Differential expression profile of long non-coding RNAs in human thoracic aortic aneurysm

Pathogenetic Significance of Long Non-Coding RNAs in the Development of Thoracic and Abdominal Aortic Aneurysms

Aortic aneurysm (AA) is a life-threatening condition with a high prevalence and risk of severe complications. The aim of this review was to summarize the data on the role of long non-coding RNAs (lncRNAs) in the development of AAs of various location. Within less than a decade of studies on the role of lncRNAs in AA, using experimental and bioinformatic approaches, scientists have obtained the data confirming the involvement of these molecules in metabolic pathways and pathogenetic mechanisms critical for the aneurysm development. Regardless of the location of pathological process (thoracic or abdominal aorta), AA was found to be associated with changes in the expression of various lncRNAs in the tissue of the affected vessels. The consistency of changes in the expression level of lncRNA, mRNA and microRNA in aortic tissues during AA development has been recordedand regulatory networks implicated in the AA pathogenesis in which lncRNAs act as competing endogenous RNAs (ceRNA networks) have been identified. It was found that the same lncRNA can be involved in different ceRNA networks and regulate different biochemical and cellular events; on the other hand, the same pathological process can be controlled by different lncRNAs. Despite some similarities in pathogenesis and overlapping of involved lncRNAs, the ceRNA networks described for abdominal and thoracic AA are different. Interactions between lncRNAs and other molecules, including those participating in epigenetic processes, have also been identified as potentially relevant to the AA pathogenesis. The expression levels of some lncRNAs were found to correlate with clinically significant aortic features and biochemical parameters. Identification of regulatory RNAs functionally significant in the aneurysm development is important for clarification of disease pathogenesis and will provide a basis for early diagnostics and development of new preventive and therapeutic drugs.

NEAT1 boosts the development of thoracic 1 aortic aneurysm through targeting miR-324-5p/RAN

BACKGROUND

Long non-coding RNAs (lncRNAs) have been identified in multiple cancers. Recently, NEAT1 is found to be up regulated in cervical cancer. Since the relationship between NEAT1 and thoracic aortic aneurysm (TAA) has not been clarified, our study focused on the role of NEAT1 in TAA.

METHODS

Bioinformatics, RNA pulls down and luciferase reporter assay were used to discover and determine miR-324-5p to be a target of NEAT1. RT-qPCR was used to examine NEAT1, RAN and miR-324-5p expression.

RESULTS

NEAT1 was up-regulated in TAA patients, as well as HAoSMC and HA-VSMC cells. Down-regulation of NEAT1 could inhibit the proliferative abilities while promoting apoptosis of TAA cells. MiR-324-5p expression was down-regulated in both TAA tissues and cells. Then, RAN was selected out as a target of miR-324-5p. More interestingly, miR-324-5p had inhibitory effects on malignant behaviors of TAA cells. RAN was negatively related with miR-324-5p while positively correlated with NEAT1 in the tissues. Finally, the data of rescue assays manifested that RAN up-regulation could countervail the influence of down-regulation of NEAT1 on TAA cells.

CONCLUSION

NEAT1 could contribute to the malignant behaviors of TAA cells by targeting miR-324-5p/RAN. NEAT1 might be an underlying target for the therapy of TAA.

Helicase-like transcription factor-deletion from the tumor microenvironment in a cell line-derived xenograft model of colorectal cancer reprogrammed the human transcriptome-S-nitroso-proteome to promote inflammation and redirect metastasis

