Potential diagnostic and therapeutic value of circular RNAs in cardiovascular diseases

Circ_0020887 Silencing Combats Hypoxic-Induced Cardiomyocyte Injury in an MiR-370-3p/CYP1B1-Dependent Manner

Targeting circular RNA has been a novel approach to preventing and limiting acute myocardial infarction (AMI). Here, we planned to investigate the role and mechanism of circ_0020887 in AMI progression.Hypoxic injury in human cardiomyocytes (AC16) was measured using cell counting kit-8 assay, 5-ethynyl-2'-deoxyuridine assay, flow cytometry, and colorimetric assay kits. RNA and protein expressions were determined using real-time quantitative PCR and western blotting. Direct interplay between RNAs was determined using dual-luciferase reporter, RNA pull-down, and RIP assays.In the plasma and hypoxia-induced AC16 cells of patients with AMI, circ_0020887 and miR-370-3p were upregulated and downregulated, respectively, concomitant with the upregulation of cytochrome P450 1B1 (CYP1B1). Circ_0020887 interference could inhibit hypoxia-induced AC16 cell apoptosis, oxidative stress, and inflammatory response. Circ_0020887 could sponge miR-370-3p, and miR-370-3p could target CYP1B1. The inhibition effect of circ_0020887 knockdown on hypoxia-induced AC16 cell injury could be reversed by the miR-370-3p inhibitor. Besides, CYP1B1 overexpression also overturned the suppressive effect of miR-370-3p on hypoxia-induced AC16 cell apoptosis, oxidative stress, and inflammatory response.In conclusion, circ_0020887 regulated the miR-370-3p/CYP1B1 axis to regulate hypoxia-induced cardiomyocyte injury, confirming that circ_0020887 might promote cardiomyocyte injury.

CircMAP3K5 promotes cardiomyocyte apoptosis in diabetic cardiomyopathy by regulating miR-22-3p/DAPK2 Axis

BACKGROUND

Diabetic cardiomyopathy (DCM) is one of the serious complications of the accumulated cardiovascular system in the long course of diabetes. To date, there is no effective treatment available for DCM. Circular RNA (circRNA) is a novel r2egulatory RNA that participates in a variety of cardiac pathological processes. However, the regulatory role of circular RNA MAP3K5 (circMAP3K5) in DCM is largely unclear.

METHODS AND RESULTS

Microarray analysis of DCM rats' heart circular RNAs was performed and the highly species-conserved circRNA mitogen-activated protein kinase kinase kinase 5 (circMAP3K5) was identified, which participates in DCM processes. High glucose-provoked cardiotoxicity leads to the up-regulation of circMAP3K5, which mechanistically contributes to cardiomyocyte cell death. Also, in high glucose-induced H9c2 cardiomyocytes, the level of apoptosis was significantly increased, as well as the expression of circMAP3K5. In contrast, the depletion of circMAP3K5 could reduce high glucose-induced apoptosis in cardiomyocytes. In terms of mechanism, circMAP3K5 acts as a miR-22-3p sponge and miR-22-3p directly target death-associated protein kinase 2 (DAPK2) in H9c2 cardiomyocytes, where in circMAP3K5 upregulates DAPK2 expression by targeting miR-22-3p. Moreover, we also found that miR-22-3p inhibitor and pcDNA DAPK2 could antagonize the protective effects brought by the depletion of circMAP3K5.

CONCLUSION

CircMAP3K5 is a highly conserved noncoding RNA that is upregulated during DCM process. We concluded that circMAP3K5 promotes high glucose-induced cardiomyocyte apoptosis by regulating the miR-22-3p/DAPK2 axis. The results of this study highlight a novel and translationally important circMAP3K5-based therapeutic approach for DCM.

