Reversing Hearing Loss

                                                         Reversing Hearing Loss

Hearing loss is a very common defect to many people no matter the age. There are many people who have been born with a hearing defect and have only used hearing aids and implants, those only work so well. Scientists have believed to find a way to improve your hearing through the genes we have. 

A recent study that they had, they saw there was ​​a gene associated with early onset deafness reversed hearing loss in mice and they hope they can eventually use this information to apply it to humans with hearing loss. They believe that this can one day lead to a solution to people with hearing issues due to genetic issues. 

To study how genetic hearing loss occurs, Steel and the other members of her team mutated spinster homolog 2 Spns2, a gene associated with early onset hearing loss and subsequent deficiency in endocochlear potential (EP). What that does is it basically works as a batter for the inner ear.

In my opinion this is a very beneficial study that they are doing regarding genetics. Many people suffer from hearing loss and so do their parents, which can lead to be a genetic hearing defect. That can help many of those people as well as people born with hearing defects that are due to genetic mutation, or lack of a gene.

Links:

https://www.the-scientist.com/magazine-issue/reversing-hearing-loss-71423https://news.mit.edu/2022/frequency-therapeutics-hearing-regeneration-0329

A Strange Genetic Link Between Humans And Sea Anemones Was Just Confirmed

 

It has just been confirmed that the same gene that allows humans to hear is found in sea anemone and allows them to sense touch. An article on Sciencealert highlights the key information from the study. Essentially, it confirms that the evolution of our senses goes back hundreds of millions of years. This is because sea anemones are the closest relative to animals with bilateral symmetry. It was confirmed that this gene is responsible for sea anemones' sense of touch by knocking out the gene thought to be responsible, pou-iv. By knocking this gene out, the researchers found that the sea anemones' tentacles grew improperly and they did not respond to touch. This is an important discovery, and further research to find if the gene is found in ancestors even farther still needs to be done. 

A Genetic Patch that Eliminates Hearing Problems associated with the DFNA9 Gene

 

According to the researchers at the Radboud University, a genetic patch can eliminate hearing problems associated with the DFNA9 gene. Usually, the mutation in the DFNA9 gene causes deafness from birth. In some cases, hearing problems can occur after forty years. If inherited a mutated copy of the gene, then hearing problems will develop later in life. If inherited two normal copies of the gene, then that person will have normal hearing. The genetic patch, known as antisense oligonucleotide, works by developing a small piece of RNA that binds to the RNA messenger from the muted DFNA9 gene. This stops the production of the mutant DFNA9 protein. Adding the genetic patch would prevent further damage to the ear. Another option to treat problems associated with the DFNA9 gene is to turn it off. This would also stop the production of the mutant DFNA9 protein.  

Articles:

https://neurosciencenews.com/genetic-patch-deafness-17935/

https://www.cell.com/molecular-therapy-family/nucleic-acids/pdf/S2162-2531(21)00068-8.pdf?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2162253121000688%3Fshowall%3Dtrue

Restoring Hearing & Balance

Normal development of an ear(left) and abnormal ear due to loss of hair cells(right)

Our inner ears all contain hair cells which are important for hearing and balance. The final number of hair cells we have in our inner ear are reached before we are even born. Over time loud noises, trauma, infections, and aging cause us to lose these hair cells which impair our hearing and balance. Around 90% of hearing loss occurs when hair cells or auditory nerves are destroyed. Around 36 million adults in the U.S. have reported some degree of hearing loss. A new study from Rockefeller University has found that two genes responsible for inner ear development can be switched on to generate more hair cells in the ear and reverse the loss of hearing and balance. The study look place at the sensory neuroscience lab at Rockefeller University, headed by post-doctoral researcher Dr. Ksenia Gnedeva. Dr. Gnedeva began her study by looking for changes in gene expression in the utricle (an inner ear structure) of mice before and after birth. She discovered that two genes were highly active before birth but later became silent after birth. The silencing of these two genes after birth is what causes hair cells to stop developing. When both of these genes were switched off in the mice, the entire ear developed abnormally. However, when Dr. Gnedeva switched on the two genes in elder mice, she found that new hair cells began to generate inside the utricles of the inner ear. Dr.Gnedeva says that she hopes her findings will allow us to generate new hair cells later on in life in order to repair the loss of hearing and balance as we age.

I was surprised to learn that 36 million people in the U.S. suffer from some sort of hearing loss. It was interesting to learn that switching on two genes in the inner ear have the possibility to restore hearing and balance later on in life. It will be interesting to see if the same results seen in the mice will also be seen in humans.

Original Article

Mutant Gene that Causes Deafness Discovered

       Researchers have recently discovered a mutant gene called Tmie that can cause deafness from birth. Scientist were then able to reintroduce the gene in mice and restore hearing, instilling new confidence that with the identification of this gene, gene therapy can be used to restore hearing in humans.

      The scientists identified the Tmie gene by studying the process of hearing, which involves mechanotransduction (the process of converting mechanical force into electrical activity). Researchers specifically looked for how signals were passed along tip link proteins and to the ion channels (essentially electric signals). They eventually found the Tmie gene, whose protein TMIE interacts with tip link proteins a connects the tip links to a piece of machinery near the ion channel.

    Researchers then bred a population of mice that lacked the gene. They studied these mice and found that without the Tmie gene, no electrical signal could be invoked in the hair cells after stimulation, meaning the mechanotransduction current is totally gone and the mice were deaf. In a second part of the experiment, researchers reintroduced Tmie into mice that had been deaf since birth and found that hearing was restored. This new breakthrough means gene therapy may be able to be used to restore hearing in humans and even possibly knock out deafness entirely in the future. 

 Article