Peter S Steyger
Ag Bell Assn For Deaf & Hard Of Hearing
Project start date: 2010-02-05
Project end date: 2015-01-31
Sponsored Links Excellgen http://Excellgen.com
Peter S Steyger
Ag Bell Assn For Deaf & Hard Of Hearing
Project start date: 2010-02-05
Project end date: 2015-01-31
Grants awarded to Peter S Steyger
LOCALIZATION OF CISPLATIN AND CISPLATIN-BINDING PROTEINS IN THE INNER EAR
Peter S Steyger, Associate Professor Of Otolary
Oregon Health And Science University, 3181 Sw Sam Jackson Pk Rd, Portland, Or 97239-3098
Grant 5R21DC010231-02 from National Institute On Deafness And Other Communication Disorders
Abstract: The anti-neoplastic drug cisplatin is essential for treating a variety of epithelial and brain tumors. However, it is ototoxic, neurotoxic and nephrotoxic, causing permanent deafness and acute kidney failure in patients treated with these drugs. The cellular distribution of cisplatin has been only detected indirectly via pathological observations, by low-resolution positron emission tomography, autoradiography, or biochemically using high-performance liquid chromatography. The long-term goal of this research is to prevent ototoxicity and permanent deafness. We have developed a fluorescently-tagged cisplatin molecule that is bio-active and can be detected within individual cells in the inner ear, kidney and other organs after systemic administration. In addition, we can use this conjugation procedure to identify cytoplasmic cisplatin-binding proteins that may reveal novel intracellular mechanisms of cytotoxicity or protection. The working hypothesis is Cisplatin trafficks to cochlear hair cells via endolymph, and binds to cytosolic proteins. The specific aims of this project are to Aim 1 characterize the cochlear distribution of cisplatin in three rodent models, Aim 2 identify the conditions that modulate cellular uptake of cisplatin in vitro, Aim 3 verify that cisplatin enters cochlear hair cells from endolymph in vivo, Aim 4 identify cisplatin-binding proteins and their distribution in the cochlea. By determining which cells take up cisplatin, the mechanisms by which it enters cells and identifying its protein-binding partners, we can begin to develop new strategies to prevent cisplatin-induced ototoxicity. This will allow clinicians to use cisplatin and related drugs more efficaciously while preserving auditory function, especially important in pediatric patients acquiring language and educational skills. Understanding the mechanisms of how cisplatin crosses the blood-labyrinth barrier to enter the cochlea is crucial to prevent cisplatin-induced ototoxicity. The proposed research will enable the development of new strategies to prevent cochlear uptake of cisplatin and its derivates and subsequent ototoxic sequelae, particularly life-long deafness, tinnitus and vestibular deficits
Keywords: (SP-4-2)-Diamminedichloroplatinum; Acute Kidney Failure; Affect; Aminoglycosides; Animal Model; Animal Models and Related Studies; Apical; Auditory; Autoradiography; Bathing; Baths; Binding; Binding (Molecular Function); Binding Proteins; Blood; Blood - brain barrier anatomy; Blood Coagulation Factor IV; Blood Vessels; Blood-Brain Barrier; Body Tissues; Brain Neoplasia; Brain Neoplasms; Brain Tumors; CDDP; Ca++ element; Calcium; Cations; Cavia; Cell Line; Cell Lines, Strains; CellLine; Cells; Childhood; Chromatography, High Performance Liquid; Chromatography, High Pressure Liquid; Chromatography, High Speed Liquid; Cis-diammine-dichloroplatinum; Cis-diamminedichloridoplatinum; Cis-diamminedichloro Platinum (II); Cis-dichloroammine Platinum (II); Cis-platinous Diamine Dichloride; Cis-platinum II; Cis-platinum II Diamine Dichloride; Cisplatin; Cisplatina; Cisplatinum; Coagulation Factor IV; Cochlea; Cochlear Organ; Cochlear duct; Cochlear structure; Common Rat Strains; Corti Cell; Cysplatyna; Cytoplasmic Protein; DDP; Data; Deafness; Development; Dichlorodiammineplatinum; Disease; Disorder; Drugs; Ductus Cochlearis; Ear, Internal; Education; Educational aspects; Endocytosis; Endolymph; Endothelial Cells; Epithelial; Epithelial