Pregnancy-associated plasma protein-A (PAPP-A) and cardiovascular disease

There is strong evidence that PAPP-A, a local regulator of insulin-like growth factor signaling through proteolytic cleavage of inhibitory binding proteins, is involved in multiple physiological processes associated with cardiovascular disease. This review will describe the various roles of PAPP-A with a focus on atherosclerosis, neointimal hyperplasia, and acute coronary syndrome in animal models and in humans.

IGF Signaling in the Heart in Health and Disease

One of the most vital processes of the body is the cardiovascular system's proper operation. Physiological processes in the heart are regulated by the balance of cardioprotective and pathological mechanisms. The insulin-like growth factor system (IGF system, IGF signaling pathway) plays a pivotal role in regulating growth and development of various cells and tissues. In myocardium, the IGF system provides cardioprotective effects as well as participates in pathological processes. This review summarizes recent data on the role of IGF signaling in cardioprotection and pathogenesis of various cardiovascular diseases, as well as analyzes severity of these effects in various scenarios.

Vascular Aging and Atherosclerosis: A Perspective on Aging

Vascular aging (VA) is recognized as a pivotal factor in the development and progression of atherosclerosis (AS). Although various epidemiological and clinical research has demonstrated an intimate connection between aging and AS, the candidate mechanisms still require thorough examination. This review adopts an aging-centric perspective to deepen the comprehension of the intricate relationship between biological aging, vascular cell senescence, and AS. Various aging-related physiological factors influence the physical system's reactions, including oxygen radicals, inflammation, lipids, angiotensin II, mechanical forces, glucose levels, and insulin resistance. These factors cause endothelial dysfunction, barrier damage, sclerosis, and inflammation for VA and promote AS via distinct or shared pathways. Furthermore, the increase of senescent cells inside the vascular tissues, caused by genetic damage, dysregulation, secretome changes, and epigenetic modifications, might be the primary cause of VA.

The role of pregnancy associated plasma protein-A in triple negative breast cancer: a promising target for achieving clinical benefits

Pregnancy associated plasma protein-A (PAPP-A) plays an integral role in breast cancer (BC), especially triple negative breast cancer (TNBC). This subtype accounts for the most aggressive BC, possesses high tumor heterogeneity, is least responsive to standard treatments and has the poorest clinical outcomes. There is a critical need to address the lack of effective targeted therapeutic options available. PAPP-A is a protein that is highly elevated during pregnancy. Frequently, higher PAPP-A expression is detected in tumors than in healthy tissues. The increase in expression coincides with increased rates of aggressive cancers. In BC, PAPP-A has been demonstrated to play a role in tumor initiation, progression, metastasis including epithelial-mesenchymal transition (EMT), as well as acting as a biomarker for predicting patient outcomes. In this review, we present the role of PAPP-A, with specific focus on TNBC. The structure and function of PAPP-A, belonging to the pappalysin subfamily, and its proteolytic activity are assessed. We highlight the link of BC and PAPP-A with respect to the IGFBP/IGF axis, EMT, the window of susceptibility and the impact of pregnancy. Importantly, the relevance of PAPP-A as a TNBC clinical marker is reviewed and its influence on immune-related pathways are explored. The relationship and mechanisms involving PAPP-A reveal the potential for more treatment options that can lead to successful immunotherapeutic targets and the ability to assist with better predicting clinical outcomes in TNBC.

The Pregnancy-Associated Plasma Protein-A (PAPP-A) Story

Pregnancy-associated plasma protein-A (PAPP-A) was first identified in the early 1970s as a placental protein of unknown function, present at high concentrations in the circulation of pregnant women. In the mid-to-late 1990s, PAPP-A was discovered to be a metzincin metalloproteinase, expressed by many nonplacental cells, that regulates local insulin-like growth factor (IGF) activity through cleavage of high-affinity IGF binding proteins (IGFBPs), in particular IGFBP-4. With PAPP-A as a cell surface-associated enzyme, the reduced affinity of the cleavage fragments results in increased IGF available to bind and activate IGF receptors in the pericellular environment. This proteolytic regulation of IGF activity is important, since the IGFs promote proliferation, differentiation, migration, and survival in various normal and cancer cells. Thus, there has been a steady growth in investigation of PAPP-A structure and function outside of pregnancy. This review provides historical perspective on the discovery of PAPP-A and its structure and cellular function, highlights key studies of the first 50 years in PAPP-A research, and introduces new findings from recent years.

Circ-UBR4 regulates the proliferation, migration, inflammation, and apoptosis in ox-LDL-induced vascular smooth muscle cells via miR-515-5p/IGF2 axis

The aim of our study is to disclose the role and underlying molecular mechanisms of circular RNA ubiquitin protein ligase E3 component n-recognin 4 (circ-UBR4) in atherosclerosis (AS). Our data showed that circ-UBR4 expression was upregulated in AS patients and oxidized low-density lipoprotein (ox-LDL)-induced vascular smooth muscle cells (VSMCs) compared with healthy volunteer and untreated VSMCs. In addition, ox-LDL stimulated proliferation, migration, and inflammation but decreased apoptosis in VSMCs, which were overturned by the inhibition of circ-UBR4. miR-515-5p was sponged by circ-UBR4, and its inhibitor reversed the inhibitory effect of circ-UBR4 knockdown on proliferation, migration, and inflammation in ox-LDL-induced VSMCs. Insulin-like growth factor2 (IGF2) was a functional target of miR-515-5p, and overexpression of IGF2 reversed the suppressive effect of miR-515-5p on ox-LDL-stimulated VSMCs proliferation, migration, and inflammation. Collectively, circ-UBR4 knockdown decreased proliferation, migration, and inflammation but stimulated apoptosis in ox-LDL-induced VSMCs by targeting the miR-515-5p/IGF2 axis.

ox-LDL regulates proliferation and apoptosis in VSMCs by controlling the miR-183-5p/FOXO1

BACKGROUND

microRNA-mRNA axes that are involved in oxidized low-density lipoprotein (ox-LDL)-induced vascular smooth muscle cells (VSMCs) proliferation/apoptosis imbalance need to be further investigated.

OBJECTIVE

To investigate the functional role of miR-183-5p/FOXO1 in VSMCs and its interaction with ox-LDL.

METHODS

RNA sequencing was used to detect transcriptome changes of VSMCs treated with ox-LDL. miR-183-5p and FOXO1 expression levels in VSMCs after ox-LDL treatment were assessed using qRT-PCR and western blotting. The regulatory effect of miR-183-5p on FOXO1 has been tried to prove using a dual-luciferase reporter assay. The functions of miR-183-5p, and FOXO1 were analyzed by CCK-8 assay and flow cytometry assay. The tissue samples or serum samples of high fat-feeding mice and carotid atherosclerosis patients were collected, and the levels of miR-183-5p/FOXO1 were analyzed.

RESULTS

RNA sequencing data showed 81 miRNAs including miR-183-5p was significantly changed after ox-LDL treatment in VSMCs. FOXO1, a miR-183-5p's potential target, was also down-regulated in ox-LDL treated cells. qRT-PCR and western blot found that expression of FOXO1 mRNA and protein significantly reduced in VSMCs treated with ox-LDL, accompanied by overexpression of miR-183-5p. miR-183-5p inhibited FOXO1 mRNA by binding to its 3' UTR. Interference miR-183-5p/FOXO1 could change proliferation/apoptosis imbalance in VSMCs under ox-LDL stimulation. Higher levels of miR-183-5p but reduced FOXO1 can be found in the thoracic aorta tissues of high fat-feeding mice. In serum samples from individuals with carotid atherosclerosis, Higher levels of miR-183-5p were observed. the miR-183-5p level was positively related to the level of serum ox-LDL in patients.

CONCLUSIONS

Aberrant expression of miR-183-5p/FOXO1 pathway mediated ox-LDL-induced proliferation/apoptosis imbalance in VSMCs. The miR-183-5p/FOXO1 axis can potentially be utilized as the target in the treatment of patients with atherosclerosis.

