You are hereMarch 31, 2016
Stem Cell Discovery Might Lead to Fix for Gene Mutation Behind Hereditary Hearing Loss
Durham, NC – A new study in STEM CELLS Translational Medicine offers people with genetic hearing loss the promise of a new therapy that just might outperform artificial cochlear implants.
Implants currently are the most effective way to treat sensorineural hearing loss, a type of hereditary hearing loss caused by genetic mutations in the hair cells — the sensory receptors of the auditory system, found in the inner ear (the cochlea). A cochlear implant helps transfer sound to the patient’s hearing nerves and enables them to hear. But many researchers believe that stem cells could offer a more comprehensive and better fix for this problem.
“If we can find a way to correct gene mutations using stem cells it might restore the normal function of the hair cells and, thus, the patient’s hearing, too,” said Jin-Fu Wang, Ph.D., a lead investigator on the study conducted with colleagues at Zhejiang University, Shanghai Jiaotong University, Wenzhou Medical University in China, and Cincinnati Children's Hospital Medical Center and Emory University in the United States.
In previous studies, induced pluripotent stem cells (iPSCs) derived from human adult somatic tissue such as skin and urinary cells have been generated from patients with ALS, spinal muscular atrophy, diabetes and other diseases for testing potential therapies and to correct disease-specific genes. The Wang team wanted to try this approach for sensorineural hearing loss.
They hypothesized that a protein-coding gene called MYO7A plays an important role in the assembly of stereocilia into bundles. (Stereocilia are the part of the hair cells that respond to fluid motion. Their bending is how hair cells sense sounds.) If they could use stem cells to repair the mutated MYO7A, that might result in proper growth of the stereocilia and correct the hearing loss.
The team began by generating three iPSC lines from the urinary cells of a 7-year-old hearing loss patient with compound MYO7A gene mutations, her asymptomatic father and a healthy 26-year-old female donor, respectively. The iPSC line from the 7-year-old hearing loss patient were used to correct the MYO7A mutation with CRISPR/Cas9 technique, resulting in morphologic and functional recovery of hair cell-like cells derived from the corrected iPSCs.
“The current findings confirmed our hypothesis and might provide further insight into what is behind sensorineural hearing loss. Our hope is this will facilitate the development of iPSC-based gene therapy for genetic disorders,” Dr. Min-Xin Guan, another lead investigator, concluded.
“In the future, transplantation of these functionally recovered cells may prove to be a promising therapy for deafness resulting from gene mutation,” said Anthony Atala, M.D., Editor-in-Chief of STEM CELLS Translational Medicine and Director of the Wake Forest Institute for Regenerative Medicine. “The authors outline a variety of obstacles that must first be overcome, including finding more efficient methods to derive the large number of cells needed for treatment and developing a method to insert the cells.”
The full article, “Genetic correction of iPSCs from a deaf patient with MYO7A mutation results in morphologic and functional recovery of the derived hair cell-like cells,” can be accessed at www.StemCellsTM.com