lectin lattices that act as scaffolds that sustain the spatial organization of signaling receptors on the cell surface, dictating its maintenance on the plasma membrane or their endocytosis. Galectin-3 induces tumor cell, endothelial cell, and leukocyte migration, favoring either the exit of tumor cells from a stressed microenvironment or the entry of endothelial cells and leukocytes, such as monocytes/macrophages into the tumor organoid. Therefore, galectin-3 plays homeostatic roles in tumors, as (i) it favors tumor cell adaptation for survival in stressed conditions; (ii) upon secretion, galectin-3 induces tumor cell detachment and migration; and (iii) it attracts monocyte/macrophage and endothelial cells to the tumor mass, inducing both directly and indirectly the process of angiogenesis. The two latter activities are potentially targetable, and specific interventions may be designed to counteract the protumoral role of extracellular

  7. Galectin-3 Determines Tumor Cell Adaptive Strategies in Stressed Tumor Microenvironments.

    Science.gov (United States)

    Cardoso, Ana Carolina Ferreira; Andrade, Luciana Nogueira de Sousa; Bustos, Silvina Odete; Chammas, Roger

    2016-01-01

    Galectin-3 is a member of the β-galactoside-binding lectin family, whose expression is often dysregulated in cancers. While galectin-3 is usually an intracellular protein found in the nucleus and in the cytoplasm, under certain conditions, galectin-3 can be secreted by an yet unknown mechanism. Under stressing conditions (e.g., hypoxia and nutrient deprivation) galectin-3 is upregulated, through the activity of transcription factors, such as HIF-1α and NF-κB. Here, we review evidence that indicates a positive role for galectin-3 in MAPK family signal transduction, leading to cell proliferation and cell survival. Galectin-3 serves as a scaffold protein, which favors the spatial organization of signaling proteins as K-RAS. Upon secretion, extracellular galectin-3 interacts with a variety of cell surface glycoproteins, such as growth factor receptors, integrins, cadherins, and members of the Notch family, among other glycoproteins, besides different extracellular matrix molecules. Through its ability to oligomerize, galectin-3 forms lectin lattices that act as scaffolds that sustain the spatial organization of signaling receptors on the cell surface, dictating its maintenance on the plasma membrane or their endocytosis. Galectin-3 induces tumor cell, endothelial cell, and leukocyte migration, favoring either the exit of tumor cells from a stressed microenvironment or the entry of endothelial cells and leukocytes, such as monocytes/macrophages into the tumor organoid. Therefore, galectin-3 plays homeostatic roles in tumors, as (i) it favors tumor cell adaptation for survival in stressed conditions; (ii) upon secretion, galectin-3 induces tumor cell detachment and migration; and (iii) it attracts monocyte/macrophage and endothelial cells to the tumor mass, inducing both directly and indirectly the process of angiogenesis. The two latter activities are potentially targetable, and specific interventions may be designed to counteract the protumoral role of extracellular

  8. Galectin-3 silencing inhibits epirubicin-induced ATP binding cassette transporters and activates the mitochondrial apoptosis pathway via β-catenin/GSK-3β modulation in colorectal carcinoma.

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    Yung-Kuo Lee

    Full Text Available Multidrug resistance (MDR, an unfavorable factor compromising the treatment efficacy of anticancer drugs, involves the upregulation of ATP binding cassette (ABC transporters and induction of galectin-3 signaling. Galectin-3 plays an anti-apoptotic role in many cancer cells and regulates various pathways to activate MDR. Thus, the inhibition of galectin-3 has the potential to enhance the efficacy of the anticancer drug epirubicin. In this study, we examined the effects and mechanisms of silencing galectin-3 via RNA interference (RNAi on the β-catenin/GSK-3β pathway in human colon adenocarcinoma Caco-2 cells. Galectin-3 knockdown increased the intracellular accumulation of epirubicin in Caco-2 cells; suppressed the mRNA expression of galectin-3, β-catenin, cyclin D1, c-myc, P-glycoprotein (P-gp, MDR-associated protein (MRP 1, and MRP2; and downregulated the protein expression of P-gp, cyclin D1, galectin-3, β-catenin, c-Myc, and Bcl-2. Moreover, galectin-3 RNAi treatment significantly increased the mRNA level of GSK-3β, Bax, caspase-3, and caspase-9; remarkably increased the Bax-to-Bcl-2 ratio; and upregulated the GSK-3β and Bax protein expressions. Apoptosis was induced by galectin-3 RNAi and/or epirubicin as demonstrated by chromatin condensation, a higher sub-G1 phase proportion, and increased caspase-3 and caspase-9 activity, indicating an intrinsic/mitochondrial apoptosis pathway. Epirubicin-mediated resistance was effectively inhibited via galectin-3 RNAi treatment. However, these phenomena could be rescued after galectin-3 overexpression. We show for the first time that the silencing of galectin-3 sensitizes MDR cells to epirubicin by inhibiting ABC transporters and activating the mitochondrial pathway of apoptosis through modulation of the β-catenin/GSK-3β pathway in human colon cancer cells.

  9. How Microgravity Changes Galectin-3 in Thyroid Follicles

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    Elisabetta Albi

    2014-01-01

    Full Text Available After long-term exposure to real microgravity thyroid gland in vivo undergoes specific changes, follicles are made up of larger thyrocytes that produce more cAMP and express more thyrotropin-receptor, caveolin-1, and sphingomyelinase and sphingomyelin-synthase; parafollicular spaces lose C cells with consequent reduction of calcitonin production. Here we studied four immunohistochemical tumor markers (HBME-1, MIB-1, CK19, and Galectin-3 in thyroid of mice housed in the Mouse Drawer System and maintained for 90 days in the International Space Station. Results showed that MIB-1 proliferative index and CK19 are negative whereas HBME-1 and Galectin-3 are overexpressed. The positivity of Galectin-3 deserves attention not only for its expression but also and especially for its localization. Our results highlighted that, in microgravity conditions, Galectin-3 leaves thyrocytes and diffuses in colloid. It is possible that the gravity force contributes to the maintenance of the distribution of the molecules in both basal membrane side and apical membrane side and that the microgravity facilitates slippage of Galectin-3 in colloid probably due to membrane remodelling-microgravity induced.

  10. Nucleocytoplasmic shuttling of galectin-3.

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    Arnoys, Eric J; Ackerman, Cheri M; Wang, John L

    2015-01-01

    A large number of observations on the nuclear versus cytoplasmic distribution of galectin-3 have been reported, correlating the presence or absence of the protein in a particular compartment of the cell to various parameters such as source of the cells under study, specific cell type, culture conditions, proliferation status of the cell/culture, or neoplastic transformation. In fact, galectin-3 exhibits the phenomenon of nucleocytoplasmic shuttling, defined as the repeated bidirectional movement of a protein across the nuclear pore complex. Nevertheless, the finding that galectin-3 can show a predominantly nuclear localization under one set of conditions and a prominent cytoplasmic localization under other conditions suggests specific and regulated mechanisms of balance between cytoplasmic anchorage, nuclear import, nuclear retention, and nuclear export. One key consideration in the understanding of these processes is the definition of the signals and receptors that mediate the transport. In this chapter, we describe the experimental procedures that have allowed us to document the phenomenon of nucleocytoplasmic shuttling and the identification of the nuclear localization signal as well as the nuclear export signal. PMID:25253159

  11. Heart failure and galectin 3.

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    Suarez, Gabriela; Meyerrose, Gary

    2014-09-01

    Innovations in medical diagnosis and treatment have led to prolongation of life of patients. Increasing the life expectancy of cardiac patients and thereby increasing the prevalence of heart failure (HF). Currently more than one million hospital admissions per year are due to HF and it has been estimated that the cost is approximately $39 billion annually in the U.S. There are two pathophysiologic myocardial mechanisms that cause HF: systolic dysfunction and diastolic dysfunction. Normal cardiac aging is characterized by morphological and structural changes that increase cardiomyocyte size, increased number of apoptosis with decreased number in myocytes, increased collagen deposition, and functional changes at cellular level. All these factors contribute to fibrotic remodeling that leads to LV diastolic stiffness, which ultimately leads to impaired diastolic function. At the same time it has been shown that galectin-3, a soluble β-galactoside-binding protein secreted by activated macrophages, promotes cardiac fibroblast proliferation, collagen deposition, and ventricular dysfunction. In this paper we review the prognostic value of galectin-3 as an independent predictor of mortality in patients with moderate to advanced chronic HF (CHF). PMID:25405161

  12. Effect of galectin-3 on the behavior of Eca-109 human esophageal cancer cells

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    Liang, Ning; Song, Xiaoming; Xie, Jian; XU, DEGUO; Liu, Fengjun; YU, XINSHUANG; Tian, Yuan; Liu, Zhen; Qiao, Lili; Zhang, Jiandong

    2014-01-01

    Galectin-3, a β-galactoside-binding lectin, is a cell adhesion molecule involved in the regulation of tumor progression. However, the importance of galectin-3 in Eca-109 human esophageal cancer cells has not yet been elucidated. In the present study, a lentiviral vector was designed for overexpression of galectin-3 in Eca-109 cells following plasmid-mediated transfection (Eca-109/Gal-3 cells). A negative lentiviral vector was introduced into Eca-109 cells as a control (Eca-109/Neo cells). Wes...

  13. Galectin-3 in patients undergoing ablation of atrial fibrillation

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    Nicolas Clementy; Eric Piver; Nazih Benhenda; Anne Bernard; Bertrand Pierre; Edouard Siméon; Laurent Fauchier; Jean-Christophe Pagès; Dominique Babuty

    2014-01-01

    Background: Mechanisms of maintenance of atrial fibrillation are known to include fibrosis. Galectin-3, as a biomarker of fibrosis, may be a valuable marker of atrial remodeling. We sought to find whether there was a link between clinical features and higher galectin-3 levels in patients with atrial fibrillation. Methods: Serum concentrations of Galectin-3 were determined in a consecutive series of patients addressed for ablation of atrial fibrillation. Results: One-hundred-and-eighty-s...

  14. Role of galectin-3 in prion infections of the CNS

    International Nuclear Information System (INIS)

    Galectin-3 is a multi-functional protein and participates in mediating inflammatory reactions. The pronounced overexpression of galectin-3 in prion-infected brain tissue prompted us to study the role of this protein in a murine prion model. Immunofluorescence double-labelling identified microglia as the major cell type expressing galectin-3. Ablation of galectin-3 did not affect PrPSc-deposition and development of gliosis. However, galectin-3-/--mice showed prolonged survival times upon intracerebral and peripheral scrapie infections. Moreover, protein levels of the lysosomal activation marker LAMP-2 were markedly reduced in prion-infected galectin-3-/--mice suggesting a role of galectin-3 in regulation of lysosomal functions. Lower mRNA levels of Beclin-1 and Atg5 in prion-infected wild-type and galectin-3-/--mice indicated an impairment of autophagy although autophagosome formation was unchanged. The results point towards a detrimental role of galectin-3 in prion infections of the CNS and suggest that endo-/lysosomal dysfunction in combination with reduced autophagy may contribute to disease development

  15. Nucleoporin Nup98 mediates galectin-3 nuclear-cytoplasmic trafficking

    International Nuclear Information System (INIS)

    Highlights: •Nuclear pore protein Nup98 is a novel binding partner of galectin-3. •Nup98 transports galectin-3 into cytoplasm. •Nup98 depletion leads to galectin-3 nuclear transport and induces growth retardation. •Nup98 may involve in ß-catenin pathway through interaction with galectin-3. -- Abstract: Nucleoporin Nup98 is a component of the nuclear pore complex, and is important in transport across the nuclear pore. Many studies implicate nucleoporin in cancer progression, but no direct mechanistic studies of its effect in cancer have been reported. We show here that Nup98 specifically regulates nucleus–cytoplasm transport of galectin-3, which is a ß-galactoside-binding protein that affects adhesion, migration, and cancer progression, and controls cell growth through the ß-catenin signaling pathway in cancer cells. Nup98 interacted with galectin-3 on the nuclear membrane, and promoted galectin-3 cytoplasmic translocation whereas other nucleoporins did not show these functions. Inversely, silencing of Nup98 expression by siRNA technique localized galectin-3 to the nucleus and retarded cell growth, which was rescued by Nup98 transfection. In addition, Nup98 RNA interference significantly suppressed downstream mRNA expression in the ß-catenin pathway, such as cyclin D1 and FRA-1, while nuclear galectin-3 binds to ß-catenin to inhibit transcriptional activity. Reduced expression of ß-catenin target genes is consistent with the Nup98 reduction and the galectin-3–nucleus translocation rate. Overall, the results show Nup98’s involvement in nuclear–cytoplasm translocation of galectin-3 and ß-catenin signaling pathway in regulating cell proliferation, and the results depicted here suggest a novel therapeutic target/modality for cancers

  16. Nucleoporin Nup98 mediates galectin-3 nuclear-cytoplasmic trafficking

    Energy Technology Data Exchange (ETDEWEB)

    Funasaka, Tatsuyoshi, E-mail: funasaka@staff.kanazawa-u.ac.jp [Laboratory of Molecular and Cellular Biology, Department of Biology, Faculty of Natural Systems, Institute of Science and Engineering, Kanazawa University, Ishikawa (Japan); Balan, Vitaly; Raz, Avraham [Department of Oncology and Pathology, Karmanos Cancer Institute, Wayne State University, School of Medicine, Detroit, MI (United States); Wong, Richard W., E-mail: rwong@staff.kanazawa-u.ac.jp [Laboratory of Molecular and Cellular Biology, Department of Biology, Faculty of Natural Systems, Institute of Science and Engineering, Kanazawa University, Ishikawa (Japan); Bio-AFM Frontier Research Center, Kanazawa Kanazawa University, Ishikawa (Japan)

    2013-04-26

    Highlights: •Nuclear pore protein Nup98 is a novel binding partner of galectin-3. •Nup98 transports galectin-3 into cytoplasm. •Nup98 depletion leads to galectin-3 nuclear transport and induces growth retardation. •Nup98 may involve in ß-catenin pathway through interaction with galectin-3. -- Abstract: Nucleoporin Nup98 is a component of the nuclear pore complex, and is important in transport across the nuclear pore. Many studies implicate nucleoporin in cancer progression, but no direct mechanistic studies of its effect in cancer have been reported. We show here that Nup98 specifically regulates nucleus–cytoplasm transport of galectin-3, which is a ß-galactoside-binding protein that affects adhesion, migration, and cancer progression, and controls cell growth through the ß-catenin signaling pathway in cancer cells. Nup98 interacted with galectin-3 on the nuclear membrane, and promoted galectin-3 cytoplasmic translocation whereas other nucleoporins did not show these functions. Inversely, silencing of Nup98 expression by siRNA technique localized galectin-3 to the nucleus and retarded cell growth, which was rescued by Nup98 transfection. In addition, Nup98 RNA interference significantly suppressed downstream mRNA expression in the ß-catenin pathway, such as cyclin D1 and FRA-1, while nuclear galectin-3 binds to ß-catenin to inhibit transcriptional activity. Reduced expression of ß-catenin target genes is consistent with the Nup98 reduction and the galectin-3–nucleus translocation rate. Overall, the results show Nup98’s involvement in nuclear–cytoplasm translocation of galectin-3 and ß-catenin signaling pathway in regulating cell proliferation, and the results depicted here suggest a novel therapeutic target/modality for cancers.

  17. Galectin-3 in heart failure pathology--"another brick in the wall"?

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    Lala, Radu I; Puschita, Maria; Darabantiu, Dan; Pilat, Luminita

    2015-06-01

    Heart failure is a disease affecting millions of patients each year, and is responsible for burdening the world with high mortality rates. More concerns come from its numerous hospital readmissions (with an estimated number of 2.6 million per year which makes it one of the leading diseases responsible for national healthcare expenditures). Despite drastic improvement of therapies in recent years, heart failure remains a progressive disease. Thus, more attention has been given to finding potential biomarkers involved in the pathological mechanisms of this disease that would potentially lead to faster diagnosis and improved prognosis. One of the emerging biomarkers that has just recently come into the spotlight is galectin-3. It was associated in recent clinical trials with both the progression and severity of heart failure. Ventricular remodelling and myocardial fibrosis are essential for heart failure development and are linked to poor outcomes. An ever-growing body of evidence places galectin-3 as an important link between inflammation and fibrosis, which play a prominent role in cardiac remodelling.This review sums up the most relevant experimental and clinical studies about galectin-3 and its potential prognostic value in heart failure. The article also provides a better understanding of this molecule's involvement in heart failure pathology by modulating cardiac fibrosis. It also weighs whether the available data on galectin-3 are consistent enough to reduce readmissions and mortality while improving diagnosis and future therapies for heart failure, versus the possibility that it is simply"another brick in the wall?" PMID:26226706

  18. Galectin-3 guides intracellular trafficking of some human serotransferrin glycoforms

    DEFF Research Database (Denmark)

    Carlsson, Carl Michael; Bengtson, Per; Cucak, Helena;

    2013-01-01

    these transferrin glycoforms differently after preloading with exogenously added galectin-3. In all, this study provides the first evidence of a functional role for transferrin glycans, in intracellular trafficking after uptake. Moreover, the galectin-3 bound glycoform increased in cancer, suggesting a...

  19. Galectin-3 In Obesity And Type 2 Diabetes

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    Pejnovic Nada

    2015-12-01

    Full Text Available Galectin-3 is an important regulator of inflammation and acts as a receptor for advanced-glycation (AGE and lipoxidation end-products (ALE. Evidence indicates a significant upregulation in circulating levels and visceral adipose tissue production of Galectin-3 in obesity and type 2 diabetes. Recent studies demonstrate development of obesity and dysregulation of glucose metabolism in Galectin-3 “knockout” (KO mice, which also develop accelerated and more severe pathology in models of atherosclerosis and metabolically-induced kidney damage. Thus, evidence that Galectin-3 is an important player in metabolic disease is accumulating. This review discusses current evidence on the connection between Galectin-3 and metabolic disease, focusing on mechanisms by which this galectin modulates adiposity, glucose metabolism and obesity-associated inflammatory responses.

  20. Galectin-3: a novel protein in cerebellar hemangioblastoma.

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    Al-Salam, Suhail; Al-Salam, Mohammed; Al Ashari, Moueid

    2013-01-01

    Hemangioblastoma (HB), a rare neoplasm of uncertain histogenesis, is characterized histologically by the presence of vacuolated; lipid-containing cells 'stromal cells' and a well developed, fine capillary network. Stromal cells are the neoplastic component of this tumor. Five-um sections were stained using streptavidin- biotin immunoperoxidase and immunofluorescent techniques. The stromal cells were uniformly "HIF-1α, Galectin-3, VEGF, VEGFR, WT-1, and bcl2," positive. Endothelial cells but not stromal cells were uniformly immunoreactive to CD31. Co-localization of HIF-1α with galectin-3 and VEGF as well as galectin-3 with VEGF in stromal cells is confirmed by immunofluorescent technique. In conclusion, the development of HB is multi-factorial and the expression of galectin-3 correlates with the expression of HIF-1α and VEGF. Galectin-3 can be used as a marker for the diagnosis of HB as well as it can be a valuable candidate for future targeting immunotherapy. PMID:23638216

  1. Research Progress of Galectin-3,Bcl-2 and Embryo Development Termination%Galectin-3和Bcl-2与胚胎停育研究进展

    Institute of Scientific and Technical Information of China (English)

    徐耀辉

    2012-01-01

    Galectin-3 is a member of galectin family,which interacts with intracellular glycoprotein,cell surface molecules and extracellular matrix proteins by its carbohydrate recognition domains, participates the progress of embryo implantation,embryogenesis and placenta formation,and establishes and maintains a close relationship with pregnancy. Inhibitors of apoptosis protein Bcl-2 and Galectin-3 have significant sequence similarity,and may have the same apoptosis pathway,which participates in the growth and differentiation of villous trophoblast cells in people's earlier pregnancy and the process of decidualization of endometrium,in addition,playing a critical role in the villous production,growth,placenta formation and in its tissue structure rebuilding and functional perfection.%Galectin-3 是半乳糖凝集素家族中的一员,能通过其糖识别域与细胞内糖蛋白、细胞表面分子和细胞外基质蛋白相互作用,参与胚胎着床、胚胎发生和胎盘形成等过程,与妊娠成功建立和维持密切相关.凋亡抑制蛋白Bcl-2与Galectin-3有明显的序列相似性,可能存在共同细胞凋亡通路,在人早孕过程中参与了绒毛滋养层细胞的增殖和分化、子宫内膜蜕膜化的过程,在绒毛的发生、发育、胎盘形成和组织结构改建及功能完善等方面发挥着重要作用.

  2. Multivalent scaffolds induce galectin-3 aggregation into nanoparticles

    Directory of Open Access Journals (Sweden)

    Candace K. Goodman

    2014-07-01

    Full Text Available Galectin-3 meditates cell surface glycoprotein clustering, cross linking, and lattice formation. In cancer biology, galectin-3 has been reported to play a role in aggregation processes that lead to tumor embolization and survival. Here, we show that lactose-functionalized dendrimers interact with galectin-3 in a multivalent fashion to form aggregates. The glycodendrimer–galectin aggregates were characterized by dynamic light scattering and fluorescence microscopy methodologies and were found to be discrete particles that increased in size as the dendrimer generation was increased. These results show that nucleated aggregation of galectin-3 can be regulated by the nucleating polymer and provide insights that improve the general understanding of the binding and function of sugar-binding proteins.

  3. The role of galectin-3 in cancer drug resistance

    OpenAIRE

    Fukumori, Tomoharu; Kanayama, Hiro-omi; Raz, Avraham

    2007-01-01

    The galectins comprise a family of 14 members of β-galactoside-binding proteins, characterized by their affinity for β-galactosides and by a conserved sequence in the carbohydrate recognition domain that bind to the carbohydrate portion of cell surface glycoproteins or glycolipids. Galectin-3, a 31 kDa gene product, is a multifunctional oncogenic protein which regulates cell growth, cell adhesion, cell proliferation, angiogenesis, and apoptosis. Recent studies have revealed that galectin-3 de...

  4. Proteomic identification of galectin-3 binding ligands and characterization of galectin-3 proteolytic cleavage in human prostasomes

    OpenAIRE

    Kovak, Matthew R.; Saraswati, Sarika; Goddard, Sabrina; Diekman, Alan B.

    2013-01-01

    Galectin-3 is a multi-functional carbohydrate binding protein that was previously characterized as a proteolytic substrate for prostate specific antigen (PSA) and was shown to be associated with prostasomes in human semen. Prostasomes are exosome-like vesicles that are secreted by the prostatic epithelium and have multiple proposed functions in normal reproduction and prostate cancer. In the current study, galectin-3 binding ligands in human prostasomes were identified and characterized with ...

  5. Expression of antigen tf and galectin-3 in fibroadenoma

    Directory of Open Access Journals (Sweden)

    Gallegos Itandehui Belem

    2012-12-01

    Full Text Available Abstract Background Fibroadenomas are benign human breast tumors, characterized by proliferation of epithelial and stromal components of the terminal ductal unit. They may grow, regress or remain unchanged, as the hormonal environment of the patient changes. Expression of antigen TF in mucin or mucin-type glycoproteins and of galectin-3 seems to contribute to proliferation and transformations events; their expression has been reported in ductal breast cancer and in aggressive tumors. Findings Lectin histochemistry, immunohistochemistry, and immunofluorescence were used to examine the expression and distribution of antigen TF and galectin-3. We used lectins from Arachis hypogaea, Artocarpus integrifolia, and Amaranthus lecuocarpus to evaluate TF expression and a monoclonal antibody to evaluate galectin-3 expression. We used paraffin-embedded blocks from 10 breast tissues diagnosed with fibroadenoma and as control 10 healthy tissue samples. Histochemical and immunofluorescence analysis showed positive expression of galectin-3 in fibroadenoma tissue, mainly in stroma, weak interaction in ducts was observed; whereas, in healthy tissue samples the staining was also weak in ducts. Lectins from A. leucocarpus and A. integrifolia specificaly recognized ducts in healthy breast samples, whereas the lectin from A. hypogaea recognized ducts and stroma. In fibroadenoma tissue, the lectins from A. integrifolia, A. Hypogaea, and A. leucocarpus recognized mainly ducts. Conclusions Our results suggest that expression of antigen TF and galectin-3 seems to participate in fibroadenoma development.

  6. Galectin-3 in patients undergoing ablation of atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Nicolas Clementy

    2014-11-01

    Conclusions: Persistent type of atrial fibrillation is an independent predictor of higher Galectin-3 concentration. This biomarker of fibrosis may be implied in the mechanisms of atrial remodeling and maintenance of atrial fibrillation, and thus be helpful for the design of therapeutic strategy in patients with atrial fibrillation.

  7. Galectin-3: a novel protein in cerebellar hemangioblastoma

    OpenAIRE

    Al-Salam, Suhail; Al-Salam, Mohammed; Ashari, Moueid Al

    2013-01-01

    Hemangioblastoma (HB), a rare neoplasm of uncertain histogenesis, is characterized histologically by the presence of vacuolated; lipid-containing cells ‘stromal cells’ and a well developed, fine capillary network. Stromal cells are the neoplastic component of this tumor. Five-um sections were stained using streptavidin- biotin immunoperoxidase and immunofluorescent techniques. The stromal cells were uniformly “HIF-1α, Galectin-3, VEGF, VEGFR, WT-1, and bcl2,” positive. Endothelial cells but n...

  8. Galectin 3 acts as an enhancer of survival responses in H. pylori-infected gastric cancer cells.

    Science.gov (United States)

    Subhash, Vinod Vijay; Ho, Bow

    2016-02-01

    Galectin 3 (Gal-3) is upregulated in gastric epithelial cells as a host response to Helicobacter pylori infection. However, the significance of Gal-3 expression in H. pylori-infected cells is not well established. We analyzed Gal-3 intracellular expression, localization, and its effects in H. pylori-infected gastric epithelial cells. The predominantly nuclear confined Gal-3 was shown to be upregulated and exported out to the cytoplasm in H. pylori-infected AGS cells. The nuclear export was channeled through CRM-1 (exportin-1) protein. Interestingly, knock down of Gal-3 expression led to reduced NF-κB promoter activity and interleukin-8 (IL-8) secretion, suggesting its pro-inflammatory roles. Furthermore, Gal-3 was found to be pro-proliferative and anti-apoptotic in nature, as its knock down caused a reduction in cell proliferation and an increase in apoptosis, respectively. Taken together, our data suggest the expression and upregulation of Gal-3 as a critical endogenous event in H. pylori infection that interferes with various intracellular events, causing prolonged cell survival, which is characteristic in carcinogenesis. PMID:27044250

  9. Labeling galectin-3 for the assessment of myocardial infarction in rats

    OpenAIRE

    Arias, Teresa; Petrov, Artiom; Chen, Jiqiu; de Haas, Hans; Pérez-Medina, Carlos; Strijkers, Gustav J.; Hajjar, Roger J; Fayad, Zahi A.; Fuster,Valentín; Narula, Jagat

    2014-01-01

    Background Galectin-3 is a ß-galactoside-binding lectin expressed in most of tissues in normal conditions and overexpressed in myocardium from early stages of heart failure (HF). It is an established biomarker associated with extracellular matrix (ECM) turnover during myocardial remodeling. The aim of this study is to test the ability of 123I-galectin-3 (IG3) to assess cardiac remodeling in a model of myocardial infarction (MI) using imaging techniques. Methods Recombinant galectin-3 was labe...

  10. Galectin-3 expression in medullary thyroid carcinoma in relation to tumor progression

    OpenAIRE

    Cvejić Dubravka S.; Savin-Žegarac Svetlana B.; Petrović Ivana M.; Paunović Ivan R.; Tatić Svetislav B.; Havelka Marija J.

    2003-01-01

    BACKGROUND: Galectin-3, a lectin with specificity for beta galactosides, is believed to be implicated in multiple biological processes through interactions with complementary glycoconjugates. Alterations in galectin-3 expression are observed in a variety of human tumors. In thyroid, this lectin has been found to be highly expressed in malignancies of epithelial origin. We analyzed galectin-3 expression in medullary thyroid carcinoma (MTC). MATERIALS AND METHODS: An immunohistochemical study u...

  11. Galectin-3: A Link between Myocardial and Arterial Stiffening in Patients with Acute Decompensated Heart Failure?

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    Radu Ioan Lala

    2016-01-01

    Full Text Available Abstract Background: Heart failure is accompanied by abnormalities in ventricular-vascular interaction due to increased myocardial and arterial stiffness. Galectin-3 is a recently discovered biomarker that plays an important role in myocardial and vascular fibrosis and heart failure progression. Objectives: The aim of this study was to determine whether galectin-3 is correlated with arterial stiffening markers and impaired ventricular-arterial coupling in decompensated heart failure patients. Methods: A total of 79 inpatients with acute decompensated heart failure were evaluated. Serum galectin-3 was determined at baseline, and during admission, transthoracic echocardiography and measurements of vascular indices by Doppler ultrasonography were performed. Results: Elevated pulse wave velocity and low arterial carotid distensibility are associated with heart failure in patients with preserved ejection fraction (p = 0.04, p = 0.009. Pulse wave velocity, carotid distensibility and Young’s modulus did not correlate with serum galectin-3 levels. Conversely, raised galectin-3 levels correlated with an increased ventricular-arterial coupling ratio (Ea/Elv p = 0.047, OR = 1.9, 95% CI (1.0‑3.6. Increased galectin-3 levels were associated with lower rates of left ventricular pressure rise in early systole (dp/dt (p=0.018 and raised pulmonary artery pressure (p = 0.046. High galectin-3 levels (p = 0.038, HR = 3.07 and arterial pulmonary pressure (p = 0.007, HR = 1.06 were found to be independent risk factors for all-cause mortality and readmissions. Conclusions: This study showed no significant correlation between serum galectin-3 levels and arterial stiffening markers. Instead, high galectin-3 levels predicted impaired ventricular-arterial coupling. Galectin-3 may be predictive of raised pulmonary artery pressures. Elevated galectin-3 levels correlate with severe systolic dysfunction and together with pulmonary hypertension are independent markers of

  12. Hypoxia Up-Regulates Galectin-3 in Mammary Tumor Progression and Metastasis.

    Science.gov (United States)

    de Oliveira, Joana T; Ribeiro, Cláudia; Barros, Rita; Gomes, Catarina; de Matos, Augusto J; Reis, Celso A; Rutteman, Gerard R; Gärtner, Fátima

    2015-01-01

    The tumor microenvironment encompasses several stressful conditions for cancer cells such as hypoxia, oxidative stress and pH alterations. Galectin-3, a well-studied member of the beta-galactoside-binding animal family of lectins has been implicated in multiple steps of metastasis as cell-cell and cell-ECM adhesion, promotion of angiogenesis, cell proliferation and resistance to apoptosis. However, both its aberrantly up- and down-regulated expression was observed in several types of cancer. Thus, the mechanisms that regulate galectin-3 expression in neoplastic settings are not clear. In order to demonstrate the putative role of hypoxia in regulating galectin-3 expression in canine mammary tumors (CMT), in vitro and in vivo studies were performed. In malignant CMT cells, hypoxia was observed to induce expression of galectin-3, a phenomenon that was almost completely prevented by catalase treatment of CMT-U27 cells. Increased galectin-3 expression was confirmed at the mRNA level. Under hypoxic conditions the expression of galectin-3 shifts from a predominant nuclear location to cytoplasmic and membrane expressions. In in vivo studies, galectin-3 was overexpressed in hypoxic areas of primary tumors and well-established metastases. Tumor hypoxia thus up-regulates the expression of galectin-3, which may in turn increase tumor aggressiveness. PMID:26222311

  13. Hypoxia Up-Regulates Galectin-3 in Mammary Tumor Progression and Metastasis.

    Directory of Open Access Journals (Sweden)

    Joana T de Oliveira

    Full Text Available The tumor microenvironment encompasses several stressful conditions for cancer cells such as hypoxia, oxidative stress and pH alterations. Galectin-3, a well-studied member of the beta-galactoside-binding animal family of lectins has been implicated in multiple steps of metastasis as cell-cell and cell-ECM adhesion, promotion of angiogenesis, cell proliferation and resistance to apoptosis. However, both its aberrantly up- and down-regulated expression was observed in several types of cancer. Thus, the mechanisms that regulate galectin-3 expression in neoplastic settings are not clear. In order to demonstrate the putative role of hypoxia in regulating galectin-3 expression in canine mammary tumors (CMT, in vitro and in vivo studies were performed. In malignant CMT cells, hypoxia was observed to induce expression of galectin-3, a phenomenon that was almost completely prevented by catalase treatment of CMT-U27 cells. Increased galectin-3 expression was confirmed at the mRNA level. Under hypoxic conditions the expression of galectin-3 shifts from a predominant nuclear location to cytoplasmic and membrane expressions. In in vivo studies, galectin-3 was overexpressed in hypoxic areas of primary tumors and well-established metastases. Tumor hypoxia thus up-regulates the expression of galectin-3, which may in turn increase tumor aggressiveness.

  14. Galectin-3与垂体泌乳素瘤侵袭性的关系%Relationship between Expression of Galectin-3 and Invasiveness of Prolactinoma

    Institute of Scientific and Technical Information of China (English)

    蒲建章; 赵洪洋; 苏群

    2006-01-01

    目的探讨Galectin-3表达和人脑垂体泌乳素(PRL)腺瘤侵袭性的关系.方法应用免疫组织化学技术SP法检测38例垂体PRL腺瘤Galectin-3的表达.结果①侵袭PRL腺瘤与非侵袭PRL腺瘤组的Galectin-3阳性表达率分别为92.0%(23/25)和38.46%(5/13),两组之间差异显著(P<0.01).②Galectin-3表达与PRL肿瘤的大小及海绵窦侵袭有关(P<0.05),但与年龄和性别无明显关系(P>0.05).结论Galectin-3与垂体PRL腺瘤侵袭性密切相关,Galectin-3可能在PRL腺瘤的侵袭性生长过程中起重要作用.

  15. Nitric oxide as a pro-apoptotic as well as anti-apoptotic modulator.

    Science.gov (United States)

    Choi, Byung-Min; Pae, Hyun-Ock; Jang, Seon Il; Kim, Young-Myeong; Chung, Hun-Taeg

    2002-01-31

    Nitric oxide (NO), synthesized from L-arginine by NO synthases, is a small, lipophilic, diffusible, highly reactive molecule with dichotomous regulatory roles in many biological events under physiological and pathological conditions. NO can promote apoptosis (pro-apoptosis) in some cells, whereas it inhibits apoptosis (anti-apoptosis) in other cells. This complexity is a consequence of the rate of NO production and the interaction with biological molecules such as metal ion, thiol, protein tyrosine, and reactive oxygen species. Long-lasting overproduction of NO acts as a pro-apoptotic modulator, activating caspase family proteases through the release of mitochondrial cytochrome c into cytosol, up-regulation of the p53 expression, and alterations in the expression of apoptosis-associated proteins, including the Bcl-2 family. However, low or physiological concentrations of NO prevent cells from apoptosis that is induced by the trophic factor withdrawal, Fas, TNFalpha/ActD, and LPS. The anti-apoptotic mechanism is understood on the basis of gene transcription of protective proteins. These include: heat shock protein, hemeoxygenase, or cyclooxygenase-2 and direct inhibition of the apoptotic executive effectors caspase family protease by S-nitrosylation of the cysteine thiol group in their catalytic site in a cell specific way. Our current understanding of the mechanisms by which NO exerts both pro- and anti-apototic action is discussed in this review article. PMID:16248976

  16. Serum Galectin-9 and Galectin-3-Binding Protein in Acute Dengue Virus Infection.

    Science.gov (United States)

    Liu, Kuan-Ting; Liu, Yao-Hua; Chen, Yen-Hsu; Lin, Chun-Yu; Huang, Chung-Hao; Yen, Meng-Chi; Kuo, Po-Lin

    2016-01-01

    Dengue fever is a serious threat for public health and induces various inflammatory cytokines and mediators, including galectins and glycoproteins. Diverse immune responses and immunological pathways are induced in different phases of dengue fever progression. However, the status of serum galectins and glycoproteins is not fully determined. The aim of this study was to investigate the serum concentration and potential interaction of soluble galectin-1, galectin-3, galectin-9, galectin-3 binding protein (galectin-3BP), glycoprotein 130 (gp130), and E-, L-, and P-selectin in patients with dengue fever in acute febrile phase. In this study, 317 febrile patients (187 dengue patients, 150 non-dengue patients that included 48 patients with bacterial infection and 102 patients with other febrile illness) who presented to the emergency department and 20 healthy controls were enrolled. Our results showed the levels of galectin-9 and galectin-3BP were significantly higher in dengue patients than those in healthy controls. Lower serum levels of galectin-1, galectin-3, and E-, L-, and P-selectin in dengue patients were detected compared to bacteria-infected patients, but not to healthy controls. In addition, strong correlation between galectin-9 and galectin-3BP was observed in dengue patients. In summary, our study suggested galectin-9 and galectin-3BP might be critical inflammatory mediators in acute dengue virus infection. PMID:27240351

  17. Galectin-3 disruption impaired tumoral angiogenesis by reducing VEGF secretion from TGFβ1-induced macrophages

    International Nuclear Information System (INIS)

    In order to study the role of galectin-3 in tumor angiogenesis associated with tumor-associated macrophages (TAM) and tumor parenchyma, the galectin-3 expression was reconstituted in Tm1 melanoma cell line that lacks this protein. Galectin-3-expressing cells (Tm1G3) and mock-vector transfected cells (Tm1N3) were injected into wild-type (WT) and galectin-3 knockout (KO) C57Bl/6 mice. Tumors originated from Tm1G3 were larger in tumor volume with enlarged functional vessels, decreased necrotic areas, and increased vascular endothelial growth factor (VEGF) protein levels. Galectin-3-nonexpressing-cells injected into WT and KO showed increased levels of transforming growth factor beta 1 (TGFβ1) and, in WT animals this feature was also accompanied by increased VEGFR2 expression and its phosphorylation. In KO animals, tumors derived from galectin-3-expressing cells were infiltrated by CD68+-cells, whereas in tumors derived from galectin-3-nonexpressing-cells, CD68+ cells failed to infiltrate tumors and accumulated in the periphery of the tumor mass. In vitro studies showed that Tm1G3 secreted more VEGF than Tm1N3 cells. In the latter case, TGFβ1 induced VEGF production. Basal secretion of VEGF was higher in WT-bone marrow-derived macrophages (BMDM) than in KO-BMDM. TGFβ1 induced secretion of VEGF only in WT-BMDM. Tm1G3-induced tumors had the Arginase I mRNA increased, which upregulated alternative macrophage (M2)/TAM induction. M2 stimuli, such as interleukin-4 (IL4) and TGFβ1, increased Arginase I protein levels and galectin-3 expression in WT- BMDM, but not in cells from KO mice. Hence, we report that galectin-3 disruption in tumor stroma and parenchyma decreases angiogenesis through interfering with the responses of macrophages to the interdependent VEGF and TGFβ1 signaling pathways

  18. Methodology and technical requirements of the galectin-3 test for the preoperative characterization of thyroid nodules.

    Science.gov (United States)

    Bartolazzi, Armando; Bellotti, Carlo; Sciacchitano, Salvatore

    2012-01-01

    In the last decade, the β-galactosyl binding protein galectin-3 has been the object of extensive molecular, structural, and functional studies aimed to clarify its biological role in cancer. Multicenter studies also contributed to discover the potential clinical value of galectin-3 expression analysis in distinguishing, preoperatively, benign from malignant thyroid nodules. As a consequence galectin-3 is receiving significant attention as tumor marker for thyroid cancer diagnosis, but some conflicting results mostly owing to methodological problems have been published. The possibility to apply preoperatively a reliable galectin-3 test method on fine needle aspiration biopsy (FNA)-derived thyroid cells represents an important achievement. When correctly applied, the method reduces consistently the gray area of thyroid FNA cytology, contributing to avoid unnecessary thyroid surgery. Although the efficacy and reliability of the galectin-3 test method have been extensively proved in several studies, its translation in the clinical setting requires well-standardized reagents and procedures. After a decade of experimental work on galectin-3-related basic and translational research projects, the major methodological problems that may potentially impair the diagnostic performance of galectin-3 immunotargeting are highlighted and discussed in detail. A standardized protocol for a reliable galectin-3 expression analysis is finally provided. The aim of this contribution is to improve the clinical management of patients with thyroid nodules, promoting the preoperative use of a reliable galectin-3 test method as ancillary technique to conventional thyroid FNA cytology. The final goal is to decrease unnecessary thyroid surgery and its related social costs. PMID:21691201

  19. Overexpression of the anti-apoptotic protein AVEN contributes to increased malignancy in hematopoietic neoplasms.

    Science.gov (United States)

    Eißmann, M; Melzer, I M; Fernández, S B M; Michel, G; Hrabě de Angelis, M; Hoefler, G; Finkenwirth, P; Jauch, A; Schoell, B; Grez, M; Schmidt, M; Bartholomae, C C; Newrzela, S; Haetscher, N; Rieger, M A; Zachskorn, C; Mittelbronn, M; Zörnig, M

    2013-05-16

    AVEN has been identified as an inhibitor of apoptosis, which binds to the adaptor protein, APAF-1, and thereby prevents apoptosome formation and mitochondrial apoptosis. Recent data have demonstrated high expression levels of AVEN messenger RNA in acute leukemias as well as a positive correlation between AVEN mRNA overexpression and poor prognosis in childhood acute lymphoblastic leukemia. On the basis of these data, we investigated the potential involvement of AVEN in tumorigenesis. First, we confirmed the overexpression of AVEN in T-cell acute lymphoblastic leukemia/lymphoma (T-ALL) patient samples. We then established a transgenic mouse model with T-cell-specific overexpression of AVEN, with which we demonstrated the oncogenic cooperation of AVEN with heterozygous loss of p53. Finally, we used a subcutaneous xenograft mouse model to show that AVEN knockdown in the T-ALL cell lines, MOLT-4 and CCRF-CEM, and in the acute myeloblastic leukemia cell line, Kasumi-1, leads to a halt in tumor growth owing to the increased apoptosis and decreased proliferation of tumor cells. Collectively, our data demonstrate that the anti-apoptotic molecule, AVEN, functions as an oncoprotein in hematopoietic neoplasms. PMID:22751129

  20. Galectin-3 and cyclin D1 expression in non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Gołecki Marcin

    2011-10-01

    Full Text Available Abstract Introduction Lung cancer is a major cause of mortality and morbidity worldwide. Galectin-3 is multifunctional protein, which is involved in regulation of cell growth, cell adhesion, cell proliferation, angiogenesis and apoptosis. Cyclin D1 together with other cyclin plays an important role in cell cycle control. Cyclin D1 regulates the G1-to-S phase transition. The aim of this study was the evaluation of correlations between clinicopathological findings and cyclin D1 and galectin-3 expression in non-small cell lung cancer (NSCLC. We wanted also to analyze the prognostic value of cyclin D1 and galectin-3 expression. Moreover we tried to evaluate the correlations between galectin-3 and cyclin D1 expression in tumor tissue. Materials and methods We used the immunochemistry method to investigate the expression of galectin-3 and cyclin D1 in the paraffin-embedded tumor tissue of 47 patients (32 men and 15 women; mean age 59.34 ± 8.90. years. We used monoclonal antibodies to cyclin D1 (NCL-L-cyclin D1-GM clone P2D11F11 NOVO CASTRA and to galectin-3 (mouse monoclonal antibody NCL-GAL3 NOVO CASTRA. Results Galectin-3 expression was positive in 18 cases (38.29% and cyclin D1 in 39 (82.97%. We showed only weak trend, that galectin-3 expression was lower in patients without lymph node involvement (p = 0.07 and cyclin D1 expression was higher in this group (p = 0.080. We didn't reveal differences in cyclin D1 and galectin-3 expression in SCC and adenocarcinoma patients. We didn't demonstrated also differences in galectin-3 and cyclin D1 expression depending on disease stage. Moreover we analyzed the prognostic value of cyclin D1 expression and galectin-3 in all examinated patients and separately in SCC and in adenocarcinoma and in all stages, but we didn't find any statistical differences. We demonstrated that in galectin-3 positive tumors cyclin D1 expression was higher (96.55% vs 61.11%, Chi2 Yatesa 7.53, p = 0.0061 and we revealed negative

  1. G3-C12 Peptide Reverses Galectin-3 from Foe to Friend for Active Targeting Cancer Treatment.

    Science.gov (United States)

    Sun, Wei; Li, Lian; Yang, Qingqing; Shan, Wei; Zhang, Zhirong; Huang, Yuan

    2015-11-01

    Galectin-3 is overexpressed by numerous carcinomas and is a potential target for active tumor treatments. On the other hand, galectin-3 also plays a key role in cancer progression and prevents cells from undergoing apoptosis, thereby offsetting the benefits of active targeting drugs. However, the relative contribution of the protective antiapoptotic effects of galectin-3 and the proapoptotic effects of galectin-3-targeted therapies has remained yet unrevealed. Here, we show that a galectin-3-binding peptide G3-C12 could reverse galectin-3 from foe to friend for active targeting delivery system. Results showed G3-C12 modified N-(2-hydroxypropyl)methacrylamide copolymer doxorubicin conjugates (G3-C12-HPMA-Dox) could internalize into galectin-3 overexpressed PC-3 cells via a highly specific ligand-receptor pathway (2.2 times higher cellular internalization than HPMA-Dox). The internalized Dox stimulated the translocation of galectin-3 to the mitochondria to prevent from apoptosis. In turn, this caused G3-C12-HPMA-Dox to concentrate into the mitochondria after binding to galectin-3 intracellularly. Initially, mitochondrial galectin-3 weakened Dox-induced mitochondrial damage; however, as time progressed, G3-C12 active-mediation allowed increasing amounts of Dox to be delivered to the mitochondria, which eventually induced higher level of apoptosis than nontargeted copolymers. In addition, G3-C12 downregulates galectin-3 expression, 0.43 times lower than control cells, which could possibly be responsible for the suppressed cell migration. Thus, G3-C12 peptide exerts sequential targeting to both cell membrane and mitochondria via regulating galectin-3, and eventually reverses and overcomes the protective effects of galectin-3; therefore, it could be a promising agent for the treatment of galectin-3-overexpressing cancers. PMID:26393405

  2. Multiple approaches to assess pectin binding to galectin-3.

    Science.gov (United States)

    Zhang, Tao; Zheng, Yi; Zhao, Dongyang; Yan, Jingmin; Sun, Chongliang; Zhou, Yifa; Tai, Guihua

    2016-10-01

    Although several approaches have been used to evaluate binding of carbohydrates to lectins, results are not always comparable, especially with larger polysaccharides. Here, we quantitatively assessed and compared binding of pectin-derived polysaccharides to galectin-3 (Gal-3) using five methods: surface plasmon resonance (SPR), bio-layer interferometry (BLI), fluorescence polarization (FP), competitive fluorescence-linked immunosorbance (cFLISA), and the well-known cell-based hemagglutination assay (G3H). Our studies revealed that whereas Gal-3-pectin binding parameters determined by SPR and BLI were comparable and correlated with inhibitory potencies from the G3H assay, results using FP and cFLISA assays were highly variable and depended greatly on the probe and mass of the polysaccharide. In the cFLISA assay, for example, pectins showed no inhibition when using the DTAF-labeled asialofetuin probe, but did when using a DTAF-labeled pectin probe. And the FP approach with the DTAF-lactose probe did not work on polysaccharides and large galactan chains, although it did work well with smaller galactans. Nevertheless, even though results derived from all of these methods are in general agreement, derived KD, IC50, and MIC values do differ. Our results reflect the variability using various techniques and therefore will be useful to investigators who are developing pectin-derived Gal-3 antagonists as anti-cancer agents. PMID:27328612

  3. Acute hantavirus infection induces galectin-3-binding protein.

    Science.gov (United States)

    Hepojoki, Jussi; Strandin, Tomas; Hetzel, Udo; Sironen, Tarja; Klingström, Jonas; Sane, Jussi; Mäkelä, Satu; Mustonen, Jukka; Meri, Seppo; Lundkvist, Ake; Vapalahti, Olli; Lankinen, Hilkka; Vaheri, Antti

    2014-11-01

    Hantaviruses are zoonotic viruses that cause life-threatening diseases when transmitted to humans. Severe hantavirus infection is manifested by impairment of renal function, pulmonary oedema and capillary leakage. Both innate and adaptive immune responses contribute to the pathogenesis, but the underlying mechanisms are not fully understood. Here, we showed that galectin-3-binding protein (Gal-3BP) was upregulated as a result of hantavirus infection both in vitro and in vivo. Gal-3BP is a secreted glycoprotein found in human serum, and increased Gal-3BP levels have been reported in chronic viral infections and in several types of cancer. Our in vitro experiments showed that, whilst Vero E6 cells (an African green monkey kidney cell line) constitutively expressed and secreted Gal-3BP, this protein was detected in primary human cells only as a result of hantavirus infection. Analysis of Gal-3BP levels in serum samples of cynomolgus macaques infected experimentally with hantavirus indicated that hantavirus infection induced Gal-3BP also in vivo. Finally, analysis of plasma samples collected from patients hospitalized because of acute hantavirus infection showed higher Gal-3BP levels during the acute than the convalescent phase. Furthermore, the Gal-3BP levels in patients with haemorrhagic fever with renal syndrome correlated with increased complement activation and with clinical variables reflecting the severity of acute hantavirus infection. PMID:25013204

  4. Galectin-3 inhibition prevents adipose tissue remodelling in obesity.

    Science.gov (United States)

    Martínez-Martínez, E; Calvier, L; Rossignol, P; Rousseau, E; Fernández-Celis, A; Jurado-López, R; Laville, M; Cachofeiro, V; López-Andrés, N

    2016-06-01

    Extracellular matrix remodelling of the adipose tissue has a pivotal role in the pathophysiology of obesity. Galectin-3 (Gal-3) is increased in obesity and mediates inflammation and fibrosis in the cardiovascular system. However, the effects of Gal-3 on adipose tissue remodelling associated with obesity remain unclear. Male Wistar rats were fed either a high-fat diet (33.5% fat) or a standard diet (3.5% fat) for 6 weeks. Half of the animals of each group were treated with the pharmacological inhibitor of Gal-3, modified citrus pectin (MCP; 100 mg kg(-1) per day) in the drinking water. In adipose tissue, obese animals presented an increase in Gal-3 levels that were accompanied by an increase in pericellular collagen. Obese rats exhibited higher adipose tissue inflammation, as well as enhanced differentiation degree of the adipocytes. Treatment with MCP prevented all the above effects. In mature 3T3-L1 adipocytes, Gal-3 (10(-8 )m) treatment increased fibrosis, inflammatory and differentiation markers. In conclusion, Gal-3 emerges as a potential therapeutic target in adipose tissue remodelling associated with obesity and could have an important role in the development of metabolic alterations associated with obesity. PMID:26853916

  5. A functional yeast survival screen of tumor-derived cDNA libraries designed to identify anti-apoptotic mammalian oncogenes.

    Directory of Open Access Journals (Sweden)

    Moritz Eißmann

    Full Text Available Yeast cells can be killed upon expression of pro-apoptotic mammalian proteins. We have established a functional yeast survival screen that was used to isolate novel human anti-apoptotic genes overexpressed in treatment-resistant tumors. The screening of three different cDNA libraries prepared from metastatic melanoma, glioblastomas and leukemic blasts allowed for the identification of many yeast cell death-repressing cDNAs, including 28% of genes that are already known to inhibit apoptosis, 35% of genes upregulated in at least one tumor entity and 16% of genes described as both anti-apoptotic in function and upregulated in tumors. These results confirm the great potential of this screening tool to identify novel anti-apoptotic and tumor-relevant molecules. Three of the isolated candidate genes were further analyzed regarding their anti-apoptotic function in cell culture and their potential as a therapeutic target for molecular therapy. PAICS, an enzyme required for de novo purine biosynthesis, the long non-coding RNA MALAT1 and the MAST2 kinase are overexpressed in certain tumor entities and capable of suppressing apoptosis in human cells. Using a subcutaneous xenograft mouse model, we also demonstrated that glioblastoma tumor growth requires MAST2 expression. An additional advantage of the yeast survival screen is its universal applicability. By using various inducible pro-apoptotic killer proteins and screening the appropriate cDNA library prepared from normal or pathologic tissue of interest, the survival screen can be used to identify apoptosis inhibitors in many different systems.

  6. Galectin-3, Renal Function, and Clinical Outcomes: Results from the LURIC and 4D Studies.

    Science.gov (United States)

    Drechsler, Christiane; Delgado, Graciela; Wanner, Christoph; Blouin, Katja; Pilz, Stefan; Tomaschitz, Andreas; Kleber, Marcus E; Dressel, Alexander; Willmes, Christoph; Krane, Vera; Krämer, Bernhard K; März, Winfried; Ritz, Eberhard; van Gilst, Wiek H; van der Harst, Pim; de Boer, Rudolf A

    2015-09-01

    Galectin-3 has been linked to incident renal disease, experimental renal fibrosis, and nephropathy. However, the association among galectin-3, renal function, and adverse outcomes has not been described. We studied this association in two large cohorts of patients over a broad range of renal function. We measured galectin-3 concentrations in baseline samples from the German Diabetes mellitus Dialysis (4D) study (1168 dialysis patients with type 2 diabetes mellitus) and the Ludwigshafen Risk and Cardiovascular Health (LURIC) study (2579 patients with coronary angiograms). Patients were stratified into three groups: eGFR of ≥90 ml/min per 1.73 m(2), 60-89 ml/min per 1.73 m(2), and <60 ml/min per 1.73 m(2). We correlated galectin-3 concentrations with demographic, clinical, and biochemical parameters. The association of galectin-3 with clinical end points was assessed by Cox proportional hazards regression within 10 years (LURIC) or 4 years (4D) of follow-up. Mean±SD galectin-3 concentrations were 12.8±4.0 ng/ml (eGFR≥90 ml/min per 1.73 m(2)), 15.6±5.4 ng/ml (eGFR 60-89 ml/min per 1.73 m(2)), 23.1±9.9 ng/ml (eGFR<60 ml/min per 1.73 m(2)), and 54.1±19.6 ng/ml (dialysis patients of the 4D study). Galectin-3 concentration was significantly associated with clinical end points in participants with impaired kidney function, but not in participants with normal kidney function. Per SD increase in log-transformed galectin-3 concentration, the risks of all-cause mortality, cardiovascular mortality, and fatal infection increased significantly. In dialysis patients, galectin-3 was associated with the combined end point of cardiovascular events. In conclusion, galectin-3 concentrations increased with progressive renal impairment and independently associated with cardiovascular end points, infections, and all-cause death in patients with impaired renal function. PMID:25568176

  7. Peptide screening to knockdown Bcl-2's anti-apoptotic activity: implications in cancer treatment.

    Science.gov (United States)

    Raghav, Pawan Kumar; Verma, Yogesh Kumar; Gangenahalli, Gurudutta U

    2012-04-01

    Bcl-2 (B cell lymphoma-2) is an anti-apoptotic member of Bcl-2 family and its overexpression causes development of several types of cancer. The BH3 domain of pro-apoptotic and BH3-only proteins is capable of binding to Bcl-2 protein to induce apoptosis. This binding is the basis for the development of novel anticancer drug which would likely antagonize Bcl-2 overexpression. In this study we have identified BH3 domain of Bax (Bax BH3) as potentially the best Bcl-2 antagonist by performing docking of BH3 peptides (peptides representing BH3 domain of pro-apoptotic and BH3-only proteins) into the Bcl-2 hydrophobic groove formed by BH3, BH1 and BH2 domains (also referred as BH3 cleft). To predict the best small antagonist for Bcl-2, three groups of small peptides (pentapeptide, tetrapeptide and tripeptide) were designed and screened against Bcl-2 which revealed the structural importance of a set of residues playing a vital role in interaction with Bcl-2. The docking and scoring function identified KRIG and KRI as specific peptides among the screened small peptides responsible for Bcl-2 neutralization and would induce apoptosis. The applied pharmacokinetic and pharmacological filters to all small peptides signify that only IGD has drug-like properties and displayed good oral bioavailability. However, the obtained binding affinity of IGD to Bcl-2 was diminutive. Hence deprotonation, amidation, acetylation, benzoylation, benzylation, and addition of phenyl, deoxyglucose and glucose fragments were performed to increase the binding affinity and to prevent its rapid degradation. Benzoylated IGD tripeptide (IGD(bzo)) was observed to have increased binding affinity than IGD with acceptable pharmacokinetic filters. In addition, stability of Bcl-2/IGD(bzo) complex was validated by Molecular Dynamics (MD) simulations revealing improved binding energy, salt bridges and strong interaction energies. This study suggests a new molecule that inhibits Bcl-2 associated cancer

  8. DIAGNOSTIC VALUE OF GALECTIN-3 LEVEL IN PATIENTS WITH CHRONIC HEART FAILURE AND TYPE 2 DIABETES

    Directory of Open Access Journals (Sweden)

    A. A. Snetkova

    2015-09-01

    Full Text Available Currently, a greater emphasis is placed on the search for additional biomarkers of chronic heart failure (CHF. Galectin-3, a marker of fibrosis and inflammation, has shown himself as a biomarker of CHF in many studies, but the dynamics of its levels in patients with concomitant diabetes mellitus (DM type 2 is not well-studied.Aim. To identify diagnostic significance of galectin-3 plasma level evaluation and its correlations with echocardiographic criteria for patients with CHF and DM type 2.Material and methods. The study included 33 patients with ischemic CHF (all patients had a history of myocardial infarction and DM type 2. The patients were divided into two groups according to the left ventricle (LV ejection fraction (EF: a group with CHF and preserved ejection fraction (PEF (EF≥50% and with CHF and reduced ejection fraction (EF<50%. Patients underwent clinical laboratory tests and Doppler echocardiography; moreover, the levels of brain natriuretic peptide (BNP and galeсtin-3 were measured.Results. The mean level of galectin-3 in blood plasma in the group with CHF and PEF was significantly higher than in the group with CHF and reduced EF (p=0.007. In the group with CHF and PEF a positive correlation between the level of galectin-3 and diastolic LV function E/E' was found (r=0.620, p=0.01. A significant correlation between galectin-3 level and LV systolic function was stated in the group with reduced EF (r=0.53; p<0.05, while in the group with PEF, the correlation was not significant (p=0.225. In the group of patients with reduced EF a negative correlation between galectin-3 and the volume of left atrium was revealed (r=-0.53; p<0.05.Conclusion. Galectin-3 can be used as a diagnostic biomarker primarily in patients with CHF and PEF.

  9. Myocardial Galectin-3 Expression Is Associated with Remodeling of the Pressure-Overloaded Heart and May Delay the Hypertrophic Response without Affecting Survival, Dysfunction, and Cardiac Fibrosis.

    Science.gov (United States)

    Frunza, Olga; Russo, Ilaria; Saxena, Amit; Shinde, Arti V; Humeres, Claudio; Hanif, Waqas; Rai, Vikrant; Su, Ya; Frangogiannis, Nikolaos G

    2016-05-01

    The β-galactoside-binding animal lectin galectin-3 is predominantly expressed by activated macrophages and is a promising biomarker for patients with heart failure. Galectin-3 regulates inflammatory and fibrotic responses; however, its role in cardiac remodeling remains unclear. We hypothesized that galectin-3 may be up-regulated in the pressure-overloaded myocardium and regulate hypertrophy and fibrosis. In normal mouse myocardium, galectin-3 was constitutively expressed in macrophages and was localized in atrial but not ventricular cardiomyocytes. In a mouse model of transverse aortic constriction, galectin-3 expression was markedly up-regulated in the pressure-overloaded myocardium. Early up-regulation of galectin-3 was localized in subpopulations of macrophages and myofibroblasts; however, after 7 to 28 days of transverse aortic constriction, a subset of cardiomyocytes in fibrotic areas contained large amounts of galectin-3. In vitro, cytokine stimulation suppressed galectin-3 synthesis by macrophages and cardiac fibroblasts. Correlation studies revealed that cardiomyocyte- but not macrophage-specific galectin-3 localization was associated with adverse remodeling and dysfunction. Galectin-3 knockout mice exhibited accelerated cardiac hypertrophy after 7 days of pressure overload, whereas female galectin-3 knockouts had delayed dilation after 28 days of transverse aortic constriction. However, galectin-3 loss did not affect survival, systolic and diastolic dysfunction, cardiac fibrosis, and cardiomyocyte hypertrophy in the pressure-overloaded heart. Despite its potential role as a prognostic biomarker, galectin-3 is not a critical modulator of cardiac fibrosis but may delay the hypertrophic response. PMID:26948424

  10. Targeting the Anti-Apoptotic Protein c-FLIP for Cancer Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Safa, Ahmad R., E-mail: asafa@iupui.edu [Department of Pharmacology and Toxicology, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States); Indiana University Simon Cancer Center, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States); Pollok, Karen E. [Department of Pharmacology and Toxicology, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States); Indiana University Simon Cancer Center, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States); Herman B. Wells Center for Pediatric Research, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States)

    2011-03-29

    Cellular FLICE (FADD-like IL-1beta-converting enzyme)-inhibitory protein (c-FLIP) is a major resistance factor and critical anti-apoptotic regulator that inhibits tumor necrosis factor-alpha (TNF-alpha), Fas-L, and TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis as well as chemotherapy-triggered apoptosis in malignant cells. c-FLIP is expressed as long (c-FLIP{sub L}), short (c-FLIP{sub S}), and c-FLIP{sub R} splice variants in human cells. c-FLIP binds to FADD and/or caspase-8 or -10 in a ligand-dependent and-independent fashion, which in turn prevents death-inducing signaling complex (DISC) formation and subsequent activation of the caspase cascade. Moreover, c-FLIP{sub L} and c-FLIP{sub S} are known to have multifunctional roles in various signaling pathways, as well as activating and/or upregulating several cytoprotective signaling molecules. Upregulation of c-FLIP has been found in various tumor types, and its downregulation has been shown to restore apoptosis triggered by cytokines and various chemotherapeutic agents. Hence, c-FLIP is an important target for cancer therapy. For example, small interfering RNAs (siRNAs) that specifically knockdown the expression of c-FLIP{sub L} in diverse human cancer cell lines augmented TRAIL-induced DISC recruitment and increased the efficacy of chemotherapeutic agents, thereby enhancing effector caspase stimulation and apoptosis. Moreover, small molecules causing degradation of c-FLIP as well as decreasing mRNA and protein levels of c-FLIP{sub L} and c-FLIP{sub S} splice variants have been found, and efforts are underway to develop other c-FLIP-targeted cancer therapies. This review focuses on (1) the functional role of c-FLIP splice variants in preventing apoptosis and inducing cytokine and drug resistance; (2) the molecular mechanisms that regulate c-FLIP expression; and (3) strategies to inhibit c-FLIP expression and function.

  11. Anti-apoptotic signaling as a cytoprotective mechanism in mammalian hibernation

    Directory of Open Access Journals (Sweden)

    Andrew N. Rouble

    2013-02-01

    Full Text Available In the context of normal cell turnover, apoptosis is a natural phenomenon involved in making essential life and death decisions. Apoptotic pathways balance signals which promote cell death (pro-apoptotic pathways or counteract these signals (anti-apoptotic pathways. We proposed that changes in anti-apoptotic proteins would occur during mammalian hibernation to aid cell preservation during prolonged torpor under cellular conditions that are highly injurious to most mammals (e.g. low body temperatures, ischemia. Immunoblotting was used to analyze the expression of proteins associated with pro-survival in six tissues of thirteen-lined ground squirrels, Ictidomys tridecemlineatus. The brain showed a concerted response to torpor with significant increases in the levels of all anti-apoptotic targets analyzed (Bcl-2, Bcl-xL, BI-1, Mcl-1, cIAP1/2, xIAP as well as enhanced phosphorylation of Bcl-2 at S70 and T56. Heart responded similarly with most anti-apoptotic proteins elevated significantly during torpor except for Bcl-xL and xIAP that decreased and Mcl-1 that was unaltered. In liver, BI-1 increased whereas cIAP1/2 decreased. In kidney, there was an increase in BI-1, cIAP and xIAP but decreases in Bcl-xL and p-Bcl-2(T56 content. In brown adipose tissue, protein levels of BI-1, cIAP1/2, and xIAP decreased significantly during torpor (compared with euthermia whereas Bcl-2, Bcl-xL, Mcl-1 were unaltered; however, Bcl-2 showed enhanced phosphorylation at Thr56 but not at Ser70. In skeletal muscle, only xIAP levels changed significantly during torpor (an increase. The data show that anti-apoptotic pathways have organ-specific responses in hibernators with a prominent potential role in heart and brain where coordinated enhancement of anti-apoptotic proteins occurred in response to torpor.

  12. Anti-apoptotic signaling and failure of apoptosis in the ischemic rat hippocampus

    DEFF Research Database (Denmark)

    Müller, Georg Johannes; Lassmann, Hans; Johansen, Flemming Fryd

    2007-01-01

    colchicine injection severed as a reference for classical apoptosis. Heat shock protein 70 (Hsp70), neuronal apoptosis inhibitory protein (NAIP) and manganese superoxide dismutase (MnSOD) were upregulated in the majority of intact CA1 neurons paralleling the occurrence of CA1 neuronal death (days 3-7) as...... well as in a proportion of apoptosis-(<50%) and necrosis-like (<30%) CA1 neurons. Colchicine did not provoke an anti-apoptotic response in DGC at all. In addition, more than 70% of apoptosis- and necrosis-like CA1 neurons had completely lost their RCC subunits suggesting bioenergetic failure; by...... contrast, following colchicine injection, 88% of all apoptotic DGC presented RCC subunits. Thus, anti-apoptotic proteins may, in a subset of ischemic CA1 neurons, prevent cell death, while in others, affected by pronounced energy failure, they may cause secondary necrosis....

  13. Relaxin has anti-apoptotic effects on human trophoblast-derived HTR-8/SV neo cells.

    Science.gov (United States)

    Lodhi, Romana S Z; Nakabayashi, Koji; Suzuki, Kaho; Yamada, Ai Y; Hazama, Rhoichi; Ebina, Yasuhiko; Yamada, Hideto

    2013-12-01

    The study was conducted to evaluate the effects of human relaxin on apoptosis in the human trophoblast derived HTR-8/SV neo cell line, which is a possible model of human extravillous trophoblasts (EVTs). HTR-8/SV neo cells, cultured in phenol red free RPMI1640 medium, were treated with different doses of human recombinant (rH2) relaxin in serum-deprived conditions. RT-PCR was used for evaluating relaxin receptor: RXFP1 and RXFP2 expression in HTR-8/SV neo cells. The cell death was examined by TUNEL assay. Furthermore, we investigated caspase-3, cleaved PARP and Bcl-2 expressions by Western blot analysis to recognize the translational effects of anti-apoptotic and pro-apoptotic proteins. RXFP1 and RXFP2 mRNA expression was observed in HTR-8/SV neo cells. Compared with untreated control cultures, treatment with rH2 relaxin, decreased TUNEL-positive rate in HTR-8/SV neo cells was observed. Western blot analysis revealed that treatment with rH2 relaxin decreased the expression of caspase-3 and cleaved PARP, but in contrast increased Bcl-2 expression in those cells. These results suggest that rH2 relaxin has anti-apoptotic effects on HTR8/SV neo cells by decreasing pro-apoptotic caspase-3 and cleaved PARP expression and up-regulating anti-apoptotic Bcl-2 expression. PMID:24070111

  14. Dynamics and prognostic role of galectin-3 in patients with advanced heart failure, during left ventricular assist device support and following heart transplantation

    OpenAIRE

    Coromilas, Ellie; Que-Xu, Em-Claire; Moore, D’Vesharronne; Kato, Tomoko S.; Wu, Christina; Ji, Ruiping; Givens, Raymond; Jorde, Ulrich P.; Takayama, Hiroo; NAKA, YOSHIFUMI; George, Isaac; Mancini, Donna; Schulze, P. Christian

    2016-01-01

    Background Galectin-3 is a marker of myocardial inflammation and fibrosis shown to correlate with morbidity and mortality in heart failure (HF). We examined the utility of galectin-3 as a marker of the severity of HF, the response of galectin-3 levels to ventricular assist device (LVAD) implantation or heart transplantation (HTx), and its use as a prognostic indicator. Methods Plasma galectin-3 was measured using a commercially available ELISA assay in patients with stable HF (n = 55), severe...

  15. Phosphorylation of galectin-3 contributes to malignant transformation of human epithelial cells via modulation of unique sets of genes.

    Science.gov (United States)

    Mazurek, Nachman; Sun, Yun Jie; Price, Janet E; Ramdas, Latha; Schober, Wendy; Nangia-Makker, Pratima; Byrd, James C; Raz, Avraham; Bresalier, Robert S

    2005-12-01

    Galectin-3 is a multifunctional beta-galactoside-binding protein implicated in apoptosis, malignant transformation, and tumor progression. The mechanisms by which galectin-3 contributes to malignant progression are not fully understood. In this study, we found that the introduction of wild-type galectin-3 into nontumorigenic, galectin-3-null BT549 human breast epithelial cells conferred tumorigenicity and metastatic potential in nude mice, and that galectin-3 expressed by the cells was phosphorylated. In contrast, BT549 cells expressing galectin-3 incapable of being phosphorylated (Ser6-->Glu Ser6-->Ala) were nontumorigenic. A microarray analysis of 10,000 human genes, comparing BT549 transfectants expressing wild-type and those expressing phosphomutant galectin-3, identified 188 genes that were differentially expressed (>2.5-fold). Genes affected by introduction of wild-type phosphorylated but not phosphomutant galectin-3 included those involved in oxidative stress, a novel noncaspase lysosomal apoptotic pathway, cell cycle regulation, transcriptional activation, cytoskeleton remodeling, cell adhesion, and tumor invasion. The reliability of the microarray data was validated by real-time reverse transcription-PCR (RT-PCR) and by Western blot analysis, and clinical relevance was evaluated by real-time RT-PCR screening of a panel of matched pairs of breast tumors. Differentially regulated genes in breast cancers that are also predicted to be associated with phospho-galectin-3 in transformed BT549 cells include C-type lectin 2, insulin-like growth factor-binding protein 5, cathepsins L2, and cyclin D1. These data show the functional diversity of galectin-3 and suggest that phosphorylation of the protein is necessary for regulation (directly or indirectly) of unique sets of genes that play a role in malignant transformation. PMID:16322222

  16. Anti-galectin-3 therapy: a new chance for multiple myeloma and ovarian cancer?

    Science.gov (United States)

    Mirandola, Leonardo; Nguyen, Diane D; Rahman, Rakhshanda L; Grizzi, Fabio; Yuefei, Yu; Figueroa, José A; Jenkins, Marjorie R; Cobos, Everardo; Chiriva-Internati, Maurizio

    2014-10-01

    Here we review the role of Galectins in the molecular pathogenesis of multiple myeloma and ovarian cancer, with a special focus on Glectin-3. Multiple myeloma is the second most common hematologic malignancy worldwide. Because the pathogenesis of multiple myeloma is still incompletely understood, there is no ultimately effective cure, and this cancer results fatal. Ovarian cancer is the most lethal gynecologic malignancy worldwide. Due to the lack of screening techniques for early detection, patients are mostly diagnosed with advanced disease, which results ultimately fatal. Multiple myeloma and ovarian cancer have different biologies, but they share a strong dependence on adhesion with extracellular matrix and other cells. Galectin-3 plays a key role in regulating such adhesive abilities of tumor cells. Here we discuss the outcomes and possible mechanism of action of a truncated, dominant negative form of Galectin-3, Galectin-3C, in these malignancies. Overall, we report that Galectin-3C is a promising new compound for effective adjuvant therapies in advanced, refractory multiple myeloma and ovarian cancer. PMID:24801755

  17. Hypoxia Up-Regulates Galectin-3 in Mammary Tumor Progression and Metastasis

    NARCIS (Netherlands)

    de Oliveira, Joana T; Ribeiro, Cláudia; Barros, Rita; Gomes, Catarina; de Matos, Augusto J; Reis, Celso A; Rutteman, Gerard R; Gärtner, Fátima

    2015-01-01

    The tumor microenvironment encompasses several stressful conditions for cancer cells such as hypoxia, oxidative stress and pH alterations. Galectin-3, a well-studied member of the beta-galactoside-binding animal family of lectins has been implicated in multiple steps of metastasis as cell-cell and c

  18. Genetic Deletion of Galectin-3 Does Not Impair Full-Thickness Excisional Skin Healing.

    Science.gov (United States)

    Walker, John T; Elliott, Christopher G; Forbes, Thomas L; Hamilton, Douglas W

    2016-05-01

    Galectin-3 has been linked to the regulation of several molecular processes essential during acute cutaneous wound healing, but a comprehensive study of the role of galectin-3 has yet to be performed. With known roles in macrophage polarization, myofibroblast differentiation, re-epithelialization, and angiogenesis, we hypothesized that genetic deletion of galectin-3 would significantly impair healing of excisional skin wounds in mice. In wild-type mice, galectin-3 expression correlated temporally with the inflammatory phase of healing. Conversely, genetic deletion of galectin-3 did not alter gross wound healing kinetics even though it resulted in delayed re-epithelialization. Wound composition was not altered up to 15 days after wounding in knockout mice, and isolated dermal fibroblast function in vitro was unchanged. We further explored, spatially, the expression of galectin-3 in human chronic wound tissue in relation to the immune cell infiltrate. We show a decreased mRNA and protein abundance in the wound edge tissue, whereas markers of neutrophils, M1 and M2 macrophages are expressed abundantly. Both transforming growth factor-β1 and tumor necrosis factor-α decrease galectin-3 mRNA abundance in chronic wound edge dermal fibroblasts in vitro, providing a potential mechanism for this decreased expression in chronic wounds. PMID:26829035

  19. Within-day variation and influence of physical exercise on circulating Galectin-3 in patients with rheumatoid arthritis and healthy individuals

    DEFF Research Database (Denmark)

    Issa, S F; Christensen, A F; Lottenburger, T; Junker, K; Lindegaard, H; Hørslev-Petersen, K; Junker, P

    2015-01-01

    controls. The participants underwent a standardized exercise programme and four blood samples were drawn before, during and after exercise. Serum Galectin-3 was quantified by ELISA (R&D systems). (1) Galectin-3 was increased at baseline in both RA subsets (P = 0.08). There were no diurnal oscillations (P...... = 0.85). Day-to-day variation amounted to 3%. (2) Baseline Galectin-3 was increased in LRA versus controls and ERA (P < 0.01 and 0.05). Physical exercise induced 10-15% Galectin-3 increments in RA and controls (P < 0.001) peaking after 1-3 h. To conclude, Galectin-3 did not exhibit circadian variation......Galectin-3 has been suggested as a pro-inflammatory mediator in rheumatoid arthritis (RA). Previous studies have reported overexpression of Galectin-3 in RA synovitis and increased levels in synovial fluid and serum in long-standing RA compared with osteoarthritis and healthy controls. Our...

