Colchicine ameliorates myocardial injury induced by coronary microembolization through suppressing pyroptosis via the AMPK/SIRT1/NLRP3 signaling pathway.

BACKGROUND: Coronary microembolization(CME)is a common complication in acute coronary syndrome and percutaneous coronary intervention, which is closely related to poor prognosis. Pyroptosis, as an inflammatory programmed cell death, has been found to be associated with CME-induced myocardial injury. Colchicine (COL) has potential benefits in coronary artery disease due to its anti-inflammatory effect. However, the role of colchicine in pyroptosis-related CME-induced cardiomyocyte injury is unclear. This study was carried out to explore the effects and mechanisms of colchicine on myocardial pyroptosis induced by CME. METHODS: The CME animal model was constructed by injecting microspheres into the left ventricle with Sprague-Dawley rats, and colchicine (0.3 mg/kg) pretreatment seven days before and on the day of modeling or compound C(CC)co-treatment was given half an hour before modeling. The study was divided into 4 groups: Sham group, CME group, CME + COL group, and CME + COL + CC group (10 rats for each group). Cardiac function, serum myocardial injury markers, myocardial histopathology, and pyroptosis-related indicators were used to evaluate the effects of colchicine. RESULTS: Colchicine pretreatment improved cardiac dysfunction and reduced myocardial injury induced by CME. The main manifestations were the improvement of left ventricular systolic function, the decrease of microinfarction area, and the decrease of mRNA and protein indexes related to pyroptosis. Mechanistically, colchicine increased the phosphorylation level of adenosine monophosphate-activated protein kinase (AMPK), promoted the expression of silent information regulation T1 (SIRT1), and inhibited the expression of NOD-like receptor pyrin containing 3 (NLRP3) to reduce myocardial pyroptosis. However, after CC co-treatment with COL, the effect of colchicine was partially reversed. CONCLUSION: Colchicine improves CME-induced cardiac dysfunction and myocardial injury by inhibiting cardiomyocyte pyroptosis through the AMPK/SIRT1/NLRP3 signaling pathway.

Retraction Notice to: MicroRNA-494 Inhibits the LRG1 Expression to Induce Proliferation and Migration of VECs in Rats following Myocardial Infarction.

[This retracts the article DOI: 10.1016/j.omtn.2019.08.007.].

Upregulation of miR-29b-3p alleviates coronary microembolization-induced myocardial injury via regulating BMF and GSK-3ß.

Coronary microembolization (CME) is an intractable complication results from acute coronary syndrome. CME-induced myocardial apoptosis was associated with progressive cardiac contractile dysfunction. miR-29b-3p has been reported implicated in variety cardiovascular diseases, but its function in CME-induced myocardial injury is yet unknown. Herein, a rat model of CME was established by injecting microspheres into the left ventricle and found that the expression level of miR-29b-3p was markedly decreased in the CME rat heart tissues. By using echocardiography, CD31 immunohistochemistry staining, hematoxylin basic fuchsin picric acid (HBFP) staining, TUNEL staining, and western blotting analysis after CME, it was found that upregulating miR-29b-3p improved cardiac dysfunction, promoted angiogenesis, decreased myocardial microinfarct area, and inhibited myocardial apoptosis. Additionally, miR-29b-3p inhibition can reverse the protective benefits of miR-29b-3p overexpression. Mechanistically, the target genes of miR-29b-3p were identified as glycogen synthase kinase 3 (GSK-3ß) and Bcl-2 modifying factor (BMF) by bioinformatics analysis and luciferase reporter experiment. Overall, our findings imply that induction of miR-29b-3p, which negatively regulates GSK-3ß and BMF expression, attenuates CME-induced myocardial injury, suggesting a novel potential therapeutic target for cardioprotective after CME.

Downregulation of miR-181a-5p alleviates oxidative stress and inflammation in coronary microembolization-induced myocardial damage by directly targeting XIAP.

