Nov 2016 Sunday Express and Daily Mail
Scientists believe they are on the brink of a cure for congenital deafness after producing stem cells to correct a hereditary defect. They have found a way of growing human cochlear cells which can be used to replace faulty ones in people deaf from birth due to a genetic error. They hope a treatment could be available to patients within five to 10 years. Professor Kazusaku Kamiya, a specialist in ear diseases who is leading the research, which was published in the journal Stem Cell Reports, said: “I am very excited by what we have done. We hope this work will lead to a cure for a form of hereditary deafness. We have found a way to make cochlear stem cells. The next step is to find a way to safely inject them into the patient’s ear. It is possible a therapy could be available within five to 10 years.” The work, which is being carried out at Juntendo University in Tokyo, Japan, aims to correct a mutation in a gene called Gap Junction Beta 2, which accounts for deafness or hearing loss for one in a thousand children. In some parts of the world mutations of this gene are responsible for as many as half the instances of congenital hearing loss. Professor Kamiya and his team have engineered and grown stem cells to replace human cochlear cells without this mutation.
Professor Kamiya and his team have engineered and grown stem cells to replace human cochlear cells
Stem cells are a type of cell that can change into another type of more specialised cell through a process known as differentiation. Think of stem cells as a fresh ball of clay that can be shaped and morphed into any cell in the body. They grow in embryos as embryonic stem cells, used to help the rapidly growing baby form the millions of different cell types it needs to grow before birth.
In adults they are used as repair cells, used to replace those we lose through damage or ageing. Human inner ear hair cells are found in the cochlea - the spiral part of the inner ear - and form a vital component of our ability to hear sound. If these 'cochlea cells' are genetically mutated, patients can be born with severe loss of hearing. They are currently treated with an artificial cochlear implant, which helps transfer sound to the patient’s hearing nerves. Many scientists believe stem cells could offer a better solution by restoring the normal function of the hair cells and, as a result, the patient’s hearing. Humans are born with about 11,000 hair cells in each ear that are vital to transmit sound. As the body ages, it experiences the slow progression of hearing loss due to the death of these cells from excessive noises, exposure to certain drugs, and ageing. One approach could be to place stem cells surgically within the cochlea so they fuse with the remaining cells in the inner ear, and develop and function as normal non-faulty hair cells.
The latest research into stem cells follows previous work led by Dr Marcelo Rivolta, from the University of Sheffield, who is also developing stem cell technologies to re-populate the deaf ear with cells vital to hearing that have been lost. This work offers hope of a cure for people with this type of hearing loss. His colleague, Dr Sarah Boddy, has also been working on a project investigating the potential of human bone marrow stem cells as a way to reverse hearing loss.
The team has shown that human bone marrow stem cells can be converted into ear-like cells after exposure to a mixture of chemicals produced by foetal cochlear cells.
Stem cells are a basic type of cell that can change into another type of more specialised cell through a process known as differentiation.