  20. The Protective Properties of the Strawberry (Fragaria ananassa) against Carbon Tetrachloride-Induced Hepatotoxicity in Rats Mediated by Anti-Apoptotic and Upregulation of Antioxidant Genes Expression Effects

    Science.gov (United States)

    Hamed, Sherifa S.; AL-Yhya, Nouf A.; El-Khadragy, Manal F.; Al-Olayan, Ebtesam M.; Alajmi, Reem A.; Hassan, Zeinab K.; Hassan, Salwa B.; Abdel Moneim, Ahmed E.

    2016-01-01

    The strawberry (Fragaria ananassa) has been extensively used to treat a wide range of ailments in many cultures. The present study was aimed at evaluating the hepatoprotective effect of strawberry juice on experimentally induced liver injury in rats. To this end, rats were introperitoneally injected with carbon tetrachloride (CCl4) with or without strawberry juice supplementation for 12 weeks and the hepatoprotective effect of strawberry was assessed by measuring serum liver enzyme markers, hepatic tissue redox status and apoptotic markers with various techniques including biochemistry, ELISA, quantitative PCR assays and histochemistry. The hepatoprotective effect of the strawberry was evident by preventing CCl4-induced increase in liver enzymes levels. Determination of oxidative balance showed that strawberry treatment significantly blunted CCl4-induced increase in oxidative stress markers and decrease in enzymatic and non-enzymatic molecules in hepatic tissue. Furthermore, strawberry supplementation enhanced the anti-apoptotic protein, Bcl-2, and restrained the pro-apoptotic proteins Bax and caspase-3 with a marked reduction in collagen areas in hepatic tissue. These findings demonstrated that strawberry (F. ananassa) juice possessed antioxidant, anti-apoptotic and anti-fibrotic properties, probably mediated by the presence of polyphenols and flavonoids compounds. PMID:27547187

  1. Skeletal muscle stem cells express anti-apoptotic ErbB receptors during activation from quiescence

    International Nuclear Information System (INIS)

    To be effective for tissue repair, satellite cells (the stem cells of adult muscle) must survive the initial activation from quiescence. Using an in vitro model of satellite cell activation, we show that erbB1, erbB2 and erbB3, members of the EGF receptor tyrosine kinase family, appear on satellite cells within 6 h of activation. We show that signalling via erbB2 provides an anti-apoptotic survival mechanism for satellite cells during the first 24 h, as they progress to a proliferative state. Inhibition of erbB2 signalling with AG825 reduced satellite cell numbers, concomitant with elevated caspase-8 activation and TUNEL labelling of apoptotic satellite cells. In serum-free conditions, satellite cell apoptosis could be largely prevented by a mixture of erbB1, erbB3 and erbB4 ligand growth factors, but not by neuregulin alone (erbB3/erbB4 ligand). Furthermore, using inhibitors specific to discrete intracellular signalling pathways, we identify MEK as a pro-apoptotic mediator, and the erbB-regulated factor STAT3 as an anti-apoptotic mediator during satellite cell activation. These results implicate erbB2 signalling in the preservation of a full compliment of satellite cells as they activate in the context of a damaged muscle

  2. Inhibition of mitochondria responsible for the anti-apoptotic effects of melatonin during ischemia-reperfusion

    Institute of Scientific and Technical Information of China (English)

    HAN Yi-xiang; ZHANG Sheng-hui; WANG Xi-ming; WU Jian-bo

    2006-01-01

    Objective: To investigate a possible mechanism responsible for anti-apoptotic effects of melatonin and provide theoretical evidences for clinical therapy. Methods: Ischemia-reperfusion mediated neuronal cell injury model was constructed in cerebellar granule neurons (CGNs) by deprivation of glucose, serum and oxygen in media. After ischemia, melatonin was added to the test groups to reach differential concentration during reperfusion. DNA fragmentation, mitochondrial transmembrane potential,mitochondrial cytochrome c release and caspase-3 activity were observed after subjecting cerebellar granule neurons to oxygen-glucose deprivation (OGD). Results: The results showed that OGD induced typical cell apoptosis change, DNA ladder and apoptosis-related alterations in mitochondrial functions including depression of mitochondrial transmembrane potential (its maximal protection ratio was 73.26%) and release of cytochrome c (its maximal inhibition ratio was 42.52%) and the subsequent activation of caspase-3 (its maximal protection ratio was 59.32%) in cytoplasm. Melatonin reduced DNA damage and inhibited release of mitochondrial cytochrome c and activation of caspase-3. Melatonin can strongly prevent the OGD-induced loss of the mitochondria membrane potential. Conclusion: Our findings suggested that the direct inhibition of mitochondrial pathway might essentially contribute to its anti-apoptotic effects in neuronal ischemia-reperfusion.

  3. Anti-apoptotic signature in thymic squamous cell carcinomas - functional relevance of anti-apoptotic BIRC3 expression in the thymic carcinoma cell line 1889c

    Directory of Open Access Journals (Sweden)

    AlexanderMarx

    2013-12-01

    Full Text Available The molecular pathogenesis of thymomas and thymic carcinomas (TCs is poorly understood and results of adjuvant therapy are unsatisfactory in case of metastatic disease and tumor recurrence. For these clinical settings, novel therapeutic strategies are urgently needed. Recently, limited sequencing efforts revealed that a broad spectrum of genes that play key roles in various common cancers are rarely affected in thymomas and thymic carcinomas, suggesting that other oncogenic principles might be important. This made us re-analyze historic expression data obtained in a spectrum of thymomas and thymic squamous cell carcinomas (TSCC with a custom made cDNA microarray. By cluster analysis, different anti-apoptotic signatures were detected in type B3 thymoma and TSCC, including overexpression of BIRC3 in TSCCs. This was confirmed by qRT-PCR in the original and an independent validation set of tumors. In contrast to several other cancer cell lines, the BIRC3-positive TSCC cell line, 1889c showed spontaneous apoptosis after BIRC3 knock-down. Targeting apoptosis genes is worth testing as therapeutic principle in TSCC.

  4. Role of Galectin-3 in Acetaminophen-Induced Hepatotoxicity and Inflammatory Mediator Production

    OpenAIRE

    Dragomir, Ana-Cristina; Sun, Richard; Mishin, Vladimir; Hall, LeRoy B.; Laskin, Jeffrey D.; Laskin, Debra L.

    2012-01-01

    Galectin-3 (Gal-3) is a β-galactoside-binding lectin implicated in the regulation of macrophage activation and inflammatory mediator production. In the present studies, we analyzed the role of Gal-3 in liver inflammation and injury induced by acetaminophen (APAP). Treatment of wild-type (WT) mice with APAP (300 mg/kg, ip) resulted in centrilobular hepatic necrosis and increases in serum transaminases. This was associated with increased hepatic expression of Gal-3 messenger RNA and protein. Im...

  5. Galectin-1 and Galectin-3 induce mitochondrial apoptotic pathway in Jurkat cells

    Science.gov (United States)

    Vasil'eva, O. A.; Isaeva, A. V.; Prokhorenko, T. S.; Zima, A. P.; Novitsky, V. V.

    2016-08-01

    Cellular malignant transformation is often accompanied by increased gene expression of low-molecular proteins of lectins family-galectins. But it is unknown how galectins promote tumor growth and malignization. Galectins-1 and galectin-3 are thought to be possible immunoregulators exerting their effects by regulating the balance of CD4+ lymphocytes. In addition it is known that tumor cells overexpressing galectins are capable of escaping immunological control, causing apoptosis of lymphocytes. The aim of the study is to investigate the role of galectin-1 and galectin-3 in the implementation of mitochondrial apoptotic pathway in Jurkat cells. Methods: Jurkat cells were used as a model for the study of T-lymphocytes. Jurkat cells were activated with antibodies to CD3 and CD28 and cultured with recombinant galectin-1 and -3. Apoptosis of Jurkat cells and depolarization of the mitochondrial membrane were assessed by flow cytometry. It was found that galectin-1 and galectin-3 have a dose-dependent pro-apoptotic effect on Jurkat cells in vitro and enlarge the number of cells with decreased mitochondrial membrane potential compared with intact cells.

  6. Galectin-3 coats the membrane of breast cells and makes a signature of tumours

    KAUST Repository

    Simone, Giuseppina

    2014-01-01

    Galectin-3, β-galactoside-binding lectin, coats the membrane of most cancer cells and is involved in metastasis and endothelium recognition as well as in evading immune surveillance through killing of activated T cells. To flag galectin as a biomarker of tumours and metastasis, it is pivotal to understand the role of this protein in different tumours and at different stages. Breast tumours have an anomalous behaviour of the galectin-3 compared to other tumour cells. Herein, FACS sorting and galactoside based assays were used to investigate the role of galectin-3 in metastasis and metastatisation of breast cancer cells. Breast galectin fingerprint at the FACS displayed a higher amount in healthy cells, compared to metastatic cells. The microfluidic assay was able to isolate tumour and metastatic cells more than healthy breast cells. Investigation was performed on samples from patients with breast tumours at stage I and stage III whilst MCF7 and EPH-4 cells were used to perform preliminary investigations. The readout of the conditioned medium (from culturing of stage I cells) fingerprint by FACS evidenced high expression of free galectin. Analysis of the results established that the galectin coating the membrane, by galactoside recognition of the breast cells, and engaged by the cells to form protein-carbohydrate complexes inside the microfluidic assay, resembled the tumour signature of tumours in breast cells whilst the galectin free is independent of those mechanisms. © 2014 The Royal Society of Chemistry.

  7. Galectin-3C inhibits tumor growth and increases the anticancer activity of bortezomib in a murine model of human multiple myeloma.

    Directory of Open Access Journals (Sweden)

    Leonardo Mirandola

    Full Text Available Galectin-3 is a human lectin involved in many cellular processes including differentiation, apoptosis, angiogenesis, neoplastic transformation, and metastasis. We evaluated galectin-3C, an N-terminally truncated form of galectin-3 that is thought to act as a dominant negative inhibitor, as a potential treatment for multiple myeloma (MM. Galectin-3 was expressed at varying levels by all 9 human MM cell lines tested. In vitro galectin-3C exhibited modest anti-proliferative effects on MM cells and inhibited chemotaxis and invasion of U266 MM cells induced by stromal cell-derived factor (SDF-1α. Galectin-3C facilitated the anticancer activity of bortezomib, a proteasome inhibitor approved by the FDA for MM treatment. Galectin-3C and bortezomib also synergistically inhibited MM-induced angiogenesis activity in vitro. Delivery of galectin-3C intravenously via an osmotic pump in a subcutaneous U266 cell NOD/SCID mouse model of MM significantly inhibited tumor growth. The average tumor volume of bortezomib-treated animals was 19.6% and of galectin-3C treated animals was 13.5% of the average volume of the untreated controls at day 35. The maximal effect was obtained with the combination of galectin-3C with bortezomib that afforded a reduction of 94% in the mean tumor volume compared to the untreated controls at day 35. In conclusion, this is the first study to show that inhibition of galectin-3 is efficacious in a murine model of human MM. Our results demonstrated that galectin-3C alone was efficacious in a xenograft mouse model of human MM, and that it enhanced the anti-tumor activity of bortezomib in vitro and in vivo. These data provide the rationale for continued testing of galectin-3C towards initiation of clinical trials for treatment of MM.

  8. Evaluation of anti-apoptotic activity of different dietary antioxidants in renal cell carcinoma against hydrogen peroxide

    Institute of Scientific and Technical Information of China (English)

    Garg Neeraj K; Mangal Sharad; Sahu Tejram; Mehta Abhinav; Vyas Suresh P; Tyagi Rajeev K

    2011-01-01

    Objective: To evaluate the anti-apoptotic and radical scavenging activities of dietary phenolics, namely ascorbic acid, -tocopherol acetate, citric acid, salicylic acid, and estimate H2O2-induced apoptosis in renal cell carcinoma cells. Methods: The intracellular antioxidant potency of antioxidants was investigated. H2O2-induced apoptosis in RCC-26 was assayed with the following parameters: cell viability (% apoptosis), nucleosomal damage and DNA fragmentation, bcl-2 levels and flow cytometery analysis (ROS production evaluation). Results: The anticancer properties of antioxidants such as ascorbic acid, - tocopherol acetate, citric acid, salicylic acid with perdurable responses were investigated. It was observed that these antioxidants had protective effect (anti-apoptotic activity) against hydrogen peroxide (H2O2) in renal cell carcinoma (RCC-26) cell line. Conclusions: This study reveals and proves the anticancer properties. However, in cancer cell lines anti-apoptotic activity can indirectly reflect the cancer promoter activity through radicals scavenging, and significantly protect nucleus and bcl-2.

  9. Anti-apoptotic treatment in mouse models of age-related hearing loss

    Institute of Scientific and Technical Information of China (English)

    Fengchan Han; Oumei Wang; Quanxiang Cai

    2016-01-01

    Age-related hearing loss (AHL), or presbycusis, is the most common neurodegenerative disorder and top communication deficit of the aged population. Genetic predisposition is one of the major factors in the development of AHL. Generally, AHL is associated with an age-dependent loss of sensory hair cells, spiral ganglion neurons and stria vascularis cells in the inner ear. Although the mechanisms leading to genetic hearing loss are not completely understood, caspase-family proteases function as important signals in the inner ear pathology. It is now accepted that mouse models are the best tools to study the mechanism of genetic hearing loss or AHL. Here, we provide a brief review of recent studies on hearing improvement in mouse models of AHL by anti-apoptotic treatment.

  10. The anti-apoptotic members of the Bcl-2 family are attractive tumor-associated antigens

    DEFF Research Database (Denmark)

    Straten, Per thor; Andersen, Mads Hald

    2010-01-01

    Anti-apoptotic members of the Bcl-2 family (Bcl-2, Bcl-X(L) and Mcl-2) are pivotal regulators of apoptotic cell death. They are all highly overexpressed in cancers of different origin in which they enhance the survival of the cancer cells. Consequently, they represent prime candidates for anti......, spontaneous cellular immune responses against the Bcl-2 family proteins have been identified as frequent features in cancer patients underscoring that these proteins are natural targets for the immune system. Thus, Bcl-2 family may serve as an important and widely applicable target for anti......-cancer immunotherapeutic strategies, alone or in the combination with conventional therapy. Here, we summarize the current knowledge of Bcl-2 family proteins as T-cell antigens, which has set the stage for the first explorative trial using these antigens in therapeutic vaccinations against cancer, and discuss future...

  11. Anti-apoptotic peptides protect against radiation-induced cell death

    International Nuclear Information System (INIS)

    The risk of terrorist attacks utilizing either nuclear or radiological weapons has raised concerns about the current lack of effective radioprotectants. Here it is demonstrated that the BH4 peptide domain of the anti-apoptotic protein Bcl-xL can be delivered to cells by covalent attachment to the TAT peptide transduction domain (TAT-BH4) and provide protection in vitro and in vivo from radiation-induced apoptotic cell death. Isolated human lymphocytes treated with TAT-BH4 were protected against apoptosis following exposure to 15 Gy radiation. In mice exposed to 5 Gy radiation, TAT-BH4 treatment protected splenocytes and thymocytes from radiation-induced apoptotic cell death. Most importantly, in vivo radiation protection was observed in mice whether TAT-BH4 treatment was given prior to or after irradiation. Thus, by targeting steps within the apoptosis signaling pathway it is possible to develop post-exposure treatments to protect radio-sensitive tissues

  12. Methane attenuates retinal ischemia/reperfusion injury via anti-oxidative and anti-apoptotic pathways.

    Science.gov (United States)

    Liu, Lin; Sun, Qinglei; Wang, Ruobing; Chen, Zeli; Wu, Jiangchun; Xia, Fangzhou; Fan, Xian-Qun

    2016-09-01

    Retinal ischemia/reperfusion injury (IRI) may cause incurable visual impairment due to neural regeneration limits. Methane was shown to exert a protective effect against IRI in many organs. This study aims to explore the possible protective effects of methane-rich saline against retinal IRI in rat. Retinal IRI was performed on the right eyes of male Sprague-Dawley rats, which were immediately injected intraperitoneally with methane-saturated saline (25ml/kg). At one week after surgery, the number of retinal ganglion cells (RGCs), total retinal thickness, visual function were measured by hematoxylin and eosin staining, FluoroGold anterograde labeling and flash visual evoked potentials. The levels of 8-hydroxy-2-deoxyguanosine (8-OHdG), 4-Hydroxy-2-nonenal (4-HNE), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), caspase-3, caspase-9, B cell lymphoma/leukemia-2 (Bcl-2) and Bcl-2 associated X protein (Bax) in retinas were assessed by immunofluorescence staining, enzyme-linked immunosorbent assay and quantitative polymerase chain reaction. As expected, methane treatment significantly improved the retinal IRI-induced RGC loss, total retinal layer thinning and visual dysfunction. Moreover, methane treatment significantly reduced the levels of oxidative stress biomarkers (8-OHdG, 4-HNE, MDA) and increased the antioxidant enzyme activities (SOD, CAT, GPx) in the retinas with IRI. Meanwhile, methane treatment significantly increased the anti-apoptotic gene (Bcl-2) expression and decreased the pro-apoptotic gene (Bax) expression, accompanied by the suppression of caspase-3 and caspase-9 activity. Thus, these data demonstrated that methane can exert a neuroprotective role against retinal IRI through anti-oxidative and anti-apoptotic pathways. PMID:27208496

  13. Anti-Apoptotic Effects of Lentiviral Vector Transduction Promote Increased Rituximab Tolerance in Cancerous B-Cells

    DEFF Research Database (Denmark)

    Ranjbar, Benyamin; Krogh, Louise Bechmann; Laursen, Maria Bach; Primo, Maria Nascimento; Marques, Sara Correia; Dybkær, Karen; Mikkelsen, Jacob Giehm

    2016-01-01

    achieved through effects of lentiviral transduction on cell death mediated by complement. Rather, reduced levels of PARP1 and persistent high levels of CD43 in Rituximab-treated GCBs demonstrate anti-apoptotic effects of lentiviral transduction that may interfere with the outcome and interpretation of...

  14. Galectin-3: a new biomarker for the diagnosis, analysis and prognosis of acute and chronic heart failure.

    Science.gov (United States)

    Hrynchyshyn, Nataliya; Jourdain, Patrick; Desnos, Michel; Diebold, Benoit; Funck, François

    2013-10-01

    Heart failure constitutes an important medical, social and economic problem. The prevalence of heart failure is estimated as 2-3% of the adult population and increases with age, despite the scientific progress of the past decade, especially the emergence of natriuretic peptides, which have been widely used as reliable markers for diagnostic and prognostic evaluation. Identification of new reliable markers for diagnosis, analysis, prognosis of mortality and prevention of hospitalization is still necessary. Galectin-3 is a soluble β-galactoside-binding protein secreted by activated macrophages. Its main action is to bind to and activate the fibroblasts that form collagen and scar tissue, leading to progressive cardiac fibrosis. Numerous experimental studies have shown the important role of galectin-3 in cardiac remodelling due to fibrosis, independent of the fibrosis aetiology. Galectin-3 is significantly increased in chronic heart failure (acute or non-acute onset), independent of aetiology. Some clinical studies have confirmed the predictive value of galectin-3 in all-cause mortality in patients with heart failure. In our review, we aim to analyse the role of galectin-3 in the development of heart failure, its value in screening and clinical decision making and its possible predictive application in follow-up as a "routine" test in an addition to established biomarkers, such as B-type natriuretic peptide and N-terminal prohormone of B-type natriuretic peptide. PMID:24090952

  15. Galectin Binding to Neo-Glycoproteins: LacDiNAc Conjugated BSA as Ligand for Human Galectin-3

    Directory of Open Access Journals (Sweden)

    Sophia Böcker

    2015-07-01

    Full Text Available Carbohydrate-lectin interactions are relatively weak. As they play an important role in biological recognition processes, multivalent glycan ligands are designed to enhance binding affinity and inhibitory potency. We here report on novel neo-glycoproteins based on bovine serum albumin as scaffold for multivalent presentation of ligands for galectins. We prepared two kinds of tetrasaccharides (N-acetyllactosamine and N,N-diacetyllactosamine terminated by multi-step chemo-enzymatic synthesis utilizing recombinant glycosyltransferases. Subsequent conjugation of these glycans to lysine groups of bovine serum albumin via squaric acid diethyl ester yielded a set of 22 different neo-glycoproteins with tuned ligand density. The neo-glycoproteins were analyzed by biochemical and chromatographic methods proving various modification degrees. The neo-glycoproteins were used for binding and inhibition studies with human galectin-3 showing high affinity. Binding strength and inhibition potency are closely related to modification density and show binding enhancement by multivalent ligand presentation. At galectin-3 concentrations comparable to serum levels of cancer patients, we detect the highest avidities. Selectivity of N,N-diacetyllactosamine terminated structures towards galectin-3 in comparison to galectin-1 is demonstrated. Moreover, we also see strong inhibitory potency of our scaffolds towards galectin-3 binding. These novel neo-glycoproteins may therefore serve as selective and strong galectin-3 ligands in cancer related biomedical research.

  16. Galectin-3 Binding Protein Secreted by Breast Cancer Cells Inhibits Monocyte-Derived Fibrocyte Differentiation.

    Science.gov (United States)

    White, Michael J V; Roife, David; Gomer, Richard H

    2015-08-15

    To metastasize, tumor cells often need to migrate through a layer of collagen-containing scar tissue which encapsulates the tumor. A key component of scar tissue and fibrosing diseases is the monocyte-derived fibrocyte, a collagen-secreting profibrotic cell. To test the hypothesis that invasive tumor cells may block the formation of the fibrous sheath, we determined whether tumor cells secrete factors that inhibit monocyte-derived fibrocyte differentiation. We found that the human metastatic breast cancer cell line MDA-MB-231 secretes activity that inhibits human monocyte-derived fibrocyte differentiation, whereas less aggressive breast cancer cell lines secrete less of this activity. Purification indicated that Galectin-3 binding protein (LGALS3BP) is the active factor. Recombinant LGALS3BP inhibits monocyte-derived fibrocyte differentiation, and immunodepletion of LGALS3BP from MDA-MB 231 conditioned media removes the monocyte-derived fibrocyte differentiation-inhibiting activity. LGALS3BP inhibits the differentiation of monocyte-derived fibrocytes from wild-type mouse spleen cells, but not from SIGN-R1(-/-) mouse spleen cells, suggesting that CD209/SIGN-R1 is required for the LGALS3BP effect. Galectin-3 and galectin-1, binding partners of LGALS3BP, potentiate monocyte-derived fibrocyte differentiation. In breast cancer biopsies, increased levels of tumor cell-associated LGALS3BP were observed in regions of the tumor that were invading the surrounding stroma. These findings suggest LGALS3BP and galectin-3 as new targets to treat metastatic cancer and fibrosing diseases. PMID:26136428

  17. Galectin-3 and HBME-1 improve the accuracy of core biopsy in indeterminate thyroid nodules.

    Science.gov (United States)

    Trimboli, Pierpaolo; Guidobaldi, Leo; Amendola, Stefano; Nasrollah, Naim; Romanelli, Francesco; Attanasio, Daniela; Ramacciato, Giovanni; Saggiorato, Enrico; Valabrega, Stefano; Crescenzi, Anna

    2016-04-01

    Core needle biopsy (CNB) has been recently described as an accurate second-line test in thyroid inconclusive cytology (FNA). Here we retrospectively investigated the potential improvement given by Galectin-3, Cytokeratin-19, and HBME-1 on the accuracy of CNB in thyroid nodules with prior indeterminate FNA report. The study included 74 nodules. At CNB diagnosis, 15 were cancers, 40 were benign, and 19 had uncertain/non-diagnostic CNB report. The above immunohistochemical (IHC) panel was analyzed in all cases. After surgery, 19 malignant and 55 benign lesions were found. All 15 cancers and all 40 benign nodules diagnosed at CNB were confirmed at final histology. Regarding the uncertain CNB group, 4 (21 %) were malignant and 15 (79 %) benign. When we considered all the series, the most accurate IHC combination was Galectin-3 plus HBME-1, while HBME-1 was the most sensitive marker in those nodules with uncertain CNB report. The combination of CNB plus IHC could indentify 19/19 cancers and 53/55 benign lesions. Sensitivity and specificity of CNB increased from 79 to 100 % and from 73 to 96 %, respectively, by adding IHC. CNB can diagnose the majority of thyroid nodules with previous indeterminate FNA cytology, while the accuracy of CNB is increased by adding Galectin-3, Cytokeratin-19, and HBME-1 panel. We suggest to adopt CNB as a second-line approach to indeterminate thyroid FNA, and apply IHC in those lesions with uncertain/non-diagnostic CNB report. This approach should improve the pre-surgical diagnosis of patients. These results should be confirmed in larger prospective series. PMID:26142180

  18. Protective effects of melittin on transforming growth factor-β1 injury to hepatocytes via anti-apoptotic mechanism

    International Nuclear Information System (INIS)

    Melittin is a cationic, hemolytic peptide that is the main toxic component in the venom of the honey bee (Apis mellifera). Melittin has multiple effects, including anti-bacterial, anti-viral and anti-inflammatory, in various cell types. However, the anti-apoptotic mechanisms of melittin have not been fully elucidated in hepatocytes. Apoptosis contributes to liver inflammation and fibrosis. Knowledge of the apoptotic mechanisms is important to develop new and effective therapies for treatment of cirrhosis, portal hypertension, liver cancer, and other liver diseases. In the present study, we investigated the anti-apoptotic effect of melittin on transforming growth factor (TGF)-β1-induced apoptosis in hepatocytes. TGF-β1-treated hepatocytes were exposed to low doses (0.5 and 1 μg/mL) and high dose (2 μg/mL) of melittin. The low doses significantly protected these cells from DNA damage in TGF-β1-induced apoptosis compared to the high dose. Also, melittin suppressed TGF-β1-induced apoptotic activation of the Bcl-2 family and caspase family of proteins, which resulted in the inhibition of poly-ADP-ribose polymerase (PARP) cleavage. These results demonstrate that TGF-β1 induces hepatocyte apoptosis and that an optimal dose of melittin exerts anti-apoptotic effects against TGF-β1-induced injury to hepatocytes via the mitochondrial pathway. These results suggest that an optimal dose of melittin can serve to protect cells against TGF-β1-mediated injury. - Highlights: → We investigated the anti-apoptotic effect of melittin on TGF-β1-induced hepatocyte. → TGF-β1 induces hepatocyte apoptosis. → TGF-β1-treated hepatocytes were exposed to low doses and high dose of melittin. → Optimal dose of melittin exerts anti-apoptotic effects to hepatocytes.

  19. Effects of advanced glycosylation end products and rosiglitazone on the expression and secretion of galectin-3 in human renal mesangial cells

    Institute of Scientific and Technical Information of China (English)

    SUN Zi-lin; MA Chan-juan; JIN Hui; YUAN Yang; LIU Nai-feng

    2009-01-01

    Background Galectin-3 is the most recently identified advanced glycosylation end products (AGEs) binding protein. This study aimed to investigate the effects of AGEs and rosiglitazone on the expression and secretion of galectin-3 in cultured human renal mesangial cells (HRMCs).Methods HRMCs were incubated with different concentrations of AGE-bovine serum albumin (BSA) (0, 50, 100, 200, and 400 mg/L) for different time (0, 24, 36, 48, and 72 hours), and exposed to AGE-BSA in the presence of different concentrations of rosiglitazone (1, 10, and 100 μmol/L). The mRNA and protein expression of galectin-3 in HRMCs were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and Westem blotting. The culture medium of HRMCs was collected and concentrated, and the content of galectin-3 in the medium was detected by Western blotting. Results Both RT-PCR and Western blotting revealed that AGE-BSA up-regulated the expression of galectin-3 in HRMCs in a concentration- (P<0.05) and time-dependent (P<0.05) manner compared with the control. Compared with the control, AGE-BSA elevated the content of galectin-3 in the culture medium of HRMCs time- and concentration-dependently (P<0.05, respectively). Both protein and mRNA expression of galectin-3, and its content in the medium of HRMCs exposed to different concentrations of rosiglitazone in the presence of AGE-BSA were increased compared with those of cells exposed to AGE-BSA alone (P<0.05). Rosiglitazone increased the expression and secretion of galectin-3 in a dose-dependent manner (P<0.05).Conclusions AGEs up-regulates the expression and secretion of galectin-3 in HRMCs. Rosiglitazone further enhances the upregulation of galectin-3 in HRMCs induced by AGEs, which suggests that rosiglitazone may play a role of reno-protection via up-regulation of galectin-3.

  20. Leptin is an anti-apoptotic effector in placental cells involving p53 downregulation.

    Directory of Open Access Journals (Sweden)

    Ayelén Rayen Toro

    Full Text Available Leptin, a peripheral signal synthetized by the adipocyte to regulate energy metabolism, can also be produced by placenta, where it may work as an autocrine hormone. We have previously demonstrated that leptin promotes proliferation and survival of trophoblastic cells. In the present work, we aimed to study the molecular mechanisms that mediate the survival effect of leptin in placenta. We used the human placenta choriocarcinoma BeWo and first trimester Swan-71 cell lines, as well as human placental explants. We tested the late phase of apoptosis, triggered by serum deprivation, by studying the activation of Caspase-3 and DNA fragmentation. Recombinant human leptin added to BeWo cell line and human placental explants, showed a decrease on Caspase-3 activation. These effects were dose dependent. Maximal effect was achieved at 250 ng leptin/ml. Moreover, inhibition of endogenous leptin expression with 2 µM of an antisense oligonucleotide, reversed Caspase-3 diminution. We also found that the cleavage of Poly [ADP-ribose] polymerase-1 (PARP-1 was diminished in the presence of leptin. We analyzed the presence of low DNA fragments, products from apoptotic DNA cleavage. Placental explants cultivated in the absence of serum in the culture media increased the apoptotic cleavage of DNA and this effect was prevented by the addition of 100 ng leptin/ml. Taken together these results reinforce the survival effect exerted by leptin on placental cells. To improve the understanding of leptin mechanism in regulating the process of apoptosis we determined the expression of different intermediaries in the apoptosis cascade. We found that under serum deprivation conditions, leptin increased the anti-apoptotic BCL-2 protein expression, while downregulated the pro-apoptotic BAX and BID proteins expression in Swan-71 cells and placental explants. In both models leptin augmented BCL-2/BAX ratio. Moreover we have demonstrated that p53, one of the key cell cycle

  1. Galectin 3

    DEFF Research Database (Denmark)

    Stoltze Gaborit, Freja; Bosselmann, Helle; Kistorp, Caroline;

    2016-01-01

    Gal-3 reflects echocardiographic measures, neurohumoral activity and renal function. The aim of this study was to evaluate the relationship between plasma concentrations of Gal-3 and neurohumoral activity, myocardial and renal function in patients with HF, including advanced echocardiographic measures...... % (27-39 %) and 30 % were in NYHA class III-IV. RESULTS: Patients with plasma concentrations of Gal-3 above the median had significantly lower estimated glomerular filtration rate (eGFR) and this association remained significant in multivariate regression analysis (β: -0.010; 95 % CI -0.012--0.008; P...... < 0.001), adjusted for age, gender, medical treatment. Plasma concentrations of Gal-3 were not associated with albuminuria (Beta: 0.008; 95 % CI:-0.028-0.045; P = 0.652). There were no association between plasma concentrations of Gal-3 and myocardial function or structure estimated by LVEF, LVmass...

  2. Anti-apoptotic peptides protect against radiation-induced cell death.

    Science.gov (United States)

    McConnell, Kevin W; Muenzer, Jared T; Chang, Kathy C; Davis, Chris G; McDunn, Jonathan E; Coopersmith, Craig M; Hilliard, Carolyn A; Hotchkiss, Richard S; Grigsby, Perry W; Hunt, Clayton R

    2007-04-01

    The risk of terrorist attacks utilizing either nuclear or radiological weapons has raised concerns about the current lack of effective radioprotectants. Here it is demonstrated that the BH4 peptide domain of the anti-apoptotic protein Bcl-xL can be delivered to cells by covalent attachment to the TAT peptide transduction domain (TAT-BH4) and provide protection in vitro and in vivo from radiation-induced apoptotic cell death. Isolated human lymphocytes treated with TAT-BH4 were protected against apoptosis following exposure to 15Gy radiation. In mice exposed to 5Gy radiation, TAT-BH4 treatment protected splenocytes and thymocytes from radiation-induced apoptotic cell death. Most importantly, in vivo radiation protection was observed in mice whether TAT-BH4 treatment was given prior to or after irradiation. Thus, by targeting steps within the apoptosis signaling pathway it is possible to develop post-exposure treatments to protect radio-sensitive tissues. PMID:17307150

  3. Heparin exerts anti-apoptotic effects on uterine explants by targeting the endocannabinoid system.

    Science.gov (United States)

    Salazar, Ana Inés; Vercelli, Claudia; Schiariti, Victoria; Davio, Carlos; Correa, Fernando; Franchi, Ana María

    2016-09-01

    Miscarriage caused by Gram-negative bacteria infecting the female genital tract is one of the most common complications of human pregnancy. Intraperitoneal administration of LPS to 7-days pregnant mice induces embryo resorption after 24 h. Here, we show that LPS induced apoptosis on uterine explants from 7-days pregnant mice and that CB1 receptor was involved in this effect. On the other hand, heparin has been widely used for the prevention of pregnancy loss in women with frequent miscarriage with or without thrombophilia. Besides its anticoagulant properties, heparin exerts anti-inflammatory, immunomodulatory and anti-apoptotic effects. Here, we sought to investigate whether the administration of heparin prevented LPS-induced apoptosis in uterine explants from 7-days pregnant mice. We found that heparin enhanced cell survival in LPS-treated uterine explants and that this effect was mediated by increasing uterine FAAH activity. Taken together, our results point towards a novel mechanism involved in the protective effects of heparin. PMID:27364950

  4. Anti-apoptotic role of retinoic acid in the inner ear of noise-exposed mice

    International Nuclear Information System (INIS)

    Exposure to loud noise can induce temporary or permanent hearing loss, and acoustic trauma is the major cause of hearing impairment in industrial nations. However, the mechanisms underlying the death of hair cells after acoustic trauma remain unclear. In addition to its involvement in cellular stress and apoptosis, the c-Jun N-terminal kinase (JNK), a member of the mitogen-activated protein kinase family, is involved in cell survival, transformation, embryonic morphogenesis, and differentiation. JNK is primarily activated by various environmental stresses including noise, and the phenotypic result appears be to cell death. All-trans retinoic acid (ATRA) is an active metabolite of vitamin A that regulates a wide range of biological processes, including cell proliferation, differentiation, and morphogenesis. We evaluated the role of ATRA in preserving hearing in mice exposed to noise that can induce permanent hearing loss. Mice fed with ATRA before and during 3 consecutive days of noise exposure had a more preserved hearing threshold than mice fed sesame oil or saline. Histological and TUNEL staining of the cochlea showed significantly enhanced preservation of the organ of Corti, including outer hair cells and relatively low apoptotic nuclei, in mice-fed ATRA than in mice-fed sesame oil or saline. Phospho-JNK immunohistochemistry showed that ATRA inhibited the activation of JNK. These results suggest that ATRA has an anti-apoptotic effect on cochleae exposed to noise

  5. Anti-apoptotic effects of Z alpha1-antitrypsin in human bronchial epithelial cells.

    LENUS (Irish Health Repository)

    Greene, C M

    2010-05-01

    alpha(1)-antitrypsin (alpha(1)-AT) deficiency is a genetic disease which manifests as early-onset emphysema or liver disease. Although the majority of alpha(1)-AT is produced by the liver, it is also produced by bronchial epithelial cells, amongst others, in the lung. Herein, we investigate the effects of mutant Z alpha(1)-AT (ZAAT) expression on apoptosis in a human bronchial epithelial cell line (16HBE14o-) and delineate the mechanisms involved. Control, M variant alpha(1)-AT (MAAT)- or ZAAT-expressing cells were assessed for apoptosis, caspase-3 activity, cell viability, phosphorylation of Bad, nuclear factor (NF)-kappaB activation and induced expression of a selection of pro- and anti-apoptotic genes. Expression of ZAAT in 16HBE14o- cells, like MAAT, inhibited basal and agonist-induced apoptosis. ZAAT expression also inhibited caspase-3 activity by 57% compared with control cells (p = 0.05) and was a more potent inhibitor than MAAT. Whilst ZAAT had no effect on the activity of Bad, its expression activated NF-kappaB-dependent gene expression above control or MAAT-expressing cells. In 16HBE14o- cells but not HEK293 cells, ZAAT upregulated expression of cIAP-1, an upstream regulator of NF-kappaB. cIAP1 expression was increased in ZAAT versus MAAT bronchial biopsies. The data suggest a novel mechanism by which ZAAT may promote human bronchial epithelial cell survival.

  6. Host cell Golgi anti-apoptotic protein (GAAP) and growth of Chlamydia pneumoniae.

    Science.gov (United States)

    Markkula, Eveliina; Hulkkonen, Jaakko; Penttilä, Tuula; Puolakkainen, Mirja

    2013-01-01

    Chlamydia pneumoniae protein CPn0809 is a type three secretion system substrate, the exact function of which in infection pathogenesis has remained unknown. In this study, we identified by yeast two-hybrid screening a potential host cell interaction partner of CPn0809, Golgi anti-apoptotic protein (GAAP), a conserved protein found in eukaryotic cells. GAAP gene is expressed at relatively constant levels and its expression remained stable also after C. pneumoniae infection. The interaction between GAAP and C. pneumoniae was suggested by transfection studies. GAAP knock-down by siRNA in infected A549 cells resulted in an increased number of C. pneumoniae genomes and growth of the bacteria as judged by quantitative PCR and inclusion counts, respectively. Silencing of GAAP did not make the A549 cells more susceptible to apoptosis per se, and infection with C. pneumoniae prevented staurosporin-induced apoptosis also in transfected cultures. Taken together, the proposed interaction between C. pneumoniae and GAAP modulates bacterial growth in A549 cells. PMID:23000903

  7. d-(+-Galactose-Conjugated Single-Walled Carbon Nanotubes as New Chemical Probes for Electrochemical Biosensors for the Cancer Marker Galectin-3

    Directory of Open Access Journals (Sweden)

    Young Key Shim

    2011-05-01

    Full Text Available d-(+-Galactose-conjugated single-walled carbon nanotubes (SWCNTs were synthesized for use as biosensors to detect the cancer marker galectin-3. To investigate the binding of galectin-3 to the d-(+-galactose-conjugated SWCNTs, an electrochemical biosensor was fabricated by using molybdenum electrodes. The binding affinities of the conjugated SWCNTs to galectin-3 were quantified using electrochemical sensitivity measurements based on the differences in resistance together with typical I-V characterization. The electrochemical sensitivity measurements of the d-(+-galactose-conjugated SWCNTs differed significantly between the samples with and without galectin-3. This indicates that d-(+-galactose-conjugated SWCNTs are potentially useful electrochemical biosensors for the detection of cancer marker galectin-3.

  8. Evaluation of anti-apoptotic activity of different dietary antioxidants in renal cell carcinoma against hydrogen peroxide

    Institute of Scientific and Technical Information of China (English)

    Garg; Neeraj; K; Mangal; Sharad; Sahu; Tejram; Mehta; Abhinav; Vyas; Suresh; P; Tyagi; Rajeev; K

    2011-01-01

    Objective:To evaluate the anti-apoptotic and radical scavenging activities of dietary phenolics, namely ascorbic acid,a-tocopherol acetate,citric acid,salicylic acid,and estimate H2O2induced apoptosis in renal cell carcinoma cells.Methods:The intracellular antioxidant potency of antioxidants was investigated.H2O-2-induced apoptosis in RCC-26 was assayed with the following parameters:cell viability(%apoptosis),nucleosomal damage and DNA fragmentation, bcl-2 levels and flow cytometery analysis(ROS production evaluation).Results:Ine anticancer properties of antioxidants such as ascorbic acid,a- tocopherol acetate,citric acid,salicylic acid with perdurable responses were investigated.It was observed that these antioxidants had protective effect(anti-apoptotic activity) against hydrogen peroxide(H2O2) in renal cell carcinoma(RCC-26) cell line.Conclusions:This study reveals and proves the anticancer properties.However,in cancer cell lines anti-apoptotic activity can indirectly reflect the cancer promoter activity through radicals scavenging,and significantly protect nucleus and bcl-2.

  9. Shiga toxin 1 interaction with enterocytes causes apical protein mistargeting through the depletion of intracellular galectin-3

    International Nuclear Information System (INIS)

    Shiga toxins (Stx) 1 and 2 are responsible for intestinal and systemic sequelae of infection by enterohemorrhagic Escherichia coli (EHEC). However, the mechanisms through which enterocytes are damaged remain unclear. While secondary damage from ischemia and inflammation are postulated mechanisms for all intestinal effects, little evidence excludes roles for more primary toxin effects on intestinal epithelial cells. We now document direct pathologic effects of Stx on intestinal epithelial cells. We study a well-characterized rabbit model of EHEC infection, intestinal tissue and stool samples from EHEC-infected patients, and T84 intestinal epithelial cells treated with Stx1. Toxin uptake by intestinal epithelial cells in vitro and in vivo causes galectin-3 depletion from enterocytes by increasing the apical galectin-3 secretion. This Shiga toxin-mediated galectin-3 depletion impairs trafficking of several brush border structural proteins and transporters, including villin, dipeptidyl peptidase IV, and the sodium-proton exchanger 2, a major colonic sodium absorptive protein. The mistargeting of proteins responsible for the absorptive function might be a key event in Stx1-induced diarrhea. These observations provide new evidence that human enterocytes are directly damaged by Stx1. Conceivably, depletion of galectin-3 from enterocytes and subsequent apical protein mistargeting might even provide a means whereby other pathogens might alter intestinal epithelial absorption and produce diarrhea.

  10. Immune-mediated beta-cell destruction in vitro and in vivo-A pivotal role for galectin-3

    DEFF Research Database (Denmark)

    Karlsen, Allan E; Størling, Zenia M; Sparre, Thomas;

    2006-01-01

    Pro-apoptotic cytokines are toxic to the pancreatic beta-cells and have been associated with the pathogenesis of Type 1 diabetes (T1D). Proteome analysis of IL-1beta exposed isolated rat islets identified galectin-3 (gal-3) as the most up-regulated protein. Here analysis of human and rat islets a...

  11. Carbohydrate-based chemical probes for the proteomic profiling of glucosidases and the emerging cancer marker galectin-3

    NARCIS (Netherlands)

    van Scherpenzeel, M.

    2010-01-01

    This thesis describes the synthesis of carbohydrate-based chemical probes to either profile glucosidases, or specifically label the emerging cancer marker galectin-3 in cell lysates. In general, chemical probe based methods can tag certain classes of proteins, and covalently label a protein or a pro

  12. Structure-based redesign of the binding specificity of anti-apoptotic Bcl-x(L).

    Science.gov (United States)

    Chen, T Scott; Palacios, Hector; Keating, Amy E

    2013-01-01

    Many native proteins are multi-specific and interact with numerous partners, which can confound analysis of their functions. Protein design provides a potential route to generating synthetic variants of native proteins with more selective binding profiles. Redesigned proteins could be used as research tools, diagnostics or therapeutics. In this work, we used a library screening approach to reengineer the multi-specific anti-apoptotic protein Bcl-x(L) to remove its interactions with many of its binding partners, making it a high-affinity and selective binder of the BH3 region of pro-apoptotic protein Bad. To overcome the enormity of the potential Bcl-x(L) sequence space, we developed and applied a computational/experimental framework that used protein structure information to generate focused combinatorial libraries. Sequence features were identified using structure-based modeling, and an optimization algorithm based on integer programming was used to select degenerate codons that maximally covered these features. A constraint on library size was used to ensure thorough sampling. Using yeast surface display to screen a designed library of Bcl-x(L) variants, we successfully identified a protein with ~1000-fold improvement in binding specificity for the BH3 region of Bad over the BH3 region of Bim. Although negative design was targeted only against the BH3 region of Bim, the best redesigned protein was globally specific against binding to 10 other peptides corresponding to native BH3 motifs. Our design framework demonstrates an efficient route to highly specific protein binders and may readily be adapted for application to other design problems. PMID:23154169

  13. Clicked and long spaced galactosyl- and lactosylcalix[4]arenes: new multivalent galectin-3 ligands

    Directory of Open Access Journals (Sweden)

    Silvia Bernardi

    2014-07-01

    Full Text Available Four novel calix[4]arene-based glycoclusters were synthesized by conjugating the saccharide units to the macrocyclic scaffold using the CuAAC reaction and using long and hydrophilic ethylene glycol spacers. Initially, two galactosylcalix[4]arenes were prepared starting from saccharide units and calixarene cores which differ in the relative dispositions of the alkyne and azido groups. Once the most convenient synthetic pathway was selected, two further lactosylcalix[4]arenes were obtained, one in the cone, the other one in the 1,3-alternate structure. Preliminary studies of the interactions of these novel glycocalixarenes with galectin-3 were carried out by using a lectin-functionalized chip and surface plasmon resonance. These studies indicate a higher affinity of lactosyl- over galactosylcalixarenes. Furthermore, we confirmed that in case of this specific lectin binding the presentation of lactose units on a cone calixarene is highly preferred with respect to its isomeric form in the 1,3-alternate structure.

  14. Paving the way for adequate myelination: The contribution of galectin-3, transferrin and iron.

    Science.gov (United States)

    Franco, Paula G; Pasquini, Laura A; Pérez, María J; Rosato-Siri, María V; Silvestroff, Lucas; Pasquini, Juana M

    2015-11-14

    Considering the worldwide incidence of well characterized demyelinating disorders such as Multiple Sclerosis (MS) and the increasing number of pathologies recently found to involve hypomyelinating factors such as micronutrient deficits, elucidating the molecular basis of central nervous system (CNS) demyelination, remyelination and hypomyelination becomes essential to the development of future neuroregenerative therapies. In this context, this review discusses novel findings on the contribution of galectin-3 (Gal-3), transferrin (Tf) and iron to the processes of myelination and remyelination and their potentially positive regulation of oligodendroglial precursor cell (OPC) differentiation. Studies were conducted in cuprizone (CPZ)-induced demyelination and iron deficiency (ID)-induced hypomyelination, and the participation of glial and neural stem cells (NSC) in the remyelination process was evaluated by means of both in vivo and in vitro assays on primary cell cultures. PMID:26296311

  15. Anti-apoptotic effects of aspirin following cerebral ischemia-reperfusion injury in rats

    Institute of Scientific and Technical Information of China (English)

    Liying Qiu; Bin Du; Ying Li; Hongbin Fan; Zhiyong Yang

    2008-01-01

    /kg aspirin decreased MDA content and increased ATP levels. However, 6 mg/kg aspirin did not have the same effect. CONCLUSION: Aspirin reduced the number of apoptotic cells following CIRI. These results suggest that the neuroprotective mechanism of aspirin could be related to elevated Bcl-2 protein levels or decreased Bax protein expression. The increase in the ratio of Bcl-2 to Bax appears to be a common anti-apoptotic mechanism of aspirin.

  16. Maspin is a deoxycholate-inducible, anti-apoptotic stress-response protein differentially expressed during colon carcinogenesis

    Directory of Open Access Journals (Sweden)

    Payne CM

    2011-10-01

    Full Text Available Claire M Payne1,2, Hana Holubec1, Cheray Crowley-Skillicorn1, Huy Nguyen1, Harris Bernstein1, George Wilcox3, Carol Bernstein11Department of Cellular and Molecular Medicine, College of Medicine, University of Arizona, 2Biomedical Diagnostics and Research, Inc, 3Tucson Medical Center, Pathology, Tucson, AZ, USAAbstract: Increased maspin expression in the colon is related to colon cancer risk and patient survival. Maspin is induced by the hydrophobic bile acid, deoxycholate (DOC, which is an endogenous carcinogen and inducer of oxidative stress and DNA damage in the colon. Persistent exposure of colon epithelial cells, in vitro, to high physiologic levels of DOC results in increased constitutive levels of maspin protein expression associated with the development of apoptosis resistance. When an apoptosis-resistant colon epithelial cell line (HCT-116RC developed in the authors' laboratory was treated with a maspin-specific siRNA probe, there was a statistically significant increase in apoptosis compared to treatment with an siRNA control probe. These results indicate, for the first time, that maspin is an anti-apoptotic protein in the colon. Immunohistochemical evaluation of maspin expression in human colonic epithelial cells during sporadic colon carcinogenesis (131 human tissues evaluated indicated a statistically significant increase in maspin protein expression beginning at the polyp stage of carcinogenesis. There was no statistically significant difference in maspin expression between hyperplastic/adenomatous polyps and colonic adenocarcinomas. The absence of "field defects" in the non-neoplastic colonic mucosa of patients with colonic neoplasia indicates that maspin may drive the growth of tumors, in part, through its anti-apoptotic function.Keywords: maspin, anti-apoptotic, bile acid-inducible, immunohistochemistry, colon cancer

  17. Anti-apoptotic phenotypes of cholestan-3β,5α,6β-triol-resistant human cholangiocytes: characteristics contributing to the genesis of cholangiocarcinoma.

    Science.gov (United States)

    Jusakul, Apinya; Loilome, Watcharin; Namwat, Nisana; Techasen, Anchalee; Kuver, Rahul; Ioannou, George N; Savard, Christopher; Haigh, W Geoffrey; Yongvanit, Puangrat

    2013-11-01

    The oxysterols cholestan-3β,5α,6β-triol (Triol) and 3-keto-cholest-4-ene (3K4) are increased in Opisthorchis viverrini-associated hamster cholangiocarcinoma and induce DNA damage and apoptosis via a mitochondria-dependent mechanism in MMNK-1 human cholangiocytes. Based on these observations, we hypothesized that chronic exposure of cholangiocytes to these pathogenic oxysterols may allow a growth advantage to a subset of these cells through selection for resistance to apoptosis, thereby contributing to cholangiocarcinogenesis. To test this hypothesis, we cultured MMNK-1 cells long-term in the presence of Triol. Alteration in survival and apoptotic factors of Triol-exposed cells were examined. Cells cultured long-term in the presence of Triol were resistant to H2O2-induced apoptosis, and demonstrated an increase in the phosphorylation of p38-α, CREB, ERK1/2 and c-Jun. Elevations in the ratio of Bcl-2/Bax and in the protein levels of anti-apoptotic factors including cIAP2, clusterin, and survivin were detected. These results show that long-term exposure of MNNK-1 cells to low doses of Triol selects for kinase-signaling molecules which regulate resistance to apoptosis and thereby enhance cell survival. Clonal expansion of such apoptosis-resistant cells may contribute to the genesis of cholangiocarcinoma. PMID:23959098

  18. Galectin-3 is a marker of myocardial and vascular fibrosis in Kawasaki disease patients with giant aneurysms

    OpenAIRE

    Numano, F; Shimizu, C.; Jimenez-Fernandez, S; Vejar, M; Oharaseki, T; K. Takahashi; Salgado, A; Tremoulet, AH; Gordon, JB; Burns, JC; Daniels, LB

    2015-01-01

    © 2015 Elsevier Ireland Ltd. Backgrounds Galectin-3 (Gal-3) is a multifunctional matricellular protein associated with heart failure and cardiovascular events. Gal-3 is required for transforming growth factor-β pathway-mediated myofibroblast activation that is a key process in coronary artery aneurysm formation in Kawasaki Disease (KD). Autopsies from young adults late after KD onset (AKD) have demonstrated bridging fibrosis throughout the myocardium and arteries. In this study, we postulated...

  19. Role of Galectin-3 in Classical and Alternative Macrophage Activation in the Liver following Acetaminophen Intoxication1

    OpenAIRE

    Dragomir, Ana-Cristina Docan; Sun, Richard; Choi, Hyejeong; Laskin, Jeffrey D.; Laskin, Debra L.

    2012-01-01

    Inflammatory macrophages have been implicated in hepatotoxicity induced by the analgesic, acetaminophen (APAP). In these studies we characterized the phenotype of macrophages accumulating in the liver following APAP intoxication and evaluated the role of galectin-3 (Gal-3) in macrophage activation. Administration of APAP (300 mg/kg, i.p.) to wild type mice resulted in the appearance of two distinct subpopulations of CD11b+ cells in the liver, which expressed high or low levels of the monocyte...

  20. Carbohydrate-based chemical probes for the proteomic profiling of glucosidases and the emerging cancer marker galectin-3

    OpenAIRE

    van Scherpenzeel, M.

    2010-01-01

    This thesis describes the synthesis of carbohydrate-based chemical probes to either profile glucosidases, or specifically label the emerging cancer marker galectin-3 in cell lysates. In general, chemical probe based methods can tag certain classes of proteins, and covalently label a protein or a protein family. This method should allow quantification within a mixture of other proteins. It could also give information about the localization of the protein in the cell, and about interactions of ...

  1. Galectin-3 in bone tumor microenvironment: a beacon for individual skeletal metastasis management.

    Science.gov (United States)

    Nakajima, Kosei; Kho, Dong Hyo; Yanagawa, Takashi; Zimel, Melissa; Heath, Elisabeth; Hogan, Victor; Raz, Avraham

    2016-06-01

    The skeleton is frequently a secondary growth site of disseminated cancers, often leading to painful and devastating clinical outcomes. Metastatic cancer distorts bone marrow homeostasis through tumor-derived factors, which shapes different bone tumor microenvironments depending on the tumor cells' origin. Here, we propose a novel insight on tumor-secreted Galectin-3 (Gal-3) that controls the induction of an inflammatory cascade, differentiation of osteoblasts, osteoclasts, and bone marrow cells, resulting in bone destruction and therapeutic failure. In the approaching era of personalized medicine, the current treatment modalities targeting bone metastatic environments are provided to the patient with limited consideration of the cancer cells' origin. Our new outlook suggests delivering individual tumor microenvironment treatments based on the expression level/activity/functionality of tumor-derived factors, rather than utilizing a commonly shared therapeutic umbrella. The notion of "Gal-3-associated bone remodeling" could be the first step toward a specific personalized therapy for each cancer type generating a different bone niche in patients afflicted with non-curable bone metastasis. PMID:27067726

  2. Conformational entropy changes upon lactose binding to the carbohydrate recognition domain of galectin-3

    International Nuclear Information System (INIS)

    The conformational entropy of proteins can make significant contributions to the free energy of ligand binding. NMR spin relaxation enables site-specific investigation of conformational entropy, via order parameters that parameterize local reorientational fluctuations of rank-2 tensors. Here we have probed the conformational entropy of lactose binding to the carbohydrate recognition domain of galectin-3 (Gal3), a protein that plays an important role in cell growth, cell differentiation, cell cycle regulation, and apoptosis, making it a potential target for therapeutic intervention in inflammation and cancer. We used 15N spin relaxation experiments and molecular dynamics simulations to monitor the backbone amides and secondary amines of the tryptophan and arginine side chains in the ligand-free and lactose-bound states of Gal3. Overall, we observe good agreement between the experimental and computed order parameters of the ligand-free and lactose-bound states. Thus, the 15N spin relaxation data indicate that the molecular dynamics simulations provide reliable information on the conformational entropy of the binding process. The molecular dynamics simulations reveal a correlation between the simulated order parameters and residue-specific backbone entropy, re-emphasizing that order parameters provide useful estimates of local conformational entropy. The present results show that the protein backbone exhibits an increase in conformational entropy upon binding lactose, without any accompanying structural changes

  3. Extracellular galectin-3 counteracts adhesion and exhibits chemoattraction in Helicobacter pylori-infected gastric cancer cells.

    Science.gov (United States)

    Subhash, Vinod Vijay; Ling, Samantha Shi Min; Ho, Bow

    2016-08-01

    Galectin-3 (Gal-3) is a β-galactoside lectin that is upregulated and rapidly secreted by gastric epithelial cells in response to Helicobacter pylori infection. An earlier study reported the involvement of H. pylori cytotoxin-associated gene A (cagA) in the expression of intracellular Gal-3. However, the role of extracellular Gal-3 and its functional significance in H. pylori-infected cells remains uncharacterized. Data presented here demonstrate secretion of Gal-3 is an initial host response event in gastric epithelial cells during H. pylori infection and is independent of CagA. Previously, Gal-3 was shown to bind to H. pylori LPS. The present study elaborates the significance of this binding, as extracellular recombinant Gal-3 (rGal-3) was shown to inhibit the adhesion of H. pylori to the gastric epithelial cells. Interestingly, a decrease in H. pylori adhesion to host cells also resulted in a decrease in apoptosis. Furthermore, the study also demonstrated a chemoattractant role of extracellular rGal-3 in the recruitment of THP-1 monocytes. This study outlines the previously unidentified roles of extracellular Gal-3 where it acts as a negative regulator of H. pylori adhesion and apoptosis in gastric epithelial cells, and as a chemoattractant to THP-1 monocytes. Our findings could contribute to the better understanding of how Gal-3 acts as a modulator under H. pylori-induced pathological conditions. PMID:27283429

  4. Pancreatic stellate cells promote proliferation and invasiveness of human pancreatic cancer cells via galectin-3

    Institute of Scientific and Technical Information of China (English)

    Hai-Biao Jiang; Ming Xu; Xing-Peng Wang

    2008-01-01

    AIM: To investigate the role of pancreatic stellate cells (PSCs) and galectin-3 (GAL-3) in the proliferation and infiltration of pancreatic cancer cell line SW1990.METHODS: Human pancreatic cancer cell line SW1990 and PSCs were cultured in vitro. Supernatant fluid of cultured PSCs and SW1990 cells was collected. Expression of GAL-3 in SW1990 cells and PSCs was detected by ELISA, RT-PCR and Western blotting. Proliferation of cultured PSCs and SW1990 cells was measured by 3-(4, 5-methylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. Infiltration of SW1990 cells was detected by a cell infiltration kit.RESULTS: SW1990 cells expressed GAL-3 and this was up-regulated by the supernatant fluid of cultured PSCs. PSCs did not express GAL-3. SW1990 cells stimulated proliferation of PSCs via GAL-3. GAL-3 antibody inhibited SW1990 cell proliferation, while the supernatant fluid of PSCs stimulated proliferation of SW1990 cells through interaction with GAL-3 protein. The supernatant fluid of PSCs enhanced the invasiveness of SW1990 cells through interaction with GAL-3.CONCLUSION: GAL-3 and PSCs were involved in the proliferation and infiltration process of pancreatic cancer cells.

  5. Shift of galectin-3 expression in the human kidney during development

    Directory of Open Access Journals (Sweden)

    Clara Gerosa

    2013-06-01

    Full Text Available Galectin-3 (Gal-3 is a member of the lectin family, including 14 mammalian galectins, and has been shown to be involved in the many biological processes. In fact it has been reported to be expressed during human nephrogenesis, in the ureteric bud tips and in the medullary regions. In 11 developing human kidney the immunoexpression of Gal-3 was studied. Previously observations on Gal-3 expression in collecting ducts were confirmed and a wild variable reactivity was detected among the range from 20 to 36 weeks of gestational age considered. Between the early and late phases of gestation two phases have been identified: the first, from 20 up to 26 weeks of gestation, with a strong reactivity and the second, from 30 to 36 weeks, with a decrease in Gal-3 expression. This finding clearly indicates a major role for Gal-3 in early human nephrogenesis ending around the 30th week of gestation. In conclusion, Gal-3 apparently plays a role in kidney development at different check points, participating both to ureteric bud proliferation and to differentiation of structures originating from the metanephric mesenchyme. Proceedings of the 9th International Workshop on Neonatology · Cagliari (Italy · October 23rd-26th, 2013 · Learned lessons, changing practice and cutting-edge research

  6. Identification of peptides in human Hsp20 and Hsp27 that possess molecular chaperone and anti-apoptotic activities

    Science.gov (United States)

    Nahomi, Rooban B.; DiMauro, Michael A.; Wang, Benlian; Nagaraj, Ram H.

    2015-01-01

    Previous studies have identified peptides in the ‘crystallin-domain’ of the small heat-shock protein (sHSP) α-crystallin with chaperone and anti-apoptotic activities. We found that peptides in heat-shock protein Hsp20 (G71HFSVLLDVKHFSPEEIAVK91) and Hsp27 (D93RWRVSLDVNHFAPDELTVK113) with sequence homology to α-crystallin also have robust chaperone and anti-apoptotic activities. Both peptides inhibited hyperthermic and chemically induced aggregation of client proteins. The scrambled peptides of Hsp20 and Hsp27 showed no such effects. The chaperone activities of the peptides were better than those from αA- and αB-crystallin. HeLa cells took up the FITC-conjugated Hsp20 peptide and, when the cells were thermally stressed, the peptide was translocated from the cytoplasm to the nucleus. The two peptides inhibited apoptosis in HeLa cells by blocking cytochrome c release from the mitochondria and caspase-3 activation. We found that scrambling the last four amino acids in the two peptides (KAIV in Hsp20 and KTLV in Hsp27) made them unable to enter cells and ineffective against stress-induced apoptosis. Intraperitoneal injection of the peptides prevented sodium-selenite-induced cataract formation in rats by inhibiting protein aggregation and oxidative stress. Our study has identified peptides from Hsp20 and Hsp27 that may have therapeutic benefit in diseases where protein aggregation and apoptosis are contributing factors. PMID:25332102

  7. Neuroglobin in Breast Cancer Cells: Effect of Hypoxia and Oxidative Stress on Protein Level, Localization, and Anti-Apoptotic Function.

    Directory of Open Access Journals (Sweden)

    Marco Fiocchetti

    Full Text Available The over-expression of human neuroglobin (NGB, a heme-protein preferentially expressed in the brain, displays anti-apoptotic effects against hypoxic/ischemic and oxidative stresses enhancing neuron survival. As hypoxic and oxidative stress injury frequently occurs in fast proliferating neoplastic tissues, here, the effect of these stressors on the level, localization, and anti-apoptotic function of NGB in wild type and NGB-stable-silenced MCF-7 breast cancer cells has been assessed. The well-known endogenous NGB inducer 17β-estradiol (E2 has been used as positive control. The median pO2 present in tumor microenvironment of breast cancer patients (i.e., 2% O2 does not affect the NGB level in breast cancer cells, whereas hydrogen peroxide and lead(IV acetate, which increase intracellular reactive oxygen species (ROS level, enhance the NGB levels outside the mitochondria and still activate apoptosis. However, E2-induced NGB up-regulation in mitochondria completely reverse lead(IV acetate-induced PARP cleavage. These results indicate that the NGB level could represent a marker of oxidative-stress in MCF-7 breast cancer cells; however, the NGB ability to respond to injuring stimuli by preventing apoptosis requires its re-allocation into the mitochondria. As a whole, present data might lead to a new direction in understanding NGB function in cancer opening new avenues for the therapeutic intervention.

  8. Neuroglobin in Breast Cancer Cells: Effect of Hypoxia and Oxidative Stress on Protein Level, Localization, and Anti-Apoptotic Function

    Science.gov (United States)

    Fiocchetti, Marco; Cipolletti, Manuela; Leone, Stefano; Naldini, Antonella; Carraro, Fabio; Giordano, Daniela; Verde, Cinzia; Ascenzi, Paolo; Marino, Maria

    2016-01-01

    The over-expression of human neuroglobin (NGB), a heme-protein preferentially expressed in the brain, displays anti-apoptotic effects against hypoxic/ischemic and oxidative stresses enhancing neuron survival. As hypoxic and oxidative stress injury frequently occurs in fast proliferating neoplastic tissues, here, the effect of these stressors on the level, localization, and anti-apoptotic function of NGB in wild type and NGB-stable-silenced MCF-7 breast cancer cells has been assessed. The well-known endogenous NGB inducer 17β-estradiol (E2) has been used as positive control. The median pO2 present in tumor microenvironment of breast cancer patients (i.e., 2% O2) does not affect the NGB level in breast cancer cells, whereas hydrogen peroxide and lead(IV) acetate, which increase intracellular reactive oxygen species (ROS) level, enhance the NGB levels outside the mitochondria and still activate apoptosis. However, E2-induced NGB up-regulation in mitochondria completely reverse lead(IV) acetate-induced PARP cleavage. These results indicate that the NGB level could represent a marker of oxidative-stress in MCF-7 breast cancer cells; however, the NGB ability to respond to injuring stimuli by preventing apoptosis requires its re-allocation into the mitochondria. As a whole, present data might lead to a new direction in understanding NGB function in cancer opening new avenues for the therapeutic intervention. PMID:27149623

  9. Increased adiposity, dysregulated glucose metabolism and systemic inflammation in Galectin-3 KO mice.

    Directory of Open Access Journals (Sweden)

    Jingbo Pang

    Full Text Available Obesity and type 2 diabetes are associated with increased production of Galectin-3 (Gal-3, a protein that modulates inflammation and clearance of glucose adducts. We used Lean and Diet-induced Obese (DIO WT and Gal-3 KO mice to investigate the role of Gal-3 in modulation of adiposity, glucose metabolism and inflammation. Deficiency of Gal-3 lead to age-dependent development of excess adiposity and systemic inflammation, as indicated by elevated production of acute-phase proteins, number of circulating pro-inflammatory Ly6C(high monocytes and development of neutrophilia, microcytic anemia and thrombocytosis in 20-week-old Lean and DIO male Gal-3 KO mice. This was associated with impaired fasting glucose, heightened response to a glucose tolerance test and reduced adipose tissue expression of adiponectin, Gal-12, ATGL and PPARγ, in the presence of maintained insulin sensitivity and hepatic expression of gluconeogenic enzymes in 20-week-old Gal-3 KO mice compared to their diet-matched WT controls. Expression of PGC-1α and FGF-21 in the liver of Lean Gal-3 KO mice was comparable to that observed in DIO animals. Impaired fasting glucose and altered responsiveness to a glucose load preceded development of excess adiposity and systemic inflammation, as demonstrated in 12-week-old Gal-3 KO mice. Finally, a role for the microflora in mediating the fasting hyperglycemia, but not the excessive response to a glucose load, of 12-week-old Gal-3 KO mice was demonstrated by administration of antibiotics. In conclusion, Gal-3 is an important modulator of glucose metabolism, adiposity and inflammation.

  10. Role of galectin-3 in classical and alternative macrophage activation in the liver following acetaminophen intoxication.

