Downregulated microRNA‐224 aggravates vulnerable atherosclerotic plaques and vascular remodeling in acute coronary syndrome through activation of the TGF‐β/Smad pathway

Role of Matrix Metalloproteinase-2 in the Development of Atherosclerosis among Patients with Coronary Artery Disease

Coronary artery disease (CAD) is a caused by atherosclerotic plaque buildup in the coronary arteries that supply blood and oxygen to the heart. Matrix metalloproteinase (MMP) is a family of zinc-dependent endopeptidase that is involved in various stages of atherosclerosis as demonstrated in in vitro and in vivo studies. MMP-2 is associated with both stable and unstable atherosclerotic plaque formation. The current review aimed to identify the role of MMP-2 in atherosclerosis development among CAD patients. Literature search was conducted through four online databases and only studies that were published from 2018 until February 2023 were included. The risk of bias was assessed by using the Newcastle-Ottawa Scale. A total of 10,622 articles were initially identified, and only eight studies that fulfilled the selection criteria were included in this review. The results showed that MMP-2 levels and activity were higher in patients with unstable CAD than those with stable CAD and healthy subjects. There was a significant association between MMP-2 levels and cardiovascular disease with MMP-14 levels, which is a pro-MMP-2 activator. In addition, two single nucleotide polymorphisms of the MMP-2 gene (rs243865 and rs243866) were significantly associated with the development of atherosclerosis. In conclusion, MMP-2 plays a crucial role in the development of atherosclerosis among patients with CAD and could be a potential target for CAD therapy.

Engineering Bioactive M2 Macrophage-Polarized, Anti-inflammatory, miRNA-Based Liposomes for Functional Muscle Repair: From Exosomal Mechanisms to Biomaterials

Severe inflammation and myogenic differentiation disorder are the major obstacles to skeletal muscle healing after injury. MicroRNAs (miRNAs) play an important role as regulatory molecules during the process of muscle healing, but the detailed mechanism of miRNA-mediated intercellular communication between myoblasts and macrophages remains unclear. Here, it is reported that myoblasts secrete miRNAs-enriched exosomes in the inflammatory environment, through which miR-224 is transferred into macrophages to inhibit M2 polarization. Further data demonstrate that WNT-9a may be a direct target of miR-224 for macrophage polarization. In turn, the secretome of M1 macrophages impairs myogenic differentiation and promotes proliferation. Single-cell integration analysis suggests that the elevation of exosome-derived miR-224 is caused by the activation of the key factor E2F1 in myoblasts and demonstrates the RB/E2F1/miR-224/WNT-9a axis. In vivo results show that treatment with antagomir-224 or liposomes containing miR-224 inhibitors suppresses fibrosis and improves muscle recovery. These findings indicate the importance of the crosstalk between myoblasts and macrophages via miRNA-containing exosomes in the regulation of macrophage polarization and myogenic differentiation/proliferation during muscle healing. This study provides a strategy for treating muscle injury through designing an M2 polarization-enabling anti-inflammatory and miRNA-based bioactive material.

Expression and role of miR-146a and SMAD4 in placental tissue of pregnant women with preeclampsia

INTRODUCTION

To investigate the expression of miR-146a in severe preeclampsia (PE) and its effect on trophoblast cell proliferation, invasion and apoptosis, as well as its relationship with SMAD4.

MATERIAL AND METHODS

Participants were divided into the severe PE group (n = 30) and the normal group (n = 30). The expression of miR-146a and SMAD4 in placenta tissue was detected by immunohistochemistry, qRT-PCR, and western blot. Trophoblast cell lines HTR-8/SVneo were cultured to detect the expression of miR-146a under the Cobalt chloride (CoCl₂ )-simulated hypoxia. The effects of miR-146a transfection on cell proliferation, invasion, apoptosis, and SMAD4 expression were analyzed.

RESULTS

Compared with the normal group, miR-146a expression was decreased and the protein and mRNA levels of SMAD4 were increased in placenta tissues of the severe PE group. Our in vitro experiments showed that the expression of miR-146a decreased after CoCl₂ treatment. Silencing miR-146a caused increased expression of SMAD4 and decreased expression of VEGF. After transfection with miR-146a inhibitor, compared with the NC group, the invasion and proliferation of HTR-8/Svneo cells were decreased, while the apoptosis was enhanced.

