and Hearing Loss
Dear Healthcare Provider,
Cord Blood Registry (CBR) provides quarterly research updates to keep you abreast of exciting advancements in stem cell science. One area that has shown vast growth is regenerative medicine-the use of stem cell based therapies to repair, replace, or regenerate impaired cells and tissues in order to restore function. This research update summarizes a recent study demonstrating that cord blood stem cells have the ability to repair damage to the inner ear, signifying that cord blood may be fundamental to the development of stem cell-based hearing loss treatments.(1)
Cord Blood Stem Cells and Hearing Loss:
Cochlear Repair by Transplantation of Human Cord Blood CD133+ Cells to Nod-Scid Mice Made Deaf with Kanamycin and Noise
Background: Hearing loss and deafness often result from permanent damage to the cells of the inner ear such as the cochlear neurons and the hair cells. Based on previous findings showing that hematopoietic stem cells (HSC) are able to differentiate into cochlear neurons and hair cells, the authors hypothesized that cord blood-derived HSC are capable of repairing permanent damage to the inner ear.
Study: Human cord blood HSC were intravenously injected into immunodeficient mice made deaf by exposure to kanamycin (an ototoxic chemical), high intensity noise, or a combination of these insults. Stem cell migration, engraftment, and tissue morphology were assessed in the mice that received HSC treatment and in non-HSC treated control mice.
Results: The authors found that HSC migrated and engrafted into the cochlea of the deaf mice and that the levels of engraftment correlated with both the severity of damage and the treatment dose. Analysis at 60 days post-treatment showed that the mice in the HSC treatment group had well-repaired cochlea with dramatic hair cell regrowth, while control mice showed no sign of repair or hair cell regeneration.
Conclusion: The study shows dramatic repair of cochlear damage in mice after intravenous infusion of cord blood HSC, suggesting a potential therapeutic strategy using cord blood stem cells in hearing rehabilitation therapies.
Researchers have already shown that cord blood stem cells hold great promise in regenerative medicine treatments for several conditions including brain injury, cardiovascular disease, and type 1 diabetes.
CBR will continue to bring you updates on new and interesting studies involving cord blood stem cells for your reference and patient discussions. If you have any questions regarding the information in this e-mail, feel free to contact me at the number listed below. In addition, if you would like to request patient education materials for your office, please contact our caregiver hotline: 1-888-588-0258.
Revoltella RP, Papini S, Rosellini A, et al. Cochlear repair by transplantation of human cord blood CD133+ cells to nod-scid mice made deaf with kanamycin and noise. Cell Transplant. 2008;17(6):665-678.
Niskar AS, Kieszak SM, Holmes A, Esteban E, Rubin C, Brody DJ. Prevalence of hearing loss among children 6 to 19 years of age: the Third National Health and Nutrition Examination Survey. JAMA. 1998;279(14):1071-1075.
National Institute on Deafness and Other Communication Disorders (NIDCD): Quick Statistics.
Available at http://www.nidcd.nih.gov/health/statistics/quick.htm. Accessed September 18, 2008.
Hearing Loss Statistics
15% of children in the US have low or high-frequency hearing loss.(2)
2 to 3 out of every 1,000 children in the US are born deaf or hard-of-hearing.(3)
4,000 new cases of sudden deafness occur each year in the US.(3)
Cord blood stem cells have been shown to repair inner ear cells, such as cochlear hair cells (shown above), that are essential to hearing. (Image courtesy of the House Ear Institute. © All rights reserved.)
Copyright © 1995-2009 CBR Systems, Inc. All Rights Reserved. Cord Blood Registry. 1200 Bayhill Drive, San Bruno, CA 94066.