Nanoparticle-mediated miR200-b delivery for the treatment of diabetic retinopathy

Abstract

We recently reported that the Ins2Akita mouse is a good model for late-onset diabetic retinopathy. Here, we investigated the effect of miR200-b, a potential anti-angiogenic factor, on VEGF receptor 2 (VEGFR-2) expression and to determine the underlying angiogenic response in mouse endothelial cells, and in retinas from aged Ins2Akita mice. MiR200-b and its native flanking sequences were amplified and cloned into a pCAG-eGFP vector directed by the ubiquitous CAG promoter (namely pCAG-miR200-b-IRES-eGFP). The plasmid was compacted by CK30PEG10K into DNA nanoparticles (NPs) for in vivo delivery. Murine endothelial cell line, SVEC4-10, was first transfected with the plasmid. The mRNA levels of VEGF and VEGFR-2 were quantified by qRT-PCR and showed significant reduction in message expression compared with lipofectamine-transfected cells. Transfection of miR200-b suppressed the migration of SVEC4-10 cells. There was a significant inverse correlation between the level of expression of miR200-b and VEGFR-2. Intravitreal injection of miR200-b DNA NPs significantly reduced protein levels of VEGFR-2 as revealed by western blot and markedly suppressed angiogenesis as evaluated by fundus imaging in aged Ins2Akita mice even after 3 months of post-injection. These findings suggest that NP-mediated miR200-b delivery has negatively regulated VEGFR-2 expression in vivo.

Plasma levels of miR‐29b and miR‐200b in type 2 diabetic retinopathy

“…The authors demonstrated experimentally that miR‐200b might alleviate DR development by down‐regulating its target gene VEGFA . Similar findings were obtained in Akita mice (a genetic model of diabetes) at 3 months after intravitreal injection of miR‐200b …”

“…Studies in vitro showed that miR‐200b is highly expressed in normal human retinal endothelial cells (hRECs), while it was down‐regulated under HG environment . Cell transfection with a miR‐200b mimic suppressed the migration of murine endothelial cells and the hRECs dysfunction by decreasing the levels of VEGF and transforming growth factor beta 1 (TGFB1), and by inhibiting vasohibin‐2, a protein that promotes the proliferation and migration of endothelial cells …”

“…16 Similar findings were obtained in Akita mice (a genetic model of diabetes) at 3 months after intravitreal injection of miR-200b. 51 During the course of this study, other investigators attempted to identify dysregulated circulating miRNAs in DR in humans. [17][18][19][20][21][22][23] These studies were carried out in patients with type 1 diabetes, 17,18 type 2 diabetes [19][20][21][22] or diabetes type not reported, 23 using serum, 18,20,22,23 plasma 19,21 or endothelial progenitor cells cultured from isolated peripheral blood mononuclear cells.…”

“…and by inhibiting vasohibin-2, a protein that promotes the proliferation and migration of endothelial cells 52. Studies on animal models had also already shown the protective effect of miR-200b on retinal diseases by inhibiting intraretinal neovascularization16,48,51,53 and endothelial to mesenchymal transition (EndMT) in diabetic retina 54. McArthur et al48 reported that miR-200b was down-regulated in retinas of STZ-induced diabetic rats and in two endothelial cell lines incubated in HG.…”

Nanoparticles as Delivery Vehicles for the Treatment of Retinal Degenerative Diseases

“…MicroRNAs (miRNAs) are a class of naturally occurring small, non-coding RNA molecules. miRNA have been recognized as a key component in regulating cell biological development and may be involved in the pathogenesis of DR, therefore CK30-PEG nanoparticle-mediated miR200-b have been delivered for the treatment of diabetic retinopathy and lead to an effective anti-angiogenic therapy for DR (Mitra et al, 2016). Thus, Polymer NPs have a tolerable safety profile with a lack of immunogenicity in the retina, thus make CK30-PEG nanoparticles become a promising non-viral gene delivery vehicle for t ocular diseases.…”