Scientists are reporting the first direct evidence that a subtle change in the physical properties of a tissue can affect its function. The finding has immediate implications for understanding several rare hearing disorders, they said, and ultimately could offer insight into such conditions as osteoporosis, arthritis, cardiovascular disease and cancer.
In their study, the scientists discovered that blocking the function of a particular molecule in the ear bone of mice decreased the hardness of the bone, causing hearing loss. Reactivating the molecule restored the bone's hardness and the animals' hearing.
The research likely explains the previously unknown cause of hearing loss in the human disease cleidocranial dysplasia, a genetic bone syndrome, said co-author Lawrence Lustig, MD, UCSF professor of otolaryngology, and may explain hearing loss associated with some other bone diseases.
More broadly, the finding reveals the molecular pathway that regulates the physical properties of extracellular matrix the interlocking mesh of molecules between cells in the ear's cochlear bone. The matrix is responsible for the hardness of human tissues, ranging from stiff bone and enamel to compliant brain and skin.
Perhaps most intriguing is the discovery that variations in the physical properties of extracellular matrix affect tissue function. This finding should lead to insights into abnormal matrix properties in the tissues of diseases throughout the body, the researchers said, including osteoporosis and arthritis.
"Our finding demonstrates that establishing and maintaining the proper calibration of physical properties is essential for healthy tissue function," said the senior author of the study, Tamara Alliston, PhD, assistant professor of orthopaedic surgery and a member of the Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research at UCSF.
Scientists have known that physical cues, such as
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University of California - San Francisco