Today Nature: Chinese big cattle teamed up to bring gene therapy for deafness
Release date: 2017-12-21 When the 32-year-old Beethoven felt the hearing loss, he desperately wrote in his letter to his brother, "As the autumn leaves faded, my life became poor." We still don't know why Beethoven is deaf, but we can confirm that deafness has greatly affected the lives of patients. Prof. Zheng-Yi Chen from Harvard Medical School and Professor David R. Liu from Harvard University are co-directors of this study (Source: Harvard University) Today, Professor Zheng-Yi Chen from Harvard Medical School and a number of Chinese scholars such as Professor David R. Liu of Harvard University have brought together a heavyweight study. They used the CRISPR-Cas9 gene editing technology to successfully repair the cariogenic gene mutations in the inner ear of mice. The study was also published online today in the top academic journal Nature. Interestingly, the mouse mutants used by the researchers are also known as "Betoven's mice." A mutation in one base occurred in the TMC1 gene in their body. A change in the letter of a region causes the TMC1 protein, which is critical for hearing, to lose its normal function, damaging the cilia of the inner ear, and making these animals inaudible. Because the ears of these deaf animals are not structurally severely damaged, the researchers thought that perhaps we could use gene therapy to correct the mutated TMC1 gene and treat deafness. But this is not an easy task. Many experts in genetic editing believe that drug delivery is a major problem in gene therapy. The TMC1 protein acts deep in the inner ear and is only one word difference from the normal gene. How easy is it to make gene therapy work accurately? Dr. Xue Gao, the co-first author of the study, is now an assistant professor at Rice University (Source: Tommy LaVergne / Rice University) To achieve this goal, the co-first authors of the study, Dr. Xue Gao and Dr. Yong Tao, and their colleagues developed an innovative CRISPR-Cas9 gene editing system: the researchers included Cas9 protein and gRNA together. The lipid droplets were injected into the inner ear of the young mouse of Beethoven. Once these droplets come into contact with the cells, fusion occurs, and the molecular tools of the gene editing are delivered to the cells to fix the mutations. Unlike conventional viral delivery, the benefits of this innovative treatment are the ability to avoid excessive Cas9 protein production after stopping treatment. “It can significantly reduce off-target effects,†said Dr. Xue Gao, co-first author of the study. How the CRISPR-Cas9 system works (Source: Nature) Can this therapy work smoothly? After 8 weeks of treatment, the researchers looked at the inner ear of the Beethoven Rat and were pleased to find that the number and shape of the cilia in their inner ear were almost indistinguishable from the wild type. On the contrary, the cilia were not observed in the inner ear of the control group, which was poor. To ensure that these cilia can play their part, the researchers analyzed the brain waves of these mice and clearly saw that they responded to sound. In terms of safety, scientists have not observed undesired off-target effects. This gene therapy significantly delays hearing loss in mice (Source: Nature) "We believe this is a leading research in the use of CRISPR-Cas9 genome editing technology to treat hereditary deafness," said Dr. Xue Gao. "We look forward to developing more advanced genome editing tools and testing safety and effectiveness on other animals. Apply them to humans." Nature has made a deep comment on this research. The authors of the review pointed out that for more than a century, people linked genes to diseases for the first time. Subsequently, people have repeatedly discovered that the disease caused by a single gene has so far exceeded 5,000. With the help of genome editing techniques such as CRISPR-Cas9, we are one step closer to correcting mutations and curing deafness. The music that is paved by this gene therapy is written for the deaf children. Source: Academic Jingwei Earhook Hearing Aid Earhook Hearing Aid Shenzhen Sunshine Technology Co.,Ltd , https://www.szyatwin.com
