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Articles 1 - 30 of 84

Full-Text Articles in Cell Biology

Nanoparticle Delivery Of Mir-34a Eradicates Long-Term-Cultured Breast Cancer Stem Cells Via Targeting C22orf28 Directly, Xiaoti Lin, Weiyu Chen, Fengqin Wei, Binhua P. Zhou, Mien-Chie Hung, Xiaoming Xie Oct 2017

Nanoparticle Delivery Of Mir-34a Eradicates Long-Term-Cultured Breast Cancer Stem Cells Via Targeting C22orf28 Directly, Xiaoti Lin, Weiyu Chen, Fengqin Wei, Binhua P. Zhou, Mien-Chie Hung, Xiaoming Xie

Molecular and Cellular Biochemistry Faculty Publications

Rationale: Cancer stem cells (CSCs) have been implicated as the seeds of therapeutic resistance and metastasis, due to their unique abilities of self-renew, wide differentiation potentials and resistance to most conventional therapies. It is a proactive strategy for cancer therapy to eradicate CSCs. Methods: Tumor tissue-derived breast CSCs (BCSC), including XM322 and XM607, were isolated by fluorescence-activated cell sorting (FACS); while cell line-derived BCSC, including MDA-MB-231.SC and MCF-7.SC, were purified by magnetic-activated cell sorting (MACS). Analyses of microRNA and mRNA expression array profiles were performed in multiple breast cell lines. The mentioned nanoparticles were constructed following the standard ...


A Naturally Generated Decoy Of The Prostate Apoptosis Response-4 Protein Overcomes Therapy Resistance In Tumors, Nikhil Hebbar, Ravshan Burikhanov, Nidhi Shukla, Shirley Qiu, Yanming Zhao, Kojo S. J. Elenitoba-Johnson, Vivek M. Rangnekar Aug 2017

A Naturally Generated Decoy Of The Prostate Apoptosis Response-4 Protein Overcomes Therapy Resistance In Tumors, Nikhil Hebbar, Ravshan Burikhanov, Nidhi Shukla, Shirley Qiu, Yanming Zhao, Kojo S. J. Elenitoba-Johnson, Vivek M. Rangnekar

Radiation Medicine Faculty Publications

Primary tumors are often heterogeneous, composed of therapy-sensitive and emerging therapy-resistant cancer cells. Interestingly, treatment of therapy-sensitive tumors in heterogeneous tumor microenvironments results in apoptosis of therapy-resistant tumors. In this study, we identify a prostate apoptosis response-4 (Par-4) amino-terminal fragment (PAF) that is released by diverse therapy-sensitive cancer cells following therapy-induced caspase cleavage of the tumor suppressor Par-4 protein. PAF caused apoptosis in cancer cells resistant to therapy and inhibited tumor growth. A VASA segment of Par-4 mediated its binding and degradation by the ubiquitin ligase Fbxo45, resulting in loss of Par-4 proapoptotic function. Conversely, PAF, which contains this VASA ...


The Glia Response After Peripheral Nerve Injury: A Comparison Between Schwann Cells And Olfactory Ensheathing Cells And Their Uses For Neural Regenerative Therapies, Matthew J Barton, James St John, Alison Wright, Jenny Ekberg Jun 2017

The Glia Response After Peripheral Nerve Injury: A Comparison Between Schwann Cells And Olfactory Ensheathing Cells And Their Uses For Neural Regenerative Therapies, Matthew J Barton, James St John, Alison Wright, Jenny Ekberg

Jenny Ekberg

The peripheral nervous system (PNS) exhibits a much larger capacity for regeneration than the central nervous system (CNS). One reason for this difference is the difference in glial cell types between the two systems. PNS glia respond rapidly to nerve injury by clearing debris from the injury site, supplying essential growth factors and providing structural support; all of which enhances neuronal regeneration. Thus, transplantation of glial cells from the PNS is a very promising therapy for injuries to both the PNS and the CNS. There are two key types of PNS glia: olfactory ensheathing cells (OECs), which populate the olfactory ...


Paracrine Regulation Of Melanocyte Genomic Stability: A Focus On Nucleotide Excision Repair, Stuart Gordon Jarrett, Katharine Marie Carter, John August D'Orazio May 2017

Paracrine Regulation Of Melanocyte Genomic Stability: A Focus On Nucleotide Excision Repair, Stuart Gordon Jarrett, Katharine Marie Carter, John August D'Orazio

Markey Cancer Center Faculty Publications

UV radiation is a major environmental risk factor for the development of melanoma by causing DNA damage and mutations. Resistance to UV damage is largely determined by the capacity of melanocytes to respond to UV injury by repairing mutagenic photolesions. The nucleotide excision repair (NER) pathway is the major mechanism by which cells correct UV photodamage. This multistep process involves the basic steps of damage recognition, isolation, localized strand unwinding, assembly of a repair complex, excision of the damage‐containing strand 3′ and 5′ to the photolesion, synthesis of a sequence‐appropriate replacement strand, and finally ligation to restore continuity ...


