Alterations of the Sialylation Machinery in Brugada Syndrome

Abstract

Brugada Syndrome (BrS) is an inherited arrhythmogenic disorder with an increased risk of sudden cardiac death. Recent evidence suggests that BrS should be considered as an oligogenic or polygenic condition. Mutations in genes associated with BrS are found in about one-third of patients and they mainly disrupt the cardiac sodium channel NaV1.5, which is considered the main cause of the disease. However, voltage-gated channel’s activity could be impacted by post-translational modifications such as sialylation, but their role in BrS remains unknown. Thus, we analyzed high risk BrS patients (n = 42) and healthy controls (n = 42) to assess an involvement of sialylation in BrS. Significant alterations in gene expression and protein sialylation were detected in Peripheral Blood Mononuclear Cells (PBMCs) from BrS patients. These changes were significantly associated with the phenotypic expression of the disease, as the size of the arrhythmogenic substrate and the duration of epicardial electrical abnormalities. Moreover, protein desialylation caused a reduction in the sodium current in an in vitro NaV1.5-overexpressing model. Dysregulation of the sialylation machinery provides definitive evidence that BrS affects extracardiac tissues, suggesting an underlying cause of the disease. Moreover, detection of these changes at the systemic level and their correlation with the clinical phenotype hint at the existence of a biomarker signature for BrS.

Analysis of the intramolecular 1,7-lactone of N-acetylneuraminic acid using HPLC–MS: relationship between detection and stability

“…Also, sialylation plays a crucial role in triggering the hypoxic response of cardiac cells [ 28 ], which could lead to new therapeutic approaches for ischemic heart disease [ 29 ]. There is also evidence that sialylation contributes to the pathology of Brugada syndrome, with sialylation levels being negatively correlated with the severity of the disease [ 30 ].

Fig.

…”