title: Expression of G protein-coupled estrogen receptor in irritable bowel syndrome and its clinical significance.
abstract: OBJECTIVE
  Estrogen is suggested to participate in pathogenesis of irritable bowel syndrome (IBS), but expression of G protein-coupled estrogen receptor (GPER) in the colon of IBS patients has never been investigated. The aim of this study was to investigate the expression of GPER and classical estrogen receptors in the colon of IBS patients and healthy controls.
  
  
  METHODS
  Colonic biopsies were obtained by endoscopy from patients with IBS (n=46) and healthy subjects (n=13). Expression of GPER, estrogen receptor α (ERα) and estrogen receptor β (ERβ) in mast cells were measured by double-labelling immunofluorescence. Quantification of mRNA expression was performed for GPER, ERα and ERβ by real-time polymerase chain reaction.
  
  
  RESULTS
  Differential distribution of GPER, ERα and ERβ were detected in human colonic mucosa. The expression of GPER in the cytoplasm of mast cells and GPER-positive cells was significantly higher in diarrhea-predominant IBS (D-IBS) patients than that in constipation-predominant IBS (C-IBS, P<0.001) patients and healthy subjects (P=0.005). ERα and ERβ were not detected in majority of mast cells in colonic mucosa and no difference of immunostaining results for ERα and ERβ was found among these three groups. A positive correlation (r=0.451, P=0.011) between GPER-positive cell counts and abdominal pain severity was observed in D-IBS group. Relative mRNA expression of GPER in D-IBS was also higher than that in C-IBS (P=0.018) and healthy subjects (P=0.011).
  
  
  CONCLUSIONS
  The present study, for the first time, demonstrated the expression of GPER in human colonic mucosa and its correlation with abdominal pain severity.
authors: Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China.
authors: Bin
authors: B
authors: Qin
authors: Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China.
authors: Lei
authors: L
authors: Dong
authors: Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China.
authors: Xiaoyan
authors: X
authors: Guo
authors: Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China.
authors: Jiong
authors: J
authors: Jiang
authors: Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China.
authors: Yangxin
authors: Y
authors: He
authors: Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China.
authors: Xiaoyan
authors: X
authors: Wang
authors: Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China.
authors: Lu
authors: L
authors: Li
authors: Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University Xi'an, China.
authors: Juhui
authors: J
authors: Zhao
mesh_terms: D015746:Abdominal Pain / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*; D000328:Adult; D001706:Biopsy; D016022:Case-Control Studies; D003106:Colon / Q000737:chemistry* / Q000473:pathology; D003113:Colonoscopy; D003248:Constipation / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*; D003967:Diarrhea / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*; D047628:Estrogen Receptor alpha / Q000032:analysis; D047629:Estrogen Receptor beta / Q000032:analysis; D005260:Female; D005455:Fluorescent Antibody Technique; D005819:Genetic Markers; D006801:Humans; D007413:Intestinal Mucosa / Q000737:chemistry* / Q000473:pathology; D043183:Irritable Bowel Syndrome / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010641:Phenotype; D011237:Predictive Value of Tests; D012333:RNA, Messenger / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction; D011960:Receptors, Estrogen / Q000032:analysis* / Q000235:genetics; D043562:Receptors, G-Protein-Coupled / Q000032:analysis* / Q000235:genetics; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; C109584:GPER1 protein, human; D005819:Genetic Markers; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D043562:Receptors, G-Protein-Coupled
keywords: G protein-coupled estrogen receptor; GPER; estrogen; estrogen receptor; irritable bowel syndrome