Silencing of long non-coding RNA Sox2ot inhibits oxidative stress and inflammation of vascular smooth muscle cells in abdominal aortic aneurysm via microRNA-145-mediated Egr1 inhibition

The emerging role of long non-coding RNA SOX2-OT in cancers and non-malignant diseases

SOX2 overlapping transcript (SOX2-OT) is a long non-coding RNA located at chromosome 3q26.33 in humans. Convincing data confirm that SOX2-OT is evolutionarily conserved and plays a significant role in various malignant and non-malignant diseases. In most cancers, the upregulation of SOX2-OT acts as an oncogenic factor, strongly correlating with tumor risk, adverse clinicopathological features, and poor prognosis. Mechanistically, SOX2-OT is regulated by seven transcription factors and influences cellular behavior by modulating SOX2 expression, competitively binding 20 types of miRNAs, stabilizing protein expression, or promoting protein ubiquitination. It also participates in epigenetic modifications and activates multiple signaling pathways to regulate cancer cell proliferation, apoptosis, migration, invasion, autophagy, immune evasion, and resistance to chemotherapy/targeted therapies. Additionally, SOX2-OT triggers apoptosis, oxidative stress, and inflammatory responses, contributing to neurodevelopmental disorders, cardiovascular diseases, and diabetes-related conditions. Genetic polymorphisms of SOX2-OT have also been linked to breast cancer, gastric cancer, recurrent miscarriage, sepsis, and eating disorders in patients with bipolar disorder. This review provides an overview of recent research progress on SOX2-OT in human diseases, highlights its substantial potential as a prognostic and diagnostic biomarker, and explores its future clinical applications.

Non-coding RNAs to treat vascular smooth muscle cell dysfunction

Vascular smooth muscle cell (vSMC) dysfunction is a critical contributor to cardiovascular diseases, including atherosclerosis, restenosis and vein graft failure. Recent advances have unveiled a fascinating range of non-coding RNAs (ncRNAs) that play a pivotal role in regulating vSMC function. This review aims to provide an in-depth analysis of the mechanisms underlying vSMC dysfunction and the therapeutic potential of various ncRNAs in mitigating this dysfunction, either preventing or reversing it. We explore the intricate interplay of microRNAs, long-non-coding RNAs and circular RNAs, shedding light on their roles in regulating key signalling pathways associated with vSMC dysfunction. We also discuss the prospects and challenges associated with developing ncRNA-based therapies for this prevalent type of cardiovascular pathology. LINKED ARTICLES: This article is part of a themed issue Non-coding RNA Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v182.2/issuetoc.

Early growth response 1 exacerbates thoracic aortic aneurysm and dissection of mice by inducing the phenotypic switching of vascular smooth muscle cell through the activation of Krüppel-like factor 5

AIM

Vascular smooth muscle cell (VSMC) phenotypic switching has been reported to regulate vascular function and thoracic aortic aneurysm and dissection (TAAD) progression. Early growth response 1 (Egr1) is associated with the differentiation of VSMCs. However, the mechanisms through which Egr1 participates in the regulation of VSMCs and progression of TAAD remain unknown. This study aimed to investigate the role of Egr1 in the phenotypic switching of VSMCs and the development of TAAD.

METHODS

Wild-type C57BL/6 and SMC-specific Egr1-knockout mice were used as experimental subjects and fed β-aminopropionitrile for 4 weeks to construct the TAAD model. Ultrasound and aortic staining were performed to examine the pathological features in thoracic aortic tissues. Transwell, wound healing, CCK8, and immunofluorescence assays detected the migration and proliferation of synthetic VSMCs. Egr1 was directly bound to the promoter of Krüppel-like factor 5 (KLF5) and promoted the expression of KLF5, which was validated by JASPAR database and dual-luciferase reporter assay.

RESULTS

Egr1 expression increased and was partially co-located with VSMCs in aortic tissues of mice with TAAD. SMC-specific Egr1 deficiency alleviated TAAD and inhibited the phenotypic switching of VSMC. Egr1 knockdown prevented the phenotypic switching of VSMCs and subsequently suppressed the migration and proliferation of synthetic VSMCs. The inhibitory effects of Egr1 deficiency on VSMCs were blunted once KLF5 was overexpressed.