Relb Expression Determines The Differential Effects Of Ascorbic Acid In Normal And Cancer Cells, Xiaowei Wei, Yong Xu, Fang Fang Xu, Luksana Chaiswing, David M. Schnell, Teresa Noel, Chi Wang, Jinfei Chen, Daret K. St. Clair, William H. St. Clair Mar 2017

Relb Expression Determines The Differential Effects Of Ascorbic Acid In Normal And Cancer Cells, Xiaowei Wei, Yong Xu, Fang Fang Xu, Luksana Chaiswing, David M. Schnell, Teresa Noel, Chi Wang, Jinfei Chen, Daret K. St. Clair, William H. St. Clair

Toxicology and Cancer Biology Faculty Publications

Cancer cells typically experience higher oxidative stress than normal cells, such that elevating pro-oxidant levels can trigger cancer cell death. Although pre-exposure to mild oxidative agents will sensitize cancer cells to radiation, this pre-exposure may also activate the adaptive stress defense system in normal cells. Ascorbic acid is a prototype redox modulator that when infused intravenously appears to kill cancers without injury to normal tissues; however, the mechanisms involved remain elusive. In this study, we show how ascorbic acid kills cancer cells and sensitizes prostate cancer to radiation therapy while also conferring protection upon normal prostate epithelial cells against radiation-induced ...


Crispr-Cas9 Mediated Nox4 Knockout Inhibits Cell Proliferation And Invasion In Hela Cells, Naser Jafari, Hyunju Kim, Rackhyun Park, Liqing Li, Minsu Jang, Andrew J. Morris, Junsoo Park, Cai Huang Jan 2017

Crispr-Cas9 Mediated Nox4 Knockout Inhibits Cell Proliferation And Invasion In Hela Cells, Naser Jafari, Hyunju Kim, Rackhyun Park, Liqing Li, Minsu Jang, Andrew J. Morris, Junsoo Park, Cai Huang

Markey Cancer Center Faculty Publications

Increased expression of NOX4 protein is associated with cancer progression and metastasis but the role of NOX4 in cell proliferation and invasion is not fully understood. We generated NOX4 knockout HeLa cell lines using the CRISPR-Cas9 gene editing system to explore the cellular functions of NOX4. After transfection of CRISPR-Cas9 construct, we performed T7 endonuclease 1 assays and DNA sequencing to generate and identify insertion and deletion of the NOX4 locus. We confirmed the knockout of NOX4 by Western blotting. NOX4 knockout cell lines showed reduced cell proliferation with an increase of sub-G1 cell population and the decrease of S ...


Analysis Of Rna Expression Of Normal And Cancer Tissues Reveals High Correlation Of Cop9 Gene Expression With Respiratory Chain Complex Components, Christina A. Wicker, Tadahide Izumi Dec 2016

Analysis Of Rna Expression Of Normal And Cancer Tissues Reveals High Correlation Of Cop9 Gene Expression With Respiratory Chain Complex Components, Christina A. Wicker, Tadahide Izumi

Toxicology and Cancer Biology Faculty Publications

BACKGROUND: The COP9 signalosome, composed of eight subunits, is implicated in cancer genetics with its deneddylase activity to modulate cellular concentration of oncogenic proteins such as IkB and TGFβ. However, its function in the normal cell physiology remains elusive. Primarily focusing on gene expression data of the normal tissues of the head and neck, the cancer genome atlas (TCGA) database was used to identify groups of genes that were expressed synergistically with the COP9 genes, particularly with the COPS5 (CSN5), which possesses the catalytic activity of COP9.

RESULTS: Expressions of seven of the COP9 genes (COPS2, COPS3, COPS4, COPS5, COPS6 ...


Pleckstrin Homology (Ph) Domain Leucine-Rich Repeat Protein Phosphatase Controls Cell Polarity By Negatively Regulating The Activity Of Atypical Protein Kinase C, Xiaopeng Xiong, Xin Li, Yang-An Wen, Tianyan Gao Oct 2016

Pleckstrin Homology (Ph) Domain Leucine-Rich Repeat Protein Phosphatase Controls Cell Polarity By Negatively Regulating The Activity Of Atypical Protein Kinase C, Xiaopeng Xiong, Xin Li, Yang-An Wen, Tianyan Gao

Markey Cancer Center Faculty Publications

The proper establishment of epithelial polarity allows cells to sense and respond to signals that arise from the microenvironment in a spatiotemporally controlled manner. Atypical PKCs (aPKCs) are implicated as key regulators of epithelial polarity. However, the molecular mechanism underlying the negative regulation of aPKCs remains largely unknown. In this study, we demonstrated that PH domain leucine-rich repeat protein phosphatase (PHLPP), a novel family of Ser/Thr protein phosphatases, plays an important role in regulating epithelial polarity by controlling the phosphorylation of both aPKC isoforms. Altered expression of PHLPP1 or PHLPP2 disrupted polarization of Caco2 cells grown in 3D cell ...


