In vivo post-transcriptional gene silencing of alpha-1 antitrypsin by adeno-associated virus vectors expressing siRNA
Authors
Cruz, Pedro E.Mueller, Christian
Cossette, Travis L.
Golant, Alexandra
Tang, Qiushi
Beattie, Stuart G.
Brantly, Mark
Campbell-Thompson, Martha
Blomenkamp, Keith S.
Teckman, Jeffrey H.
Flotte, Terence R.
Document Type
Journal ArticlePublication Date
2007-09-27Keywords
AnimalsCell Line, Tumor
Dependovirus
Disease Models, Animal
Down-Regulation
*Gene Therapy
Genetic Vectors
Hepatocytes
Humans
Mice
Mice, Transgenic
Polymorphism, Single Nucleotide
*RNA Interference
RNA, Small Interfering
alpha 1-Antitrypsin
alpha 1-Antitrypsin Deficiency
Allergy and Immunology
Genetics and Genomics
Pediatrics
Respiratory Tract Diseases
Metadata
Show full item recordAbstract
alpha-1 Antitrypsin (AAT) deficiency is one of the most common genetic diseases in North America, with a carrier frequency of approximately 4% in the US population. Homozygosity for the most common mutation (Glu342Lys, PI(*)Z) leads to the synthesis of a mutant protein, which accumulates and polymerizes within hepatocytes rather than being efficiently secreted. This lack of secretion causes severe serum deficiency predisposing to chronic lung disease. Twelve to fifteen percent of patients with PI(*)ZZ also develop liver disease, which can be severe, even in infancy. This is thought to be due to toxic effects of the accumulated mutant Z-AAT within the hepatocyte. Thus, an approach to reduce AAT-deficient liver disease will likely require some mechanism to decrease the amount of Z-AAT within hepatocytes. In this report, we describe studies of small-interfering RNAs (siRNAs) designed to downregulate endogenous AAT within hepatocytes. Three different siRNA sequences were identified and cloned into a recombinant adeno-associated virus (rAAV) backbone, either singly or as a trifunctional (3X) construct. Each had activity independently, but the levels of AAT expression in cell culture models showed the greatest decrease with the 3X construct, resulting in levels that were five-fold lower than controls. The rAAV-3X-siRNA was then packaged into AAV8 capsids and used in vivo to transduce the livers of human Z-AAT overexpressing transgenic mice. Those studies showed a decrease in total human AAT, a clearing of Z-AAT accumulation by immunohistochemistry, and a decrease in monomer Z-AAT within the liver within 3 weeks after vector injection. The rAAV8-3X-siRNA vector may hold promise as a potential therapy for patients with AAT liver disease.Source
Lab Invest. 2007 Sep;87(9):893-902. Epub 2007 Jun 25. Link to article on publisher's siteDOI
10.1038/labinvest.3700629Permanent Link to this Item
http://hdl.handle.net/20.500.14038/43797PubMed ID
17592477Related Resources
Link to Article in PubMedae974a485f413a2113503eed53cd6c53
10.1038/labinvest.3700629