ERECTILE dysfunction drug Viagra could reverse the damage that causes deafness, according to a new study.
is very common, particularly as you get older.
Scientists say Viagra could help reverse hearing loss caused by gene mutationsCredit: bymuratdeniz
In many cases, it’s caused by ageing or exposure to loud noises.
A rare form of hearing loss that’s inherited or present from birth is caused by mutations to a gene, known as CPD.
Scientists from the US and Turkiye showed how the gene affects the inner ear – and identified two possible ways of treating the condition.
This is included Viagra, as well a popular supplement.
Lead author Rong Grace Zhai, Jack Miller professor for the study of neurological diseases of neurology at the University of , said: “This study is exciting because we found a new gene mutation that’s linked to deafness, and more importantly we have a therapeutic target that can actually mitigate this condition.”
Scientists said their findings – published in the Journal of Clinical Investigation – might also apply to people with age-related hearing loss, which is far more common.
Researchers started looking into the CPD gene after identifying a distinct combination of mutations in three unrelated families from Turkiye with a congenital form of deafness known as sensorineural hearing loss, or SNHL.
The condition, usually diagnosed in early childhood and passed down through families, causes permanent hearing loss and is thought to be irreversible.
After analysing a genetic database, scientists found that other people with CPD mutations also showed signs of early onset hearing loss.
Although hearing may be improved with hearing aids and cochlear implants, there is currently no way of treating the condition itself.
To get a better idea of how the CPD gene influences hearing, they conducted a mouse study.
Normally, the CPD gene is involved in the production of the amino acid arginine, which in turn produces nitric oxide, an important neurotransmitter that helps send signals through the nervous system.
By studying the mouse inner ear, which is similar to humans, the scientists found that mutations in the CPD gene disrupted this pathway, leading to cell death in the ear’s sensory cells, especially in the delicate hairs that detect sound waves.
Prof Zhai said: “It turns out that CPD maintains the level of arginine in the cells to allow a quick signalling cascade by generating nitric oxide.
“And that’s why, although it’s expressed ubiquitously in other cells throughout the nervous system, these hair cells in particular are more sensitive or vulnerable to the loss of CPD.”
The team also used fruit flies to study the effects of CPD changes, finding that insects with gene mutations showed behavioural changes consistent with inner ear damage, like hearing loss and balance problems.
Finally, researchers tested two approaches to treating disrupted CPD pathways: arginine supplements to make up for the arginine lost due to the CPD mutation, and sildenafil – another name for Viagra – which they knew would stimulate one of the pathways affected by the loss of nitric oxide.
When the team gave mice arginine, cell death was reduced, and nitric oxide levels were restored.
Am I going deaf?
It’s not always easy to tell if you’re losing your hearing.
Common signs include:
- Difficulty hearing other people clearly and misunderstanding what they say, especially in noisy places
- Needing to ask people to repeat themselves
- Listening to music or watching TV with the volume higher than other people need
- Difficulty hearing on the phone
- Finding it hard to keep up with a conversation
- Feeling tired or stressed from having to concentrate while listening
Sometimes someone else might notice problems with your hearing before you do.
Source: NHS
The findings suggest the common supplement L-arginine may help restore some forms of hearing loss – though it’s worth noting the findings were preliminary and we can’t be sure if they apply to humans.
Viagra also reduced hearing loss-related behaviours in fruit flies and cell death.
Prof Zhai said: “What makes this really impactful is that not only do we understand the underlying cellular and molecular mechanism for this kind of deafness, but we also found a promising therapeutic avenue for these patients.
“It is a good example of our efforts to repurpose FDA approved for treating rare diseases.”
The Food and Drug Administration, or FDA, regulates drugs, food and cosmetics in the US.
The researchers plan on conducting more studies on the subject and establishing how common CPD mutations are in larger populations.
Prof Zhai said: “How many people carry variants in this gene and is there a susceptibility to deafness or age-dependent hearing loss?
“In other words, is this a risk factor for other types of sensory neuropathy?”
Researchers say their findings could apply to other types of hearing loss if they are found to be linked to gene mutations.
In the UK, Viagra is used to treat erectile problems, by increasing blood flow to the penis.
It’s worth noting that overuse of Viagra-style pills has .
