Plasma microRNAs serve as potential biomarkers for abdominal aortic aneurysm

Postoperative serum mir-28-5p level has predictive value for the prognosis after endovascular abdominal aortic aneurysm repair

BACKGROUND

We explored the clinical significance of miR-28-5p pre- and post-endovascular abdominal aortic aneurysm repair (EVAR) in abdominal aortic aneurysm (AAA) patients.

METHODS

Subjects included AAA patients receiving EVAR and non-AAA people without statistical differences from AAA patient in comorbidities/Framingham risk score. Fasting elbow venous blood (4 mL) was collected in the morning of the day of EVAR surgery and in the morning of 3 months post-EVAR. Pre-/post-EVAR serum miR-28-5p expression, AAA maximum diameter alterations, CD3+/CD4+/CD8+/TC/TG pre-/post-EVAR, and the correlations between miR-28-5p and AAA maximum diameter were investigated. Prediction of miR-28-5p on post-EVAR mortality, prognosis, and independent factors of post-EVAR death were analyzed using receiver operating characteristic curve (ROC)/Kaplan-Meier curve/univariable and multivariable Cox regression. According to the cut-off value of ROC curve for postoperative miR-28-5p was the cut-off value, and the patients were classified into the miR-28-5p high- and low-expression groups. The survival or death of both groups were compared after 48-month follow-up.

RESULTS

Serum miR-28-5p levels in AAA patients dropped post-EVAR. AAA patients showed notable differences in CD3+/CD4+/CD8+/TC/TG levels pre-/post-EVAR. The miR-28-5p low-expression group exhibited higher CD3+/CD4+ and lower CD8+/TC/TG levels. We observed a positive correlation between post-EVAR miR-28-5p and AAA maximum diameter and between the pre-/post-EVAR miR-28-5p fold change and the AAA maximum diameter change. Postoperative miR-28-5p demonstrated good predictive value for postoperative death. Hypertension, Framingham risk score, TC, TG, and miR-28-5p were independent influencing factors of post-EVAR death.

CONCLUSION

EVAR decreased serum miR-28-5p expression in AAA patients. Post-operative miR-28-5p level and pre-/post-operative fold change level are positively-correlated with AAA diameter.

Association Between Serum MicroRNAs and Abdominal Aortic Aneurysm Diagnosis and Growth

OBJECTIVE

This study aimed to examine the association between serum microRNAs (miRNAs) and diagnosis and growth of abdominal aortic aneurysm (AAA), and to test their diagnostic and prognostic value.

METHODS

The expression levels of 800 miRNA tags were assessed in 108 patients with AAA, 12 age and sex matched healthy controls (HCs), and 12 patients with peripheral artery disease (PAD) using NanoString technology. Findings were assessed in an independent sample of 66 patients with AAA and 29 age and sex matched HCs by reverse transcriptase polymerase chain reaction. AAA growth was assessed by a median of three (interquartile range [IQR] 2, 3) repeat ultrasound scans over a median follow up of 1.1 (IQR 1.0, 2.0) years. The association between the miRNA and AAA diagnosis and growth was examined by regression and linear mixed effects analyses. The diagnostic and prognostic potential of the miRNAs were examined using area under the receiver operator characteristic curve (AUC), net re-classification index (NRI), and Cox hazard analyses.

RESULTS

In comparison with HCs, a model combining clinical risk factors, let-7b-5p and miR-548n had an AUC of 98.0% (95% confidence interval [CI] 95.6 - 100.0; p = .003) for diagnosing AAA, which was a significant improvement over clinical risk factors alone (NRI 1.74; 95% CI 1.61 - 1.87; p < .001). Compared with PAD, a model combining clinical risk factors and miR-548n had an AUC of 99.6% (95% CI 98.9 - 100.0, p = .037) for diagnosing AAA, which was a significant improvement over clinical risk factors alone (NRI 1.79, 95% CI 1.68 - 1.91; p < .001). In the longitudinal cohort, none of the miRNAs were able to predict the likelihood of reaching surgical threshold diameter better than clinical risk factors alone.

CONCLUSION

Serum let-7b-5p and miR548n significantly improved the ability to diagnose AAA. None of the miRNAs had independent prognosis value in predicting AAA growth.

MiR-125b and SATB1-AS1 might be shear stress-mediated therapeutic targets

The aim of the study was to explore the potential molecular mechanism associated with shear stress on abdominal aortic aneurysm (AAA) progression. This study performed RNA sequencing on AAA patients (SQ), AAA patients after endovascular aneurysm repair (EVAR, SH), and normal controls (NC). Furthermore, we identified the differentially expressed microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNA (cirRNAs) and constructed competing endogenous RNA (ceRNA) networks. Finally, 164 differentially expressed miRNAs, 179 co-differentially expressed lncRNAs, and 440 co-differentially expressed circRNAs among the three groups were obtained. The differentially expressed miRNAs mainly enriched in 325 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Target genes associated with co-differentially expressed genes among the group of SH, SQ, and NC mainly enriched in 66 KEGG pathways. LncRNA-miRNA-mRNA interactions, including 15 lncRNAs, 63 miRNAs and 57 mRNAs, was constructed. CircRNA-miRNA-mRNA ceRNA network included 79 circRNAs, 21 miRNAs, and 49 mRNAs. Among them, KLRC2 and CSTF1, targeted by miR-125b, participated in cell-mediated immunity regulation. MiR-320-related circRNAs and SATB1-AS1 serving as the sponge of miRNAs, such as has-circ-0129245, has-circ-0138746, and has-circ-0139786, were hub genes in ceRNA network. In conclusion, AAA patients might be benefit from EVAR based on various pathways and some molecules, such as miR-125b and SATB1-AS1, related with shear stress.

Circulating miRNAs as biomarkers for diagnosis, surveillance and post-operative follow-up of abdominal aortic aneurysms

OBJECTIVE

To provide a summary of the current state of research in English medical literature on circulating miRNAs, as biomarkers for AAA. Additionally, for the most commonly mentioned circulating miRNAs in the literature, to attempt a documentation of the biological mechanisms underlying their role in AAA development.

METHODS

A literature search was undertaken in the MEDLINE database. Only reports that involved peripheral blood samples (whole blood, plasma, serum) were included. The following terms were used in combination: microrna, mirna, abdominal aortic aneurysm, human, circulating, plasma, serum, endovascular and EVAR.

RESULTS

A total of 25 reports, published from 2012 to 2022 were included with a total of 1259 patients with AAA, predominantly men (N= 1040, 90%). Six of these reports recruited healthy donors who underwent ultrasound screening for AAA as control samples. The majority of studies were undertaken in plasma samples and the most preferred microRNA profiling method was Real - Time quantitative polymerase chain reaction (qRT-PCR). The following nine miRNAs (out of a total of 76) were studied in more than two references: miR-145, miR-24, miR-33, miR-125, let-7, miR-15, miR-191, miR-29 and miR-133.

CONCLUSION

The nine miRNAs described in this study, are implicated in known pathogenetic mechanisms of AAA such as atherosclerosis, vascular smooth muscle cell phenotype switch and apoptosis, vascular inflammation, extracellular matrix degradation and lipid metabolism. Identifying disease-specific miRNAs, in combination with other clinical parameters, as indicators of AAA, is crucial for early diagnosis as well as follow-up of AAAs. For future research on miRNAs as AAA biomarkers, strict case and control group definitions, sample acquisition protocols, and miRNA expression profiling techniques are warranted.

