Expression of miRNA-26a in platelets is associated with clopidogrel resistance following coronary stenting

Association of genetic variations of 3'-UTR in clopidogrel pharmacokinetic-relevant genes with clopidogrel response in Han Chinese patients with coronary artery disease

Dual antiplatelet therapy with aspirin and clopidogrel has reduced ischemic vascular events significantly. Genetic influence, especially those in clopidogrel pharmacokinetic-relevant genes partially accounts for interindividual pharmacodynamic variability of clopidogrel. However, most studies have concentrated on the genetic variations in introns, exons, or promoters of the candidate genes, and the association between genetic variations in 3'-UTR in clopidogrel pharmacokinetic-relevant genes and clopidogrel response is unknown. In our study, ten different algorithms were applied to pick potential miRNAs targeting the clopidogrel pharmacokinetic-relevant genes. Furthermore, the correlation between miRNA expression profiles and mRNA expression of corresponding clopidogrel pharmacokinetic-relevant genes was analyzed. Through comprehensive analysis, including bioinformatics prediction and correlation analysis of miRNA and mRNA expression profiles, miR-218-5p and miR-506-5p were supposed to regulate the expression of PON1 via binding with its 3'-UTR. Moreover, PON1 rs854551 and rs854552 were located in miRNA recognizing sequences and may serve as potential miRSNPs possibly affecting PON1 expression. The rs854552 polymorphism was genotyped and platelet reactivity index (PRI) indicative of clopidogrel response was measured in 341 Chinese coronary artery disease (CAD) patients 24 h after administration of 300 mg clopidogrel. Our results showed that PON1 rs854552 had a significant influence on PRI in CAD patients, especially in patients with CYP2C19 extensive metabolic phenotype. In conclusion, PON1 rs854552 polymorphisms may affect clopidogrel response. Bioinformatics prediction followed by functional validation could aid in decoding the contribution of unexplained variations in the 3'-UTR in drug-metabolizing enzymes on clopidogrel response.

The role of clopidogrel resistance-related genetic and epigenetic factors in major adverse cardiovascular events among patients with acute coronary syndrome after percutaneous coronary intervention

Despite patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) and receiving clopidogrel therapy, some patients still experience major adverse cardiovascular events (MACEs). Clopidogrel resistance, which may be regulated by genetic and epigenetic factors, may play a role in MACEs. This study aimed to determine the association between genetic (CYP2C19 and P2Y12 polymorphisms) and epigenetic (DNA methylation of CYP2C19 and P2Y12 and miRNA-26a expression) factors and their effects on MACEs among post-PCI patients. Post-PCI patients who received a standard dosage of clopidogrel at Harapan Kita Hospital between September 2018 and June 2020 were included in this study. MACEs were observed in patients within 1 year after PCI. Platelet aggregation was assessed using light transmission aggregometry (LTA). DNA methylation of CYP2C19 and P2Y12 was assessed using the bisulfite conversion method. CYP2C19 and P2Y12 polymorphisms and miRNA-26a expression were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR). Among a total of 201 subjects, 49.8% were clopidogrel-resistant, and 14.9% experienced MACEs within 1 year after PCI (death was 7.5%). Hypomethylation of CYP2C19 (p = 0.037) and miRNA-26a upregulation (p = 0.020) were associated with clopidogrel resistance. CYP2C19^*2/^*3 polymorphisms (p = 0.047) were associated with MACEs in 1 year. This study demonstrated that hypomethylation of CYP2C19 and miRNA-26a upregulation increased the risk of clopidogrel resistance in post-PCI patients, but there was no correlation between clopidogrel resistance and MACEs. However, CYP2C19^*2/^*3 polymorphisms were the factors that predicted MACEs within 1 year.

Platelet miR-107 Participates in Clopidogrel Resistance after PCI Treatment by Regulating P2Y12

INTRODUCTION

High platelet reactivity (HPR) caused by clopidogrel tolerance is an adverse reaction of acute coronary syndrome (ACS) patients who receive clopidogrel antiplatelet therapy after percutaneous coronary intervention (PCI) surgery. Platelet microRNA (miRNA) is related to platelet reactivity. This study explored the mechanism of platelet miRNA in regulating platelet reactivity.

