Mechanistic Role of MicroRNAs in Coupling Lipid Metabolism and Atherosclerosis

CircXYLT1 suppresses oxidative stress and promotes vascular remodeling in aging mice carotid artery injury model of atherosclerosis via PTBP1

Atherosclerosis and aortic aneurysms are prevalent cardiovascular diseases in the elderly, characterized by chronic inflammation and oxidative stress. This study explores the role of CircXYLT1 in regulating oxidative stress and vascular remodeling in age-related vascular diseases. RNA sequencing revealed a significant upregulation of CircXYLT1 in the vascular tissues of aged mice, highlighting its potential role in age-related vascular diseases. Using a carotid artery wire injury model, we performed adeno-associated virus (AAV)-mediated knockdown and overexpression of CircXYLT1. Key oxidative stress markers, including reactive oxygen species (ROS) and malondialdehyde (MDA), were measured. Knockdown of CircXYLT1 increased oxidative stress and reduced antioxidant protein expression (SOD, GPX), while overexpression led to decreased oxidative damage and enhanced vascular smooth muscle cell (VSMC) proliferation. Mechanistically, CircXYLT1 interacted with PTBP1, reducing its nuclear localization and modulating downstream chemokine signaling pathways. These findings suggest that CircXYLT1 plays a critical role in vascular remodeling and oxidative stress regulation, offering potential as a therapeutic target for managing cardiovascular diseases in aging populations.

6-methylcoumarin/miR-122 suppresses hepatic Sortilin-mediated ApoB-100 secretion to attenuate aortic atherosclerosis

This study aimed to investigate the effects of hepatic microRNA-122 (miR-122) on Sortilin-mediated apolipoprotein B100 (apoB-100) secretion, and on aortic lipid deposition and atherosclerosis (AS) lesions and to clarify the antiatherosclerotic mechanism of 6-methylcoumarin (6-MC) via the modulation of miR-122. Bioinformatics analysis revealed that miR-122 was putatively overexpressed in a liver-specific manner and was downregulated in steatotic livers. miR-122 was shown to suppress the expression of Sortilin by complementarily pairing to the 3'-untranslated region (3'-UTR) of Sortilin mRNA via bioinformatics and dual-luciferase reporter assays, impeding Sortilin-mediated apoB-100 secretion from HepG2 cells. Administration of 6-MC significantly upregulated hepatocellular miR-122 levels, reducing Sortilin expression and apoB-100 secretion in HepG2 cells. The miR-122 mimic vigorously enhanced 6-MC-depressed Sortilin expression, while miR-122 inhibitor repealed the inhibitory effect of 6-MC on Sortilin expression to some extent in HepG2 cells. After internal intervention with the miR-122 precursor, and 6-MC supplementation alone or in combination with the miR-122 sponge led to the reduction in blood triglyceride (TG) levels, low-density lipoprotein-cholesterol (LDL-C) and apoB-100 and a reduction in aortic lipid deposition and AS lesions in apolipoprotein E-deficient (ApoE-/-) mice fed a high fat diet (HFD). The hepatic levels of Sortilin and apoB-100 expression were also decreased in these treated mice. In conclusion, miR-122 suppresses Sortilin expression and Sortilin-mediated apoB-100 secretion to resist circulating LDL production and aortic AS development, which is enhanced by 6-MC-upregulated miR-122 in the liver.

miR-369-3p ameliorates diabetes-associated atherosclerosis by regulating macrophage succinate-GPR91 signalling

AIMS

Diabetes leads to dysregulated macrophage immunometabolism, contributing to accelerated atherosclerosis progression. Identifying critical factors to restore metabolic alterations and promote resolution of inflammation remains an unmet goal. MicroRNAs orchestrate multiple signalling events in macrophages, yet their therapeutic potential in diabetes-associated atherosclerosis remains unclear.

METHODS AND RESULTS

miRNA profiling revealed significantly lower miR-369-3p expression in aortic intimal lesions from Ldlr-/- mice on a high-fat sucrose-containing (HFSC) diet for 12 weeks. miR-369-3p was also reduced in peripheral blood mononuclear cells from diabetic patients with coronary artery disease (CAD). Cell-type expression profiling showed miR-369-3p enrichment in aortic macrophages. In vitro, oxLDL treatment reduced miR-369-3p expression in mouse bone marrow-derived macrophages (BMDMs). Metabolic profiling in BMDMs revealed that miR-369-3p overexpression blocked the oxidized low density lipoprotein (oxLDL)-mediated increase in the cellular metabolite succinate and reduced mitochondrial respiration (OXPHOS) and inflammation [Interleukin (lL)-1β, TNF-α, and IL-6]. Mechanistically, miR-369-3p targeted the succinate receptor (GPR91) and alleviated the oxLDL-induced activation of inflammasome signalling pathways. Therapeutic administration of miR-369-3p mimics in HFSC-fed Ldlr-/- mice reduced GPR91 expression in lesional macrophages and diabetes-accelerated atherosclerosis, evident by a decrease in plaque size and pro-inflammatory Ly6Chi monocytes. RNA-Seq analyses showed more pro-resolving pathways in plaque macrophages from miR-369-3p-treated mice, consistent with an increase in macrophage efferocytosis in lesions. Finally, a GPR91 antagonist attenuated oxLDL-induced inflammation in primary monocytes from human subjects with diabetes.

CONCLUSION

These findings establish a therapeutic role for miR-369-3p in halting diabetes-associated atherosclerosis by regulating GPR91 and macrophage succinate metabolism.

HDL Levels as a Novel Predictor of Long-Term Adverse Outcomes in Patients with Heart Failure: A Retrospective Cohort Study

Background

The role of high-density lipoprotein cholesterol (HDL-C) in heart failure (HF) outcomes is contentious. We aimed to assess HDL-C's prognostic value in HF patients.

Methods

In this retrospective cohort study (2012-2022) at the First Affiliated Hospital of Xinjiang Medical University, we analyzed 4442 patients, categorized by HDL-C quartiles. We applied the Cox proportional hazards model to assess survival and report hazard ratios (HR) with 95% confidence intervals (CI).

Results

Over a decade, we recorded 1354 fatalities (42.3%) and 820 readmissions. The third HDL-C quartile (0.93-1.14 mmol/L) showed the lowest mortality rates, with reduced risks in the second and third quartiles compared to the first (Q2 HR=0.809, 95% CI 0.590-1.109; Q3 HR=0.794, 95% CI 0.564-1.118). The fourth quartile presented a lower mortality risk compared to the first (Q4 HR=0.887, 95% CI 0.693-1.134). A significant correlation existed between HDL-C levels and cardiovascular risk (HR=0.85, 95% CI 0.75-0.96, p<0.01).

Conclusion

HDL-C levels exhibit a complex association with mortality in HF, indicating the importance of HDL-C in HF prognosis and the need for tailored management strategies.

MiR-127-3p enhances macrophagic proliferation via disturbing fatty acid profiles and oxidative phosphorylation in atherosclerosis

BACKGROUND

Atherosclerosis is a chronic pathology, leading to acute coronary heart disease or stroke. MiR-127 has been found significantly upregulated in advanced atherosclerosis. But its function in atherosclerosis remains unexplored. We explored the role of miR-127-3p in regulating atherosclerosis development and its downstream mechanisms.

METHODS

The expression profile of miR-127 in carotid atherosclerotic plaques of 23 patients with severe carotid stenosis was detected by RT-qPCR and in situ hybridization. Primary bone marrow-derived macrophages (BMDM) stimulated with oxidized low-density lipoprotein were used as an in vitro model. CCK-8, EdU, RT-qPCR, and flow cytometry were used to detect the proliferative capacity and polarization of BMDM, which were infected by lentivirus-carrying plasmid to upregulate or downregulate miR-127-3p expression, respectively. RNA sequencing combined with bioinformatic analysis and targeted fatty acid metabolomics approach were used to detect the transcriptome and lipid metabolites. The association between miR-127-3p and its target was verified by dual-luciferase activity reporting and Western blotting. Oxygen consumption rate of BMDM were detected using seahorse analysis. High-cholesterol-diet-fed low density lipoprotein deficient (LDLR-/-) mice, with-or-without carotid tandem-stenosis surgery, were treated with miR-127-3p agomir or antagomir to examine its effect on plaque development and stability.

RESULTS

miR-127-3p, not -5p, is elevated in human advanced carotid atheroma and its expression is positively associated with macrophage accummulation in plaques. In vitro, miR-127-3p-overexpressed macrophage exhibites increased proliferation capacity and facilitates M1 polariztion whereas the contrary trend is present in miR-127-3p-inhibited macrophage. Stearoyl-CoA desaturase-1 (SCD1) is one potential target of miR-127-3p. miR-127-3p mimics decreases the activity of 3' untranslated regions of SCD-1. Furthermore, miR-127-3p downregulates SCD1 expression, and reversing the expression of SCD1 attenuates the increased proliferation induced by miR-127-3p overexpression in macrophage. miR-127-3p overexpression could also lead to decreased content of unsaturated fatty acids (UFAs), increased content of acetyl CoA and increased level of oxidative phosphorylation. In vivo, miR-127-3p agomir significantly increases atherosclerosis progression, macrophage proliferation and decreases SCD1 expression and the content of UFAs in aortic plaques of LDLR-/- mice. Conversely, miR-127-3p antagomir attenuated atherosclerosis, macrophage proliferation in LDLR-/- mice, and enhanced carotid plaque stability in mice with vulnerable plaque induced.

CONCLUSION

MiR-127-3p enhances proliferation in macrophages through downregulating SCD-1 expression and decreasing the content of unsaturated fatty acid, thereby promoting atherosclerosis development and decreasing plaque stability. miR-127-3p/SCD1/UFAs might provide potential therapeutic target for anti-inflammation and atherosclerosis.