Expression And Function Of Pannexins In The Inner Ear And Hearing, Hong-Bo Zhao May 2016

Expression And Function Of Pannexins In The Inner Ear And Hearing, Hong-Bo Zhao

Otolaryngology--Head & Neck Surgery Faculty Publications

Pannexin (Panx) is a gene family encoding gap junction proteins in vertebrates. So far, three isoforms (Panx1, 2 and 3) have been identified. All of three Panx isoforms express in the cochlea with distinct expression patterns. Panx1 expresses in the cochlea extensively, including the spiral limbus, the organ of Corti, and the cochlear lateral wall, whereas Panx2 and Panx3 restrict to the basal cells of the stria vascularis in the lateral wall and the cochlear bony structure, respectively. However, there is no pannexin expression in auditory sensory hair cells. Recent studies demonstrated that like connexin gap junction gene, Panx1 deficiency ...


Ampa-Kainate Receptor Inhibition Promotes Neurologic Recovery In Premature Rabbits With Intraventricular Hemorrhage, Preeti Dohare, Muhammad T. Zia, Ehsan Ahmed, Asad Ahmed, Vivek Yadala, Praveen Ballabh Mar 2016

Ampa-Kainate Receptor Inhibition Promotes Neurologic Recovery In Premature Rabbits With Intraventricular Hemorrhage, Preeti Dohare, Muhammad T. Zia, Ehsan Ahmed, Asad Ahmed, Vivek Yadala, Praveen Ballabh

NYMC Faculty Publications

Intraventricular hemorrhage (IVH) in preterm infants leads to cerebral inflammation, reduced myelination of the white matter, and neurological deficits. No therapeutic strategy exists against the IVH-induced white matter injury. AMPA-kainate receptor induced excitotoxicity contributes to oligodendrocyte precursor cell (OPC) damage and hypomyelination in both neonatal and adult models of brain injury. Here, we hypothesized that IVH damages white matter via AMPA receptor activation, and that AMPA-kainate receptor inhibition suppresses inflammation and restores OPC maturation, myelination, and neurologic recovery in preterm newborns with IVH. We tested these hypotheses in a rabbit model of glycerol-induced IVH and evaluated the expression of AMPA ...


P-Rex1 Promotes Resistance To Vegf/Vegfr-Targeted Therapy In Prostate Cancer, Hira Lal Goel, Bryan Pursell, Leonard D. Shultz, Dale L. Greiner, Rolf A Brekken, Craig W. Vander Kooi, Arthur M. Mercurio Mar 2016

P-Rex1 Promotes Resistance To Vegf/Vegfr-Targeted Therapy In Prostate Cancer, Hira Lal Goel, Bryan Pursell, Leonard D. Shultz, Dale L. Greiner, Rolf A Brekken, Craig W. Vander Kooi, Arthur M. Mercurio

Molecular and Cellular Biochemistry Faculty Publications

Autocrine VEGF signaling is critical for sustaining prostate and other cancer stem cells (CSCs), and it is a potential therapeutic target, but we observed that CSCs isolated from prostate tumors are resistant to anti-VEGF (bevacizumab) and anti-VEGFR (sunitinib) therapy. Intriguingly, resistance is mediated by VEGF/neuropilin signaling, which is not inhibited by bevacizumab and sunitinib, and it involves the induction of P-Rex1, a Rac GEF, and consequent Rac1-mediated ERK activation. This induction of P-Rex1 is dependent on Myc. CSCs isolated from the PTENpc−/− transgenic model of prostate cancer exhibit Rac1-dependent resistance to bevacizumab. Rac1 inhibition or P-Rex1 downregulation increases ...


Global Regulator Of Virulence A (Grva) Coordinates Expression Of Discrete Pathogenic Mechanisms In Enterohemorrhagic Escherichia Coli Through Interactions With Gadw-Gade, Jason K. Morgan, Ronan K. Carroll, Carly M. Harro, Khoury W Vendura, Lindsey N. Shaw, James T. Riordan Feb 2016

Global Regulator Of Virulence A (Grva) Coordinates Expression Of Discrete Pathogenic Mechanisms In Enterohemorrhagic Escherichia Coli Through Interactions With Gadw-Gade, Jason K. Morgan, Ronan K. Carroll, Carly M. Harro, Khoury W Vendura, Lindsey N. Shaw, James T. Riordan

Cell Biology, Microbiology, and Molecular Biology Faculty Publications

UNLABELLED: Global regulator of virulence A (GrvA) is a ToxR-family transcriptional regulator that activates locus of enterocyte effacement (LEE)-dependent adherence in enterohemorrhagic Escherichia coli (EHEC). LEE activation by GrvA requires the Rcs phosphorelay response regulator RcsB and is sensitive to physiologically relevant concentrations of bicarbonate, a known stimulant of virulence systems in intestinal pathogens. This study determines the genomic scale of GrvA-dependent regulation and uncovers details of the molecular mechanism underlying GrvA-dependent regulation of pathogenic mechanisms in EHEC. In a grvA-null background of EHEC strain TW14359, RNA sequencing analysis revealed the altered expression of over 700 genes, including the ...


