Upregulation of miR-223 abrogates NLRP3 inflammasome-mediated pyroptosis to attenuate oxidized low-density lipoprotein (ox-LDL)-induced cell death in human vascular endothelial cells (ECs)

LncRNA CASC11 upregulation promotes HDAC4 to alleviate oxidized low-density lipoprotein-induced injury of cardiac microvascular endothelial cells

Long noncoding RNAs (LncRNAs) are essential to regulate the pathogenesis of coronary artery disease (CAD). This study was conducted to analyze the functionality of long noncoding RNA cancer susceptibility candidate 11 (lncRNA CASC11) in oxidized low-density lipoprotein (ox-LDL)-induced injury of cardiac microvascular endothelial cells (CMECs). CMECs were treated with ox-LDL to induce the CAD cell model. The cellular expression levels of CASC11 and histone deacetylase 4 (HDAC4) were determined by real-time quantitative polymerase chain reaction or Western blot assay. Cell absorbance, apoptosis, angiogenesis, and inflammation were evaluated by cell counting kit-8, flow cytometry, tube formation, and enzyme-linked immunosorbent assays. The subcellular localization of CASC11 was examined by the nuclear/cytoplasmic fractionation assay. The binding of human antigen R (HuR) to CASC11 and HDAC4 was analyzed by RNA immunoprecipitation. HDAC4 stability was determined after actinomycin D treatment. CASC11 was found to be decreased in the CAD cell model. CASC11 upregulation increased cell viability and angiogenesis and reduced apoptosis and inflammation. CASC11 bound to HuR and improved HDAC4 expression. HDAC4 downregulation counteracted the protective role of CASC11 overexpression in CMECs. In summary, CASC11 alleviated ox-LDL-induced injury of CMECs by binding to HuR and stabilizing HDAC4.

Differential Expression of LOXL1-AS1 in Coronary Heart Disease and its Regulatory Mechanism in ox-LDL-Induced Human Coronary Artery Endothelial Cell Pyroptosis

OBJECTIVE

Coronary heart disease (CHD) is a notable contributor to the burden of human health. Dysregulated long non-coding RNAs (lncRNAs) are implicated in the pathogenesis of CHD. This study investigated the expression pattern of lncRNA LOXL1-AS1 in CHD and its regulatory mechanism in oxidized low-density lipoprotein (ox-LDL)-induced human coronary artery endothelial cell (HCAEC) pyroptosis.

METHODS

Serum was collected from 62 CHD patients and 62 healthy volunteers for the detection of LOXL1-AS1 expression. The value of LOXL1-AS1 in CHD diagnosis and major cardiovascular adverse event (MACE) prediction was analyzed using the ROC curve. LOXL1-AS1, miR-16-5p, and SNX16 expressions in ox-LDL-treated HCAECs were determined using RT-qPCR. NLPR3, cleaved-caspase-1, and GSDMD-N protein levels were measured using Western blot. IL-1β and IL-18 concentrations were measured using ELISA. The binding relationships between LOXL1-AS1 and miR-16-5p and miR-16-5p and SNX16 were verified. Functional rescue experiment was performed to verify the role of miR-16-5p in HCAEC pyroptosis.

RESULTS

LOXL1-AS1 was highly expressed in CHD patients. LOXL1-AS1 had diagnostic value for CHD and predictive value for MACE occurrence. ox-LDL-treated HCAECs showed reduced viability, increased IL-1β and IL-18 concentrations, and elevated NLPR3, cleaved-caspase-1, and GSDMD-N levels. LOXL1-AS1 silencing promoted cell viability and reduced pyroptosis. LOXL1-AS1 bound to miR-16-5p and miR-16-5p targeted SNX16. Inhibition of miR-16-5p reversed the inhibitory effect of LOXL1-AS1 silencing on HCAEC pyroptosis.

CONCLUSION

LOXL1-AS1 was elevated in CHD patients with a good diagnostic value for CHD and predictive value for MACE. LOXL1-AS1 downregulated miR-16-5p expression by binding to miR-16-5p to enhance ox-LDL-induced HCAEC pyroptosis, which may be associated with upregulation of SNX16 transcription.

