Effects of Long-Term Exercise on Age-Related Hearing Loss in Mice.
Regular physical exercise reduces the risk for obesity, cardiovascular diseases, and disability and is associated with longer lifespan expectancy (Taylor et al., 2004; Pahor et al., 2014; Anton et al., 2015; Arem et al., 2015). In contrast, decreased physical function is associated with hearing loss among older adults (Li et al., 2013; Chen et al., 2015). Here, we investigated the effects of long-term voluntary wheel running (WR) on age-related hearing loss (AHL) in CBA/CaJ mice, a well established model of AHL (Zheng et al., 1999). WR activity peaked at 6 months of age (12,280 m/d) and gradually decreased over time. At 24 months of age, the average WR distance was 3987 m/d. Twenty-four-month-old runners had less cochlear hair cell and spiral ganglion neuron loss and better auditory brainstem response thresholds at the low and middle frequencies compared with age-matched, non-WR controls. Gene ontology (GO) enrichment analysis of inner ear tissues from 6-month-old controls and runners revealed that WR resulted in a marked enrichment for GO gene sets associated with immune response, inflammatory response, vascular function, and apoptosis. In agreement with these results, there was reduced stria vascularis (SV) atrophy and reduced loss of capillaries in the SV of old runners versus old controls. Given that SV holds numerous capillaries that are essential for transporting oxygen and nutrients into the cochlea, our findings suggest that long-term exercise delays the progression of AHL by reducing age-related loss of strial capillaries associated with inflammation.



Nearly two-thirds of adults aged 70 years or older develop significant age-related hearing loss (AHL), a condition that can lead to social isolation and major communication difficulties. AHL is also associated with decreased physical function among older adults. In the current study, we show that regular exercise slowed AHL and cochlear degeneration significantly in a well established murine model. Our data suggest that regular exercise delays the progression of AHL by reducing age-related loss of strial capillaries associated with inflammation.
Department of Aging and Geriatric Research.
Chul
0000-0002-5195-6964
C
Han
Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, New York 14214, and.
Dalian
0000-0003-3302-2815
D
Ding
Department of Molecular Genetics and Microbiology.
Maria-Cecilia
MC
Lopez
Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, New York 14214, and.
Senthilvelan
S
Manohar
Gene Expression and Genotyping, Interdisciplinary Center for Biotechnology Research, and.
Yanping
Y
Zhang
Department of Aging and Geriatric Research.
Mi-Jung
0000-0002-5006-8631
MJ
Kim
Department of Aging and Geriatric Research.|Whitney Laboratory, University of Florida, St. Augustine, Florida 32080.
Hyo-Jin
HJ
Park
Department of Aging and Geriatric Research.
Karessa
K
White
Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida 32610.
Yong Hwan
YH
Kim
Whitney Laboratory, University of Florida, St. Augustine, Florida 32080.
Paul
0000-0002-5222-2612
P
Linser
Department of Applied Biological Chemistry, University of Tokyo, Yayoi, Tokyo, 113, Japan.
Masaru
0000-0001-5072-2480
M
Tanokura
Department of Aging and Geriatric Research.
Christiaan
C
Leeuwenburgh
Department of Molecular Genetics and Microbiology.
Henry V
0000-0002-8273-5320
HV
Baker
Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, New York 14214, and.
Richard J
RJ
Salvi
Department of Aging and Geriatric Research, someya@ufl.edu.
Shinichi
0000-0001-9895-6227
S
Someya
D000375:Aging; D000818:Animals; D003051:Cochlea / Q000473:pathology / Q000502:physiology*; D005081:Exercise Therapy / Q000379:methods*; D034381:Hearing Loss; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D010805:Physical Conditioning, Animal / Q000379:methods*; D005082:Physical Exertion; D011304:Presbycusis / Q000473:pathology / Q000503:physiopathology* / Q000517:prevention & control*; D016896:Treatment Outcome
aging; exercise; hearing loss; stria vascularis