Methylation of the HLTF gene in colorectal cancer (CRC) cells occurs more frequently in men than women. Progressive epigenetic silencing of HLTF in tumor cells is accompanied by negligible expression in the tumor microenvironment (TME). Cell line-derived xenografts (CDX) were established in control (Hltf+/+) and Hltf-deleted male Rag2-/-IL2rg-/- mice by direct orthotopic cell microinjection (OCMI) of HLTF+/+HCT116 Red-FLuc cells into the submucosa of the cecum. Combinatorial induction of IL6 and S100A8/A9 in the Hltf-deleted TME with ICAM-1 and IL8 in the primary tumor activated a positive feedback loop. The proinflammatory niche produced a major shift in CDX metastasis to peritoneal dissemination compared to controls. Inducible nitric oxide (iNOS) gene expression and transactivation of the iNOS-S100A8/A9 signaling complex in Hltf-deleted TME reprogrammed the human S-nitroso-proteome. POTEE, TRIM52 and UN45B were S-nitrosylated on the conserved I/L-X-C-X2-D/E motif indicative of iNOS-S100A8/A9-mediated S-nitrosylation. 2D-DIGE and protein identification by MALDI-TOF/TOF mass spectrometry authenticated S-nitrosylation of 53 individual cysteines in half-site motifs (I/L-X-C or C-X-X-D/E) in CDX tumors. POTEE in CDX tumors is both a general S-nitrosylation target and an iNOS-S100A8/A9 site-specific (Cys638) target in the Hltf-deleted TME. REL is an example of convergence of transcriptomic-S-nitroso-proteomic signaling. The gene is transcriptionally activated in CDX tumors with an Hltf-deleted TME, and REL-SNO (Cys143) was found in primary CDX tumors and all metastatic sites. Primary CDX tumors from Hltf-deleted TME shared 60% of their S-nitroso-proteome with all metastatic sites. Forty percent of SNO-proteins from primary CDX tumors were variably expressed at metastatic sites. Global S-nitrosylation of proteins in pathways related to cytoskeleton and motility was strongly implicated in the metastatic dissemination of CDX tumors. Hltf-deletion from the TME played a major role in the pathogenesis of inflammation and linked protein S-nitrosylation in primary CDX tumors with spatiotemporal continuity in metastatic progression when the tumor cells expressed HLTF.

Transcribed ultraconserved region uc.242 is a novel regulator of cardiomyocyte hypertrophy induced by angiotensin II

Cardiomyocyte hypertrophy is a response to stress or hormone stimulation and is characterized by an increase of cardiomyocyte size. Abnormal long non-coding RNA (lncRNA) expression profile has been identified in various cardiovascular diseases. Though some lncRNAs had been reported to participate in regulation of cardiac hypertrophy, the universal lncRNA profile of cardiomyocyte hypertrophy had not been established. In the present study, we aimed to identify the differentially expressed lncRNA-mRNA network in angiotensin II-stimulated cardiomyocytes, and screen the potential lncRNAs involved in regulation of cardiomyocyte hypertrophy. The hypertrophic cardiomyocytes were induced by angiotensin II (0.1 μmol/L) for 48 hours. High-throughput microarray analysis combined with quantitative real-time PCR assay were then performed to screen the differentially expressed lncRNAs and mRNAs. A total of 1577 lncRNAs and 496 mRNAs transcripts were identified differentially expressed in hypertrophic cardiomyocytes. Among them, 59 transcribed ultraconserved non-coding RNAs (T-UCRs) were found by evolutionary conservation analysis. Subsequently, the lncRNA-mRNA coexpression network was constructed based on Pearson's correlation analysis results, including 4 T-UCRs and 215 mRNAs. The results revealed that uc.242 was positively interacted with prohypertrophic genes (Hgf and Tnc). Functional study showed that inhibition of uc.242 dramatically decreased hypertrophic marker expression levels and cardiomyocyte surface area under the condition of angiotensin II stimulation. The expression of Hgf and Tnc was also decreased in cardiomyocytes after silencing of uc.242. Summarily, the present study provided crucial clues to explore therapeutic targets for pathological cardiac hypertrophy.