MiR-1281 is involved in depression disorder and the antidepressant effects of Kai-Xin-San by targeting ADCY1 and DVL1

Kai-Xin-San (KXS) is a Chinese medicine formulation that is commonly used to treat depression caused by dual deficiencies in the heart and spleen. Recent studies indicated that miRNAs were involved in the pathophysiology of depression. However, there have been few studies on the mechanism underlying the miRNAs directly mediating antidepressant at clinical level, especially in nature drugs and TCM compound. In this study, we identified circulating miRNAs defferentially expressed among the depression patients (DPs), DPs who underwent 8weeks of KXS treatment and health controls (HCs). A total of 45 miRNAs (17 were up-regulated and 28 were down-regulated) were significantly differentially expressed among three groups. Subsequently, qRT-PCR was used to verify 10 differentially expressed candidate miRNAs in more serum samples, and the results showed that 6 miRNAs (miR-1281, miR-365a-3p, miR-2861, miR-16-5p, miR-1202 and miR-451a) were consistent with the results of microarray. Among them, miR-1281, was the novel dynamically altered and appeared to be specifically related to depression and antidepressant effects of KXS. MicroRNA-gene-pathway-net analysis showed that miR-1281-regulated genes are mostly key nodes in the classical signaling pathway related to depression. Additionally, our data suggest that ADCY1 and DVL1 were the targets of miR-1281. Thus, based on the discovery of miRNA expression profiles in vivo, our findings suggest a new role for miR-1281 related to depression and demonstrated in vitro that KXS may activate cAMP/PKA/ERK/CREB and Wnt/β-catenin signal transduction pathways by down-regulating miR-1281 that targets ADCY1 and DVL1 to achieve its role in neuronal cell protection.

RelB represses miR-193a-5p expression to promote the phenotypic transformation of vascular smooth muscle cells in aortic aneurysm

Aortic aneurysm (AA) is a potentially fatal disease with the possibility of rupture, causing high mortality rates with no effective drugs for the treatment of AA. The mechanism of AA, as well as its therapeutic potential to inhibit aneurysm expansion, has been minimally explored. Small non-coding RNA (miRNAs and miRs) is emerging as a new fundamental regulator of gene expression. This study aimed to explore the role and mechanism of miR-193a-5p in abdominal aortic aneurysms (AAA). In AAA vascular tissue and Angiotensin II (Ang II)-treated vascular smooth muscle cells (VSMCs), the expression of miR-193a-5 was determined using real-time quantitative PCR (RT-qPCR). Western blotting was used to detect the effects of miR-193a-5p on PCNA, CCND1, CCNE1, and CXCR4. To detect the effect of miR-193a-5p on the proliferation and migration of VSMCs, CCK-8, and EdU immunostaining, flow cytometry, wound healing, and Transwell Chamber analysis were performed. In vitro results suggest that overexpression of miR-193a-5p inhibited the proliferation and migration of VSMCs, and its inhibition aggravated their proliferation and migration. In VSMCs, miR-193a-5p mediated proliferation by regulating CCNE1 and CCND1 genes and migration by regulating CXCR4. Further, in the Ang II-induced abdominal aorta of mice, the expression of miR-193a-5p was reduced and significantly downregulated in the serum of patients with aortic aneurysm (AA). In vitro studies confirmed that Ang II-induced downregulation of miR-193a-5p in VSMCs by upregulation of the expression of the transcriptional repressor RelB in the promoter region. This study may provide new intervention targets for the prevention and treatment of AA.

Plasma complement component C2: a potential biomarker for predicting abdominal aortic aneurysm related complications

Blood-based adjunctive measures that can reliably predict abdominal aortic aneurysm (AAA)-related complications hold promise for mitigating the AAA disease burden. In this pilot study, we sought to evaluate the prognostic performance of complement factors in predicting AAA-related clinical outcomes. We recruited consecutive AAA patients (n = 75) and non-AAA patients (n = 75) presenting to St. Michael's Hospital. Plasma levels of complement proteins were assessed at baseline, as well as prospectively measured regularly over a period of 2 years. The primary outcome was the incidence of rapidly progressing AAA (i.e. aortic expansion), defined as change in AAA diameter by either 0.5 cm in 6 months, or 1 cm in 12 months. Secondary outcomes included incidence of major adverse aortic events (MAAE) and major adverse cardiovascular events (MACE). All study outcomes (AAA diameter, MACE and MAAE) were obtained during follow-up. Multivariable adjusted Cox regression analyses were performed to assess the prognostic value of plasma C2 levels in patients with AAA regarding rapid aortic expansion and MAAE and MACE. Event-free survival rates of both groups were also compared. Compared to non-AAA patients, patients with AAA demonstrated significantly higher plasma concentrations of C1q, C4, Factor B, Factor H and Factor D, and significantly lower plasma concentrations of C2, C3, and C4b (p = 0.001). After a median of 24 months from initial baseline measurements, C2 was determined as the strongest predictor of rapid aortic expansion (HR 0.10, p = 0.040), MAAE (HR 0.09, p = 0.001) and MACE (HR 0.14, p = 0.011). Based on the data from the survival analysis, higher levels of C2 at admission in patients with AAA predicted greater risk for rapid aortic expansion and MAAE (not MACE). Plasma C2 has the potential to be a biomarker for predicting rapid aortic expansion, MAAE, and the eventual need for an aortic intervention in AAA patients.

Multiomics Data Integration Identifies New Molecular Signatures for Abdominal Aortic Aneurysm and Aortic Occlusive Disease: Implications for Early Diagnosis, Prognosis, and Therapeutic Targets

Cardiovascular disease (CVD) is the leading cause of death among adults in developed countries. Among CVDs, abdominal aortic aneurysm (AAA) and aortic occlusive disease (AOD) are of great public health importance because of the high mortality rate in the elderly population. Despite significant molecular insights into AAA and AOD, the molecular mechanisms of these diseases remain unclear, and the current lack of robust diagnostic and prognostic biomarkers requires novel approaches to biomarker discovery and molecular targeting. In this study, we performed a comparative analysis of genome-wide expression data from patients with large AAA (n = 29), small AAA (n = 20), AOD (n = 9), and controls (n = 10). Specifically, we identified the differentially expressed genes and associated molecular pathways and biological processes (BPs) in each disease. Using a systems science approach, these data were linked to comprehensive human biological networks (i.e., protein-protein interaction, transcriptional regulatory, and metabolic networks) to identify molecular signatures of the salient mechanisms of AAA and AOD. Significant alterations in lipid metabolism and valine, leucine, and isoleucine metabolism, as well as neurodegenerative diseases and sex differences in the pathogenesis of AAA and AOD were identified. In the presence of aneurysm, size-dependent changes in lipid metabolism were observed. In addition, molecules and signaling pathways related to immunity, inflammation, infectious disease, and oxidative phosphorylation were identified in common. The results of the comparative and integrative analyzes revealed important clues to disease mechanisms and reporter molecules at various levels that warrant future development as potential prognostic biomarkers and putative therapeutic targets.

