Extracellular-Vesicle Derived Biomarkers in Diabetic Neuropathy

About This Grant

PROJECT SUMMARY/ABSTRACT Diabetic neuropathy (DN) is a painful and debilitating condition that affects 50% of people with diabetes. Despite its high prevalence, the precise biological mechanisms of DN are not known and no disease arresting treatment is currently available. An important barrier to effective natural history studies and interventional clinical trials in DN has been the paucity of non-invasive, clinically meaningful biomarkers. Blood concentrations of neurofilament light chain (NFL) have proved useful in select acquired and genetic nerve disorders, however, these have important limitations as biomarkers for DN. Our recent study examining plasma NFL concentrations in youth-onset type 2 diabetes demonstrated that NFL is elevated in people with diabetes both with and without neuropathy, likely owing to its release in response to axonal injury in both the central and the peripheral nervous system (PNS). The overall goal of the proposed studies is to define specific membrane-bound extracellular vesicle (EVs)-derived protein biomarkers of PNS origin for diabetic neuropathy (DN). The analysis of proteomic profiles in EVs has recently emerged as a strategy to identify tissue specific biomarkers in several central nervous system disorders, including Down syndrome, Alzheimer's disease, Parkinson's disease, and traumatic brain injury. EVs are secreted by all cell types, however, they can be traced back to their cell of origin using their specific surface markers. We new technique derived propose to employ a broad proteomic approach to identify EV-derived biomarkers relevant to DN. Subsequently, we will translate our specific-cell type EV enrichment to evaluate whether inflammatory and neurotrophic markers can be detected in Schwann cell (SC)- EV cargo.Our overall hypothesis is that the use of these two unique technical approaches will allow for the identification of unique EV-derived protein signatures for DN. To address this hypothesis, we have developed two specific aims. In Aim 1, we will use the new Mag-Net technology to carry out a high- throughput proteomic analysis to define new EV-derived protein markers specific to DN. In Aim 2, we will interrogate the PNS using a targeted approach to examine the cargo of SC-derived EVs. We will use immunocapture techniques to target surface markers specific to SCs and examine the cargo of SC-derived EVs for inflammatory and neurotrophic markers in participants with DN, as compared to controls and two forms of genetic neuropathy. Our interdisciplinary team includes world renowned experts in diabetes, EV methodology, proteomic approaches, and neuropathy biomarker development, and is therefore in a unique position to successfully execute this work. The biomarkers use of combined argeted and untargeted approaches will maximize our ability to define new EV-derived for DN and lay the groundwork for more detailed, prospective studies. t