Glycogen dysregulation is a hallmark of aging, and aberrant glycogen drives metabolic reprogramming and pathogenesis in multiple diseases. However, glycogen heterogeneity in healthy and diseased tissues remains largely unknown. Herein, we describe a method to define spatial glycogen architecture in mouse and human tissues using matrix‐assisted laser desorption/ionization mass spectrometry imaging. This assay provides robust and sensitive spatial glycogen quantification and architecture characterization in the brain, liver, kidney, testis, lung, bladder, and even the bone. Armed with this tool, we interrogated glycogen spatial distribution and architecture in different types of human cancers. We demonstrate that glycogen stores and architecture are heterogeneous among diseases. Additionally, we observe unique hyperphosphorylated glycogen accumulation in Ewing sarcoma, a pediatric bone cancer. Using preclinical models, we correct glycogen hyperphosphorylation in Ewing sarcoma through genetic and pharmacological interventions that ablate in vivo tumor growth, demonstrating the clinical therapeutic potential of targeting glycogen in Ewing sarcoma.

The resting membrane potential enables neurons to rapidly initiate and conduct electrical signals. K2p channels are key in maintaining this membrane potential and electrical excitability. They direct the resting membrane potential toward the K⁺ equilibrium potential. Doxapram is a known blocker for a subset of K2p channels that are pH sensitive. We assessed the effects of 0.1 and 5 mM doxapram on the neural activity within the propodite-dactylopodite (PD) proprioceptive sensory organ in the walking legs of blue crabs (Callinectes sapidus). Results indicate that 0.1 mM doxapram enhances excitation, while the higher concentration 5 mM may over-excite the neurons and promote a sustained absolute refractory period until the compound is removed. The effect of 5 mM doxapram mimics the effect of 40 mM K⁺ exposure. Verapamil, another known K2p channel blocker as well as an L-type Ca²⁺ channel blocker, reduces neural activity at both 0.1 and 5 mM. Verapamil may block stretch activated channels in sensory endings, in addition to reducing the amplitude of the compound action potential with whole nerve preparations. These findings are notable as they demonstrate that doxapram has acute effects on neurons of crustaceans, suggesting a targeted K2p channel. The actions of verapamil are complex due to the potential of affecting multiple ion channels in this preparation. Crustacean neurons can aid in understanding the mechanisms of action of various pharmacological agents as more information is gained.

Background: Gliomas are primary malignant brain tumors. Among them, grade IV astrocytomas represent the most aggressive form with limited treatment options and a poor prognosis. There is a critical need for reliable prognostic biomarkers to predict patient outcomes. Methods: In this study, we evaluated the prognostic roles of glycomics in predicting outcomes of patients with glioma. To address this need, we collected a cohort of 86 patients and conducted N-linked glycomics analysis using matrix-assisted laser desorption/ionization mass spectrometry on a tissue microarray comprising 78 gliomas and 8 controls. We performed survival analyses and machine-learning-based predictive modeling to evaluate the prognostic roles of glycomic features. Results and Conclusion: Glycomic features alone displayed strong performance in classifying mortality status, achieving a mean area under the receiver operating characteristic curve (AUROC) value of 0.880 and a mean area under the precision–recall curve (AUPRC) value of 0.925, and demonstrating consistent prognostic value in survival analyses with a mean concordance index of 0.759 across repeated cross-validation. Glycomic features also showed strong performance in predicting the incidence of seizure status, with a mean AUROC value of 0.778 and a mean AUPRC value of 0.766. Additionally, top-ranked glycans from machine-learning models can effectively stratify patients based on their survival outcomes, demonstrating their potential role as prognostic biomarkers.