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In vivo expression of HGF/NK1 and GLP-1 From dsAAV vectors enhances pancreatic Ăź-cell proliferation and improves pathology in the db/db mouse model of diabetes.

Gaddy DF, Riedel MJ, Pejawar-Gaddy S, Kieffer TJ, Robbins PD - Diabetes (2010)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.

ABSTRACT

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.

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GLP-1 and HGF/NK1 gene transfer prolong normoglycemia in db/db mice. Four-week-old female db/db mice were injected intraperitoneally with 4 × 1011 vg of dsAAV–eGFP (A; n = 10), dsAAV–GLP1 (B; n = 10), or dsAAV–NK1 (C; n = 10), and blood glucose levels were monitored weekly until all mice became hyperglycemic. D: The percentage of diabetes-free animals, defined as having blood glucose levels < 280 mg/dl, are plotted against age. Although there was no difference in the incidence of diabetes, there was a significant delay in the onset in mice treated with dsAAV–GLP1 (open triangles) and dsAAV–NK1 (open circles) compared with dsAAV–eGFP-infected control animals (black squares). A P value of <0.005 by log rank test analysis was used to indicate a statistically significant percentage of normoglycemic animals.
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Figure 4: GLP-1 and HGF/NK1 gene transfer prolong normoglycemia in db/db mice. Four-week-old female db/db mice were injected intraperitoneally with 4 × 1011 vg of dsAAV–eGFP (A; n = 10), dsAAV–GLP1 (B; n = 10), or dsAAV–NK1 (C; n = 10), and blood glucose levels were monitored weekly until all mice became hyperglycemic. D: The percentage of diabetes-free animals, defined as having blood glucose levels < 280 mg/dl, are plotted against age. Although there was no difference in the incidence of diabetes, there was a significant delay in the onset in mice treated with dsAAV–GLP1 (open triangles) and dsAAV–NK1 (open circles) compared with dsAAV–eGFP-infected control animals (black squares). A P value of <0.005 by log rank test analysis was used to indicate a statistically significant percentage of normoglycemic animals.

Mentions: To examine possible therapeutic effects of GLP-1 and HGF/NK1 expression from endogenous β-cells on the course of type 2 diabetes, 4-week-old female db/db mice were treated with a single intraperitoneal injection of dsAAV–eGFP, dsAAV–GLP1, or dsAAV–NK1 and blood glucose levels were monitored weekly until all mice developed diabetes. As shown in Fig. 4A and D, 100% of mice receiving the eGFP control virus developed diabetes by 7 weeks of age. However, treatment with the GLP-1 virus significantly delayed onset of disease, with mice remaining normoglycemic as late as 10 weeks of age (Fig. 4B and D). An even greater effect was observed in animals receiving the HGF/NK1 virus (Fig. 4C and D), with animals remaining normoglycemic as late as 14 weeks of age, twice as long as control mice. These data show that, although the frequency of onset of hyperglycemia was not reduced, a single treatment with AAV expressing β-cell growth factors was sufficient to prolong normoglycemia in db/db mice.


In vivo expression of HGF/NK1 and GLP-1 From dsAAV vectors enhances pancreatic Ăź-cell proliferation and improves pathology in the db/db mouse model of diabetes.

Gaddy DF, Riedel MJ, Pejawar-Gaddy S, Kieffer TJ, Robbins PD - Diabetes (2010)

GLP-1 and HGF/NK1 gene transfer prolong normoglycemia in db/db mice. Four-week-old female db/db mice were injected intraperitoneally with 4 × 1011 vg of dsAAV–eGFP (A; n = 10), dsAAV–GLP1 (B; n = 10), or dsAAV–NK1 (C; n = 10), and blood glucose levels were monitored weekly until all mice became hyperglycemic. D: The percentage of diabetes-free animals, defined as having blood glucose levels < 280 mg/dl, are plotted against age. Although there was no difference in the incidence of diabetes, there was a significant delay in the onset in mice treated with dsAAV–GLP1 (open triangles) and dsAAV–NK1 (open circles) compared with dsAAV–eGFP-infected control animals (black squares). A P value of <0.005 by log rank test analysis was used to indicate a statistically significant percentage of normoglycemic animals.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2992772&req=5

Figure 4: GLP-1 and HGF/NK1 gene transfer prolong normoglycemia in db/db mice. Four-week-old female db/db mice were injected intraperitoneally with 4 × 1011 vg of dsAAV–eGFP (A; n = 10), dsAAV–GLP1 (B; n = 10), or dsAAV–NK1 (C; n = 10), and blood glucose levels were monitored weekly until all mice became hyperglycemic. D: The percentage of diabetes-free animals, defined as having blood glucose levels < 280 mg/dl, are plotted against age. Although there was no difference in the incidence of diabetes, there was a significant delay in the onset in mice treated with dsAAV–GLP1 (open triangles) and dsAAV–NK1 (open circles) compared with dsAAV–eGFP-infected control animals (black squares). A P value of <0.005 by log rank test analysis was used to indicate a statistically significant percentage of normoglycemic animals.
Mentions: To examine possible therapeutic effects of GLP-1 and HGF/NK1 expression from endogenous β-cells on the course of type 2 diabetes, 4-week-old female db/db mice were treated with a single intraperitoneal injection of dsAAV–eGFP, dsAAV–GLP1, or dsAAV–NK1 and blood glucose levels were monitored weekly until all mice developed diabetes. As shown in Fig. 4A and D, 100% of mice receiving the eGFP control virus developed diabetes by 7 weeks of age. However, treatment with the GLP-1 virus significantly delayed onset of disease, with mice remaining normoglycemic as late as 10 weeks of age (Fig. 4B and D). An even greater effect was observed in animals receiving the HGF/NK1 virus (Fig. 4C and D), with animals remaining normoglycemic as late as 14 weeks of age, twice as long as control mice. These data show that, although the frequency of onset of hyperglycemia was not reduced, a single treatment with AAV expressing β-cell growth factors was sufficient to prolong normoglycemia in db/db mice.

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.

ABSTRACT

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.

Show MeSH
Related in: MedlinePlus