Gene dosage of CuZnSOD and Down's syndrome: diminished prostaglandin synthesis in human trisomy 21, transfected cells and transgenic mice.

Abstract

Patients with Down's syndrome (DS) exhibit elevated activity of copper zinc superoxide dismutase (CuZnSOD) caused by the trisomy 21 state. To investigate the possible involvement of CuZnSOD gene dosage in perturbation of prostaglandin biosynthesis we analyzed transfected cells and transgenic mice that express elevated levels of human CuZnSOD. It was found that the synthesis of prostaglandin E 2 (PGE 2 ) was diminished in transfected PC12-CuZnSOD cells as well as in fibroblasts from DS patients. Primary cells derived from transgenic CuZnSOD mice showed similar reduction. Impaired biosynthesis of prostaglandins was not confined to cells grown in culture since secretion of PGE 2 and PGD 2 by kidney and cerebellum of transgenic CuZnSOD was significantly lower than in non-transgenic littermate mice. These findings strongly suggest that overexpression of the CuZnSOD gene induces a demotion in PGE 2 and PGD 2 formation and establish a connection between alteration of prostaglandin biosynthesis in trisomy 21 cells and gene dosage of CuZnSOD.