No abstract

Proof of concept for MERTK gene replacement therapy has been demonstrated utilizing different viral vectors in the Royal College of Surgeon (RCS) rat, a well characterized model of recessive retinitis pigmentosa (RP) that contains a mutation in the Mertk gene. MERTK plays a key role in renewal of photoreceptor outer segments (OS) by phagocytosis of shed OS tips. Mutations in MERTK cause impaired phagocytic activity and accumulation of OS debris in the interphotoreceptor space that ultimately leads to photoreceptor cell death. In the present study, we conducted a series of preclinical potency and GLP compliant safety evaluations of an AAV2 vector expressing human MERTK cDNA driven by the RPE-specific, VMD2 promoter. We demonstrate the potency of the vector in RCS rats by improved electroretinogram responses in treated eyes compared to contralateral untreated controls. Toxicology and biodistribution studies were performed in Sprague Dawley (SD) rats injected with two different doses of AAV vectors and buffer control. Delivery of vector in SD rats did not result in a change in ERG amplitudes of rod and cone responses relative to Balanced Salt Solution (BSS) control injected eyes indicating that administration of AAV vector did not adversely affect normal retinal function. In vivo fundoscopic analysis and postmortem retinal morphology of the vector injected eyes were normal compared to controls. Evaluation of blood smears showed the lack of transformed cells in the. All injected eyes and day 1 blood samples were positive for vector genomes and all peripheral tissues were negative. Our results demonstrate the potency and safety of the AAV2-VMD2-hMERTK vector in animal models tested. A GMP vector has been manufactured and is presently in clinical trial.

The potent proangiogenic factors IGF-1 and VEGF both stimulate SDF-1-induced angiogenesis. Local inhibition of CXCR4 is required for an antiangiogenic effect in CNV lesions.

Cross-linked hyaluronic acid gel (CHAG) has been used to prevent postoperative adhesion of abdominal tumorectomy. However, its effect on tumor cells is still unknown. This paper was designed to investigate the effect of CHAG on metastasis and growth of tumor cells. Migration and invasion assays, Western blotting, pull down assay, siRNA interference, and nude mice implantation tumor model were applied in this study. The results of in vitro experiments with gastric cancer cell line AGS and hepatic cancer cell line HepG2 showed that CHAG inhibited the migration and invasion activities, the MAPK and PI3K/Akt mediated signaling, the activation of small G proteins Rac1 and RhoA, and the expression of MMPs and PCNA initiated by EGF, through blocking the activation of EGFR. CHAG also had inhibitory effect on activation of other membrane receptors, including integrin and VEGFR. When the expression of hyaluronic acid receptors (CD44 or RHAMM) was interfered, the above inhibitory effects of CHAG still existed. In vivo experimental results showed that CHAG suppressed colonization, growth and metastasis of gastric cancer cell line SGC-7901 in peritoneal cavity of nude mice. In conclusion, CHAG had inhibitory effect on tumor cells, through covering cell surface and blocking the interaction between extracellular stimulative factors and their receptors.

Highlights d NOTCH2/3 function redundantly in the OCE to control CB morphogenesis via RBPJ d NOTCH signaling controls Nectin1 expression in the OCE to drive CB morphogenesis d Nectin1 stabilizes Cx43 in the OCE to control aqueous humor secretion and IOP d NOTCH signaling in the ICE controls vitreous protein expression and eye maintenance