Day 2 :
Duke University, USA
Keynote: Plasmonics nanoprobes: A new generation of biotools for cellular sensing, biomedical imaging and bioenergy research
Time : 09:30-10:10
Tuan Vo-Dinh is a Professor of Biomedical Engineering, Professor of Chemistry, and Director of Fitzpatrick Institute for Photonics at Duke University. He completed his BS in Physics in 1970 at École Polytechnique Fédérale de Lausanne (EPFL) in Lausanne, Switzerland, and PhD in Physical Chemistry in 1975 at ETH (Swiss Federal Institute of Technology) in Zurich, Switzerland. His research activities involve “Nanophotonics, biophotonics, nano-biosensors, biochips, molecular spectroscopy, bioimaging for medical diagnostics and therapy (nano-theranostics), personalized medicine and global health”. He has received seven R&D 100 Awards for most technologically significant advance in research and development for his pioneering research and inventions of innovative technologies. He has received Gold Medal Award, Society for Applied Spectroscopy (1988); the Languedoc-Roussillon Award (France) (1989); the Scientist of the Year Award, ORNL (1992); the Thomas Jefferson Award, Martin Marietta Corporation (1992); two Awards for Excellence in Technology Transfer, Federal Laboratory Consortium (1995, 1986) etc. He has authored over 400 publications in peer-reviewed scientific journals.
There is a strong need to develop nanoprobes for cellular sensing and imaging, which allow selective and sensitive monitoring of bio-targets and molecular processes inside and outside cellular systems related to studies of plant bio-systems relevant to biofuel production. We develop a new class of nanoprobes called inverse molecular sentinels (iMS) for nucleic acid targets (e.g., mRNAs, microRNAs, siRNAs) that will enable imaging and study of cellular functions, both in plant and microbial species using surface-enhanced Raman scattering (SERS) detection. The iMS nano-probe system is composed of three parts: A stem-loop nucleic acid probe labeled with a Raman reporter, which provides the source of the Raman signal; a plasmonic-active nanoparticle e.g. nanospheres or nano-stars and; an unlabeled capture placeholder strand. Upon exposure to the target sequences, the placeholder capture strand leaves the “open” stem-loop probe, allows the stem-loop to “close” and moves the Raman label onto the plasmonics-active metal surface; this yields a strong SERS signal. The multiplex capability of SERS is an important feature due to the narrow Raman bandwidths, which provides significant advantages over other methods. We demonstrate the multiplexing capability of the iMS technique to target RGA and PP2AA3 genes of plant cells. RGA gene belongs to a 5-gene DELLA family in Arabidopsis, which plays a critical role in controlling plant biomass. The results of this study demonstrate the feasibility of using the iMS nanoprobes for multiplex detection of important markers in bioenergy-relevant plant systems. The results obtained with the iMS sensing technology will be useful to understand and manipulate vegetative plant growth by identifying and ultimately modulating DELLA expression in specific cell types. Because DELLAs play a central role in regulating vegetative growth in flowering plants, our work will provide significant insights into novel ways to manipulate plant growth to increase biomass if renewable energy sources are for a sustainable and green future.
University of Evry, France
Keynote: Visualization and quantification of protein interactions along microtubules in mammalian cells
Time : 10:10-10:50
David Pastre is currently the Head of the SABNP Laboratory (INSERM unit U1204) and Professor at the University of Evry. He after studying Physics and Optics at the University of Montpellier, has developed a set up to collect cathodoluminescence near field. During a Post-doctoral fellowship at the University of Virginia (2000-2001), he designed a method to observe living mammalian cells at high-resolution with a scanning ion conductance microscope. As a Teacher-Researcher at the University of Evry, he deciphered the mechanisms leading to DNA absorption on mica and studied the formation of DNA and RNA/protein complexes on mica by atomic force microscopy. He is currently investigating, at the cellular and molecular levels, the dynamics and structure of RNA/protein complexes involved in the control of protein expression and the mechanisms which regulate microtubule dynamics. He also continues to develop novel methods to explore cellular and molecular processes.
