P38 MAPK Signaling Pathway Mediates Angiotensin II-Induced miR143/145 Gene Cluster Downregulation during Aortic Dissection Formation

Epigenomics in aortic dissection: From mechanism to therapeutics

Aortic dissection (AD) has an unfavorable prognosis. It requires early diagnosis, appropriate treatment strategies, and suspicion to recognize symptoms; thus, it is commonly described as an acute aortic emergency. The clinical manifestations of painless AD are complex and variable. However, there is no effective treatment to prevent the progression of AD. Therefore, study of the molecular targets and mechanisms of AD to enable prevention or early intervention is particularly important. Although multiple gene mutations have been proposed as linked to AD development, evidence that multiple epigenetic elements are strongly associated is steadily increasing. These epigenetic processes include DNA methylation, N6-methyladenosine, histone modification, non-histone posttranslational modification, and non-coding RNAs (ncRNAs). Among these processes, resveratrol targeting Sirtuin 1 (SIRT1), 5-azacytidine (5azaC) targeting DNA methyltransferase (DNMT), and vitamin C targeting ten-eleven translocation 2 (Tet2) showed unique advantages in improving AD and vascular dysfunction. Finally, we explored potential epigenetic drugs and diagnostic methods for AD, which might provide options for the future.

Emerging Role of Non-Coding RNAs in Aortic Dissection

Aortic dissection (AD) is a fatal cardiovascular acute disease with high incidence and mortality, and it seriously threatens patients’ lives and health. The pathogenesis of AD mainly includes vascular inflammation, extracellular matrix degradation, and phenotypic conversion as well as apoptosis of vascular smooth muscle cells (VSMCs); however, its detailed mechanisms are still not fully elucidated. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), are an emerging class of RNA molecules without protein-coding ability, and they play crucial roles in the progression of many diseases, including AD. A growing number of studies have shown that the dysregulation of ncRNAs contributes to the occurrence and development of AD by modulating the expression of specific target genes or the activity of related proteins. In addition, some ncRNAs exhibit great potential as promising biomarkers and therapeutic targets in AD treatment. In this review, we systematically summarize the recent findings on the underlying mechanism of ncRNA involved in AD regulation and highlight their clinical application as biomarkers and therapeutic targets in AD treatment. The information reviewed here will be of great benefit to the development of ncRNA-based therapeutic strategies for AD patients.

Lnc-OIP5-AS1 exacerbates aorta wall injury during the development of aortic dissection through upregulating TUB via sponging miR-143-3p

AIMS

Dysfunction of major cells constituting the aortic wall is the pathological basis for AD development. Determining whether non-coding RNAs can influence AD progression by regulating these cellular functions and identifying some specific non-coding RNAs is of great significance in uncovering molecular mechanisms of the development of AD.

MAIN METHODS

Microarray analyses and hierarchical clustering analysis were used to select candidate lncRNAs and miRNAs associated with AD. Dual-luciferase reporter assay, RNA immunoprecipitation, and RNA pull-down assay were performed to verify the direct bonding relationship between genes. The regulatory effects of genes on cell function were examined in a series of experiments.

KEY FINDINGS

We found that lnc-OIP5-AS1 was upregulated, whereas miR-143-3p was downregulated in cells treated with angiotensin II (AngII) and AD tissues. Lnc-OIP5-AS1 functioned as a competing endogenous RNA (ceRNA) of miR-143-3p to suppress the proliferation and mobility, but promote apoptosis of HAECs and HASMCs, and simultaneously result in the imbalances between MMP-2/9 and TIMP-2/1 in HASMCs and the excessive secretion of IL-6, IL-1β, and IL-17A of HAAFs. Moreover, overexpression or silence of TUB, a target gene of miR-143-3p, counteracted the influence of miR-143-3p or lnc-OIP5-AS1 on cells, respectively.

SIGNIFICANCE

Our findings revealed that lncRNA OIP5-AS1 exacerbates aorta intima, media, and adventitia injury in the development of AD through upregulating TUB via sponging miR-143-3p and also support more detailed future studies by providing a novel molecular basis underlying AD formation.

