Allen Ryan - US grants

Clinical evidence suggests that hearing loss during infancy and childhood increases the probability of language and learning disabilities. Experimental data suggest that such communicative disorders are due in part to changes in auditory system anatomy and function, induced by lack of acoustic experience during development. These considerations indicate the importance of understanding auditory development, and the degree to which experience can influence its course. Developmental studies can also provide insight into the function of the adult auditory system. The proposed research will investigate several current problems in normal auditory development, including: the afferent and efferent innervation of the organ of Corti; cochlear blood flow and its relationship to cochlear metabolism; ion distribution in stria vascularis and the ionic composition of endolymph; neural function in the dorsal cochlear nucleus; the growth of neurons and synapses in the cochlear nuclear complex. In addition, the neural plasticity of auditory development will be studied in a series of experiments. The effects of profound acoustic deprivation during auditory development upon the function of the auditory system will be studied. Acoustic deprivation will include surgical removal of the middle ear transmission apparatus to provide approximately 60 dB of isolation from air-conducted, and 40 dB of isolation from bone-conducted stimuli. A sound-attenuated rearing environment will provide an additional 80 dB of isolation from external sounds. Mechanical displacement of the tapes with a piezoelectric driver is used to restore auditory function. In addition, animals will be reared in an environment restricted to a 1/3 octave band of noise and assessed in adulthood with the 2-deoxyglucose technique to determine whether experience produces preferential representation in the central auditory pathway. Also, mid-cochlear lesions will be created mechanically to produce a gap in the central auditory place map, at different developmental ages. The 2-deoxyglucose technique will be used to determine whether function is restored to these regions. If so HRP labeling of primary afferents will be used to study the source of re-innervating fibers, and single unit studies will explore the function of the re-innervated neurons. Finally, the effects of neonatal lesions of the cochlear efferents will be assessed both anatomically and functionally.

Inflammatory events based upon response to antigen have been implicated in a variety of middle ear disorders including otitis media with effusion (OME). Immune responses are also intimately involved in host response to infection at this site. Investigation of the role of immunity in middle ear disorders has been hampered by a lack of basic information concerning the nature and sequelae of immune responses as they operate in the unique environment of the middle ear cavity. To address this lack, animal models of immune response in the middle ear have been developed and used to investigate the properties of immunity at this site. Areas to be studied in the present application include local production of various immunoglobulin classes in the middle ear, the potential existence of specific homing by lymphocytes to the middle ear mucosa, and the role of the eustachian tube in antigen clearance. Models of both acute and chronic immune-mediated OME have also been developed and used to explore the immune and inflammatory events which have the potential to contribute to OME. Experiments proposed include determination of whether passive sensitization with IgG1, IgG2 or IgE will transfer immune-mediated OME, exploration of the role of the eustachian tube in immune-mediated OME, determination of whether local immune response can reduce inflammation which results from expression of systemic immunity in the middle ear, and investigation of the effects of prior viral infection on middle ear immune response. The importance of several inflammatory mediators in the generation of middle ear effusion and inflammation will be assessed by direct assay of experimental effusions, and by introduction of extracted and purified mediators into the middle ear cavity. Intervention in immune-mediated OME will be explored utilizing pharmacologic agents which inhibit suspected immune and inflammatory pathways. This will both test the feasibility of intervention and provide information concerning the importance of targeted inflammatory pathways in immune-mediated middle ear disease.

Clinical evidence suggests that hearing loss during infancy and childhood increases the probability of language and learning disabilities. Experimental data suggest that such communicative disorders are due in part to changes in auditory system anatomy and function, induced by lack of acoustic experience during development. These considerations indicate the importance of understanding auditory development, and the degree to which experience can influence its course. Developmental studies can also provide insight into the function of the adult auditory system. The proposed research will investigate several current problems in normal auditory development, including: the afferent and efferent innervation of the organ of Corti; the growth of neurons and synapses in the cochlear nuclear complex; levels of neural growth factors in the developing inner ear and cochlear nucleus; and early neural function in the VIIIth nerve and cochlear nucleus. The neural plasticity of auditory development will also be studied in a series of experiments. The effects of profound acoustic deprivation during auditory development upon the function of the auditory system will be assessed. Acoustic deprivation will include surgical removal of the middle ear transmission apparatus to provide approximately 60 dB of isolation from air-conducted, and 40 dB of isolation from bone-conducted, stimuli. A sound- attenuated rearing environment will provide an additional 80 dB of isolation from external sounds. Mechanical displacement of the stapes with a piezoelectric driver is used to restore auditory function. Also, tetrodotoxin blockade of neural transmission will be used to delay the normal onset of normal auditory function. The effects of this procedure on VIIIth nerve fiber and cochlear nucleus firing patterns will be evaluated. In addition, animals will be reared in an environment restricted to a 1/3 octave band of noise. Their innervation patterns will be assessed in adulthood to determine whether experience produces preferential representation in the central auditory pathway. The influence of neonatal lesions of cochlea on the development of the olivocochlear efferents will be studied, and the effects of manipulation of growth factors on the neural development of the cochlea and cochlear nucleus will also be evaluated.