METHODS

We recruited 50 ACS/PCI patients and divided them into the HPR group (P2Y12 reaction units [PRU] ≥300) and the LPR group (PRU < 170) according to the PRU through the VerifyNow P2Y12 assay. P2Y12-related miRNAs were screened by TargetScan, miRWalk, and Gene Expression Omnibus. The expressions of P2Y12 and miRNAs in the HPR group and the LPR group were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Pearson correlation analysis was used to determine the correlation between P2Y12 and miRNAs. The interactions between P2Y12 and miR-107 were predicted by TargetScan and verified by dual-luciferase reporter assay. The regulation of miR-107 mimic or inhibitor on P2Y12 expression was detected by qRT-PCR and Western blot.

RESULTS

There were 22 patients in the LPR group and 28 patients in the HPR group. PY212 was highly expressed in the HPR group compared with the LPR group. We screened the P2Y12-related miRNAs (miR-145-5p, miR-4701-3p, miR-107, and miR-15b-5p), but only miR-107 and miR-15b-5p expressions were downregulated in the HPR group and were negatively correlated with PY212 expression. P2Y12 was the target gene of miR-107. PY212 expression was inhibited by miR-107 overexpression but suppressed by miR-107 silencing.

CONCLUSION

Platelet miR-107 participated in clopidogrel resistance in ACS/PCI patients by regulating P2Y12 expression.

MicroRNA as Biomarkers for Platelet Function and Maturity in Patients with Cardiovascular Disease

Patients with cardiovascular disease (CVD) are at increased risk of suffering myocardial infarction. Platelets are key players in thrombus formation and, therefore, antiplatelet therapy is crucial in the treatment and prevention of CVD. MicroRNAs (miRs) may hold the potential as biomarkers for platelet function and maturity. This systematic review was conducted using the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). To identify studies investigating the association between miRs and platelet function and maturity in patients with CVD, PubMed and Embase were searched on October 13 and December 13, 2020 without time boundaries. Risk of bias was evaluated using a standardized quality assessment tool. Of the 16 included studies, 6 studies were rated "good" and 10 studies were rated "fair." In total, 45 miRs correlated significantly with platelet function or maturity (rho ranging from -0.68 to 0.38, all p < 0.05) or differed significantly between patients with high platelet reactivity and patients with low platelet reactivity (p-values ranging from 0.0001 to 0.05). Only four miRs were investigated in more than two studies, namely miR-223, miR-126, miR-21 and miR-150. Only one study reported on the association between miRs and platelet maturity. In conclusion, a total of 45 miRs were associated with platelet function or maturity in patients with CVD, with miR-223 and miR-126 being the most frequently investigated. However, the majority of the miRs were only investigated in one study. More data are needed on the potential use of miRs as biomarkers for platelet function and maturity in CVD patients.

New Insights Into Platelet-enriched miRNAs: Production, Functions, Roles in Tumors, and Potential Targets for Tumor Diagnosis and Treatment

In view of the increasing number of malignant tumors worldwide and their high mortality, efforts are being made to find effective biomarkers for early detection and effective treatment measures of cancer. In recent years, the roles of platelets in tumors have attracted considerable attention. Although platelets do not have nuclei, they are rich in miRNAs, which are important molecules in platelet regulation of tumors. Platelet miRNA expression in tumor patients is abnormal and tumor-specific. Platelet miRNAs have higher accuracy and specificity than conventional tumor detection markers and circulating miRNAs in tumor diagnosis. Platelets enriched miRNAs are involved in the regulation of tumor proliferation, metastasis, tumor-related immunity, tumor-related thrombosis, and antitumor therapy. To understand the role of platelet miRNAs in tumors, this article reviews the biological functions of miRNAs in platelets and summarizes the regulatory roles of platelet miRNAs in tumors and the potential roles of platelet miRNAs in tumor diagnosis and treatment.

MicroRNA as Potential Biomarkers of Platelet Function on Antiplatelet Therapy: A Review

MicroRNAs (miRNAs) are small, non-coding RNAs, able to regulate cellular functions by specific gene modifications. Platelets are the major source for circulating miRNAs, with significant regulatory potential on cardiovascular pathophysiology. MiRNAs have been shown to modify the expression of platelet proteins influencing platelet reactivity. Circulating miRNAs can be determined from plasma, serum, or whole blood, and they can be used as diagnostic and prognostic biomarkers of platelet reactivity during antiplatelet therapy as well as novel therapeutic targets in cardiovascular diseases (CVDs). Herein, we review diagnostic and prognostic value of miRNAs levels related to platelet reactivity based on human studies, presenting its interindividual variability as well as the substantial role of genetics. Furthermore, we discuss antiplatelet treatment in the context of miRNAs alterations related to pathways associated with drug response.

