Sleeping Beauty Transposon Vectors in Liver-directed Gene Delivery of LDLR and VLDLR for Gene Therapy of Familial Hypercholesterolemia

Abstract

Plasmid-based Sleeping Beauty (SB) transposon vectors were developed and used to deliver genes for low-density lipoprotein and very-low-density lipoprotein receptors (LDLR and VLDLR, respectively) or lacZ reporter into liver of an LDLR-deficient mouse model of familial hypercholesterolemia (FH). SB transposase, SB100x, was used to integrate the therapeutic transposons into mice livers for evaluating the feasibility of the vectors in reducing high blood cholesterol and the progression of atherosclerosis. Hydrodynamic gene delivery of transposon-VLDLR into the livers of the mice resulted in initial 17-19% reductions in plasma cholesterol, and at the later time points, in a significant stabilization of the cholesterol level for the 6.5-month duration of the study compared to the control mice. Transposon-LDLR-treated animals also demonstrated a trend of stabilization in the cholesterol levels in the long term. Vector-treated mice had slightly less lipid accumulation in the liver and reduced aortic atherosclerosis. Clinical chemistry and histological analyses revealed normal liver function and morphology comparable to that of the controls during the follow-up with no safety issues regarding the vector type, transgenes, or the gene transfer method. The study demonstrates the safety and potential benefits of the SB transposon vectors in the treatment of FH.

Gene Therapy with the Sleeping Beauty Transposon System

“…In vitro, human cell lines [143] Congenital thrombotic thrombocytopenic purpura Hypercholesterolemia Tail vain hydrodynamic injection of naked DNA In vivo, mouse liver [155] Crigler-Najjar syndrome type I (hyperbilirubinemia)…”

Transposons: Moving Forward from Preclinical Studies to Clinical Trials

“…Moreover, in vivo stable inducible gene expression system can be established by transposon technology, allowing temporal control of transgene expression. 143 HD-based transposon gene transfer has been utilized to direct long-term therapeutic gene expression in various inherited and acquired genetic disease models, including hemophilia A 144,145 and B, 141,146 sickle cell disease, 147 mucopolysaccharidosis (MPS), [148][149][150] type I tyrosinemia, 151 type I diabetes, 152 familial hypercholesterolemia (FH), 153 and type I Crigler-Najjar syndrome 154 (Table 1). SB transposon in conjunction with wild-type SBase or first-generation hyperactive SBase such as SB11 and HSB5/17 were initially used and were sufficient to enhance therapeutic gene expression and correct deficient phenotypes.…”

“…156 In addition, the SB100X technology encoding low-density and very-low-density lipoprotein receptors contributed to long-term therapeutic effect in FH mice. 153 Therefore, the SB100X system holds great promise for further development of in vivo gene therapy to enhance transposition efficacy and stable expression of therapeutic genes.…”

Sleeping Beautytransposition: from biology to applications

“…For example, it was possible to ameliorate the clinical symptoms manifested in lysosomal storage disease (Aronovich et al, 2007;Aronovich et al, 2009), Crigler-Najjar syndrome (Wang et al, 2009), type-I Tyrosinemia (Montini et al, 2002;Pan et al, 2012;Wilber et al, 2007), type-I diabetes (He et al, 2004) and hypercholesterolemia (Turunen et al, 2016). It was possible to achieve longterm expression of human uridinediphosphoglucuronate glucuronosyltransferase-1A1 (pSB-hUGT1A1) in Gunn rats leading to a significant reduction in serum bilirubin levels (Wang et al, 2009).…”

“…It was possible to achieve longterm expression of human uridinediphosphoglucuronate glucuronosyltransferase-1A1 (pSB-hUGT1A1) in Gunn rats leading to a significant reduction in serum bilirubin levels (Wang et al, 2009). Similarly, phenotypic correction was achieved by expressing fumarylacetoacetate hydrolase (FAH) (Montini et al, 2002), human insulin gene precursor (He et al, 2004) and LDLR and VDLR genes (Turunen et al, 2016) in mouse models. By using the SB system, it was also possible to achieve significant reduction of pulmonary arterial pressure by delivering endothelial nitric oxide synthase (eNOS) into a rat model of pulmonary hypertension (Liu et al, 2006a).…”