    Science.gov (United States)

    Dragomir, Ana-Cristina Docan; Sun, Richard; Choi, Hyejeong; Laskin, Jeffrey D; Laskin, Debra L

    2012-12-15

    Inflammatory macrophages have been implicated in hepatotoxicity induced by the analgesic acetaminophen (APAP). In these studies, we characterized the phenotype of macrophages accumulating in the liver following APAP intoxication and evaluated the role of galectin-3 (Gal-3) in macrophage activation. Administration of APAP (300 mg/kg, i.p.) to wild-type mice resulted in the appearance of two distinct subpopulations of CD11b(+) cells in the liver, which expressed high or low levels of the monocyte/macrophage activation marker Ly6C. Whereas CD11b(+)/Ly6C(hi) macrophages exhibited a classically activated proinflammatory phenotype characterized by increased expression of TNF-α, inducible NO synthase, and CCR2, CD11b(+)/Ly6C(lo) macrophages were alternatively activated, expressing high levels of the anti-inflammatory cytokine IL-10. APAP intoxication was also associated with an accumulation of Gal-3(+) macrophages in the liver; the majority of these cells were Ly6C(hi). APAP-induced increases in CD11b(+)/Ly6C(hi) macrophages were significantly reduced in Gal-3(-/-) mice. This reduction was evident 72 h post APAP and was correlated with decreased expression of the classical macrophage activation markers, inducible NO synthase, IL-12, and TNF-α, as well as the proinflammatory chemokines CCL2 and CCL3, and chemokine receptors CCR1 and CCR2. Conversely, numbers of CD11b(+)/Ly6C(lo) macrophages increased in livers of APAP-treated Gal-3(-/-) mice; this was associated with increased expression of the alternative macrophage activation markers Ym1 and Fizz1, increased liver repair, and reduced hepatotoxicity. These data demonstrate that both classically and alternatively activated macrophages accumulate in the liver following APAP intoxication; moreover, Gal-3 plays a role in promoting a persistent proinflammatory macrophage phenotype. PMID:23175698

  11. Role of galectin-3 in acetaminophen-induced hepatotoxicity and inflammatory mediator production.

    Science.gov (United States)

    Dragomir, Ana-Cristina; Sun, Richard; Mishin, Vladimir; Hall, LeRoy B; Laskin, Jeffrey D; Laskin, Debra L

    2012-06-01

    Galectin-3 (Gal-3) is a β-galactoside-binding lectin implicated in the regulation of macrophage activation and inflammatory mediator production. In the present studies, we analyzed the role of Gal-3 in liver inflammation and injury induced by acetaminophen (APAP). Treatment of wild-type (WT) mice with APAP (300 mg/kg, ip) resulted in centrilobular hepatic necrosis and increases in serum transaminases. This was associated with increased hepatic expression of Gal-3 messenger RNA and protein. Immunohistochemical analysis showed that Gal-3 was predominantly expressed by mononuclear cells infiltrating into necrotic areas. APAP-induced hepatotoxicity was reduced in Gal-3-deficient mice. This was most pronounced at 48-72 h post-APAP and correlated with decreases in APAP-induced expression of 24p3, a marker of inflammation and oxidative stress. These effects were not due to alterations in APAP metabolism or hepatic glutathione levels. The proinflammatory proteins, inducible nitric oxide synthase (iNOS), interleukin (IL)-1β, macrophage inflammatory protein (MIP)-2, matrix metalloproteinase (MMP)-9, and MIP-3α, as well as the Gal-3 receptor (CD98), were upregulated in livers of WT mice after APAP intoxication. Loss of Gal-3 resulted in a significant reduction in expression of iNOS, MMP-9, MIP-3α, and CD98, with no effects on IL-1β. Whereas APAP-induced increases in MIP-2 were augmented at 6 h in Gal-3(-/-) mice when compared with WT mice, at 48 and 72 h, they were suppressed. Tumor necrosis factor receptor-1 (TNFR1) was also upregulated after APAP, a response dependent on Gal-3. Moreover, exaggerated APAP hepatotoxicity in mice lacking TNFR1 was associated with increased Gal-3 expression. These data demonstrate that Gal-3 is important in promoting inflammation and injury in the liver following APAP intoxication. PMID:22461450

  12. Anti-apoptotic response during anoxia and recovery in a freeze-tolerant wood frog (Rana sylvatica)

    Science.gov (United States)

    Gerber, Victoria E.M.; Wijenayake, Sanoji

    2016-01-01

    The common wood frog, Rana sylvatica, utilizes freeze tolerance as a means of winter survival. Concealed beneath a layer of leaf litter and blanketed by snow, these frogs withstand subzero temperatures by allowing approximately 65–70% of total body water to freeze. Freezing is generally considered to be an ischemic event in which the blood oxygen supply is impeded and may lead to low levels of ATP production and exposure to oxidative stress. Therefore, it is as important to selectively upregulate cytoprotective mechanisms such as the heat shock protein (HSP) response and expression of antioxidants as it is to shut down majority of ATP consuming processes in the cell. The objective of this study was to investigate another probable cytoprotective mechanism, anti-apoptosis during oxygen deprivation and recovery in the anoxia tolerant wood frog. In particular, relative protein expression levels of two important apoptotic regulator proteins, Bax and p-p53 (S46), and five anti-apoptotic/pro-survival proteins, Bcl-2, p-Bcl-2 (S70), Bcl-xL, x-IAP, and c-IAP in response to normoxic, 24 Hr anoxic exposure, and 4 Hr recovery stages were assessed in the liver and skeletal muscle using western immunoblotting. The results suggest a tissue-specific regulation of the anti-apoptotic pathway in the wood frog, where both liver and skeletal muscle shows an overall decrease in apoptosis and an increase in cell survival. This type of cytoprotective mechanism could be aimed at preserving the existing cellular components during long-term anoxia and oxygen recovery phases in the wood frog. PMID:27042393

  13. Anti-Apoptotic Protein Bcl-xL Expression in the Midbrain Raphe Region Is Sensitive to Stress and Glucocorticoids.

    Directory of Open Access Journals (Sweden)

    Galina T Shishkina

    Full Text Available Anti-apoptotic proteins are suggested to be important for the normal health of neurons and synapses as well as for resilience to stress. In order to determine whether stressful events may influence the expression of anti-apoptotic protein Bcl-xL in the midbrain and specifically in the midbrain serotonergic (5-HT neurons involved in neurobehavioral responses to adverse stimuli, adult male rats were subjected to short-term or chronic forced swim stress. A short-term stress rapidly increased the midbrain bcl-xl mRNA levels and significantly elevated Bcl-xL immunoreactivity in the midbrain 5-HT cells. Stress-induced increase in glucocorticoid secretion was implicated in the observed effect. The levels of bcl-xl mRNA were decreased after stress when glucocorticoid elevation was inhibited by metyrapone (MET, 150 mg/kg, and this decrease was attenuated by glucocorticoid replacement with dexamethasone (DEX; 0.2 mg/kg. Both short-term stress and acute DEX administration, in parallel with Bcl-xL, caused a significant increase in tph2 mRNA levels and slightly enhanced tryptophan hydroxylase immunoreactivity in the midbrain. The increasing effect on the bcl-xl expression was specific to the short-term stress. Forced swim repeated daily for 2 weeks led to a decrease in bcl-xl mRNA in the midbrain without any effects on the Bcl-xL protein expression in the 5-HT neurons. In chronically stressed animals, an increase in tph2 gene expression was not associated with any changes in tryptophan hydroxylase protein levels. Our findings are the first to demonstrate that both short-term stress and acute glucocorticoid exposures induce Bcl-xL protein expression in the midbrain 5-HT neurons concomitantly with the activation of the 5-HT synthesis pathway in these neurons.

  14. Cod glycopeptide with picomolar affinity to galectin-3 suppresses T-cell apoptosis and prostate cancer metastasis

    OpenAIRE

    Guha, Prasun; Kaptan, Engin; Bandyopadhyaya, Gargi; Kaczanowska, Sabina; Davila, Eduardo; Thompson, Keyata; Martin, Stuart S.; Dhananjaya V Kalvakolanu; Vasta, Gerardo R; Ahmed, Hafiz

    2013-01-01

    Cancer metastasis and immune suppression are critical issues in cancer therapy. Here, we show that a β-galactoside–binding lectin [galectin-3 (gal3)] that recognizes the Thomsen-Friedenreich disaccharide (TFD, Galβ1,3GalNAc) present on the surface of most cancer cells is involved in promoting angiogenesis, tumor-endothelial cell adhesion, and metastasis of prostate cancer cells, as well as evading immune surveillance through killing of activated T cells. To block gal3-mediated interactions, w...

  15. Detection of galectin-3 in patients with inflammatory bowel diseases: new serum marker of active forms of IBD?

    Czech Academy of Sciences Publication Activity Database

    Frolová, Lenka; Smetana, K. , Jr.; Borovská, Dana; Kitanovičová, Andrea; Klimešová, Klára; Janatková, I.; Malíčková, K.; Lukáš, M.; Drastich, P.; Beneš, Z.; Tučková, Ludmila; Manning, J. C.; André, S.; Gabius, H. J.; Tlaskalová, Helena

    2009-01-01

    Roč. 58, č. 8 (2009), s. 503-512. ISSN 1023-3830 R&D Projects: GA ČR GD310/08/H077; GA ČR GA303/06/0974; GA AV ČR 1QS500200572; GA MŠk 2B06155; GA MZd NR8963 Institutional research plan: CEZ:AV0Z50200510 Keywords : crohn's disease * galectin-3 * mucosal immunity Subject RIV: EC - Immunology Impact factor: 1.586, year: 2009

  16. Inverse expression of two laminin binding proteins, 67LR and galectin-3, correlates with the invasive phenotype of trophoblastic tissue.

    Science.gov (United States)

    van den Brûle, F A; Price, J; Sobel, M E; Lambotte, R; Castronovo, V

    1994-05-30

    Tumor invasion of host tissues and trophoblastic penetration of the endometrium share common biological features. Both processes involve the invasion of basement membranes, an event that is initiated by adhesion of cancer or trophoblast cells to basement membrane components and particularly to laminin. Adhesion to this latter glycoprotein is mediated through a variety of cell surface receptors. We have previously shown that the 67 kD Laminin Receptor (67LR) and a 31 kD Human Laminin Binding Protein, recently renamed galectin-3, are inversely modulated as the invasive phenotype of cancer cells progresses, with up regulation of the former, and down regulation of the latter, respectively. In this study, we examined the expression of these two proteins in 27 human trophoblastic specimens at different gestational ages using Northern and Western blot techniques. Expression of the 67LR increased from 7 weeks to a maximum at 12 weeks, when invasion is maximal, and then decreased. Expression of galectin-3 was inversely modulated by the gestational age, with a minimum expression at 12 weeks. Our data demonstrate that invasive trophoblast displays the same pattern of laminin binding proteins expression than invasive cancer cells, and further demonstrates that invasion of the extracellular matrix by trophoblast and cancer cells share common molecular mechanisms. PMID:8198600

  17. Association of anti-apoptotic Mcl-1L isoform expression with radioresistance of oral squamous carcinoma cells

    International Nuclear Information System (INIS)

    Oral cancer is a common cancer and a major health problem in the Indian subcontinent. At our laboratory Mcl-1, an anti-apoptotic member of the Bcl-2 family has been demonstrated to be overexpressed in oral cancers and to predict outcome in oral cancer patients treated with definitive radiotherapy. To study the role of Mcl-1 isoforms in radiation response of oral squamous carcinoma cells (OSCC), we investigated in the present study, the association of Mcl-1 isoform expression with radiosensitivity of OSCC, using siRNA strategy. The time course expression of Mcl-1 splice variants (Mcl-1L, Mcl-1S & Mcl-1ES) was studied by RT-PCR, western blotting & immunofluorescence, post-irradiation in oral cell lines [immortalized FBM (radiosensitive) and tongue cancer AW8507 & AW13516 (radioresistant)]of relatively differing radiosensitivities. The effect of Mcl-1L knockdown alone or in combination with ionizing radiation (IR) on cell proliferation, apoptosis & clonogenic survival, was investigated in AW8507 & AW13516 cells. Further the expression of Mcl-1L protein was assessed in radioresistant sublines generated by fractionated ionizing radiation (FIR). Three to six fold higher expression of anti-apoptotic Mcl-1L versus pro-apoptotic Mcl-1S was observed at mRNA & protein levels in all cell lines, post-irradiation. Sustained high levels of Mcl-1L, downregulation of pro-apoptotic Bax & Bak and a significant (P < 0.05) reduction in apoptosis was observed in the more radioresistant AW8507, AW13516 versus FBM cells, post-IR. The ratios of anti to pro-apoptotic proteins were high in AW8507 as compared to FBM. Treatment with Mcl-1L siRNA alone or in combination with IR significantly (P < 0.01) increased apoptosis viz. 17.3% (IR), 25.3% (siRNA) and 46.3% (IR plus siRNA) and upregulated pro-apoptotic Bax levels in AW8507 cells. Combination of siRNA & IR treatment significantly (P < 0.05) reduced cell proliferation and clonogenic survival of radioresistant AW8507 & AW13516 cells

  18. Carnosine attenuates early brain injury through its antioxidative and anti-apoptotic effects in a rat experimental subarachnoid hemorrhage model.

    Science.gov (United States)

    Zhang, Zong-yong; Sun, Bao-liang; Yang, Ming-feng; Li, Da-wei; Fang, Jie; Zhang, Shuai

    2015-03-01

    Carnosine (β-alanyl-L-histidine) has been demonstrated to provide antioxidative and anti-apoptotic roles in the animal of ischemic brain injuries and neurodegenerative diseases. The aim of this study was to examine whether carnosine prevents subarachnoid hemorrhage (SAH)-induced early brain injury (EBI) in rats. We found that intraperitoneal administration of carnosine improved neurobehavioral deficits, attenuated brain edema and blood-brain barrier permeability, and decreased reactive oxygen species level at 48 h following SAH in rat models. Carnosine treatment increased tissue copper/zinc superoxide dismutase (CuZn-SOD) and glutathione peroxidase (GSH-Px) enzymatic activities, and reduced post-SAH elevated lactate dehydrogenase (LDH) activity, the concentration of malondialdehyde (MDA), 3-nitrotyrosine (3-NT), 8-hydroxydeoxyguanosine (8-OHDG), interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) in rats. Furthermore, carnosine treatment attenuated SAH-induced microglia activation and cortical neuron apoptosis. These results indicated that administration of carnosine may provide neuroprotection in EBI following SAH in rat models. PMID:25179154

  19. Anti-Apoptotic Gene Delivery with cyclo-(d-Trp-Tyr Peptide Nanotube via Eye Drop Following Corneal Epithelial Debridement

    Directory of Open Access Journals (Sweden)

    Yu-Hsing Lee

    2015-07-01

    Full Text Available Corneal keratocyte apoptosis triggered by cornel debridement is one mechanism of corneal disorders. In this study, the feasibility of cyclo-(d-Trp-Tyr peptide nanotubes (PNTs as carriers of caspase 3 silence shRNA delivery was assessed. A model of epithelial injury by epithelial debridement was applied to investigate the feasibility of PNTs as gene delivery carriers on corneal injury. First, the PNTs were found within 2 μm in length and 300 nm in width by an atomic force microscope and confocal laser microscope system. Plasmid DNAs were observed to be associated with PNTs by atomic force microscope and confocal laser scanning microscope. The plasmids were associated with tyrosine of PNTs with a binding constant of 2.7 × 108 M−1. The stability of plasmid DNA with PNTs against the DNase was found at 60 min. Using thioflavin T pre-stained PNTs on the corneal eye drop delivery, the distribution of PNTs was in the epithelial and stroma regions. After corneal debridement, the rhodamine-labeled plasmid DNA and thioflavin T pre-stained PNTs were also delivered and could be observed in the stroma of cornea. PNTs complexed with anti-apoptotic plasmid caspase 3 silencing shRNA eye drop delivery decreased 41% of caspase 3 activity after the first dose by caspase 3 activity and Western blot analysis.

  20. Anti-inflammatory and anti-apoptotic effects of Crataegus oxyacantha on isoproterenol-induced myocardial damage.

    Science.gov (United States)

    Vijayan, Navin Alukkathara; Thiruchenduran, Mohana; Devaraj, Sivasitamparam Niranjali

    2012-08-01

    This study was designed to evaluate the anti-inflammatory and anti-apoptotic effects of the alcoholic extract of the berries of Crataegus oxyacantha (AEC), a medicinal herb, on isoproterenol-induced myocardial infarction (MI) in a rat model. Three groups of Wistar albino rats, each comprising six animals, were selected for this study. Group I rats served as control. Group II rats were given isoproterenol (85 mg/kg body weight) subcutaneously on 59th and 60th days. Group III rats were given AEC (0.5 ml/100 g body weight/day), orally on a daily basis for 60 days, and isoproterenol (85 mg/kg body weight, subcutaneously) was given on 59th and 60th days. On the 61st day, the animals were sacrificed, and marker enzymes like lactate dehydrogenase (LDH) and creatine kinase (CK) were estimated in serum. In the heart tissue sample, antioxidant status, lipid peroxidation and anti-inflammatory properties of AEC were determined. Isoproterenol significantly increased the release of LDH, CK in serum, decreased the antioxidant status in the heart along with an increase in lipid peroxidation. Nitritive stress and apoptosis were seen in isoproterenol-induced rat heart. Pre-treatment with the AEC for 60 days had a significant effect on all the above factors and maintained near normal status. The study confirms the protective effect of AEC against isoproterenol-induced inflammation and apoptosis-associated MI in rats. PMID:22350754

  1. Piezometric biosensors for anti-apoptotic protein survivin based on buried positive-potential barrier and immobilized monoclonal antibodies.

    Science.gov (United States)

    Stobiecka, Magdalena; Chalupa, Agata; Dworakowska, Beata

    2016-10-15

    The anti-apoptotic protein survivin (Sur) plays an important role in the regulation of cell division and inducing the chemotherapeutic drug resistance. The Sur protein and its mRNA have recently been studied as cancer biomarkers and potential targets for cancer therapy. In this work, we have focused on the design of immunosensors for the detection of Sur based on buried positive-potential barrier layer structure and anti-survivin antibody. The modification of solid AuQC piezoelectrodes was monitored by recording the resonance frequency shift and electrochemical measurements during each step of the sensor preparation. Our results indicate that the immunosensor with covalently bound monoclonal anti-survivin antibody can detect Sur with the limit of detection, LOD=1.7nM (S/N=3σ). The immunosensor applicability for the analysis of real samples was assessed by testing samples of cell lysate solutions obtained from human astrocytoma (glioblastoma) U-87MG cell line, with the experiments performed using the standard addition method. The good linearity of the calibration curves for PBS and lysate solutions at low Sur concentrations confirm the high specificity of the proposed biosensor and good discrimination against nonspecific interactions with lysate components. The calculations indicate that there is still room to increase the Sur capture capacity for Sur while miniaturizing the sensor. The important advantage of the sensor is that it can be reused by a simple regeneration procedure. PMID:26507667

  2. Acidosis Sensing Receptor GPR65 Correlates with Anti-Apoptotic Bcl-2 Family Member Expression in CLL Cells: Potential Implications for the CLL Microenvironment

    OpenAIRE

    Rosko, Ashley E.; McColl, Karen S.; Zhong, Fei; Ryder, Christopher B; Chang, Ming-Jin; Sattar, Abdus; Caimi, Paolo F.; Hill, Brian T; Al-harbi, Sayer; Almasan, Alexandru; Distelhorst, Clark W.

    2014-01-01

    The tumor microenvironment is generally an acidic environment, yet the effect of extracellular acidosis on chronic lymphocytic leukemia (CLL) is not well established. Here we are the first to report that the extracellular acid sensing G-protein coupled receptor, GPR65, is expressed in primary CLL cells where its level correlate strongly with anti-apoptotic Bcl-2 family member levels. GPR65 expression is found normally within the lymphoid lineage and has not been previously reported in CLL. We...

  3. Microglia-Secreted Galectin-3 Acts as a Toll-like Receptor 4 Ligand and Contributes to Microglial Activation

    Directory of Open Access Journals (Sweden)

    Miguel Angel Burguillos

    2015-03-01

    Full Text Available Inflammatory response induced by microglia plays a critical role in the demise of neuronal populations in neuroinflammatory diseases. Although the role of toll-like receptor 4 (TLR4 in microglia’s inflammatory response is fully acknowledged, little is known about endogenous ligands that trigger TLR4 activation. Here, we report that galectin-3 (Gal3 released by microglia acts as an endogenous paracrine TLR4 ligand. Gal3-TLR4 interaction was further confirmed in a murine neuroinflammatory model (intranigral lipopolysaccharide [LPS] injection and in human stroke subjects. Depletion of Gal3 exerted neuroprotective and anti-inflammatory effects following global brain ischemia and in the neuroinflammatory LPS model. These results suggest that Gal3-dependent-TLR4 activation could contribute to sustained microglia activation, prolonging the inflammatory response in the brain.

  4. Orphan Nuclear Receptor NR4A1 Binds a Novel Protein Interaction Site on Anti-apoptotic B Cell Lymphoma Gene 2 Family Proteins.

    Science.gov (United States)

    Godoi, Paulo H C; Wilkie-Grantham, Rachel P; Hishiki, Asami; Sano, Renata; Matsuzawa, Yasuko; Yanagi, Hiroko; Munte, Claudia E; Chen, Ya; Yao, Yong; Marassi, Francesca M; Kalbitzer, Hans R; Matsuzawa, Shu-Ichi; Reed, John C

    2016-07-01

    B cell lymphoma gene 2 (Bcl-2) family proteins are key regulators of programmed cell death and important targets for drug discovery. Pro-apoptotic and anti-apoptotic Bcl-2 family proteins reciprocally modulate their activities in large part through protein interactions involving a motif known as BH3 (Bcl-2 homology 3). Nur77 is an orphan member of the nuclear receptor family that lacks a BH3 domain but nevertheless binds certain anti-apoptotic Bcl-2 family proteins (Bcl-2, Bfl-1, and Bcl-B), modulating their effects on apoptosis and autophagy. We used a combination of NMR spectroscopy-based methods, mutagenesis, and functional studies to define the interaction site of a Nur77 peptide on anti-apoptotic Bcl-2 family proteins and reveal a novel interaction surface. Nur77 binds adjacent to the BH3 peptide-binding crevice, suggesting the possibility of cross-talk between these discrete binding sites. Mutagenesis of residues lining the identified interaction site on Bcl-B negated the interaction with Nur77 protein in cells and prevented Nur77-mediated modulation of apoptosis and autophagy. The findings establish a new protein interaction site with the potential to modulate the apoptosis and autophagy mechanisms governed by Bcl-2 family proteins. PMID:27129202

  5. Anti-Apoptotic Effects of Lentiviral Vector Transduction Promote Increased Rituximab Tolerance in Cancerous B-Cells

    Science.gov (United States)

    Ranjbar, Benyamin; Krogh, Louise Bechmann; Laursen, Maria Bach; Primo, Maria Nascimento; Marques, Sara Correia; Dybkær, Karen; Mikkelsen, Jacob Giehm

    2016-01-01

    Diffuse large B-cell lymphoma (DLBCL) is characterized by great genetic and clinical heterogeneity which complicates prognostic prediction and influences treatment efficacy. The most common regimen, R-CHOP, consists of a combination of anthracycline- and immuno-based drugs including Rituximab. It remains elusive how and to which extent genetic variability impacts the response and potential tolerance to R-CHOP. Hence, an improved understanding of mechanisms leading to drug tolerance in B-cells is crucial, and modelling by genetic intervention directly in B-cells is fundamental in such investigations. Lentivirus-based gene vectors are widely used gene vehicles, which in B-cells are an attractive alternative to potentially toxic transfection-based methodologies. Here, we investigate the use of VSV-G-pseudotyped lentiviral vectors in B-cells for exploring the impact of microRNAs on tolerance to Rituximab. Notably, we find that robust lentiviral transduction of cancerous B-cell lines markedly and specifically enhances the resistance of transduced germinal center B-cells (GCBs) to Rituximab. Although Rituximab works partially through complement-mediated cell lysis, increased tolerance is not achieved through effects of lentiviral transduction on cell death mediated by complement. Rather, reduced levels of PARP1 and persistent high levels of CD43 in Rituximab-treated GCBs demonstrate anti-apoptotic effects of lentiviral transduction that may interfere with the outcome and interpretation of Rituximab tolerance studies. Our findings stress that caution should be exercised exploiting lentiviral vectors in studies of tolerance to therapeutics in DLBCL. Importantly, however, we demonstrate the feasibility of using the lentiviral gene delivery platform in studies addressing the impact of specific microRNAs on Rituximab responsiveness. PMID:27045839

  6. Anti-apoptotic BFL-1 is the major effector in activation-induced human mast cell survival.

    Directory of Open Access Journals (Sweden)

    Maria Ekoff

    Full Text Available Mast cells are best known for their role in allergic reactions, where aggregation of FcεRI leads to the release of mast cell mediators causing allergic symptoms. The activation also induces a survival program in the cells, i.e., activation-induced mast cell survival. The aim of the present study was to investigate how the activation-induced survival is mediated. Cord blood-derived mast cells and the mast cell line LAD-2 were activated through FcεRI crosslinking, with or without addition of chemicals that inhibit the activity or expression of selected Bcl-2 family members (ABT-737; roscovitine. Cell viability was assessed using staining and flow cytometry. The expression and function of Bcl-2 family members BFL-1 and MCL-1 were investigated using real-time quantitative PCR and siRNA treatment. The mast cell expression of Bfl-1 was investigated in skin biopsies. FcεRI crosslinking promotes activation-induced survival of human mast cells and this is associated with an upregulation of the anti-apoptotic Bcl-2 family member Bfl-1. ABT-737 alone or in combination with roscovitine decreases viability of human mast cells although activation-induced survival is sustained, indicating a minor role for Bcl-X(L, Bcl-2, Bcl-w and Mcl-1. Reducing BFL-1 but not MCL-1 levels by siRNA inhibited activation-induced mast cell survival. We also demonstrate that mast cell expression of Bfl-1 is elevated in birch-pollen-provocated skin and in lesions of atopic dermatitis and psoriasis patients. Taken together, our results highlight Bfl-1 as a major effector in activation-induced human mast cell survival.

  7. Thymosin beta 4 protects cardiomyocytes from oxidative stress by targeting anti-oxidative enzymes and anti-apoptotic genes.

    Directory of Open Access Journals (Sweden)

    Chuanyu Wei

    Full Text Available BACKGROUND: Thymosin beta-4 (Tβ4 is a ubiquitous protein with many properties relating to cell proliferation and differentiation that promotes wound healing and modulates inflammatory mediators. The mechanism by which Tβ4 modulates cardiac protection under oxidative stress is not known. The purpose of this study is to dissect the cardioprotective mechanism of Tβ4 on H(2O(2 induced cardiac damage. METHODS: Rat neonatal cardiomyocytes with or without Tβ4 pretreatment were exposed to H(2O(2 and expression of antioxidant, apoptotic, and anti-inflammatory genes was evaluated by quantitative real-time PCR and western blotting. ROS levels were estimated by DCF-DA using fluorescent microscopy and fluorimetry. Selected antioxidant, anti-inflammatory and antiapoptotic genes were silenced by siRNA transfections in neonatal cardiomyocytes and effect of Tβ4 on H(2O(2-induced cardiac damage was evaluated. RESULTS: Pre-treatment of Tβ4 resulted in reduction of the intracellular ROS levels induced by H(2O(2 in cardiomyocytes. Tβ4 pretreatment also resulted in an increase in the expression of antiapoptotic proteins and reduction of Bax/BCl(2 ratio in the cardiomyocytes. Pretreatment with Tβ4 resulted in stimulating the expression of antioxidant enzymes copper/zinc SOD and catalase in cardiomyocytes at both transcription and translation levels. Tβ4 treatment resulted in the increased expression of anti-apoptotic and anti-inflammatory genes. Silencing of Cu/Zn SOD and catalase gene resulted in apoptotic cell death in the cardiomyocytes which was prevented by treatment with Tβ4. CONCLUSION: This is the first report that demonstrates the effect of Tβ4 on cardiomyocytes and its capability to selectively upregulate anti-oxidative enzymes, anti-inflammatory genes, and antiapoptotic enzymes in the neonatal cardiomyocytes thus preventing cell death thereby protecting the myocardium. Tβ4 treatment resulted in decreased oxidative stress and inflammation in the

  8. Regulation of ozone-induced lung inflammation and injury by the β-galactoside-binding lectin galectin-3

    Energy Technology Data Exchange (ETDEWEB)

    Sunil, Vasanthi R., E-mail: sunilva@pharmacy.rutgers.edu [Department of Pharmacology and Toxicology, Rutgers University, Ernest Mario School of Pharmacy, Piscataway, NJ (United States); Francis, Mary, E-mail: maryfranrutgers@gmail.com [Department of Pharmacology and Toxicology, Rutgers University, Ernest Mario School of Pharmacy, Piscataway, NJ (United States); Vayas, Kinal N., E-mail: kinalv5@gmail.com [Department of Pharmacology and Toxicology, Rutgers University, Ernest Mario School of Pharmacy, Piscataway, NJ (United States); Cervelli, Jessica A., E-mail: j.cervelli@pharmacy.rutgers.edu [Department of Pharmacology and Toxicology, Rutgers University, Ernest Mario School of Pharmacy, Piscataway, NJ (United States); Choi, Hyejeong, E-mail: choi@eohsi.rutgers.edu [Department of Pharmacology and Toxicology, Rutgers University, Ernest Mario School of Pharmacy, Piscataway, NJ (United States); Laskin, Jeffrey D., E-mail: jlaskin@eohsi.rutgers.edu [Department of Environmental and Occupational Medicine, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ (United States); Laskin, Debra L., E-mail: laskin@eohsi.rutgers.edu [Department of Pharmacology and Toxicology, Rutgers University, Ernest Mario School of Pharmacy, Piscataway, NJ (United States)

    2015-04-15

    Macrophages play a dual role in ozone toxicity, contributing to both pro- and anti-inflammatory processes. Galectin-3 (Gal-3) is a lectin known to regulate macrophage activity. Herein, we analyzed the role of Gal-3 in the response of lung macrophages to ozone. Bronchoalveolar lavage (BAL) and lung tissue were collected 24–72 h after exposure (3 h) of WT and Gal-3{sup -/-} mice to air or 0.8 ppm ozone. In WT mice, ozone inhalation resulted in increased numbers of proinflammatory (Gal-3{sup +}, iNOS{sup +}) and anti-inflammatory (MR-1{sup +}) macrophages in the lungs. While accumulation of iNOS{sup +} macrophages was attenuated in Gal-3{sup -/-} mice, increased numbers of enlarged MR-1{sup +} macrophages were noted. This correlated with increased numbers of macrophages in BAL. Flow cytometric analysis showed that these cells were CD11b{sup +} and consisted mainly (> 97%) of mature (F4/80{sup +}CD11c{sup +}) proinflammatory (Ly6GLy6C{sup hi}) and anti-inflammatory (Ly6GLy6C{sup lo}) macrophages. Increases in both macrophage subpopulations were observed following ozone inhalation. Loss of Gal-3 resulted in a decrease in Ly6C{sup hi} macrophages, with no effect on Ly6C{sup lo} macrophages. CD11b{sup +}Ly6G{sup +}Ly6C{sup +} granulocytic (G) and monocytic (M) myeloid derived suppressor cells (MDSC) were also identified in the lung after ozone. In Gal-3{sup -/-} mice, the response of G-MDSC to ozone was attenuated, while the response of M-MDSC was heightened. Changes in inflammatory cell populations in the lung of ozone treated Gal-3{sup -/-} mice were correlated with reduced tissue injury as measured by cytochrome b5 expression. These data demonstrate that Gal-3 plays a role in promoting proinflammatory macrophage accumulation and toxicity in the lung following ozone exposure. - Highlights: • Multiple monocytic-macrophage subpopulations accumulate in the lung after ozone inhalation. • Galectin-3 plays a proinflammatory role in ozone-induced lung injury. • In the

  9. Regulation of ozone-induced lung inflammation and injury by the β-galactoside-binding lectin galectin-3

    International Nuclear Information System (INIS)

    Macrophages play a dual role in ozone toxicity, contributing to both pro- and anti-inflammatory processes. Galectin-3 (Gal-3) is a lectin known to regulate macrophage activity. Herein, we analyzed the role of Gal-3 in the response of lung macrophages to ozone. Bronchoalveolar lavage (BAL) and lung tissue were collected 24–72 h after exposure (3 h) of WT and Gal-3-/- mice to air or 0.8 ppm ozone. In WT mice, ozone inhalation resulted in increased numbers of proinflammatory (Gal-3+, iNOS+) and anti-inflammatory (MR-1+) macrophages in the lungs. While accumulation of iNOS+ macrophages was attenuated in Gal-3-/- mice, increased numbers of enlarged MR-1+ macrophages were noted. This correlated with increased numbers of macrophages in BAL. Flow cytometric analysis showed that these cells were CD11b+ and consisted mainly (> 97%) of mature (F4/80+CD11c+) proinflammatory (Ly6GLy6Chi) and anti-inflammatory (Ly6GLy6Clo) macrophages. Increases in both macrophage subpopulations were observed following ozone inhalation. Loss of Gal-3 resulted in a decrease in Ly6Chi macrophages, with no effect on Ly6Clo macrophages. CD11b+Ly6G+Ly6C+ granulocytic (G) and monocytic (M) myeloid derived suppressor cells (MDSC) were also identified in the lung after ozone. In Gal-3-/- mice, the response of G-MDSC to ozone was attenuated, while the response of M-MDSC was heightened. Changes in inflammatory cell populations in the lung of ozone treated Gal-3-/- mice were correlated with reduced tissue injury as measured by cytochrome b5 expression. These data demonstrate that Gal-3 plays a role in promoting proinflammatory macrophage accumulation and toxicity in the lung following ozone exposure. - Highlights: • Multiple monocytic-macrophage subpopulations accumulate in the lung after ozone inhalation. • Galectin-3 plays a proinflammatory role in ozone-induced lung injury. • In the absence of gal-3, inflammatory cells with a myeloid derived suppressor cell phenotype contribute to tissue repair

  10. Histone deacetylase inhibitors strongly sensitise neuroblastoma cells to TRAIL-induced apoptosis by a caspases-dependent increase of the pro- to anti-apoptotic proteins ratio

    International Nuclear Information System (INIS)

    Neuroblastoma (NB) is the second most common solid childhood tumour, an aggressive disease for which new therapeutic strategies are strongly needed. Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis in most tumour cells, but not in normal tissues and therefore represents a valuable candidate in apoptosis-inducing therapies. Caspase-8 is silenced in a subset of highly malignant NB cells, which results in full TRAIL resistance. In addition, despite constitutive caspase-8 expression, or its possible restoration by different strategies, NB cells remain weakly sensitive to TRAIL indicating a need to develop strategies to sensitise NB cells to TRAIL. Histone deacetylase inhibitors (HDACIs) are a new class of anti-cancer agent inducing apoptosis or cell cycle arrest in tumour cells with very low toxicity toward normal cells. Although HDACIs were recently shown to increase death induced by TRAIL in weakly TRAIL-sensitive tumour cells, the precise involved sensitisation mechanisms have not been fully identified. NB cell lines were treated with various doses of HDACIs and TRAIL, then cytotoxicity was analysed by MTS/PMS proliferation assays, apoptosis was measured by the Propidium staining method, caspases activity by colorimetric protease assays, and (in)activation of apoptotic proteins by immunoblotting. Sub-toxic doses of HDACIs strongly sensitised caspase-8 positive NB cell lines to TRAIL induced apoptosis in a caspases dependent manner. Combined treatments increased the activation of caspases and Bid, and the inactivation of the anti-apoptotic proteins XIAP, Bcl-x, RIP, and survivin, thereby increasing the pro- to anti-apoptotic protein ratio. It also enhanced the activation of the mitochondrial pathway. Interestingly, the kinetics of caspases activation and inactivation of anti-apoptotic proteins is accelerated by combined treatment with TRAIL and HDACIs compared to TRAIL alone. In contrast, cell surface expression of TRAIL

  11. 半乳糖凝集素-3与垂体泌乳素瘤细胞增殖的关系%Relationship between the expression of galectin-3 and proliferation of prolactinoma

    Institute of Scientific and Technical Information of China (English)

    蒲建章; 赵洪洋; 苏群

    2006-01-01

    目的探讨半乳糖凝集素-3(Galectin-3)表达和人脑垂体泌乳素腺瘤细胞增殖的关系.方法应用免疫组化SP法检测38例垂体泌乳素腺瘤组织中Galectin-3及增殖细胞核抗原(PCNA)表达.结果侵袭组的Galectin-3阳性表达率极显著高于非侵袭组(P《0.01).侵袭组的PCNA阳性表达率显著高于非侵袭组(P《0.05).Galectin-3与PCNA表达之间呈正相关(r=0.33,P《0.05).结论 Galectin-3与垂体泌乳素腺瘤细胞增殖密切相关,Galectin-3可能在垂体PRL腺瘤的细胞增殖和侵袭过程中起重要作用.

  12. Gene Expression Profiling in Lungs of Chronic Asthmatic Mice Treated with Galectin-3: Downregulation of Inflammatory and Regulatory Genes

    Directory of Open Access Journals (Sweden)

    Esther López

    2011-01-01

    Full Text Available Background. Asthma is a disorder characterized by a predominance of Th2 cells and eosinophilic inflammation. Suppressors of cytokine signaling (SOCS proteins act as negative regulators of cytokine signaling. In particular, SOCS1 and SOCS3 play an important role in immune response by controlling the balance between Th1 and Th2 cells. In a previous study, we demonstrated that treatment of chronic asthmatic mice with gene therapy using plasmid encoding galectin-3 (Gal-3 led to an improvement in Th2 allergic inflammation. Methods. Using a microarray approach, this study endeavored to evaluate the changes produced by therapeutic Gal-3 delivered by gene therapy in a well-characterized mouse model of chronic airway inflammation. Results were confirmed by real-time RT-PCR, Western blot and immunohistochemical analysis. Results. We identify a set of genes involved in different pathways whose expression is coordinately decreased/increased in mice treated with Gal-3 gene therapy. We report a correlation between Gal-3 treatment and inhibition of SOCS1 and SOCS3 expression in lungs. Conclusion. These results suggest that negative regulation of SOCS1 and 3 following Gal-3 treatment could be a valuable therapeutic approach in allergic disease.

  13. Cell surface galectin-3 defines a subset of chemoresistant gastrointestinal tumor-initiating cancer cells with heightened stem cell characteristics.

    Science.gov (United States)

    Ilmer, Matthias; Mazurek, Nachman; Byrd, James C; Ramirez, Karen; Hafley, Margarete; Alt, Eckhard; Vykoukal, Jody; Bresalier, Robert S

    2016-01-01

    Recurrence of gastrointestinal adenocarcinomas after surgery and chemotherapy may be attributed, in part, to the presence of a small population of tumor-initiating cancer stem cells (CSC). The expression of galectin-3 (Gal3), a multifunctional oncolectin, has been associated with biological behaviors associated with CSC. We examined the ability of Gal3 to characterize the CSC phenotype, and to identify a clinically important gastrointestinal cancer CSC population. Human colorectal and pancreatic cancer cell lines were sorted to identify subpopulations expressing commonly used CSC markers, and Gal3-positive CSC subpopulations. The association of Gal3 with the stem cell properties and alterations of these phenotypes by manipulation of Gal3 expression was examined. Gastrointestinal cancer cell lines contain both Gal3-positive and Gal3-negative subpopulations. Gal3-positive CSCs are characterized by high ALDH activity, enhanced self-renewal ability in vitro (sphere formation) and tumor forming ability in vivo, and resistance to chemotherapeutic agents and death-receptor-mediated apoptosis compared to Gal3-negative CSCs. Silencing Gal3 modifies this behavior. Cell surface Gal3 expression identifies a subset of CSCs in gastrointestinal cancers with high levels of stem cell characteristics, including chemoresistance. This may provide a platform for developing treatment strategies that target CSC. PMID:27512958

  14. Cod glycopeptide with picomolar affinity to galectin-3 suppresses T-cell apoptosis and prostate cancer metastasis.

    Science.gov (United States)

    Guha, Prasun; Kaptan, Engin; Bandyopadhyaya, Gargi; Kaczanowska, Sabina; Davila, Eduardo; Thompson, Keyata; Martin, Stuart S; Kalvakolanu, Dhananjaya V; Vasta, Gerardo R; Ahmed, Hafiz

    2013-03-26

    Cancer metastasis and immune suppression are critical issues in cancer therapy. Here, we show that a β-galactoside-binding lectin [galectin-3 (gal3)] that recognizes the Thomsen-Friedenreich disaccharide (TFD, Galβ1,3GalNAc) present on the surface of most cancer cells is involved in promoting angiogenesis, tumor-endothelial cell adhesion, and metastasis of prostate cancer cells, as well as evading immune surveillance through killing of activated T cells. To block gal3-mediated interactions, we purified a glycopeptide from cod (designated TFD100) that binds gal3 with picomolar affinity. TFD100 blocks gal3-mediated angiogenesis, tumor-endothelial cell interactions, and metastasis of prostate cancer cells in mice at nanomolar levels. Moreover, apoptosis of activated T cells induced by either recombinant gal3 or prostate cancer patient serum-associated gal3 was inhibited at nanomolar concentration of TFD100. Because the gal3-TFD interaction is a key factor driving metastasis in most epithelial cancers, this high-affinity TFD100 should be a promising antimetastatic agent for the treatment of various cancers, including prostate adenocarcinoma. PMID:23479624

  15. Deletion of Galectin-3 Enhances Xenobiotic Induced Murine Primary Biliary Cholangitis by Facilitating Apoptosis of BECs and Release of Autoantigens.

    Science.gov (United States)

    Arsenijevic, Aleksandar; Milovanovic, Marija; Milovanovic, Jelena; Stojanovic, Bojana; Zdravkovic, Natasa; Leung, Patrick S C; Liu, Fu-Tong; Gershwin, M Eric; Lukic, Miodrag L

    2016-01-01

    Galectin-3 (Gal-3) is a carbohydrate binding lectin, with multiple roles in inflammatory diseases and autoimmunity including its antiapoptotic effect on epithelial cells. In particular, increased expression of Gal-3 in epithelial cells is protective from apoptosis. Based on the thesis that apoptosis of biliary epithelial cells (BECs) is critical to the pathogenesis of Primary Biliary Cholangitis (PBC), we have analyzed the role of Gal-3 in the murine model of autoimmune cholangitis. We took advantage of Gal-3 knockout mice and immunized them with a mimotope of the major mitochondrial autoantigen of PBC, 2-octynoic acid (2-OA) coupled to BSA (2OA-BSA) and evaluated the natural history of subsequent disease, compared to control wild-type mice, by measuring levels of antibodies to PDC-E2, immunohistology of liver, and expression of Gal-3. We report herein that deletion of Gal-3 significantly exacerbates autoimmune cholangitis in these mice. This is manifested by increased periportal infiltrations, bile duct damage, granulomas and fibrosis. Interestingly, the BECs of Gal-3 knockout mice had a higher response to apoptotic stimuli and there were more pro-inflammatory lymphocytes and dendritic cells (DCs) in the livers of Gal-3 knockout mice. In conclusion, Gal-3 plays a protective role in the pathways that lead to the inflammatory destruction of biliary epithelial cells. PMID:26996208

  16. ROLE OF PANCREATIC STELLATE CELLS AND GALECTIN-3 ON PROLIFERATION AND INFILTRATION OF HUMAN PANCREATIC CANCER CELL LINE SW1990

    Institute of Scientific and Technical Information of China (English)

    JIANG Hai-biao; XU Ming; WANG Xing-peng

    2008-01-01

    Objective To investigate the role of pancreatic stellate cells (PSCs) and galectin-3 (GAL-3)on the proliferation and infiltration of pancreatic cancer cell line SW1990. Methods Human pancreatic cancercell line SW1990 and PSCs were cultured in vitro. Supernatant of cultured PSCs and SW1990 cells was collected.Expressions of GAL-3 in SW1990 cells and PSCs were detected by ELISA, RT-PCR and Western blot. Theproliferation of those cultured PSCs and SW1990 cells were measured by MTT assay and flowcytometry. Infiltrationof SW1990 cells was detected by cell infiltration kit. Results SW1990 cells expressed GAL-3 and the expressionwas up-regulated by the supernatant fluid of cultured PSCs. PSCs did not express GAL-3. SW1990 cells couldstimulate the proliferation of PSCs via GAL-3. GAL-3 antibody could inhibit SW1990 cells proliferation andinfiltration, which indicated that supernatant of PSCs might stimulate the proliferation of SW1990 cells through theinteraction with GAL-3 protein. The supernatant fluid of PSCs could enhance the invasiveness of SW1990 cellsthrough the interaction with GAL-3. Conclusion GAL-3 and PSCs was involved in the proliferation andinfiltration process of pancreatic cancer.

  17. PACS-2 mediates the ATM and NF-κB-dependent induction of anti-apoptotic Bcl-xL in response to DNA damage.

    Science.gov (United States)

    Barroso-González, J; Auclair, S; Luan, S; Thomas, L; Atkins, K M; Aslan, J E; Thomas, L L; Zhao, J; Zhao, Y; Thomas, G

    2016-09-01

    Nuclear factor kappa B (NF-κB) promotes cell survival in response to genotoxic stress by inducing the expression of anti-apoptotic proteins including Bcl-xL, which protects mitochondria from stress-induced mitochondrial outer membrane permeabilization (MOMP). Here we show that the multifunctional sorting protein Pacs-2 (phosphofurin acidic cluster sorting protein-2) is required for Bcl-xL induction following DNA damage in primary mouse thymocytes. Consequently, in response to DNA damage, Pacs-2(-/-) thymocytes exhibit a blunted induction of Bcl-xL, increased MOMP and accelerated apoptosis. Biochemical studies show that cytoplasmic PACS-2 promotes this DNA damage-induced anti-apoptotic pathway by interacting with ataxia telangiectasia mutated (ATM) to drive NF-κB activation and induction of Bcl-xL. However, Pacs-2 was not required for tumor necrosis factor-α-induced NF-κB activation, suggesting a role for PACS-2 selectively in NF-κB activation in response to DNA damage. These findings identify PACS-2 as an in vivo mediator of the ATM and NF-κB-dependent induction of Bcl-xL that promotes cell survival in response to DNA damage. PMID:26943323

  18. Tumor targeting and SPECT imaging properties of an {sup 111}In-labeled galectin-3 binding peptide in prostate carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Deutscher, Susan L. [Department of Biochemistry, University of Missouri-Columbia School of Medicine, Columbia, MO 65211 (United States); Research Division, Harry S. Truman Veterans Hospital, Columbia, MO 65201 (United States); Figueroa, Said D. [Research Division, Harry S. Truman Veterans Hospital, Columbia, MO 65201 (United States); Kumar, Senthil R. [Department of Biochemistry, University of Missouri-Columbia School of Medicine, Columbia, MO 65211 (United States)], E-mail: kumars@missouri.edu

    2009-02-15

    Introduction: Galectin-3 (gal-3) is a carbohydrate binding protein that has been implicated in cell adhesion, tumor invasion and metastasis. The objective of this study was to evaluate the tumor targeting and imaging properties of a gal-3 binding peptide selected by phage display in a mouse model of metastatic human prostate carcinoma expressing gal-3. Methods: A gal-3 binding peptide, ANTPCGPYTHDCPVKR, was synthesized with a Gly-Ser-Gly (GSG) spacer and 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA) and then radiolabeled with {sup 111}In. The in vitro cell binding properties of {sup 111}In-DOTA-(GSG)-ANTPCGPYTHDCPVKR were determined in metastatic human PC3-M prostate carcinoma cells. The pharmacokinetics and single-photon emission computed tomographic (SPECT/CT) imaging with the radiolabeled peptide were evaluated in SCID mice bearing human PC3-M prostate carcinoma tumor xenografts. Results: The radiolabeled peptide bound with a 50% inhibitory concentration of 191{+-}10.2 nM to cultured PC3-M prostate carcinoma cells. In vivo tumor uptake and retention coupled with fast whole-body clearance of the peptide were demonstrated in PC3-M tumor-bearing SCID mice. The tumor uptake rates of the radiolabeled peptide were 1.27{+-}0.10%ID/g at 30 min, 0.82{+-}0.15%ID/g at 1 h and 0.57{+-}0.09%ID/g at 2 h. MicroSPECT/CT studies revealed good tumor uptake of {sup 111}In-DOTA-(GSG)-ANTPCGPYTHDCPVKR 2 h postinjection, while uptake in normal organs was low, with the exception of the kidneys. Conclusions: In vitro cell binding along with tumor uptake of {sup 111}In-DOTA-(GSG)-ANTPCGPYTHDCPVKR in PC3-M human prostate carcinoma tumor-bearing SCID mice suggests the potential of this peptide as a radiopharmaceutical for imaging of gal-3-expressing prostate tumors.

  19. Targeting anti-apoptotic Bcl-2 by AT-101 to increase radiation efficacy: data from in vitro and clinical pharmacokinetic studies in head and neck cancer

    International Nuclear Information System (INIS)

    Pro-survival Bcl-2 family members can promote cancer development and contribute to treatment resistance. Head and neck squamous cell carcinoma (HNSCC) is frequently characterized by overexpression of anti-apoptotic Bcl-2 family members. Increased levels of these anti-apoptotic proteins have been associated with radio- and chemoresistance and poor clinical outcome. Inhibition of anti-apoptotic Bcl-2 family members therefore represents an appealing strategy to overcome resistance to anti-cancer therapies. The aim of this study was to evaluate combined effects of radiation and the pan-Bcl-2 inhibitor AT-101 in HNSCC in vitro. In addition, we determined human plasma levels of AT-101 obtained from a phase I/II trial, and compared these with the effective in vitro concentrations to substantiate therapeutic opportunities. We examined the effect of AT-101, radiation and the combination on apoptosis induction and clonogenic survival in two HNSCC cell lines that express the target proteins. Apoptosis was assessed by bis-benzimide staining to detect morphological nuclear changes and/or by propidium iodide staining and flow-cytometry analysis to quantify sub-diploid apoptotic nuclei. The type of interaction between AT-101 and radiation was evaluated by calculating the Combination Index (CI) and by performing isobolographic analysis. For the pharmacokinetic analysis, plasma AT-101 levels were measured by HPLC in blood samples collected from patients enrolled in our clinical phase I/II study. These patients with locally advanced HNSCC were treated with standard cisplatin-based chemoradiotherapy and received dose-escalating oral AT-101 in a 2-weeks daily schedule every 3 weeks. In vitro results showed that AT-101 enhances radiation-induced apoptosis with CI’s below 1.0, indicating synergy. This effect was sequence-dependent. Clonogenic survival assays demonstrated a radiosensitizing effect with a DEF37 of 1.3 at sub-apoptotic concentrations of AT-101. Pharmacokinetic analysis

  20. Analysis of effects by CK19, TPO, galectin-3 and HBME-1 protein expression for pathological diagnosis of thyroid tumor%CK19、TPO、Galectin-3与 HBME-1蛋白表达对甲状腺肿瘤病理诊断作用分析

    Institute of Scientific and Technical Information of China (English)

    郭健; 张世豪; 延丽雅; 陈辉娥

    2015-01-01

    Objective To investigate the expressions of cytokeratin 19 (CK19), thyroid peroxidase (TPO), Galectin-3, and human bone marrow endothelial cell markers (HBME-1) in thyroid lesions and their effects for pathological diagnosis of thyroid tumor. Methods Pathological samples were collected in 134 cases of thyroid cancer (123 cases of papillary carcinoma and 11 cases of follicular carcinoma), 34 cases of thyroid adenoma, 20 cases of nodositas goiter and 10 cases of Hashimoto thyroiditis. Their expressions of CK19, TPO, Galectin-3, and HBME-1 were detected. Results The difference of CK19, TPO, Galectin-3, and HBME-1 expressions between benign and malignant tissues in thyroid tumor had statistical significance (P<0.05). Combined detection of four indicators had the sensitivity and specificity as 96.3% and 100.0% for diagnosis of benign and malignant thyroid tumor. Conclusion In malignant thyroid tumor, the positive expressions of CK19, Galectin-3, and HBME-1 were increased, while that of TPO was deficient. Combined detection of four indicators provides important diagnostic value for benign and malignant thyroid tumor.%目的:探讨甲状腺病变中的细胞角蛋白19(CK19)、甲状腺过氧化物酶(TPO)、半乳糖凝集素-3(Galectin-3)与人骨髓内皮细胞标记物(HBME-1)表达及其对甲状腺肿瘤病理诊断的价值。方法收集134例甲状腺癌(123例乳头状癌和11例滤泡癌)、34例甲状腺腺瘤、20例结节性甲状腺腺肿以及10例桥本甲状腺炎患者的病理标本,检测其 CK19、TPO、Galectin-3与 HBME-1的表达情况。结果CK19、TPO、Galectin-3与 HBME-1在甲状腺肿瘤良性组织和恶性组织中的阳性表达率比较,差异有统计学意义(P<0.05);四项指标联合检测对于甲状腺肿瘤良恶性诊断的敏感度和特异度分别为96.3%和100.0%。结论甲状腺恶性肿瘤中 CK19、Galectin-3与 HBME-1阳性表达增高,而 TPO 表达缺失,四项指标联合检测对于甲状腺肿瘤良恶

  1. Kaurene diterpene induces apoptosis in U87 human malignant glioblastoma cells by suppression of anti-apoptotic signals and activation of cysteine proteases

    Energy Technology Data Exchange (ETDEWEB)

    Lizarte, F.S. Neto; Tirapelli, D.P.C. [Universidade de São Paulo, Departamento de Cirurgia e Anatomia, Faculdade de Medicina de Ribeirão Preto, Ribeirão Preto, SP (Brazil); Ambrosio, S.R. [Universidade de Franca, Núcleo de Pesquisa em Ciências e Tecnologia, Franca, SP (Brazil); Tirapelli, C.R. [Universidade de São Paulo, Laboratório de Farmacologia, Departamento de Enfermagem Psiquiátrica e Ciências Humanas, Escola de Enfermagem de Ribeirão Preto, Ribeirão Preto, SP (Brazil); Oliveira, F.M. [Universidade de São Paulo, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Ribeirão Preto, SP (Brazil); Novais, P.C. [Universidade de São Paulo, Departamento de Cirurgia e Anatomia, Faculdade de Medicina de Ribeirão Preto, Ribeirão Preto, SP (Brazil); Peria, F.M.; Oliveira, H.F. [Universidade de São Paulo, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Ribeirão Preto, SP (Brazil); Carlotti, C.G. Junior; Tirapelli, L.F. [Universidade de São Paulo, Departamento de Cirurgia e Anatomia, Faculdade de Medicina de Ribeirão Preto, Ribeirão Preto, SP (Brazil)

    2013-01-11

    Gliomas are the most common and malignant primary brain tumors in humans. Studies have shown that classes of kaurene diterpene have anti-tumor activity related to their ability to induce apoptosis. We investigated the response of the human glioblastoma cell line U87 to treatment with ent-kaur-16-en-19-oic acid (kaurenoic acid, KA). We analyzed cell survival and the induction of apoptosis using flow cytometry and annexin V staining. Additionally, the expression of anti-apoptotic (c-FLIP and miR-21) and apoptotic (Fas, caspase-3 and caspase-8) genes was analyzed by relative quantification (real-time PCR) of mRNA levels in U87 cells that were either untreated or treated with KA (30, 50, or 70 µM) for 24, 48, and 72 h. U87 cells treated with KA demonstrated reduced viability, and an increase in annexin V- and annexin V/PI-positive cells was observed. The percentage of apoptotic cells was 9% for control cells, 26% for cells submitted to 48 h of treatment with 50 µM KA, and 31% for cells submitted to 48 h of treatment with 70 µM KA. Similarly, in U87 cells treated with KA for 48 h, we observed an increase in the expression of apoptotic genes (caspase-8, -3) and a decrease in the expression of anti-apoptotic genes (miR-21 and c-FLIP). KA possesses several interesting properties and induces apoptosis through a unique mechanism. Further experiments will be necessary to determine if KA may be used as a lead compound for the development of new chemotherapeutic drugs for the treatment of primary brain tumors.

  2. Anti-apoptotic activity of caffeic acid, ellagic acid and ferulic acid in normal human peripheral blood mononuclear cells: a Bcl-2 independent mechanism.

    Science.gov (United States)

    Khanduja, Krishan Lal; Avti, Pramod Kumar; Kumar, Surender; Mittal, Nidhi; Sohi, Kiranjit Kaur; Pathak, Chander Mohan

    2006-02-01

    Polyphenols have been shown to induce apoptosis in a variety of tumor cells including leukemia both in vitro and in vivo. However, their action on normal human peripheral blood mononuclear cells (PBMCs) during oxidative stress remains to be explored. In this study, we have evaluated the anti-apoptotic and radical scavenging activities of dietary phenolics, namely caffeic acid (CA), ellagic acid (EA) and ferulic acid (FA). H2O2-induced apoptosis in normal human PBMCs was assayed by phosphotidylserine externalization, nucleosomal damage and DNA fragmentation. Incubation of PBMCs with 5 mM H2O2 led to increased Annexin-V binding to externalized phosphatidyl serine (PS), an event of pre-apoptotic stage of the cell. Peripheral blood mononuclear cells pretreated with phenolics could resist H2O2-induced apoptotic damage. Caffeic acid (60 and 120 microM) and EA (100 and 200 microM) caused no change in externalization of PS, whereas FA (100 and 200 microM) increased externalization of PS in PBMCs treated with H2O2. The effects of phenolics were abolished to a large extent by culturing the PBMCs for 24 h after washing the phenolics from the medium. Inhibitory activities of these phenolics on lipid peroxidation were in the order of EAanti-apoptotic effect of EA, CA and FA in PBMCs seems to be through the Bcl-2 independent mechanism. PMID:16459021

  3. Kaurene diterpene induces apoptosis in U87 human malignant glioblastoma cells by suppression of anti-apoptotic signals and activation of cysteine proteases

    International Nuclear Information System (INIS)

    Gliomas are the most common and malignant primary brain tumors in humans. Studies have shown that classes of kaurene diterpene have anti-tumor activity related to their ability to induce apoptosis. We investigated the response of the human glioblastoma cell line U87 to treatment with ent-kaur-16-en-19-oic acid (kaurenoic acid, KA). We analyzed cell survival and the induction of apoptosis using flow cytometry and annexin V staining. Additionally, the expression of anti-apoptotic (c-FLIP and miR-21) and apoptotic (Fas, caspase-3 and caspase-8) genes was analyzed by relative quantification (real-time PCR) of mRNA levels in U87 cells that were either untreated or treated with KA (30, 50, or 70 µM) for 24, 48, and 72 h. U87 cells treated with KA demonstrated reduced viability, and an increase in annexin V- and annexin V/PI-positive cells was observed. The percentage of apoptotic cells was 9% for control cells, 26% for cells submitted to 48 h of treatment with 50 µM KA, and 31% for cells submitted to 48 h of treatment with 70 µM KA. Similarly, in U87 cells treated with KA for 48 h, we observed an increase in the expression of apoptotic genes (caspase-8, -3) and a decrease in the expression of anti-apoptotic genes (miR-21 and c-FLIP). KA possesses several interesting properties and induces apoptosis through a unique mechanism. Further experiments will be necessary to determine if KA may be used as a lead compound for the development of new chemotherapeutic drugs for the treatment of primary brain tumors

  4. Thymoquinone Ameliorates Cadmium-Induced Nephrotoxicity, Apoptosis, and Oxidative Stress in Rats is Based on its Anti-Apoptotic and Anti-Oxidant Properties.

    Science.gov (United States)

    Erboga, Mustafa; Kanter, Mehmet; Aktas, Cevat; Sener, Umit; Fidanol Erboga, Zeynep; Bozdemir Donmez, Yeliz; Gurel, Ahmet

    2016-03-01

    Cadmium (Cd), an environmental and industrial pollutant, generates free radicals responsible for oxidative stress. Cd can also lead to various renal toxic damage such as the proximal tubules and glomerulus dysfunction. Thymoquinone (TQ) is the main constituent of the essential oil obtained from black seeds (Nigella sativa) and has various pharmacological effects. The aim of the present study was to examine the nephroprotective, anti-oxidant, and anti-apoptotic effect of the TQ against Cd-induced nephrotoxicity. A total of 24 male Wistar albino rats were divided into three groups: control, Cd-treated, and Cd-treated with TQ; each group contain eight animals. The Cd-treated group was injected subcutaneously with CdCl2 dissolved in saline in the amount of 2 ml/kg/day for 30 days, resulting in a dosage of 1 mg/kg Cd. The rats in TQ-treated groups were given TQ (50 mg/kg body weight) once a day orally together with first Cd injection during the study period. The histopathological studies in the kidney of rats also showed that TQ markedly reduced the toxicity of Cd and preserved the normal histological architecture of the renal tissue. Immunohistochemical analysis revealed that TQ significantly decreased the Cd-induced over expression of nuclear factor-κB in renal tissue. Furthermore, TQ treatment resulted in decreased the number of apoptotic cells. TQ significantly suppressed lipid peroxidation, compensated deficits in the anti-oxidant defenses (reduced superoxide dismutase, glutathione peroxidase and catalase activities) in renal tissue resulted from Cd administration. These findings suggest that the nephroprotective potential of TQ in Cd toxicity might be due to its anti-oxidant and anti-apoptotic properties, which could be useful for achieving optimum effects in Cd-induced nephrotoxicity. PMID:26226832

  5. Mitogenic and Anti-apoptotic Effects of Insulin in En-dometrial Cancer Cells Are Phosphatidylinositol 3-ki-nase/Akt Dependent

    Institute of Scientific and Technical Information of China (English)

    Shaofang HUA; Fengxia XUE; Jing ZHAO

    2009-01-01

    Background and objective Endometrial carcinoma is the most common gynecologic malignancy in the world. Although the insulin-resistant state or hyperinsulinemia was recently suggested as a potent risk factor for endometrial carcinogenesis and progression, there is only limited supporting evidence and the mechanism is unclear. In this study, we explored the roles of phosphatidylinositol 3-k/nase (PI3K)/Akt signaling pathway in the response of a human endometrial cancer cell line, Ishikawa3-H-12 cells, to insulin.Methods The Ishikawa 3-H-12 cells were serum-starved and then stimulated by insulin at various concentrations and for different time periods. To identify the insnlin-mediated signal pathway in the cells, LY294002, a selective inhibitor of PI3K, was used. The proliferation and the apoptotic rates were determined with methyl thiazolyl tetrazolium (MTT) and flow cytometric assays, respectively.Results The insulin receptor positive Ishikawa 3-H-12 cells had enhanced proliferation upon insulin stimulation in a rinse-and time-dependent manner. The growth promoting effect of insulin was blocked when the cells were pre-incubated with LY294002 for 60 rains.Insulin was able to protect the cells from serum-starvation-induced apoptosis in a concentration-dependent manner, while the anti-apoptotic effects of insulin was reversed by adding LY294002. Treatment with insulin at 1 μM for 15 rain resulted in an increased level of activated Akt The insulin-induced Akt activation was inhibited by LY294002 in a dose-dependent manner.Conclusion Insulin activates PI3K/Akt signaling pathway and is a mitogenic and anti-apoptotic agent for Ishikewa 3-H-12 endometrial cancer cells.

  6. CK19、Galectin-3在甲状腺良恶性肿瘤中的表达及其临床意义%The Expression of CK19,Galectin-3 in Benign and Malignant Thyroid Tumor and Its Clinical Significance

    Institute of Scientific and Technical Information of China (English)

    杜岗; 马艳波

    2014-01-01

    目的:检测细胞角蛋白-19(CK19)、半乳糖凝集素-3(Galectin-3)在甲状腺良恶性肿瘤中的表达情况,探讨其在鉴别诊断甲状腺良恶性肿瘤中的临床意义。方法:收集2012年1月-2013年12月在山西医科大学第一附属医院行手术切除并且经病理证实的80例甲状腺肿瘤组织标本,包括40例甲状腺癌手术标本、40例甲状腺瘤手术标本,采用免疫组化技术检测CK19、Galectin-3在甲状腺良恶性肿瘤中的表达情况,实验结果根据阳性细胞的百分率和染色强度进行评价,两组间样本率的比较用独立样本字2检验(检验水准α=0.0167),应用灵敏度、特异度及诊断符合率评价CK19、Galectin-3在鉴别诊断甲状腺良恶性肿瘤中的价值。结果:CK19在甲状腺癌和甲状腺瘤中的阳性率分别为100%(40/40)、37.50%(15/40),差异具有统计学意义(P<0.001),CK19在鉴别诊断甲状腺良恶性肿瘤中的评价结果显示:灵敏度为100%、特异度为62.50%、诊断符合率为81.25%;Galectin-3在甲状腺癌和甲状腺瘤中的阳性率分别为80.00%(32/40)、25.00%(10/40),差异具有统计学意义(P<0.001),Galectin-3在鉴别诊断甲状腺良恶性肿瘤中的评价结果显示:灵敏度为80.00%、特异度为75.00%、诊断符合率为77.50%。结论:CK19、Galectin-3在甲状腺癌中的阳性表达明显增强,可作为鉴别诊断甲状腺良恶性肿瘤的重要辅助指标,联合检测可提高甲状腺癌的诊断率。%Objective:To detect the expression of CK19,Galectin-3 in benign and malignant thyroid tumor,and to investigate the clinical significance in the differential diagnosis of benign and malignant thyroid tumor.Method:80 cases of thyroid tumor tissue specimens between January 2012 to December 2013 were collected from the first affiliated hospital of Shanxi Medical University.All specimens had been proved by pathology,including 40 cases of

  7. Inhibition of Advanced Glycation and Absence of Galectin-3 Prevent Blood-Retinal Barrier Dysfunction during Short-Term Diabetes

    Directory of Open Access Journals (Sweden)

    Paul Canning

    2007-01-01

    Full Text Available Breakdown of the inner blood-retinal barrier (iBRB occurs early in diabetes and is central to the development of sight-threatening diabetic macular edema (DME as retinopathy progresses. In the current study, we examined how advanced glycation end products (AGEs forming early in diabetes could modulate vasopermeability factor expression in the diabetic retina and alter inter-endothelial cell tight junction (TJ integrity leading to iBRB dysfunction. We also investigated the potential for an AGE inhibitor to prevent this acute pathology and examined a role of the AGE-binding protein galectin-3 (Gal-3 in AGE-mediated cell retinal pathophysiology. Diabetes was induced in C57/BL6 wild-type (WT mice and in Gal-3−/− transgenic mice. Blood glucose was monitored and AGE levels were quantified by ELISA and immunohistochemistry. The diabetic groups were subdivided, and one group was treated with the AGE-inhibitor pyridoxamine (PM while separate groups of WT and Gal-3−/− mice were maintained as nondiabetic controls. iBRB integrity was assessed by Evans blue assay alongside visualisation of TJ protein complexes via occludin-1 immunolocalization in retinal flat mounts. Retinal expression levels of the vasopermeability factor VEGF were quantified using real-time RT-PCR and ELISA. WT diabetic mice showed significant AGE -immunoreactivity in the retinal microvasculature and also showed significant iBRB breakdown (P<.005. These diabetics had higher VEGF mRNA and protein expression in comparison to controls (P<.01. PM-treated diabetics had normal iBRB function and significantly reduced diabetes-mediated VEGF expression. Diabetic retinal vessels showed disrupted TJ integrity when compared to controls, while PM-treated diabetics demonstrated near-normal configuration. Gal-3−/− mice showed significantly less diabetes-mediated iBRB dysfunction, junctional disruption, and VEGF expression changes than their WT counterparts. The data suggests an AGE

  8. Galectin-3 mediates cross-talk between K-Ras and Let-7c tumor suppressor microRNA.

    Directory of Open Access Journals (Sweden)

    Ran Levy

    Full Text Available BACKGROUND: Galectin-3 (Gal-3 and active (GTP-bound K-Ras contribute to the malignant phenotype of many human tumors by increasing the rate of cell proliferation, survival, and migration. These Gal-3-mediated effects result from a selective binding to K-Ras.GTP, causing increased nanoclustering in the cell membrane and leading to robust Ras signaling. Regulation of the interactions between Gal-3 and active K-Ras is not fully understood. METHODS AND FINDINGS: To gain a better understanding of what regulates the critical interactions between these two proteins, we examined the role of Gal-3 in the regulation of K-Ras by using Gal-3-knockout mouse embryonic-fibroblasts (Gal-3-/- MEFs and/or Gal-3/Gal-1 double-knockout MEFs. We found that knockout of Gal-3 induced strong downregulation (∼60% of K-Ras and K-Ras.GTP. The downregulation was somewhat more marked in the double-knockout MEFs, in which we also detected robust inhibition(∼50% of ERK and Akt activation. These additional effects are probably attributable to inhibition of the weak interactions of K-Ras.GTP with Gal-1. Re-expression of Gal-3 reversed the phenotype of the Gal-3-/- MEFs and dramatically reduced the disappearance of K-Ras in the presence of cycloheximide to the levels seen in wild-type MEFs. Furthermore, phosphorylation of Gal-3 by casein kinase-1 (CK-1 induced translocation of Gal-3 from the nucleus to the cytoplasm and the plasma membrane, leading to K-Ras stabilization accompanied by downregulation of the tumor suppressor miRNA let-7c, known to negatively control K-Ras transcription. CONCLUSIONS: Our results suggest a novel cross-talk between Gal-3-mediated downregulation of let 7c microRNA (which in turn negatively regulates K-Ras transcription and elucidates the association among Gal-3 let-7c and K-Ras transcription/translation, cellular compartmentalization and activity.

  9. Expression of Pokemon and Galectin-3 proteins in gastric carcinoma tissue%胃癌组织中Pokemon和半乳糖凝集素-3蛋白的表达

    Institute of Scientific and Technical Information of China (English)

    李志猛; 乔军波; 张谢夫; 赵春临

    2010-01-01

    目的:检测胃癌组织中Pokemon和半乳糖凝集素-3(Galectin-3)蛋白的表达情况.方法:采用免疫组织化学SP法检测76例胃癌组织和16例正常胃黏膜组织中Pokemon和Galectin-3的表达,并分析其与临床病理特征的关系.结果:胃癌组织中Pokemon蛋白阳性表达率为59.2%(45/76),Galectin-3蛋白阳性表达率为82.9%(63/76),均高于正常胃黏膜组织的18.8%(3/16)和12.5%(2/16)(χ2=8.671,P=0.003;χ2=28.284,P<0.001).胃癌组织中Pokemon与Galectin-3的阳性表达与淋巴结转移(χ2分别为10.787和11.626,P均=0.001)、pTNM分期(χ2=12.903,P<0.0010;χ2=6.435,P=0.011)和浸润深度(χ2分别为11.849和11.701,P均=0.003)有关,且Pokemon与Galectin-3表达有关联(χ2=5.253,rP=0.254,P=0.022).结论:Pokemon及Galectin-3与胃癌的侵袭、转移有关.

  10. Matrigel and Activin A promote cell-cell contact and anti-apoptotic activity in cultured human retinal pigment epithelium cells.

    Science.gov (United States)

    Guo, Xiaoling; Zhu, Deliang; Lian, Ruiling; Han, Yuting; Guo, Yonglong; Li, Zhijie; Tang, Shibo; Chen, Jiansu

    2016-06-01

    Age-related macular degeneration (AMD) is a leading cause of blindness among the aging population. Currently, replacement of diseased retinal pigment epithelium (RPE) cells with transplanted healthy RPE cells could be a feasible approach for AMD therapy. However, maintaining cell-cell contact and good viability of RPE cells cultured in vitro is difficult and fundamentally determines the success of RPE cell transplantation. This study was conducted to examine the role of Matrigel and Activin A (MA) in regulating cell-cell contact and anti-apoptotic activity in human RPE (hRPE) cells, as assessed by atomic force microscopy (AFM), scanning electron microscope (SEM), immunofluorescence staining, quantitative polymerase chain reaction (qPCR) analysis, Annexin V/propidium iodide (PI) analysis, mitochondrial membrane potential (△Ψ m) assays, intracellular reactive oxygen species (ROS) assays and Western blotting. hRPE cells cultured in vitro could maintain their epithelioid morphology after MA treatment over at least 4 passages. The contact of N-cadherin to the lateral cell border was promoted in hRPE cells at P2 by MA. MA treatment also enhanced the expression of tight junction-associated genes and proteins, such as Claudin-1, Claudin-3, Occludin and ZO-1, as well as polarized ZO-1 protein distribution and barrier function, in cultured hRPE cells. Moreover, MA treatment decreased apoptotic cells, ROS and Bax and increased △Ψ m and Bcl2 in hRPE cells under serum withdrawal-induced apoptosis. In addition, MA treatment elevated the protein expression levels of β-catenin and its target proteins, including Cyclin D1, c-Myc and Survivin, as well as the gene expression levels of ZO-1, β-catenin, Survivin and TCF-4, all of which could be down-regulated by the Wnt/β-catenin pathway inhibitor XAV-939. Taken together, MA treatment could effectively promote cell-cell contact and anti-apoptotic activity in hRPE cells, partly involving the Wnt/β-catenin pathway. This study

  11. Increased ratio of anti-apoptotic to pro-apoptotic Bcl2 gene-family members in lithium-responders one month after treatment initiation

    Directory of Open Access Journals (Sweden)

    Lowthert Lori

    2012-09-01

    Full Text Available Abstract Background Lithium is considered by many as the gold standard medication in the management of bipolar disorder (BD. However, the clinical response to lithium is heterogeneous, and the molecular basis for this difference in response is unknown. In the present study, we sought to determine how the peripheral blood gene expression profiles of patients with bipolar disorder (BD changed over time following intitiation of treatment with lithium, and whether differences in those profiles over time were related to the clinical response. Methods Illumina Sentrix Beadchip (Human-6v2 microarrays containing > 48,000 transcript probes were used to measure levels of expression of gene-expression in peripheral blood from 20 depressed subjects with BD prior to and every two weeks during 8 weeks of open-label treatment with lithium. Changes in gene-expression were compared between treatment responders (defined as a decrease in the Hamilton Depression Rating Scale of 50% or more and non-responders. Pathway analysis was conducted using GeneGO Metacore software. Results 127 genes showed a differential response in responders vs. non-responders. Pathway analysis showed that regulation of apoptosis was the most significantly affected pathway among these genes. Closer examination of the time-course of changes among BCL2 related genes showed that in lithium-responders, one month after starting treatment with lithium, several anti-apoptotic genes including Bcl2 and insulin receptor substrate 2 (IRS2 were up-regulated, while pro-apoptotic genes, including BCL2-antagonist/killer 1 (BAK1 and BCL2-associated agonist of cell death (BAD, were down-regulated. In contrast, in lithium non-responders, BCL2 and IRS2 were down-regulated, while BAK1 and BAD up-regulated at the one-month time-point. Conclusions These results suggest that differential changes in the balance of pro- and anti- apoptotic gene-expression following treatment with lithium may explain some of

  12. Interaction of a putative BH3 domain of clusterin with anti-apoptotic Bcl-2 family proteins as revealed by NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong-Hwa; Ha, Ji-Hyang [Medical Proteomics Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of); Kim, Yul [Department of Bio and Brain Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Bae, Kwang-Hee [Medical Proteomics Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of); Park, Jae-Yong [Department of Physiology, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju, Gyeongnam 660-751 (Korea, Republic of); Choi, Wan Sung [Department of Anatomy and Neurobiology, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju, Gyeongnam 660-751 (Korea, Republic of); Yoon, Ho Sup [Division of Structural and Computational Biology, School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637511 (Singapore); Park, Sung Goo; Park, Byoung Chul [Medical Proteomics Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of); Yi, Gwan-Su, E-mail: gsyi@kaist.ac.kr [Department of Bio and Brain Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Chi, Seung-Wook, E-mail: swchi@kribb.re.kr [Medical Proteomics Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of)

    2011-05-20

    Highlights: {yields} Identification of a conserved BH3 motif in C-terminal coiled coil region of nCLU. {yields} The nCLU BH3 domain binds to BH3 peptide-binding grooves in both Bcl-X{sub L} and Bcl-2. {yields} A conserved binding mechanism of nCLU BH3 and the other pro-apoptotic BH3 peptides with Bcl-X{sub L}. {yields} The absolutely conserved Leu323 and Asp328 of nCLU BH3 domain are critical for binding to Bcl-X{sub L.} {yields} Molecular understanding of the pro-apoptotic function of nCLU as a novel BH3-only protein. -- Abstract: Clusterin (CLU) is a multifunctional glycoprotein that is overexpressed in prostate and breast cancers. Although CLU is known to be involved in the regulation of apoptosis and cell survival, the precise molecular mechanism underlying the pro-apoptotic function of nuclear CLU (nCLU) remains unclear. In this study, we identified a conserved BH3 motif in C-terminal coiled coil (CC2) region of nCLU by sequence analysis and characterized the molecular interaction of the putative nCLU BH3 domain with anti-apoptotic Bcl-2 family proteins by nuclear magnetic resonance (NMR) spectroscopy. The chemical shift perturbation data demonstrated that the nCLU BH3 domain binds to pro-apoptotic BH3 peptide-binding grooves in both Bcl-X{sub L} and Bcl-2. A structural model of the Bcl-X{sub L}/nCLU BH3 peptide complex reveals that the binding mode is remarkably similar to those of other Bcl-X{sub L}/BH3 peptide complexes. In addition, mutational analysis confirmed that Leu323 and Asp328 of nCLU BH3 domain, absolutely conserved in the BH3 motifs of BH3-only protein family, are critical for binding to Bcl-X{sub L}. Taken altogether, our results suggest a molecular basis for the pro-apoptotic function of nCLU by elucidating the residue specific interactions of the BH3 motif in nCLU with anti-apoptotic Bcl-2 family proteins.