Nuclear Paraspeckle Assembly Transcript 1 Enhances Hydrogen Peroxide-Induced Human Vascular Smooth Muscle Cell Injury by Regulating miR-30d-5p/A Disintegrin and Metalloprotease 10

BACKGROUND

Nuclear paraspeckle assembly transcript 1 (NEAT1) has been reported to be involved in the progression of many cancers; however, the role and mechanisms underlying NEAT1 in abdominal aortic aneurysm (AAA) remain unclear.Methods and Results:The expression of NEAT1, miR-30d-5p and A disintegrin and metalloprotease 10 (ADAM10) was measured by qRT-PCR and western blot. Functional experiments were conducted by using a CCK-8 assay, EDU assay, flow cytometry, western blot, ELISA, and commercial kits. The target relation was confirmed by dual-luciferase reporter assay and the RIP assay. It was then found that NEAT1 was upregulated in peripheral blood of AAA patients ~3.46-fold, smooth muscle cells (SMCs) isolated from AAA tissues ~2.6-fold and in a hydrogen peroxide (H₂O₂)-induced injury model of human vascular SMC (HVSMCs) ~2.0- and 3.9-fold at 50 µmol/L and 200 µmol/L H₂O₂treatment, respectively. NEAT1 deletion attenuated H₂O₂-induced cell proliferation promotion (40.0% vs. 74.3%), apoptosis inhibition (25.0% vs. 13.5%), and reduction of inflammatory response and oxidative stress in HVSMCs. Mechanistically, NEAT1 targeted miR-30d-5p to prevent the degradation of its target, ADAM10, in HVSMCs. Further rescue experiments suggested miR-30d-5p inhibition mitigated the effects of NEAT1 deletion on H₂O₂-induced HVSMCs. Moreover, ADAM10 overexpression counteracted the inhibitory functions of miR-30d-5p on H₂O₂-evoked HVSMC injury.

CONCLUSIONS

NEAT1 promoted H₂O₂-induced HVSMC injury by inducing cell apoptosis, inflammation and oxidative stress through miR-30d-5p/ADAM10 axis, indicating the possible involvement of NEAT1 in the pathogenesis of AAA.

MiR-191 as a Key Molecule in Aneurysmal Aortic Remodeling

Abdominal aortic aneurysms (AAA) are a complex disease with an unclear pathomechanism. A positive family history is emphasized as a significant risk factor, and a nonspecific model of inheritance suggests participation of epigenetic regulation in the pathogenesis of this disease. Past studies have implicated microRNAs in the development of AAA; therefore in this project, we measured miR-191 levels in AAA patients and compared them with a control group. We found that miR-191 levels were significantly elevated in aneurysmal patients, although this did not correlate with the available clinical data. We then developed an in vitro model where, using cells with an endothelial phenotype, we determined the effect of miR-191 on the transcriptome using RNA sequencing. Subsequent pathway analysis established that some of the perturbations mediated by miR-191 can be explained by several processes which have long been observed and described in literature as accompanying the development of abdominal aortic aneurysms.

MiR-222-3p downregulation prompted the migration, invasion and recruitment of endothelial progenitor cells via ADIPOR1 expression increase-induced AMKP activation

BACKGROUND

Clinical data show that aneurysm rupture causes high mortality in aged men. MicroRNAs (miRNAs) were reported to regulate endothelial progenitor cells (EPCs) which play a vital role in repairing endothelial damage and maintaining vascular integrity. This study identified a novel miRNA regulator for the functions of EPCs in aneurysm repair.

METHODS

Abdominal aortic aneurysm (AAA) model was established on Sprague-Dawley rats which later underwent antagomiR-222 treatment. The histopathological changes of AAA rats were examined by hematoxylin-eosin staining. Flow cytometry was performed to quantify EPCs in peripheral blood and identify EPCs isolated from the rat femur. The potential target of miR-222-3p was predicted by TargetScan v7.2 and validated by Dual-luciferase reporter assay. The effects of miR-222-3p and ADIPOR1 on the migration, invasion and tube formation of EPCs were evaluated by wound healing, Transwell and tube formation assays. The expressions of miR-222-3p and ADIPOR1 in aortic aneurysm tissues and EPCs were assessed by qRT-PCR or Western blot.

RESULTS

AAA exhibited histopathological abnormality, a decreased number of EPCs in the peripheral blood and an increased miR-222-3p expression. AntagomiR-222 injection reversed all these phenomena in AAA rats. Upregulating miR-222-3p expression inhibited the migration, invasion, and tube formation of EPCs, and the expressions of ADIPOR1 and phosphorylated-AMKP, while downregulating miR-222-3p expression exerted opposite effects in EPCs. ADIPOR1 was identified as a target gene of miR-222-3p. Overexpressing ADIPOR1 abrogated the effects of miR-222-3p upregulation on EPCs.

CONCLUSION

Downregulated miR-222-3p prompted the migration, invasion and recruitment of EPCs by targeting ADIPOR1-induced AMKP activation.

Circulating Biomarkers for the Prediction of Abdominal Aortic Aneurysm Growth

BACKGROUND

Abdominal aortic aneurysm represents a distinct group of vascular lesions, in terms of surveillance and treatment. Screening and follow-up of patients via duplex ultrasound has been well established and proposed by current guidelines. However, serum circulating biomarkers could earn a position in individualized patient surveillance, especially in cases of aggressive AAA growth rates. A systematic review was conducted to assess the correlation of AAA expansion rates with serum circulating biomarkers.

METHODS

A data search of English medical literature was conducted, using PubMed, EMBASE, and CENTRAL, until 7 March 2021, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement (PRISMA) guidelines. Studies reporting on humans, on abdominal aortic aneurysm growth rates and on serum circulating biomarkers were included. No statistical analysis was conducted.

RESULTS

A total of 25 studies with 4753 patients were included. Studies were divided in two broad categories: Those reporting on clinically applicable (8 studies) and those reporting on experimental (17 studies) biomarkers. Twenty-three out of 25 studies used duplex ultrasound (DUS) for following patients. Amongst clinically applicable biomarkers, D-dimers, LDL-C, HDL-C, TC, ApoB, and HbA1c were found to bear the most significant association with AAA growth rates. In terms of the experimental biomarkers, PIIINP, osteopontin, tPA, osteopontin, haptoglobin polymorphisms, insulin-like growth factor I, thioredoxin, neutrophil extracellular traps (NETs), and genetic factors, as polymorphisms and microRNAs were positively correlated with increased AAA expansion rates.

CONCLUSION

In the presence of future robust data, specific serum biomarkers could potentially form the basis of an individualized surveillance strategy of patients presenting with increased AAA growth rates.

Potential Target miR-455 Delaying Arterial Stenosis Progression Through PTEN

Background: Vascular smooth muscle cells (VSMC) underwent phenotypic switching upon stimulation signals, and this is the prerequisite for their proliferation and migration. Previous work revealed that miR-455 may be involved in vascular stenosis. Thus, this study aimed to explore potential targets and mechanisms underlying the dynamics of miR-455 in vascular stenosis.

Methods: miR-455 and PTEN expression levels were studied in normal and stenosis tissue, as well as in VSMC in proliferation model. Manipulating miR-455 expression levels was achieved by transfection of either miR-455 mimic or inhibitor, and its effect on cell proliferation was studied by CCK-8 assay. Its effect on gene expression was studied by RT-qPCR and western blot. The expression regulation mechanism was studied by luciferase reporter system. Finally, the effect of miR-455 on regulating vascular stenosis was studied using a rat balloon-injured carotid artery stenosis model.

