title: Human colon tissue in organ culture: calcium and multi-mineral-induced mucosal differentiation.
abstract: We have recently shown that a multi-mineral extract from the marine red algae, Lithothamnion calcareum, suppresses colon polyp formation and inflammation in mice. In the present study, we used intact human colon tissue in organ culture to compare responses initiated by Ca(2+) supplementation versus the multi-mineral extract. Normal human colon tissue was treated for 2 d in culture with various concentrations of calcium or the mineral-rich extract. The tissue was then prepared for histology/immunohistochemistry, and the culture supernatants were assayed for levels of type I procollagen and type I collagen. At higher Ca(2+) concentrations or with the mineral-rich extract, proliferation of epithelial cells at the base and walls of the mucosal crypts was suppressed, as visualized by reduced Ki67 staining. E-cadherin, a marker of differentiation, was more strongly expressed at the upper third of the crypt and at the luminal surface. Treatment with Ca(2+) or with the multi-mineral extract influenced collagen turnover, with decreased procollagen and increased type I collagen. These data suggest that calcium or mineral-rich extract has the capacity to (1) promote differentiation in human colon tissue in organ culture and (2) modulate stromal function as assessed by increased levels of type I collagen. Taken together, these data suggest that human colon tissue in organ culture (supporting in vivo finding in mice) will provide a valuable model for the preclinical assessment of agents that regulate growth and differentiation in the colonic mucosa.
authors.affiliation: Department of Pathology, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, MI 48109-5602, USA. mdame@med.umich.edu
authors.forename: Michael K
authors.initials: MK
authors.lastname: Dame
authors.forename: Indiradevi
authors.initials: I
authors.lastname: Veerapaneni
authors.forename: Narasimharao
authors.initials: N
authors.lastname: Bhagavathula
authors.forename: Madhav
authors.initials: M
authors.lastname: Naik
authors.forename: James
authors.initials: J
authors.lastname: Varani
mesh_terms: D015415:Biomarkers; D015820:Cadherins; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects*; D024042:Collagen Type I / Q000032:analysis; D003106:Colon / Q000166:cytology*; D003111:Colonic Polyps / Q000188:drug therapy / Q000517:prevention & control*; D045424:Complex Mixtures / Q000032:analysis / Q000494:pharmacology*; D006652:Histological Techniques; D006801:Humans; D007150:Immunohistochemistry; D008954:Models, Biological; D009924:Organ Culture Techniques / Q000379:methods*; D000461:Rhodophyta / Q000737:chemistry*
chemical_list: D015415:Biomarkers; D015820:Cadherins; D024042:Collagen Type I; D045424:Complex Mixtures; D002118:Calcium