  13. Interaction of a putative BH3 domain of clusterin with anti-apoptotic Bcl-2 family proteins as revealed by NMR spectroscopy

    International Nuclear Information System (INIS)

    Highlights: → Identification of a conserved BH3 motif in C-terminal coiled coil region of nCLU. → The nCLU BH3 domain binds to BH3 peptide-binding grooves in both Bcl-XL and Bcl-2. → A conserved binding mechanism of nCLU BH3 and the other pro-apoptotic BH3 peptides with Bcl-XL. → The absolutely conserved Leu323 and Asp328 of nCLU BH3 domain are critical for binding to Bcl-XL. → Molecular understanding of the pro-apoptotic function of nCLU as a novel BH3-only protein. -- Abstract: Clusterin (CLU) is a multifunctional glycoprotein that is overexpressed in prostate and breast cancers. Although CLU is known to be involved in the regulation of apoptosis and cell survival, the precise molecular mechanism underlying the pro-apoptotic function of nuclear CLU (nCLU) remains unclear. In this study, we identified a conserved BH3 motif in C-terminal coiled coil (CC2) region of nCLU by sequence analysis and characterized the molecular interaction of the putative nCLU BH3 domain with anti-apoptotic Bcl-2 family proteins by nuclear magnetic resonance (NMR) spectroscopy. The chemical shift perturbation data demonstrated that the nCLU BH3 domain binds to pro-apoptotic BH3 peptide-binding grooves in both Bcl-XL and Bcl-2. A structural model of the Bcl-XL/nCLU BH3 peptide complex reveals that the binding mode is remarkably similar to those of other Bcl-XL/BH3 peptide complexes. In addition, mutational analysis confirmed that Leu323 and Asp328 of nCLU BH3 domain, absolutely conserved in the BH3 motifs of BH3-only protein family, are critical for binding to Bcl-XL. Taken altogether, our results suggest a molecular basis for the pro-apoptotic function of nCLU by elucidating the residue specific interactions of the BH3 motif in nCLU with anti-apoptotic Bcl-2 family proteins.

  14. Biliverdin reductase/bilirubin mediates the anti-apoptotic effect of hypoxia in pulmonary arterial smooth muscle cells through ERK1/2 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Song, Shasha [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Wang, Shuang [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Biopharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081 (China); Ma, Jun; Yao, Lan; Xing, Hao; Zhang, Lei; Liao, Lin [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Zhu, Daling, E-mail: dalingz@yahoo.com [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Biopharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081 (China)

    2013-08-01

    Inhibition of pulmonary arterial smooth muscle cell (PASMC) apoptosis induced by hypoxia plays an important role in pulmonary arterial remodeling leading to aggravate hypoxic pulmonary arterial hypertension. However, the mechanisms of hypoxia acting on PASMC apoptosis remain exclusive. Biliverdin reductase (BVR) has many essential biologic roles in physiological and pathological processes. Nevertheless, it is unclear whether the hypoxia-induced inhibition on PASMC apoptosis is mediated by BVR. In the present work, we found BVR majorly localized in PASMCs and was up-regulated in levels of protein and mRNA by hypoxia. Then we studied the contribution of BVR to anti-apoptotic response of hypoxia in PASMCs. Our results showed that siBVR, blocking generation of bilirubin, reversed the effect of hypoxia on enhancing cell survival and apoptotic protein (Bcl-2, procasepase-9, procasepase-3) expression, preventing nuclear shrinkage, DNA fragmentation and mitochondrial depolarization in starved PASMCs, which were recovered by exogenous bilirubin. Moreover, the inhibitory effect of bilirubin on PASMC apoptosis under hypoxic condition was blocked by the inhibitor of ERK1/2 pathway. Taken together, our data indicate that BVR contributes to the inhibitory process of hypoxia on PASMC apoptosis, which is mediated by bilirubin through ERK1/2 pathway. Highlights: • BVR expresses in PASMC and is up-regulated by hypoxia in protein and mRNA levels. • BVR/bilirubin contribute to the inhibitive process of hypoxia on PASMC apoptosis. • Bilirubin protects PASMC from apoptosis under hypoxia via ERK1/2 pathway.

  15. Biliverdin reductase/bilirubin mediates the anti-apoptotic effect of hypoxia in pulmonary arterial smooth muscle cells through ERK1/2 pathway

    International Nuclear Information System (INIS)

    Inhibition of pulmonary arterial smooth muscle cell (PASMC) apoptosis induced by hypoxia plays an important role in pulmonary arterial remodeling leading to aggravate hypoxic pulmonary arterial hypertension. However, the mechanisms of hypoxia acting on PASMC apoptosis remain exclusive. Biliverdin reductase (BVR) has many essential biologic roles in physiological and pathological processes. Nevertheless, it is unclear whether the hypoxia-induced inhibition on PASMC apoptosis is mediated by BVR. In the present work, we found BVR majorly localized in PASMCs and was up-regulated in levels of protein and mRNA by hypoxia. Then we studied the contribution of BVR to anti-apoptotic response of hypoxia in PASMCs. Our results showed that siBVR, blocking generation of bilirubin, reversed the effect of hypoxia on enhancing cell survival and apoptotic protein (Bcl-2, procasepase-9, procasepase-3) expression, preventing nuclear shrinkage, DNA fragmentation and mitochondrial depolarization in starved PASMCs, which were recovered by exogenous bilirubin. Moreover, the inhibitory effect of bilirubin on PASMC apoptosis under hypoxic condition was blocked by the inhibitor of ERK1/2 pathway. Taken together, our data indicate that BVR contributes to the inhibitory process of hypoxia on PASMC apoptosis, which is mediated by bilirubin through ERK1/2 pathway. Highlights: • BVR expresses in PASMC and is up-regulated by hypoxia in protein and mRNA levels. • BVR/bilirubin contribute to the inhibitive process of hypoxia on PASMC apoptosis. • Bilirubin protects PASMC from apoptosis under hypoxia via ERK1/2 pathway

  16. Anti-apoptotic Activity of Ginsenoside Rb1 in Hydrogen Peroxide-treated Chondrocytes: Stabilization of Mitochondria and the Inhibition of Caspase-3.

    Science.gov (United States)

    Na, Ji-Young; Kim, Sokho; Song, Kibbeum; Lim, Kyu-Hee; Shin, Gee-Wook; Kim, Jong-Hoon; Kim, Bumseok; Kwon, Young-Bae; Kwon, Jungkee

    2012-07-01

    Chondrocyte apoptosis has been recognized as an important factor in the pathogenesis of osteoarthritis (OA). Hydrogen peroxide (H2O2), which produces reactive oxygen species, reportedly induces apoptosis in chondrocytes. The ginsenoside Rb1 (GRb1) is the principal component in ginseng and has been shown to have a variety of biological activities, such as anti-arthritis, anti-inflammation, and anti-tumor activities. In this study, we evaluated the effects of G-Rb1 on the mitochondrial permeability transition (MPT) and caspase-3 activity of chondrocyte apoptosis induced by H2O2. Cultured rat articular chondrocytes were exposed to H2O2 with or without G-Rb1 and assessed for viability, MPT, Bcl-xL/Bax expression, caspase-3 activity, and apoptosis. The co-treatment with G-Rb1 showed an inhibition of MPT, caspase-3 activity, and cell death. Additionally, the levels of the apoptotic protein Bax were significantly lower and the levels of the anti-apoptotic protein Bcl-xL were higher compared with H2O2 treatment alone. The results of this study demonstrate that G-Rb1 protects chondrocytes against H2O2-induced apoptosis, at least in part via the inhibition of MPT and caspase-3 activity. These results demonstrate that G-Rb1 is a potentially useful drug for the treatment of OA patients. PMID:23717124

  17. Histone demethylase Jmjd3 regulates osteoblast apoptosis through targeting anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bim.

    Science.gov (United States)

    Yang, Di; Okamura, Hirohiko; Teramachi, Jumpei; Haneji, Tatsuji

    2016-04-01

    Posttranslational modifications including histone methylation regulate gene transcription through directly affecting the structure of chromatin. Trimethylation of histone H3K27 (H3K27me3) contributes to gene silencing and the histone demethylase Jumonji domain-containing 3 (Jmjd3) specifically removes the methylation of H3K27me3, followed by the activation of gene expression. In the present study, we explored the roles of Jmjd3 in regulating osteoblast apoptosis. Knockdown of Jmjd3 promoted osteoblast apoptosis induced by serum deprivation with decreased mitochondrial membrane potential and increased levels of caspase-3 activation, PARP cleavage, and DNA fragmentation. B cell lymphoma-2 (Bcl-2), an anti-apoptotic protein, was down-regulated by knockdown of Jmjd3 through retaining H3K27me3 on its promoter region. Knockdown of Jmjd3 increased the pro-apoptotic activity of Bim through inhibiting ERK-dependent phosphorylation of Bim. Protein kinase D1 (PKD1), which stimulates ERK phosphorylation, decreased in the Jmjd3-knockdown cells and introduction of PKD1 relieved osteoblast apoptosis in the Jmjd3-knockdown cells through increasing ERK-regulated Bim phosphorylation. These results suggest that Jmjd3 regulates osteoblast apoptosis through targeting Bcl-2 expression and Bim phosphorylation. PMID:26795455

  18. Induction of apoptosis in sea bream fibroblasts by Vibrio harveyi haemolysin and evidence for an anti-apoptotic role of heat shock protein 70.

    Science.gov (United States)

    Deane, E E; Jia, A; Qu, Z; Chen, J-X; Zhang, X-H; Woo, N Y S

    2012-04-01

    In this study, we exposed black sea bream, Mylio macrocephalus (Basilewsky), fibroblast (BSF) and silver sea bream, Sparus sarba Forsskål, fibroblast (SSF) cell lines to a recombinant Vibrio harveyi haemolysin (VHH) and investigated mechanisms involved in apoptosis. A decrease in mitochondrial membrane potential, followed by an increase in caspase 3 activity, occurred within 2-8 h of VHH exposure, in both cell lines; however, VHH did not alter cellular levels of reactive oxygen species. As heat shock protein 70 (HSP70) is known to prevent the onset of apoptosis in certain mammalian cells, we aimed to test whether such a protective effect is operative in VHH-exposed fibroblasts. The amounts of HSP70 were elevated in SSF and BSF via an acute heat shock or an acute heat shock followed by a 6 h recovery. It was found that the VHH-mediated reduction in mitochondrial membrane potential was suppressed in cells that had a 6 h post-heat shock recovery, and the protective effect of heat shock-induced HSP70 was attenuated following treatment of cells with the HSP70 inhibitor, quercetin. This study demonstrates how haemolysin causes cell death via induction of apoptosis and provides evidence as to the role of HSP70 as an anti-apoptotic factor. PMID:27081923

  19. Peptides derived from human galectin-3 N-terminal tail interact with its carbohydrate recognition domain in a phosphorylation-dependent manner

    Energy Technology Data Exchange (ETDEWEB)

    Berbís, M. Álvaro [Chemical and Physical Biology Department, Centro de Investigaciones Biológicas, CSIC, 28040 Madrid (Spain); André, Sabine [Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians University, 80539 Munich (Germany); Cañada, F. Javier [Chemical and Physical Biology Department, Centro de Investigaciones Biológicas, CSIC, 28040 Madrid (Spain); Pipkorn, Rüdiger [Central Peptide Synthesis Unit, German Cancer Research Center, 69120 Heidelberg (Germany); Ippel, Hans [Department of Biochemistry, CARIM, University of Maastricht, Maastricht (Netherlands); Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Mayo, Kevin H. [Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Kübler, Dieter [Biomolecular Interactions, German Cancer Research Center, 69120 Heidelberg (Germany); Gabius, Hans-Joachim [Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians University, 80539 Munich (Germany); Jiménez-Barbero, Jesús, E-mail: jjbarbero@cib.csic.es [Chemical and Physical Biology Department, Centro de Investigaciones Biológicas, CSIC, 28040 Madrid (Spain)

    2014-01-03

    Highlights: •Galectin-3 is composed of a carbohydrate recognition domain and an N-terminal tail. •Synthetic peptides derived from the tail are shown to interact with the CRD. •This interaction is modulated by Ser- and Tyr-phosphorylation of the peptides. -- Abstract: Galectin-3 (Gal-3) is a multi-functional effector protein that functions in the cytoplasm and the nucleus, as well as extracellularly following non-classical secretion. Structurally, Gal-3 is unique among galectins with its carbohydrate recognition domain (CRD) attached to a rather long N-terminal tail composed mostly of collagen-like repeats (nine in the human protein) and terminating in a short non-collagenous terminal peptide sequence unique in this lectin family and not yet fully explored. Although several Ser and Tyr sites within the N-terminal tail can be phosphorylated, the physiological significance of this post-translational modification remains unclear. Here, we used a series of synthetic (phospho)peptides derived from the tail to assess phosphorylation-mediated interactions with {sup 15}N-labeled Gal-3 CRD. HSQC-derived chemical shift perturbations revealed selective interactions at the backface of the CRD that were attenuated by phosphorylation of Tyr 107 and Tyr 118, while phosphorylation of Ser 6 and Ser 12 was essential. Controls with sequence scrambling underscored inherent specificity. Our studies shed light on how phosphorylation of the N-terminal tail may impact on Gal-3 function and prompt further studies using phosphorylated full-length protein.

  20. Spinal but not cortical microglia acquire an atypical phenotype with high VEGF, galectin-3 and osteopontin, and blunted inflammatory responses in ALS rats.

    Science.gov (United States)

    Nikodemova, Maria; Small, Alissa L; Smith, Stephanie M C; Mitchell, Gordon S; Watters, Jyoti J

    2014-09-01

    Activation of microglia, CNS resident immune cells, is a pathological hallmark of amyotrophic lateral sclerosis (ALS), a neurodegenerative disorder affecting motor neurons. Despite evidence that microglia contribute to disease progression, the exact role of these cells in ALS pathology remains unknown. We immunomagnetically isolated microglia from different CNS regions of SOD1(G93A) rats at three different points in disease progression: presymptomatic, symptom onset and end-stage. We observed no differences in microglial number or phenotype in presymptomatic rats compared to wild-type controls. Although after disease onset there was no macrophage infiltration, there were significant increases in microglial numbers in the spinal cord, but not cortex. At disease end-stage, microglia were characterized by high expression of galectin-3, osteopontin and VEGF, and concomitant downregulated expression of TNFα, IL-6, BDNF and arginase-1. Flow cytometry revealed the presence of at least two phenotypically distinct microglial populations in the spinal cord. Immunohistochemistry showed that galectin-3/osteopontin positive microglia were restricted to the ventral horns of the spinal cord, regions with severe motor neuron degeneration. End-stage SOD1(G93A) microglia from the cortex, a less affected region, displayed similar gene expression profiles to microglia from wild-type rats, and displayed normal responses to systemic inflammation induced by LPS. On the other hand, end-stage SOD1(G93A) spinal microglia had blunted responses to systemic LPS suggesting that in addition to their phenotypic changes, they may also be functionally impaired. Thus, after disease onset, microglia acquired unique characteristics that do not conform to typical M1 (inflammatory) or M2 (anti-inflammatory) phenotypes. This transformation was observed only in the most affected CNS regions, suggesting that overexpression of mutated hSOD1 is not sufficient to trigger these changes in microglia. These

  1. Peptides derived from human galectin-3 N-terminal tail interact with its carbohydrate recognition domain in a phosphorylation-dependent manner

    International Nuclear Information System (INIS)

    Highlights: •Galectin-3 is composed of a carbohydrate recognition domain and an N-terminal tail. •Synthetic peptides derived from the tail are shown to interact with the CRD. •This interaction is modulated by Ser- and Tyr-phosphorylation of the peptides. -- Abstract: Galectin-3 (Gal-3) is a multi-functional effector protein that functions in the cytoplasm and the nucleus, as well as extracellularly following non-classical secretion. Structurally, Gal-3 is unique among galectins with its carbohydrate recognition domain (CRD) attached to a rather long N-terminal tail composed mostly of collagen-like repeats (nine in the human protein) and terminating in a short non-collagenous terminal peptide sequence unique in this lectin family and not yet fully explored. Although several Ser and Tyr sites within the N-terminal tail can be phosphorylated, the physiological significance of this post-translational modification remains unclear. Here, we used a series of synthetic (phospho)peptides derived from the tail to assess phosphorylation-mediated interactions with 15N-labeled Gal-3 CRD. HSQC-derived chemical shift perturbations revealed selective interactions at the backface of the CRD that were attenuated by phosphorylation of Tyr 107 and Tyr 118, while phosphorylation of Ser 6 and Ser 12 was essential. Controls with sequence scrambling underscored inherent specificity. Our studies shed light on how phosphorylation of the N-terminal tail may impact on Gal-3 function and prompt further studies using phosphorylated full-length protein

  2. Introduction of the anti-apoptotic baculovirus p35 gene in passion fruit induces herbicide tolerance, reduced bacterial lesions, but does not inhibits passion fruit woodiness disease progress induced by cowpea aphid-borne mosaic virus (CABMV).

    Science.gov (United States)

    de Freitas, Daniele Scandiucci; Coelho, Marly C Felipe; Souza, Manoel T; Marques, Abi; Ribeiro, E Bergmann Morais

    2007-01-01

    The introduction of anti-apoptotic genes into plants leads to resistance to environmental stress and broad-spectrum disease resistance. The anti-apoptotic gene (p35) from a baculovirus was introduced into the genome of passion fruit plants by biobalistics. Eleven regenerated plants showed the presence of the p35 gene by PCR and/or dot blot hybridization. Transcriptional analysis of regenerated plants showed the presence of specific p35 transcripts in 9 of them. Regenerated plants containing the p35 gene were inoculated with the cowpea aphid-borne mosaic virus (CABMV), the bacterium Xanthomonas axonopodis pv passiflorae, and the herbicide, glufosinate, (Syngenta). None of the plants showed resistance to CABMV. Regenerated plants (p35+) showed less than half of local lesions showed by non-transgenic plants when inoculated with X. axonopodis and some p35+ plants showed increased tolerance to the glufosinate herbicide when compared to non-transgenic plants. PMID:17016672

  3. Teduglutide, a glucagon-like peptide 2 analogue: a novel protective agent with anti-apoptotic and anti-oxidant properties in mice with lung injury.

    Science.gov (United States)

    Arda-Pirincci, Pelin; Oztay, Fusun; Bayrak, Bertan Boran; Yanardag, Refiye; Bolkent, Sehnaz

    2012-12-01

    Teduglutide is a long-acting synthetic analogue of human glucagon-like peptide-2 (GLP-2). GLP-2 regulates cell proliferation and apoptosis as well as normal physiology in the gastrointestinal tract. In the present study, possible cytoprotective and reparative effects of teduglutide were analyzed on a mouse model with lung injury induced by tumor necrosis factor-alpha (TNF-α) and actinomycin D (Act D). BALB/c mice were divided into six groups: control mice (I), mice injected intraperitoneally with 15 μg/kg TNF-α (II), 800 μg/kg Act D (III), Act D 2 min prior to TNF-α administration with the same doses (IV), mice injected subcutaneously with 200 μg/kg teduglutide every 12h for 10 consecutive days (V), and mice given Act D 2 min prior to TNF-α administration on day 11 after receiving teduglutide for 10 days (VI). The TNF-α/Act D administration made the lung a sensitive organ to damage. Mice lung subjected to TNF-α/Act D were characterized by the disruption of alveolar wall, induced pulmonary endothelial/epithelial cell apoptosis and expression of active caspase-3. These mice exhibited an increase in lipid peroxidation, glutathione levels, and activities of myeloperoxidase, superoxide dismutase, catalase, glutathione peroxidase and xanthine oxidase, as well as reduced tissue factor and sodium-potassium/ATPase activities. Teduglutide pretreatment regressed the structural damage, cell apoptosis and oxidative stress by reducing lipid peroxidation in mice received TNF-α/Act D. GLP-2 receptors were present on the cell membrane of type II pneumocytes and interstitial cells. Thus, teduglutide can be suggested as a novel protective agent, which possesses anti-apoptotic and anti-oxidant properties, against lung injury. PMID:23059393

  4. Anti-Apoptotic and Pro-Survival Effect of Alpinate Oxyphyllae Fructus (AOF in a d-Galactose-Induced Aging Heart

    Directory of Open Access Journals (Sweden)

    Yung-Ming Chang

    2016-03-01

    Full Text Available Aging, a natural biological/physiological phenomenon, is accelerated by reactive oxygen species (ROS accumulation and identified by a progressive decrease in physiological function. Several studies have shown a positive relationship between aging and chronic heart failure (HF. Cardiac apoptosis was found in age-related diseases. We used a traditional Chinese medicine, Alpinate Oxyphyllae Fructus (AOF, to evaluate its effect on cardiac anti-apoptosis and pro-survival. Male eight-week-old Sprague–Dawley (SD rats were segregated into five groups: normal control group (NC, d-Galactose-Induced aging group (Aging, and AOF of 50 (AL (AOF low, 100 (AM (AOF medium, 150 (AH (AOF high mg/kg/day. After eight weeks, hearts were measured by an Hematoxylin–Eosin (H&E stain, Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL-assays and Western blotting. The experimental results show that the cardiomyocyte apoptotic pathway protein expression increased in the d-Galactose-Induced aging groups, with dose-dependent inhibition in the AOF treatment group (AL, AM, and AH. Moreover, the expression of the pro-survival p-Akt (protein kinase B (Akt, Bcl-2 (B-cell lymphoma 2, anti-apoptotic protein (Bcl-xL protein decreased significantly in the d-Galactose-induced aging group, with increased performance in the AOF treatment group with levels of p-IGFIR and p-PI3K (Phosphatidylinositol-3′ kinase (PI3K to increase by dosage and compensatory performance. On the other hand, the protein of the Sirtuin 1 (SIRT1 pathway expression decreased in the aging groups and showed improvement in the AOF treatment group. Our results suggest that AOF strongly works against ROS-induced aging heart problems.

  5. Anti-Apoptotic and Pro-Survival Effect of Alpinate Oxyphyllae Fructus (AOF) in a d-Galactose-Induced Aging Heart.

    Science.gov (United States)

    Chang, Yung-Ming; Chang, Hen-Hong; Kuo, Wei-Wen; Lin, Hung-Jen; Yeh, Yu-Lan; Padma Viswanadha, Vijaya; Tsai, Chin-Chuan; Chen, Ray-Jade; Chang, Hsin-Nung; Huang, Chih-Yang

    2016-01-01

    Aging, a natural biological/physiological phenomenon, is accelerated by reactive oxygen species (ROS) accumulation and identified by a progressive decrease in physiological function. Several studies have shown a positive relationship between aging and chronic heart failure (HF). Cardiac apoptosis was found in age-related diseases. We used a traditional Chinese medicine, Alpinate Oxyphyllae Fructus (AOF), to evaluate its effect on cardiac anti-apoptosis and pro-survival. Male eight-week-old Sprague-Dawley (SD) rats were segregated into five groups: normal control group (NC), d-Galactose-Induced aging group (Aging), and AOF of 50 (AL (AOF low)), 100 (AM (AOF medium)), 150 (AH (AOF high)) mg/kg/day. After eight weeks, hearts were measured by an Hematoxylin-Eosin (H&E) stain, Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-assays and Western blotting. The experimental results show that the cardiomyocyte apoptotic pathway protein expression increased in the d-Galactose-Induced aging groups, with dose-dependent inhibition in the AOF treatment group (AL, AM, and AH). Moreover, the expression of the pro-survival p-Akt (protein kinase B (Akt)), Bcl-2 (B-cell lymphoma 2), anti-apoptotic protein (Bcl-xL) protein decreased significantly in the d-Galactose-induced aging group, with increased performance in the AOF treatment group with levels of p-IGFIR and p-PI3K (Phosphatidylinositol-3' kinase (PI3K)) to increase by dosage and compensatory performance. On the other hand, the protein of the Sirtuin 1 (SIRT1) pathway expression decreased in the aging groups and showed improvement in the AOF treatment group. Our results suggest that AOF strongly works against ROS-induced aging heart problems. PMID:27043531

  6. Galectin-3 immunostaining in thyroid neoplasms Imunomarcação por galectina-3 em neoplasias de tireóide

    Directory of Open Access Journals (Sweden)

    Marcos Emanuel de Alcântara Segura

    2005-10-01

    Full Text Available Although fine-needle aspiration biopsy (FNAB of the thyroid gland is the most important presurgical proceeding in defining the malignancy of a nodular lesion, it has limitations such as shared cytological morphology between malignant and benign lesions. Galectin-3, a b-galactoside-binding lectin is expressed mainly by malignant thyroid neoplasms. Fifty-seven specimens, including 14 papillary carcinomas, 22 follicular carcinomas and 21 follicular adenomas were tested for immunohistochemical staining against galectin-3. Normal thyroid adjacent to neoplastic tissue was also examined in 48 cases. All cases of papillary carcinoma were cytoplasmic stained, 18 cases of follicular carcinoma were cytoplasmic stained, and one case of follicular adenoma showed nuclear staining. No case of normal thyroid showed immunoreactivity. Sensitivity, specificity, positive predictive value and negative predictive value were respective 88%, 98%, 96%, and 94%. Galectin-3 expression is a valuable evidence of malignancy in cases where cytomorphological features are not conclusive. This immunomediated method could increase diagnosis accuracy for FNAB, thus making surgery indication more precise.A punção aspirativa por agulha fina de tireóide é o método pré-cirúrgico mais importante na definição da malignidade de uma lesão nodular. Entretanto esse procedimento apresenta limitações, como características morfológicas comuns entre neoplasias malignas e benignas. A expressão de uma lectina ligante de b-galactosídeos chamada galectina-3, aumentada em neoplasias malignas de tireóide, poderia ser utilizada como marcador de malignidade para neoplasias de tireóide. Cinqüenta e sete casos, entre eles 14 carcinomas papilares, 22 carcinomas foliculares e 21 adenomas foliculares, foram estudados quanto à expressão da galectina-3 por métodos imuno-histoquímicos. O tecido tireoidiano normal, adjacente ao tecido neoplásico, também foi avaliado em 48 casos. Todos

  7. Plasma levels of galectin-3-binding protein reflect type I interferon activity and are increased in patients with systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Nielsen, Christoffer T; Lood, Christian; Østergaard, Ole; Iversen, Line V; Voss, Anne; Bengtsson, Anders; Jacobsen, Søren; Heegaard, Niels H H

    2014-01-01

    OBJECTIVE: Simple measures of type I interferon (IFN) activity constitute highly attractive biomarkers in systemic lupus erythematosus (SLE). We explore galectin-3-binding protein (G3BP) as a novel measure of type I IFN activity and serum/plasma biomarker in large independent cohorts of patients...... with SLE and controls. METHODS: Serum and plasma G3BP concentrations were quantified using ELISA. Type I IFN activity was assessed by Mx1 reporter gene expression assays and correlated to serum G3BP concentrations (SLE-IFN-α, n=26 and healthy controls (HCs), n=10). Plasma G3BP concentrations in the SLE......-Denmark (DK) (n=70) and SLE-Sweden (SE) (n=68) cohorts were compared with the HC-DK (n=47) and HC-SE (n=50) cohorts and patients with systemic sclerosis (n=111). In 15 patients with SLE, serum G3BP in consecutive samples was correlated to disease activity. Correlation analysis between G3BP, clinical...

  8. Expression changes of antioxidant, apoptotic, anti-apoptotic genes and miR-15b-34a-21-98 in over tissue by using erythromycin, quinacrine and tetracycline in non-surgical sterilization.

    Science.gov (United States)

    Kara, Murat; Yumrutas, Onder; Atilgan, Remzi; Baspinar, Melike; Sapmaz, Ekrem; Kuloglu, Tuncay

    2014-12-01

    In the present study, effects on expression of antioxidant, apoptotic and anti-apoptotic genes (GSR, GRX3, SOD1, RAI-NOS, HSP7, BAX, Bcl-2, CASP3 and MDH1) of substances being used in non-surgical sterilization such as quinacrine, erythromycin and tetracycline were evaluated in over tissue. Moreover, expression of some specific mi-RNA (miR-15b, miR-21, miR34a and miR-98) that playing a role in apoptosis was determined in same tissue. Prospective comparative experimental study. Genetics and Histology laboratory. Total number of 28 Wistar albino 12-14 week old female rats with regular cycles and 200-220 grams in weight. Total RNA was isolated from tissues by using a RNA isolation kit. Gene expression levels were evaluated by Real-Time PCR method. Tubal passage and fibrosis induction in tissues was observed in the histochemical analysis. In the statistical analysis of data Kruskal-Wallis variance analysis and Mann-Whitney U test were used and p tetracycline were significantly higher than control. Results of the present study suggest that the doses treated of quinacrine, erythromycin and tetracycline used in non-surgical sterilization effect poorly the expression of anti-oxidant, apoptotic and anti-apoptotic genes, but the expression of miR-34 playing the role in apoptosis increased after treatment of these substances. PMID:25195052

  9. Usefulness of Combining Galectin-3 and BIVA Assessments in Predicting Short- and Long-Term Events in Patients Admitted for Acute Heart Failure

    Directory of Open Access Journals (Sweden)

    Benedetta De Berardinis

    2014-01-01

    Full Text Available Introduction. Acute heart failure (AHF is associated with a higher risk for the occurrence of rehospitalization and death. Galectin-3 (GAL3 is elevated in AHF patients and is an indicator in predicting short-term mortality. The total body water using bioimpedance vector analysis (BIVA is able to identify mortality within AHF patients. The aim of this study was to evaluate the short- and long-term predictive value of GAL3, BIVA, and the combination of both in AHF patients in Emergency Department (ED. Methods. 205 ED patients with AHF were evaluated by testing for B type natriuretic peptide (BNP and GAL3. The primary endpoint was death and rehospitalization at 30, 60, 90, and 180 days and 12 and 18 months. AHF patients were evaluated at the moment of ED arrival with clinical judgment and GAL3 and BIVA measurement. Results. GAL3 level was significantly higher in patients >71 years old, and with eGFR17.8 ng/mL shows significant survival difference. At multivariate Cox regression analysis GAL3 is an independent variable to predict death + rehospitalization with a value of 32.24 ng/mL at 30 days (P<0.005. Conclusion. In patients admitted for AHF an early assessment of GAL3 and BIVA seems to be useful in identifying patients at high risk for death and rehospitalization at short and long term. Combining the biomarker and the device could be of great utility since they monitor the severity of two pathophysiological different mechanisms: heart fibrosis and fluid overload.

  10. Expression of ck-19, galectin-3 and hbme-1 in the differentiation of thyroid lesions: systematic review and diagnostic meta-analysis

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    de Matos Leandro

    2012-08-01

    Full Text Available Abstract Background To distinguish between malignant and benign lesions of the thyroid gland histological demonstration is often required since the fine-needle aspiration biopsy method applied pre-operatively has some limitations. In an attempt to improve diagnostic accuracy, markers using immunocytochemistry and immunohistochemistry techniques have been studied, mainly cytokeratin-19 (CK-19, galectin-3 (Gal-3 and Hector Battifora mesothelial-1 (HBME-1. However, current results remain controversial. The aim of the present article was to establish the diagnostic accuracy of CK-19, Gal-3 and HBME-1 markers, as well as their associations, in the differentiation of malignant and benign thyroid lesions. Methods A systematic review of published articles on MEDLINE and The Cochrane Library was performed. After establishing inclusion and exclusion criteria, 66 articles were selected. The technique of meta-analysis of diagnostic accuracy was employed and global values of sensitivity, specificity, area under the summary ROC curve, and diagnostic odds ratio (dOR were calculated. Results For the immunohistochemistry technique, the positivity of CK-19 for the diagnosis of malignant thyroid lesions demonstrated global sensitivity of 81% and specificity of 73%; for Gal-3, sensitivity of 82% and specificity of 81%; and for HBME-1, sensitivity of 77% and specificity of 83%. The association of the three markers determined sensitivity of 85%, specificity of 97%, and diagnostic odds ratio of 95.1. Similar results were also found for the immunocytochemistry assay. Conclusion This meta-analysis demonstrated that the three immunomarkers studied are accurate in pre- and postoperative diagnosis of benign and malignant thyroid lesions. Nevertheless, the search for other molecular markers must continue in order to enhance this diagnostic accuracy since the results found still show a persistency of false-negative and false-positive tests. Virtual slides Http

  11. Galectina-3 em tumores de próstata: imuno-histoquímica e análise digital de imagens Galectin-3 in prostatic tumours: immunohistochemistry and digital image analysis

    Directory of Open Access Journals (Sweden)

    Jorge Luiz Silva Araújo-Filho

    2006-12-01

    Full Text Available A imuno-histoquímica é uma técnica de grande ajuda no diagnóstico de doenças da próstata, incluindo os tumores. De igual importância, a análise digital de imagens vem sendo cada vez mais utilizada em estudos de alterações na próstata. O presente estudo teve como objetivo quantificar morfometricamente a expressão da galectina-3 através da imuno-histoquímica em tecidos de próstata normal (PN, hiperplasia benigna da próstata (HPB e adenocarcinoma prostático (AP. Fragmentos cirúrgicos de tecido prostático com AP (n = 10, HPB (n = 12 e PN (n = 10 foram fixados em formalina, submetidos à rotina histológica e embebidos em parafina. Foram feitos cortes histológicos (4µm montados em lâminas e corados com hematoxilina e eosina (HE para confirmar o diagnóstico. As amostras teciduais selecionadas foram incubadas com anticorpo monoclonal antigalectina-3 por uma hora em temperatura ambiente (37ºC e então incubadas com um anticorpo secundário. A revelação foi realizada após incubação com diaminobenzidina (DAB e peróxido de hidrogênio. A análise morfométrica foi realizada mediante uma estação de análise digital de imagens, que consiste num microscópio óptico acoplado a uma câmera digital ligada a um computador equipado com o software de análise OPTIMAS®. Nas células de adenocarcinoma foi observada diminuição significativa na marcação (p Immunohistochemistry helps pathologists in the diagnosis of prostatic diseases, mainly carcinomas. Equally important, digital image analysis is being increasingly used to study alterations in the prostate. The present work aims to morphometrically quantify the immunostain of galectin-3 expressed in normal prostate (NP, benign hyperplasia (BH and prostatic adenocarcinoma (PA in humans. Immunohistochemistry was developed using monoclonal anti-galectin-3 antibody. Surgical specimens from different patients with BH (n = 12, PA (n = 10 and NP (n = 10 were fixed in formalin, processed

  12. Galectin-3 Ablation Enhances Liver Steatosis, but Attenuates Inflammation and IL-33-Dependent Fibrosis in Obesogenic Mouse Model of Nonalcoholic Steatohepatitis.

    Science.gov (United States)

    Jeftic, Ilija; Jovicic, Nemanja; Pantic, Jelena; Arsenijevic, Nebojsa; Lukic, Miodrag L; Pejnovic, Nada

    2015-01-01

    The importance of Galectin-3 (Gal-3) in obesity-associated liver pathology is incompletely defined. To dissect the role of Gal-3 in fibrotic nonalcoholic steatohepatitis (NASH), Gal-3-deficient (LGALS3(-/-)) and wild-type (LGALS3(+/+)) C57Bl/6 mice were placed on an obesogenic high fat diet (HFD, 60% kcal fat) or standard chow diet for 12 and 24 wks. Compared to WT mice, HFD-fed LGALS3(-/-) mice developed, in addition to increased visceral adiposity and diabetes, marked liver steatosis, which was accompanied with higher expression of hepatic PPAR-γ, Cd36, Abca-1 and FAS. However, as opposed to LGALS3(-/-) mice, hepatocellular damage, inflammation and fibrosis were more extensive in WT mice which had an elevated number of mature myeloid dendritic cells, proinflammatory CD11b(+)Ly6C(hi) monocytes/macrophages in liver, peripheral blood and bone marrow, and increased hepatic CCL2, F4/80, CD11c, TLR4, CD14, NLRP3 inflammasome, IL-1β and NADPH-oxidase enzymes mRNA expression. Thus, obesity-driven greater steatosis was uncoupled with attenuated fibrotic NASH in Gal-3-deficient mice. HFD-fed WT mice had a higher number of hepatocytes that strongly expressed IL-33 and hepatic CD11b(+)IL-13(+) cells, increased levels of IL-33 and IL-13 and up-regulated IL-33, ST2 and IL-13 mRNA in liver compared with LGALS3(-/-) mice. IL-33 failed to induce ST2 upregulation and IL-13 production by LGALS3(-/-) peritoneal macrophages in vitro. Administration of IL-33 in vivo enhanced liver fibrosis in HFD-fed mice in both genotypes, albeit to a significantly lower extent in LGALS3(-/-) mice, which was associated with less numerous hepatic IL-13-expressing CD11b(+) cells. The present study provides evidence of a novel role for Gal-3 in regulating IL-33-dependent liver fibrosis. PMID:26018806

  13. Oncostatic-Cytoprotective Effect of Melatonin and Other Bioactive Molecules: A Common Target in Mitochondrial Respiration

    OpenAIRE

    Nicola Pacini; Fabio Borziani

    2016-01-01

    For several years, oncostatic and antiproliferative properties, as well as thoses of cell death induction through 5-methoxy-N-acetiltryptamine or melatonin treatment, have been known. Paradoxically, its remarkable scavenger, cytoprotective and anti-apoptotic characteristics in neurodegeneration models, such as Alzheimer’s disease and Parkinson’s disease are known too. Analogous results have been confirmed by a large literature to be associated to the use of many other bioactive molecules such...

  14. Human bronchial epithelial cells exposed in vitro to diesel exhaust particles exhibit alterations in cell rheology and cytotoxicity associated with decrease in antioxidant defenses and imbalance in pro- and anti-apoptotic gene expression.

    Science.gov (United States)

    Seriani, Robson; de Souza, Claudia Emanuele Carvalho; Krempel, Paloma Gava; Frias, Daniela Perroni; Matsuda, Monique; Correia, Aristides Tadeu; Ferreira, Márcia Zotti Justo; Alencar, Adriano Mesquita; Negri, Elnara Marcia; Saldiva, Paulo Hilário Nascimento; Mauad, Thais; Macchione, Mariangela

    2016-05-01

    Diesel exhaust particles (DEPs) from diesel engines produce adverse alterations in cells of the airways by activating intracellular signaling pathways and apoptotic gene overexpression, and also by influencing metabolism and cytoskeleton changes. This study used human bronchial epithelium cells (BEAS-2B) in culture and evaluates their exposure to DEPs (15ug/mL for 1 and 2 h) in order to determine changes to cell rheology (viscoelasticity) and gene expression of the enzymes involved in oxidative stress, apoptosis, and cytotoxicity. BEAS-2B cells exposed to DEPs were found to have a significant loss in stiffness, membrane stability, and mitochondrial activity. The genes involved in apoptosis [B cell lymphoma 2 (BCL-2 and caspase-3)] presented inversely proportional expressions (p = 0.05, p = 0.01, respectively), low expression of the genes involved in antioxidant responses [SOD1 (superoxide dismutase 1); SOD2 (superoxide dismutase 2), and GPx (glutathione peroxidase) (p = 0.01)], along with an increase in cytochrome P450, family 1, subfamily A, polypeptide 1 (CYP1A1) (p = 0.01). These results suggest that alterations in cell rheology and cytotoxicity could be associated with oxidative stress and imbalance between pro- and anti-apoptotic genes. PMID:26856867

  15. The N-terminus and alpha-5, alpha-6 helices of the pro-apoptotic protein Bax, modulate functional interactions with the anti-apoptotic protein Bcl-xL

    Directory of Open Access Journals (Sweden)

    Sowdhamini R

    2007-05-01

    Full Text Available Abstract Background Bcl-2 family proteins are key regulators of mitochondrial integrity and comprise both pro- and anti-apoptotic proteins. Bax a pro-apoptotic member localizes as monomers in the cytosol of healthy cells and accumulates as oligomers in mitochondria of apoptotic cells. The Bcl-2 homology-3 (BH3 domain regulates interactions within the family, but regions other than BH3 are also critical for Bax function. Thus, the N-terminus has been variously implicated in targeting to mitochondria, interactions with BH3-only proteins as well as conformational changes linked to Bax activation. The transmembrane (TM domains (α5-α6 helices in the core and α9 helix in the C-terminus in Bax are implicated in localization to mitochondria and triggering cytotoxicity. Here we have investigated N-terminus modulation of TM function in the context of regulation by the anti-apoptotic protein Bcl-xL. Results Deletion of 29 amino acids in the Bax N-terminus (Bax 30–192 caused constitutive accumulation at mitochondria and triggered high levels of cytotoxicity, not inhibited by Bcl-xL. Removal of the TM domains (Bax 30–105 abrogated mitochondrial localization but resulted in Bcl-xL regulated activation of endogenous Bax and Bax-Bak dependent apoptosis. Inclusion of the α5-α6 helices/TMI domain (Bax 30–146 phenocopied Bax 30–192 as it restored mitochondrial localization, Bcl-xL independent cytotoxicity and was not dependent on endogenous Bax-Bak. Inhibition of function and localization by Bcl-xL was restored in Bax 1–146, which included the TM1 domain. Regardless of regulation by Bcl-xL, all N-terminal deleted constructs immunoprecipitated Bcl-xLand converged on caspase-9 dependent apoptosis consistent with mitochondrial involvement in the apoptotic cascade. Sub-optimal sequence alignments of Bax and Bcl-xL indicated a sequence similarity between the α5–α6 helices of Bax and Bcl-xL. Alanine substitutions of three residues (T14A-S15A-S16A in

  16. Combined Treatment of Hydroxytyrosol with Carbon Monoxide-Releasing Molecule-2 Prevents TNF α -Induced Vascular Endothelial Cell Dysfunction through NO Production with Subsequent NF κ B Inactivation

    OpenAIRE

    Houda Zrelli; Che Wei Wu; Nahla Zghonda; Hidehisa Shimizu; Hitoshi Miyazaki

    2013-01-01

    This study investigated the atheroprotective properties of olive oil polyphenol, hydroxytyrosol (HT), in combination with carbon monoxide-releasing molecule-2 (CORM-2) that acts as a carbon monoxide donor using vascular endothelial cells (VECs). Our results showed that CORM-2 could strengthen the cytoprotective and anti-apoptotic effects of HT against TNF α -induced cellular damage by enhancing cell survival and the suppression of caspase-3 activation. While HT alone attenuated NF κ Bp65 phos...

  17. Syntheses, Structures, and Characterization of Metal Carbonyl Complexes as Photoactive CO Releasing Molecules and their Biological Utility Towards Eradication of Cancer

    OpenAIRE

    Carrington, Samantha

    2016-01-01

    Carbon monoxide (CO) has recently been shown to elicit various salutary effects in mammalian physiology. This small molecule has shown to exert a multitude of actions, which includes, vasoregulation, inflammation reduction and anti-apoptotic actions in normal cells. Interestingly, in hyperproliferative cells, CO has shown to induce significant pro-apoptotic effects, which can be exploited therapeutically towards cancer eradication. However, the ability to deliver CO in a target-specific mann...

  18. IL-6 regulates Mcl-1L expression through the JAK/PI3K/Akt/CREB signaling pathway in hepatocytes: implication of an anti-apoptotic role during liver regeneration.

    Directory of Open Access Journals (Sweden)

    Chia-Hung Chou

    Full Text Available AIMS: To investigate the role and the regulation of the long variant of myeloid cell leukemia-1 protein (Mcl-1L during liver regeneration. BACKGROUND: Liver regeneration is an important phenomenon after liver injury. The rat partial hepatectomy (PH model was used to characterize liver regeneration and Mcl-1L expression after PH. METHODS: Male Wistar rats were subjected to 70% PH. The expression of mcl-1L mRNA was determined by quantitative RT-PCR, and protein levels were analyzed by Western blot analysis and immunohistochemistry during liver regeneration. Functional evaluations of Mcl-1L were tested using chemical inhibition (flavopiridol, genetic inhibition (siRNA of Mcl-1L production, and by assaying for annexin V levels and DNA ladder formation. Serum IL-6 levels were determined by enzyme immunoassays; signal transduction of IL-6-regulated Mcl-1L expression was verified by chemical inhibitors and decoy double-stranded oligodeoxynucleotides. RESULTS: High levels of Mcl-1L were observed in remnant tissue at 4 h after PH. Administration of flavopiridol decreased Mcl-1L accumulation and also inhibited liver regeneration. IL-6 administration promoted the accumulation of Mcl-1L in rat hepatocytes, an effect that was impaired by siRNA treatments that reduced Mcl-1L production. Chemical inhibition and decoy oligonucleotide competition demonstrated that IL-6-induced Mcl-1L production required signaling mediated by JAK kinase, phosphoinositide 3-kinase (PI3K, and cAMP response-element-binding (CREB proteins. CONCLUSION: Mcl-1L is an anti-apoptotic protein induced during liver regeneration after PH in rats. The expression of Mcl-1L is induced by IL-6 through the JAK/PI3K/Akt/CREB signaling pathway. Chemotherapy drugs that depend on Mcl-1L- or IL-6-related signaling should be considered carefully before use in patients undergoing hepatectomy for malignant tumor resection.

  19. The Anti-Apoptotic Role of Neuroglobin

    Directory of Open Access Journals (Sweden)

    Thomas Brittain

    2012-11-01

    Full Text Available The small heme-protein neuroglobin is expressed at high concentrations in certain brain neurons and in the rod cells of the retina. This paper reviews the many studies which have recently identified a protective role for neuroglobin, in a wide range of situations involving apoptotic cell death. The origins of this protective mechanism are discussed in terms of both experimental results and computational modeling of the intrinsic pathway of apoptosis, which shows that neuroglobin can intervene in this process by a reaction with released mitochondrial cytochrome c. An integrated model, based on the various molecular actions of both neuroglobin and cytochrome c, is developed, which accounts for the cellular distribution of neuroglobin.

  20. The anti-apoptotic and cardioprotective effects of salvianolic acid a on rat cardiomyocytes following ischemia/reperfusion by DUSP-mediated regulation of the ERK1/2/JNK pathway.

    Directory of Open Access Journals (Sweden)

    Tongda Xu

    +I/R group. SAA exerts an anti-apoptotic role against myocardial IRI by inhibiting DUSP2-mediated JNK dephosphorylation and activating DUSP4/16-mediated ERK1/2 phosphorylation.

  1. 半乳糖凝集素-3在邻苯二甲酸二丁酯致大鼠尿道下裂发生中的表达%Differential expression of galectin-3 in the hypospadiac male rats induced by Di-n-butyl phthalate

    Institute of Scientific and Technical Information of China (English)

    常俊锴; 魏云飞; 冯宁翰; 张炜

    2010-01-01

    目的 利用邻苯二甲酸二丁酯(DBP)胚胎期暴露导致SD大鼠尿道下裂发生的动物模型,观察半乳糖凝集素-3(galectin-3)在尿道下裂与正常大鼠生殖结节中的差异表达,探讨其在DBP致大鼠尿道下裂发生中的作用.方法 SD孕鼠20只,随机分为2组,妊娠14~18 d(GD14~18)实验组和对照组分别给予DBP 800 mg/(kg·d)和大豆油2 ml/d灌胃,GD19剖宫产后统计子鼠数、雄性子鼠出生体质量(BW)及肛门生殖器距离(AGD)、尿道下裂发生率,取两组雄性子鼠生殖结节,运用免疫印迹法和免疫组织化学方法分析galectin-3的表达.结果 尿道下裂仅实验组发生,发生率为40%,每窝子鼠数、雄性子鼠BW及AGD/BW在实验组分别为(8.90±1.25)只、(5.12±0.24)g、(0.57±0.03)mm/g,在对照组分别为(13.20±1.46)只、(6.72±0.42)g、(0.66±0.07)mm/g,差异有统计学意义(P<0.05);galectin-3在尿道下裂组的相对表达量为0.603±0.014(n=10),正常对照组为0.851±0.015(n=10),差异有统计学意义(P<0.05);galectin-3主要定位于生殖结节上皮细胞,尿道下裂组染色强度明显弱于对照组.结论 染毒期间DBP对雄性子鼠有明显毒性作用,改变了生殖结节中galectin-3的表达,影响了上皮细胞增殖、凋亡及尿生殖褶的融合.%Objective To verify the differential expression of galectin-3 in the genital tubercle (GT) of hypospadiac rats induced by maternal exposure to Di-n-butyl phthalate (DBP) and normal control rats in order to further explore the mechanism of hypospadias. Methods Twenty pregnant SD rats were randomly divided into two groups which were given DBP and soybean oil gavage at the dose of 800 mg/(kg·d) and 2 ml/d separately during the 14-18th day of pregnancy. Fetal rats per fossa, birth weight ( BW) , ano-genital distance (AGD), hapospadias incidence, and harvested GT of fetal rats at GD19.The expression of galectin-3 was analyzed by Western blotting and immunohistochemistry. Results The

  2. Small Molecule Inhibitors of Bcl-2 Family Proteins for Pancreatic Cancer Therapy

    International Nuclear Information System (INIS)

    Pancreatic cancer (PC) has a complex etiology and displays a wide range of cellular escape pathways that allow it to resist different treatment modalities. Crucial signaling molecules that function downstream of the survival pathways, particularly at points where several of these pathways crosstalk, provide valuable targets for the development of novel anti-cancer drugs. Bcl-2 family member proteins are anti-apoptotic molecules that are known to be overexpressed in most cancers including PC. The anti-apoptotic machinery has been linked to the observed resistance developed to chemotherapy and radiation and therefore is important from the targeted drug development point of view. Over the past ten years, our group has extensively studied a series of small molecule inhibitors of Bcl-2 against PC and provide solid preclinical platform for testing such novel drugs in the clinic. This review examines the efficacy, potency, and function of several small molecule inhibitor drugs targeted to the Bcl-2 family of proteins and their preclinical progress against PC. This article further focuses on compounds that have been studied the most and also discusses the anti-cancer potential of newer class of Bcl-2 drugs

  3. Expressão de galectina-3 e beta-catenina em lesões pré-malignas e carcinomatosas de língua de camundongos Galectin-3 and beta-catenin expression in premalignant and carcinomatous lesions in tongue of mice

    Directory of Open Access Journals (Sweden)

    Juliana Moreira de Almeida Sant'ana

    2011-02-01

    Full Text Available INTRODUÇÃO: A galectina-3 (GAL3 apresenta importantes papéis na biologia tumoral e recentemente foi mostrada a sua participação na via de sinalização Wnt, translocando a beta-catenina para o núcleo. Expressão alterada de GAL3 e beta-catenina tem sido descrita em cânceres, mas não há estudos avaliando a expressão de ambas em displasias e carcinomas desenvolvidos em modelos de carcinogênese de língua. OBJETIVOS: Estudar a expressão de GAL3 e beta-catenina em lesões displásicas e carcinomas induzidos experimentalmente em língua de camundongos. MATERIAL E MÉTODOS: Vinte camundongos C57BL/6 machos foram desafiados com 4NQO na água de beber por 16 semanas e sacrificados na semana 16 e 32. Após o sacrifício, as línguas foram removidas, processadas, coradas por hematoxilina e eosina (HE para detecção de displasias e carcinomas. Ensaio imuno-histoquímico foi realizado para determinar o índice de positividade para GAL3 e beta-catenina nessas lesões, bem como uma correlação entre elas em carcinomas. RESULTADOS: O número de camundongos afetados por carcinoma aumentou entre as semanas 16 e 32 (22,2% vs. 88,9% e o de displasia diminuiu (66,7% vs. 11,1%. Um aumento de células positivas para beta-catenina não membranosa e GAL3 citoplasmática foi observado nas displasias e nos carcinomas, mas essa diferença não foi estatisticamente significativa. No entanto, um aumento estatisticamente significativo de GAL3 nuclear foi observado na evolução de displasia para carcinoma (p = 0,04. Nenhuma correlação foi encontrada entre beta-catenina e GAL3. CONCLUSÃO: Tanto nas displasias quanto nos carcinomas a via de sinalização Wnt está ativa, e o aumento de GAL3 nuclear nos carcinomas sugere um papel na transformação maligna do epitélio lingual.INTRODUCTION: Galectin-3 plays pivotal role in tumor biology and its participation in Wnt signaling pathway translocating beta-catenin into the nucleus has been recently demonstrated

  4. Small molecules reveal an alternative mechanism of Bax activation.

    Science.gov (United States)

    Brahmbhatt, Hetal; Uehling, David; Al-Awar, Rima; Leber, Brian; Andrews, David

    2016-04-15

    The pro-apoptotic protein Bax commits a cell to death by permeabilizing the mitochondrial outer membrane (MOM). To obtain small-molecule probes for elucidating the molecular mechanism(s) of Bax activation, we screened for compounds that induced Bax-mediated liposome permeabilization. We identified five structurally different small molecules that promoted both Bax targeting to and oligomerization at membranes. All five compounds initiated Bax oligomerization in the absence of membranes by a mechanism unlike Bax activation by Bcl-2 homology 3 domain (BH3) proteins. Some of the compounds induced Bax/Bak-dependent apoptosis in cells. Activation of Bax by the most active compound was poorly inhibited by the anti-apoptotic protein Bcl-XL and requires a cysteine residue at position 126 of Bax that is not required for activation by BH3 proteins. Our results reveal a novel pathway for Bax activation independent of pro-apoptotic BH3 proteins that may have important implications for the regulation of Bax activity in cells. PMID:26916338

  5. Oncostatic-Cytoprotective Effect of Melatonin and Other Bioactive Molecules: A Common Target in Mitochondrial Respiration.

    Science.gov (United States)

    Pacini, Nicola; Borziani, Fabio

    2016-01-01

    For several years, oncostatic and antiproliferative properties, as well as thoses of cell death induction through 5-methoxy-N-acetiltryptamine or melatonin treatment, have been known. Paradoxically, its remarkable scavenger, cytoprotective and anti-apoptotic characteristics in neurodegeneration models, such as Alzheimer's disease and Parkinson's disease are known too. Analogous results have been confirmed by a large literature to be associated to the use of many other bioactive molecules such as resveratrol, tocopherol derivatives or vitamin E and others. It is interesting to note that the two opposite situations, namely the neoplastic pathology and the neurodegeneration, are characterized by deep alterations of the metabolome, of mitochondrial function and of oxygen consumption, so that the oncostatic and cytoprotective action can find a potential rationalization because of the different metabolic and mitochondrial situations, and in the effect that these molecules exercise on the mitochondrial function. In this review we discuss historical and general aspects of melatonin, relations between cancers and the metabolome and between neurodegeneration and the metabolome, and the possible effects of melatonin and of other bioactive molecules on metabolic and mitochondrial dynamics. Finally, we suggest a common general mechanism as responsible for the oncostatic/cytoprotective effect of melatonin and of other molecules examined. PMID:26959015

  6. Oncostatic-Cytoprotective Effect of Melatonin and Other Bioactive Molecules: A Common Target in Mitochondrial Respiration

    Directory of Open Access Journals (Sweden)

    Nicola Pacini

    2016-03-01

    Full Text Available For several years, oncostatic and antiproliferative properties, as well as thoses of cell death induction through 5-methoxy-N-acetiltryptamine or melatonin treatment, have been known. Paradoxically, its remarkable scavenger, cytoprotective and anti-apoptotic characteristics in neurodegeneration models, such as Alzheimer’s disease and Parkinson’s disease are known too. Analogous results have been confirmed by a large literature to be associated to the use of many other bioactive molecules such as resveratrol, tocopherol derivatives or vitamin E and others. It is interesting to note that the two opposite situations, namely the neoplastic pathology and the neurodegeneration, are characterized by deep alterations of the metabolome, of mitochondrial function and of oxygen consumption, so that the oncostatic and cytoprotective action can find a potential rationalization because of the different metabolic and mitochondrial situations, and in the effect that these molecules exercise on the mitochondrial function. In this review we discuss historical and general aspects of melatonin, relations between cancers and the metabolome and between neurodegeneration and the metabolome, and the possible effects of melatonin and of other bioactive molecules on metabolic and mitochondrial dynamics. Finally, we suggest a common general mechanism as responsible for the oncostatic/cytoprotective effect of melatonin and of other molecules examined.

  7. 乙醛脱氢酶2在糖尿病大鼠心肌缺血/再灌注损伤中的抗凋亡作用%Anti-apoptotic role of mitochondrial aldehyde dehydrogenase 2 in myocardial ischemia/reperfusion injury in diabetic rats

    Institute of Scientific and Technical Information of China (English)

    王洪巨; 康品方; 叶红伟; 于影; 王晓梅; 高琴

    2012-01-01

    目的 观察乙醛脱氢酶2(ALDH2)在糖尿病大鼠心肌缺血/再灌注凋亡发生中的作用.方法 大鼠分为正常组、糖尿病组和ALDH2激动剂乙醇+糖尿病组.4周后行离体心肌缺血/再灌注(I/R).测定复灌期间冠脉流出液中乳酸脱氢酶(LDH)含量.检测心肌组织细胞ALDH2、caspase-3的活性;RT-PCR测定左心室前壁心尖组织Bcl-2、Bax mRNA的表达.结果 与正常大鼠I/R相比,糖尿病大鼠复灌期冠脉流出液中LDH释放增加,心肌组织caspase-3活性增加,ALDH2活性降低,Bcl-2/Bax mRNA比值降低;与糖尿病大鼠心肌I/R相比,ALDH2激动剂乙醇使得心肌复灌期间冠脉流出液中LDH释放减少,心肌caspase,-3活性降低,ALDH2活性增高,Bcl-2/Bax mRNA比值增高.结论 增强ALDH2在糖尿病大鼠心肌中的表达对缺血/再灌注损伤有明显的保护作用;其机制可能与抑制细胞凋亡的发生有关.%Objective To evaluate the anti-apoptotic effect of aldehyde dehydrogenase 2 (ALDH2) on myocardial ischemia/ reperfusion (I/R) injury in diabetic rats. Methods Normal male SD rats were divided into normal, diabetes and ethanol (the agonist of ALDH2) + diabetes groups. In the latter two groups, diabetes was induced by an intraperitoneal injection of 55 mg/kg STZ. Four weeks after the modeling, myocardial I/R was mimicked ex vivo, and lactate dehydrogenase (LDH) content in the coronary flow was determined. The activities of caspase-3 and ALDH2 were evaluated, and the expressions of Bd-2 and Bax mRNA in the left anterior myocardium were detected using RT-PCR. Results In diabetic group, LDH release and caspase-3 activity were increased, while ALDH2 activity and Bd-2/Bax mRNA expression were decreased as compared to those in normal control group. Compared with the diabetic group, ALDH2 agonist ethanol significantly reduced LDH release and caspase-3 activity, increased ALDH2 activity and Bd-2/Bax mRNA expression. Condusion In diabetic rats, enhanced ALDH2 expression

  8. The conveyor belt hypothesis for thymocyte migration: participation of adhesion and de-adhesion molecules

    Directory of Open Access Journals (Sweden)

    Villa-Verde D.M.S.

    1999-01-01

    Full Text Available Thymocyte differentiation is the process by which bone marrow-derived precursors enter the thymus, proliferate, rearrange the genes and express the corresponding T cell receptors, and undergo positive and/or negative selection, ultimately yielding mature T cells that will represent the so-called T cell repertoire. This process occurs in the context of cell migration, whose cellular and molecular basis is still poorly understood. Kinetic studies favor the idea that these cells leave the organ in an ordered pattern, as if they were moving on a conveyor belt. We have recently proposed that extracellular matrix glycoproteins, such as fibronectin, laminin and type IV collagen, among others, produced by non-lymphoid cells both in the cortex and in the medulla, would constitute a macromolecular arrangement allowing differentiating thymocytes to migrate. Here we discuss the participation of both molecules with adhesive and de-adhesive properties in the intrathymic T cell migration. Functional experiments demonstrated that galectin-3, a soluble ß-galactoside-binding lectin secreted by thymic microenvironmental cells, is a likely candidate for de-adhesion proteins by decreasing thymocyte interaction with the thymic microenvironment.

  9. Photoisomerisable molecules

    OpenAIRE

    Peris Fajarnes, Eduardo Víctor; Mata Martínez, José Antonio; Márquez Linares, Francisco Manuel; Sabater Picot, María José

    2005-01-01

    [EN] The invention relates to a molecule comprising at least one carbon-carbon double bond which is substituted by at least one cyclopentadienyl-metal-cyclopentadienyl complex, having the cis/trans isomerisation property, in a reversible manner in response to the absorption of light. Preferably, the rest of the molecule comprises a dendrimer of any generation, advantageously of the polypropylenimine octaamine type. The inventive molecule can be used as a molecular switch and in various differ...

  10. Enumerating molecules.

    Energy Technology Data Exchange (ETDEWEB)

    Visco, Donald Patrick, Jr. (, . Tennessee Technological University, Cookeville, TN); Faulon, Jean-Loup Michel; Roe, Diana C.

    2004-04-01

    This report is a comprehensive review of the field of molecular enumeration from early isomer counting theories to evolutionary algorithms that design molecules in silico. The core of the review is a detail account on how molecules are counted, enumerated, and sampled. The practical applications of molecular enumeration are also reviewed for chemical information, structure elucidation, molecular design, and combinatorial library design purposes. This review is to appear as a chapter in Reviews in Computational Chemistry volume 21 edited by Kenny B. Lipkowitz.

  11. Chinese herb related molecules of cancer-cell-apoptosis: a minireview of progress between Kanglaite injection and related genes

    Directory of Open Access Journals (Sweden)

    Dong Qian

    2008-08-01

    Full Text Available Abstract Many kinds of Chinese herb had been confirmed to have the character of anti-tumor, clinical reports about anti-tumor effects of Chinese herb had also been found in recent years, but most of the reports were focused on the clinical treatment of effectiveness for Chinese herb, on the other hand, review about Chinese herbal related with molecules on cancer-cell-apoptosis was seldom, many scientists could not believe such kinds of clinical describes about anti-tumor effects for Chinese herb, because these describes were lack of molecular biology evidence. Kanglaite(KLT injection is an anti-tumor new drug which extracts from Chinese medicine-coix seed with modern advanced pharmaceutical technology, it is also a new biphase extended-spectrum anticancer medicine, the food and drug administration(FDA of United States also approved a phase II trial of KLT to test its efficacy in treating non-small-cell lung cancer. Some studies show it could inhibit some anti-apoptotic gene and activate some pro-apoptotic gene, its injection solution is one of the new anticancer medicine that can significantly inhibit a various kinds of tumor cells, so it has become the core of research that how to further explore KLT injection to promote tumor cell apoptosis by impacting on related genes. In this review, the relationship between KLT and some tumor cell apoptosis molecules had been discussed and reviewed generally.

  12. Chinese herb related molecules of cancer-cell-apoptosis: a minireview of progress between Kanglaite injection and related genes.

    Science.gov (United States)

    Lu, Yun; Li, Chang-Sheng; Dong, Qian

    2008-01-01

    Many kinds of Chinese herb had been confirmed to have the character of anti-tumor, clinical reports about anti-tumor effects of Chinese herb had also been found in recent years, but most of the reports were focused on the clinical treatment of effectiveness for Chinese herb, on the other hand, review about Chinese herbal related with molecules on cancer-cell-apoptosis was seldom, many scientists could not believe such kinds of clinical describes about anti-tumor effects for Chinese herb, because these describes were lack of molecular biology evidence. Kanglaite(KLT) injection is an anti-tumor new drug which extracts from Chinese medicine-coix seed with modern advanced pharmaceutical technology, it is also a new biphase extended-spectrum anticancer medicine, the food and drug administration(FDA) of United States also approved a phase II trial of KLT to test its efficacy in treating non-small-cell lung cancer. Some studies show it could inhibit some anti-apoptotic gene and activate some pro-apoptotic gene, its injection solution is one of the new anticancer medicine that can significantly inhibit a various kinds of tumor cells, so it has become the core of research that how to further explore KLT injection to promote tumor cell apoptosis by impacting on related genes. In this review, the relationship between KLT and some tumor cell apoptosis molecules had been discussed and reviewed generally. PMID:18718024

  13. Simultaneous gene silencing of KRAS and anti-apoptotic genes as a multitarget therapy

    Science.gov (United States)

    Werner, Kristin; Lademann, Franziska; Thepkaysone, May-Linn; Jahnke, Beatrix; Aust, Daniela E.; Kahlert, Christoph; Weber, Georg; Weitz, Jürgen; Grützmann, Robert; Pilarsky, Christian

    2016-01-01

    Pancreatic cancer is one of the most lethal tumor types worldwide and an effective therapy is still elusive. Targeted therapy focused against a specific alteration is by definition unable to attack broad pathway signaling modification. Tumor heterogeneity will render targeted therapies ineffective based on the regrowth of cancer cell sub-clones. Therefore multimodal therapy strategies, targeting signaling pathways simultaneously should improve treatment. SiRNAs against KRAS and the apoptosis associated genes BCLXL, FLIP, MCL1L, SURVIVIN and XIAP were transfected into human and murine pancreatic cancer cell lines. Induction of apoptosis was measured by Caspase 3/7 activation, subG1 FACS analysis and PARP cleavage. The therapeutic approach was tested in a subcutaneous allograft model with a murine cancer cell line. By using siRNAs as a systematic approach to remodel signal transduction in pancreatic cancer the results showed increasing inhibition of proliferation and apoptosis induction in vitro and in vivo. Thus, siRNAs are suitable to model multimodal therapy against signaling pathways in pancreatic cancer. Improvements in in vivo delivery of siRNAs against a multitude of targets might therefore be a potential therapeutic approach. PMID:26716649

  14. Homologous recombination control by the anti-apoptotic onco-protein Bcl-2

    International Nuclear Information System (INIS)

    This research thesis deals with the different biological mechanisms, notably the repair and apoptosis mechanisms induced by irradiation in cells. After a presentation of the genotoxic stress and DNA repair mechanisms, the author discusses the cellular response to a DNA double-strand break, and the regulation of these response mechanisms (how a cellular response emerges: life or death). The next part deals with the apoptosis (cell death by necrosis or apoptosis), and presents the BCL-2 protein family. Results are then reported on laboratory studies of the effect of this protein family

  15. Integrin-linked kinase: a hypoxia-induced anti-apoptotic factor exploited by cancer cells.

    Science.gov (United States)

    Abboud, Elizabeth R; Coffelt, Seth B; Figueroa, Yanira G; Zwezdaryk, Kevin J; Nelson, Anne B; Sullivan, Deborah E; Morris, Cindy B; Tang, Yan; Beckman, Barbara S; Scandurro, Aline B

    2007-01-01

    Based on cDNA microarray results, integrin-linked kinase (ILK) emerged as an interesting candidate in hypoxia-mediated survival mechanisms employed by cancer cells. This notion was confirmed here by the following observations: the 5' promoter region of the ilk gene contains hypoxia responsive elements (HRE) that bind hypoxia-inducible factor (HIF) transcription factor complexes and drive HRE-luciferase gene expression in reporter assays; ILK protein and kinase activity are induced following hypoxia; downstream targets of ILK signaling are induced following hypoxia treatment; inhibition of ILK leads to increased apoptosis; and HIF and ILK are co-localized within human cancer tissues. The identification of ILK as a player in hypoxia survival signaling employed by cancer cells further validates ILK as a unique target for cancer therapy. PMID:17143519

  16. Mechanisms of 4-Hydroxy-2-nonenal Induced Pro- and Anti-Apoptotic Signaling

    OpenAIRE

    Chaudhary, Pankaj; Sharma, Rajendra; Sharma, Abha; Vatsyayan, Rit; Yadav, Sushma; SINGHAL, SHARAD S.; Rauniyar, Navin; Prokai, Laszlo; Awasthi, Sanjay; Awasthi, Yogesh C.

    2010-01-01

    In recent years, 4-hydroxy-2-nonenal (4-HNE) has emerged as an important second messenger in cell cycle signaling. Here we demonstrate that 4-HNE induces signaling for apoptosis via both, the Fas mediated extrinsic and the p53 mediated intrinsic pathways in HepG2 cells. 4-HNE induces Fas-mediated DISC independent apoptosis pathway by activating ASK1, JNK and caspase-3. In parallel treatment of 4-HNE to HepG2 cells also induces apoptosis by p53 pathway through activation of Bax, p21, JNK, and ...

  17. Investigations of extracellular matrix proteases, apoptotic and anti-apoptotic factors in the bovine corpus luteum

    OpenAIRE

    Kliem, Heike

    2006-01-01

    The study is subdivided into two different parts: the first part deals with the development of a method to gain uterus milk in vivo during the preimplantation periode in cattle for the investigation of regulatory factors. The second part investigates different proteases in bovine follicles 20 hours after GnRH (Gonadotropin releasing hormone) injection (shortly bevor ovulation) for comparable as well as in the corpus luteum (CL) during oestrous cycle and induced luteolysis. In addition apoptot...

  18. Anti-apoptotic role of Sonic hedgehog protein at the early stages of nervous system organogenesis.

    Science.gov (United States)

    Charrier, J B; Lapointe, F; Le Douarin, N M; Teillet, M A

    2001-10-01

    In vertebrates the neural tube, like most of the embryonic organs, shows discreet areas of programmed cell death at several stages during development. In the chick embryo, cell death is dramatically increased in the developing nervous system and other tissues when the midline cells, notochord and floor plate, are prevented from forming by excision of the axial-paraxial hinge (APH), i.e. caudal Hensen's node and rostral primitive streak, at the 6-somite stage ( Charrier, J. B., Teillet, M.-A., Lapointe, F. and Le Douarin, N. M. (1999). Development 126, 4771-4783). In this paper we demonstrate that one day after APH excision, when dramatic apoptosis is already present in the neural tube, the latter can be rescued from death by grafting a notochord or a floor plate fragment in its vicinity. The neural tube can also be recovered by transplanting it into a stage-matched chick embryo having one of these structures. In addition, cells engineered to produce Sonic hedgehog protein (SHH) can mimic the effect of the notochord and floor plate cells in in situ grafts and transplantation experiments. SHH can thus counteract a built-in cell death program and thereby contribute to organ morphogenesis, in particular in the central nervous system. PMID:11641224

  19. Human RIF1 encodes an anti-apoptotic factor required for DNA repair

    OpenAIRE

    Wang, Haibo; Zhao, Ailian; Chen, Lin; Zhong, Xueyan; Liao, Ji; Gao, Min; Cai, Minghua; Lee, Dong-Hyun; Jing LI; Chowdhury, Dipanjan; Yang, Yun-Gui; Pfeifer, Gerd P.; Yen, Yun; Xu, Xingzhi

    2009-01-01

    Human Rap1-interacting protein 1 (RIF1) contributes to the ataxia telangiectasia, mutated-mediated DNA damage response against the dexterous effect of DNA lesions and plays a critical role in the S-phase checkpoint. However, the molecular mechanisms by which human RIF1 conquers DNA aberrations remain largely unknown. We here showed that inhibition of RIF1 expression by small interfering RNA led to defective homologous recombination-mediated DNA double-strand break repair and sensitized cancer...

