RNA Interference Targeting Hypoxia Inducible Factor 1α Reduces Post-Operative Adhesions in Rats

Segura, Tatiana; Schmokel, Hugo; Hubbell, Jeffrey A.

doi:10.1016/j.jss.2006.07.045

« Previous Next »Journal of Surgical Research
Volume 141, Issue 2 , Pages 162-170, August 2007

RNA Interference Targeting Hypoxia Inducible Factor 1α Reduces Post-Operative Adhesions in Rats

Tatiana Segura, Ph.D.
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Bioengineering and Institute of Chemical Sciences and Engineering, Lausanne, Switzerland
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California
Hugo Schmokel, Ph.D., D.V.M.
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Bioengineering and Institute of Chemical Sciences and Engineering, Lausanne, Switzerland
Jeffrey A. Hubbell, Ph.D.
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Bioengineering and Institute of Chemical Sciences and Engineering, Lausanne, Switzerland
- To whom correspondence and reprint requests should be addressed at: Jeffrey A. Hubbell, EPFL SV-LMRP, Station 15, CH-1015 Lausanne, Switzerland.

Received 3 April 2006 published online 13 June 2007.

Background

To investigate the use of RNA interference mediated gene down-regulation targeting hypoxia inducible factor 1α (HIF-1α) and plasminogen activator inhibitor 1 (PAI-1) in an effort to prevent abdominal adhesion formation.

Materials and methods

Real time PCR and a PAI-1 protein activity assay were used in vitro to determine the efficacy of small interfering RNAs (siRNAs). For in vivo experiments, 57 white female rats were operated to generate ischemic and serosal injury to the uterine horns, and treated with saline, siRNA_Lamin A/C (negative control), siRNA_HIF-1α, siRNA_PAI-1, or siRNA_HIF-1α plus siRNA_PAI-1. The cationic polyer poly(ethylenimine) (PEI) was used as the delivery vehicle for all siRNAs delivered in vivo. Adhesions were analyzed by a blinded surgeon 8 days post-surgery.

Results

After in vitro transfection with siRNA, at least 69% gene down-regulation was obtained for all siRNAs tested. In vitro siRNA-mediated down-regulation of HIF-1α, PAI-1 or their simultaneous delivery resulted in a significant decrease of PAI-1 protein activity (at least P < 0.05). Administration of 4 nmol siRNA_HIF-1α/PEI complexes after injury to the uterine horns achieved a statistical reduction of post-operative adhesion formation with a reduction by 52% (P < 0.05). Delivery of 4 nmol siRNA_PAI-1/PEI complexes and the simultaneous delivery of 2 nmol siRNA_HIF-1α plus 2 nmol siRNA_PAI-1, resulted in a reduction of abdominal adhesion by 36% and 42%, respectively, with the reduction being statistically significant when compared directly to the saline control (P < 0.01).

Conclusion

These data show that administration of siRNA/PEI complexes within the peritoneal cavity can be used to prevent post-operative abdominopelvic adhesions.

Key Words: siRNA, polyethyleneimine, non-viral, abdominal adhesion prevention