Fight Aging!

This open access paper presents an interesting view on age-related hearing loss, a contrast to more frequently reported efforts to regenerate hair cells in the ear known to be lost in old age:

Hearing loss constitutes a major health problem affecting 16% of the adult population worldwide. Aging is the main risk factor associated with hearing impairment. Age-related sensorineural hearing loss (SNHL) is the third most common disability of the elderly affecting about half of the population over 75 years old. SNHL is a pathology of the cochlea that is generally regarded as mechanical or chemical damage-induced hair cell death triggering spiral ganglion neuron (SGN) death and subsequent dysfunction of auditory nerve. Recent researches in SNHL field have lead to a more complex vision of the relationship between inner ear damage and SNHL. Indeed, SGN loss without hair cell damage or death was observed.

Interestingly, cholesterol homeostasis and metabolism are central to numerous pathologies including neurodegenerative diseases, and regulate the many of the processes involved in neuron survival and functionality. Consequently, interfering with cholesterol homeostasis should afford innovative therapeutic strategies to improve the care of SNHL. Even if studies related to cholesterol homeostasis in inner ear are scarce, some reports support a relationship between cholesterol homeostasis deregulation and SNHL. Indeed, atherosclerosis, high plasma total cholesterol, and low HDL levels are positively correlated with SNHL. The most plausible explanation is that hypercholesterolemia triggers the stenosis of spiral modiolar artery leading to cochlear ischemia and subsequent SNHL. Consequently, therapies that limit high plasma cholesterol level could be useful to prevent SNHL caused by cochlear ischemia.

Link: http://journal.frontiersin.org/article/10.3389/fnagi.2015.00003/full