Cells; Factor IV; Goals; Guinea Pigs; HPLC; Hair Cells; Hemato-Encephalic Barrier; High Pressure Liquid Chromatography; In Vitro; Individual; Ion Channel; Ionic Channels; Kidney; Kidney Failure, Acute; Kidney Insufficiency, Acute; Labyrinth; Language; Life; Ligand Binding Protein; Liquid substance; Lytotoxicity; Mammals, Guinea Pigs; Mammals, Mice; Mammals, Rats; Mass Spectrum; Mass Spectrum Analysis; Media, Scala; Medical Imaging, Positron Emission Tomography; Medication; Membrane Channels; Methods and Techniques; Methods, Other; Mice; Molecular Interaction; Murine; Mus; Nephrotoxic; Occluding Junctions; Organ; PET; PET Scan; PET imaging; PETSCAN; PETT; Patients; Peptide Biosynthesis, Ribosomal; Perfusion; Perilymph; Peyrone`s Chloride; Peyrone`s Salt; Pharmaceutic Preparations; Pharmaceutical Agent; Pharmaceutical Preparations; Pharmaceuticals; Pharmacologic Substance; Pharmacological Substance; Photometry/Spectrum Analysis, Mass; Platinum Diamminodichloride; Platinum, Diaminedichloro-, cis- (8CI); Platinum, diamminedichloro-, (SP-4-2)-; Positron Emission Tomography Scan; Positron-Emission Tomography; Procedures; Protein Binding; Protein Biosynthesis; Protein Biosynthesis, Ribosomal; Protein Synthesis, Ribosomal; Proteins; Proton Magnetic Resonance Spectroscopic Imaging; Rad.-PET; Radioautography; Rat; Rattus; Renal Failure, Acute; Renal Insufficiency, Acute; Research; Resolution; Reticuloendothelial System, Blood; Ringing-Buzzing-Tinnitus; Risk; Rodent Model; Route; Scala Medias; Sensory; Spectrometry, Mass; Spectroscopy, Mass; Spectrum Analyses, Mass; Spectrum Analysis, Mass; Stria Vascularis; Surface; Techniques; Testing; Tight Junctions; Time; Tinnitus; Tissues; Urinary System, Kidney; Work; Zonula Occludens; apical membrane; basolateral membrane; cis dichlorodiammineplatinum; cis platinum compound; cis-Diaminedichloroplatinum; cis-Diamminedichloroplatinum; cis-Diamminedichloroplatinum(II); cis-Dichlorodiammineplatinum(II); cis-Platinum; cultured cell line; cytotoxicity; disease/disorder; drug/agent; ear hair cell; extracellular; fluid; gene product; in vitro Model; in vivo; inner ear; liquid; macromolecule; model organism; neoplastic; neurotoxic; novel; ototoxicity; pediatric; prevent; preventing; protein synthesis; renal; skills; trafficking; tumors in the brain; uptake; vascular
Relevance: NARRATIVE Understanding the mechanisms of how cisplatin crosses the blood-labyrinth barrier to enter the cochlea is crucial to prevent cisplatin-induced ototoxicity. The proposed research will enable the development of new strategies to prevent cochlear uptake of cisplatin and its derivates and subsequent ototoxic sequelae, particularly life-long deafness, tinnitus and vestibular deficits
Project start date: 2009-07-01
Project end date: 2011-06-30
Budget start date: 1-JUL-2010
Budget end date: 30-JUN-2011
PFA/PA: PA-06-181
5R21DC010231-02 (2010): $188719
THREE RESEARCH SYMPOSIA ON HEARING LOSS ATTRACTING DIVERSE AUDIENCES
Peter S Steyger
Ag Bell Assn For Deaf & Hard Of Hearing, Assn For Deaf And Hard Of Hearing, Washington, Dc 20007
Grant 1R13DC010951-01 from National Institute On Deafness And Other Communication Disorders
Abstract: The Alexander Graham Bell association for the Deaf and hard of Hearing (AG Bell) requests financial support from NIDCD for the presentation of three research symposia in 2010, 2012 and 2014. AG Bell has a strong track record of producing high quality conferences/scientific meetings that are relevant to the scientific mission of the NIH and to public health. Since 2000, AG Bell has been coordinating conferences in conjunction with NIDCD that improve scientific education and work toward improving outcomes for those who are deaf or hard of hearing. Conferences bring together hearing health scientist with individuals and families affected by hearing loss to bridge the gap between bench research and practical applications that improve hearing outcomes. Past symposia have drawn an average of 1,000 participants composed of individuals who are deaf or hard of hearing, hearing health