New siRNA therapeutics to halt diabetic kidney disease

PROJECT SUMMARY/ABSTRACT Chronic kidney disease (CKD) is an urgent health problem in the U.S., afflicting ~15% of Americans and costing the healthcare system $120 billion/year. Despite the availability of glucose-normalizing drugs, diabetes remains the leading cause of renal failure. Current treatments depend on glucose and hypertension control that cannot completely prevent diabetic nephropathy and progressive renal dysfunction. A major feature of diabetic nephropathy is inflammation, driven by the upregulation of adhesion proteins in renal endothelium and subsequent recruitment of inflammatory immune cells into renal tissue. Previous work has shown that knockout of the adhesion protein ICAM1 attenuates diabetic nephropathy in mouse models of type 1 and 2 diabetes. However, there is a lack of clinically viable technologies that can act on these findings. An FDA-approved lipid nanoparticle (LNP) siRNA drug, patisiran, is capable of safely inducing efficient (>80%) and durable (up to one month) gene knockdown in humans. As LNPs typically accumulate in the liver, this approach has not been broadly applicable to other tissues. This application seeks to develop new LNPs for efficient siRNA delivery to renal endothelium, to test the hypothesis that knockdown of ICAM1 is protective against type 1 and 2 diabetic nephropathy. The goal of Aim 1 (K99 phase) is to identify LNPs capable of efficient siRNA delivery to renal endothelium through high-throughput in vivo screening. A panel of DNA-barcoded LNPs with varying compositions will be screened for functional siRNA delivery to the renal endothelium using a new workflow. Isolated barcodes will be analyzed by deep sequencing to deduce LNP parameters that mediate renal endothelial delivery and inform subsequent, refined screens. Lead LNPs will be individually validated and assessed for knockdown efficiency, duration, and safety. During the R00 phase, LNP efficacy will be tested in multiple models of type 1 and 2 diabetic nephropathy. These models capture human diabetic nephropathy features of ICAM1 upregulation, albuminuria, renal fibrosis, and macrophage infiltration into renal tissue. LNPs carrying ICAM1 siRNA will be tested for efficacy in prophylactic (before disease onset) and therapeutic (after disease onset) models. Successful completion of this work could enable new, precision medicine approaches that target inflammatory drivers of diabetic nephropathy. The PI, Gary Liu, aims to lead a lab that develops new renal therapeutics and arrest disease progression. A major focus will be gene therapies for kidney diseases. To prepare him for this role, this K99/R00 application includes training and coursework in DNA barcoding, deep sequencing, and bioinformatics; nephrology and diabetic nephropathy; LNP technology; and inclusive mentoring. Moreover, this application will enable the PI to disseminate work at conferences, network, and apply for faculty positions. Training will occur at the Koch Institute of MIT in the laboratories of Profs. Robert Langer and Giovanni Traverso, which will provide the resources and intellectual expertise necessary to carry out the work.