11-cis-retinal and Teratoma

To determine whether transplantation of embryonic stem (ES) cells into the subretinal space of rhodopsin-knockout mice has a tumorigenic effect.. Mouse ES-cell-derived neural precursor cells carrying the sequence for the green fluorescent protein (GFP) gene were grafted subretinally into the eyes of rhodopsin(-/-) mice, whereas control animals underwent sham surgery. Eyes were retrieved after 2, 4, and 8 weeks after cell injection or sham surgery for histologic analysis.. Gross morphologic, histologic, and immunohistochemical analysis of eyes at 2 and 4 weeks after engraftment exhibited no morphologic alterations, whereas neoplasia formation was detected in 50% of the eyes evaluated at 8 weeks after engraftment. Because the neoplasias expressed differentiation characteristics of the different germ layers, they were considered to be teratomas. The resultant tumor formation affected almost all layers of the eye, including the retina, the vitreous, and the choroid.. Although ES cells may provide treatment for degenerative disease in the future, their unlimited self-renewal and high differentiation potential poses the risk of tumor induction after engraftment. Thus, more care must be taken before using ES cell transplantation as a therapeutic option for patients with degenerative disease.

Topics: Animals; Cell Differentiation; Cell Line; Cell Survival; Eye Neoplasms; Green Fluorescent Proteins; Immunohistochemistry; Injections; Luminescent Agents; Male; Mice; Mice, Knockout; Neurons; Retina; Rhodopsin; Staining and Labeling; Stem Cell Transplantation; Stem Cells; Teratoma; Time Factors

We report the use of UDPgalactose:N-acetyl-D-glucosaminyl-glycopeptide 4-beta-D-galactosyl-transferase (EC 2.4.1.38), purified from bovine milk, to detect nonreducing terminal N-acetylglucosamine residues on glycoproteins immobilized on nitrocellulose by electrophoretic transfer from sodium dodecyl sulfate-polyacrylamide gels. Soluble galactosyltransferase incorporates radiolabeled galactose from the substrate UDP-[6-3H]galactose into the appropriate immobilized acceptor with high specificity. Incorporation is proportional to substrate amount and is saturable with time. The kinetics of labeling are independent of substrate amount. Half-maximal incorporation occurs by 4 h and saturation occurs by 16 h. We have used galactosyltransferase as a probe (i) to verify the presence of nonreducing terminal N-acetylglucosamine residues in bovine rod outer segment membrane rhodopsin and in several glycoproteins in F9 murine teratocarcinoma cells and (ii) to detect previously reported endo-beta-N-acetylglucosaminidase activity in a commercial preparation of endoglycosidase F.

Topics: Acetylglucosamine; Acetylglucosaminidase; Animals; Cattle; Cell Line; Collodion; Galactosyltransferases; Glucosamine; Glycoproteins; Glycoside Hydrolases; Kinetics; Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; Mice; Milk; Neoplasm Proteins; Oxidation-Reduction; Rhodopsin; Solubility; Teratoma