Circular RNAs Variously Participate in Coronary Atherogenesis

Over the past decade, numerous studies have shown that circular RNAs (circRNAs) play a significant role in coronary artery atherogenesis and other cardiovascular diseases. They belong to the class of non-coding RNAs and arise as a result of non-canonical splicing of premature RNA, which results in the formation of closed single-stranded circRNA molecules that lack 5'-end caps and 3'-end poly(A) tails. circRNAs have broad post-transcriptional regulatory activity. Acting as a sponge for miRNAs, circRNAs compete with mRNAs for binding to miRNAs, acting as competing endogenous RNAs. Numerous circRNAs are involved in the circRNA-miRNA-mRNA regulatory axes associated with the pathogenesis of cardiomyopathy, chronic heart failure, hypertension, atherosclerosis, and coronary artery disease. Recent studies have shown that сirc_0001445, circ_0000345, circ_0093887, сircSmoc1-2, and circ_0003423 are involved in the pathogenesis of coronary artery disease (CAD) with an atheroprotective effect, while circ_0002984, circ_0029589, circ_0124644, circ_0091822, and circ_0050486 possess a proatherogenic effect. With their high resistance to endonucleases, circRNAs are promising diagnostic biomarkers and therapeutic targets. This review aims to provide updated information on the involvement of atherogenesis-related circRNAs in the pathogenesis of CAD. We also discuss the main modern approaches to detecting and studying circRNA-miRNA-mRNA interactions, as well as the prospects for using circRNAs as biomarkers and therapeutic targets for the treatment of cardiovascular diseases.

RNA Sequencing Reveals the Differentially Expressed circRNAs between Stable and Unstable Carotid Atherosclerotic Plaques

Objective. This study aimed to identify circular RNA profiles (circRNAs) via high-throughput RNA sequencing and distinguish the differentially expressed (DE) circRNAs between stable and unstable plaques. Methods. RNA sequencing was performed on unstable and stable carotid plaque samples obtained from patients with carotid artery stenosis. DE circRNAs were screened, and six DE circRNAs were verified using quantitative real-time PCR (qRT-PCR). Functional evaluation of the DE circRNAs was conducted via Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Results. We screened 344 DE circRNAs in unstable plaques, consisting of 342 upregulated and 2 downregulated circRNAs. GO analysis showed that the host genes of the upregulated circRNAs were related to ER to Golgi transport vesicle membrane, endocytic vesicle membrane, and Ran GTPase binding. KEGG analysis revealed that the host genes of the upregulated circRNAs were primarily associated with protein processing in endoplasmic reticulum, lysine degradation, homologous recombination, epithelial cell signaling in Helicobacter pylori infection, and yersinia infection. The results of qRT-PCR verified three upregulated DE circRNAs and two downregulated DE circRNAs in unstable plaques. Conclusion. Hsa-circ-0001523, hsa-circ-0008950, hsa-circ-0000571, hsa-circ-0001946, and hsa-circ-0000745 may be involved in regulating the stability of atherosclerotic plaques and serves as a therapeutic target for unstable plaques.

CircHSPG2 knockdown attenuates hypoxia-induced apoptosis, inflammation, and oxidative stress in human AC16 cardiomyocytes by regulating the miR-1184/MAP3K2 axis

Circular RNAs (circRNAs) have been identified as vital regulators in cardiovascular diseases, including acute myocardial infarction (AMI). In this study, the function and mechanism of circRNA heparan sulfate proteoglycan 2 (circHSPG2) in hypoxia-induced injury in AC16 cardiomyocytes were investigated. AC16 cells were stimulated with hypoxia to establish an AMI cell model in vitro. Real-time quantitative PCR and western blot assays were performed to quantify the expression levels of circHSPG2, microRNA-1184 (miR-1184), and mitogen-activated protein kinase kinase kinase 2 (MAP3K2). Counting Kit-8 (CCK-8) assay was used to measure cell viability. Flow cytometry was performed to detect cell cycle and apoptosis. Enzyme-linked immunosorbent assay (ELISA) was used to determine the expression of inflammatory factors. Dual-luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays were used to analyze the relationship between miR-1184 and circHSPG2 or MAP3K2. In AMI serum, circHSPG2 and MAP3K2 mRNA were highly expressed and miR-1184 was down-regulated. Hypoxia treatment elevated HIF1α expression and repressed cell growth and glycolysis. Moreover, hypoxia promoted cell apoptosis, inflammation, and oxidative stress in AC16 cells. Hypoxia-induced circHSPG2 expression in AC16 cells. CircHSPG2 knockdown alleviated hypoxia-induced AC16 cell injury. CircHSPG2 directly targeted miR-1184, and miR-1184 targeted and suppressed MAP3K2. Inhibition of miR-1184 or overexpression of MAP3K2 abolished the alleviated effect of circHSPG2 knockdown on hypoxia-induced AC16 cell injury. Overexpression of miR-1184 relieved hypoxia-induced impairment in AC16 cells by MAP3K2. CircHSPG2 could regulate MAP3K2 expression through miR-1184. CircHSPG2 knockdown protected AC16 cells from hypoxia-induced injury by regulating the miR-1184/MAP3K2 cascade.

