30 results on '"PIWNICA A"'
Search Results
2. A fluorescence-coupled assay for gamma aminobutyric acid (GABA) reveals metabolic stress-induced modulation of GABA content in neuroendocrine cancer.
- Author
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Joseph E Ippolito and David Piwnica-Worms
- Subjects
Medicine ,Science - Abstract
Pathways involved in the synthesis of the neurotransmitter gamma-aminobutyric acid (GABA) have been implicated in the pathogenesis of high grade neuroendocrine (NE) neoplasms as well as neoplasms from a non-NE lineage. Using The Cancer Genome Atlas, overexpression of the GABA synthetic enzyme, glutamate decarboxylase 1 (GAD1), was found to be associated with decreased disease free-survival in prostate adenocarcinoma and decreased overall survival in clear cell renal cell carcinomas. Furthermore, GAD1 was found to be expressed in castrate-resistant prostate cancer cell lines, but not androgen-responsive cell lines. Using a novel fluorescence-coupled enzymatic microplate assay for GABA mediated through reduction of resazurin in a prostate neuroendocrine carcinoma (PNEC) cell line, acid microenvironment-induced stress increased GABA levels while alkaline microenvironment-induced stress decreased GABA through modulation of GAD1 and glutamine synthetase (GLUL) activities. Moreover, glutamine but not glucose deprivation decreased GABA through modulation of GLUL. Consistent with evidence in prokaryotic and eukaryotic organisms that GABA synthesis mediated through GAD1 may play a crucial role in surviving stress, GABA may be an important mediator of stress survival in neoplasms. These findings identify GABA synthesis and metabolism as a potentially important pathway for regulating cancer cell stress response as well as a potential target for therapeutic strategies.
- Published
- 2014
- Full Text
- View/download PDF
3. PDE7B is a novel, prognostically significant mediator of glioblastoma growth whose expression is regulated by endothelial cells.
- Author
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Michael D Brooks, Erin Jackson, Nicole M Warrington, Jingqin Luo, Jason T Forys, Sara Taylor, Diane D Mao, Jeffrey R Leonard, Albert H Kim, David Piwnica-Worms, Robi D Mitra, and Joshua B Rubin
- Subjects
Medicine ,Science - Abstract
Cell-cell interactions between tumor cells and constituents of their microenvironment are critical determinants of tumor tissue biology and therapeutic responses. Interactions between glioblastoma (GBM) cells and endothelial cells (ECs) establish a purported cancer stem cell niche. We hypothesized that genes regulated by these interactions would be important, particularly as therapeutic targets. Using a computational approach, we deconvoluted expression data from a mixed physical co-culture of GBM cells and ECs and identified a previously undescribed upregulation of the cAMP specific phosphodiesterase PDE7B in GBM cells in response to direct contact with ECs. We further found that elevated PDE7B expression occurs in most GBM cases and has a negative effect on survival. PDE7B overexpression resulted in the expansion of a stem-like cell subpopulation in vitro and increased tumor growth and aggressiveness in an in vivo intracranial GBM model. Collectively these studies illustrate a novel approach for studying cell-cell interactions and identifying new therapeutic targets like PDE7B in GBM.
- Published
- 2014
- Full Text
- View/download PDF
4. Single-cell resolution imaging of retinal ganglion cell apoptosis in vivo using a cell-penetrating caspase-activatable peptide probe.
- Author
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Xudong Qiu, James R Johnson, Bradley S Wilson, Seth T Gammon, David Piwnica-Worms, and Edward M Barnett
- Subjects
Medicine ,Science - Abstract
Peptide probes for imaging retinal ganglion cell (RGC) apoptosis consist of a cell-penetrating peptide targeting moiety and a fluorophore-quencher pair flanking an effector caspase consensus sequence. Using ex vivo fluorescence imaging, we previously validated the capacity of these probes to identify apoptotic RGCs in cell culture and in an in vivo rat model of N-methyl- D-aspartate (NMDA)-induced neurotoxicity. Herein, using TcapQ488, a new probe designed and synthesized for compatibility with clinically-relevant imaging instruments, and real time imaging of a live rat RGC degeneration model, we fully characterized time- and dose-dependent probe activation, signal-to-noise ratios, and probe safety profiles in vivo. Adult rats received intravitreal injections of four NMDA concentrations followed by varying TcapQ488 doses. Fluorescence fundus imaging was performed sequentially in vivo using a confocal scanning laser ophthalmoscope and individual RGCs displaying activated probe were counted and analyzed. Rats also underwent electroretinography following intravitreal injection of probe. In vivo fluorescence fundus imaging revealed distinct single-cell probe activation as an indicator of RGC apoptosis induced by intravitreal NMDA injection that corresponded to the identical cells observed in retinal flat mounts of the same eye. Peak activation of probe in vivo was detected 12 hours post probe injection. Detectable fluorescent RGCs increased with increasing NMDA concentration; sensitivity of detection generally increased with increasing TcapQ488 dose until saturating at 0.387 nmol. Electroretinography following intravitreal injections of TcapQ488 showed no significant difference compared with control injections. We optimized the signal-to-noise ratio of a caspase-activatable cell penetrating peptide probe for quantitative non-invasive detection of RGC apoptosis in vivo. Full characterization of probe performance in this setting creates an important in vivo imaging standard for functional evaluation of future probe analogues and provides a basis for extending this strategy into glaucoma-specific animal models.
- Published
- 2014
- Full Text
- View/download PDF
5. F11R is a novel monocyte prognostic biomarker for malignant glioma.
- Author
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Winnie W Pong, Jason Walker, Todd Wylie, Vincent Magrini, Jingqin Luo, Ryan J Emnett, Jaebok Choi, Matthew L Cooper, Malachi Griffith, Obi L Griffith, Joshua B Rubin, Gregory N Fuller, David Piwnica-Worms, Xi Feng, Dolores Hambardzumyan, John F DiPersio, Elaine R Mardis, and David H Gutmann
- Subjects
Medicine ,Science - Abstract
Brain tumors (gliomas) contain large populations of infiltrating macrophages and recruited microglia, which in experimental murine glioma models promote tumor formation and progression. Among the barriers to understanding the contributions of these stromal elements to high-grade glioma (glioblastoma; GBM) biology is the relative paucity of tools to characterize infiltrating macrophages and resident microglia. In this study, we leveraged multiple RNA analysis platforms to identify new monocyte markers relevant to GBM patient outcome.High-confidence lists of mouse resident microglia- and bone marrow-derived macrophage-specific transcripts were generated using converging RNA-seq and microarray technologies and validated using qRT-PCR and flow cytometry. Expression of select cell surface markers was analyzed in brain-infiltrating macrophages and resident microglia in an induced GBM mouse model, while allogeneic bone marrow transplantation was performed to trace the origins of infiltrating and resident macrophages. Glioma tissue microarrays were examined by immunohistochemistry, and the Gene Expression Omnibus (GEO) database was queried to determine the prognostic value of identified microglia biomarkers in human GBM.We generated a unique catalog of differentially-expressed bone marrow-derived monocyte and resident microglia transcripts, and demonstrated that brain-infiltrating macrophages acquire F11R expression in GBM and following bone-marrow transplantation. Moreover, mononuclear cell F11R expression positively correlates with human high-grade glioma and additionally serves as a biomarker for GBM patient survival, regardless of GBM molecular subtype.These studies establish F11R as a novel monocyte prognostic marker for GBM critical for defining a subpopulation of stromal cells for future potential therapeutic intervention.