CONCLUSION

The expression of miR-146a decreased in severe PE and was negatively correlated with SMAD4 expression. The expression of miR-146a was inhibited under hypoxia, and the low expression of miR-146a affected the proliferation, invasion, and apoptosis of trophoblast cells.

Histone Deacetylase 1 Depletion Alleviates Coronary Heart Disease Via the MicroRNA-182-Mediated Transforming Growth Factor β/Smad Signaling Pathway

ABSTRACT

Histone deacetylase (HDAC) determines the acetylation status of histones, thereby regulating gene expression. HDAC inhibitors have been demonstrated to suppress cardiomyocyte growth in vitro and in vivo. We assessed here whether HDAC1 exerts an aggravating effect on coronary heart disease (CHD). Epigenetic probe array revealed that HDAC1 was overexpressed in patients with CHD. HDAC1 was then downregulated in rat cardiomyocytes, and microRNA microarray analysis was performed to detect downstream targets of HDAC1, followed by chromatin immunoprecipitation validation. HDAC1 inhibited miR-182 expression through deacetylation. miR-182 was poorly expressed in patients with CHD. Using enzyme-linked immunosorbent assay, Reverse transcription-quantitative PCR, hematoxylin-eosin staining, terminal deoxynucleotidyl transferase (TdT)-mediated 2'-deoxyuridine 5'-triphosphate (dUTP) nick-end labeling assay, and immunohistochemistry, we observed that HDAC1 downregulation promoted cardiac function, restored lipid levels, reduced myocardial injury markers and inflammatory factors, and alleviated myocardial tissue damage and apoptosis in CHD rats. By contrast, miR-182 downregulation exacerbated injury in rats in the presence of HDAC1 knockdown. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the target genes of miR-182 were mainly enriched in the transforming growth factor (TGF)-β/Smad pathway. Western blot also validated that HDAC1/miR-182 modulated the TGF-β/Smad pathway activity. Our results demonstrated that HDAC1 repressed miR-182 and activated the TGF-β/Smad pathway to promote CHD.

Targeting Circulating lncRNA ENST00000538705.1 Relieves Acute Coronary Syndrome via Modulating ALOX15

Objective

Acute coronary syndrome (ACS) is the most dangerous and deadly form of coronary heart disease. Herein, we aimed to explore ACS-specific circulating lncRNAs and their regulatory mechanisms.

Methods

This study collected serum samples from ACS patients and healthy controls for microarray analysis. Dysregulated circulating lncRNAs and mRNAs were determined with |log2fold − change| > 1 and p < 0.05. lncRNA-mRNA coexpression analysis was carried out. ENST00000538705.1 and ALOX15 expression was further verified in serum specimens. In human coronary artery endothelial cells (HCAECs), ENST00000538705.1 and ALOX15 were knocked out through transfecting specific siRNAs. Thereafter, proliferation and migration were investigated with CCK-8 and wound-healing assays. Myocardial infarction rat models were established and administrated with siRNAs against ENST00000538705.1 or ALOX15. Myocardial damage was investigated with H&E staining, and serum TC, LDL, and HDL levels were measured.

Results

Microarray analysis identified 353 dysregulated circulating lncRNAs and 441 dysregulated circulating mRNAs in ACS. Coexpression analysis indicated the interaction between ENST00000538705.1 and ALOX15. RT-qPCR confirmed the remarkable upregulation of circulating ENST00000538705.1 and ALOX15 in ACS patients. In HCAECs, ENST00000538705.1 knockdown lowered the expression of ALOX15 but ALOX15 did not alter the expression of ENST00000538705.1. Silencing ENST00000538705.1 or ALOX15 weakened the proliferation and migration of HCAECs. Additionally, knockdown of ENST00000538705.1 or ALOX15 relieved myocardial damage, decreased serum TC and LDL levels, and elevated HDL levels in myocardial infarction rats.

Conclusion

Collectively, our findings demonstrate that circulating ENST00000538705.1 facilitates ACS progression through modulating ALOX15, which provide potential targets for ACS treatment.

