Project description:Myocardial ischemia-reperfusion injury (MIRI) is a major threat to heart functional integrity and pharmacological means to achieve cardioprotection are sorely needed. The sequential hypoxic/normoxic status of the cardiac tissue triggers life-threatening damages through the activation of multiple intra-cellular pathways. Heart tolerance to MIRI varies according to a day-night cycle and is regulated by components of the molecular clock such as the transcriptional repressor and nuclear receptor REV-ERBα. Timed REV-ERBα antagonism alleviates sensitivity to myocardial infarction in mice. Here we show that timed administration of digoxin is cardioprotective by triggering REV-ERBα protein degradation and involves the anti-apoptotic factor p21. Kinomics and transcriptomic assays revealed that in several cardiomyocyte cellular models, digoxin and other cardiotonic steroids induced multiple signaling pathways at subinotropic doses. Pharmacological inhibition and knockdown approaches revealed that inhibition of phosphatidylinositol 3- and of Src tyrosine-kinase partially alleviated digoxin-induced REV-ERBα degradation, which was fully prevented upon proteasome inhibition. REV44 ERBα is increasingly ubiquitinylated in digoxin-treated cells, and its degradation depends on its ability to bind its natural ligand, heme. In normal conditions, the proteasomal degradation of REV-ERBα is controlled by several known (HUWE1, FXW7, SIAH2) or novel (CBL, UBE4B) E3 ubiquitin ligases. Only SIAH2 together with the proteasome subunit PSMB5 contributed to the digoxin-induced degradation of REV-ERBα. Taken together, these results show that controlling REV-ERBα proteostasis is an appealing cardioprotective strategy, and bring further support to the rationale, timed use of CTS in prophylactic cardiac preconditioning to MIRI.
Project description:Mixed MCBA PBFM dosing of wild-type C57BL/6Crl mice. 80 mg/kg total bile acid dose (10 mg/kg individual MCBA). MCBAs included in the dosing included AlaCA, AspCA, GluCA, LeuCA, PheCA, SerCA, ThrCA, and TyrCA.
Project description:Digoxin, a cardiac glycoside widely used in humans, acts through disruption to central carbon metabolism via on target inhibition of the Na+/K+ ATPase. Acute Digoxin treatment remodels the tumor microenvironment, leading to cell-type specific transcriptional reprogramming of metabolic processes.
Project description:The goals of this study are to measure the microarray profiling of digoxin treated group versus vehicle control group in a 12 weeks HFD induced gene changes in liver tissue. The 'WT_LIVER" samples are from mice fed normal chow and not treated with digoxin, and the "HFD-WT" samples are from mice fed a high-fat diet and not treated with digoxin.
Project description:Mixed MCBA PBFM dosing of wild-type C57BL/6Crl mice. 80 mg/kg total bile acid dose (10 mg/kg individual MCBA). MCBAs included in the dosing included AlaCA, AspCA, GluCA, LeuCA, PheCA, SerCA, ThrCA, and TyrCA.
Project description:Transcriptional profiling of mouse cardiac tissue treated with 15mg/kg doxorubicin in 10 ml/kg saline over an acute time course (0.5-120 hours) compared to time matched control animals treated with 10ml/kg saline. Two colour microarrays with time matched controls against 15mg/kg doxorubicin cardiac tissue. Time points studied were 0.5, 1, 2, 12, 24 and 120 hours following dosing, biological replicates n=>3 independent animals at each time point, technical replicate n>1 with reverse labelling at each time point. One array printed onto two slides (A and B), one replicate per array.
Project description:Transcriptional profiling of mouse cardiac tissue treated with 25mg/kg DMNQ in 10 ml/kg arachis oil over an acute time course (5 minutes-120 hours) compared to time matached control animals treated with 10ml/kg arachis oil Two colour microarrays with time matched controls against 25mg/kg DMNQ cardiac tissue. Time points studied were 5, 10, 15, 20, 30, 45 minutes and 1, 1.5, 2, 5, 12, 24, 120 hours following dosing, biological replicates n=>2 independent animals at each time point, technical replicate n>1 with reverse labelling at each time point. One array printed onto two slides (A and B), one replicate per array.