Limits...
Gene therapy in a humanized mouse model of familial hypercholesterolemia leads to marked regression of atherosclerosis.

Kassim SH, Li H, Vandenberghe LH, Hinderer C, Bell P, Marchadier D, Wilson A, Cromley D, Redon V, Yu H, Wilson JM, Rader DJ - PLoS ONE (2010)

Bottom Line: A single intravenous injection of AAV8.mLDLR was found to significantly reduce plasma cholesterol and non-HDL cholesterol levels in chow-fed animals at doses as low as 3×10(9) genome copies/mouse.Collectively, the results presented herein suggest that AAV8-based gene therapy for FH may be feasible and support further development of this approach.The pre-clinical data from these studies will enable for the effective translation of gene therapy into the clinic for treatment of FH.

View Article: PubMed Central - PubMed

Affiliation: Gene Therapy Program, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.

ABSTRACT

Background: Familial hypercholesterolemia (FH) is an autosomal codominant disorder caused by mutations in the low-density lipoprotein receptor (LDLR) gene. Homozygous FH patients (hoFH) have severe hypercholesterolemia leading to life threatening atherosclerosis in childhood and adolescence. Mice with germ line interruptions in the Ldlr and Apobec1 genes (Ldlr(-/-)Apobec1(-/-)) simulate metabolic and clinical aspects of hoFH, including atherogenesis on a chow diet.

Methods/principal findings: In this study, vectors based on adeno-associated virus 8 (AAV8) were used to deliver the gene for mouse Ldlr (mLDLR) to the livers of Ldlr(-/-)Apobec1(-/-) mice. A single intravenous injection of AAV8.mLDLR was found to significantly reduce plasma cholesterol and non-HDL cholesterol levels in chow-fed animals at doses as low as 3×10(9) genome copies/mouse. Whereas Ldlr(-/-)Apobec1(-/-) mice fed a western-type diet and injected with a control AAV8. vector experienced a further 65% progression in atherosclerosis over 2 months compared with baseline mice, Ldlr(-/-)Apobec1(-/-) mice treated with AAV8.mLDLR realized an 87% regression of atherosclerotic lesions after 3 months compared to baseline mice. Immunohistochemical analyses revealed a substantial remodeling of atherosclerotic lesions.

Conclusions/significance: Collectively, the results presented herein suggest that AAV8-based gene therapy for FH may be feasible and support further development of this approach. The pre-clinical data from these studies will enable for the effective translation of gene therapy into the clinic for treatment of FH.

Show MeSH

Related in: MedlinePlus

AAV8.TBG.mLDLR mediated regression of atherosclerotic lesions in high-fat fed Ldlr-/-Apobec1-/-mice.(A) En face Sudan IV staining. Mouse aortas were pinned and stained with Sudan IV, which stains neutral lipids. Representative aortas from animals treated with 1×10∧11 of AAV8.TBG.nLacZ, 1×10∧11 of AAV8.TBG.mLDLR at day 60 after vector administration (day 120 on high-fat diet), or at baseline (day 60 on high-fat diet) are shown. (B) The percent Sudan IV staining of the total aortic surface in baseline (n = 10), AAV.TBG.nLacZ (n = 9) and AAV8.TBG.mLDLR (n = 10) was determined as described under Materials and Methods. Aortic roots from these mice were stained with oil red o (C) or hematoxylin and eosin (H&E) (D) 10× magnification. Quantification was conducted on oil red o lesions (E) as described in the materials and methods. Each column represents mean ± s.d. *P<0.05, **P<0.01, ***P<0.001, ‡ P<0.001. (F) H&E stained aortic roots at 40× magnification show a thin fibrous cap and expanded necrotic core in lesions of baseline and AAV8.nLacZ treated mice compared to AAV8.mLDLR injected animals.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2957433&req=5