Signaling pathways and targeted therapy for myocardial infarction

Although the treatment of myocardial infarction (MI) has improved considerably, it is still a worldwide disease with high morbidity and high mortality. Whilst there is still a long way to go for discovering ideal treatments, therapeutic strategies committed to cardioprotection and cardiac repair following cardiac ischemia are emerging. Evidence of pathological characteristics in MI illustrates cell signaling pathways that participate in the survival, proliferation, apoptosis, autophagy of cardiomyocytes, endothelial cells, fibroblasts, monocytes, and stem cells. These signaling pathways include the key players in inflammation response, e.g., NLRP3/caspase-1 and TLR4/MyD88/NF-κB; the crucial mediators in oxidative stress and apoptosis, for instance, Notch, Hippo/YAP, RhoA/ROCK, Nrf2/HO-1, and Sonic hedgehog; the controller of myocardial fibrosis such as TGF-β/SMADs and Wnt/β-catenin; and the main regulator of angiogenesis, PI3K/Akt, MAPK, JAK/STAT, Sonic hedgehog, etc. Since signaling pathways play an important role in administering the process of MI, aiming at targeting these aberrant signaling pathways and improving the pathological manifestations in MI is indispensable and promising. Hence, drug therapy, gene therapy, protein therapy, cell therapy, and exosome therapy have been emerging and are known as novel therapies. In this review, we summarize the therapeutic strategies for MI by regulating these associated pathways, which contribute to inhibiting cardiomyocytes death, attenuating inflammation, enhancing angiogenesis, etc. so as to repair and re-functionalize damaged hearts.

Abnormal expression of long non-coding RNA rhabdomyosarcoma 2-associated transcript (RMST) participates in the pathological mechanism of atherosclerosis by regulating miR-224-3p

Study shows that long non-coding RNA (lncRNA) plays a regulatory role in cardiovascular diseases, and the mechanism of rhabdomyosarcoma 2-associated transcript (RMST) in atherosclerosis (AS) is still unclear. This study aimed to evaluate the expression of RMST and its possible role in the occurrence of AS. RMST and miR-224-3p level in serum and human umbilical vein endothelial cells (HUVECs) were determined by real-time quantitative PCR (RT-qPCR). In vitro atherosclerotic cell model was achieved by treating HUVECs with ox-LDL. Receiver operating characteristic (ROC) curve assessed the diagnostic value of RMST in AS, and Pearson correlation coefficient estimated the correlation of RMST with carotid intima-media thickness (CIMT) and carotid-femoral pulse wave velocity (cfPWV). Cell counting kit-8 (CCK-8) assay and Enzyme-linked immunosorbent assay (ELISA) were performed to evaluate the effect of RMST on cell viability and inflammatory response. The luciferase analysis was used to validate the relationship between RMST and miR-224-3p. The results showed that in serum and HUVECs, RMST levels were increased, while miR-224-3p level was decreased. ROC curve suggested that RMST had clinical diagnostic value for AS. Besides, CIMT and cfPWV were positively correlated with RMST levels, respectively. In HUVECs, RMST-knockdown notably improved the cell viability and inhibited the production of inflammatory factors. Moreover, miR-224-3p was the target of RMST. In conclusion, RMST has the potential to be a diagnostic marker for AS. RMST-knockdown contributes to the enhancement of cell viability and the inhibition of inflammatory response, which may provide new insights into the conquest of AS.

MicroRNAs involved in the TGF-β signaling pathway in atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory vascular disease with a multifactorial pathogenesis. It becomes a global health concern, especially causing an array of fatal consequences among the elderly. However, the mechanisms of AS remain unexplained. The transforming growth factor-β (TGF-β) signaling pathway is widely involved in the inflammation, immune function, proliferation, differentiation，and apoptosis in vivo. Based on previous researches, it has not been confirmed whether the TGF-β pathway promotes or inhibits atherosclerosis. Furthermore, more and more studies have found that microRNAs can regulate atherosclerosis through the TGF-β signaling pathway. In this review, we summarize and discuss the role of microRNAs in the pathogenesis of atherosclerosis via the TGF-β signaling pathway.

