title: Decreased serum level of HMGB1 and MyD88 during human aging progress in healthy individuals.
abstract: OBJECTIVE
  Previous studies have suggested that high mobility group box-1 protein (HMGB1) binds to the toll-like receptor 4 (TLR4) signaling mediates the progression of various inflammatory diseases. But the roles of HMGB1 and TLR4 in aging remain poorly unknown. In this study, we aimed to investigate the serum levels of HMGB1 and myeloid differentiation factor 88 (MyD88), which is one of TLR4's intracellular adaptor proteins during human aging process and their relevance with cathepsin B (CTSB).
  
  
  METHODS
  This research was conducted using the blood samples provided by healthy people (n = 90, 63 men and 27 women). Subjects were subdivided into groups with respect to age: young (about 25 years old, n = 30), middle age (about 40 years old, n = 30), and aged (above 65 years old, n = 30). Altered serum levels of HMGB1, MyD88 and CTSB were measured using an enzyme-linked immunosorbent assay.
  
  
  RESULTS
  The serum levels of HMGB1 and MyD88 were significantly decreased in the aged group compared with those in the young group. Linear regression analysis showed that HMGB1 and MyD88 positively correlated with CTSB among the whole healthy people. A negative correlation was determined between MyD88 and age.
  
  
  CONCLUSIONS
  The serum levels of HMGB1 and MyD88 significantly decreased with age. MyD88, but not HMGB1, was negatively correlated with age.
authors.affiliation: Department of Gerontology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600, Yi Shan road, Shanghai, 200233, People's Republic of China. fuguoxiang888@163.com.
authors.forename: Guo-Xiang
authors.initials: GX
authors.lastname: Fu
authors.affiliation: Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA.
authors.forename: Alex F
authors.initials: AF
authors.lastname: Chen
authors.affiliation: Department of Gerontology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600, Yi Shan road, Shanghai, 200233, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: Shanghai Sixth People's Hospital Jinshan Branch, No. 147 Health Road, Zhujing Town, Jinshan District, Shanghai, 201500, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Shanghai Sixth People's Hospital Jinshan Branch, No. 147 Health Road, Zhujing Town, Jinshan District, Shanghai, 201500, People's Republic of China.
authors.forename: Ying-Jia
authors.initials: YJ
authors.lastname: Gu
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D002401:Cathepsin B / Q000378:metabolism*; D005260:Female; D024243:HMGB1 Protein / Q000097:blood / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D053594:Myeloid Differentiation Factor 88 / Q000097:blood / Q000378:metabolism; D012044:Regression Analysis; D015398:Signal Transduction / Q000502:physiology; D051197:Toll-Like Receptor 4 / Q000097:blood / Q000378:metabolism
chemical_list: D024243:HMGB1 Protein; D053594:Myeloid Differentiation Factor 88; D051197:Toll-Like Receptor 4; D002401:Cathepsin B
keywords: Aging; Cathepsin B; HMGB1; MyD88