BACKGROUND: Coronary microembolization (CME) is a complicated problem that commonly arises in the context of coronary angioplasty. MicroRNAs play crucial roles in cardiovascular diseases. However, the role and mechanism of miR-181a-5p in CME-induced myocardial injury remains unclear. METHODS: We established CME rat models. Cardiac function was detected by echocardiography. Haematoxylin-basic fuchsin-picric acid staining was used to measure micro-infarction size. Serum samples and cell culture supernatants were evaluated via enzyme-linked immunosorbent assay. Cellular reactive oxygen species were determined by dichloro-dihydro-fluorescein diacetate assay, and the other oxidative stress related parameters were assayed by spectrophotometry. The dual-luciferase reporter (DLR) assay and RNA pulldown were conducted to validate the association between miR-181a-5p and X-linked inhibitor of apoptosis protein (XIAP). The expression of miR-181a-5p and XIAP mRNA were determined by quantitative reverse transcription polymerase chain reaction. Proteins were evaluated via immunoblotting. The viability of the cell was evaluated via cell counting kit-8 assay. RESULTS: The miR-181a-5p level was significantly increased in CME myocardial tissues. Downregulation of miR-181a-5p improved CME-induced cardiac dysfunction and alleviated myocardial oxidative stress and inflammatory injury, whereas miR-181a-5p exhibited the opposite effects. Then, the DLR assay and RNA pulldown results revealed that miR-181a-5p directly targeting on XIAP. The XIAP level was found to be remarkably decreased after CME. XIAP overexpression attenuated CME-induced myocardial oxidative stress and inflammatory injury. Finally, in vitro rescue experiments revealed that knockdown of XIAP could abolish the protective effects of miR-181a-5p knockdown on hypoxia-induced cardiomyocyte oxidative stress and inflammatory injury. CONCLUSIONS: Downregulation of miR-181a-5p alleviates CME-induced myocardial damage by suppressing myocardial oxidative stress and inflammation through directly targeting XIAP.

Overexpression of lncRNA TUG1 Alleviates NLRP3 Inflammasome-Mediated Cardiomyocyte Pyroptosis Through Targeting the miR-186-5p/XIAP Axis in Coronary Microembolization-Induced Myocardial Damage.

Coronary microembolization (CME) is a complicated problem that commonly arises in the context of coronary angioplasty. The lncRNA taurine-up regulated gene 1 (TUG1), significantly contributes to cardiovascular diseases; however, its contribution to CME-induced myocardial damage remains elusive. Herein, we establish the rat CME model and investigate the role of TUG1 in CME. The cell viability was evaluated via CCK-8 assay. Serum and cell culture supernatant samples were evaluated via ELISA. The dual luciferase reporter (DLR) assay, RIP, and RNA-pull down were conducted to validate the associations between TUG1 and miR-186-5p as well as miR-186-5p and XIAP. The expression of TUG1, miR-186-5p, and XIAP mRNA were determined by RT-qPCR, and proteins were evaluated via immuneblotting. As a result, TUG1 and XIAP were significantly down-regulated, and the miR-186-5p level was found to be remarkably up-regulated in CME myocardial tissues. Overexpression of TUG1 alleviated CME-induced myocardial injury and pyroptosis, whereas TUG1 knockdown showed the opposite effects. The DLR assay, RIP, and RNA-pull down results reveal that TUG1 directly targets miR-186-5p and miR-186-5p directly targets XIAP. In vitro rescue experiments show that TUG1 overexpression alleviates LPS-caused cardiomyocyte injury and pyroptosis via sponging miR-186-5p and regulating XIAP, and depression of miR-186-5p reduces LPS-induced cardiomyocyte injury and pyroptosis by targeting XIAP. Concludingly, the overexpression of TUG1 alleviates NLRP3 inflammasome-mediated cardiomyocyte pyroptosis through targeting the miR-186-5p/XIAP axis in CME-induced myocardial injury.

Nicorandil inhibits cardiomyocyte apoptosis and improves cardiac function by suppressing the HtrA2/XIAP/PARP signaling after coronary microembolization in rats.

Cardiomyocyte apoptosis is a key factor in the deterioration of cardiac function after coronary microembolization (CME). Nicorandil (NIC) affects myocardial injury, which may be related to the inhibition of apoptosis. However, the specific mechanism of cardioprotection has not been elucidated. Therefore, we analyzed the impact of NIC on cardiac function in rats subjected to CME and its effect on the high-temperature requirement peptidase 2/X-linked inhibitor of apoptosis protein/poly ADP-ribose polymerase (HtrA2/XIAP/PARP) pathway. Sprague Dawley rats were divided into four groups: Sham, CME, CME + NIC, and CME + UCF. Echocardiography was performed 9 hours after CME. Myocardial injury markers were evaluated in blood samples, and the heart tissue was collected for hematoxylin-eosin staining, hematoxylin basic fuchsin picric acid staining staining, TdT-mediated DUTP nick end labeling (TUNEL) staining, Western blot analysis of the HtrA2/XIAP/PARP pathway, and transmission electron microscopy. NIC ameliorated cardiac dysfunctioncaused by CME and reduced serum levels of CK-MB and LDH. In addition, NIC decreased myocardial microinfarct size and apoptotic index. NIC reduced the Bax/Bcl-2 ratio, levels of cleaved caspase 3/9, cytoplasmic HtrA2, and cleaved PARP, and increased the level of XIAP. The effects of NIC were similar to those of the HtrA2 inhibitor, UCF101. This study demonstrated that NIC reduces CME-induced myocardial injury, reduces mitochondrial damage, and improves myocardial function. The reduction in cardiomyocyte apoptosis by NIC may be mediated by the HtrA2/XIAP/PARP signaling pathway.