- Published
- 2013
- Full Text
- View/download PDF
6. CXCL12 mediates trophic interactions between endothelial and tumor cells in glioblastoma.
- Author
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Shyam Rao, Rajarshi Sengupta, Eun Joo Choe, B Mark Woerner, Erin Jackson, Tao Sun, Jeffrey Leonard, David Piwnica-Worms, and Joshua B Rubin
- Subjects
Medicine ,Science - Abstract
Emerging evidence suggests endothelial cells (EC) play a critical role in promoting Glioblastoma multiforme (GBM) cell proliferation and resistance to therapy. The molecular basis for GBM-EC interactions is incompletely understood. We hypothesized that the chemokine CXCL12 and its receptor CXCR4 could mediate direct interactions between GBM cells and tumor-associated endothelial cells and that disruption of this interaction might be the molecular basis for the anti-tumor effects of CXCR4 antagonists. We investigated this possibility in vivo and in an in vitro co-culture model that incorporated extracellular matrix, primary human brain microvascular ECs (HBMECs) and either an established GBM cell line or primary GBM specimens. Depletion of CXCR4 in U87 GBM cells blocked their growth as intracranial xenografts indicating that tumor cell CXCR4 is required for tumor growth in vivo. In vitro, co-culture of either U87 cells or primary GBM cells with HBMECs resulted in their co-localization and enhanced GBM cell growth. Genetic manipulation of CXCL12 expression and pharmacological inhibition of its receptors CXCR4 and CXCR7 revealed that the localizing and trophic effects of endothelial cells on GBM cells were dependent upon CXCL12 and CXCR4. These findings indicate that the CXCL12/CXCR4 pathway directly mediates endothelial cell trophic function in GBMs and that inhibition of CXCL12-CXCR4 signaling may uniquely target this activity. Therapeutic disruption of endothelial cell trophic functions could complement the structural disruption of anti-angiogenic regimens and, in combination, might also improve the efficacy of radiation and chemotherapy in treating GBMs.
- Published
- 2012
- Full Text
- View/download PDF
7. Contributions made by CDC25 phosphatases to proliferation of intestinal epithelial stem and progenitor cells.
- Author
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Gwanghee Lee, Sofia Origanti, Lynn S White, Jinwu Sun, Thaddeus S Stappenbeck, and Helen Piwnica-Worms
- Subjects
Medicine ,Science - Abstract
The CDC25 protein phosphatases drive cell cycle advancement by activating cyclin-dependent protein kinases (CDKs). Humans and mice encode three family members denoted CDC25A, -B and -C and genes encoding these family members can be disrupted individually with minimal phenotypic consequences in adult mice. However, adult mice globally deleted for all three phosphatases die within one week after Cdc25 disruption. A severe loss of absorptive villi due to a failure of crypt epithelial cells to proliferate was observed in the small intestines of these mice. Because the Cdc25s were globally deleted, the small intestinal phenotype and loss of animal viability could not be solely attributed to an intrinsic defect in the inability of small intestinal stem and progenitor cells to divide. Here, we report the consequences of deleting different combinations of Cdc25s specifically in intestinal epithelial cells. The phenotypes arising in these mice were then compared with those arising in mice globally deleted for the Cdc25s and in mice treated with irinotecan, a chemotherapeutic agent commonly used to treat colorectal cancer. We report that the phenotypes arising in mice globally deleted for the Cdc25s are due to the failure of small intestinal stem and progenitor cells to proliferate and that blocking cell division by inhibiting the cell cycle engine (through Cdc25 loss) versus by inducing DNA damage (via irinotecan) provokes a markedly different response of small intestinal epithelial cells. Finally, we demonstrate that CDC25A and CDC25B but not CDC25C compensate for each other to maintain the proliferative capacity of intestinal epithelial stem and progenitor cells.
- Published
- 2011
- Full Text
- View/download PDF
8. Bioluminescent imaging reveals divergent viral pathogenesis in two strains of Stat1-deficient mice, and in αßγ interferon receptor-deficient mice.
- Author
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Tracy Jo Pasieka, Lynne Collins, Megan A O'Connor, Yufei Chen, Zachary M Parker, Brent L Berwin, David R Piwnica-Worms, and David A Leib
- Subjects
Medicine ,Science - Abstract
Pivotal components of the IFN response to virus infection include the IFN receptors (IFNR), and the downstream factor signal transducer and activator of transcription 1 (Stat1). Mice deficient for Stat1 and IFNR (Stat1(-/-) and IFNαßγR(-/-) mice) lack responsiveness to IFN and exhibit high sensitivity to various pathogens. Here we examined herpes simplex virus type 1 (HSV-1) pathogenesis in Stat1(-/-) mice and in IFNαßγR(-/-) mice following corneal infection and bioluminescent imaging. Two divergent and paradoxical patterns of infection were observed. Mice with an N-terminal deletion in Stat1 (129Stat1(-/-) (N-term)) had transient infection of the liver and spleen, but succumbed to encephalitis by day 10 post-infection. In stark contrast, infection of IFNαßγR(-/-) mice was rapidly fatal, with associated viremia and fulminant infection of the liver and spleen, with infected infiltrating cells being primarily of the monocyte/macrophage lineage. To resolve the surprising difference between Stat1(-/-) and IFNαßγR(-/-) mice, we infected an additional Stat1(-/-) strain deleted in the DNA-binding domain (129Stat1(-/-) (DBD)). These 129Stat1(-/-) (DBD) mice recapitulated the lethal pattern of liver and spleen infection seen following infection of IFNαßγR(-/-) mice. This lethal pattern was also observed when 129Stat1(-/-) (N-term) mice were infected and treated with a Type I IFN-blocking antibody, and immune cells derived from 129Stat1(-/-) (N-term) mice were shown to be responsive to Type I IFN. These data therefore show significant differences in viral pathogenesis between two commonly-used Stat1(-/-) mouse strains. The data are consistent with the hypothesis that Stat1(-/-) (N-term) mice have residual Type I IFN receptor-dependent IFN responses. Complete loss of IFN signaling pathways allows viremia and rapid viral spread with a fatal infection of the liver. This study underscores the importance of careful comparisons between knockout mouse strains in viral pathogenesis, and may also be relevant to the causation of HSV hepatitis in humans, a rare but frequently fatal infection.