The functions of many proteins and their interplay remain elusive, which limits the developments of diagnostic and treatment of many human diseases. To address this issue, methods are currently developed to decipher protein interactions in cells. We recently developed a new technology to probe protein interactions (PPI) along microtubules in specifically engineered mammalian cells by fluorescence microscopy. A bait protein is brought to microtubules and the presence of putative molecular partners, attracted by the bait protein, is then detected on microtubules by fluorescence microscopy. Here, we present the advantages of this technology compared to other approaches and its latest developments. The domain of applications are broad spanning from discovery of new drugs that target protein or mRNA interactions, identifying molecular targets, exploring the consequences of mutations and the possible corrections of pathogenic consequences.
University of Houston, USA
Keynote: Bio-manufacturing of gout medicine
Time : 11:10-11:50
Colchicine is one of the most important alkaloid-based antigout drugs with anticancer potential which is unique to Colchicaceae. Gloriosa superba L is a very successful commercial source of plant-based pharmaceutical colchicine. However, high colchicine production is challenging and the cultivation is labor-intensive, time consuming, and expensive. Indeed, there is no bio-manufacturing technology for the production of plant-based colchicine. A new biotechnological bio-rhizome engineering platform is emerging from G. superba. Author will discuss recent advances in bio-rhizome to bio-manufacture therapeutic colchicine.
Ganapathy Sivakumar is currently an Assistant Professor in Department of Engineering and Technology at University of Houston, USA. He completed his PhD and Post-doctoral degree in the areas of Biotechnology, Molecular Chemistry, Bio-process Engineering. He has experience in Industrial Biotechnology. He has over 40 publications. He is also Editorial Board Member of several journals. He serves as an expert of grant proposals as well as numerous scientific journals. His laboratory focuses on metabolic and bioprocess engineering of colchicine pathway and developing potential anticancer medicine.
- Integrative Biology
Location: Waterfront 1
Bernard S Lopez
Institut Gustave Roussy, France
Institute Gustave Roussy, France
Title: Promoter sequences of genes controlling genome stability are altered in late G2 phase, following low/endogenous replication stress
Time : 11:50-12:15
Bernard Lopez has completed his PhD at the age of 27 years from University of Lyon I and postdoctoral studies from Curie Institute (Paris), followed by a sabbatical from and Brandeis university (Waltham, Ms, USA). He is first class research director at CNRS (French state organisation for basic research). He has published more than 70 papers in reputed journals and has been serving as a scientific advisor of many organizations.
Replication stress is an endogenous stress that can be at the origin of senescence or tumour initiation. Replication stress can generates mitosis defects including anaphases bridges, expression of common fragile sites, extra-centrosomes and multipolar segregations. All these troubles generate uneven chromosome segregation and aneuploidy. This suggests that DNA damages arising from replication should reach mitosis. To test this hypothesis wen checked the accumulation of foci of RPA, which recognize single-stranded DNA, in cells in late G2, following a low or endogenous replication stress. Cells treated with low doses of hydroxyurea (HU, 10 µM) or untreated cells defective for homologous recombination (HR); which plays a pivotal role in the resumption of arrested replication forks, both experience an increase in the number of RPA foci, in late G2 phase. These foci do not colocalise with progressing replication forks completing replication, and thus should correspond to spontaneous replication fork arrest. ChIP-seq analysis with RPA antibodies in G2 phase, reveals two types of enrichment efficiency. Highly enriched sequences (more than 400) do not contained fragile sites and correspond to early replicating sequences. Interestingly many of these sequences correspond to transcription starting sites (TSS), revealing thus the conflict between replication and transcription. Among the genes involved a set of 10 genes involved in DNA damage response and cell cycle checkpoint have been selected and specific chromatin-IP experiment confirmed the binding of RPA after HU. Therefore promoters of genes controlling genome stability are hot spots of endogenous/low replication stress favouring damaged cells to escape to cell surveillance. Therefore should amplify genome instability.
Technion ‐ Israel Institute of Technology, Israel
Title: NELF‐E is recruited to DNA double‐strand break sites to promote transcriptional repression and repair
Time : 12:15-12:40
Nabieh Ayoub began his scientific career at the Hebrew University (1989-1993) where he received a BSc in Biology. He has done his Master’s degree with distinction in Genetics (1994-1996) studying chromosome X inactivation. Supported by the Levy Eshkool Fellowship from the Israeli Ministry of Science, he pursued his PhD in the study of heterochromatic gene regulation under the supervision of Professor Amikam Cohen at Hadassah Medical School, the Hebrew University (1997-2002). He is an Assistant Professor at the Israel Institute of Technology – Technion. In 2016, he was prompted to the degree of Associate Professor with tenure.