CircRNA-miRNA interactions in atherogenesis

Atherosclerosis is the major cause of coronary artery disease (CAD) which includes unstable angina, myocardial infarction, and heart failure. The onset of atherogenesis, a process of atherosclerotic lesion formation in the intima of arteries, is driven by lipid accumulation, a vicious cycle of reactive oxygen species (ROS)-induced oxidative stress and inflammatory reactions leading to endothelial cell (EC) dysfunction, vascular smooth muscle cell (VSMC) activation, and foam cell formation which further fuel plaque formation and destabilization. In recent years, there is a surge in the number of publications reporting the involvement of circular RNAs (circRNAs) in the pathogenesis of cardiovascular diseases, cancers, and metabolic syndromes. These studies have advanced our understanding on the biological functions of circRNAs. One of the most common mechanism of action of circRNAs reported is the sponging of microRNAs (miRNAs) by binding to the miRNAs response element (MRE), thereby indirectly increases the transcription of their target messenger RNAs (mRNAs). Individual networks of circRNA-miRNA-mRNA associated with atherogenesis have been extensively reported, however, there is a need to connect these findings for a complete overview. This review aims to provide an update on atherogenesis-related circRNAs and analyze the circRNA-miRNA-mRNA interactions in atherogenesis. The atherogenic mechanisms and clinical relevance of each atherogenesis-related circRNA were systematically discussed for better understanding of the knowledge gap in this area.

A novel circUBR4/miR-491-5p/NRP2 ceRNA network regulates oxidized low-density lipoprotein-induced proliferation and migration in vascular smooth muscle cells

ABSTRACT

Vascular smooth muscle cells (VSMCs) play critical roles in the progression of atherosclerosis. Circular RNA (circRNA) ubiquitin protein ligase E3 component n-recognin 4 (circUBR4) has been shown to regulate VSMC migration and proliferation. Here, we sought to identify the mechanism in the regulation of circUBR4. CircUBR4, microRNA (miR)-491-5p and Neuropilin-2 (NRP2) were quantified by quantitative real-time PCR (qRT-PCR) and western blot. Cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8) and 5-Ethynyl-2'-Deoxyuridine (EDU) assays. Cell migration was examined by wound-healing and transwell invasion assays. The direct relationship between miR-491-5p and circUBR4 or NRP2 was validated by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Our data indicated that in VSMCs, ox-LDL induced circUBR4 expression. Silencing endogenous circUBR4 attenuated VSMC proliferation and migration induced by ox-LDL. Mechanistically, circUBR4 targeted miR-491-5p by pairing to miR-491-5p. Moreover, miR-491-5p was identified as a downstream mediator of circUBR4 function in ox-LDL-treated VSMCs. NRP2 was a direct target of miR-491-5p, and circUBR4 acted as a competing endogenous RNA (ceRNA) for miR-491-5p to regulate NRP2 expression. Additionally, NRP2 was a functionally downstream effector of miR-491-5p in regulating ox-LDL-evoked VSMC proliferation and migration. Our findings identify a new ceRNA network, the circUBR4/miR-491-5p/NRP2 axis, for the regulation of circUBR4 in VSMC migration and proliferation.

Expression and Functional Analysis of lncRNAs Involved in Platelet-Derived Growth Factor-BB-Induced Proliferation of Human Aortic Smooth Muscle Cells

Abnormal proliferation of vascular smooth muscle cells (VSMCs) is a common feature of many vascular remodeling diseases. Because long non-coding RNAs (lncRNAs) play a critical role in cardiovascular diseases, we analyzed the key lncRNAs that regulate VSMC proliferation. Microarray analysis identified 2,643 differentially expressed lncRNAs (DELs) and 3,720 differentially expressed coding genes (DEGs) between fetal bovine serum (FBS) starvation-induced quiescent human aortic smooth muscle cells (HASMCs) and platelet-derived growth factor-BB (PDGF-BB)-stimulated proliferative HASMCs. Gene Ontology and pathway analyses of the identified DEGs and DELs demonstrated that many lncRNAs were enriched in pathways related to cell proliferation. One of the upregulated lncRNAs in proliferative HASMC was HIF1A anti-sense RNA 2 (HIF1A-AS2). HIF1A-AS2 suppression decreased HASMC proliferation via the miR-30e-5p/CCND2 mRNA axis. We have thus identified key DELs and DEGs involved in the regulation of PDGF-BB induced HASMC proliferation. Moreover, HIF1A-AS2 promotes HASMC proliferation, suggesting its potential involvement in VSMC proliferative vascular diseases.

Myocardial Infarction-associated Transcript Knockdown Inhibits Cell Proliferation, Migration, and Invasion Through miR-490-3p/Intercellular Adhesion Molecule 1 Axis in Oxidized Low-density Lipoprotein-induced Vascular Smooth Muscle Cells

Emerging evidence has demonstrated that long noncoding RNAs are related to the pathogenesis of atherosclerosis. We aimed to investigate the roles and molecular mechanisms of myocardial infarction-associated transcript (MIAT) in the proliferation, migration, and invasion of oxidized low-density lipoprotein (ox-LDL)-induced vascular smooth muscle cells (VSMCs). Quantitative real-time polymerase chain reaction was conducted to determine the levels of MIAT, microRNA490-3p (miR-490-3p), and intercellular adhesion molecule 1 (ICAM1). Cell Counting Kit-8 assay was performed to assess cell proliferation. Transwell assay was used to evaluate cell migration and invasion. Western blot assay was performed to measure the protein levels of proliferating cell nuclear antigen, N-cadherin, matrix metalloprotein-9, and ICAM1. Dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays were conducted to verify the relationship between miR-490-3p and MIAT or ICAM1. MIAT was elevated in atherosclerosis patients' serum and ox-LDL-induced VSMCs. MIAT knockdown suppressed cell proliferation, migration, and invasion in ox-LDL-stimulated VSMCs. MIAT acted as a sponge of miR-490-3p, and miR-490-3p deficiency overturned the inhibition of MIAT knockdown on VSMC proliferation, migration, and invasion. ICAM1 was a direct target of miR-490-3p, and ICAM1 silencing repressed the proliferation, migration, and invasion of ox-LDL-stimulated VSMCs. Moreover, ICAM1 overexpression reversed the impacts of MIAT knockdown on ox-LDL-induced VSMC proliferation, migration, and invasion. MIAT knockdown could depress cell proliferation, migration, and invasion through miR-490-3p/ICAM1 axis in ox-LDL-induced VSMCs.

Knockdown of H19 Attenuates Ox-LDL-induced Vascular Smooth Muscle Cell Proliferation, Migration, and Invasion by Regulating miR-599/PAPPA Axis

ABSTRACT

Long noncoding RNAs could participate in the development of atherosclerosis (AS). However, the underlying mechanism by which long noncoding RNA H19 is implicated in AS remains largely unknown. In this study, we investigated the function of H19 on cell proliferation, migration, and invasion in oxidized low-density lipoprotein (ox-LDL)-treated human aortic vascular smooth muscle cells (HA-VSMCs), and on hyperlipidemia response in high-fat diet (HFD)-treated ApoE-/- mice. Moreover, we explored the target interaction among H19, microRNA (miR)-599, and pappalysin 1 (PAPPA). Our results showed that H19 expression was elevated in serum samples of patients with AS and ox-LDL-treated HA-VSMC. H19 silence mitigated ox-LDL-induced proliferation, migration, and invasion of HA-VSMCs. H19 acted as a sponge for miR-599, and miR-599 knockdown reversed the suppressive effect of H19 silence on proliferation, migration, and invasion of HA-VSMCs. PAPPA was a target of miR-599 and attenuated the inhibitive role of miR-599 in HA-VSMC processes. H19 knockdown repressed PAPPA expression by increasing miR-599. Moreover, H19 interference alleviated hyperlipidemia response in HFD-treated ApoE-/- mice. Collectively, knockdown of H19 inhibited proliferation, migration, and invasion of ox-LDL-treated HA-VSMCs and hyperlipidemia response in HFD-treated ApoE-/- mice by regulating miR-599/PAPPA axis, indicating H19 might act as a potential target for the treatment of AS.