The role of pyroptosis in endothelial dysfunction induced by diseases

Most organs in the body rely on blood flow, and vesicular damage is the leading cause of injury in multiple organs. The endothelium, as the barriers of vessels, play a critical role in ensuring vascular homeostasis and angiogenesis. The rapid development of risk factors in endothelial injuries has been seen in the past decade, such as smoking, infectious, and diabetes mellites. Pyroptotic endothelium is an inflammatory mode of governed endothelial cell death that depend on the metabolic disorder and severe infectious such as atherosclerosis, and sepsis-related acute lung injury, respectively. Pyroptotic endothelial cells need GSDMD cleaved into N- and C-terminal by caspase1, and the cytokines are released by a pore constructed by the N-terminal of GSDMD in the membrane of ECs, finally resulting in severe inflammation and pyroptotic cell death. This review will focus on the patho-physiological and pharmacological pathways of pyroptotic endothelial metabolism in diseases. Overall, this review indicates that pyroptosis is a significant risk factor in diseases and a potential drug target in related diseases.

The role of pyroptosis in endothelial dysfunction induced by diseases

Most organs in the body rely on blood flow, and vesicular damage is the leading cause of injury in multiple organs. The endothelium, as the barriers of vessels, play a critical role in ensuring vascular homeostasis and angiogenesis. The rapid development of risk factors in endothelial injuries has been seen in the past decade, such as smoking, infectious, and diabetes mellites. Pyroptotic endothelium is an inflammatory mode of governed endothelial cell death that depend on the metabolic disorder and severe infectious such as atherosclerosis, and sepsis-related acute lung injury, respectively. Pyroptotic endothelial cells need GSDMD cleaved into N- and C-terminal by caspase1, and the cytokines are released by a pore constructed by the N-terminal of GSDMD in the membrane of ECs, finally resulting in severe inflammation and pyroptotic cell death. This review will focus on the patho-physiological and pharmacological pathways of pyroptotic endothelial metabolism in diseases. Overall, this review indicates that pyroptosis is a significant risk factor in diseases and a potential drug target in related diseases.

Transcription factor GATA1 represses oxidized-low density lipoprotein-induced pyroptosis of human coronary artery endothelial cells

BACKGROUND

Atherosclerosis (AS) is defined as a chronic inflammatory disorder underly the pathogenesis of cardiovascular diseases (CVDs). Endothelial pyroptosis is associated with AS-like diseases and other CVDs.

OBJECTIVE

This work was designed to expound on the effect of GATA-binding protein 1 (GATA1) on pyroptosis of human coronary artery endothelial cells (HCAECs) in AS.

METHODS

HCAECs were treated with oxidized-low density lipoprotein (ox-LDL) to establish HCAEC injury models. Plasmids for overexpressing GATA1 or silencing retinoic acid-related orphan receptor α (RORα) were transfected into HCAECs. Thereafter, the mRNA levels of GATA1 and RORα in HCAECs were detected using real-time quantitative polymerase chain reaction. HCAEC viability was examined using the cell counting kit-8 method. The levels of pyroptosis-related proteins NOD-like receptor protein 3 (NLRP3), cleaved-Caspase-1, N-terminal of gasdermin D (GSDMD-N), and pyroptosis-related inflammatory cytokines interleukin (IL)-1β and IL-18 were determined using Western blot and enzyme-linked immunosorbent assays, respectively. The targeting relationship between GATA1 and RORα was verified using the chromatin-immunoprecipitation assay. Then, the rescue experiment was conducted to explore the effect of RORα on pyroptosis of ox-LDL-treated HCAECs.

RESULTS

In ox-LDL-treated HCAECs, GATA1 and RORα expressions were decreased, HCAEC viability was reduced, and the levels of NLRP3, cleaved-Caspase1, GSDMD-N, IL-1β, and IL-18 were elevated. GATA1 overexpression increased HCAEC viability and attenuated pyroptosis. GATA1 bound to the RORα promoter region to stimulate RORα transcription, and RORα suppression facilitated ox-LDL-induced pyroptosis of HCAECs.

CONCLUSIONS

GATA1 activated RORα transcription and therefore limited pyroptosis of ox-LDL-treated HCAECs.