Double-strand breaks (DSBs) trigger rapid and transient transcription pause to prevent collisions between repair and transcription machineries at damage sites. Little is known about the mechanisms that ensure transcription block after DNA damage. Here we reveal a novel role of the negative elongation factor, NELF, in blocking transcription activity nearby DSBs. We show that NELF-E and NELF-A are rapidly recruited to DSB sites. Furthermore, NELF-E recruitment and its repressive activity are both required for switching off transcription at DSBs. Remarkably, using I-Sce-I endonuclease and CRISPR-Cas9 systems, we observed that NELF-E is preferentially recruited, in a PARP1-dependent manner, to DSBs induced upstream transcriptionally active rather than inactive genes. Moreover, the presence of RNA polymerase II is a prerequisite for the preferential recruitment of NELF-E to DNA breakage sites. Additionally, we demonstrate that NELF-E is required for intact repair of DSBs. Altogether, our data identified NELF complex as a new component in the DNA damage response.
Technion ‐ Israel Institute of Technology, Israel
Title: Localized LoxL3-dependent fibronectin oxidation regulates myofiber stretch and integrin-mediated adhesion
Time : 12:40-13:05
Peleg Hasson has completed his PhD at the age of 33 years from the Hebrew University, Jerusalem, Israel University and continued his postdoctoral studies at the MRC-National Institute of Medical Research, London. He has started his own lab at the Technion's Rappaport Faculty of Medicine in 2010.
For muscles to function, myofibers have to stretch and anchor at the myotendinous junction (MTJ), a region rich in extracellular matrix (ECM). Integrin signaling is required for MTJ formation, and mutations affecting the cascade lead to muscular dystrophies in mice and humans. Underlying mechanisms for integrin activation at the MTJ and ECM modifications regulating its signaling are unclear. We show that lysyl oxidase-like 3 (LoxL3) is a key regulator of integrin signaling that ensures localized control of the cascade. In LoxL3 mutants, myofibers anchor prematurely or overshoot to adjacent somites, and are loose and lack tension. We find that LoxL3 complexes with and directly oxidizes Fibronectin (FN), an ECM scaffold protein and integrin ligand enriched at the MTJ. We identify a mechanism whereby localized LoxL3 secretion from myofiber termini oxidizes FN, promoting FN polymerization thus priming it for integrin activation at the tips of myofibers and ensuring correct positioning and anchoring of myofibers along the MTJ.
Professor Ravid has completed his PhD from Tel Avi University in 2001 and postdoctoral studies from University of California, Davis, School of Medicine and fom Yale University, School of Medicine. He is faculty member at the Department of Biological Chemisty, Faculty of Life Sciences, the Hebrew University of Jerusalem, since 2007. His Lab research focuses on the mechanisms underlying protein quality control and degradation by the ubiquitin-proteasome system, using the budding yeast Saccharomyces cerevisiae as a model organism.
The ubiquitin-proteasome system (UPS) for protein degradation has been under intensive study, and yet, we have only partial understanding of mechanisms by which proteins are selected to be targeted for proteolysis. One of the obstacles in studying these recognition pathways is the limited repertoire of known degradation signals (degrons). To better understand what determines the susceptibility of intracellular proteins to degradation by the UPS, we developed an unbiased method for large-scale identification of eukaryotic degrons. Using a reporter-based high-throughput competition assay, followed by deep sequencing, we measured a degradation potency index for thousands of native polypeptides in a single experiment. We further used this method to identify protein quality control (PQC)-specific and compartment-specific degrons. Our method provides an unprecedented insight into the yeast degrome, and it can readily be modified to study protein degradation signals and pathways in other organisms and in various settings.
Shenzhen University Health Science Center, China
Title: Toll-like receptor 2-mediated MAPKs and NF-κB activation requires GNAO1-dependent pathway in human mast cell
Time : 14:25-14:50
Yangyang Yu is professor at center for diabetes, obesity and metabolism in department of physiology, Shenzhen University Health Science Center, Shenzhen, Guangdong province, China.
