Thanks to the persistent efforts of scientists, we may be closer to finding a cure to hearing impairment. They have discovered a gene therapy that could work to reverse hearing loss.
America’s Statistics on Hearing Loss
According to the National Institute on Deafness and Other Communication Disorders approximately, “18 percent of adults aged 20-69 have speech-frequency hearing loss in both ears.”
This is “from among those who report 5 or more years of exposure to very loud noise at work, as compared to 5.5 percent of adults with speech-frequency hearing loss in both ears who report no occupational noise exposure.
And approximately 15% of American adults (37.5 million) aged 18 and over report some trouble hearing.”
Unfortunately, twice as many men than women, experience hearing loss problems. And this sometimes has to do with occupational hazards.
They also report that of the nearly 38.7 million people having this problem, 28.8 million could see better effects. However, they would have to receive hearing loss treatment or hearing aids.
The Causes of Hearing Loss
One of the primary reasons why people lose their hearing is that they incur some damage to their auditory hair cells.
Another attributing factor is age.
However, those who work in environments that have constant loud noises are at an even greater risk. In addition, they get ear infections, head trauma and other ear degenerative illnesses.
Protecting your hearing is important. So wear the necessary gears when you in these conditions.
About the Auditory Hair Cells
Without hearing, you would not be able to be sufficiently conscious about what is happening around you. That is why, even when you are asleep, you still maintain some level of hearing.
It lets us know if we are in danger, or if someone is trying to get our attention.
So, hearing is made possible by a number of parts in your ears. One such is the auditory hair cells, which are small sensory cells. They are located in the cochlea, which is in the inner ear.
These cells are what causes us to hear and without them, we will go deaf.
The auditory hair cells have stereocilia, which are hair-like projections. They take care of changing the vibration of sounds into electrical signals. And then these signals are sent to the brain.
Once we lose these cells, we stop hearing. Human beings cannot naturally grow them back. However, other species in the animal kingdom can.
This includes birds and fishes.
Exploring Gene Therapy to Reverse Hearing Loss
According to St. Jude Children’s Research Hospital physician, Jian Zuo, Ph.D., “The process involves down-regulating expression of the protein p27 and up-regulating the expression of the protein ATOH1.”
Jian Zuo and his team explored genetic manipulation to cause the re-growth of the auditory hair cells.
What Did the Team Do?
At his laboratory, the team focused on “the identification and characterization of genes important for the development and degeneration of cerebellar Purkinje cells and inner ear hair cells.
They are taking two complementary approaches. The first, positional cloning of mouse mutant genes, takes advantage of recent advances in the mouse genome project.”
The scientists explored genetic manipulation by removing the p27 protein in mice and improving the presence of ATOH1.
Dr. Jian Zuo and his team exposed the test mice to extremely loud noises, which caused hair cell damage. But once that occurred, they noticed something else.
Even though the original cells died, those cells that supported the hair cells before, they began to change into auditory hair cells.
This was caused by certain proteins working together.
So the scientists discovered that when they deleted the p27, then GATA3 proteins increased and impacted the amount of POU4F3 proteins. This too linked to the increase of ATOH1, which directly caused a re-growth of auditory hair cells in the mice.
So, they learned that the ATOH1 is what was necessary for this occurrence. For human beings, we have an increased presence of this when our bodies are developing in the womb.
Once we come out, it no longer continues.
So, Dr. Jian Zuo and his team, surmise that there is a strong possibility that this development can be replicated in human beings, at the genetic level.
They posit that it could be done if the genes, which are responsible for the POU4F3, GATA3 and p27 proteins are altered, are manipulated.
Related Work by Dr. Jian Zuo
The application of this discovery to reverse hearing loss can be applied in other areas.
Zuo said, “Work in other organs has shown that reprogramming cells is rarely accomplished by manipulating a single factor.
This study suggests that supporting cells in the cochlea are no exception and may benefit from therapies that target the proteins identified in this study.”
So, we wait with bated breath for more finding to come out of his work. And maybe soon, we can truly implement this hearing loss cure.