title: Correction of anemia in uremic mice by genetically modified peritoneal mesothelial cells.
abstract: BACKGROUND
  During peritoneal dialysis, mesothelial cells become detached from the peritoneum and accumulate in the dialysate. Our aim was to evaluate the potential of peritoneal effluent (PF)-derived human peritoneal mesothelial cells (HPMC) as target for gene therapy. We used erythropoietin (EPO) as our target gene.
  
  
  METHODS
  Various extracellular matrixes (ECM) were tested for optimal adhesion and growth of HPMC. The EPO gene was introduced to mouse peritoneal mesothelial cells (MPMC) and HPMC by transfection or retroviral transduction. EPO secretion from PMC was measured by enzyme-linked immunosorbent assay (ELISA) and by the TF-1 cell proliferation assay. We performed intraperitoneal or intramuscular transplantations of the genetically modified cells into regular or 5/6 nephrectomized Balb/c mice and nude mice. Finally, we measured serum EPO and hematocrit levels.
  
  
  RESULTS
  ECM-coated plates provided up to sixfold increase in the efficiency of PMC isolation from PF. Gelatin coated dishes (20 microg/cm2) were found optimal for isolation of PF-HPMC. RPR-120535 liposome was found to be best for PMC transduction. In vitro studies showed EPO secretion from modified HPMC over 6 months. Intraperitoneal transplantation aided with collagen matrix was the most effective. EPO, in MPMC transplanted mice, was detected up to 3 weeks (peak at 13 +/- 1 mIU/mL), and anemia of uremic mice was corrected (35.3 +/- 0.9 mIU/mL to 41.9 +/- 1.1 mIU/mL).
  
  
  CONCLUSIONS
  PF-HPMC can be considered as an appropriate target for gene therapy since these cells can be efficiently isolated, modified, and transplanted. Nevertheless, implantation techniques in the peritoneum should be directed at obtaining longer duration of transgene expression in vivo, and means should be developed for enabling regulated expression of the gene.
authors.affiliation: Department of Nephrology, Soroka University Medical Center, Ben-Gurion University, Beer-Sheva, Israel.
authors.forename: Tom
authors.initials: T
authors.lastname: Einbinder
authors.forename: Yuval
authors.initials: Y
authors.lastname: Sufaro
authors.forename: Igor
authors.initials: I
authors.lastname: Yusim
authors.forename: Gerardo
authors.initials: G
authors.lastname: Byk
authors.forename: Jutta
authors.initials: J
authors.lastname: Passlick-Deetjen
authors.forename: Cidio
authors.initials: C
authors.lastname: Chaimovitz
authors.forename: Amos
authors.initials: A
authors.lastname: Douvdevani
mesh_terms: D000740:Anemia / Q000209:etiology / Q000628:therapy*; D000818:Animals; D001202:Ascitic Fluid; D002448:Cell Adhesion; D002455:Cell Division; D002469:Cell Separation / Q000379:methods; D004847:Epithelial Cells / Q000502:physiology / Q000637:transplantation*; D004848:Epithelium; D004921:Erythropoietin / Q000235:genetics*; D015316:Genetic Therapy / Q000379:methods*; D006400:Hematocrit; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D010531:Peritoneal Dialysis, Continuous Ambulatory; D010537:Peritoneum / Q000166:cytology*; D012190:Retroviridae / Q000235:genetics; D014161:Transduction, Genetic; D014162:Transfection; D014511:Uremia / Q000150:complications*
chemical_list: D004921:Erythropoietin