Abstract 3258: Tissue Engineered Graft Grown in the Mouse Peritoneal Cavity: the role of peritoneal-derived stem/progenitor cells
Backgroud: We have generated bioengineered blood vessels in mouse peritoneal cavity in order to test the hypothesis that the mouse peritoneum contains primitive cells with regenerative potential.
Methods: Plastic tubing templates were implanted into the mouse peritoneum and harvested after 8 weeks. The template tubing became covered with tissue and, after the tubing had been carefully removed, the tissue capsules were transplanted into the abdominal aorta of the same mice in which they were grown, as interposition grafts.
Results: High frequency micro-ultrasound image analysis of the tissue capsule grafts demonstrated that they remained patent following grafting. While the harvested tissue capsules did not express vascular cell markers, the tissue grafts were lined with endothelial-like cells, and the vessel wall cells stained for α-actin, suggesting that tissue capsule cells acquired phenotype of vascular cells. Thus, we hypothesized that the mouse peritoneum contains a population of primitive cells with a stem/progenitor cell phenotype. To test this, we determined the presence of side population cells and Lin-/Sca-1+/c-kit+ cells within the resident peritoneal population. Approximately 0.10 ± 0.05% (n = 6) of total peritoneal cells excluded Hoechst 33342 dye, similar to the level found with bone marrow cells. Flow cytometry analysis showed that 3.6 ± 0.1% (n ± 6) of peritoneal-derived cells expressed stem cell markers (Lin−/Sca-1+/c-kit+), compared to 1.9 ± 0.2% (n = 6) for bone marrow-derived positive control. Furthermore, sex-mismatch competitive repopulation assays and re-transplantation experiments (n = 10) showed that the reconstituted bone marrow from the transplanted animals contains a cell population derived from donor cells of peritoneal origin, and these cells have long-term regeneration capabilities. The gene expression profiling revealed that peritoneal cells display a gene expression program that is involved with development and morphogenesis events.
Conclusions: The mouse peritoneum contains multiple distinct stem cell populations or primitive precursors capable of regenerating bioengineered tissues and reconstituting the hematopoietic system of lethally irradiated mice.