Identification Of Novel Cyclic Lipopeptides From A Positional Scanning Combinatorial Library With Enhanced Antibacterial And Antibiofilm Activities, Nina Bionda, Renee M. Fleeman, César De La Fuente-Núñez, Maria C. Rodriguez, Fany Reffuveille, Lindsey N. Shaw, Irena Pastar, Stephen C Davis, Robert E W Hancock, Predrag Cudic Jan 2016

Identification Of Novel Cyclic Lipopeptides From A Positional Scanning Combinatorial Library With Enhanced Antibacterial And Antibiofilm Activities, Nina Bionda, Renee M. Fleeman, César De La Fuente-Núñez, Maria C. Rodriguez, Fany Reffuveille, Lindsey N. Shaw, Irena Pastar, Stephen C Davis, Robert E W Hancock, Predrag Cudic

Cell Biology, Microbiology, and Molecular Biology Faculty Publications

Treating bacterial infections can be difficult due to innate or acquired resistance mechanisms, and the formation of biofilms. Cyclic lipopeptides derived from fusaricidin/LI-F natural products represent particularly attractive candidates for the development of new antibacterial and antibiofilm agents, with the potential to meet the challenge of bacterial resistance to antibiotics. A positional-scanning combinatorial approach was used to identify the amino acid residues responsible for driving antibacterial activity, and increase the potency of these cyclic lipopeptides. Screening against the antibiotic resistant ESKAPE pathogens revealed the importance of hydrophobic as well as positively charged amino acid residues for activity of this ...


Mir494 Reduces Renal Cancer Cell Survival Coinciding With Increased Lipid Droplets And Mitochondrial Changes, Punashi Dutta, Edward Haller, Arielle Sharp, Meera Nanjundan Jan 2016

Mir494 Reduces Renal Cancer Cell Survival Coinciding With Increased Lipid Droplets And Mitochondrial Changes, Punashi Dutta, Edward Haller, Arielle Sharp, Meera Nanjundan

Cell Biology, Microbiology, and Molecular Biology Faculty Publications

Background: miRNAs can regulate cellular survival in various cancer cell types. Recent evidence implicates the formation of lipid droplets as a hallmark event during apoptotic cell death response. It is presently unknown whether MIR494, located at 14q32 which is deleted in renal cancers, reduces cell survival in renal cancer cells and if this process is accompanied by changes in the number of lipid droplets.

Methods: 769-P renal carcinoma cells were utilized for this study. Control or MIR494 mimic was expressed in these cells following which cell viability (via crystal violet) and apoptotic cell numbers (via Annexin V/PI staining) were ...


Hyaluronidase And Hyaluronan Oligosaccharides Promote Neurological Recovery After Intraventricular Hemorrhage, Govindaiah Vinukonda, Preeti Dohare, Arslan Arshad, Muhammad T. Zia, Sanjeet Panda, Ritesh Korumilli, Praveen Ballabh Jan 2016

Hyaluronidase And Hyaluronan Oligosaccharides Promote Neurological Recovery After Intraventricular Hemorrhage, Govindaiah Vinukonda, Preeti Dohare, Arslan Arshad, Muhammad T. Zia, Sanjeet Panda, Ritesh Korumilli, Praveen Ballabh

NYMC Faculty Publications

Intraventricular hemorrhage (IVH) in premature infants results in inflammation, arrested oligodendrocyte progenitor cell (OPC) maturation, and reduced myelination of the white matter. Hyaluronan (HA) inhibits OPC maturation and complexes with the heavy chain (HC) of glycoprotein inter-α-inhibitor to form pathological HA (HC-HA complex), which exacerbates inflammation. Therefore, we hypothesized that IVH would result in accumulation of HA, and that either degradation of HA by hyaluronidase treatment or elimination of HCs from pathological HA by HA oligosaccharide administration would restore OPC maturation, myelination, and neurological function in survivors with IVH. To test these hypotheses, we used the preterm rabbit model of ...


