Liver-Specific Nonviral Gene Delivery of Fibroblast Growth Factor 21 Protein Expression in Mice Regulates Body Mass and White/Brown Fat Respiration.

Nathaniel G Girer,Aditya Joshi,Craig Porter,Andrew J Murton,Cornelis J Elferink,Massoud Motamedi,Igor Patrikeev,Victoria G Rontoyanni

doi:10.1124/jpet.121.000514

Abstract

Viral-mediated in vivo gene delivery methods currently dominate among therapeutic strategies within the clinical and experimental settings, albeit with well documented limitations arising from immunologic constraints. In this study, we demonstrate the utility of nonviral hepatotropic in vivo gene delivery of unpackaged expression constructs, including one encoding fibroblast growth factor 21 (FGF21). FGF21 is an important hepatokine whose expression positively correlates with therapeutic outcomes across various animal models of obesity. Our data demonstrate that FGF21 expression can be restored into the livers of immunocompetent FGF21 knockout mice for at least 2 weeks after a single injection with an FGF21 expression plasmid. In wild-type C57BL6/J mice, in vivo transfection with an FGF21-expressing plasmid induced weight loss, decreased adiposity, and activated thermogenesis in white fat within 2 weeks. Furthermore, in vivo FGF21 gene delivery protected C57BL6/J mice against diet-induced obesity by decreasing adiposity and increasing uncoupling protein 1–dependent thermogenesis in brown fat and by boosting respiratory capacity in subcutaneous and perigonadal white fat. Together, the data illustrate a facile and effective methodology for delivering prolonged protein expression specifically to the liver. We contend that this method will find utility in basic science research as a practical means to enhance in vivo studies characterizing liver protein function. We further believe our data provide a rationale for further exploring the potential clinical utility of nonviral gene therapy in mouse models of disease.Significance StatementThis study presents a valuable method for nonviral gene delivery in mice that improves upon existing techniques. The data provide a rationale for further exploring the potential clinical utility of nonviral gene therapy in mouse models of disease and will likely enhance in vivo studies characterizing liver protein function.

Highlights

Gene therapy as an approach to disease management/treatment has proven quite promising, and the United States has already approved multiple gene therapies for clinical use
We demonstrate the utility of nonviral hepatotropic in vivo gene delivery of unpackaged expression constructs, including one encoding fibroblast growth factor 21 (FGF21)
Liver-specific gene delivery is primarily achieved through either hydrodynamic delivery or associated virus (AAV) infection

Summary

Introduction

Gene therapy as an approach to disease management/treatment has proven quite promising, and the United States has already approved multiple gene therapies for clinical use. Gene therapy approaches are especially useful for the treatment of hepatic diseases, as. Liver-specific gene delivery has successfully been achieved through either hydrodynamic delivery or adeno-associated virus (AAV) infection. Hydrodynamic delivery is harsh and technically demanding, requiring very large intravenous injection volumes ($8%–10% body mass) delivered in a matter of seconds. The viruses elicit a robust innate immune response in immunocompetent organisms that precludes repeated administration of the viruses (Manno et al, 2006). These limitations place constraints on their clinical application and undermine the utility of expression constructs in research animal models. The development of more amenable strategies for gene delivery warrants investigation

Methods

Results

Conclusion