Impact of Anticoagulation and Sample Processing on the Quantification of Human Blood-Derived microRNA Signatures

Blood-derived microRNA signatures have emerged as powerful biomarkers for predicting and diagnosing cardiovascular disease, cancer, and metabolic disorders. Platelets and platelet-derived microvesicles are a major source of microRNAs. We have previously shown that the inappropriate anticoagulation and storage of blood samples causes substantial platelet activation that is associated with the release of platelet-stored molecules into the plasma. However, it is currently unclear if circulating microRNA levels are affected by artificial platelet activation due to suboptimal plasma preparation. To address this issue, we used a standardized RT-qPCR test for 12 microRNAs (thrombomiR^®, TAmiRNA GmbH, Vienna, Austria) that have been associated with cardiovascular and thrombotic diseases and were detected in platelets and/other hematopoietic cells. Blood was prevented from coagulating with citrate–theophylline–adenosine–dipyridamole (CTAD), sodium citrate, or ethylenediaminetetraacetic acid (EDTA) and stored for different time periods either at room temperature or at 4 °C prior to plasma preparation and the subsequent quantification of microRNAs. We found that five microRNAs (miR-191-5p, miR-320a, miR-21-5p, miR-23a-3p, and miR-451a) were significantly increased in the EDTA plasma. Moreover, we observed a time-dependent increase in plasma microRNAs that was most pronounced in the EDTA blood stored at room temperature for 24 h. Furthermore, significant correlations between microRNA levels and plasma concentrations of platelet-stored molecules pointed towards in vitro platelet activation. Therefore, we strongly recommend to (i) use CTAD as an anticoagulant, (ii) process blood samples as quickly as possible, and (iii) store blood samples at 4 °C whenever immediate plasma preparation is not feasible to generate reliable data on blood-derived microRNA signatures.

miRNAs in drug response variability: potential utility as biomarkers for personalized medicine

MicroRNAs (miRNAs) are 18-22 nucleotide RNA molecules that modulate the expression of multiple protein-encoding genes at the post-transcriptional level. Almost all physiological conditions are probably modulated by miRNAs, including pharmacological response. Indeed, acting on the regulation of numerous genes involved in the pharmacokinetics and pharmacodynamics of drugs, differences in the levels of circulating miRNAs or genetic variants in the sequences of the miRNA genes can contribute to interindividual variability in drug response, both in terms of toxicity and efficacy. For their stability in body fluids and the easy availability and accurate quantification, miRNAs could be ideal biomarkers of individual response to drugs. This review aims to give an overview on the available studies that have investigated the relationship between miRNAs and response to drugs in different classes of diseases and considered their possible clinical application as therapy response predictive biomarkers. A comprehensive search was conducted from the international web database PubMed. We included papers that investigated the relationship between miRNAs and response to drugs, published before January 2019.

Coding SNPs in hsa-miR-1343-3p and hsa-miR-6783-3p target sites of CYP2C19 modulates clopidogrel response in individuals with cardiovascular diseases

AIMS

To investigate the impact of microRNA target SNPs (mirSNPs) and their interaction with miRNAs on important drug-metabolizing enzymes, transporters and target genes for prediction of clopidogrel drug response in cardiovascular disease individuals.

MAIN METHODS

A prospective cross-sectional study was conducted on 292 individuals undergoing clopidogrel drug therapy. All the enrolled participants were administered 300 mg loading dose followed by 75 mg dose of maintenance therapy. Platelet aggregations were measured before administration of the loading dose and 2 h post fifth day dose of clopidogrel maintenance therapy. Clopidogrel carboxylic acid metabolite from plasma and urine were analyzed post maintenance therapy using the RP-HPLC method. Genotyping of mirSNP's shortlisted through in silico analysis was performed by tetra ARMS PCR and validated by Sanger DNA sequencing. The levels of selected miRNAs were estimated by the TaqMan-PCR assay. Functional validation of mirSNPs was performed in HepG2 cells after transfecting with the selected gene and miRNA mimics. Protein expressions were analyzed by western blot.

KEY FINDINGS

23% of enrolled individuals showed resistance to clopidogrel therapy. Out of 13 mirSNP's analyzed, CYP2C19 rs4244285 was associated with clopidogrel drug resistance and clopidogrel carboxylic acid metabolite in urine and plasma. hsa-miR-1343-3p and hsa-miR-6783-3p levels were significantly high in individuals with CYP2C19 rs4244285 mutant genotype and these miRNAs down-regulated the protein expression of CYP2C19.

SIGNIFICANCE

We demonstrated the role of coding mirSNP (rs4244285) in the regulation of the CYP2C19 gene through miRNAs and its implications to clopidogrel drug response prediction in the Indian population.