  20. Proliferation and survival molecules implicated in the inhibition of BRAF pathway in thyroid cancer cells harbouring different genetic mutations

    International Nuclear Information System (INIS)

    Thyroid carcinomas show a high prevalence of mutations in the oncogene BRAF which are inversely associated with RAS or RET/PTC oncogenic activation. The possibility of using inhibitors on the BRAF pathway as became an interesting therapeutic approach. In thyroid cancer cells the target molecules, implicated on the cellular effects, mediated by inhibition of BRAF are not well established. In order to fill this lack of knowledge we studied the proliferation and survival pathways and associated molecules induced by BRAF inhibition in thyroid carcinoma cell lines harbouring distinct genetic backgrounds. Suppression of BRAF pathway in thyroid cancer cell lines (8505C, TPC1 and C643) was achieved using RNA interference (RNAi) for BRAF and the kinase inhibitor, sorafenib. Proliferation analysis was performed by BrdU incorporation and apoptosis was accessed by TUNEL assay. Levels of protein expression were analysed by western-blot. Both BRAF RNAi and sorafenib inhibited proliferation in all the cell lines independently of the genetic background, mostly in cells with BRAFV600E mutation. In BRAFV600E mutated cells inhibition of BRAF pathway lead to a decrease in ERK1/2 phosphorylation and cyclin D1 levels and an increase in p27Kip1. Specific inhibition of BRAF by RNAi in cells with BRAFV600E mutation had no effect on apoptosis. In the case of sorafenib treatment, cells harbouring BRAFV600E mutation showed increase levels of apoptosis due to a balance of the anti-apoptotic proteins Mcl-1 and Bcl-2. Our results in thyroid cancer cells, namely those harbouring BRAFV600Emutation showed that BRAF signalling pathway provides important proliferation signals. We have shown that in thyroid cancer cells sorafenib induces apoptosis by affecting Mcl-1 and Bcl-2 in BRAFV600E mutated cells which was independent of BRAF. These results suggest that sorafenib may prove useful in the treatment of thyroid carcinomas, particularly those refractory to conventional treatment and harbouring BRAF

  1. CD molecules 2005: human cell differentiation molecules

    Czech Academy of Sciences Publication Activity Database

    Zola, H.; Swart, B.; Nicholson, I.; Aasted, B.; Bensussan, A.; Boumsell, L.; Buckley, C.; Clark, G.; Drbal, Karel; Engel, P.; Hart, D.; Hořejší, Václav; Isacke, C.; Macardle, P.; Malavasi, F.; Mason, D.; Olive, D.; Saalmüller, A.; Schlossman, S.F.; Schwartz-Albiez, R.; Simmons, P.; Tedder, T.F.; Uguccioni, M.; Warren, H.

    2005-01-01

    Roč. 106, č. 9 (2005), s. 3123-3126. ISSN 0006-4971 Institutional research plan: CEZ:AV0Z5052915 Keywords : CD molecules * leukocyte antigen Subject RIV: EC - Immunology Impact factor: 10.131, year: 2005

  2. Apoptosis-related molecules and radiation response in human oral cancers

    International Nuclear Information System (INIS)

    The ability of the tumor cells to respond to radiotherapy depends upon their intrinsic radiosensitivity, which may be partly governed by molecules of the intrinsic cell death pathway. To identify the defects in this pathway in oral cancers, transcript expression analysis of the pathway members was done using the Ribonuclease protection assay in oral cell lines and tumors. The intrinsic apoptosis pathway was found to be deregulated in oral cell lines and majority of oral tumors with altered expression of Mcl-l, bclxl, survivin, p53 and p16 mRNA. To identify factors associated with radiosensitivity, differential gene expression profiles of radiation-treated versus untreated oral cell lines of differing radiosensitivities was carried out. To assess the predictive value of above altered molecules in radiotherapy outcome in oral cancer patients, pretreated biopsies from thirty nine oral cancer patients were examined for the expression of the apoptotic markers using immunohistochemistry and their expression was correlated with the clinico pathological parameters. High expression of Mcl-1 (p = 0.05) and PCNA (p = 0.007) was seen to be associated with poor disease free survival. High expression of Bcl-xL was associated with poor response to radiotherapy treatment. PCNA (p=0.04) and Mcl-1 (p=0.05) emerged as independent prognostic markers for predicting disease free survival in oral cancers treated with primary radiotherapy. A predominant overexpression of anti-apoptotic Mcl-1L over pro-apoptotic Mcl-1S isoform was observed in the oral cancer cell lines and oral tumors. An inverse correlation was observed between Mcl-1L expression and apoptosis induction in AW8507 cell line post-radiation treatment supporting its pro-survival role. A rapid and short induction of Mcl-1L versus sustained induction of Mcl-1L was observed in the relatively more radiosensitive FBM versus AW8507 respectively. siRNA treatment in combination with IR demonstrated significant induction of apoptosis

  3. Formation of Ultracold Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Cote, Robin [Univ. of Connecticut, Storrs, CT (United States)

    2016-01-28

    Advances in our ability to slow down and cool atoms and molecules to ultracold temperatures have paved the way to a revolution in basic research on molecules. Ultracold molecules are sensitive of very weak interactions, even when separated by large distances, which allow studies of the effect of those interactions on the behavior of molecules. In this program, we have explored ways to form ultracold molecules starting from pairs of atoms that have already reached the ultracold regime. We devised methods that enhance the efficiency of ultracold molecule production, for example by tuning external magnetic fields and using appropriate laser excitations. We also investigates the properties of those ultracold molecules, especially their de-excitation into stable molecules. We studied the possibility of creating new classes of ultra-long range molecules, named macrodimers, thousand times more extended than regular molecules. Again, such objects are possible because ultra low temperatures prevent their breakup by collision. Finally, we carried out calculations on how chemical reactions are affected and modified at ultracold temperatures. Normally, reactions become less effective as the temperature decreases, but at ultracold temperatures, they can become very effective. We studied this counter-intuitive behavior for benchmark chemical reactions involving molecular hydrogen.

  4. Trapping molecules on chips

    CERN Document Server

    Santambrogio, Gabriele

    2015-01-01

    In the last years, it was demonstrated that neutral molecules can be loaded on a microchip directly from a supersonic beam. The molecules are confined in microscopic traps that can be moved smoothly over the surface of the chip. Once the molecules are trapped, they can be decelerated to a standstill, for instance, or pumped into selected quantum states by laser light or microwaves. Molecules are detected on the chip by time-resolved spatial imaging, which allows for the study of the distribution in the phase space of the molecular ensemble.

  5. Galectin-3 is a new MerTK-specific eat-me signal

    OpenAIRE

    Caberoy, Nora B.; Alvarado, Gabriela; Bigcas, Jo-Lawrence; Li, Wei

    2012-01-01

    Phagocytosis of apoptotic cells and cellular debris is a critical process of maintaining tissue and immune homeostasis. Defects in the phagocytosis process cause autoimmunity and degenerative diseases. Phagocytosis ligands or “eat-me” signals control the initiation of the process by linking apoptotic cells to receptors on phagocyte surface and triggering signaling cascades for cargo engulfment. Eat-me signals are traditionally identified on a case-by-case basis with challenges, and the identi...

  6. Galectin-3 binding protein links circulating microparticles with electron dense glomerular deposits in lupus nephritis

    DEFF Research Database (Denmark)

    Nielsen, C T; Østergaard, O; Rekvig, O P;

    2015-01-01

    , explore putative clinical correlates, and examine if G3BP is present in immune complex deposits in kidney biopsies from patients with lupus nephritis. METHODS: Numbers of annexin V-binding and G3BP-exposing plasma microparticles from 56 SLE patients and 36 healthy controls were determined by flow...... kidney biopsies from one non-SLE control and from patients with class IV (n = 2) and class V (n = 1) lupus nephritis using co-localization immune electron microscopy. RESULTS: Microparticle-G3BP, microparticle-C1q and microparticle-immunoglobulins were significantly (P < 0.01) increased in SLE patients...... disease activity were found. Immune electron microscopy showed co-localization of G3BP with in vivo-bound IgG in glomerular electron dense immune complex deposits in all lupus nephritis biopsies. CONCLUSIONS: Both circulating microparticle-G3BP numbers as well as G3BP expression are increased in SLE...

  7. Electron correlation in molecules

    CERN Document Server

    Wilson, S

    2007-01-01

    Electron correlation effects are of vital significance to the calculation of potential energy curves and surfaces, the study of molecular excitation processes, and in the theory of electron-molecule scattering. This text describes methods for addressing one of theoretical chemistry's central problems, the study of electron correlation effects in molecules.Although the energy associated with electron correlation is a small fraction of the total energy of an atom or molecule, it is of the same order of magnitude as most energies of chemical interest. If the solution of quantum mechanical equatio

  8. Electron-molecule collisions

    CERN Document Server

    Takayanagi, Kazuo

    1984-01-01

    Scattering phenomena play an important role in modern physics. Many significant discoveries have been made through collision experiments. Amongst diverse kinds of collision systems, this book sheds light on the collision of an electron with a molecule. The electron-molecule collision provides a basic scattering problem. It is scattering by a nonspherical, multicentered composite particle with its centers having degrees of freedom of motion. The molecule can even disintegrate, Le., dissociate or ionize into fragments, some or all of which may also be molecules. Although it is a difficult problem, the recent theoretical, experimental, and computational progress has been so significant as to warrant publication of a book that specializes in this field. The progress owes partly to technical develop­ ments in measurements and computations. No less important has been the great and continuing stimulus from such fields of application as astrophysics, the physics of the earth's upper atmosphere, laser physics, radiat...

  9. Single molecules and nanotechnology

    CERN Document Server

    Vogel, Horst

    2007-01-01

    This book focuses on recent advances in the rapidly evolving field of single molecule research. These advances are of importance for the investigation of biopolymers and cellular biochemical reactions, and are essential to the development of quantitative biology. Written by leading experts in the field, the articles cover a broad range of topics, including: quantum photonics of organic dyes and inorganic nanoparticles their use in detecting properties of single molecules the monitoring of single molecule (enzymatic) reactions single protein (un)folding in nanometer-sized confined volumes the dynamics of molecular interactions in biological cells The book is written for advanced students and scientists who wish to survey the concepts, techniques and results of single molecule research and assess them for their own scientific activities.

  10. Optothermal Molecule Trap

    OpenAIRE

    Duhr, Stefan; Braun, Dieter

    2006-01-01

    Thermophoresis moves molecules along temperature gradients, typically from hot to cold. We superpose fluid flow with thermophoretic molecule flow under well defined microfluidic conditions, imaged by fluorescence microscopy. DNA is trapped and accumulated 16-fold in regions where both flows move in opposite directions. Strong 800-fold accumulation is expected, however with slow trapping kinetics. The experiment is equally described by a three-dimensional and one-dimensional analytical model. ...

  11. Beneficial effects of carbon monoxide-releasing molecule-2 (CORM-2) on acute doxorubicin cardiotoxicity in mice: Role of oxidative stress and apoptosis

    International Nuclear Information System (INIS)

    Doxorubicin (DXR) has been used in variety of human malignancies for decades. Despite its efficacy in cancer, clinical usage is limited because of its cardiotoxicity, which has been associated with oxidative stress and apoptosis. Carbon monoxide-releasing molecules (CORMs) have been shown to reduce the oxidative damage and apoptosis. The present study investigated the effects of CORM-2, a fast CO-releaser, against DXR-induced cardiotoxicity in mice using biochemical, histopathological and gene expression approaches. CORM-2 (3, 10 and 30 mg/kg/day) was administered intraperitoneally (i.p.) for 10 days and terminated the study on day 11. DXR (20 mg/kg, i.p.) was injected before 72 h of termination. Mice treated with DXR showed cardiotoxicity as evidenced by elevation of serum creatine kinase (CK) and lactate dehydrogenase (LDH), tissue malondialdehyde (MDA), caspase-3 and decrease the level of total antioxidant status (TAS) in heart tissues. Pre- and post-treatment with CORM-2 (30 mg/kg, i.p.) elicited significant improvement in CK, LDH, MDA, caspase-3 and TAS levels. Histopathological studies showed that cardiac damage with DXR has been reversed with CORM-2 + DXR treatment. There was dramatic decrease in hematological count in DXR-treated mice, which has been improved with CORM-2. Furthermore, there was also elevation of mRNA expression of heme oxygenase-1, hypoxia inducible factor-1 alpha, vascular endothelial growth factor and decrease in inducible-nitric oxide synthase expression upon treatment with CORM-2 that might be linked to cardioprotection. These data suggest that CORM-2 treatment provides cardioprotection against acute doxorubicin-induced cardiotoxicity in mice and this effect may be attributed to CORM-2-mediated antioxidant and anti-apoptotic properties.

  12. Expression of human carcinoembryonic antigen-related cell adhesion molecule 6 and alveolar progenitor cells in normal and injured lungs of transgenic mice.

    Science.gov (United States)

    Lin, Shin-E; Barrette, Anne Marie; Chapin, Cheryl; Gonzales, Linda W; Gonzalez, Robert F; Dobbs, Leland G; Ballard, Philip L

    2015-12-01

    Carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) is expressed in the epithelium of various primate tissues, including lung airway and alveoli. In human lung, CEACAM6 is developmentally and hormonally regulated, protects surfactant function, has anti-apoptotic activity and is dysregulated in cancers. We hypothesized that alveolar CEACAM6 expression increases in lung injury and promotes cell proliferation during repair. Studies were performed in CEABAC transgenic mice-containing human CEACAM genes. The level of CEACAM6 in adult CEABAC lung was comparable to that in human infants; expression occurred in epithelium of airways and of some alveoli but rarely co-localized with markers of type I or type II cells. Ten days after bleomycin instillation, both the number of CEACAM6(+) cells and immunostaining intensity were elevated in injured lung areas, and there was increased co-localization with type I and II cell markers. To specifically address type II cells, we crossed CEABAC mice with animals expressing EGFP driven by the SP-C promoter. After bleomycin injury, partially flattened, elongated epithelial cells were observed that expressed type I cell markers and were primarily either EGFP(+) or CEACAM6(+). In cell cycle studies, mitosis was greater in CEACAM6(+) non-type II cells versus CEACAM6(+)/EGFP(+) cells. CEACAM6 epithelial expression was also increased after hyperoxic exposure and LPS instillation, suggesting a generalized response to acute lung injuries. We conclude that CEACAM6 expression is comparable in human lung and the CEABAC mouse. CEACAM6 in this model appears to be a marker of a progenitor cell population that contributes to alveolar epithelial cell replenishment after lung injury. PMID:26702074

  13. Towards single molecule switches.

    Science.gov (United States)

    Zhang, Jia Lin; Zhong, Jian Qiang; Lin, Jia Dan; Hu, Wen Ping; Wu, Kai; Xu, Guo Qin; Wee, Andrew T S; Chen, Wei

    2015-05-21

    The concept of using single molecules as key building blocks for logic gates, diodes and transistors to perform basic functions of digital electronic devices at the molecular scale has been explored over the past decades. However, in addition to mimicking the basic functions of current silicon devices, molecules often possess unique properties that have no parallel in conventional materials and promise new hybrid devices with novel functions that cannot be achieved with equivalent solid-state devices. The most appealing example is the molecular switch. Over the past decade, molecular switches on surfaces have been intensely investigated. A variety of external stimuli such as light, electric field, temperature, tunneling electrons and even chemical stimulus have been used to activate these molecular switches between bistable or even multiple states by manipulating molecular conformations, dipole orientations, spin states, charge states and even chemical bond formation. The switching event can occur either on surfaces or in break junctions. The aim of this review is to highlight recent advances in molecular switches triggered by various external stimuli, as investigated by low-temperature scanning tunneling microscopy (LT-STM) and the break junction technique. We begin by presenting the molecular switches triggered by various external stimuli that do not provide single molecule selectivity, referred to as non-selective switching. Special focus is then given to selective single molecule switching realized using the LT-STM tip on surfaces. Single molecule switches operated by different mechanisms are reviewed and discussed. Finally, molecular switches embedded in self-assembled monolayers (SAMs) and single molecule junctions are addressed. PMID:25757483

  14. Physical activation of molecules

    International Nuclear Information System (INIS)

    A brief review of processes of physical activation of molecules on the basis of phenomena of electronic and vibrational excitation, electron polarization is presented. Consideration is given to activation by electron impact, photo-, magneto- and mechanoactivation, as well as to radiation activation, proceeding under the effect of high-power radiations (102-107 eV). The character of disturbance of molecules, participating in chemical reactions, under the effect of different types of ionizing radiation (α-particles, electrons, γ-quanta etc.) is discussed

  15. Prebiologically Important Interstellar Molecules

    Science.gov (United States)

    Kuan, Y.-J.; Huang, H.-C.; Charnley, S. B.; Tseng, W.-L.; Snyder, L. E.; Ehrenfreund, P.; Kisiel, Z.; Thorwirth, S.; Bohn, R. K.; Wilson, T. L.

    2004-06-01

    Understanding the organic chemistry of molecular clouds, particularly the formation of biologically important molecules, is fundamental to the study of the processes which lead to the origin, evolution and distribution of life in the Galaxy. Determining the level of molecular complexity attainable in the clouds, and the nature of the complex organic material available to protostellar disks and the planetary systems that form from them, requires an understanding of the possible chemical pathways and is therefore a central question in astrochemistry. We have thus searched for prebiologically important molecules in the hot molecular cloud cores: Sgr B2(N-LMH), W51 e1/e2 and Orion-KL. Among the molecules searched: Pyrimidine is the unsubstituted ring analogue for three of the DNA and RNA bases. 2H-Azirine and Aziridine are azaheterocyclic compounds. And Glycine is the simplest amino acid. Detections of these interstellar organic molecular species will thus have important implications for Astrobiology. Our preliminary results indicate a tentative detection of interstellar glycine. If confirmed, this will be the first detection of an amino acid in interstellar space and will greatly strengthen the thesis that interstellar organic molecules could have played a pivotal role in the prebiotic chemistry of the early Earth.

  16. Atoms, Molecules, and Compounds

    CERN Document Server

    Manning, Phillip

    2007-01-01

    Explores the atoms that govern chemical processes. This book shows how the interactions between simple substances such as salt and water are crucial to life on Earth and how those interactions are predestined by the atoms that make up the molecules.

  17. Exotic helium molecules

    International Nuclear Information System (INIS)

    We study the photo-association of an ultracold cloud of magnetically trapped helium atoms: pairs of colliding atoms interact with one or two laser fields to produce a purely long range 4He2(23S1-23P0) molecule, or a 4He2(23S1-23S1) long range molecule. Light shifts in one photon photo-association spectra are measured and studied as a function of the laser polarization and intensity, and the vibrational state of the excited molecule. They result from the light-induced coupling between the excited molecule, and bound and scattering states of the interaction between two metastable atoms. Their analysis leads to the determination of the scattering length a = (7.2 ± 0.6) ruling collisions between spin polarized atoms. The two photon photo-association spectra show evidence of the production of polarized, long-range 4He2(23S1-23S1) molecules. They are said to be exotic as they are made of two metastable atoms, each one carrying a enough energy to ionize the other. The corresponding lineshapes are calculated and decomposed in sums and products of Breit-Wigner and Fano profiles associated to one and two photon processes. The experimental spectra are fit, and an intrinsic lifetime τ = (1.4 ± 0.3) μs is deduced. It is checked whether this lifetime could be limited by spin-dipole induced Penning autoionization. This interpretation requires that there is a quasi-bound state close to the dissociation threshold in the singlet interaction potential between metastable helium atoms for the theory to match the experiment. (author)

  18. OMG: Open Molecule Generator

    Directory of Open Access Journals (Sweden)

    Peironcely Julio E

    2012-09-01

    Full Text Available Abstract Computer Assisted Structure Elucidation has been used for decades to discover the chemical structure of unknown compounds. In this work we introduce the first open source structure generator, Open Molecule Generator (OMG, which for a given elemental composition produces all non-isomorphic chemical structures that match that elemental composition. Furthermore, this structure generator can accept as additional input one or multiple non-overlapping prescribed substructures to drastically reduce the number of possible chemical structures. Being open source allows for customization and future extension of its functionality. OMG relies on a modified version of the Canonical Augmentation Path, which grows intermediate chemical structures by adding bonds and checks that at each step only unique molecules are produced. In order to benchmark the tool, we generated chemical structures for the elemental formulas and substructures of different metabolites and compared the results with a commercially available structure generator. The results obtained, i.e. the number of molecules generated, were identical for elemental compositions having only C, O and H. For elemental compositions containing C, O, H, N, P and S, OMG produces all the chemically valid molecules while the other generator produces more, yet chemically impossible, molecules. The chemical completeness of the OMG results comes at the expense of being slower than the commercial generator. In addition to being open source, OMG clearly showed the added value of constraining the solution space by using multiple prescribed substructures as input. We expect this structure generator to be useful in many fields, but to be especially of great importance for metabolomics, where identifying unknown metabolites is still a major bottleneck.

  19. Bacterial invasion reconstructed molecule by molecule

    Energy Technology Data Exchange (ETDEWEB)

    Werner, James H [Los Alamos National Laboratory

    2009-01-01

    We propose to visualize the initial stages of bacterial infection of a human host cell with unmatched spatial and temporal resolution. This work will develop a new capability for the laboratory (super-resolution optical imaging), will test unresolved scientific hypotheses regarding host-pathogen interaction dynamics, and leverages state of the art 3D molecular tracking instrumentation developed recently by our group. There is much to be gained by applying new single molecule tools to the important and familiar problem of pathogen entry into a host cell. For example, conventional fluorescence microscopy has identified key host receptors, such as CD44 and {alpha}5{beta}1 integrin, that aggregate near the site of Salmonella typhimurium infection of human cells. However, due to the small size of the bacteria ({approx} 2 {micro}m) and the diffraction of the emitted light, one just sees a fluorescent 'blob' of host receptors that aggregate at the site of attachment, making it difficult to determine the exact number of receptors present or whether there is any particular spatial arrangement of the receptors that facilitates bacterial adhesion/entry. Using newly developed single molecule based super-resolution imaging methods, we will visualize how host receptors are directed to the site of pathogen adhesion and whether host receptors adopt a specific spatial arrangement for successful infection. Furthermore, we will employ our 3D molecular tracking methods to follow the injection of virulence proteins, or effectors, into the host cell by the pathogen Type III secretion system (TTSS). We expect these studies to provide mechanistic insights into the early events of pathogen infection that have here-to-fore been technically beyond our reach. Our Research Goals are: Goal 1--Construct a super-resolution fluorescence microscope and use this new capability to image the spatial distribution of different host receptors (e.g. CD44, as {alpha}5{beta}1 integrin) at the

  20. Molecules without electrons

    International Nuclear Information System (INIS)

    Electrons are the glue that holds the atoms in molecules together. Without them the positive charges of nuclei would repel each other, and the world would be a much simpler place. But in the quest to gain control over matter at a fundamental level, physicists in Russia and Canada have come up with a way of binding charged nuclei without any electrons. Instead the researchers use intense laser light. (U.K.)

  1. Atoms, molecules & elements

    CERN Document Server

    Graybill, George

    2007-01-01

    Young scientists will be thrilled to explore the invisible world of atoms, molecules and elements. Our resource provides ready-to-use information and activities for remedial students using simplified language and vocabulary. Students will label each part of the atom, learn what compounds are, and explore the patterns in the periodic table of elements to find calcium (Ca), chlorine (Cl), and helium (He) through hands-on activities.

  2. Single Molecule Mechanochemistry

    Science.gov (United States)

    Li, Shaowei; Zhang, Yanxing; Ho, Wilson; Wu, Ruqian; Ruqian Wu, Yanxing Zhang Team; Wilson Ho, Shaowei Li Team

    Mechanical forces can be used to trigger chemical reactions through bending and stretching of chemical bonds. Using the reciprocating movement of the tip of a scanning tunneling microscope (STM), mechanical energy can be provided to a single molecule sandwiched between the tip and substrate. When the mechanical pulse center was moved to the outer ring feature of a CO molecule, the reaction rate was significantly increased compared with bare Cu surface and over Au atoms. First, DFT calculations show that the presence of CO makes the Cu cavity more attractive toward H2 Second, H2 prefers the horizontal adsorption geometry in the Cu-Cu and Au-Cu cavities and no hybridization occurs between the antibonding states of H2 and states of Cu atoms. While H2 loses electrons from its bonding state in all three cavities, the filling of its anti-bonding state only occurs in the CO-Cu cavity. Both make the CO-Cu cavity much more effectively to chop the H2 molecule. Work was supported by the National Science Foundation Center for Chemical Innovation on Chemistry at the Space-Time Limit (CaSTL) under Grant No. CHE-1414466.

  3. Photonic Molecule Lasers Revisited

    Science.gov (United States)

    Gagnon, Denis; Dumont, Joey; Déziel, Jean-Luc; Dubé, Louis J.

    2014-05-01

    Photonic molecules (PMs) formed by coupling two or more optical resonators are ideal candidates for the fabrication of integrated microlasers, photonic molecule lasers. Whereas most calculations on PM lasers have been based on cold-cavity (passive) modes, i.e. quasi-bound states, a recently formulated steady-state ab initio laser theory (SALT) offers the possibility to take into account the spectral properties of the underlying gain transition, its position and linewidth, as well as incorporating an arbitrary pump profile. We will combine two theoretical approaches to characterize the lasing properties of PM lasers: for two-dimensional systems, the generalized Lorenz-Mie theory will obtain the resonant modes of the coupled molecules in an active medium described by SALT. Not only is then the theoretical description more complete, the use of an active medium provides additional parameters to control, engineer and harness the lasing properties of PM lasers for ultra-low threshold and directional single-mode emission. We will extend our recent study and present new results for a number of promising geometries. The authors acknowledge financial support from NSERC (Canada) and the CERC in Photonic Innovations of Y. Messaddeq.

  4. Hepatitis E virus ORF2 protein activates the pro-apoptotic gene CHOP and anti-apoptotic heat shock proteins.

    Directory of Open Access Journals (Sweden)

    Lijo John

    Full Text Available BACKGROUND: Hepatitis E virus (HEV is a non-enveloped plus-strand RNA virus that causes acute hepatitis. The capsid protein open reading frame 2 (ORF2 is known to induce endoplasmic reticulum stress in ORF2 expressing cells. METHODOLOGY/PRINCIPAL FINDINGS: In this study we found that HEV ORF2 activates the expression of the pro-apoptotic gene C/EBP homologous protein (CHOP. ORF2 stimulates the CHOP promoter mainly through AARE (amino acid response elements and to a minor extent the ERSE (endoplasmic reticulum stress response elements. Activating transcription factor 4 (ATF4 protein binds and activates the AARE regulatory sites of the CHOP promoter. ORF2 expression also leads to increased phosphorylation of eukaryotic initiation factor 2 alpha (eIF2α that in turn initiates the translation of ATF4 mRNA. The pro-apoptotic gene CHOP is an important trigger to initiate endoplasmic reticulum stress induced apoptosis. However, the activation of CHOP by ORF2 in this study did not induce apoptosis, nor did BCL2-associated X protein (Bax translocate to mitochondria. Microarray analysis revealed an ORF2 specific increased expression of chaperones Hsp72, Hsp70B', and co-chaperone Hsp40. Co-immunoprecipitation (Co-IP and in silico molecular docking analysis suggests that HEV ORF2 interacts with Hsp72. In addition, Hsp72 shows nuclear accumulation in ORF2 expressing cells. CONCLUSIONS/SIGNIFICANCE: These data provide new insight into simultaneously occurring counter-acting effects of HEV ORF2 that may be part of a strategy to prevent host suicide before completion of the viral replication cycle.

  5. Arctigenin Treatment Protects Against Brain Damage Through an Anti-inflammatory and Anti-apoptotic Mechanism After Needle Insertion

    OpenAIRE

    Jie Song; Na Li; Xia Yang; Zhong Gao; Liang Kong; Yingjia Yao; Yanan Jiao; Yuhui Yan; Shaoheng Li; Zhenyu Tao; Guan Lian; Jingxian Yang; Tingguo Kang

    2016-01-01

    Convection enhanced delivery (CED) infuses drugs directly into brain tissue. Needle insertion is required and results in a stab wound injury (SWI). Subsequent secondary injury involves the release of inflammatory and apoptotic cytokines, which have dramatic consequences on the integrity of damaged tissue, leading to the evolution of a pericontusional-damaged area minutes to days after in the initial injury. The present study investigated the capacity for arctigenin (ARC) to prevent secondary ...

  6. Identification of a novel senolytic agent, navitoclax, targeting the Bcl-2 family of anti-apoptotic factors.

    Science.gov (United States)

    Zhu, Yi; Tchkonia, Tamara; Fuhrmann-Stroissnigg, Heike; Dai, Haiming M; Ling, Yuanyuan Y; Stout, Michael B; Pirtskhalava, Tamar; Giorgadze, Nino; Johnson, Kurt O; Giles, Cory B; Wren, Jonathan D; Niedernhofer, Laura J; Robbins, Paul D; Kirkland, James L

    2016-06-01

    Clearing senescent cells extends healthspan in mice. Using a hypothesis-driven bioinformatics-based approach, we recently identified pro-survival pathways in human senescent cells that contribute to their resistance to apoptosis. This led to identification of dasatinib (D) and quercetin (Q) as senolytics, agents that target some of these pathways and induce apoptosis preferentially in senescent cells. Among other pro-survival regulators identified was Bcl-xl. Here, we tested whether the Bcl-2 family inhibitors, navitoclax (N) and TW-37 (T), are senolytic. Like D and Q, N is senolytic in some, but not all types of senescent cells: N reduced viability of senescent human umbilical vein epithelial cells (HUVECs), IMR90 human lung fibroblasts, and murine embryonic fibroblasts (MEFs), but not human primary preadipocytes, consistent with our previous finding that Bcl-xl siRNA is senolytic in HUVECs, but not preadipocytes. In contrast, T had little senolytic activity. N targets Bcl-2, Bcl-xl, and Bcl-w, while T targets Bcl-2, Bcl-xl, and Mcl-1. The combination of Bcl-2, Bcl-xl, and Bcl-w siRNAs was senolytic in HUVECs and IMR90 cells, while combination of Bcl-2, Bcl-xl, and Mcl-1 siRNAs was not. Susceptibility to N correlated with patterns of Bcl-2 family member proteins in different types of human senescent cells, as has been found in predicting response of cancers to N. Thus, N is senolytic and acts in a potentially predictable cell type-restricted manner. The hypothesis-driven, bioinformatics-based approach we used to discover that dasatinib (D) and quercetin (Q) are senolytic can be extended to increase the repertoire of senolytic drugs, including additional cell type-specific senolytic agents. PMID:26711051

  7. A Single Amino Acid Change (Asp 53→ Ala53) Converts Survivin from Anti-apoptotic to Pro-apoptotic

    Science.gov (United States)

    Song, Zhiyin; Liu, Shixin; He, He; Hoti, Naser; Wang, Yi; Feng, Shanshan; Wu, Mian

    2004-01-01

    Survivin is a member of the inhibitor of apoptosis protein (IAP) family that has been implicated in both apoptosis inhibition and cell cycle control. Recently, Survivin has attracted growing attention because of its tumor-specific expression and potential applications in tumor therapy. However, its inhibitory mechanism and subcellular localization remain controversial. Here, we report a novel Survivin mutant Surv-D53A, which displays a function opposite to Survivin and a distinctive subcellular distribution compared with its wild-type counterpart. Surv-D53A was shown to induce apoptosis in a p53-independent manner, indicating that tumor suppressor p53 is not involved in its apoptosis pathway. Surv-D53A was shown to markedly sensitize apoptosis induced by TRAIL, doxorubicin, and RIP3. We also demonstrated that similar to wild-type Survivin, Surv-D53A was localized in cytoplasm in interphase and to midbody at telophase. However, it fails to colocalize in chromosomes with Aurora-B in metaphase as wt-Survivin. Surv-D53A mutant is less stable than wt-Survivin and is degraded more rapidly by ubiquitin-proteasome pathway. Additionally, we found that Surv-D53A interacts with wt-Survivin to form heterodimer or with itself to form mutant homodimer, which may account for the loss of its antiapoptotic function. Finally, unlike Survivin*Survivin, neither Surv-D53A*Survivin nor Surv-D53A*Surv-D53A is able to bind to Smac/DIABLO, which may explain the underlying mechanism for its abolishment of antiapoptotic activity of Survivin. PMID:14699067

  8. A Single Amino Acid Change (Asp 53→ Ala53) Converts Survivin from Anti-apoptotic to Pro-apoptotic

    OpenAIRE

    Song, Zhiyin; Liu, Shixin; He, He; Hoti, Naser; Wang, Yi; Feng, Shanshan; Wu, Mian

    2004-01-01

    Survivin is a member of the inhibitor of apoptosis protein (IAP) family that has been implicated in both apoptosis inhibition and cell cycle control. Recently, Survivin has attracted growing attention because of its tumor-specific expression and potential applications in tumor therapy. However, its inhibitory mechanism and subcellular localization remain controversial. Here, we report a novel Survivin mutant Surv-D53A, which displays a function opposite to Survivin and a distinctive subcellul...

  9. Dynamical Binding of Hydrogen Bond Surrogate-Derived Bak Helices to Anti-apoptotic Protein Bcl-xL

    OpenAIRE

    Bao, Ju; Dong, Xiao Y.; John Z. H. Zhang; Arora, Paramjit S.

    2009-01-01

    A new peptide modification strategy was recently developed to replace the i to i+4 hydrogen bond of the main chain of an a-helix with a carbon-carbon covalent bond to afford highly stable constrained α-helices, termed Hydrogen Bond Surrogate (HBS) helices. HBS helices that mimic the Bak BH3 domains were experimentally demonstrated to target protein Bcl-xL with high affinity. In this study, molecular dynamics (MD) simulation is used to understand how the covalent modification of the natural Ba...

  10. Regulation of dental pulp stem cell's anti-apoptotic ability and proliferation through over-expression of Bcl-2

    OpenAIRE

    Liu, Yuan; 刘源

    2014-01-01

    The pulp organ is retained in the pulp chamber of teeth and maintains the biological and physiological vitality of the surrounding dentin. It works as a biosensor and generates secondary dentine and tertiary dentine to resist tooth abrasion and pathogenic stimuli (Zhang and Yelick, 2010). However, dental pulp is vulnerable to injury (Smulson and Sieraski, 1989). Most people experience some irreversible pulpal diseases during their lifetime. Hence, pulp regeneration is one of the research task...

  11. Candida albicans induces pro-inflammatory and anti-apoptotic signals in macrophages as revealed by quantitative proteomics and phosphoproteomics

    DEFF Research Database (Denmark)

    Reales-Calderón, Jose Antonio; Sylvester, Marc; Strijbis, Karin;

    2013-01-01

    Macrophages play a pivotal role in the prevention of Candida albicans infections. Yeast recognition and phagocytosis by macrophages is mediated by Pattern Recognition Receptors (PRRs) that initiate downstream signal transduction cascades by protein phosphorylation and dephosphorylation. We expose...

  12. Anti-apoptotic effect of San Huang Shel Shin Tang cyclodextrin complex (SHSSTc) on CCl4 -induced hepatotoxicity in rats.

    Science.gov (United States)

    Yang, Cheng-Hsun; Ting, Wei-Jen; Shen, Chia-Yao; Hsu, Hsi-Hsien; Lin, Yueh-Min; Kuo, Chia-Hua; Tsai, Fuu-Jen; Tsai, Chang-Hai; Tsai, Yuhsin; Huang, Chih-Yang

    2016-06-01

    The metabolic loading is heavier in liver especially when injured or inflammation. San Huang Shel Shin Tang (SHSST) was an old traditional herbal decoction, which composed with Rheum officinale Baill, Scutellaria baicalnsis Geprgi and Coptis chinensis Franch (1:1:2 in weight), can provide a liver protection effects. We used a beta-cyclodextrin (β-CD) drug modification method in reduce of the necessary dose of the SHSST. As the results, the FAS-FADD expressions leaded apoptosis in CCl4 intraperitoneal (IP) injection induced acute liver injury in rats. Silymarin, baicalein, SHSST, and SHSST β-CD complex (SHSSTc) pretreatments protected liver through the decreasing of the expressions of FAS-FADD and downstream caspase-3 and caspase-8. Particularly, SHSSTc (30 mg/kg day) treatment enhanced cell survival pathway activation through the PI3K, Akt and Bad phosphorylation. Compared with SHSST as well as silymarin and baicalein, SHSSTc provided a magnificent liver protection effect, especially in survival pathway activation/TUNEL-apoptotic cell reduction/serum cholesterol level suppression. All these data suggested that β-CD complex modified the SHSST and promoted the bioavailability and liver protection effects. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 663-670, 2016. PMID:25447754

  13. Role of connexin 43 in the mechanism of action of alendronate: dissociation of anti-apoptotic and proliferative signaling pathways

    OpenAIRE

    Lezcano, V; Bellido, T; LI, Plotkin; Boland, R; Morelli, S.

    2012-01-01

    Bisphosphonates (BPs) inhibit osteocyte and osteoblast apoptosis via opening of connexin (Cx) 43 hemichannels and activating the extracellular signal regulated kinases ERKs. Previously, we hypothesized that intracellular survival signaling is initiated by interaction of BPs with Cx43. However, using whole cell binding assays with [3H]-alendronate, herein we demonstrated the presence of saturable, specific and high affinity binding sites in the Cx43-expressing ROS 17/2.8 osteoblastic cells, au...

  14. Role of connexin 43 in the mechanism of action of alendronate: dissociation of anti-apoptotic and proliferative signaling pathways.

    Science.gov (United States)

    Lezcano, V; Bellido, T; Plotkin, L I; Boland, R; Morelli, S

    2012-02-15

    Bisphosphonates (BPs) inhibit osteocyte and osteoblast apoptosis via opening of connexin (Cx) 43 hemichannels and activating the extracellular signal regulated kinases ERKs. Previously, we hypothesized that intracellular survival signaling is initiated by interaction of BPs with Cx43. However, using whole cell binding assays with [(3)H]-alendronate, herein we demonstrated the presence of saturable, specific and high affinity binding sites in the Cx43-expressing ROS 17/2.8 osteoblastic cells, authentic osteoblasts and MLO-Y4 cells expressing Cx43 or not, as well as in HeLa cells lacking Cx43 expression and ROS 17/2.8 cells pretreated with agents that disassemble Cx channels. In addition, both BPs and the PTP inhibitor Na(3)VO(4) increased proliferation of cells expressing Cx43 or not. Furthermore, although BPs are internalized and inhibit intracellular enzymes in osteoclasts, whether the drugs penetrate non-resorptive bone cells is not known. To clarify this, we evaluated the osteoblastic uptake of AF-ALN, a fluorescently labeled analog of alendronate. AF-ALN was rapidly internalized in cells expressing Cx43 or not indicating that this process is not mediated via Cx43 hemichannels. Altogether, these findings suggest that although required for triggering intracellular survival signaling by BPs, Cx43 is dispensable for cellular BP binding, its uptake, as well as the proliferative effects of these agents. PMID:22230328

  15. Anti-apoptotic and anti-inflammatory effects of naringin on cisplatin-induced renal injury in the rat.

    Science.gov (United States)

    Chtourou, Yassine; Aouey, Baktha; Aroui, Sonia; Kebieche, Mohammed; Fetoui, Hamadi

    2016-01-01

    Nephrotoxicity is a common complication of cisplatin chemotherapy and thus limits the use of cisplatin in clinic. Naringin, a natural flavonoid, plays important roles in inflammation and apoptosis in some inflammatory diseases; however, its roles in cisplatin-induced nephrotoxicity remain unclear. In this study, we first assessed the involvement of ROS overproduction and inflammation in cisplatin-induced nephrotoxicity in aged rats, and then we investigated the changes of renal function, histological injury, inflammatory response, and apoptosis in renal tissues after treatment with naringin (20, 50 or 100 mg/kg body weight). Cisplatin resulted in an increase of renal markers, lipid peroxidation, protein and DNA oxidation, and ROS formation. Renal tumor necrosis factor-α (TNF-α) and nitrite levels were also elevated. Expressions of nuclear factor-kappa B (NF-κB), inductible nitric oxide synthase (iNOS), caspase-3 and p53 were up-regulated in renal tissues of Cis-treated rats compared with the normal control group. Histopathological changes were also observed in cisplatin group. Adminstration of naringin at different doses (25, 50 and 100 mg/kg) was able to protect against the deterioration in kidney function, abrogate the decline in antioxidant enzyme activities and suppressed the increase in TBARS, nitrite and TNF-α concentrations. Moreover, naringin inhibited NF-κB and iNOS pathways, caspase-3 and p53 activation and improved the histological changes induced by cisplatin. In conclusion, our studies suggest that oxidative stress and inflammation might play important roles in the development of cisplatin-induced nephrotoxicity and naringin might become an effective therapeutic strategy for this disease. PMID:26612654

  16. Characterisation of Anti-Apoptotic Signalling Pathways in Hepatocytes activated by alpha-Lipoic Acid and Atrial Natriuretic Peptide

    OpenAIRE

    Kulhanek-Heinze, Stefanie

    2004-01-01

    Both, the R-enantiomer of the antioxidant alpha-lipoic acid (R-LA) and the hormone atrial natriuretic peptide (ANP) are known to exert potent hepatoprotective action. The present work characterises alpha-lipoic acid- and ANP-mediated signal transduction pathways involved in the regulation of apoptotic cell death in two different models: primary hepatocytes and ischemic isolated perfused rat livers. alpha-lipoic acid was shown to protect isolated hepatocytes from TNF-alpha-/ActinomycinD-in...

  17. CREB mediates the insulinotropic and anti-apoptotic effects of GLP-1 signaling in adult mouse β-cells

    Directory of Open Access Journals (Sweden)

    Soona Shin

    2014-11-01

    Conclusions: In sum, our studies using conditional gene deletion put into question current notions about the importance of CREB in regulating β-cell function and mass. However, we reveal an important role for CREB in the β-cell response to GLP-1 receptor signaling, further validating CREB as a therapeutic target for diabetes.

  18. Mmu-miR-702 functions as an anti-apoptotic mirtron by mediating ATF6 inhibition in mice.

    Science.gov (United States)

    Zhang, Wei-Guang; Chen, Lin; Dong, Qin; He, Juan; Zhao, Han-Dong; Li, Feng-Lan; Li, Hui

    2013-12-01

    MicroRNAs (miRNAs) are a group of endogenous, small, noncoding RNAs that function as key post-transcriptional regulators. miRNAs are involved in many biological processes including apoptosis. In this study, mouse miR-702 (mmu-miR-702), a mirtron derived from the 13th intron of the Plod3 gene, was identified as a regulator of anti-apoptosis. mmu-miR-702 was down-regulated after treatment with the apoptosis-inducer isoproterenol both in vivo and in vitro. According to over-expression experiments, mmu-miR-702 inhibited apoptosis as well as the expression levels of a subset of apoptosis-related genes including activating transcription factor 6 (ATF6). An interaction between mmu-miR-702 and the ATF6 3'-UTR binding site was confirmed using luciferase reporter and western blot assays. This is the first report of ATF6 interaction with miRNA. Although the possible existence of miR-702 in the human genome is low, our results indicate that mirtrons also participate in the process of apoptosis and may provide a novel study strategy for apoptosis. PMID:24035931

  19. Carbon Monoxide Releasing Molecule-A1 (CORM-A1) Improves Neurogenesis: Increase of Neuronal Differentiation Yield by Preventing Cell Death

    Science.gov (United States)

    Almeida, Ana S.; Soares, Nuno L.; Vieira, Melissa; Gramsbergen, Jan Bert

    2016-01-01

    Cerebral ischemia and neurodegenerative diseases lead to impairment or death of neurons in the central nervous system. Stem cell based therapies are promising strategies currently under investigation. Carbon monoxide (CO) is an endogenous product of heme degradation by heme oxygenase (HO) activity. Administration of CO at low concentrations produces several beneficial effects in distinct tissues, namely anti-apoptotic and anti-inflammatory. Herein the CO role on modulation of neuronal differentiation was assessed. Three different models with increasing complexity were used: human neuroblastoma SH-S5Y5 cell line, human teratocarcinoma NT2 cell line and organotypic hippocampal slice cultures (OHSC). Cell lines were differentiated into post-mitotic neurons by treatment with retinoic acid (RA) supplemented with CO-releasing molecule A1 (CORM-A1). CORM-A1 positively modulated neuronal differentiation, since it increased final neuronal production and enhanced the expression of specific neuronal genes: Nestin, Tuj1 and MAP2. Furthermore, during neuronal differentiation process, there was an increase in proliferative cell number (ki67 mRNA expressing cells) and a decrease in cell death (lower propidium iodide (PI) uptake, limitation of caspase-3 activation and higher Bcl-2 expressing cells). CO supplementation did not increase the expression of RA receptors. In the case of SH-S5Y5 model, small amounts of reactive oxygen species (ROS) generation emerges as important signaling molecules during CO-promoted neuronal differentiation. CO’s improvement of neuronal differentiation yield was validated using OHSC as ex vivo model. CORM-A1 treatment of OHSC promoted higher levels of cells expressing the neuronal marker Tuj1. Still, CORM-A1 increased cell proliferation assessed by ki67 expression and also prevented cell death, which was followed by increased Bcl-2 expression, decreased levels of active caspase-3 and PI uptake. Likewise, ROS signaling emerged as key factors in CO

  20. Watching single molecules dance

    Science.gov (United States)

    Mehta, Amit Dinesh

    Molecular motors convert chemical energy, from ATP hydrolysis or ion flow, into mechanical motion. A variety of increasingly precise mechanical probes have been developed to monitor and perturb these motors at the single molecule level. Several outstanding questions can be best approached at the single molecule level. These include: how far does a motor progress per energy quanta consumed? how does its reaction cycle respond to load? how many productive catalytic cycles can it undergo per diffusional encounter with its track? and what is the mechanical stiffness of a single molecule connection? A dual beam optical trap, in conjunction with in vitro ensemble motility assays, has been used to characterize two members of the myosin superfamily: muscle myosin II and chick brain myosin V. Both move the helical polymer actin, but myosin II acts in large ensembles to drive muscle contraction or cytokinesis, while myosin V acts in small numbers to transport vesicles. An optical trapping apparatus was rendered sufficiently precise to identify a myosin working stroke with 1nm or so, barring systematic errors such as those perhaps due to random protein orientations. This and other light microscopic motility assays were used to characterize myosin V: unlike myosin II this vesicle transport protein moves through many increments of travel while remaining strongly bound to a single actin filament. The step size, stall force, and travel distance of myosin V reveal a remarkably efficient motor capable of moving along a helical track for over a micrometer without significantly spiraling around it. Such properties are fully consistent with the putative role of an organelle transport motor, present in small numbers to maintain movement over long ranges relative to cellular size scales. The contrast between myosin II and myosin V resembles that between a human running on the moon and one walking on earth, where the former allows for faster motion when in larger ensembles but for less

  1. Ultra-cold molecule production.

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez-Serrano, Jamie; Chandler, David W.; Strecker, Kevin; Rahn, Larry A.

    2005-12-01

    The production of Ultra-cold molecules is a goal of many laboratories through out the world. Here we are pursuing a unique technique that utilizes the kinematics of atomic and molecular collisions to achieve the goal of producing substantial numbers of sub Kelvin molecules confined in a trap. Here a trap is defined as an apparatus that spatially localizes, in a known location in the laboratory, a sample of molecules whose temperature is below one degree absolute Kelvin. Further, the storage time for the molecules must be sufficient to measure and possibly further cool the molecules. We utilize a technique unique to Sandia to form cold molecules from near mass degenerate collisions between atoms and molecules. This report describes the progress we have made using this novel technique and the further progress towards trapping molecules we have cooled.

  2. Magnetic field modification of ultracold molecule-molecule collisions

    OpenAIRE

    Tscherbul, T. V.; Suleimanov, Yu. V.; Aquilanti, V.; Krems, R.V.

    2008-01-01

    We present an accurate quantum mechanical study of molecule-molecule collisions in the presence of a magnetic field. The work focusses on the analysis of elastic scattering and spin relaxation in collisions of O2(3Sigma_g) molecules at cold (~0.1 K) and ultracold (~10^{-6} K) temperatures. Our calculations show that magnetic spin relaxation in molecule-molecule collisions is extremely efficient except at magnetic fields below 1 mT. The rate constant for spin relaxation at T=0.1 K and a magnet...

  3. Passing Current through Touching Molecules

    DEFF Research Database (Denmark)

    Schull, G.; Frederiksen, Thomas; Brandbyge, Mads;

    2009-01-01

    The charge flow from a single C-60 molecule to another one has been probed. The conformation and electronic states of both molecules on the contacting electrodes have been characterized using a cryogenic scanning tunneling microscope. While the contact conductance of a single molecule between two...

  4. Efficient single molecule detection and single molecule photochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Affleck, R.L.; Ambrose, W.P.; Goodwin, P.M. [Los Alamos National Lab., NM (United States)] [and others

    1996-12-31

    Single molecule detection efficiencies greater than 90% in flowing sample streams can be attained by confining the sample to the center of the excitation laser beam and photobleaching the reagent stream immediately before it enters the detection flow cell. Photolysis of single molecules of B-Phycoerythrin dissolved in aqueous solution is observed as an abrupt cessation of the fluorescence from these molecules as they flow through {approximately}40 pl probe volume. An analysis of the survival times of individual molecules in the laser beams yields the photodestruction quantum yield of the molecule. Photon pair correlation measurements of the fluorescence detected from single B-PE molecules demonstrate that the molecule fluoresces from only one bilin chromophore at a time.

  5. Carbon monoxide-Releasing Molecule-2 (CORM-2 attenuates acute hepatic ischemia reperfusion injury in rats

    Directory of Open Access Journals (Sweden)

    Zhang Weihui

    2010-05-01

    Full Text Available Abstract Background Hepatic ischemia-reperfusion injury (I/Ri is a serious complication occurring during liver surgery that may lead to liver failure. Hepatic I/Ri induces formation of reactive oxygen species, hepatocyte apoptosis, and release of pro-inflammatory cytokines, which together causes liver damage and organ dysfunction. A potential strategy to alleviate hepatic I/Ri is to exploit the potent anti-inflammatory and cytoprotective effects of carbon monoxide (CO by application of so-called CO-releasing molecules (CORMs. Here, we assessed whether CO released from CORM-2 protects against hepatic I/Ri in a rat model. Methods Forty male Wistar rats were randomly assigned into four groups (n = 10. Sham group underwent a sham operation and received saline. I/R group underwent hepatic I/R procedure by partial clamping of portal structures to the left and median lobes with a microvascular clip for 60 minutes, yielding ~70% hepatic ischemia and subsequently received saline. CORM-2 group underwent the same procedure and received 8 mg/kg of CORM-2 at time of reperfusion. iCORM-2 group underwent the same procedure and received iCORM-2 (8 mg/kg, which does not release CO. Therapeutic effects of CORM-2 on hepatic I/Ri was assessed by measuring serum damage markers AST and ALT, liver histology score, TUNEL-scoring of apoptotic cells, NFkB-activity in nuclear liver extracts, serum levels of pro-inflammatory cytokines TNF-α and IL-6, and hepatic neutrophil infiltration. Results A single systemic infusion with CORM-2 protected the liver from I/Ri as evidenced by a reduction in serum AST/ALT levels and an improved liver histology score. Treatment with CORM-2 also up-regulated expression of the anti-apoptotic protein Bcl-2, down-regulated caspase-3 activation, and significantly reduced the levels of apoptosis after I/Ri. Furthermore, treatment with CORM-2 significantly inhibited the activity of the pro-inflammatory transcription factor NF-κB as measured in

  6. Photochemistry of biological molecules

    International Nuclear Information System (INIS)

    Earlier studies of the photodamage induced by 254nm irradiation of linear alanine peptides in the solid state have been supplemented by an investigation into the gaseous photoproducts from the cyclic dipeptide, 3,6-dimethyl-2,5-diketopiperazine. The trans and cis isomers have been prepared and the photoproducts compared with those from the DL-mixture. The conformation of the molecule did influence the yield of gaseous products. CO was produced by peptide bond rupture with concomitant release of hydrogen. C02 was also produced. The use of N- and C-deuterated analogues together with relevant crystallographic and EPR data has enabled a detailed study of the mechanism of photodegradation to be made, from which it was concluded that the methyl protons are not inert but rather are the major source of the hydrogen observed on photolysis. (author)

  7. Forces in molecules.

    Science.gov (United States)

    Hernández-Trujillo, Jesús; Cortés-Guzmán, Fernando; Fang, De-Chai; Bader, Richard F W

    2007-01-01

    Chemistry is determined by the electrostatic forces acting within a collection of nuclei and electrons. The attraction of the nuclei for the electrons is the only attractive force in a molecule and is the force responsible for the bonding between atoms. This is the attractive force acting on the electrons in the Ehrenfest force and on the nuclei in the Feynman force, one that is countered by the repulsion between the electrons in the former and by the repulsion between the nuclei in the latter. The virial theorem relates these forces to the energy changes resulting from interactions between atoms. All bonding, as signified by the presence of a bond path, has a common origin in terms of the mechanics determined by the Ehrenfest, Feynman and virial theorems. This paper is concerned in particular with the mechanics of interaction encountered in what are classically described as 'nonbonded interactions'--are atoms that 'touch' bonded or repelling one another? PMID:17328425

  8. Lanthanide single molecule magnets

    CERN Document Server

    Tang, Jinkui

    2015-01-01

    This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs, and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures – an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and...

  9. Lanthanide single molecule magnets

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jinkui; Zhang, Peng [Chinese Academy of Sciences, Changchun (China). Changchun Inst. of Applied Chemistry

    2015-10-01

    This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures - an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and explore new directions.

  10. Reactions of oriented molecules.

    Science.gov (United States)

    Brooks, P R

    1976-07-01

    Beams of oriented molecules have been used to directly study geometrical requirements in chemical reactions. These studies have shown that reactivity is much greater in some orientations than others and demonstrated the existence of steric effects. For some reactions portions of the orientation results are in good accord with traditional views of steric hindrance, but for others it is clear that our chemical intuition needs recalibrating. Indeed, the information gained from simultaneously orienting the reactants and observing the scattering angle of the products may lead to new insights about the detailed mechanism of certain reactions. Further work must be done to extend the scope and detail of the studies described here. More detailed information is needed on the CH(3)I reaction and the CF(3)I reaction. The effects of alkyl groups of various sizes and alkali metals of various sizes are of interest. In addition, reactions where a long-lived complex is formed should be studied to see if orientation is important. Finally, it would be of interest to apply the technique to the sort of reactions that led to our interest in the first place: the S(N)2 displacements in alkyl halides where the fascinating Walden inversion occurs. PMID:17793988

  11. Molecule-based magnets

    Indian Academy of Sciences (India)

    J V Yakhmi

    2009-06-01

    The conventional magnetic materials used in current technology, such as, Fe, Fe2O3, Cr2O3, SmCo5, Nd2Fe14B etc are all atom-based, and their preparation/processing require high temperature routes. Employing self-assembly methods, it is possible to engineer a bulk molecular material with long-range magnetic order, mainly because one can play with the weak intermolecular interactions. Since the first successful synthesis of molecular magnets in 1986, a large variety of them have been synthesized, which can be categorized on the basis of the chemical nature of the magnetic units involved: organic-, metal-based systems, heterobimetallic assemblies, or mixed organic–inorganic systems. The design of molecule-based magnets has also been extended to the design of poly-functional molecular magnets, such as those exhibiting second-order optical nonlinearity, liquid crystallinity, or chirality simultaneously with long-range magnetic order. Solubility, low density and biocompatibility are attractive features of molecular magnets. Being weakly coloured, unlike their opaque classical magnet ‘cousins’ listed above, possibilities of photomagnetic switching exist. Persistent efforts also continue to design the ever-elusive polymer magnets towards applications in industry. While providing a brief overview of the field of molecular magnetism, this article highlights some recent developments in it, with emphasis on a few studies from the author’s own lab.

  12. Tunnelling of a molecule

    International Nuclear Information System (INIS)

    A quantum-mechanical description of tunnelling is presented for a one-dimensional system with internal oscillator degrees of freedom. The 'charged diatomic molecule' is frustrated on encountering a barrier potential by its centre of charge not being coincident with its centre of mass, resulting in transitions amongst internal states. In an adiabatic limit, the tunnelling of semiclassical coherent-like oscillator states is shown to exhibit the Hartman and Bueuttiker-Landauer times tH and tBL, with the time dependence of the coherent state parameter for the tunnelled state given by α(t) = α e-iω(t+Δt) , Δt = tH - itBL. A perturbation formalism is developed, whereby the exact transfer matrix can be expanded to any desired accuracy in a suitable limit. An 'intrinsic' time, based on the oscillator transition rate during tunnelling, transmission or reflection, is introduced. In simple situations the resulting intrinsic tunnelling time is shown to vanish to lowest order. In the general case a particular (nonzero) parametrisation is inferred, and its properties discussed in comparison with the literature on tunnelling times for both wavepackets and internal clocks. Copyright (1998) CSIRO Australia

  13. Organic Molecules in Meteorites

    Science.gov (United States)

    Martins, Zita

    2015-08-01

    Carbonaceous meteorites are primitive samples from the asteroid belt, containing 3-5wt% organic carbon. The exogenous delivery of organic matter by carbonaceous meteorites may have contributed to the organic inventory of the early Earth. The majority (>70%) of the meteoritic organic material consist of insoluble organic matter (IOM) [1]. The remaining meteoritic organic material (Haber-Bosch type gas-grain reactions after the meteorite parent body cooled to lower temperatures [13, 14].The analysis of the abundances and distribution of the organic molecules present in meteorites helps to determine the physical and chemical conditions of the early solar system, and the prebiotic organic compounds available on the early Earth.[1] Cody and Alexander (2005) GCA 69, 1085. [2] Cronin and Chang (1993) in: The Chemistry of Life’s Origin. pp. 209-258. [3] Martins and Sephton (2009) in: Amino acids, peptides and proteins in organic chemistry. pp. 1-42. [4] Martins (2011) Elements 7, 35. [5] Botta et al. (2007) MAPS 42, 81. [6] Martins et al. (2015) MAPS, in press. [7] Cooper and Cronin (1995) GCA 59, 1003. [8] Glavin et al. (2006) MAPS. 41, 889. [9] Glavin et al. (2011) MAPS 45, 1948. [10] Elsila et al. (2005) GCA 5, 1349. [11] Glavin and Dworkin (2009) PNAS 106, 5487. [12] Pizzarello et al. (2003) GCA 67, 1589. [13] Chan et al. (2012) MAPS. 47, 1502. [14] Burton et al. (2011) MAPS 46, 1703.

  14. Thread bonds in molecules

    CERN Document Server

    Ivlev, B

    2015-01-01

    Unusual chemical bonds are proposed. Each bond is almost covalent but is characterized by the thread of a small radius $\\sim 0.6\\times 10^{-11}$cm, between two nuclei in a molecule. The main electron density is concentrated outside the thread as in a covalent bond. The thread is formed by the electron wave function which has a tendency to be singular on it. The singularity along the thread is cut off by electron "vibrations" due to the interaction with zero point electromagnetic oscillations. The electron energy has its typical value of (1-10)eV. Due to the small tread radius the uncertainty of the electron momentum inside the thread is large resulting in a large electron kinetic energy $\\sim 1 MeV$. This energy is compensated by formation of a potential well due to the reduction of the energy of electromagnetic zero point oscillations. This is similar to formation of a negative van der Waals potential. Thread bonds are stable and cannot be created or destructed in chemical or optical processes.

  15. Strongly interacting ultracold polar molecules

    Science.gov (United States)

    Gadway, Bryce; Yan, Bo

    2016-08-01

    This paper reviews recent advances in the study of strongly interacting systems of dipolar molecules. Heteronuclear molecules feature large and tunable electric dipole moments, which give rise to long-range and anisotropic dipole–dipole interactions. Ultracold samples of dipolar molecules with long-range interactions offer a unique platform for quantum simulations and the study of correlated many-body physics. We provide an introduction to the physics of dipolar quantum gases, both electric and magnetic, and summarize the multipronged efforts to bring dipolar molecules into the quantum regime. We discuss in detail the recent experimental progress in realizing and studying strongly interacting systems of polar molecules trapped in optical lattices, with particular emphasis on the study of interacting spin systems and non-equilibrium quantum magnetism. Finally, we conclude with a brief discussion of the future prospects for studies of strongly interacting dipolar molecules.

  16. Strongly interacting ultracold polar molecules

    CERN Document Server

    Gadway, Bryce

    2016-01-01

    This paper reviews recent advances in the study of strongly interacting systems of dipolar molecules. Heteronuclear molecules feature large and tunable electric dipole moments, which give rise to long-range and anisotropic dipole-dipole interactions. Ultracold samples of dipolar molecules with long-range interactions offer a unique platform for quantum simulations and the study of correlated many-body physics. We provide an introduction to the physics of dipolar quantum gases, both electric and magnetic, and summarize the multipronged efforts to bring dipolar molecules into the quantum regime. We discuss in detail the recent experimental progress in realizing and studying strongly interacting systems of polar molecules trapped in optical lattices, with particular emphasis on the study of interacting spin systems and non-equilibrium quantum magnetism. Finally, we conclude with a brief discussion of the future prospects for studies of strongly interacting dipolar molecules.

  17. Molecules Best Paper Award 2012

    Directory of Open Access Journals (Sweden)

    Derek J. McPhee

    2012-02-01

    Full Text Available Molecules starts to institute the “Best Paper” award to recognize these outstanding papers in the area of natural products, medicinal chemistry and molecular diversity published in Molecules. We are pleased to announce the first “Molecules Best Paper Award” for 2012. Nominations were selected by the editor-in-chief and selected editorial board members from all the papers published in 2008. [...

  18. Molecules Best Paper Award 2014

    Directory of Open Access Journals (Sweden)

    Derek J. McPhee

    2014-01-01

    Full Text Available Molecules instituted some years ago a “Best Paper” award to recognize the most outstanding papers in the area of natural products, medicinal chemistry and molecular diversity published each year in Molecules. We are pleased to announce the third “Molecules Best Paper Award” for 2014. The winners were chosen by the Editor-in-Chief and selected editorial board members from among all the papers published in 2010. Reviews and research papers were evaluated separately.

  19. Molecules Best Paper Award 2013

    Directory of Open Access Journals (Sweden)

    Derek J. McPhee

    2013-02-01

    Full Text Available Molecules has started to institute a "Best Paper" award to recognize the most outstanding papers in the area of natural products, medicinal chemistry and molecular diversity published in Molecules. We are pleased to announce the second "Molecules Best Paper Award" for 2013. Candidates were chosen by the Editor-in-Chief and selected editorial board members from among all the papers published in 2009.

  20. Recoiling DNA Molecule: Simulation & Experiment

    OpenAIRE

    Neto, Jose Coelho; Dickman, Ronald; Mesquita, O. N.

    2002-01-01

    Single molecule DNA experiments often generate data from force versus extension measurements involving the tethering of a microsphere to one end of a single DNA molecule while the other is attached to a substrate. We show that the persistence length of single DNA molecules can also be measured based on the recoil dynamics of these DNA-microsphere complexes if appropriate corrections are made to the friction coefficient of the microsphere in the vicinity of the substrate. Comparison between co...

  1. Labelled molecules, modern research implements

    International Nuclear Information System (INIS)

    Details of the synthesis of carbon 14- and tritium-labelled molecules are examined. Although the methods used are those of classical organic chemistry the preparation of carbon 14-labelled molecules differs in some respects, most noticeably in the use of 14CO2 which requires very special handling techniques. For the tritium labelling of organic molecules the methods are somewhat different, very often involving exchange reactions. The following are described in turn: the so-called Wilzbach exchange method; exchange by catalysis in solution; catalytic hydrogenation with tritium; reductions with borotritides. Some applications of labelled molecules in organic chemistry, biochemistry and pharmacology are listed

  2. STM investigation of surfactant molecules

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Adsorption and self-organization of sodium alkyl sulfonates (STS and SHS) have been studied on HOPG by using the in situ scanning tunneling microscopy (STM). Both SHS and STS molecules adsorb on the HOPG surface and form long-range well-ordered monolayers. The neighboring molecules in different rows form a "head to head" configuration. In the high-resolution images of STS and SHS molecules, one end of the molecules shows bright spots which are attributed to the SO3- groups.

  3. Molecules Best Paper Award 2015

    Directory of Open Access Journals (Sweden)

    Derek J. McPhee

    2015-01-01

    Full Text Available Molecules instituted some years ago a “Best Paper” award to recognize the most outstanding papers in the area of organic synthesis, natural products, medicinal chemistry and molecular diversity published each year in Molecules. We are pleased to announce the third “Molecules Best Paper Award” for 2015. The winners were chosen by the Editor-in-Chief and selected editorial board members from among all the papers published in 2011. Reviews and research papers were evaluated separately. We are pleased to announce that the following eight papers have won the Molecules Best Paper Award for 2015:[...

  4. Aromatic molecules as spintronic devices

    International Nuclear Information System (INIS)

    In this paper, we study the spin-dependent electron transport through aromatic molecular chains attached to two semi-infinite leads. We model this system taking into account different geometrical configurations which are all characterized by a tight binding Hamiltonian. Based on the Green's function approach with a Landauer formalism, we find spin-dependent transport in short aromatic molecules by applying external magnetic fields. Additionally, we find that the magnetoresistance of aromatic molecules can reach different values, which are dependent on the variations in the applied magnetic field, length of the molecules, and the interactions between the contacts and the aromatic molecule

  5. Single-molecule magnet engineering

    DEFF Research Database (Denmark)

    Pedersen, Kasper Steen; Bendix, Jesper; Clérac, Rodolphe

    2014-01-01

    to delicately tune, for instance, the properties of molecules that behave as "magnets", the so-called single-molecule magnets (SMMs). Although many interesting SMMs have been prepared by a more or less serendipitous approach, the assembly of predesigned, isolatable molecular entities into higher nuclearity...

  6. When water molecules meet air

    OpenAIRE

    Hsie, Cho-Shuen; Campen, R. Kramer; Verde, Ana Vila; Bolhuis, Peter; Nienhuys, Han-Kwang; Bonn, Mischa

    2012-01-01

    About 70% of our planet is covered in water. Most of that water exists as water in the bulk – the neighbors of water molecules are other water molecules – and only a small fraction of molecules are at the air-water interface. Despite the small relative abundance of interfacial water, it is of the utmost importance: it governs the chemistry involving the surface of oceans and seawater aerosols, or the small water droplets forming clouds. Reactions at the air-water interface are directly releva...

  7. Quantum transport through aromatic molecules

    International Nuclear Information System (INIS)

    In this paper, we study the electronic transport properties through aromatic molecules connected to two semi-infinite leads. The molecules are in different geometrical configurations including arrays. Using a nearest neighbor tight-binding approach, the transport properties are analyzed into a Green's function technique within a real-space renormalization scheme. We calculate the transmission probability and the Current-Voltage characteristics as a function of a molecule-leads coupling parameter. Our results show different transport regimes for these systems, exhibiting metal-semiconductor-insulator transitions and the possibility to employ them in molecular devices

  8. BIMEL is a key effector molecule in oxidative stress-mediated apoptosis in acute myeloid leukemia cells when combined with arsenic trioxide and buthionine sulfoximine

    International Nuclear Information System (INIS)

    Arsenic trioxide (ATO) is reported to be an effective therapeutic agent in acute promyelocytic leukemia (APL) through inducing apoptotic cell death. Buthionine sulfoximine (BSO), an oxidative stress pathway modulator, is suggested as a potential combination therapy for ATO-insensitive leukemia. However, the precise mechanism of BSO-mediated augmentation of ATO-induced apoptosis is not fully understood. In this study we compared the difference in cell death of HL60 leukemia cells treated with ATO/BSO and ATO alone, and investigated the detailed molecular mechanism of BSO-mediated augmentation of ATO-induced cell death. HL60 APL cells were used for the study. The activation and expression of a series of signal molecules were analyzed with immunoprecipitation and immunoblotting. Apoptotic cell death was detected with caspases and poly (ADP-ribose) polymerase activation. Generation of intracellular reactive oxygen species (ROS) was determined using a redox-sensitive dye. Mitochondrial outer membrane permeabilization was observed with a confocal microscopy using NIR dye and cytochrome c release was determined with immunoblotting. Small interfering (si) RNA was used for inhibition of gene expression. HL60 cells became more susceptible to ATO in the presence of BSO. ATO/BSO-induced mitochondrial injury was accompanied by reduced mitochondrial outer membrane permeabilization, cytochrome c release and caspase activation. ATO/BSO-induced mitochondrial injury was inhibited by antioxidants. Addition of BSO induced phosphorylation of the pro-apoptotic BCL2 protein, BIMEL, and anti-apoptotic BCL2 protein, MCL1, in treated cells. Phosphorylated BIMEL was dissociated from MCL1 and interacted with BAX, followed by conformational change of BAX. Furthermore, the knockdown of BIMEL with small interfering RNA inhibited the augmentation of ATO-induced apoptosis by BSO. The enhancing effect of BSO on ATO-induced cell death was characterized at the molecular level for clinical use

  9. Theoretical Investigations Regarding Single Molecules

    DEFF Research Database (Denmark)

    Pedersen, Kim Georg Lind

    interfere destructively or constructively. Destructive interference effects in electron transport could potentially improve thermo-electrics, organic logic circuits and energy harvesting. We have investigated destructive interference in off-resonant transport through organic molecules, and have found a set...

  10. Polar molecule dominated electrorheological effect

    Institute of Scientific and Technical Information of China (English)

    Lu Kun-Quan; Shen Rong; Wang Xue-Zhao; Sun Gang; Wen Wei-Jia; Liu Ji-Xing

    2006-01-01

    The yield stress of our newly developed electrorheological (ER) fluids consisting of dielectric nano-particles suspended in silicone oil reaches hundreds of kPa, which is orders of magnitude higher than that of conventional ones. We found that the polar molecules adsorbed on the particles play a decisive role in such new ER fluids. To explain this polar molecule dominated ER (PM-ER) effect a model is proposed based on the interaction of polar molecule-charge between the particles, where the local electric field is significantly enhanced and results in the polar molecules aligning in the direction of the electric field. The model can well explain the giant ER effect and a near-linear dependence of the yield stress on the electric field. The main effective factors for achieving high-performance PM-ER fluids are discussed. The PM-ER fluids with the yield stress higher than one MPa can be expected.

  11. Nuclear molecules with three clusters

    International Nuclear Information System (INIS)

    Full text: Recently, in the cold fusion of 252 Cf, indications where found for the existence of nuclear molecules with three clusters. The system identified is 96 Sr + 10 Be + 146 Ba. In the first half of the talk the geometric model for three-cluster molecules is resumed and calculations done are presented. Problems and restrictions of the geometric model will be discussed. In the second half an Ansatz for an algebraic model for nuclear molecules is given. In a first step we restrict to two clusters only, which might have an application to standard two-cluster molecules. A Hamiltonian is proposed. The mapping to a geometric potential is described, which is fitted to the calculation of internuclear potentials using double-folding techniques. (Author)

  12. Single-Molecule DNA Analysis

    Science.gov (United States)

    Efcavitch, J. William; Thompson, John F.

    2010-07-01

    The ability to detect single molecules of DNA or RNA has led to an extremely rich area of exploration of the single most important biomolecule in nature. In cases in which the nucleic acid molecules are tethered to a solid support, confined to a channel, or simply allowed to diffuse into a detection volume, novel techniques have been developed to manipulate the DNA and to examine properties such as structural dynamics and protein-DNA interactions. Beyond the analysis of the properties of nucleic acids themselves, single-molecule detection has enabled dramatic improvements in the throughput of DNA sequencing and holds promise for continuing progress. Both optical and nonoptical detection methods that use surfaces, nanopores, and zero-mode waveguides have been attempted, and one optically based instrument is already commercially available. The breadth of literature related to single-molecule DNA analysis is vast; this review focuses on a survey of efforts in molecular dynamics and nucleic acid sequencing.

