shRNA interference of NLRP3 inflammasome alleviate ischemia reperfusion-induced myocardial damage through autophagy activation

Modulation of NLRP3 Inflammasome: Advantages of Chinese Herbal Medicine in Treating Myocardial Ischemia/Reperfusion Injury

Myocardial ischemia/reperfusion (I/R) injury is characterized by severe inflammation and oxidative stress, and involves the recruitment and activation of immune cells, the release of pro-inflammatory cytokines, and the generation of reactive oxygen species (ROS). The NOD-like receptor protein 3 (NLRP3) inflammasome, a multiprotein complex, is activated when exposed to different danger signals like excessive ROS, changes in ionic flux, and mitochondrial dysfunction. Once the NLRP3 inflammasome is activated, it promotes the maturation and release of pro-inflammatory cytokines such as interleukin-1β and interleukin-18, which contributes to the inflammatory storm in myocardial I/R injury. This inflammatory cascade not only leads to adverse cardiac remodeling but also impairs cardiac function, ultimately exacerbating the clinical outcomes of myocardial infarction. Despite the critical role of the NLRP3 inflammasome in myocardial I/R injury, there is a significant absence of effective therapeutic strategies to address it in clinical practice. In recent years, Chinese herbal medicine has emerged as a promising candidate in the therapeutic landscape of myocardial I/R injury. Chinese herbal medicine exerts its cardioprotective effects through various mechanisms of inhibiting NLRP3 inflammasomes, including enhancing mitochondrial function, reducing ROS generation, inhibiting the release of pro-inflammatory cytokines, and suppressing pyroptosis. This review emphasizes the therapeutic potential of Chinese herbal medicine and its extracts to inhibit NLRP3 inflammasomes in an effort to develop effective treatments for myocardial I/R injury. It likewise summarizes the research results of Chinese herbal medicine interventions for myocardial I/R injury by the mechanism of regulating the NLRP3 inflammasome, providing insights for the development of effective treatments for myocardial I/R injury.

Insights into the role of FGF21 in coronary heart disease

Coronary heart disease (CHD) remains a leading cause of global mortality, with an alarming increase in its incidence among the younger population in recent years. This has amplified the need for early diagnostic markers and advances in therapeutic strategies to improve patient outcomes. Fibroblast growth factor 21 (FGF21), an endocrine hormone crucial for the regulation of metabolic homeostasis, has garnered significant attention over the past decade, owing to its role in cardiovascular health. FGF21 exerts cardioprotective effects through various mechanisms, including regulation of myocardial energy metabolism, prevention of cardiac cell death, suppression of inflammation, and reduction of oxidative stress in the heart. Given these properties, FGF21 shows considerable promise as a pharmacological agent for the management of CHD. Moreover, it has emerged as a promising biomarker for the diagnosis and prognostic assessment of CHD. This review aims to clarify the molecular mechanisms underlying the favorable effects of FGF21 on CHD and its related risk factors, thereby providing valuable insights for future research on the role of FGF21 in CHD management.

Comprehensive view of macrophage autophagy and its application in cardiovascular diseases

Cardiovascular diseases (CVDs) are the primary drivers of the growing public health epidemic and the leading cause of premature mortality and economic burden worldwide. With decades of research, CVDs have been proven to be associated with the dysregulation of the inflammatory response, with macrophages playing imperative roles in influencing the prognosis of CVDs. Autophagy is a conserved pathway that maintains cellular functions. Emerging evidence has revealed an intrinsic connection between autophagy and macrophage functions. This review focuses on the role and underlying mechanisms of autophagy-mediated regulation of macrophage plasticity in polarization, inflammasome activation, cytokine secretion, metabolism, phagocytosis, and the number of macrophages. In addition, autophagy has been shown to connect macrophages and heart cells. It is attributed to specific substrate degradation or signalling pathway activation by autophagy-related proteins. Referring to the latest reports, applications targeting macrophage autophagy have been discussed in CVDs, such as atherosclerosis, myocardial infarction, heart failure, and myocarditis. This review describes a novel approach for future CVD therapies.