- Published
- 2011
- Full Text
- View/download PDF
9. The ARF tumor suppressor regulates bone remodeling and osteosarcoma development in mice.
- Author
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Daniel A Rauch, Michelle A Hurchla, John C Harding, Hongju Deng, Lauren K Shea, Mark C Eagleton, Stefan Niewiesk, Michael D Lairmore, David Piwnica-Worms, Thomas J Rosol, Jason D Weber, Lee Ratner, and Katherine N Weilbaecher
- Subjects
Medicine ,Science - Abstract
The ARF tumor suppressor regulates p53 as well as basic developmental processes independent of p53, including osteoclast activation, by controlling ribosomal biogenesis. Here we provide evidence that ARF is a master regulator of bone remodeling and osteosarcoma (OS) development in mice. Arf(-/-) mice displayed increased osteoblast (OB) and osteoclast (OC) activity with a significant net increase in trabecular bone volume. The long bones of Arf(-/-) mice had increased expression of OB genes while Arf(-/-) OB showed enhanced differentiation in vitro. Mice transgenic for the Tax oncogene develop lymphocytic tumors with associated osteolytic lesions, while Tax+Arf(-/-) mice uniformly developed spontaneous OS by 7 months of age. Tax+Arf(-/-) tumors were well differentiated OS characterized by an abundance of new bone with OC recruitment, expressed OB markers and displayed intact levels of p53 mRNA and reduced Rb transcript levels. Cell lines established from OS recapitulated characteristics of the primary tumor, including the expression of mature OB markers and ability to form mineralized tumors when transplanted. Loss of heterozygosity in OS tumors arising in Tax+Arf(+/-) mice emphasized the necessity of ARF-loss in OS development. Hypothesizing that inhibition of ARF-regulated bone remodeling would repress development of OS, we demonstrated that treatment of Tax+Arf(-/-) mice with zoledronic acid, a bisphosphonate inhibitor of OC activity and repressor of bone turnover, prevented or delayed the onset of OS. These data describe a novel role for ARF as a regulator of bone remodeling through effects on both OB and OC. Finally, these data underscore the potential of targeting bone remodeling as adjuvant therapy or in patients with genetic predispositions to prevent the development of OS.
- Published
- 2010
- Full Text
- View/download PDF
10. Cerenkov radiation energy transfer (CRET) imaging: a novel method for optical imaging of PET isotopes in biological systems.
- Author
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Robin S Dothager, Reece J Goiffon, Erin Jackson, Scott Harpstrite, and David Piwnica-Worms
- Subjects
Medicine ,Science - Abstract
Positron emission tomography (PET) allows sensitive, non-invasive analysis of the distribution of radiopharmaceutical tracers labeled with positron (β(+))-emitting radionuclides in small animals and humans. Upon β(+) decay, the initial velocity of high-energy β(+) particles can momentarily exceed the speed of light in tissue, producing Cerenkov radiation that is detectable by optical imaging, but is highly absorbed in living organisms.To improve optical imaging of Cerenkov radiation in biological systems, we demonstrate that Cerenkov radiation from decay of the PET isotopes (64)Cu and (18)F can be spectrally coupled by energy transfer to high Stokes-shift quantum nanoparticles (Qtracker705) to produce highly red-shifted photonic emissions. Efficient energy transfer was not detected with (99m)Tc, a predominantly γ-emitting isotope. Similar to bioluminescence resonance energy transfer (BRET) and fluorescence resonance energy transfer (FRET), herein we define the Cerenkov radiation energy transfer (CRET) ratio as the normalized quotient of light detected within a spectral window centered on the fluorophore emission divided by light detected within a spectral window of the Cerenkov radiation emission to quantify imaging signals. Optical images of solutions containing Qtracker705 nanoparticles and [(18)F]FDG showed CRET ratios in vitro as high as 8.8±1.1, while images of mice with subcutaneous pseudotumors impregnated with Qtracker705 following intravenous injection of [(18)F]FDG showed CRET ratios in vivo as high as 3.5±0.3.Quantitative CRET imaging may afford a variety of novel optical imaging applications and activation strategies for PET radiopharmaceuticals and other isotopes in biomaterials, tissues and live animals.
- Published
- 2010
- Full Text
- View/download PDF
11. Single-cell resolution imaging of retinal ganglion cell apoptosis in vivo using a cell-penetrating caspase-activatable peptide probe
- Author
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James R. Johnson, David Piwnica-Worms, Seth T. Gammon, Edward M. Barnett, Bradley Wilson, and Xudong Qiu
- Subjects
Retinal Ganglion Cells ,Fluorescence-lifetime imaging microscopy ,Image Processing ,lcsh:Medicine ,Apoptosis ,Toxicology ,0302 clinical medicine ,Engineering ,Molecular Cell Biology ,Fluorescein Angiography ,lcsh:Science ,Clinical Neurophysiology ,0303 health sciences ,Multidisciplinary ,Microscopy, Confocal ,medicine.diagnostic_test ,Cell Death ,Systems Biology ,Statistics ,Anatomy ,Animal Models ,medicine.anatomical_structure ,Retinal ganglion cell ,Caspases ,Medicine ,Single-Cell Analysis ,Molecular probe ,Preclinical imaging ,Research Article ,Biotechnology ,Neurotoxicology ,N-Methylaspartate ,Biology ,Biostatistics ,Fluorescence ,03 medical and health sciences ,Model Organisms ,In vivo ,Diagnostic Medicine ,medicine ,Electroretinography ,Animals ,Statistical Methods ,030304 developmental biology ,Retina ,lcsh:R ,Glaucoma ,Rats ,Ophthalmology ,Molecular Probes ,Signal Processing ,030221 ophthalmology & optometry ,Biophysics ,Rat ,lcsh:Q ,sense organs ,Ex vivo ,Mathematics - Abstract
Peptide probes for imaging retinal ganglion cell (RGC) apoptosis consist of a cell-penetrating peptide targeting moiety and a fluorophore-quencher pair flanking an effector caspase consensus sequence. Using ex vivo fluorescence imaging, we previously validated the capacity of these probes to identify apoptotic RGCs in cell culture and in an in vivo rat model of N-methyl- D-aspartate (NMDA)-induced neurotoxicity. Herein, using TcapQ488, a new probe designed and synthesized for compatibility with clinically-relevant imaging instruments, and real time imaging of a live rat RGC degeneration model, we fully characterized time- and dose-dependent probe activation, signal-to-noise ratios, and probe safety profiles in vivo. Adult rats received intravitreal injections of four NMDA concentrations followed by varying TcapQ488 doses. Fluorescence fundus imaging was performed sequentially in vivo using a confocal scanning laser ophthalmoscope and individual RGCs displaying activated probe were counted and analyzed. Rats also underwent electroretinography following intravitreal injection of probe. In vivo fluorescence fundus imaging revealed distinct single-cell probe activation as an indicator of RGC apoptosis induced by intravitreal NMDA injection that corresponded to the identical cells observed in retinal flat mounts of the same eye. Peak activation of probe in vivo was detected 12 hours post probe injection. Detectable fluorescent RGCs increased with increasing NMDA concentration; sensitivity of detection generally increased with increasing TcapQ488 dose until saturating at 0.387 nmol. Electroretinography following intravitreal injections of TcapQ488 showed no significant difference compared with control injections. We optimized the signal-to-noise ratio of a caspase-activatable cell penetrating peptide probe for quantitative non-invasive detection of RGC apoptosis in vivo. Full characterization of probe performance in this setting creates an important in vivo imaging standard for functional evaluation of future probe analogues and provides a basis for extending this strategy into glaucoma-specific animal models.
