Inner ear supporting cells protect hair cells by secreting HSP70

An underlying cause of hearing loss is the death of sensory hair cells in the inner ear, which can be damaged in response to a variety of factors including the use of aminoglycoside antibiotics. Previous research has shown that sensory hair cell death in response to antibiotic treatment can be prevented by triggering the expression of HSP70, a member of the heat shock family of proteins that are induced by cellular stress.

In this issue of the Journal of Clinical Investigation, Lisa Cunningham and colleagues at the National Institutes of Health investigate the mechanism underlying the protective effect of HSP70 on antibiotic induced hair cell loss. This group found that HSP70 is produced and secreted by the supporting cells of the inner ear in response to heat shock. Extracellular HSP70 produced either by supporting cells or added exogenously prevented antibiotic induced hair cell death.

In the companion commentary Rona Giffard and colleagues at the Stanford University School of Medicine point out that there are no current treatments for prevention of aminoglycoside induced hearing loss and that extracellular HSP70 has potential to be used therapeutically.