Indomethacin-induced sialic acid-mediated changes in surface markers from "cortical type" to "medullary type" in murine thymoma line EL-4.
The effect of indomethacin (INDO), a specific inhibitor of prostaglandin (PG) synthesis, on the expression of markers during thymocyte differentiation such as Thy-1, H-2K, and peanut agglutinin (PNA) receptor was examined by immunofluorescence, using poorly differentiated thymoma, EL-4, as the indicator cells. EL-4 cells grown in the culture medium in the presence of INDO exhibited lower levels of Thy-1 and PNA, and a higher level of H-2K, compared with the EL-4 cells grown in medium without INDO. The decrease in PNA level by INDO was attributed to an increased density of sialic acid bound to PNA receptors on the cell surface, because treatment with neuraminidase (Nase) released more sialic acid from such cells, as compared with control cells, and markedly increased the detectable amounts of PNA receptors. On the other hand, a decrease of Thy-1 or an increase of H-2K may be ascribed to the decrease of Nase-resistant sialic acid on the cell surface, determined by analyses with FITC-LPA, sialic acid-specific lectin, and by metabolic labeling of surface sialic acid. These results suggest that the PG-system modulates the metabolism of sialic acid located on the thymocyte surface and alters the expression of surface markers of thymocytes.
D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D015232:Dinoprostone; D005434:Flow Cytometry; D006183:H-2 Antigens / Q000032:analysis; D007213:Indomethacin / Q000494:pharmacology*; D037102:Lectins; D051379:Mice; D009439:Neuraminidase; D019887:Peanut Agglutinin; D011453:Prostaglandins / Q000502:physiology; D011458:Prostaglandins E / Q000494:pharmacology; D012794:Sialic Acids / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology; D018800:Thy-1 Antigens; D013945:Thymoma; D013950:Thymus Gland / Q000166:cytology*
D000954:Antigens, Surface; D006183:H-2 Antigens; D037102:Lectins; D019887:Peanut Agglutinin; D011453:Prostaglandins; D011458:Prostaglandins E; D012794:Sialic Acids; D018800:Thy-1 Antigens; D009439:Neuraminidase; D015232:Dinoprostone; D007213:Indomethacin