Muscone ameliorates myocardial ischemia‒reperfusion injury by promoting myocardial glycolysis

Objective

The incidence of acute myocardial infarction (AMI) is increasing yearly. With the use of thrombolysis or percutaneous coronary intervention (PCI), the mortality rate of acute myocardial infarction has been significantly reduced. However, reperfusion can cause additional myocardial injury. There is still a lack of effective drugs to treat I/R injury, and it is urgent to find new therapeutic drugs.

Methods

In this study, network pharmacology was used to predict potential targets and biological processes involved in Muscone-mediated treatment of acute myocardial infarction. To model ischemia‒reperfusion injury, a hypoxia-reoxygenation model and in vivo ischemia‒reperfusion injury C57BL/6 mice model was constructed. Mice were treated with Muscone i.p. for 4 weeks. We detected the cardiac function on day 28.The expression levels of the apoptotic proteins Caspase-3 and Bax and the anti-apoptotic protein Bcl-2 were detected by immunoblotting after Muscone treatment of AC16 cells and in vivo. Additionally, the gene expression levels of the PUMA and p53 were analyzed by qRT‒PCR. Molecular docking was used to evaluate the binding energy between Muscone and NLRP3-related proteins. Immunoblotting and qRT‒PCR were used to assess the expression levels of NLRP3 signaling pathway-related proteins (NLRP3, ASC, and Caspase-1) and the NLRP3 gene, respectively. Moreover, the extracellular acidification rate of AC16 cells was measured using the Seahorse system to evaluate glycolysis levels after Muscone treatment. The expression of the key glycolytic enzyme PKM2 was analyzed by immunoblotting and qRT‒PCR. Finally, ChIP‒qPCR was performed to determine the levels of histone modifications (H3K4me3, H3K27me3, and H2AK119Ub) in the PKM2 promoter region.

Results

GO functional enrichment analysis revealed that muscone was involved in regulating the biological processes (BP) of AMI, which mainly included negative regulation of the apoptosis signaling pathway, the response to lipopolysaccharide, and blood pressure regulation. The cellular components (CC) involved in muscone-mediated regulation of AMI mainly included lipid rafts, membrane microdomains, and membrane regions. The molecular functions (MF) involved in muscone-mediated regulation of AMI mainly included oxidoreductase activity, nuclear receptor activity, and transcription factor activity. In vitro results indicated that muscone treatment could inhibit the expression levels of Bax and Caspase-3 in AC16 cells after ischemia‒reperfusion while increasing the expression level of the antiapoptotic protein Bcl-2. Muscone significantly suppressed the transcription levels of p53 and PUMA in AC16 cells. Molecular docking suggested that muscone could bind well with the Cryo-EM structure of NEK7(PDB ID:6NPY). Further investigation of inflammatory pathways revealed that muscone could inhibit the expression level of NLRP3 in AC16 cells and reduce the expression levels of Caspase-1 and Caspase recruitment domain. Fluorescent quantitative PCR experiments showed that muscone significantly inhibited the transcription of NLRP3. Moreover, we found that muscone could enhance the glycolytic efficiency of AC16 cells, which may be related to the increased protein expression of PKM2 in AC16 cells. Fluorescent quantitative PCR showed that muscone could increase the transcription level of PKM2. Chromatin immunoprecipitation assays showed that muscone treatment increased the expression level of H3K4me3 in the PKM2 promoter region and inhibited the levels of H3K27me3 and H2AK119Ub in the PKM2 promoter region.

Conclusion

Muscone promoted myocardial glycolysis and inhibited NLRP3 pathway activation to improve myocardial ischemia‒reperfusion injury.

Blocking RIPK2 Function Alleviates Myocardial Ischemia/Reperfusion Injury by Regulating the AKT and NF-κB Pathways

OBJECTIVE

Inflammation and oxidation brought on by myocardial ischemia-reperfusion (MI/R) injury lead to cardiomyocyte apoptosis and necrosis. The receptor interacting serine/threonine kinase 2 (RIPK2) plays significant roles in oxidative stress and excessive inflammation. The purpose of this research is to examine the roles of RIPK2 in MI/R injury.

