Correlation between accelerated presbycusis and decreased immune functions

• Published in: Experimental gerontology Vol. 38; no. 3; pp. 319 - 325
• Main Authors: Iwai, Hiroshi, Lee, Shinryu, Inaba, Muneo, Sugiura, Kikuya, Baba, Susumu, Tomoda, Koichi, Yamashita, Toshio, Ikehara, Susumu
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01.03.2003
• Subjects: Aging - physiology; Animals; Auditory brainstem response; Autoimmunity; Degeneration; Evoked Potentials, Auditory, Brain Stem - drug effects; Evoked Potentials, Auditory, Brain Stem - immunology; Glucocorticoids - pharmacology; Immune impairment; Mice; Mice, Inbred Strains; Mitogen response; Pathogenic environment; Prednisolone; Prednisolone - pharmacology; Presbycusis; Presbycusis - immunology; Random Allocation; Specific pathogen-free conditions; Spiral ganglion cell; Autoimmunity; Pathogenic environment; Auditory brainstem response; Degeneration; Specific pathogen-free conditions; Mitogen response; Presbycusis; Immune impairment; Prednisolone; Spiral ganglion cell
• ISSN: 0531-5565; 1873-6815
• DOI: 10.1016/S0531-5565(02)00177-8

The aim of the current study is to analyze the relationship between presbycusis and the immune system, which is affected by pathogenic environments, and to devise a strategy for the prevention of presbycusis using the SAMP1 mouse, an animal model for accelerated senescence that shows both immunological dysfunction and hearing loss caused by the impairment of spiral ganglion cells in the cochlea. When these mice were bred in different pathogenic environments, we found that the development of age-related diseases such as presbycusis was delayed in the mice bred under clean conditions. Prednisolone administration showed no significant prevention of the development of presbycusis in the mice, suggesting that autoimmune mechanisms are not involved in the acceleration of presbycusis. It is conceivable that pathogen-induced infections impose a severe stress on the host, impairing the host's immune functions. A reduction in the number of pathogens may therefore prevent the acceleration of the aging process. These findings suggest that not only the gene backgrounds but also immune functions affect the development of presbycusis in SAMP1 mice. Further studies into the relationship between systemic immune functions and the neuro-generation system may provide additional information about the treatment for age-related diseases.