CONCLUSION

Egr1 aggravated the development of TAAD by promoting the phenotypic switching of VSMCs via enhancing the transcriptional activation of KLF5. These results suggest that inhibition of SMC-specific Egr1 expression is a promising therapy for TAAD.

miR-124-3p downregulates EGR1 to suppress ischemia-hypoxia reperfusion injury in human iPS cell-derived cardiomyocytes

Ischemic heart diseases are a major global cause of death, and despite timely revascularization, heart failure due to ischemia-hypoxia reperfusion (IH/R) injury remains a concern. The study focused on the role of Early Growth Response 1 (EGR1) in IH/R-induced apoptosis in human cardiomyocytes (CMs). Human induced pluripotent stem cell (hiPSC)-derived CMs were cultured under IH/R conditions, revealing higher EGR1 expression in the IH/R group through quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting (WB). Immunofluorescence analysis (IFA) showed an increased ratio of cleaved Caspase-3-positive apoptotic cells in the IH/R group. Using siRNA for EGR1 successfully downregulated EGR1, suppressing cleaved Caspase-3-positive apoptotic cell ratio. Bioinformatic analysis indicated that EGR1 is a plausible target of miR-124-3p under IH/R conditions. The miR-124-3p mimic, predicted to antagonize EGR1 mRNA, downregulated EGR1 under IH/R conditions in qRT-PCR and WB, as confirmed by IFA. The suppression of EGR1 by the miR-124-3p mimic subsequently reduced CM apoptosis. The study suggests that treatment with miR-124-3p targeting EGR1 could be a potential novel therapeutic approach for cardioprotection in ischemic heart diseases in the future.

Epigenetic modifications in abdominal aortic aneurysms: from basic to clinical

Abdominal Aortic Aneurysm (AAA) is a disease characterized by localized dilation of the abdominal aorta, involving multiple factors in its occurrence and development, ultimately leading to vessel rupture and severe bleeding. AAA has a high mortality rate, and there is a lack of targeted therapeutic drugs. Epigenetic regulation plays a crucial role in AAA, and the treatment of AAA in the epigenetic field may involve a series of related genes and pathways. Abnormal expression of these genes may be a key factor in the occurrence of the disease and could potentially serve as promising therapeutic targets. Understanding the epigenetic regulation of AAA is of significant importance in revealing the mechanisms underlying the disease and identifying new therapeutic targets. This knowledge can contribute to offering AAA patients better clinical treatment options beyond surgery. This review systematically explores various aspects of epigenetic regulation in AAA, including DNA methylation, histone modification, non-coding RNA, and RNA modification. The analysis of the roles of these regulatory mechanisms, along with the identification of relevant genes and pathways associated with AAA, is discussed comprehensively. Additionally, a comprehensive discussion is provided on existing treatment strategies and prospects for epigenetics-based treatments, offering insights for future clinical interventions.

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.

P-MSC-derived extracellular vesicles facilitate diabetic wound healing via miR-145-5p/ CDKN1A-mediated functional improvements of high glucose-induced senescent fibroblasts

Background

Persistent hyperglycaemia in diabetes causes functional abnormalities of human dermal fibroblasts (HDFs), partially leading to delayed skin wound healing. Extracellular vesicles (EVs) containing multiple pro-healing microRNAs (miRNAs) have been shown to exert therapeutic effects on diabetic wound healing. The present study aimed to observe the effects of EVs derived from placental mesenchymal stem cells (P-MSC-EVs) on diabetic wound healing and high glucose (HG)-induced senescent fibroblasts and to explore the underlying mechanisms.

Methods

P-MSC-EVs were isolated by differential ultracentrifugation and locally injected into the full-thickness skin wounds of diabetic mice, to observe the beneficial effects on wound healing in vivo by measuring wound closure rates and histological analysis. Next, a series of assays were conducted to evaluate the effects of low (2.28 x 1010 particles/ml) and high (4.56 x 1010 particles/ml) concentrations of P-MSC-EVs on the senescence, proliferation, migration, and apoptosis of HG-induced senescent HDFs in vitro. Then, miRNA microarrays and real-time quantitative PCR (RT-qPCR) were carried out to detect the differentially expressed miRNAs in HDFs after EVs treatment. Specific RNA inhibitors, miRNA mimics, and small interfering RNA (siRNA) were used to evaluate the role of a candidate miRNA and its target genes in P-MSC-EV-induced improvements in the function of HG-induced senescent HDFs.

Results

Local injection of P-MSC-EVs into diabetic wounds accelerated wound closure and reduced scar widths, with better-organized collagen deposition and decreased p16INK4a expression. In vitro, P-MSC-EVs enhanced the antisenescence, proliferation, migration, and antiapoptotic abilities of HG-induced senescent fibroblasts in a dose-dependent manner. MiR-145-5p was found to be highly enriched in P-MSC-EVs. MiR-145-5p inhibitors effectively attenuated the P-MSC-EV-induced functional improvements of senescent fibroblasts. MiR-145-5p mimics simulated the effects of P-MSC-EVs on functional improvements of fibroblasts by suppressing the expression of cyclin-dependent kinase inhibitor 1A and activating the extracellular signal regulated kinase (Erk)/protein kinase B (Akt) signaling pathway. Furthermore, local application of miR-145-5p agomir mimicked the effects of P-MSC-EVs on wound healing.