Conditioned Media of Choroid Plexus Epithelium Cells Attenuates High Pi-Induced Calcification of MOVAS Cells by Inhibiting ROS-Mediated Signal Pathways

Vascular calcification was an independent risk of cardiovascular and cerebrovascular diseases (CCDs). Studies reported that conditioned media of choroid plexus epithelium cells (CPECs-CM) showed potential neuroprotective effects. However, the protective effect of CPECs-CM against vascular calcification (VC) has not been reported yet. Herein, high phosphate (HPi)–induced calcification model in mouse aortic vascular smooth muscle cells (MOVAS) was established, and the protective effects and underlying mechanism of CPECs-CM against HPi-induced calcification were explored. The results indicated that CPEC cells were successfully isolated and cultured, and CPECs-CM co-treatment significantly inhibited HPi-induced calcification of MOVAS cells through blocking alkaline phosphatase activity and expression. CPECs-CM co-treatment also suppressed reactive oxide species–mediated DNA damage in HPi-treated MOVAS cells. Moreover, dysfunction of MAPKs and PI3K/AKT pathways both contributed to HPi-induced calcification of MOVAS cells, and CPECs-CM co-treatment attenuated HPi-induced calcification by normalizing MAPKs and PI3K/AKT expression. Taken together, our findings provide evidence that CPECs-CM had the potential to inhibit vascular calcification with potent application in chemoprevention and chemotherapy of human CCD.

Irbesartan inhibits metastasis by interrupting the adherence of tumor cell to endothelial cell induced by angiotensin II in hepatocellular carcinoma

Background

The use of angiotensin II inhibitors is associated with a low risk of recurrence and metastasis in hepatocellular carcinoma (HCC) patients. Vascular cell adhesion molecule-1 (VCAM-1) is a key factor in tumor metastasis.

Methods

The effects of angiotensin II and irbesartan (an angiotensin II inhibitor) on HCC were explored with a xenograft model, microarray analysis and cell adhesion experiments. The relationship between the expression of VCAM-1 in HCC tissues and prognosis was analyzed with public and our institutional clinical databases. The effects of angiotensin II, irbesartan and VCAM-1 on adhesion and metastasis in HCC were explored with a xenograft model and cell adhesion experiments. The regulatory mechanisms were analyzed by Western blot analysis.

Results

Angiotensin II type 1 receptor and VCAM-1 were expressed in HCC tissues. Irbesartan inhibited HCC growth and metastasis in vivo and weakened the adhesion of HCC cells to endothelial cells, an effect that was enhanced by angiotensin II. VCAM-1 was found to be an independent risk factor for recurrence and survival in HCC patients with microvascular invasion. Angiotensin II upregulated VCAM-1 expression, and this upregulation was inhibited by irbesartan. Angiotensin II enhanced adhesion mainly by promoting the expression of VCAM-1 in HCC cells. Irbesartan inhibited the expression of VCAM-1 by reducing p38/MAPK phosphorylation activated by angiotensin II in HCC cells.

Conclusions

Irbesartan attenuates metastasis by inhibiting angiotensin II-activated VCAM-1 via the p38/MAPK pathway in HCC.

Regulatory Master Genes Identification and Drug Repositioning by Integrative mRNA-miRNA Network Analysis for Acute Type A Aortic Dissection

Acute type A aortic dissection (ATAAD) is a life-threatening disease. The understanding of its pathogenesis and treatment approaches remains unclear. In the present work, differentially expressed genes (DEGs) from two ATAAD datasets GSE52093 and GSE98770 were filtered. Transcription factor TEAD4 was predicted as a key modulator in protein-protein interaction (PPI) network. Weighted correlation network analysis (WGCNA) identified five modules in GSE52093 and four modules in GSE98770 were highly correlated with ATAAD. 71 consensus DEGs of highly correlated modules were defined and functionally annotated. L1000CDS² was executed to predict drug for drug repositioning in ATAAD treatment. Eight compounds were filtered as potential drugs. Integrative analysis revealed the interaction network of five differentially expressed miRNA and 16 targeted DEGs. Finally, master DEGs were validated in human ATAAD samples and AD cell model in vitro. TIMP3 and SORBS1 were downregulated in ATAAD samples and AD cell model, while PRUNE2 only decreased in vitro. Calcium channel blocker and glucocorticoid receptor agonist might be potential drugs for ATAAD. The present study offers potential targets and underlying molecular mechanisms ATAAD pathogenesis, prevention and drug discovery.

