A recent study published in the Science Translational Medicine journal has shed light on a novel method of delivering treatment to the inner ear, which effectively reversed hearing loss in mice. The researchers have shared their intriguing findings.
"These findings demonstrate that cerebrospinal fluid transport comprises an accessible route for gene delivery to the adult inner ear and may represent an important step towards using gene therapy to restore hearing in humans," said Maiken Nedergaard, MD, DMSc at University of Rochester.
Hearing loss is primarily caused by damage to hair cells in the cochlea. This damage can be attributed to several factors including gene mutations, exposure to loud noises, and aging. While dead and damaged hair cells do not self-repair, studies have indicated that various treatments and therapies can repair these cells and reverse hearing loss in mice, according to a news release from Advanced Audiology & Hearing Care.
In a collaborative study conducted by researchers at the University of Rochester, the University of Copenhagen, and the Karolinska Institute in Stockholm, Sweden, further exploration was made into how treatments are transported to the inner ear. The focus was on the glymphatic system - a process through which the brain flushes out debris and toxins using cerebrospinal fluid. The team discovered that this system could potentially be used to deliver treatments to the inner ear, as per a news release from Advanced Audiology & Hearing Care.
The researchers also identified a gateway into the cochlea known as the cochlear aqueduct. They found it acts as a conduit separating cerebrospinal fluid from both the inner ear and other parts of the brain. Utilizing this understanding, they mapped out how cerebrospinal fluid flows from different parts of the brain through this aqueduct. They then injected gene therapy into this fluid which subsequently flowed into the inner ear restoring hearing in mice. This information was revealed in a news release from Advanced Audiology & Hearing Care.
The reversal of hearing loss and the discovery of this new method of delivering treatment to the inner ear has left researchers optimistic. Nedergaard, senior author of the study, stated, "This new delivery route into the ear may not only serve the advancement of auditory research but also prove useful when translated to humans with progressive genetic-mediated hearing loss," according to a news release from Advanced Audiology & Hearing Care.
