Identification Of Mitochondrial Function-associated LncRNAs In Septic Mice Myocardium

Background Sepsis is an infection-induced emergent medical condition which can lead to multiple organ dysfunction syndrome and shock.Septic patients with cardiac dysfunction were prone to have poor prognosis and high risk of death.The pathogenesis of septic cardiomyopathy remains unclear yet,but studies in recent years have proved that mitochondrial dysfunction is the key event of myocardial damage during sepsis.Long non-coding RNAs(lnc RNAs),defined as non-coding transcripts with lengths of more than 200 nucleotides,have been demonstrated to participate in a wide range of cellular biological processes.More and more evidences have shown that lnc RNAs were important regulators in many heart diseases such as cardiac hypertrophy,myocardial infarction,arrhythmia,etc.Although some lnc RNAs such as MALAT1,HOTAIR,and NEAT1 which was proved to regulate the apoptosis and immune response have been shown to involve in the process of septic myocardial injury,whether other lnc RNAs also take part in the cellular and molecular pathophysiology of septic hearts is still unknown.It has been reported that mitochondrial function can be regulated by lnc RNAs in cancer,which might act as a valuable target for new strategy of cancer treatment.Whether the mitochondrial dysfunction is also modulated by lnc RNAs and the mechanism of regulation in septic cardiomyopathy is unclear.Objectives The aims of present study were to analyze long non-coding RNA(lnc RNA)and m RNA expression profiles in mice septic cardiac injury model,and to identify the potential lnc RNAs and m RNAs that might be responsible for cardiac mitochondrial dysfunction during sepsis.Methods 1)Sepsis mice model was established in C57BL/6 mice by injecting LPS(10mg/kg)intraperitoneally.2)HL-1 cells were treated with LPS(30?g/ml)to induce inflammatory injury.3)lnc RNA and m RNA expression profile in LPS and control mice hearts were constructed by using microarray analysis.4)Prediction of lnc RNA-m RNA interaction were performed by using Pearson correlation test,gene location and complementary sequences analysis.5)GO and KEGG PATHWAY were used to analyse the function and the pathway enrichments of differential expressed lnc RNAs and m RNAs.6)Mitochondrial morphology was observed under transmission electron microscope.MDA content,SOD and GSH-Px activities,and ATP levels were evaluated using commercial kits.7)Cellular survival was measured by using CCK-8 kit.8)Location of lnc RNA were detected by RNA FISH technology.Results 1)A total of 1275 lnc RNAs were differentially expressed in septic myocardium compared with that of control group,471 of them were upregulated and 804 of them were downregulated.And 2769 m RNAs were dysregulated in septic mice heart,of which 1158 were upregulated and 1611 were downregulated.2)GO and KEGG PATHWAY showed that the function of differentially expressed lnc RNAs and m RNAs are mainly related to the process of inflammation,cell death and energy metabolism.3)Cardiac mitochondrial showed an obvious swelling and loss of cristae in LPStreated mice.MDA content of cardiac tissue was increased,while mitochondrial anti-oxidative enzymes and ATP level were decreased in septic mice.4)We predicted the mitochondria-related differentially expressed lnc RNAs in septic myocardium,and found they were mainly involved in the regulation of apoptotic pathways and MAPK signaling pathways.5)Expression of lnc RNA NONMMUG058263 was decreased both in LPS-teated mice heart and HL-1 cells.si RNA NONMMUG058263 could aggravate LPSinduced cellular injury,but NONMMUG058263 overexpression protect HL-1 cells from LPS attack.6)NONMMUG058263 was mainly located in cytoplasm.Bioinformatics analyse predicted mi R-143-3p/MYO6 might be the downstream of NONMMUG058263.In vitro experiment,we found that LPS treatment caused increased mi R-143-3p expression and increased MYO6 expression increased.Conclusion In this study,we explored the differentially expressed lnc RNA and m RNA profiles of myocardium in septic mice hearts,and predicted some specific lnc RNAs and their potential target m RNAs that might lead to mitochondrial dysfunction.These findings might provide a panoramic view of lnc RNAs which would likely be involved in the mitochondrial dysfunction in septic cardiomyopathy,and provide effective information for the further basic research and new clinical treatment strategies from the perspective of lnc RNA.