Iron deficiency promotes aortic medial degeneration via destructing cytoskeleton of vascular smooth muscle cells

BACKGROUND

Aortic dissection (AD) and aortic aneurysm (AA) are critical illnesses with an unclear pathogenetic mechanism that seriously threaten human life. Aortic medial degeneration (AMD) is the main pathological feature of AD and AA. Diseases of iron metabolism can cause a variety of physiological dysfunctions. In this study, we aimed to clarify the state of iron metabolism in patients with AD and AA, and to explore the effect of iron metabolism on AMD.

METHODS

A total of 200 patients with AD or AA, and 60 patients with hypertension were included in the study. Blood samples were drawn immediately when patients were admitted to the hospital. Aortic specimens from patients with Stanford type A AD were obtained at the time of surgery. The status of iron metabolism in the circulation and the aortic wall was analyzed. In addition, apolipoprotein E knockout mice were fed chow with a different iron content, and angiotensin II (Ang II) was used to induce AMD. Furthermore, transferrin receptor 1 knockout (TFR1-/-) mice were used to study the effects of iron deficiency (ID) on aortic development, to observe the effects of different iron metabolism status on the formation of AMD in mice, and to explore the cytoskeleton of vascular smooth muscle cells (VSMCs) under different iron metabolism.

RESULTS

Patients with AMD were iron deficient. ID is associated with the development of AMD in hypertensive patients. Iron-deficient feeding combined with Ang II pumping promoted the formation of AMD and significantly shortened the survival time of mice. ID significantly impaired the cytoskeleton of VSMCs.

CONCLUSIONS

Our results highlighted that ID was associated with the formation of AMD in patients with hypertension. In this study, we identified a novel mechanism behind VSMCs dysfunction that was induced by ID, thereby suggesting iron homeostasis as a future precaution in patients with hypertension based on its important role in the maintenance of VSMC function.

Non-coding RNAs in aortic dissection: From biomarkers to therapeutic targets

Aortic dissection (AD) is the rupture of the aortic intima, causing the blood in the cavity to enter the middle of the arterial wall. Without urgent and proper treatment, the mortality rate increases to 50% within 48 hours. Most patients present with acute onset of symptoms, including sudden severe pain and complex and variable clinical manifestations, which can be easily misdiagnosed. Despite this, the molecular mechanisms underlying AD are still unknown. Recently, non‐coding RNAs have emerged as novel regulators of gene expression. Previous studies have proven that ncRNAs can regulate several cardiovascular diseases; therefore, their potential as clinical biomarkers and novel therapeutic targets for AD has aroused widespread interest. To date, several studies have reported that microRNAs are crucially involved in AD progression. Additionally, several long non‐coding RNAs and circular RNAs have been found to be differentially expressed in AD samples, suggesting their potential roles in vascular physiology and disease. In this review, we discuss the functions of ncRNAs in AD pathophysiology and highlight their potential as biomarkers and therapeutic targets for AD. Meanwhile, we present the animal models previously used for AD research, as well as the specific methods for constructing mouse or rat AD models.

Knock-out of MicroRNA 145 impairs cardiac fibroblast function and wound healing post-myocardial infarction

Prevention of infarct scar thinning and dilatation and stimulation of scar contracture can prevent progressive heart failure. Since microRNA 145 (miR-145) plays an important role in cardiac fibroblast response to wound healing and cardiac repair after an myocardial infarction (MI), using a miR-145 knock-out (KO) mouse model, we evaluated contribution of down-regulation of miR-145 to cardiac fibroblast and myofibroblast function during adverse cardiac remodelling. Cardiac function decreased more and the infarct size was larger in miR-145 KO than that in WT mice after MI and this phenomenon was accompanied by a decrease in cardiac fibroblast-to-myofibroblast differentiation. Quantification of collagen I and α-SMA protein levels as well as wound contraction revealed that transdifferentiation of cardiac fibroblasts into myofibroblasts was lower in KO than WT mice. In vitro restoration of miR-145 induced more differentiation of fibroblasts to myofibroblasts and this effect involved the target genes Klf4 and myocardin. MiR-145 contributes to infarct scar contraction in the heart and the absence of miR-145 contributes to dysfunction of cardiac fibroblast, resulting in greater infarct thinning and dilatation. Augmentation of miR-145 could be an attractive target to prevent adverse cardiac remodelling after MI by enhancing the phenotypic switch of cardiac fibroblasts to myofibroblasts.

