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. 2021 Apr 30;129(1):98–113. doi: 10.1161/CIRCRESAHA.120.318402

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© 2021 The Authors.

Circulation Research is published on behalf of the American Heart Association, Inc., by Wolters Kluwer Health, Inc. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial-NoDerivs License, which permits use, distribution, and reproduction in any medium, provided that the original work is properly cited, the use is noncommercial, and no modifications or adaptations are made.

This article is made available via the PMC Open Access Subset for unrestricted re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the COVID-19 pandemic or until permissions are revoked in writing. Upon expiration of these permissions, PMC is granted a perpetual license to make this article available via PMC and Europe PMC, consistent with existing copyright protections.

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Figure 3. — Glucose-induced arrhythmogenic action potentials are CaMKIIδ (Ca²⁺/calmodulin-dependent protein kinase II)-S280 O-GlcNAcylation dependent. A, Action potential duration (APD) prolongation and alternans (S, short; L, long) were increased by acute high-glucose treatment in wild-type (WT) myocytes (n=16 cells from 9 animals). B, Arrhythmogenic APD responses were prevented by CaMKIIδ-cardiac-specific knockout (cKO; n=21 cells from 8 animals). C and D, CaMKIIδ-S280A knock-in (n=15 ells from 8 animals) but not mutated Met281Val and Met282Val (MMVV; n=17 cells from 9 animals) was resistant to glucose-induced acute APD changes. Nested t test. E and F, Glucose-induced APD changes were prevented by CaMKIIδ-cKO, S280A, intracellular Ca²⁺ buffering (EGTA) or the O-GlcNAc transferase inhibitor OSMI-1 (αR-[[(1,2-dihydro-2-oxo-6-quinolinyl)sulfonyl]amino]-N-(2-furanylmethyl)-2-methoxy-N-(2-thienylmethyl)-benzeneacetamide) but enhanced by the O-GlcNAcase inhibitor Thiamet-G (Thm-G) in WT. Ang II (angiotensin II) further enhanced arrhythmogenic APD changes, which was prevented by CaMKIIδ-cKO, MMVV, or in NOX2^−/− (NADPH oxidase 2; n=total number of cells/animals is reported in the figure). Nested 1-way ANOVA, followed by Dunnett multiple comparisons test was used to compare 3 groups. Nested t test was used to compare 2 groups.