LINC00472 regulates vascular smooth muscle cell migration and proliferation via regulating miR-149-3p

LncRNAs are one group of gene modulators functioning via several mechanisms in pathological and physiological conditions. We noted that LINC00472 expression level is elevated in atherosclerotic coronary tissues compared with normal coronary artery samples. LINC00472 is also upregulated in vascular smooth muscle cells (VSMCs) induced by TNF-α and PDGF-BB. Ectopic expression of LINC00472 induced VSMC migration and proliferation. The predicted binding sequence between miR-149-3p and LINC00472 was analyzed by LncBase Predicted. Overexpression of miR-149-3p decreases the luciferase activity of wild-type reporter plasmid, but not the mutant one. Ectopic expression of LINC00472 suppresses the expression of miR-149-3p in VSMCs. Furthermore, we demonstrated that miR-149-3p expression is decreased in atherosclerotic coronary tissues. MiR-149-3p was downregulated in VSMCs induced by TNF-α and PDGF-BB. Overexpression of LINC00472 induces VSMC migration and proliferation via regulating miR-149-3p. These data suggested that LINC00472 acts a critical role in the migration and proliferation of VSMCs partly via modulating miR-149-3p.

Constructing a ceRNA-immunoregulatory network associated with the development and prognosis of human atherosclerosis through weighted gene co-expression network analysis

There is now overwhelming experimental and clinical evidence that atherosclerosis (AS) is a chronic inflammatory disease. The recent discovery of a new group of mediators known as competing endogenous RNA (ceRNA) offers a unique opportunity for investigating immunoregulation in AS. In this study, we used gene expression profiles from GEO database to construct a lncRNA-miRNA-mRNA ceRNA network during AS plaque development through weighted gene co-expression network analysis (WGCNA). GO annotation and pathway enrichment analysis suggested that the ceRNA network was mainly involved in the immune response. CIBERSORT and GSVA were used to calculate the immune cell infiltration score and identified macrophage as hub immunocyte in plaque development. A macrophage related ceRNA subnetwork was constructed through correlation analysis. Samples from Biobank of Karolinska Endarterectomy (BiKE) were used to identify prognostic factors from the subnetwork and yielded 7 hub factors that can predict ischemic events including macrophage GSVA score and expression value of AL138756.1, CTSB, MAFB, LYN, GRK3, and BID. A nomogram based on the key factors was established. GSEA identified that the PD1 signaling pathway was negatively associated with these prognostic factors which may explain the cardiovascular side effect of immune checkpoint therapy in anti-tumor treatment.

Plasma exosome-derived microRNAs expression profiling and bioinformatics analysis under cross-talk between increased low-density lipoprotein cholesterol level and ATP-sensitive potassium channels variant rs1799858

Background

Exosome-derived microRNAs (exo-miRs) as messengers play important roles, in the cross-talk between genetic [ATP-sensitive potassium channels (KATP) genetic variant rs1799858] and environmental [elevated serum low-density lipoprotein cholesterol (LDL-C) level] factors, but the plasma exo-miRs expression profile and its role in biological processes from genotype to phenotype remain unclear.

Methods

A total of 14 subjects with increased LDL-C serum levels (≥ 1.8 mmol/L) were enrolled in the study. The KATP rs1799858 was genotyped by the Sequenom MassARRAY system. The plasma exo-miRs expression profile was identified by next-generation sequencing.

Results

64 exo-miRs were significantly differentially expressed (DE), among which 44 exo-miRs were up-regulated and 20 exo-miRs were down-regulated in those subjects carrying T-allele (TT + CT) of rs1799858 compared to those carrying CC genotype. The top 20 up-regulated DE-exo-miRs were miR-378 family, miR-320 family, miR-208 family, miR-483-5p, miR-22-3p, miR-490-3p, miR-6515-5p, miR-31-5p, miR-210-3p, miR-17-3p, miR-6807-5p, miR-497-5p, miR-33a-5p, miR-3611 and miR-126-5p. The top 20 down-regulated DE-exo-miRs were let-7 family, miR-221/222 family, miR-619-5p, miR-6780a-5p, miR-641, miR-200a-5p, miR-581, miR-605-3p, miR-548ar-3p, miR-135a-3p, miR-451b, miR-509-3-5p, miR-4664-3p and miR-224-5p. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were subsequently implemented to identify the top 10 DE-exo-miRs related specific target genes and signaling pathways. Only 5 DE-exo-miRs were validated by qRT-PCR as follows: miR-31-5p, miR-378d, miR-619-5p, miR-320a-3p and let-7a-5p (all P < 0.05).

Conclusion

These results firstly indicated the plasma exo-miRs expression profile bridging the link between genotype (KATP rs1799858) and phenotype (higher LDL-C serum level), these 5 DE-exo-miRs may be potential target intermediates for molecular intervention points.

Transfer of microRNA-221 from mesenchymal stem cell-derived extracellular vesicles inhibits atherosclerotic plaque formation

Mesenchymal stem cells (MSCs) have emerged as a cell-based therapy in many diseases including atherosclerosis (AS) due to their capability of immunomodulation and tissue regeneration. However, the pathway for MSCs' antiatherosclerotic activity remains to be elucidated. Here, we test the hypothesis that microRNA-221 (miR-221) from MSC-derived extracellular vesicles (EVs) alleviates AS. Male ApoE-/- mice were fed a high-fat diet for 12 weeks to induce AS, and were then treated with human bone marrow mesenchymal stem cell-derived EVs by tail vein injection. The expression pattern of miR-221 and N-acetyltransferase-1 (NAT1) in AS mice was characterized by quantitative RNA analysis and their interaction was identified by dual-luciferase reporter gene assay. In other studies, human arterial smooth muscle cells treated with oxidized low-density lipoprotein-were co-cultured with MSC-released EVs to evaluate the EV-mediated transfer of miR-221. NAT1 was highly expressed in atherosclerotic lesions. Adenovirus-mediated NAT1 knockdown resulted in a reduced lipid deposition in AS mice. Human bone marrow mesenchymal stem cell -derived EVs carrying miR-221 were internalized by human arterial smooth muscle cells and transferred their miR-221 contents to downregulate the target gene NAT1. Injection of miR-221-containing EVs inhibited lipid deposition in AS mice, in part by downregulating NAT1. The present study provides evidence that miR-221 shuttled by MSC-derived EVs can inhibit atherosclerotic plaque formation in AS model mice, suggesting that miR-221 may serve as a target for improving MSC-based therapeutic strategy against AS.

Hsa-circ_0010283 Regulates Oxidized Low-Density Lipoprotein-Induced Proliferation and Migration of Vascular Smooth Muscle Cells by Targeting the miR-133a-3p/Pregnancy-Associated Plasma Protein A Axis

BACKGROUND

The dysfunction of vascular smooth muscle cells (VSMCs) contributes to the development of atherosclerosis. This study aimed to investigate the role of circular RNA-0010283 (circ_0010283) in oxidized low-density lipoprotein (ox-LDL)-treated VSMCs and the associated action mechanism.

METHODS AND RESULTS

The expression of circ_0010283 was investigated using quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was monitored by using a 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Cell apoptosis was detected by using flow cytometry assay. A transwell assay was performed to observe migration and invasion, and a scratch assay was implemented to test migration. The expression of proliferation, apoptosis and migration/invasion-related proteins was measured by using a western blot. The targeted relationship was predicted by using a bioinformatics tool (Starbase) and verified by using a dual-luciferase reporter assay, a RNA immunoprecipitation (RIP) assay and a RNA pull-down assay. circ_0010283 was highly expressed in serum samples from atherosclerosis patients and ox-LDL-treated human VSMCs (HVSMCs). circ_0010283 knockdown suppressed ox-LDL-induced proliferation, migration and invasion in HVSMCs. MicroRNA-133a-3p (miR-133a-3p) was confirmed as a target of circ_0010283, and miR-133a-3p deficiency reversed the effects of circ_0010283 knockdown. Moreover, pregnancy-associated plasma protein A (PAPPA) was targeted by miR-133a-3p, and PAPPA overexpression reversed the effects of miR-133a-3p restoration. Interestingly, circ_0010283 could regulate PAPPA expression by mediating miR-133a-3p.