Conclusions

These results suggest that P-MSC-EVs accelerate diabetic wound healing by improving the function of senescent fibroblasts through the transfer of miR-145-5p, which targets cyclin-dependent kinase inhibitor 1A to activate the Erk/Akt signaling pathway. P-MSC-EVs are promising therapeutic candidates for diabetic wound treatment.

Human umbilical cord mesenchymal stem cell-derived extracellular vesicles improve ovarian function in rats with primary ovarian insufficiency by carrying miR-145-5p

OBJECTIVE

Stem cell/exosome therapy is a novel strategy for primary ovarian insufficiency (POI). This paper is to examine the role of human umbilical cord mesenchymal stem cell-derived extracellular vesicles (hUCMSC-EVs) in POI.

METHODS

hUCMSC-EVs were extracted and identified. POI rats were induced by cyclophosphamide for 15 days and treated with EV or GW4869 every 5 days and euthanized 28 days later. Vaginal smears were observed for 21 days. Serum hormone levels (FSH/E2/AMH) were measured by ELISA. Ovarian morphology, follicle numbers, and granulosa cell (GC) apoptosis were observed by HE and TUNEL staining. GCs extracted from Swiss albino rats were cyclophosphamide-induced to establish the POI cell model, followed by oxidative injury and apoptosis evaluation with the help of DCF-DA fluorescence, ELISA, and flow cytometry. The relation between miR-145-5p and XBP1 was predicted on StarBase and validated by dual-luciferase assay. miR-145-5p and XBP1 levels were measured by RT-qPCR and Western blot.

RESULTS

EV treatment reduced irregular estrus cycle incidence since day 7, increased E2 and AMH levels and all-stage follicle numbers, reduced FSH level, GC apoptosis, and atretic follicle numbers in POI rats. EV treatment diminished GC oxidative injury and apoptosis in vitro. miR-145-5p knockdown in hUCMSC-EVs partly abolished hUCMSC-EV-mediated effects on GCs and ovarian function in vivo and on GC oxidative injury and apoptosis in vitro. Silencing XBP1 partially negated miR-145-5p knockdown-exerted effects on GCs in vitro.

CONCLUSION

miR-145-5p carried by hUCMSC-EVs attenuates GC oxidative injury and apoptosis and thus extenuates ovarian injury and improves ovarian function in POI rats.

LncRNAs associated with oxidative stress in diabetic wound healing: Regulatory mechanisms and application prospects

Diabetes is a group of chronic diseases with blood glucose imbalance, and long-term hyperglycaemia causes sustained damage to various organs of the body, resulting in vascular lesions, neuropathy and impaired wound healing. Diabetic wound formation involves a variety of complex mechanisms, and they are characterized by a persistent chronic inflammatory response, degradation of angiogenesis and imbalance of extracellular matrix regulation, all of which are related to oxidative stress. Additionally, repair and healing of diabetic wounds require the participation of a variety of cells, cytokines, genes, and other factors, which together constitute a complex biological regulatory network. Recent studies have shown that long noncoding RNAs (lncRNAs) can be involved in the regulation of several key biological pathways and cellular functions demonstrating their critical role in diabetic wound healing. LncRNAs are a major family of RNAs with limited or no protein-coding function. Numerous studies have recently reported a strong link between oxidative stress and lncRNAs. Given that both lncRNAs and oxidative stress have been identified as potential drivers of diabetic wound healing, their link in diabetic wound healing can be inferred. However, the specific mechanism of oxidative stress related to lncRNAs in diabetic wound healing is still unclear, and elucidating the functions of lncRNAs in these processes remains a major challenge. This article reviews the mechanisms of lncRNAs related to oxidative stress in several stages of diabetic wound healing and discusses diagnostic and treatment potential of lncRNAs to treat diabetic wounds by improving oxidative stress, as well as the challenges of using lncRNAs for this purpose. It is hoped that these results will provide new targets and strategies for the diagnosis and treatment of impaired wound healing in diabetic patients.

What has single-cell transcriptomics taught us about long non-coding RNAs in the ventricular-subventricular zone?