- Published
- 2014
12. CXCL12 mediates trophic interactions between endothelial and tumor cells in glioblastoma
- Author
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B. Mark Woerner, Shyam Rao, Eun Joo Choe, David Piwnica-Worms, Jeffrey R. Leonard, Rajarshi Sengupta, Joshua B. Rubin, Tao Sun, and Erin Jackson
- Subjects
Chemokine ,Anatomy and Physiology ,Cell Culture Techniques ,Fluorescent Antibody Technique ,lcsh:Medicine ,CXCR4 ,Polymerase Chain Reaction ,Extracellular matrix ,0302 clinical medicine ,Immune Physiology ,Molecular Cell Biology ,Basic Cancer Research ,U87 ,RNA, Small Interfering ,Receptor ,lcsh:Science ,Neurological Tumors ,0303 health sciences ,Multidisciplinary ,biology ,Brain ,Immunohistochemistry ,Endothelial stem cell ,Oncology ,030220 oncology & carcinogenesis ,Gene Knockdown Techniques ,Medicine ,Cellular Types ,Signal Transduction ,Research Article ,Receptors, CXCR4 ,Blotting, Western ,Immunology ,Enzyme-Linked Immunosorbent Assay ,03 medical and health sciences ,Cell Line, Tumor ,In Situ Nick-End Labeling ,Humans ,Biology ,030304 developmental biology ,DNA Primers ,Cell growth ,lcsh:R ,Endothelial Cells ,Cancers and Neoplasms ,Molecular Development ,Molecular biology ,Chemokine CXCL12 ,nervous system diseases ,Microscopy, Fluorescence ,Cell culture ,Immune System ,Microvessels ,Cancer research ,biology.protein ,Clinical Immunology ,lcsh:Q ,Glioblastoma ,Developmental Biology ,Neuroscience - Abstract
Emerging evidence suggests endothelial cells (EC) play a critical role in promoting Glioblastoma multiforme (GBM) cell proliferation and resistance to therapy. The molecular basis for GBM-EC interactions is incompletely understood. We hypothesized that the chemokine CXCL12 and its receptor CXCR4 could mediate direct interactions between GBM cells and tumor-associated endothelial cells and that disruption of this interaction might be the molecular basis for the anti-tumor effects of CXCR4 antagonists. We investigated this possibility in vivo and in an in vitro co-culture model that incorporated extracellular matrix, primary human brain microvascular ECs (HBMECs) and either an established GBM cell line or primary GBM specimens. Depletion of CXCR4 in U87 GBM cells blocked their growth as intracranial xenografts indicating that tumor cell CXCR4 is required for tumor growth in vivo. In vitro, co-culture of either U87 cells or primary GBM cells with HBMECs resulted in their co-localization and enhanced GBM cell growth. Genetic manipulation of CXCL12 expression and pharmacological inhibition of its receptors CXCR4 and CXCR7 revealed that the localizing and trophic effects of endothelial cells on GBM cells were dependent upon CXCL12 and CXCR4. These findings indicate that the CXCL12/CXCR4 pathway directly mediates endothelial cell trophic function in GBMs and that inhibition of CXCL12-CXCR4 signaling may uniquely target this activity. Therapeutic disruption of endothelial cell trophic functions could complement the structural disruption of anti-angiogenic regimens and, in combination, might also improve the efficacy of radiation and chemotherapy in treating GBMs.
- Published
- 2012
13. Bioluminescent Imaging Reveals Divergent Viral Pathogenesis in Two Strains of Stat1-Deficient Mice, and in αßγ Interferon Receptor-Deficient Mice
- Author
-
Brent Berwin, Tracy Jo Pasieka, Yufei Chen, Megan A. O'Connor, Lynne Collins, Zachary M. Parker, David A. Leib, and David Piwnica-Worms
- Subjects
Viral pathogenesis ,Immunology ,lcsh:Medicine ,Neuroinvasiveness ,Viremia ,Spleen ,Herpesvirus 1, Human ,Receptor, Interferon alpha-beta ,Microbiology ,Virus ,Pathogenesis ,03 medical and health sciences ,Mice ,Immune system ,Interferon ,Virology ,medicine ,Animals ,STAT1 ,lcsh:Science ,Biology ,Immunity to Infections ,030304 developmental biology ,Receptors, Interferon ,Mice, Knockout ,0303 health sciences ,Multidisciplinary ,biology ,030306 microbiology ,lcsh:R ,Immunity ,Herpes Simplex ,medicine.disease ,Innate Immunity ,3. Good health ,Animal Models of Infection ,medicine.anatomical_structure ,STAT1 Transcription Factor ,Liver ,Luminescent Measurements ,biology.protein ,Medicine ,lcsh:Q ,Clinical Immunology ,Viral Transmission and Infection ,medicine.drug ,Research Article - Abstract
Pivotal components of the IFN response to virus infection include the IFN receptors (IFNR), and the downstream factor signal transducer and activator of transcription 1 (Stat1). Mice deficient for Stat1 and IFNR (Stat1(-/-) and IFNαßγR(-/-) mice) lack responsiveness to IFN and exhibit high sensitivity to various pathogens. Here we examined herpes simplex virus type 1 (HSV-1) pathogenesis in Stat1(-/-) mice and in IFNαßγR(-/-) mice following corneal infection and bioluminescent imaging. Two divergent and paradoxical patterns of infection were observed. Mice with an N-terminal deletion in Stat1 (129Stat1(-/-) (N-term)) had transient infection of the liver and spleen, but succumbed to encephalitis by day 10 post-infection. In stark contrast, infection of IFNαßγR(-/-) mice was rapidly fatal, with associated viremia and fulminant infection of the liver and spleen, with infected infiltrating cells being primarily of the monocyte/macrophage lineage. To resolve the surprising difference between Stat1(-/-) and IFNαßγR(-/-) mice, we infected an additional Stat1(-/-) strain deleted in the DNA-binding domain (129Stat1(-/-) (DBD)). These 129Stat1(-/-) (DBD) mice recapitulated the lethal pattern of liver and spleen infection seen following infection of IFNαßγR(-/-) mice. This lethal pattern was also observed when 129Stat1(-/-) (N-term) mice were infected and treated with a Type I IFN-blocking antibody, and immune cells derived from 129Stat1(-/-) (N-term) mice were shown to be responsive to Type I IFN. These data therefore show significant differences in viral pathogenesis between two commonly-used Stat1(-/-) mouse strains. The data are consistent with the hypothesis that Stat1(-/-) (N-term) mice have residual Type I IFN receptor-dependent IFN responses. Complete loss of IFN signaling pathways allows viremia and rapid viral spread with a fatal infection of the liver. This study underscores the importance of careful comparisons between knockout mouse strains in viral pathogenesis, and may also be relevant to the causation of HSV hepatitis in humans, a rare but frequently fatal infection.
