Background Atrial fibrillation (AF) is one of the most prevalent sustained arrhythmias, however, epidemiological data may understate its actual prevalence. Meanwhile, AF is considered to be a major cause of ischemic strokes due to irregular heart-rhythm, coexisting chronic vascular inflammation, and renal insufficiency, and blood stasis. We studied co-expressed genes to understand relationships between atrial fibrillation (AF) and stroke and reveal potential biomarkers and therapeutic targets of AF-related stroke. Methods AF-and stroke-related differentially expressed genes (DEGs) were identified via bioinformatic analysis Gene Expression Omnibus (GEO) datasets GSE79768 and GSE58294, respectively. Subsequently, extensive target prediction and network analyses methods were used to assess protein–protein interaction (PPI) networks, Gene Ontology (GO) terms and pathway enrichment for DEGs, and co-expressed DEGs coupled with corresponding predicted miRNAs involved in AF and stroke were assessed as well. Results We identified 489, 265, 518, and 592 DEGs in left atrial specimens and cardioembolic stroke blood samples at < 3, 5, and 24 h, respectively. LRRK2 , CALM1 , CXCR4 , TLR4 , CTNNB1 , and CXCR2 may be implicated in AF and the hub-genes of CD19 , FGF9 , SOX9 , GNGT1 , and NOG may be associated with stroke. Finally, co-expressed DEGs of ZNF566 , PDZK1IP1 , ZFHX3 , and PITX2 coupled with corresponding predicted miRNAs, especially miR-27a-3p, miR-27b-3p, and miR-494-3p may be significantly associated with AF-related stroke. Conclusion AF and stroke are related and ZNF566 , PDZK1IP1 , ZFHX3 , and PITX2 genes are significantly associated with novel biomarkers involved in AF-related stroke. Electronic supplementary material The online version of this article (10.1186/s12967-019-1790-x) contains supplementary material, which is available to authorized users.

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Background: Given the importance of microvascular injury in infarct formation and expansion, development of therapeutic strategies for microvascular protection against myocardial ischemia/reperfusion injury (IRI) is of great interest. Here, we explored the molecular mechanisms underlying the protective effects of the SGLT2 inhibitor dapagliflozin (DAPA) against cardiac microvascular dysfunction mediated by IRI. Methods: DAPA effects were evaluated both in vivo , in mice subjected to IRI, and in vitro , in human coronary artery endothelial cells (HCAECs) exposed to hypoxia/reoxygenation (H/R). DAPA pretreatment attenuated luminal stenosis, endothelial swelling, and inflammation in cardiac microvessels of IRI-treated mice. Results: In H/R-challenged HCAECs, DAPA treatment improved endothelial barrier function, endothelial nitric oxide synthase (eNOS) activity, and angiogenic capacity, and inhibited H/R-induced apoptosis by preventing cofilin-dependent F-actin depolymerization and cytoskeletal degradation. Inhibition of H/R-induced xanthine oxidase (XO) activation and upregulation, sarco(endo)plasmic reticulum calcium-ATPase 2 (SERCA2) oxidation and inactivation, and cytoplasmic calcium overload was further observed in DAPA-treated HCAECs. DAPA also suppressed calcium/Calmodulin (CaM)-dependent kinase II (CaMKII) activation and cofilin phosphorylation, and preserved cytoskeleton integrity and endothelial cell viability following H/R. Importantly, the beneficial effects of DAPA on cardiac microvascular integrity and endothelial cell survival were largely prevented in IRI-treated SERCA2-knockout mice. Conclusions: These results indicate that DAPA effectively reduces cardiac microvascular damage and endothelial dysfunction during IRI through inhibition of the XO-SERCA2-CaMKII-cofilin pathway.

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Ketogenic diet (KD) is popular in diabetic patients but its cardiac safety and efficiency on the heart are unknown. The aim of the present study is to determine the effects and the underlined mechanisms of KD on cardiac function in diabetic cardiomyopathy (DCM). We used db/db mice to model DCM, and different diets (regular or KD) were used. Cardiac function and interstitial fibrosis were determined. T-regulatory cell (Treg) number and functions were evaluated. The effects of ketone body (KB) on fatty acid (FA) and glucose metabolism, mitochondria-associated endoplasmic reticulum membranes (MAMs), and mitochondrial respiration were assessed. The mechanisms via which KB regulated MAMs and Tregs were addressed. KD improved metabolic indices in db/db mice. However, KD impaired cardiac diastolic function and exacerbated ventricular fibrosis. Proportions of circulatory CD4+CD25+Foxp3+ cells in whole blood cells and serum levels of IL-4 and IL-10 were reduced in mice fed with KD. KB suppressed the differentiation to Tregs from naive CD4+ T cells. Cultured medium from KB-treated Tregs synergically activated cardiac fibroblasts. Meanwhile, KB inhibited Treg proliferation and productions of IL-4 and IL-10. Treg MAMs, mitochondrial respiration and respiratory complexes, and FA synthesis and oxidation were all suppressed by KB while glycolytic levels were increased. L-carnitine reversed Treg proliferation and function inhibited by KB. Proportions of ST2L+ cells in Tregs were reduced by KB, as well as the production of ST2L ligand, IL-33. Reinforcement expressions of ST2L in Tregs counteracted the reductions in MAMs, mitochondrial respiration, and Treg proliferations and productions of Treg cytokines IL-4 and IL-10. Therefore, despite the improvement of metabolic indices, KD impaired Treg expansion and function and promoted cardiac fibroblast activation and interstitial fibrosis. This could be mainly mediated by the suppression of MAMs and fatty acid metabolism inhibition via blunting IL-33/ST2L signaling.