Involvement of Myeloid Cells and Noncoding RNA in Abdominal Aortic Aneurysm Disease

Significance: Abdominal aortic aneurysm (AAA) is a potentially fatal condition, featuring the possibility of high-mortality rupture. To date, prophylactic surgery by means of open surgical repair or endovascular aortic repair at specific thresholds is considered standard therapy. Both surgical options hold different risk profiles of short- and long-term morbidity and mortality. Targeting early stages of AAA development to decelerate disease progression is desirable. Recent Advances: Understanding the pathomechanisms that initiate formation, maintain growth, and promote rupture of AAA is crucial to developing new medical therapeutic options. Inflammatory cells, in particular macrophages, have been investigated for their contribution to AAA disease for decades, whereas evidence on lymphocytes, mast cells, and neutrophils is sparse. Recently, there has been increasing interest in noncoding RNAs (ncRNAs) and their involvement in disease development, including AAA. Critical Issues: The current evidence on myeloid cells and ncRNAs in AAA largely originates from small animal models, making clinical extrapolation difficult. Although it is feasible to collect surgical human AAA samples, these tissues reflect end-stage disease, preventing examination of critical mechanisms behind early AAA formation. Future Directions: Gaining more insight into how myeloid cells and ncRNAs contribute to AAA disease, particularly in early stages, might suggest nonsurgical AAA treatment options. The utilization of large animal models might be helpful in this context to help bridge translational results to humans.

The Role of Long Non-Coding RNAs in Intracranial Aneurysms and Subarachnoid Hemorrhage

Intracranial aneurysms (IAs) represent the most complex and relevant problem of modern neurology and neurosurgery. They serve as one of the main causes of non-traumatic subarachnoid hemorrhage (SAH), causing up to 85% of all cases of intracranial hemorrhage, which is associated with frequent disability and high mortality among patients. Unfortunately, the molecular mechanisms of the development and rupture of IAs are still under study. Long non-coding RNAs (lncRNAs) are non-coding RNAs that typically have a length of more than 200 nucleotides. It is known that lncRNAs regulate many processes, such as transcription, translation, cell differentiation, regulation of gene expression, and regulation of the cell cycle. In recent years, a lot of evidence has established their role in human diseases from oncology to cardiovascular disease. Recent studies have shown that lncRNAs may be involved in the pathogenesis of IAs. The study of lncRNAs and its targets in various pathological conditions of a person is a rapidly developing field, and it is likely that the knowledge obtained from these studies regarding the pathogenesis of intracranial aneurysms will have the potential to use lncRNAs in therapy, as well as in the diagnosis and prediction of high aneurysms risk of rupture.

Dysregulated long non-coding RNAs involved in regulation of matrix degradation during type-B aortic dissection pathogenesis

Thoracic aortic dissection (TAD) is a catastrophic disease with the rupture of aortic media resulted mainly from the degradation of extracellular matrix. With the deep study of long non-coding RNAs (lncRNAs) in cardiovascular diseases, the correlation between lncRNAs and the TAD pathogenesis is under revealed. In this study, we aimed to screen the differentially expressed lncRNAs involved in the regulation of matrix degradation during type-B aortic dissection (TBAD), whose pathogenesis is more similar to atherosclerosis. A total of 393 aberrantly expressed lncRNAs and 432 aberrantly expressed mRNAs were identified in the descending aortic samples from TBAD patients. Then, co-expression analysis was applied to analyze the correlation between the top five differentially expressed lncRNAs and aberrantly expressed mRNAs, so as to screen the lncRNAs involved in the regulation of matrix degradation. The results showed that two transcripts from lnc-TNFSF14 (lnc-TNFSF14-2, and lnc-TNFSF14-3) were negatively interacted with MMP14 and MMP19. Subsequently, quantitative real-time PCR assay confirmed that lnc-TNFSF14-2 were negatively correlated with MMP14 (r_s = - 0.8180) and MMP19 (r_s = - 0.8449), and lnc-TNFSF14-3 was also negatively correlated with MMP14 (r_s = - 0.7098) and MMP19 (r_s = - 0.7728) in descending aorta from TBAD patients (n = 20). Overall, our study found the aberrant lncRNAs expression profiles in TBAD, and identified lnc-TNFSF14 as a potential target regulating matrix degradation. The results also provided crucial clues for lncRNAs function research on TBAD development.

Long Noncoding RNAs CARMN, LUCAT1, SMILR, and MALAT1 in Thoracic Aortic Aneurysm: Validation of Biomarkers in Clinical Samples

Materials and Methods

Relative expression of lncRNAs CARMN, LUCAT1, SMILR, and MALAT1 was tested in clinical aortic tissue and blood plasma samples from TAA and non-TAA patients using the qRT-PCR method. The Mann–Whitney U test was used to compare ΔCt values between the study groups. ROC curve analysis was performed to evaluate the diagnostic value of plasma lncRNAs.