Alprostadil Injection Attenuates Coronary Microembolization-Induced Myocardial Injury Through GSK-3ß/Nrf2/HO-1 Signaling-Mediated Apoptosis Inhibition.

OBJECTIVE: Coronary microembolization (CME) results in progressive contractile dysfunction associated with cardiomyocyte apoptosis. Alprostadil injection improves microcirculation, which is effective in treating various cardiovascular disorders. However, the therapeutic effects of alprostadil in CME-induced myocardia injury remain unknown. Therefore, we evaluated the effects of alprostadil injection on cardiac protection in a rat model of CME and explored the underlying mechanisms. METHODS: A rat model of CME was established by injecting polyethylene microspheres into the left ventricle. After injection of microspheres, rats in the alprostadil group received alprostadil via tail vein within 2 minutes. Cardiac function, histological alterations in myocardium, serum c-troponin I (cTnI) levels, myocardium adenosine triphosphate (ATP) concentrations, the activity of superoxide dismutase (SOD) and malondialdehyde (MDA) content in myocardium, and myocardial apoptosis-related proteins were detected 12 hours after CME modeling. RESULTS: Compared with the Sham group, ATP concentrations, SOD activity in the myocardium, and cardiac function were significantly decreased in a rat model of CME. In addition, serum cTnI levels, MDA content, expression levels of pro-apoptotic proteins, and the number of TUNEL-positive nuclei were remarkably higher in CME group than those in the Sham group. However, alprostadil treatment notably reduced serum cTnI levels and expression levels of pro-apoptotic proteins, while noticeably improved cardiac function, and accelerated SOD activity in the myocardium following CME. Additionally, it was unveiled that the protective effects of alprostadil injection inhibit CME-induced myocardial apoptosis in the myocardium potentially through regulation of the GSK-3ß/Nrf2/HO-1 signaling pathway. CONCLUSION: Alprostadil injection seems to significantly suppress oxidative stress, alleviate myocardial apoptosis in the myocardium, and improve cardiac systolic and diastolic functions following CME by regulating the GSK-3ß/Nrf2/HO-1 signaling pathway.

Long non-coding RNA CASC7 is associated with the pathogenesis of heart failure via modulating the expression of miR-30c.

MiRNAs can be used as promising diagnostic biomarkers of heart failure, while lncRNAs act as competing endogenous RNAs of miRNAs. In this study, we collected peripheral blood monocytes from subjects with or without HF to explore the association between certain lncRNAs, miRNAs and HF. Heart failure patients with preserved or reduced ejection fraction were recruited for investigation. ROC analysis was carried out to evaluate the diagnostic values of certain miRNAs and lncRNAs in HF. Luciferase assays were used to study the regulatory relationship between above miRNAs and lncRNAs. LncRNA overexpression was used to explore the effect of certain miRNAs in H9C2 cells. Expression of miR-30c was significantly decreased in the plasma and peripheral blood monocytes of patients suffering from heart failure, especially in these with reduced ejection fraction. On the contrary, the expression of lncRNA-CASC7 was remarkably increased in the plasma and peripheral blood monocytes of patients suffering from heart failure. Both miR-30c and lncRNA-CASC7 expression showed a promising efficiency as diagnostic biomarkers of heart failure. Luciferase assays indicated that miR-30c played an inhibitory role in lncRNA-CASC7 and IL-11 mRNA expression. Moreover, the overexpression of lncRNA-CASC7 suppressed the expression of miR-30c while evidently increasing the expression of IL-11 mRNA and protein in H9C2 cells. This study clarified the relationship among miR-30c, lncRNA-CASC7 and IL-11 expression and the risk of heart failure and showed that lncRNA-CASC7 is potentially involved in the pathogenesis of HF via modulating the expression of miR-30c.

