Efficient gene delivery to pancreatic islets with ultrasonic microbubble destruction technology

doi:10.1073/pnas.0602921103

Efficient gene delivery to pancreatic islets with ultrasonic microbubble destruction technology

*Department of Internal Medicine, Cardiology Section, Baylor University Medical Center, Baylor Heart and Vascular Institute, 621 North Hall Street, Suite H030, Dallas, TX 75226;
^†Institute of Metabolic Disease, Baylor University Medical Center, Dallas, TX 75246;
^‡Department of Internal Medicine, Division of Cardiology, and
^§Center for Biomedical Invention, University of Texas Southwestern Medical Center, Dallas, TX 75390; and
^¶Sarah W. Stedman Nutrition and Metabolism Center, Departments of Pharmacology and Cancer Biology and Medicine, Duke University Medical Center, Durham, NC 27710

Communicated by Roger H. Unger, University of Texas Southwestern Medical Center, Dallas, TX, April 13, 2006 (received for review January 20, 2005)

Abstract

This study describes a method of gene delivery to pancreatic islets of adult, living animals by ultrasound targeted microbubble destruction (UTMD). The technique involves incorporation of plasmids into the phospholipid shell of gas-filled microbubbles, which are then infused into rats and destroyed within the pancreatic microcirculation with ultrasound. Specific delivery of genes to islet beta cells by UTMD was achieved by using a plasmid containing a rat insulin 1 promoter (RIP), and reporter gene expression was regulated appropriately by glucose in animals that received a RIP–luciferase plasmid. To demonstrate biological efficacy, we used UTMD to deliver RIP–human insulin and RIP–hexokinase I plasmids to islets of adult rats. Delivery of the former plasmid resulted in clear increases in circulating human C-peptide and decreased blood glucose levels, whereas delivery of the latter plasmid resulted in a clear increase in hexokinase I protein expression in islets, increased insulin levels in blood, and decreased circulating glucose levels. We conclude that UTMD allows relatively noninvasive delivery of genes to pancreatic islets with an efficiency sufficient to modulate beta cell function in adult animals.

Footnotes

^‖To whom correspondence should be addressed. E-mail: paulgr{at}baylorhealth.edu
Author contributions: S.C., S.A.J., C.B.N., and P.A.G. designed research; S.C., R.B., B.-z.Y., C.B.N., and P.A.G. performed research; J.-h.D., R.B., B.-z.Y., R.V.S., and H.E.H. contributed new reagents/analytic tools; S.C., J.-h.D., R.V.S., S.A.J., H.E.H., C.B.N., and P.A.G. analyzed data; and S.C., J.-h.D., C.B.N., and P.A.G. wrote the paper.
Conflict of interest statement: No conflicts declared.
Abbreviations:

Abbreviations:

DsRed,

Discosoma sp. red fluorescent protein;

RIP,

rat insulin 1 promoter;

RLU,

relative light units;

UTMD,

ultrasound targeted microbubble destruction.