Micro-RNA as a new biomarker of activity of the cytochrome system P-450: significance for predicting the antiplatelet action of P2Y12 receptor inhibitors

MicroRNAs are short non - coding RNAs that correlate with the levels of platelet activation which can be utilized as a biomarker when guiding P2Y12 inhibitors therapy. In this literature review, the perspectives of microRNA as a novel biomarker are discussed when guiding P2Y12 inhibitors therapy among the patients with coronary artery disease.

Microarray-based measurement of microRNA-449c-5p levels in hepatocellular carcinoma and bioinformatic analysis of potential signaling pathways

The clinical role and potential molecular mechanisms of microRNA-449c-5p (miR-449c-5p) in hepatocellular carcinoma (HCC) tissues remains unclear. Combining multiple bioinformatic tools, we studied the miR-449c-5p expression levels in HCC tissues and explored possible target genes and related signaling pathways. First, miR-449c-5p expression data from microarrays provided by publicly available sources were mined and analyzed using various meta-analysis methods. Next, genes that were downregulated after miR-449c-5p mimic transfection into HCC cells were identified, and in silico methods were used to predict potential target genes. Several bioinformatic assessments were also performed to evaluate the possible signaling pathways of miR-449c-5p in HCC. Five microarrays were included in the current study, including GSE98269, GSE64632, GSE74618, GSE40744 and GSE57555. The standard mean difference was 0.44 (0.07-0.80), and the area under the curve was 0.68 (0.63-0.72), as assessed by meta-analyses, which consistently indicated the upregulation of miR-449c-5p in HCC tissues. A total of 2244 genes were downregulated after miR-449c-5p mimic transfection into an HCC cell line, while 5217 target genes were predicted by in silico methods. The overlap of these two gene pools led to a final group of 428 potential target genes of miR-449c-5p. These 428 potential target genes were primarily enriched in the homologous recombination pathway, which includes DNA Polymerase Delta 3 (POLD3). Data mining with Oncomine and the Human Protein Atlas showed a decreasing trend in POLD3 mRNA and protein levels in HCC tissue samples. This evidence suggests that miR-449c-5p could play an essential role in HCC through various pathways and that POLD3 could be a potential miR-449c-5p target. However, these in silico findings should be validated with further experiments.

Modulation of miR-26a-5p and miR-15b-5p Exosomal Expression Associated with Clopidogrel-Induced Hepatotoxicity in HepG2 Cells

Clopidogrel is an essential antiplatelet drug used to prevent thrombosis complications associated with atherosclerosis. However, hepatotoxicity is a potential adverse effect related to clopidogrel therapy. Exosome-derived miRNAs may be useful for improved monitoring of drug response and hepatotoxicity risk. In the present study, the expression of several exosomal miRNAs (miR-26a-5p, miR-145-5p, miR-15b-5p, and miR-4701-3p) and cell-derived mRNA targets (PLOD2, SENP5, EIF4G2, HMGA2, STRADB, and TLK1) were evaluated in HepG2 cells treated with clopidogrel (6.25, 12.5, 25, 50, and 100 μM) for 24 and 48 h. Then, clopidogrel cytotoxicity was evaluated by analyzing DNA fragmentation and the cell cycle profile using flow cytometry. Differential expression of exosome-derived miRNAs and cell-derived mRNAs was analyzed by RT-qPCR. Exposure of HepG2 cells to high concentrations of clopidogrel (50 and 100 μM) for 24 h caused significant DNA fragmentation (17.6 and 44.4%, respectively; p < 0.05) and 48 h (26.8 and 48.9%, respectively; p < 0.05), indicating cellular toxicity. Upregulation of miR-26a-5p and downregulation of miR-15b-5p was observed in cells exposed to 100 μM clopidogrel for 24 and 48 h. The miR-26a-5p target mRNAs HMGA2, EIF4G2, STRADB, and SENP5 were downregulated in HepG2 cells following exposure to cytotoxic concentrations of clopidogrel (50 and 100 μM) for 24 h, and HMGA2 levels remained low after 48 h of treatment. TLK1, a target of miR-15b-5p, was downregulated by 50 and 100 μM clopidogrel at 24 h. In conclusion, our results suggest that exposure to high concentrations of clopidogrel modulates the expression of exosomal miR-26a-5p and miR-15b-5p and their target mRNAs in HepG2 cells. Dysregulation of these miRNAs maybe modulate the regulatory pathways involved in clopidogrel-induced liver injury.