Results: High expression levels of miR-455 were detected in both stenosis arterial tissues and VSMC proliferation models. In contrast, the expression levels of PTEN were downregulated in these systems. miR-455 transfected VSMC showed higher levels of proliferation and decreased levels of PTEN. Potential binding sites between miR-455 and PTEN 3′UTR were predicted and confirmed. NF-kB p65 was found to bind directly on miR-455 promoter region and regulate its transcription. The progression of arterial stenosis could be delayed by introducing miR-455 antagomir.

Conclusions: The p65/miR-455/PTEN signaling pathway plays a crucial role in regulating VSMC proliferation and vascular stenosis. This indicated that miR-455 is a novel target that would help improve treatment outcomes in patients suffering from vascular stenosis.

Identification of a Plasma Microrna Signature as Biomarker of Subaneurysmal Aortic Dilation in Patients with High Cardiovascular Risk

Patients with subaneurysmal aortic dilation (SAD; 25–29 mm diameter) are likely to progress to true abdominal aortic aneurysm (AAA). Despite these patients having a higher risk of all-cause mortality than subjects with aortic size <24 mm, early diagnostic biomarkers are lacking. MicroRNAs (miRs) are well-recognized potential biomarkers due to their differential expression in different tissues and their stability in blood. We have investigated whether a plasma miRs profile could identify the presence of SAD in high cardiovascular risk patients. Using qRT-PCR arrays in plasma samples, we determined miRs differentially expressed between SAD patients and patients with normal aortic diameter. We then selected 12 miRs to be investigated as biomarkers by construction of ROC curves. A total of 82 significantly differentially expressed miRs were found by qPCR array, and 12 were validated by qRT-PCR. ROC curve analyses showed that seven selected miRs (miR-28-3p, miR-29a-3p, miR-93-3p, miR-150-5p, miR-338-3p, miR-339-3p, and miR-378a-3p) could be valuable biomarkers for distinguishing SAD patients. MiR-339-3p showed the best sensitivity and specificity, even after combination with other miRs. Decreased miR-339-3p expression was associated with increased aortic abdominal diameter. MiR-339-3p, alone or in combination with other miRs, could be used for SAD screening in high cardiovascular risk patients, helping to the early diagnosis of asymptomatic AAA.

MicroRNA-1281 as a Novel Circulating Biomarker in Patients With Diabetic Retinopathy

Objective: Recently, the role of circulating miRNAs as non-invasive biomarkers for the identification and monitoring of diabetes microvascular complications has emerged. Herein, we aimed to: identify circulating miRNAs differentially expressed in patients with and without diabetic retinopathy (DR); examine their predictive value; and understand their pathogenic impact. Methods: Pooled serum samples from randomly selected matched patients with type 2 diabetes, either with or without DR, were used for initial serum miRNA profiling. Validation of the most relevant miRNAs was thereafter conducted by RT-qPCR in an extended sample of patients with DR and matched controls. Results: Following miRNA profiling, 43 miRNAs were significantly up- or down-regulated in patients with DR compared with controls. After individual validation, 5 miRNAs were found significantly overexpressed in patients with DR. One of them, miR-1281, was the most up-regulated and appeared to be specifically related to DR. Furthermore, secreted levels of miR-1281 were increased in high glucose-cultured retinal cells, and there was evidence of a potential link between glucose-induced miR-1281 up-regulation and DR. Conclusion: Our findings suggest miR-1281 as a circulating biomarker of DR. Also, they highlight the pathogenic significance of miR-1281, providing insights for a new potential target in treating DR.

Identification of Novel microRNA Profiles Dysregulated in Plasma and Tissue of Abdominal Aortic Aneurysm Patients

microRNAs (miRNAs) are small RNAs that regulate different biological processes. Our objective was to identify miRNAs dysregulated in plasma and tissue of patients with abdominal aortic aneurysm (AAA) and explore new potential targets involved in AAA. Fifty-seven subjects were recruited for a plasma study (30 AAA patients, 16 healthy volunteers and 11 patients with atherosclerosis). The expression level of 179 miRNAs was screened in plasma from a subset of samples, and dysregulated miRNAs were validated in the entire study population. Dysregulated miRNAs were also quantified in aortic tissue of 21 AAA patients and 8 organ donors. Applying a gene set enrichment analysis, an interaction map of dysregulated miRNAs and their targets was built, and selected targets were quantified in tissue samples. miR-27b-3p and miR-221-3p were overexpressed in plasma of AAA patients compared with healthy controls, 1.6 times and 1.9 times, respectively. In AAA tissue, six miRNAs (miR-1, miR-27b-3p, miR-29b-3p, miR-133a-3p, miR-133b, and miR-195-5p) were underexpressed from 1.6 to 4.8 times and four miRNAs (miR-146a-5p, miR-21-5p, miR-144-3p, and miR-103a-3p) were overexpressed from 1.3 to 7.2 times. Thrombospondin-2, a target of miR-195-5p, was increased in AAA tissue and negatively correlated with the expression of miR-195-5p, suggesting their involvement in a common regulatory mechanism.

Dysregulation of microRNA Modulatory Network in Abdominal Aortic Aneurysm

Abdominal artery aneurysm (AAA) refers to abdominal aortic dilatation of 3 cm or greater. AAA is frequently underdiagnosed due to often asymptomatic character of the disease, leading to elevated mortality due to aneurysm rupture. MiRNA constitute a pool of small RNAs controlling gene expression and is involved in many pathologic conditions in human. Targeted panel detecting altered expression of miRNA and genes involved in AAA would improve early diagnosis of this disease. In the presented study, we selected and analyzed miRNA and gene expression signatures in AAA patients. Next, generation sequencing was applied to obtain miRNA and gene-wide expression profiles from peripheral blood mononuclear cells in individuals with AAA and healthy controls. Differential expression analysis was performed using DESeq2 and uninformative variable elimination by partial least squares (UVE-PLS) methods. A total of 31 miRNAs and 51 genes were selected as the most promising biomarkers of AAA. Receiver operating characteristics (ROC) analysis showed good diagnostic ability of proposed biomarkers. Genes regulated by selected miRNAs were determined in silico and associated with functional terms closely related to cardiovascular and neurological diseases. Proposed biomarkers may be used for new diagnostic and therapeutic approaches in management of AAA. The findings will also contribute to the pool of knowledge about miRNA-dependent regulatory mechanisms involved in pathology of that disease.

Micro-RNA signatures in monozygotic twins discordant for congenital heart defects

Background

MicroRNAs (miRNAs) are small RNAs regulating gene expression post-transcriptionally. Recent studies demonstrated that miRNAs are involved in the development of congenital heart defects (CHD). In this study, we aimed at identifying the specific patterns of miRNAs in blood of monozygotic twin pairs discordant for CHD and to assess whether miRNAs might be involved in the development or reflect the consequences of CHD.

Methods

miRNA microarray analysis and Real-Time Quantitative PCR (RT-qPCR) were employed to determine the miRNA abundance level from 12 monozygotic twins discordant for CHD and their non-CHD co-twins (n = 12). Enrichment analyses of altered miRNAs were performed using bioinformatics tools.