CONCLUSIONS

circ_0010283 participated in ox-LDL-induced dysfunctions of HVSMCs by modulating the miR-133a-3p/PAPPA pathway, suggesting that circ_0010283 might be associated with atherosclerosis pathogenesis.

miR-490: A potential biomarker and therapeutic target in cancer and other diseases

MicroRNAs (miRNAs) are small non-coding RNAs that function as posttranscriptional gene regulators. Among a pool of >2600 known human mature miRNAs, only a small subset have been functionally interrogated and a further smaller pool shown to be associated with the pathogenesis of a variety of diseases suggesting their critical role in maintaining homeostasis. Here, we draw your attention to one such miRNA, miR-490, that has been reported to be deregulated in a myriad of diseases (23 diseases) ranging from cardiomyopathy, depression, and developmental disorders to many cancer types (28 cancer types), such as hepatocellular carcinoma, gastric cancer, cancers of the reproductive and central nervous system among others. The prognostic and diagnostic potential of miR-490 has been reported in many diseases including cancer underlining its clinical relevance. We also collate a complex plethora of epigenetic (histone and DNA methylation), transcriptional (TF), and posttranscriptional (lncRNA and circRNA) mechanisms that have been shown to tightly regulate miR-490 levels. The targets of miR-490 involve a range of cancer-related genes involved in the regulation of various cancer hallmarks like cell proliferation, migration, and invasion, apoptotic cell death, angiogenesis, and so forth. Overall, our in-depth review highlights for the first time the emerging role of miR-490 in disease pathology, diagnosis, and prognosis that assigns a unique therapeutic potential to miR-490 in the era of precision medicine.

Circular RNA circ_0029589 regulates proliferation, migration, invasion, and apoptosis in ox-LDL-stimulated VSMCs by regulating miR-424-5p/IGF2 axis

BACKGROUND

Circular RNAs (circRNAs) have been identified to be critical mediators in the progression of atherosclerosis (AS). However, the exact roles and molecular mechanism of circ_0029589 in AS are far from understood.

METHODS

Vascular smooth muscle cells (VSMCs) stimulated by oxidized low-density lipoprotein (ox-LDL) were served as a cellular model of AS. The expression levels of circ_0029589, microRNA (miR)-424-5p, and insulin-like growth factor 2 (IGF2) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot analysis. Cell proliferation was determined by Cell Counting Kit-8 (CCK-8) assay and colony formation assay. Cell apoptosis, migration and invasion were examined by flow cytometry and transwell assay. The relationship between miR-424-5p and circ_0029589 or IGF2 was predicted by starbase and verified by dual-luciferase reporter assay.

RESULTS

Circ_0029589 and IGF2 were upregulated and miR-424-5p was downregulated in VSMCs treated with ox-LDL. Silence of circ_0029589 inhibited proliferation, migration and invasion but induced apoptosis in ox-LDL-treated VSMCs. MiR-424-5p was a target of circ_0029589 and its knockdown reversed the effects of circ_0029589 interference on proliferation, migration, invasion, and apoptosis in ox-LDL-stimulated VSMCs. IGF2 was a target of miR-424-5p and miR-424-5p overexpression suppressed proliferation, migration and invasion while promoted apoptosis in ox-LDL-treated VSMCs by downregulating IGF2. Circ_0029589 positively modulated IGF2 expression by sponging miR-424-5p.

CONCLUSION

Circ_0029589 silence might inhibit the progression of AS by regulating miR-424-5p/IGF2 axis, providing a novel mechanism for pathogenesis of AS.

HIX003209 promotes vascular smooth muscle cell migration and proliferation through modulating miR-6089

Accumulating references have showed that long noncoding RNAs (lncRNAs) act important roles in the development of human diseases. The role and expression of HIX003209 remains unclear in the pathogenesis of atherosclerosis. We showed that HIX003209 expression was upregulated in atherosclerotic coronary tissues compared to normal coronary artery samples. HIX003209 was overexpressed in vascular smooth muscle cells (VSMCs) induced by inflammatory mediators including tumor necrosis factor-α(TNF-α), ox-LDL and latelet-derived growth factor-BB (PDGF-BB). Ectopic expression of HIX003209 enhanced cell growth and migration and induced inflammatory mediators secretion such as interleukin 6 (IL-6), TNF-α and IL-1β in VSMCs. Furthermore, we showed that miR-6089 was downregulated in atherosclerotic coronary tissues compared to normal coronary artery samples. There was a negative association between expression of HIX003209 and miR-6089 in atherosclerotic coronary tissues. MiR-6089 expression was decreased in VSMCs induced by inflammatory mediators including TNF-α, ox-LDL and PDGF-BB. Dual luciferase analysis showed that miR-6089 overexpression decreased luciferase activity of HIX003209 WT-type 3’-UTR but not the mut-type 3’-UTR. Overexpression of HIX003209 suppressed the expression of miR-6089 in VSMCs. Ectopic expression of HIX003209 induced cell growth, migration and the secretion of inflammatory mediators via regulating miR-6089 expression. These data suggested that HIX003209 promoted VSMCs proliferation, migration and the secretion of inflammatory mediators partly via regulating miR-6089.

Proteomics Profiling Reveals Insulin-Like Growth Factor 1, Collagen Type VI α-2 Chain, and Fermitin Family Homolog 3 as Potential Biomarkers of Plaque Erosion in ST-Segment Elevated Myocardial Infarction

BACKGROUND

Plaque erosion (PE) has been considered a secondary pathogenesis of ST-segment elevated myocardial infarction (STEMI) following plaque rupture (PR). Previous studies demonstrated that they had different demographic and histology characteristics and need different treatment strategy. But there are few non-invasive plasma biomarkers for distinguishing them. The present study aimed to identify non-invasive predictive biomarkers for PE and PR in patients with STEMI.

METHODS AND RESULTS

A total 108 patients were recruited and grouped into a PE group (n=36), a PR group (n=36), and an unstable angina pectoris (UAP) (n=36) group for analysis. A 9-plex tandem mass tag (TMT)-based proteomics was used to compare plasma protein profiles of PE, PR, and UAP. In total, 36 significant differential proteins (DPs) were identified among groups, 10 of which were screened out using bio-information analysis and validated with enzyme-linked immunosorbent assay (ELISA). The relationship of angiography and optical coherence tomography (OCT) imaging data and the 10 target DPs was analyzed statistically. Logistic regression showed elevated collagen type VI α-2 chain (COL6A2) and insulin-like growth factor 1 (IGF1), and decreased fermitin family homolog 3 (FERMT3), were positively associated with PE. Multivariate analysis indicated IGF1, FERMT3, and COL6A2 had independent predictive ability for PE. IGF1 was inversely correlated with lumen stenosis and the lipid arc of the plaque.

CONCLUSIONS

IGF1, COL6A2, and FERMT3 are potential predictive biomarkers of PE in STEMI patients. And IGF1 was negatively correlated with the developing of culprit plaque.

Downregulation of miR-637 promotes vascular smooth muscle cell proliferation and migration via regulation of insulin-like growth factor-2

Background

Dysregulation of the proliferation and migration of vascular smooth muscle cells (VSMCs) is a crucial cause of atherosclerosis. MiR-637 exerts an antiproliferative effect on multiple human cells. Its impact on atherosclerosis remains largely unexplored.

Methods

Real-time PCR was used to determine miR-637 expression in samples from atherosclerosis patients and animal models. Its expression in VSMC dysfunction models (induced by ox-LDL) was also measured. The proliferation and migration of VSMCs were respectively tested using CCK-8 and Transwell assays, and apoptosis was measured using flow cytometry. The Targetscan database was used to predict the target genes of miR-637. Interaction between miR-637 and the potential target gene was validated via real-time PCR, western blotting and a luciferase reporter assay.