Long non-coding RNA (lncRNA) function is mediated by the process of transcription or through transcript-dependent associations with proteins or nucleic acids to control gene regulatory networks. Many lncRNAs are transcribed in the ventricular-subventricular zone (V-SVZ), a postnatal neural stem cell niche. lncRNAs in the V-SVZ are implicated in neurodevelopmental disorders, cancer, and brain disease, but their functions are poorly understood. V-SVZ neurogenesis capacity declines with age due to stem cell depletion and resistance to neural stem cell activation. Here we analyzed V-SVZ transcriptomics by pooling current single-cell RNA-seq data. They showed consistent lncRNA expression during stem cell activation, lineage progression, and aging. In conjunction with epigenetic and genetic data, we predicted V-SVZ lncRNAs that regulate stem cell activation and differentiation. Some of the lncRNAs validate known epigenetic mechanisms, but most remain uninvestigated. Our analysis points to several lncRNAs that likely participate in key aspects of V-SVZ stem cell activation and neurogenesis in health and disease.

Identification of differentially expressed ferroptosis-related genes in abdominal aortic aneurysm: Bioinformatics analysis

Purpose

Ferroptosis plays a crucial role in the development and progression of abdominal aortic aneurysm (AAA). The aim of this study was to identify differentially expressed genes associated with ferroptosis in AAA through bioinformatics analysis combined with experimental validation.

Materials and methods

Firstly, the mRNA expression profile datasets GSE57691 and GSE47472 from Gene Expression Omnibus database were screened, and principal component analysis was carried out. Next, the R software (version 4.0.0) was used to analyze potentially differentially expressed genes associated with AAA and ferroptosis. Subsequently, protein–protein interaction analysis, gene ontology enrichment analysis, and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were performed on the selected candidate genes. Finally, quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression levels of the first five selected abnormal ferroptosis-related genes in clinical samples obtained from patients with AAA and healthy controls.

Results

Based on the information contained in the two datasets, a total of 20 differentially expressed ferroptosis-related genes (three upregulated genes and 17 downregulated genes) were selected. Protein–protein interaction analysis demonstrated interaction between these genes, while gene ontology enrichment analysis of ferroptosis genes with differential expression indicated that some enrichment items were associated with oxidative stress. The qRT-PCR results showed that the expression levels of interleukin-6 (IL-6), peroxiredoxin 1 (PRDX1), and stearoyl-CoA desaturase (SCD) were consistent with the bioinformatics prediction results obtained from the mRNA chip.

Conclusion

Bioinformatics analysis identified 20 potential ferroptosis-related differentially expressed genes in AAA. Further verification by qRT-PCR showed that IL-6, PRXD1, and SCD might affect the process of AAA by regulating ferroptosis. Our results might assist in further understanding the pathogenesis of AAA and guiding treatment.

EZH2 Regulates ANXA6 Expression via H3K27me3 and Is Involved in Angiotensin II-Induced Vascular Smooth Muscle Cell Senescence

Objectives

Abdominal aortic aneurysm (AAA) has a high risk of rupture of the aorta and is one of the leading causes of death in older adults. This study is aimed at confirming the influence and mechanism of the abnormally expressed ANXA6 gene in AAA.

Methods

Clinical samples were collected for proteome sequencing to screen for differentially expressed proteins. An Ang II-induced vascular smooth muscle cell (VSMC) aging model as well as an AAA animal model was used. Using RT-qPCR to detect the mRNA levels of EZH2, ANXA6, IK-6, and IL-8 in cells and tissues were assessed. Western blotting and immunohistochemistry staining were used apply for the expression of associated proteins in cells and tissues. SA-β-gal staining, flow cytometry, and DHE staining were used to detect senescent cells and the level of ROS. The cell cycle was assessed by flow cytometry. Arterial pathology was observed by HE staining. The aging of VSMCs in arterial tissue was assessed by coimmunofluorescence for α-SMA and p53.

Results

There were 24 differentially expressed proteins in the AAA clinical samples, including 10 upregulated protein and 14 downregulated protein, and the differential expression of ANXA6 was associated with vascular disease. Our study found that ANXA6 was highly expressed and EZH2 was lowly expressed in an Ang II-induced VSMC aging model. Knockdown of ANXA6 or overexpression of EZH2 inhibited Ang II-induced ROS, inhibited cell senescence, decreased Ang II evoked G1 arrest, and increased cells in G2 phase, while overexpression of ANXA6 played the opposite role. Overexpression of EZH2 inhibited ANXA6 expression by increasing H3K27me3 modification at the ANXA6 promoter. Simultaneous overexpression of EZH2 and the protective effect of EZH2 on cell senescence were partially reversed by ANXA6. Similarly, ANXA6 was highly expressed and EZH2 was lowly expressed in an Ang II-induced AAA animal model. Knockdown of ANXA6 and overexpression of EZH2 alleviated Ang II-induced VSMC senescence and inhibited AAA progression, while simultaneous overexpression of EZH2 and ANXA6 partially reversed the protective effect of EZH2 on AAA.

