title: [Effects of erythropoietin on mesenchymal stem cells' function of differentiation and secretion cultured under acute kidney injury microenvironment].
abstract: OBJECTIVE
  To explore the effects of erythropoietin (EPO) on the differentiation and secretion of cultured bone marrow-derived mesenchymal stem cells (BM-MSC) in the microenvironment of acute kidney injury (AKI).
  
  
  METHODS
  C57BL/6 murine BM-MSC (mBM-MSC) were successfully isolated by the methods of Percoll density gradient centrifugation and adherence cultivation. The AKI murine model was induced by ischemia/reperfusion (I/R). The homogenate supernatants were prepared for normal and I/R murine kidney. P3-mBM-MSC were treated differently: Group A: low glucose DMEM medium with 10% fetal bovine serum, Group B: normal murine kidney homogenate supernatant intervention, Group C: I/R kidney homogenate supernatant intervention, Group D: I/R kidney homogenate supernatant plus different concentrations of EPO (1, 5, 10, 50 U/ml). Each group was incubated for 1, 3, 5 and 7 days. Inverted microscope was used to observe the morphological changes of these cells and their ultrastructural changes were observed by transmission electron microscope. Cytokeratin-18 was detected by flow cytometry. The levels of bone morphogenetic protein-7 (BMP-7), hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) were detected by ELISA in culture medium.
  
  
  RESULTS
  The cells yielded a high expression of CD29 and CD44 and a low expression of CD34 and CD45. Compared with Groups A and B, the cells of Group C presented oval and short fusiform shapes. After the intervention of EPO, Group D showed a cobble appearance. More organelles were also found. A trace expression of CK18 was found in Groups A and B. A positive expression of CK18 was significantly higher in Groups C and D than Groups A and B (P < 0.01). The expression of EPO 50 U/ml at Day 5 and 7 was higher than Group C of the same time (5 d: 35.22 ± 4.04 vs 8.72 ± 0.38, 7 d: 42.00 ± 5.39 vs 13.20 ± 1.14, both P < 0.01). The results of ELISA showed that the levels of BMP-7, HGF and VEGF in Group C decreased significantly (P < 0.01 or P < 0.05).
  
  
  CONCLUSIONS
  The intervention of EPO may boost the differentiation of mBM-MSC but reverse its low secretion.
authors.affiliation: Department of Nephrology, No. 455 Hospital of PLA, Shanghai, China.
authors.forename: Nan-mei
authors.initials: NM
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Tian
authors.forename: Wei-wei
authors.initials: WW
authors.lastname: Wang
authors.forename: Guo-feng
authors.initials: GF
authors.lastname: Han
authors.forename: Jin
authors.initials: J
authors.lastname: Cheng
authors.forename: Jian
authors.initials: J
authors.lastname: Huang
authors.forename: Jin-yuan
authors.initials: JY
authors.lastname: Zhang
mesh_terms: D058186:Acute Kidney Injury / Q000378:metabolism*; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D004921:Erythropoietin / Q000494:pharmacology*; D005434:Flow Cytometry; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D004921:Erythropoietin