GJA1 and metabolic syndrome: The immunoprecipitation revealed that Cx40 and Cx43 were markedly O-GlcNAcylated in the MetS-VLDL group (Cx40, P = 0.0313 vs control; Cx43, P = 0.017 vs control) (Fig. 4); whereas Normal-VLDL did not increase O-GlcNAcylation of Cx40 and Cx43 at the same concentration with the same duration of treatment.