Characterization of LncRNA expression profile and identification of functional LncRNAs associated with unstable angina

Role of LncRNAs in the Pathogenesis of Coronary Artery Disease

Coronary artery disease (CAD), caused by coronary artery occlusion, is a common cardiovascular disease worldwide. Long non-coding RNAs (lncRNAs) are implicated in the regulation of endothelial cell injury, angiogenesis, plaque formation, and other pathological mechanisms in CAD by acting on different cell types. Some lncRNAs are significantly upregulated in CAD patients; however, other lncRNAs are significantly downregulated. Differential expression of lncRNAs in CAD patients enables them to be exploited as potential biomarkers to evaluate disease progression and diagnosis/prognosis in CAD patients. In this study, we reviewed the role of lncRNAs in the development of different clinical subtypes of CAD.

Circulating long non-coding RNA Coromarker expression correlated with inflammation, coronary artery stenosis, and plaque vulnerability in patients with coronary artery disease

BACKGROUND

The aim of the study was to assess the correlation between circulating long non-coding RNA (lncRNA) OTTHUMT00000387022 (named Coromarker) expression and disease severity, inflammatory cytokine levels, and plaque vulnerability in patients with coronary artery disease (CAD).

METHODS

A total of 134 participants who received coronary angiography were enrolled and classified them as CAD patients (N = 89) and controls (N = 45). Blood samples were obtained from all subjects. Quantitative polymerase chain reaction was used to evaluate Coromarker expression. The enzyme-linked immunosorbent test was used to measure inflammatory cytokines including high sensitivity C reactive protein (hsCRP), interleukin (IL)-1β (IL-1β), IL-6, NOD-like receptor protein 3 (NLRP3), and markers of coronary plaque stability including matrix metallopeptidase 9 (MMP-9) and soluble CD40 ligand (sCD40L). The severity of coronary stenosis was determined from the Gensini Score.

RESULTS

LncRNA Coromarker expression was elevated to a greater extent in CAD patients than in control subjects before and after adjustments for age/gender (both p < 0.001); it was an independent predictor of CAD risk (area under curve: 0.824, 95% CI: 0.732-0.915). Additionally, Coromarker expression was significantly associated with Gensini Score (r = 0.574, p < 0.001), hsCRP (r = 0.221, p = 0.015), IL-1β (r = 0.351, p < 0.001), IL-6 (r = 0.286, p < 0.01), and NLRP3 levels (r = 0.312, p < 0.001). Coromarker expression was found to be linked with MMP-9 (r = 0.260, p < 0.01) and sCD40L (r = 0.441, p < 0.001).

CONCLUSION

Circulating lncRNA Coromarker expression correlates with increased disease severity and inflammation as well as plaque vulnerability in patients with CAD.

Targeting Circulating lncRNA ENST00000538705.1 Relieves Acute Coronary Syndrome via Modulating ALOX15

Objective

Acute coronary syndrome (ACS) is the most dangerous and deadly form of coronary heart disease. Herein, we aimed to explore ACS-specific circulating lncRNAs and their regulatory mechanisms.

Methods

This study collected serum samples from ACS patients and healthy controls for microarray analysis. Dysregulated circulating lncRNAs and mRNAs were determined with |log2fold − change| > 1 and p < 0.05. lncRNA-mRNA coexpression analysis was carried out. ENST00000538705.1 and ALOX15 expression was further verified in serum specimens. In human coronary artery endothelial cells (HCAECs), ENST00000538705.1 and ALOX15 were knocked out through transfecting specific siRNAs. Thereafter, proliferation and migration were investigated with CCK-8 and wound-healing assays. Myocardial infarction rat models were established and administrated with siRNAs against ENST00000538705.1 or ALOX15. Myocardial damage was investigated with H&E staining, and serum TC, LDL, and HDL levels were measured.

Results

Microarray analysis identified 353 dysregulated circulating lncRNAs and 441 dysregulated circulating mRNAs in ACS. Coexpression analysis indicated the interaction between ENST00000538705.1 and ALOX15. RT-qPCR confirmed the remarkable upregulation of circulating ENST00000538705.1 and ALOX15 in ACS patients. In HCAECs, ENST00000538705.1 knockdown lowered the expression of ALOX15 but ALOX15 did not alter the expression of ENST00000538705.1. Silencing ENST00000538705.1 or ALOX15 weakened the proliferation and migration of HCAECs. Additionally, knockdown of ENST00000538705.1 or ALOX15 relieved myocardial damage, decreased serum TC and LDL levels, and elevated HDL levels in myocardial infarction rats.

