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Wilcox DM, Yang R, Morgan SJ, Nguyen PT, Voorbach MJ, Jung PM, Haasch DL, Lin E, Bush EN, Opgenorth TJ, Jacobson PB, Collins CA, Rondinone CM, Surowy T, Landschulz KT. Delivery of RNAi reagents in murine models of obesity and diabetes. J RNAi Gene Silencing 2006; 3:225-36. [PMID: 19771218 PMCID: PMC2737213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 11/13/2006] [Accepted: 11/15/2006] [Indexed: 11/21/2022]
Abstract
RNA interference (RNAi) is an exciting new tool to effect acute in vivo knockdown of genes for pharmacological target validation. Testing the application of this technology to metabolic disease targets, three RNAi delivery methods were compared in two frequently utilized preclinical models of obesity and diabetes, the diet-induced obese (DIO) and B6.V-Lep<ob>/J (ob/ob) mouse. Intraperitoneal (i.p.) and high pressure hydrodynamic intravenous (i.v.) administration of naked siRNA, and low pressure i.v. administration of shRNA-expressing adenovirus were assessed for both safety and gene knockdown efficacy using constructs targeting cJun N-terminal kinase 1 (JNK1). Hydrodynamic delivery of siRNA lowered liver JNK1 protein levels 40% in DIO mice, but was accompanied by iatrogenic liver damage. The ob/ob model proved even more intolerant of this technique, with hydrodynamic delivery resulting in severe liver damage and death of most animals. While well-tolerated, i.p. injections of siRNA in DIO mice did not result in any knockdown or phenotypic changes in the mice. On the other hand, i.v. injected adenovirus expressing shRNA potently reduced expression of JNK1 in vivo by 95% without liver toxicity. In conclusion, i.p. and hydrodynamic injections of siRNA were ineffective and/or inappropriate for in vivo gene targeting in DIO and ob/ob mice, while adenovirus-mediated delivery of shRNA provided a relatively benign and effective method for exploring liver target silencing.
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Affiliation(s)
- Denise M Wilcox
- Metabolic Disease Research, in vivo Chemical Genomics, Department R4CY, 100 Abbott Park Road, Abbott Laboratories, Abbott Park, IL 60064, USA,Correspondence to: Denise Wilcox, , Tel: +847 937 5790, Fax: +847 938 1656
| | - Ruojing Yang
- Metabolic Disease Research, in vivo Chemical Genomics, Department R4CY, 100 Abbott Park Road, Abbott Laboratories, Abbott Park, IL 60064, USA
| | - Sherry J Morgan
- Metabolic Disease Research, in vivo Chemical Genomics, Department R4CY, 100 Abbott Park Road, Abbott Laboratories, Abbott Park, IL 60064, USA
| | - Phong T Nguyen
- Metabolic Disease Research, in vivo Chemical Genomics, Department R4CY, 100 Abbott Park Road, Abbott Laboratories, Abbott Park, IL 60064, USA
| | - Martin J Voorbach
- Metabolic Disease Research, in vivo Chemical Genomics, Department R4CY, 100 Abbott Park Road, Abbott Laboratories, Abbott Park, IL 60064, USA
| | - Paul M Jung
- Metabolic Disease Research, in vivo Chemical Genomics, Department R4CY, 100 Abbott Park Road, Abbott Laboratories, Abbott Park, IL 60064, USA
| | - Deanna L Haasch
- Metabolic Disease Research, in vivo Chemical Genomics, Department R4CY, 100 Abbott Park Road, Abbott Laboratories, Abbott Park, IL 60064, USA
| | - Emily Lin
- Metabolic Disease Research, in vivo Chemical Genomics, Department R4CY, 100 Abbott Park Road, Abbott Laboratories, Abbott Park, IL 60064, USA,UIC College of Medicine, Chicago, IL 60612-7302, USA
| | - Eugene N Bush
- Metabolic Disease Research, in vivo Chemical Genomics, Department R4CY, 100 Abbott Park Road, Abbott Laboratories, Abbott Park, IL 60064, USA
| | - Terry J Opgenorth
- Metabolic Disease Research, in vivo Chemical Genomics, Department R4CY, 100 Abbott Park Road, Abbott Laboratories, Abbott Park, IL 60064, USA
| | - Peer B Jacobson
- Metabolic Disease Research, in vivo Chemical Genomics, Department R4CY, 100 Abbott Park Road, Abbott Laboratories, Abbott Park, IL 60064, USA
| | - Christine A Collins
- Metabolic Disease Research, in vivo Chemical Genomics, Department R4CY, 100 Abbott Park Road, Abbott Laboratories, Abbott Park, IL 60064, USA
| | - Cristina M Rondinone
- Metabolic Disease Research, in vivo Chemical Genomics, Department R4CY, 100 Abbott Park Road, Abbott Laboratories, Abbott Park, IL 60064, USA
| | - Terry Surowy
- Metabolic Disease Research, in vivo Chemical Genomics, Department R4CY, 100 Abbott Park Road, Abbott Laboratories, Abbott Park, IL 60064, USA
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Xu H, Wilcox D, Nguyen P, Voorbach M, Suhar T, Morgan SJ, An WF, Ge L, Green J, Wu Z, Gimeno RE, Reilly R, Jacobson PB, Collins CA, Landschulz K, Surowy T. Hepatic knockdown of mitochondrial GPAT1 in ob/ob mice improves metabolic profile. Biochem Biophys Res Commun 2006; 349:439-48. [PMID: 16935266 DOI: 10.1016/j.bbrc.2006.08.071] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Accepted: 08/15/2006] [Indexed: 10/24/2022]
Abstract
Glycerol-3-phosphate acyltransferase (GPAT) controls the first step of triglyceride (TAG) synthesis. Three distinct GPAT activities have been identified, two localized in mitochondria and one in microsomes. Mitochondrial GPAT1 (mtGPAT1) is abundantly expressed in the liver and constitutes approximately 50% of total GPAT activities in this organ. Hepatic mtGPAT1 activity is elevated in obese rodents. Mice deficient in mtGPAT1 have an improved lipid profile. To investigate if beneficial effects can result from reduced hepatic expression of mtGPAT1 in adult obese mice, adenoviral vector-based short hairpin RNA interference (shRNA) technology was used to knockdown mtGPAT1 expression in livers of ob/ob mice. Reduced expression of mtGPAT1 mRNA in liver of ob/ob mice resulted in dramatic and dose dependent reduction in mtGPAT1 activity. Reduced hepatic TAG, diacylglycerol, and free fatty acid, as well as reduced plasma cholesterol and glucose, were also observed. Fatty acid composition analysis revealed decrease of C16:0 in major lipid species. Our results demonstrate that acute reduction of mtGPAT1 in liver of ob/ob mice reduces TAG synthesis, which points to a role for mtGPAT1 in the correction of obesity and related disorders.
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Affiliation(s)
- Haiyan Xu
- Metabolic Disease Research, Abbott Laboratories, Abbott Park, IL 60064, USA.
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