Results

We found significantly reduced CARMN (p = 0.033) and LUCAT1 (p = 0.009) expression in aortic tissue samples from TAA patients. Relative expression of MALAT1 (p = 0.117) and SMILR (p = 0.610) did not differ in aortic tissue between the TAA and non-TAA groups. Expression of both LUCAT1 and SMILR was significantly decreased in TAA patients' blood plasma compared to controls (p = 0.018 and p = 0.032, respectively). However, only LUCAT1 showed the ability to discriminate aneurysmal disease in patients' blood plasma (AUC = 0.654, 95%CI = 0.534‐0.775, p = 0.018).

Conclusions

We have shown that the expression of lncRNAs CARMN and LUCAT1 is reduced in dilated aortic tissue and that the LUCAT1 and SMILR expression is lower in the blood plasma of TAA patients. Decreased LUCAT1 expression in TAA patients' blood plasma may have diagnostic potential in discriminating patients with TAA.

Inhibition of HIF1A-AS1 promoted starvation-induced hepatocellular carcinoma cell apoptosis by reducing HIF-1α/mTOR-mediated autophagy

BACKGROUND

Hepatocellular carcinoma (HCC) is still a major health burden in China considering its high incidence and mortality. Long non-coding RNAs (lncRNAs) were found playing vital roles in tumor progression, suggesting a new way of diagnosis and prognosis prediction, or treatment of HCC. This study was designed to investigate the role of HIF1A-AS1 during the progression of HCC and to explore its related mechanisms.

METHODS

The expression of HIF1A-AS1 was detected in 50 paired carcinoma tissues and adjacent normal tissues by quantitative real-time PCR assay. HCC cell apoptosis was induced by nutrient-deficient culture medium and detected by Cell Counting Kit-8 and flow cytometer assays. HIF1A-AS1 inhibition in HCC cells was accomplished by small interfering RNA transfection.

RESULTS

HIF1A-AS1 was overexpressed in HCC tissues and was associated with tumor size, TNM stage, and lymph node metastasis. Compared with the low HIF1A-AS1 group, the high HIF1A-AS1 group had a shorter overall survival and a worse disease-free survival. HIF1A-AS1 expression was significantly higher in HCC cell lines (7721 and Huh7) than that in normal hepatocyte cell line L02 under normal culture condition. However, under nutrient-deficient condition, HIF1A-AS1 expression was significantly increased in both HCC and normal hepatocyte cell lines and was increased with the prolongation of nutrient-free culture. Inhibition of HIF1A-AS1 promoted starvation-induced HCC cell apoptosis. Furthermore, inhibition of HIF1A-AS1 could also reduce starvation-induced HCC cell autophagy. The expression of HIF-1α and phosphorylated mTOR was significantly decreased in HCC cells after HIF1A-AS1 inhibition.

CONCLUSIONS

HIF1A-AS1, overexpressed in HCC and associated with HCC prognosis, could regulate starvation-induced HCC cell apoptosis by reducing HIF-1α/mTOR-mediated autophagy, promoting HCC cell progression.

Long Noncoding RNAs in Pathological Cardiac Remodeling: A Review of the Update Literature

