title: [Dynamic study and screening of new markers of spermatogonial stem cells by iTRAQ protein mass spectrometry].
abstract: OBJECTIVE
  To study the dynamic changes in the protein marker expression in the spermatogonial stem cells (SSCs) of mice at different ages by iTRAQ protein mass spectrometry and to screen new markers using the bioinformatic proteome database.
  
  
  METHODS
  Based on the postnatal weeks, we divided 80 healthy male C57BL/6 mice into eight age groups of equal number, harvested their testicular tissues, extracted proteins following purification of the SSCs by compound enzyme digestion and magnetic-activated cell sorting. Then we analyzed and identified proteins using two-dimensional electrophoresis, protein mass spectrometry, and protein database information.
  
  
  RESULTS
  Totally, 248,510 mass spectra were obtained from the MS experiment and 1132 proteins were identified. By the criteria of >1.2-fold for protein abundance difference and P value <0.05, we identified 298 differentially expressed proteins and 9 currently known makers of SSCs (PCNA, GFRalpha1, CDH1, Annexin A7, UCHL1, VASA, CD49f, CD29, and PLZf). Compara- tive analysis showed different expressions of the proteins in the SSCs of the mice of different ages, and the differences in the expressions of GFRalpha1, CD49f, and CD29 were consistent with the findings in other published literature. Ten proteins (P63, CD71, CD98, K19, ACE, K18, K15, K17, SH2, and SH3) were selected as SSC markers to be further studied.
  
  
  CONCLUSIONS
  The proteins in SSCs are differentially expressed in mice of different ages. The technology of iTRAQ protein mass spectrometry can be used to analyze and compare the proteome information of mouse SSCs, obtain differentially expressed proteins in mice of different ages, and thus offers a new ap- proach to further analysis and study of the function and roles of these differential proteins.
authors.forename: Liang-hong
authors.initials: LH
authors.lastname: Ma
authors.forename: Jia
authors.initials: J
authors.lastname: Tian
authors.forename: Xiu-ying
authors.initials: XY
authors.lastname: Pei
authors.forename: Yan-rong
authors.initials: YR
authors.lastname: Wang
authors.forename: Pei-jun
authors.initials: PJ
authors.lastname: Li
mesh_terms: D053687:Adult Stem Cells / Q000166:cytology / Q000378:metabolism*; D000367:Age Factors; D000818:Animals; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D002469:Cell Separation / Q000379:methods; D015180:Electrophoresis, Gel, Two-Dimensional; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D008810:Mice, Inbred C57BL; D011506:Proteins / Q000032:analysis* / Q000378:metabolism; D013093:Spermatogonia / Q000166:cytology*
chemical_list: D015415:Biomarkers; D011506:Proteins