ABSTRACT
BACKGROUND@#The molecular mechanisms of heart failure (HF) are still poorly understood. Circular RNA (circRNA) has been discovered in the heart in increasing numbers of studies. The goal of this research is to learn more about the potential roles of circRNAs in HF.@*METHODS & RESULTS@#We used RNA sequencing data to identify the characteristics of circRNAs expressed in the heart and discovered that the majority of circRNAs screened were less than 2000 nt. Additionally, chromosomes One and Y had the most and least number of circRNAs, respectively. After excluding duplicate host genes and intergenic circRNAs, a total of 238 differentially expressed circRNAs (DECs) and 203 host genes were discovered. However, only four of the 203 host genes of DECs were examined in HF differentially expressed genes. Another study used Gene Oncology analysis of DECs host genes to elucidate the underlying pathogenesis of HF, and it found that binding and catalytic activity accounted for a large portion of DECs. Immune system, metabolism, and signal transduction pathways were significantly enriched. Furthermore, 1052 potentially regulated miRNAs from the top 40 DECs were collected to build a circRNA-miRNA network, and it was discovered that 470 miRNAs can be regulated by multiple circRNAs, while others are regulated by a single circRNA. In addition, a comparison of the top 10 mRNAs in HF and their targeted miRNAs revealed that DDX3Y and UTY were regulated by the most and least circRNA, respectively.@*CONCLUSION@#These findings demonstrated circRNAs have species and tissue specific expression patterns; while circRNA expression is independent on host genes, the same types of genes in DECs and DEGs worked in HF. Our findings would contribute to a better understanding of the critical roles of circRNAs and lay the groundwork for future studies of HF molecular functions.
ABSTRACT
Objective: To investigate the feasibility of echocardiography-guided closed-chest repeated intraventricular blood sampling in mice, and to clarify the maximum blood volume that can be collected by this method, and whether the method can be used for long-term repeated blood collection in mice. Methods: Twenty-four male C57BL/6J mice (10-14 weeks old) were divided into the terminal experiment group (n=4, for investigating the maximum blood amount that could be sampled at one time), the repeated 0.5 ml blood collection group (n=10, sampling 0.5 ml whole blood each time, once every two days for consecutive 4 weeks), and the repeated 0.75 ml blood collection group (n=10, sampling 0.75 ml whole blood each time, once every two days for consecutive 4 weeks). High-frequency echocardiography was used to display the largest section of the left ventricle, guiding the insulin syringe needle through the thorax into the left ventricle for blood collection. In the repeated 0.5 ml blood collection group, echocardiography was used to detect the cardiac structure and function before blood collection, three minutes after blood collection, and one week after the last (the 14th) blood collection. Results: We successfully performed echocardiography-guided closed-chest intraventricular blood sampling, with an average operating time (88±19)s per mouse, and a maximum blood volume (1.43±0.11)ml per mouse. In the repeated 0.5 ml blood collection group, heart rate, left ventricular ejection fraction, left ventricular fractional shortening, left ventricular end-diastolic dimension and left ventricular posterior wall end-diastolic thickness remained uncganged before the first blood collection and after 4 weeks of repeated blood collection (all P>0.05). No death in the repeated 0.5 ml blood collection group. However, in the 0.75 ml blood collection group, two mice died before the end point. Conclusions: The echocardiography-guided closed-chest intraventricular blood sampling is a safe, minimally invasive, convenient and efficient method, and can be used repeatedly for long-term blood collection in mice.