METHODS

The in vivo animal model was constructed by acute coronary I/R, and the in vitro cell model was established by oxygen and glucose deprivation/reperfusion (OGD/R)-stimulated cardiomyocyte injury. RIPK2 expression was examined using qRT-PCR and Western blot. CCK-8 was proposed as a method for detecting cell proliferation. ELISA was utilized to measure inflammatory cytokines (TNF-α, IL-6, and IL-1β) and myocardial injury indicators (CK-MB, Mb, cTnI, and LDH). The levels of MDA and ROS were determined by the kit and fluorescent probe. H&E was conducted to assess MI/R injury after silencing of RIPK2.

RESULTS

In MI/R rats and OGD/R-treated H9C2 cardiomyocytes, RIPK2 was overexpressed at both the mRNA and protein levels. RIPK2 inhibition promoted cell proliferation while inhibiting apoptosis, as evidenced by decreased TUNEL-positive cells and cleaved caspase-3. RIPK2 inhibition reduced MDA and ROS levels, as well as the contents of inflammatory factors. RIPK2 silencing reduced CK-MB, Mb, cTnI, and LDH levels in rat serum and alleviated MI/R injury. Furthermore, RIPK2 inhibition increased p-AKT while decreasing NF-B p-p65 expression.

CONCLUSION

Silencing of RIPK2 reduced apoptosis, proinflammatory factors, and oxidative stress in MI/R by activating AKT and suppressing NF-κB signals, suggesting a potential therapeutic strategy for MI/R injury.

NLRP3 Inflammasome/Pyroptosis: A Key Driving Force in Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DCM), a serious diabetic complication, is a kind of low-grade inflammatory cardiovascular disorder. Due to the high risk of morbidity and mortality, DCM has demanded the attention of medical researchers worldwide. The pathophysiological nature of DCM is intricate, and the genesis and development of which are a consequence of the coaction of many factors. However, the exact pathogenesis mechanism of DCM remains unclear. Pyroptosis is a newly identified programmed cell death (PCD) that is directly related to gasdermin D(GSDMD). It is characterized by pore formation on the cell plasma membrane, the release of inflammatory mediators, and cell lysis. The initiation of pyroptosis is closely correlated with NOD-like receptor 3 (NLRP3) activation, which activates caspase-1 and promotes the cleaving of GSDMD. In addition to adjusting the host’s immune defense, NLRP3 inflammasome/pyroptosis plays a critical role in controlling the systemic inflammatory response. Recent evidence has indicated that NLRP3 inflammasome/pyroptosis has a strong link with DCM. Targeting the activation of NLRP3 inflammasome or pyroptosis may be a hopeful therapeutic strategy for DCM. The focus of this review is to summarize the relevant mechanisms of pyroptosis and the relative contributions in DCM, highlighting the potential therapeutic targets in this field.

Targeting the NLRP3 inflammasome in cardiovascular diseases

The NACHT, leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3) inflammasome is an intracellular sensing protein complex that plays a major role in innate immunity. Following tissue injury, activation of the NLRP3 inflammasome results in cytokine production, primarily interleukin(IL)-1β and IL-18, and, eventually, inflammatory cell death - pyroptosis. While a balanced inflammatory response favors damage resolution and tissue healing, excessive NLRP3 activation causes detrimental effects. A key involvement of the NLRP3 inflammasome has been reported across a wide range of cardiovascular diseases (CVDs). Several pharmacological agents selectively targeting the NLRP3 inflammasome system have been developed and tested in animals and early phase human studies with overall promising results. While the NLRP3 inhibitors are in clinical development, multiple randomized trials have demonstrated the safety and efficacy of IL-1 blockade in atherothrombosis, heart failure and recurrent pericarditis. Furthermore, the non-selective NLRP3 inhibitor colchicine has been recently shown to significantly reduce cardiovascular events in patients with chronic coronary disease. In this review, we will outline the mechanisms driving NLRP3 assembly and activation, and discuss the pathogenetic role of the NLRP3 inflammasome in CVDs, providing an overview of the current and future therapeutic approaches targeting the NLRP3 inflammasome.

