Differential Transcriptome Profile In Rats Model Of Post-infarction Heart Failure By RNA-sequencing And Function Exploration

Heart failure?HF? is a progressive and irreversible pathological process. By now, a variety of evidence has been proved that HF was the process of a variety of genes altering expression levels, forming a complex network to regulate the pathological process of heart failure, which was closely related to the prognosis of heart failure. However, the mechanism is not fully clear. To study the genetic regulatory mechanism and key pathways of HF from the trascriptome level has become a hotspot in the field of cardiovascular.The present study constructed the rat model of post-infarction heart failure by ligating the anterior descending coronary artery, detected the m RNA expression profile in left ventricular myocardial tissue of both the HF group and the control group by RNA-sequencing, and analyzed the differentially expressed genes?DEGs? as well as the transcriptome characteristics. GO annotation, KEGG pathway analysis and GSEA analysis of DEGs were performed to help us understand the main biological function and biochemical pathways involved, as well as the signal transduction pathways of DEGs. To validate the accuracy of sequencing data, we performed the real-time quantitative PCR?q PCR? using the same sample as the sequencing. Additionally, several genes?Agpat1, Mtfp1, Pdk4, et al? were tested in 8 weeks and 10 weeks after operation both in m RNA level and protein level, aiming to detect the time expression patterns of different periods after myocardial infarction and discuss the potential role in the heart failure progress. Finally, we verified the mi RNA-m RNA target interaction between mi R-122-5p and Agpat1 by dual-luciferase reporter gene system, and then preliminarily explored the cardiomyocyte apoptosis effect of mi R-122a-5p through loss of function?with mi RNA inhibitor? and gain of function?with mi RNA mimics? and Agpat1 through construction of over-expression vector.Results: 1. We induced rat myocardial infarction-induced heart failure through thoracotomy anterior descending coronary artery ligation method. Stable heart failure was formed 10 weeks after operation. 2. The transcriptome profile in left ventricular myocardial tissue between control group and HF group were obtained through RNA-sequencing. And the differential gene clustering analysis showed that there was a variety of changes in gene expression pattern between control group and HF group. 3. The DEG analysis showed 427 differential expressed genes with 357 up-regulated genes and 70 down-regulated genes when compared to control group. 4. GO,KEGG and GSEA analysis based on these DEGs were performed.It suggested that compared with the reference genome, these candidate genes enriched in biological regulation,multicellular organisms and stress reaction in GO analysis, and mainly enriched in extracellular matrix receptor interactions, osteoclast differentiation, gelling spot, toll-like receptors signaling pathways and hematopoietic cell pathways in KEGG analysis.The significantly enriched GESA pathways were mainly involved in signal transduction, immune regulation, substance and energy metabolism, biological synthesis. 5. The detection of various DEGs in 4 weeks, 8 weeks and 10 weeks after operation showed that the m RNA and protein levels of specific genes changed with time in the development of heart failure after myocardial infarction: 1) the expression levels of Agpat1 and Dusp1 gradually decreased suggesting their protective role in HF; 2) the expression levels of Pdk4 gradually increased revealing that it might be involved in the pathogenesis of HF and be the potential biomarker of HF; 3) the expression of Mtfp1 was significantly up-regulated at 8 weeks after myocardial infarction, however decreased gradually and significantly lower than the control group at 10 weeks after myocardial infarction,which suggested that Mtfp1 played different roles at different periods of HF progression. 6. The cardiomyocyte apoptosis effect of mi R-122a-5p with or without Ang II and H₂O₂ induction was confirmed through loss of function?with mi RNA inhibitor? and gain of function?with mi RNA mimics? in the myocardial apoptosis model. 7. The mi RNA-m RNA target interaction between mi R-122-5p and Agpat1 was proved by dual-luciferase reporter gene system. 8. The protective role of Agpat1 in cell apoptosis was confirmed by construction of over-expression vector in vitro studies.Conclusion: 1. This study has shown the significant changes in myocardial tissue expression profile in the rat model of post-infarction heart failure.Several pathways and related genes including signal transduction, immune regulation, substance and energy metabolism were involved in the progression of HF. 2. This study confirmed the dynamic expresseion patterns of Agpat1, Dusp1, Mtfp1 and Pdk4 in different periods of post-infarction heart failure, which suggested that genes might have different roles in different time of HF. 3. mi R-122a-5p could induce cardiomoyocyte apoptosis by down-regulating Agpat1 expression,so the inhibition of mi R-122a-5p and the increase of Agpat1 may be the effective means to prevent cardiomoyocyte apoptosis and ventricular remodeling.