title: CXCL8 enhances proliferation and growth and reduces apoptosis in endometrial stromal cells in an autocrine manner via a CXCR1-triggered PTEN/AKT signal pathway.
abstract: BACKGROUND
  Chemokine CXCL8 (also known as IL-8) has been identified as a potential regulator of endometrial stromal cells (ESCs), but it is unclear how CXCL8 regulates the survival of ESCs in the pathogenesis of endometriosis.
  
  
  METHODS
  We assessed the secretion of CXCL8 by enzyme-linked immunosorbent assays and the expression of its receptors, CXCR1 and CXCR2, by in-cell Western assay and immunohistochemistry. The effects of CXCL8 on the activation or expression of various cell mediators were also investigated by in-cell Western assay. The effects of CXCL8 on the proliferation, growth and apoptosis of ESCs in vitro were assessed by BrdU assays, cell counts and annexin V labeling, respectively.
  
  
  RESULTS
  Secretion of CXCL8 and expression of CXCR1 in the eutopic ESCs from women with endometriosis were significantly higher than that in control ESCs, but the expression of CXCR2 showed no significant difference between these two cell types. CXCL8 stimulated proliferation and growth and reduced apoptosis of ESCs in an autocrine manner, and these effects were abolished by anti-human CXCL8 and CXCR1 neutralizing antibodies and by a PI3K/Akt inhibitor. Moreover, CXCL8 up-regulated the expression of the anti-apoptotic proteins, survivin and Bcl-2, inhibited the expression of the Phosphatase and tensin homolog (PTEN) and activated the phosphorylation of Akt.
  
  
  CONCLUSIONS
  This study suggests that CXCL8 and CXCR1 are involved in the pathogenesis of endometriosis by up-regulating proliferation and growth and restricting apoptosis in ESCs by activating the PTEN/Akt pathway and mediating the expression of survivin and Bcl-2.
authors.affiliation: Laboratory for Reproductive Immunology, Hospital & Institute of Obstetrics and Gynecology,  IBS, Fudan University Shanghai Medical College, Shanghai 200011,  China.
authors.forename: Ming-Qing
authors.initials: MQ
authors.lastname: Li
authors.forename: Xue-Zhen
authors.initials: XZ
authors.lastname: Luo
authors.forename: Yu-Han
authors.initials: YH
authors.lastname: Meng
authors.forename: Jie
authors.initials: J
authors.lastname: Mei
authors.forename: Xiao-Yong
authors.initials: XY
authors.lastname: Zhu
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Jin
authors.forename: Da-Jin
authors.initials: DJ
authors.lastname: Li
mesh_terms: D000328:Adult; D017209:Apoptosis; D001973:Bromodeoxyuridine / Q000494:pharmacology; D049108:Cell Enlargement; D049109:Cell Proliferation; D004715:Endometriosis / Q000378:metabolism; D004717:Endometrium / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D051034:Inhibitor of Apoptosis Proteins / Q000378:metabolism; D016209:Interleukin-8 / Q000502:physiology*; D008875:Middle Aged; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D023062:Receptors, Interleukin-8A / Q000378:metabolism*; D000077022:Survivin; D015854:Up-Regulation
chemical_list: C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D016209:Interleukin-8; D019253:Proto-Oncogene Proteins c-bcl-2; D023062:Receptors, Interleukin-8A; D000077022:Survivin; D051057:Proto-Oncogene Proteins c-akt; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human; D001973:Bromodeoxyuridine