Results

Compared with non-CHD co-twins, profiling analysis indicated 34 miRNAs with a significant difference in abundance level (p<0.05, fold change ≥ 1.3), of which 11 miRNAs were up-regulated and 23 miRNAs were down-regulated. Seven miRNAs were validated with RT-qPCR including miR-511-3p, miR-1306-5p, miR-421, miR-4707-3p, miR-4732-3p, miR-5189-3p, and miR-890, and the results were consistent with microarray analysis. Five miRNAs namely miR-511-3p, miR-1306-5p, miR-4732-3p, miR-5189-3p, and miR-890 were found to be significantly up-regulated in twins < 10 years old. Bioinformatics analysis showed that the 7 validated miRNAs were involved in phosphatidylinositol signaling, gap junction signaling, and adrenergic signaling in cardiomyocytes.

Conclusions

Our data show deregulated miRNA abundance levels in the peripheral blood of monozygotic twins discordant for CHD, and identify new candidates for further analysis, which may contribute to understanding the development of CHD in the future. Bioinformatics analysis indicated that the target genes of these miRNAs are likely involved in signaling and communication of cardiomyocytes.

The Expression Profile of MicroRNAs in Small and Large Abdominal Aortic Aneurysms

Background

Abdominal aortic aneurysms (AAA) are relatively frequent in elderly population, and their ruptures are related with high mortality rate. There are no actually used laboratory markers predicting the AAA development, course, and rupture. MicroRNAs are small noncoding molecules involved in posttranscriptional gene expression regulation, influencing processes on cell and tissue levels, and are actually in focus due to their potential to become diagnostic or prognostic markers in various diseases.

Methods

Tissue samples of AAA patients and healthy controls were collected, from which miRNA was isolated. Microarray including the complete panel of 2549 miRNAs was used to find expression miRNA profiles that were analysed in three subgroups: small (N = 10) and large (N = 6) aneurysms and healthy controls (N = 5). Fold changes between expression in aneurysms and normal tissue were calculated including corresponding p values, adjusted to multiple comparisons.

Results

Six miRNAs were found to be significantly dysregulated in small aneurysms (miR-7158-5p, miR-658, miR-517-5p, miR-122-5p, miR-326, and miR-3180) and 162 in large aneurysms, in comparison with the healthy control. Ten miRNAs in large aneurysms with more than two-fold significant change in expression were identified: miR-23a-3p, miR-24-3p, miR-27a-3p, miR-27b-3p, miR-30d-5p, miR-193a-3p, miR-203a-3p, miR-365a-3p, miR-4291, and miR-3663-3p and all, but the last one was downregulated in aneurysmal walls.

Conclusion

We confirmed some previously identified miRNAs (miR-23/27/24 family, miR-193a, and miR-30) as associated with AAA pathogenesis. We have found other, yet in AAA unidentified miRNAs (miR-203a, miR-3663, miR-365a, and miR-4291) for further analyses, to investigate more closely their possible role in pathogenesis of aneurysms. If their role in AAA development is proved significant in future, they can become potential markers or treatment targets.

Roles of microRNAs in abdominal aortic aneurysm pathogenesis and the possibility of their use as biomarkers

Abdominal aortic aneurysm (AAA) is a dangerous condition involving pathological dilation of the aortic wall. Due to the asymptomatic course of this disease and the dangerous consequences of its rupture, it is important to identify its specific bio-markers expressed as early as possible. Different expression profiles of microRNAs (miRNAs) were detected in patients diagnosed with AAA. MicroRNAs are small non-coding RNA molecules that regulate the expression of other genes at the translation stage. miRNAs affecting translation can lead to abnormal remodeling of extracellular matrix, inhibition of the cell cycle, cell aging or intensified inflammation. This review summarizes current knowledge about the role of microRNAs in the context of formation and development of abdominal aorta aneurysm and the possibility of using some miRNAs as bio-markers, and also provides basic information about miRNAs and aneurysms.

Dysregulation of microRNAs and target genes networks in human abdominal aortic aneurysm tissues

BACKGROUND

Abdominal aortic aneurysm (AAA) is a pathological enlargement of infrarenal aorta close to the aortic bifurcation, and it is an important cause of mortality in the elderly. Therefore, the biomarker identification for early diagnosis is of great interest for clinical benefit. It is known that microRNAs (miRNAs) have important roles via target genes regulation in many diseases. This study aimed to identify miRNAs and their target genes involved in the pathogenesis of AAA.

METHODS

Tissue samples were obtained from patients who underwent AAA surgery and from organ donors (control group). Quantitative PCR Array was applied to assess 84 genes and 384 miRNAs aiming to identify differentially expressed targets (AAA n = 6, control n = 6), followed by validation in a new cohort (AAA n = 18, control n = 6) by regular qPCR. The functional interaction between validated miRNAs and target genes was performed by the Ingenuity Pathway Analysis (IPA) software.

RESULTS

The screening cohort assessed by PCR array identified 10 genes and 59 miRNAs differentially expressed (≥2-fold change, p<0.05). Among these, IPA identified 5 genes and 9 miRNAs with paired interaction. ALOX5, PTGIS, CX3CL1 genes, and miR-193a-3p, 125b-5p, 150-5p maintained a statistical significance in the validation cohort. IPA analysis based on the validated genes and miRNAs revealed that eicosanoid and metalloproteinase/TIMP synthesis are potentially involved in AAA.

CONCLUSION

Paired interactions of differentially expressed ALOX5, PTGIS, CX3CL1 genes, and miR-193b-3p, 125b-5p, 150-5p revealed a potentially significant role of the eicosanoid synthesis and metalloproteinase/TIMP pathways in the AAA pathogenesis.

Exploring biomarkers in the overactive bladder: Alterations in miRNA levels of a panel of genes in patients with OAB

AIMS

It has been demonstrated that there are abundant stable microRNAs (miRNAs) in plasma, which is potentially disease-specific. Adrenergic and muscarinic pathways play an important role in voiding physiology. Alterations in the levels of miRNAs are thought to influence the regulation of these pathways at the molecular level. The aim of this study was to investigate the relationship of miRNAs with overactive bladder pathogenesis and to provide a new perspective to treatment approaches.

METHODS

This study included patients with an overactive bladder (OAB) diagnosis and a healthy control group. All patients completed a validated OAB-V8 questionnaire. The relative expression levels of 12 miRNAs were examined in plasma by PCR. Receiver operating characteristic (ROC) curves were generated to evaluate the diagnostic qualification of miRNAs.

RESULTS

The relative expression levels of let-7b-5p, miR-92a-3p, miR-98-5p, miR-142-3p, and miR-200c-3p were significantly upregulated and miR-139-5p was significantly downregulated in patients with OAB and no correlation was determined between the levels of miRNAs with OAB symptom score. Among the miRNAs, miR-98-5p provided the highest diagnostic accuracy alone (area under curve [AUC] = 0.79) in ROC analysis. The combination of miR-98-5p + miR-139-5p was seen to be a good indicator (AUC = 0.839).

CONCLUSIONS

These results suggest that alteration of the miRNA levels can be used as auxiliary parameters to explain the pathophysiology of OAB syndrome and could shed light on new treatment options.

