-Original-

Different Patterns of Acetylation and Dimethylation of Histone H3 between Young and Aged Cases with Chronic Tonsillitis: Influences of Inflammation and Aging

Akihiko Saito¹, Ken-ichi Watanabe¹, Seiko Egawa² and Kimihiro Okubo¹

¹Department of Otorhinolaryngology, Nippon Medical School, Tokyo, Japan
²Department of Molecular Pathology, Institute of Development and Aging Sciences, Graduate School of Medicine, Nippon Medical School, Kanagawa, Japan

Introduction: Epigenetics is now considered to be crucially involved in normal genetics and differentiation and in pathological conditions, such as cancer, aging, and inflammation. Epigenetic mechanisms involve DNA methylation and histone modifications. The purpose of this study was to investigate the effects of inflammation on epigenetics in young subjects and the effect of aging.
Materials and Methods: The palatine tonsils were extracted from child and adult patients with chronic tonsillitis. Hematoxylin-eosin staining was performed to examine the morphology of the palatine tonsils. A fluorescence immunological examination was also performed to detect acetyl-histone H3 or dimethyl-histone H3. Confocal scanning microscopy was used for observations.
Results: Acetylated histone H3 was detected in tonsils from child patients but not from adult patients. Dimethylated histone H3 was not detected in tonsils from either group of patients. Degeneration of the tonsillar structures was apparent in tonsils from adult patients.
Discussion: The differential expression of acetylated histone H3 Lys9 may reflect immunological differences between young and aged tonsils. The decrease observed in the activity of histone methyltransferase induced the down-regulated expression of methylated histone H3.
Conclusion: Our results suggest that epigenetic changes participate in chronic inflammation and aging in the palatine tonsils. Although the results do not lead to a direct treatment, the epigenetic pathogenesis of chronic inflammation, such as immunoglobulin A nephropathy, by focal infections will be described in greater detail in future studies, which will lead to new treatments being developed.

J Nippon Med Sch 2016; 83: 54-61

Keywords
epigenetics, histone modification, chronic tonsillitis, acetylation, dimethylation

Correspondence to
Ken-ichi Watanabe, MD, PhD, Department of Otorhinolaryngology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan
watanabe@nms.ac.jp

Received, October 20, 2014
Accepted, December 14, 2015