Partial support is requested to host a Conference on the Molecular Biology of Hearing and Deafness, to be held under the aegis of the University of California, San Diego, in May of 1992. The specific aims of this symposium are to encourage the utilization of molecular biology techniques in research on hearing and deafness, to facilitate interaction and collaboration between different laboratories engaged in molecular biology research in the auditory system, to foster collaboration between basic scientists and clinicians with related interests in the molecular biology of deafness, and to obtain an unbiased and critical appraisal of molecular biology research currently being performed in the auditory system. An additional goal is to provide a training in state-of-the-art molecular biology techniques through hands-on workshops. Recent developments in molecular biology will be reviewed by experts who work in other systems. Free papers will be solicited and abstracts reviewed for selection. The proceedings of this conference will be published in a timely manner so that ideas and controversies emerging from the meeting will be widely disseminated.

Partial support is requested to host a second Conference on the Molecular Biology of Hearing and Deafness, to be held in Bethesda, MD in October 1995. The specific aims of this conference ar to review recent progress in molecular biology research related to hearing and deafness, to promote the integration of molecular biology methods with other techniques in auditory research, to facilitate interaction and collaboration between different laboratories engaged in molecular biological studies in the auditory system, and to foster collaboration between basic scientists and clinicians with related interests in the molecular biology of deafness. Recent developments in molecular biology will be reviewed by experts who work in the auditory and in other systems. An additional goal is to provide training in state-of-the-art molecular biology techniques through hands-on workshops. In order to make the conference more accessible to individuals without molecular biology experience, a tutorial on molecular biology, genetics and molecular genetics will be offered on the afternoon prior to meeting. Free papers will be solicited and abstracts reviewed for inclusion in the conference.

Partial support is requested to host third Conference on the Molecular Biology of Hearing and Deafness, to be held in Bethesda, MD on October 1998. The Specific aims of this conference are to review recent progress in molecular biology research related to hearing and deafness, to promote integration of molecular biology methods with other techniques in auditory research, to facilitate interaction and collaboration between different laboratories engaged in molecular biological studies in the auditory system, and to foster collaboration between basic scientists and clinicians with related interests in the molecular biology of deafness. Recent developments in molecular biology will be reviewed by experts who work in the auditory and in other systems. In order to make the conference more accessible to individuals without molecular biology experience, a tutorial on molecular biology, genetics and molecular genetics will be offered on the evening prior to meeting. Free papers will be solicited and abstracts reviewed for inclusion in the conference.

DESCRIPTION (provided by applicant): Partial support is requested to host the 7th Conference on the Molecular Biology of Hearing and Deafness. The conference will be held in Boston, MA in June, 2009. The aims of the conference are to: 1) promote research in emerging areas of molecular biology that have not been extensively applied to the auditory system;2) review progress in molecular biology related to hearing and deafness;3) facilitate interaction and collaboration between different laboratories engaged in molecular auditory research, as well as between basic scientists and clinicians;4) encourage translational research that can lead to diagnostics and therapeutics for the treatment of hearing disorders;and 5) provide outreach to patient advocacy groups and schools in the Boston area, with education on the genetics of deafness and hearing research. Speakers from outside of the auditory system will address applications of high-throughput sequencing, computational genetics and the HapMap project, molecular evolution and disease mapping, recent advances in molecular biology of the visual system, as well as additional topics. Auditory sessions will include, but are not limited to: molecular genetics;epigenetic mechanisms;development;integrated gene function;the molecular basis of hearing and vestibular disorders;genetic screening and gene therapy;and regeneration. Support is requested to offer scholarships for minority attendees and trainees, defray the travel costs of some invited participants, and support other costs associated with hosting the conference. Project Narrative: Partial support is requested to host the 7th Conference on the Molecular Biology of Hearing and Deafness. The Conference will be held in Boston, MA in June, 2009. Topics of the Conference include, but are not limited to: molecular genetics and gene mapping of inherited deafness;mutational heterogeneity and deafness phenotypes;families of functionally related deafness genes;complex genetics in inherited deafness;molecular regulation of auditory development;genetics of cell phenotype in the inner ear;molecular basis of hair cell transduction;central auditory system;auditory tissue specific gene activity and expression profilin;cochlear damage, regeneration and repair;molecular diagnostics of deafness mutations;molecular biology of otologic disease: etiology and therapy.