professionals (including audiologist, speech language pathologists, educators of the deaf, otolaryngologists and researchers in the hearing health field), as well as parents of children who are deaf or hard of hearing. Our past symposia have been highly rated and well attended at AG Bell´s biennial conventions. The 2010 conference will address the reasons for loss of function in the cochlear - the part of the inner ear that is responsible for hearing - as well as cutting edge research that may translate into improved treatments for hearing loss. This topic will facilitate AG Bell´s ultimate goal to improve communication between biomedical researchers and individuals who benefit from their efforts. The conference will be held in Orlando, FL in June 2010. The 2010 symposium will address the reasons for loss of function in the cochlea - the part of the inner ear that is responsible for hearing - as well as cutting edge research that may translate into improved treatments for hearing loss. This topic will also facilitate AG Bell´s ultimate goal to improve communication between biomedical researchers and individuals who benefit from their efforts
Keywords: Hearing Loss; Hypoacuses; Hypoacusis; Research; conference; hearing impairment; symposium
Project start date: 2010-02-05
Project end date: 2013-01-31
Budget start date: 5-FEB-2010
Budget end date: 31-JAN-2011
PFA/PA: PA-08-149
1R13DC010951-01 (2010): $28245
IN VIVO AND IN VITRO HAIR BUNDLE REGENERATION AFTER GENT
Peter S Steyger
Otolaryn & Head & Neck Surgeryoregon Health & Science University
3181 Sw Sam Jackson Pk Rd
portland, Or 972393098
Grant 5R03DC003028-03 from National Institute On Deafness And Other Communication Disorders IRG: ZDC1
Abstract: Mature amphibian otolith hair cells display a variety of adaptation kinetics which confer stimulus encoding and frequency selective properties. Adapting hair cells do not retain information about sustained hair bundle displacement, and thus are most sensitive to dynamic stimuli. Adaptation is mediated by calcium and a cytoplasmic motor which releases tension on the stereociliary tip-links, mechanically closing the transduction channels. The most likely candidate for this cytoplasmic motor is a myosin isoform. Thus, antisera against stereociliary myosin and transduction channels can be used as markers of hair cell functional maturity. Previous studies have also shown that hair cell regeneration in amphibian otolith organs can occur in mitotically-blocked organotypic cultures, and suggested that non-mitotic hair cell regeneration might be accomplished by the phenotypic conversion of supporting cells into hair cells. Alternatively, immature hair bundles might develop in damaged hair cells undergoing repair, or post-mitotic progenitor cells undergoing terminal differentiation. We will use gentamicin sulfate to induce hair cell degeneration in bullfrogs in vivo, and in organotypic cultures of bullfrog otolithic organs. We will then use immunocytochemical, histochemical, and ultrastructural techniques to study the subsequent labeling patterns in regenerating hair bundles. The proposed experiments have been designed to determine if in vitro labeling patterns for hair bundle regeneration accurately reflect those in vivo. We will test the hypotheses that immature hair bundles develop on either surviving. but damaged, hair cells, and/or immature hair cells derived from either post-mitotic progenitors or converting supporting cells in vivo and in mitotic and mitotically-blocked organotypic cultures. We will also investigate the temporal organization of soluble and filamentous actin in the early stages of hair bundle repair in damaged hair cells and/or cuticular plate and hair bundle development in post-mitotic progenitors and converting supporting cells in mitotically-blocked cultures. This will reveal labeling pafterns in damaged hair cells-undergoing repair, immature hair cells derived from post-mitotic progenitors, and/or converting supporting cells. We will also test the hypothesis that immature hair bundles possess myosin and transduction channels, and if so, at what size of hair bundle development they are expressed. The expression of myosin I- and transduction channel proteins in a specific bundle size or larger will allow these bundles to be selected and tested for hair cell function in future electrophysiological studies. This work might suggest new directions for rehabilitation of hair cell loss in hearing and vestibular disorders
