Newswise — Researchers from the University of Virginia School of Medicine have made a significant breakthrough in understanding how the cells responsible for our hearing can regenerate themselves after sustaining damage. This newfound knowledge has the potential to revolutionize the development of more effective treatments and preventive measures for hearing loss.

The inner ear contains specialized cells called "hair cells" that play a crucial role in our auditory perception and sense of balance. These hair cells derive their name from the hair-like structures that adorn their surfaces, acting as mechanical receptors for detecting sound. Until now, it was widely believed that once auditory hair cells were destroyed, they were irreversibly lost. However, the UVA Health study demonstrates that these delicate cells possess inherent regenerative abilities, enabling them to repair themselves when exposed to damaging factors such as loud noises or various forms of stress.

The lead researcher, Dr. Jung-Bum Shin from UVA's Department of Neuroscience, emphasized the significance of comprehending the intrinsic mechanisms governing the repair and maintenance of these hair cells. While the scientific community has devoted considerable efforts to regenerating sensory hair cells, it is equally important to delve into the understanding of their inherent repair processes. By gaining deeper insights into these mechanisms, researchers can potentially develop strategies to strengthen and augment the repair capabilities of these cells. One potential future approach involves the utilization of pharmaceutical interventions that stimulate repair programs.

Dr. Shin further explains that when replacing damaged hair cells becomes challenging, the focus shifts towards repairing them instead. This dual strategy, combining regeneration and repair, holds immense promise for advancing treatments for hearing loss and related conditions. The findings of this research open up new avenues for therapeutic advancements, potentially leading to improved treatments and preventive measures for hearing loss in the future.

Hearing Repair

Hair cells are incredibly delicate by nature, as they need to be sensitive to sound while enduring continuous mechanical stress in their role. Prolonged exposure to loud noise can cause various forms of damage to these hair cells, particularly affecting the cores of their hair-like structures known as stereocilia. However, recent research led by Shin has unveiled a remarkable self-repair process employed by these hair cells.

The key to this repair mechanism lies in a protein called XIRP2, which possesses the ability to detect damage within the cores composed of actin, a vital substance. Shin and his team discovered that XIRP2 first detects the damage and then relocates to the site of damage, replenishing the cores by generating new actin.

Shin expressed excitement over this groundbreaking revelation, emphasizing the novel way in which XIRP2 can sense and respond to distortions in the actin backbone caused by damage. This discovery not only holds significance for hair cell research but also extends to the broader field of cell biology.

As a result of their pioneering work, Shin and his colleagues have received a substantial grant of over $2.3 million from the National Institutes of Health (grant R01DC021176). This funding will support further research to delve into the intricacies of core repair. By gaining a deeper understanding of this process, scientists will be better equipped to develop innovative strategies for combating hearing loss, including age-related hearing loss, which affects a significant portion of older adults.

Shin further highlights the importance of unraveling the internal mechanisms through which hair cells counteract wear and tear, particularly in the context of age-related hearing loss. Understanding these mechanisms holds the key to identifying preventative measures for age-related hearing loss. Moreover, this knowledge has the potential to extend its impact to associated conditions such as Alzheimer's disease and other forms of dementia.

Findings Published

The researchers have published their findings in the scientific journal eLife. The article is open access, meaning it is free to read.

The research team consisted of Elizabeth L. Wagner, Jun-Sub Im, Stefano Sala, Maura I. Nakahata, Terence E. Imbery, Sihan Li, Daniel Chen, Katherine Nimchuk, Yael Noy, David W. Archer, Wenhao Xu, George Hashisaki, Karen B. Avraham, Patrick W. Oakes and Shin. The researchers have no financial interest in the work.

The research was supported by the National Institutes of Health’s National Institute on Deafness and Other Communication Disorders, grants R01DC014254, R56DC017724, R01DC018842, R01DC011835 and 1F31DC017370-01. Additional support was provided by the Owens Family Foundation, the Virginia Lions Hearing Foundation, and a National Science Foundation CAREER Award.

Journal Link: eLife