RESUMO
The present study was performed in four renal cell lines to evaluate their capability to: (1) produce and express transforming growth factor alpha (TGFalpha), its respective receptor, the epidermal growth factor receptor (EGFr) and the small G protein, RhoA, and (2) exhibit morphogenetic properties when grown on Matri-cell substrates. The cell lines were derived from normal (Madin-Darby canine kidney cells), embryonic (SK-NEP-1 and 293 cells), and cancerous (human renal adenocarcinoma cells) kidneys. TGFalpha messenger ribonucleic acid, evaluated by a nonradioactive in situ hybridization technique, was found to be expressed in all the cell lines. Large amounts of TGFalpha peptide were observed in all four cell lines, while EGFr was highly expressed only in cancerous ACHN and embryonic-tumor SK-NEP-1 cells. RhoA peptide was found in appreciable amounts in SK-NEP-1 and 293 cells (compared to the other two cell lines). The morphogenetic properties of the four cell lines were assessed, by culturing them on Matri-cell dishes: SK-NEP-1 cells alone were found to grow in three-dimensional structures forming clusters and worm-like cellular aggregates. This feature was displayed by SK-NEP-1 cells but not by the other three cell lines, and may be connected with the contemporary presence of RhoA, EGFr, and TGFalpha found in significant amounts only in the SK-NEP-1 cell line.
Assuntos
Fator de Crescimento Epidérmico/fisiologia , Rim/fisiologia , Fator de Crescimento Transformador alfa/fisiologia , Proteína rhoA de Ligação ao GTP/fisiologia , Animais , Células Cultivadas , Cães , Fator de Crescimento Epidérmico/genética , Fator de Crescimento Epidérmico/metabolismo , Rim/citologia , Morfogênese , RNA Mensageiro/genética , Fator de Crescimento Transformador alfa/genética , Fator de Crescimento Transformador alfa/metabolismo , Proteína rhoA de Ligação ao GTP/genética , Proteína rhoA de Ligação ao GTP/metabolismoRESUMO
Heparin, heparan sulfate and chondroitin sulfate were evaluated for their possible role on proliferation and differentiation of hematological precursor cells from cord blood. For these purposes, different concentrations of glycosaminoglycans were added to methyl-cellulose in colony assay performed with human cord blood derived cells. A volume of 10 microg/ml heparin induces a significant increase of both granulocyte-monocyte and granulocyte colonies, and a decrease of erythroid-colonies, more evident in the presence of 100 microg/ml. Heparan sulfate-treatment induces a significant increase of all granulocyte-monocyte colonies derived from CFU-granulocyte-monocyte, CFU-granulocyte and CFU-monocyte precursors. A significant decrease of multipotent cells was also observed. On the other hand, chondroitin sulfate induces an increase of granulocyte-colonies and a decrease of erythroid-colonies. Glycosaminoglycans with different structure may be useful to increase the number of specific colonies. The selective and differential binding of glycosaminoglycans with several growth factors and the regulation of their activities is discussed.