MicroRNA-494 Inhibits the LRG1 Expression to Induce Proliferation and Migration of VECs in Rats following Myocardial Infarction.

Myocardial infarction (MI) is a life-threatening cardiac event that results in extreme damage to the heart muscle. The Wnt signaling pathway has been implicated in the development of heart diseases. Hence, the current study aimed to investigate the role of microRNA (miRNA) in association with the Wnt signaling pathway to identify potential candidates for MI therapy. Differentially expressed miRNAs associated with MI occurrence were screened, and miR-494 was selected for subsequent experiments. Sprague-Dawley rats were included to establish a MI model via intraperitoneal injection of 0.1 mg/kg atropine sulfate and 40 mg/kg pentobarbital sodium. Then, the interaction between miR-494 and LRG1 was identified. The effect of miR-494 on expression of the Wnt signaling pathway-related genes, proliferation, migration, and invasion ability of fibroblasts and vascular endothelial cells (VECs) was subsequently evaluated through a series of gain- and loss-of-function experiments. The results revealed that miR-494 was poorly expressed and LRG1 was highly expressed in MI rats. miR-494 targets and downregulates LRG1, which resulted in the inactivation of the Wnt signaling pathway and promoted proliferation, migration, and invasion ability of fibroblasts and VECs. In conclusion, this study provided evidence suggesting that overexpressed miR-494 could potentially promote the proliferation, migration, and invasion of fibroblasts and VECs in MI through the inactivation of the Wnt signaling pathway by binding to LRG1.

Inhibition of lncRNA TUG1 upregulates miR-142-3p to ameliorate myocardial injury during ischemia and reperfusion via targeting HMGB1- and Rac1-induced autophagy.

BACKGROUND: Long non-coding RNAs (lncRNAs) play a central role in regulating heart diseases. In the present study, we examined the effects of lncRNA taurine up-regulated gene 1 (TUG1) in ischemia/reperfusion (I/R)- or hydrogen peroxide-challenged cardiomyocytes, with specific focus on autophagy-induced cell apoptosis. METHODS: The expressions of miR-142-3p and TUG1 in H2O2-challenged cardiomyocytes and I/R-injured heart tissue were measured by RT-qPCR. Cell death was measured by trypan blue staining assay. Cell apoptosis was determined by Annexin V/PI staining and TUNEL assay. Autophagy was examined by quantifying cells or tissues containing LC3+ autophagic vacuoles by immunofluorescence, or by measuring the expressions of autophagy-related biomarkers by Western blot. The direct interaction between miR-142-3p and TUG1, high mobility group box 1 protein (HMGB1), or Ras-related C3 botulinum toxin substrate 1 (Rac1) was examined using luciferase reporter assay. The significance of miR-142-3p and TUG1 on cell apoptosis or autophagy was examined using both gain-of-function and loss-of-function approaches. The importance of HMGB1 or Rac1 was assessed using siRNA-mediated gene silencing. RESULTS: miR-142-3p was down-regulated, while TUG1 up-regulated in H2O2-challenged cardiomyocytes in vitro and I/R-injured heart tissues in vivo. Functionally, inhibition of TUG1 and overexpression of miR-142-3p inhibited cell apoptosis and autophagy in cardiomyocytes. The function of TUG1 were achieved by sponging miR-142-3p and releasing the suppression of the putative targets of miR-142-3p, HMGB1 and Rac1. Both HMGB1 and Rac1 essentially mediated cell apoptosis and autophagy induced by TUG1. CONCLUSIONS: TUG1, by targeting miR-142-3p and up-regulating HMGB1 and Rac1, plays a central role in stimulating autophagic cell apoptosis in ischemia/hypoxia-challenged cardiomyocytes. Down-regulating TUG1 or up-regulating miR-142-3p may ameliorate myocardial injury and protect against acute myocardial infarction.

The mechanism of miR-142-3p in coronary microembolization-induced myocardiac injury via regulating target gene IRAK-1.

