Preclinical Validation of Novel Fluorescently Labeled Compounds to Treat Neurodegenerative Hearing Loss
Abstract
Background: The proposed research addresses a FY14/15 CRMRP NSRRA focus area on hearing loss, with a specific focus on neurodegenerative hearing loss, which commonly accompanies traumatic brain injury (TBI). There is an unmet medical need to develop pharmacologic therapies for hearing loss. We address that need, and the focus area on preclinical research to restore function, by studying a neuroregenerative potential of bisphosphonates, which are FDA-approved for the treatment of bone diseases such as osteoporosis. By utilizing drug repositioning, we expedite translation of our research to a potential future clinical trial. Our research also indirectly addresses the focus area of pain management because metabolites that we study are known to mediate pain. Our experiments test the hypothesis that bisphosphonates promote cochlear synaptogenesis and neurogenesis, and that this regenerative effect is mediated by ERK inhibition and decrease in farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate levels (GGPP). Progress: We have developed an in vitro model to study synaptopathy based on application of kainic acid to murine cochlear explants. We have used this model to begin studying synaptogenic potential of a specific bisphosphonate, zoledronate, in vitro. In parallel, we have developed and published a mouse model of cochlear synaptopathy in vivo. Using this model, we have obtained preliminary data demonstrating a synapthogenic potential of zoledronate in vivo. Because bisphosphonates signal via ERK, whose activation is affected by osteoprotegerin (OPG), we studied and described, for the first time, cochlear expression of OPG-related molecules TNF-related apoptosis-inducing ligand (TRAIL) and its signaling death receptor 5 (DR5). With an eye toward an ultimate clinical trial, we have studied limitations of current audiograms in predicting specific cellular damage, and have identified optical tools that have a potential of quantifying neuronal damage in vivo.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2016
- Accession Number
- AD1034331
Entities
People
- Konstantina M. Stankovic
Organizations
- Massachusetts Eye and Ear Infirmary