title: Difference in the expression of hormone receptors and fibrotic markers in the human peritoneum--implications for therapeutic targets to prevent encapsulating peritoneal sclerosis.
abstract: OBJECTIVE
  Encapsulating peritoneal sclerosis (EPS) is a rare but life-threatening complication of peritoneal dialysis (PD). The optimal management of patients with EPS is uncertain. In the present study, we investigated differences in the expression of nuclear receptors [progesterone (PR), androgen (AR), vitamin D (VDR), and glucocorticoid (GCR)] in the human peritoneum. We also investigated estrogen receptor (ER), matrix metalloproteinase 9 (MMP9), and transforming growth factor β1 (TGFβ1) in the context of their potential role in tamoxifen therapy.
  
  
  METHODS
  We analyzed clinical and histologic characteristics of 72 peritoneal biopsy specimens (22 from EPS patients, 11 from PD patients, 15 from uremic patients, and 24 from control subjects undergoing hernia repair). For immunophenotyping, we used antibodies against VDR, GCR, ER, PR, AR, MMP9, and TGFβ1.
  
  
  RESULTS
  In human peritoneum, VDR and GCR are highly expressed (98.6% and 87.3% respectively). Except in the case of VDR (p = 0.0012), we observed no significant difference in receptor expression between the groups. Expression of ER and PR was sparse (11.4% and 31% respectively), with higher expression in women, and AR was absent. Minimal MMP9 expression and moderate TGFβ1 expression were observed in all groups. The differences between the groups were nonsignificant.
  
  
  CONCLUSIONS
  Nuclear receptors are present in human peritoneum. Except in the case of VDR, the pattern for any one group is nonspecific. Glucocorticoids, vitamin D, and angiotensin converting-enzyme inhibitors or angiotensin II receptor blockers (via the vitamin D/angiotensin II pathway) might be suitable interventions for preservation of the integrity of the peritoneal membrane. The mechanism of action of tamoxifen is still not elucidated, ER expression in the peritoneum is sparse, and data about the studied pathways (MMP9, TGFβ) are inconsistent.
authors: Division of General Internal Medicine and Nephrology, Department of Internal Medicine, Robert-Bosch-Hospital, Stuttgart, Germany. niko.braun@rbk.de
authors: Niko
authors: N
authors: Braun
authors: Peter
authors: P
authors: Fritz
authors: Dagmar
authors: D
authors: Biegger
authors: Martin
authors: M
authors: Kimmel
authors: Fabian
authors: F
authors: Reimold
authors: Christoph
authors: C
authors: Ulmer
authors: M Dominik
authors: MD
authors: Alscher
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000032:analysis / Q000096:biosynthesis*; D008875:Middle Aged; D056627:Peritoneal Fibrosis / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control*; D010537:Peritoneum / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D018160:Receptors, Cytoplasmic and Nuclear / Q000032:analysis / Q000096:biosynthesis*; D053773:Transforming Growth Factor beta1 / Q000032:analysis / Q000096:biosynthesis*
chemical_list: D015415:Biomarkers; D018160:Receptors, Cytoplasmic and Nuclear; D053773:Transforming Growth Factor beta1; D020780:Matrix Metalloproteinase 9