LncRNA Neat1 Is Involved In Heart Failure Development By Regulating S100a8 Expression

Background:Heart failure is a syndrome of symptoms and signs caused by a variety of causes of heart dysfunction,which reduces the quality of life of patients and leads to a shortened life span of patients,and is also the last part of the progression of various cardiovascular diseases.In recent years,the incidence of heart failure continues to increase all over the world,and the research on the pathogenesis of heart failure is still the hot spot of medical research at present,thus providing new possibilities for the treatment of heart failure.Previous studies have suggested that neuroendocrine,inflammation,oxidative stress,and myocardial remodeling are the underlying mechanisms leading to the onset of heart failure.Currently,inflammation is considered to be a major contributor to heart failure.Inflammation can lead to heart damage,and pro-inflammatory mediators also play a crucial role in the occurrence and development of heart failure.In recent years,with the continuous development of biomedicine,the role of non-coding RNA has been discovered,and it is involved in the pathophysiological process of many diseases.Non-coding RNAs(nc RNAs)account for about 98% of the entire human genome,among which long non-coding RNAs(lnc RNAs)are single-stranded RNAs with a length of more than 200 nucleotides,which have no coding ability and play an important role in the progression of cardiovascular diseases.A large number of differentially expressed lnc RNAs were found in the serum of patients with heart failure,suggesting that differentially expressed lnc RNAs may be related to myocardial dysfunction leading to heart failure.Studies have shown that the inflammation-related gene S100a8 plays an important role.S100a8 acts as a key pro-inflammatory alarm protein and can lead to myocardial cell apoptosis.However,studies on the regulatory mechanism of S100a8 are still unclear.To provide a new method for the occurrence,development,diagnosis,and treatment of heart failure.Purpose:In this study,ascending aorta coarctation(TAC)was used to construct a mouse model of heart failure,and gene sequencing was performed on the heart tissues to screen out m RNAs and Lnc RNAs with a different expressions.The Lnc RNAs associated with S100a8 were identified by Pearson coefficient calculation and conservative analysis,and the expression of target lnc RNA was verified by q PCR in the mice cardiac that are heart failure.Subsequently,the expression of target Lnc RNA in mice after TAC further interfered,and the expression changes of S100a8 were detected by q PCR and Western blot.The expression level of target lnc RNA was detected in the serum of selected patients with heart failure,to evaluate the diagnosis and treatment value of target Lnc RNA in heart failure disease.Methods:1.Animal experiment:A mouse model of heart failure was constructed after ascending aorta coarctation,and Lnc RNA and m RNA gene sequencing were performed on the heart tissues.It was found that genes related to inflammation were significantly differentially expressed,and s100a8 expression was significantly up-regulated.To this end,we analyzed Gene expression in mouse models by transcriptome sequencing,calculated the Pearson coefficient,constructed gene-lncr NA co-expression analysis,and obtained lnc RNAs related to S100a8.Lnc RNA neat1 was finally selected as the Lnc RNA related to S100a8,which may be the upstream regulatory gene of S100a8 by q PCR verification in mice with heart failure after TAC and conservative analysis of Lnc RNA.Then ASO technology was used to interfere with the expression of lnc RNA neat1 in mice after TAC(provided by Guangzhou Ruibo Company),and q PCR and Western blot were used to verify the expression level of S100a8 in the heart tissue of mice after lnc RNA neat1 knockout.2.Clinical Trials:Heart failure group(16 cases): 4 cases in each NYHA cardiac function grade Ⅰ-Ⅳ;Control group(7 cases,excluding patients diagnosed with heart failure).The medical history and relevant examination results of the selected patients were recorded,and then the sera of the selected patients were collected for q PCR detection,and the CT values of target Lnc RNA in all serum samples were recorded.Finally,SPSS 25.0 was used for statistical analysis,and Graph Pad Prism9.0.0 was used for plotting.Results:1.Animal experiment:(1)4 weeks after the TAC operation,the LVEF of mice in the experimental group was found to be less than 45%.Lnc RNA and m RNA second-generation sequencing analyses were conducted on the heart tissues of mice in the experimental group and control group.The differentially expressed genes related to inflammation were significant,and S100a8 expression was significantly up-regulated,while S100A9 expression was not.There must be precise regulatory mechanisms.Therefore,we constructed a Lnc RNA-m RNA co-expression network by calculating the Pearson coefficient.Lnc RNAs associated with S100a8 expression were screened out(lnc RNA AW112010,lnc RNA Prr33,lnc RNA Neat1,lnc RNA 9530082P21Rik).(2)The expression levels of the four screened lnc RNAs were then verified by q PCR in the heart tissue of heart failure mice,and the results showed that Lnc RNA AW112010 and lnc RNA Prr33 were down-regulated in the cardiac tissue of cardiac failure mice,which was inconsistent with the expected results of the experiment.Lnc RNA Neat1 and lnc RNA 9530082P21 Rik were upregulated in the heart tissue of heart failure mice,which was consistent with the results of the bioinformatic analysis.Therefore,Lnc RNA Neat1 and lnc RNA 9530082P21 Rik were selected as Lnc RNSAs to be studied.(3)Due to the low conservatism of Lnc RNA,lnc RNA Neat1 was found to have high conservatism and homology between humans and mice through conservative analysis of Lnc RNA.Therefore,Lnc RNA Neat1 was selected as the target Lnc RNA to explore its regulatory relationship with S100a8.(4)ASO technology was applied to interfere with the expression of lnc RNA Neat1 in mice after TAC(provided by Guangzhou Ruibo Company).There were 3 mice in the experimental group and 3 mice in the control group.After the TAC operation,each mouse in the experimental group was injected with lnc RNA Neat1 15 umol in the tail vein,while the control group was injected with the same dose of normal saline in the tail vein.At 4 weeks,the mice were sacrificed,and the hearts were sampled.q PCR and Western blot confirmed that S100a8 expression in the experimental group was down-regulated,the LVEF in the experimental group was higher than that in the control group,and the heart function was improved.2.Clinical Trials:The expression level of Lnc RNA Neat1 in the serum of patients with heart failure was significantly higher than that of the control group(non-patients with heart failure).The expression level of Lnc RNA Neat1 increased with NYHA grading of heart failure,indicating that lnc RNA Neat1 expression level could represent the severity of heart failure.Conclusion:Lnc RNA Neat1 is involved in the occurrence and development of heart failure by regulating the expression of S100a8,which is expected to be a new biomarker for the diagnosis and treatment of heart failure.