Keywords: ear hair cell, gentamicin, nervous system regeneration, neurotoxicology actin, aphidicolin, cell cycle, myosin ATPase Rana, organ culture, transmission electron microscopy
Project start date: 1997-01-01
Project end date: 1998-12-31
5R03DC003028-03 (1998): $52150
7R03DC003028-02 (1997): $17730
Functional Similarities In Renal And Cochlear Epithelia
Peter S Steyger
Oregon Health And Science University 3181 Sw Sam Jackson Pk Rd Portland, Or 972393098
Grant 5R21DC006084-02 from National Institute On Deafness And Other Communication Disorders IRG: ZDC1
Abstract: Aminoglycosides are clinically essential for treating life-threatening Gram-negative bacterial infections, e.g., meningitis, and in preventing infection in burns and premature babies. However, there is a high incidence of ototoxicity and sensory hair cell death. Sensitive hair cell function is dependent on a structurally and physiologically intact ear. Thus, studies to determine mechanisms of ototoxicity have used intact animals, or inner ear explants excised from animals. There are a number of functional, toxicological, and pharmacological similarities between inner ear cells and cells of the kidney tubules. To exploit these similarities, we have developed cloned sub-lines of currently-available kidney cell lines to determine their validity as in vitro models to study the mechanisms of aminoglycoside transport and toxicity in the inner ear. Using the aminoglycoside gentamicin, we propose to use cloned kidney cells to study two distinct aspects of aminoglycoside ototoxicity 1) Like hair cells, proximal tubule epithelial cells of the kidney are among the few cell types that are toxicologically sensitive to clinical doses of aminoglycosides. These cell types also share pharmacological sensitivities to several other drugs. We will use a clone of OK cells, a proximal kidney tubule line, to determine the feasibility of using proximal tubule cells as valid in vitro models of aminoglycoside uptake and toxicity by hair cells. 2) Little work has been done to determine the mechanism of drug entry into the endolymph. Research suggests that hair cell uptake of aminoglycosides is across the apical membrane that is exposed only to the highly-regulated endolymph. Thus, pathways of drug entry into the endolymph will be highly-potent sites of intervention to prevent ototoxicity during treatment. The various epithelia surrounding the endolymph are cumbersome to acquire as explants in the quantity and proper configurations to facilitate direct examination of aminoglycoside transit across these epithelia. Therefore, we have developed a kidney distal tubule cell line to use as a model for aminoglycoside transport across the various epithelia enclosing the endolymph compartment. Distal tubule cells share several characteristics with inner ear epithelia such as the marginal cells of the stria vascularis. We will use a clone of MDCK cells, a distal tubule line, to determine the feasibility of using distal tubule cells as valid in vitro models for aminoglycoside transport across the epithelia enclosing the scala media. Results obtained from both studies will periodically be compared with animal models for confirmation. Preliminary data obtained with use of our cloned kidney cell lines have already dramatically changed our understanding of aminoglycoside entry into, distribution within, and transit across epithelia. Both of these in vitro models should provide powerful tools for finding co-therapeutics to reduce or eliminate ototoxicity during aminoglycoside treatment, blocking both toxic events in the hair cells and drug access to the endolymph and, thus, the hair cells.
