Background  Transmural heterogeneity of the transient outward potassium current (I_to) is a major contributor to J-wave syndrome (JWS). However, the underlying molecular mechanisms remain elusive. The present study aimed to investigate the role of cardiac injury-related bclaf1-interacting lncRNA (lncCIRBIL) in JWS and to delineate the molecular mechanisms.  Methods  Whole-cell patch-clamp techniques were used to record ionic currents and action potentials (APs). Protein and mRNA expression related to Ito current were assessed. RNA immunoprecipitation, RNA Pulldown, mRNA stability, and decapping assays were performed to dissect the underlying mechanisms.  Results  Plasma lncCIRBIL levels were significantly reduced in JWS patients and cold-induced JWS mice. Knockout of lncCIRBIL increased the incidence of J-wave and the susceptibility to ventricular arrhythmia in mice. In lncCIRBIL-deficient mice, the transmural gradient of Kv4.2 expression and Ito current density was markedly enhanced in the right ventricle, but not the left ventricle. In contrast, cardiomyocyte-specific transgenic overexpression of lncCIRBIL produced the opposite effects. In human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), the conserved human homologous fragment of lncCIRBIL (hcf-CIRBIL) suppressed Ito, attenuated the AP notch, and prolonged APD20. Mechanistically, lncCIRBIL directly binds to up-frameshift protein1 (UPF1), promoting KCND2 mRNA decay by enhancing its decapping.  Conclusions  LncCIRBIL modulates the transmural heterogeneity of KCND2 expression by regulating UPF1-mediated mRNA decay. Inhibition of lncCIRBIL exacerbates JWS by enhancing right ventricular Ito heterogeneity, whereas its overexpression exerts protective effects. These findings identify lncCIRBIL as a potential therapeutic target for J-wave syndrome.

Acute liver injury (ALI) is characterized by apoptosis, inflammation, and oxidative stress, and pathogenic mechanism of ALI is poorly understood. Apoptosis-stimulating of p53 protein 1 (ASPP1) is involved in environmental responses, tumor growth, and NF-_KB activity, which is of critical importance to ALI. However, the role of ASPP1 in ALI remains largely unexplored. The current study aimed to determine the role of ASPP1 in ALI induced by CCl4 and the underlying mechanism. ASPP1 expression was detected in wild type (WT) mice with ALI induced by CCl4. The function of ASPP1 in ALI induced by CCl4 was investigated using conventional knockout ASPP1 mice. ASPP1 expression significantly increased in ALI mice at 24 hours after CCl4 injection. Deletion of ASSP1 ameliorated apoptosis, inflammation, and necrosis in ALI relative to WT mice. In addition, deficiency of ASPP1 improved liver flood flow as well as ALT and AST levels. The levels of phosphorylated p65 and phosphorylated IκBα were lower in ASPP1-/- mice than in WT mice with ALI. These results implicate that deletion of ASPP1 may act via inhibition of the NF-кB pathway and protect mice from ALI, which may be a new potential therapeutic target for the treatment of ALI.