Plasma Extracellular MicroRNAs Associated With Cardiovascular Disease Risk Factors in Middle-Aged and Older Adults

BACKGROUND

Extracellular microRNAs (miRNAs) are a class of noncoding RNAs that remain stable in the extracellular milieu, where they contribute to various physiological and pathological processes by facilitating intercellular signaling. Previous studies have reported associations between miRNAs and cardiovascular diseases (CVDs); however, the plasma miRNA signatures of CVD and its risk factors have not been fully elucidated at the population level.

METHODS AND RESULTS

Plasma miRNA levels were measured in 4440 FHS (Framingham Heart Study) participants. Linear regression analyses were conducted to test the cross-sectional associations of each miRNA with 8 CVD risk factors. Prospective analyses of the associations of miRNAs with new-onset obesity, hypertension, type 2 diabetes, CVD, and all-cause mortality were conducted using proportional hazards regression. Replication was carried out in 1999 RS (Rotterdam Study) participants. Pathway enrichment analyses were conducted and target genes were predicted for miRNAs associated with ≥5 risk factors in the FHS. In the FHS, 6 miRNAs (miR-193b-3p, miR-122-5p, miR-365a-3p, miR-194-5p, miR-192-5p, and miR-193a-5p) were associated with ≥5 risk factors. This miRNA signature was enriched for pathways associated with CVD and several genes annotated to these pathways were predicted targets of the identified miRNAs. Furthermore, miR-193b-3p, miR-194-5p, and miR-193a-5p were each associated with ≥2 risk factors in the RS. Prospective analysis revealed 8 miRNAs associated with all-cause mortality in the FHS.

CONCLUSIONS

These findings highlight associations between miRNAs and CVD risk factors that may provide valuable insights into the underlying pathogenesis of CVD.

The translational potential of miR-26 in atherosclerosis and development of agents for its target genes ACC1/2, COL1A1, CPT1A, FBP1, DGAT2, and SMAD7

Atherosclerosis is one of the leading causes of death worldwide. miR-26 is a potential biomarker of atherosclerosis. Standardized diagnostic tests for miR-26 (MIR26-DX) have been developed, but the fastest progress has been in predicting the efficacy of IFN-α therapy for hepatocellular carcinoma (HCC, phase 3). MiR-26 slows atherosclerosis development by suppressing ACC1/2, ACLY, ACSL3/4, ALDH3A2, ALPL, BMP2, CD36, COL1A1, CPT1A, CTGF, DGAT2, EHHADH, FAS, FBP1, GATA4, GSK3β, G6PC, Gys2, HMGA1, HMGB1, LDLR, LIPC, IL-1β, IL-6, JAG2, KCNJ2, MALT1, β-MHC, NF-κB, PCK1, PLCβ1, PYGL, RUNX2, SCD1, SMAD1/4/5/7, SREBF1, TAB3, TAK1, TCF7L2, and TNF-α expression. Many agents targeting these genes, such as the ACC1/2 inhibitors GS-0976, PF-05221304, and MK-4074; the DGAT2 inhibitors IONIS-DGAT2Rx, PF-06427878, PF-0685571, and PF-07202954; the COL1A1 inhibitor HT-100; the stimulants 68Ga-CBP8 and RCT-01; the CPT1A inhibitors etomoxir, perhexiline, and teglicar; the FBP1 inhibitors CS-917 and MB07803; and the SMAD7 inhibitor mongersen, have been investigated in clinical trials. Interestingly, miR-26 better reduced intima-media thickness (IMT) than PCSK9 or CT-1 knockout. Many PCSK9 inhibitors, including alirocumab, evolocumab, inclisiran, AZD8233, Civi-007, MK-0616, and LIB003, have been investigated in clinical trials. Recombinant CT-1 was also investigated in clinical trials. Therefore, miR-26 is a promising target for agent development. miR-26 promotes foam cell formation by reducing ABCA1 and ARL4C expression. Multiple materials can be used to deliver miR-26, but it is unclear which material is most suitable for mass production and clinical applications. This review focuses on the potential use of miR-26 in treating atherosclerosis to support the development of agents targeting it.

Circulating miRNA 122-5p Expression Predicts Mortality and Cardiovascular Events in Chronic Hemodialysis Patients: A Multicentric, Pilot, Prospective Study

BACKGROUND

Despite patients undergoing chronic hemodialysis (HD) being notoriously prone to adverse cardiovascular (CV) events, risk prediction in this population remains challenging. miRNA 122-5p, a short, non-coding RNA predominantly involved in lipid and carbohydrate metabolism, has recently been related to the onset and progression of CV disease.

METHODS

We run a pilot, multicenter, longitudinal, observational study to evaluate the clinical significance and prognostic usefulness of circulating miRNA 122-5p in a multicentric cohort of 74 individuals on maintenance HD.

RESULTS

Patients displayed lower circulating miRNA 122-5p as compared to healthy controls (p = 0.004). At correlation analyses, ALT (β = 0.333; p = 0.02), E/e' (β = 0.265; p = 0.02) and CRP (β = -0.219; p = 0.041) were independent predictors of miRNA 122-5p levels. During a median follow-up of 22 months (range of 1-24), 30 subjects (40.5%) experienced a composite endpoint of all-cause mortality and fatal/non-fatal CV events. Baseline circulating miRNA 122-5p was higher in these subjects (p = 0.01) and it predicted a significantly higher risk of endpoint occurrence (Kaplan-Meier crude HR 3.192; 95% CI 1.529-6.663; p = 0.002; Cox regression adjusted HR 1.115; 95% CI 1.009-1.232; p = 0.03).

CONCLUSIONS

Altered miRNA 122-5p levels in HD patients may reflect hepatic and CV damage and may impart important prognostic information for improving CV risk prediction in this particular setting.

Lnc-HULC, miR-122, and sirtulin-1 as potential diagnostic biomarkers for psoriasis and their association with the development of metabolic syndrome during the disease course

Psoriasis is a persistent inflammatory skin disorder driven by T cells. The disease is characterized by aberrant keratinocytes (KCs) differentiation, epidermal proliferation, and excessive hyperplasia of veins and arteries. The purpose of the study was to identify the levels of circulating lnc-HULC, miR-122, and Sirtuin 1 (SIRT-1) in psoriatic patients, evaluate their possible roles as diagnostic biomarkers, and link their levels with the development of metabolic syndrome during psoriasis progression. This study included 176 participants. The subjects were divided into four groups, with 44 participants in each group. All patients have undergone a complete history taking and clinical examination. Laboratory investigations included Low-density lipoprotein (LDL), High-density lipoprotein (HDL), Triglycerides (TG), Fasting blood sugar (FBS), and cholesterol plasma levels. Serum levels of miR-122 and lnc-HULC were examined by qRT-PCR. Serum levels of SIRT-1 were examined by ELISA. The serum concentrations of lnc-HULC and miR-122 were significantly higher in psoriatic participants compared to controls. Psoriatic patients' serum concentrations of SIRT-1 were much lower than those of healthy individuals. There was a negative association between SIRT-1 concentration and BMI, disease duration, PASI score, LDL, and cholesterol levels. The blood levels of lnc-HULC, miR-122, and SIRT-1 in psoriasis patients provide a promising role as diagnostic biomarkers in patients with and without metabolic syndrome.

microRNA-223 and microRNA-126 are clinical indicators for predicting the plaque stability in carotid atherosclerosis patients

Studies have demonstrated the essential functions of microRNAs (miRNAs) in cardiovascular disease. Herein, we explored the roles of miR-126 and miR-223 in the prediction of plaque stability in carotid atherosclerosis (CA).Patients with CA (N = 52) and healthy volunteers (N = 25) were recruited as the study subjects and controls. First, a miRNA microarray was performed to analyze the differentially expressed miRNAs in the serum of normal controls and patients with CA. Next, the correlations of miR-223 and miR-126 expression with plaque stability-related factors were analyzed. Then, the predictive efficacy of miR-223 and miR-126 on plaque stability was analyzed by the ROC curve, and the targeting relationships of miR-223 and miR-126 with COX2 were verified. Finally, the relationship between COX2 expression and CA plaque stability was analyzed. miR-223 and miR-126 were decreased in the serum of CA patients and had good diagnostic efficacy for CA. miR-223 and miR-126 in the serum of CA patients with unstable plaques were lower than that in patients with stable plaques. miR-223 and miR-126 were negatively correlated with plaque instability-related indicators, while COX2, a direct target of miR-223 and miR-126, was positively related to plaque instability-related indicators. Lowly expressed miR-223 and miR-126 in the serum of CA patients can be used as indicators for plaque stability.

Mitochondrial microRNAs Are Dysregulated in Patients with Fabry Disease

Fabry disease (FD) is a lysosomal storage disorder caused by mutations in the gene for α-galactosidase A, inducing a progressive accumulation of globotriaosylceramide (GB3) and its metabolites in different organs and tissues. GB3 deposition does not fully explain the clinical manifestations of FD, and other pathogenetic mechanisms have been proposed, requiring the identification of new biomarkers for monitoring FD patients. Emerging evidence suggests the involvement of mitochondrial alterations in FD. Here, we propose mitochondrial-related microRNAs (miRs) as potential biomarkers of mitochondrial involvement in FD. Indeed, we demonstate that miRs regulating different aspects of mitochondrial homeostasis including expression and assembly of respiratory chain, mitogenesis, antioxidant capacity, and apoptosis are consistently dysregulated in FD patients. Our data unveil a novel noncoding RNA signature of FD patients, indicating mitochondrial-related miRs as new potential pathogenic players and biomarkers in FD. SIGNIFICANCE STATEMENT: This study demonstrates for the first time that a specific signature of circulating mitochondrial miRs (mitomiRs) is dysregulated in FD patients. MitomiRs regulating fundamental aspects of mitochondrial homeostasis and fitness, including expression and assembly of the respiratory chain, mitogenesis, antioxidant capacity, and apoptosis are significantly dysregulated in FD patients. Taken together, these new findings introduce mitomiRs as unprecedented biomarkers of FD and point at mitochondrial dysfunction as a novel potential mechanistic target for therapeutic approaches.