Results

MiR-637 expression was significantly lower in atherosclerosis patient and animal model samples. It also decreased in a dose- and time-dependent manner in animal models with ox-LDL-induced atherosclerosis. Transfection with miR-637 mimics suppressed the proliferation and migration of VSMCs while promoting apoptosis, while transfection with miR-637 inhibitors had the opposite effects. We also validated that insulin-like growth factor-2 (IGF-2), a crucial factor in the pathogenesis of atherosclerosis, serves as a target gene for miR-637.

Conclusion

MiR-637 targeting IGF-2 contributes to atherosclerosis inhibition and could be a potential target for this disease.

microRNA profiling in the Weddell seal suggests novel regulatory mechanisms contributing to diving adaptation

Background

The Weddell Seal (Leptonychotes weddelli) represents a remarkable example of adaptation to diving among marine mammals. This species is capable of diving > 900 m deep and remaining underwater for more than 60 min. A number of key physiological specializations have been identified, including the low levels of aerobic, lipid-based metabolism under hypoxia, significant increase in oxygen storage in blood and muscle; high blood volume and extreme cardiovascular control. These adaptations have been linked to increased abundance of key proteins, suggesting an important, yet still understudied role for gene reprogramming.

In this study, we investigate the possibility that post-transcriptional gene regulation by microRNAs (miRNAs) has contributed to the adaptive evolution of diving capacities in the Weddell Seal.

Results

Using small RNA data across 4 tissues (brain, heart, muscle and plasma), in 3 biological replicates, we generate the first miRNA annotation in this species, consisting of 559 high confidence, manually curated miRNA loci. Evolutionary analyses of miRNA gain and loss highlight a high number of Weddell seal specific miRNAs.

Four hundred sixteen miRNAs were differentially expressed (DE) among tissues, whereas 80 miRNAs were differentially expressed (DE) across all tissues between pups and adults and age differences for specific tissues were detected in 188 miRNAs. mRNA targets of these altered miRNAs identify possible protective mechanisms in individual tissues, particularly relevant to hypoxia tolerance, anti-apoptotic pathways, and nitric oxide signal transduction. Novel, lineage-specific miRNAs associated with developmental changes target genes with roles in angiogenesis and vasoregulatory signaling.

Conclusions

Altogether, we provide an overview of miRNA composition and evolution in the Weddell seal, and the first insights into their possible role in the specialization to diving.

Metalloproteinase PAPP-A regulation of IGF-1 contributes to polycystic kidney disease pathogenesis

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic cause of end-stage renal disease (ESRD). The treatment options for ADPKD are limited. We observed an upregulation in several IGF-1 pathway genes in the kidney of Pkd1RC/RC mice, a model of ADPKD. Pregnancy-associated plasma protein A (PAPP-A), a metalloproteinase that cleaves inhibitory IGF binding proteins (IGFBPs), increasing the local bioactivity of IGF-1, was highly induced in the kidney of ADPKD mice. PAPP-A levels were high in cystic fluid and kidneys of humans with ADPKD. Our studies further showed that PAPP-A transcription in ADPKD was mainly regulated through the cAMP/CREB/CBP/p300 pathway. Pappa deficiency effectively inhibited the development of cysts in the Pkd1RC/RC mice. The role of PAPP-A in cystic disease appears to be regulation of the IGF-1 pathway and cellular proliferation in the kidney. Finally, preclinical studies demonstrated that treatment with a monoclonal antibody that blocks the proteolytic activity of PAPP-A against IGFBP4 ameliorated ADPKD cystic disease in vivo in Pkd1RC/RC mice and ex vivo in embryonic kidneys. These data indicated that the PAPP-A/IGF-1 pathway plays an important role in the growth and expansion of cysts in ADPKD. Our findings introduce a therapeutic strategy for ADPKD that involves the inhibition of PAPP-A.

Identifying the key microRNAs implicated in atrial fibrillation

OBJECTIVE

This study investigated the potential microRNAs (miRNAs) having a diagnostic value in atrial fibrillation (AF).

METHODS

The miRNA and mRNA expression profiles of atrial tissue from healthy individuals and patients with AF were downloaded from the Gene Expression Omnibus database. Differentially expressed miRNAs/mRNAs (DEMis/DEMs) were identified in patients with AF. Furthermore, an interaction network between DEMis and DMEs was constructed. The biological processes, molecular functions, and signaling pathways of DEMs were enriched. Then, the diagnostic values of candidate DECs among healthy individuals and patients with AF were preliminarily evaluated in the GSE101586, GSEE101684, and GSE112214 datasets.

RESULTS

Twenty DEMis were identified in patients with AF, including seven upregulated and 13 downregulated DEMis. Furthermore, 2,307 DEMs were identified in patients with AF. In the DEMi-DEM interaction network, downregulated miR-193b and upregulated miR-16 interacted with the most targeted DEMs, which interacted with 72 and 65 targeted DEMs, respectively. The targeted DEMs were significantly enriched in biological functions including apoptosis and the PI3K-Akt, mTOR, Hippo, HIF-1, and ErbB signaling pathways. Four of the 20 DEMis (i.e., miR-490-3p, miR-630, miR-146b-5p, and miR-367) had a potential value to distinguish patients with AF from healthy individuals in the GSE68475, GSE70887, and GSE28954 datasets. The area under the curve values for those four DEMis were 0.751, 0.719, 0.709, and 0.7, respectively.

CONCLUSION

DEMis might play key roles in AF progression through the mTOR and Hippo signaling pathways. miR-409-3p, miR-630, miR-146b-5p, and miR-367 had a potential diagnostic value to discriminate patients with AF from healthy controls in this study.

Retracted Article: Long non-coding RNA MEG3 inhibits cell proliferation, migration, invasion and enhances apoptosis in non-small cell lung cancer cells by regulating the miR-31-5p/TIMP3 axis

Non-small cell lung cancer (NSCLC) is a malignant lung cancer and accounts for 80% of lung cancer-related deaths. Long non-coding RNA maternally expressed gene 3 (MEG3) has been identified as a tumor suppressor in multiple cancers. However, the regulatory mechanism of MEG3 in NSCLC development is still largely unknown. The expression levels of MEG3, microRNA-31-5p (miR-31-5p) and tissue inhibitor of metalloproteinase 3 (TIMP3) in NSCLC tumors and cells were measured by quantitative real time polymerase chain reaction (qRT-PCR). Cell viability, apoptosis, migration and invasion were detected by cell counting kit-8 (CCK-8), flow cytometry, western blotting and transwell assays, respectively. Xenograft mouse models were established by subcutaneously injecting NSCLC cells stably transfected with Lenti-pcDNA or Lenti-MEG3. The interaction between miR-31-5p and MEG3 or TIMP3 was validated by luciferase reporter and RNA immunoprecipitation (RIP) assays. MEG3 and TIMP3 levels were up-regulated, whereas miR-31-5p expression was down-regulated in NSCLC tumors and cells compared with normal tissues and cells. Overexpression of MEG3 repressed cell proliferation, migration and invasion, but induced apoptosis in NSCLC cells. More importantly, MEG3 effectively hindered tumor growth in vivo. Next, luciferase reporter and RIP assays confirmed the interaction between miR-31-5p and MEG3 or TIMP3. Pearson's correlation coefficient revealed that miR-31-5p was inversely correlated with MEG3 or TIMP3. Rescue experiments indicated that MEG3 regulated TIMP3 expression by sponging miR-31-5p in NSCLC cells. Thus, MEG3 inhibited cell proliferation, migration and invasion, but enhanced apoptosis in NSCLC cells through up-regulating TIMP3 expression by regulating miR-31-5p, indicating novel biomarkers for the therapy of NSCLC.

Non-small cell lung cancer (NSCLC) is a malignant lung cancer and accounts for 80% of lung cancer-related deaths.