Long non-coding RNA THRIL is upregulated in coronary heart disease and binds to microRNA-424 to upregulate TXNIP in mice

Cardiovascular disease, particularly coronary heart disease (CHD), is one of the diseases with the highest fatality. The close correlation between long non-coding RNAs (lncRNAs) and the occurrence and development of myocardial injury has been highlighted recently. This article mainly focused on the regulation of THRIL on myocardial injury caused by CHD in mice. After establishment of a mouse model with CHD, a lncRNA microarray analysis was performed on mouse myocardial tissues to detect differentially expressed lncRNAs, followed by RT-qPCR validation. CHD was induced in mice by high-fat diet feeding and THRIL was silenced using si-THRIL. The results showed that treating CHD mice with si-THRIL attenuated myocardial damage by restoring LVEF, LVFS, and HDL-C levels, while lowering HMI, LVMI, TC, TG, LDL-C, CK-MB, and cTnI levels. Meanwhile, mechanistical studies using bioinformatics prediction, dual-luciferase and subcellular fractionation assays revealed that THRIL bound to microRNA (miR)-424, inhibited miR-424 interaction with TXNIP and promoted TXNIP expression in the myocardial tissues. The cardioprotective effects of si-THRIL on mice were attenuated when miR-424 was downregulated. Moreover, TXNIP exerted its effects on myocardial injury by mediating the p53 pathway. Taken together, this study demonstrated that THRIL inhibition alleviates myocardial injury in CHD possibly through the miR-424/TXNIP/p53 axis.

Differentiated expression of long non-coding RNA-small nucleolar RNA host gene 8 in atherosclerosis and its molecular mechanism

Atherosclerosis (AS) is one of the most common cardiovascular diseases, and the incidence is increasing year by year. Many studies have shown that long non-coding RNA plays a vital role in the pathogenesis of AS. This study aimed to explore the role and mechanism of lncRNA-small nucleolar RNA host gene 8 (SNHG8) in AS. The expressions of serum lncSNHG8 and miR-224-3p were determined by quantitative real-time polymerase chain reaction (qRT-PCR). The diagnostic meaning of lncSNHG8 in AS was estimated by Receiver operating characteristic (ROC) curve. The correlation between lncSNHG8 and various clinical indicators, as well as miR-244-3p was evaluated by Pearson correlation coefficient analysis. Cell proliferation and migration were estimated by cell counting kit-8 (CCK-8) and Transwell assay. The interaction between lncSNHG8 and miR-224-3p was proved by luciferase reporter gene assay. The expression level of lncSNHG8 was increased in AS patients, while miR-224-3p expression was decreased. The ROC curve indicated that lncSNHG8 with high serum expression had the ability to distinguish AS. Pearson correlation coefficient exhibited that the level of miR-224-3p was negatively correlated with the level of lncSNHG8. The results of cell experiments indicated that inhibition of the expression of lncSNHG8 significantly inhibited the proliferation and migration of vascular smooth muscle cells (VSMCs). Luciferase reporter gene experiments confirmed that there was a target relationship between lncSNHG8 and miR-224-3p. In conclusion, lncSNHG8 had high diagnostic value for AS. It promoted the proliferation and migration of VSMCs by adsorption and inhibition of miR-224-3p.

microRNA-3646 serves as a diagnostic marker and mediates the inflammatory response induced by acute coronary syndrome

Acute coronary syndrome (ACS) is one of the main syndromes of coronary artery disease with high mortality. The identification of biomarkers associated with disease occurrence and progression could improve early detection and risk prediction. This study was aimed to reveal the clinical significance and function of miR-3646 in ACS.

The expression of miR-3646 was evaluated in ACS patients, healthy volunteers, and non-ACS patients and estimated the clinical significance of miR-3646. The ACS modeling rats were also established in this study to explore the potential mechanism underlying the function of miR-3646. miR-3646 was upregulated in ACS patients compared with healthy volunteers and non-ACS patients. The expression of miR-3646 was positively correlated with the severity and progression of ACS patients and could discriminate ACS patients from healthy volunteers and non-ACS patients. The knockdown of miR-3646 could reverse the inflammatory response induced by ACS.miR-3646 serves as a diagnostic biomarker for ACS. The knockdown of miR-3646 could alleviate ACS by reversing inflammatory response. These results provide a potential therapeutic target of ACS.