The role of microRNAs in prethrombotic status associated with coronary artery disease

The acute cardiovascular events following thrombus formation is a primary cause of morbidity and mortality of patients with coronary artery disease (CAD). Numerous studies have shown that a prethrombotic status, which can be defined as an imbalance between the procoagulant and anticoagulant conditions, would exist for a period of time before thrombogenesis. Therefore, early diagnosis and intervention of prethrombotic status are important for reducing acute cardiovascular events. However, none of prethrombotic indicators have been identified as golden standard for diagnosis of prethrombotic status to date. MicroRNAs (miRNAs), a class of short non-coding RNAs, have been shown to be involved in pathophysiologic processes related to prethrombotic status, such as endothelial dysfunction, platelet activation, impaired fibrinolysis and elevated procoagulant factors, etc. Owing to their multiple and fine-tuning impacts on gene expression, miRNAs raise a novel understanding in the underlying mechanism of prethrombotic status. This review aims to discuss the role of miRNAs in prethrombotic status, especially the differently expressed miRNAs in CAD, which may be meaningful for developing promising diagnostic biomarkers and therapeutic strategies for CAD patients in future.

Pharmacokinetic and Pharmacodynamic Responses to Clopidogrel: Evidences and Perspectives

Clopidogrel has significantly reduced the incidence of recurrent atherothrombotic events in patients with acute coronary syndrome (ACS) and in those undergoing percutaneous coronary intervention (PCI). However, recurrence events still remain, which may be partly due to inadequate platelet inhibition by standard clopidogrel therapy. Genetic polymorphisms involved in clopidogrel’s absorption, metabolism, and the P2Y12 receptor may interfere with its antiplatelet activity. Recent evidence indicated that epigenetic modification may also affect clopidogrel response. In addition, non-genetic factors such as demographics, disease complications, and drug-drug interactions can impair the antiplatelet effect of clopidogrel. The identification of factors contributing to the variation in clopidogrel response is needed to improve platelet inhibition and to reduce risk for cardiovascular events. This review encompasses the most recent updates on factors influencing pharmacokinetic and pharmacodynamic responses to clopidogrel.

Expression and mechanism of action of miR-196a in epithelial ovarian cancer

OBJECTIVE

To explore the expression, biological function and possible mechanism of action of microRNA molecular-196a (miR-196a) in epithelial ovarian cancer.

METHODS

RT-PCR was used to detect the expression quantities of epithelial ovarian tissue, benign ovarian tissue, normal ovary epithelial tissue, ovarian cancer cell lines and miR-196a in normal ovarian epithelial cells to analyze the relationship between the expression of miR-196a and the clinical pathologic parameters of ovarian cancer. Among those cell lines, the cell line of which miR-196a expressed the most or least was selected and transfected the ovarian cancer cell line by using negative control plasma and miR-196a inhibitor. After transfection, RT-PCR was used to test the expression quantity of miR-196a, Transwell chamber method was applied to determine the migration and invasion abilities of ovarian carcinoma cells and Western blot was employed to detect the expression of HOXA10 protein.

RESULTS

The relative expression quantities of miR-196a in ovarian cancer tissue and benign ovarian tissue were significantly higher than that in normal ovarian epithelial tissue, and the expression quantity of miR-196a in ovarian cancer tissue was distinctively higher than that in benign ovarian tissue (P < 0.05). Among 78 cases of epithelial ovarian cancer, the expression quantities of miR-196a in patients with low differentiation were all significantly higher than those in patients with high differentiation (P < 0.05). The expression of miR-196a showed no significant relation with age, clinical stage and whether CA125 was positive or not in patients (P > 0.05). Compared with normal ovarian epithelial cell line IOSE80, the expression quantities of miR-196a of all ovarian cancer cell lines increased obviously and differences were statistically significant (P < 0.05). Among them, the expression of miR-196a of ovarian cancer cell line SKOV3 was the highest, while it decreased significantly (4.678 ± 0.785 vs. 2.131 ± 0.345, t = 2.938, P < 0.05) after the ovarian cancer cell line SKOV3 was transfected by miR-196a inhibitor. The results of Transwell chamber method showed that the migration and invasion abilities of ovarian cancer cells SKOV3 were declined significantly after the expression of miR-196a was down-regulated and the difference showed statistical significance (P < 0.05). The results of Western blot revealed that the relative expression of HOXA10 decreased distinctly after the expression of miR-196a was down-regulated and also the difference showed statistical significance (P < 0.05).

CONCLUSIONS

The miR-196a might serve as a cancer-promoting gene to promote the migration and invasion of epithelial ovarian cancer by downstream target gene HOXA10.