title: The Impacts of Cellular Senescence in Elderly Pneumonia and in Age-Related Lung Diseases That Increase the Risk of Respiratory Infections.
abstract: Pneumonia generates considerable negative impacts on the elderly. Despite the widespread uses of vaccines and appropriate antibiotics, the morbidity and mortality of elderly pneumonia are significantly higher compared to the counterparts of young populations. The definitive mechanisms of high vulnerability in the elderly against pathogen threats are unclear. Age-associated, chronic low-grade inflammation augments the susceptibility and severity of pneumonia in the elderly. Cellular senescence, one of the hallmarks of aging, has its own characteristics, cell growth arrest and senescence-associated secretory phenotype (SASP). These properties are beneficial if the sequence of senescence-clearance-regeneration is transient in manner. However, persisting senescent cell accumulation and excessive SASP might induce sustained low-grade inflammation and disruption of normal tissue microenvironments in aged tissue. Emerging evidence indicates that cellular senescence is a key component in the pathogenesis of chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF), which are known to be age-related and increase the risk of pneumonia. In addition to their structural collapses, COPD and IPF might increase the vulnerability to pathogen insults through SASP. Here, we discuss the current advances in understanding of the impacts of cellular senescence in elderly pneumonia and in these chronic lung disorders that heighten the risk of respiratory infections.
authors.affiliation: Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki; Kihara 5200, Kiyotake, Miyazaki 889-1692, Japan. yanagi@med.miyazaki-u.ac.jp.
authors.forename: Shigehisa
authors.initials: S
authors.lastname: Yanagi
authors.affiliation: Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki; Kihara 5200, Kiyotake, Miyazaki 889-1692, Japan. hironobu_tsubouchi@med.miyazaki-u.ac.jp.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Tsubouchi
authors.affiliation: Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki; Kihara 5200, Kiyotake, Miyazaki 889-1692, Japan. ayako_miura@med.miyazaki-u.ac.jp.
authors.forename: Ayako
authors.initials: A
authors.lastname: Miura
authors.affiliation: Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki; Kihara 5200, Kiyotake, Miyazaki 889-1692, Japan. ayako_matsuo@med.miyazaki-u.ac.jp.
authors.forename: Ayako
authors.initials: A
authors.lastname: Matsuo
authors.affiliation: Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki; Kihara 5200, Kiyotake, Miyazaki 889-1692, Japan. nobuhiro@med.miyazaki-u.ac.jp.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Matsumoto
authors.affiliation: Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki; Kihara 5200, Kiyotake, Miyazaki 889-1692, Japan. nakazato@med.miyazaki-u.ac.jp.
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Nakazato
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D016922:Cellular Senescence; D060467:Disease Resistance; D004198:Disease Susceptibility; D006801:Humans; D008171:Lung Diseases / Q000150:complications* / Q000175:diagnosis / Q000209:etiology*; D010641:Phenotype; D011014:Pneumonia / Q000150:complications* / Q000175:diagnosis / Q000209:etiology*; D020545:Respiratory Mucosa / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000209:etiology*; D012306:Risk
keywords: aging; antimicrobial defense system; cellular senescence; chronic obstructive pulmonary disease; elderly pneumonia; idiopathic pulmonary fibrosis; senescence-associated secretory phenotype