Induction of microRNA hsa-let-7d-5p, and repression of HMGA2, contribute protection against lipid accumulation in macrophage 'foam' cells

Accumulation of excess cholesterol and cholesteryl ester in macrophage 'foam' cells within the arterial intima characterises early 'fatty streak' atherosclerotic lesions, and is accompanied by epigenetic changes, including altered expression of microRNA sequences which determine of gene and protein expression. This study established that exposure to lipoproteins, including acetylated LDL, induced macrophage expression of microRNA hsa-let-7d-5p, a sequence previously linked with tumour suppression, and repressed expression of one of its target genes, high mobility group AT hook 2 (HMGA2). A let-7d-5p mimic repressed expression of HMGA2 (18%; p < 0.05) while a marked increase (2.9-fold; p < 0.05) in expression of HMGA2 was noted in the presence of let-7d-5p inhibitor. Under these conditions, let-7d-5p mimic significantly (p < 0.05) decreased total (10%), free (8%) and cholesteryl ester (21%) mass, while the inhibitor significantly (p < 0.05) increased total (29%) and free cholesterol (29%) mass, compared with the relevant controls. Let-7d-5p inhibition significantly (p < 0.05) increased endogenous biosynthesis of cholesterol (38%) and cholesteryl ester (39%) pools in macrophage 'foam' cells, without altering the cholesterol efflux pathway, or esterification of exogenous radiolabelled oleate. Let-7d-5p inhibition in sterol-loaded cells increased the level of HMGA2 protein (32%; p < 0.05), while SiRNA knockdown of this protein (29%; p < 0.05) resulted in a (21%, p < 0.05) reduction in free cholesterol mass. Thus, induction of let-7d-5p, and repression of its target HMGA2, in macrophages is a protective response to the challenge of increased cholesterol influx into these cells; dysregulation of this response may contribute to atherosclerosis and other disorders such as cancer.

Cell type-specific microRNA therapies for myocardial infarction

Current interventions fail to recover injured myocardium after infarction and prompt the need for development of cardioprotective strategies. Of increasing interest is the therapeutic use of microRNAs to control gene expression through specific targeting of mRNAs. In this Review, we discuss current microRNA-based therapeutic strategies, describing the outcomes and limitations of key microRNAs with a focus on target cell types and molecular pathways. Last, we offer a perspective on the outlook of microRNA therapies for myocardial infarction, highlighting the outstanding challenges and emerging strategies.

LncRNA AK087124/miR-224-5p/PTEN axis modulates endothelial cell injury in atherosclerosis through apoptosis and AKT signaling pathway

Noncoding RNAs (ncRNAs) have been shown to play important roles in atherosclerosis-related endothelial cells dysfunction during atherosclerosis processes. In the study, our purpose was to discover new long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) via competitively interacting each other to regulate the pathogenesis process of atherosclerosis. We investigated the roles of lncRNA AK087124 and miR-224-5p in atherosclerotic pathogenesis and found that AK087124 was up-regulated while miR-224-5p was down-regulated in in the plasma and plaque from atherosclerotic mice compared with normal mice. Ox-LDL was used to establish the mouse aorta endothelial cell (MAEC) injury model. The function study indicated that knockdown of AK087124 inhibited ox-LDL induced endothelial apoptosis and inflammatory response. Bioinformatic prediction combining with luciferase assays indicated that AK087124 could sponge miR-224-5p and enhance the PTEN expression which is a target of miR-224-5p. RNA pull down assays also showed that biotin-miR-224-5p probe could interacted directly with AK087124 and PTEN. Pearson correlation analysis further demonstrated that AK087124 and PTEN expression are negatively correlated with miR-224-5p. Rescue study revealed that miR-224-5p silencing and PTEN overexpression both can reverse the effect of AK087124 on the ox-LDL induced endothelial injury. These data indicated that AK087124 and miR-224-5p could be potential biomarkers and target molecules to treatment and diagnosis for atherosclerosis.

Adipose-Derived Mesenchymal Stem Cells-Derived Exosomes Carry MicroRNA-671 to Alleviate Myocardial Infarction Through Inactivating the TGFBR2/Smad2 Axis