High HDL (High-Density Lipoprotein) Cholesterol Increases Cardiovascular Risk in Hypertensive Patients

BACKGROUND

Emerging evidence suggests that elevated circulating levels of HDL-C (high-density lipoprotein cholesterol) could be linked to an increased mortality risk. However, to the best of our knowledge, the relationship between HDL-C and specific cardiovascular events has never been investigated in patients with hypertension.

METHODS

To fill this knowledge gap, we analyzed the relationship between HDL-C levels and cardiovascular events in hypertensive patients within the Campania Salute Network in Southern Italy.

RESULTS

We studied 11 987 patients with hypertension, who were followed for 25 534 person-years. Our population was divided in 3 groups according to the HDL-C plasma levels: HDL-C<40 mg/dL (low HDL-C); HDL-C between 40 and 80 mg/dL (medium HDL-C); and HDL-C>80 mg/dL (high HDL-C). At the follow-up analysis, adjusting for potential confounders, we observed a total of 245 cardiovascular events with a significantly increased risk of cardiovascular events in the low HDL-C group and in the high HDL-C arm compared with the medium HDL-C group. The spline analysis revealed a nonlinear U-shaped association between HDL-C levels and cardiovascular outcomes. Interestingly, the increased cardiovascular risk associated with high HDL-C was not confirmed in female patients.

CONCLUSIONS

Our data demonstrate that there is a U-shaped association between HDL-C and the risk of cardiovascular events in male patients with hypertension.

The Role of MicroRNAs in Hyperlipidemia: From Pathogenesis to Therapeutical Application

Hyperlipidemia is a common metabolic disorder with high morbidity and mortality, which brings heavy burden on social. Understanding its pathogenesis and finding its potential therapeutic targets are the focus of current research in this field. In recent years, an increasing number of studies have proved that miRNAs play vital roles in regulating lipid metabolism and were considered as promising therapeutic targets for hyperlipidemia and related diseases. It is demonstrated that miR-191, miR-222, miR-224, miR-27a, miR-378a-3p, miR-140-5p, miR-483, and miR-520d-5p were closely associated with the pathogenesis of hyperlipidemia. In this review, we provide brief overviews about advances in miRNAs in hyperlipidemia and its potential clinical application value.

Hydroalcoholic extract of dill and aerobic training prevents high-fat diet-induced metabolic risk factors by improving miR-33 and miR-223 expression in rat liver

Exercise training and medicinal herb supplementation may improve microRNAs (miRNAs) expression associated with obesity. This study aimed to assess the effects of 10 weeks of aerobic training (AT) and dill extract (DE) on miR-33 and miR-223 expression of liver in high-fat diet (HFD)-induced obese rats. Forty male Wistar rats were fed a defined high-fat (n = 32) and standard (n = 8, nonobese control [NC]) diet. After obesity induction, obese rats were randomly allocated to four groups: AT, DE, AT + DE, and obese control (OC). Rats were euthanized and plasma and liver tissue samples were collected after the intervention. The liver expression of miR-33 was lower in the AT, DE, AT + DE, and NC groups compared with the OC group. Also, the liver miR-223 expression was higher in the AT, DE, AT + DE, and NC groups compared with the OC group. Moreover, the liver expression of miR-223 in the AT + DE group was higher compared with the AT and DE groups. The AT, DE, AT + DE, and NC groups had lower liver TC compared with the OC group. Also, the plasma level of apolipoprotein B (Apo B) was significantly lower, and liver HDL-C was significantly higher in the AT + DE and NC groups compared with the OC group. These findings show that long-term AT combined with the intake of DE may improve the plasma levels of Apo B, and TC and HDL-C levels in the liver, which is probably due to AT and DE positive effects on miR-33 and miR-223 in the liver of obese rats. PRACTICAL APPLICATIONS: Aerobic training reduces overweight and obesity health problems, however, the duration and intensity of the exercise training distinguish between individuals. We used an integrated approach combining pharmacological and non-pharmacological as a medical strategy to prevent HFD-induced metabolic injury in obese rats. The present results discovered that a combination of AT + DE intervention improves the miR-33 and miR-223 in the liver of obese rats.

miR-1290 promotes IL-8-mediated vascular endothelial cell adhesion by targeting GSK-3β

BACKGROUND

MicroRNA-1290 (miR-1290) has been reported to be involved in many diseases and play a key role during the development process. However, the role of miR-1290 in atherosclerosis (AS) is still unclear.

METHODS AND RESULTS

The current study showed that the expressions of miR-1290 were high in serum of patients with hyperlipidemia. The functional role of miR-1290 were then investigated in human umbilical vein endothelial cells (HUVECs). Here, we found that miR-1290 expressions were notably enhanced in HUVECs mediated by IL-8. miR-1290 inhibitor repressed monocytic THP-1 cells adhesion to HUVECs by regulating ICAM-1 and VCAM-1, inhibited proliferation through regulating cyclinD1 and PCNA, and inhibited inflammatory response by regulating IL-1β. Mechanistically, we verified that miR-1290 mimic was able to directly target the 3'-UTR of GSK-3β mRNA using luciferase reporter assay. Knockdown of GSK-3β (si-GSK-3β) promoted HUVECs adhesion and the expression of IL-1β, and partially restore the depression effect of miR-1290 inhibitor on HUVECs adhesion and inflammation. In contrast, si-GSK-3β inhibited the proliferation of HUVECs and the expression of cyclinD1 and PCNA.

CONCLUSIONS

In summary, our study revealed that miR-1290 promotes IL-8-mediated the adhesion of HUVECs by targeting GSK-3β. However, GSK-3β is not the target protein for miR-1290 to regulate the proliferation of HUVECs. Our findings may provide potential target in atherosclerosis treatment.

MiRNA-130a promotes inflammation to accelerate atherosclerosis via the regulation of proliferator-activated receptor γ (PPARγ) expression

OBJECTIVE

In this study, we aimed to evaluate the possible function of miR-130a in atherosclerosis (AS), protection against AS, and its molecular biological mechanism.

METHODS

Apoe-/- mice were fed a high-fat diet as the AS mice model. Human umbilical vein endothelial cells (HUVECs) were used as in vitro model. Serum samples or cells were used to measure the expression of inflammation. Serum samples or cells were used to determine MiRNA expression profiles using the edgeR tool from Bioconductor. Western Blot analysis was used to assess protein expressions of proliferator-activated receptor γ (PPARγ) and nuclear factor (NF)-κB.

RESULTS

MiRNA-130a expression was up-regulated in atherosclerotic mice. In addition, over-expression of miRNA-130a promoted inflammation factors [tumor necrosis factor (TNF)-α and interleukin (IL)-1β, IL-6, and IL-8] in the in vitro model of AS. However, down-regulation of miRNA-130a reduced inflammation (suppressed TNF-α, IL-1β, IL-6 and IL-8) in the in vitro model. Furthermore, over-expression of miRNA-130a could also suppress the protein expression of PPARγ and induce NF-κB protein expression in the in vitro model. However, suppression of miRNA-130a induced the protein expression of PPARγ and suppressed NF-κB protein expression in the in vitro model of AS. Activation of PPARγ reduced the pro-inflammatory effects of miRNA-130a on the AS-induced in vitro model.

CONCLUSION

These results strongly support that miRNA-130a suppression can protect against atherosclerosis through inhibiting inflammation by regulating the PPARγ/ NF-κB expression.

Pioglitazone combined with atorvastatin promotes plaque stabilization in a rabbit model

OBJECTIVE

It is not yet clear whether plaque inflammation and cardiovascular events are reduced further when pioglitazone and atorvastatin are combined. Our study aimed to determine whether pioglitazone combined with atorvastatin can restrain the progression of atherosclerosis and promote plaque stabilization in a rabbit model.

METHOD AND RESULT

Thirty rabbits were randomly divided into an atherosclerosis group, an atorvastatin group, and an atorvastatin plus pioglitazone group. The atherosclerosis model was induced using balloon injury and feeding a high-fat diet. Plasma samples were then used to analyze glucose, triglycerides (TG), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), high-sensitivity C-reactive protein (hs-CRP), and matrix metalloproteinase-9 (MMP-9). The area percentage of atherosclerotic plaques was analyzed by hematoxylin-eosin staining. The relative reductions in TG and LDL-C and the increase in HDL-C levels were significantly greater in the combination therapy group than in the atorvastatin monotherapy group (TG: -33.60 ± 7.17% vs -24.16 ± 8.04%, p < 0.001; LDL-C: -42.89 ± 1.63% vs -37.13 ± 1.35%, p < 0.001; and HDL-C: 25.18 ± 5.53% vs 10.43 ± 6.31%, p < 0.001). The relative reductions in hs-CRP and MMP-9 levels were significantly greater in the combination therapy group than in the atorvastatin monotherapy group (-69.38 ± 1.06% vs-53.73 ± 1.92%, p < 0.001; -32.77 ± 2.49% vs -13.36 ± 1.66%, p < 0.001). The area percentage of atherosclerotic plaques was significantly smaller in the atorvastatin group (47.75%, p < 0.05) and in the atorvastatin plus pioglitazone group (22.57%, p < 0.05) than in the atherosclerosis group (84.08%, p < 0.05).

CONCLUSION

We can thus conclude that the combination treatment of atorvastatin and pioglitazone provided additive benefits on inflammatory parameters and lipid metabolism. Pioglitazone combined with atorvastatin can further restrain the progression of atherosclerosis and promote plaque stabilization in a rabbit model.

General Perspectives for the Treatment of Atherosclerosis

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Atherosclerosis, a cardiovascular disease, is at the top of the list among the diseases leading to death. Although the biochemical and pathophysiological cascades involved within the development of atherosclerosis have been identified clearly, its nature is quite complex to be treated with a single agent targeting a pathway. Therefore, many natural and synthetic compounds have been suggested for the treatment of the disease. The majority of the drugs employed target one of the single components of the pathological outcomes, resulting in many times less effective and longterm treatments. In most cases, treatment options prevent further worsening of the symptoms rather than a radical treatment. Consequently, the current review has been prepared to focus on the validated and non-validated targets of atherosclerosis as well as the alternative treatment options such as hydroxymethyl glutaryl coenzyme A (HMG-CoA) reductase inhibitors, acyl-CoA cholesterol acyl transferase (ACAT) inhibitors, lipoprotein lipase stimulants, bile acid sequestrants, and some antioxidants. Related to the topic, both synthetic compounds designed employing medicinal chemistry skills and natural molecules becoming more popular in drug development are scrutinized in this mini review.