Microarray profiling of circular RNAs in LPS-induced Beas-2B cells and identification of circ_2979 as a potential biomarker for ARDS

Acute respiratory distress syndrome (ARDS) is a major cause of high mortality and morbidity in critically ill patients. Circular RNAs (CircRNAs) are widely expressed in numerous tissues and are associated with various diseases. However, the role of circRNAs in ARDS remains unclear. In this study, we found that cell viability and proliferation were reduced in lipopolysaccharide (LPS)-induced Beas-2B cells. Microarray analysis identified 1131 differentially expressed circRNAs in LPS-treated Beas-2B cells, with 623 circRNAs significantly upregulated and 508 circRNAs strongly downregulated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed significant enrichment and indicated potential functions and pathways of differentially expressed circRNAs. Reverse transcription-polymerase chain reaction (RT-PCR) analysis confirmed that expression of circ_2979, circ_5438, circ_4557 and circ_2066 in LPS-induced Beas-2B cells was consistent with the results obtained by RNA sequencing (RNA-seq). Additionally, we recruited 17 patients with ARDS and 13 healthy volunteers and found that expression of circ_2979 in serum was significantly increased in the patients with ARDS compared with healthy volunteers. Spearman's analyses indicated that circ_2979 was correlated with partial pressure of carbon dioxide in arterial blood (PaCO₂), the ratio of partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO₂/FiO₂), interleukin 2 receptor (IL-2R) and fibrinogen (FIB). The results suggested that circRNAs may play an important role in the progression of ARDS, and that circ_2979 may serve as a diagnosis and prognosis biomarker for ARDS.

Circ_ARHGAP32 acts as miR-665 sponge to upregulate FGF2 to promote ox-LDL induced vascular smooth muscle cells proliferation and migration

BACKGROUND: Circular RNA (circRNA) is considered to be an important regulator of human diseases, including atherosclerosis (AS). However, the role of circ_ARHGAP32 in AS formation needs further confirmation. OBJECTIVE: To explore the role of circ_ARHGAP32 in AS formation. METHODS: Oxidized low density lipoprotein (ox-LDL) was used to treat vascular smooth muscle cells (VSMCs) to mimic AS cell models in vitro. The expression of circ_ARHGAP32, microRNA (miR)-665, and fibroblast growth factor 2 (FGF2) was analyzed by quantitative real-time PCR. VSMCs function was measured by EdU assay, cell counting kit 8 assay and transwell assay. Protein expression was determined using western blot analysis. Dual-luciferase reporter assay and RNA pull-down assay were performed to verify RNA interaction. RESULTS: Circ_ARHGAP32 was highly expressed in AS patients and ox-LDL-induced VSMCs. Knockdown of circ_ARHGAP32 repressed ox-LDL-induced proliferation and migration in VSMCs. Circ_ARHGAP32 sponged miR-665 to positively regulate FGF2. MiR-665 inhibitor reversed the regulation of sh-circ_ARHGAP32 on ox-LDL-induced VSMCs proliferation and migration. MiR-665 also had a suppressive effect on the proliferation and migration of ox-LDL-induced VSMCs, and this effect could be reversed by FGF2 overexpression. CONCLUSIONS: Circ_ARHGAP32 might be a potential target for AS treatment, which promoted ox-LDL-induced VSMCs proliferation and migration by regulating miR-665/FGF2 network.