Retracted Article: Knockdown of long non-coding RNA OIP5-AS1 suppresses cell proliferation and migration in ox-LDL-induced human vascular smooth muscle cells (hVMSCs) through targeting miR-152-3p/PAPPA axis

Emerging evidence has demonstrated that long non-coding RNA Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) is associated with cellular behaviors among malignant tumors. However, the role of OIP5-AS1 in atherosclerosis remains largely undefined. The aim of this study was to explore the expression and role of OIP5-AS1 in a cell model of atherosclerosis, as well as the underlying mechanism. We found that expression of OIP5-AS1 was upregulated in human vascular smooth muscle cells (hVMSCs) under oxidized low density lipoprotein (ox-LDL) administration, and knockdown of OIP5-AS1 suppressed cell viability (CCK-8) and proliferating cell nuclear antigen (PCNA) protein level in ox-LDL-treated hVMSCs, as well as inhibited cell migration rate (wound healing assay) and protein expression of matrix metalloproteinase (MMP)-2 and MMP-9. Mechanically, OIP5-AS1 functioned as competing endogenous RNA (ceRNA) to positively regulate PAPPA expression through sponging miRNA-152-3p (miR-152), and pregnancy-associated plasma protein A (PAPPA) was identified as a downstream target gene for miR-152. Moreover, expression of miR-152 was downregulated and PAPPA was upregulated in ox-LDL-treated hVMSCs. Similarly to OIP5-AS1 knockdown, miR-215 overexpression could inhibit cell proliferation and migration of hVMSCs administrated by ox-LDL, which was abated by PAPPA upregulation. Moreover, miR-215 downregulation partially reversed the suppressive role of OIP5-AS1 knockdown as well. In conclusion, knockdown of OIP5-AS1 suppressed ox-LDL-treated hVMSC proliferation and migration presumably through targeting miR-152/PAPPA axis, suggesting a novel OIP5-AS1/miR-152/PAPPA pathway in atherogenesis.

PAPP-A and the IGF system in atherosclerosis: what's up, what's down?

Pregnancy-associated plasma protein-A (PAPP-A) is a metalloproteinase with a well-established role in releasing bioactive insulin-like growth factor-1 (IGF-1) from IGF-binding protein-2, -4, and -5 by proteolytic processing of these. The IGF system has repeatedly been suggested to be involved in the pathology of atherosclerosis, and both PAPP-A and IGF-1 are proposed biomarkers and therapeutic targets for this disease. Several experimental approaches based on atherosclerosis mouse models have been undertaken to obtain causative and mechanistic insight to the role of these molecules in atherogenesis. However, reports seem conflicting. The literature suggests that PAPP-A is detrimental, while IGF-1 is beneficial. This raises important questions that need to be addressed. Here we summarize the various studies and discuss potential underlying explanations for this seemingly inconsistency with the objective of better understanding complexities and limitations when manipulating the IGF system in mouse models of atherosclerosis. A debate clarifying what's up and what's down is highly warranted going forward with the ultimate goal of improving atherosclerosis therapy by targeting the IGF system.

Replication timing networks reveal a link between transcription regulatory circuits and replication timing control

DNA replication occurs in a defined temporal order known as the replication timing (RT) program and is regulated during development, coordinated with 3D genome organization and transcriptional activity. However, transcription and RT are not sufficiently coordinated to predict each other, suggesting an indirect relationship. Here, we exploit genome-wide RT profiles from 15 human cell types and intermediate differentiation stages derived from human embryonic stem cells to construct different types of RT regulatory networks. First, we constructed networks based on the coordinated RT changes during cell fate commitment to create highly complex RT networks composed of thousands of interactions that form specific functional subnetwork communities. We also constructed directional regulatory networks based on the order of RT changes within cell lineages, and identified master regulators of differentiation pathways. Finally, we explored relationships between RT networks and transcriptional regulatory networks (TRNs) by combining them into more complex circuitries of composite and bipartite networks. Results identified novel trans interactions linking transcription factors that are core to the regulatory circuitry of each cell type to RT changes occurring in those cell types. These core transcription factors were found to bind cooperatively to sites in the affected replication domains, providing provocative evidence that they constitute biologically significant directional interactions. Our findings suggest a regulatory link between the establishment of cell-type-specific TRNs and RT control during lineage specification.

Long noncoding RNA LINC00968 promotes endothelial cell proliferation and migration via regulating miR-9-3p expression

Long noncoding RNAs (lncRNAs) have been showed to play a crucial role in pathogenesis and development of cardiovascular diseases. Our study aimed to study the expression and functional role of lncRNA LINC00968 in the development of coronary artery disease (CAD). We showed that the LINC00968 expression level was upregulated in the CAD tissues compared with normal arterial tissues. In addition, we showed that the expression level of LINC00968 was upregulated by oxidized low-density lipoprotein (oxLDL) treatment in endothelial cell. Ectopic expression of LINC00968 regulated the proliferation and migration of endothelial cell. Moreover, we showed that overexpression of LINC00968 inhibited miR-9-3p expression in an endothelial cell. Furthermore, we demonstrated that the miR-9-3p expression was downregulated in the CAD samples compared with normal arterial tissues and the expression level of miR-9-3p was downregulated by oxLDL treatment in endothelial cell. Finally, we showed that ectopic expression of LINC00968 promoted endothelial cell proliferation and migration partly through regulating miR-9-3p expression. These results suggested that LINC00968 plays a crucial role in the progression of the CAD.

IGF-1 and cardiovascular disease

Atherosclerosis is an inflammatory arterial pathogenic condition, which leads to ischemic cardiovascular diseases, such as coronary artery disease and myocardial infarction, stroke, and peripheral arterial disease. Atherosclerosis is a multifactorial disorder and its pathophysiology is highly complex. Changes in expression of multiple genes coupled with environmental and lifestyle factors initiate cascades of adverse events involving multiple types of cells (e.g. vascular endothelial cells, smooth muscle cells, and macrophages). IGF-1 is a pleiotropic factor, which is found in the circulation (endocrine IGF-1) and is also produced locally in arteries (endothelial cells and smooth muscle cells). IGF-1 exerts a variety of effects on these cell types in the context of the pathogenesis of atherosclerosis. In fact, there is an increasing body of evidence suggesting that IGF-1 has beneficial effects on the biology of atherosclerosis. This review will discuss recent findings relating to clinical investigations on the relation between IGF-1 and cardiovascular disease and basic research using animal models of atherosclerosis that have elucidated some of the mechanisms underlying atheroprotective effects of IGF-1.

The microRNAs Regulating Vascular Smooth Muscle Cell Proliferation: A Minireview

Vascular smooth muscle cell (VSMC) proliferation plays a critical role in atherosclerosis. At the beginning of the pathologic process of atherosclerosis, irregular VSMC proliferation promotes plaque formation, but in advanced plaques VSMCs are beneficial, promoting the stability and preventing rupture of the fibrous cap. Recent studies have demonstrated that microRNAs (miRNAs) expressed in the vascular system are involved in the control of VSMC proliferation. This review summarizes recent findings on the miRNAs in the regulation of VSMC proliferation, including miRNAs that exhibit the inhibition or promotion of VSMC proliferation, and their targets mediating the regulation of VSMC proliferation. Up to now, most of the studies were performed only in cultured VSMC. While the modulation of miRNAs is emerging as a promising strategy for the regulation of VSMC proliferation, most of the effects of miRNAs and their targets in vivo require further investigation.

miR-26a inhibits atherosclerosis progression by targeting TRPC3

Background

Atherosclerosis, a chronic multi-factorial vascular disease, has become a predominant cause of a variety of cardiovascular disorders. miR-26a was previously reported to be involved in atherosclerosis progression. However, the underlying mechanism of miR-26a in atherosclerosis remains to be further explained.