Recent Highlights of Research on miRNAs as Early Potential Biomarkers for Cardiovascular Complications of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) and its complications pose a serious threat to the life and health of patients around the world. The most dangerous complications of this disease are vascular complications. Microvascular complications of T2DM include retinopathy, nephropathy, and neuropathy. In turn, macrovascular complications include coronary artery disease, peripheral artery disease, and cerebrovascular disease. The currently used diagnostic methods do not ensure detection of the disease at an early stage, and they also do not predict the risk of developing specific complications. MicroRNAs (miRNAs) are small, endogenous, noncoding molecules that are involved in key processes, such as cell proliferation, differentiation, and apoptosis. Recent research has assigned them an important role as potential biomarkers for detecting complications related to diabetes. We suggest that utilizing miRNAs can be a routine approach for early diagnosis and prognosis of diseases and may enable the development of better therapeutic approaches. In this paper, we conduct a review of the latest reports demonstrating the usefulness of miRNAs as biomarkers in the vascular complications of T2DM.

Stable Cells with NF-κB-ZsGreen Fused Genes Created by TALEN Editing and Homology Directed Repair for Screening Anti-inflammation Drugs

Background

NF-κB is a sequence-specific DNA-binding transcription factor that plays key roles in inflammation and cancer. It is well known that NF-κB is over-activated in these diseases. NF-κB inhibitors are therefore developed as promising drugs for these diseases. However, finding NF-κB inhibitors is dependent on effective screening platforms.

Methods

For providing an easy and visualizable tool for screening NF-κB inhibitors, and other NF-κB-related studies, this study edited all five genes of NF-κB family (RELA, RELB, CREL, NF-κB1, NF-κB2) in three different cell lines (293T, HepG2, and PANC1) with both TALEN and CRISPR. The edited NF-κB genes were repaired by homology-dependent repair using a linear homologous donor containing ZsGreen coding sequence. The edit efficiency was thus directly evaluated by detecting cellular fluorescence. The editing efficiency was also confirmed by PCR detection of NF-κB-ZsGreen fused genes.

Results

It was found that all genes were more efficiently edited by TALEN in all cells than CRISPR. The positive cells were then isolated from the TALEN-edited cell pool by flow cytometry. The purified positive cells were finally evaluated by regulating NF-κB activity with a known NF-κB inhibitor, BAY 11-7082, and an NF-κB-targeting artificial microRNA, miR533. The results revealed that all the labeled NF-κB genes responded well to the two kinds of NF-κB activity regulators in all cell lines.

Conclusion

This study thus obtained 15 cell lines with NF-κB-ZsGreen fused genes, which provide an easy and visualizable tool for screening NF-κB inhibitors and other NF-κB-related studies.

Long non-coding RNA MALAT1 and its target microRNA-125b associate with disease risk, severity, and major adverse cardiovascular event of coronary heart disease

Background

This study aimed to explore the correlation of long non‐coding RNA metastasis‐associated lung adenocarcinoma transcript 1 (lncRNA MALAT1) with microRNA (miR)‐125b and further investigated their associations with disease risk, severity, and prognosis of coronary heart disease (CHD).

Methods

Totally, 230 patients who underwent diagnostic coronary angiography were recruited; meanwhile, 140 of them were diagnosed as CHD and the remaining 90 non‐CHD patients served as controls. Plasma sample was collected from each participant for lncRNA MALAT1 and miR‐125b mRNA expression detection by reverse transcription‐quantitative polymerase chain reaction. The extent of coronary stenosis was evaluated by the Gensini score, and major adverse cardiovascular event (MACE) occurrence during the follow‐up was documented in CHD patients.

Results

Long non‐coding RNA metastasis‐associated lung adenocarcinoma transcript 1 relative expression was increased, but miR‐125b relative expression was decreased in CHD patients compared with controls. ROC curve exhibited that lncRNA MALAT1 and miR‐125b were of good value in differentiating CHD patients from controls, and further logistic regression analysis verified their independent correlation with CHD risk. Furthermore, lncRNA MALAT1 presented a closely negative correlation with miR‐125b in CHD patients, while it presented a weakly negative association with miR‐125b in controls. In CHD patients, lncRNA MALAT1 was positively correlated with Gensini score, total cholesterol, low‐density lipoprotein cholesterol, C‐reactive protein, tumor necrosis factor α, interleukin (IL)‐1β, IL‐6, IL‐17, and accumulating MACE occurrence; reversely, miR‐125b presented a opposite trend.

Conclusion

Long non‐coding RNA metastasis‐associated lung adenocarcinoma transcript 1 might be associated with increased CHD risk, severity, and accumulating MACE incidence via negative interaction with miR‐125b, suggesting their possible clinical application as biomarkers in the CHD screening and surveillance.

Nourin-Dependent miR-137 and miR-106b: Novel Early Inflammatory Diagnostic Biomarkers for Unstable Angina Patients

BACKGROUND

Currently, no blood biomarkers exist that can diagnose unstable angina (UA) patients. Nourin is an early inflammatory mediator rapidly released within 5 min by reversible ischemic myocardium, and if ischemia persists, it is also released by necrosis. Nourin is elevated in acute coronary syndrome (ACS) patients but not in symptomatic noncardiac and healthy subjects. Recently, circulating microRNAs (miRNAs) have been established as markers of disease, including cardiac injury and inflammation.

OBJECTIVES

To profile and validate the potential diagnostic value of Nourin-dependent miR-137 (marker of cell damage) and miR-106b-5p (marker of inflammation) as early biomarkers in suspected UA patients and to investigate the association of their target and regulating genes.

METHODS

Using Nourin amino acid sequence, an integrated bioinformatics analysis was conducted. Analysis indicated that Nourin is a direct target for miR-137 and miR-106b-5p in myocardial ischemic injury. Two linked molecular networks of lncRNA/miRNAs/mRNAs were also retrieved, including CTB89H12.4/miR-137/FTHL-17 and CTB89H12.4/miR-106b-5p/ANAPC11. Gene expression profiling was assessed in serum samples collected at presentation to an emergency department (ED) from: (1) UA patients (n = 30) (confirmed by invasive coronary angiography with stenosis greater than 50% and troponin level below the clinical decision limit); (2) patients with acute ST elevation myocardial infarction (STEMI) (n = 16) (confirmed by persistent ST-segment changes and elevated troponin level); and 3) healthy subjects (n = 16).

RESULTS

Gene expression profiles showed that miR-137 and miR-106b-5p were significantly upregulated by 1382-fold and 192-fold in UA compared to healthy, and by 2.5-fold and 4.6-fold in STEMI compared to UA, respectively. Healthy subjects showed minimal expression profile. Receiver operator characteristics (ROC) analysis revealed that the two miRNAs were sensitive and specific biomarkers for assessment of UA and STEMI patients. Additionally, Spearman's correlation analysis revealed a significant association of miRNAs with the associated mRNA targets and the regulating lncRNA.

CONCLUSIONS

Nourin-dependent gene expression of miR-137 and miR-106b-5p are novel blood-based biomarkers that can diagnose UA and STEMI patients at presentation and stratify severity of myocardial ischemia, with higher expression in STEMI compared to UA. Early diagnosis of suspected UA patients using the novel Nourin biomarkers is key for initiating guideline-based therapy that improves patients' health outcomes.

Circulating miRNAs Are Associated with the Systemic Extent of Atherosclerosis: Novel Observations for miR-27b and miR-146

The mechanisms that regulate the systemic extent of atherosclerosis are not fully understood. We investigated whether the expression of circulating miRNAs is associated with the extent of stable atherosclerosis to a single territory or multiple territories (polyvascular) and with the severity of atherosclerosis in each territory. Ninety-four participants were prospectively recruited and divided into five age- and sex-matched groups: presenting no atherosclerosis, isolated coronary atherosclerosis, coronary and lower extremity atherosclerosis, coronary and carotid atherosclerosis, and atherosclerosis of the coronary, lower extremity, and carotid territories. The expression of six circulating miRNAs with distinct biological roles was assessed. The expression of miR-27b and miR-146 differed across groups (p < 0.05), showing a decrease in the presence of atherosclerosis, particularly in the three territories. miR-27b and miR-146 expression decreased in association with a higher severity of coronary, lower extremity, and carotid atherosclerosis. Polyvascular atherosclerosis involving the three territories was independently associated with a decreased miR-27b and miR-146 expression. Both miRNAs presented an area under the curve of ≥0.75 for predicting polyvascular atherosclerosis involving the three territories. To conclude, miR-27b and miR-146 were associated with the presence of severe polyvascular atherosclerosis and with the atherosclerosis severity in each territory. Both are potential biomarkers of severe systemic atherosclerosis.

Mir-1, miR-122, miR-132, and miR-133 Are Related to Subclinical Aortic Atherosclerosis Associated with Metabolic Syndrome

Previously, miR-1, miR-122, miR-126, miR-132, miR-133, and miR-370 were found to be related to coronary artery disease (CAD) progression. However, their relationship with subclinical atherosclerosis, especially in subjects with metabolic syndrome, is unknown. Therefore, our aim was to determine their relationship with arterial markers of subclinical atherosclerosis. Metabolic syndrome subjects (n = 182) with high cardiovascular risk but without overt cardiovascular disease (CVD) were recruited from the Lithuanian High Cardiovascular Risk (LitHiR) primary prevention program. The ardio-ankle vascular index (CAVI), augmentation index normalized to a heart rate of 75 bpm (AIxHR75), aortic pulse wave velocity (AoPWV), and carotid artery stiffness were assessed. MicroRNAs (miRs) were analyzed in serum. Pearson correlation and a univariate linear regression t-test showed that miR-1, miR-133b, and miR-133a were negatively associated with CAVI mean, whereas miR-122 was positively associated. MiR-1, miR-133b and miR-133a, and miR-145 were negatively associated with AIxHR75. MiR-122 correlated negatively with AoPWV. In multivariate linear regression models, miR-133b and miR-122 predicted CAVImean, miR-133 predicted AIxHR75, and miR-122 predicted AoPWV. MiR-132 predicted right carotid artery stiffness, and miR-1 predicted left carotid artery stiffness. The addition of smoking to miR-133b and miR-122 enhanced the prediction of CAVI. Age and triglycerides enhanced the prediction of AoPWV by miR-122. A cluster of four miRs are related to subclinical atherosclerosis in subjects with metabolic syndrome. Combined, they may have a more substantial diagnostic or prognostic value than any single miR. Future follow-up studies are needed to establish their clinical relevance.