- Published
- 2011
14. A Generator-Produced Gallium-68 Radiopharmaceutical for PET Imaging of Myocardial Perfusion
- Author
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Sharma, Vijay, primary, Sivapackiam, Jothilingam, additional, Harpstrite, Scott E., additional, Prior, Julie L., additional, Gu, Hannah, additional, Rath, Nigam P., additional, and Piwnica-Worms, David, additional
- Published
- 2014
- Full Text
- View/download PDF
15. PDE7B Is a Novel, Prognostically Significant Mediator of Glioblastoma Growth Whose Expression Is Regulated by Endothelial Cells
- Author
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Brooks, Michael D., primary, Jackson, Erin, additional, Warrington, Nicole M., additional, Luo, Jingqin, additional, Forys, Jason T., additional, Taylor, Sara, additional, Mao, Diane D., additional, Leonard, Jeffrey R., additional, Kim, Albert H., additional, Piwnica-Worms, David, additional, Mitra, Robi D., additional, and Rubin, Joshua B., additional
- Published
- 2014
- Full Text
- View/download PDF
16. Single-Cell Resolution Imaging of Retinal Ganglion Cell Apoptosis In Vivo Using a Cell-Penetrating Caspase-Activatable Peptide Probe
- Author
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Qiu, Xudong, primary, Johnson, James R., additional, Wilson, Bradley S., additional, Gammon, Seth T., additional, Piwnica-Worms, David, additional, and Barnett, Edward M., additional
- Published
- 2014
- Full Text
- View/download PDF
17. A Fluorescence-Coupled Assay for Gamma Aminobutyric Acid (GABA) Reveals Metabolic Stress-Induced Modulation of GABA Content in Neuroendocrine Cancer
- Author
-
Ippolito, Joseph E., primary and Piwnica-Worms, David, additional
- Published
- 2014
- Full Text
- View/download PDF
18. PDE7B Is a Novel, Prognostically Significant Mediator of Glioblastoma Growth Whose Expression Is Regulated by Endothelial Cells
- Author
-
David Piwnica-Worms, Nicole M. Warrington, Michael D. Brooks, Jason T. Forys, Sara Taylor, Diane D. Mao, Joshua B. Rubin, Jeffrey R. Leonard, Robi D. Mitra, Erin Jackson, Jingqin Luo, and Albert H. Kim
- Subjects
Cell signaling ,Microarrays ,Angiogenesis ,Cell ,Mice, Nude ,lcsh:Medicine ,Cell Communication ,Astrocytoma ,Biology ,Research and Analysis Methods ,Mice ,Downregulation and upregulation ,Cancer stem cell ,Cell Line, Tumor ,Basic Cancer Research ,Medicine and Health Sciences ,medicine ,Animals ,Humans ,Bioluminescence imaging ,Stem Cell Niche ,lcsh:Science ,Neurological Tumors ,Cells, Cultured ,Cyclic Nucleotide Phosphodiesterases, Type 7 ,Multidisciplinary ,lcsh:R ,Endothelial Cells ,Biology and Life Sciences ,Computational Biology ,Cancers and Neoplasms ,Glioma ,Coculture Techniques ,In vitro ,Cell biology ,Bioassays and Physiological Analysis ,medicine.anatomical_structure ,Neurology ,Oncology ,Cell culture ,Neoplastic Stem Cells ,lcsh:Q ,Glioblastoma ,Glioblastoma Multiforme ,Research Article - Abstract
Cell-cell interactions between tumor cells and constituents of their microenvironment are critical determinants of tumor tissue biology and therapeutic responses. Interactions between glioblastoma (GBM) cells and endothelial cells (ECs) establish a purported cancer stem cell niche. We hypothesized that genes regulated by these interactions would be important, particularly as therapeutic targets. Using a computational approach, we deconvoluted expression data from a mixed physical co-culture of GBM cells and ECs and identified a previously undescribed upregulation of the cAMP specific phosphodiesterase PDE7B in GBM cells in response to direct contact with ECs. We further found that elevated PDE7B expression occurs in most GBM cases and has a negative effect on survival. PDE7B overexpression resulted in the expansion of a stem-like cell subpopulation in vitro and increased tumor growth and aggressiveness in an in vivo intracranial GBM model. Collectively these studies illustrate a novel approach for studying cell-cell interactions and identifying new therapeutic targets like PDE7B in GBM.