Mesenchymal stem cells (MSCs) and their derived extracellular vesicles have been reported as promising tools for the management of heart disease. The aim of this study was to explore the function of adipose-derived MSCs (adMSCs)-derived exosomes (Exo) in the progression of myocardial infarction (MI) and the molecules involved. Mouse cardiomyocytes were treated with oxygen-glucose deprivation (OGD) to mimic an MI condition in vitro. The adMSCs-derived Exo were identified and administrated into the OGD-treated cardiomyocytes, and then the viability and apoptosis of cells, and the secretion of fibrosis- and inflammation-related cytokines in cells were determined. Differentially expressed microRNAs (miRNAs) in cells after Exo treatment were screened using a microarray analysis. The downstream molecules regulated by miR-671 were explored through bioinformatic analysis. Involvements of miR-671 and transforming growth factor beta receptor 2 (TGFBR2) in the exosome-mediated events were confirmed by rescue experiments. A murine model with MI was induced and treated with Exo for functional experiments in vivo. Compared to phosphate-buffered saline treatment, the Exo treatment significantly enhanced viability while reduced apoptosis of cardiomyocytes, and in reduced myocardial fibrosis and inflammation both in vitro and in vivo. miR-671 was significantly upregulated in cells after Exo treatment. Downregulation of miR-671 blocked the protective functions of Exo. miR-671 targeted TGFBR2 and suppressed phosphorylation of Smad2. Artificial downregulation of TGFBR2 enhanced viability of the OGD-treated cardiomyocytes. This study suggested that adMSC-derived exosomal miR-671 directly targets TGFBR2 and reduces Smad2 phosphorylation to alleviate MI-like symptoms both in vivo and in vitro.

TGF-β: The missing link in obesity-associated airway diseases?

Obesity is emerging as a global public health epidemic. The co-morbidities associated with obesity significantly contribute to reduced quality of life, mortality, and global healthcare burden. Compared to other asthma comorbidities, obesity prominently engenders susceptibility to inflammatory airway diseases such as asthma and chronic obstructive pulmonary disease (COPD), contributes to greater disease severity and evokes insensitivity to current therapies. Unlike in other metabolic diseases associated with obesity, the mechanistic link between obesity and airway diseases is only poorly defined. Transforming growth factor-β (TGF-β) is a pleiotropic inflammatory cytokine belonging to a family of growth factors with pivotal roles in asthma. In this review, we summarize the role of TGF-β in major obesity-associated co-morbidities to shed light on mechanisms of the diseases. Literature evidence shows that TGF-β mechanistically links many co-morbidities with obesity through its profibrotic, remodeling, and proinflammatory functions. We posit that TGF-β plays a similar mechanistic role in obesity-associated inflammatory airway diseases such as asthma and COPD. Concerning the role of TGF-β on metabolic effects of obesity, we posit that TGF-β has a similar mechanistic role in obesity-associated inflammatory airway diseases in interplay with different comorbidities such as hypertension, metabolic diseases like type 2 diabetes, and cardiomyopathies. Future studies in TGF-β-dependent mechanisms in obesity-associated inflammatory airway diseases will advance our understanding of obesity-induced asthma and help find novel therapeutic targets for prevention and treatment.

The antagonistic effects and mechanisms of microRNA-26a action in hypertensive vascular remodelling

BACKGROUND AND PURPOSE

Hypertensive vascular remodelling is responsible for end-organ damage and is the result of increased extracellular matrix accumulation and excessive vascular smooth muscle cell (VSMC) proliferation. MicroRNA-26a (miR-26a), a non-coding small RNA, is involved in several cardiovascular diseases. We aimed to validate the effect and mechanisms of miR-26a in hypertensive vascular remodelling.

EXPERIMENTAL APPROACH

Male spontaneously hypertensive rats (SHRs) were injected intravenously with recombinant adeno-associated virus-miR-26a. Samples of thoracic aorta were examined histologically with H&E staining. In vitro, angiotensin II (AngII)-induced VSMCs cultured from thoracic aortae of female Sprague-Dawley rats, were transfected with miR-26a mimic or inhibitor. Western blots, qRT-PCR and immunohistological methods were used, along with chromatin-immunoprecipitation and luciferase reporter assays. Specific siRNAs were used to silence Smad production in VSMCs KEY RESULTS: Levels of miR-26a were lower in the thoracic aorta and plasma of SHRs than in WKY rats. Overexpression of miR-26a inhibited extracellular matrix deposition by targeting connective tissue growth factor (CTGF) and decreased VSMC proliferation by regulating the enhancer of zeste homologue 2 (EZH2)/p21 pathway both in vitro and in vivo. AngII-mediated Smad3 activation suppressed miR-26a expression, which in turn promoted Smad3 activation via targeted regulation of Smad4, leading to further down-regulation of miR-26a.