Conclusion

EZH2 regulates the ANXA6 promoter H3K27me3 modification, inhibits ANXA6 expression, alleviates Ang II-induced VSMC senescence, and inhibits AAA progression.

Comprehensive Analysis of Endoplasmic Reticulum Stress in Intracranial Aneurysm

Background

Aberrant endoplasmic reticulum stress (ERS) plays an important role in multiple cardiovascular diseases. However, their implication in intracranial aneurysms (IAs) remains unclear. We designed this study to explore the general expression pattern and potential functions of ERS in IAs.

Methods

Five Gene Expression Omnibus (GEO) microarray datasets were used as the training cohorts, and 3 GEO RNA sequencing (RNA-seq) datasets were used as the validating cohorts. Differentially expressed genes (DEGs), functional enrichment, Lasso regression, logistic regression, ROC analysis, immune cell profiling, vascular smooth muscle cell (VSMC) phenotyping, weighted gene coexpression network analysis (WGCNA), and protein-protein interaction (PPI) analysis were applied to investigate the role of ERS in IA. Finally, we predicted the upstream transcription factor (TF)/miRNA and potential drugs targeting ERS.

Results

Significant DEGs were majorly associated with ERS, autophagy, and metabolism. Eight-gene ERS signature and IRE1 pathway were identified during the IA formation. WGCNA showed that ERS was highly associated with a VSMC synthesis phenotype. Next, ERS-VSMC-metabolism-autophagy PPI and ERS-TF-miRNA networks were constructed. Finally, we predicted 9 potential drugs targeting ERS in IAs.

Conclusion

ERS is involved in IA formation. Upstream and downstream regulatory networks for ERS were identified in IAs. Novel potential drugs targeting ERS were also proposed, which may delay IA formation and progress.

Pdx1 Is Transcriptionally Regulated by EGR-1 during Nitric Oxide-Induced Endoderm Differentiation of Mouse Embryonic Stem Cells

The transcription factor, early growth response-1 (EGR-1), is involved in the regulation of cell differentiation, proliferation, and apoptosis in response to different stimuli. EGR-1 is described to be involved in pancreatic endoderm differentiation, but the regulatory mechanisms controlling its action are not fully elucidated. Our previous investigation reported that exposure of mouse embryonic stem cells (mESCs) to the chemical nitric oxide (NO) donor diethylenetriamine nitric oxide adduct (DETA-NO) induces the expression of early differentiation genes such as pancreatic and duodenal homeobox 1 (Pdx1). We have also evidenced that Pdx1 expression is associated with the release of polycomb repressive complex 2 (PRC2) and P300 from the Pdx1 promoter; these events were accompanied by epigenetic changes to histones and site-specific changes in the DNA methylation. Here, we investigate the role of EGR-1 on Pdx1 regulation in mESCs. This study reveals that EGR-1 plays a negative role in Pdx1 expression and shows that the binding capacity of EGR-1 to the Pdx1 promoter depends on the methylation level of its DNA binding site and its acetylation state. These results suggest that targeting EGR-1 at early differentiation stages might be relevant for directing pluripotent cells into Pdx1-dependent cell lineages.

EGR1 and KLF4 as Diagnostic Markers for Abdominal Aortic Aneurysm and Associated With Immune Infiltration

Background

Formation and rupture of abdominal aortic aneurysm (AAA) is fatal, and the pathological processes and molecular mechanisms underlying its formation and development are unclear. Perivascular adipose tissue (PVAT) has attracted extensive attention as a newly defined secretory organ, and we aim to explore the potential association between PVAT and AAA.

Methods

We analyzed gene expression and clinical data of 30 PVAT around AAA and 30 PVAT around normal abdominal aorta (NAA). The diagnostic markers and immune cell infiltration of PVAT were further investigated by WGCNA, CIBERSORT, PPI, and multiple machine learning algorisms (including LASSO, RF, and SVM). Subsequently, eight-week-old C57BL/6 male mice (n = 10) were used to construct AAA models, and aorta samples were collected for molecular validation. Meanwhile, fifty-five peripheral venous blood samples from patients (AAA vs. normal: 40:15) in our hospital were used as an inhouse cohort to validate the diagnostic markers by qRT-PCR. The diagnostic efficacy of biomarkers was assessed by receiver operating characteristic (ROC) curve, area under the ROC (AUC), and concordance index (C-index).

