Sensorineural hearing loss (SNHL) specifically has etiologies including trauma, infectious conditions, ototoxin exposure, and trauma. Hearing loss affects millions of Americans in every age group, and it can be either conductive or sensorineural. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. (2021) The Use of Stem Cells in the Treatment of Sensorineural Hearing Loss.
* Corresponding author: Vincent S Gallicchio, Department of Biological Sciences, College of Science, Clemson University, Clemson, South Carolina, USAĬitation: Keller AC, Gallicchio VS.
Gallicchio *ĭepartment of Biological Sciences, College of Science, Clemson University, Clemson, South Carolina, USA News Research News Releases Journal News Medical News Science News Life News Business News Expert Pitch Google Fact Check Research Alert Marketplace News With Video/Audio Multimedia RSS Feeds byĪubrey C Keller and Vincent S. "Similar epigenetic modifications may also prove useful in other non-regenerating tissues, such as the retina, kidney, lung, and heart.Latest News Coronavirus News Currently Embargoed "Our study raises the possibility of using therapeutic drugs, gene editing, or other strategies to make epigenetic modifications that tap into the latent regenerative capacity of inner ear cells as a way to restore hearing," said Segil. Likewise, supporting cells from the vestibular system, which naturally maintained H3K4me1, were still primed for transdifferentiation into adulthood. However, if the scientists added a drug to prevent the loss of H3K4me1, the supporting cells remained temporarily primed for transdifferentiation. Unfortunately with age, the supporting cells of the cochlea gradually lost H3K4me1, causing them to exit the primed state. During transdifferentiation of a supporting cell to a hair cell, the presence of H3K4me1 is crucial to activate the correct genes for hair cell development. However, at the same time, in the newborn mouse supporting cells, the hair cell genes were kept "primed" to activate by the presence of yet a different histone decoration, H3K4me1. In the supporting cells of the newborn mouse cochlea, the scientists found that hair cell genes were suppressed by both the lack of an activating molecule, H3K27ac, and the presence of the repressive molecule, H3K27me3. In this way, epigenetic modifications regulate gene activity and control the emergent properties of the genome. In response to these decorations known as "epigenetic modifications," the histone proteins wrap the DNA into each cell nucleus, controlling which genes are turned "on" by being loosely wrapped and accessible, and which are turned "off" by being tightly wrapped and inaccessible. To turn genes on and off, the body relies on activating and repressive molecules that decorate the proteins known as histones.
In supporting cells, the hundreds of genes that instruct transdifferentiation into hair cells are normally turned off. By one week of age, mice lose this regenerative capacity - also lost in humans, probably before birth.īased on these observations, postdoctoral scholar Litao Tao, PhD, graduate student Haoze (Vincent) Yu, and their colleagues took a closer look at neonatal changes that cause supporting cells to lose their potential for transdifferentiation. However, for the first few days of life, lab mice retain an ability for supporting cells to transform into hair cells through a process known as "transdifferentiation," allowing recovery from hearing loss. When the delicate hair cells incur damage from loud noises, certain prescription drugs, or other harmful agents, the resulting hearing loss is permanent in older mammals. In the inner ear, the hearing organ, which is the cochlea, contains two major types of sensory cells: "hair cells" that have hair-like cellular projections that receive sound vibrations and so-called "supporting cells" that play important structural and functional roles. "Our study suggests new gene engineering approaches that could be used to channel some of the same regenerative capability present in embryonic inner ear cells." "Permanent hearing loss affects more than 60 percent of the population that reaches retirement age," said Segil, who is a Professor in the Department of Stem Cell Biology and Regenerative Medicine, and the USC Tina and Rick Caruso Department of Otolaryngology - Head and Neck Surgery.
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