Influence of epithelial‐mesenchymal interaction on the viability of facial mesenchyme II: Synthesis of basement‐membrance components during tissue recombination

Abstract

The presence of basement-membrane components during tissue separation procedures was determined employing monoclonal antibodies to laminin and type IV collagen. In addition, the reconstitution of basement-membrane components and the formation of the basement-membrane were examined in isolated epithelium and mesenchyme and in tissue recombination. Epithelium and mesenchyme of maxillary processes of chick embryos were separated by a variety of protocols, including those employed in a prior study (Saber et al: Anat. Rec. 225:56-66, 1989). Results indicated that the protocol previously employed did not remove basement-membrane components after enzymatic tissue separation. A revised protocol in which the basement-membrane components (i.e., laminin and type IV collagen) were removed from isolated tissues prior to recombination revealed that a developmental compartment and a gradient of cell viability, comparable in size and dimensions to that observed in the study of Saber et al. (ibid.) was present in the mesenchyme of recombined explants. Type IV collagen and laminin, therefore, do not appear to be required initially during tissue recombination in order for subsequent growth-sustaining effects to be expressed. Additional studies revealed, however, that synthesis of basement-membrane components occurred not only in isolated tissues but was altered markedly by tissue recombination. Culture of isolated tissues demonstrated induction of laminin synthesis in separated epithelium by 24 hours and induction of collagen synthesis in isolated mesenchyme by 24 hours. Recombination of epithelium and mesenchyme, however, resulted in rapid induction of laminin synthesis within 1 hour. Recombination of epithelium and mesenchyme after 24 hours resulted in the presence of laminin not only in epithelium but in mesenchyme as well. Both tissues were required for basement-membrane formation which appeared to be fully reconstituted by 24 hours in culture. These observations indicate that recombination in culture alters the pattern of synthetic activity of these basement-membrane components. These can be characterized as "early" (temporal) and "late" spatial) responses by the recombined tissues.

Basement Membrane Formation of Fetal Mouse Intestinal Epithelial Cells in Organoid Cultures

“…Studies by Sanderson et al 11986] indi cated that, during myogenesis in vitro, fibroblasts must be in close proximity to myotubes in order for a continuous basement membrane to form. Xu et al [1990] reported that recombination of epithelium and mesenchyme from the maxillary process resulted in rapid induction of the synthe sis of laminin. Vachon et al 11993] reported that synthesis and deposition of basement membrane heparan sulfate pro teoglycan were exclusively observed in co-culture with epi thelial and mesenchymal cells.…”

Reorganized small intestine from fetal mouse as an in vitro wound healing model

“…1-3 Extracellular matrix and growth factors are also known to be important for the proliferation and differentiation of epithelial cells. [4][5][6][7][8][9] Epithelial cells from embryonic or fetal lung proliferate in monolayer culture but do not differentiate. 10 However, with the introduction of collagen-coated plates, some progress was made in this field.…”