Methods

High-fat diet (HFD)-fed apolipoprotein E (apoE)^-/- mice and oxidized low-density lipoprotein (ox-LDL)-stimulated human aortic endothelial cells (HAECs) were established as in vivo and in vitro models of atherosclerosis. RT-qPCR and western blot analysis were performed to measure the expression of miR-26a and transient receptor potential canonical 3 (TRPC3), respectively. Binding between miR-26a and TRPC3 was predicted with bioinformatics software and verified using a dual luciferase reporter assay. The effects of miR-26a on the lipid accumulation, atherosclerotic lesion, and inflammatory response in HFD-fed apoE^-/- mice were investigated by a colorimetric enzymatic assay system, hematoxylin-eosin and oil-Red-O staining, and ELISA, respectively. Additionally, the effects of miR-26a or combined with TRPC3 on cell viability, apoptosis and the nuclear factor-kappa B (NF-κB) pathway in ox-LDL-stimulated HAECs were evaluated by MTT assay, TUNEL assay, and western blot, respectively.

Results

miR-26a was downregulated in HFD-fed apoE^-/- mice and ox-LDL-stimulated HAECs. miR-26a overexpression inhibited the pathogenesis of atherosclerosis by attenuating hyperlipidemia, atherosclerotic lesion and suppressing inflammatory response in HFD-fed apoE^-/- mice. Moreover, miR-26a overexpression suppressed inflammatory response and the NF-κB pathway, promoted cell viability and inhibited apoptosis in ox-LDL-stimulated HAECs. Additionally, TRPC3 was demonstrated to be a direct target of miR-26a. Enforced expression of TRPC3 reversed the effects of miR-26a on cell viability, apoptosis, and the NF-κB pathway in ox-LDL-treated HAECs.

Conclusions

miR-26a alleviated the development of atherosclerosis by regulating TRPC3, providing a potential target for atherosclerosis treatment.

Cardiovascular Risk Factors and Markers

Cardiovascular risk is assessed for the prediction and appropriate management of patients using collections of identified risk markers obtained from clinical questionnaire information, concentrations of certain blood molecules (e.g., N-terminal proB-type natriuretic peptide fragment and soluble receptors of tumor-necrosis factor-α and interleukin-2), imaging data using various modalities, and electrocardiographic variables, in addition to traditional risk factors.

The Role of MicroRNAs in Arterial Stiffness and Arterial Calcification. An Update and Review of the Literature

Arterial stiffness is an independent risk factor for fatal and non-fatal cardiovascular events, such as systolic hypertension, coronary artery disease, stroke, and heart failure. Moreover it reflects arterial aging which in many cases does not coincide with chronological aging, a fact that is in large attributed to genetic factors. In addition to genetic factors, microRNAs (miRNAs) seem to largely affect arterial aging either by advancing or by regressing arterial stiffness. MiRNAs are small RNA molecules, ~22 nucleotides long that can negatively control their target gene expression posttranscriptionally. Pathways that affect main components of stiffness such as fibrosis and calcification seem to be influenced by up or downregulation of specific miRNAs. Identification of this aberrant production of miRNAs can help identify epigenetic changes that can be therapeutic targets for prevention and treatment of vascular diseases. The present review summarizes the specific role of the so far discovered miRNAs that are involved in pathways of arterial stiffness.

Adenovirus-Mediated Gene Transfer of microRNA-21 Sponge Inhibits Neointimal Hyperplasia in Rat Vein Grafts

Background:Vein graft failure due to neointimal hyperplasia remains an important and unresolved complication of cardiovascular surgery. microRNA-21 (miR-21) plays a major role in regulating vascular smooth muscle cell (VSMC) proliferation and phenotype transformation. Thus, the purpose of this study was to determine whether adenovirus-mediated miR-21 sponge gene therapy was able to inhibit neointimal hyperplasia in rat vein grafts.

Methods:Adenovirus-mediated miR-21 sponge was used to inhibit VSMC proliferation in vitro and neointimal formation in vivo. To improve efficiency of delivery gene transfer to the vein grafts, 20% poloxamer F-127 gel was used to increase virus contact time and 0.25% trypsin to increase virus penetration. Morphometric analyses and cellular proliferation were assessed for neointimal hyperplasia and VSMC proliferation.

Results:miR-21 sponge can significantly decrease the expression of miR-21 and proliferation in cultured VSMCs. Cellular proliferation rates were significantly reduced in miR-21 sponge-treated grafts compared with controls at 28 days after bypass surgery (14.6±9.4 vs 34.9±10.8%, P=0.0032). miR-21 sponge gene transfer therapy reduced the intimal/media area ratio in vein grafts compared with the controls (1.38±0.08 vs. 0.6±0.10, P<0.0001). miR-21 sponge treatment also improved vein graft hemodynamics. We further identified that phosphatase and tensin homolog (PTEN) is a potential target gene that was involved in the miR-21-mediated effect on neointimal hyperplasia in vein grafts.

Conclusions:Adenovirus-mediated miR-21 sponge gene therapy effectively reduced neointimal formation in vein grafts. These results suggest that there is potential for miR-21 sponge to be used to prevent vein graft failure.

LncRNA BANCR facilitates vascular smooth muscle cell proliferation and migration through JNK pathway

Deregulated migration and proliferation of vascular smooth muscle cells (VSMCs) acts a crucial role in the pathogenesis of many cardiovascular diseases such as atherosclerosis, coronary heart disease and hypertension. Long noncoding RNAs (lncRNAs) play crucial functional roles in a lot of biological processes such as cell development, cell proliferation, differentiation and invasion. In our study, we demonstrated that the BANCR expression level was upregulated in the atherosclerotic plaques tissues compared to in the normal vessels tissues. TNF-α could emhance the VSMCs proliferation. The expression level of BANCR and p-JNK were upregulated and activated in the proliferating VSMCs. Overexpression of BANCR enhanced VSMCs proliferation and migration. Elevated expression of BANCR induced JNK activation, which can be decreased by the specific JNK inhibitor SP600125. We demonstrated that ectopic expression of BANCR increased the VSMCs proliferation and migration through activating JNK pathway. These data suggested that lncRNA BANCR acts a crucial role in the regulating VSMCs proliferation and migration partly by activating the JNK pathway.

MiR-448 promotes vascular smooth muscle cell proliferation and migration in through directly targeting MEF2C

Abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) is a critical process in various cardiovascular diseases such as coronary artery disease (CAD), atherosclerosis, stroke, and hypertension. MicroRNAs (miRNAs) are small, short, and noncoding RNAs that inhibit gene expression through binding to the 3'-UTR (3' untranslated regions) of target gene mRNAs. We showed that the expression of miR-448 was upregulated in VSMCs from coronary atherosclerotic plaques compared with normal coronary artery tissues. We also found that PDGF-bb promoted VSMCs proliferation and could induce miR-448 expression. Ectopic miR-448 expression induced VSMCs proliferation. Overexpression of miR-448 induced ki-67 mRNA and protein expression. Moreover, we identified MEF2C was a direct target of miR-448 in VSMCs. Overexpression of miR-448 promoted VSMCs migration. Furthermore, overexpression of MEF2C decreased miR-448-induced VSMCs proliferation and migration. These evidences suggested that miR-448 played an important role in the proliferation and migration of VSMCs.

Oxidized low-density lipoprotein stimulates epithelial sodium channels in endothelial cells of mouse thoracic aorta

BACKGROUND AND PURPOSE

The epithelial sodium channel (ENaC) is expressed in endothelial cells and acts as a negative modulator of vasodilatation. Oxidized LDL (ox-LDL) is a key pathological factor in endothelial dysfunction. In the present study we examined the role of ENaC in ox-LDL-induced endothelial dysfunction and its associated signal transduction pathway.

EXPERIMENTAL APPROACH

Patch clamp techniques combined with pharmacological approaches were used to examine ENaC activity in the endothelial cells of a split-open mouse thoracic aorta. Western blot analysis was used to determine ENaC expression in the aorta. The aorta relaxation was measured using a wire myograph assay.

