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Millions afflicted with Chagas disease and other disorders of aberrant glycosylation suffer symptoms consistent with altered electrical signaling such as arrhythmias, decreased neuronal conduction velocity, and hyporeflexia. Cardiac, neuronal, and muscle electrical signaling is controlled and modulated by changes in voltage-gated ion channel activity that occur through physiological and pathological processes such as development, epilepsy, and cardiomyopathy. Glycans attached to ion channels alter channel activity through isoform-specific mechanisms. Here we show that regulated and aberrant glycosylation modulate cardiac ion channel activity and electrical signaling through a cell-specific mechanism. Data show that nearly half of 239 glycosylation-associated genes (glycogenes) were significantly differentially expressed among neonatal and adult atrial and ventricular myocytes. The N-glycan structures produced among cardiomyocyte types were markedly variable. Thus, the cardiac glycome, defined as the complete set of glycan structures produced in the heart, is remodeled. One glycogene, ST8sia2, a polysialyltransferase, is expressed only in the neonatal atrium. Cardiomyocyte electrical signaling was compared in control and ST8sia2 (؊/؊) neonatal atrial and ventricular myocytes. Action potential waveforms and gating of less sialylated voltage-gated Na ؉ channels were altered consistently in ST8sia2 (؊/؊) atrial myocytes. ST8sia2 expression had no effect on ventricular myocyte excitability. Thus, the regulated (between atrium and ventricle) and aberrant (knockout in the neonatal atrium) expression of a single glycogene was sufficient to modulate cardiomyocyte excitability. A mechanism is described by which cardiac function is controlled and modulated through physiological and pathological processes that involve regulated and aberrant glycosylation. action potentials ͉ cardiomyocyte ͉ glycomics ͉ ion channels ͉ sialic acids

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A converging public health crisis is emerging because the opioid epidemic is fueling a surge in infectious diseases, such as human immunodeficiency virus infection with or without AIDS, the viral hepatitides, infective endocarditis, and skin and soft-tissue infections. An integrated strategy is needed to tailor preventive and therapeutic approaches toward infectious diseases in people who misuse and/or are addicted to opioids and to concurrently address the underlying predisposing factor for the infections—opioid use disorder. This commentary highlights the unique and complementary roles that the infectious diseases and substance use disorder communities can play in addressing this crisis of dual public health concerns.