DESCRIPTION (provided by applicant): Partial support is requested to host a fifth Conference on the Molecular Biology of Hearing and Deafness. The Conference will be held in Bethesda, MD in October, 2004. The specific aims of the Conference are to: 1) review progress in molecular biology related to hearing and deafness, by inviting scientists involved in significant recent research to present their results, and by soliciting free papers reporting research at the molecular level related to the auditory system; 2) facilitate interaction and collaboration between different laboratories engaged in molecular auditory research, and between basic scientists and clinicians with related interests in the molecular biology of deafness; 3) encourage research on the molecular biology of hearing and deafness, especially as integrated with other aspects of auditory system biology; and 4) review recent developments in the broader field of molecular biology, and obtain an unbiased and critical appraisal of molecular biology research currently being performed in the auditory system by invited outside discussants. Topics of the Conference include, but are not limited to: molecular genetics and gene mapping of inherited deafness; mutational heterogeneity and deafness phenotypes; families of functionally related deafness genes; complex genetics in inherited deafness; molecular regulation of auditory development; genetics of cell phenotype in the inner ear; molecular basis of hair cell transduction; central auditory system; auditory tissue specific gene activity and expression profiling; cochlear damage, regeneration and repair; molecular diagnostics of deafness mutations; molecular biology of otologic disease: etiology and therapy. Partial support is requested to defray travel costs of invited participants and to permit a registration fee low enough to encourage participation by junior faculty, postdoctoral fellows and students.

[unreadable] DESCRIPTION (provided by applicant): The impact of immunological mechanisms in many otolaryngological diseases has only recently been recognized. Viral contributions to the disorders of our specialty are also poorly understood. The availability of molecular methods to study these mechanisms, and to investigate many other clinical and scientific problems relevant to otolaryngology, has increased dramatically over the past decade. Surgery in general, and otolaryngology as a specialty, have been slow to recognize the importance of these areas of research. As a result, there are relatively few opportunities available for training in immunology, virology, and molecular biology research within our specialty. Over the past 25 years, the UCSD Division of Otolaryngology has steadily expanded its research in these areas, until we now have a well-established faculty and cadre of collaborators at UCSD, at nearby research institutes, including the Salk Institute and Scripps Research Institute, and at local biotechnology firms. The available talents of these investigators provide a unique and fertile training ground for young academicians who wish to pursue these areas of research so that otolaryngology can assure itself that a select group of well-trained, clinically-oriented researchers will be generated. To this end, we propose to continue our postdoctoral research training program. The trainees for such a program would be selected from MD's who wish to pursue at least two years of fellowship training during their otolaryngology residency. Trainees would receive advanced basic science or clinical research training in the application of advanced immunology, virology, and molecular biology methods to research problems in otolaryngology. They would also receive instruction in the responsible conduct of research, project design and implementation, publication of results, and grant writing skills. This has proven effective for our past trainees, several of whom are currently in full-time academic positions, and three of whom are clinician-investigators receiving funding from the NIH. [unreadable] [unreadable] [unreadable]

[unreadable] DESCRIPTION (provided by applicant): Otitis media is one of the largest public health problems of young children. Otitis media is thought to be a multifactorial condition that can result from a variety of inciting events. However, once initiated, otitis media often converges on a final common pathway of inflammation, effusion and tissue hyperplasia that in turn can produce temporary and even permanent hearing loss. Upon resolution of otitis media the hyperplastic middle ear mucosa can recover to a condition at or close to its original structure, although permanent changes including fibrosis and osteoneogenesis sometimes occur. In the previous period of support, we identified several growth factors that can contribute to mucosal hyperplasia. In the current application, we propose to study mechanisms that control tissue hyperplasia and recovery of normal mucosal structure during otitis media. We will identify intracellular pathways that are activated in middle ear cells by growth factors, and determine whether inhibition of these pathways can reduce tissue hyperplasia during otitis media. We also propose to identify pathways controlling cell loss during recovery of the middle ear mucosa. We will determine whether stimulation or inhibition of activity in these pathways affects recovery from otitis media. Concurrent with these studies we will evaluate changes in the phenotype of the bacterial strain used to induce otitis media, to explore the potential for these changes to influence middle ear responses. [unreadable] [unreadable] [unreadable]