Role of NLRP3 Inflammasome in Myocardial Ischemia-Reperfusion Injury and Ventricular Remodeling

Reperfusion therapy is the optimal therapy for acute myocardial infarction (AMI), but acute inflammatory injury and chronic heart failure (HF) after myocardial ischemia and reperfusion (MI/R) remain the leading cause of death after AMI. Pyroptosis, a newly discovered form of cell death, has been proven to play a significant role in the acute reperfusion process and the subsequent chronic process of ventricular remodeling. Current research shows that multiple stimuli activate the pyroptotic signaling pathway and contribute to cell death and nonbacterial inflammation after MI/R. These stimuli promote the assembly of the nucleotide-binding and oligomerization-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome by activating NLRP3. The mature NLRP3 inflammasome cleaves procaspase-1 to active caspase-1, which leads to mature processing of interleukin (IL)-18, IL-1β, and gasdermin D (GSDMD) protein. That eventually results in cell lysis and generation of nonbacterial inflammation. The present review summarizes the mechanism of NLRP3 inflammasome activation after MI/R and discusses the role that NLRP3-mediated pyroptosis plays in the pathophysiology of MI/R injury and ventricular remodeling. We also discuss potential mechanisms and targeted therapy for which there is evidence supporting treatment of ischemic heart disease.

Retinol-Binding Protein 4 Promotes Cardiac Injury After Myocardial Infarction Via Inducing Cardiomyocyte Pyroptosis Through an Interaction With NLRP3

Background

Acute myocardial infarction (AMI) is one of the leading causes of cardiovascular morbidity and mortality worldwide. Pyroptosis is a form of inflammatory cell death that plays a major role in the development and progression of cardiac injury in AMI. However, the underlying mechanisms for the activation of pyroptosis during AMI are not fully elucidated.

Methods and Results

Here we show that RBP4 (retinol‐binding protein 4), a previous identified proinflammatory adipokine, was increased both in the myocardium of left anterior descending artery ligation‐induced AMI mouse model and in ischemia‐hypoxia‒induced cardiomyocyte injury model. The upregulated RBP4 may contribute to the activation of cardiomyocyte pyroptosis in AMI because overexpression of RBP4 activated NLRP3 (nucleotide‐binding oligomerization domain‐like receptor family pyrin domain‐containing 3) inflammasome, promoted the precursor cleavage of Caspase‐1, and subsequently induced GSDMD (gasdermin‐D)‐dependent pyroptosis. In contrast, knockdown of RBP4 alleviated ischemia‐hypoxia‒induced activation of NLRP3 inflammasome signaling and pyroptosis in cardiomyocytes. Mechanistically, coimmunoprecipitation assay showed that RBP4 interacted directly with NLRP3 in cardiomyocyte, while genetic knockdown or pharmacological inhibition of NLRP3 attenuated RBP4‐induced pyroptosis in cardiomyocytes. Finally, knockdown of RBP4 in heart decreased infarct size and protected against AMI‐induced pyroptosis and cardiac dysfunction in mice.

Conclusions

Taken together, these findings reveal RBP4 as a novel modulator promoting cardiomyocyte pyroptosis via interaction with NLRP3 in AMI. Therefore, targeting cardiac RBP4 might represent a viable strategy for the prevention of cardiac injury in patients with AMI.

Beclin1 controls caspase-4 inflammsome activation and pyroptosis in mouse myocardial reperfusion-induced microvascular injury

BACKGROUND

Myocardial reperfusion injury is often accompanied by cell death and inflammatory reactions. Recently, pyroptosis is gradually recognized as pivotal role in cardiovascular disease. However, little is known about the regulatory role of beclin1 in the control of caspase-4 activation and pyroptosis. The present study confirmed whether beclin1 regulates caspase-4 mediated pyroptosis and thereby protects Human Cardiac microvascular endothelial cells (HCMECs) against injury.

