The Role Of Proteases In Deafness; Generation Of A Knockout Mouse For Tmprss3 As A Model Of Autosomal Recessive Deafness
Funder
National Health and Medical Research Council
Funding Amount
$70,880.00
Summary
Age-related hearing loss is the most common type of human hearing impairment, affecting approximately half the population by the age of 80. The interaction of predisposing genetic factors with environmental factors is responsible for most age-related hearing loss. Genes underlying genetically inherited hearing impairment also affect susceptibility to age-related hearing loss. Approximately 1-1000 children are born deaf and ~50% of these cases have a genetic cause. Autosomal recessively-inherited ....Age-related hearing loss is the most common type of human hearing impairment, affecting approximately half the population by the age of 80. The interaction of predisposing genetic factors with environmental factors is responsible for most age-related hearing loss. Genes underlying genetically inherited hearing impairment also affect susceptibility to age-related hearing loss. Approximately 1-1000 children are born deaf and ~50% of these cases have a genetic cause. Autosomal recessively-inherited defects are responsible for most cases of genetic deafness (70%) and patients have no other medical problems, indicating that only the inner ear is affected. Genes previously identified for genetic forms of deafness can be broadly classified as either ion channels (e.g. connexins) or structural proteins (e.g. myosins and collagens). We recently identified a novel gene, a transmembrane serine protease, TMPRSS3, which is mutated both in familial and sporadic cases of deafness. Different classes of mutations may cause either deafness from birth or childhood onset deafness. Thus, reduced expression or abnormal function of TMPRSS3 may be involved in age-related hearing loss. This discovery was the first description of a protease involved in hearing loss and the first gene family involved in congenital deafness for which a ready hypothesis for involvement in age-related hearing loss can be made. We will generate and characterize a mouse model to investigate the role of TMPRSS3 in inner ear function and development. We will also isolate and characterize additional members of the transmembrane protease gene family to investigate further the role of proteases in both genetic and age-related hearing loss. This may lead to a greater understanding of the function of the auditory system and, eventually, to new therapeutic protocols.Read moreRead less