Toll-like receptors (TLRs) expressed on mast cells are essential for effective host defense against a wide variety of pathogens. Previous studies have demonstrated that TLR2 agonists Pam3CSK4 and PGN both stimulated IL-8 release in human mast cells. To determine the molecular basis for this phenomenon, we utilized a human mast cell line LAD2 cells. We found that only release of IL-8 stimulated by Pam3CSK4 was TLR2-mediated, which was confirmed by specific TLR2 shRNA. Heterotrimeric G proteins have been previously implicated in TLRs signaling in macrophages and monocytes. In the current study, we showed that PamCSK4 induced the activation of MAPKs, NF-κB, PI3K-Akt and Ca2+-calcineurin-NFAT signaling cascades in LAD2 cells. Go proteins were required for the activation of MAPKs and NF-κB in TLR2 stimulated LAD2 cells. Therefore, genetic depletion of Gαo proteins also leaded to reduction of IL-8 release in LAD2 cells. Taken together, the data presented here suggest that TLR2 activation in human mast cells promotes the release of inflammatory mediators via distinct signaling pathways that partially depends on Go protein action.
Weizmann Institute of Science, Israel
Title: Dynamic location of integration sites on host genomes during lateral gene transfer processes in live bacteria
Time : 14:50-15:15
Rinat Arbel-Goren completed her PhD in 2002 in Life Sciences at the Department of Molecular Biology of the Cell, Weizmann Institute of Science Rehovot, Israel, under Prof. Y. Zick. From 2002-2005, she carried out a Postdoc in the Department of Immunology, under Prof Y. Reisner. Since 2006 she is a Staff Scientist in the Department of Physics of Complex Systems, Weizmann Institute of Science, in the lab of Prof. J. Stavans. In addition to the above, her current research topics include:Effects of post-transcriptional regulation by small-RNAs on phenotypic variability; Effects of phenotypic variability during development in cyanobacteria.
During horizontal gene transfer processes, imported exogenous DNA sequences integrate at unique sites in the host bacterial genome, driving genetic diversity. One example is viral infection, which is known to allow the acquisition of pathogenic traits.After entering an Escherichia coli cell, the ∼5x104-long bacteriophage λ DNA must locate a unique site among ∼5x106 possible sites on the bacterial genome, with high efficiency and within physiological times, to integrate and establish lysogeny. What are the mechanisms that allow it to do it?We followed the targeting process in individual live E. coli cells in real-time, by marking fluorescently both the phage DNA after entry into the host, and a chromosomal sequence near the integration site. Surprisingly, we found that λ DNA does not carry out an active search. Instead, it remains confined near its entry point into the cell following infection, preferentially at the poles, where it undergoes limited diffusion. The encounter between the 15 bp-long target sequence on the chromosome and the recombination site on the viral genome is facilitated by thedirected motion of bacterial DNA generated during chromosome replication and segregation.A different mechanism of target location is observed during conjugation betweenB. subtilis cells: integrating conjugating elements imported from donor cells carry out anomalous diffusion within host cellsin their search for their target insertion sites, which move concomitantly, driven by replication of the host genome. These finding demonstrate that there are different solutions to the target location problemduring horizontal gene transfer processes.
University of Putra, Malaysia
Time : 15:15-15:40
Peter Waziri completed his MSc at University of Nottingham in 2013. He is currently a PhD student in Medicinal Chemistry at University of Putra, Malaysia. In the last two years, he worked on “The isolation of bioactive components in plants for use in cancer therapy”.
Liver cancer is a leading cause of death in the world with an increasing burden in Asia and sub-Saharan Africa. The therapeutic options for liver cancers are inadequate and survival after diagnosis is very low. This situation actually creates the need for studies on natural products that can complement and provide suitable alternatives to the current therapeutic measures. In the current study, we used clausenidin isolated from Clausena excavata Burm. f. to treat liver cancer (hepG2) cells. The plant is a shrub used in Asian folk medicine to treat cancer patients locally but there is little or no scientific evidence supporting its therapeutic use. We evaluated the cytotoxicity of clausenidin as well as its effect on reactive oxygen species production in hepG2 cells. In addition, we carried out an ultra-structural investigation of the clausenidin-treated cells to identify potential mechanisms through which clausenidin induce cell death in hepG2 cells. Our results reveal that clausenidin induces cytotoxic effects in hepG2 cells in a dose dependent manner with significant increase in the production of reactive oxygen species. Cell death was found to have occurred via apoptotic and non-apoptotic routes as revealed by the results of DNA fragmentation analysis and transmission electron microscopy respectively. The present study lends credence to the use of Clausena excavata to treat cancer patients in Asia and demonstrates the potential of clausenidin in the biotherapy of liver cancer.