  13. Absorption characteristics of bacteriorhodopsin molecules

    Indian Academy of Sciences (India)

    H K T Kumar; K Appaji Gowda

    2000-03-01

    The bacteriorhodopsin molecule absorbs light and undergoes a series of structural transformation following a well-defined photocycle. The complex photocycle is transformed to an equivalent level diagram by considering the lifetime of the intermediate states. Assuming that only and states are appreciably populated at any instant of time, the level diagram is further simplified to two-level system. Based on the rate equations for two-level system, an analytic expression for the absorption coefficient of bacteriorhodopsin molecule is derived. It is applied to study the behaviour of absorption coefficient of bacteriorhodopsin film in the visible wavelength region of 514 nm. The dependence of absorption coefficient of bacteriorhodopsin film on the thickness of the film, total number density of active molecules and initial number density of molecules in -state is presented in the graphical form.

  14. Ultracold molecules and ultracold chemistry

    OpenAIRE

    Softley, Tim; Bell, Martin

    2009-01-01

    Abstract The recent development of a range of new methods for producing samples of gas phase molecules that are translationally cold (T < 1 K) or ultracold (T < 1 mK) is driving efforts to study reactive and inelastic collisional processes in these temperature regimes. In this review article the new methods for cold/ultracold molecule production are reviewed in the context of their potential or current use in collisional studies and progress in the application of these methods i...

  15. Galectin-3 augments tumor initiating property and tumorigenicity of lung cancer through interaction with β-catenin

    OpenAIRE

    Chung, Ling-Yen; Tang, Shye-Jye; Wu, Yi-Ching; Sun, Guang-Huan; Liu, Huan-Yun; Sun, Kuang-Hui

    2014-01-01

    Cancer stem cells (CSCs) are comprised of a rare sub-population of cells in tumors that have been proposed to be responsible for high recurrence rates and resistance to chemotherapy. Galectins are highly expressed in cancers that correlate with the aggressiveness of tumors. Galectins may also promote the resistance of cancer cells to chemotherapy. However, the role of galectins in CSCs remains unknown. In this study, sphere formation was used to enrich H1299 human lung CSCs that had self-rene...

  16. Galectin-3, a biomarker linking oxidative stress and inflammation with the clinical outcomes of patients with atherothrombosis

    DEFF Research Database (Denmark)

    Madrigal-Matute, Julio; Lindholt, Jes Sandal; Fernandez-Garcia, Carlos Ernesto; Benito-Martin, Alberto; Burillo, Elena; Zalba, Guillermo; Beloqui, Oscar; Llamas-Granda, Patricia; Ortiz, Alberto; Egido, Jesus; Blanco-Colio, Luis Miguel; Martin-Ventura, Jose Luis

    2014-01-01

    .24, 95% confidence interval: 1.06 to 4.73, P<0.05). CONCLUSIONS: Gal-3 extracellular levels could reflect key underlying mechanisms involved in atherosclerosis etiology, development, and plaque rupture, such as inflammation, infiltration of circulating cells and oxidative stress. Moreover, circulating...... a circulating biomarker has been demonstrated in patients with heart failure, but its importance as a biomarker in atherothrombosis is still unknown. METHODS AND RESULTS: Because Gal-3 is involved in monocyte-to-macrophage transition, we used fresh isolated monocytes and the in vitro model of...

  17. Placental Expression Patterns of Galectin-1, Galectin-2, Galectin-3 and Galectin-13 in Cases of Intrauterine Growth Restriction (IUGR

    Directory of Open Access Journals (Sweden)

    Stefan Hutter

    2016-04-01

    Full Text Available Galectins (gal are members of the mammalian β-galactoside-binding proteins and recognize Galβ1-4GlcNAc and Galβ1-4GalNac (Thomsen-Friedenreich antigen (TF sequences of several cell surface oligosaccharides. In this study, gal-1, -2, -3 and -13 were investigated systematically in the trophoblast and decidua compartment of intrauterine growth restriction (IUGR placentas and normal third trimester control placentas and stratified by fetal gender and gestational age. Within this study, 29 third trimester placentas after delivery were analyzed. Fetal gender was equally divided within both groups, and immunohistochemical staining was analyzed according to fetal gender and gestational age. Double immune-fluorescence with trophoblast-specific markers was used to identify galectin-expressing cells at the feto-maternal interface in the decidua. Gal-3 was significantly downregulated only in the extravillous trophoblast of IUGR placentas. In contrast, expressions of gal-2 and gal-13 were downregulated in both villous and extravillous trophoblast cells of IUGR placentas. In addition, gal-2 and gal-13 showed a highly correlated expression scheme in the placenta. There are significant gender-specific expression patterns for single prototype galectins with downregulation of gal-2 and gal-13 of male gender placentas in cases of IUGR. Gal-3 as the chimera type galectin shows only little gender-specific differences in expression, which disappear in IUGR cases.

  18. Raman Optical Activity Spectra for Large Molecules through Molecules-in-Molecules Fragment-Based Approach.

    Science.gov (United States)

    Jovan Jose, K V; Raghavachari, Krishnan

    2016-02-01

    We present an efficient method for the calculation of the Raman optical activity (ROA) spectra for large molecules through the molecules-in-molecules (MIM) fragment-based method. The relevant higher energy derivatives from smaller fragments are used to build the property tensors of the parent molecule to enable the extension of the MIM method for evaluating ROA spectra (MIM-ROA). Two factors were found to be particularly important in yielding accurate results. First, the link-atom tensor components are projected back onto the corresponding host and supporting atoms through the Jacobian projection method, yielding a mathematically rigorous method. Second, the long-range interactions between fragments are taken into account by using a less computationally expensive lower level of theory. The performance of the MIM-ROA model is calibrated on the enantiomeric pairs of 10 carbohydrate benchmark molecules, with strong intramolecular interactions. The vibrational frequencies and ROA intensities are accurately reproduced relative to the full, unfragmented, results for these systems. In addition, the MIM-ROA method is employed to predict the ROA spectra of d-maltose, α-D-cyclodextrin, and cryptophane-A, yielding spectra in excellent agreement with experiment. The accuracy and performance of the benchmark systems validate the MIM-ROA model for exploring ROA spectra of large molecules. PMID:26760444

  19. Vibrational Circular Dichroism Spectra for Large Molecules through Molecules-in-Molecules Fragment-Based Approach.

    Science.gov (United States)

    Jose, K V Jovan; Beckett, Daniel; Raghavachari, Krishnan

    2015-09-01

    We present the first implementation of the vibrational circular dichroism (VCD) spectrum of large molecules through the Molecules-in-Molecules (MIM) fragment-based method. An efficient projection of the relevant higher energy derivatives from smaller fragments to the parent molecule enables the extension of the MIM method for the evaluation of VCD spectra (MIM-VCD). The overlapping primary subsystems in this work are constructed from interacting fragments using a number-based scheme and the dangling bonds are saturated with link hydrogen atoms. Independent fragment calculations are performed to evaluate the energies, Hessian matrix, atomic polar tensor (APT), and the atomic axial tensor (AAT). Subsequently, the link atom tensor components are projected back onto the corresponding host and supporting atoms through the Jacobian projection method, as in the ONIOM approach. In the two-layer model, the long-range interactions between fragments are accounted for using a less computationally intensive lower level of theory. The performance of the MIM model is calibrated on the d- and l-enantiomers of 10 carbohydrate benchmark molecules, with strong intramolecular interactions. The vibrational frequencies and VCD intensities are accurately reproduced relative to the full, unfragmented, results for these systems. In addition, the MIM-VCD method is employed to predict the VCD spectra of perhydrotriphenylene and cryptophane-A, yielding spectra in agreement with experiment. The accuracy and performance of the benchmark systems validate the MIM-VCD model for exploring vibrational circular dichroism spectra of large molecules. PMID:26575919

  20. The Molecule Cloud - compact visualization of large collections of molecules

    Directory of Open Access Journals (Sweden)

    Ertl Peter

    2012-07-01

    Full Text Available Abstract Background Analysis and visualization of large collections of molecules is one of the most frequent challenges cheminformatics experts in pharmaceutical industry are facing. Various sophisticated methods are available to perform this task, including clustering, dimensionality reduction or scaffold frequency analysis. In any case, however, viewing and analyzing large tables with molecular structures is necessary. We present a new visualization technique, providing basic information about the composition of molecular data sets at a single glance. Summary A method is presented here allowing visual representation of the most common structural features of chemical databases in a form of a cloud diagram. The frequency of molecules containing particular substructure is indicated by the size of respective structural image. The method is useful to quickly perceive the most prominent structural features present in the data set. This approach was inspired by popular word cloud diagrams that are used to visualize textual information in a compact form. Therefore we call this approach “Molecule Cloud”. The method also supports visualization of additional information, for example biological activity of molecules containing this scaffold or the protein target class typical for particular scaffolds, by color coding. Detailed description of the algorithm is provided, allowing easy implementation of the method by any cheminformatics toolkit. The layout algorithm is available as open source Java code. Conclusions Visualization of large molecular data sets using the Molecule Cloud approach allows scientists to get information about the composition of molecular databases and their most frequent structural features easily. The method may be used in the areas where analysis of large molecular collections is needed, for example processing of high throughput screening results, virtual screening or compound purchasing. Several example visualizations of large

  1. Electron Collisions with Large Molecules

    Science.gov (United States)

    McKoy, Vincent

    2006-10-01

    In recent years, interest in electron-molecule collisions has increasingly shifted to large molecules. Applications within the semiconductor industry, for example, require electron collision data for molecules such as perfluorocyclobutane, while almost all biological applications involve macromolecules such as DNA. A significant development in recent years has been the realization that slow electrons can directly damage DNA. This discovery has spurred studies of low-energy collisions with the constituents of DNA, including the bases, deoxyribose, the phosphate, and larger moieties assembled from them. In semiconductor applications, a key goal is development of electron cross section sets for plasma chemistry modeling, while biological studies are largely focused on understanding the role of localized resonances in inducing DNA strand breaks. Accurate calculations of low-energy electron collisions with polyatomic molecules are computationally demanding because of the low symmetry and inherent many-electron nature of the problem; moreover, the computational requirements scale rapidly with the size of the molecule. To pursue such studies, we have adapted our computational procedure, known as the Schwinger multichannel method, to run efficiently on highly parallel computers. In this talk, we will present some of our recent results for fluorocarbon etchants used in the semiconductor industry and for constituents of DNA and RNA. In collaboration with Carl Winstead, California Institute of Technology.

  2. Laser spectroscopy of cold molecules

    CERN Document Server

    Borri, Simone

    2016-01-01

    This paper reviews the recent results in high-resolution spectroscopy on cold molecules. Laser spectroscopy of cold molecules addresses issues of symmetry violation, like in the search for the electric dipole moment of the electron and the studies on energy differences in enantiomers of chiral species; tries to improve the precision to which fundamental physical constants are known and tests for their possible variation in time and space; tests quantum electrodynamics, and searches for a fifth force. Further, we briefly review the recent technological progresses in the fields of cold molecules and mid-infrared lasers, which are the tools that mainly set the limits for the resolution that is currently attainable in the measurements.

  3. Technetium-aspirin molecule complexes

    International Nuclear Information System (INIS)

    Technetium-aspirin and technetium-aspirin-like molecule complexes were prepared. The structure of N-acetylanthranilic acid (NAA) has been decided through CNDO calculations. The ionization potential and electron affinity of the NAA molecule as well as the charge densities were calculated. The electronic absorption spectra of Tc(V)-Asp and Tc(V)-ATS complexes have two characteristic absorption bands at 450 and 600 nm, but the Tc(V)-NAA spectrum has one characteristic band at 450 nm. As a comparative study, Mo-ATS complex was prepared and its electronic absorption spectrum is comparable with the Tc-ATS complex spectrum. (author)

  4. Phase structure of soliton molecules

    International Nuclear Information System (INIS)

    Temporal optical soliton molecules were recently demonstrated; they potentially allow further increase of data rates in optical telecommunication. Their binding mechanism relies on the internal phases, but these have not been experimentally accessible so far. Conventional frequency-resolved optical gating techniques are not suited for measurement of their phase profile: Their algorithms fail to converge due to zeros both in their temporal and their spectral profile. We show that the VAMPIRE (very advanced method of phase and intensity retrieval of E-fields) method performs reliably. With VAMPIRE the phase profile of soliton molecules has been measured, and further insight into the mechanism is obtained

  5. Phase structure of soliton molecules

    Science.gov (United States)

    Hause, A.; Hartwig, H.; Seifert, B.; Stolz, H.; Böhm, M.; Mitschke, F.

    2007-06-01

    Temporal optical soliton molecules were recently demonstrated; they potentially allow further increase of data rates in optical telecommunication. Their binding mechanism relies on the internal phases, but these have not been experimentally accessible so far. Conventional frequency-resolved optical gating techniques are not suited for measurement of their phase profile: Their algorithms fail to converge due to zeros both in their temporal and their spectral profile. We show that the VAMPIRE (very advanced method of phase and intensity retrieval of E -fields) method performs reliably. With VAMPIRE the phase profile of soliton molecules has been measured, and further insight into the mechanism is obtained.

  6. Orbital molecules in electronic materials

    Energy Technology Data Exchange (ETDEWEB)

    Attfield, J. Paul, E-mail: j.p.attfield@ed.ac.uk [Centre for Science at Extreme Conditions and School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JZ (United Kingdom)

    2015-04-01

    Orbital molecules are made up of coupled orbital states on several metal ions within an orbitally ordered (and sometimes also charge-ordered) solid such as a transition metal oxide. Spin-singlet dimers are known in many materials, but recent discoveries of more exotic species such as 18-electron heptamers in AlV{sub 2}O{sub 4} and magnetic 3-atom trimerons in magnetite (Fe{sub 3}O{sub 4}) have shown that orbital molecules constitute a general new class of quantum electronic states in solids.

  7. Recoiling DNA Molecule Simulation & Experiment

    CERN Document Server

    Neto, J C; Mesquita, O N; Neto, Jose Coelho; Dickman, Ronald

    2002-01-01

    Many recent experiments with single DNA molecules are based on force versus extension measurements and involve tethering a microsphere to one of its extremities and the other to a microscope coverglass. In this work we show that similar results can also be obtained by studying the recoil dynamics of the tethered microspheres. Computer simulations of the corresponding Langevin equation indicate which assumptions are required for a reliable analysis of the experimental recoil curves. We have measured the persistence length A of single naked DNA molecules and DNA-Ethidium Bromide complexes using this approach.

  8. Teaching lasers to control molecules

    International Nuclear Information System (INIS)

    We simulate a method to teach a laser pulse sequences to excite specified molecular states. We use a learning procedure to direct the production of pulses based on ''fitness'' information provided by a laboratory measurement device. Over a series of pulses the algorithm learns an optimal sequence. The experimental apparatus, which consists of a laser, a sample of molecules and a measurement device, acts as an analog computer that solves Schroedinger's equation n/Iexactly, in real time. We simulate an apparatus that learns to excite specified rotational states in a diatomic molecule

  9. Exotic helium molecules; Molecules exotiques d'helium

    Energy Technology Data Exchange (ETDEWEB)

    Portier, M

    2007-12-15

    We study the photo-association of an ultracold cloud of magnetically trapped helium atoms: pairs of colliding atoms interact with one or two laser fields to produce a purely long range {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}P{sub 0}) molecule, or a {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}S{sub 1}) long range molecule. Light shifts in one photon photo-association spectra are measured and studied as a function of the laser polarization and intensity, and the vibrational state of the excited molecule. They result from the light-induced coupling between the excited molecule, and bound and scattering states of the interaction between two metastable atoms. Their analysis leads to the determination of the scattering length a = (7.2 {+-} 0.6) ruling collisions between spin polarized atoms. The two photon photo-association spectra show evidence of the production of polarized, long-range {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}S{sub 1}) molecules. They are said to be exotic as they are made of two metastable atoms, each one carrying a enough energy to ionize the other. The corresponding lineshapes are calculated and decomposed in sums and products of Breit-Wigner and Fano profiles associated to one and two photon processes. The experimental spectra are fit, and an intrinsic lifetime {tau} = (1.4 {+-} 0.3) {mu}s is deduced. It is checked whether this lifetime could be limited by spin-dipole induced Penning autoionization. This interpretation requires that there is a quasi-bound state close to the dissociation threshold in the singlet interaction potential between metastable helium atoms for the theory to match the experiment. (author)

  10. Multiphoton dissociation of polyatomic molecules

    International Nuclear Information System (INIS)

    The dynamics of infrared multiphoton excitation and dissociation of SF6 was investigated under collision free conditions by a crossed laser-molecular beam method. In order to understand the excitation mechanism and to elucidate the requirements of laser intensity and energy fluence, a series of experiments were carried out to measure the dissociation yield dependences on energy fluence, vibrational temperature of SF6, the pulse duration of the CO2 laser and the frequency in both one and two laser experiments. Translational energy distributions of the SF5 dissociation product measured by time of flight and angular distributions and the dissociation lifetime of excited SF6 as inferred from the observation of secondary dissociation of SF5 into SF4 and F during the laser pulse suggest that the dynamics of dissociation of excited molecules is dominated by complete energy randomization and rapid intramolecular energy transfer on a nanosecond timescale, and can be adequately described by RRKM theory. An improved phenomenological model including the initial intensity dependent excitation, a rate equation describing the absorption and stimulated emission of single photons, and the unimolecular dissociation of excited molecules is constructed based on available experimental results. The model shows that the energy fluence of the laser determines the excitation of molecules in the quasi-continuum and the excess energy with which molecules dissociate after the laser pulse. The role played by the laser intensity in multiphoton dissociation is more significant than just that of overcoming the intensity dependent absorption in the lowest levels. 63 references

  11. Tunneling Ionization of Diatomic Molecules

    DEFF Research Database (Denmark)

    Svensmark, Jens Søren Sieg

    2016-01-01

    of tunneling ionizaion of molecules is presented and the results of numerical calculations are shown. One perhaps surprising result is, that the frequently used Born-Oppenheimer approximation breaks down for weak fields when describing tunneling ionization. An analytic theory applicable in the weak...

  12. Monitoring Molecules: Insights and Progress

    OpenAIRE

    Wightman, R Mark

    2014-01-01

    In August, 2014, neuroscientists and physical scientists gathered together on the campus of the University of California, Los Angeles to discuss how to monitor molecules in neuroscience. This field has seen significant growth since its inception in the 1970s. Here, the advances in this field are documented, including its advance into understanding the actions that specific neurotransmitters mediate during behavior.

  13. Azobenzene-functionalized cascade molecules

    DEFF Research Database (Denmark)

    Archut, A.; Vogtle, F.; De Cola, L.;

    1998-01-01

    Cascade molecules bearing up to 32 azobenzene groups in the periphery have been prepared from poly(propylene imine) dendrimers and N-hydroxysuccinimide esters. The dendritic azobenzene species show similar isomerization properties as the corresponding azobenzene monomers. The all-E azobenzene den...

  14. Engineering crystals of dendritic molecules.

    Science.gov (United States)

    Lukin, Oleg; Schubert, Dirk; Müller, Claudia M; Schweizer, W Bernd; Gramlich, Volker; Schneider, Julian; Dolgonos, Grygoriy; Shivanyuk, Alexander

    2009-07-01

    A detailed single-crystal X-ray study of conformationally flexible sulfonimide-based dendritic molecules with systematically varied molecular architectures was undertaken. Thirteen crystal structures reported in this work include 9 structures of the second-generation dendritic sulfonimides decorated with different aryl groups, 2 compounds bearing branches of both second and first generation, and 2 representatives of the first generation. Analysis of the packing patterns of 9 compounds bearing second-generation branches shows that despite their lack of strong directive functional groups there is a repeatedly reproduced intermolecular interaction mode consisting in an anchor-type packing of complementary second-generation branches of neighbouring molecules. The observed interaction tolerates a wide range of substituents in meta- and para-positions of the peripheral arylsulfonyl rings. Quantum chemical calculations of the molecule-molecule interaction energies agree at the qualitative level with the packing preferences found in the crystalline state. The calculations can therefore be used as a tool to rationalize and predict molecular structures with commensurate and non-commensurate branches for programming of different packing modes in crystal. PMID:19549870

  15. Nucleic Acids as Information Molecules.

    Science.gov (United States)

    McInerney, Joseph D.

    1996-01-01

    Presents an activity that aims at enabling students to recognize that DNA and RNA are information molecules whose function is to store, copy, and make available the information in biological systems, without feeling overwhelmed by the specialized vocabulary and the minutia of the central dogma. (JRH)

  16. Quantum interferometry with complex molecules

    OpenAIRE

    Arndt, Markus; Hornberger, Klaus

    2009-01-01

    This chapter reviews recent experiments on matter wave interferometry with large molecules. Starting from an elementary introduction to matter wave physics we discuss far-field diffraction and near-field interferometry with thermally excited many-body systems. We describe the constraints imposed by decoherence and dephasing effects, and present an outlook to the future challenges in macromolecule and cluster interferometry.

  17. Molecule-by-Molecule Writing Using a Focused Electron Beam

    DEFF Research Database (Denmark)

    Van Dorp, Willem F.; Zhang, Xiaoyan; Feringa, Ben L.; Hansen, Thomas Willum; Wagner, Jakob Birkedal; De Hosson, Jeff Th. M.

    2012-01-01

    The resolution of lithography techniques needs to be extended beyond their current limits to continue the trend of miniaturization and enable new applications. But what is the ultimate spatial resolution? It is known that single atoms can be imaged with a highly focused electron beam. Can single...... atoms also be written with an electron beam? We verify this with focused electron-beam-induced deposition (FEBID), a direct-write technique that has the current record for the smallest feature written by (electron) optical lithography. We show that the deposition of an organometallic precursor on...... graphene can be followed molecule-by-molecule with FEBID. The results show that mechanisms that are inherent to the process inhibit a further increase in control over the process. Hence, our results present the resolution limit of (electron) optical lithography techniques. The writing of isolated...

  18. Simultaneous gene silencing of Bcl-2, XIAP and Survivin re-sensitizes pancreatic cancer cells towards apoptosis

    International Nuclear Information System (INIS)

    Pancreatic ductal adenocarcinoma shows a distinct apoptosis resistance, which contributes significantly to the aggressive nature of this tumor and constrains the effectiveness of new therapeutic strategies. Apoptosis resistance is determined by the net balance of the cells pro-and anti-apoptotic 'control mechanisms'. Numerous dysregulated anti-apoptotic genes have been identified in pancreatic cancer and seem to contribute to the high anti-apoptotic buffering capacity. We aimed to compare the benefit of simultaneous gene silencing (SGS) of several candidate genes with conventional gene silencing of single genes. From literature search we identified the anti-apoptotic genes XIAP, Survivin and Bcl-2 as commonly upregulated in pancreatic cancer. We performed SGS and silencing of single candidate genes using siRNA molecules in two pancreatic cancer cell lines. Effectiveness of SGS was assessed by qRT-PCR and western blotting. Apoptosis induction was measured by flow cytometry and caspase activation. Simultaneous gene silencing reduced expression of the three target genes effectively. Compared to silencing of a single target or control, SGS of these genes resulted in a significant higher induction of apoptosis in pancreatic cancer cells. In the present study we performed a subliminal silencing of different anti-apoptotic target genes simultaneously. Compared to silencing of single target genes, SGS had a significant higher impact on apoptosis induction in pancreatic cancer cells. Thereby, we give further evidence for the concept of an anti-apoptotic buffering capacity of pancreatic cancer cells

  19. Simultaneous gene silencing of Bcl-2, XIAP and Survivin re-sensitizes pancreatic cancer cells towards apoptosis

    Directory of Open Access Journals (Sweden)

    Grützmann Robert

    2010-07-01

    Full Text Available Abstract Background Pancreatic ductal adenocarcinoma shows a distinct apoptosis resistance, which contributes significantly to the aggressive nature of this tumor and constrains the effectiveness of new therapeutic strategies. Apoptosis resistance is determined by the net balance of the cells pro-and anti-apoptotic "control mechanisms". Numerous dysregulated anti-apoptotic genes have been identified in pancreatic cancer and seem to contribute to the high anti-apoptotic buffering capacity. We aimed to compare the benefit of simultaneous gene silencing (SGS of several candidate genes with conventional gene silencing of single genes. Methods From literature search we identified the anti-apoptotic genes XIAP, Survivin and Bcl-2 as commonly upregulated in pancreatic cancer. We performed SGS and silencing of single candidate genes using siRNA molecules in two pancreatic cancer cell lines. Effectiveness of SGS was assessed by qRT-PCR and western blotting. Apoptosis induction was measured by flow cytometry and caspase activation. Results Simultaneous gene silencing reduced expression of the three target genes effectively. Compared to silencing of a single target or control, SGS of these genes resulted in a significant higher induction of apoptosis in pancreatic cancer cells. Conclusions In the present study we performed a subliminal silencing of different anti-apoptotic target genes simultaneously. Compared to silencing of single target genes, SGS had a significant higher impact on apoptosis induction in pancreatic cancer cells. Thereby, we give further evidence for the concept of an anti-apoptotic buffering capacity of pancreatic cancer cells.

  20. Ballonet String Model of Molecules

    Directory of Open Access Journals (Sweden)

    Gavril NIAC

    2008-06-01

    Full Text Available Strings of ballonets, modelling rows of orbitals, are assembled to molecule models by crossing them properly. The ballonets at the ends of the strings of 2, 3, 4 or 5 spheres represent bonding orbitals of hydrogen with other elements like C, N or O (the proton being inside the sphere, as well as nonbonding orbitals. The ballonets between them are modelling bonding orbitals among elements other than hydrogen - except the double bond in diborane, the atomic cores laying at the junction of two or more spheres.Advantages of elastic sphere models range from self-adjusting bond angles to resistance when closing cycles like cyclopropane or modeling double bonds.Examples comprise alkanes, including platonic hydrocarbons, ethene, acetylene, and some inorganic molecules.

  1. Electrochemical detection of single molecules.

    Science.gov (United States)

    Fan, F R; Bard, A J

    1995-02-10

    The electrochemical behavior of a single molecule can be observed by trapping a small volume of a dilute solution of the electroactive species between an ultramicroelectrode tip with a diameter of approximately 15 nanometers and a conductive substrate. A scanning electrochemical microscope was used to adjust the tip-substrate distance ( approximately 10 nanometers), and the oxidation of [(trimethylammonio)methyl] ferrocene (Cp(2)FeTMA(+)) to Cp(2)FeTMA(2+) was carried out. The response was stochastic, and anodic current peaks were observed as the molecule moved into and out of the electrode-substrate gap. Similar experiments were performed with a solution containing two redox species, ferrocene carboxylate (Cp(2)FeCOO(-)) and Os(bpy)(3)(2+) (bpy is 2,2'-bipyridyl). PMID:17813918

  2. Observing electron motion in molecules

    International Nuclear Information System (INIS)

    We study analytically the possibility for monitoring electron motion in a molecule using two ultrashort laser pulses. The first prepares a coherent superposition of two electronic molecular states whereas the second (attosecond pulse) photoionizes the molecule. We show that interesting information about electron dynamics can be obtained from measurement of the photoelectron spectra as a function of the time delay between two pulses. In particular, asymmetries in photoelectron angular distribution provide a simple signature of the electron motion within the initial time-dependent coherently coupled two molecular states. Both asymmetries and electron spectra show very strong two-centre interference patterns. We illustrate these effects using as an example a dissociating hydrogen molecular ion probed by the attosecond pulses

  3. Nano trap for polar molecules

    International Nuclear Information System (INIS)

    A new ac/dc monopole trap for neutral polar particles, introduced and explored by Blümel (2011 Phys. Rev. A 83 045402 and 2011 Eur. Phys. J. D 64 85–101), is significantly advanced in several directions. (1) Previously shown to work only for polar classical particles and polar macro-molecules, the trap is shown to work for polar diatomic molecules. (2) A homogeneous electric field, optionally switched on for improved stability in the angular direction, leads to stable trapping in higher order stability regions of the Mathieu equation. (3) Based on the Floquet formalism, analytical and numerical calculations are presented that show that the trap is quantum mechanically stable. (4) Definition and derivation of a quantum pseudo-potential allow a qualitative understanding of the quantum trapping mechanism. (5) It is shown that the proposed ac/dc trap may be realized experimentally using currently available scanning tunnelling microscopy technology. (paper)

  4. Laser tunneling from aligned molecules

    CERN Document Server

    Smeenk, C T L; Sokolov, A V; Spanner, M; Lee, K F; Staudte, A; Villeneuve, D M; Corkum, P B

    2013-01-01

    We study multi-photon ionization from N_2, O_2 and benzene using circularly polarized light. By examining molecular frame photo-electron angular distributions, we illustrate how multi-photon ionization acts a momentum-selective probe of the local electron density in the Dyson orbitals for these molecules. We find good agreement with calculations based on a tunneling model and including saturation effects.

  5. Metagenomic small molecule discovery methods

    OpenAIRE

    Charlop-Powers, Zachary; Milshteyn, Aleksandr; Brady, Sean F

    2014-01-01

    Metagenomic approaches to natural product discovery provide the means of harvesting bioactive small molecules synthesized by environmental bacteria without the requirement of first culturing these organisms. Advances in sequencing technologies and general metagenomic methods are beginning to provide the tools necessary to unlock the unexplored biosynthetic potential encoded by the genomes of uncultured environmental bacteria. Here, we highlight recent advances in sequence- and functional- bas...

  6. Bioactive molecules from sea hares.

    Science.gov (United States)

    Kamiya, H; Sakai, R; Jimbo, M

    2006-01-01

    Sea hares, belonging to the order Opisthobranchia, subclass Gastropoda, are mollusks that have attracted many researchers who are interested in the chemical defense mechanisms of these soft and "shell-less" snails. Numbers of small molecules of dietary origin have been isolated from sea hares and some have ecologically relevant activities, such as fish deterrent activity or toxicity. Recently, however, greater attention has been paid to biomedically interesting sea hare isolates such as dolastatins, a series of antitumor peptide/macrolides isolated from Dolabella auricularia. Another series of bioactive peptide/macrolides, as represented by aplyronines, have been isolated from sea hares in Japanese waters. Although earlier studies indicated the potent antitumor activity of aplyronines, their clinical development has never been conducted because of the minute amount of compound available from the natural source. Recent synthetic studies, however, have made it possible to prepare these compounds and analogs for a structure-activity relationship study, and started to uncover their unique action mechanism towards their putative targets, microfilaments. Here, recent findings of small antitumor molecules isolated from Japanese sea hares are reviewed. Sea hares are also known to produce cytotoxic and antimicrobial proteins. In contrast to the small molecules of dietary origin, proteins are the genetic products of sea hares and they are likely to have some primary physiological functions in addition to ecological roles in the sea hare. Based on the biochemical properties and phylogenetic analysis of these proteins, we propose that they belong to one family of molecule, the "Aplysianin A family," although their molecular weights are apparently divided into two groups. Interestingly, the active principles in Aplysia species and Dolabella auricularia were shown to be L-amino acid oxidase (LAAO), a flavin enzyme that oxidizes an alpha-amino group of the substrate with

  7. Simple molecules as complex systems.

    Science.gov (United States)

    Furtenbacher, Tibor; Arendás, Péter; Mellau, Georg; Császár, Attila G

    2014-01-01

    For individual molecules quantum mechanics (QM) offers a simple, natural and elegant way to build large-scale complex networks: quantized energy levels are the nodes, allowed transitions among the levels are the links, and transition intensities supply the weights. QM networks are intrinsic properties of molecules and they are characterized experimentally via spectroscopy; thus, realizations of QM networks are called spectroscopic networks (SN). As demonstrated for the rovibrational states of H2(16)O, the molecule governing the greenhouse effect on earth through hundreds of millions of its spectroscopic transitions (links), both the measured and first-principles computed one-photon absorption SNs containing experimentally accessible transitions appear to have heavy-tailed degree distributions. The proposed novel view of high-resolution spectroscopy and the observed degree distributions have important implications: appearance of a core of highly interconnected hubs among the nodes, a generally disassortative connection preference, considerable robustness and error tolerance, and an "ultra-small-world" property. The network-theoretical view of spectroscopy offers a data reduction facility via a minimum-weight spanning tree approach, which can assist high-resolution spectroscopists to improve the efficiency of the assignment of their measured spectra. PMID:24722221

  8. Functional molecules in electronic circuits.

    Science.gov (United States)

    Weibel, Nicolas; Grunder, Sergio; Mayor, Marcel

    2007-08-01

    Molecular electronics is a fascinating field of research contributing to both fundamental science and future technological achievements. A promising starting point for molecular devices is to mimic existing electronic functions to investigate the potential of molecules to enrich and complement existing electronic strategies. Molecules designed and synthesized to be integrated into electronic circuits and to perform an electronic function are presented in this article. The focus is set in particular on rectification and switching based on molecular devices, since the control over these two parameters enables the assembly of memory units, likely the most interesting and economic application of molecular based electronics. Both historical and contemporary solutions to molecular rectification are discussed, although not exhaustively. Several examples of integrated molecular switches that respond to light are presented. Molecular switches responding to an electrochemical signal are also discussed. Finally, supramolecular and molecular systems with intuitive application potential as memory units due to their hysteretic switching are highlighted. Although a particularly attractive feature of molecular electronics is its close cooperation with neighbouring disciplines, this article is written from the point of view of a chemist. Although the focus here is largely on molecular considerations, innovative contributions from physics, electro engineering, nanotechnology and other scientific disciplines are equally important. However, the ability of the chemist to correlate function with structure, to design and to provide tailor-made functional molecules is central to molecular electronics. PMID:17637951

  9. Water molecules orientation in surface layer

    Science.gov (United States)

    Klingo, V. V.

    2000-08-01

    The water molecules orientation has been investigated theoretically in the water surface layer. The surface molecule orientation is determined by the direction of a molecule dipole moment in relation to outward normal to the water surface. Entropy expressions of the superficial molecules in statistical meaning and from thermodynamical approach to a liquid surface tension have been found. The molecules share directed opposite to the outward normal that is hydrogen protons inside is equal 51.6%. 48.4% water molecules are directed along to surface outward normal that is by oxygen inside. A potential jump at the water surface layer amounts about 0.2 volts.

  10. The neural cell adhesion molecule

    DEFF Research Database (Denmark)

    Berezin, V; Bock, E; Poulsen, F M

    2000-01-01

    During the past year, the understanding of the structure and function of neural cell adhesion has advanced considerably. The three-dimensional structures of several of the individual modules of the neural cell adhesion molecule (NCAM) have been determined, as well as the structure of the complex...... between two identical fragments of the NCAM. Also during the past year, a link between homophilic cell adhesion and several signal transduction pathways has been proposed, connecting the event of cell surface adhesion to cellular responses such as neurite outgrowth. Finally, the stimulation of neurite...

  11. The molecule-metal interface

    CERN Document Server

    Koch, Norbert; Wee, Andrew Thye Shen

    2013-01-01

    Reviewing recent progress in the fundamental understanding of the molecule-metal interface, this useful addition to the literature focuses on experimental studies and introduces the latest analytical techniques as applied to this interface.The first part covers basic theory and initial principle studies, while the second part introduces readers to photoemission, STM, and synchrotron techniques to examine the atomic structure of the interfaces. The third part presents photoelectron spectroscopy, high-resolution UV photoelectron spectroscopy and electron spin resonance to study the electroni

  12. Dissociation Energies of Diatomic Molecules

    Institute of Scientific and Technical Information of China (English)

    FAN Qun-Chao; SUN Wei-Guo

    2008-01-01

    Molecular dissociation energies of 10 electronic states of alkali molecules of KH, 7LID, 7LiH, 6LiH, NaK, NaLi and NaRb are studied using the highest three accurate vibrational energies of each electronic state, and an improved parameter-free analytical formula which is obtained starting from the LeRoy-Bernstein vibrational energy expression near the dissociation limit. The results show that as long as the highest three vibrational energies are accurate, the current analytical formula will give accurate theoretical dissociation energies Detheory, which are in excellent agreement with the experimental dissociation energies Dexpte.

  13. XUV ionization of aligned molecules

    Energy Technology Data Exchange (ETDEWEB)

    Kelkensberg, F.; Siu, W.; Gademann, G. [FOM Institute AMOLF, Science Park 104, NL-1098 XG Amsterdam (Netherlands); Rouzee, A.; Vrakking, M. J. J. [FOM Institute AMOLF, Science Park 104, NL-1098 XG Amsterdam (Netherlands); Max-Born-Institut, Max-Born Strasse 2A, D-12489 Berlin (Germany); Johnsson, P. [FOM Institute AMOLF, Science Park 104, NL-1098 XG Amsterdam (Netherlands); Department of Physics, Lund University, Post Office Box 118, SE-221 00 Lund (Sweden); Lucchini, M. [Department of Physics, Politecnico di Milano, Istituto di Fotonica e Nanotecnologie CNR-IFN, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Lucchese, R. R. [Department of Chemistry, Texas A and M University, College Station, Texas 77843-3255 (United States)

    2011-11-15

    New extreme-ultraviolet (XUV) light sources such as high-order-harmonic generation (HHG) and free-electron lasers (FELs), combined with laser-induced alignment techniques, enable novel methods for making molecular movies based on measuring molecular frame photoelectron angular distributions. Experiments are presented where CO{sub 2} molecules were impulsively aligned using a near-infrared laser and ionized using femtosecond XUV pulses obtained by HHG. Measured electron angular distributions reveal contributions from four orbitals and the onset of the influence of the molecular structure.

  14. Hydrophobic Porous Material Adsorbs Small Organic Molecules

    Science.gov (United States)

    Sharma, Pramod K.; Hickey, Gregory S.

    1994-01-01

    Composite molecular-sieve material has pore structure designed specifically for preferential adsorption of organic molecules for sizes ranging from 3 to 6 angstrom. Design based on principle that contaminant molecules become strongly bound to surface of adsorbent when size of contaminant molecules is nearly same as that of pores in adsorbent. Material used to remove small organic contaminant molecules from vacuum systems or from enclosed gaseous environments like closed-loop life-support systems.

  15. Electric dipole moment of diatomic molecules

    International Nuclear Information System (INIS)

    The calculation of the electric dipole moment of diatomic molecules by the Variational Cellular Method is presented, discussed and compared with the semiempirical CNDO/2 method. The molecule HF is taken as example. It is also shown that the value of the electric dipole moment by the VCM improves considerably when the electronegativity of the atoms of the molecule is taken into account. (Author)

  16. Ultrafast electron diffraction from aligned molecules

    Energy Technology Data Exchange (ETDEWEB)

    Centurion, Martin [Univ. of Nebraska, Lincoln, NE (United States)

    2015-08-17

    The aim of this project was to record time-resolved electron diffraction patterns of aligned molecules and to reconstruct the 3D molecular structure. The molecules are aligned non-adiabatically using a femtosecond laser pulse. A femtosecond electron pulse then records a diffraction pattern while the molecules are aligned. The diffraction patterns are then be processed to obtain the molecular structure.

  17. Optoelectronics of Molecules and Polymers

    CERN Document Server

    Moliton, André

    2006-01-01

    Optoelectronic devices are being developed at an extraordinary rate. Organic light emitting diodes, photovoltaic devices and electro-optical modulators are pivotal to the future of displays, photosensors and solar cells, and communication technologies. This book details the theories underlying the relevant mechanisms in organic materials and covers, at a basic level, how the organic components are made. The first part of this book introduces the fundamental theories used to detail ordered solids and localised energy levels. The methods used to determine energy levels in perfectly ordered molecular and macromolecular systems are discussed, making sure that the effects of quasi-particles are not missed. The function of excitons and their transfer between two molecules are studied, and the problems associated with interfaces and charge injection into resistive media are presented. The second part details technological aspects such as the fabrication of devices based on organic materials by dry etching. The princ...

  18. Photoluminescence of a Plasmonic Molecule.

    Science.gov (United States)

    Huang, Da; Byers, Chad P; Wang, Lin-Yung; Hoggard, Anneli; Hoener, Ben; Dominguez-Medina, Sergio; Chen, Sishan; Chang, Wei-Shun; Landes, Christy F; Link, Stephan

    2015-07-28

    Photoluminescent Au nanoparticles are appealing for biosensing and bioimaging applications because of their non-photobleaching and non-photoblinking emission. The mechanism of one-photon photoluminescence from plasmonic nanostructures is still heavily debated though. Here, we report on the one-photon photoluminescence of strongly coupled 50 nm Au nanosphere dimers, the simplest plasmonic molecule. We observe emission from coupled plasmonic modes as revealed by single-particle photoluminescence spectra in comparison to correlated dark-field scattering spectroscopy. The photoluminescence quantum yield of the dimers is found to be surprisingly similar to the constituent monomers, suggesting that the increased local electric field of the dimer plays a minor role, in contradiction to several proposed mechanisms. Aided by electromagnetic simulations of scattering and absorption spectra, we conclude that our data are instead consistent with a multistep mechanism that involves the emission due to radiative decay of surface plasmons generated from excited electron-hole pairs following interband absorption. PMID:26165983

  19. Photonic molecules and spectral engineering

    CERN Document Server

    Boriskina, Svetlana V

    2012-01-01

    This chapter reviews the fundamental optical properties and applications of pho-tonic molecules (PMs) - photonic structures formed by electromagnetic coupling of two or more optical microcavities (photonic atoms). Controllable interaction between light and matter in photonic atoms can be further modified and en-hanced by the manipulation of their mutual coupling. Mechanical and optical tunability of PMs not only adds new functionalities to microcavity-based optical components but also paves the way for their use as testbeds for the exploration of novel physical regimes in atomic physics and quantum optics. Theoretical studies carried on for over a decade yielded novel PM designs that make possible lowering thresholds of semiconductor microlasers, producing directional light emission, achieving optically-induced transparency, and enhancing sensitivity of microcavity-based bio-, stress- and rotation-sensors. Recent advances in material science and nano-fabrication techniques make possible the realization of opt...

  20. Diamond Molecules Found in Petroleum

    Science.gov (United States)

    Carlson, R. M. K.; Dahl, J. E. P.; Liu, S. G.; Olmstead, M. M.; Buerki, P. R.; Gat, R.

    We recently reported [1,2] the discovery and isolation of new members of the hydrogen-terminated diamond series, ˜1 to ˜2 nm sized higher diamondoids from petroleum. Crystallographic studies [1,2] revealed a wealth of diamond molecules that are nanometer-sized rods, helices, discs, pyramids, etc. Highly rigid, well-defined, readily derivatizable structures make them valuable molecular building blocks for nanotechnology. We now produce certain higher diamondoids in gram quantities. Although more stable than graphite particles of comparable size, higher diamondoids are extraordinarily difficult to synthesize. Attempts to synthesize them were abandoned in the 1980's. We examined extracts of diamond-containing materials synthesized by CO2 laser-induced gas-phase synthesis [3] and commercial CVD in an attempt to detect diamantane to undecamantane. However, high-sensitivity GCMS detected no diamondoids in these materials.

  1. Anti-cancer Lead Molecule

    KAUST Repository

    Sagar, Sunil

    2014-04-17

    Derivatives of plumbagin can be selectively cytotoxic to breast cancer cells. Derivative `A` (Acetyl Plumbagin) has emerged as a lead molecule for testing against estrogen positive breast cancer and has shown low hepatotoxicity as well as overall lower toxicity in nude mice model. The toxicity of derivative `A` was determined to be even lower than vehicle control (ALT and AST markers). The possible mechanism of action identified based on the microarray experiments and pathway mapping shows that derivative `A` could be acting by altering the cholesterol-related mechanisms. The low toxicity profile of derivative `A` highlights its possible role\\'as future anti-cancer drug and/or as an adjuvant drug to reduce the toxicity of highly toxic chemotherapeutic\\'drugs

  2. Symmetries in nuclei and molecules

    International Nuclear Information System (INIS)

    Recent progress in two different fronts is reported. First, the concept of bisection of a harmonic oscillator or hydrogen atom, used in the past in establishing the connection between U(3) and O(4), is generalized into multisection (trisection, tetra section, etc.). It is then shown that all symmetries of the N-dimensional anisotropic harmonic oscillator with rational ratios of frequencies (RHO), some of which are underlying the structure of superdeformed and hyperdeformed nuclei, can be obtained from the U(N) symmetry of the corresponding isotropic oscillator with the appropriate combination of multisections. Furthermore, it is seen that bisections of the N-dimensional hydrogen atom, which possesses an O(N+1) symmetry, lead to the U(N) symmetry, so that further multisections of the hydrogen atom lead to the symmetries of the N-dim RHO. The opposite is in general not true, i.e. multisections of U(N) do not lead to O(N+1) symmetries, the only exception being the occurrence of O(4) after the bisection of U(3). Second, it is shown that there is evidence that the recently observed in superdeformed nuclear bands δ I=4 bifurcation is also occurring in normal deformed bands of actinides and rare earths, in hyperdeformed nuclear bands, as well as in rotational bands of diatomic molecules. In addition there is evidence that a δ I=8 bifurcation, of the same order of magnitude as the δ I=4 one, is observed in superdeformed nuclear bands and rotational bands of diatomic molecules. (author)

  3. Stability of small exotic molecules

    International Nuclear Information System (INIS)

    Complete text of publication follows. Three and four unit-charge particles with different masses may form bound states depending on the mass ratios. The aim of this work is to find out how many particles of unit charges can be put together to form bound states. We explore the possibility of the formation of stable N = 5,6...-particle systems of unit charges. We use a variational approach, in which the trial function is constructed out of generalised Gaussians whose parameters are determined by stochastic sampling. For few-body bound states this method has been shown to produce accurate results. First we made calculations for the five-body system (m+, m-, m+, m-, M+) with 0 ≤ σ ≤ ∞, where σ = m/M. We found that the binding energy of the system is larger than the nearest threshold for 0 ≤ σ ≤ 1.81, so the system in this region of mass ratio is bound. In the case of the system (m+, m-, m-, M+, M+) we cannot find a bound state for σ = 0. For 1 ≤ σ ≤ ∞, however, the system is bound. By decreasing σ from σ = 1, the binding energy is reduced, and around σ = 0.4 the system dissociates into (m-, m-, M+, M+) plus m+. Some six-body systems are under study, and cases have been found both for the existence and non-existence of bound states. From this study we can learn, e.g. that an H2 molecule cannot bind a positron and the positronium molecule can bind a proton, but it cannot bind an electron, unless we make the extra electron non-identical with the others. By comparing systems formed by identical and non-identical particles, we can point out the role of the Pauli principle in reducing the binding energy. (author)

  4. A preliminary study of the anti-inflammatory and anti-apoptotic effects of crocin against gastric ischemia-reperfusion injury in rats

    OpenAIRE

    Seyyed Ali Mard; Zahra Nikraftar; Yaghoob Farbood; Esrafil Mansouri

    2015-01-01

    The aim of the present study was to investigate the protective effect of crocin on gastric mucosal lesions caused by ischemia-reperfusion (I/R) injury in rats. Thirty-two male rats were randomly divided into sham, I/R, I/R + crocin pretreatment and crocin alone groups. To induce I/R lesions, the celiac artery was clamped for 30 min, and the clamp was then removed to allow reperfusion for 3 h. Crocin-pretreated rats received crocin (15 mg/kg, i.p.) 30 min prior to the induction of I/R injury. ...

  5. Lack of involvement of strand s1'A of the viral serpin CrmA in anti-apoptotic or caspase-inhibitory functions

    Energy Technology Data Exchange (ETDEWEB)

    Simonovic, Miljan; Denault, Jean-Bernard; Salvesen, Guy S.; Volz, Karl; Gettins, Peter G.W. (Brunham); (UIC); (Burnham)

    2010-11-30

    CrmA is a cowpox virus serpin required for full host infectivity and virulence. Residues 51-56 (DKNKDD), the only region that differs significantly from related viral serpins, were investigated for functional importance. A 1.6 {angstrom} X-ray structure reported here showed that this region can adopt either structured or unstructured conformations. Three variants were expressed, one with the region 51-56 deleted, one substituted by alanines, and one in which this region was replaced by the sequence encoded in smallpox virus. NMR showed that the region is an exposed, flexible loop that can be deleted without perturbing the serpin. The region is also very susceptible to proteolysis. Significantly, inhibition of caspases 1 and 8 was unaffected by the mutations, and each of the variants was as effective as wild-type CrmA in promoting survival from apoptosis induced by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Thus, although the 51-56 region of CrmA is unique, and is exposed and highly susceptible to proteolysis, any in vivo role must involve a function other than proteinase inhibition or cell sparing.

  6. Review of the apoptosis pathways in pancreatic cancer and the anti-apoptotic effects of the novel sea cucumber compound, Frondoside A.

    Science.gov (United States)

    Li, X; Roginsky, A B; Ding, X-Z; Woodward, C; Collin, P; Newman, R A; Bell, R H; Adrian, T E

    2008-09-01

    Pancreatic cancer cells are resistant to the growth-inhibitory and apoptosis-inducing effects of conventional chemotherapeutic agents. There are multiple genetic and epigenetic events during the process of carcinogenesis that enable the cancer cells to avoid normal growth constraints and apoptosis. Investigation of the mechanisms involved has led to multiple strategies that encourage cell death and apoptosis to occur. The pathways involved are summarized in this review, together with some recently developed strategies to promote cell death in this cancer and with a particular focus on the frondoside A, a novel triterpenoid glycoside isolated from the Atlantic sea cucumber, Cucumaria frondosa. Frondoside A inhibited proliferation of AsPC-1 human pancreatic cancer cells in a concentration- and time-dependent manner, as measured by (3)H-thymidine incorporation and cell counting. In concert with inhibition of cell growth, frondoside A induced significant morphological changes consistent with apoptosis. Propidium iodide DNA staining showed an increase of sub-G0/G1 cell population of apoptotic cells induced by frondoside A. Frondoside A-induced apoptosis was confirmed by annexin V binding and TUNEL assay. Furthermore, western blotting showed a decrease in expression of Bcl-2 and Mcl-1, an increase in Bax expression, activation of caspases 3, 7, and 9, and an increase in the expression of the cyclin-dependent kinase inhibitor, p21. These findings show that frondoside A induced apoptosis in human pancreatic cancer cells through the mitochondrial pathway and activation of the caspase cascade. Finally, a very low concentration of frondoside A (10 mug/kg/day) inhibited growth of AsPC-1 xenografts in athymic mice. In conclusion, new chemotherapeutic agents are desperately needed for pancreatic cancer because of the poor responsiveness to currently available treatment options. Frondoside A has potent growth inhibitory effects on human pancreatic cancer cells, and the inhibition of proliferation is accompanied by marked apoptosis. Frondoside A may be valuable for the treatment or chemoprevention of this devastating disease. PMID:18837899

  7. SP600125 enhances the anti-apoptotic capacity and migration of bone marrow mesenchymal stem cells treated with tumor necrosis factor-α.

    Science.gov (United States)

    Wei, Bo; Bai, Xizhuang; Chen, Kang; Zhang, Xiaonan

    2016-07-01

    Osteoarthritis (OA) and rheumatoid arthritis (RA) are chronic disorders associated with inflammation of joints characterized by damage to the underlying cartilage and bone. Bone marrow mesenchymal stem cells (BMSCs) are candidates for regeneration of bone and cartilage, which is inhibited by inflammatory cytokines in OA and RA, in particular tumor necrosis factor-α (TNF-α). This study aimed to investigate if the c-Jun N-terminal kinases (JNK)-specific inhibitor SP600125 could enhance the anti-apoptosis and migration of BMSCs treated with TNF-α. The level of apoptosis was evaluated via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)/4',6-diamidino-2-phenylindole (DAPI) staining, annexin V/propidium iodide (PI) staining and western blotting. Migration of BMSCs was assessed using transwell migration chambers. We showed that the survival capacity and migration of BMSCs was significantly inhibited by TNF-α, which was blocked by pretreatment with SP600125. In the presence of SP600125, expression of cleaved caspase-9/-3 and p53 as well as the ratio of Bax to Bcl-2 was significantly decreased compared to treatment with TNF-α alone. Our results therefore indicate that SP600125 improves the migration capacity of TNF-α-treated BMSCs and exerts a significant effect on the viability of TNF-α-treated BMSCs through reducing the up-regulation of p53, caspase-9/-3 and the Bcl-2 family induced by TNF-α. These findings suggest that SP600125 is of potential use in promoting the regeneration of bone and cartilage in OA and RA. PMID:27233606

  8. Anti-apoptotic effects of novel phenolic antioxidant isolated from the Pacific oyster (Crassostrea gigas) on cultured human hepatocytes under oxidative stress.

    Science.gov (United States)

    Fuda, Hirotoshi; Watanabe, Mitsugu; Hui, Shu-Ping; Joko, Sae; Okabe, Hiroaki; Jin, Shigeki; Takeda, Seiji; Miki, Emiko; Watanabe, Takayuki; Chiba, Hitoshi

    2015-06-01

    The antioxidant, and hepatoprotective properties of 3,5-dihydroxy-4-methoxybenzyl alcohol (DHMBA), a natural phenolic antioxidant isolated from the Pacific oyster, were defined using cultured human hepatocyte-derived cells (C3A). DHMBA showed no cytotoxicity at 62.5-500μM, as well as chlorogenic acid (CGA), vitamin C, and vitamin E. However, butylated hydroxytoluene, eicosapentaenoic acid, docosahexaenoic acid and catechin reduced cell viability. In the presence of the prooxidant 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH), DHMBA at 125-500μM improved cell viability, whereas CGA had no effect. DNA ladder formation and flow-cytometric studies indicated that DHMBA inhibited AAPH-induced apoptosis and necrosis. CGA was ineffective. Thus, DHMBA is a novel, potent antioxidant, effectively protecting cultured hepatocytes from apoptosis and necrosis caused by oxidative stress. Additionally, the concentration of DHMBA was determined by mass spectrometry to be 24.4μmol/kg wet oyster meat, and three polyphenols (gentisic acid, daidzein, and matairesinol) were newly identified in the oyster extracts. PMID:25624228

  9. Expression of anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax after delayed paraplegia induced by ischemia/reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    Bibo Liu; Miao Liu; Duoning Wang; Wei Ma; Shengli Dang

    2006-01-01

    BACKGROUND:Operation of spine does not involve in spinal cord;however,spinal cord injury occurs at post-operation induced by unclear factors.Meanwhile,after decompression of lumbar spinal canal,symptoms are severer and severer.In addition,during extirpation of oervical and lumbar intervertabral disc,spinal cord and its vessels are not damaged,but spinal cord injury is also suffered from patients with partial improvement.All statuses mentioned above are related to expressed changes of bc/-2 gene inhibiting apoptosis and bax gene accelerating apoptosis.OBJECTIVE:To observe motor function of hindlimbs of ischemia/reperfusion model in rabbits at various time points after reperfusion and expressions of apoptosis correlated protein Bcl-2 and Bax.DESIGN:Completely randomized grouping design and contrast study.SEITING:Department of Orthopedics,the First Affiliated Hospital of Medical School,Xi'an Jiao Tong University.MATERIALS:Forty-eight New Zealand white rabbits of both genders were randomly divided into sham operation group(n=24) and model group(n=24),and then,rabbits in each group were observed at four time points:8,24,72 and 168 hours after reperfusion,with 6 in each time point.Rabbit-anti-rabbit Bcl-2 antibody and rabbit-anti-rabbit Bax antibody were provided by Boster Company.The procedures were accordant to the METHODS:The experiment was carried out at Laboratory of Orthopaedics of First Affiliated Hospital of Medical School,Xi'an Jiao Tong University from April to August 2005.①Delayed paralysis models of spinal cord after ischemia/reperfusion were established based on method of Zivin et al.Animals in sham operation group underwent an exposure of abdominal aorta but the aorta was not occluded.②Motor function of hindlimb was observed 8,24,72 and 168 hours after reperfusion.A grade of 0-5 was assigned to each animal (grade 0:no voluntary hind limb function;grade 5:normal hop;grades 0-3:paraplegia).③The lumbar segment of the spinal cord(L3 to L5)was used for morphological studies at 168 hours after reperfusion and cut into sections with the thickness of 4μm:and then,the sections were stained with hematoxylin and eosin and observed under optic microscope.④After dewaxing,paraffin sections were used to detect expression of Bcl-2 and Bax proteins With Strept-Avidin-Biotin Complex,(SABC)kit(Wuhan Boster Company).The detailed operation was accordant to kit instruction.⑤Sections under the same staining condition but at various time points were measured with Image-Pro Plus Version 5.1 for Window TM (Median Cybemetics,Inc.USA.)to detect average integrated absorbency of positive cells of Bcl-2 and Bax protein.⑥Measurament data were compared with one-way analysis of variance and ttest. MAIN OUTCOME MEASURES:①Hind limb motor function deficit;②Histopathological examination;③Expression of Bcl-2 and Bax proteins at different reperfusion time points in spinal cord.RESULTS:All the 48 rabbits were involved in the analysis of results.①Motor function of hindlimb:Rabbits did not have paralysis in sham operation group.Rabbits in model group did not have paralysis at 8 hours after repertusion,but had delayed paralysis at 24,72 and 168 hours after reperfusion.Grade of motor function was lower than that in sham operation group(t=15.65,20.55.29.00,P.<0.01),similar to that in sham operation group at 8 hours after reperfusion and decreased obviously at 24 hours after reperfusion.②Pathological changes of spinal cord tissue:Spinal cord tissue was normal in sham operation group.With the reperfusion time passing by.necrosis of neurons in spinal cord tissue in model group was increased,inflammatory reaction was strengthened gradually and pathological changes were obvious at 72 hours after reperfusion.③Exprasslons of Bcl-2 and Bax protein:At 8 hours after reperfusion,expressions were similar in both sham operation group and model group(Bcl-2:20.42±4.22,19.63±2.72;Bax:5.22±1.24,4.82±1.52,P>0.05);expression of Bcl-2 was decreased obviously at 24 hours after reperfusion(8.09±0.96,t=9.78,P<0.05)and reached the lowest value at 72 hours after reperfusion(6.08±1.51,t=11.06,P<0.05).However,expression of Bax was increased obviously at 24 hours after reperfusion(12.84±1.77,f=7.88,P<0.05)and reached peak at 72 hours after reperfusion(15.84±5.19,t=4.42,P<0.05).At 168 hours after reperfusion,structure of gray matter was damaged severely and only a few of neurons survived.However,numbers of positive glial cells in white matter were increased,and expression of Bax was higher than that in sham operation group(9.41±1.53,t=6.44,P<0.05).CONCLUSION:Ischemia/reperfusion injury of spinal cord can induce decrease of motor function of experimental animals and cause apoptosis.Changes of both of them are general coincidence with changes of Bcl-2 and Bax expressions with the reperfusion time passing by.

  10. Pro- and anti-apoptotic effects of p53 in cisplatin-treated human testicular cancer are cell context-dependent

    NARCIS (Netherlands)

    di Pietro, Alessandra; Koster, Roelof; Boersma-van Eck, Wytske; Dam, Wendy A.; Mulder, Nanno H.; Gietema, Jourik A.; de Vries, Elisabeth G. E.; de Jong, Steven

    2012-01-01

    In murine testicular cancer (TC) cells wild-type p53 contributes to sensitivity to DNA-damaging drugs in a dose-dependent way. In human TC, however, the role of wild-type p53 functionality in chemotherapeutic response remains elusive. We analyzed functionality of wild-type p53 in cisplatin sensitivi

  11. Anti-apoptotic ARC protein confers chemoresistance by controlling leukemia-microenvironment interactions through a NFκB/IL1β signaling network

    KAUST Repository

    Carter, Bing Z.

    2016-04-11

    To better understand how the apoptosis repressor with caspase recruitment domain (ARC) protein confers drug resistance in acute myeloid leukemia (AML), we investigated the role of ARC in regulating leukemia-mesenchymal stromal cell (MSC) interactions. In addition to the previously reported effect on AML apoptosis, we have demonstrated that ARC enhances migration and adhesion of leukemia cells to MSCs both in vitro and in a novel human extramedullary bone/bone marrow mouse model. Mechanistic studies revealed that ARC induces IL1β expression in AML cells and increases CCL2, CCL4, and CXCL12 expression in MSCs, both through ARC-mediated activation of NFκB. Expression of these chemokines in MSCs increased by AML cells in an ARC/IL1β-dependent manner; likewise, IL1β expression was elevated when leukemia cells were co-cultured with MSCs. Further, cells from AML patients expressed the receptors for and migrated toward CCL2, CCL4, and CXCL12. Inhibition of IL1β suppressed AML cell migration and sensitized the cells co-cultured with MSCs to chemotherapy. Our results suggest the existence of a complex ARC-regulated circuit that maintains intimate connection of AML with the tumor microenvironment through NFκB/IL1β-regulated chemokine receptor/ligand axes and reciprocal crosstalk resulting in cytoprotection. The data implicate ARC as a promising drug target to potentially sensitize AML cells to chemotherapy.

  12. Irinotecan treatment and senescence failure promote the emergence of more transformed and invasive cells that depend on anti-apoptotic Mcl-1

    OpenAIRE

    Jonchère, Barbara; Vétillard, Alexandra; Toutain, Bertrand; Lam, David; Bernard, Anne Charlotte; Henry, Cécile; Trécesson, Sophie De Carné; Gamelin, Erick; Juin, Philippe; Guette, Catherine; Coqueret, Olivier

    2014-01-01

    Induction of senescence by chemotherapy was initially characterized as a suppressive response that prevents tumor cell proliferation. However, in response to treatment, it is not really known how cells can survive senescence and how irreversible this pathway is. In this study, we analyzed cell escape in response to irinotecan, a first line treatment used in colorectal cancer that induced senescence. We detected subpopulations of cells that adapted to chemotherapy and resumed proliferation. Su...

  13. Anti-apoptotic phenotypes of cholestan-3β,5α,6β-triol-resistant human cholangiocytes: characteristics contributing to the genesis of cholangiocarcinoma

    OpenAIRE

    Jusakul, Apinya; Loilome, Watcharin; Namwat, Nisana; Techasen, Anchalee; Kuver, Rahul; Ioannou, George; Savard, Christopher; Haigh, W. Geoffrey; Yongvanit, Puangrat

    2013-01-01

    The oxysterols cholestan-3β, 5α, 6β-triol (Triol) and 3-keto-cholest-4-ene (3K4) are increased in Opisthorchis viverrini-associated hamster cholangiocarcinoma and induce DNA damage and apoptosis via a mitochondria-dependent mechanism in MMNK-1 human cholangiocytes. Based on these observations, we hypothesized that chronic exposure of cholangiocytes to these pathogenic oxysterols may allow a growth advantage to a subset of these cells through selection for resistance to apoptosis, thereby cont...

  14. Elevated Levels of Uterine Anti-Apoptotic Signaling May Activate NFKB and Potentially Confer Resistance to Caspase 3-Mediated Apoptotic Cell Death During Pregnancy in Mice1

    OpenAIRE

    Jeyasuria, Pancharatnam; Subedi, Kalpana; Suresh, Arvind; Condon, Jennifer C.

    2011-01-01

    Preserving the uterus in a state of relative quiescence is vital to the maintenance of a successful pregnancy. Elevated cytoplasmic levels of uterine caspase 3 during pregnancy have been proposed as a potential regulator of uterine quiescence through direct targeting and disabling of the uterine contractile architecture. However, despite highly elevated levels of uterine caspase 3 during pregnancy, there is minimal evidence of apoptosis. This current study defines the mechanism whereby the pr...

  15. Elevated Levels of Uterine Anti-Apoptotic Signaling May Activate NFKB and Potentially Confer Resistance to Caspase 3-Mediated Apoptotic Cell Death During Pregnancy in Mice1

    Science.gov (United States)

    Jeyasuria, Pancharatnam; Subedi, Kalpana; Suresh, Arvind; Condon, Jennifer C.

    2011-01-01

    Preserving the uterus in a state of relative quiescence is vital to the maintenance of a successful pregnancy. Elevated cytoplasmic levels of uterine caspase 3 during pregnancy have been proposed as a potential regulator of uterine quiescence through direct targeting and disabling of the uterine contractile architecture. However, despite highly elevated levels of uterine caspase 3 during pregnancy, there is minimal evidence of apoptosis. This current study defines the mechanism whereby the pregnant uterine myocyte may harness the tocolytic activity of active caspases while avoiding apoptotic cell death. Using the pregnant mouse model, we have analyzed the uterus for changes in pro- and antiapoptotic signaling patterns associated with the advancing stages of pregnancy. Briefly, we have found that members of the IAP family, such as SURVIVIN and XIAP, and the Bcl2 family members, such as MCL1, are elevated in the uterine myocyte during late gestation. The IAP family members are the only endogenous inhibitors of active caspase 3, and MCL1 limits activation of caspase 3 by suppressing proapoptotic signaling. Elevated XIAP levels partner with SURVIVIN, resulting in increased levels of the antiapoptotic MCL1 via NFKB activation; these together have the potential to limit both the activity and level of active caspase 3 in the pregnant uterus as term approaches. We propose that modification of these antiapoptotic signaling partners allows the pregnant uterus to escape the apoptotic action of elevated active caspase 3 levels but also functions to limit the levels of active uterine caspase 3 near term. PMID:21566000

  16. The anti-inflammatory and anti-apoptotic effects of gallic acid against mucosal inflammation- and erosions-induced by gastric ischemia-reperfusion in rats

    OpenAIRE

    Mard, Seyyed Ali; Mojadami, Shahnaz; Farbood, Yaghoob; Gharib Naseri, Mohammad Kazem

    2015-01-01

    The present study aimed to evaluate the protective effect of gallic acid on gastric mucosal lesions caused by ischemia-reperfusion (I/R) injury in rat. Forty male rats were randomly divided into sham, control (I/R injury) and three gallic acid-pretreated groups. To induce I/R lesions, the celiac artery was clamped for 30 min and then the clamp was removed to allow reperfusion for 6 hr. Pretreated rats received gallic acid (15, 30 or 60 mg kg-1, intraperitoneally) 30 min prior to the induction...

  17. The role of an anti-apoptotic Mcl-1 protein in regulation of colon cancer cell sensitivity to trail-induced apoptosis

    Czech Academy of Sciences Publication Activity Database

    Vaculová, Alena; Hofmanová, Jiřina; Zatloukalová, Jiřina; Kozubík, Alois

    Brno, 2007. s. 84-85. ISBN 978-80-239-9591-6. [Analytical Cytometry IV. 23.06.2007-26.06.2007, Brno] R&D Projects: GA AV ČR(CZ) 1QS500040507; GA ČR(CZ) GA524/07/1178 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : apoptosis * TRAIL * Mcl-1 Subject RIV: BO - Biophysics

  18. Neuronal low-density lipoprotein receptor-related protein 1 (LRP1) enhances the anti-apoptotic effect of intravenous immunoglobulin (IVIg) in ischemic stroke.

    Science.gov (United States)

    Lok, Ker Zhing; Manzanero, Silvia; Arumugam, Thiruma V

    2016-08-01

    The low-density lipoprotein receptor-related protein 1 (LRP1) is a multifunctional and multi-ligand endocytic receptor abundantly expressed in neurons. Intravenous immunoglobulin (IVIg) is a purified preparation of plasma-derived human immunoglobulin used for the treatment of several neurological inflammatory disorders, and proposed for the treatment of stroke for its potent neuroprotective effects. LRP1 has been shown to be involved in the transcytosis of IVIg, and IVIg-LRP1 interaction leads to LRP1 tyrosine phosphorylation, which may contribute to the anti-inflammatory effects of IVIg. However, the question remains whether IVIg could induce its neuroprotective effects via LRP1 in neurons under ischemic stroke conditions. In cultured neurons and in a transient ischemic mouse model, ischemia decrease LRP1 levels and phosphorylation, and IVIg blocks these effects. In ischemic neurons, LRP1 antagonism by receptor associated protein (RAP) enhances the activation of pro-death signaling pathways such as nuclear factor-kappa B (NF-κB), mitogen-activated protein kinases (MAPKs), and caspase-3, and IVIg reduces these effects. When applied to ischemic neuronal cultures, RAP induces a dramatic drop in Akt activation, and IVIg reverses this effect, as it does with the decrease in Bcl-2 levels caused by ischemic injury in the presence of RAP. Altogether, these results show evidence of LRP1 expression and activity modulation by IVIg, and support the role of LRP1 as a partner of IVIg in the execution of its neuroprotective effects. PMID:27181517

  19. The effect of marathon on mRNA expression of anti-apoptotic and pro-apoptotic proteins and sirtuins family in male recreational long-distance runners

    Directory of Open Access Journals (Sweden)

    Russo Matteo

    2010-05-01

    Full Text Available Abstract Background A large body of evidence shows that a single bout of strenuous exercise induces oxidative stress in circulating human lymphocytes leading to lipid peroxidation, DNA damage, mitochondrial perturbations, and protein oxidation. In our research, we investigated the effect of physical load on the extent of apoptosis in primary cells derived from blood samples of sixteen healthy amateur runners after marathon (a.m.. Results Blood samples were collected from ten healthy amateur runners peripheral blood mononuclear cells (PBMCs were isolated from whole blood and bcl-2, bax, heat shock protein (HSP70, Cu-Zn superoxide dismutase (SOD, Mn-SOD, inducible nitric oxide synthase (i-NOS, SIRT1, SIRT3 and SIRT4 (Sirtuins RNA levels were determined by Northern Blot analysis. Strenuous physical load significantly increased HSP70, HSP32, Mn-SOD, Cu-Zn SOD, iNOS, GADD45, bcl-2, forkhead box O (FOXO3A and SIRT1 expression after the marathon, while decreasing bax, SIRT3 and SIRT4 expression (P Conclusion These data suggest that the physiological load imposed in amateur runners during marathon attenuates the extent of apoptosis and may interfere with sirtuin expression.

  20. Antioxidant, anti-inflammatory, anti-apoptotic, and skin regenerative properties of an Aloe vera-based extract of Nerium oleander leaves (NAE-8®

    Directory of Open Access Journals (Sweden)

    Benson KF

    2015-05-01

    Full Text Available Kathleen F Benson,1 Robert A Newman,2,3 Gitte S Jensen1 1NIS Labs, Klamath Falls, Oregon, USA; 2University of Texas MD Anderson Cancer Center, Houston, TX, USA; 3Nerium Biotechnology, Inc, San Antonio, TX, USA Objective: The goal for this study was to evaluate the effects of an Aloe vera-based Nerium oleander extract (NAE-8®, compared to an extract of A. vera gel alone (ALOE, and to an aqueous extract of N. oleander (AQ-NOE in bioassays pertaining to dermatologic potential with respect to antioxidant protection, anti-inflammatory effects, and cytokine profiles in vitro. Methods: Cellular antioxidant protection was evaluated in three separate bioassays: The cellular antioxidant protection of erythrocytes (CAP-e assay, protection of cellular viability and prevention of apoptosis, and protection of intracellular reduced glutathione levels, where the last two assays were performed using human primary dermal fibroblasts. Reduction of intracellular formation of reactive oxygen species (ROS was tested using polymorphonuclear cells in the absence and presence of oxidative stress. Changes to cytokine and chemokine profiles when whole blood cells and human primary dermal fibroblasts were exposed to test products were determined using a 40-plex Luminex array as a method for exploring the potential cross-talk between circulating and skin-resident cells. Results: The NAE-8® provided significantly better antioxidant protection in the CAP-e bioassay than AQ-NOE. NAE-8® and AQ-NOE both protected cellular viability and intracellular reduced glutathione, and reduced the ROS formation significantly when compared to control cells, both under inflamed and neutral culture conditions. ALOE showed minimal effect in these bioassays. In contrast to the NAE-8®, the AQ-NOE showed induction of inflammation in the whole blood cultures, as evidenced by the high induction of CD69 expression and secretion of a number of inflammatory cytokines. The treatment of dermal fibroblasts with NAE-8® resulted in selective secretion of cytokines involved in collagen and hyaluronan production as well as re-epithelialization during wound healing. Conclusion: NAE-8®, a novel component of a commercial cosmetic product, showed beneficial antioxidant protection in several cellular models, without the induction of leukocyte activation and secretion of inflammatory cytokines. The biological efficacy of NAE-8® was unique from both ALOE and AQ-NOE. Keywords: CAP-e bioassay, dermal fibroblasts, oxidative damage, ROS formation, safety

  1. The effects of two common edible herbs, Ipomoea aquatica and Enhydra fluctuans, on cadmium-induced pathophysiology: a focus on oxidative defence and anti-apoptotic mechanism

    OpenAIRE

    Dua, Tarun K; Dewanjee, Saikat; Khanra, Ritu; Bhattacharya, Niloy; Bhaskar, Bhuvan; Zia-Ul-Haq, Muhammad; De Feo, Vincenzo

    2015-01-01

    Background Ipomoea aquatica (Convolvulaceae) and Enhydra fluctuans (Asteraceae), two aquatic vegetables, are traditionally used against heavy metal toxicity in traditional medicines in India. The present study aimed to explore the protective role of edible (aqueous) extracts of I. aquatica (AEIA) and E. fluctuans (AEEF) against Cd-intoxication. Methods The extracts were chemically standardized by spectroscopic and HPLC analysis. The cytoprotective roles of AEIA and AEEF were measured on mouse...

