Project description:Transcriptomic analysis of synchonized AC16 cells after 0-6-12-18 or 24 h of digoxin treatment (5µM) We used microarrays to detail the global programme of gene expression
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: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:Non-medullary thyroid cancer (NMTC) is the most frequent endocrine tumor with in most cases a good prognosis. Unfortunately, 30-40% of patients with metastatic NMTC are unresponsive to 131-I radioactive iodide (RAI) treatment as a result of tumor dedifferentiation. Autophagy has emerged as an important mechanism involved in NMTC dedifferentiation. Furthermore, activation of autophagy by cardiac glycosides such as digoxin has been demonstrated to induce effective in vitro redifferentiation of poorly differentiated and anaplastic thyroid cancer cell lines, thereby restoring sensitivity to RAI treatment. However, the in vivo effects of digoxin treatment on tumor differentiation in NMTC patients remains unclear. In the present retrospective clinical study, archived tumor material obtained from NMTC patients that received digoxin as treatment of heart disease before and after NMTC diagnosis was investigated. By a national PALGA-PHARMO database search, 11 digoxin-treated NMTC patients were included encompassing all major histological NMTC subtypes. In addition, 11 control NMTC patients never treated with digoxin were included that were matched for age, gender, histological tumor type, TNM staging and genetic profile. From the collected tumor material, autophagy activity has been determined by LC3 immunofluorescent staining and RNA expression profiles have been generated by RNA sequencing to assess differential expression of thyroid-specific genes. Interestingly, the results indicate that tumor material from digoxin-treated NMTC patients exhibit significantly higher autophagy activity as compared to tumor material of matched control NMTC patients. Moreover, in all 11 tumor tissues obtained from digoxin-treated NTMC patients the differentiation status was profoundly higher as compared to the matched control NMTC patients, of which the effect size was however dependent on histological NMTC subtypes and genetic profile of the tumor. In conclusion, treatment of NMTC with digoxin before and after NMTC diagnosis is associated with a higher tumor differentiation grade as compared to tumor tissue from closely matched NMTC patients not treated with digoxin. These in vivo data confirm our previous in vitro findings and provide accumulating evidence that digoxin could represent a beneficial adjunctive treatment modality to improve RAI sensitivity in patients with RAI-refractory thyroid carcinoma.
Project description:We report the effect of FDA approved digoxin treatment (50nM for 48h) on the gene expression and alternative splices in control human pluripotent stem cells derived mesenchymal stem cells. Our results demonstrate the effect of digoxin treatment on alternative splice as 258 skipping exons were identified after digoxin treatment. Concerning the gene expression, our results also highlight on the large effect of digoxin treatment on the modulation of gene expression.
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.