[unreadable] DESCRIPTION (provided by applicant): Otitis media is one of the largest public health problems of young children. Otitis media is thought to be a multifactorial condition that can result from a variety of inciting events. However, once initiated, otitis media often converges on a final common pathway of inflammation, effusion and tissue hyperplasia that in turn can produce temporary and even permanent hearing loss. Upon resolution of otitis media the hyperplastic middle ear mucosa can recover to a condition at or close to its original structure, although permanent changes including fibrosis and osteoneogenesis sometimes occur. In the previous period of support, we identified several growth factors that can contribute to mucosal hyperplasia. In the current application, we propose to study mechanisms that control tissue hyperplasia and recovery of normal mucosal structure during otitis media. We will identify intracellular pathways that are activated in middle ear cells by growth factors, and determine whether inhibition of these pathways can reduce tissue hyperplasia during otitis media. We also propose to identify pathways controlling cell loss during recovery of the middle ear mucosa. We will determine whether stimulation or inhibition of activity in these pathways affects recovery from otitis media. Concurrent with these studies we will evaluate changes in the phenotype of the bacterial strain used to induce otitis media, to explore the potential for these changes to influence middle ear responses. [unreadable] [unreadable] [unreadable]

DESCRIPTION (provided by applicant): The education of clinician-scientists is of paramount importance to the field of Otolaryngology. The need for interface between science and medicine, the importance of clinicians that value scientific research, and the increased importance of evidence-based medicine in health care all argue for research training of physicians. Moreover, the impact of immunological mechanisms in many otolaryngological diseases has received increased attention in the past decade, and we are seeing an increase in the use of immune/inflammatory therapeutics in our field. Yet Otolaryngology remains behind many other areas of medicine in immunologic research. As an example, the area of innate immunity mediated by pathogen receptors has seen a dramatic expansion in the broader field of immunology and infectious diseases over the past 15 years, and the head and neck represent a major pathogen interface. However, only within the last few years has an increase in pathogen receptor research been seen in Otolaryngology. Similarly, the availability of molecular methods has also transformed research in immunology and other areas of biomedicine. However, the use of molecular methods by clinician-scientists in Otolaryngology has lagged. Over the past 30 years, the UCSD Division of Otolaryngology has steadily expanded its research in both immunology and molecular biology, until we have a well-established cadre of investigators. The available talents of these investigators provide a unique and fertile training ground for young academicians who wish to pursue these arenas of research, so that otolaryngology can assure itself that a select group of well-trained, clinically-oriented researchers will be generated. To this end, we propose to continue our postdoctoral research-training program. The trainees for this program will be selected from MD's who wish to pursue eighteen months of full-time research training during their otolaryngology residency. Trainees will receive advanced basic science, translational or clinical research training in the application of advanced immunology and molecular biology methods to research problems in otolaryngology. However, recognizing the difficulties inherent in training clinician-scientists, we also provide training in research collaboration and team-building, combining research with clinical practice, and effective grant-writing skills. Trainees will also receive instruction in the research ethics, responsible conduct of research, project design and implementation, and publication of results. PUBLIC HEALTH RELEVANCE: Training physicians in Otolaryngology to perform research is of critical importance to the future of the field. Only through research that is performed in a rigorous manner by highly trained physician-scientists will diseases be understood and new treatments be developed. The proposed training will prepare otolaryngologists for careers in academic medicine that include research.