Phlpp Negatively Regulates Cell Motility Through Inhibition Of Akt Activity And Integrin Expression In Pancreatic Cancer Cells, Alena J. Smith, Yang-An Wen, Payton D. Stevens, Jingpeng Liu, Chi Wang, Tianyan Gao Jan 2016

Phlpp Negatively Regulates Cell Motility Through Inhibition Of Akt Activity And Integrin Expression In Pancreatic Cancer Cells, Alena J. Smith, Yang-An Wen, Payton D. Stevens, Jingpeng Liu, Chi Wang, Tianyan Gao

Markey Cancer Center Faculty Publications

Pancreatic adenocarcinoma is currently the fourth leading cause for cancer-related mortality. Malignant progression of pancreatic cancer depends not only on rapid proliferation of tumor cells but also on increased cell motility. In this study, we showed that increased PHLPP expression significantly reduced the rate of migration in pancreatic ductal adenocarcinoma (PDAC) cells whereas knockdown of PHLPP had the opposite effect. In addition, cell motility at the individual cell level was negatively regulated by PHLPP as determined using time-lapse imaging. Interestingly, the expression of β1 and β4 integrin proteins were decreased in PHLPP overexpressing cells and increased in PHLPP knockdown cells ...


Age-Associated Methylation Suppresses Spry1, Leading To A Failure Of Re-Quiescence And Loss Of The Reserve Stem Cell Pool In Elderly Muscle., Anne Bigot, William J Duddy, Zamalou G Ouandaogo, Elisa Negroni, Virginie Mariot, Svetlana Ghimbovschi, Brennan Harmon, Aurore Wielgosik, Camille Loiseau, Joseph Devaney, Julie Dumonceaux, Gillian Butler-Browne, Vincent Mouly, Stéphanie Duguez Nov 2015

Age-Associated Methylation Suppresses Spry1, Leading To A Failure Of Re-Quiescence And Loss Of The Reserve Stem Cell Pool In Elderly Muscle., Anne Bigot, William J Duddy, Zamalou G Ouandaogo, Elisa Negroni, Virginie Mariot, Svetlana Ghimbovschi, Brennan Harmon, Aurore Wielgosik, Camille Loiseau, Joseph Devaney, Julie Dumonceaux, Gillian Butler-Browne, Vincent Mouly, Stéphanie Duguez

Genomics and Precision Medicine Faculty Publications

The molecular mechanisms by which aging affects stem cell number and function are poorly understood. Murine data have implicated cellular senescence in the loss of muscle stem cells with aging. Here, using human cells and by carrying out experiments within a strictly pre-senescent division count, we demonstrate an impaired capacity for stem cell self-renewal in elderly muscle. We link aging to an increased methylation of the SPRY1 gene, a known regulator of muscle stem cell quiescence. Replenishment of the reserve cell pool was modulated experimentally by demethylation or siRNA knockdown of SPRY1. We propose that suppression of SPRY1 by age-associated ...


A Mitochondria-Anchored Isoform Of The Actin-Nucleating Spire Protein Regulates Mitochondrial Division, Uri Manor, Sadie Bartholomew, Gonen Golani, Eric Christenson, Michael Kozlov, Henry Higgs, James Spudich, Jennifer Lippincott-Schwartz Aug 2015

A Mitochondria-Anchored Isoform Of The Actin-Nucleating Spire Protein Regulates Mitochondrial Division, Uri Manor, Sadie Bartholomew, Gonen Golani, Eric Christenson, Michael Kozlov, Henry Higgs, James Spudich, Jennifer Lippincott-Schwartz

Open Dartmouth: Faculty Open Access Scholarship

Mitochondrial division, essential for survival in mammals, is enhanced by an inter-organellar process involving ER tubules encircling and constricting mitochondria. The force for constriction is thought to involve actin polymerization by the ER-anchored isoform of the formin protein inverted formin 2 (INF2). Unknown is the mechanism triggering INF2-mediated actin polymerization at ER-mitochondria intersections. We show that a novel isoform of the formin-binding, actin-nucleating protein Spire, Spire1C, localizes to mitochondria and directly links mitochondria to the actin cytoskeleton and the ER. Spire1C binds INF2 and promotes actin assembly on mitochondrial surfaces. Disrupting either Spire1C actin- or formin-binding activities reduces mitochondrial constriction ...