- Published
- 2014
19. F11R Is a Novel Monocyte Prognostic Biomarker for Malignant Glioma
- Author
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Pong, Winnie W., primary, Walker, Jason, additional, Wylie, Todd, additional, Magrini, Vincent, additional, Luo, Jingqin, additional, Emnett, Ryan J., additional, Choi, Jaebok, additional, Cooper, Matthew L., additional, Griffith, Malachi, additional, Griffith, Obi L., additional, Rubin, Joshua B., additional, Fuller, Gregory N., additional, Piwnica-Worms, David, additional, Feng, Xi, additional, Hambardzumyan, Dolores, additional, DiPersio, John F., additional, Mardis, Elaine R., additional, and Gutmann, David H., additional
- Published
- 2013
- Full Text
- View/download PDF
20. F11R Is a Novel Monocyte Prognostic Biomarker for Malignant Glioma
- Author
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Gregory N. Fuller, Vincent Magrini, David H. Gutmann, Jaebok Choi, Obi L. Griffith, Matthew L. Cooper, Jingqin Luo, John F. DiPersio, Dolores Hambardzumyan, Todd Wylie, Xi Feng, David Piwnica-Worms, Winnie W. Pong, Joshua B. Rubin, Elaine R. Mardis, Jason Walker, Malachi Griffith, and Ryan J. Emnett
- Subjects
Male ,Pathology ,medicine.medical_specialty ,Stromal cell ,lcsh:Medicine ,Receptors, Cell Surface ,Biology ,Monocytes ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Glioma ,medicine ,Animals ,Cluster Analysis ,Humans ,lcsh:Science ,030304 developmental biology ,Mice, Knockout ,0303 health sciences ,Multidisciplinary ,Tissue microarray ,Microglia ,Cluster of differentiation ,Gene Expression Profiling ,Monocyte ,lcsh:R ,Prognosis ,medicine.disease ,nervous system diseases ,Gene Expression Regulation, Neoplastic ,Transplantation ,Gene expression profiling ,Disease Models, Animal ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,lcsh:Q ,Neoplasm Grading ,Cell Adhesion Molecules ,Biomarkers ,Research Article - Abstract
Objective: Brain tumors (gliomas) contain large populations of infiltrating macrophages and recruited microglia, which in experimental murine glioma models promote tumor formation and progression. Among the barriers to understanding the contributions of these stromal elements to high-grade glioma (glioblastoma; GBM) biology is the relative paucity of tools to characterize infiltrating macrophages and resident microglia. In this study, we leveraged multiple RNA analysis platforms to identify new monocyte markers relevant to GBM patient outcome. Methods: High-confidence lists of mouse resident microglia- and bone marrow-derived macrophage-specific transcripts were generated using converging RNA-seq and microarray technologies and validated using qRT-PCR and flow cytometry. Expression of select cell surface markers was analyzed in brain-infiltrating macrophages and resident microglia in an induced GBM mouse model, while allogeneic bone marrow transplantation was performed to trace the origins of infiltrating and resident macrophages. Glioma tissue microarrays were examined by immunohistochemistry, and the Gene Expression Omnibus (GEO) database was queried to determine the prognostic value of identified microglia biomarkers in human GBM. Results: We generated a unique catalog of differentially-expressed bone marrow-derived monocyte and resident microglia transcripts, and demonstrated that brain-infiltrating macrophages acquire F11R expression in GBM and following bone-marrow transplantation. Moreover, mononuclear cell F11R expression positively correlates with human high-grade glioma and additionally serves as a biomarker for GBM patient survival, regardless of GBM molecular subtype. Significance: These studies establish F11R as a novel monocyte prognostic marker for GBM critical for defining a subpopulation of stromal cells for future potential therapeutic intervention.
- Published
- 2013
21. CXCL12 Mediates Trophic Interactions between Endothelial and Tumor Cells in Glioblastoma
- Author
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Rao, Shyam, primary, Sengupta, Rajarshi, additional, Choe, Eun Joo, additional, Woerner, B. Mark, additional, Jackson, Erin, additional, Sun, Tao, additional, Leonard, Jeffrey, additional, Piwnica-Worms, David, additional, and Rubin, Joshua B., additional
- Published
- 2012
- Full Text
- View/download PDF
22. Bioluminescent Imaging Reveals Divergent Viral Pathogenesis in Two Strains of Stat1-Deficient Mice, and in αßγ Interferon Receptor-Deficient Mice
- Author
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Pasieka, Tracy Jo, primary, Collins, Lynne, additional, O'Connor, Megan A., additional, Chen, Yufei, additional, Parker, Zachary M., additional, Berwin, Brent L., additional, Piwnica-Worms, David R., additional, and Leib, David A., additional
- Published
- 2011
- Full Text
- View/download PDF
23. Contributions Made by CDC25 Phosphatases to Proliferation of Intestinal Epithelial Stem and Progenitor Cells
- Author
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Lee, Gwanghee, primary, Origanti, Sofia, additional, White, Lynn S., additional, Sun, Jinwu, additional, Stappenbeck, Thaddeus S., additional, and Piwnica-Worms, Helen, additional
- Published
- 2011
- Full Text
- View/download PDF
24. The ARF Tumor Suppressor Regulates Bone Remodeling and Osteosarcoma Development in Mice
- Author
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Rauch, Daniel A., primary, Hurchla, Michelle A., additional, Harding, John C., additional, Deng, Hongju, additional, Shea, Lauren K., additional, Eagleton, Mark C., additional, Niewiesk, Stefan, additional, Lairmore, Michael D., additional, Piwnica-Worms, David, additional, Rosol, Thomas J., additional, Weber, Jason D., additional, Ratner, Lee, additional, and Weilbaecher, Katherine N., additional
- Published
- 2010
- Full Text
- View/download PDF
25. Cerenkov Radiation Energy Transfer (CRET) Imaging: A Novel Method for Optical Imaging of PET Isotopes in Biological Systems
- Author
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Dothager, Robin S., primary, Goiffon, Reece J., additional, Jackson, Erin, additional, Harpstrite, Scott, additional, and Piwnica-Worms, David, additional
- Published
- 2010
- Full Text
- View/download PDF
26. Contributions Made by CDC25 Phosphatases to Proliferation of Intestinal Epithelial Stem and Progenitor Cells
- Author
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Jinwu Sun, Sofia Origanti, Lynn S. White, Gwanghee Lee, Thaddeus S. Stappenbeck, and Helen Piwnica-Worms
- Subjects
CDC25A ,Anatomy and Physiology ,Mouse ,Cell division ,Cdc25 ,lcsh:Medicine ,Mice ,03 medical and health sciences ,Model Organisms ,0302 clinical medicine ,Cyclin-dependent kinase ,Molecular Cell Biology ,Intestine, Small ,Genetics ,Homeostasis ,Signaling in Cellular Processes ,Animals ,cdc25 Phosphatases ,Progenitor cell ,lcsh:Science ,Biology ,Cell Proliferation ,030304 developmental biology ,Mice, Knockout ,0303 health sciences ,Multidisciplinary ,biology ,Cell growth ,Stem Cells ,lcsh:R ,Epithelial Cells ,Animal Models ,Cell cycle ,3. Good health ,Cell biology ,Mitotic Signaling ,Adult Stem Cells ,030220 oncology & carcinogenesis ,biology.protein ,lcsh:Q ,Gene Function ,Cellular Types ,Stem cell ,Physiological Processes ,Cell Division ,Gene Deletion ,Research Article ,Developmental Biology ,Signal Transduction - Abstract
The CDC25 protein phosphatases drive cell cycle advancement by activating cyclin-dependent protein kinases (CDKs). Humans and mice encode three family members denoted CDC25A, -B and -C and genes encoding these family members can be disrupted individually with minimal phenotypic consequences in adult mice. However, adult mice globally deleted for all three phosphatases die within one week after Cdc25 disruption. A severe loss of absorptive villi due to a failure of crypt epithelial cells to proliferate was observed in the small intestines of these mice. Because the Cdc25s were globally deleted, the small intestinal phenotype and loss of animal viability could not be solely attributed to an intrinsic defect in the inability of small intestinal stem and progenitor cells to divide. Here, we report the consequences of deleting different combinations of Cdc25s specifically in intestinal epithelial cells. The phenotypes arising in these mice were then compared with those arising in mice globally deleted for the Cdc25s and in mice treated with irinotecan, a chemotherapeutic agent commonly used to treat colorectal cancer. We report that the phenotypes arising in mice globally deleted for the Cdc25s are due to the failure of small intestinal stem and progenitor cells to proliferate and that blocking cell division by inhibiting the cell cycle engine (through Cdc25 loss) versus by inducing DNA damage (via irinotecan) provokes a markedly different response of small intestinal epithelial cells. Finally, we demonstrate that CDC25A and CDC25B but not CDC25C compensate for each other to maintain the proliferative capacity of intestinal epithelial stem and progenitor cells.
