In vivo expression of HGF/NK1 and GLP-1 From dsAAV vectors enhances pancreatic ß-cell proliferation and improves pathology in the db/db mouse model of diabetes.
OBJECTIVE
The purpose of the current study was to determine whether double-stranded adeno-associated virus (dsAAV)-mediated in vivo expression of β-cell growth factors, glucagon-like peptide-1 (GLP-1) and the NK1 fragment of hepatocyte growth factor (HGF/NK1) in β-cells, improves pathology in the db/db mouse model of type 2 diabetes. RESEARCH DESIGN AND METHODS; The glucoregulatory actions of GLP-1 and full-length HGF are well characterized. Here, we test the ability of HGF/NK1 to induce proliferation of exogenous islets and MIN6 β-cells. In addition, we target both GLP-1 and HGF/NK1 to endogenous β-cells using dsAAV vectors containing the mouse insulin-II promoter. We compare the abilities of these gene products to induce islet proliferation in vitro and in vivo and characterize their abilities to regulate diabetes after AAV-mediated delivery to endogenous islets of db/db mice.


RESULTS
Recombinant HGF/NK1 induces proliferation of isolated islets, and dsAAV-mediated expression of both GLP-1 and HGF/NK1 induces significant β-cell proliferation in vivo. Furthermore, both GLP-1 and HGF/NK1 expressed from dsAAV vectors enhance β-cell mass and insulin secretion in vivo and significantly delay the onset of hyperglycemia in db/db mice.


CONCLUSIONS
A single treatment with dsAAV vectors expressing GLP-1 or HGF/NK1 enhances islet growth and significantly improves pathology in a mouse model of type 2 diabetes. This represents the first example of a successful use of HGF/NK1 for diabetes therapy, providing support for direct AAV-mediated in vivo delivery of β-cell growth factors as a novel therapeutic strategy for the treatment of type 2 diabetes.
Gaddy
Daniel F
DF
Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
Riedel
Michael J
MJ
Pejawar-Gaddy
Sharmila
S
Kieffer
Timothy J
TJ
Robbins
Paul D
PD
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D017931:DNA Primers; D000229:Dependovirus / Q000235:genetics / Q000472:pathogenicity; D003921:Diabetes Mellitus, Experimental / Q000235:genetics / Q000473:pathology*; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics / Q000473:pathology; D005260:Female; D017930:Genes, Reporter; D005822:Genetic Vectors; D052216:Glucagon-Like Peptide 1 / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000235:genetics; D017228:Hepatocyte Growth Factor / Q000235:genetics* / Q000494:pharmacology; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010446:Peptide Fragments / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000494:pharmacology
D017931:DNA Primers; D010446:Peptide Fragments; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins; D017228:Hepatocyte Growth Factor; D052216:Glucagon-Like Peptide 1