Reduction of islet amylin expression and basal secretion by adenovirus-mediated delivery of amylin antisense cDNA.

Reduction of amylin content and secretion in rat islets was attempted by transduction with an adenovirus bearing a 0.2-kb fragment of rat amylin cDNA inserted in the antisense orientation (AdCMV-alpha amylin). Exposure of islets to AdCMV-alpha amylin at a multiplicity of infection (moi) of 200 (1.2 x 10(7) pfu/ml) reduced amylin mRNA levels by 37 +/- 5% (p < 0.005), whereas infection with an adenovirus expressing the reporter gene of beta-galactosidase (AdCMV-lacz) did not modify amylin expression. Transduction with the antisense construct was specifically associated with the decrease (30 +/- 6%; p < 0.001) in the amylin content. Insulin content was unaltered in AdCMV-alpha amylin islets compared to AdCMV-lacz-transduced or untransduced cells. Basal amylin secretion (2.8 mM glucose) was 36 +/- 3% (p < 0.005) lower in AdCMV-alpha amylin islets than in untransduced or AdCMV-lacz-transduced islets. In contrast, no difference in amylin secretion in response to high glucose concentrations (16.7 mM) was detected in AdCMV-alpha amylin-transduced islets. Thus, a reduction of amylin content and basal secretion in islet cells can be achieved by the adenovirus-mediated expression of antisense RNA.