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Handy, D. E.

Publications and source records attributed to Handy, D. E..

2 recordsLinked to original sources

NetMedGPT - A network medicine foundation model for extensive disease mechanism mining and drug repurposing

Network medicine leverages large biomedical knowledge graphs (KGs) to model disease mechanisms and identify therapeutic opportunities. However, most deep learning approaches that use KGs in biomedicine remain task-specific, limiting their ability to generalize across diverse applications within a unified framework. Here, we introduce NetMedGPT, a transformer-based foundation model trained on a large-scale biomedical KG using masked token prediction. By learning contextualized representations of biomedical nodes, NetMedGPT enables unified, zero-shot inference across different drug discovery tasks. Specifically, in five tasks, i.e., predicting the association of drugs with indications, targets, adverse drug reactions, contraindications, and off-label uses, NetMedGPT consistently outperforms all specialized baselines, achieving area under the precision-recall curve gains of between 2.2% and 26%. When evaluated on independent external datasets, NetMedGPT outperformed baseline on an expert-curated clinical indications set and also preferentially prioritized clinically relevant drug-disease pairs in ClinicalTrials.gov. NetMedGPTs generative capability further supports the construction of mechanistically plausible subnetworks offering biological insights. NetMedGPT provides a unified foundation model for network medicine that supports scalable hypothesis generation and provides potential to accelerate drug repurposing. We further provided an interactive interface (https://prototypes.cosy.bio/chatnetmedgpt/) that allows users to obtain model inferences through natural-language queries.

bioinformatics↗

High glucose-induced ubiquitylation of G6PD leads to the injury of podocyte

Oxidative stress contributes substantially to podocyte injury in diabetic kidney disease. The mechanism of hyperglycemia-induced oxidative stress in podocytes is not fully understood. Glucose-6-phosphate dehydrogenase is critical in maintaining NADPH, an important cofactor for antioxidant system. Here, we hypothesized that high glucose induces ubiquitylation and degradation of G6PD, which injures podocytes by reactive oxygen species (ROS) accumulation. We found that both G6PD protein expression and G6PD activity was decreased in kidneys of both diabetic patients and diabetic rodents. Overexpressing G6PD reversed redox imbalance and podocyte apoptosis induced by high glucose and palmitate. Inhibition of G6PD induced podocyte apoptosis. In G6PD deficient mice, podocyte apoptosis was also largely increased. High glucose had no effect on G6PD mRNA level but it caused decreased G6PD protein expression, which was mediated by the ubiquitin proteasome pathway. Furthermore, von Hippel-Lindau (VHL), an E3 ubiquitin ligase subunit, directly bound to G6PD and degraded G6PD through ubiquitylating G6PD on lysine residues 366/403. Our data suggest that high glucose induces ubiquitylation of G6PD by VHL, which leads to ROS accumulation and podocyte injury.

cell biology↗