Dissecting the transcriptome in cardiovascular disease

The human transcriptome comprises a complex network of coding and non-coding RNAs implicated in a myriad of biological functions. Non-coding RNAs exhibit highly organized spatial and temporal expression patterns and are emerging as critical regulators of differentiation, homeostasis, and pathological states, including in the cardiovascular system. This review defines the current knowledge gaps, unmet methodological needs, and describes the challenges in dissecting and understanding the role and regulation of the non-coding transcriptome in cardiovascular disease. These challenges include poor annotation of the non-coding genome, determination of the cellular distribution of transcripts, assessment of the role of RNA processing and identification of cell-type specific changes in cardiovascular physiology and disease. We highlight similarities and differences in the hurdles associated with the analysis of the non-coding and protein-coding transcriptomes. In addition, we discuss how the lack of consensus and absence of standardized methods affect reproducibility of data. These shortcomings should be defeated in order to make significant scientific progress and foster the development of clinically applicable non-coding RNA-based therapeutic strategies to lessen the burden of cardiovascular disease.

Clec4e signalling influences left-ventricular functional recovery in a murine model of myocardial ischemia-reperfusion injury

Introduction

The acute inflammatory response contributes substantially to functional recovery and remodelling of the left ventricle after acute ischemic injury. Previously, we have shown that the C-Type Lectin Receptor CLEC4E plays a role in early leukocyte recruitment during the acute inflammatory response of ischemia-reperfusion injury (I/R). However, the role of CLEC4E signalling in functional recovery of the left ventricle after I/R remains unknown. Therefore, we studied the chronic inflammatory response and left-ventricular remodelling in murine gene deletion model of Clec4e, subjected to I/R.

Methods

In anesthetized C57Bl6/J wild-type (n=14) and Clec4e−/− (n=13) mice, we transiently occluded the left-descending artery for 60 min, followed by 4 weeks reperfusion (I/R). A blood sample was collected at 90 minutes reperfusion to measure high-sensitivity troponin I (TnI) levels, as a surrogate marker of cardiac damage. At 4 weeks, mice underwent MRI (7T) to investigate the effect of Clec4e-gene deletion on LV-remodelling.

Results

Plasma TnI-levels showed no statistical difference between both groups, indicating that the initial insult was comparable. In wild-type mice, plasma TnI-levels negatively correlated with ejection fraction (EF, R2=0.92 p<0.0001) at 4 weeks I/R, while Clec4e−/− mice showed preserved EF, irrespective of 90 minutes TnI-levels. MRI-analysis at 4 weeks after I/R showed significantly smaller end-diastolic and end-systolic volumes in Clec4e−/− mice, together with a trend towards a higher ejection fraction, suggesting better preserved structural and functional LV-remodelling (Fig.1).

Conclusion

The inflammatory leukocyte-associated Clec4e signalling pathway impairs functional recovery of the left ventricle after myocardial I/R injury. Inhibition of the Clec4e receptor may be a promising strategy in the treatment of ischemic injury.

Figure 1

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Scholarship Ir. Jozef en Mevr. Reinhilde De Swerts 2018-2022 by the Royal Academy of Medicine of Belgium

Tranexamic acid to reduce bleeding after dental extraction in patients treated with non-vitamin K oral anticoagulants: design and rationale of the EXTRACT-NOAC trial

Bleeding after dental extraction in patients treated with non-vitamin K oral anticoagulants (NOAC) may lead to unplanned reinterventions and interruption of anticoagulation, thereby exposing patients to a risk of thromboembolism. We have designed a study (EXTRACT-NOAC) to investigate whether tranexamic acid (TXA) mouthwash decreases bleeding after extraction in such patients. The study is a randomised, double-blind, placebo-controlled trial. We plan to randomise 236 patients listed for dental extraction and treated with NOAC to 10% TXA mouthwash or placebo. Patients are instructed to use the mouthwash before the dental extraction, and three times a day for three days thereafter. The primary outcome is oral bleeding. Secondary outcomes include type of bleeding, procedural bleeding score, number of reinterventions after oral bleeding, and number of interruptions in NOAC treatment. Any bleeding from sources other than the mouth, and thrombotic events, are recorded as safety outcomes. Patients are followed-up for seven days. This study will provide evidence to guide the management of patients taking NOAC who need teeth extracted.

Friable coronary arteries are link between pathogenesis and treatment of spontaneous coronary artery dissection

Spontaneous coronary artery dissection (SCAD) is increasingly being diagnosed as the cause of an acute coronary syndrome, especially in young patients. We report the case of a 32-year-old woman with postpartum SCAD of the left main and left anterior descending coronary artery which required the implantation of two drug-eluting stents. We present a literature study that correlates the pathogenesis of SCAD to the treatment options. Non-atherosclerotic SCAD is clearly associated with connective tissue disorders, vasculitis, and the peripartum period with its hormonal and haemodynamic changes. The coronary arteries of these SCAD patients are friable and should be approached with caution. Percutaneous coronary intervention has a reported success rate of only 65% and may cause propagation of the dissection. Lately, more and more authors suggest the possibility of a conservative approach in the absence of remaining cardiac ischaemia, even in this era of percutaneous stent implantation.