[Development of gene therapy for encapsulating peritoneal sclerosis by a chimeric DNA-RNA hammerhead ribozyme targeting TGF-beta1 mRNA].

ABSTRACT

BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is a rare and devastating fibrotic complication in patients treated with peritoneal dialysis. Transforming growth factor-beta1 (TGF-beta1) has been reported to be a pivotal factor in the induction of EPS. Ribozymes are RNA molecules that enzymatically cleave the target mRNAs and are expected to be utilized as a novel nucleic acid-based therapy. We examined the effects of the chimeric DNA-RNA hammerhead ribozyme targeting TGF-beta1 mRNA on a peritoneal sclerosis rat model to develop a possible gene therapy for EPS. METHODS: To create an animal model of peritoneal sclerosis, rats were given a daily intraperitoneal injection of chlorhexidine gluconate and ethanol dissolved in saline (CHX) for 14 days. On day 4, the chimeric ribozyme or mismatch ribozyme was intraperitoneally injected. On day 15, samples of peritoneum were obtained from the rats, and expression of TGF-beta1 mRNA and fibronectin mRNA in peritoneal tissues were evaluated by quantitative real-time PCR analysis. RESULTS: Injections of CHX significantly increased the submesothelial thickness, and increased the expression of TGF-beta1 and fibronectin mRNA in the rat peritoneum. Treatment with the chimeric ribozyme significantly reduced the CHX-induced peritoneal thickness, and expression of TGF-beta1, and fibronectin mRNA in peritoneal tissues. CONCLUSIONS: These results indicate that the chimeric DNA-RNA hammerhead ribozyme targeting TGF-beta1 mRNA has the potential for use as a gene therapy agent for EPS.