• Colonic mucosal replacement by syngeneic small intestinal stem cell transplantation.

      Tait, I S; Evans, Gareth S; Flint, Neil; Campbell, F C; University Department of Surgery, Ninewells Hospital and Medical School, Dundee, Scotland. (1994-01)
      A novel method of colonic mucosal replacement by transplantation of disaggregated small intestinal epithelium is described. Thirty-one inbred rats had the ascending colon isolated, and surgical mucosectomy was performed on the "free" loop. Epithelial cell aggregates were isolated from postnatal small intestine using collagenase and dispase digestion, then 20 microL of the cell suspension was "seeded" over the denuded colonic muscle of 25 recipient rats. Six control rats had surgical mucosectomy only. All loops were retrieved after 14 days for histologic examination. Stem cell lineage studies were used with selective staining protocols to identify enterocytes, goblet cells, entero-endocrine cells, and Paneth cells. A neomucosa with typical small bowel morphology including crypts and villi and all four stem cell lineages was regenerated by transplanted cells on the colonic muscle in 19 of 25 (76%) recipients. Control loops showed no epithelial regrowth confirming total mucosectomy. With appropriate stromal support, transplanted small intestinal stem cells have the capacity to re-epithelialize denuded colonic muscle with small bowel neomucosa.
    • Generation of neomucosa in vivo by transplantation of dissociated rat postnatal small intestinal epithelium.

      Tait, I S; Flint, Neil; Campbell, F C; Evans, Gareth S; Department of Surgery, Ninewells Hospital and Medical School, Dundee, UK. (1994-04)
      A novel method to study the generation of rat small intestinal mucosa, by transplantation of disaggregated postnatal rat small intestinal epithelium is described. Cellular aggregates, comprised of epithelium with attached proliferative cells and closely associated stromal tissue, were isolated from postnatal rat small intestine by enzymatic digestion, then grafted immediately to the subcutaneous plane of adult recipients. On graft retrieval after 14 days, 39% of cellular transplants to nude mice, and 84% of cellular transplants to inbred rats had developed into small intestine-like structures. These structures were comprised of a circumferential layer of epithelium surrounding a central mucin filled lumen. This neomucosal layer exhibited well formed crypts and villi, and contained all epithelial stem cell lineages i.e. absorptive enterocytes, goblet cells, Paneth's cells and entero-endocrine cells. Proliferative activity within this neomucosa was confined to crypt regions as in normal postnatal small intestine. Developmental maturation within the regenerated neomucosa was demonstrated by organotypic morphogenesis, i.e. formation of mature crypts and villi, and progressive cytodifferentiation with increased numbers of goblet cells, entero-endocrine cells and Paneth's cells. Altered patterns of brush border enzyme expression further confirmed a temporal progression of development within neomucosal enterocytes. It is concluded that after "extensive" mucosal disaggregation, postnatal small intestinal epithelial progenitor cells retain the capacity for organotypic regeneration of neomucosa when transplanted to ectopic sites in adult recipients. These small aggregates of epithelium and stroma are capable of generating the topographical signals necessary for the three dimensional regeneration of this tissue. Furthermore, the multipotent generative potential of the stem cells within these cellular aggregates is maintained with production of all progeny.
    • Influence of cell interactions in a novel model of postnatal mucosal regeneration.

      Patel, H R; Tait, I S; Evans, Gareth S; Campbell, F C; University Department of Surgery, Ninewells Hospital and Medical School, Dundee. (1996-05)
      BACKGROUND AND AIMS: Conventional models of postnatal mucosal regeneration are cumbersome and limited: a novel model is described here. In addition, the influence of cell interactions on mucosal regeneration is examined within the model. METHODS: Postnatal rat small intestinal mucosa was digested by enzymes to yield heterotypic cell aggregates (CA). CA colony forming ability, growth, and limited cytodifferentiation were assessed in vitro. CA were transplanted subcutaneously and retrieved for histological examination at staggered intervals to assess neomucosal morphogenesis and cytodifferentiation in vivo. Cell interactions in CA were disrupted by enzymes, thus producing cell suspensions (CS). Regeneration by CA and CS were compared. RESULTS: CA produced proliferative colonies in vitro and showed a temporal sequence of neomucosal morphogenesis and differentiation in vivo. CA colonies were more numerous within 24 hours of primary culture and had greater cellularity by 96 hours than CS colonies. Alkaline phosphatase was expressed only by 258 of 696 CA colonies (37%). CA subcutaneous grafts (48 of 56 (87%)) regenerated small intestinal neomucosa while CS were unsuccessful. CONCLUSION: These methods provide a model of mucosal regeneration which includes constituent processes of colony formation, growth, neomucosal morphogenesis, and cytodifferentiation. Preservation of cell interactions within CA seems advantageous to regeneration within the model.
    • Progress with small bowel enterocyte culture and transplantation.

      Tait, I S; Flint, N; Evans, Gareth S; Potten, Christopher S; Hopwood, D; Campbell, F C; Department of Surgery, Ninewells Hospital and Medical School, Dundee, Scotland. (1992-06)
    • Transplantation of cultured small bowel enterocytes.

      Campbell, F C; Tait, I S; Flint, Neil; Evans, Gareth S; Department of Surgery, University of Dundee. (1993-09)