Role of NLRP3 inflammasome in systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune rheumatic disease with high mortality, which is featured by inflammation, vascular damage, and aggressive fibrosis. To date, the pathogenesis of SSc remains unclear and effective treatments are still under research. Active NLRP3 recruits downstream proteins such as ASC and caspase-1 and assembles into inflammasome, resulting in excretion of inflammatory cytokines including IL-1β and IL-18, as well as in pyroptosis mediated by gasdermin D. Various studies demonstrated that NLRP3 inflammasome might be involved in the mechanism of tenosynovitis, arthritis, fibrosis, and vascular damage. The pathophysiological changes might be due to the activation of proinflammatory Th2 cells, profibrotic M2 macrophages, B cells, fibroblasts, and endothelial cells. Here, we review the studies focused on NLRP3 inflammasome activation, its association with innate and adaptive immune cells, endothelium injury, and differentiation of fibroblasts in SSc. Furthermore, we summarize the prospect of therapy targeting NLRP3 pathway.

Non-coding RNAs in necroptosis, pyroptosis, and ferroptosis in cardiovascular diseases

Accumulating evidence has proved that non-coding RNAs (ncRNAs) play a critical role in the genetic programming and gene regulation of cardiovascular diseases (CVDs). Cardiovascular disease morbidity and mortality are rising and have become a primary public health issue that requires immediate resolution through effective intervention. Numerous studies have revealed that new types of cell death, such as pyroptosis, necroptosis, and ferroptosis, play critical cellular roles in CVD progression. It is worth noting that ncRNAs are critical novel regulators of cardiovascular risk factors and cell functions by mediating pyroptosis, necroptosis, and ferroptosis. Thus, ncRNAs can be regarded as promising therapeutic targets for treating and diagnosing cardiovascular diseases. Recently, there has been a surge of interest in the mediation of ncRNAs on three types of cell death in regulating tissue homeostasis and pathophysiological conditions in CVDs. Although our understanding of ncRNAs remains in its infancy, the studies reviewed here may provide important new insights into how ncRNAs interact with CVDs. This review summarizes what is known about the functions of ncRNAs in modulating cell death-associated CVDs and their role in CVDs, as well as their current limitations and future prospects.

Diabetes Mellitus Promotes the Development of Atherosclerosis: The Role of NLRP3

Atherosclerosis is one of the main complications of diabetes mellitus, involving a variety of pathogenic factors. Endothelial dysfunction, inflammation, and oxidative stress are hallmarks of diabetes mellitus and atherosclerosis. Although the ability of diabetes to promote atherosclerosis has been demonstrated, a deeper understanding of the underlying biological mechanisms is critical to identifying new targets. NLRP3 plays an important role in both diabetes and atherosclerosis. While the diversity of its activation modes is one of the underlying causes of complex effects in the progression of diabetes and atherosclerosis, it also provides many new insights for targeted interventions in metabolic diseases.

Circ_ROBO2/miR-186-5p/TRIM14 axis regulates oxidized low-density lipoprotein-induced cardiac microvascular endothelial cell injury

Background

Coronary artery disease (CAD) is one of the main risks of death, which is mainly caused by coronary arteries arteriosclerosis. Circular RNAs (circRNAs) have shown important regulatory roles in cardiovascular diseases. We amid to explore the role of circ_ROBO2 in CAD.

Methods

Cardiac microvascular endothelial cells (CMECs) stimulated by oxidized low-density lipoprotein (ox-LDL) were served as the cellular model of CAD. Real-time quantitative polymerase chain reaction (RT-qPCR) and western blot assay were performed to detect RNA levels and protein levels, respectively. Cell proliferation was assessed by 5-ethynyl-2′-deoxyuridine (EdU) assay and Cell Counting Kit-8 (CCK-8) assay. Flow cytometry was employed for measuring cell apoptosis. Matrigel tube formation assay was used to evaluate angiogenesis ability. The intermolecular interaction was predicted by bioinformatics analysis and verified by dual-luciferase reporter and RNA-pull down assays.