A Laminin 511 Matrix Is Regulated By Taz And Functions As The Ligand For The Alpha6bbeta1 Integrin To Sustain Breast Cancer Stem Cells, Cheng Chang, Hira Lal Goel, Huijie Gao, Bryan M. Pursell, Leonard D. Shultz, Dale L. Greiner, Sulev Ingerpuu, Manuel Patarroyo, Shiliang Cao, Elgene Lim, Junhao Mao, Karen Kulju. Mckee, Peter D. Yurchenco, Arthur M. Mercurio May 2015

A Laminin 511 Matrix Is Regulated By Taz And Functions As The Ligand For The Alpha6bbeta1 Integrin To Sustain Breast Cancer Stem Cells, Cheng Chang, Hira Lal Goel, Huijie Gao, Bryan M. Pursell, Leonard D. Shultz, Dale L. Greiner, Sulev Ingerpuu, Manuel Patarroyo, Shiliang Cao, Elgene Lim, Junhao Mao, Karen Kulju. Mckee, Peter D. Yurchenco, Arthur M. Mercurio

Arthur M. Mercurio

Understanding how the extracellular matrix impacts the function of cancer stem cells (CSCs) is a significant but poorly understood problem. We report that breast CSCs produce a laminin (LM) 511 matrix that promotes self-renewal and tumor initiation by engaging the alpha6Bbeta1 integrin and activating the Hippo transducer TAZ. Although TAZ is important for the function of breast CSCs, the mechanism is unknown. We observed that TAZ regulates the transcription of the alpha5 subunit of LM511 and the formation of a LM511 matrix. These data establish a positive feedback loop involving TAZ and LM511 that contributes to stemness in breast cancer.


Nuclear Transport Of Single Molecules: Dwell Times At The Nuclear Pore Complex, Ulrich Kubitscheck, David Grunwald, Andreas Hoekstra, Daniel Rohleder, Thorsten Kues, Jan Peter Siebrasse, Reiner Peters Nov 2014

Nuclear Transport Of Single Molecules: Dwell Times At The Nuclear Pore Complex, Ulrich Kubitscheck, David Grunwald, Andreas Hoekstra, Daniel Rohleder, Thorsten Kues, Jan Peter Siebrasse, Reiner Peters

David Grünwald

The mechanism by which macromolecules are selectively translocated through the nuclear pore complex (NPC) is still essentially unresolved. Single molecule methods can provide unique information on topographic properties and kinetic processes of asynchronous supramolecular assemblies with excellent spatial and time resolution. Here, single-molecule far-field fluorescence microscopy was applied to the NPC of permeabilized cells. The nucleoporin Nup358 could be localized at a distance of 70 nm from POM121-GFP along the NPC axis. Binding sites of NTF2, the transport receptor of RanGDP, were observed in cytoplasmic filaments and central framework, but not nucleoplasmic filaments of the NPC. The dwell times of ...


Intranuclear Binding Kinetics And Mobility Of Single Native U1 Snrnp Particles In Living Cells, David Grunwald, Beatrice Spottke, Volker Buschmann, Ulrich Kubitscheck Nov 2014

Intranuclear Binding Kinetics And Mobility Of Single Native U1 Snrnp Particles In Living Cells, David Grunwald, Beatrice Spottke, Volker Buschmann, Ulrich Kubitscheck

David Grünwald

Uridine-rich small nuclear ribonucleoproteins (U snRNPs) are splicing factors, which are diffusely distributed in the nucleoplasm and also concentrated in nuclear speckles. Fluorescently labeled, native U1 snRNPs were microinjected into the cytoplasm of living HeLa cells. After nuclear import single U1 snRNPs could be visualized and tracked at a spatial precision of 30 nm at a frame rate of 200 Hz employing a custom-built microscope with single-molecule sensitivity. The single-particle tracks revealed that most U1 snRNPs were bound to specific intranuclear sites, many of those presumably representing pre-mRNA splicing sites. The dissociation kinetics from these sites showed a multiexponential decay ...


Autonomy And Robustness Of Translocation Through The Nuclear Pore Complex: A Single-Molecule Study, Thomas Dange, David Grunwald, Antje Grunwald, Reiner Peters, Ulrich Kubitscheck Nov 2014

Autonomy And Robustness Of Translocation Through The Nuclear Pore Complex: A Single-Molecule Study, Thomas Dange, David Grunwald, Antje Grunwald, Reiner Peters, Ulrich Kubitscheck

David Grünwald

All molecular traffic between nucleus and cytoplasm occurs via the nuclear pore complex (NPC) within the nuclear envelope. In this study we analyzed the interactions of the nuclear transport receptors kapalpha2, kapbeta1, kapbeta1DeltaN44, and kapbeta2, and the model transport substrate, BSA-NLS, with NPCs to determine binding sites and kinetics using single-molecule microscopy in living cells. Recombinant transport receptors and BSA-NLS were fluorescently labeled by AlexaFluor 488, and microinjected into the cytoplasm of living HeLa cells expressing POM121-GFP as a nuclear pore marker. After bleaching the dominant GFP fluorescence the interactions of the microinjected molecules could be studied using video microscopy ...


