title: Differential levels of cathepsin B and L in serum between young and aged healthy people and their association with matrix metalloproteinase 2.
abstract: OBJECTIVE
  Most publications describe cathepsin B and L as tumor and metastasis factors. These proteases also play a very important role in aging process. The aim of this study was to evaluate the serum level of cathepsin B and L with aging and their association with matrix metalloproteinase 2 (MMP2), which was reported to associate with age-related diseases.
  
  
  METHODS
  This research was conducted using blood samples provided by healthy people (n=90, 63 men and 27 women). Subjects were subdivided into groups with respect to age: young (about 18-30 years old, n=30), middle age (about 36-50 years old, n=30), and aged (above 56 years old, n=30). Altered serum level of cathepsin B, cathepsin L, and MMP2 with aging was studied by enzyme-linked immunosorbent assay (ELISA) and Western blotting using discriminative antibodies specific for each factor.
  
  
  RESULTS
  ELISA and Western blotting revealed that the serum level of cathepsin L and MMP2, but not cathepsin B significantly decreased in aged group compared with young group. Cathepsin L positively correlates with MMP2 among the whole healthy people (r(2)=0.869, p<0.0001).
  
  
  CONCLUSIONS
  The serum level of cathepsin L decreased with age, while cathepsin B remained no significant difference between young and aged individuals. In addition, cathepsin L positively correlates with MMP2.
  
  
  CONCLUSIONS
  The cathepsin L may be used as a monitoring index in age-related diseases.
  
  
  CONCLUSIONS
  In addition to cathepsin B, cathepsin L may be also involved in the aging process.
authors.affiliation: Department of Gerontology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, PR China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: Jin Shan Branch Hospital of Sixth People's Hospital of Shanghai, No. 147 Health Road, Zhujing Town, Jinshan District, Shanghai 201500, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Jin Shan Branch Hospital of Sixth People's Hospital of Shanghai, No. 147 Health Road, Zhujing Town, Jinshan District, Shanghai 201500, PR China.
authors.forename: Ying-Jia
authors.initials: YJ
authors.lastname: Gu
authors.affiliation: Jin Shan Branch Hospital of Sixth People's Hospital of Shanghai, No. 147 Health Road, Zhujing Town, Jinshan District, Shanghai 201500, PR China.
authors.forename: Yi-Fan
authors.initials: YF
authors.lastname: Zhao
authors.affiliation: Jin Shan Branch Hospital of Sixth People's Hospital of Shanghai, No. 147 Health Road, Zhujing Town, Jinshan District, Shanghai 201500, PR China.
authors.forename: Yan-Wu
authors.initials: YW
authors.lastname: Zhou
authors.affiliation: Department of Gerontology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, PR China. Electronic address: fuguoxiang888@163.com.
authors.forename: Guo-Xiang
authors.initials: GX
authors.lastname: Fu
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000375:Aging / Q000097:blood* / Q000378:metabolism; D015153:Blotting, Western; D002401:Cathepsin B / Q000097:blood*; D056668:Cathepsin L / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000097:blood / Q000378:metabolism*; D008875:Middle Aged; D055815:Young Adult
chemical_list: D002401:Cathepsin B; D056668:Cathepsin L; D020778:Matrix Metalloproteinase 2
keywords: Aging; Cathepsin B; Cathepsin L; Serum