Results

The expression of circ_ROBO2 was upregulated in CAD patients and ox-LDL-induced CMECs. Treatment of ox-LDL suppressed cell proliferation and angiogenic ability as well as promoted the apoptosis of CMECs partly by upregulating circ_ROBO2. MicroRNA-186-5p (miR-186-5p) was identified as a target of circ_ROBO2, and circ_ROBO2 knockdown attenuated ox-LDL-induced damage in CMECs by sponging miR-186-5p. Tripartite motif containing 14 (TRIM14) acted as a target of miR-186-5p, and TRIM14 overexpression alleviated miR-186-5p-mediated inhibitory effect on ox-LDL-induced injury in CMECs. Circ_ROBO2 positively regulated TRIM14 expression by sponging miR-186-5p.

Conclusion

Circ_ROBO2 played a promoting role in ox-LDL-induced CMECs injury by sponging miR-186-5p and regulating TRIM14, providing a promising treatment strategy for CAD.

Mechanisms of Oxidized LDL-Mediated Endothelial Dysfunction and Its Consequences for the Development of Atherosclerosis

Atherosclerosis is an immuno-metabolic disease involving chronic inflammation, oxidative stress, epigenetics, and metabolic dysfunction. There is compelling evidence suggesting numerous modifications including the change of the size, density, and biochemical properties in the low-density lipoprotein (LDL) within the vascular wall. These modifications of LDL, in addition to LDL transcytosis and retention, contribute to the initiation, development and clinical consequences of atherosclerosis. Among different atherogenic modifications of LDL, oxidation represents a primary modification. A series of pathophysiological changes caused by oxidized LDL (oxLDL) enhance the formation of foam cells and atherosclerotic plaques. OxLDL also promotes the development of fatty streaks and atherogenesis through induction of endothelial dysfunction, formation of foam cells, monocyte chemotaxis, proliferation and migration of SMCs, and platelet activation, which culminate in plaque instability and ultimately rupture. This article provides a concise review of the formation of oxLDL, enzymes mediating LDL oxidation, and the receptors and pro-atherogenic signaling pathways of oxLDL in vascular cells. The review also explores how oxLDL functions in different stages of endothelial dysfunction and atherosclerosis. Future targeted pathways and therapies aiming at reducing LDL oxidation and/or lowering oxLDL levels and oxLDL-mediated pro-inflammatory responses are also discussed.

GSDMD-mediated pyroptosis: a critical mechanism of diabetic nephropathy

Pyroptosis is a recently identified mechanism of programmed cell death related to Caspase-1 that triggers a series of inflammatory reactions by releasing several proinflammatory factors such as IL-1β and IL-18. The process is characterised by the rupture of cell membranes and the release of cell contents through the mediation of gasdermin (GSDM) proteins. GSDMD is an important member of the GSDM family and plays a critical role in the two pathways of pyroptosis. Diabetic nephropathy (DN) is a microvascular complication of diabetes and a major cause of end-stage renal disease. Recently, it was revealed that GSDMD-mediated pyroptosis plays an important role in the occurrence and development of DN. In this review, we focus on two types of kidney cells, tubular epithelial cells and renal podocytes, to illustrate the mechanism of pyroptosis in DN and provide new ideas for the prevention, early diagnosis and molecular therapy of DN.

Oxidized LDL-regulated microRNAs for evaluating vascular endothelial function: molecular mechanisms and potential biomarker roles in atherosclerosis

As a simple monolayer, vascular endothelial cells can respond to physicochemical stimuli. In addition to promoting the formation of foam cells, oxidized low-density lipoprotein (ox-LDL) contributes to the atherosclerotic process through different mechanisms, including endothelial cell dysfunction. As conserved noncoding RNAs, microRNAs (miRNAs) naturally lie in different genomic positions and post-transcriptionally regulate the expression of many genes. They participate in integrated networks formed under stress to maintain cellular homeostasis, vascular inflammation, and metabolism. These small RNAs constitute therapeutic targets in different diseases, including atherosclerosis, and their role as biomarkers is crucial given their detectability even years before the emergence of diseases. This review was performed to investigate the role of ox-LDL-regulated miRNAs in atherosclerosis, their molecular mechanisms, and their application as biomarkers of vascular endothelial cell dysfunction.

microRNA-22-3p plays a protective role in a murine asthma model through the inhibition of the NLRP3-caspase-1-IL-1β axis

NEW FINDINGS

What is the central question of this study? How does miR-22-3p exert a protective role in asthma? What is the main finding and its importance? Upregulation of miR-22-3p hampered airway inflammation and release of inflammatory cytokines through blocking the activation of the NLRP3-caspase-1-IL-1β signalling pathway in asthma.