METHODS

TTC and Evan's blue dye, western blot, immunofluorescence and immunohistochemistry staining were performed in wild mice and transgenic mice with overexpression of beclin 1(BECN1-Tg). CMECs were transfected with a beclin1 lentivirus. The cell cytotoxicity was analyzed by LDH-Cytotoxicity Assay Kit. The protein levels of autophagy protein (Beclin1, p62 and LC3II/LC3I) and caspase-4/GSDMD pathway were determined by western blot. Autophagic vacuoles in cells were monitored with RFP-GFP-LC3 using fluorescence microscope.

RESULTS

I/R caused caspase-4 activity and gasdermin D expression increase in vivo and in vitro. Overexpression of beclin1 in heart tissue and CMECs suppressed the caspase-4 activity and decreased the levels of gasdermin D; meanwhile beclin1 overexpression also reduced IL-1β levels, promoted autophagy (p62 expression was inhibited while LC3II expression was increased) in the heart and CMECs. Interestingly, beclin1 overexpression increased animal survival and attenuated myocardial infarct size (45 ± 6.13 vs 22 ± 4.37), no-reflow area (39 ± 5.22 vs 16 ± 2.54) post-myocardial ischemia reperfusion.

CONCLUSIONS

Induction of beclin-1 signaling can be a potential therapeutic target in myocardial reperfusion-induced microvascular injury. Video Abstract.

Interleukin-18 accelerates cardiac inflammation and dysfunction during ischemia/reperfusion injury by transcriptional activation of CXCL16

Myocardial ischemia/reperfusion(I/R) injury elicits an inflammatory response that drives tissue damage and cardiac remodeling. The trafficking and recruitment of inflammatory cells are controlled by C-X-C motif chemokine ligands and their receptors. CXCL16, a hallmark of acute coronary syndromes, is responsible for the recruitment of macrophages, monocytes and T lymphocytes. However, its role in cardiac I/R injury remains poorly characterized. Here we reported that CXCL16-mediated cardiac infiltration of CD11b⁺Ly6C⁺ cells played a crucial role in IL-18-induced myocardial inflammation, apoptosis and left ventricular(LV) dysfunction during I/R. Treatment with CXCL16 shRNA attenuated I/R-induced cardiac injury, LV remodeling and cardiac inflammation by reducing the recruitment of inflammatory cells and the release of TNFα, IL-17 and IFN-γ in the heart. We found that I/R-mediated NLRP3/IL-18 signaling pathway triggered CXCL16 transcription in cardiac vascular endothelial cells(VECs). Two binding sites of FOXO3 were found at the promoter region of CXCL16. By luciferase report assay and ChIP analysis, we confirmed that FOXO3 was responsible for endothelial CXCL16 transcription. A pronounced reduction of CXCL16 was observed in FOXO3 siRNA pretreated-VECs. Further experiments revealed that IL-18 activated FOXO3 by promoting the phosphorylation of STAT3 but not STAT4. An interaction between FOXO3 and STAT3 enhanced the transcription of CXCL16 induced by FOXO3. Treatment with Anakinra or Stattic either effectively inhibited IL-18-mediated nuclear import of FOXO3 and CXCL16 transcription. Our findings suggested that IL-18 accelerated I/R-induced cardiac damage and dysfunction through activating CXCL-16 and CXCL16-mediated cardiac infiltration of the CD11b⁺Ly6C⁺ cells. CXCL16 might be a novel therapeutic target for the treatment of I/R-related ischemic heart diseases.

The Interplay between Autophagy and NLRP3 Inflammasome in Ischemia/Reperfusion Injury

Ischemia/reperfusion (I/R) injury is characterized by a limited blood supply to organs, followed by the restoration of blood flow and reoxygenation. In addition to ischemia, blood flow recovery can also lead to very harmful injury, especially inflammatory injury. Autophagy refers to the transport of cellular materials to the lysosomes for degradation, leading to the conversion of cellular components and offering energy and macromolecular precursors. It can maintain the balance of synthesis, decomposition and reuse of the intracellular components, and participate in many physiological processes and diseases. Inflammasomes are a kind of protein complex. Under physiological and pathological conditions, as the cellular innate immune signal receptors, inflammasomes sense pathogens to trigger an inflammatory response. TheNLRP3 inflammasome is the most deeply studied inflammasome and is composed of NLRP3, the adaptor apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and pro-caspase-1. Its activation triggers the cleavage of pro-interleukin (IL)-1β and pro-IL-18 mediated by caspase-1 and promotes a further inflammatory process. Studies have shown that autophagy and the NLRP3 inflammasome play an important role in the process of I/R injury, but the relevant mechanisms have not been fully explained, especially how the interaction between autophagy and the NLRP3 inflammasome participates in I/R injury, which remains to be further studied. Therefore, we reviewed the recent studies about the interplay between autophagy and the NLRP3 inflammasome in I/R injury and analyzed the mechanisms to provide the theoretical references for further research in the future.