- Published
- 2011
27. The ARF Tumor Suppressor Regulates Bone Remodeling and Osteosarcoma Development in Mice
- Author
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Jason D. Weber, Katherine N. Weilbaecher, Thomas J. Rosol, Daniel Rauch, David Piwnica-Worms, Stefan Niewiesk, Michael Dale Lairmore, Lee Ratner, John C. S. Harding, Michelle A. Hurchla, Lauren Shea, Mark C. Eagleton, and Hongju Deng
- Subjects
Anatomy and Physiology ,Mouse ,Tumor Physiology ,medicine.medical_treatment ,lcsh:Medicine ,Osteoclasts ,Zoledronic Acid ,Bone remodeling ,Mice ,0302 clinical medicine ,Molecular Cell Biology ,Basic Cancer Research ,Bone and Soft Tissue Sarcomas ,Tumor Suppressor Protein p14ARF ,lcsh:Science ,Musculoskeletal System ,Osteosarcoma ,0303 health sciences ,Multidisciplinary ,Diphosphonates ,Cancer Risk Factors ,Imidazoles ,Osteoblast ,Animal Models ,Gene Products, tax ,Primary tumor ,medicine.anatomical_structure ,Oncology ,030220 oncology & carcinogenesis ,Medicine ,Bone Remodeling ,Cellular Types ,Cancer Prevention ,Research Article ,Heterozygote ,medicine.medical_specialty ,Transgene ,Bone Marrow Cells ,Mice, Transgenic ,Biology ,Predisposing Conditions and Syndromes ,03 medical and health sciences ,Model Organisms ,Osteoclast ,Internal medicine ,medicine ,Animals ,Bone ,030304 developmental biology ,Osteoblasts ,Models, Genetic ,Oncogene ,lcsh:R ,Carcinoma ,Cancers and Neoplasms ,Bisphosphonate ,Genes, p53 ,medicine.disease ,Mice, Inbred C57BL ,Endocrinology ,Cancer research ,lcsh:Q ,Tumor Suppressor Protein p53 - Abstract
The ARF tumor suppressor regulates p53 as well as basic developmental processes independent of p53, including osteoclast activation, by controlling ribosomal biogenesis. Here we provide evidence that ARF is a master regulator of bone remodeling and osteosarcoma (OS) development in mice. Arf(-/-) mice displayed increased osteoblast (OB) and osteoclast (OC) activity with a significant net increase in trabecular bone volume. The long bones of Arf(-/-) mice had increased expression of OB genes while Arf(-/-) OB showed enhanced differentiation in vitro. Mice transgenic for the Tax oncogene develop lymphocytic tumors with associated osteolytic lesions, while Tax+Arf(-/-) mice uniformly developed spontaneous OS by 7 months of age. Tax+Arf(-/-) tumors were well differentiated OS characterized by an abundance of new bone with OC recruitment, expressed OB markers and displayed intact levels of p53 mRNA and reduced Rb transcript levels. Cell lines established from OS recapitulated characteristics of the primary tumor, including the expression of mature OB markers and ability to form mineralized tumors when transplanted. Loss of heterozygosity in OS tumors arising in Tax+Arf(+/-) mice emphasized the necessity of ARF-loss in OS development. Hypothesizing that inhibition of ARF-regulated bone remodeling would repress development of OS, we demonstrated that treatment of Tax+Arf(-/-) mice with zoledronic acid, a bisphosphonate inhibitor of OC activity and repressor of bone turnover, prevented or delayed the onset of OS. These data describe a novel role for ARF as a regulator of bone remodeling through effects on both OB and OC. Finally, these data underscore the potential of targeting bone remodeling as adjuvant therapy or in patients with genetic predispositions to prevent the development of OS.