Conclusion

Collectively, our findings demonstrate that circulating ENST00000538705.1 facilitates ACS progression through modulating ALOX15, which provide potential targets for ACS treatment.

Long noncoding RNAs regulated spermatogenesis in varicocele-induced spermatogenic dysfunction

Objectives

To evaluate the expression, potential functions and mechanisms of long noncoding RNAs (lncRNAs) in the pathogenesis of varicocele (VC)‐induced spermatogenic dysfunction.

Materials and Methods

We established a rat model with left experimental VC and divided rats into the sham group, the VC group, and the surgical treatment group (each group, n = 10). Haematoxylin and eosin (HE) staining and sperm quality were analysed to evaluate spermatogenesis function. LncRNA expression profiles were analysed using lncRNA‐Seq (each group n = 3) and validated using quantitative real‐time polymerase chain reaction (each group n = 10). Correlation analysis and gene target miRNA prediction were used to construct competing endogenous RNA network. The regulated signalling pathway and spermatogenic dysfunction of differentially expressed lncRNAs (DE lncRNAs) were validated by Western blot.

Results

HE detection and sperm quality analysis showed that VC could induce spermatogenic dysfunction. Eight lncRNAs were upregulated and three lncRNAs were downregulated in the VC group compared with the sham group and surgical treatment group. The lncRNA of NONRATG002949.2, NONRATG001060.2, NONRATG013271.2, NONRATG022879.2, NONRATG023424.2, NONRATG005667.2 and NONRATG010686.2 were significantly negatively related to sperm quality, while NONRATG027523.1, NONRATG017183.2 and NONRATG023747.2 were positively related to sperm quality. The lncRNAs promote spermatogenic cell apoptosis and inhibit spermatogonia and spermatocyte proliferation and meiotic spermatocytes by regulating the PI3K–Akt signalling pathway.

Conclusion

DE lncRNAs may be potential biomarkers for predicting the risk of spermatogenic dysfunction in VC and the effect of surgical repair. These DE lncRNAs promote spermatogenic dysfunction by regulating the PI3K–Akt signalling pathway.

Characterization of LncRNA expression profile and identification of functional LncRNAs associated with unstable angina

Background

Increasing evidences suggest that long noncoding RNAs (lncRNAs) play critical roles in the pathogenesis of coronary artery disease (CAD). However, the association between lncRNAs expression profiles and unstable angina (UA) remained poorly known. Thus, the present study aims to investigate expression patterns, biological functions, and diagnostic value of lncRNAs in UA.

Methods

The present study explored the lncRNA and mRNA expression profiles in peripheral blood mononuclear cells (PBMCs) of UA patients and normal coronary artery (NCA) controls using RNA‐seq. The biological function of differentially expressed lncRNAs was analyzed using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The expression of the selected lncRNAs was validated in another 44 UA patients and 46 NCA controls. Receiver operating characteristic curve (ROC) was performed to evaluate the diagnostic value of lncRNAs for UA.

Results

A total of 98 lncRNAs and 615 mRNAs were observed differentially expressed in PBMCs of UA patients as compared to NCA controls. The 10 most upregulated lncRNAs were LNC_000226, DANCR, RP1‐167A14.2, LNC_002091, LNC_001526, LNC_001165, LNC_002772, LNC_000088, LNC_001226, and FAM157C, and the 10 most downregulated lncRNAs were RP11‐734I18.1, RP11‐185E8.1, RP11‐360I2.1, LNC_001302, LNC_001287, RN7SL471P, LNC_000914, LINC01506, RP11‐160E2.6, and LNC_000995. LNC_000226 and MALAT1 have high area under the curve values (AUC) for distinguishing UA from NCA patients (0.810 and 0.799, respectively), and the combination of MALAT1 and LNC_000226 increased the AUC value to 0.878.

Conclusions

The present study added our understanding about the lncRNA expression profile in UA patients and provided potential biomarkers for the diagnosis of UA.