Targeted Gene Therapy and Nanomedicine Approaches to Treat Corneal Diseases

点击翻译按钮获取中文摘要

Corneal scarring from ocular trauma is a major cause of blindness in veterans, active military personnel and civilians affecting 1.5 million Americans each year. Presently, over 167,000 Veterans are legally blind, 1.5 million suffer significantly compromised vision, and >7000 veterans are becoming blind each year. The annual cost for treating blindness in America is $139 billion. Current therapies offer short-term relief, cause multiple side effects and often fails to treat preexisting corneal scars for which corneal transplant surgery is a standard of care. With current funding we have successfully identified potentially the first non-surgical therapy to cure pre-existing corneal scars in vivo, uncovered epigenetic mechanisms regulating corneal fibrosis, established novel single and 2-gene therapies to block myofibroblast formation, characterized novel TGFβ DNA-binding proteins, developed a canine in vivo corneal fibrosis model, and identified many newer molecular targets, genes, and drugs to control corneal fibrosis or thinning as evident from 22 publications. Our central hypothesis is that nanoparticle-mediated gene therapy offers long-term relief from corneal blindness without significant side effects and long-term goal remains the development of innovative bench- to-bedside translational nanomedicine approaches to cure pre- and post-corneal scarring in vivo. This project tests 5 novel hypotheses formulated into 3 independent aims: 1) Tests the hypothesis that PEI2- GNPs-mediated Id3 gene (Inhibitor of differentiation) delivery into rabbit stroma will limit transdifferentiation of stromal fibroblast to myofibroblast (a key mechanism causing undesirable wound healing and fibrosis) in the cornea in vivo by disrupting the binding of E-proteins to the promoter of α-smooth muscle actin (TGFβ downstream target gene). 2) Tests 2 hypotheses that (a) PEI2-GNPs-delivered localized HGF+BMP7 gene therapy eliminates preexisting corneal scarring in vivo via mechanisms in which HGF eradicates corneal scarring by selective apoptosis in myofibroblasts and BMP7 prevents re-emergence of new wound healing due to death of established myofibroblasts by counterbalancing profibrotic Smads and (b) HGF+BMP7 delivery into stroma does not compromise characteristic collagen fibrillogenesis required for corneal clarity, maintains normal corneal homeostasis, and is safe to the eye in vivo. 3) Tests 2 novel hypotheses (a) stromal fibroblast differentiation to myofibroblast proceeds via α-smooth muscle actin (TGFβ1 downstream target gene) and is tightly controlled by the co-repressor (5'-TG-3'-interacting factor (TGIF)1, TGIF2, and SnoN) and co-activator (CBP and p300), and (b) the transdifferentiation process can be arrested by the over-expression of identified co-repressor or silencing of co-activator efficiently in vivo in a rabbit model. Successful completion of the proposed research fills critical knowledge gaps and significantly improve our understanding of molecular mechanisms regulating corneal wound healing, lead development of novel nanomedicine approaches for corneal blindness and significantly advances the fibrosis research field.