Loss of exosomal LncRNA HCG15 prevents acute myocardial ischemic injury through the NF-\u03baB/p65 and p38 pathways

Beiyou Lin,Jie Xiong,Kun Wang,Yuan Yuan,Lile Shi,Yumin Qiu,Xiaofei Jiang,Xin Liu,Lintao Zhong,Haoyu Song,Chuanghong Lu,Jianjun Xu,Ang Chen,Xi Chen

doi:10.1038/s41419-021-04281-8

Abstract

Exosomes are nanosized bilayer membrane vesicles that may mediate intercellular communication by transporting bioactive molecules, including noncoding RNAs, mRNAs, and proteins. Research has shown that exosomes play an important role in acute myocardial infarction (AMI), but the function and regulation of exosomal long noncoding RNAs (lncRNAs) in AMI are unclear. Thus, RNA sequencing (RNA-Seq) was conducted to investigate the exosomal lncRNA transcriptome from MI patients and identified 65 differentially expressed lncRNAs between the MI and control groups. HCG15, one of the differentially expressed lncRNAs, was verified to have the highest correlation with cTnT by qRT-PCR, and it also contributed to the diagnosis of AMI by receiver operating characteristic (ROC) analysis. Upregulation of HCG15 expression facilitated cardiomyocyte apoptosis and inflammatory cytokine production and inhibited cell proliferation. We also confirmed that HCG15 was mainly wrapped in exosomes from AC16 cardiomyocytes under hypoxia, which contributed to cardiomyocyte apoptosis, the release of inflammatory factors, and inhibition of cell proliferation via the activation of the NF-κB/p65 and p38 pathways, whereas suppressing the expression of HCG15exerted opposite effects, In addition, Overexpression of HCG15 aggravated cardiac IR injury in C57BL/6J mice. This study not only helps elucidate exosomal lncRNA function in AMI pathogenesis but also contributes to the development of novel therapeutic strategies.

Highlights

Acute myocardial infarction (AMI), which is mainly caused by coronary artery occlusion and myocardial ischemia, remains a serious cardiovascular disease with high morbidity and mortality [1, 2]
SiRNAs targeting long noncoding RNAs (lncRNAs) HLA complex group 15 (HCG15) were was upregulated in exosomes from AMI patients and hypoxiainduced cells, which resulted in cardiomyocyte apoptosis, the release of inflammatory cytokines and inhibition of cell proliferation
Identification of differentially expressed exosomal lncRNAs from the serum of AMI patients The expression profiles of exosomal lncRNAs from six AMI patients and six matched healthy controls were determined by RNA sequencing (RNA-Seq), and their clinical characteristics are shown in Supplementary Table 1

Summary

INTRODUCTION

Acute myocardial infarction (AMI), which is mainly caused by coronary artery occlusion and myocardial ischemia, remains a serious cardiovascular disease with high morbidity and mortality [1, 2]. RNA sequencing (RNA-Seq) was performed to investigate the exosomal lncRNA transcriptome from AMI patients, and an anoxic model of AC16 cardiomyocytes was established. SiRNAs targeting lncRNA HCG15 were was upregulated in exosomes from AMI patients and hypoxiainduced cells, which resulted in cardiomyocyte apoptosis, the release of inflammatory cytokines and inhibition of cell proliferation. RNA-Seq analysis Total RNA of exosomes (20 μg) from six AMI patients and six healthy controls (clinical characteristics shown in Supplementary Table 1) was extracted using TRIzol reagent (Life Technologies, USA) following the instructions. AC16 cells and isolated exosomes were washed with PBS and resuspended in SDS lysis buffer followed by centrifugation at 4 °C and 16,000 × g for 30 min and supernatant collection. Comparisons between groups were performed using Student’s t test for two groups of data and one-way ANOVA followed by Tukey’s multiple comparison test for multiple groups of data. p < 0.05 was considered statistically significant

RESULTS

Lin et al 4

DISCUSSION

CONCLUSIONS

ETHICS STATEMENT