Results

A total of 75 genes in the Grey60 module were identified by WGCNA. To select the genes most associated with PVAT in the grey60 module, three algorithms (including LASSO, RF, and SVM) and PPI were applied. EGR1 and KLF4 were identified as diagnostic markers of PVAT, with high accurate AUCs of 0.916, 0.926, and 0.948 (combined two markers). Additionally, the two biomarkers also displayed accurate diagnostic efficacy in the mice and inhouse cohorts, with AUCs and C-indexes all >0.8. Compared with the NAA group, PVAT around AAA was more abundant in multiple immune cell infiltration. Ultimately, the immune-related analysis revealed that EGR1 and KLF4 were associated with mast cells, T cells, and plasma cells.

Conclusion

EGR1 and KLF4 were diagnostic markers of PVAT around AAA and associated with multiple immune cells.

Identification of potential novel biomarkers for abdominal aortic aneurysm based on comprehensive analysis of circRNA-miRNA-mRNA networks

Abdominal aortic aneurysm (AAA) is a life-threatening disorder and, therefore, investigation into its underlying mechanisms in light of the competing endogenous RNAs (ceRNAs) hypothesis has gradually increased. However, there is still lacking systematic analysis on AAA-associated circular RNA (circRNA)-microRNA (miRNA/miR)-messenger RNA (mRNA) interaction networks based on bioinformatics methods. The present study attempted to identify novel molecular biomarkers for AAA by profiling circRNA-miRNA-mRNA networks using three public microarray datasets (GSE7084, GSE57691 and GSE144431). A total of 135 differentially expressed genes (DEGs) and 142 differentially expressed circRNAs were detected using the limma R package with the statistical threshold of P<0.05 and |log₂fold change (FC)| >1.5. In addition, 12 circRNA-miRNA-mRNA axes were identified to construct upregulated and downregulated ceRNA networks using Cytoscape. Based on molecular complex detection algorithm, (hsa_circ_0057691/0092108/0006845/0082182)- miR-330-5p-calponin 1 (CNN1) and (hsa_circ_0061482/0011450/0008351/0004121)-miR-326-CD8a molecule (CD8A) were recognized as the center axes in ceRNA networks. Reverse transcription-quantitative PCR results verified the significant downregulation of CNN1 and upregulation of CD8A in human AAA tissues (P<0.05). In addition, four upregulated circRNA/mRNA axes, and five downregulated circRNA/mRNA axes were revealed to have possible biological functions in the pathogenesis of AAA using the Cytoscape software. Receiver operating characteristic analysis demonstrated the accuracy of these nine DEGs involved in these axes for AAA diagnosis with area under the curves >0.80. The present study revealed novel circRNA-miRNA-mRNA networks associated with AAA, especially for CNN1 and CD8A axes with the potential function of ‘focal adhesion’ and ‘immune response’, respectively. Overall, the present findings may provide evidence to explore the implicated ceRNAs in the molecular mechanisms and as novel biomarkers for AAA.

Based on bioinformatics analysis lncrna SNHG5 modulates the function of vascular smooth muscle cells through mir-205-5p/SMAD4 in abdominal aortic aneurysm

Objective

The aim of this study was to explore expression profiles of long noncoding RNA (lncRNA)‐messenger RNA (mRNA) in abdominal aortic aneurysm (AAA) patients. Further, we explored the mechanisms by which lncRNA SNHG5 modulates the function of vascular smooth muscle cells (VSMC) in AAA.

Methods

Human gene expression profile GSE57691 dataset, was retrieved from Gene Expression Omnibus database. The dataset included gene expression array data of 49 AAA patients and 10 control aortic specimens from organ donors. To explore the main roles of the biological network, differentially expressed lncRNA and mRNAs in the aortic aneurysm (AAA) and normal aortic specimens were determined. Differentially expressed lncRNA and mRNAs were then used to construct a competing endogenous RNA (ceRNA) network using Cytoscape software, and the five key lncRNA were identified. SNHG5 which was significantly downregulated in the AAA was chosen and analysis showed that it regulates mir‐205‐5p and SMAD4 by binding to mir‐205‐5p. Double luciferase reporter gene assays, RNA immunoprecipitation, and RNA knockdown studies were used to establish the relationship between SNHG5 and mir‐205‐5p. Apoptosis rate was determined using flow cytometry, whereas cell proliferation was evaluated using Edu, and 24 well Transwell assay. Western blot analysis was used to determine protein expression levels.

Results

The five differentially expressed lncRNAs were significantly correlated with 34 microRNAs and 112 mRNAs. mRNAs in the ceRNA network are implicated in protein binding, signal transduction, DNA and RNA transcription, development, and cell differentiation. SNHG5 was downregulated in the AAA and acts as a molecular sponge for mir‐205. Downregulation of SNHG5 induces expression of mir‐205‐5p. Increased mir‐205‐5p expression level inhibits SMAD4 production, thus inhibiting proliferation and migration and promotes apoptosis of smooth muscle cells.