The TGF-β pathway plays a key role in aortic aneurysms

Aortic dissection and aortic aneurysms are currently among the most high-risk cardiovascular diseases due to their rapid onset and high mortality. Although aneurysm research has been extensive, the pathogenesis remains unknown. Studies have found that the TGF-β/Smad pathway and aneurysm formation appear linked. For example, the TGF-β signaling pathway was significantly activated in aneurysm development and aortic dissection. Aneurysms are not, however, mitigated following knockdown of TGF-β signaling pathway-related genes. Incidence and mortality rate of ruptured thoracic aneurysms increase with the down-regulation of the classical TGF-β signaling pathway. In this review, we summarize recent findings and evaluate the differential role of classical and non-classical TGF-β pathways on aortic aneurysm. It is postulated that the TGF-β signaling pathway is necessary to maintain vascular function, but over-activation will promote aneurysms whereas over-inhibition will lead to bypass pathway over-activation and promote aneurysm occurrence.

Regulatory Mechanism of MicroRNA-145 in the Pathogenesis of Acute Aortic Dissection

PURPOSE

Previous studies have confirmed that microRNAs play important roles in the pathogenesis of acute aortic dissection (AAD). Here, we aimed to explore the role of miR-145 and its regulatory mechanism in the pathogenesis of AAD.

MATERIALS AND METHODS

AAD tissue samples were harvested from patients with aortic dissection and normal donors. Rat aortic vascular smooth muscle cells (VSMCs) were transfected with miR-145 mimic/inhibitor or negative control mimic/inhibitor. Gene and protein expression was measured in human aortic dissection tissue specimens and VSMCs by qRT-PCR and Western blot. Luciferase reporter assay was applied to verify whether connective tissue growth factor (CTGF) was a direct target of miR-145 in VSMCs. Methyl thiazolyl tetrazolium assay was used to detect VSMC viability.

RESULTS

miR-145 expression was downregulated in aortic dissection tissues and was associated with the survival of patients with AAD. Overexpression of miR-145 promoted VSMC proliferation and inhibited cell apoptosis. Moreover, CTGF, which was increased in aortic dissection tissues, was decreased by miR-145 mimic and increased by miR-145 inhibitor. Furthermore, CTGF was confirmed as a target of miR-145 and could reverse the promotion effect of miR-145 on the progression of AAD.

CONCLUSION

miR-145 suppressed the progression of AAD by targeting CTGF, suggesting that a miR-145/CTGF axis may provide a potential therapeutic target for AAD.

Inhibition of miR-148a-3p resists hepatocellular carcinoma progress of hepatitis C virus infection through suppressing c-Jun and MAPK pathway

Objectives

The present study was committed to investigate the role of miR‐148a‐3p in HCC infected with hepatitis C virus (HCV) and the regulatory mechanism of miR‐148a‐3p/c‐Jun/MAPK signalling pathway.

Methods

Differential analysis and GSEA analysis were performed with R packages. QRT‐PCR and Western blot were used to detect RNA or protein level, respectively. The targeted relationship between miR‐148a‐3p and c‐Jun was predicted by TargetScan database and determined by double luciferase reporter assay. MTT assay and flow cytometry were used to evaluate cell proliferation, cell cycle and cell apoptosis, respectively.

Results

C‐Jun was up‐regulated, and MAPK signalling pathway was activated in HCV‐infected HCC cells. C‐Jun expression regulated inflammation‐related gene expression and had an influence on cell proliferation, cell cycle and cell apoptosis. MiR‐148a‐3p, down‐regulated in HCV‐infected HCC cells, could target c‐Jun mRNA to suppress c‐Jun protein expression.

Conclusions

MiR‐148a‐3p suppressed the proliferation of HCC cells infected with HCV through targeting c‐Jun mRNA.