CONCLUSION AND IMPLICATIONS

Our data show that AngII stimulated a Smads/miR-26a positive feedback loop, which further reduced expression of miR-26a, leading to collagen production and VSMC proliferation and consequently vascular remodelling. MiR-26a has an antagonistic effect on hypertensive vascular remodelling and can be a strategy for treating hypertensive vascular remodelling.

M1 macrophages-derived extracellular vesicles elevate microRNA-185-3p to aggravate the development of atherosclerosis in ApoE-/- mice by inhibiting small mothers against decapentaplegic 7

OBJECTIVE

Extracellular vesicles (EVs) are vital mediators of transferring microRNAs (miRNAs). We focused on effect of miR-185-3p that mediated by macrophages-derived EVs on atherosclerosis (AS) by targeting small mothers against decapentaplegic 7 (Smad7).

METHODS

EVs were extracted from M1 macrophages and identified. ApoE-/- mice were treated with EVs, EVs containing miR-185-3p inhibitor or mimic, then the pathological changes of mouse aorta were observed. The levels of blood lipid, cell adhesion molecules, oxidative stress factors, inflammatory factors, and proliferation and apoptosis of vascular endothelial cells were assessed. Expression of miR-185-3p and Smad7 was detected and the targeting relationship between miR-185-3p and Smad7 was validated.

RESULTS

MiR-185-3p was upregulated while Smad7 was downregulated in atherosclerotic mouse aorta. M1 macrophages-derived EVs elevated miR-185-3p to promote development of AS pathology and levels of blood lipid, endothelial cellular adhesion, oxidative stress factors and inflammatory factors, suppressed cell proliferation and promoted cell apoptosis of vascular endothelial cells in atherosclerotic mice through downregulating Smad7. Smad7 was a target gene of miR-185-3p and miR-185-3p could inhibit expression of Smad7.

CONCLUSION

M1 macrophages-derived EVs and upregulated miR-185-3p aggravated the development of AS in ApoE-/- mice by negatively regulating Smad7. This research may further the understanding of AS mechanism.

HDAC1-mediated deacetylation of HIF1α prevents atherosclerosis progression by promoting miR-224-3p-mediated inhibition of FOSL2

We intended to characterize functional relevance of microRNA (miR)-224-3p in endothelial cell (EC) apoptosis and reactive oxygen species (ROS) accumulation in atherosclerosis, considering also the integral involvement of histone deacetylase 1 (HDAC1)-mediated hypoxia-inducible factor-1α (HIF1α) deacetylation. The binding affinity between miR-224-3p and Fos-like antigen 2 (FOSL2) was predicted and validated. Furthermore, we manipulated miR-224-3p, FOSL2, HDAC1, and HIF1α expression in oxidized low-density lipoprotein (ox-LDL)-induced ECs, aiming to clarify their effects on cell activities, inflammation, and ROS level. Additionally, we examined the impact of miR-224-3p on aortic atherosclerotic plaque and lesions in a high-fat-diet-induced atherosclerosis model in ApoE^−/− mice. Clinical atherosclerotic samples and ox-LDL-induced human aortic ECs (HAECs) exhibited low HDAC1/miR-224-3p expression and high HIF1α/FOSL2 expression. miR-224-3p repressed EC cell apoptosis, inflammatory responses, and intracellular ROS levels through targeting FOSL2. HIF1α reduced miR-224-3p expression to accelerate EC apoptosis and ROS accumulation. Moreover, HDAC1 inhibited HIF1α expression by deacetylation, which in turn enhanced miR-224-3p expression to attenuate EC apoptosis and ROS accumulation. miR-224-3p overexpression reduced atherosclerotic lesions in vivo. In summary, HDAC1 overexpression may enhance the anti-atherosclerotic and endothelial-protective effects of miR-224-3p-mediated inhibition of FOSL2 by deacetylating HIF1α, underscoring a novel therapeutic insight against experimental atherosclerosis.