Effects of Tranilast on Inflammasome and Macrophage Phenotype in a Mouse Model of Myocardial Infarction

Acute myocardial infarction (AMI) has been a devastating actuality and accounts for half of cardiovascular emergency department visits. Nucleotide oligomerization domain, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3) inflammasome participates in the mediation of myocardial inflammation during AMI. Therefore, this study aimed to reveal the therapeutic function of tranilast, an agent targeting NLRP3, for AMI. AMI mouse model was first established by transient myocardial ischemia. Western blot and quantitative reverse transcription polymerase chain reaction assay were performed to estimate the expression levels of related genes. Flow cytometry was used to analyze the macrophage types, and the therapeutic effects of tranilast were estimated by echocardiographic analysis and Masson's trichrome stain. We demonstrated that AMI induced the activation of NLRP3 inflammasome in the heart tissues of mice with AMI. Tranilast decreased the expression of interleukin-1β and cleaved caspase-1 in bone marrow-derived macrophages and thus re-educated M1-macrophages toward the M2-phenotype both in vitro and in vivo. Tranilast inhibited the activation in the heart tissues of AMI mice and thus improved cardiac functional recovery in the AMI mouse model. In conclusion, we revealed that tranilast ameliorated myocardial infarction by inhibiting NLRP3 inflammasome and re-educating macrophage phenotype in this study.

Gene therapy for cardiovascular diseases in China: basic research

Cardiovascular disease has become a major disease affecting health in the whole world. Gene therapy, delivering foreign normal genes into target cells to repair damages caused by defects and abnormal genes, shows broad prospects in treating different kinds of cardiovascular diseases. China has achieved great progress of basic gene therapy researches and pathogenesis of cardiovascular diseases in recent years. This review will summarize the latest research about gene therapy of proteins, epigenetics, including noncoding RNAs and genome-editing technology in myocardial infarction, cardiac ischemia-reperfusion injury, atherosclerosis, muscle atrophy, and so on in China. We wish to highlight some important findings about the essential roles of basic gene therapy in this field, which might be helpful for searching potential therapeutic targets for cardiovascular disease.

Hydroxysafflor yellow A inhibits hypoxia/reoxygenation-induced cardiomyocyte injury via regulating the AMPK/NLRP3 inflammasome pathway

Hydroxysafflor yellow A (HSYA) is an effective therapeutic agent that alleviates myocardial ischaemia/reperfusion injury (MIRI), but the exact mechanisms remain elusive. The aim of this study was to investigate the potential protective effect of HSYA against MIRI through mechanisms related to NLRP3 inflammasome regulation. In this study, hypoxia/reoxygenation (H/R)-induced H9c2 cardiomyocytes were treated with HSYA or the AMPK inhibitor, compound C (CC). Our results showed that HSYA pretreatment improved cardiomyocyte viability, maintained mitochondrial membrane potential, reduced apoptotic cardiomyocytes, decreased caspase-3 activity, and inhibited NOD-like receptor 3 (NLRP3) inflammasome activation during H/R injury. Moreover, the inhibition of AMPK activation by the CC inhibitor partially abolished the effects of HSYA treatment, including suppressing the upregulation of NLRP3 inflammasome components (NLRP3, caspase-1 and interleukin-1β) and promoting autophagy (LC3-II/LC3-I and p62). In conclusion, the protective mechanism of HSYA in H/R-induced cardiomyocyte injury is associated with inhibiting NLRP3 inflammasome activation through the AMPK signalling pathway.