Downregulation of microRNA-143-5p is required for the promotion of odontoblasts differentiation of human dental pulp stem cells through the activation of the mitogen-activated protein kinases 14-dependent p38 mitogen-activated protein kinases signaling pathway

MicroRNAs (miRNAs) play critical roles in various biological processes including cell differentiation. Some researchers suggested that the p38 mitogen-activated protein kinases (MAPK) signaling pathway had an effect on regulating the odontoblastic differentiation of human dental pulp stem cells (hDPSCs). This study focuses on the effects of miR-143-5p on hDPSCs by regulating the p38 MAPK signaling pathway. The targeting relationship of MAPK14 and miR-143-5p targets were verified by TargetScan and dual-luciferase reporter gene assay. Through overexpression of miR-143-5p or silencing of miR-143-5p, expressions of miR-143-5p, MAPK14, Ras, MAPK kinase (MKK) 3/6, dentin sialophosphoprotein (DSPP), alkaline phosphatase (ALP), and osteocalcin (OCN) were detected by reverse transcription quantitative polymerase chain reaction. Protein expressions of MAPK14, Ras, and MKK3/6 were determined by western blot analysis. ALP and alizarin red S staining were used to detect mineralization. Initially, MAPK14 was found to be negatively regulated by miR-143-5p. Meanwhile, the upregulated miR-143-5p decreased the p38 MAPK signaling pathway related genes (MAPK14, Ras, and MKK3/6) and odontoblastic differentiation markers (ALP, DSPP, and OCN) expression. On the contrary, the downregulated miR-143-5p increased the p38 MAPK signaling pathway related genes (MAPK14, Ras, and MKK3/6) and odontoblastic differentiation markers (ALP, DSPP, and OCN) expression. Furthermore, ALP activity and mineralized nodules increased after downregulation of miR-143-5p, and after its upregulation, ALP activity and mineralized nodules decreased. Our data suggest that poor expression of miR-143-5p promotes hDPSCs odontoblastic differentiation through the activation of the p38 MAPK signaling pathway by upregulating MAPK14.

COPD rat model is more susceptible to cold stress and PM2.5 exposure and the underlying mechanism

The purpose of this study is to verify the hypothesis that chronic obstructive pulmonary disease (COPD) model rat is more susceptible to cold stress and fine particulate matter (PM_2.5) exposure than the healthy rat, and explore the related mechanism. COPD rat model, established with cigarette smoke and lipopolysaccharide intratracheal instillation, were exposed to cold stress (0 °C) and PM_2.5 (0, 3.2, 12.8 mg/ml). After that, the levels of superoxide dismutase, inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α), monocyte chemotactic protein 1 (MCP-1) and angiotensin Ⅱ (Ang-Ⅱ) in lung were measured, as well as the expression levels of lung 8-hydroxy-2-deoxyguanosine (8-OHdG), nuclear factor kappa B (NF-κB), heme-oxygenase-1 (HO-1) and nuclear factor erythroid-2-related factor 2 (Nrf2). There were significant positive relationships between PM_2.5 and lung level of iNOS, TNF-α, MCP-1 and Ang-Ⅱ, lung function and pathologic damage in COPD rats. The HO-1, NF-κB and 8-OHdG were found highly expressed in COPD rat lung, particularly at the higher PM_2.5 dose of cold stress groups, while Nrf2 was found declined. Thus, COPD rats may be more susceptible to cold stress and PM_2.5 exposure. Cold stress may aggravate PM_2.5-induced toxic effects in the lung of COPD rats through increasing Ang-Ⅱ/NF-κB signaling pathway and suppressing Nrf2 signaling pathway.

Non-coding RNAs in aneurysmal aortopathy

Aortic aneurysms represent a major public health burden, and currently have no medical treatment options. The pathophysiology behind these aneurysms is complex and variable, depending on location and underlying cause, and generally involves progressive dysfunction of all elements of the aortic wall. Changes in smooth muscle behavior, endothelial signaling, extracellular matrix remodeling, and to a variable extent inflammatory signaling and cells, all contribute to the dilation of the aorta, ultimately resulting in high mortality and morbidity events including dissection and rupture. A large number of researchers have identified non-coding RNAs as crucial regulators of aortic aneurysm development, both in humans and in animal models. While most work to-date has focused on microRNAs, intriguing information has also begun to emerge regarding the role of long-non-coding RNAs. This review summarizes the currently available data regarding the involvement of non-coding RNAs in aneurysmal aortopathies. Going forward, these represent key potential therapeutic targets that might be leveraged in the future to slow or prevent aortic aneurysm formation, progression and rupture.