Scientists have restored hearing to deaf gerbils using human embryonic stem cells in an advance that could eventually help people with an intractable form of deafness caused by nerve damage.
The procedure needs further animal research to assess safety and long-term effectiveness, but researchers said on Wednesday the experiment was an important proof of concept, marking a further advance in the growing field of regenerative medicine.
Marcelo Rivolta from Britain’s University of Sheffield, who led the research, said the first patients could receive cell therapy for hearing loss in clinical trials in “a few years.”
After treating 18 gerbils with complete deafness in one ear, his team reported in the journal Nature that stem cells produced an average 46 percent recovery in hearing function, as measured by electrical signals in the animals’ brains.
“If this was a human patient, it would mean going from being so deaf as to be unable to hear a lorry or truck on the street, to being able to maintain a conversation,” Rivolta told reporters. “What we have shown here is functional recovery using human stem cells, which is unique.”
Gerbils were selected for the test because their hearing range is similar to that of humans, while mice — the usual choice for laboratory tests — hear at higher frequencies.
The animals were deafened using a drug to destroy their auditory nerves, before receiving an injection of about 50,000 human embryonic stem cells, which had previously been treated with growth factors to coax them into becoming ear cells.
The response among the gerbils varied, depending on how well the new cells were integrated into the cochlea, the spiral-shaped cavity in the inner ear.
Deafness is caused primarily by loss of sensory hair cells in the ear and auditory nerves. Since these cells are created only in the womb, there is no way to repair them once they have been damaged, resulting in permanent hearing loss.
Cochlear implants offer a partial solution to loss of hair cells, but there is no treatment for nerve loss, or auditory neuropathy, which accounts for between 10 percent and 15 percent of cases of profound deafness.
Rivolta said stem-cell treatment would initially address nerve damage, although it could also be used in a wider range of patients if it was used in combination with implants.
Significant uncertainties remain, though.
In particular, the ability of embryonic stem cells to morph into any of the other cell types in the body means they can cause tumors — something that was not seen in the 10-week gerbil study, but which Rivolta said needed longer study.
Another danger is that transplanted cells may be rejected by the recipient’s immune system.
The research on deafness parallels more advanced work on the eye, where stem cells have already been shown to improve vision in small-scale human tests.
Doctors hope one day to use stem cells to treat a wide range of diseases, such as Parkinson’s, diabetes and cancer, but localized approaches in the eye or ear may be a promising first step, since fewer cells are involved.
Ralph Holme of the charity Action on Hearing Loss, which helped fund the Sheffield research, said the work was “tremendously encouraging” and gave hope of a fix to some types of hearing loss in the future.
“For the millions of people for whom hearing loss is eroding their quality of life, this can’t come soon enough,” he said.
MONEY MATTERS: Xi was to highlight projects such as a new high-speed railway between Belgrade and Budapest, as Serbia is entirely open to Chinese trade and investment Serbian President Aleksandar Vucic yesterday said that “Taiwan is China” as he made a speech welcoming Chinese President Xi Jinping (習近平) to Belgrade, state broadcaster Radio Television of Serbia (RTS) said. “We have a clear and simple position regarding Chinese territorial integrity,” he told a crowd outside the government offices while Xi applauded him. “Yes, Taiwan is China.” Xi landed in Belgrade on Tuesday night on the second leg of his European tour, and was greeted by Vucic and most government ministers. Xi had just completed a two-day trip to France, where he held talks with French President Emmanuel Macron as the
With the midday sun blazing, an experimental orange and white F-16 fighter jet launched with a familiar roar that is a hallmark of US airpower, but the aerial combat that followed was unlike any other: This F-16 was controlled by artificial intelligence (AI), not a human pilot, and riding in the front seat was US Secretary of the Air Force Frank Kendall. AI marks one of the biggest advances in military aviation since the introduction of stealth in the early 1990s, and the US Air Force has aggressively leaned in. Even though the technology is not fully developed, the service is planning
INTERNATIONAL PROBE: Australian and US authorities were helping coordinate the investigation of the case, which follows the 2015 murder of Australian surfers in Mexico Three bodies were found in Mexico’s Baja California state, the FBI said on Friday, days after two Australians and an American went missing during a surfing trip in an area hit by cartel violence. Authorities used a pulley system to hoist what appeared to be lifeless bodies covered in mud from a shaft on a cliff high above the Pacific. “We confirm there were three individuals found deceased in Santo Tomas, Baja California,” a statement from the FBI’s office in San Diego, California, said without providing the identities of the victims. Australian brothers Jake and Callum Robinson and their American friend Jack Carter
CUSTOMS DUTIES: France’s cognac industry was closely watching the talks, fearing that an anti-dumping investigation opened by China is retaliation for trade tensions French President Emmanuel Macron yesterday hosted Chinese President Xi Jinping (習近平) at one of his beloved childhood haunts in the Pyrenees, seeking to press a message to Beijing not to support Russia’s war against Ukraine and to accept fairer trade. The first day of Xi’s state visit to France, his first to Europe since 2019, saw respectful, but sometimes robust exchanges between the two men during a succession of talks on Monday. Macron, joined initially by EU Commission President Ursula von der Leyen, urged Xi not to allow the export of any technology that could be used by Russia in its invasion