  2. Spin polarization effect of Ni2 molecule

    Institute of Scientific and Technical Information of China (English)

    Yan Shi-Ying; Zhu Zheng-He

    2008-01-01

    The density functional theory (DFT) method (b3p86) of Gaussian 03 is used to optimize the structure of the Ni2 molecule. The result shows that the ground state for the Ni2 molecule is a 5-multiple state, symbolizing a spin polarization effect existing in the Ni2 molecule, a transition metal molecule, but no spin pollution is found because the wavefunction of the ground state does not mingle with wavefunctions of higher-energy states. So the ground state for Ni2 molecule, which is a 5-multiple state, is indicative of spin polarization effect of the Ni2 molecule, that is, there exist 4 parallel spin electrons in Ni2 molecule. The number of non-conjugated electrons is greatest. These electrons occupy different spatial orbitals so that the energy of the Ni2 molecule is minimized. It can be concluded that the effect of parallel spin in the Ni2 molecule is larger than that of the conjugated molecule, which is obviously related to the effect of electron d delocalization. In addition, the Murrell-Sorbie potential functions with the parameters of the ground state and other states of the Ni2 molecule are derived. The dissociation energy De for the ground state of the Ni2 molecule is 1.835 eV, equilibrium bond length Re is 0.2243 nm, vibration frequency ωe is 262.35 cm-1. Its force constants f2, f3 and f4 are 1.1901 aJ.nm-2, 5.8723 aJ.nm-3, and 21.2505 aJ.nm-4 respectively. The other spectroscopic data for the ground state of the Ni2 molecule ωexe, Be and αe are 1.6315cm-1, 0.1141 cm-1, and 8.0145×10-4 cm-1 respectively.

  3. Spin polarization effect for Cr2 molecule

    Institute of Scientific and Technical Information of China (English)

    Yan Shi-Ying

    2008-01-01

    Density functional theory (DFT) (B3P86) of Ganssian 03 has been used to optimize the structure of the Cr2 molecule, a transition metal element molecule. The result shows that the ground state for the Cr2 molecule is a 13-multiple state, indicating that there exists a spin polarization effect in the Cr2 molecule. Meanwhile, we have not found any spin pollution because the wave function of the ground state does not mingle with wave functions of higher-energy states. So the ground state for Cr2 molecule being a 13-multiple state is indicative of spin polarization effect of the Cr2 molecule among transition metal elements, that is, there are 12 parallel spin electrons in the Cr2 molecule. The number of non-conjugated electrons is greatest. These electrons occupy different spatial orbitals so that the energy of the Cr2 molecule is minimized. It can be concluded that the effect of parallel spin in the Cr2 molecule is larger than the effect of the conjugated molecule, which is obviously related to the effect of electron d delocalization. In addition,the Murrell-Sorbie potential functions with the parameters for the ground state and other states of the Cr2 molecule are derived. The dissociation energy De for the ground state of the Cr2 molecule is 0.1034eV, equilibrium bond length Re is 0.3396nm, and vibration frequency ωe is 73.81cm-1. Its force constants f2, f3 and f4 are 0.0835, -0.2831 and 0.3535 aJ·nm-4 respectively. The other spectroscopic data for the ground state of the Cr2 molecule ωeχe, Be and αe are 1.2105, 0.0562 and 7.2938 × 10-4cm-1 respectively.

  4. Coordination programming of photofunctional molecules.

    Science.gov (United States)

    Sakamoto, Ryota; Kusaka, Shinpei; Hayashi, Mikihiro; Nishikawa, Michihiro; Nishihara, Hiroshi

    2013-01-01

    Our recent achievements relating to photofunctional molecules are addressed. Section 1 discloses a new concept of photoisomerization. Pyridylpyrimidine-copper complexes undergo a ring inversion that can be modulated by the redox state of the copper center. In combination with an intermolecular photoelectron transfer (PET) initiated by the metal-to-ligand charge transfer (MLCT) transition of the Cu(I) state, we realize photonic regulation of the ring inversion. Section 2 reports on the first examples of heteroleptic bis(dipyrrinato)zinc(II) complexes. Conventional homoleptic bis(dipyrrinato)zinc(II) complexes suffered from low fluorescence quantum yields, whereas the heteroleptic ones feature bright fluorescence even in polar solvents. Section 3 describes our new findings on Pechmann dye, which was first synthesized in 1882. New synthetic procedures for Pechmann dye using dimethyl bis(arylethynyl)fumarate as a starting material gives rise to its new structural isomer. We also demonstrate potentiality of a donor-acceptor-donor type of Pechmann dye in organic electronics. PMID:23563859

  5. Coordination Programming of Photofunctional Molecules

    Directory of Open Access Journals (Sweden)

    Hiroshi Nishihara

    2013-04-01

    Full Text Available Our recent achievements relating to photofunctional molecules are addressed. Section 1 discloses a new concept of photoisomerization. Pyridylpyrimidine-copper complexes undergo a ring inversion that can be modulated by the redox state of the copper center. In combination with an intermolecular photoelectron transfer (PET initiated by the metal-to-ligand charge transfer (MLCT transition of the Cu(I state, we realize photonic regulation of the ring inversion. Section 2 reports on the first examples of heteroleptic bis(dipyrrinatozinc(II complexes. Conventional homoleptic bis(dipyrrinatozinc(II complexes suffered from low fluorescence quantum yields, whereas the heteroleptic ones feature bright fluorescence even in polar solvents. Section 3 describes our new findings on Pechmann dye, which was first synthesized in 1882. New synthetic procedures for Pechmann dye using dimethyl bis(arylethynylfumarate as a starting material gives rise to its new structural isomer. We also demonstrate potentiality of a donor-acceptor-donor type of Pechmann dye in organic electronics.

  6. Single Molecule Studies of Chromatin

    Energy Technology Data Exchange (ETDEWEB)

    Jeans, C; Thelen, M P; Noy, A

    2006-02-06

    In eukaryotic cells, DNA is packaged as chromatin, a highly ordered structure formed through the wrapping of the DNA around histone proteins, and further packed through interactions with a number of other proteins. In order for processes such as DNA replication, DNA repair, and transcription to occur, the structure of chromatin must be remodeled such that the necessary enzymes can access the DNA. A number of remodeling enzymes have been described, but our understanding of the remodeling process is hindered by a lack of knowledge of the fine structure of chromatin, and how this structure is modulated in the living cell. We have carried out single molecule experiments using atomic force microscopy (AFM) to study the packaging arrangements in chromatin from a variety of cell types. Comparison of the structures observed reveals differences which can be explained in terms of the cell type and its transcriptional activity. During the course of this project, sample preparation and AFM techniques were developed and optimized. Several opportunities for follow-up work are outlined which could provide further insight into the dynamic structural rearrangements of chromatin.

  7. Single-molecule stochastic resonance

    CERN Document Server

    Hayashi, K; Manosas, M; Huguet, J M; Ritort, F; 10.1103/PhysRevX.2.031012

    2012-01-01

    Stochastic resonance (SR) is a well known phenomenon in dynamical systems. It consists of the amplification and optimization of the response of a system assisted by stochastic noise. Here we carry out the first experimental study of SR in single DNA hairpins which exhibit cooperatively folding/unfolding transitions under the action of an applied oscillating mechanical force with optical tweezers. By varying the frequency of the force oscillation, we investigated the folding/unfolding kinetics of DNA hairpins in a periodically driven bistable free-energy potential. We measured several SR quantifiers under varied conditions of the experimental setup such as trap stiffness and length of the molecular handles used for single-molecule manipulation. We find that the signal-to-noise ratio (SNR) of the spectral density of measured fluctuations in molecular extension of the DNA hairpins is a good quantifier of the SR. The frequency dependence of the SNR exhibits a peak at a frequency value given by the resonance match...

  8. NMR of dielectrically oriented molecules

    International Nuclear Information System (INIS)

    General information on experimental aspects of EFNMR is given. It is shown that the complete 14N quadrupole tensor (qct) of pyridine and pyrimidine in the liquid state is accessible to EFNMR. Information obtained about 17O qct in liquid nitromethane, is compared with results from other techniques. The 33S qct in liquid sulfolane is investigated. The EFNMR results, combined with those from spin-lattice relaxation time measurements and from Hartree-Fock-Slater MO calculations, allowed the complete assignment of the 33S qct. The quadrupole coupling of both 10B and 11B in a carborane compound is investigated and, together with the results of spin-lattice relaxation time measurements, detailed information about the assignment of the boron qct's could be derived. EFNMR studies of apolar molecules are described. A limitation in EFNMR is the inhomogeneity (delta B) of the magnetic field, which is introduced by the use of non-spinning sample cells. A way out is the detection of zero quantum transitions, their widths being independent of delta B. The results and prospectives of this approach are shown for the simple three spin 1/2 system of acrylonitrile in which the small dipolar proton-proton couplings could be revealed via zero quantum transitions. (Auth.)

  9. NMR studies of oriented molecules

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, S.W.

    1981-11-01

    Deuterium and proton magnetic resonance are used in experiments on a number of compounds which either form liquid crystal mesophases themselves or are dissolved in a liquid crystal solvent. Proton multiple quantum NMR is used to simplify complicated spectra. The theory of nonselective multiple quantum NMR is briefly reviewed. Benzene dissolved in a liquid crystal are used to demonstrate several outcomes of the theory. Experimental studies include proton and deuterium single quantum (..delta..M = +-1) and proton multiple quantum spectra of several molecules which contain the biphenyl moiety. 4-Cyano-4'-n-pentyl-d/sub 11/-biphenyl (5CB-d/sub 11/) is studied as a pure compound in the nematic phase. The obtained chain order parameters and dipolar couplings agree closely with previous results. Models for the effective symmetry of the biphenyl group in 5CB-d/sub 11/ are tested against the experimental spectra. The dihedral angle, defined by the planes containing the rings of the biphenyl group, is found to be 30 +- 2/sup 0/ for 5DB-d/sub 11/. Experiments are also described for 4,4'-d/sub 2/-biphenyl, 4,4' - dibromo-biphenyl, and unsubstituted biphenyl.

  10. Observation of pendular butterfly Rydberg molecules

    CERN Document Server

    Niederprüm, Thomas; Eichert, Tanita; Lippe, Carsten; Pérez-Ríos, Jesús; Greene, Chris H; Ott, Herwig

    2016-01-01

    Obtaining full control over the internal and external quantum states of molecules is the central goal of ultracold chemistry and allows for the study of coherent molecular dynamics, collisions and tests of fundamental laws of physics. When the molecules additionally have a permanent electric dipole moment, the study of dipolar quantum gases and spin-systems with long-range interactions as well as applications in quantum information processing are possible. Rydberg molecules constitute a class of exotic molecules, which are bound by the interaction between the Rydberg electron and the ground state atom. They exhibit extreme bond lengths of hundreds of Bohr radii and giant permanent dipole moments in the kilo-Debye range. A special type with exceptional properties are the so-called butterfly molecules, whose electron density resembles the shape of a butterfly. Here, we report on the photoassociation of butterfly Rydberg molecules and their orientation in a weak electric field. Starting from a Bose-Einstein cond...

  11. Rotational Cooling of Trapped Polyatomic Molecules.

    Science.gov (United States)

    Glöckner, Rosa; Prehn, Alexander; Englert, Barbara G U; Rempe, Gerhard; Zeppenfeld, Martin

    2015-12-01

    Controlling the internal degrees of freedom is a key challenge for applications of cold and ultracold molecules. Here, we demonstrate rotational-state cooling of trapped methyl fluoride molecules (CH_{3}F) by optically pumping the population of 16 M sublevels in the rotational states J=3, 4, 5 and 6 into a single level. By combining rotational-state cooling with motional cooling, we increase the relative number of molecules in the state J=4, K=3, M=4 from a few percent to over 70%, thereby generating a translationally cold (≈30  mK) and nearly pure state ensemble of about 10^{6} molecules. Our scheme is extendable to larger sets of initial states, other final states, and a variety of molecule species, thus paving the way for internal-state control of ever-larger molecules. PMID:26684114

  12. Rotational cooling of trapped polyatomic molecules

    CERN Document Server

    Glöckner, Rosa; Englert, Barbara G U; Rempe, Gerhard; Zeppenfeld, Martin

    2015-01-01

    Controlling the internal degrees of freedom is a key challenge for applications of cold and ultracold molecules. Here, we demonstrate rotational-state cooling of trapped methyl fluoride molecules (CH3F) by optically pumping the population of 16 M-sublevels in the rotational states J=3,4,5, and 6 into a single level. By combining rotational-state cooling with motional cooling, we increase the relative number of molecules in the state J=4, K=3, M=4 from a few percent to over 70%, thereby generating a translationally cold (~30mK) and nearly pure state ensemble of about 10^6 molecules. Our scheme is extendable to larger sets of initial states, other final states and a variety of molecule species, thus paving the way for internal-state control of ever larger molecules.

  13. Broadband single-molecule excitation spectroscopy

    Science.gov (United States)

    Piatkowski, Lukasz; Gellings, Esther; van Hulst, Niek F.

    2016-01-01

    Over the past 25 years, single-molecule spectroscopy has developed into a widely used tool in multiple disciplines of science. The diversity of routinely recorded emission spectra does underpin the strength of the single-molecule approach in resolving the heterogeneity and dynamics, otherwise hidden in the ensemble. In early cryogenic studies single molecules were identified by their distinct excitation spectra, yet measuring excitation spectra at room temperature remains challenging. Here we present a broadband Fourier approach that allows rapid recording of excitation spectra of individual molecules under ambient conditions and that is robust against blinking and bleaching. Applying the method we show that the excitation spectra of individual molecules exhibit an extreme distribution of solvatochromic shifts and distinct spectral shapes. Importantly, we demonstrate that the sensitivity and speed of the broadband technique is comparable to that of emission spectroscopy putting both techniques side-by-side in single-molecule spectroscopy.

  14. Laser cooling of a diatomic molecule

    CERN Document Server

    Shuman, E S; DeMille, D

    2011-01-01

    It has been roughly three decades since laser cooling techniques produced ultracold atoms, leading to rapid advances in a vast array of fields. Unfortunately laser cooling has not yet been extended to molecules because of their complex internal structure. However, this complexity makes molecules potentially useful for many applications. For example, heteronuclear molecules possess permanent electric dipole moments which lead to long-range, tunable, anisotropic dipole-dipole interactions. The combination of the dipole-dipole interaction and the precise control over molecular degrees of freedom possible at ultracold temperatures make ultracold molecules attractive candidates for use in quantum simulation of condensed matter systems and quantum computation. Also ultracold molecules may provide unique opportunities for studying chemical dynamics and for tests of fundamental symmetries. Here we experimentally demonstrate laser cooling of the molecule strontium monofluoride (SrF). Using an optical cycling scheme re...

  15. Dynamics of a linear magnetic "microswimmer molecule"

    OpenAIRE

    Babel, Sonja; Löwen, Hartmut; Menzel, Andreas M.

    2015-01-01

    In analogy to nanoscopic molecules that are composed of individual atoms, we consider an active "microswimmer molecule". It is built up from three individual magnetic colloidal microswimmers that are connected by harmonic springs and hydrodynamically interact with each other. In the ground state, they form a linear straight molecule. We analyze the relaxation dynamics for perturbations of this straight configuration. As a central result, with increasing self-propulsion, we observe an oscillat...

  16. Making "Operations" inside a Single Molecule

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Free and delicate manipulation of single molecules has long been expected by scientists so as to realize specific functions. In the 1990s, the laboratory led by Prof. Wison Ho from the University of California was successful in inducing chemical reactions at the single molecule level with scanning tunneling microscopy (STM), revealing the extensive potentials of "single molecule operation." However, until recently, researchers have failed to utilize the reaction to give rise to special physical properties.

  17. Scanning tunneling microscopy of biological molecules

    International Nuclear Information System (INIS)

    Scanning Tunnelling Microscopy (STM) has been used to image a number of biological molecules including thrombospondin and glycoprotein 88 (GP88). In this paper, STM images which clearly resolve the morphology of these molecules are presented. Ultimately, it is hoped that STM will provide information about the interaction between these molecules after overcoming problems associated with sample preparation and reproducibility of results which are discussed. 4 refs., 2 figs

  18. Charge correlations in polaron hopping through molecules

    OpenAIRE

    Schmidt, Benjamin B.; Hettler, Matthias H.; Schön, Gerd

    2009-01-01

    In many organic molecules the strong coupling of excess charges to vibrational modes leads to the formation of polarons, i.e., a localized state of a charge carrier and a molecular deformation. Incoherent hopping of polarons along the molecule is the dominant mechanism of transport at room temperature. We study the far-from-equilibrium situation where, due to the applied bias, the induced number of charge carriers on the molecule is high enough such that charge correlations become relevant. W...

  19. RNA Reactions One Molecule at a Time

    OpenAIRE

    Tinoco, Ignacio; Chen, Gang; Qu, Xiaohui

    2010-01-01

    Much of the dynamics information is lost in bulk measurements because of the population averaging. Single-molecule methods measure one molecule at a time; they provide knowledge not obtainable by other means. In this article, we review the application of the two most widely used single-molecule methods—fluorescence resonance energy transfer (FRET) and force versus extension measurements—to several RNA reactions. First, we discuss folding/unfolding studies on a hairpin ribozyme that revealed m...

  20. Single-molecule recognition imaging microscopy

    OpenAIRE

    Stroh, C.; Wang, H.; Bash, R.; B Ashcroft; Nelson, J.; Gruber, H; Lohr, D.; Lindsay, S M; Hinterdorfer, P.

    2004-01-01

    Atomic force microscopy is a powerful and widely used imaging technique that can visualize single molecules and follow processes at the single-molecule level both in air and in solution. For maximum usefulness in biological applications, atomic force microscopy needs to be able to identify specific types of molecules in an image, much as fluorescent tags do for optical microscopy. The results presented here demonstrate that the highly specific antibody–antigen interaction can be used to gener...

  1. Ultracold polar molecules near quantum degeneracy

    OpenAIRE

    Ospelkaus, S.; Ni, K.-K.; de Miranda, M. H. G.; Neyenhuis, B.; Wang, D; Kotochigova, S.; Julienne, P. S.; Jin, D. S.; J. Ye

    2008-01-01

    We report the creation and characterization of a near quantum-degenerate gas of polar $^{40}$K-$^{87}$Rb molecules in their absolute rovibrational ground state. Starting from weakly bound heteronuclear KRb Feshbach molecules, we implement precise control of the molecular electronic, vibrational, and rotational degrees of freedom with phase-coherent laser fields. In particular, we coherently transfer these weakly bound molecules across a 125 THz frequency gap in a single step into the absolute...

  2. Production and Trapping of Ultracold Polar Molecules

    Energy Technology Data Exchange (ETDEWEB)

    David, DeMille [Yale Univ., New Haven, CT (United States)

    2015-04-21

    We report a set of experiments aimed at the production and trapping of ultracold polar molecules. We begin with samples of laser-cooled and trapped Rb and Cs atoms, and bind them together to form polar RbCs molecules. The binding is accomplished via photoassociation, which uses a laser to catalyze the sticking process. We report results from investigation of a new pathway for photoassociation that can produce molecules in their absolute ground state of vibrational and rotational motion. We also report preliminary observations of collisions between these ground-state molecules and co-trapped atoms.

  3. Single-molecule pulling: phenomenology and interpretation

    CERN Document Server

    Franco, Ignacio; Schatz, George C

    2012-01-01

    Single-molecule pulling techniques have emerged as versatile tools for probing the noncovalent forces holding together the secondary and tertiary structure of macromolecules. They also constitute a way to study at the single-molecule level processes that are familiar from our macroscopic thermodynamic experience. In this Chapter, we summarize the essential phenomenology that is typically observed during single-molecule pulling, provide a general statistical mechanical framework for the interpretation of the equilibrium force spectroscopy and illustrate how to simulate single-molecule pulling experiments using molecular dynamics.

  4. Electron-molecule interactions and their applications

    CERN Document Server

    Christophorou, L G

    1984-01-01

    Electron-Molecule Interactions and Their Applications, Volume 2 provides a balanced and comprehensive account of electron-molecule interactions in dilute and dense gases and liquid media. This book consists of six chapters. Chapter 1 deals with electron transfer reactions, while Chapter 2 discusses electron-molecular positive-ion recombination. The electron motion in high-pressure gases and electron-molecule interactions from single- to multiple-collision conditions is deliberated in Chapter 3. In Chapter 4, knowledge on electron-molecule interactions in gases is linked to that on similar proc

  5. Circularly Polarized Luminescence from Simple Organic Molecules.

    Science.gov (United States)

    Sánchez-Carnerero, Esther M; Agarrabeitia, Antonia R; Moreno, Florencio; Maroto, Beatriz L; Muller, Gilles; Ortiz, María J; de la Moya, Santiago

    2015-09-21

    This article aims to show the identity of "circularly polarized luminescent active simple organic molecules" as a new concept in organic chemistry due to the potential interest of these molecules, as availed by the exponentially growing number of research articles related to them. In particular, it describes and highlights the interest and difficulty in developing chiral simple (small and non-aggregated) organic molecules able to emit left- or right-circularly polarized light efficiently, the efforts realized up to now to reach this challenging objective, and the most significant milestones achieved to date. General guidelines for the preparation of these interesting molecules are also presented. PMID:26136234

  6. Reactive scattering of halogen molecules

    International Nuclear Information System (INIS)

    A study of the endoergic, bimolecular reactions of F2 with I2, ICl, and HI in a crossed molecular beam experiment is described. The trihalogens IIF, ClIF, and HIF were directly observed as the products of these reactions. At high collision energies a second reactive channel producing IF becomes important. Product angular and velocity distributions show that this IF does not result from a four-center exchange reaction. Measured threshold energies for the formation of IIF, ClIF, and HIF yield lower bounds to the stabilities of these molecules, with respect to the separated atoms, of 69, 81, and 96 kcal/mole, respectively. Analysis of product center-of-mass angular distributions indicates that a slightly nonlinear approach is most effective in bringing about reaction to form the stable triatomic radical. Also described is a crossed molecular beam study of the Cl + Br2 → BrCl + Br reaction at collision energies from 6.8 to 17.7 kcal/mole. The results indicate that this reaction has the characteristics of an exoergic reaction on an attractive potential energy surface with early energy release. Reagent translational energy is very efficiently channeled into product internal energy. At high collision energy the reaction appears to approach the spectator stripping limit. Finally, a series of computer programs which can be used to carry out the requisite data analysis for crossed molecular beam reactive scattering experiments are described. These programs recover the reactive scattering center-of-mass flux distribution from the measured angular and velocity distributions of the products

  7. Submillimeter Spectroscopy of Hydride Molecules

    Science.gov (United States)

    Phillips, T. G.

    1998-05-01

    Simple hydride molecules are of great importance in astrophysics and astrochemistry. Physically they dominate the cooling of dense, warm phases of the ISM, such as the cores and disks of YSOs. Chemically they are often stable end points of chemical reactions, or may represent important intermediate stages of the reaction chains, which can be used to test the validity of the process. Through the efforts of astronomers, physicists, chemists, and laboratory spectroscopists we have an approximate knowledge of the abundance of some of the important species, but a great deal of new effort will be required to achieve the comprehensive and accurate data set needed to determine the energy balance and firmly establish the chemical pathways. Due to the low moment of inertia, the hydrides rotate rapidly and so have their fundamental spectral lines in the submillimeter. Depending on the cloud geometry and temperature profile they may be observed in emission or absorption. Species such as HCl, HF, OH, CH, CH(+) , NH_2, NH_3, H_2O, H_2S, H_3O(+) and even H_3(+) have been detected, but this is just a fraction of the available set. Also, most deduced abundances are not nearly sufficiently well known to draw definitive conclusions about the chemical processes. For example, the most important coolant for many regions, H_2O, has a possible range of deduced abundance of a factor of 1000. The very low submillimeter opacity at the South Pole site will be a significant factor in providing a new capabilty for interstellar hydride spectroscopy. The new species and lines made available in this way will be discussed.

  8. Spin polarization effect for Fe2 molecule

    Institute of Scientific and Technical Information of China (English)

    Yan Shi-Ying; Zhu Zheng-He

    2006-01-01

    This paper uses the density functional theory (DFT)(B3p86) of Gaussian03 to optimize the structure of Fe2 molecule. The result shows that the ground state for Fe2 molecule is a 9-multiple state, which shows spin polarization effect of Fe2 molecule of transition metal elements for the first time. Meanwhile, we have not found any spin pollution because the wavefunction of the ground state does not mingle with wavefunctions with higher energy states. So, that the ground state for Fe2 molecule is a 9-multiple state is indicative of the spin polarization effect of Fe2 molecule of transition metal elements. That is, there exist 8 parallel spin electrons. The non-conjugated electron is greatest in number. These electrons occupy different spacious tracks, so that the energy of the Fe2 molecule is minimized. It can be concluded that the effect of parallel spin of the Fe2 molecule is larger than the effect of the conjugated molecule, which is obviously related to the effect of electron d delocalization. In addition, the Murrell-Sorbie potential functions with the parameters for the ground state and other states of Fe2 molecule are derived. Dissociation energy De for the ground state of Fe2 molecule is 2.8586ev, equilibrium bond length Re is 0.2124nm, vibration frequency ωe is 336.38 cm-1. Its force constants f2, f3, and f4 are 1.8615aJ·nm-2, -8.6704a J·nm-3, 29.1676aJ·nm-4 respectively. The other spectroscopic data for the ground state of Fe2 moleculeωeχe, Be, αe are 1.5461 cm-1, 0.1339 cm-1, 7.3428×10-4 cm-1 respectively.

  9. Spin polarization effect for Tc2 molecule

    Institute of Scientific and Technical Information of China (English)

    Yan Shi-Ying; Zhu Zheng-He

    2004-01-01

    Density functional method (DFT) (B3p86) of Gaussian98 has been used to optimize the structure of the Tc2 molecule. The result shows that the ground state for Tc2 molecule is an 11-multiple state and its electronic configuration is 11∑- g, which shows the spin polarization effect of Tc2 molecule of a transition metal element for the first time.Meanwhile, we have not found any spin pollution because the wavefunction of the ground state does not mingle with wavefunctions of higher energy states. So, that the ground state for Tc2 molecule is an 11-multiple state is indicative of the spin polarization effect of Tc2 molecule of a transition metal element: that is, there exist 10 parallel spin electrons. The non-conjugated electron is greatest in number. These electrons occupy different spacious tracks, so that the energy of Tc2 molecule is minimized. It can be concluded that the effect of parallel spin of the Tc2 molecule is larger than the effect of the conjugated molecule, which is obviously related to the effect of electron d delocalization.In addition, the Murrell-Sorbie potential functions with the parameters for the ground state 11∑- g and other states of Tc2 molecule are derived. Dissociation energy De for the ground state of Tc2 molecule is 2.266eV, equilibrium bond length Re is 0.2841nm, vibration frequency ωe is 178.52cm-1. Its force constants f2, f3, and f4 are 0.9200aJ.nm-2,-3.5700aJ.nm-3, 11.2748aJ.nm-4 respectively. The other spectroscopic data for the ground state of Tc2 molecule ωexe,Be, αe are 0.5523cm- 1, 0.0426cm- 1, 1.6331 × 10-4cm- 1 respectively.

  10. Molecule-oriented programming in Java

    NARCIS (Netherlands)

    Bergstra, J.A.

    2002-01-01

    Molecule-oriented programming is introduced as a programming style carrying some perspective for Java. A sequence of examples is provided. Supporting the development of the molecule-oriented programming style several matters are introduced and developed: profile classes allowing the representation o

  11. Controlled contact to a C-60 molecule

    DEFF Research Database (Denmark)

    Neel, N.; Kröger, J.; Limot, L.; Frederiksen, Thomas; Brandbyge, Mads

    2007-01-01

    The tip of a low-temperature scanning tunneling microscope is approached towards a C-60 molecule adsorbed at a pentagon-hexagon bond on Cu(100) to form a tip-molecule contact. The conductance rapidly increases to approximate to 0.25 conductance quanta in the transition region from tunneling to...

  12. Infrared emission from electronically excited biacetyl molecules

    NARCIS (Netherlands)

    Drent, E.; Kommandeur, J.

    1971-01-01

    The infrared emission of electronically excited biacetyl molecules in the gas phase at low pressure was observed. Some experimental details are given, and it is shown that the emission derives from biacetyl molecules in their triplet state. The emission is dependent on the wavelength of excitation.

  13. Single molecule fluorescence detection on functionalized surfaces

    International Nuclear Information System (INIS)

    Full text: The immobilization of organic molecules on surfaces is important for various applications in nanolithography and also essential in novel detectors for matter wave interferometry. We use fluorescence imaging up to the single molecule level to study the suppression of long-range surface diffusion of ZnTPP on pyridine functionalized surfaces. (author)

  14. Small azomethine molecules and their use in photovoltaic devices

    NARCIS (Netherlands)

    Dingemans, T.J.; Petrus, M.L.

    2015-01-01

    The present invention is in the field of a small azomethine molecule having photovoltaic characteristics, a method of synthesizing said molecule, use of said molecule in a photovoltaic device, a solar cell comprising said molecule, and a film comprising said molecule. The present molecules may find

  15. Spin polarization effect for Co2 molecule

    Institute of Scientific and Technical Information of China (English)

    Yan Shi-Ying; Bao Wen-Sheng

    2007-01-01

    The density functional theory (DFT)(b3p86) of Gaussian 03 has been used to optimize the structure of the Co2molecule, a transition metal element molecule. The result shows that the ground state for the Co2 molecule is a 7-multiple state, indicating a spin polarization effect in the Co2 molecule. Meanwhile, we have not found any spin pollution because the wavefunction of the ground state is not mingled with wavefunctions of higher-energy states. So for the ground state of Co2 molecule to be a 7-multiple state is the indicative of spin polarization effect of the Co2molecule, that is, there exist 6 parallel spin electrons in a Co2 molecule. The number of non-conjugated electrons is the greatest. These electrons occupy different spacial orbitals so that the energy of the Co2 molecule is minimized. It can be concluded that the effect of parallel spin in the Co2 molecule is larger than the effect of the conjugated molecule,which is obviously related to the effect of electron d delocalization. In addition, the Murrell-Sorbie potential functions with the parameters for the ground state and the other states of the Co2 molecule are derived. The dissociation energy De for the ground state of Co2 molecule is 4.0489eV, equilibrium bond length Re is 0.2061 nm, and vibration frequency 11.2222 aJ.nm-4respectively(1 a.J=10-18 J). The other spectroscopic data for the ground state of Co2 molecule ωexe,Be, and αe are 0.7202 cm-1, 0.1347 cm-1, and 2.9120× 10-1 cm-1 respectively. And ωexe is the non-syntonic part of frequency, Be is the rotational constant, αe is revised constant of rotational constant for non-rigid part of Co2 molecule.

  16. The symmetry of single-molecule conduction.

    Science.gov (United States)

    Solomon, Gemma C; Gagliardi, Alessio; Pecchia, Alessandro; Frauenheim, Thomas; Di Carlo, Aldo; Reimers, Jeffrey R; Hush, Noel S

    2006-11-14

    We introduce the conductance point group which defines the symmetry of single-molecule conduction within the nonequilibrium Green's function formalism. It is shown, either rigorously or to within a very good approximation, to correspond to a molecular-conductance point group defined purely in terms of the properties of the conducting molecule. This enables single-molecule conductivity to be described in terms of key qualitative chemical descriptors that are independent of the nature of the molecule-conductor interfaces. We apply this to demonstrate how symmetry controls the conduction through 1,4-benzenedithiol chemisorbed to gold electrodes as an example system, listing also the molecular-conductance point groups for a range of molecules commonly used in molecular electronics research. PMID:17115774

  17. Chemical principles of single-molecule electronics

    Science.gov (United States)

    Su, Timothy A.; Neupane, Madhav; Steigerwald, Michael L.; Venkataraman, Latha; Nuckolls, Colin

    2016-03-01

    The field of single-molecule electronics harnesses expertise from engineering, physics and chemistry to realize circuit elements at the limit of miniaturization; it is a subfield of nanoelectronics in which the electronic components are single molecules. In this Review, we survey the field from a chemical perspective and discuss the structure-property relationships of the three components that form a single-molecule junction: the anchor, the electrode and the molecular bridge. The spatial orientation and electronic coupling between each component profoundly affect the conductance properties and functions of the single-molecule device. We describe the design principles of the anchor group, the influence of the electronic configuration of the electrode and the effect of manipulating the structure of the molecular backbone and of its substituent groups. We discuss single-molecule conductance switches as well as the phenomenon of quantum interference and then trace their fundamental roots back to chemical principles.

  18. Small-molecule-dependent split aptamer ligation.

    Science.gov (United States)

    Sharma, Ashwani K; Heemstra, Jennifer M

    2011-08-17

    Here we describe the first use of small-molecule binding to direct a chemical reaction between two nucleic acid strands. The reported reaction is a ligation between two fragments of a DNA split aptamer using strain-promoted azide-alkyne cycloaddition. Utilizing the split aptamer for cocaine, we demonstrate small-molecule-dependent ligation that is dose-dependent over a wide range of cocaine concentrations and is compatible with complex biological fluids such as human blood serum. Moreover, studies of split aptamer ligation at varying salt concentrations and using structurally similar analogues of cocaine have revealed new insight into the assembly and small-molecule binding properties of the cocaine split aptamer. The ability to translate the presence of a small-molecule target into the output of DNA ligation is anticipated to enable the development of new, broadly applicable small-molecule detection assays. PMID:21761903

  19. Extracting Models in Single Molecule Experiments

    Science.gov (United States)

    Presse, Steve

    2013-03-01

    Single molecule experiments can now monitor the journey of a protein from its assembly near a ribosome to its proteolytic demise. Ideally all single molecule data should be self-explanatory. However data originating from single molecule experiments is particularly challenging to interpret on account of fluctuations and noise at such small scales. Realistically, basic understanding comes from models carefully extracted from the noisy data. Statistical mechanics, and maximum entropy in particular, provide a powerful framework for accomplishing this task in a principled fashion. Here I will discuss our work in extracting conformational memory from single molecule force spectroscopy experiments on large biomolecules. One clear advantage of this method is that we let the data tend towards the correct model, we do not fit the data. I will show that the dynamical model of the single molecule dynamics which emerges from this analysis is often more textured and complex than could otherwise come from fitting the data to a pre-conceived model.

  20. The Homology Relation between Molecules: a Revival of an Old Way for Classification of Molecules

    OpenAIRE

    Dobrowolski, Jan Cz.

    2009-01-01

    The homology (homolo) relation between molecules was introduced. This relation is a generalization of an old idea of series of homologous compounds. The homolo relation operates on a molecule by removing all the structural fragments that are identical with a certain selected fragment. As a result a multiset of fragments is produced. It was shown that the homolo relation is an equivalence relation in a set of molecules. Thus, by choosing various reference fragments, the molecules can be classi...

  1. Novel Applications of Buffer-Gas Cooling to Cold Atoms, Diatomic Molecules, and Large Molecules

    OpenAIRE

    Drayna, Garrett Korda

    2016-01-01

    Cold gases of atoms and molecules provide a system for the exploration of a diverse set of physical phenomena. For example, cold gasses of magnetically and electrically polar atoms and molecules are ideal systems for quantum simulation and quantum computation experiments, and cold gasses of large polar molecules allow for novel spectroscopic techniques. Buffer-gas cooling is a robust and widely applicable method for cooling atoms and molecules to temperatures of approximately 1 Kelvin. In thi...

  2. High Harmonic Generation from Rotationally Excited Molecules

    Science.gov (United States)

    Lock, Robynne M.

    2011-12-01

    High harmonic generation (HHG) is understood through a three-step model. A strong laser field ionizes an atom or molecule. The free electron propagates in the laser field and may recombine with the atom or molecule leading to the generation of extreme ultraviolet or soft x-ray light at odd harmonics of the fundamental. Since the wavelength of the recombining electron is on the order of internuclear distances in molecules, HHG acts as a probe of molecular structure and dynamics. Conversely, control of the molecules leads to control of the properties (intensity, phase, and polarization) of the harmonic emission. Rotationally exciting molecules provides field-free molecular alignment at time intervals corresponding to fractions of the rotational period of the molecule. Alignment is necessary for understanding how the harmonic emission depends on molecular structure and alignment. Additionally, HHG acts as a probe of the rotational wavepackets. This thesis reports three experiments on HHG from rotationally excited molecules. Before we can use HHG as a probe of complex molecular dynamics or control harmonic properties through molecules, the harmonic emission from aligned, linear molecules must first be understood. To that end, the first experiment measures the intensity and phase of harmonics generated from N 2O and N2 near times of strong alignment revealing interferences during recombination. The second experiment demonstrates HHG as a sensitive probe of rotational wavepacket dynamics in CO2 and N2O, revealing new revival features not detected by any other probe. The final experiment focuses on understanding and controlling the polarization state of the harmonic emission. Generating elliptically polarized harmonics would be very useful for probing molecular and materials systems. We observe an elliptical dichroism in polarization-resolved measurements of the harmonic emission from aligned N2 and CO2 molecules, revealing evidence for electron-hole dynamics between the

  3. Search for complex organic molecules in space

    Science.gov (United States)

    Ohishi, Masatoshi

    2016-07-01

    It was 1969 when the first organic molecule in space, H2CO, was discovered. Since then many organic molecules were discovered by using the NRAO 11 m (upgraded later to 12 m), Nobeyama 45 m, IRAM 30 m, and other highly sensitive radio telescopes as a result of close collaboration between radio astronomers and microwave spectroscopists. It is noteworthy that many famous organic molecules such as CH3OH, C2H5OH, (CH3)2O and CH3NH2 were detected by 1975. Organic molecules were found in so-called hot cores where molecules were thought to form on cold dust surfaces and then to evaporate by the UV photons emitted from the central star. These days organic molecules are known to exist not only in hot cores but in hot corinos (a warm, compact molecular clump found in the inner envelope of a class 0 protostar) and even protoplanetary disks. As was described above, major organic molecules were known since 1970s. It was very natural that astronomers considered a relationship between organic molecules in space and the origin of life. Several astronomers challenged to detect glycine and other prebiotic molecules without success. ALMA is expected to detect such important materials to further consider the gexogenous deliveryh hypothesis. In this paper I summarize the history in searching for complex organic molecules together with difficulties in observing very weak signals from larger species. The awfully long list of references at the end of this article may be the most useful part for readers who want to feel the exciting discovery stories.

  4. Spin polarization effect for Mn2 molecule

    Institute of Scientific and Technical Information of China (English)

    Yan Shi-Ying; Xu Guo-Liang

    2007-01-01

    The density functional theory method (DFT) (b3p86) of Gaussian 03 has been used to optimize the structure of the Mn2 molecule.The result shows that the ground state of the Mn2 molecule is an 11-multiple state,indicating a spin polarization effect in the Mn2 molecule,a transition metal element molecule.Meanwhile,we have not found any spin pollution because the wavefunction of the ground state does not mingle with wavefunctions of higher-energy states.So the ground state for Mn2 molecule being of an 11-multiple state is the indicative of spin polarization effect of the Mn2 molecule among those in the transition metal elements:that is,there are 10 parallel spin electrons in a Mn2 molecule.The number of non-conjugated electrons is the greatest.These electrons occupy different spacious orbitals so that the energy of the Mn2 molecule is minimized.It can be concluded that the effect of parallel spin in the Mn2 molecule is larger than the effect of the conjugated molecule,which is obviously related to the effect of electron d delocalization.In addition,the Murrell-Sorbie potential functions with the parameters for the ground state and other states of the Mn2 molecule are derived.The dissociation energy De for the ground state of the Mn2 molecule is 1.4477eV,equilibrium bond length Re is 0.2506 nm,vibration frequency ωe is 211.51 cm-1.Its force constants,f2,f3,and f4 are 0.7240 aJ·nm-2,-3.35574 aJ·nm-3,11.4813 aJ·nm-4 respectively. The other spectroscopic data for the ground state of the Mn2 molecule ωeχe,Be,αe are 1.5301 cm-1,0.0978 cm-1,7.7825×10-4 cm-1 respectively.

  5. Tuning the Magnetic Anisotropy of Single Molecules.

    Science.gov (United States)

    Heinrich, Benjamin W; Braun, Lukas; Pascual, Jose I; Franke, Katharina J

    2015-06-10

    The magnetism of single atoms and molecules is governed by the atomic scale environment. In general, the reduced symmetry of the surrounding splits the d states and aligns the magnetic moment along certain favorable directions. Here, we show that we can reversibly modify the magnetocrystalline anisotropy by manipulating the environment of single iron(II) porphyrin molecules adsorbed on Pb(111) with the tip of a scanning tunneling microscope. When we decrease the tip-molecule distance, we first observe a small increase followed by an exponential decrease of the axial anisotropy on the molecules. This is in contrast to the monotonous increase observed earlier for the same molecule with an additional axial Cl ligand ( Nat. Phys. 2013 , 9 , 765 ). We ascribe the changes in the anisotropy of both species to a deformation of the molecules in the presence of the attractive force of the tip, which leads to a change in the d level alignment. These experiments demonstrate the feasibility of a precise tuning of the magnetic anisotropy of an individual molecule by mechanical control. PMID:25942560

  6. Molecules-in-Molecules: An Extrapolated Fragment-Based Approach for Accurate Calculations on Large Molecules and Materials.

    Science.gov (United States)

    Mayhall, Nicholas J; Raghavachari, Krishnan

    2011-05-10

    We present a new extrapolated fragment-based approach, termed molecules-in-molecules (MIM), for accurate energy calculations on large molecules. In this method, we use a multilevel partitioning approach coupled with electronic structure studies at multiple levels of theory to provide a hierarchical strategy for systematically improving the computed results. In particular, we use a generalized hybrid energy expression, similar in spirit to that in the popular ONIOM methodology, that can be combined easily with any fragmentation procedure. In the current work, we explore a MIM scheme which first partitions a molecule into nonoverlapping fragments and then recombines the interacting fragments to form overlapping subsystems. By including all interactions with a cheaper level of theory, the MIM approach is shown to significantly reduce the errors arising from a single level fragmentation procedure. We report the implementation of energies and gradients and the initial assessment of the MIM method using both biological and materials systems as test cases. PMID:26610128

  7. Single molecule microscopy and spectroscopy: concluding remarks.

    Science.gov (United States)

    van Hulst, Niek F

    2015-01-01

    Chemistry is all about molecules: control, synthesis, interaction and reaction of molecules. All too easily on a blackboard, one draws molecules, their structures and dynamics, to create an insightful picture. The dream is to see these molecules in reality. This is exactly what "Single Molecule Detection" provides: a look at molecules in action at ambient conditions; a breakthrough technology in chemistry, physics and biology. Within the realms of the Royal Society of Chemistry, the Faraday Discussion on "Single Molecule Microscopy and Spectroscopy" was a very appropriate topic for presentation, deliberation and debate. Undoubtedly, the Faraday Discussions have a splendid reputation in stimulating scientific debates along the traditions set by Michael Faraday. Interestingly, back in the 1830's, Faraday himself pursued an experiment that led to the idea that atoms in a compound were joined by an electrical component. He placed two opposite electrodes in a solution of water containing a dissolved compound, and observed that one of the elements of the compound accumulated on one electrode, while the other was deposited on the opposite electrode. Although Faraday was deeply opposed to atomism, he had to recognize that electrical forces were responsible for the joining of atoms. Probably a direct view on the atoms or molecules in his experiment would have convinced him. As such, Michael Faraday might have liked the gathering at Burlington House in September 2015 (). Surely, with the questioning eyes of his bust on the 1st floor corridor, the non-believer Michael Faraday has incited each passer-by to enter into discussion and search for deeper answers at the level of single molecules. In these concluding remarks, highlights of the presented papers and discussions are summarized, complemented by a conclusion on future perspectives. PMID:26606461

  8. Understanding Polymer Properties through Imaging of Molecules.

    Science.gov (United States)

    Sheiko, Sergei

    2008-03-01

    The unique advantage of Scanning Probe Microscopy (SPM) is that it allows imaging of flexible polymer molecules, whose overall size and local curvature are below the optical resolution limit. The role of molecular visualization has grown to be especially profound with the synthesis of complex macromolecules whose structure is difficult to confirm using conventional techniques such as NMR and light scattering. This is especially true for molecules that are branched, heterogeneous, and polydisperse. Here, SPM images provide unambiguous proof of the molecular architecture along with accurate analysis of size, conformation, and ordering of molecules on surfaces. The unique advantage of SPM is that one obtains molecular dimensions in direct space. This offers more opportunities for statistical analysis including fractionation of molecules by size, branching topology, and chemical composition as well as sorting out the irrelevant species. Unlike molecular characterization of static molecules, it remains challenging to study molecules as they move and react on surfaces. We will discuss pioneering AFM studies of flowing monolayers one molecule at a time. Through use of AFM, the flow process was monitored over a broad range of length scales from the millimeter long precursor film all the way down to the movements of individual molecules within the film. Molecular imaging enabled independent measurements both the driving and frictional forces that control spreading rate. In these studies, one also discovered a new type of flow instability in polymer monolayers caused by flow-induced conformational transitions. Recently, molecular imaging has been successfully used to monitor adsorption-induced degradation of branched molecules. These experiments open an entirely new perspective in chemistry wherein the chemical bonds can be mechanically activated upon the physical contact of a macromolecule with a substrate. This research directly impacts coatings, lubrication, heterogeneous

  9. Imaging Cold Molecules on a Chip

    CERN Document Server

    Marx, S; Abel, M J; Zehentbauer, T; Meijer, G; Santambrogio, G

    2013-01-01

    We present the integrated imaging of cold molecules in a microchip environment. The on-chip de- tection is based on REMPI, which is quantum-state-selective and generally applicable. We demon- strate and characterize time-resolved spatial imaging and subsequently use it to analyze the effect of a phase-space manipulation sequence aimed at compressing the velocity distribution of a molec- ular ensemble with a view to future high-resolution spectroscopic studies. The realization of such on-chip measurements adds the final fundamental component to the molecule chip, offering a new and promising route for investigating cold molecules.

  10. The MHC molecules of nonmammalian vertebrates

    DEFF Research Database (Denmark)

    Kaufman, J; Skjoedt, K; Salomonsen, J

    1990-01-01

    encoding polymorphic class I and class II molecules) and evidence for polymorphic class I and class II molecules in reptiles. However, many details differ from the mammals, and it is not clear whether these reflect historical accident or selection for different lifestyles or environment. For example, the...... ontogeny and the consequences for the immune system and survival of the animals. These animals also differ markedly in the level of MHC polymorphism. Another difference from mammals is the presence of previously uncharacterized molecules. In Xenopus and reptiles, there are two populations of class I alpha...

  11. Rotational cooling of trapped polyatomic molecules

    OpenAIRE

    Glöckner, Rosa; Prehn, Alexander; Englert, Barbara G. U.; Rempe, Gerhard; Zeppenfeld, Martin

    2015-01-01

    Controlling the internal degrees of freedom is a key challenge for applications of cold and ultracold molecules. Here, we demonstrate rotational-state cooling of trapped methyl fluoride molecules (CH3F) by optically pumping the population of 16 M-sublevels in the rotational states J=3,4,5, and 6 into a single level. By combining rotational-state cooling with motional cooling, we increase the relative number of molecules in the state J=4, K=3, M=4 from a few percent to over 70%, thereby genera...

  12. Aligning molecules with intense nonresonant laser fields

    DEFF Research Database (Denmark)

    Larsen, J.J.; Safvan, C.P.; Sakai, H.;

    1999-01-01

    Molecules in a seeded supersonic beam are aligned by the interaction between an intense nonresonant linearly polarized laser field and the molecular polarizability. We demonstrate the general applicability of the scheme by aligning I2, ICl, CS2, CH3I, and C6H5I molecules. The alignment is probed by...... mass selective two dimensional imaging of the photofragment ions produced by femtosecond laser pulses. Calculations on the degree of alignment of I2 are in good agreement with the experiments. We discuss some future applications of laser aligned molecules....

  13. Tunable optical absorption in silicene molecules

    KAUST Repository

    Mokkath, Junais Habeeb

    2016-07-13

    Two-dimensional materials with a tunable band gap that covers a wide range of the solar spectrum hold great promise for sunlight harvesting. For this reason, we investigate the structural, electronic, and optical properties of silicene molecules using time dependent density functional theory. We address the influence of the molecular size, buckling, and charge state as well as that of a dielectric environment. Unlike planar graphene molecules, silicene molecules prefer to form low-buckled structures with strong visible to ultraviolet optical response. We also identify molecular plasmons.

  14. Handbook of single-molecule electronics

    CERN Document Server

    Moth-Poulsen, Kasper

    2015-01-01

    Single-molecule electronics has evolved as a vibrant research field during the last two decades. The vision is to be able to create electronic components at the highest level of miniaturization-the single molecule. This book compiles and details cutting-edge research with contributions from chemists, physicists, theoreticians, and engineers. It covers all aspects of single-molecule electronics, from the theory through experimental realizations and the chemical synthesis of molecular components to the implementation of molecular components in future integrated circuits. This book describes in d

  15. Single Molecule Biophysics Experiments and Theory

    CERN Document Server

    Komatsuzaki, Tamiki; Takahashi, Satoshi; Yang, Haw; Silbey, Robert J; Rice, Stuart A; Dinner, Aaron R

    2011-01-01

    Discover the experimental and theoretical developments in optical single-molecule spectroscopy that are changing the ways we think about molecules and atoms The Advances in Chemical Physics series provides the chemical physics field with a forum for critical, authoritative evaluations of advances in every area of the discipline. This latest volume explores the advent of optical single-molecule spectroscopy, and how atomic force microscopy has empowered novel experiments on individual biomolecules, opening up new frontiers in molecular and cell biology and leading to new theoretical approaches

  16. Non-sequential double ionization of molecules

    CERN Document Server

    Prauzner-Bechcicki, J S; Eckhardt, B; Zakrzewski, J; Prauzner-Bechcicki, Jakub S.; Sacha, Krzysztof; Eckhardt, Bruno; Zakrzewski, Jakub

    2004-01-01

    Double ionization of diatomic molecules by short linearly polarized laser pulses is analyzed. We consider the final stage of the ionization process, that is the decay of a highly excited two electron molecule, which is formed after re-scattering. The saddles of the effective adiabatic potential energy close to which simultaneous escape of electrons takes place are identified. Numerical simulations of the ionization of molecules show that the process can be dominated by either sequential or non-sequential events. In order to increase the ratio of non-sequential to sequential ionizations very short laser pulses should be applied.

  17. A Classification Scheme For Toroidal Molecules

    CERN Document Server

    Berger, J; Berger, Jorge; Avron, Joseph E.

    1995-01-01

    We construct a class of periodic tilings of the plane, which corresponds to toroidal arrangements of trivalent atoms, with pentagonal, hexagonal and heptagonal rings. Each tiling is characterized by a set of four integers and determines a toroidal molecule. The tiling rules are motivated by geometric considerations and the tiling patterns are rich enough to describe a wide class of toroidal carbon molecules, with a broad range of shapes and numbers of atoms. The molecular dimensions are simply related to the integers that determine the tiling. The configurational energy and the delocalisation energy of several molecules obtained in this way were computed for Tersoff and H\\"uckel models. The results indicate that many of these molecules are not strained, and may be expected to be stable. We studied the influence of size on the H\\"{u}ckel spectrum: it bears both similarities and differences as compared with the case of tubules.

  18. Molecular junctions: Single-molecule contacts exposed

    Science.gov (United States)

    Nichols, Richard J.; Higgins, Simon J.

    2015-05-01

    Using a scanning tunnelling microscopy-based method it is now possible to get an atomistic-level description of the most probable binding and contact configuration for single-molecule electrical junctions.

  19. Synaptic Cell Adhesion Molecules in Alzheimer's Disease

    Science.gov (United States)

    Leshchyns'ka, Iryna

    2016-01-01

    Alzheimer's disease (AD) is a neurodegenerative brain disorder associated with the loss of synapses between neurons in the brain. Synaptic cell adhesion molecules are cell surface glycoproteins which are expressed at the synaptic plasma membranes of neurons. These proteins play key roles in formation and maintenance of synapses and regulation of synaptic plasticity. Genetic studies and biochemical analysis of the human brain tissue, cerebrospinal fluid, and sera from AD patients indicate that levels and function of synaptic cell adhesion molecules are affected in AD. Synaptic cell adhesion molecules interact with Aβ, a peptide accumulating in AD brains, which affects their expression and synaptic localization. Synaptic cell adhesion molecules also regulate the production of Aβ via interaction with the key enzymes involved in Aβ formation. Aβ-dependent changes in synaptic adhesion affect the function and integrity of synapses suggesting that alterations in synaptic adhesion play key roles in the disruption of neuronal networks in AD. PMID:27242933

  20. Models, mysteries, and magic of molecules

    CERN Document Server

    Boeyens, Jan CA

    2007-01-01

    Molecules have for a long time been of central importance in chemistry as the basis on which all new products and materials have been designed, developed and interpreted. Since the discovery and characterization of active biomolecules, biology has also been transformed into a molecular science. With the new developments of molecular devices, single-molecule spectroscopy, time-resolved x-ray diffraction and the study of mass-selected clusters in molecular beams, materials science and electronics may move in the same direction. The understanding of molecules and the dynamics of their transition between isolated and assembled states rests on three pillars: structure, activity and function. Enormous progress has been made in the experimental study of molecules by diffraction and spectroscopic analysis, directed at all three of the basic aspects. In the process molecular scientists have developed efficient working models in terms of which to design and interpret their experiments. A vital feature of such models is...

  1. Stochastic Models of Molecule Formation on Dust

    Science.gov (United States)

    Charnley, Steven; Wirstroem, Eva

    2011-01-01

    We will present new theoretical models for the formation of molecules on dust. The growth of ice mantles and their layered structure is accounted for and compared directly to observations through simulation of the expected ice absorption spectra

  2. The evolution of polymorphic compatibility molecules

    NARCIS (Netherlands)

    Boer, R.J. de

    1995-01-01

    Several primitive colonial organisms distinguish self from nonself by means of polymorphic compatibility molecules bearing similarity to the major histocompatibility complex (MHC). The evolution of such polymorphisms is generally explained in terms of resistance to parasites. Ignoring parasites, I d

  3. Novel electrostatic trap for cold polar molecules

    Institute of Scientific and Technical Information of China (English)

    Xu Xue-Yan; Ma Hui; Yin Jian-Ping

    2007-01-01

    We propose a novel scheme in which cold polar molecules are trapped by an electrostatic field generated by the combination of a pair of parallel transparent electrodes (i.e., two infinite transparent plates) and a ring electrode (i.e., a ring wire). The spatial distributions of the electrostatic fields from the above charged wire and the charged plates and the corresponding Stark potentials for cold CO molecules are calculated; the dependences of the trap centre position on the geometric parameters of the electrode are analysed. We also discuss the loading process of cold molecules from a cold molecular beam into our trap. This study shows that the proposed scheme is not only simple and convenient to trap, manipulate and control cold polar molecules in weak-field-seeking states, but also provides an opportunity to study cold collisions and collective quantum effects in a variety of cold molecular systems, etc.

  4. Global warming and SF6 molecule

    Directory of Open Access Journals (Sweden)

    Gajević Jelena

    2006-01-01

    Full Text Available In this paper the basic SF6 molecule physical characteristics are given concerning its influence on global warming and green house effect. Absorption and relaxation characteristics of this molecule have been investigated within the frame of nonlinear molecule – strong laser field interaction in different gas mixtures. All experiments have been performed on a different gas mixture pressures to analyze and investigate relaxation and energy transfer characteristics of absorbing molecules and non-absorbing collision partners. To show the SF6 absorption and relaxation and energy transfer capability comparison between SF6 and C2H4 was given using the same experimental conditions and argon as a buffer gas. All measurement points and their calculated values presented in this paper have been obtained using the infrared-pulsed photoacoustics technique adopted for atmospheric and subatmospheric pressures.

  5. Sisyphus Cooling of Electrically Trapped Polyatomic Molecules

    CERN Document Server

    Zeppenfeld, M; Glöckner, R; Prehn, A; Mielenz, M; Sommer, C; van Buuren, L D; Motsch, M; Rempe, G

    2012-01-01

    The rich internal structure and long-range dipole-dipole interactions establish polar molecules as unique instruments for quantum-controlled applications and fundamental investigations. Their potential fully unfolds at ultracold temperatures, where a plethora of effects is predicted in many-body physics, quantum information science, ultracold chemistry, and physics beyond the standard model. These objectives have inspired the development of a wide range of methods to produce cold molecular ensembles. However, cooling polyatomic molecules to ultracold temperatures has until now seemed intractable. Here we report on the experimental realization of opto-electrical cooling, a paradigm-changing cooling and accumulation method for polar molecules. Its key attribute is the removal of a large fraction of a molecule's kinetic energy in each step of the cooling cycle via a Sisyphus effect, allowing cooling with only few dissipative decay processes. We demonstrate its potential by reducing the temperature of about 10^6 ...

  6. Single-Molecule Studies in Live Cells

    Science.gov (United States)

    Yu, Ji

    2016-05-01

    Live-cell single-molecule experiments are now widely used to study complex biological processes such as signal transduction, self-assembly, active trafficking, and gene regulation. These experiments' increased popularity results in part from rapid methodological developments that have significantly lowered the technical barriers to performing them. Another important advance is the development of novel statistical algorithms, which, by modeling the stochastic behaviors of single molecules, can be used to extract systemic parameters describing the in vivo biochemistry or super-resolution localization of biological molecules within their physiological environment. This review discusses recent advances in experimental and computational strategies for live-cell single-molecule studies, as well as a selected subset of biological studies that have utilized these new technologies.

  7. Electron-impact-induced tryptophan molecule fragmentation

    International Nuclear Information System (INIS)

    In our investigation, we have studied the interactions of low-energy (<70 eV) electrons with tryptophan molecule belonging to the essential amino acids in order to probe the intrinsic properties of the molecule and trace its change(s) under the electron impact. The fragmentation of a gas-phase tryptophan molecule by low-energy electrons was studied both experimentally and theoretically. Various positively charged fragments were observed and analyzed. A special attention was paid to the energy characteristics of the ionic fragment yield. The geometrical parameters of the initial molecule rearrangement were also analyzed. The fragmentation observed was due to either a simple bond cleavage or more complex reactions involving molecular rearrangements

  8. Polyatomic molecules under intense femtosecond laser irradiation.

    Science.gov (United States)

    Konar, Arkaprabha; Shu, Yinan; Lozovoy, Vadim V; Jackson, James E; Levine, Benjamin G; Dantus, Marcos

    2014-12-11

    Interaction of intense laser pulses with atoms and molecules is at the forefront of atomic, molecular, and optical physics. It is the gateway to powerful new tools that include above threshold ionization, high harmonic generation, electron diffraction, molecular tomography, and attosecond pulse generation. Intense laser pulses are ideal for probing and manipulating chemical bonding. Though the behavior of atoms in strong fields has been well studied, molecules under intense fields are not as well understood and current models have failed in certain important aspects. Molecules, as opposed to atoms, present confounding possibilities of nuclear and electronic motion upon excitation. The dynamics and fragmentation patterns in response to the laser field are structure sensitive; therefore, a molecule cannot simply be treated as a "bag of atoms" during field induced ionization. In this article we present a set of experiments and theoretical calculations exploring the behavior of a large collection of aryl alkyl ketones when irradiated with intense femtosecond pulses. Specifically, we consider to what extent molecules retain their molecular identity and properties under strong laser fields. Using time-of-flight mass spectrometry in conjunction with pump-probe techniques we study the dynamical behavior of these molecules, monitoring ion yield modulation caused by intramolecular motions post ionization. The set of molecules studied is further divided into smaller sets, sorted by type and position of functional groups. The pump-probe time-delay scans show that among positional isomers the variations in relative energies, which amount to only a few hundred millielectronvolts, influence the dynamical behavior of the molecules despite their having experienced such high fields (V/Å). High level ab initio quantum chemical calculations were performed to predict molecular dynamics along with single and multiphoton resonances in the neutral and ionic states. We propose the

  9. Spin polarization effect for Os2 molecule

    Institute of Scientific and Technical Information of China (English)

    Xie An-Dong; Yan Shi-Ying; Zhu Zheng-He; Fu Yi-Bei

    2005-01-01

    Density functional Theory (DFT) (B3p86) of Gaussian03 has been used to optimize the structure of Os2 molecule.The result shows that the ground state for Os2 molecule is 9-multiple state and its electronic configuration is 9∑+g,which shows spin polarization effect of Os2 molecule of transition metal elements for the first time. Meanwhile, we have not found any spin pollution because the wavefunction of the ground state does not mingle with wavefunctions with higher energy states. So, the fact that the ground state for Os2 molecule is a 9-multiple state is indicative of spin polarization effect of Os2 molecule of transition metal elements. That is, there exist 8 parallel spin electrons.The non-conjugated electron is greatest in number. These electrons occupy different spacious tracks, so that the energy of Os2 molecule is minimized. It can be concluded that the effect of parallel spin of Os2 molecule is larger than the effect of the conjugated molecule, which is obviously related to the effect of electron d delocalization. In addition, the Murrell-Sorbie potential functions with the parameters for the ground state 9∑+g and other states of Os2 molecule are derived. Dissociation energy De for the ground state of Os2 molecule is 3.3971eV, equilibrium bond length Re is 0.2403nm, vibration frequency ωe is 235.32cm-1. Its force constants f2, f3, and f4 are 3.1032×102aJ.nm-2,-14.3425×103aJ.nm-3 and 50.5792×104aJ.nm-4 respectively. The other spectroscopic data for the ground state of Os2 molecule ωeχe, Be and αe are 0.4277cm-1, 0.0307cm-1 and 0.6491× 10-4cm-1 respectively.

  10. The coordination chemistry of saturated molecules

    OpenAIRE

    Bercaw, John E.; Labinger, Jay A.

    2007-01-01

    Our understanding of bonding in transition metal complexes, as well as our ability to use that understanding in the synthesis and application of new species, has evolved over the last 100 years; and in some sense this special feature on the coordination chemistry of saturated molecules may be considered to represent its culmination. The nature of complexes between transition metal ions and neutral molecules such as ammonia was first correctly described by Werner around the beginning of the 20...

  11. Single Molecule Applications of Quantum Dots

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Elmelund; Jauffred, Liselotte; Brewer, Jonathan R.;

    2013-01-01

    tracking single lipids in lipid bilayers, 4) two-photon fluorescence correlation spectroscopy of QDs and 5) optical trapping and excitation of single QDs. In all of these applications, the focus is on the single particle sensitivity level of QDs. The high applicability of QDs in live cell imaging...... experiments held together with the prospects in localization microscopy and single molecule manipulation experiments gave QDs a promising future in single molecule research....

  12. Dissociation of ultracold molecules with Feshbach resonances

    OpenAIRE

    Dürr, Stephan; Volz, Thomas; Rempe, Gerhard

    2004-01-01

    Ultracold molecules are associated from an atomic Bose-Einstein condensate by ramping a magnetic field across a Feshbach resonance. The reverse ramp dissociates the molecules. The kinetic energy released in the dissociation process is used to measure the widths of 4 Feshbach resonances in 87Rb. This method to determine the width works remarkably well for narrow resonances even in the presence of significant magnetic-field noise. In addition, a quasi-mono-energetic atomic wave is created by ju...

  13. Properties of molecules in tunnel junctions

    OpenAIRE

    Yeriskin, Irene

    2013-01-01

    Molecular tunnel junctions involve studying the behaviour of a single molecule sandwiched between metal leads. When a molecule makes contact with electrodes, it becomes open to the environment which can heavily influence its properties, such as electronegativity and electron transport. While the most common computational approaches remain to be single particle approximations, in this thesis it is shown that a more explicit treatment of electron interactions can be required. By studying an ope...

  14. Small Molecule Subgraph Detector (SMSD) toolkit

    OpenAIRE

    Rahman Syed; Bashton Matthew; Holliday Gemma L; Schrader Rainer; Thornton Janet M

    2009-01-01

    Abstract Background Finding one small molecule (query) in a large target library is a challenging task in computational chemistry. Although several heuristic approaches are available using fragment-based chemical similarity searches, they fail to identify exact atom-bond equivalence between the query and target molecules and thus cannot be applied to complex chemical similarity searches, such as searching a complete or partial metabolic pathway. In this paper we present a new Maximum Common S...

  15. Biological mechanisms, one molecule at a time

    OpenAIRE

    Tinoco, Ignacio; Gonzalez, Ruben L.

    2011-01-01

    The last 15 years have witnessed the development of tools that allow the observation and manipulation of single molecules. The rapidly expanding application of these technologies for investigating biological systems of ever-increasing complexity is revolutionizing our ability to probe the mechanisms of biological reactions. Here, we compare the mechanistic information available from single-molecule experiments with the information typically obtained from ensemble studies and show how these tw...

  16. The Escape Rate of a Molecule

    Energy Technology Data Exchange (ETDEWEB)

    Knauf, Andreas, E-mail: knauf@mi.uni-erlangen.de; Krapf, Markus [Universitaet Erlangen-Nuernberg, Department Mathematik (Germany)

    2010-06-15

    We show existence and give an implicit formula for the escape rate of the n-centre problem of celestial mechanics for high energies. Furthermore we give precise computable estimates of this rate. This exponential decay rate plays an important role especially in semiclassical scattering theory of n-atomic molecules. Our result shows that the diameter of a molecule is measurable in a (classical) high-energy scattering experiment.

  17. Vibrational spectroscopy of polar molecules with superradiance

    Science.gov (United States)

    Lin, Guin-Dar; Yelin, Susanne F.

    2013-07-01

    We investigate cooperative phenomena and superradiance for vibrational transitions in polar molecule spectroscopy of high optical-depth samples. Such cooperativity comes from the build-up of inter-particle coherence through dipole-dipole interactions and leads to speed-up of decay processes. We compare our calculation to recent work and find very good agreement, suggesting that superradiant effects need to be taken into account in a wide variety of ultracold molecule experiments, including vibrational and rotational states.

  18. Electron affinities of atoms, molecules, and radicals

    International Nuclear Information System (INIS)

    We review briefly but comprehensively the theoretical, semiempirical and experimental methods employed to determine electron affinities (EAs) of atoms, molecules and radicals, and summarize the EA data obtained by these methods. The detailed processes underlying the principles of the experimental methods are discussed very briefly. It is, nonetheless, instructive to recapitulate the definition of EA and those of the related quantities, namely, the vertical detachment energy, VDE, and the vertical attachment energy, VAE. The EA of an atom is defined as the difference in total energy between the ground state of the neutral atom (plus the electron at rest at infinity) and its negative ion. The EA of a molecule is defined as the difference in energy between the neutral molecule plus an electron at rest at infinity and the molecular negative ion when both, the neutral molecules and the negative ion, are in their ground electronic, vibrational and rotational states. The VDE is defined as the minimum energy required to eject the electron from the negative ion (in its ground electronic and nuclear state) without changing the internuclear separation; since the vertical transition may leave the neutral molecule in an excited vibrational/rotational state, the VDE, although the same as the EA for atoms is, in general, different (larger than), from the EA for molecules. Similarly, the VAE is defined as the difference in energy between the neutral molecule in its ground electronic, vibrational and rotational states plus an electron at rest at infinity and the molecular negative ion formed by addition of an electron to the neutral molecule without allowing a change in the intermolecular separation of the constituent nuclei; it is a quantity appropriate to those cases where the lowest negative ion state lies above the ground states of the neutral species and is less or equal to EA

  19. Do triatomic molecules echo atomic periodicity?

    Energy Technology Data Exchange (ETDEWEB)

    Hefferlin, R., E-mail: hefferln@southern.edu; Barrow, J. [Southern Adventist University, PO Box 370, Collegedale, Tennessee 37315 (United States)

    2015-03-30

    Demonstrations of periodicity among triatomic-molecular spectroscopic constants underscore the role of the periodic law as a foundation of chemistry. The objective of this work is to prepare for another test using vibration frequencies ν{sub 1} of free, ground-state, main-group triatomic molecules. Using data from four data bases and from computation, we have collected ν{sub 1} data for molecules formed from second period atoms.

  20. Single-molecule dynamics at variable temperatures

    OpenAIRE

    Zondervan, Rob

    2006-01-01

    Single-molecule optics has evolved from a specialized variety of optical spectroscopy at low temperatures into a versatile tool to address questions in physics, chemistry, biology, and materials science. In this thesis, the potential of single-molecule (and ensemble) optical microscopy at variable temperatures is demonstrated: Electron transfer has been identified as a crucial step in the photodynamics of organic fluorophores, and long-term memory effects have been discovered in the relaxatio...

  1. Interfacial energies of systems of chiral molecules

    OpenAIRE

    Braides, Andrea; Garroni, Andrea; Palombaro, Mariapia

    2016-01-01

    We consider a simple model for the assembly of chiral molecules in two dimensions driven by maximization of the contact area. We derive a macroscopic model described by a parameter taking nine possible values corresponding to the possible minimal microscopic patterns and modulated phases of the chiral molecules. We describe the overall behaviour by means of an interaction energy of perimeter type between such phases. This energy is a crystalline perimeter energy, highlighting preferred direct...

  2. Hadronic molecules in the heavy baryon spectrum

    International Nuclear Information System (INIS)

    We study possible baryon molecules in the non-strange heavy baryon spectrum. We include configurations with a heavy-meson and a light baryon. We find several structures, in particular we can understand the Λc(2940) as a D*N molecule with JP = 3/2− quantum numbers. We also find D(*)Δ candidates for the recently discovered Xc(3250) resonance

  3. Modelling water molecules inside cyclic peptide nanotubes

    Science.gov (United States)

    Tiangtrong, Prangsai; Thamwattana, Ngamta; Baowan, Duangkamon

    2016-03-01

    Cyclic peptide nanotubes occur during the self-assembly process of cyclic peptides. Due to the ease of synthesis and ability to control the properties of outer surface and inner diameter by manipulating the functional side chains and the number of amino acids, cyclic peptide nanotubes have attracted much interest from many research areas. A potential application of peptide nanotubes is their use as artificial transmembrane channels for transporting ions, biomolecules and waters into cells. Here, we use the Lennard-Jones potential and a continuum approach to study the interaction of a water molecule in a cyclo[(- D-Ala- L-Ala)_4-] peptide nanotube. Assuming that each unit of a nanotube comprises an inner and an outer tube and that a water molecule is made up of a sphere of two hydrogen atoms uniformly distributed over its surface and a single oxygen atom at the centre, we determine analytically the interaction energy of the water molecule and the peptide nanotube. Using this energy, we find that, independent of the number of peptide units, the water molecule will be accepted inside the nanotube. Once inside the nanotube, we show that a water molecule prefers to be off-axis, closer to the surface of the inner nanotube. Furthermore, our study of two water molecules inside the peptide nanotube supports the finding that water molecules form an array of a 1-2-1-2 file inside peptide nanotubes. The theoretical study presented here can facilitate thorough understanding of the behaviour of water molecules inside peptide nanotubes for applications, such as artificial transmembrane channels.

