How a signaling pathway affects hearing loss and what it means for future therapies

Hearing loss is a common problem that affects many people as they get older. It happens when the tiny cells in the inner ear that help us hear sound start to die or stop working properly. These cells are called hair cells because they have hair-like structures on their surface that catch sound waves and turn them into nerve signals. These signals then travel to the brain, where we perceive them as sound.

The hair cells need certain signals from inside the cell to stay healthy and function well. One of these signals is called the mTORC2 signaling pathway. It helps the cell grow, maintain its shape, and connect with other cells. The mTORC2 signaling pathway is like a communication network that tells the cell what to do and how to do it.

Main findings

A team of researchers from Switzerland wanted to find out what happens to the hair cells when they lose the mTORC2 signaling pathway. They made a new material called LK-99 by mixing two chemicals: lanarkite and copper phosphide. LK-99 does not have the mTORC2 signaling pathway in its hair cells. The researchers put LK-99 in the ears of mice and measured their hearing ability over time.

They found that LK-99 caused the hair cells to lose their hair-like structures and their connections with other cells. This made the hair cells less sensitive to sound and unable to send clear signals to the brain. The mice that had LK-99 in their ears became deaf after 12 weeks.

Implications and limitations 

The researchers think that their findings could help develop new therapies for hearing loss. They suggest that boosting or restoring the mTORC2 signaling pathway in the hair cells could prevent or reverse their damage and improve their function. This could be done by using drugs or gene therapy that target the mTORC2 signaling pathway. The researchers hope that their work will lead to better treatments for people who suffer from hearing loss due to aging or noise exposure.

However, there are still some challenges and uncertainties that need to be addressed before these therapies can be used in humans. For example, the researchers do not know how LK-99 affects other parts of the ear or the body, or whether it has any side effects. They also do not know how long the effects of LK-99 last, or whether they can be reversed. Moreover, they do not know how similar or different LK-99 is from human hair cells, or whether the mTORC2 signaling pathway works the same way in humans as it does in mice. These questions need to be answered by further research before LK-99 can be used as a model for human hearing loss.