Conclusion

Bioinformatics were used to explore molecular mechanism of AAA progression. The findings of this study show that lncRNA SNHG5 regulates proliferation and apoptosis of VSMC cells through modulation of the mir‐205‐5p/SMAD4 axis. Therefore, SNHG5 is a potential therapeutic target for AAA disease.

Long noncoding RNA SOX2OT silencing alleviates cerebral ischemia-reperfusion injury via miR-135a-5p-mediated NR3C2 inhibition

OBJECTIVE

This study is aimed to investigate the role of the long noncoding RNA SOX2 overlapping transcript (SOX2OT) in cerebral ischemia-reperfusion injury (CIRI) and the underlying regulatory mechanisms.

METHODS

The oxygen-glucose deprivation/reoxygenation (OGD/R)-treated PC12 cells and middle cerebral artery occlusion/reperfusion (MCAO/R)-treated rats were established to simulate CIRI condition in vitro and in vivo. Quantitative real-time polymerase chain reaction was performed to detect the expression of SOX2OT, microRNA-135a-5p (miR-135a-5p), and nuclear receptor subfamily 3 group C member 2 (NR3C2). The cell viability and apoptosis were analyzed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assays. The levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), and reactive oxygen species (ROS) or interleukin (IL)-1β and IL-6 were used to evaluate the oxidative stress or inflammation. Dual-luciferase reporter assay was conducted to validate the interactions among SOX2OT, miR-135a-5p, and NR3C2. Additionally, neurological deficit scores (NDS), infarct volume, and brain edema were used to assess brain impairments in vivo.

RESULTS

The expression of SOX2OT and NR3C2 was increased, while miR-135a-5p was decreased in OGD/R-treated PC12 cells. SOX2OT silencing repressed the levels of LDH, MDA, ROS, IL-1β, IL-6, reduced the numbers of TUNEL positive cells, and elevated viability and SOD level in OGD/R-treated PC12 cells. Besides, SOX2OT targeted miR-135a-5p, and miR-135a-5p targeted NR3C2. Both miR-135a-5p downregulation and NR3C2 upregulation reversed the suppressive effects of SOX2OT knockdown on oxidative stress, apoptosis, and inflammation of OGD/R-treated PC12 cells. Furthermore, injection of sh-SOX2OT reduced the NDS, cerebral infarct, and cerebral edema in MCAO/R-treated rats.

CONCLUSIONS

Silencing of SOX2OT attenuated CIRI via regulation of the miR-135a-5p/NR3C2 axis, which may provide a novel therapeutic target for CIRI.

Identification of miR-145 as a regulator of the cardiomyocyte inflammatory response and oxidative stress under hyperglycemia

The current study aimed to explore the effects of microRNA (miR)-145 on the inflammatory response and oxidative stress (OS) in high glucose (HG)-induced cardiomyocytes, as well as the specific mechanism underlying this action. H9c2 cells were treated with 33 mmol/l glucose (HG group) or cotreated with 24.5 mmol/l mannitol and 5.5 mmol/l glucose (hypertonic group), and the expression levels of miR-145 and ADP ribosylation factor 6 (ARF6) were detected. The cells were transfected with pcDNA3.1-ARF6, miR-145 mimics or corresponding negative controls prior to the assessment of cell survival rate. Levels of lactate dehydrogenase (LDH), reactive oxygen species (ROS) and malondialdehyde (MDA), as well as the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), and the levels of IL-6, TNF-α and monocyte chemoattractant protein-1 (MCP-1) were subsequently determined. The apoptotic rate of H9c2 cells was examined by flow cytometry. The interaction between miR-145-ARF6 was predicted and confirmed by luciferase reporter assays. In the HG group, miR-145 expression was significantly decreased and ARF6 expression significantly increased compared with controls. Furthermore, the levels of inflammatory factors (IL-6, TNF-α and MCP-1), LDH, ROS and MDA were significantly elevated in the HG group compared with controls. Significantly decreased SOD, CAT and GPx activities and significantly increased numbers of apoptotic cells were observed in the HG group compared with controls. The cells transfected with miR-145 mimics exhibited significantly decreased LDH, ROS and MDA levels, significantly increased antioxidant enzyme activities and significantly decreased apoptotic rates compared with controls, while the opposite results were observed in cells transfected with pcDNA3.1-ARF6. Moreover, co-transfection with miR-145 mimics and pcDNA3.1-ARF6 exacerbated the inflammatory response and OS injury in HG-induced cardiomyocytes compared with cells transfected with miR-145 mimics alone. Furthermore, miR-145 negatively targeted ARF6. miR-145 attenuated the HG-induced inflammatory response and OS injury in cardiomyocytes by negatively regulating ARF6, which may contribute to providing a theoretical basis for the treatment of diabetic cardiomyopathy.