  4. Bipolar Conductance Switching of Single Anthradithiophene Molecules.

    Science.gov (United States)

    Borca, Bogdana; Schendel, Verena; Pétuya, Rémi; Pentegov, Ivan; Michnowicz, Tomasz; Kraft, Ulrike; Klauk, Hagen; Arnau, Andrés; Wahl, Peter; Schlickum, Uta; Kern, Klaus

    2015-12-22

    Single molecular switches are basic device elements in organic electronics. The pentacene analogue anthradithiophene (ADT) shows a fully reversible binary switching between different adsorption conformations on a metallic surface accompanied by a charge transfer. These transitions are activated locally in single molecules in a low-temperature scanning tunneling microscope . The switching induces changes between bistable orbital structures and energy level alignment at the interface. The most stable geometry, the "off" state, which all molecules adopt upon evaporation, corresponds to a short adsorption distance at which the electronic interactions of the acene rings bend the central part of the molecule toward the surface accompanied by a significant charge transfer from the metallic surface to the ADT molecules. This leads to a shift of the lowest unoccupied molecular orbital down to the Fermi level (EF). In the "on" state the molecule has a flat geometry at a larger distance from the surface; consequently the interaction is weaker, resulting in a negligible charge transfer with an orbital structure resembling the highest occupied molecular orbital when imaged close to EF. The potential barrier between these two states can be overcome reversibly by injecting charge carriers locally into individual molecules. Voltage-controlled current traces show a hysteresis characteristic of a bipolar switching behavior. The interpretation is supported by first-principles calculations. PMID:26580569

  5. Auxin biology revealed by small molecules.

    Science.gov (United States)

    Ma, Qian; Robert, Stéphanie

    2014-05-01

    The plant hormone auxin regulates virtually every aspect of plant growth and development and unraveling its molecular and cellular modes of action is fundamental for plant biology research. Chemical genomics is the use of small molecules to modify protein functions. This approach currently rises as a powerful technology for basic research. Small compounds with auxin-like activities or affecting auxin-mediated biological processes have been widely used in auxin research. They can serve as a tool complementary to genetic and genomic methods, facilitating the identification of an array of components modulating auxin metabolism, transport and signaling. The employment of high-throughput screening technologies combined with informatics-based chemical design and organic chemical synthesis has since yielded many novel small molecules with more instantaneous, precise and specific functionalities. By applying those small molecules, novel molecular targets can be isolated to further understand and dissect auxin-related pathways and networks that otherwise are too complex to be elucidated only by gene-based methods. Here, we will review examples of recently characterized molecules used in auxin research, highlight the strategies of unraveling the mechanisms of these small molecules and discuss future perspectives of small molecule applications in auxin biology. PMID:24252105

  6. Self-Assemblies of novel molecules, VECAR

    Science.gov (United States)

    Shrestha, Bijay; Kim, Hye-Young; Lee, Soojin; Novak, Brian; Moldovan, Dorel

    2015-03-01

    VECAR is a newly synthesized molecule, which is an amphiphilic antioxidant molecule that consists of two molecular groups, vitamin-E and Carnosine, linked by a hydrocarbon chain. The hydrocarbon chain is hydrophobic and both vitamin-E and Carnosine ends are hydrophilic. In the synthesis process, the length of the hydrophobic chain of VECAR molecules can vary from the shortest (n =0) to the longest (n =18), where n indicates the number of carbon atoms in the chain. We conducted MD simulation studies of self-assembly of VECAR molecules in water using GROMACS on LONI HPC resources. Our study shows that there is a strong correlation between the shape and atomistic structure of the self-assembled nano-structures (SANs) and the chain-length (n) of VECAR molecules. We will report the results of data analyses including the atomistic structure of each SANs and the dynamic and energetic mechanisms of their formation as function of time. In summary, both VECAR molecules of chain-length n =18 and 9 form worm-like micelles, which may be used as a drug delivery system. This research is supported by the Louisiana Board of Regents-RCS Grant (LEQSF(2012-15)-RD-A-19).

  7. Dissociation and Decay of Ultra-cold Sodium Molecules

    OpenAIRE

    Mukaiyama, T.; Abo-Shaeer, J. R.; Xu, K.; Chin, J. K.; Ketterle, W.

    2003-01-01

    The dissociation of ultracold molecules is studied by ramping an external magnetic field through a Feshbach resonance. The observed dissociation energy shows non-linear dependence on the ramp speed and directly yields the strength of the atom-molecule coupling. In addition, inelastic molecule-molecule and molecule-atom collisions are characterized.

  8. Spin polarization effect for molecule Ta2

    Institute of Scientific and Technical Information of China (English)

    Xie An-Dong

    2006-01-01

    Density functional theory (DFT) (B3p86) has been used to optimize the structure of the molecule Taa- The result shows that the ground state of molecule Ta,2 is a 7- multiple state and its electronic configuration is 7∑+u which shows the spin polarization effect for molecule Ta2 of transition metal elements for the first time. Meanwhile, spin pollution has not been found because the wavefunction of the ground state does not mix with those of higher states. So, the fact that the ground state of molecule Ta2 is a 7-multiple state indicates a spin polarization effect of molecule Ta2 of the transition metal elements, i.e. there exist 6 parallel spin electrons and the non-conjugated electrons are greatest in number. These electrons occupy different space orbitals so that the energy of molecule Ta2 is minimized. It can be concluded that the effect of parallel spin of the molecule Ta2 is larger than the effect of the conjugated molecule, which is obviously related to the effect of d-electron delocalization. In addition, the Murrell-Sorbie potential functions with parameters for the ground state 7∑+u and other states of the molecule Ta2 are derived. The dissociation energy De, equilibrium bond length Re and vibration frequency ωe for the ground state of molecule Ta2 are 4.5513eV, 0.2433nm and 173.06cm-1, respectively. Its force constants f2,f3 and f4 are 1.5965×l02aJ·nm-2,-6.4722×l03aJ·nm-3 and 29.4851×04aJ·nm-4, respectively. Other spectroscopic data ωe χe, Be and αe for the ground state of Ta2 are 0.2078cm-1, 0.0315cm-1 and 0.7858×104 cm-1, respectively.

  9. Quantifying molecule-surface interactions using AFM-based single-molecule manipulation

    Science.gov (United States)

    Tautz, F. S.; Wagner, C.; Temirov, R.; Fournier, N.; Green, M.; Esat, T.; Leinen, P.; Groetsch, A.; Ruiz, V. G.; Tkatchenko, A.; Li, C.; Muellen, K.; Rohlfing, M.

    2015-03-01

    Scanning probe microscopy plays an important role in the investigation of molecular adsorption. Promising, is the possibility to probe the molecule-surface interaction while tuning its strength through AFM tip-induced single-molecule manipulation. Here, we outline a strategy to achieve quantitative understanding of such manipulation experiments. The example of qPlus sensor based PTCDA molecule lifting experiments is used to demonstrate how different aspects of the molecule-surface interaction, namely the short-range adsorption potential, the asymptotic van der Waals potential, local chemical bonds which are the source of the surface corrugation, and molecule-molecule interactions can be measured with SPM and interpreted by the help of force-field simulations.

  10. Image Analysis of Defocused Single-molecule Images for Three-dimensional Molecule Orientation Studies

    OpenAIRE

    Patra, D; Gregor, I.; Enderlein, J.

    2004-01-01

    An efficient algorithm for pattern matching has been developed based on least-squares analysis of fitting a discrete set of master patterns against measured images. This algorithm has been applied to determine three-dimensional molecule orientations in defocused single-molecule images. The developed algorithm exploits the excellent agreement between electrodynamic calculations of single-molecule emission and experimentally measured images. The procedure is found to be reliable and simple and ...

  11. Clusters of mobile molecules in supercooled water

    Science.gov (United States)

    Giovambattista, Nicolas; Buldyrev, Sergey V.; Stanley, H. Eugene; Starr, Francis W.

    2005-07-01

    We study the spatially heterogeneous dynamics in water via molecular dynamics simulations using the extended simple point charge potential. We identify clusters formed by mobile molecules and study their properties. We find that these clusters grow in size and become more compact as temperature decreases. We analyze the probability density function of cluster size, and we study the cluster correlation length. We find that clusters appear to be characterized by a fractal dimension consistent with that of lattice animals. We relate the cluster size and correlation length to the configurational entropy, Sconf . We find that these quantities depend weakly on 1/Sconf . In particular, the linearity found between the cluster mass n* and 1/Sconf suggests that n* may be interpreted as the mass of the cooperatively rearranging regions that form the basis of the Adam-Gibbs approach to the dynamics of supercooled liquids. We study the motion of molecules within a cluster, and find that each molecule preferentially follows a neighboring molecule in the same cluster. Based on this finding we hypothesize that stringlike cooperative motion may be a general mechanism for molecular rearrangement of complex, as well as simple liquids. By mapping each equilibrium configuration onto its corresponding local potential energy minimum or inherent structure (IS), we are able to compare the mobile molecule clusters in the equilibrium system with the molecules forming the clusters identified in the transitions between IS. We find that (i) mobile molecule clusters obtained by comparing different system configurations and (ii) clusters obtained by comparing the corresponding IS are completely different for short time scales, but are the same on the longer time scales of diffusive motion.

  12. Electromechanical Properties of Single Molecule Devices

    Science.gov (United States)

    Bruot, Christopher

    Understanding the interplay between the electrical and mechanical properties of single molecules is of fundamental importance for molecular electronics. The sensitivity of charge transport to mechanical fluctuations is a key problem in developing long lasting molecular devices. Furthermore, harnessing this response to mechanical perturbation, molecular devices which can be mechanically gated can be developed. This thesis demonstrates three examples of the unique electromechanical properties of single molecules. First, the electromechanical properties of 1,4-benzenedithiol molecular junctions are investigate. Counterintuitively, the conductance of this molecule is found to increase by more than an order of magnitude when stretched. This conductance increase is found to be reversible when the molecular junction is compressed. The current-voltage, conductance-voltage and inelastic electron tunneling spectroscopy characteristics are used to attribute the conductance increase to a strain-induced shift in the frontier molecular orbital relative to the electrode Fermi level, leading to resonant enhancement in the conductance. Next, the effect of stretching-induced structural changes on charge transport in DNA molecules is studied. The conductance of single DNA molecules with lengths varying from 6 to 26 base pairs is measured and found to follow a hopping transport mechanism. The conductance of DNA molecules is highly sensitive to mechanical stretching, showing an abrupt decrease in conductance at surprisingly short stretching distances, with weak dependence on DNA length. This abrupt conductance decrease is attributed to force-induced breaking of hydrogen bonds in the base pairs at the end of the DNA sequence. Finally, the effect of small mechanical modulation of the base separation on DNA conductance is investigated. The sensitivity of conductance to mechanical modulation is studied for molecules of different sequence and length. Sequences with purine-purine stacking

  13. Mining for Molecules in the Milky Way

    Science.gov (United States)

    2008-06-01

    Scientists are using the giant Robert C. Byrd Green Bank Telescope (GBT) to go prospecting in a rich molecular cloud in our Milky Way Galaxy. They seek to discover new, complex molecules in interstellar space that may be precursors to life. The GBT and Molecules The Robert C. Byrd Green Bank Telescope and some molecules it has discovered. CREDIT: Bill Saxton, NRAO/AUI/NSF "Clouds like this one are the raw material for new stars and planets. We know that complex chemistry builds prebiotic molecules in such clouds long before the stars and planets are formed. There is a good chance that some of these interstellar molecules may find their way to the surface of young planets such as the early Earth, and provide a head start for the chemistry of life. For the first time, we now have the capability to make a very thorough and methodical search to find all the chemicals in the clouds," said Anthony Remijan, of the National Radio Astronomy Observatory (NRAO). In the past three years, Remijan and his colleagues have used the GBT to discover ten new interstellar molecules, a feat unequalled in such a short time by any other team or telescope. The scientists discovered those molecules by looking specifically for them. However, they now are changing their strategy and casting a wide net designed to find whatever molecules are present, without knowing in advance what they'll find. In addition, they are making their data available freely to other scientists, in hopes of speeding the discovery process. The research team presented its plan to the American Astronomical Society's meeting in St. Louis, MO. As molecules rotate and vibrate, they emit radio waves at specific frequencies. Each molecule has a unique pattern of such frequencies, called spectral lines, that constitutes a "fingerprint" identifying that molecule. Laboratory tests can determine the pattern of spectral lines that identifies a specific molecule. Most past discoveries came from identifying a molecule's pattern in

  14. Conduction mechanisms and stability of single molecule nanoparticle/molecule/nanoparticle junctions

    International Nuclear Information System (INIS)

    Nanoparticle/molecule/nanoparticle dimer assemblies have been successfully trapped by dielectrophoresis across nanogap electrodes, enabling temperature dependent charge transport measurements through an oligomeric phenylene ethynylene molecule, and transition from direct tunnelling to Fowler-Nordheim tunnelling is observed at ∼1.5 V. Samples formed by dielectrophoresis show better contact stability than those formed by receding meniscus. The junction shows stable operation over several weeks in a vacuum, but current increases with time upon exposure to air, possibly due to the adsorbed water molecules near the molecule/gold nanoparticle contacts

  15. The reaction dynamics of alkali dimer molecules and electronically excited alkali atoms with simple molecules

    Energy Technology Data Exchange (ETDEWEB)

    Hou, H [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

    1995-12-01

    This dissertation presents the results from the crossed molecular beam studies on the dynamics of bimolecular collisions in the gas phase. The primary subjects include the interactions of alkali dimer molecules with simple molecules, and the inelastic scattering of electronically excited alkali atoms with O2. The reaction of the sodium dimers with oxygen molecules is described in Chapter 2. Two reaction pathways were observed for this four-center molecule-molecule reaction, i.e. the formations of NaO2 + Na and NaO + NaO. NaO2 products exhibit a very anisotropic angular distribution, indicating a direct spectator stripping mechanism for this reaction channel. The NaO formation follows the bond breaking of O2, which is likely a result of a charge transfer from Na2 to the excited state orbital of O2-. The scattering of sodium dimers from ammonium and methanol produced novel molecules, NaNH3 and Na(CH3OH), respectively. These experimental observations, as well as the discussions on the reaction dynamics and the chemical bonding within these molecules, will be presented in Chapter 3. The lower limits for the bond dissociation energies of these molecules are also obtained. Finally, Chapter 4 describes the energy transfer between oxygen molecules and electronically excited sodium atoms.

  16. Single-Molecule Electronics with Cross- Conjugated Molecules: Quantum Interference, IETS and Non-Equilibrium "Temperatures"

    DEFF Research Database (Denmark)

    Jørgensen, Jacob Lykkebo

    , which is characterised by destructive quantum interference. The molecules are cross-conjugated, which means that the two parts of the molecules are conjugated to a third part, but not to each other. This gives rise to an anti-resonance in the trans- mission. In the low bias and low temperature regime......, the electrons can tunnel in- elastically from the left to the right electrode. This is the process behind inelastic electron tunnelling spectroscopy (IETS), which is a single-molecule spectroscopic method, where the vibrational ngerprint of a molecule is di- rectly observed by the tunnelling current...

  17. Preparation and manipulation of molecules for fundamental physics tests

    OpenAIRE

    Tarbutt, M. R.; Hudson, J. J.; Sauer, B. E.; Hinds, E. A.

    2008-01-01

    This paper is a chapter from an upcoming book on cold molecule physics. In it we describe techniques for the preparation and manipulation of cold molecules. We further describe techniques for applying said cold molecules to tests of fundamental physics.

  18. Quantum Computer Using Coupled Quantum Dot Molecules

    CERN Document Server

    Wu, N J; Natori, A; Yasunaga, H; Wu*, Nan-Jian

    1999-01-01

    We propose a method for implementation of a quantum computer using artificial molecules. The artificial molecule consists of two coupled quantum dots stacked along z direction and one single electron. One-qubit and two-qubit gates are constructed by one molecule and two coupled molecules, respectively.The ground state and the first excited state of the molecule are used to encode the |0> and |1> states of a qubit. The qubit is manipulated by a resonant electromagnetic wave that is applied directly to the qubit through a microstrip line. The coupling between two qubits in a quantum controlled NOT gate is switched on (off) by floating (grounding) the metal film electrodes. We study the operations of the gates by using a box-shaped quantum dot model and numerically solving a time-dependent Schridinger equation, and demonstrate that the quantum gates can perform the quantum computation. The operating speed of the gates is about one operation per 4ps. The reading operation of the output of the quantum computer can...

  19. Ultracold polar molecules near quantum degeneracy.

    Science.gov (United States)

    Ospelkaus, S; Ni, K K; de Miranda, M H G; Neyenhuis, B; Wang, D; Kotochigova, S; Julienne, P S; Jin, D S; Ye, J

    2009-01-01

    We report the creation and characterization of a near quantum-degenerate gas of polar 40K-87Rb molecules in their absolute rovibrational ground state. Starting from weakly bound heteronuclear KRb Feshbach molecules, we implement precise control of the molecular electronic, vibrational, and rotational degrees of freedom with phase-coherent laser fields. In particular, we coherently transfer these weakly bound molecules across a 125 THz frequency gap in a single step into the absolute rovibrational ground state of the electronic ground potential. Phase coherence between lasers involved in the transfer process is ensured by referencing the lasers to two single components of a phase-stabilized optical frequency comb. Using these methods, we prepare a dense gas of 4 x 10(4) polar molecules at a temperature below 400 nK. This fermionic molecular ensemble is close to quantum degeneracy and can be characterized by a degeneracy parameter of T/T(F) = 3. We have measured the molecular polarizability in an optical dipole trap where the trap lifetime gives clues to interesting decay mechanisms. Given the large measured dipole moment of the KRb molecules of 0.5 Debye, the study of quantum degenerate molecular gases interacting via strong dipolar interactions is now within experimental reach. PACS numbers: 37.10.Mn, 37.10.Pq. PMID:20151553

  20. Difference Raman spectroscopy of DNA molecules

    International Nuclear Information System (INIS)

    In this paper the micro-Raman spectra of calf DNA for different points of DNA sample have been recorded. The Raman spectra were made with help of difference Raman spectroscopy technique. Raman spectra were recorded with high spatial resolution from different points of the wet and dry samples in different spectral range (100÷4000cm−1) using two lasers: argon (514.5 nm) and helium -neon (632.8 nm). The significant differences in the Raman spectra for dry and wet DNA and for different points of DNA molecules were observed. The obtained data on difference Raman scattering spectra of DNA molecules may be used for identification of DNA types and for analysis of genetic information associated with the molecular structure of this molecule

  1. Complex Molecule Formation in Grain Mantles

    CERN Document Server

    Hall, P

    2010-01-01

    Context: Complex molecules such as ethanol and dimethyl ether have been observed in a number of hot molecular cores and hot corinos. Attempts to model the molecular formation process using gas phase only models have so far been unsuccessful. Aims : To demonstrate that grain surface processing is a viable mechanism for complex molecule formation in these environments. Methods: A variable environment parameter computer model has been constructed which includes both gas and surface chemistry. This is used to investigate a variety of cloud collapse scenarios. Results: Comparison between model results and observation shows that by combining grain surface processing with gas phase chemistry complex molecules can be produced in observed abundances in a number of core and corino scenarios. Differences in abundances are due to the initial atomic and molecular composition of the core/corino and varying collapse timescales. Conclusions: Grain surface processing, combined with variation of physical conditions, can be reg...

  2. Collision data involving hydro-carbon molecules

    International Nuclear Information System (INIS)

    Hydro-carbon molecules are abundantly produced when graphites are used as internal wall materials of hydrogen plasmas and strongly influence properties of low temperature plasmas near the edges as well as those of high temperature plasmas at the center. In this report, following simple description of the production mechanisms of hydro-carbon molecules under the interactions between graphite and hydrogen plasma, the present status of collision data for hydro-carbon molecules by electron impact is discussed and the relevant data are summarized in a series of figures and tables. It should also be noted that, in addition to fusion plasmas, these hydrocarbon data compiled here are quite useful in other applications such as plasma chemistry and material processing. (author)

  3. Watching single protein molecules in action

    DEFF Research Database (Denmark)

    Heiðarsson, Pétur Orri

    . This knowledge-gap is partly due to our inability to unveil the details of folding mechanisms that can be buried in the ensemble-averaged output of traditional bulk methods. Single-molecule techniques have provided a perspective beyond the ensemble average and enable studying the folding trajectories...... of protein molecules in unprecedented detail. These methods can, in principle, detect rare folding or misfolding events, and ultimately lead to a reconstruction of the free energy landscape. In this thesis, the folding mechanism of both single- and double-domain proteins is unraveled using single......-molecule optical tweezers. We first focused on the mechanical properties and unfolding pathway of the four-helix acyl-CoA binding protein (ACBP). Contrary to previous studies which have shown protein native states to be brittle, we observed extraordinary compliance for ACBP along two orthogonal pulling axis, with...

  4. Sample preparation for single molecule localization microscopy.

    Science.gov (United States)

    Allen, John R; Ross, Stephen T; Davidson, Michael W

    2013-11-21

    Single molecule localization-based optical nanoscopy was introduced in 2006, surpassing traditional diffraction-limited resolutions by an order of magnitude. Seven years later, this superresolution technique is continuing to follow a trend of increasing popularity and pervasiveness, with the proof-of-concept work long finished and commercial implementations now available. However one important aspect that tends to become lost in translation is the importance of proper sample preparation, with very few resources addressing the considerations that must be made when preparing samples for imaging with single molecule level sensitivity. Presented here is a an in-depth analysis of all aspects of sample preparation for single molecule superresolution, including both live and fixed cell preparation, choice of fluorophore, fixation and staining techniques, and imaging buffer considerations. PMID:24084850

  5. Organization of Lipid Molecules within Biomembranes

    Directory of Open Access Journals (Sweden)

    M. Benhamou

    2008-01-01

    Full Text Available In this review, we report on the organization of lipid molecules forming biomembranes. More precisely, the question is how these amphiphiles phase separate under a change of a suitable parameter, like temperature, pressure or membrane environment. The mixture may undergo a lateral or transversal phase separations. This essentially depends on two principal factors, which are the structure (length of hydrocarbon chains of lipid molecules and the curvature asymmetry of membranes. When the former dominates, a lateral separation is then expected. In contrary, for those biomembranes of high curvature asymmetry, a vertical separation is rather observed. We examine the problem from a static (phase diagrams and kinetics (relaxation in time point of view. Finally, the discussion is also extended to the phase separation between lipid molecules and cholesterol in biomembranes (formation of rafts, between phospholipids and grafted polymers on liposomes, or between surfactant and its co-surfactant in bilayer systems.

  6. Photodissociation and excitation of interstellar molecules

    International Nuclear Information System (INIS)

    Apart from a rather long introduction containing some elementary astrophysics, quantum chemistry and spectroscopy and an incomplete, historical review of molecular observations, this thesis is divided into three sections. In part A, a rigorous quantum chemical and dynamical study is made of the photodissociation processes in the OH and HCl molecules. In part B, the cross sections obtained in part A are used in various astrophysical problems such as the study of the abundances of the OH and HCl molecules in interstellar clouds, the use of the OH abundance as a measure of the cosmic ray ionization rate, the lifetime of the OH radical in comets and the abundance of OH in the solar photosphere. Part C discusses the excitation of the C2 molecule under interstellar conditions, its use as a diagnostic probe of the temperature, density and strength of the radiation field in interstellar clouds. Quadrupole moments and oscillator strengths are analyzed. (Auth.)

  7. Single-molecule studies using magnetic traps.

    Science.gov (United States)

    Lionnet, Timothée; Allemand, Jean-François; Revyakin, Andrey; Strick, Terence R; Saleh, Omar A; Bensimon, David; Croquette, Vincent

    2012-01-01

    In recent years, techniques have been developed to study and manipulate single molecules of DNA and other biopolymers. In one such technique, the magnetic trap, a single DNA molecule is bound at one end to a glass surface and at the other to a magnetic microbead. Small magnets, whose position and rotation can be controlled, pull on and rotate the microbead. This provides a simple method to stretch and twist the molecule. The system allows one to apply and measure forces ranging from 10(-3) to >100 pN. In contrast to other techniques, the force measurement is absolute and does not require calibration of the sensor. In this article, we describe the principle of the magnetic trap, as well as its use in the measurement of the elastic properties of DNA and the study of DNA-protein interactions. PMID:22194259

  8. Protein Scaffolding for Small Molecule Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Baker, David [Univ. of Washington, Seattle, WA (United States)

    2014-09-14

    We aim to design hybrid catalysts for energy production and storage that combine the high specificity, affinity, and tunability of proteins with the potent chemical reactivities of small organometallic molecules. The widely used Rosetta and RosettaDesign methodologies will be extended to model novel protein / small molecule catalysts in which one or many small molecule active centers are supported and coordinated by protein scaffolding. The promise of such hybrid molecular systems will be demonstrated with the nickel-phosphine hydrogenase of DuBois et. al.We will enhance the hydrogenase activity of the catalyst by designing protein scaffolds that incorporate proton relays and systematically modulate the local environment of the catalyticcenter. In collaboration with DuBois and Shaw, the designs will be experimentally synthesized and characterized.

  9. Single Molecule Sensitive FRET in Attoliter Droplets

    CERN Document Server

    Milas, Peker; Gamari, Ben D; Goldner, Lori S

    2013-01-01

    Single molecular-pair fluorescence resonance energy transfer (spFRET) has become an cross-disciplinary tool for understanding molecular folding and interactions. While providing detailed information about the individual members of a molecular ensemble, this technique is always limited by fluorophore brightness and stability. In the case of diffusing molecules, the experiment is further limited by the number of photons that can be collected during the time it takes for a molecule to diffuse across the detection volume. To maximize the number of photons it is common to either increase the detection volume at the expense of increased background, or increase the diffusion time by adding glycerol or sucrose to increase viscosity. Here we demonstrate that FRET from attoliter volume (100 nm radius) aqueous droplets in perfluorinated oil has significantly higher signal-to-noise and a much wider dynamic range than FRET from molecules diffusing in solution. However, our measurements also reveal a droplet environment th...

  10. Multiphoton processes in isolated atoms and molecules

    International Nuclear Information System (INIS)

    The theory of coherent excitation of a multilevel quantum mechanical system is developed. Damping of the system is taken into account by the use of a density matrix formalism. General properties of the wave function and/or the density matrix are discussed. The physical implications for the behavior of the system are described, together with possible applications of the formalism, including the infrared multiphoton excitation of molecules, and optical pumping in alkali atoms. Experimental results are presented on the infrared multiphoton dissociation of molecules, followed by a discussion of the general features of this process. The experimental results were obtained using a crossed laser and molecular beam method, and the emphasis is on determining the properties of the dissociating molecule and the dissociation products. The dissociation process is shown to be described very well by the standard statistical theory (RRKM theory) of unimolecular reactions, a brief presentation of which is also included

  11. Observational astrochemistry: The quest for interstellar molecules

    Directory of Open Access Journals (Sweden)

    Guélin M.

    2012-01-01

    Full Text Available Over 160 molecular species, not counting isotopologues, have been identified in circumstellar envelopes and interstellar clouds. These species have revealed a wealth of familiar, as much as exotic molecules and in complex organic (and silicon compounds, that was fully unexpected in view of the harshness of surrounding conditions: vanishingly low densities, extreme temperatures and intense embedding UV radiation. They illustrate the diversity of astrochemistry and show robust prebiotic molecules may be. In this lecture, we review the quest for interstellar molecules and show how tributary it is from theoretical ideas and technology developments. A. A. Penzias, who discovered interstellar CO and the 2.7 K Cosmic Background radiation, used to joke that astronomical research is easy: the great questions have largely been formulated; one only has to wait until technological progress makes it possible to answer.

  12. A Nonvolatile Plasmonic Switch Employing Photochromic Molecules

    International Nuclear Information System (INIS)

    We demonstrate a surface plasmon-polariton (SPP) waveguide all-optical switch that combines the unique physical properties of small molecules and metallic (plasmonic) nanostructures. The switch consists of a pair of gratings defined in an aluminum film coated with a 65 nm thick layer of photochromic (PC) molecules. The first grating couples a signal beam consisting of free space photons to SPPs that interact effectively with the PC molecules. These molecules can reversibly be switched between transparent and absorbing states using a free space optical pump. In the transparent (signal 'on') state, the SPPs freely propagate through the molecular layer, and in the absorbing (signal 'off') state, the SPPs are strongly attenuated. The second grating serves to decouple the SPPs back into a free space optical beam, enabling measurement of the modulated signal with a far-field detector. In a preliminary study, the switching behavior of the PC molecules themselves was confirmed and quantified by surface plasmon resonance spectroscopy. The excellent (16%) overlap of the SPP mode profile with the thin layer of switching molecules enabled efficient switching with power densities of ∼6.0 mW/cm2 in 1.5 (micro)m x 8 (micro) m devices, resulting in plasmonic switching powers of 0.72 nW per device. Calculations further showed that modulation depths in access of 20 dB can easily be attained in optimized designs. The quantitative experimental and theoretical analysis of the nonvolatile switching behavior in this letter guides the design of future nanoscale optically or electrically pumped optical switches.

  13. Small Molecule Subgraph Detector (SMSD toolkit

    Directory of Open Access Journals (Sweden)

    Rahman Syed

    2009-08-01

    Full Text Available Abstract Background Finding one small molecule (query in a large target library is a challenging task in computational chemistry. Although several heuristic approaches are available using fragment-based chemical similarity searches, they fail to identify exact atom-bond equivalence between the query and target molecules and thus cannot be applied to complex chemical similarity searches, such as searching a complete or partial metabolic pathway. In this paper we present a new Maximum Common Subgraph (MCS tool: SMSD (Small Molecule Subgraph Detector to overcome the issues with current heuristic approaches to small molecule similarity searches. The MCS search implemented in SMSD incorporates chemical knowledge (atom type match with bond sensitive and insensitive information while searching molecular similarity. We also propose a novel method by which solutions obtained by each MCS run can be ranked using chemical filters such as stereochemistry, bond energy, etc. Results In order to benchmark and test the tool, we performed a 50,000 pair-wise comparison between KEGG ligands and PDB HET Group atoms. In both cases the SMSD was shown to be more efficient than the widely used MCS module implemented in the Chemistry Development Kit (CDK in generating MCS solutions from our test cases. Conclusion Presently this tool can be applied to various areas of bioinformatics and chemo-informatics for finding exhaustive MCS matches. For example, it can be used to analyse metabolic networks by mapping the atoms between reactants and products involved in reactions. It can also be used to detect the MCS/substructure searches in small molecules reported by metabolome experiments, as well as in the screening of drug-like compounds with similar substructures. Thus, we present a robust tool that can be used for multiple applications, including the discovery of new drug molecules. This tool is freely available on http://www.ebi.ac.uk/thornton-srv/software/SMSD/

  14. A toy model for a diatomic molecule

    Science.gov (United States)

    Hecker Denschlag, Johannes

    2016-08-01

    We introduce a toy model for a diatomic molecule which is based on coupling electronic and nuclear spins to a rigid rotor. Despite its simplicity, the model can be used scientifically to analyze and understand complex molecular hyperfine spectra. In addition, the model has educational value as a number of fundamental symmetries and conservation laws of the molecule can be studied. Because of its simple structure, the model can be readily implemented as a computer program with comparatively short computing times on the order of a few seconds.

  15. Relativistic Scott correction for atoms and molecules

    DEFF Research Database (Denmark)

    Solovej, Jan Philip; Sørensen, Thomas Østergaard; Spitzer, Wolfgang Ludwig

    2010-01-01

    We prove the first correction to the leading Thomas-Fermi energy for the ground state energy of atoms and molecules in a model where the kinetic energy of the electrons is treated relativistically. The leading Thomas-Fermi energy, established in [25], as well as the correction given here, are of...... semiclassical nature. Our result on atoms and molecules is proved from a general semiclassical estimate for relativistic operators with potentials with Coulomb-like singularities. This semiclassical estimate is obtained using the coherent state calculus introduced in [36]. The paper contains a unified treatment...

  16. Allosteric small-molecule kinase inhibitors

    DEFF Research Database (Denmark)

    Wu, Peng; Clausen, Mads Hartvig; Nielsen, Thomas E.

    2015-01-01

    Small-molecule kinase inhibitors are invaluable targeted therapeutics for the treatment of various human diseases, especially cancers. While the majority of approved and developed preclinical small-molecule inhibitors are characterized as type I or type II inhibitors that target the ATP......-binding pocket of kinases, the remarkable sequential and structural similarity among ATP pockets renders the selective inhibition of kinases a daunting challenge. Therefore, targeting allosteric pockets of kinases outside the highly conversed ATP pocket has been proposed as a promising alternative to overcome...

  17. Chemical activation of molecules during coordination

    International Nuclear Information System (INIS)

    Activation processes of N2, O2, NO molecules in transition metal complexes and electron reconstructions of coordination sphere of compounds, related with it, were considered on tha basis of single-parameter approximation of vibronic activation theory. A special attention is paid to CO molecule activation in carbonyl complexes of transition metals (V, Nb, Mo, W, Tc, Re, Ru and others) and lanthanides. The effect of metal oxidation degree, the nature of metal and ligand, complex structure on chemical activation processes is analyzed

  18. Organic- and molecule-based magnets

    Indian Academy of Sciences (India)

    Joel S Miller

    2006-07-01

    The discovery of organic- and molecule-based magnets has led to design and synthesis of several families with magnetic ordering temperatures as high as ∼ 125° C. Examples of soft and hard magnets with coercivities as high as 27 kOe have also been reported. Examples from our laboratory of organic-based magnets using the tetracya- noethylene radical anion, [TCNE]$^{\\bullet -}$, are discussed. In addition, several molecule-based magnets based on Prussian Blue structured materials as well as dicyanamide are discussed.

  19. Collisional Transitions in Interstellar Asymmetric Top Molecules

    Science.gov (United States)

    Chandra, Suresh

    2012-07-01

    For the study of a molecule in interstellar space or in circumstellar envelopes of an evolved star, one has to deal with a multi-level system in the molecule. These levels are connected through radiative as well as collisional transitions. The NLTE effects in a molecule come in the picture only when collisional transitions are present. Computation of collisional rates is quite cumbersome task. Besides emission and absorption, two anomalous phenomena: (i) MASER action and (ii) Anomalous absorption (Absorption against the CMB) are shown by some molecules in interstellar space. Both of these phenomena are good examples of NLTE prevailing in the interstellar space and circumstellar envelopes of evolved stars. In the present talk, we shall discuss about the collisional transitions between rotational levels in a molecule. The collisional rate coefficients for the rotational transition J τ → J' τ' at the kinetic temperature T, averaged over the Maxwellian distribution are C(J τ → J' τ'|T) = \\Big(\\frac{8 k T}{π μ}\\Big)^{1/2} \\Big(\\frac{1}{k T}\\Big)^2 \\int_0^\\infty σ (J τ → J' τ'|E) E {e}^{-E/kT} {d} E where μ is the reduced mass of the system and the cross section σ(J τ → J' τ'|E) for the transition is \\begin{eqnarray} σ (J τ → J' τ'|E) = \\sum_{L M M'} S(J, τ, J', τ'|L, M, M') q(L, M, M'|E) The q(L, M, M'|E) are the parameters which can be obtained from the software MOLSCAT. The spectroscopic coefficients, S ( J, τ, J', τ'|L, M, M'), depend on the wave-functions of the molecules and on the angular momentum coupling factors: S(J, τ, J', τ'|L, M, M') = \\sum_{p, p', q, q'} g^p_{J τ} g^q_{J τ} g^{p'}_{J' τ'} g^{q'}_{J' τ'} \\big \\big Here, \\big represents the Clebsch-Gorden coefficient. The g-coefficients can be obtained from laboratory analysis of the molecule and the parameters q(L, M, M'|E) can be obtained with the help of the software MOLSCAT for a known interaction potential. As an example, we shall discuss collisional

  20. Single-molecule electrophoresis. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Castro, A.; Shera, E.B.

    1996-05-22

    A novel method for the detection and identification of single molecules in solution has been devised, computer-simulated, and experimentally achieved. The technique involves the determination of electrophoretic velocities by measuring the time required by individual molecules to travel a fixed distance between two laser beams. Computer simulations of the process were performed beforehand in order to estimate the experimental feasibility of the method, and to determine the optimum values for the various experimental parameters. Examples of the use of the technique for the ultrasensitive detection and identification of rhodamine-6G, a mixture of DNA restriction fragments, and a mixture of proteins in aqueous solution are presented.

  1. Vibrational spectroscopy of polar molecules with superradiance

    CERN Document Server

    Lin, Guin-Dar

    2013-01-01

    We investigate cooperative phenomena and superradiance for vibrational transitions in polar molecule spectroscopy when a high optical-depth (OD) sample is studied. Such cooperativity comes from the build-up of inter-particle coherence through dipole-dipole interactions and leads to the speed-up of decay process. We compare our calculation to recent work [Deiglmayr et al., Eur. Phys. J. D 65, 99 (2011)] and find very good agreement, suggesting that superradiant effects need to be included in a wide variety of ultracold molecule setups including vibrational and rotational states.

  2. Matter-wave interferometer for large molecules

    CERN Document Server

    Brezger, B; Uttenthaler, S; Petschinka, J; Arndt, M; Zeilinger, Anton

    2002-01-01

    We demonstrate a near-field Talbot-Lau interferometer for C-70 fullerene molecules. Such interferometers are particularly suitable for larger masses. Using three free-standing gold gratings of one micrometer period and a transversally incoherent but velocity-selected molecular beam, we achieve an interference fringe visibility of 40 % with high count rate. Both the high visibility and its velocity dependence are in good agreement with a quantum simulation that takes into account the van der Waals interaction of the molecules with the gratings and are in striking contrast to a classical moire model.

  3. Photoassociative production of ultracold heteronuclear ytterbium molecules

    Energy Technology Data Exchange (ETDEWEB)

    Borkowski, Mateusz; Ciurylo, Roman [Instytut Fizyki, Uniwersytet Mikolaja Kopernika, ul. Grudziadzka 5/7, PL-87-100 Torun (Poland); Julienne, Paul S. [Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland, 100 Bureau Drive, Stop 8423, Gaithersburg, Maryland 20899-8423 (United States); Yamazaki, Rekishu; Takahashi, Yoshiro [Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); CREST, JST, 4-1-8 Honcho Kawaguchi, Saitama 332-0012 (Japan); Hara, Hideaki; Taie, Shintaro; Sugawa, Seiji; Takasu, Yosuke [Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Enomoto, Katsunari [Department of Physics, University of Toyama, Toyama 930-8555 (Japan)

    2011-09-15

    We report observations of photoassociation (PA) spectra near the intercombination line in isotopic mixtures of ultracold ytterbium gases. Several heteronuclear bound states have been found for the excited {sup 170}Yb{sup 174}Yb and {sup 174}Yb{sup 176}Yb molecules. We develop a single-channel mass-scaled interaction model for the excited state molecule which well reproduces the measured bound state energies. This is an important step toward optical control of interactions in mixtures of ultracold ytterbium gases using heteronuclear optical Feshbach resonances. The model developed is applicable in collisions of other similar systems, such as cadmium and mercury.

  4. Extracellular Molecules Involved in Cancer Cell Invasion

    Energy Technology Data Exchange (ETDEWEB)

    Stivarou, Theodora; Patsavoudi, Evangelia, E-mail: epatsavoudi@pasteur.gr [Department of Biochemistry, Hellenic Pasteur Institute, Athens 11521 (Greece); Technological Educational Institute of Athens, Egaleo, Athens 12210 (Greece)

    2015-01-26

    Nowadays it is perfectly clear that understanding and eradicating cancer cell invasion and metastasis represent the crucial, definitive points in cancer therapeutics. During the last two decades there has been a great interest in the understanding of the extracellular molecular mechanisms involved in cancer cell invasion. In this review, we highlight the findings concerning these processes, focusing in particular on extracellular molecules, including extracellular matrix proteins and their receptors, growth factors and their receptors, matrix metalloproteinases and extracellular chaperones. We report the molecular mechanisms underlying the important contribution of this pool of molecules to the complex, multi-step phenomenon of cancer cell invasion.

  5. Scanning probe microscopy characterisation of immobilised enzyme molecules on a biosensor surface: visualisation of individual molecules

    Directory of Open Access Journals (Sweden)

    JOE G. SHAPTER

    2004-02-01

    Full Text Available Scanning probe microscopy techniques were used to study immobilised enzyme molecules of glucose oxidase (GOD on a biosensor surface. The study was carried out in order to optimise atomic force microscopy (AFM imaging and reveal the molecular resolution of individual GOD molecules. Chemically modified AFM tips and the light tapping mode were found to be the optimal conditions for imaging soft biomolecules such as GOD. The information obtained from the AFM images included spatial distribution and organization of the enzyme molecules on the surface, surface coverage and shape, size and orientation of individual molecules. Two typical shapes of GOD molecules were found, spherical and butterfly, which are in accordance with the shapes obtained from scanning tunnelling microscopy (STM images. Using a model of the orientation of the GOD molecules on the surface, these shapes are assigned to the enzyme standing and lying on the surface. After AFM tip deconvolution, the size of the spherical shaped GOD molecules was found to be 12 ± 2.1 nm in diameter, whereas the butterfly shapes were 16.5 ± 3.3 nm ´10.2 ± 2.5 nm. Corresponding STM images showed smaller lateral dimensions of 10 ± 1 nm ´ 6 ± 1 nm and 6.5 ± 1 nm ´ 5 ± 1 nm. The disagreement between these two techniques is attributed to the deformation of the GOD molecules caused by the tapping process.

  6. Single Molecule Analysis Research Tool (SMART: an integrated approach for analyzing single molecule data.

    Directory of Open Access Journals (Sweden)

    Max Greenfeld

    Full Text Available Single molecule studies have expanded rapidly over the past decade and have the ability to provide an unprecedented level of understanding of biological systems. A common challenge upon introduction of novel, data-rich approaches is the management, processing, and analysis of the complex data sets that are generated. We provide a standardized approach for analyzing these data in the freely available software package SMART: Single Molecule Analysis Research Tool. SMART provides a format for organizing and easily accessing single molecule data, a general hidden Markov modeling algorithm for fitting an array of possible models specified by the user, a standardized data structure and graphical user interfaces to streamline the analysis and visualization of data. This approach guides experimental design, facilitating acquisition of the maximal information from single molecule experiments. SMART also provides a standardized format to allow dissemination of single molecule data and transparency in the analysis of reported data.

  7. Making More-Complex Molecules Using Superthermal Atom/Molecule Collisions

    Science.gov (United States)

    Shortt, Brian; Chutjian, Ara; Orient, Otto

    2008-01-01

    A method of making more-complex molecules from simpler ones has emerged as a by-product of an experimental study in outer-space atom/surface collision physics. The subject of the study was the formation of CO2 molecules as a result of impingement of O atoms at controlled kinetic energies upon cold surfaces onto which CO molecules had been adsorbed. In this study, the O/CO system served as a laboratory model, not only for the formation of CO2 but also for the formation of other compounds through impingement of rapidly moving atoms upon molecules adsorbed on such cold interstellar surfaces as those of dust grains or comets. By contributing to the formation of increasingly complex molecules, including organic ones, this study and related other studies may eventually contribute to understanding of the origins of life.

  8. Long-lived dipolar molecules and Feshbach molecules in a 3D optical lattice

    CERN Document Server

    Chotia, Amodsen; Moses, Steven A; Yan, Bo; Covey, Jacob P; Foss-Feig, Michael; Rey, Ana Maria; Jin, Deborah S; Ye, Jun

    2011-01-01

    We have realized long-lived ground-state polar molecules in a 3D optical lattice, with a lifetime of up to 25 s, which is limited only by off-resonant scattering of the trapping light. Starting from a 2D optical lattice, we observe that the lifetime increases dramatically as a small lattice potential is added along the tube-shaped lattice traps. The 3D optical lattice also dramatically increases the lifetime for weakly bound Feshbach molecules. For a pure gas of Feshbach molecules, we observe a lifetime of >20 s in a 3D optical lattice; this represents a 100-fold improvement over previous results. This lifetime is also limited by off-resonant scattering, the rate of which is related to the size of the Feshbach molecule. Individually trapped Feshbach molecules in the 3D lattice can be converted to pairs of K and Rb atoms and back with nearly 100% efficiency.

  9. Spinal but not cortical microglia acquire an atypical phenotype with high VEGF, galectin-3 and osteopontin, and blunted inflammatory responses in ALS rats

    OpenAIRE

    Nikodemova, Maria; Small, Alissa L.; Smith, Stephanie M.C.; Mitchell, Gordon S.; Watters, Jyoti J.

    2013-01-01

    Activation of microglia, CNS resident immune cells, is a pathological hallmark of amyotrophic lateral sclerosis (ALS), a neurodegenerative disorder affecting motor neurons. Despite evidence that microglia contribute to disease progression, the exact role of these cells in ALS pathology remains unknown. We immunomagnetically isolated microglia from different CNS regions of SOD1G93A rats at three different points in disease progression: presymptomatic, symptom onset and end-stage. We observed n...

  10. Self and directed assembly: people and molecules.

    Science.gov (United States)

    James, Tony D

    2016-01-01

    Self-assembly and directed-assembly are two very important aspects of supramolecular chemistry. As a young postgraduate student working in Canada with Tom Fyles my introduction to Supramolecular Chemistry was through the self-assembly of phospholipid membranes to form vesicles for which we were developing unimolecular and self-assembling transporter molecules. The next stage of my development as a scientist was in Japan with Seiji Shinkai where in a "Eureka" moment, the boronic acid templating unit (directed-assembly) of Wulff was combined with photoinduced electron transfer systems pioneered by De Silva. The result was a turn-on fluorescence sensor for saccharides; this simple result has continued to fuel my research to the present day. Throughout my career as well as assembling molecules, I have enjoyed bringing together researchers in order to develop collaborative networks. This is where molecules meet people resulting in assemblies worth more than the individual "molecule" or "researcher". My role in developing networks with Japan was rewarded by the award of a Daiwa-Adrian Prize in 2013 and I was recently rewarded for developing networks with China with an Inaugural CASE Prize in 2015. PMID:27340435

  11. Progress in Computational Electron-Molecule Collisions

    Science.gov (United States)

    Rescigno, Tn

    1997-10-01

    The past few years have witnessed tremendous progress in the development of sophisticated ab initio methods for treating collisions of slow electrons with isolated small molecules. Researchers in this area have benefited greatly from advances in computer technology; indeed, the advent of parallel computers has made it possible to carry out calculations at a level of sophistication inconceivable a decade ago. But bigger and faster computers are only part of the picture. Even with today's computers, the practical need to study electron collisions with the kinds of complex molecules and fragments encountered in real-world plasma processing environments is taxing present methods beyond their current capabilities. Since extrapolation of existing methods to handle increasingly larger targets will ultimately fail as it would require computational resources beyond any imagined, continued progress must also be linked to new theoretical developments. Some of the techniques recently introduced to address these problems will be discussed and illustrated with examples of electron-molecule collision calculations we have carried out on some fairly complex target gases encountered in processing plasmas. Electron-molecule scattering continues to pose many formidable theoretical and computational challenges. I will touch on some of the outstanding open questions.

  12. Uranium-mediated activation of small molecules.

    Science.gov (United States)

    Arnold, Polly L

    2011-08-28

    Molecular complexes of uranium are capable of activating a range of industrially and economically important small molecules such as CO, CO(2), and N(2); new and often unexpected reactions provide insight into an element that needs to be well-understood if future clean-energy solutions are to involve nuclear power. PMID:21614341

  13. Photoelectron spectroscopy of heavy atoms and molecules

    International Nuclear Information System (INIS)

    The importance of relativistic interactions in the photoionization of heavy atoms and molecules has been investigated by the technique of photoelectron spectroscopy. In particular, experiments are reported which illustrate the effects of the spin-orbit interaction in the neutral ground state, final ionic states and continuum states of the photoionization target

  14. Comprehensive Map of Molecules Implicated in Obesity.

    Directory of Open Access Journals (Sweden)

    Jaisri Jagannadham

    Full Text Available Obesity is a global epidemic affecting over 1.5 billion people and is one of the risk factors for several diseases such as type 2 diabetes mellitus and hypertension. We have constructed a comprehensive map of the molecules reported to be implicated in obesity. A deep curation strategy was complemented by a novel semi-automated text mining system in order to screen 1,000 full-length research articles and over 90,000 abstracts that are relevant to obesity. We obtain a scale free network of 804 nodes and 971 edges, composed of 510 proteins, 115 genes, 62 complexes, 23 RNA molecules, 83 simple molecules, 3 phenotype and 3 drugs in "bow-tie" architecture. We classify this network into 5 modules and identify new links between the recently discovered fat mass and obesity associated FTO gene with well studied examples such as insulin and leptin. We further built an automated docking pipeline to dock orlistat as well as other drugs against the 24,000 proteins in the human structural proteome to explain the therapeutics and side effects at a network level. Based upon our experiments, we propose that therapeutic effect comes through the binding of one drug with several molecules in target network, and the binding propensity is both statistically significant and different in comparison with any other part of human structural proteome.

  15. Comprehensive Map of Molecules Implicated in Obesity.

    Science.gov (United States)

    Jagannadham, Jaisri; Jaiswal, Hitesh Kumar; Agrawal, Stuti; Rawal, Kamal

    2016-01-01

    Obesity is a global epidemic affecting over 1.5 billion people and is one of the risk factors for several diseases such as type 2 diabetes mellitus and hypertension. We have constructed a comprehensive map of the molecules reported to be implicated in obesity. A deep curation strategy was complemented by a novel semi-automated text mining system in order to screen 1,000 full-length research articles and over 90,000 abstracts that are relevant to obesity. We obtain a scale free network of 804 nodes and 971 edges, composed of 510 proteins, 115 genes, 62 complexes, 23 RNA molecules, 83 simple molecules, 3 phenotype and 3 drugs in "bow-tie" architecture. We classify this network into 5 modules and identify new links between the recently discovered fat mass and obesity associated FTO gene with well studied examples such as insulin and leptin. We further built an automated docking pipeline to dock orlistat as well as other drugs against the 24,000 proteins in the human structural proteome to explain the therapeutics and side effects at a network level. Based upon our experiments, we propose that therapeutic effect comes through the binding of one drug with several molecules in target network, and the binding propensity is both statistically significant and different in comparison with any other part of human structural proteome. PMID:26886906

  16. Orbits in the H2O molecule

    NARCIS (Netherlands)

    Efstathiou, K; Contopoulos, G

    2001-01-01

    We study the forms of the orbits in a symmetric configuration of a realistic model of the H2O molecule with particular emphasis on the periodic orbits. We use an appropriate Poincare surface of section (PSS) and study the distribution of the orbits on this PSS for various energies. We find both orde

  17. Chiral Sensitivity in Electron-Molecule Interactions

    Science.gov (United States)

    Dreiling, Joan

    2015-09-01

    All molecular forms of life possess a chiral asymmetry, with amino acids and sugars found respectively in L- and D-enantiomers only. The primordial origin of this enantiomeric excess is unknown. One possible explanation is given by the Vester- Ulbricht hypothesis, which suggests that left-handed electrons present in beta-radiation, produced by parity-violating weak decays, interacted with biological precursors and preferentially destroyed one of the two enantiomers. Experimental tests of this idea have thus far yielded inconclusive results. We show direct evidence for chirally-dependent bond breaking through a dissociative electron attachment (DEA) reaction when spin-polarized electrons are incident on gas-phase chiral molecules. This provides unambiguous evidence for a well-defined, chirally-sensitive destructive molecular process and, as such, circumstantial evidence for the Vester-Ulbricht hypothesis. I will also present the results of our systematic study of the DEA asymmetry for different chiral halocamphor molecules. Three halocamphor molecules were investigated: 3-bromocamphor (C10H15BrO), 3-iodocamphor(C10H15IO), and 10-iodocamphor. The DEA asymmetries collected for bromocamphor and iodocamphor are qualitatively different, suggesting that the atomic number of the heaviest atom in the molecule plays a crucial role in the asymmetric interactions. The DEA asymmetry data for 3- and 10-iodocamphor have the same qualitative behavior, but the 10-iodocamphor asymmetry is about twice as large at the lowest energies investigated, so the location of the heavy atom in the camphor molecule also affects the asymmetries. This work was performed at the University of Nebraska-Lincoln. This project is funded by NSF Grant PHY-1206067.

  18. Electron attachment to the SF6 molecule

    Science.gov (United States)

    Smirnov, B. M.; Kosarim, A. V.

    2015-09-01

    Various models for transition between electron and nuclear subsystems are compared in the case of electron attachment to the SF6 molecule. Experimental data, including the cross section of electron attachment to this molecule as a function of the electron energy and vibrational temperature, the rate constants of this process in swarm experiments, and the rates of the chemionization process involving Rydberg atoms and the SF6 molecule, are collected and treated. Based on the data and on the resonant character of electron capture into an autodetachment ion state in accordance with the Breit-Wigner formula, we find that intersection of the molecule and negative ion electron terms proceeds above the potential well bottom of the molecule with the barrier height 0.05-0.1 eV, and the transition between these electron terms has both the tunnel and abovebarrier character. The limit of small electron energies e for the electron attachment cross section at room vibrational temperature takes place at ɛ ≪ 2 meV, while in the range 2 meV ≪ ɛ ≪ 80 meV, the cross section is inversely proportional to ɛ. In considering the attachment process as a result of the interaction between the electron and vibrational degrees of freedom, we find the coupling factor f between them to be f = aT at low vibrational temperatures T with a ≈ 3 × 10-4 K-1. The coupling factor is independent of the temperature at T > 400 K.

  19. Molecules for Fluorescence Detection of Specific Chemicals

    Science.gov (United States)

    Fedor, Steve

    2008-01-01

    A family of fluorescent dye molecules has been developed for use in on-off fluorescence detection of specific chemicals. By themselves, these molecules do not fluoresce. However, when exposed to certain chemical analytes in liquid or vapor forms, they do fluoresce (see figure). These compounds are amenable to fixation on or in a variety of substrates for use in fluorescence-based detection devices: they can be chemically modified to anchor them to porous or non-porous solid supports or can be incorporated into polymer films. Potential applications for these compounds include detection of chemical warfare agents, sensing of acidity or alkalinity, and fluorescent tagging of proteins in pharmaceutical research and development. These molecules could also be exploited for use as two-photon materials for photodynamic therapy in the treatment of certain cancers and other diseases. A molecule in this family consists of a fluorescent core (such as an anthracene or pyrene) attached to two end groups that, when the dye is excited by absorption of light, transfer an electron to the core, thereby quenching the fluorescence. The end groups can be engineered so that they react chemically with certain analytes. Upon reaction, electrons on the end groups are no longer available for transfer to the core and, consequently, the fluorescence from the core is no longer quenched. The chemoselectivity of these molecules can be changed by changing the end groups. For example, aniline end groups afford a capability for sensing acids or acid halides (including those contained in chemical warfare agents). Pyridine or bipyridyl end groups would enable sensing of metal ions. Other chemicals that can be selectively detected through suitable choice of end groups include glucose and proteins. Moreover, the fluorescent cores can be changed to alter light-absorption and -emission characteristics: anthracene cores fluoresce at wavelengths around 500 nm, whereas perylene cores absorb and emit at

  20. Prebiotic molecules and interstellar grain clumps

    International Nuclear Information System (INIS)

    It is stated that interstellar molecules detected by radioastronomical techniques in galactic clouds cover a wide range of types and complexities. Amongst the heaviest recently discovered is cyanodiacetylene. There have also been earlier detections of precursors to the simplest amino-acid, glycine and probably detections of polyoxymethylene polymers and co-polymers. A possible identification of organic molecules of even greater complexity is here discussed, together with implications for the commencement of biological activity. The large departures from thermodynamic equilibrium in the interstellar medium and the co-existence of solid grains, molecules, radicals, ions, and uv photons provide conditions that are ideal for production of 'exotic' molecular species. The effect of clumping of dust grains is discussed. The possible spectral identification of highly complex organic species in the interstellar medium is also discussed and reference is made to a property common to a wide class of such molecules, that is, an absorption band centered at 2,200 A. It is tempting to identify this feature with the well-known 2,200 A band of the interstellar extinction curve. It is thought that it may be tentatively concluded that the data so far obtained could be interpreted as independent new chemical evidence of the existence of composite grain clumps in the interstellar medium and in carbonaceous chondrites, and that these grain clumps probably include a significant mass fraction of highly complex organic pre-biotic molecules that could have led to the start and dispersal of biological activity on the Earth and elsewhere in the Galaxy. Processes of natural selection probably also played an important part, particularly in the production of self-replicable peptide chains. The problem of protection of pre-biotic material against external disruptive agencies, such as u/v light, is also discussed. (U.K.)

  1. Defining specificity and on-target activity of BH3-mimetics using engineered B-ALL cell lines.

    Science.gov (United States)

    Koss, Brian; Ryan, Jeremy; Budhraja, Amit; Szarama, Katherine; Yang, Xue; Bathina, Madhavi; Cardone, Michael H; Nikolovska-Coleska, Zaneta; Letai, Anthony; Opferman, Joseph T

    2016-03-01

    One of the hallmarks of cancer is a resistance to the induction of programmed cell death that is mediated by selection of cells with elevated expression of anti-apoptotic members of the BCL-2 family. To counter this resistance, new therapeutic agents known as BH3-mimetic small molecules are in development with the goal of antagonizing the function of anti-apoptotic molecules and promoting the induction of apoptosis. To facilitate the testing and modeling of BH3-mimetic agents, we have developed a powerful system for evaluation and screening of agents both in culture and in immune competent animal models by engineering mouse leukemic cells and re-programming them to be dependent on exogenously expressed human anti-apoptotic BCL-2 family members. Here we demonstrate that this panel of cell lines can determine the specificity of BH3-mimetics to individual anti-apoptotic BCL-2 family members (BCL-2, BCL-XL, BCL-W, BFL-1, and MCL-1), demonstrate whether cell death is due to the induction of apoptosis (BAX and BAK-dependent), and faithfully assess the efficacy of BH3-mimetic small molecules in pre-clinical mouse models. These cells represent a robust and valuable pre-clinical screening tool for validating the efficacy, selectivity, and on-target action of BH3-mimetic agents. PMID:26862853

  2. Handbook of Single-Molecule Biophysics

    CERN Document Server

    Hinterdorfer, Peter

    2009-01-01

    The last decade has seen the development of a number of novel biophysical methods that allow the manipulation and study of individual biomolecules. The ability to monitor biological processes at this fundamental level of sensitivity has given rise to an improved understanding of the underlying molecular mechanisms. Through the removal of ensemble averaging, distributions and fluctuations of molecular properties can be characterized, transient intermediates identified, and catalytic mechanisms elucidated. By applying forces on biomolecules while monitoring their activity, important information can be obtained on how proteins couple function to structure. The Handbook of Single-Molecule Biophysics provides an introduction to these techniques and presents an extensive discussion of the new biological insights obtained from them. Coverage includes: Experimental techniques to monitor and manipulate individual biomolecules The use of single-molecule techniques in super-resolution and functional imaging Single-molec...

  3. Is the focus on "molecules" obsolete?

    Science.gov (United States)

    Whitesides, George M

    2013-01-01

    The technologies developed in analytical chemistry have defined in spectacular detail the properties of molecules. The field now faces enormously important and interesting problems of which molecules are only a part: for example, understanding the nature of life; helping to manage megacities, oceans, and atmospheres; and making health care (especially diagnostics) affordable and relevant. The emergence of these problems involving molecular systems raises the issue of how (and what) analytical chemistry should teach. Historically, it has been essential to chemistry in teaching the science of measurement. As complicated analytical techniques proliferate, it must consider how to balance teaching the uses of sophisticated devices and the fundamentals of analysis and measurement. This review (by an admiring but nonanalytical chemist) sketches the essential role of analytical methods--especially simple ones made up on the spot--in guiding research in new fields, with examples from self-assembled monolayers, soft lithography, paper diagnostics, and self-assembly; and suggests issues in teaching. PMID:23772657

  4. Is the Focus on ``Molecules'' Obsolete?

    Science.gov (United States)

    Whitesides, George M.

    2013-06-01

    The technologies developed in analytical chemistry have defined in spectacular detail the properties of molecules. The field now faces enormously important and interesting problems of which molecules are only a part: for example, understanding the nature of life; helping to manage megacities, oceans, and atmospheres; and making health care (especially diagnostics) affordable and relevant. The emergence of these problems involving molecular systems raises the issue of how (and what) analytical chemistry should teach. Historically, it has been essential to chemistry in teaching the science of measurement. As complicated analytical techniques proliferate, it must consider how to balance teaching the uses of sophisticated devices and the fundamentals of analysis and measurement. This review (by an admiring but nonanalytical chemist) sketches the essential role of analytical methods—especially simple ones made up on the spot—in guiding research in new fields, with examples from self-assembled monolayers, soft lithography, paper diagnostics, and self-assembly; and suggests issues in teaching.

  5. Exploring $X(5568)$ as a meson molecule

    CERN Document Server

    Agaev, S S; Sundu, H

    2016-01-01

    The parameters, i.e. the mass and decay constant of the exotic $X_b(5568)$ state newly observed by D0 Collaboration, as well as the decay width of the process $X_b \\to B_s^{0}\\pi^{+}$ are explored using $B\\overline{K}$ molecule assumption on its structure. Computational methods employed here encompass QCD two-point and light-cone sum rules, latter being considered in the soft-meson approximation. The obtained results are compared with the data of the D0 Collaboration, as well as with the predictions of the diquark-antidiquark model. This comparison strengthens the diquark-antidiquark picture for the $X_b(5568)$ state rather than a meson molecule structure.

  6. Imaging Genetic Molecules At Atomic Resolution

    Science.gov (United States)

    Coles, L. Stephen

    1993-01-01

    Proposed method of imaging informational polymeric biological molecules at atomic resolution enables determination of sequences of component monomers about 10 to the 3rd power to 10 to the 4th power times as fast as conventional methods do. Accelerates research on genetic structures of animals and plants. Also contributes significantly to imaging processes like scanning electron microscopy (SEM), atomic-force microscopy (AFM), and scanning tunneling microscopy (STM) in cases in which necessary to locate or identify small specimens on relatively large backgrounds and subtract background images to obtain images of specimens in isolation. V-grooves on silicon wafer laid out in square pattern, intersections of which marked to identify coordinates. Specimen molecules held in grooves for reproducible positioning and scanning by AFM or STM.

  7. Photochemical dynamics of surface oriented molecules

    International Nuclear Information System (INIS)

    The period 8/01/91-7/31/92 is the first year of a new project titled ''Photochemical Dynamics of Surface Oriented Molecules'', initiated with DOE Support. The main objective of this project is to understand the dynamics of elementary chemical reactions by studying photochemical dynamics of surface-oriented molecules. In addition, the mechanisms of photon-surface interactions need to be elucidated. The strategy is to carry out experiments to measure the translational energy distribution, as a function of the angle from the surface normal, of the photoproducts by time-of-flight (TOF) technique by varying the photon wavelength, intensity, polarization, and pulse duration. By choosing adsorbates with different bonding configuration, the effects of adsorbate orientation on surface photochemical dynamics can be studied

  8. - Fourier Transform Infrared Spectroscopy of Small - Molecules

    Science.gov (United States)

    Li, G.; Bernath, P. F.

    2011-06-01

    A series of small boron-containing molecules were synthesized in the gas phase using a tube furnace. High-resolution spectra of these species were recorded in either emission or absorption in the mid-infrared region using a Bruker IFS-125HR spectrometer. Our observations contain vibration-rotation bands of BO, the V1 and V3 bands of HBO, the V1 and V3 bands of HBS, the V1 band of FBO, and the V1 band of HBF2. The vibrational bands of HOBO, BF2OH and other boron-containing molecules may also be present. Ab initio calculations were performed at the MRCI level to assist in the vibrational assignments. Preliminary assignments of the spectra for these species will be reported.

  9. Interstellar molecules - Formation in solar nebulae

    Science.gov (United States)

    Anders, E.

    1973-01-01

    Herbig's (1970) hypothesis that solar nebulae might be the principal source of interstellar grains and molecules is investigated. The investigation includes the determination of physical and chemical conditions in the early solar system. The production of organic compounds in the solar nebula is studied, and the compounds in meteorites are compared with those obtained in Miller-Urey and Fischer-Tropsch-type (FTT) reactions, taking into consideration aliphatic hydrocarbons, aromatic hydrocarbons, purines, pyrimidines, amino acids, porphyrins, and aspects of carbon-isotope fractionation. It is found that FTT reactions account reasonably well for all well-established features of organic matter in meteorites investigated. The distribution of compounds produced by FTT reactions is compared with the distribution of interstellar molecules. Biological implications of the results are considered.

  10. Chirally-sensitive electron-molecule interactions

    Science.gov (United States)

    Dreiling, J. M.; Gay, T. J.

    2015-09-01

    All molecular forms of life have chemically-specific handedness. However, the origin of these asymmetries is not understood. A possible explanation was suggested by Vester and Ulbricht immediately following the discovery of parity violation in 1957: chiral beta radiation in cosmic rays may have preferentially destroyed one enantiomeric form of various biological precursors. In the experiments reported here, we observed chiral specificity in two electron- molecule interactions: quasi-elastic scattering and dissociative electron attachment. Using low- energy longitudinally spin-polarized (chiral) electrons as substitutes for beta rays, we found that chiral bromocamphor molecules exhibited both a transmission and dissociative electron attachment rate that depended on their handedness for a given direction of incident electron spin. Consequently, these results, especially those with dissociative electron attachment, connect the universal chiral asymmetry of the weak force with a molecular breakup process, thereby demonstrating the viability of the Vester-Ulbricht hypothesis.

  11. Photoassociative Excitation Spectroscopy of Excimer Molecules

    Science.gov (United States)

    Jones, Ronald Blake

    Laser excitation spectroscopy of transitions having dissociative ground states was explored as a tool for the study of excimer molecules. Since the repulsive nature of the ground state constrains collision pairs to large internuclear transitions, bound >=ts free excitation spectra contain more structure than the bound to free fluorescence spectra for the same molecules, therefore containing more information about the potential surfaces. Unique properties of the photoassociative excitation spectroscopy technique are described which allow the dependence of the dipole transition moment on the internuclear separation (mu (R)) to be extracted in a very direct manner. Excitation spectra are presented for the B >=ts X transitions of KrF and XeI for the wavelength (lambda) interval 206 nm KrI are given. This work required the development of a tunable VUV source, which is described.

  12. Modelling proton transfer in water molecule chains

    CERN Document Server

    Korzhimanov, Artem; Shutova, Tatiana; Samuelsson, Goran

    2011-01-01

    The process of protons transport in molecular water chains is of fundamental interest for many biological systems. Although many features of such systems can be analyzed using large-scale computational modeling, other features are better understood in terms of simplified model problems. Here we have tested, analytically and numerically, a model describing the classical proton hopping process in molecular water chains. In order to capture the main features of the proton hopping process in such molecular chains, we use a simplified model for our analysis. In particular, our discrete model describes a 1D chain of water molecules situated in an external protein channel structure, and each water molecule is allowed to oscillate around its equilibrium point in this system, while the protons are allowed to move along the line of neighboring oxygen atoms. The occurrence and properties of nonlinear solitary transport structures, allowing for much faster proton transport, are discussed, and the possible implications of...

  13. Photoluminescence of a quantum-dot molecule

    International Nuclear Information System (INIS)

    The coherent coupling of quantum dots is a sensitive indicator of the energy and phase relaxation processes taking place in the nanostructure components. We formulate a theory of low-temperature, stationary photoluminescence from a quantum-dot molecule composed of two spherical quantum dots whose electronic subsystems are resonantly coupled via the Coulomb interaction. We show that the coupling leads to the hybridization of the first excited states of the quantum dots, manifesting itself as a pair of photoluminescence peaks with intensities and spectral positions strongly dependent on the geometric, material, and relaxation parameters of the quantum-dot molecule. These parameters are explicitly contained in the analytical expression for the photoluminescence differential cross section derived in the paper. The developed theory and expression obtained are essential in interpreting and analyzing spectroscopic data on the secondary emission of coherently coupled quantum systems

  14. Atomic Rydberg Reservoirs for Polar Molecules

    CERN Document Server

    Zhao, Bo; Pupillo, Guido; Zoller, Peter

    2011-01-01

    We discuss laser dressed dipolar and Van der Waals interactions between atoms and polar molecules, so that a cold atomic gas with laser admixed Rydberg levels acts as a designed reservoir for both elastic and inelastic collisional processes. The elastic scattering channel is characterized by large elastic scattering cross sections and repulsive shields to protect from close encounter collisions. In addition, we discuss a dissipative (inelastic) collision where a spontaneously emitted photon carries away (kinetic) energy of the collision partners, thus providing a significant energy loss in a single collision. This leads to the scenario of rapid thermalization and cooling of a molecule in the mK down to the \\mu K regime by cold atoms.

  15. Artifacts in single-molecule localization microscopy.

    Science.gov (United States)

    Burgert, Anne; Letschert, Sebastian; Doose, Sören; Sauer, Markus

    2015-08-01

    Single-molecule localization microscopy provides subdiffraction resolution images with virtually molecular resolution. Through the availability of commercial instruments and open-source reconstruction software, achieving super resolution is now public domain. However, despite its conceptual simplicity, localization microscopy remains prone to user errors. Using direct stochastic optical reconstruction microscopy, we investigate the impact of irradiation intensity, label density and photoswitching behavior on the distribution of membrane proteins in reconstructed super-resolution images. We demonstrate that high emitter densities in combination with inappropriate photoswitching rates give rise to the appearance of artificial membrane clusters. Especially, two-dimensional imaging of intrinsically three-dimensional membrane structures like microvilli, filopodia, overlapping membranes and vesicles with high local emitter densities is prone to generate artifacts. To judge the quality and reliability of super-resolution images, the single-molecule movies recorded to reconstruct the images have to be carefully investigated especially when investigating membrane organization and cluster analysis. PMID:26138928

  16. Vibrational and coherence dynamics of molecules

    CERN Document Server

    Zhang, Zhedong

    2015-01-01

    We {\\it analytically} investigate the population and coherence dynamics and relaxations in the vibrational energy transport in molecules. The corresponding two time scales $t_1$ and $t_2$ are explored. Coherence-population entanglement is found to considerably promote the time scale $t_2$ for dephasing and the amplitude of coherence. This is attributed to the suppression of the environment-induced drift force by coherence. Moreover the population imbalance (magnetization) is shown to be significantly amplified with the coherence-population entanglement. Contrary to the previous studies, we exactly elucidate a coherent process by showing $t_1molecules dissolved in D$_2$O. Finally we explore the coherence effect on the heat current at the macroscopic level.

  17. Multichannel quantum defect theory for ro-vibrational transitions in ultracold molecule-molecule collisions

    OpenAIRE

    Hazra, Jisha; Ruzic, Brandon P.; Balakrishnan, N.; Bohn, John L.

    2014-01-01

    Multichannel quantum defect theory (MQDT) has been widely applied to resonant and non-resonant scattering in a variety of atomic collision processes. In recent years, the method has been applied to cold collisions with considerable success, and it has proven to be a computationally viable alternative to full-close coupling (CC) calculations when spin, hyperfine and external field effects are included. In this paper, we describe a hybrid approach for molecule-molecule scattering that includes ...

  18. Femtosecond dynamics of molecules and clusters

    OpenAIRE

    Baumert, Thomas,; Thalweiser, Rainer; Weiss, V.; Wiedenmann, Ernst; Gerber, Gustav

    1994-01-01

    The real-time dynamics of multiphoton ionization and fragmentation of molecules - Na_2 , Na_3 - and clusters - Na_n, Hg_n - has been studied in molecular beam experiments employing ion and electron spectroscopy together with femtosecond pump-probe techniques. Experiments with Na_2 and Na_3 reveal unexpected features of the dynamics of the absorption of several photons as seen in the one- and three dimensional vibrational wave packet motion in different potential surfaces and...

  19. Excitonic molecules in type-II superlattices

    Science.gov (United States)

    Tsuchiya, T.; Katayama, S.; Ando, T.

    1998-01-01

    Excitonic molecules in GaAs/AlAs type-II superlattices are numerically investigated. In spite of large difference of electronic structures between type-II and type-I superlattices, variational calculations show that the configuration of particles is similar to that in type-I superlattices. This is because the layer width is smaller than the extent of excitonic wavefunctions in the direction parallel to the layers in the present superlattices.

  20. Isatin, a versatile molecule: studies in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Barbara, E-mail: barbara.iq@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2013-05-15

    Isatin is a small, versatile and widely applicable pharmacological molecule. These characteristics make isatin and its derivatives attractive to many research groups as resources for chemical and pharmacological studies. Although it has a relatively simple structure, isatin is a useful chemical scaffold for a variety of chemical transformations. This article discusses several studies performed by Brazilian groups, including investigations of its structural changes, biological assay designs and new methods for the synthesis of isatin. (author)