ABSTRACT
In the field of regenerative medicine,much consideration has been given to stem/progenitor cells for the future treatment of acute and chronic renal failure.For this strategy to be effective,however,cell biological information about tubule development within the diseased organ is needed.Unresolved cell-biological issues relating to this kind of treatment include①the integration of stem/progenitor cells,②their differentiation into site-specific cell types,and③the spatial formation of new tubules.To better understand the mechanisms related to this technology,renal tubules were generated at the interphase of an artificial interstitium by using advanced culture techniques.Stern/progenitor cells derived from neonatal rabbit kidney were covered with layers of polyester fleece,placed in a perfusion culture container,and superfused for 13 days with fresh and chemically defined Iscove's Modified Dulbeccos Medium(IMDM) containing aldosterone (1×10-7mol/L).The spatial growth of tubules was registered by scanning electron microscopy(SEM) and on whole mounts or cryosections labeled with soybean agglutinin,silver stain and monoclonal antibodies reacting with collagen type Ⅲor laminin γ1.SEM revealed that the generated tubules were completely covered by a basal lamina.The lamina fibroreticularis exhibited numerous fibers connecting the basal aspect of generated tubules with the surrounding polyester fibers.Cryosections labeled with monoclonal antibodies anti-collagen type Ⅲ and silver stain demonstrated the formation of numerous fibers spanning between the basal lamina of generated tubules and neighboring polyester fibers.In matured kidney tubules the samg arrangement of collagen type Ⅲ fibers is observed as that for generated tubules.This work shows that collagen type Ⅲ is a relevant molecular linker between the basal aspect of generated renal tubules and the polyester fibers of the artificial interstitium.