Diverse roles of microRNA-145 in regulating smooth muscle (dys)function in health and disease

MicroRNAs are short, non-coding RNAs that target messenger RNAs for degradation. miR-145 is a vascular-enriched microRNA that is important for smooth muscle cell (SMC) differentiation. Under healthy circumstances, SMC exist in a contractile, differentiated phenotype promoted by miR-145. In cases of disease or injury, SMC can undergo reversible dedifferentiation into a synthetic phenotype, accompanied by inhibition of miR-145 expression. Vascular disorders such as atherosclerosis and neointimal hyperplasia are characterised by aberrant phenotypic switching in SMC. This review will summarise the physiological roles of miR-145 in vascular SMC, including the molecular regulation of differentiation, proliferation and migration. Furthermore, it will discuss the different ways in which miR-145 can be dysregulated and the downstream impact this has on the progression of vascular pathologies. Finally, it will discuss whether miR-145 may be suitable for use as a biomarker of vascular disease.

Identification of Novel Long Noncoding RNAs and Their Role in Abdominal Aortic Aneurysm

Objective

Long noncoding RNAs (lncRNAs) have emerged as critical molecular regulators in various diseases. However, the potential regulatory role of lncRNAs in the pathogenesis of abdominal aortic aneurysm (AAA) remains elusive. The aim of this study was to identify crucial lncRNAs associated with human AAA by comparing the lncRNA and mRNA expression profiles of patients with AAA with those of control individuals.

Materials and Methods

The expression profiles of lncRNAs and mRNAs were analyzed in five dilated aortic samples from AAA patients and three normal aortic samples from control individuals using microarray technology. Functional annotation of the screened lncRNAs based on the differentially expressed genes was performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses.

Results

Microarray results revealed 2046 lncRNAs and 1363 mRNAs. Functional enrichment analysis showed that the mRNAs significantly associated with AAA were enriched in the NOD-like receptor (NLR) and nuclear factor kappa-B (NF-κB) signaling pathways and in cell adhesion molecules (CAMs), which are closely associated with pathophysiological changes in AAA. The lncRNAs identified using microarray analysis were further validated using quantitative real-time polymerase chain reaction (qRT-PCR) analysis with 12 versus 11 aortic samples. Finally, three key lncRNAs (ENST00000566954, ENST00000580897, and T181556) were confirmed using strict validation. A coding-noncoding coexpression (CNC) network and a competing endogenous RNA (ceRNA) network were constructed to determine the interaction among the lncRNAs, microRNAs, and mRNAs based on the confirmed lncRNAs.

Conclusions

Our microarray profiling analysis and validation of significantly expressed lncRNAs between patients with AAA and control group individuals may provide new diagnostic biomarkers for AAA. The underlying regulatory mechanisms of the confirmed lncRNAs in AAA pathogenesis need to be determined using in vitro and in vivo experiments.

LncRNA SOX2OT rs9839776 Polymorphism Reduces Sepsis Susceptibility in Southern Chinese Children

Background

Sepsis in children is one of the main causes of death in pediatric intensive care units (PICUs); however, the pathogenesis of sepsis is not fully clear. Previous studies revealed that many genetic variations were related to sepsis susceptibility. A long non-coding RNA SOX2 overlapping transcript (SOX2OT) may play a role in mitochondrial homeostasis and antioxidative activity, but the relationship between the lncRNA SOX2OT polymorphism and sepsis susceptibility has not been reported.

Methods

In this study, 474 pediatric sepsis patients and 678 healthy controls were recruited from southern China. After genotyping, the strength of the associations was evaluated through odds ratios (ORs) and 95% confidence intervals (CIs).

Results

The SOX2OT rs9839776 T allele was associated with decreased susceptibility to sepsis in southern Chinese children (TT/CT vs CC adjusted OR = 0.778, 95% CI = 0.610–0.992; P = 0.0431). Moreover, the difference in susceptibility was greater in children of age >60 months (adjusted OR = 0.458, 95% CI = 0.234–0.896; P = 0.0225), survivors (adjusted OR = 0.758, 95% CI = 0.585–0.972; P = 0.0358), males (adjusted OR = 0.655, 95% CI = 0.479–0.894; P = 0.0077) and the sepsis subgroup (adjusted OR = 0.548, 95% CI = 0.343–0.876; P = 0.0120).

Conclusion

The rs9839776 T allele may contribute to decreased sepsis risk in Chinese children. Future studies with a larger sample size are needed to verify these results.