title: Alteration in endometrial proteins during early- and mid-secretory phases of the cycle in women with unexplained infertility.
abstract: BACKGROUND
  Compromised receptivity of the endometrium is a major cause of unexplained infertility, implantation failure and subclinical pregnancy loss. In order to investigate the changes in endometrial protein profile as a cause of unexplained infertility, the current study was undertaken to analyze the differentially expressed proteins of endometrium from early-secretory (LH+2) to mid-secretory phase (LH+7), in women with unexplained infertility.
  
  
  METHODS
  2-D gel electrophoresis was performed to analyze the proteomic changes between early- (n = 8) and mid-secretory (n = 8) phase endometrium of women with unexplained infertility. The differentially expressed protein spots were identified by LC-MS analysis and validated by immunoblotting and immuno-histochemical analysis in early- (n = 4) and mid-secretory (n = 4) phase endometrium of infertile women. Validated proteins were also analyzed in early- (n = 4) and mid-secretory (n = 4) phase endometrium of fertile women.
  
  
  RESULTS
  Nine proteins were found to be differentially expressed between early- and mid- secretory phases of endometrium of infertile women. The expression of Ras-related protein Rap-1b, Protein disulfide isomerase A3, Apolipoprotein-A1 (Apo-A1), Cofilin-1 and RAN GTP-binding nuclear protein (Ran) were found to be significantly increased, whereas, Tubulin polymerization promoting protein family member 3, Superoxide dismutase [Cu-Zn], Sorcin, and Proteasome subunit alpha type-5 were significantly decreased in mid- secretory phase endometrium of infertile women as compared to early-secretory phase endometrium of infertile women. Validation of 4 proteins viz. Sorcin, Cofilin-1, Apo-A1 and Ran were performed in separate endometrial biopsy samples from infertile women. The up-regulated expression of Sorcin and down-regulated expression of Cofilin-1 and Apolipoprotein-A1, were observed in mid-secretory phase as compared to early-secretory phase in case of fertile women.
  
  
  CONCLUSIONS
  De-regulation of the expression of Sorcin, Cofilin-1, Apo-A1 and Ran, during early- to mid-secretory phase may have physiological significance and it may be one of the causes for altered differentiation and/or maturation of endometrium, in women with unexplained infertility.
authors.affiliation: Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India; Department of Biochemistry, Jamia Hamdard (Hamdard University), New Delhi, India.
authors.forename: Murli
authors.initials: M
authors.lastname: Manohar
authors.affiliation: Department of Obstetrics & Gynaecology, King George's Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Huma
authors.initials: H
authors.lastname: Khan
authors.affiliation: Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India.
authors.forename: Vijay Kumar
authors.initials: VK
authors.lastname: Sirohi
authors.affiliation: Department of Obstetrics & Gynaecology, King George's Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Vinita
authors.initials: V
authors.lastname: Das
authors.affiliation: Department of Obstetrics & Gynaecology, King George's Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Anjoo
authors.initials: A
authors.lastname: Agarwal
authors.affiliation: Department of Obstetrics & Gynaecology, King George's Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Amita
authors.initials: A
authors.lastname: Pandey
authors.affiliation: Department of Biochemistry, Jamia Hamdard (Hamdard University), New Delhi, India.
authors.forename: Waseem Ahmad
authors.initials: WA
authors.lastname: Siddiqui
authors.affiliation: Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India.
authors.forename: Anila
authors.initials: A
authors.lastname: Dwivedi
mesh_terms: D000328:Adult; D016632:Apolipoprotein A-I / Q000235:genetics / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D016022:Case-Control Studies; D051338:Cofilin 1 / Q000235:genetics / Q000378:metabolism; D004717:Endometrium / Q000378:metabolism*; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000235:genetics / Q000378:metabolism*; D008183:Luteal Phase / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000235:genetics / Q000378:metabolism; D019704:Protein Disulfide-Isomerases / Q000235:genetics / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D020668:rap GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D016632:Apolipoprotein A-I; D002135:Calcium-Binding Proteins; D051338:Cofilin 1; C503113:SRI protein, human; D013482:Superoxide Dismutase; C576985:PSMA5 protein, human; D046988:Proteasome Endopeptidase Complex; C116753:RAP1B protein, human; D020668:rap GTP-Binding Proteins; D019704:Protein Disulfide-Isomerases; C085868:PDIA3 protein, human