Effective glycemic control achieved by transplanting non-viral cationic liposome-mediated VEGF-transfected islets in streptozotocin-induced diabetic mice

Abstract

Hypoxic damage is one of the major causes of islet graft failure and VEGF is known to play a crucial role in revascularization. To address the effectiveness of a cationic lipid reagent as a VEGF gene carrier, and the beneficial effect of VEGF-transfected islets on glycemic control, we used effectene lipid reagent in a transfection experiment using mouse islets. Transfection efficiencies were highest for 4 µg/µL cDNA and 25 µL effectene and cell viabilities were also satisfactory under this condition, and the overproduction of VEGF mRNA and protein were confirmed from conditioned cells. A minimal number of VEGF-transfected islets (100 IEQ/animal) were transplanted into streptozotocin (STZ)-induced diabetic mice. Hyperglycemia was not controlled in the islet transplantation (IT)-alone group (0/8) (nondiabetic glucose mice number/total recipient mice number) or in the IT-pJDK control vector group (0/8). However, hyperglycemia was completely abrogated in the IT-pJDK-VEGF transduced group (8/8), and viable islets and increased VEGF-transfected grafts vascularization were observed in renal capsules. These studies support the usefulness of VEGFtransfected islet delivery using a cationic lipid reagent to achieve euglycemia using a minimal number of islets.

Gene transfer using liposome-complexed adenovirus seems to overcome limitations due to coxsackievirus and adenovirus receptor-deficiency of cancer cells, both in vitro and in vivo

“…We also observed that commercially available liposome, Lipopectin, was not effective in gene expression in agreement with a previous report (Byk et al, 1998). Intratumoral injection of a complex of adenovirus and liposome led to enhanced adenoviral transduction compared to injecting just the adenovirus alone (Lee et al, 2000;Chae et al, 2005). Lipofectamin-mediated gene transfer was noted to be ineffective in liver-directed gene transfer in non-human primates (Sullivan et al, 1997).…”

Transgene and islet cell delivery systems using nano-sized carriers for the treatment of diabetes mellitus

“…Normalized blood glucose levels in the long termKawakami et al (2001)[86] Cationic lipid reagentVEGFDirect transplantationLeft kidney capsuleNormalized blood glucose level. Preserved transplanted islet cells with increasing vascularizationChae et al (2005)[43] R3V6 peptide micellessiRNA-iNOS, 17b-estradiolDirect transplantationLeft kidney capsuleImproved glycemic control. Reduced apoptosis of transplanted islet cellsHwang et al (2015)[87] Magnetic iron oxide nanoparticlessiRNA-human caspase-3Direct transplantationLeft kidney capsuleDecreased apoptosis in transplanted islet cellsWang et al (2011)[88] Magnetic iron oxide nanoparticlessiRNA-β 2 microglobulinDirect transplantationLeft kidney capsuleDelayed onset of diabetes mellitus caused by immune rejectionWang et al (2012)[89]

Abbreviations : GLP-1: glucagon-like peptide-1; IBMIR: instant blood-mediated inflammatory reactions; PEG: polyethylene glycol; PGA: polyglycolic acid; PET: polyethylene terephthalate; bFGF: basic fibroblast growth factor; CR1: soluble complement receptor 1; PVA: polyvinyl alcohol hydrogel; VEGF: vascular endothelial growth factor; R3V6: three arginine and six valine; siRNA: short interfering RNA; iNOS: inducible nitric oxide synthase.

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“…Islet cells over-expressing GLP-1 or vascular endothelial growth factor were shown to preserve mass and function better compared with control islet cells when transplanted into the kidney capsule of a mouse model of diabetes mellitus [43,54]. Another study reported that inducible nitric oxide synthase-siRNA and 17b-estradiol-siRNA using the R3V6 peptide vector, which comprises three arginine and six valine and which forms self-assembled micelles in aqueous solution, transplanted into islet cells and delivered into the renal subcapsular space of a mouse model of diabetes mellitus suppressed cytokine-induced transplanted islet cell destruction, resulting in better control of blood glucose levels [87].…”

Gene Therapy to Improve Pancreatic Islet Transplantation for Type 1 Diabetes Mellitus

“…A number of studies have investigated VEGF in islet transplantation, either delivered as a protein or via gene therapy [135,136]. Olsson and colleagues [137] found that while the culture of islets with VEGF improved graft revascularization one month post-transplantation, VEGF treated islets had similar or worse vascular engraftment compared to control islets.…”