Gene therapy for a mouse model of glucose transporter-1 deficiency syndrome

Abstract

ObjectiveWe generated an adeno-associated virus (AAV) vector in which the human SLC2A1 gene was expressed under the synapsin I promoter (AAV-hSLC2A1) and examined if AAV-hSLC2A1 administration can lead to functional improvement in GLUT1-deficient mice.MethodsAAV-hSLC2A1 was injected into heterozygous knock-out murine Glut1 (GLUT1+/−) mice intraperitoneally (systemic; 1.85 × 1011 vg/mouse) or intra-cerebroventricularly (local; 1.85 × 1010 vg/mouse). We analyzed GLUT1 mRNA and protein expression, motor function using rota-rod and footprint tests, and blood and cerebrospinal fluid (CSF) glucose levels.ResultsVector-derived RNA was detected in the cerebrum for both injection routes. In the intra-cerebroventricular injection group, exogenous GLUT1 protein was strongly expressed in the cerebral cortex and hippocampus near the injection site. In the intraperitoneal injection group, exogenous GLUT1 protein was mildly expressed in neural cells throughout the entire central nervous system. The motor function test and CSF/blood glucose ratio were significantly improved following intra-cerebroventricular injection.ConclusionsAAV-hSLC2A1 administration produced exogenous GLUT1 in neural cells and improved CSF glucose levels and motor function of heterozygous knock-out murine Glut1 mice.

Gene therapy for Glut1‐deficient mouse using an adeno‐associated virus vector with the human intrinsic GLUT1 promoter

“…Figure shows the results of the rota‐rod test at the age of 10 and 14 weeks. There was a significant deference between GLUT1 +/+ mice and control GLUT1 +/– mice (GLUT1 +/– mice after intracerebroventricular injection with saline) at 10 and 14 weeks, as reported previously . The rota‐rod test at the age of 10 and 14 weeks of the AAV‐GLUT1 injection group (AAV vector with GLUT1 promoter group) showed a trend for motor function improvement compared to the AAV‐h SLC2A1 injection group (AAV vector with synapsin I promoter group).…”

“…After intracerebroventricular injection, the average body weight of AAV‐treated GLUT1 +/– mice at the age of 14 weeks, corresponding to 8 weeks after intracerebroventricular injection, was 22.3 ± 1.6 g ( n = 12) (see Supporting information, Figure S9a). At the age of 14 weeks, the average cerebral hemisphere weight of GLUT1 +/+ mice (163.3 ± 5.5 mg, n = 6) and GLUT1 +/– mice (136.6 ± 6.6 mg, n = 6) were significantly different ( p < 0.05), as reported previously . After intracerebroventricular injection, the cerebral hemisphere weight of AAV‐treated GLUT1 +/– mice at the age of 14 weeks, corresponding to 8 weeks after intracerebroventricular injection, was 150 ± 4.4 mg ( n = 11) (see Supporting information, Figure S9b).…”

“…CNS administration of AAV‐GLUT1 to GLUT1 +/– mice was performed using this vector. We assessed two doses of AAV‐GLUT1 for CNS administration to GLUT1 +/– mice: the low dose (1.85 × 10 10 vg/mouse) was exactly the same dose of AAV‐h SLC2A1 injection as reported previously and the high dose (6.5 × 10 10 vg/mouse) was the maximum dose allowable according to the maximal volume of the bilateral lateral ventricles.…”

“…To assess the efficacy of the generated AAV vector, we injected it into Glut1 ‐deficient mice. We used the same mice as reported previously; mice with heterozygous knockout of the murine Glut1 gene (GLUT1 +/– mice) were generated by the Department of Molecular Biopharmacy and Genetics, Graduate School of Pharmaceutical Sciences, Tohoku University (Sendai, Japan) . These mice have microcephaly, impaired motor activity, epileptic discharges on electroencephalography, hypoglycorrhachia and decreased brain glucose uptake by positron emission tomography scanning .…”

“…For control GLUT1 +/– mice, saline (a total of 5 μL) was injected into the bilateral lateral ventricles at 6 weeks after birth. Additionally, to investigate the optimal promoter for a curative AAV vector, a synapsin I promoter‐inserted AAV vector (AAV‐h SLC2A1 ) was also injected into the GLUT1 +/– mice at 6 weeks after birth intracerebroventricularly, as described in a previous study …”