Role of Noncoding RNAs in the Pathogenesis of Abdominal Aortic Aneurysm

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

Elucidating the contributory role of microRNA to cardiovascular diseases (a review)

Cardiovascular diseases encompassing atherosclerosis, aortic aneurysms, restenosis, and pulmonary arterial hypertension, remain the leading cause of morbidity and mortality worldwide. In response to a range of stimuli, the dynamic interplay between biochemical and biomechanical mechanisms affect the behaviour and function of multiple cell types, driving the development and progression of cardiovascular diseases. Accumulating evidence has highlighted microRNAs (miRs) as significant regulators and micro-managers of key cellular and molecular pathophysiological processes involved in predominant cardiovascular diseases, including cell mitosis, motility and viability, lipid metabolism, generation of inflammatory mediators, and dysregulated proteolysis. Human pathological and clinical studies have aimed to identify select microRNA which may serve as biomarkers of disease and their progression, which are discussed within this review. In addition, I provide comprehensive coverage of in vivo investigations elucidating the modulation of distinct microRNA on the pathophysiology of atherosclerosis, abdominal aortic aneurysms, restenosis, and pulmonary arterial hypertension. Collectively, clinical and animal studies have begun to unravel the complex and often diverse effects microRNAs and their targets impart during the development of cardiovascular diseases and revealed promising therapeutic strategies through which modulation of microRNA function may be applied clinically.

Phosphatidylinositol 3-Kinase-DNA Methyltransferase 1-miR-1281-Histone Deacetylase 4 Regulatory Axis Mediates Platelet-Derived Growth Factor-Induced Proliferation and Migration of Pulmonary Artery Smooth Muscle Cells

BACKGROUND

Platelet-derived growth factor BB, a potent mitogen of pulmonary artery smooth muscle cells (PASMCs), has been implicated in pulmonary arterial remodeling, which is a key pathogenic feature of pulmonary arterial hypertension. Previous microRNA profiling in platelet-derived growth factor BB-treated PASMCs found a significantly downregulated microRNA, miR-1281, but it has not been associated with any cellular function, and we investigated the possibility.

METHODS AND RESULTS

Real-time quantitative reverse transcription-polymerase chain reaction assay proved that downregulation of miR-1281 was a conserved phenomenon in human and rat PASMCs. Overexpression and inhibition of miR-1281 in PASMCs promoted and suppressed, respectively, the cell proliferation and migration. Bioinformatic prediction and 3'-untranslated region reporter assay identified histone deacetylase 4 to be a direct target of miR-1281. Supporting this, proliferation and migration assay demonstrated the cellular function of histone deacetylase 4 is inversely correlated with that of miR-1281. Mechanistically, it is found that platelet-derived growth factor BB activates the phosphatidylinositol 3-kinase pathway, which then induces the expression of DNA methyltransferase 1, leading to enhanced methylation of a flanking CpG island and repressed miR-1281 expression. Finally, a reduced miR-1281 level was consistently identified in hypoxic PASMCs in vitro, in pulmonary arteries of rats with monocrotaline-induced pulmonary arterial hypertension, and in serum of patients with coronary heart disease-pulmonary arterial hypertension. These data suggest that there may be a diagnostic and therapeutic use for miR-1281.

CONCLUSIONS

Herein, we report a novel regulatory axis, phosphatidylinositol 3-kinase-DNA methyltransferase 1-miR-1281-histone deacetylase 4, integrating multiple epigenetic regulators that participate in platelet-derived growth factor BB-stimulated PASMC proliferation and migration and pulmonary vascular remodeling.

Dual-Targeted Theranostic Delivery of miRs Arrests Abdominal Aortic Aneurysm Development

Abdominal aortic aneurysm (AAA) is an often deadly disease without medical, non-invasive treatment options. The upregulation of vascular cell adhesion molecule-1 (VCAM-1) on aortic endothelium provides an early target epitope for a novel biotechnological theranostic approach. MicroRNA-126 was used as a therapeutic agent, based on its capability to downregulate VCAM-1 expression in endothelial cells and thereby reduces leukocyte adhesion and exerts anti-inflammatory effects. Ultrasound microbubbles were chosen as carriers, allowing both molecular imaging as well as targeted therapy of AAA. Microbubbles were coupled with a VCAM-1-targeted single-chain antibody (scFv_mVCAM-1) and a microRNA-126 mimic (M₁₂₆) constituting theranostic microbubbles (Targ^MB-M₁₂₆). Targ^MB-M₁₂₆ downregulates VCAM-1 expression in vitro and in an in vivo acute inflammatory murine model. Most importantly, using Targ^MB-M₁₂₆ and ultrasound-guided burst delivery of M₁₂₆, the development of AAA in an angiotensin-II-induced mouse model can be prevented. Overall, we describe a unique biotechnological theranostic approach with the potential for early diagnosis and long-sought-after medical therapy of AAA.

MicroRNAs as possible biomarkers for screening of aortic aneurysms: a systematic review and validation study

CONTEXT

There is an urgent need to identify non-invasive biomarkers for the early detection of aortic aneurysms, preceding a fatal event. The potential role for MicroRNAs (miRNAs) as diagnostic markers for aortic aneurysms was investigated through the present systematic review.

OBJECTIVE

To perform a comprehensive review on published studies examining the association of miRNAs with aortic aneurysms and further validate these results with plasma samples collected from thoracic aortic aneurysm (TAA) patients.

METHODS

The literature search was performed via numerous databases and articles were only included if they fulfilled the predefined eligibility criteria. The miRNAs reported three times or more with expression consistency were validated using plasma samples from TAA patients collected before and following surgery.

RESULTS

Twenty-four articles were selected from the literature search and 11 miRNAs were chosen for validation using our samples. The miRNAs which were further validated were found to follow the trend in the regulation pattern as with the majority of the published data. MiRNA hsa-miR-193a-5p was found to be significantly down-regulated in the plasma samples collected before the aneurysmal removal when compared with postsurgical serum samples.

CONCLUSIONS

Numerous miRNAs have been associated with aortic aneurysms, and specifically hsa-miR-193a-5p and hsa-miR-30b-5p; therefore they warrant further investigation as potential biomarkers. Registration: The protocol of the review was registered in Prospero Databases (ID: CRD42016039953).

Differential microRNA expression in human placentas of term intra-uterine growth restriction that regulates target genes mediating angiogenesis and amino acid transport

Placental insufficiency leading to intrauterine growth restriction (IUGR) demonstrates perturbed gene expression affecting placental angiogenesis and nutrient transfer from mother to fetus. To understand the post-transcriptional mechanisms underlying such placental gene expression changes, our objective was to identify key non-coding microRNAs that express biological function. To this end, we initially undertook microarrays targeting microRNAs in a small sub-set of placentas of appropriate (AGA) versus small for gestational age (SGA) weight infants, and observed up-regulation of 97 miRs and down-regulation of 44 miRs in SGA versus AGA. In a larger cohort of samples (AGA, n = 21; SGA, n = 11; IUGR subset, n = 5), we validated by qRT-PCR differential expression of three specific microRNAs (miR-10b, -363 and -149) that target genes mediating angiogenesis and nutrient transfer. Validation yielded an increase in miR-10b and -363 expression of ~2.5-fold (p<0.02 each) in SGA versus AGA, and of ~3-fold (p<0.005) in IUGR versus AGA, with no significant change despite a trending increase in miR-149. To further establish a cause-and-effect paradigm, employing human HTR8 trophoblast cells, we assessed the effect of nutrient deprivation on miR expression and inhibition of endogenous miRs on target gene expression. In-vitro nutrient deprivation (~50%) increased the expression of miR-10b and miR-149 by 1.5-fold (p<0.02) while decreasing miR-363 (p<0.0001). Inhibition of endogenous miRs employing antisense sequences against miR-10b, -363 and -149 revealed an increase respectively in the expression of the target genes KLF-4 (transcription factor which regulates angiogenesis), SNAT1 and 2 (sodium coupled neutral amino acid transporters) and LAT2 (leucine amino acid transporter), which translated into a similar change in the corresponding proteins. Finally to establish functional significance we performed dual-luciferase reporter assays with 3'-insertion of miR-10b alone and observed a ~10% reduction in the 5'-luciferase activity versus the control. Lastly, we further validated by microarray and employing MirWalk software that the pathways and target genes identified by differentially expressed miRs in SGA/IUGR compared to AGA are consistent in a larger cohort. We have established the biological significance of various miRs that target common transcripts mediating pathways of importance, which are perturbed in the human IUGR placenta.