Nuclear Pore Component Nup98 Is A Potential Tumor Suppressor And Regulates Posttranscriptional Expression Of Select P53 Target Genes, Stephan Singer, Ruiying Zhao, Anthony M. Barsotti, Anette Ouwehand, Mina Fazollahi, Elias Coutavas, Kai Breuhahn, Olaf Neumann, Thomas Longerich, Tobias Pusterla, Maureen A. Powers, Keith M. Giles, Peter J. Leedman, Jochen Hess, David Grunwald, Harmen J. Bussemaker, Robert H. Singer, Peter Schirmacher, Carol Prives Nov 2014

Nuclear Pore Component Nup98 Is A Potential Tumor Suppressor And Regulates Posttranscriptional Expression Of Select P53 Target Genes, Stephan Singer, Ruiying Zhao, Anthony M. Barsotti, Anette Ouwehand, Mina Fazollahi, Elias Coutavas, Kai Breuhahn, Olaf Neumann, Thomas Longerich, Tobias Pusterla, Maureen A. Powers, Keith M. Giles, Peter J. Leedman, Jochen Hess, David Grunwald, Harmen J. Bussemaker, Robert H. Singer, Peter Schirmacher, Carol Prives

David Grünwald

The p53 tumor suppressor utilizes multiple mechanisms to selectively regulate its myriad target genes, which in turn mediate diverse cellular processes. Here, using conventional and single-molecule mRNA analyses, we demonstrate that the nucleoporin Nup98 is required for full expression of p21, a key effector of the p53 pathway, but not several other p53 target genes. Nup98 regulates p21 mRNA levels by a posttranscriptional mechanism in which a complex containing Nup98 and the p21 mRNA 3'UTR protects p21 mRNA from degradation by the exosome. An in silico approach revealed another p53 target (14-3-3sigma) to be similarly regulated by Nup98. The ...


Id2 Complexes With The Snag Domain Of Snai1 Inhibiting Snai1-Mediated Repression Of Integrin Beta4, Cheng Chang, Xiaofang Yang, Bryan Pursell, Arthur M. Mercurio Nov 2014

Id2 Complexes With The Snag Domain Of Snai1 Inhibiting Snai1-Mediated Repression Of Integrin Beta4, Cheng Chang, Xiaofang Yang, Bryan Pursell, Arthur M. Mercurio

Arthur M. Mercurio

The epithelial-mesenchymal transition (EMT) is a fundamental process that underlies development and cancer. Although the EMT involves alterations in the expression of specific integrins that mediate stable adhesion to the basement membrane, such as alpha6beta4, the mechanisms involved are poorly understood. Here, we report that Snai1 inhibits beta4 transcription by increasing repressive histone modification (trimethylation of histone H3 at K27 [H3K27Me3]). Surprisingly, Snai1 is expressed and localized in the nucleus in epithelial cells, but it does not repress beta4. We resolved this paradox by discovering that Id2 complexes with the SNAG domain of Snai1 on the beta4 promoter and constrains ...


Serum Dioxins And Polychlorinated Biphenyls Are Associated With Growth Among Russian Boys, Jane Burns, Paige Williams, Oleg Sergeyev, Susan Korrick, Mary Lee, Boris Revich, Larisa Altshul, Julie Del Prato, Olivier Humblet, Donald Patterson, Wayman Turner, Larry Needham, Mikhail Starovoytov, Russ Hauser Sep 2014

Serum Dioxins And Polychlorinated Biphenyls Are Associated With Growth Among Russian Boys, Jane Burns, Paige Williams, Oleg Sergeyev, Susan Korrick, Mary Lee, Boris Revich, Larisa Altshul, Julie Del Prato, Olivier Humblet, Donald Patterson, Wayman Turner, Larry Needham, Mikhail Starovoytov, Russ Hauser

Mary M. Lee

OBJECTIVE: We evaluated the associations of serum dioxins and polychlorinated biphenyls (PCBs) with longitudinally assessed growth measurements among peripubertal Russian boys.

METHODS: A total of 499 boys from Chapaevsk, Russia, aged 8 to 9 years were enrolled in the study from 2003 to 2005 and were followed prospectively for 3 years. Blood samples were collected and physical examinations were conducted at entry and repeated at annual study visits. Multivariate mixed-effects regression models for repeated measures were used to examine the associations of serum dioxins and PCBs with longitudinal measurements of BMI, height, and height velocity.

RESULTS: Serum dioxin (total 2005 ...


Measurement Of Mullerian Inhibiting Substance Facilitates Management Of Boys With Microphallus And Cryptorchidism, Madhusmita Misra, David Maclaughlin, Patricia Donahoe, Mary Lee Sep 2014

Measurement Of Mullerian Inhibiting Substance Facilitates Management Of Boys With Microphallus And Cryptorchidism, Madhusmita Misra, David Maclaughlin, Patricia Donahoe, Mary Lee

Mary M. Lee

Mullerian inhibiting substance (MIS) is a gonadal hormone expressed in a sexually dimorphic pattern. In males, serum MIS reflects Sertoli cell function and provides an estimate of seminiferous tubular integrity. We examined the role of MIS determination in the evaluation of boys with microphallus (n = 62) and/or cryptorchidism (n = 156). MIS was normal in 69.2% of boys with isolated microphallus compared with 38.1% of boys with microphallus and coexisting cryptorchidism (P < 0.05). In the cryptorchid group, MIS was normal in 46.8%, low in 24.4%, and absent in 28.8%. Normal values for age were ...