pone-0013424-g005: AAV8.TBG.mLDLR mediated regression of atherosclerotic lesions in high-fat fed Ldlr-/-Apobec1-/-mice.(A) En face Sudan IV staining. Mouse aortas were pinned and stained with Sudan IV, which stains neutral lipids. Representative aortas from animals treated with 1×10∧11 of AAV8.TBG.nLacZ, 1×10∧11 of AAV8.TBG.mLDLR at day 60 after vector administration (day 120 on high-fat diet), or at baseline (day 60 on high-fat diet) are shown. (B) The percent Sudan IV staining of the total aortic surface in baseline (n = 10), AAV.TBG.nLacZ (n = 9) and AAV8.TBG.mLDLR (n = 10) was determined as described under Materials and Methods. Aortic roots from these mice were stained with oil red o (C) or hematoxylin and eosin (H&E) (D) 10× magnification. Quantification was conducted on oil red o lesions (E) as described in the materials and methods. Each column represents mean ± s.d. *P<0.05, **P<0.01, ***P<0.001, ‡ P<0.001. (F) H&E stained aortic roots at 40× magnification show a thin fibrous cap and expanded necrotic core in lesions of baseline and AAV8.nLacZ treated mice compared to AAV8.mLDLR injected animals.

Mentions: Evolution of pre-existing atherosclerotic lesions was assessed by two independent methods. In the first method the aortas were opened from the arch to the iliac bifurication and stained with Oil Red O (Fig. 5A); morphometric analyses quantified the percent of aorta stained with Oil Red O along the entire length of the aorta (Fig. 5B). Two months of high fat diet resulted in extensive atherosclerosis covering 20% of the aorta reflecting the baseline disease at the time of vector; this increased to 33% over an additional two month period following treatment with the AAV8.TBG.nLacZ vector, representing a 65% further progression in atherosclerosis. In contrast, treatment with the AAV8.TBG.mLDLR vector led to a regression of atherosclerosis by 87% over two months, from 20% of the aorta covered by atherosclerosis at baseline to only 2.6% of the aorta covered by atherosclerosis 60 days after vector administration.


Gene therapy in a humanized mouse model of familial hypercholesterolemia leads to marked regression of atherosclerosis.

Kassim SH, Li H, Vandenberghe LH, Hinderer C, Bell P, Marchadier D, Wilson A, Cromley D, Redon V, Yu H, Wilson JM, Rader DJ - PLoS ONE (2010)

AAV8.TBG.mLDLR mediated regression of atherosclerotic lesions in high-fat fed Ldlr-/-Apobec1-/-mice.(A) En face Sudan IV staining. Mouse aortas were pinned and stained with Sudan IV, which stains neutral lipids. Representative aortas from animals treated with 1×10∧11 of AAV8.TBG.nLacZ, 1×10∧11 of AAV8.TBG.mLDLR at day 60 after vector administration (day 120 on high-fat diet), or at baseline (day 60 on high-fat diet) are shown. (B) The percent Sudan IV staining of the total aortic surface in baseline (n = 10), AAV.TBG.nLacZ (n = 9) and AAV8.TBG.mLDLR (n = 10) was determined as described under Materials and Methods. Aortic roots from these mice were stained with oil red o (C) or hematoxylin and eosin (H&E) (D) 10× magnification. Quantification was conducted on oil red o lesions (E) as described in the materials and methods. Each column represents mean ± s.d. *P<0.05, **P<0.01, ***P<0.001, ‡ P<0.001. (F) H&E stained aortic roots at 40× magnification show a thin fibrous cap and expanded necrotic core in lesions of baseline and AAV8.nLacZ treated mice compared to AAV8.mLDLR injected animals.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2957433&req=5