ABSTRACT

Asthma, a great public health burden, is triggered by inflammatory responses in the airways and these are not addressed appropriately by current therapies. This study aims to investigate the regulatory mechanism of microRNA-22-3p (miR-22-3p) on the proliferation of bronchial epithelial cells exposed to lipopolysaccharide (LPS) and expression of pro-inflammatory cytokines in a murine asthma model challenged by ovalbumin. We first confirmed the downregulation of miR-22-3p in the murine asthma model and bronchial epithelial cells. miR-22-3p remarkably reversed the decline in bronchial epithelial cell viability, enhancement in apoptosis rate and release of inflammatory factors induced by LPS. miR-22-3p targeted and conversely regulated NACHT, LRR and PYD domains-containing protein 3 (NLRP3). Overexpression of NLRP3 counteracted the inhibitory effect of miR-22-3p on inflammatory damage in bronchial epithelial cells through activation of caspase-1/interleukin (IL)-1β. In an in vivo model, overexpression of miR-22-3p significantly attenuated airway obstruction and tissue damage in mice. In summary, our study underscores that miR-22-3p serves both as a negative regulator of the NLRP3-caspase-1-IL-1β axis and as a protective factor against the inflammatory response, suggesting a future therapeutic role in asthma.

Pyroptosis is a critical immune-inflammatory response involved in atherosclerosis

Pyroptosis is a form of programmed cell death activated by various stimuli and is characterized by inflammasome assembly, membrane pore formation, and the secretion of inflammatory cytokines (IL-1β and IL-18). Atherosclerosis-related risk factors, including oxidized low-density lipoprotein (ox-LDL) and cholesterol crystals, have been shown to promote pyroptosis through several mechanisms that involve ion flux, ROS, endoplasmic reticulum stress, mitochondrial dysfunction, lysosomal rupture, Golgi function, autophagy, noncoding RNAs, post-translational modifications, and the expression of related molecules. Pyroptosis of endothelial cells, macrophages, and smooth muscle cells in the vascular wall can induce plaque instability and accelerate atherosclerosis progression. In this review, we focus on the pathogenesis, influence, and therapy of pyroptosis in atherosclerosis and provide novel ideas for suppressing pyroptosis and the progression of atherosclerosis.

Therapeutic Potential of Carbon Monoxide (CO) and Hydrogen Sulfide (H2S) in Hemolytic and Hemorrhagic Vascular Disorders-Interaction between the Heme Oxygenase and H2S-Producing Systems

Over the past decades, substantial work has established that hemoglobin oxidation and heme release play a pivotal role in hemolytic/hemorrhagic disorders. Recent reports have shown that oxidized hemoglobins, globin-derived peptides, and heme trigger diverse biological responses, such as toll-like receptor 4 activation with inflammatory response, reprogramming of cellular metabolism, differentiation, stress, and even death. Here, we discuss these cellular responses with particular focus on their mechanisms that are linked to the pathological consequences of hemorrhage and hemolysis. In recent years, endogenous gasotransmitters, such as carbon monoxide (CO) and hydrogen sulfide (H₂S), have gained a lot of interest in connection with various human pathologies. Thus, many CO and H₂S-releasing molecules have been developed and applied in various human disorders, including hemolytic and hemorrhagic diseases. Here, we discuss our current understanding of oxidized hemoglobin and heme-induced cell and tissue damage with particular focus on inflammation, cellular metabolism and differentiation, and endoplasmic reticulum stress in hemolytic/hemorrhagic human diseases, and the potential beneficial role of CO and H₂S in these pathologies. More detailed mechanistic insights into the complex pathology of hemolytic/hemorrhagic diseases through heme oxygenase-1/CO as well as H₂S pathways would reveal new therapeutic approaches that can be exploited for clinical benefit.