Coronary microembolization (CME) is a common complication seen during primary percutaneous coronary intervention (pPCI). CME-induced myocardiac inflammation is the primary cause of myocardiac injury. Dysregulated miR-142-3p has been implicated in multiple cardiovascular diseases and is significantly downregulated in CME-induced myocardial injury. However, the role of miR-142-3p in CME-induced myocardial injury is unclear. This study herein built a porcine CME model by infusing microembolization spheres into the left anterior descending branch via a microcatheter, and detected the downregulation of miR-142-3p in the myocardial tissues of CME pigs. Echocardiography, hematoxylin basic fuchsin picric acid (HBFP) staining, and western blotting of NF-κB p65, TNF-α, IL-1ß, and IL-6 showed that the pharmacological overexpression of miR-142-3p using agomiR has improved cardiac function and attenuated CME-induced myocardiac inflammatory response, while its inhibition using antagomiR demonstrated inverse effects. Moreover, in vitro experiments demonstrated IRAK-1 as a direct target gene of miR-142-3p. Luciferase reporter assays, quantitative real-time polymerase chain reaction and western blotting demonstrated its effects in controlling the inflammation of cardiomyocytes. It is noteworthy that miR-142-3p was found to be decreased in the plasma of STEMI patients undergoing pPCI with no-reflow, indicating a potential clinical relevance of miR-142-3p. The receiver-operator characteristic curve indicated that plasma miR-142-3p might be an independent predictor of no-reflow during pPCI in patients with STEMI. Therefore, overexpression of miR-142-3p acts as a novel therapy for CME-induced myocardial injury.

microRNA-26a-5p affects myocardial injury induced by coronary microembolization by modulating HMGA1.

Coronary microembolization (CME) occurs when atherosclerotic plaque debris is detached during the treatment of acute coronary syndrome with Percutaneous Coronary Intervention (PCI). The complications of distal microvascular embolism, including local myocardial inflammation, are the main causes of myocardial damage and are a strong predictor of poor long-term prognosis and major cardiac adverse events. microRNAs (miRNAs) are involved in the pathophysiological processes of cardiovascular inflammatory diseases. Dysregulation of microRNA (miR)-26a-5p, in particular, is associated with a variety of cardiovascular diseases. However, the role of miR-26a-5p in CME-induced myocardial injury is unclear. In this study, we developed an animal model of CME by injecting microembolic balls into the left ventricle of rats and found that miR-26a-5p expression decreased in myocardial tissue in response. Using a miR-26a-5p mimic, echocardiography, hematoxylin-eosin staining, and Western blot analysis we found that the diminished cardiac function and myocardial inflammation induced by CME is alleviated by miR-26a-5p overexpression. Furthermore, our results show that inhibitors of miR-26a-5p have the opposite effect. In addition, in vitro experiments using real-time PCR, Western blot analysis, and a dual luciferase reporter gene show that HMGA1 is a target gene of miR-26a-5p. Thus, overexpression of miR-26a-5p could be a novel therapy to improve CME-induced myocardial damage.

Role of TLR4/MyD88/NF-κB signaling pathway in coronary microembolization-induced myocardial injury prevented and treated with nicorandil.

Coronary microembolization (CME) is a common complication during the treatment of acute coronary syndrome (ACS) and percutaneous coronary intervention (PCI). Nicorandil can be used to prevent myocardial injury after PCI to reduce the incidence of coronary no-reflow and slow flow, and play a role in myocardial protection, suggesting that its mechanism may be related to the inhibition of CME-induced inflammation of cardiomyocytes. However, the specific mechanism remains unclear. This study investigated the myocardial protective effects of nicorandil pretreatment on CME-induced myocardial injury and the specific mechanism of its inhibition of myocardial inflammation. An CME rat model exhibited CME-induced myocardial inflammation and the elevation of serum tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-1ß based on echocardiography, myocardial enzyme detection, hematoxylin and eosin (HE) and hematoxylin-basic fuchsin-picric acid (HBFP) stainings, ELISA, quantitative real-time PCR, and western blotting. Nicorandil treatment seven days before CME induction effectively inhibited myocardial inflammation, ameliorated myocardial injury, and improved cardiac function, mainly by inhibiting Toll-like receptor 4 (TLR4)-mediated myeloid differentiation primary response protein 88 (MyD88)-dependent nuclear factor-kappa B (NF-κB) signaling. Rat neonatal cardiomyocyte experiments further confirmed that nicorandil ameliorated lipopolysaccharide (LPS)-induced myocardial inflammation and improved cardiomyocyte survival. The specific mechanisms mainly involved the inhibition of TLR4/MyD88/NF-κB signaling and the reduction of the inflammatory cytokines TNF-α and IL-1ß released from cardiomyocytes. In summary, nicorandil significantly protected cardiomyocytes from CME-induced myocardial injury mainly by inhibiting TLR4/MyD88/NF-κB signaling, thereby reducing the onset of CME-induced myocardial inflammation. This could be one of the important mechanisms for reducing postoperative myocardial injury via PCI-preoperative prophylactic treatment with nicorandil.