pone-0013424-g005: AAV8.TBG.mLDLR mediated regression of atherosclerotic lesions in high-fat fed Ldlr-/-Apobec1-/-mice.(A) En face Sudan IV staining. Mouse aortas were pinned and stained with Sudan IV, which stains neutral lipids. Representative aortas from animals treated with 1×10∧11 of AAV8.TBG.nLacZ, 1×10∧11 of AAV8.TBG.mLDLR at day 60 after vector administration (day 120 on high-fat diet), or at baseline (day 60 on high-fat diet) are shown. (B) The percent Sudan IV staining of the total aortic surface in baseline (n = 10), AAV.TBG.nLacZ (n = 9) and AAV8.TBG.mLDLR (n = 10) was determined as described under Materials and Methods. Aortic roots from these mice were stained with oil red o (C) or hematoxylin and eosin (H&E) (D) 10× magnification. Quantification was conducted on oil red o lesions (E) as described in the materials and methods. Each column represents mean ± s.d. *P<0.05, **P<0.01, ***P<0.001, ‡ P<0.001. (F) H&E stained aortic roots at 40× magnification show a thin fibrous cap and expanded necrotic core in lesions of baseline and AAV8.nLacZ treated mice compared to AAV8.mLDLR injected animals.
Mentions: Evolution of pre-existing atherosclerotic lesions was assessed by two independent methods. In the first method the aortas were opened from the arch to the iliac bifurication and stained with Oil Red O (Fig. 5A); morphometric analyses quantified the percent of aorta stained with Oil Red O along the entire length of the aorta (Fig. 5B). Two months of high fat diet resulted in extensive atherosclerosis covering 20% of the aorta reflecting the baseline disease at the time of vector; this increased to 33% over an additional two month period following treatment with the AAV8.TBG.nLacZ vector, representing a 65% further progression in atherosclerosis. In contrast, treatment with the AAV8.TBG.mLDLR vector led to a regression of atherosclerosis by 87% over two months, from 20% of the aorta covered by atherosclerosis at baseline to only 2.6% of the aorta covered by atherosclerosis 60 days after vector administration.

Bottom Line: A single intravenous injection of AAV8.mLDLR was found to significantly reduce plasma cholesterol and non-HDL cholesterol levels in chow-fed animals at doses as low as 3×10(9) genome copies/mouse.Collectively, the results presented herein suggest that AAV8-based gene therapy for FH may be feasible and support further development of this approach.The pre-clinical data from these studies will enable for the effective translation of gene therapy into the clinic for treatment of FH.

View Article: PubMed Central - PubMed

Affiliation: Gene Therapy Program, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.

ABSTRACT

Background: Familial hypercholesterolemia (FH) is an autosomal codominant disorder caused by mutations in the low-density lipoprotein receptor (LDLR) gene. Homozygous FH patients (hoFH) have severe hypercholesterolemia leading to life threatening atherosclerosis in childhood and adolescence. Mice with germ line interruptions in the Ldlr and Apobec1 genes (Ldlr(-/-)Apobec1(-/-)) simulate metabolic and clinical aspects of hoFH, including atherogenesis on a chow diet.

Methods/principal findings: In this study, vectors based on adeno-associated virus 8 (AAV8) were used to deliver the gene for mouse Ldlr (mLDLR) to the livers of Ldlr(-/-)Apobec1(-/-) mice. A single intravenous injection of AAV8.mLDLR was found to significantly reduce plasma cholesterol and non-HDL cholesterol levels in chow-fed animals at doses as low as 3×10(9) genome copies/mouse. Whereas Ldlr(-/-)Apobec1(-/-) mice fed a western-type diet and injected with a control AAV8. vector experienced a further 65% progression in atherosclerosis over 2 months compared with baseline mice, Ldlr(-/-)Apobec1(-/-) mice treated with AAV8.mLDLR realized an 87% regression of atherosclerotic lesions after 3 months compared to baseline mice. Immunohistochemical analyses revealed a substantial remodeling of atherosclerotic lesions.

Conclusions/significance: Collectively, the results presented herein suggest that AAV8-based gene therapy for FH may be feasible and support further development of this approach. The pre-clinical data from these studies will enable for the effective translation of gene therapy into the clinic for treatment of FH.

Show MeSH
Related in: MedlinePlus