Prognostic Value and Clinicopathological Features of MicroRNA-206 in Various Cancers: A Meta-Analysis

It has been reported that microRNA-206(miR-206) plays an important role in cancers and could be used as a prognostic biomarker. However, the results are controversial. Therefore, we summarize all available evidence and present a meta-analysis to estimate the prognostic value of miR-206 in various cancers. The relevant studies were collected by searching PubMed, EMBASE, and Web of Science databases until August 21, 2020. Hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were applied to explore the association between miR-206 and survival results and clinicopathologic features. Sources of heterogeneity were investigated by subgroup analysis and sensitivity analysis. Publication bias was evaluated using Egger's test. Twenty articles involving 2095 patients were included in the meta-analysis. The pooled HR showed that low miR-206 expression was significantly associated with unfavourable overall survival (OS) (HR = 2.03, 95 CI%: 1.53-2.70, P < 0.01). In addition, we found that low miR-206 expression predicted significantly negative association with tumor stage (III-IV VS. I-II) (OR = 4.20, 95% CI: 2.17-8.13, P < 0.01), lymph node status (yes VS. no) (OR = 3.58, 95%: 1.51-8.44, P = 0.004), distant metastasis (yes VS. no) (OR = 3.19, 95%: 1.07-9.50, P = 0.038), and invasion depth (T3 + T4 vs. T2 + T1) (OR = 2.43, 95%: 1.70-3.49, P < 0.01). miR-206 can be used as an effective prognostic indicator in various cancers. Further investigations are warranted to validate the present results.

Paeonol inhibits NLRP3 mediated inflammation in rat endothelial cells by elevating hyperlipidemic rats plasma exosomal miRNA-223

Atherosclerosis (AS) is a multifactorial chronic inflammatory disease, and hyperlipidemia is the important factors leading to AS, which can cause vascular endothelial dysfunction. Paeonol (Pae) is a potential therapeutic drug for AS, and we have previously shown that Pae regulated the expression of monocytes-derived exosomal microRNA-223 (miR-223). However, the mechanisms of the anti-AS effect of Pae are still not fully understood. In this study, we aim to investigate if Pae could inhibit NLRP3 inflammasome mediated inflammation via elevating hyperlipidemic rats plasma-derived exosomal miR-223. We used high-fat-diet induced hyperlipidemic rats as model for further investigation. Rats were treated with Pae (75, 150 or 300 mg/kg) orally, and then exosomes were isolated from hyperlipidemic rat plasma by ultracentrifugation. In vivo experiments confirmed that Pae markedly reduced serum TC, TG, IL-1β, and IL-6 levels. Both CCK-8 and trypan blue staining showed that the survival rate of rat aortic endothelial cells (RAECs) in the Pae-exo group was higher than that in the model group. Also, Pae-exo dose-dependently increased the survival rate of RAECs and reduced inflammatory cytokines level (IL-1β, and IL-6). Furthermore, Pae-exo successfully increased the expression of exosomal miR-223 and relieved inflammatory secretion. Finally, decreased expression of NLRP3, ASC, caspase-1 and ICAM-1 indicated that Pae-exo attenuated inflammatory reaction of RAECs by suppressing NLRP3 signaling pathway. Altogether, our results showed that Pae inhibited the downstream NLRP3 inflammasome pathway by increasing the level of miR-223 in plasma derived exosomes of hyperlipidemic rats, providing new insights in the treatment of AS with the use of Pae.

Association of miR-4293 rs12220909 polymorphism with cancer risk: A meta-analysis of 8394 subjects

BACKGROUND

Several studies have investigated miR-4293 rs12220909 polymorphisms and cancer susceptibility and yielded different results. Because of this controversy, we designed a meta-analysis to assess comprehensively the association of the rs12220909 polymorphism with cancer risk.

METHODS

Relevant articles were collected by searching the databases of PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and WanFang. Data on rs12220909 in cancer patients and controls were extracted. Sensitivity analyses and publication bias assessments were performed.

RESULTS

Five studies with 3820 cases and 4574 controls were included in our meta-analysis. Pooled analyses showed that the rs12220909 polymorphism was not associated with cancer risk in any genetic model. (C vs G: odds ratio [OR] = 0.89, 95% confidence interval [CI] = 0.74-1.07; GC vs GG: OR = 0.83, 95% CI = 0.67-1.03; CC vs GG: OR = 1.06, 95% CI = 0.82-1.36; CC+GC vs GG: OR = 0.84, 95% CI = 0.69-1.03; CC vs GC+GG: OR = 1.10, 95% CI = 0.85-1.40).

CONCLUSIONS

Our results indicate that rs12220909 is not associated with cancer risk. Larger, well-designed multicenter studies are needed to further explore the association of miR-4293 rs12220909 polymorphism with cancer risk.

Circulating miR-1 as a potential predictor of left ventricular remodeling following acute ST-segment myocardial infarction using cardiac magnetic resonance

Background

The identification of patients with a high likelihood of left ventricular (LV) remodeling with a high-risk prognosis has critical implications for risk stratification after acute ST-segment elevation myocardial infarction (STEMI). This study aimed to evaluate the relationship between circulating miR-1 and 6-month post-infarct LV remodeling based on cardiac magnetic resonance (CMR) imaging.

Methods

A total of 80 patients with a first STEMI treated with primary percutaneous coronary intervention (PCI) who underwent CMR imaging 1 week and 6 months after STEMI were evaluated. The percentage changes of LV ejection fraction (LVEF), LV end-diastolic volume (LVEDV), LV end-systolic volume index (LVESV) at 1 week and 6 months after PCI (%ΔLVEF, %ΔLVEDV and %ΔLVESV) were calculated. miR-1 was measured using polymerase chain reaction (PCR)-based technologies in plasma samples that were collected at admission. The study group was divided into two groups based on a 10% cutoff value for the percentage of change in the LV end-diastolic volume (%ΔLVEDV): remodeling at high risk of major adverse cardiac events (MACEs) (%ΔLVEDV ≥10%, termed the LV remodeling group) and remodeling at lower risk of MACEs (%ΔLVEDV <10%, termed the non-LV remodeling group). The associations of miR-1 expression with the %ΔLVEDV, percentage change in the LV end-systolic volume (%ΔLVESV), and percentage change in the LV ejection fraction at follow-up were estimated.

Results

Twenty-two patients (27.5%) showed adverse LV remodeling, and 58 patients (72.5%) did not show adverse LV remodeling at the 6-month follow-up of CMR. The mean LVEF, LVEDV index, and LVESV index values at 1 week were 50.6%±8.2%, 74.6±12.8 mL/m², and 37.2±10.2 mL/m², respectively. Mean LVEF at follow-up (53.5%±10.6%) was increased compared with baseline (P<0.001). There were significant decreases in LVEDV index and LVESV index values at follow-up (72.0±14.9 mL/m² and 33.7±11.0 mL/m², respectively; P=0.009 and P<0.001, respectively). The expression of miR-1 at admission was positively correlated with the %ΔLVEDV (r=0.611, P<0.001) and %ΔLVESV (r=0.268, P=0.016). Receiver operating characteristic (ROC) analysis showed that miR-1 expression predicted LV remodeling with an area under the curve (AUC) value of 0.68 (95% CI: 0.56-0.78). Compared with the clinical factors of peak creatine kinase-myocardial band (CK-MB) and peak troponin T level, peak logNT-proBNP showed the highest predictive power, with an AUC value of 0.75 (95% CI: 0.64-0.84). A model including the clinical, CMR, and miR-1 factors showed greater predictive power (P=0.034) than a model including only clinical and CMR factors, with AUCs of 0.89 (95% CI: 0.80-0.95) and 0.81 (95% CI: 0.71-0.89), respectively.

Conclusions

Circulating miR-1 at admission is an independent predictor of LV remodeling 6 months after STEMI. miR-1 showed incremental value in predicting LV remodeling compared with the clinical and CMR measurements.

Non-coding RNAs in Physiological Cardiac Hypertrophy

Non-coding RNA (ncRNA) is a class of RNAs that are not act as translational protein templates. They are involved in the regulation of gene transcription, RNA maturation and protein translation, participating in a variety of physiological and physiological processes. NcRNAs have important functions, and are recently one of the hotspots in biomedical research. Cardiac hypertrophy is classified into physiological cardiac hypertrophy and pathological cardiac hypertrophy. Different from pathological cardiac hypertrophy, physiological cardiac hypertrophy usually developed during exercise, pregnancy, normal postnatal growth, accompanied with preservation or improvement of systolic function, while no cardiac fibrosis. In this chapter, we will briefly introduce the definition, characteristics, and functions of ncRNAs, including miRNAs, lncRNAs, and circRNAs, as well as a summary of the existing bioinformatics online databases which commonly used in the study of ncRNAs. Specially, this chapter will be focused on the characteristics and the underlying mechanisms about physiological cardiac hypertrophy. Furthermore, the regulatory mechanism of ncRNAs in physiological hypertrophy and the latest research progress will be summarized. Taken together, exploring physiologic cardiac hypertrophy-specific ncRNAs might be a unique research perspective that provides new point of view for interventions in heart failure and other cardiovascular diseases.