Adipose-Derived Stem Cells-Derived Exosomes with High Amounts of Circ_0001747 Alleviate Hypoxia/Reoxygenation-Induced Injury in Myocardial Cells by Targeting MiR-199b-3p/MCL1 Axis

Recent studies demonstrated that circular RNAs play important roles in exosome-mediated cardio-protective effects after acute myocardial infarction (AMI). A previous study reported that circ_0001747 level is down-regulated in mouse hypoxia/reoxygenation (H/R) injury model. However, its biological role and working mechanism in AMI remain largely unknown.Exosomes were isolated from the culture supernatant of adipose-derived stem cells (ADSCs) using an ExoQuick precipitation kit. We treated mouse myocardial cells HL-1 with H/R to explore the role of exosomal circ_0001747 in AMI pathology. Cell viability, proliferation, apoptosis, and inflammation were analyzed by Cell Counting Kit-8 assay, 5-ethynyl-2'-deoxyuridine assay, flow cytometry, and enzyme-linked immunosorbent assay. Dual-luciferase reporter assay and RNA immunoprecipitation assay were conducted to confirm the interaction between microRNA-199b-3p (miR-199b-3p) and circ_0001747 or MCL1 apoptosis regulator, BCL2 family member (MCL1).H/R-induced HL-1 dysfunction was attenuated by the incubation of exosomes derived from ADSCs, especially the exosomes with high amounts of circ_0001747. Circ_0001747 directly targeted miR-199b-3p in HL-1 cells. miR-199b-3p overexpression partly overturned exosomal circ_0001747-mediated protective effects in H/R-induced HL-1 cells. MCL1 was a direct target of miR-199b-3p in HL-1 cells. miR-199b-3p silencing alleviated H/R-induced damage in HL-1 cells partly by up-regulating MCL1. Circ_0001747 can elevate the messenger RNA and protein levels of MCL1 by sequestering miR-199b-3p.Overall, these results indicated that ADSCs-derived exosomes with high amounts of circ_0001747 attenuated H/R-induced HL-1 dysfunction partly by targeting miR-199b-3p/MCL1 signaling.

Targeting Epigenetics and Non-coding RNAs in Myocardial Infarction: From Mechanisms to Therapeutics

Myocardial infarction (MI) is a complicated pathology triggered by numerous environmental and genetic factors. Understanding the effect of epigenetic regulation mechanisms on the cardiovascular disease would advance the field and promote prophylactic methods targeting epigenetic mechanisms. Genetic screening guides individualised MI therapies and surveillance. The present review reported the latest development on the epigenetic regulation of MI in terms of DNA methylation, histone modifications, and microRNA-dependent MI mechanisms and the novel therapies based on epigenetics.

Emerging roles of circRNAs in the pathological process of myocardial infarction

Myocardial infarction (MI) is defined as cardiomyocyte death in a clinical context consistent with ischemic insult. MI remains one of the leading causes of morbidity and mortality worldwide. Although there are a number of effective clinical methods for the diagnosis and treatment of MI, further investigation of novel biomarkers and molecular therapeutic targets is required. Circular RNAs (circRNAs), novel non-coding RNAs, have been reported to function mainly by acting as microRNA (miRNA) sponges or binding to RNA-binding proteins (RBPs). The circRNA-miRNA-mRNA (protein) regulatory pathway regulates gene expression and affects the pathological mechanisms of various diseases. Undoubtedly, a more comprehensive understanding of the relationship between MI and circRNA will lay the foundation for the development of circRNA-based diagnostic and therapeutic strategies for MI. Therefore, this review summarizes the pathophysiological process of MI and various approaches to measure circRNA levels in MI patients, tissues, and cells; highlights the significance of circRNAs in the regulation MI pathogenesis and development; and provides potential clinical insight for the diagnosis, prognosis, and treatment of MI.

The potential of using blood circular RNA as liquid biopsy biomarker for human diseases

Circular RNA (circRNA) is a novel class of single-stranded RNAs with a closed loop structure. The majority of circRNAs are formed by a back-splicing process in pre-mRNA splicing. Their expression is dynamically regulated and shows spatiotemporal patterns among cell types, tissues and developmental stages. CircRNAs have important biological functions in many physiological processes, and their aberrant expression is implicated in many human diseases. Due to their high stability, circRNAs are becoming promising biomarkers in many human diseases, such as cardiovascular diseases, autoimmune diseases and human cancers. In this review, we focus on the translational potential of using human blood circRNAs as liquid biopsy biomarkers for human diseases. We highlight their abundant expression, essential biological functions and significant correlations to human diseases in various components of peripheral blood, including whole blood, blood cells and extracellular vesicles. In addition, we summarize the current knowledge of blood circRNA biomarkers for disease diagnosis or prognosis.

