title: The aged testis. A good model to find proteins involved in age-related changes of testis by proteomic analysis.
abstract: OBJECTIVE
  To explore associated proteins involved in age-related changes of the testis and better understand the roles of these proteins in the human testis.
  
  
  METHODS
  We used two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spec trometry analysis to identify differentially expressed proteins between the aged and the normal control groups. The L-lactate dehydrogenase C chain (LDHC) protein, a previous testis-specific protein, was found to be downregulated in the aged testis and was further tested with western blot and immunohistochemical analysis to verify the result of the LDHC protein in 2-DE.
  
  
  RESULTS
  Twelve differentially expressed proteins were identified. Among those proteins, 3 were upregulated and 9 were downregulated in the aged group. The results of western blot and immunohistochemical analysis confirmed the expression of LDHC downregulation in the aged testis. Some proteins identified had little well-known function in the human testis, as follows: AKR7A3, FDXR, PGAM1, SEPT2 and HMGCS2.
  
  
  CONCLUSIONS
  Our results imply that the aged testis can be a good model to find associated proteins involved in age-related changes of the testis. It can be useful to understand the roles of those proteins in the testis.
authors.affiliation: Department of Urology, Nanfang Hospital, Southern Medical University, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Urology, Nanfang Hospital, Southern Medical University, PR China.
authors.forename: Ya-guang
authors.initials: YG
authors.lastname: Zou
authors.affiliation: Department of Urology, Nanfang Hospital, Southern Medical University, PR China.
authors.forename: Wen-bin
authors.initials: WB
authors.lastname: Guo
authors.affiliation: Department of Urology, Nanfang Hospital, Southern Medical University, PR China.
authors.forename: Jing-ping
authors.initials: JP
authors.lastname: Li
authors.affiliation: Department of Urology, Nanfang Hospital, Southern Medical University, PR China.
authors.forename: Jin-can
authors.initials: JC
authors.lastname: He
authors.affiliation: Department of Urology, Nanfang Hospital, Southern Medical University, PR China.
authors.forename: Jian-ming
authors.initials: JM
authors.lastname: Li
authors.affiliation: Department of Urology, Nanfang Hospital, Southern Medical University, PR China.
authors.forename: Xiang-ming
authors.initials: XM
authors.lastname: Mao
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D015536:Down-Regulation; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D008297:Male; D008875:Middle Aged; D011506:Proteins / Q000032:analysis*; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013737:Testis / Q000033:anatomy & histology / Q000737:chemistry* / Q000502:physiology*; D055815:Young Adult
chemical_list: D007527:Isoenzymes; D011506:Proteins; D007770:L-Lactate Dehydrogenase; C409673:lactate dehydrogenase C4