The Mitochondria-Associated ER Membranes Are Novel Subcellular Locations Enriched for Inflammatory-Responsive MicroRNAs

The mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) are specific ER domains that contact the mitochondria and function to facilitate communication between ER and mitochondria. Disruption of contact between the mitochondria and ER is associated with a variety of pathophysiological conditions including neurodegenerative diseases. Considering the many cellular functions of MAMs, we hypothesized that MAMs play an important role in regulating microRNA (miRNA) activity linked to its unique location between mitochondria and ER. Here we present new findings from human and rat brains indicating that the MAMs are subcellular sites enriched for specific miRNAs. We employed subcellular fractionation and TaqMan® RT-qPCR miRNA analysis to quantify miRNA levels in subcellular fractions isolated from male rat brains and six human brain samples. We found that MAMs contain a substantial number of miRNAs and the profile differs significantly from that of cytosolic, mitochondria, or ER. Interestingly, MAMs are particularly enriched in inflammatory-responsive miRNAs, including miR-146a, miR-142-3p, and miR-142-5p in both human and rat brains; miR-223 MAM enrichment was observed only in human brain samples. Further, mitochondrial uncoupling or traumatic brain injury in male rats resulted in the alteration of inflammatory miRNA enrichment in the isolated subcellular fractions. These observations demonstrate that miRNAs are distributed differentially in organelles and may re-distribute between organelles and the cytosol in response to cellular stress and metabolic demands.

Microbiota-governed microRNA-204 impairs endothelial function and blood pressure decline during inactivity in db/db mice

An impaired decline in blood pressure at rest is typical in people with diabetes, reflects endothelial dysfunction, and increases the risk of end-organ damage. Here we report that microRNA-204 (miR-204) promotes endothelial dysfunction and impairment in blood pressure decline during inactivity. We show that db/db mice overexpress miR-204 in the aorta, and its absence rescues endothelial dysfunction and impaired blood pressure decline during inactivity despite obesity. The vascular miR-204 is sensitive to microbiota, and microbial suppression reversibly decreases aortic miR-204 and improves endothelial function, while the endothelial function of mice lacking miR-204 remained indifferent to the microbial alterations. We also show that the circulating miR-122 regulates vascular miR-204 as miR-122 inhibition decreases miR-204 in endothelial cells and aorta. This study establishes that miR-204 impairs endothelial function, promotes impairment in blood pressure decline during rest, and opens avenues for miR-204 inhibition strategies against vascular dysfunction.

Role of microRNAs in Hemophilia and Thrombosis in Humans

MicroRNAs (miRNA) play an important role in gene expression at the posttranscriptional level by targeting the untranslated regions of messenger RNA (mRNAs). These small RNAs have been shown to control cellular physiological processes including cell differentiation and proliferation. Dysregulation of miRNAs have been associated with numerous diseases. In the past few years miRNAs have emerged as potential biopharmaceuticals and the first miRNA-based therapies have entered clinical trials. Our recent studies suggest that miRNAs may also play an important role in the pathology of genetic diseases that are currently considered to be solely due to mutations in the coding sequence. For instance, among hemophilia A patients there exist a small subset, with normal wildtype genes; i.e., lacking in mutations in the coding and non-coding regions of the F8 gene. Similarly, in many patients with missense mutations in the F8 gene, the genetic defect does not fully explain the severity of the disease. Dysregulation of miRNAs that target mRNAs encoding coagulation factors have been shown to disturb gene expression. Alterations in protein levels involved in the coagulation cascade mediated by miRNAs could lead to bleeding disorders or thrombosis. This review summarizes current knowledge on the role of miRNAs in hemophilia and thrombosis. Recognizing and understanding the functions of miRNAs by identifying their targets is important in identifying their roles in health and diseases. Successful basic research may result in the development and improvement of tools for diagnosis, risk evaluation or even new treatment strategies.

MALAT1/miR-15b-5p/MAPK1 mediates endothelial progenitor cells autophagy and affects coronary atherosclerotic heart disease via mTOR signaling pathway

Objective: Present study focused on the influence of lncRNA MALAT1 on coronary atherosclerotic heart disease (CAD) by regulating miR-15b-5p/MAPK1 and mTOR signaling pathway.

Method: Differentially expressed genes and activated pathway were investigated through bioinformatics analysis. QRT-PCR was conducted to verify expression of MALAT1, miR-15b-5p and MAPK1 in CAD blood samples and endothelial progenitor cells (EPCs). In addition, the interactions among MALAT1, miR-15b-5p and MAPK1 were revealed by Luciferase reporter assay. Cell autophagy of EPCs was examined by Cyto-ID Autophagy Detection Kit and transmission electron microscope. MTT assay and flow cytometry were carried out to assess cell viability and apoptosis in different interference conditions. Western blot was performed to testify the expression of pERK1/2 (MAPK1), phosphorylated mTOR, ATG1 and LC3-II. Vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) were detected by qRT-PCR. Finally, the effect of lncRNA MALAT1 on cell autophagy and atherogenesis was tested in vivo.

Results: MALAT1 was overexpressed in CAD blood samples and EPCs. Knockdown of MALAT1 and MAPK1 promoted cell viability, autophagy and further suppressed the development of CAD. AntagoMALAT1 protects mice against atherosclerosis.

Conclusion: LncRNA MALAT1 inhibited EPCs autophagy and increased cell viability while repressed apoptosis of CAD via activating mTOR signaling pathway.

MicroRNA-144 Silencing Protects Against Atherosclerosis in Male, but Not Female Mice

OBJECTIVE

Atherosclerosis is a leading cause of death in developed countries. MicroRNAs act as fine-tuners of gene expression and have been shown to have important roles in the pathophysiology and progression of atherosclerosis. We, and others, previously demonstrated that microRNA-144 (miR-144) functions to post-transcriptionally regulate ABCA1 (ATP binding cassette transporter A1) and plasma HDL (high-density lipoprotein) cholesterol levels. Here, we explore how miR-144 inhibition may protect against atherosclerosis. Approach and Results: We demonstrate that miR-144 silencing reduced atherosclerosis in male, but not female low-density lipoprotein receptor null (Ldlr-/-) mice. MiR-144 antagonism increased circulating HDL cholesterol levels, remodeled the HDL particle, and enhanced reverse cholesterol transport. Notably, the effects on HDL and reverse cholesterol transport were more pronounced in male mice suggesting sex-specific differences may contribute to the effects of silencing miR-144 on atherosclerosis. As a molecular mechanism, we identify the oxysterol metabolizing enzyme CYP7B1 (cytochrome P450 enzyme 7B1) as a miR-144 regulated gene in male, but not female mice. Consistent with miR-144-dependent changes in CYP7B1 activity, we show decreased levels of 27-hydroxycholesterol, a known proatherogenic sterol and the endogenous substrate for CYP7B1 in male, but not female mice.

CONCLUSIONS

Our data demonstrate silencing miR-144 has sex-specific effects and that treatment with antisense oligonucleotides to target miR-144 might result in enhancements in reverse cholesterol transport and oxysterol metabolism in patients with cardiovascular disease.

Association between the transporters ABCA1/G1 and the expression of miR-33a/144 and the carotid intima media thickness in patients with arterial hypertension

ATP-binding cassette membrane transporters (ABC), functions as an outflow facilitator of phospholipids and cellular cholesterol, playing an important role in the development of atherosclerosis and arterial hypertension. ABC's transporters could post-transcriptionally regulated by miRs. Evaluate the association in the transporters ABCA1 and ABCG1 with the expression of miR-33a and miR-144 and the carotid intima media thickness (cIMT) in patients with essential arterial hypertension. The miR-33a-5p, miR-144-3p and mRNA ABCA1 and ABCG1 expression in monocytes from Mexican hypertensive patients were examined by RT-PCR. The miR-33a and miR-144 expression in monocytes and mRNA ABCA1 and ABCG1 from Mexican hypertensive patients were examined by RT-PCR. This study involved 84 subjects (42 normotensive subjects and 42 patients with essential hypertension). Our study revealed that miR-33a expression (p = 0.001) and miR-144 (p = 0.985) were up-regulated, meanwhile, ABCA1 and ABCG1 transporters were down-regulated (p = 0.007 and p = 0.550 respectively) in hypertensive patients compared with the control group. The trend remains for miR33a/ABCA1 in presence of cIMT. Moreover, an inverse correlation was found with the expression levels of ABCA1 and ABCG1 as well as in HDL-C with miR-33a and miR-144. Our results showed an increase in the expression of miR-33a and miR-144 and an inverse correlation in their target ABCA1 and ABCG1; it may be associated with essential arterial hypertension in patients with cIMT and as consequence for atheromatous plaque.

Genetic and Functional Variants Analysis of the GATA6 Gene Promoter in Acute Myocardial Infarction

Background: Acute myocardial infarction (AMI) which is a specific type of coronary artery disease (CAD), is caused by the combination of genetic factors and acquired environment. Although some common genetic variations have been recorded to contribute to the development of CAD and AMI, more genetic factors and potential molecular mechanisms remain largely unknown. The GATA6 gene is expressed in the heart during embryogenesis and is also detected in vascular smooth muscle cells (VSMCs), different human primary endothelial cells (ECs), and vascular ECs in mice. To date, no studies have directly linked GATA6 gene with regulation of the CAD.

Methods: In this study, we used a case-control study to investigate and analyze the genetic variations and functional variations of the GATA6 gene promoter region in AMI patients and controls. A variety of statistical analysis methods were utilized to analyze the association of single nucleotide polymorphisms (SNPs) with AMI. Functional analysis of DNA sequence variants (DSVs) was performed using a dual luciferase reporter assay. In vitro, electrophoretic mobility shift assay (EMSA) was selected to examine DNA-protein interactions.

