Effective and safe gene-based delivery of GLP-1 using chitosan/plasmid-DNA therapeutic nanocomplexes in an animal model of type 2 diabetes

Abstract

Glucagon-like peptide-1 (GLP-1) is an incretin hormone that regulates blood glucose level post-prandially. It has been proposed that GLP-1 can be used in type 2 diabetes (T2D) mellitus treatment because of its insulinotropic action. Despite its remarkable advantages, GLP-1 suffers the disadvantage of an extremely short half-life owing to its degradation by the dipeptidyl peptidase IV protease. One way of overcoming this drawback is GLP-1 gene delivery. Here we show effective and safe gene-based delivery of GLP-1 using chitosan/plasmid-DNA therapeutic nanocomplexes (TNCs) in Zucker diabetic fatty (ZDF) animal model of T2D. The expression plasmid fused the GLP-1 gene to a Furin cleavage site was driven by a cytomegalovirus promoter/enhancer. TNCs were prepared by mixing this plasmid with chitosans of specific molecular weight (MW), degree of deacetylation (DDA) and ratio of chitosan amine to DNA phosphate (N:P ratio). Animals injected with the TNC chitosan 92-10-5 (DDA-MW-N:P) showed GLP-1 plasma levels of about fivefold higher than that in non-treated animals and the insulinotropic effect of recombinant GLP-1 was shown by a threefold increase in plasma insulin concentration when compared with untreated animals. Intraperitoneal glucose tolerance tests revealed an efficacious decrease of blood glucose compared with controls for up to 24 days after treatment, where injections of this formulation allowed near-normalization of blood glucose level. TNCs composed of specific chitosans and GLP-1-expressing plasmid constructs showed an impressive ability to harness the profound therapeutic potential of GLP-1 for the treatment of T2D mellitus.

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

“…Decreased blood glucose levelMandke and Singh (2012)[27] Cationic nanomicelles comprising chitosanGLP-1-plasmid DNAIntestinesSubcutaneous injection in dorsal or intramuscular injection in hind legsEnhanced insulin secretion. Improved glucose toleranceJean et al (2011)[28] ABPExendin-4 plasmid DNAWhole bodyIntravenous injectionDecreased blood glucose levelKim et al (2012)[29] Ultrasound-targeted microbubbleANGPTL8 plasmid DNAWhole bodyIntravenous injectionPromoted the proliferation of aged β cells and expandedthe β cell mass. Improved glucose tolerance andincreased the fasting blood insulin levelChen et al (2006)[30]

Abbreviations : PDX-1: pancreas/duodenum homeobox protein 1; ISL-1: insulin gene enhancer protein-1; GLP-1: glucagon-like peptide-1; DNA: deoxyribonucleic acid; AAV: adeno-associated viral vector; HGF/NK1: N and K1 domains of hepatocyte growth factor; REG3: regenerating islet-derived protein 3; IL-2: interleukin-2; PEI: polyethylenimine; ATR3: activating transcription factor 3; ER: endoplasmic reticulum; IL-4: interleukin-4; IL-10: interleukin-10; ABP: arginine-grafted bioreducible polymer; ANGPTL8: angiopoietin-like protein 8.

10.1080/20022727.2017.1341758-F0001Figure 1.Viral and non-viral vectors for the treatment of renal fibrosis in vivo .

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“…Several studies have reported the treatment effects of GLP-1 transgene delivery to the intestines using non-viral vectors in animal models of diabetes mellitus in vivo [24,28,54]. Delivery of GLP-1 transgene with cationic nanomicelles comprising chitosan or arginine-grafted bioreducible polymer to the intestines was reported to have insulinotropic effects in animal models of diabetes mellitus [24,28,54].…”

“…Delivery of GLP-1 transgene with cationic nanomicelles comprising chitosan or arginine-grafted bioreducible polymer to the intestines was reported to have insulinotropic effects in animal models of diabetes mellitus [24,28,54]. It was reported that co-delivery of GLP-1 transgene to the intestines with other molecules could enhance the treatment effects for diabetes mellitus [18,20,21,26].…”

Nanomedicine and Drug Delivery Strategies for Treatment of Genetic Diseases

“…For instance, addition of albumin to polyplexes improves penetration through the sputum and provides transfection in CF (Di Gioia, et al, 2008). Bioadhesive and pH-responsive properties of chitosan nanoparticles, along with its lack of toxicity, can also benefit delivery of gene therapies (Agnihotri, et al, 2004), including oral gene delivery applications such that of coagulation factor VIII in a hemophilia mouse model (Dhadwar, et al, 2010) or glucagon-liked peptide 1 (GLP-1) to reduce blood glucose in diabetes (Jean, et al, 2011).…”

Oral Gene Application Using Chitosan-DNA Nanoparticles Induces Transferable Tolerance

“…It was shown that feeding of factor VIII-encoding chitosan-DNA NP to hemophilia A mice resulted in increased factor VIII plasma levels (6,15) and that oral application of erythropoietin-encoding chitosan-DNA NP led to a significant increase of hematocrit levels (8). In rodent models of diabetes, chitosan-DNA NP encoding insulin or glucagon-like peptide 1 were able to decrease blood glucose concentrations (23,31,32). In addition, there is potential for chitosan-DNA NP to be used for immune modulation.…”