High rate fabrication of copper and copper-gold electrodes by laser-induced selective electroless plating for enzyme-free glucose sensing

In the current study, the method of Selective Surface Activation Induced by Laser (SSAIL) was used for the fabrication of metallic and bimetallic structures based on copper and gold on the surface of glass and glass-ceramics. It was shown that the fabricated electrodes are suitable for non-enzymatic detection of biologically essential analytes such as glucose. The implemented approach allows performing high-rate metallization of various dielectrics. Voltammetric methods were applied to evaluate the electrocatalytic activity of the obtained structures, which were used as working electrodes. The most promising results were revealed by copper–gold electrode structures manufactured on glass-ceramics. For these structures, sensitivity towards glucose sensing was 3060 μA mM⁻¹ cm⁻². The linear range of glucose detection varied between 0.3 and 1000 μM. Besides, the manufactured electrodes exhibited high selectivity and long-term stability.

In the current study, the method of Selective Surface Activation Induced by Laser (SSAIL) was used for the fabrication of metallic and bimetallic structures based on copper and gold on the surface of glass and glass-ceramics.

Impact of diurnal temperature range on cardiovascular disease hospital admissions among Chinese farmers in Dingxi (the Northwest China)

Background

Diurnal temperature range (DTR) has been widely applied in exploring its effect on cardiovascular disease (CVD). However, few studies have investigated the correlations between DTR and CVD in poor rural areas in China. This study aimed to examine the association between DTR and CVD in rural China.

Methods

A distributed lag nonlinear model was used to evaluate the relationship between DTR and CVD risk among farmers living in the city of Dingxi (Northwest China) in the period from January 1, 2016 to December 31, 2019.

Results

We observed nonlinear M-patterns between the relative risk (RR) of DTR (reference: median DTR, 12 °C) and CVD hospitalizations in all subgroups. The peak RR of CVD was noticed at DTR of 6 °C (total: 1.418; men: 1.546; women: 1.403; young: 1.778; old: 2.549) and 17 °C (total: 1.781; men: 1.937; women: 1.712; young: 2.233; old: 1.798). The adverse effect of DTR on CVD risk was more pronounced in females (RR 1.438) and elderly (RR 2.034) than males (RR 1.141) and younger adults (RR 1.852) at the extremely low (5th, 4 °C) DTR. The reverse was observed at the extremely high DTR (95th, 19 °C) (male: 1.267; females: 0.993; young: 1.586; old: 1.212).

Conclusions

DTR is associated with CVD morbidity. This association was more pronounced in women and elderly, but men and younger peoples at extremely high DTR (19 °C). Future measures should take DTR into account to prevent CVD among susceptible populations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02065-8.

Copper and Nickel Microsensors Produced by Selective Laser Reductive Sintering for Non-Enzymatic Glucose Detection

In this work, the method of selective laser reductive sintering was used to fabricate the sensor-active copper and nickel microstructures on the surface of glass-ceramics suitable for non-enzymatic detection of glucose. The calculated sensitivities for these microsensors are 1110 and 2080 μA mM⁻¹·cm⁻² for copper and nickel, respectively. Linear regime of enzymeless glucose sensing is provided between 0.003 and 3 mM for copper and between 0.01 and 3 mM for nickel. Limits of glucose detection for these manufactured micropatterns are equal to 0.91 and 2.1 µM for copper and nickel, respectively. In addition, the fabricated materials demonstrate rather good selectivity, long-term stability and reproducibility.

Circular RNAs and Cardiovascular Regeneration

circular RNAs (circRNAs) are a type of non-coding RNAs that are widely present in eukaryotic cells. They have the characteristics of stable structure, high abundance, and cell or tissue specific expression. circRNAs are single-stranded RNAs that are covalently back spliced to form closed circular loops. They may participate in gene expression and regulation through a variety of action modes. circRNAs can encode proteins or function by acting as miRNA sponges for protein translation. Since 2016, a growing number of research studies have shown that circRNAs play important role in the pathogenesis of cardiovascular disease. With the construction of circRNA database, the differential expression of circRNAs in the heart tissue samples from different species and the gradual elucidation of its mode of action in disease may become an ideal diagnosis biomarker and an effective therapeutic target. What can be expected surely has a broader application prospect. In this review, we summarize recent publications on circRNA biogenesis, expression profiles, functions, and the most recent studies of circRNAs in the field of cardiovascular diseases with special emphasis on cardiac regeneration.