Results: A total of 705 subjects were enrolled in the study. Ten DSVs were found in AMI patients (n = 352) and controls (n = 353), including seven SNPs. One novel heterozygous DSV, (g.22168409 A > G), and two SNPs, [g.22168362 C > A(rs1416421760) and g.22168521 G > T(rs1445501474)], were reported in three AMI patients, which were not found in controls. The relevant statistical analysis, including allele and genotype frequencies between AMI patients and controls, five genetic models, linkage disequilibrium (LD) and haplotype analysis, and SNP–SNP interactions, suggested no statistical significance (P > 0.05). The transcriptional activity of GATA6 gene promoter was significantly increased by the DSV (g.22168409 A > G) and SNP [g.22168362 C > A(rs1416421760)]. The EMSA revealed that the DSV (g.22168409 A > G) and SNP [g.22168362 C > A(rs1416421760)] evidently influenced the binding of transcription factors.

Conclusion: In conclusion, the DSV (g.22168409 A > G) and SNP [g.22168362 C > A(rs1416421760)] may increase GATA6 levels in both HEK-293 and H9c2 cell lines by affecting the binding of transcription factors. Whether the two variants identified in the GATA6 gene promoter can promote the development and progression of human AMI by altering GATA6 levels still requires further studies to verify.

MicroRNA-125b in vascular diseases: An updated systematic review of pathogenetic implications and clinical applications

Epigenetic changes, particularly non‐coding RNAs, have been implicated extensively in the pathogenesis of vascular diseases. Specific miRNAs are involved in the differentiation, phenotypic switch, proliferation, apoptosis, cytokine production and matrix deposition of endothelial cells and/or vascular smooth muscle cells. MicroRNA‐125b has been studied in depth for its role in carcinogenesis with a double‐edged role; that is, it can act as an oncogene in some cancer types and as a tumour suppressor gene in others. However, cumulative evidence from the use of advanced miRNA profiling techniques and bioinformatics analysis suggests that miR‐125b can be a potential mediator and useful marker of vascular diseases. Currently, the exact role of miR‐125b in vascular diseases is not known. In this systematic review, we intend to provide an updated compilation of all the recent findings of miR‐125b in vascular diseases, using a systematic approach of retrieving data from all available reports followed by data summarization. MiR‐125b serves as a pathogenic player in multiple vascular pathologies involving endothelia and vascular smooth muscle cells and also serves as a diagnostic marker for vascular diseases. We further provide a computational biologic presentation of the complex network of miR‐125b and its target genes within the scope of vascular diseases.

Dedifferentiation of Primary Hepatocytes is Accompanied with Reorganization of Lipid Metabolism Indicated by Altered Molecular Lipid and miRNA Profiles

Aim: Primary human hepatocytes (PHHs) undergo dedifferentiation upon the two-dimensional (2D) culture, which particularly hinders their utility in long-term in vitro studies. Lipids, as a major class of biomolecules, play crucial roles in cellular energy storage, structure, and signaling. Here, for the first time, we mapped the alterations in the lipid profile of the dedifferentiating PHHs and studied the possible role of lipids in the loss of the phenotype of PHHs. Simultaneously, differentially expressed miRNAs associated with changes in the lipids and fatty acids (FAs) of the dedifferentiating PHHs were investigated. Methods: PHHs were cultured in monolayer and their phenotype was monitored morphologically, genetically, and biochemically for five days. The lipid and miRNA profile of the PHHs were analyzed by mass spectrometry and Agilent microarray, respectively. In addition, 24 key genes involved in the metabolism of lipids and FAs were investigated by qPCR. Results: The typical morphology of PHHs was lost from day 3 onward. Additionally, ALB and CYP genes were downregulated in the cultured PHHs. Lipidomics revealed a clear increase in the saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) containing lipids, but a decrease in the polyunsaturated fatty acids (PUFA) containing lipids during the dedifferentiation of PHHs. In line with this, FASN, SCD, ELOVL1, ELOVL3, and ELOVL7 were upregulated but ELOVL2 was downregulated in the dedifferentiated PHHs. Furthermore, differentially expressed miRNAs were identified, and the constantly upregulated miR-27a and miR-21, and downregulated miR-30 may have regulated the synthesis, accumulation and secretion of PHH lipids during the dedifferentiation. Conclusion: Our results showed major alterations in the molecular lipid species profiles, lipid-metabolizing enzyme expression as wells as miRNA profiles of the PHHs during their prolonged culture, which in concert could play important roles in the PHHs’ loss of phenotype. These findings promote the understanding from the dedifferentiation process and could help in developing optimal culture conditions, which better meet the needs of the PHHs and support their original phenotype.

Postprandial Circulating miRNAs in Response to a Dietary Fat Challenge

Postprandial lipemia has many physiopathological effects, some of which increase the risk of cardiovascular disease. MicroRNAs (miRNAs) can be found in almost all biological fluids, but their postprandial kinetics are poorly described. We aimed to profile circulating miRNAs in response to a fat challenge. In total, 641 circulating miRNAs were assessed by real-time PCR in plasmas from mice two hours after lipid gavage. Mice with intestine-specific loss of Dicer were screened to identify potential miRNAs released by the intestine. A total of 68 miRNAs were selected for further validation. Ten circulating miRNAs were finally validated as responsive to postprandial lipemia, including miR-206-3p, miR-543-3p, miR-466c-5p, miR-27b-5p, miR-409-3p, miR-340-3p, miR-1941-3p, miR-10a-3p, miR-125a-3p, and miR-468-3p. Analysis of their possible tissues of origin/target showed an enrichment of selected miRNAs in liver, intestine, brain, or skeletal muscle. miR-206, miR-27b-5p, and miR-409-3p were validated in healthy humans. Analysis of their predicted target genes revealed their potential involvement in insulin/insulin like growth factor (insulin/IGF), angiogenesis, cholecystokinin B receptor signaling pathway (CCKR), inflammation or Wnt pathways for mice, and in platelet derived growth factor (PDGF) and CCKR signaling pathways for humans. Therefore, the current study shows that certain miRNAs are released in the circulation in response to fatty meals, proposing them as potential novel therapeutic targets of lipid metabolism.

Effects of high-fat diet on growth performance, lipid accumulation and lipid metabolism-related MicroRNA/gene expression in the liver of grass carp (Ctenopharyngodon idella)

An 8 week experiment was conducted to evaluate the effects of dietary fat on growth and on the accumulation of lipids and the expression of lipid metabolism-related microRNAs (miRNAs) and genes in grass carp (Ctenopharyngodon idella). Two diets (normal fat diet (NFD), 60 g/kg lipid content; high fat diet (HFD), 160 g/kg lipid content) were fed to triplicate groups of 35 fish [initial weight of (40.0 ± 0.5) g]. The results showed that increased dietary fat did not lead to significant differences in the feed conversion rate (FCR) and specific growth rate (SGR) (P > .05), but the HFD significantly increased the hepatosomatic index (HSI) (P < .05). The serum high density lipoprotein-cholesterol (HDLC) level was significantly increased in the HFD group (P < .05). Oil Red O staining showed that both the size and amounts of lipid droplets in the liver of fish fed a diet with 2 g/kg lipid content increased significantly. In the liver of fish fed with 160 g/kg dietary fat, the expression of mir-33a, mir-30, mir-122 and mir-16 significantly decreased (P < .05). In contrast, the expression of sterol regulatory element-binding transcription factor 1 (SREBP1), peroxisome proliferator-activated receptor gamma (PPARγ), liver X receptor alpha (LXRα) and ATP-binding cassette transporter A1 (ABCA1) significantly increased (P < .05). In conclusion, 2 g/kg dietary fat did not influence growth but altered the expression of miRNAs and genes related to lipid metabolism in the liver of grass carp, which caused severe lipid deposition.

Characterization of MicroRNA and Gene Expression Profiles Following Ricin Intoxication

Ricin, derived from the castor bean plant, is a highly potent toxin, classified as a potential bioterror agent. Current methods for early detection of ricin poisoning are limited in selectivity. MicroRNAs (miRNAs), which are naturally occurring, negative gene expression regulators, are known for their tissue specific pattern of expression and their stability in tissues and blood. While various approaches for ricin detection have been investigated, miRNAs remain underexplored. We evaluated the effect of pulmonary exposure to ricin on miRNA expression profiles in mouse lungs and peripheral blood mononuclear cells (PBMCs). Significant changes in lung tissue miRNA expression levels were detected following ricin intoxication, specifically regarding miRNAs known to be involved in innate immunity pathways. Transcriptome analysis of the same lung tissues revealed activation of several immune regulation pathways and immune cell recruitment. Our work contributes to the understanding of the role of miRNAs and gene expression in ricin intoxication.

MicroRNA-92a promotes vascular smooth muscle cell proliferation and migration through the ROCK/MLCK signalling pathway

To identify the interaction between known regulators of atherosclerosis, microRNA-92a (miR-92a), Rho-associated coiled-coil-forming kinase (ROCK) and myosin light chain kinase (MLCK), we examined their expressions during proliferation and migration of platelet-derived growth factor-BB (PDGF-BB)-regulated vascular smooth muscle cells (VSMCs), both in vivo and in vitro. During the formation of atherosclerosis plaque in mice, a parallel increase in expression levels of MLCK and miR-92a was observed while miR-92a expression was reduced in ML-7 (an inhibitor of MLCK) treated mice and in MLCK-deficient VSMCs. In vitro results indicated that both MLCK and miR-92a shared the same signalling pathway. Transfection of miR-92a mimic partially restored the effect of MLCK's deficiency and antagonized the effect of Y27632 (an inhibitor of ROCK) on the down-regulation of VSMCs activities. ML-7 increased the expression of Kruppel-like factor 4 (KLF4, a target of miR-92a), and siRNA-KLF4 increased VSMCs' activity level. Consistently, inhibition of either MLCK or ROCK enhanced the KLF4 expression. Moreover, we observed that ROCK/MLCK up-regulated miR-92a expression in VSMCs through signal transducer and activator of transcription 3 (STAT3) activation. In conclusion, the activation of ROCK/STAT3 and/or MLCK/STAT3 may up-regulate miR-92a expression, which subsequently inhibits KLF4 expression and promotes PDGF-BB-mediated proliferation and migration of VSMCs. This new downstream node in the ROCK/MLCK signalling pathway may offer a potential intervention target for treatment of atherosclerosis.