Augmented Growth Hormone (Gh) Secretory Burst Frequency And Amplitude Mediate Enhanced Gh Secretion During A Two-Day Fast In Normal Men, Mark Hartman, Johannes Veldhuis, Michael Johnson, Mary Lee, K. Alberti, Eugene Samojlik, Michael Thorner Sep 2014

Augmented Growth Hormone (Gh) Secretory Burst Frequency And Amplitude Mediate Enhanced Gh Secretion During A Two-Day Fast In Normal Men, Mark Hartman, Johannes Veldhuis, Michael Johnson, Mary Lee, K. Alberti, Eugene Samojlik, Michael Thorner

Mary M. Lee

Serum GH concentrations are increased in fasted or malnourished human subjects. We investigated the dynamic mechanisms underlying this phenomenon in nine normal men by analyzing serum GH concentrations measured in blood obtained at 5-min intervals over 24 h on a control (fed) day and on the second day of a fast with a multiple-parameter deconvolution method to simultaneously resolve endogenous GH secretory and clearance rates. Two days of fasting induced a 5-fold increase in the 24-h endogenous GH production rate [78 +/- 12 vs. 371 +/- 57 micrograms/Lv (Lv, liter of distribution volume) or 0.24 +/- 0.038 vs. 1.1 ...


Temporal Trends In Serum Concentrations Of Polychlorinated Dioxins, Furans, And Pcbs Among Adult Women Living In Chapaevsk, Russia: A Longitudinal Study From 2000 To 2009, Olivier Humblet, Oleg Sergeyev, Larisa Altshul, Susan A. Korrick, Paige L. Williams, Claude Emond, Linda S. Birnbaum, Jane S. Burns, Mary M. Lee, Boris Revich, Andrey Shelepchikov, Denis Feshin, Russ Hauser Sep 2014

Temporal Trends In Serum Concentrations Of Polychlorinated Dioxins, Furans, And Pcbs Among Adult Women Living In Chapaevsk, Russia: A Longitudinal Study From 2000 To 2009, Olivier Humblet, Oleg Sergeyev, Larisa Altshul, Susan A. Korrick, Paige L. Williams, Claude Emond, Linda S. Birnbaum, Jane S. Burns, Mary M. Lee, Boris Revich, Andrey Shelepchikov, Denis Feshin, Russ Hauser

Mary M. Lee

BACKGROUND: The present study assessed the temporal trend in serum concentrations of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls (PCBs) among residents of a Russian town where levels of these chemicals are elevated due to prior industrial activity.

METHODS: Two serum samples were collected from eight adult women (in 2000 and 2009), and analyzed with gas chromatography-high-resolution mass spectrometry.

RESULTS: The average total toxic equivalency (TEQ) decreased by 30% (from 36 to 25 pg/g lipid), and the average sum of PCB congeners decreased by 19% (from 291 to 211 ng/g lipid). Total TEQs decreased for seven of the eight women ...


Transient Hyperthyroidism In An Adolescent With Hydatidiform Mole, Madhusmita Misra, Lynne Levitsky, Mary Lee Sep 2014

Transient Hyperthyroidism In An Adolescent With Hydatidiform Mole, Madhusmita Misra, Lynne Levitsky, Mary Lee

Mary M. Lee

No abstract provided.


Mullerian Inhibiting Substance In Humans: Normal Levels From Infancy To Adulthood, Mary Lee, Patricia Donahoe, Tomonobu Hasegawa, Bernard Silverman, Gretchen Crist, Sharon Best, Yukihiro Hasegawa, Richard Noto, David Schoenfeld, David Maclaughlin Sep 2014

Mullerian Inhibiting Substance In Humans: Normal Levels From Infancy To Adulthood, Mary Lee, Patricia Donahoe, Tomonobu Hasegawa, Bernard Silverman, Gretchen Crist, Sharon Best, Yukihiro Hasegawa, Richard Noto, David Schoenfeld, David Maclaughlin

Mary M. Lee

Mullerian-inhibiting substance (MIS) is a gonadal hormone synthesized by Sertoli cells of the testis and granulosa cells of the ovary. To facilitate the use of MIS for the evaluation of intersex disorders and as a tumor marker in women with MIS-expressing ovarian tumors, we measured MIS in 600 serum samples from males and females. These data show that mean MIS values for males rise rapidly during the first year of life and are highest during late infancy, then gradually decline until puberty. In contrast, MIS values in females are lowest at birth and exhibit a minimal increase throughout the prepubertal ...