Abstract
Aniridia is a rare congenital syndrome that is associated with reduced visual acuity and progressive loss of vision. Aniridia patients may also develop systemic health issues associated with defects in the pancreas, digestive, and central nervous systems. The spectrum of symptoms associated with aniridia is due to haploinsufficiency of the paired box 6 gene (PAX6) and its role in the development and maintenance of the affected tissues. Here, we isolated pancreatic islets from mice heterozygous for Pax6 to test whether a Pax6-specific miRNA suppression (target protector) strategy can restore PAX6 protein levels. We show that miR-7 and miR-375 target specific sites within the Pax6 3′ UTR in a mouse pancreatic β-insulinoma cell line. Tough decoys (Tuds) against miR-7 and miR-375 increase expression of a mouse Pax6 3′ UTR luciferase reporter and increase PAX6 protein levels in these cells. Finally, we demonstrate that the shielding of the miR-7 binding site with a target protector restores PAX6 protein levels in the Pax6 heterozygous islets. The data presented here represent a proof of concept for RNA-based therapy for the progressive defects associated with aniridia and suggest the target protector approach may be a useful therapeutic strategy for other haploinsufficiency diseases.
Highlights
PAX6 is a critical transcription factor for the development of the eye, brain, and pancreas
We show that miR-7 and miR-375 provide a modest level of control over PAX6 protein levels in the beta cell insulinoma cell line (b-TC-6)
We evaluated whether the miRNA regulating Pax[6] can be therapeutically targeted to restore PAX6 protein levels in islets isolated from a mouse model of aniridia, called the small eye dickie (Pax6SeyDey) mouse
Summary
PAX6 is a critical transcription factor for the development of the eye, brain, and pancreas. Haploinsufficiency of PAX6 leads to aniridia in humans, a rare eye disorder named for underdevelopment of the iris.[1,2] there is a spectrum of ocular symptoms associated with aniridia, and most major eye structures are impacted.[1,2] Patients are born with low vision primarily due to hypomorphic fovea but will frequently experience a progressive loss of vision due to cataracts, corneal clouding, and glaucoma.[1] In addition, aniridia is associated with several non-ocular conditions such as obesity, glucose intolerance and diabetes, and anosmia.[3,4] These conditions are due to a requirement for PAX6 expression for the development and maintenance of the brain, pancreas, and gut.[5,6,7] The progressive nature of the disease reflects an ongoing requirement for PAX6 expression and suggests there may be an opportunity for therapeutic intervention postnatally. Haploinsufficiency associated with this disorder means that patients should be immune tolerant to
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