Changes in expression of microRNA potentially targeting key regulators of lipid metabolism in primary gilthead sea bream hepatocytes exposed to phthalates or flame retardants

Metabolism disrupting chemicals (MDCs) belong to the group of endocrine-disrupting chemicals (EDCs) and are known to affect endocrine and metabolic functions of liver. There is growing evidence that MDCs may also act modulating the expression levels of micro ribonucleic acids (miRNAs) and thus affecting post-transcriptional expression of hundreds of target genes. Herein, we used a gilthead sea bream in vitro hepatocyte model for analyzing the effects of an exposure to phthalates (i.e. DiDP) or flame retardants (i.e.TMCP) on the expression levels of three miRNAs (i.e. MiR133, MiR29 and MiR199a) selected on the basis of their regulatory roles in signaling pathways related to lipid metabolism. Following computational identification of genes that are regulated by the selected miRNAs, we identified six miRNA targets to be tested in differential gene expression analysis. To determine whether lipid metabolism was altered we have also measured the intracellular total cholesterol and triglyceride levels. The results of our study show that DiDP/TMCP exposure leads to a general decrease in the expression profiles of each miRNA leading to a corresponding upregulation of almost all their putative targets. In addition, these findings were also associated to a corresponding increased hepatocellular lipid content. The present study thus contributes to support the importance of these small molecules in regulating MDC-induced expression of genes associated with hepatic lipid metabolism and highlights the need for more toxicological studies examining miRNAs transcriptional regulatory networks controlling metabolic alterations in fish.

MicroRNAs or Long Noncoding RNAs in Diagnosis and Prognosis of Coronary Artery Disease

Coronary artery disease (CAD) is the result of atherosclerotic plaque development in the wall of the coronary arteries. The underlying mechanism involves atherosclerosis of the arteries of the heart which is a relatively complex process comprising several steps. In CAD, atherosclerosis induces functional and structural changes. The pathogenesis of CAD results from various changes in and interactions between multiple cell types in the artery walls; these changes mainly include endothelial cell (EC) dysfunction, vascular smooth muscle cell (SMC) alteration, lipid deposition and macrophage activation. Various blood markers associated with an increased risk for cardiovascular endpoints have been identified; however, few have yet been shown to have a diagnostic impact or important clinical implications that would affect patient management. Noncoding RNAs, especially microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), can be stable in plasma and other body fluids and could therefore serve as biomarkers for some diseases. Many studies have shown that some miRNAs and lncRNAs play key roles in heart and vascular development and in cardiac pathophysiology. Thus, we summarize here the latest research progress, focusing on the molecular mechanism of miRNAs and lncRNAs in CAD, with the intent of seeking new targets for the treatment of heart disease.

New Insights Into the Comorbidity of Coronary Heart Disease and Depression

Coronary heart disease (CHD) and depression are common disorders that markedly impair quality of life and impose a great financial burden on society. They are also frequently comorbid, exacerbating patient condition, and worsening prognosis. This comorbidity strongly suggests shared pathologic mechanisms. This review focuses on the incidence of depression in patients with CHD, deleterious effects of depression on CHD symptoms, and the potential mechanisms underlying comorbidity. In addition to the existing frequent mechanisms that are well known for decades, this review summarized interesting and original potential mechanisms to underlie the comorbidity, such as endocrine substances, gut microbiome, and microRNA. Finally, there are several treatment strategies for the comorbidity, involving drugs and psychotherapy, which may provide a theoretical basis for further basic research and clinical investigations on improved therapeutic interventions.

Downregulation of GATA6 in mTOR-inhibited human aortic endothelial cells: effects on TNF-α-induced VCAM-1 expression and monocytic cell adhesion

Increased expression of vascular cell adhesion molecule 1 (VCAM-1) on the aortic endothelium is an early marker of atherogenesis, promoted in part by elevated levels of inflammatory cytokines such as TNF-α. Mammalian target of rapamycin (mTOR) is a ubiquitous signaling molecule that has been considered to contribute to diverse cellular processes through mTOR complex 1 (mTORC1) or complex 2 (mTORC2). This study aimed to elucidate the role of mTOR signaling in TNF-α-induced VCAM-1 expression by the arterial endothelium. Primary human aortic endothelial cells (HAECs) were treated with low-dose (0.1 ng/ml) TNF-α, and VCAM-1 expression was measured by real-time quantitative PCR, Western blot analysis, and flow cytometry. Inhibition of mTOR through siRNA-mediated depletion or treatment with chemical inhibitors rapamycin or torin 1 suppressed VCAM1 transcription, which translated to inhibition of VCAM-1 surface expression by HAECs and concomitant decreased adhesion of monocytes. A promoter luciferase assay and chromatin immunoprecipitation indicated that mTOR regulated VCAM1 transcription through a mechanism involving transcription factor GATA6. Activation of PKC-α and an increase in miR-200a-3p expression, caused by mTOR inhibition but not disruption of mTORC1 or mTORC2 singly or together, decreased TNF-α-induced GATA6 expression and its enrichment at the VCAM1 promoter. In conclusion, mTOR inhibition activates PKC-α independently of disruption of mTORC1 and/or mTORC2, which challenges the conventional wisdom regarding mTOR signaling. Moreover, mTOR signals through transcriptional and posttranscriptional mechanisms to elicit maximal cytokine-induced endothelial inflammation that precedes atherosclerosis. NEW & NOTEWORTHY Both mammalian target of rapamycin (mTOR) complex 1 (mTORC1) and mTORC2 contribute to PKC-α activation in the human aortic endothelium. Inhibition of mTOR is not equivalent to disruption of mTORC1 and/or mTORC2 in affecting human aortic endothelial cell signaling. Specifically, inhibition of mTOR causes PKC-α activation and miR-200a-3p upregulation, which independently suppresses TNF-α-induced transcription factor GATA6 expression and subsequently inhibits VCAM-1 expression and monocytic cell adhesion onto the aortic endothelium.

Tissue-specific epigenetics of atherosclerosis-related ANGPT and ANGPTL genes

Aim:

To understand tissue-specific regulation of angiopoietin/angiopoietin-like (ANGPT/ANGPTL) genes (especially the five genes embedded in introns of host genes) and their association with atherosclerosis.

Methods:

Transcription and epigenomic databases from various normal tissues were examined in the vicinity of ANGPT1, ANGPT2, ANGPTL1, ANGPTL2, ANGPTL3, ANGPTL4 and ANGPTL8.

Results:

We identified tissue-specific enhancer chromatin regions that are likely to regulate transcription of ANGPT/ANGPTL genes and were intragenic, intergenic or host gene-linked. In addition, we found atherosclerosis-linked differentially methylated regions associated with ANGPT2 and with sequences encoding miR-145, a microRNA that targets ANGPT2 mRNA in cancers.

Conclusion:

Our findings implicate enhancers as major contributors to tissue-specific expression of ANGPT/ANGPTL genes, which play critical roles in angiogenesis, atherosclerosis, cancer, and inflammatory and metabolic diseases.

A Practical Guide to miRNA Target Prediction

MicroRNAs (miRNAs) are small endogenous noncoding RNA molecules that posttranscriptionally regulate gene expression. Since their discovery, a huge number of miRNAs have been identified in a wide range of species. Through binding to the 3' UTR of mRNA, miRNA can block translation or stimulate degradation of the targeted mRNA, thus affecting nearly all biological processes. Prediction and identification of miRNA target genes is crucial toward understanding the biology of miRNAs. Currently, a number of sophisticated bioinformatics approaches are available to perform effective prediction of miRNA target sites. In this chapter, we present the major features that most algorithms take into account to efficiently predict miRNA target: seed match, free energy, conservation, target site accessibility, and contribution of multiple binding sites. We also give an overview of the frequently used bioinformatics tools for miRNA target prediction. Understanding the basis of these prediction methodologies may help users to better select the appropriate tools and analyze their output.

Association of Polymorphisms in miRNA Processing Genes With Type 2 Diabetes Mellitus and Its Vascular Complications in a Southern Chinese Population

Objective: To evaluate the potential association between the genetic variants in miRNA processing genes (RAN, XPO5, DICER1, and TARBP2) and susceptibility to type 2 diabetes mellitus (T2DM) and its vascular complications, as well as to further investigate their interaction with environmental factors in type 2 diabetes. Methods: We conducted a case-control study in genotyping of five polymorphic loci, including RAN rs14035, XPO5 rs11077, DICER1 rs13078, DICER1 rs3742330, and TARBP2 rs784567, in miRNA processing genes to explore the risk factors for T2DM and diabetic vascular complications. Haplotype analyses, interactions of gene-gene and interactions of gene-environment were performed too. Results: We identified a 36% decreased risk of developing T2DM in individuals with the minor A allele in DICER1 rs13078 (OR: 0.64; 95%CI: 0.42-0.95; P: 0.026). The AA haplotype in DICER1 was also associated with a protective effect on T2DM compared with the AT haplotype (OR: 0.63; 95%CI: 0.42-0.94; P-value: 0.023). T2DM patients with the TT+TC genotype at RAN rs14035 had a 1.89-fold higher risk of developing macrovascular complications than patients with the CC genotype (OR: 1.89; 95%CI: 1.04-3.45; P-value: 0.037). We also identified two three-factor interaction models. One is a three-factor [DICER1 rs13078, body mass index (BMI), and triglyceride (TG)] interaction model for T2DM (OR: 5.93; 95%CI: 1.25-28.26; P = 0.025). Another three-factor [RAN rs14035, hypertension (HP), and duration of T2DM (DOD)] interaction model was found for macrovascular complications of T2DM (OR = 41.60, 95%CI = 11.75-147.35, P < 0.001). Conclusion: Our study provides new evidence that two single nucleotide polymorphisms (SNPs) of the miRNA processing genes, DICER1 and RAN, and their interactions with certain environmental factors might contribute to the risk of T2DM and its vascular complications in the southern Chinese population.