Current perspectives on inhibitory SMAD7 in health and disease

Transforming growth factor β (TGF-β) family members play an extensive role in cellular communication that orchestrates both early development and adult tissue homeostasis. Aberrant TGF-β family signaling is associated with a pathological outcome in numerous diseases, and in-depth understanding of molecular and cellular processes could result in therapeutic benefit for patients. Canonical TGF-β signaling is mediated by receptor-regulated SMADs (R-SMADs), a single co-mediator SMAD (Co-SMAD), and inhibitory SMADs (I-SMADs). SMAD7, one of the I-SMADs, is an essential negative regulator of the pleiotropic TGF-β and bone morphogenetic protein (BMP) signaling pathways. In a negative feedback loop, SMAD7 inhibits TGF-β signaling by providing competition for TGF-β type-1 receptor (TβRI), blocking phosphorylation and activation of SMAD2. Moreover, SMAD7 recruits E3 ubiquitin SMURF ligases to the type I receptor to promote ubiquitin-mediated proteasomal degradation. In addition to its role in TGF-β and BMP signaling, SMAD7 is regulated by and implicated in a variety of other signaling pathways and functions as a mediator of crosstalk. This review is focused on SMAD7, its function in TGF-β and BMP signaling, and its role as a downstream integrator and crosstalk mediator. This crucial signaling molecule is tightly regulated by various mechanisms. We provide an overview of the ways by which SMAD7 is regulated, including noncoding RNAs (ncRNAs) and post-translational modifications (PTMs). Finally, we discuss its role in diseases, such as cancer, fibrosis, and inflammatory bowel disease (IBD).

Sex-specific microRNAs in women with diabetes and left ventricular diastolic dysfunction or HFpEF associate with microvascular injury

Left ventricular diastolic dysfunction (LVDD) and heart failure with preserved ejection fraction (HFpEF) are microcirculation defects following diabetes mellitus (DM). Unrecognized HFpEF is more prevalent in women with diabetes compared to men with diabetes and therefore sex-specific diagnostic strategies are needed. Previously, we demonstrated altered plasma miRs in DM patients with microvascular injury [defined by elevated plasma Angiopoietin-2 (Ang-2) levels]. This study hypothesized the presence of sex-differences in plasma miRs and Ang-2 in diabetic (female) patients with LVDD or HFpEF. After a pilot study, we assessed 16 plasma miRs in patients with LVDD (n = 122), controls (n = 244) and female diabetic patients (n = 10). Subsequently, among these miRs we selected and measured plasma miR-34a, -224 and -452 in diabetic HFpEF patients (n = 53) and controls (n = 52). In LVDD patients, miR-34a associated with Ang-2 levels (R² 0.04, R = 0.21, p = 0.001, 95% CI 0.103–0.312), with plasma levels being diminished in patients with DM, while women with an eGFR < 60 ml/min and LVDD had lower levels of miR-34a, -224 and -452 compared to women without an eGFR < 60 ml/min without LVDD. In diabetic HFpEF women (n = 28), plasma Ang-2 levels and the X-chromosome located miR-224/452 cluster increased compared to men. We conclude that plasma miR-34a, -224 and -452 display an association with the microvascular injury marker Ang-2 and are particularly targeted to women with LVDD or HFpEF.

Upregulated miR-224-5p suppresses osteoblast differentiation by increasing the expression of Pai-1 in the lumbar spine of a rat model of congenital kyphoscoliosis

Congenital scoliosis is defined by the presence of structural anatomical malformations that arise from failures of vertebral formation or segmentation before and after birth. The understanding of genetic background and key genes for congenital scoliosis is still poor. We herein report that the excess expression of plasminogen activator inhibitor-1 (Pai-1) induced by the upregulation of miR-224-5p is involved in the pathogenesis of congenital kyphoscoliosis through impaired osteoblast differentiation. We first investigated the variety and progression of abnormalities of the lumbar spines in Ishibashi (IS) rats, a rat model of congenital kyphoscoliosis. The rats had already shown fusion and division of the primary ossification center at postnatal day 4. Over time, the rats showed various abnormalities of the lumbar spine, including the fusion of the annular epiphyseal nucleus. At postnatal day 42, spinal curvature was clearly observed due to the fusion of the vertebral bodies. Using a microRNA array, we found that the expression of miR-224-5p was increased in the lumbar spine of the rats at postnatal day 4. The expression of Pai-1, which is involved in osteoblast differentiation regulated by miR-224-5p, was also increased, while the levels of type I collagen, a marker of osteoblast differentiation, were decreased in the lumbar spine. These results indicate that the aberrant expression of miRNA-224-5p and its target genes is involved in the impaired osteoblast differentiation and may provide a partial molecular explanation for the pathogenesis of congenital scoliosis.