Keywords: aminoglycoside antibiotic, cochlea, epithelium, kidney, ototoxin, cytotoxicity, drug adverse effect, ear hair cell, gentamicin, cell line, molecular cloning, tissue /cell culture
Project start date: 2003-03-15
Project end date: 2006-02-28
5R21DC006084-02 (2004): $151000
1R21DC006084-01 (2003): $147940
HAIR CELL RESPONSES TO OTOTOXIC DRUGS
Peter S Steyger, Associate Professor Of Otolary
Oregon Health And Science University, 3181 Sw Sam Jackson Pk Rd, Portland, Or 97239-3098
Grant 5R01DC004555-08 from National Institute On Deafness And Other Communication Disorders
Abstract: Aminoglycoside antibiotics are essential for battling life-threatening bacterial sepsis. Aminoglycosides also cause permanent deafness/balance disorders and nephrotoxicity in more than 120,000 individuals each year in the US, particularly in infants and premature babies. The long-term goal of this research is to prevent cochlear uptake of aminoglycosides and thus ototoxicity, to preserve auditory function. Progress in the previous project period revealed that the cellular uptake of aminoglycosides can be blocked in vitro, and that non-selective cation channels enhance the clearance of aminoglycosides. In this proposal, we will investigate how aminoglycosides are transported from the vasculature, across the blood-labyrinth barrier into the cochlear fluids and tissues in vivo, and develop strategies to this transport to prevent aminoglycoside-induced inner ear sensory hair cell death. Our working hypothesis is that pharmacological agents can reduce aminoglycoside uptake and toxicity in the cochlea. The specific aims of this project are First, to regulate aminoglycoside uptake in vitro, by identifying how pharmacological agents change the intra-cellular milieu of model cell lines and cochlear explants to enhance or inhibit aminoglycoside uptake and clearance. We will monitor intracellular calcium and pH levels, the resting potential and membrane resistance (Aim 1). Second, to preserve auditory function and morphology in vivo using inhibitors of aminoglycoside uptake. We will assess the efficacy of aminoglycoside-uptake inhibitors using auditory brainstem response audiometry, confocal microscopy of hair cell morphology, and constructing cytocochleograms (Aim 2). And thirdly, to identify the intra-cochlear route of aminoglycosides from the vasculature to the sensory hair cells. We will use cochlear perfusion techniques, and sample cochlear fluids to determine if aminoglycosides enter hair cells from endolymph or perilymph. We will then verify that aminoglycoside uptake-inhibitors reduce the intra-cochlear transport of aminoglycosides by one or both routes (Aim 3). Identification of mechanisms that reduce aminoglycoside transport into, and within, the cochlea will determine if currently-available drugs can be used as co-therapeutics to preserve auditory function during life-saving aminoglycoside therapy. In addition, identifying intracellular mechanisms (drug-induced or otherwise) that enhance aminoglycoside uptake provides new insight for clinicians to screen patients for pre-existing conditions and medications that elevate the risk of aminoglycoside toxicity in patients. Understanding mechanisms of how aminoglycosides antibiotics cross the blood-labyrinth barrier to enter the inner ear fluids is crucial in preventing aminoglycoside-induced ototoxicity. The proposed research will enable us to develop strategies to prevent the entry of aminoglycosides into the inner ear fluids and therefore ototoxic sequelae, particularly life-long deafness, tinnitus and vestibular deficits