Jun Yao completed his PhD at Pennsylvania State University, Department of Biology, USA in 2007. He is a Principal Investigator of School of Life Sciences at Tsinghua University, China. In recent years, he has published more than 10 papers in reputed journals.
Bipolar disorder (BD) is a complex neuropsychiatric disorder that is characterized by intermittent episodes of mania and depression; without treatment, 15% of patients commit suicide. Hence, BD has been ranked by the WHO as a top disorder of morbidity and lost productivity. Previous neuropathological studies have revealed a series of alterations in the brains of BD patients or animal models, such as reduced glial cell number in the patient prefrontal cortex, up-regulated activities of the PKA/PKC pathways, and changes in neurotransmission. However, the roles and causation of these changes in BD have been too complex to exactly determine the pathology of the disease. Furthermore, while some patients show remarkable improvement with lithium treatment, for yet unknown reasons, other patients are refractory to lithium treatment. Therefore, developing an accurate and powerful biological model for BD has been a challenge. The introduction of induced pluripotent stem cell (iPSC) technology has provided a new approach. Here, we developed a human BD iPSC model and investigated the cellular phenotypes of hippocampal dentate gyrus-like neurons derived from patient iPSCs. Guided by RNA-seq expression profiling, we detected mitochondrial abnormalities in young BD neurons using mitochondrial assays and, using both patch clamp recording and somatic Ca2+ imaging, we observed hyperactive action potential (AP) firing. This hyperexcitability phenotype of young BD neurons was selectively reversed by lithium treatment only in neurons derived from the patients who also responded to lithium treatment. Therefore, hyperexcitability is one early endophenotype of BD, and our BD iPSC model may be useful for the development of new therapies and drugs aimed at clinical treatment of this disease.
Institute of General Pathology and Pathophysiology, Russia
Braga E.A. has completed her PhD at the age of 28 at Lomonosov Moscow State University, Bioorganic Chemistry Department. She has taken a part in Russian Human Genome Project and HUGO. She was an Invited Principle Investigator at Karolinska Institute (Stockholm, Sweden, 1999-2000). She completed her full Dr. of Biology Sc. at Engelhardt Institute of Molecular Biology in 2007. She is a head of Laboratory of Pathogenomics and Transcriptomics at Institute of General Pathology and Pathophysiology, Moscow, Russia. She has published more than 70 papers in reputed Journals.
Epigenetic mechanisms including DNA methylation and interaction between miRNAs and mRNAs are the most dynamic mechanisms of genes deregulation in cancer. The aim of this study was to identify novel miRNAs, involved in down-regulation of some cancer-associated genes, and could be down-regulated itself by DNA methylation, in breast cancer (BC). We analyzed expression and methylation profiles of 20 tumor-suppressor miRNAs and 15 cancer-associated genes, which interactions were predicted by algorithms of miRWalk 2.0 database. Representative set of 58 paired (tumor/normal) BC samples; methylation-specific PCR, qPCR and the IBM SPSS Statistics Base 20 software package were used. We first observed hypermethylation of MIR-127, -132, -1258, -193a, and hypomethylation of MIR-191. Using qPCR, we established a strong correlation between promoter methylation and expression levels of 12 miRNA genes, confirming the functional importance of altered methylation patterns. The significant negative correlations were revealed between expression level alterations for the following pairs: CCND1 – miR-212-3p, -34a-5p, -34c-3p; BCL2 – miR-24-2-5p, -212-3p, -124-3p; BCL6 – miR-34a-5p, -24-2-5p. The results of transfection of MCF7 cell line with miR-124-3p duplex strengthened hypothesis on direct or indirect interaction of this miRNA with BCL2 mRNA. Thus, systemic role of hypermethylation in deregulation of miRNAs and its targets was shown, and novel potential interactions of 5 miRNAs with CCND1, BCL2, and BCL6, being involved in cell cycle regulation, apoptosis, EMT and metastasis, were suggested, that could be useful as missing chains in signaling pathways and potential targets in complex BC therapy. This work was financially supported by the Russian Science Foundation grant 14-15-00654.