Cardiac remodeling is a self-regulatory response of the myocardium and vasculature under the stressful condition. Cardiomyocytes (CMs), vascular smooth muscle cells (VSMCs), endothelial cells (ECs), and cardiac fibroblasts (CFs) are all involved in this process, characterized by change of morphological structures and mechanical/chemical activities as well as metabolic patterns. Despite current development of consciousness, the control of cardiac remodeling remains unsatisfactory, and to further explore the underlying mechanism and seek the optimal therapeutic targets is still the urgent need in clinical practice. It is now emerging that long noncoding RNAs (lncRNAs) play key regulatory roles in these adverse responses: lncRNA TUG1, AK098656, TRPV1, GAS5, Giver, and Lnc-Ang362 have been indicated in hypertension-related vascular remodeling, H19, TUG1, UCA1, MEG3, APPAT, and lincRNA-p21 in atherosclerosis (AS), and HIF1A-AS1 and Lnc-HLTF-5 in aortic aneurysm (AA). In addition, Neat1, AK139328, APF, CAIF, AK088388, CARL, MALAT1, HOTAIR, XIST, and NRF are involved in postischemia myocardial remodeling, while Mhrt, Chast, CHRF, ROR, H19, Plscr4, and MIAT are involved in myocardial hypertrophy, and MALAT1, wisper, MEG3, and H19 are involved in extracellular matrix (ECM) reconstitution. Signaling to specific miRNAs by acting as endogenous sponge (ceRNA) was the main form that regulates the target gene expression during cardiac remodeling. This review will underline the updates of lncRNAs and lncRNA-miRNA interactions in maladaptive remodeling and also cast light on their potential roles as therapeutic targets, hoping to provide supportive background for following research.

RNA-Seq analysis and functional characterization revealed lncRNA NONRATT007560.2 regulated cardiomyocytes oxidative stress and apoptosis induced by high glucose

Hyperglycemia in diabetic patients would cause cardiomyocytes oxidative stress and apoptosis due to the excessive reactive oxygen species (ROS) accumulation, leading to progressive deterioration of cardiac structure and function. Long noncoding RNAs (lncRNAs) play essential roles on controlling oxidative stress and apoptotic activity. In the present study, RNA sequencing was used to detect the differentially expressed lncRNAs during high glucose-induced cardiomyocytes oxidative stress and apoptosis. A total of 306/400 lncRNAs were identified as differentially expressed, including 156/198 lncRNAs with increased expression and 150/202 lncRNAs with decreased expression at 24 hours/48 hours after high-glucose stimulation respectively. Among these dysregulated lncRNAs, 45 lncRNAs were consistently differentially expressed in cardiomyocytes at both two time points after high-glucose stimulation. Twenty lncRNAs were upregulated and 25 lncRNAs were downregulated at both 24 hours and 48 hours, respectively. The top three upregulated lncRNAs, NONRATT029805.2, NONRATT007560.2, and NONRATT002486.2 were selected for functional studies to determine the role in oxidative stress-related apoptosis. The results showed that inhibition of non-ratt007560.2 could abate the formation of ROS and reduce apoptosis, suggesting NONRATT007560.2 might play critical roles in the development of cardiomyopathy. The dysregulated lncRNAs might participate in regulating cardiomyocytes oxidative stress and apoptosis. These findings would be important theoretical and experimental basis for investigation on diabetic cardiomyopathy pathogenesis.

Role of Noncoding RNAs in the Pathogenesis of Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a local dilatation of the abdominal aortic vessel wall and is among the most challenging cardiovascular diseases as without urgent surgical intervention, ruptured AAA has a mortality rate of >80%. Most patients present acutely after aneurysm rupture or dissection from a previously asymptomatic condition and are managed by either surgery or endovascular repair. Patients usually are old and have other concurrent diseases and conditions, such as diabetes mellitus, obesity, and hypercholesterolemia making surgical intervention more difficult. Collectively, these issues have driven the search for alternative methods of diagnosing, monitoring, and treating AAA using therapeutics and less invasive approaches. Noncoding RNAs-short noncoding RNAs (microRNAs) and long-noncoding RNAs-are emerging as new fundamental regulators of gene expression. Researchers and clinicians are aiming at targeting these microRNAs and long noncoding RNAs and exploit their potential as clinical biomarkers and new therapeutic targets for AAAs. While the role of miRNAs in AAA is established, studies on long-noncoding RNAs are only beginning to emerge, suggesting their important yet unexplored role in vascular physiology and disease. Here, we review the role of noncoding RNAs and their target genes focusing on their role in AAA. We also discuss the animal models used for mechanistic understanding of AAA. Furthermore, we discuss the potential role of microRNAs and long noncoding RNAs as clinical biomarkers and therapeutics.