CircSLC8A1 and circNFIX can be used as auxiliary diagnostic markers for sudden cardiac death caused by acute ischemic heart disease

Sudden cardiac death (SCD) caused by acute ischemic heart disease (IHD) is a major cause of sudden death worldwide. Circular RNAs (circRNAs) are abundant in the heart and play important roles in cardiovascular diseases, but the role of circRNAs as biomarkers in the forensic diagnosis of SCD caused by acute IHD remains poorly characterized. To investigate the potential of two heart-enriched circRNAs, circNFIX and circSLC8A1, we explored the expression of these two circRNAs in different kinds of commonly used IHD models, and further verified their expressions in forensic autopsy cases. The results from both the IHD rat and H9c2 cell models revealed that circSlc8a1 level was upregulated, while the circNfix level was elevated in the early stage of ischemia and subsequently downregulated. The time-dependent expression patterns of the two circRNAs suggested their potential as SCD biomarkers. In autopsy cases, the results showed that the expression of these two circRNAs in the myocardium with acute IHD-related SCDs corresponded to the observations in the ischemic models. Further analysis related to myocardial ischemia indicated that circSLC8A1 showed high sensitivity and specificity for myocardial infarction and was positively correlated with creatine kinase MB in pericardial fluid. Downregulated circNFIX level could indicate the ischemic myocardial damage, and it was negatively correlated with the coronary artery stenosis grade. The combination of circSLC8A1 and circNFIX had better performance to discriminate IHD-related SCDs. The results suggested that circSLC8A1 and circNFIX may be used as auxiliary diagnostic markers for SCD caused by acute IHD in forensic medicine.

Circ_0065149 Alleviates Oxidized Low-Density Lipoprotein-Induced Apoptosis and Inflammation in Atherosclerosis by Targeting miR-330-5p

Background

Atherosclerosis is a risk factor for cardiovascular diseases. However, the roles of Circular RNAs (circRNAs) in atherosclerosis is unknown. Our study aimed to explore the effects of circ_0065149 in the pathogenesis of atherosclerosis.

Methods

The expression of circ_0065149 ox-LDL-induced in human umbilical vein endothelial cells (HUVECs) was assessed by RT-PCR. Cell viability, lactate dehydrogenase leakage, apoptosis, invasion, and migration were assessed in HUVECs. Dual luciferase reporter system was carried out to determine the interaction between miR-330-5p and circ_0065149.

Results

Our results showed that circ_0065149 was significantly lower in the ox-LDL-induced HUVECs. Overexpression of circ_0065149 promoted the cell viability and inhibited the apoptosis of ox-LDL-induced HUVECs. Overexpression of circ_0065149 also promoted the migration and invasion of ox-LDL-induced HUVECs. The expression of miR-330-5p was inhibited by overexpression of circ_0065149. Furthermore, circ_0065149 overexpression significantly inhibited the expressions of nuclear NF-κBp65 and suppressed the production of TNF-α, IL-6, and IL-1β in ox-LDL-induced HUVECs, which was rescued by the miR-330-5p mimic.

Conclusion

These findings suggest that circ_0065149 plays an important role in the proliferation, apoptosis, and inflammatory response of HUVECs via targeting miR-330-5p.

Knockdown of circ_0060745 alleviates acute myocardial infarction by suppressing NF-κB activation

It has been shown that circRNAs are involved in the development of heart diseases. However, few studies explored the role of circRNAs in acute myocardial infarction (AMI). The present study aims to investigate the role of circ_0060745 in the pathogenesis of AMI. We found that the expression of circ_0060745 was significantly increased in the myocardium of AMI mice and was mainly expressed in myocardial fibroblasts. The knockdown of circ_0060745 decreased myocardial infarct size and improved systolic cardiac functions after AMI. The knockdown of circ_0060745 in cardiac fibroblasts inhibited the migration of peritoneal macrophage, the apoptosis of cardiomyocytes and the expressions of IL‐6, IL‐12, IL‐1β, TNF‐α and NF‐κB under hypoxia. Overexpression of circ_0060745 caused an increase in infarct size and worsened cardiac functions after AMI. In summary, our findings showed that knockdown of circ_0060745 mitigates AMI by suppressing cardiomyocyte apoptosis and inflammation. These protective effects could be attributed to inhibition of NF‐κB activation.