DESCRIPTION (provided by applicant): Partial support is requested for Conferences on the Molecular Biology of Hearing and Deafness (MBHD). This series of meetings has been held successfully since 1992, which argues strongly for the continued success of the future Conferences. The 8th Conference will occur at the Welcome Trust Conference Center at the Sanger Institute in Hinxton, near Cambridge, U.K., on July 6-9, 2011. Support for this conference would be used to reduce the cost of attendance for U.S. students/ postdoctoral fellows and under-represented minority scientists, since existing support for such travel is restricted to U.K. and European candidates. Support is also requested for the 9th Conference, to be held in La Jolla, CA in October of 2013, and the 10th Conference, to be held in the U.K. in 2015. Specific Aims 1. To promote research in emerging areas of molecular biology. These currently include: massively parallel, next-generation sequencing;epigenetics;and comparative genomics;which have experienced significant recent growth due to technical advances and accumulating sequence data. 2. To review progress in molecular biology related to hearing and deafness by inviting scientists involved in significant recent research to present their results, and by soliciting free papers reporting research at the molecular level related to the auditory system. 3. To facilitate interaction and collaboration between different laboratories engaged in molecular auditory research, as well as between basic scientists and clinicians with related interests in the molecular biology and molecular genetics of deafness. 4. To promote translational research that can lead to diagnostics and therapeutics for the treatment of hearing disorders. 5. To encourage trainees and scientists from under-represented minorities to enter careers in the molecular biology of hearing and deafness. 6. To provide outreach to patients, patient advocacy groups, clinicians and schools in the local area, for education in the genetics of deafness and hearing research. PUBLIC HEALTH RELEVANCE: Partial support is requested for Conferences on the Molecular Biology of Hearing and Deafness, an ongoing series of meetings designed to bring together researchers in different topics, including molecular genetics/gene discovery;the molecular basis of auditory function;development;the molecular basis of otologic disorders;hair cell regeneration, and molecular medicine/gene therapy for diseases of hearing. The meetings will also review recent developments in molecular methodologies and promote the interaction of scientists and trainees to share recent results, encourage new studies and collaborations, encourage the translation of basic science results to the clinic, and provide outreach to hearing handicapped patients and clinicians working in this area. The 8th Conference will be held on the campus of the Sanger Institute near Cambridge, England on July 6-9, 2011, the 9th Conference in La Jolla, CA in October of 2013, and the 10th Conference in the U.K. in July of 2015.

DESCRIPTION (provided by applicant): Treatment for chronic otitis media often involves surgery, including tympanostomy tubes which provide aeration and allow the penetration of topical medications through the tympanic membrane. Such local drug treatment has been found to be highly effective. However, surgery is expensive and in many parts of the world is not practical, leading to hearing loss and deaths due to otitis media in the developing world. To enhance medical treatment of middle ear disorders, we used sequential selection of phage-display peptide libraries to identify rare, novel peptides that actively cross the tympanic membrane while transporting cargo. Preliminary data indicate that a bacteriophage bearing one of these peptides enters the middle ear at 106 times the rate of an untargeted phage. We propose to extend this work by determining the rate and saturation level of transtympanic transport for all identified peptides. We will evaluate the external ear, tympanic membrane and middle ear after transtympanic peptide exposure, to determine whether there are any adverse effects, and assess the ability of peptides to carry drugs and to influence a middle ear infection. We will also determine whether these peptides cross the human tympanic membrane, and characterize the binding partners that mediate transtympanic transport. The proposed research will lead to an entirely novel paradigm for the treatment of middle ear diseases. Transtympanic drug delivery would achieve higher middle ear drug levels and avoid side- or off-target effects, when compared to systemic medications. This methodology will have widespread applications for the treatment of otitis media and other middle ear conditions.

DESCRIPTION (provided by applicant): Partial support is requested for Conferences on the Molecular Biology of Hearing and Deafness (MBHD). This series of meetings has been held successfully since 1992, which argues strongly for the continued success of the future Conferences. The 8th Conference will occur at the Welcome Trust Conference Center at the Sanger Institute in Hinxton, near Cambridge, U.K., on July 6-9, 2011. Support for this conference would be used to reduce the cost of attendance for U.S. students/ postdoctoral fellows and under-represented minority scientists, since existing support for such travel is restricted to U.K. and European candidates. Support is also requested for the 9th Conference, to be held in La Jolla, CA in October of 2013, and the 10th Conference, to be held in the U.K. in 2015. Specific Aims 1. To promote research in emerging areas of molecular biology. These currently include: massively parallel, next-generation sequencing; epigenetics; and comparative genomics; which have experienced significant recent growth due to technical advances and accumulating sequence data. 2. To review progress in molecular biology related to hearing and deafness by inviting scientists involved in significant recent research to present their results, and by soliciting free papers reporting research at the molecular level related to the auditory system. 3. To facilitate interaction and collaboration between different laboratories engaged in molecular auditory research, as well as between basic scientists and clinicians with related interests in the molecular biology and molecular genetics of deafness. 4. To promote translational research that can lead to diagnostics and therapeutics for the treatment of hearing disorders. 5. To encourage trainees and scientists from under-represented minorities to enter careers in the molecular biology of hearing and deafness. 6. To provide outreach to patients, patient advocacy groups, clinicians and schools in the local area, for education in the genetics of deafness and hearing research.