- Published
- 2010
28. Cerenkov Radiation Energy Transfer (CRET) Imaging: A Novel Method for Optical Imaging of PET Isotopes in Biological Systems
- Author
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David Piwnica-Worms, Erin Jackson, Scott E. Harpstrite, Robin S. Dothager, and Reece J. Goiffon
- Subjects
Luminescence ,Photon ,Fluorophore ,lcsh:Medicine ,02 engineering and technology ,Radiation ,7. Clean energy ,030218 nuclear medicine & medical imaging ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Positron ,Nuclear magnetic resonance ,Animals ,Emission spectrum ,lcsh:Science ,Physics ,Multidisciplinary ,business.industry ,lcsh:R ,021001 nanoscience & nanotechnology ,Förster resonance energy transfer ,Energy Transfer ,chemistry ,Positron-Emission Tomography ,Radiology and Medical Imaging/PET and SPECT Imaging ,lcsh:Q ,Radiology and Medical Imaging/Radionuclide Imaging ,Radiopharmaceuticals ,0210 nano-technology ,Nuclear medicine ,business ,Preclinical imaging ,Research Article ,Biotechnology - Abstract
Background Positron emission tomography (PET) allows sensitive, non-invasive analysis of the distribution of radiopharmaceutical tracers labeled with positron (β+)-emitting radionuclides in small animals and humans. Upon β+ decay, the initial velocity of high-energy β+ particles can momentarily exceed the speed of light in tissue, producing Cerenkov radiation that is detectable by optical imaging, but is highly absorbed in living organisms. Principal Findings To improve optical imaging of Cerenkov radiation in biological systems, we demonstrate that Cerenkov radiation from decay of the PET isotopes 64Cu and 18F can be spectrally coupled by energy transfer to high Stokes-shift quantum nanoparticles (Qtracker705) to produce highly red-shifted photonic emissions. Efficient energy transfer was not detected with 99mTc, a predominantly γ-emitting isotope. Similar to bioluminescence resonance energy transfer (BRET) and fluorescence resonance energy transfer (FRET), herein we define the Cerenkov radiation energy transfer (CRET) ratio as the normalized quotient of light detected within a spectral window centered on the fluorophore emission divided by light detected within a spectral window of the Cerenkov radiation emission to quantify imaging signals. Optical images of solutions containing Qtracker705 nanoparticles and [18F]FDG showed CRET ratios in vitro as high as 8.8±1.1, while images of mice with subcutaneous pseudotumors impregnated with Qtracker705 following intravenous injection of [18F]FDG showed CRET ratios in vivo as high as 3.5±0.3. Conclusions Quantitative CRET imaging may afford a variety of novel optical imaging applications and activation strategies for PET radiopharmaceuticals and other isotopes in biomaterials, tissues and live animals.
- Published
- 2010
29. Single-Cell Resolution Imaging of Retinal Ganglion Cell Apoptosis In Vivo Using a Cell-Penetrating Caspase-Activatable Peptide Probe.
- Author
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Qiu, Xudong, Johnson, James R., Wilson, Bradley S., Gammon, Seth T., Piwnica-Worms, David, and Barnett, Edward M.
- Subjects
RETINAL ganglion cells ,APOPTOSIS ,CELL imaging ,CELL-penetrating peptides ,CASPASES ,FLUOROPHORES ,METHYL aspartate - Abstract
Peptide probes for imaging retinal ganglion cell (RGC) apoptosis consist of a cell-penetrating peptide targeting moiety and a fluorophore-quencher pair flanking an effector caspase consensus sequence. Using ex vivo fluorescence imaging, we previously validated the capacity of these probes to identify apoptotic RGCs in cell culture and in an in vivo rat model of N-methyl- D-aspartate (NMDA)-induced neurotoxicity. Herein, using TcapQ488, a new probe designed and synthesized for compatibility with clinically-relevant imaging instruments, and real time imaging of a live rat RGC degeneration model, we fully characterized time- and dose-dependent probe activation, signal-to-noise ratios, and probe safety profiles in vivo. Adult rats received intravitreal injections of four NMDA concentrations followed by varying TcapQ488 doses. Fluorescence fundus imaging was performed sequentially in vivo using a confocal scanning laser ophthalmoscope and individual RGCs displaying activated probe were counted and analyzed. Rats also underwent electroretinography following intravitreal injection of probe. In vivo fluorescence fundus imaging revealed distinct single-cell probe activation as an indicator of RGC apoptosis induced by intravitreal NMDA injection that corresponded to the identical cells observed in retinal flat mounts of the same eye. Peak activation of probe in vivo was detected 12 hours post probe injection. Detectable fluorescent RGCs increased with increasing NMDA concentration; sensitivity of detection generally increased with increasing TcapQ488 dose until saturating at 0.387 nmol. Electroretinography following intravitreal injections of TcapQ488 showed no significant difference compared with control injections. We optimized the signal-to-noise ratio of a caspase-activatable cell penetrating peptide probe for quantitative non-invasive detection of RGC apoptosis in vivo. Full characterization of probe performance in this setting creates an important in vivo imaging standard for functional evaluation of future probe analogues and provides a basis for extending this strategy into glaucoma-specific animal models. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
30. Bioluminescent Imaging Reveals Divergent Viral Pathogenesis in Two Strains of Stat1-Deficient Mice, and in &agr;&bgr;&ygr; Interferon Receptor-Deficient Mice.
- Author
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Pasieka, Tracy Jo, Collins, Lynne, O'Connor, Megan A., Yufei Chen, Parker, Zachary M., Berwin, Brent L., Piwnica-Worms, David R., and Leib, David A.
- Subjects
VIRAL disease treatment ,TRANSCRIPTION factors ,BIOLUMINESCENCE ,DIAGNOSTIC imaging ,LABORATORY mice ,INTERFERON receptors ,DNA-binding proteins ,CELLULAR signal transduction ,HERPES simplex virus - Abstract
Pivotal components of the IFN response to virus infection include the IFN receptors (IFNR), and the downstream factor signal transducer and activator of transcription 1 (Stat1). Mice deficient for Stat1 and IFNR (Stat1
-/- and IFNaßcR-/- mice) lack responsiveness to IFN and exhibit high sensitivity to various pathogens. Here we examined herpes simplex virus type 1 (HSV-1) pathogenesis in Stat1-/- mice and in IFNaßcR-/- mice following corneal infection and bioluminescent imaging. Two divergent and paradoxical patterns of infection were observed. Mice with an N-terminal deletion in Stat1 (129Stat1-/- (N-term)) had transient infection of the liver and spleen, but succumbed to encephalitis by day 10 post-infection. In stark contrast, infection of IFNaßcR-/- mice was rapidly fatal, with associated viremia and fulminant infection of the liver and spleen, with infected infiltrating cells being primarily of the monocyte/macrophage lineage. To resolve the surprising difference between Stat1-/- and IFNaßcR-/- mice, we infected an additional Stat1-/- strain deleted in the DNA-binding domain (129Stat1-/- (DBD)). These 129Stat1-/- (DBD) mice recapitulated the lethal pattern of liver and spleen infection seen following infection of IFN&agr;&bgr;&ggr;R-/- mice. This lethal pattern was also observed when 129Stat1-/- (N-term) mice were infected and treated with a Type I IFN-blocking antibody, and immune cells derived from 129Stat1-/- (N-term) mice were shown to be responsive to Type I IFN. These data therefore show significant differences in viral pathogenesis between two commonly-used Stat1-/- mouse strains. The data are consistent with the hypothesis that Stat1-/- (N-term) mice have residual Type I IFN receptor-dependent IFN responses. Complete loss of IFN signaling pathways allows viremia and rapid viral spread with a fatal infection of the liver. This study underscores the importance of careful comparisons between knockout mouse strains in viral pathogenesis, and may also be relevant to the causation of HSV hepatitis in humans, a rare but frequently fatal infection. [ABSTRACT FROM AUTHOR]- Published
- 2011
- Full Text
- View/download PDF
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