LncRNA TUG1 protects against cardiomyocyte ischaemia reperfusion injury by inhibiting HMGB1

The aim of this study was to investigate whether lncRNA TUG1 could mediate the progression of ischemia-reperfusion injury following acute myocardial infraction. Mouse cardiomyocytes HL-1 cells were subjected to oxygen glucose deprivation followed by reperfusion (OGD/R) to induce myocardial I/R injury. The expression of TUG1 was detected by real-time PCR. Overexpression or down expression of TUG1 was performed in mouse HL-1 cardiomyocytes. The myocardial cell viability and apoptosis were respectively detected. In addition, the expression levels of inflammatory factors, apoptosis-related proteins and HMGB1 proteins were detected. Besides, an inhibitor of HMGB1 was used to treat cells to verify the relationship between TUG1 and HMGB1 protein. The expression of TUG1 was significantly up-regulated in OGD/R-induced myocardial HL-1 cells. The overexpression of TUG1-induced inflammation and apoptosis in OGD-R-induced myocardial HL-1 cells. Knock down of TUG1 protected OGD/R-induced myocardial I/R injury by inhibiting HMGB1 expression. Suppression of lncRNA TUG1 may prevent myocardial I/R injury following acute myocardial infarction via inhibiting HMGB1 expression.

Interaction among inflammasome, autophagy and non-coding RNAs: new horizons for drug

Autophagy and inflammasomes are shown to interact in various situations including infectious disease, cancer, diabetes and neurodegeneration. Since multiple layers of molecular regulators contribute to the interplay between autophagy and inflammasome activation, the detail of such interplay remains largely unknown. Non-coding RNAs (ncRNAs), which have been implicated in regulating an expanding list of cellular processes including immune defense against pathogens and inflammatory response in cancer and metabolic diseases, may join in the crosstalk between inflammasomes and autophagy in physiological or disease conditions. In this review, we summarize the latest research on the interlink among ncRNAs, inflammasomes and autophagy and discuss the emerging role of these three in multiple signaling transduction pathways involved in clinical conditions. By analyzing these intriguing interconnections, we hope to unveil the mechanism inter-regulating these multiple processes and ultimately discover potential drug targets for some refractory diseases.

Targeting autophagy in cardiac ischemia/reperfusion injury: A novel therapeutic strategy

Acute myocardial infarction (AMI) is one of the leading causes of morbidity worldwide. Myocardial reperfusion is known as an effective therapeutic choice against AMI. However, reperfusion of blood flow induces ischemia/reperfusion (I/R) injury through different complex processes including ion accumulation, disruption of mitochondrial membrane potential, the formation of reactive oxygen species, and so forth. One of the processes that gets activated in response to I/R injury is autophagy. Indeed, autophagy acts as a "double-edged sword" in the pathology of myocardial I/R injury and there is a controversy about autophagy being beneficial or detrimental. On the basis of the autophagy effect and regulation on myocardial I/R injury, many studies targeted it as a therapeutic strategy. In this review, we discuss the role of autophagy in I/R injury and its targeting as a therapeutic strategy.

The role of mitochondria in NLRP3 inflammasome activation

The NLRP3 inflammasome is a multiprotein platform which is activated upon cellular infection or stress. Its activation leads to caspase-1-dependent secretion of proinflammatory cytokines like interleukin-1β (IL-1β) and IL-18, and an inflammatory form of cell death termed as pyroptosis. Recent studies have unveiled the pivotal roles of mitochondria in initiation and regulation of the NLRP3 (nucleotide-binding domain, leucine-rich-repeat containing family, pyrin domain-containing 3) inflammasome. NLRP3 activators induce mitochondrial destabilization, NLRP3 deubiquitination, linear ubiquitination of ASC, and externalization or release of mitochondria-derived molecules such as cardiolipin and mitochondrial DNA. These molecules bind to NLRP3 that is translocated on mitochondria and activate the NLRP3 inflammasome. Here we review recently described mechanisms by which mitochondria regulate NLRP3 inflammasome activation.