KEY RESULTS

Ox-LDL, but not LDL, significantly increased ENaC activity in the endothelial cells attached to split-open thoracic aortas, and the increase was inhibited by a lectin-like ox-LDL receptor-1 (LOX-1) antagonist (κ-carrageenan), an NADPH oxidase inhibitor (apocynin), and a scavenger of ROS (TEMPOL). Sodium nitroprusside, an NO donor, diminished the ox-LDL-mediated activation of ENaC, and this effect was abolished by inhibiting soluble guanylate cyclase (sGC) and PKG. Ox-LDL reduced the endothelium-dependent vasodilatation of the aorta pectoralis induced by ACh, and this reduction was partially restored by blocking ENaC.

CONCLUSION AND IMPLICATIONS

Ox-LDL stimulates ENaC in endothelial cells through LOX-1 receptor-mediated activation of NADPH oxidase and accumulation of intracellular ROS. Since the stimulation of ENaC can be reversed by elevating NO, we suggest that both inhibition of ENaC and an elevation of NO may protect the endothelium from ox-LDL-induced dysfunction.

LINKED ARTICLES

This article is part of a themed section on Spotlight on Small Molecules in Cardiovascular Diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.8/issuetoc.

High-throughput sequencing of pituitary and hypothalamic microRNA transcriptome associated with high rate of egg production

Background

MicroRNAs exist widely in viruses, plants and animals. As endogenous small non-coding RNAs, miRNAs regulate a variety of biological processes. Tissue miRNA expression studies have discovered numerous functions for miRNAs in various tissues of chicken, but the regulation of miRNAs in chicken pituitary and hypothalamic development related to high and low egg-laying performance has remained unclear.

Results

In this study, using high-throughput sequencing technology, we sequenced two tissues (pituitary and hypothalamus) in 3 high- and 3 low-rate egg production Luhua chickens at the age of 300 days. By comparing low- and high-rate egg production chickens, 46 known miRNAs and 27 novel miRNAs were identified as differentially expressed (P < 0.05). Six differentially expressed known miRNAs, which are expressed in both tissues, were used in RT-qPCR validation and SNP detection. Among them, seven SNPs in two miRNA precursors (gga-miR-1684a and gga-miR-1434) were found that might enhance or reduce the production of the mature miRNAs. In addition, 124 and 30 reciprocally expressed miRNA-target pairs were identified by RNA-seq in pituitary and hypothalamic tissues, respectively and randomly selected candidate miRNA and miRNA-target pairs were validated by RT-qPCR in Jiuyuan black fowl. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation illustrated that a large number of egg laying-related pathways were enriched in the high-rate egg production chickens, including ovarian steroidogenesis and steroid hormone biosynthesis.

Conclusions

These differentially expressed miRNAs and their predicted target genes, especially identified reciprocally expressed miRNA-target pairs, advance the study of miRNA function and egg production associated miRNA identification. The analysis of the miRNA-related SNPs and their effects provided insights into the effects of SNPs on miRNA biogenesis and function. The data generated in this study will further our understanding of miRNA regulation mechanisms in the chicken egg-laying process.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-017-3644-3) contains supplementary material, which is available to authorized users.

Unveiling the Impact of the Genomic Architecture on the Evolution of Vertebrate microRNAs

Eukaryotic genomes frequently exhibit interdependency between transcriptional units, as evidenced by regions of high gene density. It is well recognized that vertebrate microRNAs (miRNAs) are usually embedded in those regions. Recent work has shown that the genomic context is of utmost importance to determine miRNA expression in time and space, thus affecting their evolutionary fates over long and short terms. Consequently, understanding the inter- and intraspecific changes on miRNA genomic architecture may bring novel insights on the basic cellular processes regulated by miRNAs, as well as phenotypic evolution and disease-related mechanisms.

Function, Role, and Clinical Application of MicroRNAs in Vascular Aging

Vascular aging, a specific type of organic aging, is related to age-dependent changes in the vasculature, including atherosclerotic plaques, arterial stiffness, fibrosis, and increased intimal thickening. Vascular aging could influence the threshold, process, and severity of various cardiovascular diseases, thus making it one of the most important risk factors in the high mortality of cardiovascular diseases. As endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) are the main cell biological basis of these pathology changes of the vasculature, the structure and function of ECs and VSMCs play a key role in vascular aging. MicroRNAs (miRNAs), small noncoding RNAs, have been shown to regulate the expression of multiple messenger RNAs (mRNAs) posttranscriptionally, contributing to many crucial aspects of cell biology. Recently, miRNAs with functions associated with aging or aging-related diseases have been studied. In this review, we will summarize the reported role of miRNAs in the process of vascular aging with special emphasis on EC and VSMC functions. In addition, the potential application of miRNAs to clinical practice for the diagnosis and treatment of cardiovascular diseases will also be discussed.

Aging-associated changes in microRNA expression profile of internal anal sphincter smooth muscle: Role of microRNA-133a

A comprehensive genomic and proteomic, computational, and physiological approach was employed to examine the (previously unexplored) role of microRNAs (miRNAs) as regulators of internal anal sphincter (IAS) smooth muscle contractile phenotype and basal tone. miRNA profiling, genome-wide expression, validation, and network analyses were employed to assess changes in mRNA and miRNA expression in IAS smooth muscles from young vs. aging rats. Multiple miRNAs, including rno-miR-1, rno-miR-340-5p, rno-miR-185, rno-miR-199a-3p, rno-miR-200c, rno-miR-200b, rno-miR-31, rno-miR-133a, and rno-miR-206, were found to be upregulated in aging IAS. qPCR confirmed the upregulated expression of these miRNAs and downregulation of multiple, predicted targets (Eln, Col3a1, Col1a1, Zeb2, Myocd, Srf, Smad1, Smad2, Rhoa/Rock2, Fn1, Tagln v2, Klf4, and Acta2) involved in regulation of smooth muscle contractility. Subsequent studies demonstrated an aging-associated increase in the expression of miR-133a, corresponding decreases in RhoA, ROCK2, MYOCD, SRF, and SM22α protein expression, RhoA-signaling, and a decrease in basal and agonist [U-46619 (thromboxane A₂ analog)]-induced increase in the IAS tone. Moreover, in vitro transfection of miR-133a caused a dose-dependent increase of IAS tone in strips, which was reversed by anti-miR-133a. Last, in vivo perianal injection of anti-miR-133a reversed the loss of IAS tone associated with age. This work establishes the important regulatory effect of miRNA-133a on basal and agonist-stimulated IAS tone. Moreover, reversal of age-associated loss of tone via anti-miR delivery strongly implicates miR dysregulation as a causal factor in the aging-associated decrease in IAS tone and suggests that miR-133a is a feasible therapeutic target in aging-associated rectoanal incontinence.

Ox-LDL Upregulates IL-6 Expression by Enhancing NF-κB in an IGF2-Dependent Manner in THP-1 Macrophages

Interleukin 6 (IL-6) is a pro-inflammatory cytokine that is well established as a vital factor in determining the risk of coronary heart disease and pathogenesis of atherosclerosis. Moreover, accumulating evidences have shown that oxidized low-density lipoprotein (ox-LDL) can promote IL-6 expression in macrophages. Nevertheless, the underlying mechanism of how ox-LDL upregulates IL-6 expression remains largely unexplained. We found that the expression of insulin-like growth factor 2 (IGF2), nuclear factor kappa B (NF-κB), and IL-6 was upregulated at both the messenger RNA (mRNA) and protein levels in a dose-dependent manner when treated with 0, 25, 50, or 100 μg/mL of ox-LDL for 48 h in THP-1 macrophages. Moreover, overexpression of IGF2 significantly upregulated NF-κB and IL-6 expressions in THP-1 macrophages. However, the upregulation of NF-κB and IL-6 expressions induced by ox-LDL were significantly abolished by IGF2 small interfering RNA (siRNA) in THP-1 macrophages. Further studies indicated the upregulation of IL-6 induced by ox-LDL could be abolished when treated with NF-κB siRNA in THP-1 macrophages. Ox-LDL might upregulate IL-6 in the cell and its secretion via enhancing NF-κB in an IGF2-dependent manner in THP-1 macrophages.