sample sizes and a high resolution of clinical phenotypes and medication are required, while accounting for variables known to affect the gut microbiome. Finally, drug effects are often dose-dependent, yet dosage is rarely considered in microbiome studies.To overcome these limitations, we propose a general framework for separating disease from treatment associations in multi-omics cross-sectional studies and apply it to gut metagenomic, host clinical and metabolomic measurements of 2,173 European residents from the multicentre MetaCardis cohort. The MetaCardis cohort includes patients with metabolic syndrome, severe and morbid obesity, T2D, acute and chronic coronary artery disease and heart failure, and healthy control individuals. Considering cardiometabolic disease (CMD) and herein frequently prescribed medications, we investigated drug-hostmicrobiome associations for eight major indications (antidiabetic,

The elevation of SR Ca(2+) load--in the absence of beta-adrenergic stimulation--is sufficient to increase the propensity for triggered arrhythmias in RyR2(R4496C+/-) cardiomyocytes. Stabilization of RyR2 by JTV-519 effectively reduces these triggered arrhythmias.

Key pointsr Impaired calcium (Ca 2+ ) signalling is the main contributor to depressed ventricular contractile function and occurrence of arrhythmia in heart failure (HF). waves resulted from the combined action of enhanced IICR and increased activity of sarcolemmal Na + -Ca 2+ exchange depolarizing the cell membrane. In conclusion, the data support the hypothesis that in atrial myocytes from hearts with left ventricular failure, enhanced CaTs during ECC exert positive inotropic effects on atrial contractility which facilitates ventricular filling and contributes to maintaining cardiac output. However, HF atrial cells were also more susceptible to developing arrhythmogenic Ca 2+ waves which might form the substrate for atrial rhythm disorders frequently encountered in HF.

2+load. Comparable increases of cytoplasmic CaTs induced by ␤-adrenoceptor stimulation or elevation of extracellular Ca 2+could not mimic the endothelin-1 effects on nuclear CaTs, suggesting that endothelin-1 specifically modulates nuclear Ca 2+ signalling. Thus, endothelin-1 enhances nuclear CaTs in atrial myocytes by increasing fractional Ca 2+ release from perinuclear stores. This effect is mediated by the coupling of endothelin receptor A to PLC-Ins(1,4,5)P 3 signalling and might contribute to excitation-transcription coupling.

Quantification of subcellularly resolved Ca²⁺ signals in cardiomyocytes is essential for understanding Ca²⁺ fluxes in excitation-contraction and excitation-transcription coupling. The properties of fluorescent indicators in intracellular compartments may differ, thus affecting the translation of Ca²⁺-dependent fluorescence changes into [Ca²⁺] changes. Therefore, we determined the in situ characteristics of a frequently used Ca²⁺ indicator, Fluo-4, and a ratiometric Ca²⁺ indicator, Asante Calcium Red, and evaluated their use for reporting and quantifying cytoplasmic and nucleoplasmic Ca²⁺ signals in isolated cardiomyocytes. Ca²⁺ calibration curves revealed significant differences in the apparent Ca²⁺ dissociation constants of Fluo-4 and Asante Calcium Red between cytoplasm and nucleoplasm. These parameters were used for transformation of fluorescence into nucleoplasmic and cytoplasmic [Ca²⁺]. Resting and diastolic [Ca²⁺] were always higher in the nucleoplasm. Systolic [Ca²⁺] was usually higher in the cytoplasm, but some cells (15%) exhibited higher systolic [Ca²⁺] in the nucleoplasm. Ca²⁺ store depletion or blockade of Ca²⁺ leak pathways eliminated the resting [Ca²⁺] gradient between nucleoplasm and cytoplasm, whereas inhibition of inositol 1,4,5-trisphosphate receptors by 2-APB reversed it. The results suggest the presence of significant nucleoplasmic-to-cytoplasmic [Ca²⁺] gradients in resting myocytes and during the cardiac cycle. Nucleoplasmic [Ca²⁺] in cardiomyocytes may be regulated via two mechanisms: diffusion from the cytoplasm and active Ca²⁺ release via inositol 1,4,5-trisphosphate receptors from perinuclear Ca²⁺ stores.