Keywords: Acute Kidney Failure; Agonist; Aminoglycoside Agents; Aminoglycoside Antibiotics; Aminoglycoside Drugs; Aminoglycosides; Anti-Bacterial Agents; Antibacterial Agents; Antibiotics, Aminoglycoside; Antidiuretic Hormone; Antidiuretic Hormones; Arachidonic Acids; Audiogram; Audiometric Test; Audiometry; Auditory; Auditory Brainstem Responses; Bacteria; Bacterial Infections; Binding; Binding (Molecular Function); Blood; Blood Coagulation Factor IV; Body Tissues; Ca++ element; Calcium; Cations; Cavia; Cell Death; Cell Line; Cell Lines, Strains; CellLine; Cells; Cellular Morphology; Chemicals; Clear Cell; Coagulation Factor IV; Cochlea; Cochlear Organ; Cochlear duct; Cochlear structure; Confocal Microscopy; Corti Cell; Data; Deafness; Diuretics; Drug Kinetics; Drugs; Ductus Cochlearis; Ear, Internal; Endolymph; Epithelial Cells; Epithelium; Eukaryote; Eukaryotic Cell; Factor IV; Fluorescence Agents; Fluorescent Agents; Fluorescent Dyes; Ganglion of Corti; Garamicin; Garamycin; Genoptic; Genoptic S.O.P.; Gentamicins; Glycosides; Goals; Guinea Pigs; Hair Cells; In Vitro; Individual; Infant; Infant, Premature; Intermediary Metabolism; Kidney Failure, Acute; Kidney Insufficiency, Acute; Kidney Tubules, Proximal; Labyrinth; Life; Lipids; Liquid substance; Lytotoxicity; METBL; Mammals, Guinea Pigs; Mammals, Mice; Measurement; Media, Scala; Medication; Membrane; Membrane Potentials; Metabolic Processes; Metabolism; Methods and Techniques; Methods, Other; Mice; Modeling; Molecular Interaction; Monitor; Morphology; Murine; Mus; Nephrotoxic; Nerve Cells; Nerve Unit; Neural Cell; Neurocyte; Neurons; Patients; Perfusion; Perilymph; Pharmaceutic Preparations; Pharmaceutical Agent; Pharmaceutical Preparations; Pharmaceuticals; Pharmacokinetics; Pharmacologic Substance; Pharmacological Substance; Premature Infant; Prevention Measures; Prophylactic treatment; Prophylaxis; Proximal Kidney Tubules; Receptor Protein; Renal Failure, Acute; Renal Insufficiency, Acute; Research; Resistance; Resting Potentials; Reticuloendothelial System, Blood; Ringing-Buzzing-Tinnitus; Risk; Route; Sampling; Scala Medias; Scala Tympani; Sensory Hair; Sepsis; Spiral Ganglion; Stria Vascularis; Structure of spiral ganglion; TRPV channel; TRPV1; TRPV1 gene; Techniques; Testing; Therapeutic; Tinnitus; Tissues; Toxic effect; Toxicities; Translational Research; Translational Research Enterprise; Translational Science; Transmembrane Potentials; Tympanus, Scala; U-Gencin; Vanilloid; Vasopressins; Work; Wounds and Injuries; aminoglycoside-induced ototoxicity; anti-bacterial; antibacterial; bacterial disease; beta-Hypophamine; bloodstream infection; cell morphology; cultured cell line; cytotoxic; cytotoxicity; drug mechanism; drug/agent; ear hair cell; equilibration disorder; eukaryotida; experiment; experimental research; experimental study; extracellular; fluid; fluorescent dye/probe; in vitro Model; in vivo; inhibitor; inhibitor/antagonist; inner ear; insight; liquid; membrane structure; necrocytosis; nephrotoxicity; neuronal; ototoxicity; premature baby; premature infant human; preterm baby; preterm infant; preterm infant human; preterm neonate; prevent; preventing; receptor; renal proximal tubule; research study; resistant; response; spiral ganglion; translation research enterprise; uptake
Project start date: 2000-07-01
Project end date: 2011-05-31
Budget start date: 1-JUN-2010
Budget end date: 31-MAY-2011
PFA/PA: PA-07-070
5R01DC004555-08 (2010): $323978
5R01DC004555-07 (2009): $327250
3R01DC004555-07S1 (2009): $154009
5R01DC004555-05 (2005): $302000
Sponsored Links Excellgen http://Excellgen.com
5R01DC004555-04 (2004): $302000
5R01DC004555-03 (2003): $315456
5R01DC004555-02 (2002): $318612
1R01DC004555-01A1 (2001): $302000
2R56DC004555-06 (2007): $385000
IN VIVO AND IN VITRO HAIR BUNDLE REGENERATION AFTER GENT
Peter S Steyger
Good Samaritan Hosp & Med Ctr(prtlnd,or)
1015 Nw 22nd Ave
portland, Or 97210
Grant 1R03DC003028-01A1 from National Institute On Deafness And Other Communication Disorders IRG: ZDC1
Project start date: 1997-01-01
Project end date: 1997-07-31
1R03DC003028-01A1 (1997): $9202
MYOSIN/TRANSDUCTION CHANNELS--REGENERATING HAIR BUNDLES
Peter S Steyger
Good Samaritan Hosp & Med Ctr(prtlnd,or)
1015 Nw 22nd Ave
portland, Or 97210
Grant 1R55DC003028-01 from National Institute On Deafness And Other Communication Disorders IRG: ZDC1
Project start date: 1996-09-30
Project end date: 1996-12-31
1R55DC003028-01 (1996): $60000