Circulating microRNAs in patients with intracranial aneurysms

Introduction

We compared circulating microRNA (miRNA) levels in plasma of patients with intracranial aneurysms (IA) to those of controls as a first step towards finding potential biomarkers for individuals at high risk of IA development and its subsequent rupture.

Patients and methods

Using a PCR array we measured 370 miRNAs in plasma of 15 patients with prior aneurysmal subarachnoid hemorrhage (aSAH), of whom 11 had an additional unruptured IA (UIA), and of 15 controls. MiRNAs with a difference in levels with an absolute fold change (FC) > 1.2 and p<0.01 were further tested using real-time (RT) PCR in an additional independent set of 15 aSAH patients, 15 untreated UIA patients and 15 controls for replication (absolute FC >1.2 and p<0.05). We used receiver operating characteristic (ROC) curves to illustrate the diagnostic potential of these miRNAs.

Results

Three of five miRNAs with a difference in levels in the PCR array study were replicated with miRNA-183-5p decreased in all patients (FC = -2.2, p = 1.7x10^-3), miRNA-200a-3p increased in aSAH patients (FC = 1.8, p = 2.8x10^-2) and miRNA-let7b-5p decreased in UIA patients (FC = -1.7, p = 1.27x10^-3) as compared to controls. In distinguishing aSAH patients from controls, the area under the ROC curve (AUC) was 0.80 (95% confidence interval (95% CI) 0.63–0.97) for miRNA-183-5p, and 0.74 (95% CI 0.55–0.94) for miRNA-200a-3p. In distinguishing untreated UIA patients from controls, AUC was 0.83 (95% CI 0.69–0.98) for miRNA-183-5p and 0.92 (95% CI 0.81–1) for miRNA-let-7b.

Discussion/Conclusions

We identified three specific circulating miRNAs that are able to discriminate between IA patients and controls. Follow-up studies should assess if these miRNAs may be used biomarkers for identifying individuals at high risk of IA development and its subsequent rupture.

H2S regulates endothelial nitric oxide synthase protein stability by promoting microRNA-455-3p expression

The aims of the present study are to determine whether hydrogen sulfide (H₂S) is involved in the expression of endothelial nitric oxide synthase (eNOS) and nitric oxide (NO) production, and to identify the role of microRNA-455-3p (miR-455-3p) during those processes. In cultured human umbilical vein endothelial cells (HUVECs), the expression of miR-455-3p, eNOS protein and the NO production was detected after administration with 50 μM NaHS. The results indicated that H₂S could augment the expression of miR-455-3p and eNOS protein, leading to the increase of NO level. We also found that overexpression of miR-455-3p in HUVECs increased the protein levels of eNOS whereas inhibition of miR-455-3p decreased it. Moreover, H₂S and miR-455-3p could no longer increase the protein level of eNOS in the presence of proteasome inhibitor, MG-132. In vivo, miR-455-3p and eNOS expression were considerably increased in C57BL/6 mouse aorta, muscle and heart after administration with 50 μmol/kg/day NaHS for 7 days. We also identified that H₂S levels and miR-455-3p expression increased in human atherosclerosis plaque while H₂S levels decreased in plasma of atherosclerosis patients. Our data suggest that the stability of eNOS protein and the NO production could be regulated by H₂S through miR-455-3p.

Circulating miRNAs and their target genes associated with arsenism caused by coal-burning

Endemic arsenism, caused by burning coal containing high levels of arsenic, is found only in the Guizhou and Shanxi Provinces of China. Dysregulated microRNAs (miRNAs), detected in the blood, are emerging as promising biomarkers. At present, little is known about the change and clinical efficacy of circulating miRNAs in patients with endemic arsenism produced by burning of coal. Here, we determined, by using TaqMan Human miRNA Array Chips, the differential expression of plasma miRNAs between patients with arsenism caused by coal-burning and a control group. Four increased miRNAs (miR-21, miR-145, miR-155, and miR-191) were verified in a larger sample by quantitative real-time PCR. Furthermore, bioinformatics and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were used to associate changes in plasma levels of the miRNAs with their functions and their effects on various pathways. The results of chip array assays show that the levels of miR-21, miR-141, miR-148a, miR-145, miR-155, miR-191, miR-218, and miR-491 were most prominently increased and that the levels of miR-200b, miR-200c, miR-26, and miR-34c were decreased. The qRT-PCR results confirm that the circulating levels of miR-21, miR-145, miR-155, and miR-191 are increased in patients with arsenism caused by coal-burning. KEGG analyses show that these miRNAs inhibit the target genes of pathways related to immune inflammation, oxidative stress, and DNA damage repair. Therefore, the four miRNAs may be biomarkers of endemic arsenism caused by coal-burning. Further studies with larger samples should be performed to confirm these findings and to elucidate the underlying mechanisms.

Upregulation of MicroRNA-15a Contributes to Pathogenesis of Abdominal Aortic Aneurysm (AAA) by Modulating the Expression of Cyclin-Dependent Kinase Inhibitor 2B (CDKN2B)

Background

The objective of the present study was to identify the association between miR-15a-5p and CDKN2B, and their roles in regulating the development of abdominal aortic aneurysm (AAA).

Material/Methods

We searched the miRNA database online (www.mirdb.org) and used a luciferase reporter assay system to study the regulatory relationship between miR-15a-5p and CDKN2B. We also conducted real-time PCR and Western blot analysis to study the mRNA and protein expression level of CDKN2B among different patient groups (participants with abdominal aortic aneurysm (AAA) and normal controls) or cells treated with scramble control, miR-15a-5p mimics, CDKN2B siRNA, and miR-15a-5p inhibitors.

Results

We found that CDKN2B was a virtual target of miR-15a-5p with potential binding sites in the 3′UTR of CDKN2B (77–83 bp). We also showed that miR-15a-5p could bind to the CDKN2B 3′UTR, resulting in a significant decrease in luciferase activity compared with the scramble control. Furthermore, we found that the cells isolated from AAA participants showed an over-expression of miR-15a-5p compared to the normal controls, while the CDKN2B mRNA and protein expression level of the AAA group were much lower than the normal control group. Additionally, the expression of CDKN2B mRNA and the protein of the cells transfected with miR-15a-5p mimics and CDKN2B siRNA was downregulated, while the cells showed upregulated expression subsequent to transfection with miR-15a-5p inhibitors compared to the scramble control.

