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VA NORTHERN CALIFORNIA HEALTH CARE SYS
California
Approximately 25% of US Veterans have diabetes and the annual mortality rate due to diabetes in Veterans is almost double of the rate in Veterans without diabetes. The presence of diabetes in the Veteran population is an important cause of disability due to complications such as cardiovascular disease, neuropathy, retinopathy, and kidney disease. Recent studies have indicated higher rates of new onset diabetes in Veterans who have had COVID-19 and analysis of Veterans using the Million Veteran Database indicate a growing identification of new onset type 1 diabetes (T1D) in adults. Almost half of the newly diagnosed cases of T1D are adults and there is an unmet medical need to identify treatments to prevent or halt progression of the disease. 12-lipoxygenase (12-LOX) is a lipid-generating enzyme produced by various sites including pancreatic islet beta cells. 12- LOX expression is elevated in obesity, Type 2 diabetes ( T2D) and T1D. We showed that 12-LOX protein is increased in islets of auto-antibody-positive and Type 1 and Type 2 individuals. 12-LOX products are highly pro-inflammatory and reduce pancreatic beta cell function and viability. 12-LOX lipids lead to oxidative and endoplasmic reticulum stress and macrophage activation. Genetic deletion of 12-LOX in mouse models improves insulin signaling and prevents T1D development. We earlier discovered a highly selective 12-LOX inhibitor, ML-355, through a comprehensive screening, followed by iterative medicinal chemistry optimization. ML-355 has been licensed and pre-clinical and phase 1 safety testing has been successfully completed and found to be safe. ML-355 is in a phase 2 clinical trial for intravenous administration for a hematologic indication as the inhibitor is not sufficiently orally bio-available for chronic diabetes use. We recently discovered a new 12-LOX inhibitor, Slug001, which manifests increased potency both in vitro and in rescuing inflamed human islet cells, relative to ML355. We propose to explore this novel structural space with a suite of modifications of Slug001, guided by our computational modeling of ML355 docking. The goal in Aim 1 is to derivatize Slug001 and fill the active site cavity more efficiently so that the inhibitor potency can be increased more than its current 7-fold improvement relative to ML355 and have improved oral bioavailability. The docking model will greatly enhance the identification of promising new inhibitors. Of the six Slug001 lead derivatives, we have already synthesized several and shown that Slug002 is as potent as Slug001 but has better solubility. The completed studies will generate novel inhibitors and a new VA patent. In Aim 1 of the proposal, we will synthesize the new molecules and measure their potency and selectivity. Established methods, comparing potency with docking scores, will allow us to quickly design these derivatives, increase their potency and then subject them to our human diabetic cellular assays established in Aim 2. The derivatives of Slug001 will be screened by the Holman laboratory against the LOX isozymes (5-LOX, 12-LOX, 15-LOX-1, 15-LOX-2) to establish their selectivity. In Aim 2 we will test the efficacy of the inhibitors in a reliable and novel human functional Islet beta cell line and then move to testing in primary cadaveric human pancreatic islets. The testing will utilize using our established and validated assays to test effects on insulin secretion and protection from cytokine mediated damage. Our expectation at the completion of this pilot, is to move the lead compound (s) into a novel in humanized 12-LOX mouse model of T1D that will facilitate rapid translation to clinical testing. The proposed project will provide a new way to address the high rates of adult-onset Type 1 diabetes and complications in the Veteran population.