Conclusions

The data revealed a negative regulatory role of miR-15a-5p in the apoptosis of smooth muscle cells via targeting CDKN2B, and showed that miR-15a-5p could be a novel therapeutic target of AAA.

Genetic and Epigenetic Regulation of Aortic Aneurysms

Aneurysms are characterized by structural deterioration of the vascular wall leading to progressive dilatation and, potentially, rupture of the aorta. While aortic aneurysms often remain clinically silent, the morbidity and mortality associated with aneurysm expansion and rupture are considerable. Over 13,000 deaths annually in the United States are attributable to aortic aneurysm rupture with less than 1 in 3 persons with aortic aneurysm rupture surviving to surgical intervention. Environmental and epidemiologic risk factors including smoking, male gender, hypertension, older age, dyslipidemia, atherosclerosis, and family history are highly associated with abdominal aortic aneurysms, while heritable genetic mutations are commonly associated with aneurysms of the thoracic aorta. Similar to other forms of cardiovascular disease, family history, genetic variation, and heritable mutations modify the risk of aortic aneurysm formation and provide mechanistic insight into the pathogenesis of human aortic aneurysms. This review will examine the relationship between heritable genetic and epigenetic influences on thoracic and abdominal aortic aneurysm formation and rupture.

Screening of circulating microRNA biomarkers for prevalence of abdominal aortic aneurysm and aneurysm growth

BACKGROUND AND AIMS

MicroRNA (miR) are important regulators of gene expression and biological processes and have recently been suggested as possible biomarkers for abdominal aortic aneurysm (AAA) disease. The aim of the present study was to assess the role of miR as biomarkers for initiation and progression of AAA disease, through evaluation of a wide range of miRs in a large population-based cohort, with AAA patients with linked clinical data regarding risk factors, AAA size and growth, as well as controls.

METHODS

The expression of the 172 most commonly expressed miRs in plasma was analyzed by real-time PCR in samples from 169 screening-detected AAA patients and 48 age-matched controls.

RESULTS

For 103 miRs, there was a significant difference in expression between AAA and controls. Of these, 20 miRs were differently expressed between fast and slow growing aneurysms. These miRs target genes known to be involved in AAA disease as well as novel genes and pathways. By combining the top altered miRs together with clinical variables, strong predictive values, determining growth of AAA, were obtained (area under curve = 0.86, p < 0.001).

CONCLUSIONS

This large cohort study identified several novel miRs with altered expression in AAA patients when compared to controls. Assessment of miR expression may offer an opportunity to predict disease progression and aneurysm growth.

Epigenetics and Peripheral Artery Disease

The term epigenetics is usually used to describe inheritable changes in gene function which do not involve changes in the DNA sequence. These typically include non-coding RNAs, DNA methylation and histone modifications. Smoking and older age are recognised risk factors for peripheral artery diseases, such as occlusive lower limb artery disease and abdominal aortic aneurysm, and have been implicated in promoting epigenetic changes. This brief review describes studies that have associated epigenetic factors with peripheral artery diseases and investigations which have examined the effect of epigenetic modifications on the outcome of peripheral artery diseases in mouse models. Investigations have largely focused on microRNAs and have identified a number of circulating microRNAs associated with human peripheral artery diseases. Upregulating or antagonising a number of microRNAs has also been reported to limit aortic aneurysm development and hind limb ischemia in mouse models. The importance of DNA methylation and histone modifications in peripheral artery disease has been relatively little studied. Whether circulating microRNAs can be used to assist identification of patients with peripheral artery diseases and be modified in order to improve the outcome of peripheral artery disease will require further investigation.

Prospective and therapeutic screening value of non-coding RNA as biomarkers in cardiovascular disease

Non-coding RNA (ncRNA) is a class of genetic, epigenetic and translational regulators, containing short and long transcripts with intriguing abilities for use as biomarkers due to their superordinate role in disease development. In the past five years many of these have been investigated in cardiovascular diseases (CVD), mainly myocardial infarction (MI) and heart failure. To extend this view, we summarize the existing data about ncRNA as biomarker in the whole entity of CVDs by literature-based review and comparison of the identified candidates. The myomirs miRNA-1, -133a/b, -208a, -499 with well-defined cellular functions have proven equal to classic protein biomarkers for disease detection in MI. Other microRNAs (miRNAs) were reproducibly found to correlate with disease, disease severity and outcome in heart failure, stroke, coronary artery disease (CAD) and aortic aneurysm. An additional utilization has been discovered for therapeutic monitoring. The function of long non-coding transcripts is only about to be unraveled, yet shows great potential for outcome prediction. ncRNA biomarkers have a distinct role if no alternative test is available or has is performing poorly. With increasing mechanistic understanding, circulating miRNA and long non-coding transcripts will provide useful disease information with high predictive power.

The Discovery of Novel Genomic, Transcriptomic, and Proteomic Biomarkers in Cardiovascular and Peripheral Vascular Disease: The State of the Art

Cardiovascular disease (CD) and peripheral vascular disease (PVD) are leading causes of mortality and morbidity in western countries and also responsible of a huge burden in terms of disability, functional decline, and healthcare costs. Biomarkers are measurable biological elements that reflect particular physiological or pathological states or predisposition towards diseases and they are currently widely studied in medicine and especially in CD. In this context, biomarkers can also be used to assess the severity or the evolution of several diseases, as well as the effectiveness of particular therapies. Genomics, transcriptomics, and proteomics have opened new windows on disease phenomena and may permit in the next future an effective development of novel diagnostic and prognostic medicine in order to better prevent or treat CD. This review will consider the current evidence of novel biomarkers with clear implications in the improvement of risk assessment, prevention strategies, and medical decision making in the field of CD.

Micro-RNAs in abdominal aortic aneurysms: insights from animal models and relevance to human disease

Abdominal aortic aneurysm (AAA) is a major health concern and may be associated with high rates of mortality linked to acute complications. Diagnosis and treatment are, respectively, based on imaging and surgical techniques. Drug-based therapies are still mostly ineffective, which highlight a real unmet need. Major pathophysiological mechanisms leading to aneurysm formation involve inflammatory processes, degradation of the extracellular matrix, and loss of smooth muscle cells. However, the precise cellular and molecular pathways are still poorly understood. Recently, microRNAs have emerged as major intracellular players in a wide range of biological processes, and their stability in extracellular medium within microvesicles has led to propose them as mediators of intercellular crosstalk and as potential biomarkers and therapeutic targets in a variety of disease settings. To date, several studies have been performed to address the involvement of micro-RNAs (miRs) in aneurysm formation and complications. Here, we discuss the roles and implications of miRs in animal models and their relevance to human AAA.

Surrogate Markers of Abdominal Aortic Aneurysm Progression

The natural course of many abdominal aortic aneurysms (AAA) is to gradually expand and eventually rupture and monitoring the disease progression is essential to their management. In this publication, we review surrogate markers of AAA progression. AAA diameter remains the most widely used and important marker of AAA growth. Standardized reporting of reproducible methods of measuring AAA diameter is essential. Newer imaging assessments, such as volume measurements, biomechanical analyses, and functional and molecular imaging, as well as circulating biomarkers, have potential to add important information about AAA progression. Currently, however, there is insufficient evidence to recommend their routine use in clinical practice.